Damage caused by underground coal mining is a serious problem in mining areas in China; therefore, studying and obtaining the rules of ground movement and deformation under different geological conditions is of great ...Damage caused by underground coal mining is a serious problem in mining areas in China; therefore, studying and obtaining the rules of ground movement and deformation under different geological conditions is of great importance. The numerical software ANSYS was used in this study to simulate mining processes under two special geological conditions： （1） thick unconsolidated soil layer and thin bedrock; （2） thin soil layer and thick bedrock. The rules for ground movement and deformation for different soil layer to bedrock ratios were obtained. On the basis of these rules, a prediction parameter modified model of the influence function was proposed, which is suitable for different values of unconsolidated soil layer thickness. The prediction results were verified using two sets of typical field data.展开更多
Hemiplegia caused by stroke indicates dysfunction of the network between the brain and limbs, namely collateral shock in the brain. Contralateral needling is the insertion of needles into acupoints on the relative hea...Hemiplegia caused by stroke indicates dysfunction of the network between the brain and limbs, namely collateral shock in the brain. Contralateral needling is the insertion of needles into acupoints on the relative healthy side of the body to treat diseases such as apoplexy. However, there is little well-designed and controlled clinical evidence for this practice. This study investigated whether contralateral needling could treat hemiplegia after acute ischemic stroke in 106 randomly selected patients with acute ischemic stroke. These patients were randomly assigned to three groups： 45 in the contralateral needling group, receiving acupuncture on the unaffected limbs; 45 in the conven- tional acupuncture group, receiving acupuncture on the hemiplegic limbs; and 16 in the control group, receiving routine treatments without acupuncture. Acupuncture at acupoints Chize （LU5） in the upper limb and Jianliao （TEl4） in the lower limb was performed for 45 minutes daily for 30 consecutive days. The therapeutic effective rate, Neurological Deficit Score, Modified Barthel Index and FugI-Meyer Assessment were evaluated. The therapeutic effective rate of contralateral nee- dling was higher than that of conventional acupuncture （46.67% vs. 31.11%, P 〈 0.05）. The neuro- logical deficit score of contralateral needling was significantly decreased compared with conven- tional acupuncture （P 〈 0.01）. The Modified Barthel Index and FugI-Meyer Assessment score of contralateral needling increased more significantly than those of conventional acupuncture （both P 〈 0.01）. The present findings suggest that contralateral needling unblocks collaterals and might be more effective than conventional acupuncture in the treatment of hemiplegia following acute ischemic stroke.展开更多
Among the five members of AUX1/LAX genes coding for auxin carriers in rice,only OsAUX1 and OsAUX3 have been reported.To understand the function of the other AUX1/LAX genes,two independent alleles of osaux4 mutants,osa...Among the five members of AUX1/LAX genes coding for auxin carriers in rice,only OsAUX1 and OsAUX3 have been reported.To understand the function of the other AUX1/LAX genes,two independent alleles of osaux4 mutants,osaux4-1 and osaux4-2,were constructed using the CRISPR/Cas9 editing system.Homozygous osaux4-1 or osaux4-2 exhibited shorter primary root(PR)and longer root hair(RH)compared to the wild-type Dongjin(WT/DJ),and lost response to indoleacetic acid(IAA)treatment.OsAUX4 is intensively expressed in roots and localized on the plasma membrane,suggesting that OsAUX4 might function in the regulation of root development.The decreased meristem cell division activity and the downregulated expression of cell cycle genes in root apices of osaux4 mutants supported the hypothesis that OsAUX4 positively regulates PR elongation.OsAUX4 is expressed in RH,and osaux4 mutants showing longer RH compared to WT/DJ implies that OsAUX4 negatively regulates RH development.Furthermore,osaux4 mutants are insensitive to Pi starvation(-Pi)and OsAUX4 effects on the-Pi response is associated with altered expression levels of Pi starvation-regulated genes,and auxin distribution/contents.This study revealed that OsAUX4 not only regulates PR and RH development but also plays a regulatory role in crosstalk between auxin and-Pi signaling.展开更多
Drought is one of the abiotic stresses limiting the production of soybean(Glycine max).Elucidation of the genetic and molecular basis of the slow-wilting(SW)trait of this crop offers the prospect of its genetic improv...Drought is one of the abiotic stresses limiting the production of soybean(Glycine max).Elucidation of the genetic and molecular basis of the slow-wilting(SW)trait of this crop offers the prospect of its genetic improvement.A panel of 188 accessions and a set of recombinant inbred lines produced from a cross between cultivars Liaodou 14 and Liaodou 21 were used to identify quantitative-trait loci(QTL)associated with SW.Plants were genotyped by Specific-locus amplified fragment sequencing and seedling leaf wilting was assessed under three water-stress treatments.A genome-wide association study identified 26 SW-associated single-nucleotide polymorphisms(SNPs),including three located in a 248-kb linkage-disequilibrium(LD)block on chromosome 2.Linkage mapping revealed a major-effect QTL,qSW2,associated with all three treatments and adjacent to the LD block.Fine mapping in a BC_(2)F_(3) population derived from a backcross between Liaodou 21 and R26 confined qSW2 to a 60-kb interval.Gene expression and sequence variation analysis identified the gene Glyma.02 g218100,encoding an auxin transcription factor,as a candidate gene for qSW2.Our results will contribute significantly to improving drought-resistant soybean cultivars by providing genetic information and resources.展开更多
This research was to assess the dietary copper(Cu)requirement of broiler chickens fed a practical cornsoybean meal diet during 22—42 d of age.A total of 288 numbered Arbor Acres male broilers at 22 d of age were rand...This research was to assess the dietary copper(Cu)requirement of broiler chickens fed a practical cornsoybean meal diet during 22—42 d of age.A total of 288 numbered Arbor Acres male broilers at 22 d of age were randomly allotted 6 treatments with 8 replicate cages(6 broilers per cage)per treatment.Broilers were fed a Cu-unsupplemented corn-soybean meal basal diet(control,containing 7.36 mg Cu/kg)or the basal diet added with 3,6,9,12,or 15 mg Cu/kg from CuSO_(4)·5H_(2)O for 21 d.Quadratic,asymptotic and broken-line models were fitted and the best fitted models were selected to determine dietary Cu requirements.The results revealed that the contents of Cu in serum and liver,m RNA expression levels of Cu-and zinc-containing superoxide dismutase(CuZnSOD)in liver and monoamine oxidase b(MAO B)in heart,as well as protein expression level of CuZnSOD in liver were affected(P<0.05)by supplemental Cu levels,and the above indices varied linearly and quadratically(P<0.05)with increasing Cu levels.Dietary Cu requirements assessed according to the best fitted broken-line models(P<0.05)of the above indexes were 10.45—13.81 mg/kg.It was concluded that mRNA expression levels of CuZnSOD in liver and MAO B in heart,as well as liver CuZnSOD protein expression level were new specific sensitive biomarkers for estimating dietary Cu requirements,and the dietary Cu requirement was recommended to be 14 mg/kg to support Cu metabolic needs related to key Cucontaining enzymes in broilers fed the corn-soybean meal diet during 22—42 d of age,which was higher than the dietary Cu requirement(8 mg/kg)for broilers at the corresponding stage suggested by the Chinese Feeding Standard of Chicken.展开更多
The residual subsidence caused by underground mining in mountain area has a long subsidence duration time and great potential harm,which seriously threatens the safety of people's production and life in the mining...The residual subsidence caused by underground mining in mountain area has a long subsidence duration time and great potential harm,which seriously threatens the safety of people's production and life in the mining area.Therefore,it is necessary to use appropriate monitoring methods and mathematical models to effectively monitor and predict the residual subsidence caused by underground mining.Compared with traditional level survey and InSAR(Interferometric Synthetic Aperture Radar)technology,GNSS(Global Navigation Satellite System)online monitoring technology has the advantages of long-term monitoring,high precision and more flexible monitoring methods.The empirical equation method of residual subsidence in mining subsidence is effectively combined with the rock creep equation,which can not only describe the residual subsidence process from the mechanism,but also predict the residual subsidence.Therefore,based on GNSS online monitoring technology,combined with the mining subsidence model of mountain area and adding the correlation coefficient of the compaction degree of caving broken rock and the Kelvin model of rock mechanics,this paper constructs the residual subsidence time series model of arbitrary point on the ground in mountain area.Through the example,the predicted results of the model in the inversion parameter phase and the dynamic prediction phase are compared with the measured data sequence.The results show that the model can carry out effective numerical calculation according to the GNSS monitoring data of any point on the ground,and the model prediction effect is good,which provides a new method for the prediction of residual subsidence in mountain mining.展开更多
Shear wave splitting(SWS)is regarded as the most effective geophysical method to delineate mantle flow fields by detecting seismic azimuthal anisotropy in the earth's upper mantle,especially in tectonically active...Shear wave splitting(SWS)is regarded as the most effective geophysical method to delineate mantle flow fields by detecting seismic azimuthal anisotropy in the earth's upper mantle,especially in tectonically active regions such as subduction zones.The Aleutian-Alaska subduction zone has a convergence rate of approximately 50 mm/yr,with a trench length reaching nearly 2800 km.Such a long subduction zone has led to intensive continental deformation and numerous strong earthquakes in southern and central Alaska,while northern Alaska is relatively inactive.The sharp contrast makes Alaska a favorable locale to investigate the impact of subduction on mantle dynamics.Moreover,the uniqueness of this subduction zone,including the unusual subducting type,varying slab geometry,and atypical magmatic activity and composition,has intrigued the curiosity of many geoscientists.To identify different sources of seismic anisotropy beneath the Alaska region and probe the influence of a geometrically varying subducting slab on mantle dynamics,extensive SWS analyses have been conducted in the past decades.However,the insufficient station and azimuthal coverage,especially in early studies,not only led to some conflicting results but also strongly limited the in-depth investigation of layered anisotropy and the estimation of anisotropy depth.With the completion of the Transportable Array project in Alaska,recent studies have revealed more detailed mantle structures and characteristics based on the dense station coverage and newly collected massive seismic data.In this study,we review significant regional-and continental-scale SWS studies in the Alaska region and conclude the mantle flow fields therein,to understand how a geometrically varying subducting slab alters the regional mantle dynamics.The summarized mantle flow mechanisms are believed to be conducive to the understanding of seismic anisotropy patterns in other subduction zones with a complicated tectonic setting.展开更多
液化空气储能(liquefied air energy storage, LAES)因其存储规模大和不受地理条件限制的独特优势,可参与现有燃煤机组的调峰改造,以推进新型电力系统的建设发展。为此提出一种与燃煤机组耦合的新型LAES系统,并且建立耦合系统的热力学...液化空气储能(liquefied air energy storage, LAES)因其存储规模大和不受地理条件限制的独特优势,可参与现有燃煤机组的调峰改造,以推进新型电力系统的建设发展。为此提出一种与燃煤机组耦合的新型LAES系统,并且建立耦合系统的热力学模型和经济性模型,分析储能容量变化对耦合系统的影响。结果表明:与某670 MW燃煤机组耦合时,可以综合考虑选择44.2 MW/176.8 MW·h的液化空气储能系统。在燃煤机组的3种低负荷(30%THA、40%THA和50%THA)工况下,耦合运行的LAES系统的往返效率在51%左右,比单独运行的LAES系统高出大约9个百分点。耦合运行的LAES系统的投资收益率接近10%,14 a之内可实现投资回收。敏感性分析显示增大峰谷电价差有利于提升系统的经济性能。展开更多
Background Our previous studies demonstrated that divalent organic iron(Fe)proteinate sources with higher complexation or chelation strengths as expressed by the greater quotient of formation(Qf)values displayed highe...Background Our previous studies demonstrated that divalent organic iron(Fe)proteinate sources with higher complexation or chelation strengths as expressed by the greater quotient of formation(Qf)values displayed higher Fe bioavailabilities for broilers.Sodium iron ethylenediaminetetraacetate(NaFeEDTA)is a trivalent organic Fe source with the strongest chelating ligand EDTA.However,the bioavailability of Fe when administered as NaFeEDTA in broilers and other agricultural animals remains untested.Herein,the chemical characteristics of 12 NaFeEDTA products were determined.Of these,one feed grade NaFeEDTA(Qf=2.07×10^(8)),one food grade NaFeEDTA(Qf=3.31×10^(8)),and one Fe proteinate with an extremely strong chelation strength(Fe-Prot ES,Qf value=8,590)were selected.Their bioavailabilities relative to Fe sulfate(FeSO_(4)·7H_(2)O)for broilers fed with a conventional corn-soybean meal diet were evaluated during d 1 to 21 by investigating the effects of the above Fe sources and added Fe levels on the growth performance,hematological indices,Fe contents,activities and gene expressions of Fe-containing enzymes in various tissues of broilers.Results NaFeEDTA sources varied greatly in their chemical characteristics.Plasma Fe concentration(PI),transferrin saturation(TS),liver Fe content,succinate dehydrogenase(SDH)activities in liver,heart,and kidney,catalase(CAT)activity in liver,and SDH mRNA expressions in liver and kidney increased linearly(P<0.05)with increasing levels of Fe supplementation.However,differences among Fe sources were detected(P<0.05)only for PI,liver Fe content,CAT activity in liver,SDH activities in heart and kidney,and SDH mRNA expressions in liver and kidney.Based on slope ratios from multiple linear regressions of the above indices on daily dietary analyzed Fe intake,the average bioavailabilities of Fe-Prot ES,feed grade NaFeEDTA,and food grade NaFeEDTA relative to the inorganic FeSO_(4)·7H_(2)O(100%)for broilers were 139%,155%,and 166%,respectively.Conclusions The bioavailabilities of organic Fe sou展开更多
Graph neural networks(GNNs)have achieved remarkable performance in a variety of graph-related tasks.Recent evidence in the GNN community shows that such good performance can be attributed to the homophily prior;i.e.,c...Graph neural networks(GNNs)have achieved remarkable performance in a variety of graph-related tasks.Recent evidence in the GNN community shows that such good performance can be attributed to the homophily prior;i.e.,connected nodes tend to have similar features and labels.However,in heterophilic settings where the features of connected nodes may vary significantly,GNN models exhibit notable performance deterioration.In this work,we formulate this problem as prior-data confict and propose a model called the mixture-prior graph neural network(MPGNN).First,to address the mismatch of homophily prior on heterophilic graphs,we introduce the non-informative prior,which makes no assumptions about the relationship between connected nodes and learns such relationship from the data.Second,to avoid performance degradation on homophilic graphs,we implement a soft switch to balance the effects of homophily prior and non-informative prior by learnable weights.We evaluate the performance of MPGNN on both synthetic and real-world graphs.Results show that MPGNN can effectively capture the relationship between connected nodes,while the soft switch helps select a suitable prior according to the graph characteristics.With these two designs,MPGNN outperforms state-of-the-art methods on heterophilic graphs without sacrificing performance on homophilic graphs.展开更多
With the gradual development and modernization of satellite navigation systems,using observation information from multi-GNss has become one of the hot-spot issues in recent years.Multi-system loose combinations form d...With the gradual development and modernization of satellite navigation systems,using observation information from multi-GNss has become one of the hot-spot issues in recent years.Multi-system loose combinations form double-difference observation equations within their respective systems,and the positioning effect is improved.However,the interchangeability and compatible interoperability between global navigation satellite systems(GNSS)cannot be truly realized.At the same time,when the number of visible satellites decreases abruptly,the positioning performance deteriorates sharply.This paper focuses on the GNsS multi-system tight combination relative positioning technique,gives a mathe-matical model of multi-system tight combination relative positioning considering differential inter-system bias(DISB),and analyzes the time-varying characteristics of DISB at overlapping and non-overlapping frequencies among GPS/Galileo,GPS/BDS,and GPS/QZSS in terms of receiver brand,tem-perature,and receiver restart.The GNsS tight combination relative positioning performance is verified by static data from Curtin University and dynamic data measured at Taiyuan University of Technology.The results show that compared with loose combination,the ambiguity-fixed rate increases from 62.18%to 97.60%for static data and from 74.97%to 99.53%for dynamic data when the elevation mask angle is 50°,resulting in a significant improvement in positioning performance.展开更多
Organometal halide perovskite has drawn much attention due to their high light-absorption coefficient,outstanding carrier mobility,and long-range charge-transport lengths.The most remarkable progress made by this type...Organometal halide perovskite has drawn much attention due to their high light-absorption coefficient,outstanding carrier mobility,and long-range charge-transport lengths.The most remarkable progress made by this type of perovskite materials is in the field of photovoltaics[1–4].The power conversion efficiency(PCE)of perovskite solar cells(PSCs)has exceeded 25%since they were first used as the active layer in solar cells in 2009[5].展开更多
All-polymer solar cells(all-PSCs) have received extensive attention due to their excellent mechanical robustness and performance stability. However, the power conversion efficiency(PCE) of all-PSCs still lags behind t...All-polymer solar cells(all-PSCs) have received extensive attention due to their excellent mechanical robustness and performance stability. However, the power conversion efficiency(PCE) of all-PSCs still lags behind those of organic solar cells(OSCs)based on non-fullerene small molecule acceptors. Herein, we report highly efficient all-PSCs via sequential deposition(SD) with donor and acceptor layers coated sequentially to optimize the film microstructure. Compared with the bulk heterojunction(BHJ)all-PSCs, an optimized morphology with vertical component distribution was achieved for the SD-processed all-PSCs due to the synergistic effect of swelling of polymer films and using additive. Such strategy involves using chlorobenzene as the first layer processing-solvent for polymer donor, chloroform as the second processing-solvent for polymer acceptor with trace 1-chloronaphthalene, efficiently promoting exciton dissociation and charge extraction and reducing trap-assisted recombination.Consequently, over 16% all-PSCs fabricated via SD method was realized for the first time, which is much higher than that(15.2%) of its BHJ counterpart and also among the highest PCEs in all-PSCs. We have further demonstrated the generality of this approach in various all-polymer systems. This work indicates that the SD method can yield excellent all-PSCs and provides a facile approach to fabricating high-performance all-PSCs.展开更多
The western North Pacific summer monsoon(WNPSM)is an important subcomponent of the Asian summer monsoon.The equatorial zonal wind(EZW)in the lower troposphere over the western Pacific may play a critical role in the e...The western North Pacific summer monsoon(WNPSM)is an important subcomponent of the Asian summer monsoon.The equatorial zonal wind(EZW)in the lower troposphere over the western Pacific may play a critical role in the evolution of the El Niño-Southern Oscillation(ENSO).The possible linkage between the EZW over the western Pacific and the offequatorial monsoonal winds associated with the WNPSM and its decadal changes have not yet been fully understood.Here,we find a non-stationary relationship between the WNPSM and the western Pacific EZW,significantly strengthening their correlation around the late 1980s/early 1990s.This observed shift in the WNPSM–EZW relationship could be explained by the changes in the related sea surface temperature(SST)configurations across the tropical oceans.The enhanced influence from the springtime tropical North Atlantic,summertime tropical central Pacific,and maritime continent SST anomalies may be working together in contributing to the recent intensified WNPSM–EZW co-variability.The observed recent strengthening of the WNPSM–EZW relationship may profoundly impact the climate system,including prompting more effective feedback from the WNPSM on subsequent ENSO evolution and bolstering a stronger biennial tendency of the WNPSM–ENSO coupled system.The results obtained herein imply that the WNPSM,EZW,ENSO,and the tropical North Atlantic SST may be closely linked within a unified climate system with a quasi-biennial rhythm occurring during recent decades,accompanied by a reinforcement of the WNPSM–ENSO interplay quite possibly triggered by enhanced tropical Pacific–Atlantic cross-basin interactions.These results highlight the importance of the tropical Atlantic cross-basin influences in shaping the spatial structure of WNPSM-related wind anomalies and the WNPSM–ENSO interaction.展开更多
The power conversion efficiencies(PCEs)of organic solar cells(OSCs)have improved considerably in recent years with the development of fused-ring electron acceptors(FREAs).Currently,FREAs-based OSCs have achieved high ...The power conversion efficiencies(PCEs)of organic solar cells(OSCs)have improved considerably in recent years with the development of fused-ring electron acceptors(FREAs).Currently,FREAs-based OSCs have achieved high PCEs of over 19%in single-junction OSCs.Whereas the relatively high synthetic complexity and the low yield of FREAs typically result in high production costs,hindering the commercial application of OSCs.In contrast,noncovalently fused-ring electron acceptors(NFREAs)can compensate for the shortcomings of FREAs and facilitate large-scale industrial production by virtue of the simple structure,facile synthesis,high yield,low cost,and reasonable efficiency.At present,OSCs based on NFREAs have exceeded the PCEs of 15%and are expected to reach comparable efficiency as FREAs-based OSCs.Here,recent advances in NFREAs in this review provide insight into improving the performance of OSCs.In particular,this paper focuses on the effect of the chemical structures of NFREAs on the molecule conformation,aggregation,and packing mode.Various molecular design strategies,such as core,side-chain,and terminal group engineering,are presented.In addition,some novel polymer acceptors based on NFREAs for all-polymer OSCs are also introduced.In the end,the paper provides an outlook on developing efficient,stable,and low-cost NFREAs for achieving commercial applications.展开更多
This paper investigated the porosity controlling factors for tight sandstone reservoir in the Daniudi gas field, Ordos Basin based on an integrated petrographic, petrophysical and geostatistical analyses, and proposed...This paper investigated the porosity controlling factors for tight sandstone reservoir in the Daniudi gas field, Ordos Basin based on an integrated petrographic, petrophysical and geostatistical analyses, and proposed a comprehensive prediction model for reservoir porosity. Compaction was found to be a key factor for causing reservoir densification. The degree of sandstone compaction appears to be affected by grain sizes and sorting. Under normal compaction conditions（e.g., cement content less than 6%, and with no dissolution）, the variation in reservoir porosity with burial depth can be well correlated with grain compositions, grain sizes, and sorting. Based on qualitative examination of the controlling factors for reservoir porosities, geostatistics were used to quantify the effects of various geological parameters on reservoir porosities. A statistical model for comprehensive prediction of porosity was then established, on the assumption that the present reservoir porosity directly relates to both normal compaction and diagenesis. This model is easy to use, and has been validated with measured porosity data. The porosity controlling factors and the comprehensive porosity prediction can be used to quantify effects of the main controlling factors and their interaction on reservoir property evolution, and may provide a reference model for log interpretation.展开更多
Developing dopant-free hole-transporting materials(HTMs)for high-performance perovskite solar cells(PVSCs)has been a very active research topic in recent years since HTMs play a critical role in optimizing interfacial...Developing dopant-free hole-transporting materials(HTMs)for high-performance perovskite solar cells(PVSCs)has been a very active research topic in recent years since HTMs play a critical role in optimizing interfacial charge carrier kinetics and in turn determining device performance.Here,a novel dendritic engineering strategy is first utilized to design HTMs with a D-A type molecular framework,and diphenylamine and/or carbazole is selected as the building block for constructing dendrons.All HTMs show good thermal stability and excellent film morphology,and the key optoelectronic properties could be fine-tuned by varying the dendron structure.Among them,MPA-Cz-BTI and MCz-Cz-BTI exhibit an improved interfacial contact with the perovskite active layer,and non-radiative recombination loss and charge transport loss can be effectively suppressed.Consequently,high power conversion efficiencies(PCEs)of 20.8%and 21.35%are achieved for MPA-Cz-BTI and MCz-Cz-BTI based devices,respectively,accompanied by excellent long-term storage stability.More encouragingly,ultrahigh fill factors of 85.2%and 83.5%are recorded for both devices,which are among the highest values reported to date.This work demonstrates the great potential of dendritic materials as a new type of dopant-free HTMs for high-performance PVSCs with excellent FF.展开更多
Subsidence data acquisition methods are crucial to mining subsidence research and an essential component of achieving the goal of environmentally friendly coal mining.The origin and history of the existing methods of ...Subsidence data acquisition methods are crucial to mining subsidence research and an essential component of achieving the goal of environmentally friendly coal mining.The origin and history of the existing methods of field monitoring,calcula-tion,and simulation were introduced.It summarized and analyzed the main applications,flaws and solutions,and improve-ments of these methods.Based on this analysis,the future developing directions of subsidence data acquisition methods were prospected and suggested.The subsidence monitoring methods have evolved from conventional ground monitoring to combined methods involving ground-based,space-based,and air-based measurements.While the conventional methods are mature in technology and reliable in accuracy,emerging remote sensing technologies have obvious advantages in terms of reducing field workload and increasing data coverage.However,these remote sensing methods require further technological development to be more suitable for monitoring mining subsidence.The existing subsidence calculation methods have been applied to various geological and mining conditions,and many improvements have already been made.In the future,more attention should be paid to unifying the studies of calculation methods and mechanical principles.The simulation methods are quite dependent on the similarity of the model to the site conditions and are generally used as an auxiliary data source for subsidence studies.The cross-disciplinary studies between subsidence data acquisition methods and other technologies should be given serious consideration,as they can be expected to lead to breakthroughs in areas such as theories,devices,software,and other aspects.展开更多
Gaseous nitrogen （N2） makes up 78% of the earth＇s at- mosphere; its incorporation into a wide range of biological macromolecules molecules, such as nucleic acids and amino acids, makes it an essential part of all l...Gaseous nitrogen （N2） makes up 78% of the earth＇s at- mosphere; its incorporation into a wide range of biological macromolecules molecules, such as nucleic acids and amino acids, makes it an essential part of all life on earth. However, as nitrogen gas is inert, it remains unavailable to most organisms, including plants. Thus, in order to be useful for fertilizer production, gaseous nitrogen needs first to be converted into bioavailable organic nitrogen in processes which are inefficient and rate-limiting for agricultural pro- duction. It was not until about 100 years ago that BASF were able to produce synthetic ammonia, the main ingredient for fertilizer production, on an industrial scale from pressurized air using the Haber--Bosch process. This chemical process was not only an impressive technical feat that helped Haber （1918） and Bosch （1931） earn Nobel Prizes but also enabled farmers to achieve the high yields that drive modern agriculture.展开更多
The open-circuit voltage(Voc) of all-polymer solar cells(all-PSCs) is typically lower than 0.9 V even for the most efficient ones.Large energy loss is the main reason for limiting Voc and efficiency of all-PSCs. Herei...The open-circuit voltage(Voc) of all-polymer solar cells(all-PSCs) is typically lower than 0.9 V even for the most efficient ones.Large energy loss is the main reason for limiting Voc and efficiency of all-PSCs. Herein, through materials design using electron deficient building blocks based on bithiophene imides, the lowest unoccupied molecular orbital(LUMO) energy levels of polymer acceptors can be effectively tuned, which resulted in a reduced energy loss induced by charge generation and recombination loss due to the suppressed charge-transfer(CT) state absorption. Despite a negligible driving force, all-PSC based on the polymer donor and acceptor combination with well-aligned energy levels exhibited efficient charge transfer and achieved an external quantum efficiency over 70% while maintaining a large Voc of 1.02 V, leading to a 9.21% efficiency. Through various spectroscopy approaches, this work sheds light on the mechanism of energy loss in all-PSCs, which paves an avenue to achieving efficient all-PSCs with large Voc and drives the further development of all-PSCs.展开更多
文摘Damage caused by underground coal mining is a serious problem in mining areas in China; therefore, studying and obtaining the rules of ground movement and deformation under different geological conditions is of great importance. The numerical software ANSYS was used in this study to simulate mining processes under two special geological conditions： （1） thick unconsolidated soil layer and thin bedrock; （2） thin soil layer and thick bedrock. The rules for ground movement and deformation for different soil layer to bedrock ratios were obtained. On the basis of these rules, a prediction parameter modified model of the influence function was proposed, which is suitable for different values of unconsolidated soil layer thickness. The prediction results were verified using two sets of typical field data.
基金partially funded by a grant from Ningxia Science and Technology Support Project,No.2012ZYS207
文摘Hemiplegia caused by stroke indicates dysfunction of the network between the brain and limbs, namely collateral shock in the brain. Contralateral needling is the insertion of needles into acupoints on the relative healthy side of the body to treat diseases such as apoplexy. However, there is little well-designed and controlled clinical evidence for this practice. This study investigated whether contralateral needling could treat hemiplegia after acute ischemic stroke in 106 randomly selected patients with acute ischemic stroke. These patients were randomly assigned to three groups： 45 in the contralateral needling group, receiving acupuncture on the unaffected limbs; 45 in the conven- tional acupuncture group, receiving acupuncture on the hemiplegic limbs; and 16 in the control group, receiving routine treatments without acupuncture. Acupuncture at acupoints Chize （LU5） in the upper limb and Jianliao （TEl4） in the lower limb was performed for 45 minutes daily for 30 consecutive days. The therapeutic effective rate, Neurological Deficit Score, Modified Barthel Index and FugI-Meyer Assessment were evaluated. The therapeutic effective rate of contralateral nee- dling was higher than that of conventional acupuncture （46.67% vs. 31.11%, P 〈 0.05）. The neuro- logical deficit score of contralateral needling was significantly decreased compared with conven- tional acupuncture （P 〈 0.01）. The Modified Barthel Index and FugI-Meyer Assessment score of contralateral needling increased more significantly than those of conventional acupuncture （both P 〈 0.01）. The present findings suggest that contralateral needling unblocks collaterals and might be more effective than conventional acupuncture in the treatment of hemiplegia following acute ischemic stroke.
基金This project was funded by grants from the National Key Research and Development Program of China(2016YFD0100400)the Zhejiang Provincial Natural Science Foundation of China(LZ19C020001)the National Natural Science Foundation of China(32060451).
文摘Among the five members of AUX1/LAX genes coding for auxin carriers in rice,only OsAUX1 and OsAUX3 have been reported.To understand the function of the other AUX1/LAX genes,two independent alleles of osaux4 mutants,osaux4-1 and osaux4-2,were constructed using the CRISPR/Cas9 editing system.Homozygous osaux4-1 or osaux4-2 exhibited shorter primary root(PR)and longer root hair(RH)compared to the wild-type Dongjin(WT/DJ),and lost response to indoleacetic acid(IAA)treatment.OsAUX4 is intensively expressed in roots and localized on the plasma membrane,suggesting that OsAUX4 might function in the regulation of root development.The decreased meristem cell division activity and the downregulated expression of cell cycle genes in root apices of osaux4 mutants supported the hypothesis that OsAUX4 positively regulates PR elongation.OsAUX4 is expressed in RH,and osaux4 mutants showing longer RH compared to WT/DJ implies that OsAUX4 negatively regulates RH development.Furthermore,osaux4 mutants are insensitive to Pi starvation(-Pi)and OsAUX4 effects on the-Pi response is associated with altered expression levels of Pi starvation-regulated genes,and auxin distribution/contents.This study revealed that OsAUX4 not only regulates PR and RH development but also plays a regulatory role in crosstalk between auxin and-Pi signaling.
基金The study was supported by the National Natural Science Foundation of China(32101795,32301782)National Key Research and Development Program of China(2016YFD0100201-01)+2 种基金Liaoning Provincial Major Special Project of Agricultural Science and Technology(2022JH1/10200002,2021JH1/10400038)Key Research and Development Plan of Liaoning Science and Technology Department(2021JH2/1020027)Shenyang Seed Industry Innovation Project(22-318-2-12).
文摘Drought is one of the abiotic stresses limiting the production of soybean(Glycine max).Elucidation of the genetic and molecular basis of the slow-wilting(SW)trait of this crop offers the prospect of its genetic improvement.A panel of 188 accessions and a set of recombinant inbred lines produced from a cross between cultivars Liaodou 14 and Liaodou 21 were used to identify quantitative-trait loci(QTL)associated with SW.Plants were genotyped by Specific-locus amplified fragment sequencing and seedling leaf wilting was assessed under three water-stress treatments.A genome-wide association study identified 26 SW-associated single-nucleotide polymorphisms(SNPs),including three located in a 248-kb linkage-disequilibrium(LD)block on chromosome 2.Linkage mapping revealed a major-effect QTL,qSW2,associated with all three treatments and adjacent to the LD block.Fine mapping in a BC_(2)F_(3) population derived from a backcross between Liaodou 21 and R26 confined qSW2 to a 60-kb interval.Gene expression and sequence variation analysis identified the gene Glyma.02 g218100,encoding an auxin transcription factor,as a candidate gene for qSW2.Our results will contribute significantly to improving drought-resistant soybean cultivars by providing genetic information and resources.
基金supported by Jiangsu Shuang Chuang Tuan Dui program(JSSCTD202147)Jiangsu Shuang Chuang Ren Cai program(JSSCRC2021541)+1 种基金Young Elite Scientists Sponsorship Program by CAST(2022QNRC001)the Initiation Funds of Yangzhou University for Distinguished Scientists
文摘This research was to assess the dietary copper(Cu)requirement of broiler chickens fed a practical cornsoybean meal diet during 22—42 d of age.A total of 288 numbered Arbor Acres male broilers at 22 d of age were randomly allotted 6 treatments with 8 replicate cages(6 broilers per cage)per treatment.Broilers were fed a Cu-unsupplemented corn-soybean meal basal diet(control,containing 7.36 mg Cu/kg)or the basal diet added with 3,6,9,12,or 15 mg Cu/kg from CuSO_(4)·5H_(2)O for 21 d.Quadratic,asymptotic and broken-line models were fitted and the best fitted models were selected to determine dietary Cu requirements.The results revealed that the contents of Cu in serum and liver,m RNA expression levels of Cu-and zinc-containing superoxide dismutase(CuZnSOD)in liver and monoamine oxidase b(MAO B)in heart,as well as protein expression level of CuZnSOD in liver were affected(P<0.05)by supplemental Cu levels,and the above indices varied linearly and quadratically(P<0.05)with increasing Cu levels.Dietary Cu requirements assessed according to the best fitted broken-line models(P<0.05)of the above indexes were 10.45—13.81 mg/kg.It was concluded that mRNA expression levels of CuZnSOD in liver and MAO B in heart,as well as liver CuZnSOD protein expression level were new specific sensitive biomarkers for estimating dietary Cu requirements,and the dietary Cu requirement was recommended to be 14 mg/kg to support Cu metabolic needs related to key Cucontaining enzymes in broilers fed the corn-soybean meal diet during 22—42 d of age,which was higher than the dietary Cu requirement(8 mg/kg)for broilers at the corresponding stage suggested by the Chinese Feeding Standard of Chicken.
基金supported by the Natural Science Foundation of Shanxi Province,China(202203021211153)National Natural Science Foundation of China(51704205).
文摘The residual subsidence caused by underground mining in mountain area has a long subsidence duration time and great potential harm,which seriously threatens the safety of people's production and life in the mining area.Therefore,it is necessary to use appropriate monitoring methods and mathematical models to effectively monitor and predict the residual subsidence caused by underground mining.Compared with traditional level survey and InSAR(Interferometric Synthetic Aperture Radar)technology,GNSS(Global Navigation Satellite System)online monitoring technology has the advantages of long-term monitoring,high precision and more flexible monitoring methods.The empirical equation method of residual subsidence in mining subsidence is effectively combined with the rock creep equation,which can not only describe the residual subsidence process from the mechanism,but also predict the residual subsidence.Therefore,based on GNSS online monitoring technology,combined with the mining subsidence model of mountain area and adding the correlation coefficient of the compaction degree of caving broken rock and the Kelvin model of rock mechanics,this paper constructs the residual subsidence time series model of arbitrary point on the ground in mountain area.Through the example,the predicted results of the model in the inversion parameter phase and the dynamic prediction phase are compared with the measured data sequence.The results show that the model can carry out effective numerical calculation according to the GNSS monitoring data of any point on the ground,and the model prediction effect is good,which provides a new method for the prediction of residual subsidence in mountain mining.
基金supported by the Outstanding Youth Project of Natural Science Foundation of Heilongjiang(YQ2023D006).
文摘Shear wave splitting(SWS)is regarded as the most effective geophysical method to delineate mantle flow fields by detecting seismic azimuthal anisotropy in the earth's upper mantle,especially in tectonically active regions such as subduction zones.The Aleutian-Alaska subduction zone has a convergence rate of approximately 50 mm/yr,with a trench length reaching nearly 2800 km.Such a long subduction zone has led to intensive continental deformation and numerous strong earthquakes in southern and central Alaska,while northern Alaska is relatively inactive.The sharp contrast makes Alaska a favorable locale to investigate the impact of subduction on mantle dynamics.Moreover,the uniqueness of this subduction zone,including the unusual subducting type,varying slab geometry,and atypical magmatic activity and composition,has intrigued the curiosity of many geoscientists.To identify different sources of seismic anisotropy beneath the Alaska region and probe the influence of a geometrically varying subducting slab on mantle dynamics,extensive SWS analyses have been conducted in the past decades.However,the insufficient station and azimuthal coverage,especially in early studies,not only led to some conflicting results but also strongly limited the in-depth investigation of layered anisotropy and the estimation of anisotropy depth.With the completion of the Transportable Array project in Alaska,recent studies have revealed more detailed mantle structures and characteristics based on the dense station coverage and newly collected massive seismic data.In this study,we review significant regional-and continental-scale SWS studies in the Alaska region and conclude the mantle flow fields therein,to understand how a geometrically varying subducting slab alters the regional mantle dynamics.The summarized mantle flow mechanisms are believed to be conducive to the understanding of seismic anisotropy patterns in other subduction zones with a complicated tectonic setting.
文摘液化空气储能(liquefied air energy storage, LAES)因其存储规模大和不受地理条件限制的独特优势,可参与现有燃煤机组的调峰改造,以推进新型电力系统的建设发展。为此提出一种与燃煤机组耦合的新型LAES系统,并且建立耦合系统的热力学模型和经济性模型,分析储能容量变化对耦合系统的影响。结果表明:与某670 MW燃煤机组耦合时,可以综合考虑选择44.2 MW/176.8 MW·h的液化空气储能系统。在燃煤机组的3种低负荷(30%THA、40%THA和50%THA)工况下,耦合运行的LAES系统的往返效率在51%左右,比单独运行的LAES系统高出大约9个百分点。耦合运行的LAES系统的投资收益率接近10%,14 a之内可实现投资回收。敏感性分析显示增大峰谷电价差有利于提升系统的经济性能。
基金funded by Jiangsu Shuang Chuang Tuan Dui program (JSSCTD202147)Jiangsu Shuang Chuang Ren Cai program (JSSCRC2021541)+1 种基金Young Elite Scientists Sponsorship Program by CAST (2022QNRC001)the Initiation Funds of Yangzhou University for Distinguished Scientists
文摘Background Our previous studies demonstrated that divalent organic iron(Fe)proteinate sources with higher complexation or chelation strengths as expressed by the greater quotient of formation(Qf)values displayed higher Fe bioavailabilities for broilers.Sodium iron ethylenediaminetetraacetate(NaFeEDTA)is a trivalent organic Fe source with the strongest chelating ligand EDTA.However,the bioavailability of Fe when administered as NaFeEDTA in broilers and other agricultural animals remains untested.Herein,the chemical characteristics of 12 NaFeEDTA products were determined.Of these,one feed grade NaFeEDTA(Qf=2.07×10^(8)),one food grade NaFeEDTA(Qf=3.31×10^(8)),and one Fe proteinate with an extremely strong chelation strength(Fe-Prot ES,Qf value=8,590)were selected.Their bioavailabilities relative to Fe sulfate(FeSO_(4)·7H_(2)O)for broilers fed with a conventional corn-soybean meal diet were evaluated during d 1 to 21 by investigating the effects of the above Fe sources and added Fe levels on the growth performance,hematological indices,Fe contents,activities and gene expressions of Fe-containing enzymes in various tissues of broilers.Results NaFeEDTA sources varied greatly in their chemical characteristics.Plasma Fe concentration(PI),transferrin saturation(TS),liver Fe content,succinate dehydrogenase(SDH)activities in liver,heart,and kidney,catalase(CAT)activity in liver,and SDH mRNA expressions in liver and kidney increased linearly(P<0.05)with increasing levels of Fe supplementation.However,differences among Fe sources were detected(P<0.05)only for PI,liver Fe content,CAT activity in liver,SDH activities in heart and kidney,and SDH mRNA expressions in liver and kidney.Based on slope ratios from multiple linear regressions of the above indices on daily dietary analyzed Fe intake,the average bioavailabilities of Fe-Prot ES,feed grade NaFeEDTA,and food grade NaFeEDTA relative to the inorganic FeSO_(4)·7H_(2)O(100%)for broilers were 139%,155%,and 166%,respectively.Conclusions The bioavailabilities of organic Fe sou
基金Project supported by the National University of Defense Technology Foundation(Nos.ZK20-09 and ZK21-17)the Natural Science Foundation of Hunan Province,China(No.2021JJ40692)the National Key R&D Program of China(No.2021YFB0300101)。
文摘Graph neural networks(GNNs)have achieved remarkable performance in a variety of graph-related tasks.Recent evidence in the GNN community shows that such good performance can be attributed to the homophily prior;i.e.,connected nodes tend to have similar features and labels.However,in heterophilic settings where the features of connected nodes may vary significantly,GNN models exhibit notable performance deterioration.In this work,we formulate this problem as prior-data confict and propose a model called the mixture-prior graph neural network(MPGNN).First,to address the mismatch of homophily prior on heterophilic graphs,we introduce the non-informative prior,which makes no assumptions about the relationship between connected nodes and learns such relationship from the data.Second,to avoid performance degradation on homophilic graphs,we implement a soft switch to balance the effects of homophily prior and non-informative prior by learnable weights.We evaluate the performance of MPGNN on both synthetic and real-world graphs.Results show that MPGNN can effectively capture the relationship between connected nodes,while the soft switch helps select a suitable prior according to the graph characteristics.With these two designs,MPGNN outperforms state-of-the-art methods on heterophilic graphs without sacrificing performance on homophilic graphs.
基金supported by the Natural Science Foundation of Shanxi Provincial(Grant No.202203021211153)the Basic Research Program of Shanxi Province(Grant No.202203021212284)+2 种基金Open Foundation of the State Key Laboratory of Satellite Navigation System and Equipment Technology(Grant No.CEPNT2022B07)the Open Foundation of the State Key Laboratory of Geodesy and Earth's Dynamics(Grant No.SKLGED2022-3-4)the research on application technology of Beidou in the field of energy and power(Grant No.CEEC2022-ZDYF-01).
文摘With the gradual development and modernization of satellite navigation systems,using observation information from multi-GNss has become one of the hot-spot issues in recent years.Multi-system loose combinations form double-difference observation equations within their respective systems,and the positioning effect is improved.However,the interchangeability and compatible interoperability between global navigation satellite systems(GNSS)cannot be truly realized.At the same time,when the number of visible satellites decreases abruptly,the positioning performance deteriorates sharply.This paper focuses on the GNsS multi-system tight combination relative positioning technique,gives a mathe-matical model of multi-system tight combination relative positioning considering differential inter-system bias(DISB),and analyzes the time-varying characteristics of DISB at overlapping and non-overlapping frequencies among GPS/Galileo,GPS/BDS,and GPS/QZSS in terms of receiver brand,tem-perature,and receiver restart.The GNsS tight combination relative positioning performance is verified by static data from Curtin University and dynamic data measured at Taiyuan University of Technology.The results show that compared with loose combination,the ambiguity-fixed rate increases from 62.18%to 97.60%for static data and from 74.97%to 99.53%for dynamic data when the elevation mask angle is 50°,resulting in a significant improvement in positioning performance.
基金supported by the National Natural Science Foundation of China (51573076, 21801124)Shenzhen Basic Research Fund (JYJ20170817105905899)
文摘Organometal halide perovskite has drawn much attention due to their high light-absorption coefficient,outstanding carrier mobility,and long-range charge-transport lengths.The most remarkable progress made by this type of perovskite materials is in the field of photovoltaics[1–4].The power conversion efficiency(PCE)of perovskite solar cells(PSCs)has exceeded 25%since they were first used as the active layer in solar cells in 2009[5].
基金supported by the National Natural Science Foundation of China (52173172, 52173171, 21774055)the Natural Science Foundation for Distinguished Young Scholars of Guangdong Province (2021B1515020027)+4 种基金the Shenzhen Science and Technology Innovation Commission (JCYJ202103243104813035,JCYJ20180504165709042)the Open Fund of the State Key Laboratory of Luminescent Materials and Devices (South China University of Technology)China Postdoctoral Science Foundation (2021M700062)the financial support from the Natural Research Foundation of Korea (2016M1A2A2940911, 2015M1A2A2057506)the support of the Guangdong Provincial Key Laboratory Program (2021B1212040001) from the Department of Science and Technology of Guangdong Province。
文摘All-polymer solar cells(all-PSCs) have received extensive attention due to their excellent mechanical robustness and performance stability. However, the power conversion efficiency(PCE) of all-PSCs still lags behind those of organic solar cells(OSCs)based on non-fullerene small molecule acceptors. Herein, we report highly efficient all-PSCs via sequential deposition(SD) with donor and acceptor layers coated sequentially to optimize the film microstructure. Compared with the bulk heterojunction(BHJ)all-PSCs, an optimized morphology with vertical component distribution was achieved for the SD-processed all-PSCs due to the synergistic effect of swelling of polymer films and using additive. Such strategy involves using chlorobenzene as the first layer processing-solvent for polymer donor, chloroform as the second processing-solvent for polymer acceptor with trace 1-chloronaphthalene, efficiently promoting exciton dissociation and charge extraction and reducing trap-assisted recombination.Consequently, over 16% all-PSCs fabricated via SD method was realized for the first time, which is much higher than that(15.2%) of its BHJ counterpart and also among the highest PCEs in all-PSCs. We have further demonstrated the generality of this approach in various all-polymer systems. This work indicates that the SD method can yield excellent all-PSCs and provides a facile approach to fabricating high-performance all-PSCs.
基金This work was supported by the National Natural Science Foundation of China(Grant No:41776031)the National Key Research and Development Program of China(Grant 2018YFC1506903)+1 种基金the team project funding of scientific research innovation for universities in Guangdong province(Grant 2019KCXTF021)the program for scientific research start-up funds of Guangdong Ocean University(Grant R17051).
文摘The western North Pacific summer monsoon(WNPSM)is an important subcomponent of the Asian summer monsoon.The equatorial zonal wind(EZW)in the lower troposphere over the western Pacific may play a critical role in the evolution of the El Niño-Southern Oscillation(ENSO).The possible linkage between the EZW over the western Pacific and the offequatorial monsoonal winds associated with the WNPSM and its decadal changes have not yet been fully understood.Here,we find a non-stationary relationship between the WNPSM and the western Pacific EZW,significantly strengthening their correlation around the late 1980s/early 1990s.This observed shift in the WNPSM–EZW relationship could be explained by the changes in the related sea surface temperature(SST)configurations across the tropical oceans.The enhanced influence from the springtime tropical North Atlantic,summertime tropical central Pacific,and maritime continent SST anomalies may be working together in contributing to the recent intensified WNPSM–EZW co-variability.The observed recent strengthening of the WNPSM–EZW relationship may profoundly impact the climate system,including prompting more effective feedback from the WNPSM on subsequent ENSO evolution and bolstering a stronger biennial tendency of the WNPSM–ENSO coupled system.The results obtained herein imply that the WNPSM,EZW,ENSO,and the tropical North Atlantic SST may be closely linked within a unified climate system with a quasi-biennial rhythm occurring during recent decades,accompanied by a reinforcement of the WNPSM–ENSO interplay quite possibly triggered by enhanced tropical Pacific–Atlantic cross-basin interactions.These results highlight the importance of the tropical Atlantic cross-basin influences in shaping the spatial structure of WNPSM-related wind anomalies and the WNPSM–ENSO interaction.
基金Natural Science Foundation for Distinguished Young Scholars of Guangdong Province,Grant/Award Number:2021B1515020027Science and Technology Projects in Guangzhou,Grant/Award Number:202201000002+4 种基金Shenzhen Science and Technology Innovation Commission,Grant/Award Numbers:JCYJ202103243104813035,JCYJ20180504165709042GuangDong Basic and Applied Basic Research Foundation,Grant/Award Number:2021A1515110892China Postdoctoral Science Foundation,Grant/Award Number:2021M700062Open Fund of the State Key Laboratory of Luminescent Materials and Devices,Grant/Award Number:2022-skllmd-17X.G.,H.S.,and Y.J.are thankful for the financial support from the Songshan Lake Materials Laboratory,Grant/Award Number:2021SLABFK03。
文摘The power conversion efficiencies(PCEs)of organic solar cells(OSCs)have improved considerably in recent years with the development of fused-ring electron acceptors(FREAs).Currently,FREAs-based OSCs have achieved high PCEs of over 19%in single-junction OSCs.Whereas the relatively high synthetic complexity and the low yield of FREAs typically result in high production costs,hindering the commercial application of OSCs.In contrast,noncovalently fused-ring electron acceptors(NFREAs)can compensate for the shortcomings of FREAs and facilitate large-scale industrial production by virtue of the simple structure,facile synthesis,high yield,low cost,and reasonable efficiency.At present,OSCs based on NFREAs have exceeded the PCEs of 15%and are expected to reach comparable efficiency as FREAs-based OSCs.Here,recent advances in NFREAs in this review provide insight into improving the performance of OSCs.In particular,this paper focuses on the effect of the chemical structures of NFREAs on the molecule conformation,aggregation,and packing mode.Various molecular design strategies,such as core,side-chain,and terminal group engineering,are presented.In addition,some novel polymer acceptors based on NFREAs for all-polymer OSCs are also introduced.In the end,the paper provides an outlook on developing efficient,stable,and low-cost NFREAs for achieving commercial applications.
基金supported by the China National Science and Technology Special Funds (No. 2016ZX05009-002)Sinopec Key Project (No. ZDP17008)+1 种基金Joint Key Petrochemical Project Funded by the National Natural Science Foundation of China (No. U1262203)Project of Graduate Innovation Program in China University of Petroleum (East China) (No. YCX20150007)
文摘This paper investigated the porosity controlling factors for tight sandstone reservoir in the Daniudi gas field, Ordos Basin based on an integrated petrographic, petrophysical and geostatistical analyses, and proposed a comprehensive prediction model for reservoir porosity. Compaction was found to be a key factor for causing reservoir densification. The degree of sandstone compaction appears to be affected by grain sizes and sorting. Under normal compaction conditions（e.g., cement content less than 6%, and with no dissolution）, the variation in reservoir porosity with burial depth can be well correlated with grain compositions, grain sizes, and sorting. Based on qualitative examination of the controlling factors for reservoir porosities, geostatistics were used to quantify the effects of various geological parameters on reservoir porosities. A statistical model for comprehensive prediction of porosity was then established, on the assumption that the present reservoir porosity directly relates to both normal compaction and diagenesis. This model is easy to use, and has been validated with measured porosity data. The porosity controlling factors and the comprehensive porosity prediction can be used to quantify effects of the main controlling factors and their interaction on reservoir property evolution, and may provide a reference model for log interpretation.
基金the National Natural Science Foundation of China(21805128,21774055,61775091)Shenzhen Key Laboratory Project(ZDSYS201602261933302)+2 种基金Shenzhen Innovation Committee(JCYJ20180504165851864)Shenzhen Innovation Committee(JCYJ20170818141216288)the Seed Funding for Strategic Interdisciplinary Research Scheme of the University of Hong Kong。
文摘Developing dopant-free hole-transporting materials(HTMs)for high-performance perovskite solar cells(PVSCs)has been a very active research topic in recent years since HTMs play a critical role in optimizing interfacial charge carrier kinetics and in turn determining device performance.Here,a novel dendritic engineering strategy is first utilized to design HTMs with a D-A type molecular framework,and diphenylamine and/or carbazole is selected as the building block for constructing dendrons.All HTMs show good thermal stability and excellent film morphology,and the key optoelectronic properties could be fine-tuned by varying the dendron structure.Among them,MPA-Cz-BTI and MCz-Cz-BTI exhibit an improved interfacial contact with the perovskite active layer,and non-radiative recombination loss and charge transport loss can be effectively suppressed.Consequently,high power conversion efficiencies(PCEs)of 20.8%and 21.35%are achieved for MPA-Cz-BTI and MCz-Cz-BTI based devices,respectively,accompanied by excellent long-term storage stability.More encouragingly,ultrahigh fill factors of 85.2%and 83.5%are recorded for both devices,which are among the highest values reported to date.This work demonstrates the great potential of dendritic materials as a new type of dopant-free HTMs for high-performance PVSCs with excellent FF.
基金supported by the Natural Science Foundation of Shanxi Province,China (201901D111074,20210302124437).
文摘Subsidence data acquisition methods are crucial to mining subsidence research and an essential component of achieving the goal of environmentally friendly coal mining.The origin and history of the existing methods of field monitoring,calcula-tion,and simulation were introduced.It summarized and analyzed the main applications,flaws and solutions,and improve-ments of these methods.Based on this analysis,the future developing directions of subsidence data acquisition methods were prospected and suggested.The subsidence monitoring methods have evolved from conventional ground monitoring to combined methods involving ground-based,space-based,and air-based measurements.While the conventional methods are mature in technology and reliable in accuracy,emerging remote sensing technologies have obvious advantages in terms of reducing field workload and increasing data coverage.However,these remote sensing methods require further technological development to be more suitable for monitoring mining subsidence.The existing subsidence calculation methods have been applied to various geological and mining conditions,and many improvements have already been made.In the future,more attention should be paid to unifying the studies of calculation methods and mechanical principles.The simulation methods are quite dependent on the similarity of the model to the site conditions and are generally used as an auxiliary data source for subsidence studies.The cross-disciplinary studies between subsidence data acquisition methods and other technologies should be given serious consideration,as they can be expected to lead to breakthroughs in areas such as theories,devices,software,and other aspects.
文摘Gaseous nitrogen （N2） makes up 78% of the earth＇s at- mosphere; its incorporation into a wide range of biological macromolecules molecules, such as nucleic acids and amino acids, makes it an essential part of all life on earth. However, as nitrogen gas is inert, it remains unavailable to most organisms, including plants. Thus, in order to be useful for fertilizer production, gaseous nitrogen needs first to be converted into bioavailable organic nitrogen in processes which are inefficient and rate-limiting for agricultural pro- duction. It was not until about 100 years ago that BASF were able to produce synthetic ammonia, the main ingredient for fertilizer production, on an industrial scale from pressurized air using the Haber--Bosch process. This chemical process was not only an impressive technical feat that helped Haber （1918） and Bosch （1931） earn Nobel Prizes but also enabled farmers to achieve the high yields that drive modern agriculture.
基金Guo X is grateful to the Shenzhen Science and Technology Innovation Commission(JCYJ20170817105905899,JCYJ20180504165709042)Sun H thanks the National Natural Science Foundation of China(21801124)+3 种基金Liu B thanks China Scholarship Council Fund(201906010074)This work was supported by the National Natural Science Foundation of China(21903017)the Center for Computational Science and Engineering of Southern University of Science and Technology(SUSTech)We thank Ziang Wu and Han Young Woo at Korea University for performing GIWAXS measurements,thank Dr.Yinhua Yang at the Materials Characterization and Preparation Center,SUSTech for NMR measurement.
文摘The open-circuit voltage(Voc) of all-polymer solar cells(all-PSCs) is typically lower than 0.9 V even for the most efficient ones.Large energy loss is the main reason for limiting Voc and efficiency of all-PSCs. Herein, through materials design using electron deficient building blocks based on bithiophene imides, the lowest unoccupied molecular orbital(LUMO) energy levels of polymer acceptors can be effectively tuned, which resulted in a reduced energy loss induced by charge generation and recombination loss due to the suppressed charge-transfer(CT) state absorption. Despite a negligible driving force, all-PSC based on the polymer donor and acceptor combination with well-aligned energy levels exhibited efficient charge transfer and achieved an external quantum efficiency over 70% while maintaining a large Voc of 1.02 V, leading to a 9.21% efficiency. Through various spectroscopy approaches, this work sheds light on the mechanism of energy loss in all-PSCs, which paves an avenue to achieving efficient all-PSCs with large Voc and drives the further development of all-PSCs.
