This paper aims at exploring the tectonic characteristics of the South China Continent （SCC） and extracting the universal tec- tonic rules from these characteristics,to help enrich the plate tectonic theory and bett...This paper aims at exploring the tectonic characteristics of the South China Continent （SCC） and extracting the universal tec- tonic rules from these characteristics,to help enrich the plate tectonic theory and better understand the continental dynamic system. For this purpose, here we conduct a multi-disciplinary investigation and combine it with the previous studies to reas- sess the tectonics and evolution of SCC and propose that the tectonic framework of the continent comprises two blocks, three types of tectonic units, four deformation systems, and four evolutionary stages with distinctive mechanism and tectonic characteris- tics since the Neoproterozoic. The four evolutionary stages are： （1） The amalgamation and break-up of the Neoproterozoic plates, typically the intracontinental rifting. （2） The early Paleozoic and Mesozoic intracontinental orogeny confined by plate tectonics, forming two composite tectonic domains. （3） The parallel operation of the Yangtze cratonization and intracontinental orogeny, and multi-phase reactivation of the Yangtze craton. （4） The association and differentiation evolution of plate tectonics and intraconti- nental tectonics, and the dynamic characteristics under the Meso-Cenozoic modem global plate tectonic regime.展开更多
The Mianle tectonic zone (Mianle zone), an ancient suture zone in addition to the Shangdan suture in the Qinling-Dabie orogenic belt, marks an important tectonic division geo-logically separating north from south and ...The Mianle tectonic zone (Mianle zone), an ancient suture zone in addition to the Shangdan suture in the Qinling-Dabie orogenic belt, marks an important tectonic division geo-logically separating north from south and connecting east with west in China continent. To de-termine present structural geometry and kinematics in the Mianle tectonic zone and to recon-struct the formation and evolution history involving plate subduction and collision in the Qinling-Dabie orogenic belt, through a multidisciplinary study, are significant for exploring the mountain-building orogenesis of the central orogenic system and the entire process of the major Chinese continental amalgamation during the Indosinian.展开更多
Based on observing and analyzing the typical soil animals, the flexible unsmoothness is defined, which is the moving unsmoothness made by the flexible deformation of the structural units, and its characteristics of re...Based on observing and analyzing the typical soil animals, the flexible unsmoothness is defined, which is the moving unsmoothness made by the flexible deformation of the structural units, and its characteristics of reducing adhesion and resistance is analyzed. The tests show that on the same conditions, compared with 45 Steel, the adhesion of the field_mouse’s fur is reduced by about 35%, its sliding resistance is reduced by about 80%.展开更多
Systematic studies of the ophiolites and associated volcanics stretching more than 1500 km from the Derni-Nanping-Pipasi-Kangxian area in the west to the Qingshuihe area of the south Dabie Mountains in the east indica...Systematic studies of the ophiolites and associated volcanics stretching more than 1500 km from the Derni-Nanping-Pipasi-Kangxian area in the west to the Qingshuihe area of the south Dabie Mountains in the east indicate the existence of a suture zone (the Mianl黣 suture) and a vanished paleo-ocean basin (the Mianl黣 paleo-ocean basin) in the region. From west to east, ophiolitic mlange associations distribute discontinuously along the suture. Rock assem-blages include ophiolite, island arc and oceanic island rock series. The Mianl黣 paleo-ocean basin experienced its major formation and expending episode during the Carboniferous-Permian period. The finding of the suture zone and the paleo-ocean basin is tectonically significant in timing the collision between the North China-Qinling and Yangtze blocks and determining the formation and evolution of the Qinling orogenic belt.展开更多
This study examined effects of dietary protein sources and levels on intestinal health of 21 to 35 d-old weaned piglets fed antibiotics-free diets. A total of 150 weaned piglets(21 d of age) were allotted to 5 dietary...This study examined effects of dietary protein sources and levels on intestinal health of 21 to 35 d-old weaned piglets fed antibiotics-free diets. A total of 150 weaned piglets(21 d of age) were allotted to 5 dietary treatment groups. Diets were formulated, based on corn-soybean meal, with different protein sources(fish meal and soy protein concentrate) to provide different dietary CP levels. Piglets within 5 dietary treatments were fed diets as follows, respectively: 1) control diet of 17% CP(control); 2) 19% CP diets formulated with more soy protein concentrate(SPC19); 3) fish meal(FM19); 4) 23.7% CP diets formulated with more soy protein concentrate(SPC23); 5) fish meal(FM23). The results showed that piglets from control group had higher ADG and lower incidence of diarrhea compared with those of other groups(P < 0.05). The incidence of diarrhea of piglets in FM19 group was lower than those from SPC23 group and FM23 group(P < 0.05). With the higher CP levels, villous height and villous height to crypt depth ratio of piglets in the duodenum and jejunum were decreased(P < 0.05), but crypt depth was increased(P < 0.05). Comparing control group and other groups, we found the expression of inflammatory cytokines interleukin-1β(IL-1β) and interferon-γ(IFN-γ) were increased(P < 0.05) in the jejunum and colon of piglets, as did cystic fibrosis transmembrane conductance regulators(CFTR) in the distal colon. The relative transcript abundance of Zonula occludens-1(ZO-1) in the jejunum, and occludin in the jejunum and ileum of piglets fed 23.7% CP diets were reduced compared with those fed control diet(P < 0.05). In conclusion, the 17% CP diet without in-feed antibiotics helped improve growth performance and relief of diarrhea of 21 to 35 d-old weaned piglets. Dietary CP level, rather than its source(either fish meal or soy protein concentrate), has more significant impacts on the growth performance and intestinal health of 21 to 35 d-old weaned piglets when fed antibiotics-free diets.展开更多
N6-Methyladenine (6mA)DNA methylation has recently been implicated as a potential new epigenetic marker in eukaryotes,including the dioot modelArabidopsis thaliana.However,the conservation and divergence of 6mA distri...N6-Methyladenine (6mA)DNA methylation has recently been implicated as a potential new epigenetic marker in eukaryotes,including the dioot modelArabidopsis thaliana.However,the conservation and divergence of 6mA distribution patterns and functions in plants remain elusive.Here we report high-quality 6mA methylomes at single-nucleotide resolution in rice based on substantially improved genome sequences of two rice cultivars,Nipponbare (Nip;Japonica)and 93-11 (Indica).Analysis of 6mA genomic distribution and its association with transcription suggest that 6mA distribution and function is rather conserved between rice and Arabidopsis.We found that 6mA levels are positively correlated with the expression of key stressrelated genes,which may be responsible for the difference in stress tolerance between Nip and 93-11. Moreover,we showed that mutations in DDM1 cause defects in plant growth and decreased 6mA level. Our results reveal that 6mA is a conserved DNA modification that is positively associated with gene expression and contributes to key agronomic traits in plants.展开更多
Ozone pollution over the Pearl River Delta (PRD) in October 2004 has been simulated using the regional air quality models Models-3/CMAQ and CAMx. The results from both models were evaluated and compared with the obser...Ozone pollution over the Pearl River Delta (PRD) in October 2004 has been simulated using the regional air quality models Models-3/CMAQ and CAMx. The results from both models were evaluated and compared with the observed concentrations from 12 monitoring stations. By integrated process rate analysis, the influences of different physical and chemical processes were quantified, and the causes of the deviations between the two models were investigated. Both CMAQ and CAMx repro- duced the magnitudes and variations of ozone at most stations over the PRD. The correlation coefficients (R) between the sim- ulated results and monitoring data were 0.73 for CMAQ and 0.74 for CAMx. The normalized mean bias (NMB) for CMAQ and CAMx over the 12 sites was ?8.5% and 8.8% on average, respectively. The normalized mean error (NME) for CMAQ and CAMx was 36.7% and 37.9%, respectively. The correlation between the results of two models was very high (R = 0.92), and their simulated ozone spatial distributions exhibited common features. But the values obtained using CMAQ simulation were about 17% lower than those obtained using CAMx on average. The results of simulations using the two models were not identical in certain regions, or for different types of monitoring stations. The differences in dry deposition, reaction parameters and vertical transport near the Pearl River Estuary can account for the discrepancies in the results obtained using the two models. In the upwind areas, the discrepancy in the boundary concentration of the finest nest was the main cause of the higher values obtained using CAMx compared with those obtained using CMAQ. There is a need for CAMx to provide more choices of dry deposition algo- rithms. Improvement of the calculation methods for photolysis rates would also improve the ozone simulation of CMAQ.展开更多
This experiment studied the effects of dietary protein sources and levels on the gut health of piglets,p H value,and concentrations of microbial metabolites(ammonia-N,volatile fatty acids [VFA],and polyamines) in the ...This experiment studied the effects of dietary protein sources and levels on the gut health of piglets,p H value,and concentrations of microbial metabolites(ammonia-N,volatile fatty acids [VFA],and polyamines) in the distal colonic and proximal colonic digesta of piglets weaned at 21 d of age.A total of 150 early-weaned piglets were allotted randomly to 5 diets: 1) control diet(CT; 17% CP),2) CT formulated with more soy protein concentrate(SPC19; 19% CP),3) more fish meal(FM19; 19% CP),4) CT formulated with more soy protein concentrate(SPC23; 23% CP),and 5) more fish meal(FM23; 23%CP).Results showed high protein level increased fecal score(P < 0.05),but different protein sources did not(P > 0.05).The p H value and ammonia-N concentration of digesta in the proximal and distal colon of FM23 were significantly higher(P < 0.05) than those of CT.Acetic acid,propionic acid,butyric acid and valeric acid concentrations in the proximal colon of FM23 exceeded those of CT,SPC19,and FM19(P < 0.05);however,isobutyric acid and isovaleric acid were not affected(P > 0.05).Histamine and spermidine concentrations of FM23 were higher than those of other treatments(P < 0.05).Propionic acid and butyric acid concentrations in the distal colon were higher of FM23 than of FM19(P < 0.05); putrescine,histamine and spermidine were higher of FM23 than of LP and FM19(P < 0.05).It was concluded that high dietary CP content increased microbial metabolites(ammonia-N,histamine,putrescine) in colonic digesta and aggravated piglets' diarrhea.展开更多
The potentials of gas generation by kerogen in the late period and by crude oil cracking are closely related to the origin of natural gas in the high- to over mature ma- rine area and their exploration perspectives. T...The potentials of gas generation by kerogen in the late period and by crude oil cracking are closely related to the origin of natural gas in the high- to over mature ma- rine area and their exploration perspectives. The carbon structure of kerogens, with different types and at different evolution stages, have been experimentally studied using the high magnetic field solid 13C nuclear magnetic resonance technique in order to determine the oil and gas potential of kerogens. Results show that the contents of gas potential carbon(GPC) of types I, II, III kerogens at the high- to over mature stage are very low, indicating their weak gas-generating capacity and limited gas production; however, the content of oil potential carbon(OPC) of the low mature type I kerogen is much higher, implying that a large amount of crude oil generated during the oil-generating period will be the material for later gas generation by oil cracking. The kinetic experiment of gas generation by crude oil cracking shows that, when the temperature is about 160℃(Ro=1.6%), the crude oil will start to produce large amounts of gas; the temperature range for major gas generation of crude oil is higher than that of the kerogens, and the gas production is 2 to 4 times higher than that of kerogens. The natural gas de- rived from oil cracking (called oil-cracked gas) is much abundant in methyl hexamethylene, which is quite different from the natural gas produced by thermal degradation of kerogens (named kerogen degradation gas) at high- to over mature stage.展开更多
Size-resolved aerosol samples were collected by MOUDI in four seasons in 2007 in Beijing. The PM10 and PM1.8mass concentrations were 166.0 ± 120.5 and 91.6 ± 69.7 μg/m^3, respectively,throughout the measure...Size-resolved aerosol samples were collected by MOUDI in four seasons in 2007 in Beijing. The PM10 and PM1.8mass concentrations were 166.0 ± 120.5 and 91.6 ± 69.7 μg/m^3, respectively,throughout the measurement, with seasonal variation： nearly two times higher in autumn than in summer and spring. Serious fine particle pollution occurred in winter with the PM1.8/PM10 ratio of 0.63, which was higher than other seasons. The size distribution of PM showed obvious seasonal and diurnal variation, with a smaller fine mode peak in spring and in the daytime. OM（organic matter = 1.6 × OC（organic carbon）） and SIA（secondary inorganic aerosol） were major components of fine particles, while OM, SIA and Ca^2＋were major components in coarse particles. Moreover, secondary components, mainly SOA（secondary organic aerosol） and SIA,accounted for 46%-96% of each size bin in fine particles, which meant that secondary pollution existed all year. Sulfates and nitrates, primarily in the form of（NH4）2SO4, NH4NO3, Ca SO4, Na2SO4 and K2SO4, calculated by the model ISORROPIA II, were major components of the solid phase in fine particles. The PM concentration and size distribution were similar in the four seasons on non-haze days, while large differences occurred on haze days, which indicated seasonal variation of PM concentration and size distribution were dominated by haze days. The SIA concentrations and fractions of nearly all size bins were higher on haze days than on non-haze days, which was attributed to heterogeneous aqueous reactions on haze days in the four seasons.展开更多
The Helanshan tectonic belt is located to the west of the Ordos Basin, and separates the Alxa(or Yinshan)Massif to the west from the Ordos block to the east. Triassic sedimentation in the Helanshan tectonic belt recor...The Helanshan tectonic belt is located to the west of the Ordos Basin, and separates the Alxa(or Yinshan)Massif to the west from the Ordos block to the east. Triassic sedimentation in the Helanshan tectonic belt records important information about tectono-sedimentary process between the Alxa Massif and the Ordos block. Detailed geological mapping and investigation on the lithological package, sedimentary facies and paleocurrent orientation have been conducted on the Middle to Upper Triassic clastic rocks in the Helanshan tectonic belt. The succession is characterized by upward-fining sequence and comprises coarse grained alluvial-fluvial facies in the lower part as well as deltaic-lacustrine facies in the upper part. Based on detailed study and comparisons on the sedimentary sequence along various sections, the Middle to Upper Triassic strata have been revealed that show clear southeastward-deepening sedimentary differentiation and transgression from southwest to northeast, which are consistent with the southeastward flowing paleocurrent. These features indicate a southeastward-dipping paleogeography in the Helanshan tectonic belt, which was original western part of southeastward orientated fluviallacustrine system in the northwestern proto-Ordos Basin. Further to the east, the Triassic succession in the Ordos Basin displays gradually thickening and alluvial-fluvial system flowed from southeast to northwest, showing a huge thick sedimentary wedge in the western basin margin. Together with the Late Permiane Early Triassic closure of the Paleo-Asian Ocean to the north, the Late Triassic extensional structures and diabase dykes in the Helanshan tectonic belt, all the above sedimentary features could be mostly interpreted as records of an extensional basin correlated to post-collisional collapse of the Central Asian Orogenic Belt.展开更多
A numerical model for determining fishing net configuration and load is developed, based on the lumped masses method. The model is used to analyze the influences on the net of gravity sea cage by different sinker weig...A numerical model for determining fishing net configuration and load is developed, based on the lumped masses method. The model is used to analyze the influences on the net of gravity sea cage by different sinker weights in uniform flow. The net of gravity sea cage is simulated under different current velocities and sinker weights. In order to verify the validity of the numerical results, model test results made by Lader and Enerhaug are cited and compared with the numerical ones. The results of numerical simulation agree well with the experimental ones and the agreement is within an error range of 13% under different velocities and sinker weights. The numerical results indicate that increasing the sinker weight can effectively reduce the net deformation, but the total drag force on the net will increase accordingly. Results will give references for better knowledge of the hydrodynamic behavior of gravity sea cage.展开更多
Next-generation sequencing(NGS) technology is capable of sequencing millions or billions of DNA molecules simultaneously.Therefore, it represents a promising tool for the analysis of molecular targets for the initial ...Next-generation sequencing(NGS) technology is capable of sequencing millions or billions of DNA molecules simultaneously.Therefore, it represents a promising tool for the analysis of molecular targets for the initial diagnosis of disease, monitoring of disease progression, and identifying the mechanism of drug resistance. On behalf of the Tumor Biomarker Committee of the Chinese Society of Clinical Oncology(CSCO) and the China Actionable Genome Consortium(CAGC), the present expert group hereby proposes advisory guidelines on clinical applications of NGS technology for the analysis of cancer driver genes for precision cancer therapy. This group comprises an assembly of laboratory cancer geneticists, clinical oncologists, bioinformaticians,pathologists, and other professionals. After multiple rounds of discussions and revisions, the expert group has reached a preliminary consensus on the need of NGS in clinical diagnosis, its regulation, and compliance standards in clinical sample collection. Moreover, it has prepared NGS criteria, the sequencing standard operation procedure(SOP), data analysis, report, and NGS platform certification and validation.展开更多
Three-dimensional(3D)printing technology is becoming a promising method for fabricating highly complex ceramics owing to the arbitrary design and the infinite combination of materials.Insufficient density is one of th...Three-dimensional(3D)printing technology is becoming a promising method for fabricating highly complex ceramics owing to the arbitrary design and the infinite combination of materials.Insufficient density is one of the main problems with 3D printed ceramics,but concentrated descriptions of making dense ceramics are scarce.This review specifically introduces the principles of the four 3D printing technologies and focuses on the parameters of each technology that affect the densification of 3D printed ceramics,such as the performance of raw materials and the interaction between energy and materials.The technical challenges and suggestions about how to achieve higher ceramic density are presented subsequently.The goal of the presented work is to comprehend the roles of critical parameters in the subsequent 3D printing process to prepare dense ceramics that can meet the practical applications.展开更多
The existence and subduction of the eastern Mianl oceanic basin in the south Qinling belt are keys to understand the Qinling orogen. Based on geological mapping, several volcanic slices have been identified in Tumen, ...The existence and subduction of the eastern Mianl oceanic basin in the south Qinling belt are keys to understand the Qinling orogen. Based on geological mapping, several volcanic slices have been identified in Tumen, Zhoujiawan, Xiaofu and Yuantan areas, which distribute in the northern margin of the Dahong Mountains (DHM), and thrust into the Sanli-gang-Sanyang fault. These slices consist mainly of diabases, basaltic-andesitic lavas, pyroclastic rocks and a minor tuff. The geochemistry of the basalts, andesites,and diabases is characterized by depleting in Nb and Ta, enriching in Th and LILE (e.g.K, Rb, Ba), and undifferentiating in HFSE. These geochemical characteristics suggest that the original magma of these rocks was derived from a mantle wedge above a subduction zone, and formed in an island-arc setting in Carboniferous-early Triassic. Comparing with the ophiolites and island-arc volcanic rocks in Mianxian-Leyang area to the west, it is reasonable to consider that there had been an oceanic basin connecting with the Mianle ancient ocean to the westward, distributing along the south edge of the Tongbai-Dabie block. In view of the ophiolite in Huashan area and these island-arc volcanic rocks along the north of the Dahong Mountains, it is suggested that there had been a plate tectonic evolutionary history with oceanic basin rifting and subduction in this region.展开更多
Geomechanics in deep mines becomes more complex and structural support in soft rock can be very difficult.Highly stressed soft rock subject to expansion deformation is particularly difficult to control.The Tiefa Coal ...Geomechanics in deep mines becomes more complex and structural support in soft rock can be very difficult.Highly stressed soft rock subject to expansion deformation is particularly difficult to control.The Tiefa Coal Industry Group Daqiang Coal Mine is used as an example.A ventilation shaft,à550 horsehead,is located in tertiary soft rock.Analysis of the reasons for deformation shows an intumescent rock,which is easily damaged.Field observations and theoretical analysis led to a design capable of stabilizing the rock.A combination of spray,anchors,anchor bolts,and soft corner coupled truss supports allowed the deformation to be controlled.This provides a model for similar designs when support of a horsehead roadway is required.展开更多
Wide color gamut(WCG) backlight for liquid crystal display(LCD) utilizing white light-emitting diodes(LED) has attracted considerable attention for their high efficiency and color reduction.In this review,recent devel...Wide color gamut(WCG) backlight for liquid crystal display(LCD) utilizing white light-emitting diodes(LED) has attracted considerable attention for their high efficiency and color reduction.In this review,recent developments in crystal structure,luminescence and applications of phosphors for wide color gamut LED backlight are introduced.As novel red phosphors,Mn4+activate fluoride and aluminate phosphors are advanced in quantum efficiency,thermal quenching and color saturation for their characteristic spectrum with broad excitation band and linear emission.The crystal structure and fluorescence properties of Mn4+doped fluosilicate,fluorogermanate,fluotitanate,as well as Sr4 Al14O25,CaAl12O19 and BaMgAl10O17 phosphors are discussed in detail.A serial of narrow-band red-emitting Eu2+,Eu3+and Pr3+-doped nitride silicates and molybdate phosphors are also introduced.Rare-earth-doped oxynitride and silicate green-emitting phosphors have attracted more and more attention because of the wide excitation,narrow emission,high quenching temperature,high quantum efficiency,such as β-sialon:Eu2+,Ba3Si6O12N2:Eu2+,MSi2O2N2:Eu2+(M=Ca,Sr,Ba),y-AlON:Mn2+and Ca3Sc2Si3O12:Ce3+.All above phosphors demonstrate their adaptability in wide color gamut LCD display.Especially for Mn4+doped fluosilicate red phosphor and β-sialon:Eu2+green phosphor.To achieve an ultra-high color gamut in white LED backlight and against the OLED,innovative narrow-band-emission red and green phosphor materials with independent intellectual property rights are continuously pursed.展开更多
Background:Bone metastases are common in patients with advanced cancer.Bisphosphonates(BPs) could prevent or delay the development of skeleton-related events(SREs).The present study aimed to identify the clinical feat...Background:Bone metastases are common in patients with advanced cancer.Bisphosphonates(BPs) could prevent or delay the development of skeleton-related events(SREs).The present study aimed to identify the clinical features of and treatment strategies for Chinese patients with bone metastases.Methods:Consecutive cancer patients who had bone metastases and received BP treatment were enrolled.A questionnaire was developed to collect the patients' clinical data,as well as information on the diagnosis and management of bone metastases.Physicians' awareness of the guidelines and knowledge of the application of BP were also assessed.Results:A total of 3223 patients with lung cancer(36.5%),breast cancer(30.9%),prostate cancer(8.5%),and gastrointestinal cancer(5.7%) were included in this study.The sites of bone metastases were the thoracic spine(56.0%),lumbar spine(47.1%),ribs(32.6%),and pelvis(23.2%).The SRE frequency was the highest in patients with multiple myeloma(36.6%),followed by those with lung cancer(25.9%),breast cancer(20.2%),prostate cancer(18.2%),and gastrointestinal cancer(17.3%).Irradiation to the bone was the most frequent SRE(58%in lung cancer patients,45%in breast cancer patients,and 48%in prostate cancer patients).Our survey also showed that 45.5%of patients received BP within 3 months after their diagnosis of bone metastases,whereas the remaining 54.5%of patients did not receive BP treatment until at least 3 months after their diagnosis of bone metastases.The SRE frequency in the former group was significantly lower than that in the latter group(4.0%vs.42.3%,P < 0.05).In patients with more than 6 months of continuous BP treatment,the mean time to the first SRE was significantly longer than that in patients with less than 6 months of continuous BP treatment(7.2 vs.3.4 months,P < 0.05).In addition,12.2%of the physicians were not aware of the efficacy of BP in preventing and delaying SRE.Only half(52.3%) of the physicians agreed that the BP treatment should persist for at least 6 months unless it was intol展开更多
Alzheimer's disease(AD)is the most common cognitive disorder in the elderly.Its main clinical manifestations are cognitive decline(C),behavioral and psychological symptoms(B),and a decline in the activities of dai...Alzheimer's disease(AD)is the most common cognitive disorder in the elderly.Its main clinical manifestations are cognitive decline(C),behavioral and psychological symptoms(B),and a decline in the activities of daily living(A),also known as ABC symptoms.Early identification and evaluation of ABC symptoms are helpful for establishing the accurate diagnosis,comprehensive treatment,and prognosis of AD.To guide Chinese clinical practice for optimization of the comprehensive management of AD,in 2018,The Academy of Cognitive Disorder of China gathered 22 neurologists and gerontologists in China to build a consensus on the comprehensive management of AD.Based on a review of the evidence,the consensus summarizes the pathogenesis,pathological changes,clinical manifestations,evaluation,diagnosis,drug and non-drug treatment,and patient care for AD.Focus group discussion was used to establish a flowchart of comprehensive ABC management for AD patients.The new consensus provides a feasible AD management process for clinicians.展开更多
Halogenation is a very efficient chemical modification method to tune the molecular energy levels, absorption spectra and molecular packing of organic semiconductors. Recently, in the field of organic solar cells(OSCs...Halogenation is a very efficient chemical modification method to tune the molecular energy levels, absorption spectra and molecular packing of organic semiconductors. Recently, in the field of organic solar cells(OSCs), both fluorine-and chlorinesubstituted photovoltaic materials, including donors and acceptors, demonstrated their great potentials in achieving high power conversion efficiencies(PCEs), raising a question that how to make a decision between fluorination and chlorination when designing materials. Herein, we systemically studied the impact of fluorination and chlorination on the properties of resulting donors(PBDB-T-2 F and PBDB-T-2 Cl) and acceptors(IT-4 F and IT-4 Cl). The results suggest that all the OSCs based on different donor and acceptor combinations can deliver good PCEs around 13%–14%. Chlorination is more effective than fluorination in downshifting the molecular energy levels and broadening the absorption spectra. The influence of chlorination and fluorination on the crystallinity of the resulting materials is dependent on their introduction positions. As chlorination has the advantage of easy synthesis, it is more attractive in designing low-cost photovoltaic materials and therefore may have more potential in largescale applications.展开更多
基金supported by the special grant of Ministry of Science and Technology of the People’s Republic of China for State Key Laboratory of Continental Dynamics,Northwest University,the key research project of Sinopec Group(Grant No.YPH08012)the National Natural Science Foundation of China(Grant Nos.41190072,41190073,41190074,41190070)
文摘This paper aims at exploring the tectonic characteristics of the South China Continent （SCC） and extracting the universal tec- tonic rules from these characteristics,to help enrich the plate tectonic theory and better understand the continental dynamic system. For this purpose, here we conduct a multi-disciplinary investigation and combine it with the previous studies to reas- sess the tectonics and evolution of SCC and propose that the tectonic framework of the continent comprises two blocks, three types of tectonic units, four deformation systems, and four evolutionary stages with distinctive mechanism and tectonic characteris- tics since the Neoproterozoic. The four evolutionary stages are： （1） The amalgamation and break-up of the Neoproterozoic plates, typically the intracontinental rifting. （2） The early Paleozoic and Mesozoic intracontinental orogeny confined by plate tectonics, forming two composite tectonic domains. （3） The parallel operation of the Yangtze cratonization and intracontinental orogeny, and multi-phase reactivation of the Yangtze craton. （4） The association and differentiation evolution of plate tectonics and intraconti- nental tectonics, and the dynamic characteristics under the Meso-Cenozoic modem global plate tectonic regime.
基金This work was supported by the National Natu-ral Science Foundation of China (Grant Nos. 49732080, 40234041).
文摘The Mianle tectonic zone (Mianle zone), an ancient suture zone in addition to the Shangdan suture in the Qinling-Dabie orogenic belt, marks an important tectonic division geo-logically separating north from south and connecting east with west in China continent. To de-termine present structural geometry and kinematics in the Mianle tectonic zone and to recon-struct the formation and evolution history involving plate subduction and collision in the Qinling-Dabie orogenic belt, through a multidisciplinary study, are significant for exploring the mountain-building orogenesis of the central orogenic system and the entire process of the major Chinese continental amalgamation during the Indosinian.
文摘Based on observing and analyzing the typical soil animals, the flexible unsmoothness is defined, which is the moving unsmoothness made by the flexible deformation of the structural units, and its characteristics of reducing adhesion and resistance is analyzed. The tests show that on the same conditions, compared with 45 Steel, the adhesion of the field_mouse’s fur is reduced by about 35%, its sliding resistance is reduced by about 80%.
基金This work was jointly supported by the Teachingand Research Award Program for Outstanding Young Teachers inHigher Education Institutions of MOE, Chinathe National NaturalScience Foundation of China (Grant Nos. 49732080, 40234041).
文摘Systematic studies of the ophiolites and associated volcanics stretching more than 1500 km from the Derni-Nanping-Pipasi-Kangxian area in the west to the Qingshuihe area of the south Dabie Mountains in the east indicate the existence of a suture zone (the Mianl黣 suture) and a vanished paleo-ocean basin (the Mianl黣 paleo-ocean basin) in the region. From west to east, ophiolitic mlange associations distribute discontinuously along the suture. Rock assem-blages include ophiolite, island arc and oceanic island rock series. The Mianl黣 paleo-ocean basin experienced its major formation and expending episode during the Carboniferous-Permian period. The finding of the suture zone and the paleo-ocean basin is tectonically significant in timing the collision between the North China-Qinling and Yangtze blocks and determining the formation and evolution of the Qinling orogenic belt.
基金financially supported by China Agriculture Research System (CARS-36) (2013B060400039 to 2011A020102009)National Basic Research Program of China (2013CB127301, and 2013CB127304)+1 种基金Science and Technology Planning Project of Guangdong Province (2013B060400039,2013A061401020)Special Program for Guangdong Research Institutions' Innovation and Construction(2012B060600005)
文摘This study examined effects of dietary protein sources and levels on intestinal health of 21 to 35 d-old weaned piglets fed antibiotics-free diets. A total of 150 weaned piglets(21 d of age) were allotted to 5 dietary treatment groups. Diets were formulated, based on corn-soybean meal, with different protein sources(fish meal and soy protein concentrate) to provide different dietary CP levels. Piglets within 5 dietary treatments were fed diets as follows, respectively: 1) control diet of 17% CP(control); 2) 19% CP diets formulated with more soy protein concentrate(SPC19); 3) fish meal(FM19); 4) 23.7% CP diets formulated with more soy protein concentrate(SPC23); 5) fish meal(FM23). The results showed that piglets from control group had higher ADG and lower incidence of diarrhea compared with those of other groups(P < 0.05). The incidence of diarrhea of piglets in FM19 group was lower than those from SPC23 group and FM23 group(P < 0.05). With the higher CP levels, villous height and villous height to crypt depth ratio of piglets in the duodenum and jejunum were decreased(P < 0.05), but crypt depth was increased(P < 0.05). Comparing control group and other groups, we found the expression of inflammatory cytokines interleukin-1β(IL-1β) and interferon-γ(IFN-γ) were increased(P < 0.05) in the jejunum and colon of piglets, as did cystic fibrosis transmembrane conductance regulators(CFTR) in the distal colon. The relative transcript abundance of Zonula occludens-1(ZO-1) in the jejunum, and occludin in the jejunum and ileum of piglets fed 23.7% CP diets were reduced compared with those fed control diet(P < 0.05). In conclusion, the 17% CP diet without in-feed antibiotics helped improve growth performance and relief of diarrhea of 21 to 35 d-old weaned piglets. Dietary CP level, rather than its source(either fish meal or soy protein concentrate), has more significant impacts on the growth performance and intestinal health of 21 to 35 d-old weaned piglets when fed antibiotics-free diets.
基金The Ministry of Science and Technology of the People's Republic of China (2016YFD0101001)to X.G.,National Natural Science Foundation of China (31871606,31671670)to X.G.,Recruitment program of Global Youth Expert of China to X.G.,and Fundamental Research funds for Central Non-profit Scientific Institution (1610392017001)to X.G.
文摘N6-Methyladenine (6mA)DNA methylation has recently been implicated as a potential new epigenetic marker in eukaryotes,including the dioot modelArabidopsis thaliana.However,the conservation and divergence of 6mA distribution patterns and functions in plants remain elusive.Here we report high-quality 6mA methylomes at single-nucleotide resolution in rice based on substantially improved genome sequences of two rice cultivars,Nipponbare (Nip;Japonica)and 93-11 (Indica).Analysis of 6mA genomic distribution and its association with transcription suggest that 6mA distribution and function is rather conserved between rice and Arabidopsis.We found that 6mA levels are positively correlated with the expression of key stressrelated genes,which may be responsible for the difference in stress tolerance between Nip and 93-11. Moreover,we showed that mutations in DDM1 cause defects in plant growth and decreased 6mA level. Our results reveal that 6mA is a conserved DNA modification that is positively associated with gene expression and contributes to key agronomic traits in plants.
基金supported by theNational High Technology Research and Development Program of China (2006AA06A306 & 2006AA06A308)a special fund of the State Key Joint Laboratory of Environmental Simulation and Pollution Controlthe European Commission Framework Program 7 Project CityZen (212095)
文摘Ozone pollution over the Pearl River Delta (PRD) in October 2004 has been simulated using the regional air quality models Models-3/CMAQ and CAMx. The results from both models were evaluated and compared with the observed concentrations from 12 monitoring stations. By integrated process rate analysis, the influences of different physical and chemical processes were quantified, and the causes of the deviations between the two models were investigated. Both CMAQ and CAMx repro- duced the magnitudes and variations of ozone at most stations over the PRD. The correlation coefficients (R) between the sim- ulated results and monitoring data were 0.73 for CMAQ and 0.74 for CAMx. The normalized mean bias (NMB) for CMAQ and CAMx over the 12 sites was ?8.5% and 8.8% on average, respectively. The normalized mean error (NME) for CMAQ and CAMx was 36.7% and 37.9%, respectively. The correlation between the results of two models was very high (R = 0.92), and their simulated ozone spatial distributions exhibited common features. But the values obtained using CMAQ simulation were about 17% lower than those obtained using CAMx on average. The results of simulations using the two models were not identical in certain regions, or for different types of monitoring stations. The differences in dry deposition, reaction parameters and vertical transport near the Pearl River Estuary can account for the discrepancies in the results obtained using the two models. In the upwind areas, the discrepancy in the boundary concentration of the finest nest was the main cause of the higher values obtained using CAMx compared with those obtained using CMAQ. There is a need for CAMx to provide more choices of dry deposition algo- rithms. Improvement of the calculation methods for photolysis rates would also improve the ozone simulation of CMAQ.
基金financially supported by National Basic Research Program of China (NO.2013CB127304 and 2013CB127301)National Science and Technology Support Program (2012BAD39B01-5)+2 种基金Science and Technology Planning Project of Guangdong Province (2013A061401020,2016A020210041)Operating Funds for Guangdong Provincial Key Laboratory of Animal Breeding and Nutrition (2014B030301054)China Agriculture Research System (CARS-36)
文摘This experiment studied the effects of dietary protein sources and levels on the gut health of piglets,p H value,and concentrations of microbial metabolites(ammonia-N,volatile fatty acids [VFA],and polyamines) in the distal colonic and proximal colonic digesta of piglets weaned at 21 d of age.A total of 150 early-weaned piglets were allotted randomly to 5 diets: 1) control diet(CT; 17% CP),2) CT formulated with more soy protein concentrate(SPC19; 19% CP),3) more fish meal(FM19; 19% CP),4) CT formulated with more soy protein concentrate(SPC23; 23% CP),and 5) more fish meal(FM23; 23%CP).Results showed high protein level increased fecal score(P < 0.05),but different protein sources did not(P > 0.05).The p H value and ammonia-N concentration of digesta in the proximal and distal colon of FM23 were significantly higher(P < 0.05) than those of CT.Acetic acid,propionic acid,butyric acid and valeric acid concentrations in the proximal colon of FM23 exceeded those of CT,SPC19,and FM19(P < 0.05);however,isobutyric acid and isovaleric acid were not affected(P > 0.05).Histamine and spermidine concentrations of FM23 were higher than those of other treatments(P < 0.05).Propionic acid and butyric acid concentrations in the distal colon were higher of FM23 than of FM19(P < 0.05); putrescine,histamine and spermidine were higher of FM23 than of LP and FM19(P < 0.05).It was concluded that high dietary CP content increased microbial metabolites(ammonia-N,histamine,putrescine) in colonic digesta and aggravated piglets' diarrhea.
基金This work was supported by the National 973 Natural Gas Project (Grant No, 2001CB209 100).
文摘The potentials of gas generation by kerogen in the late period and by crude oil cracking are closely related to the origin of natural gas in the high- to over mature ma- rine area and their exploration perspectives. The carbon structure of kerogens, with different types and at different evolution stages, have been experimentally studied using the high magnetic field solid 13C nuclear magnetic resonance technique in order to determine the oil and gas potential of kerogens. Results show that the contents of gas potential carbon(GPC) of types I, II, III kerogens at the high- to over mature stage are very low, indicating their weak gas-generating capacity and limited gas production; however, the content of oil potential carbon(OPC) of the low mature type I kerogen is much higher, implying that a large amount of crude oil generated during the oil-generating period will be the material for later gas generation by oil cracking. The kinetic experiment of gas generation by crude oil cracking shows that, when the temperature is about 160℃(Ro=1.6%), the crude oil will start to produce large amounts of gas; the temperature range for major gas generation of crude oil is higher than that of the kerogens, and the gas production is 2 to 4 times higher than that of kerogens. The natural gas de- rived from oil cracking (called oil-cracked gas) is much abundant in methyl hexamethylene, which is quite different from the natural gas produced by thermal degradation of kerogens (named kerogen degradation gas) at high- to over mature stage.
基金supported by the National Natural Science Foundation of China (Nos. 41175018, 41475113)the special fund of the State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry (No. LAPC-KF-2014-01)
文摘Size-resolved aerosol samples were collected by MOUDI in four seasons in 2007 in Beijing. The PM10 and PM1.8mass concentrations were 166.0 ± 120.5 and 91.6 ± 69.7 μg/m^3, respectively,throughout the measurement, with seasonal variation： nearly two times higher in autumn than in summer and spring. Serious fine particle pollution occurred in winter with the PM1.8/PM10 ratio of 0.63, which was higher than other seasons. The size distribution of PM showed obvious seasonal and diurnal variation, with a smaller fine mode peak in spring and in the daytime. OM（organic matter = 1.6 × OC（organic carbon）） and SIA（secondary inorganic aerosol） were major components of fine particles, while OM, SIA and Ca^2＋were major components in coarse particles. Moreover, secondary components, mainly SOA（secondary organic aerosol） and SIA,accounted for 46%-96% of each size bin in fine particles, which meant that secondary pollution existed all year. Sulfates and nitrates, primarily in the form of（NH4）2SO4, NH4NO3, Ca SO4, Na2SO4 and K2SO4, calculated by the model ISORROPIA II, were major components of the solid phase in fine particles. The PM concentration and size distribution were similar in the four seasons on non-haze days, while large differences occurred on haze days, which indicated seasonal variation of PM concentration and size distribution were dominated by haze days. The SIA concentrations and fractions of nearly all size bins were higher on haze days than on non-haze days, which was attributed to heterogeneous aqueous reactions on haze days in the four seasons.
基金Financial supports for this study were jointly supported by the National Natural Science Foundation of China (Grant Nos.41421002 and 41602109)most special fund from the State Key Laboratory of Continental Dynamics, Northwest University, Shaanxi Postdoctoral Science Foundation, National Science and Technology Special Grant (No. 2016ZX05006-007)China Geological SurveyGrant (No. DD20189614)
文摘The Helanshan tectonic belt is located to the west of the Ordos Basin, and separates the Alxa(or Yinshan)Massif to the west from the Ordos block to the east. Triassic sedimentation in the Helanshan tectonic belt records important information about tectono-sedimentary process between the Alxa Massif and the Ordos block. Detailed geological mapping and investigation on the lithological package, sedimentary facies and paleocurrent orientation have been conducted on the Middle to Upper Triassic clastic rocks in the Helanshan tectonic belt. The succession is characterized by upward-fining sequence and comprises coarse grained alluvial-fluvial facies in the lower part as well as deltaic-lacustrine facies in the upper part. Based on detailed study and comparisons on the sedimentary sequence along various sections, the Middle to Upper Triassic strata have been revealed that show clear southeastward-deepening sedimentary differentiation and transgression from southwest to northeast, which are consistent with the southeastward flowing paleocurrent. These features indicate a southeastward-dipping paleogeography in the Helanshan tectonic belt, which was original western part of southeastward orientated fluviallacustrine system in the northwestern proto-Ordos Basin. Further to the east, the Triassic succession in the Ordos Basin displays gradually thickening and alluvial-fluvial system flowed from southeast to northwest, showing a huge thick sedimentary wedge in the western basin margin. Together with the Late Permiane Early Triassic closure of the Paleo-Asian Ocean to the north, the Late Triassic extensional structures and diabase dykes in the Helanshan tectonic belt, all the above sedimentary features could be mostly interpreted as records of an extensional basin correlated to post-collisional collapse of the Central Asian Orogenic Belt.
基金This study was financially supported by the National Natural Science Foundation of China under contract No. 50279002the National ＂863＂ High Technology Project of China under contract Nos 2001AA623010 and 2003AA623010the Program for Changjiang Scholars and Innovative Research Team in University of China under contract No. IRT0420.
文摘A numerical model for determining fishing net configuration and load is developed, based on the lumped masses method. The model is used to analyze the influences on the net of gravity sea cage by different sinker weights in uniform flow. The net of gravity sea cage is simulated under different current velocities and sinker weights. In order to verify the validity of the numerical results, model test results made by Lader and Enerhaug are cited and compared with the numerical ones. The results of numerical simulation agree well with the experimental ones and the agreement is within an error range of 13% under different velocities and sinker weights. The numerical results indicate that increasing the sinker weight can effectively reduce the net deformation, but the total drag force on the net will increase accordingly. Results will give references for better knowledge of the hydrodynamic behavior of gravity sea cage.
基金supported by grants from Guangdong Provincial Key Lab of Translational Medicine in Lung Cancer (Grant No. 2017B030314120)General Research Project of Guangzhou Science and Technology Bureau (Grant No. 201607010391)+1 种基金National Key Research and Development Program of China (Grant No. 2016YFC1303800)Guangdong Provincial Applied S&T R&D Program (Grant No. 2016B020237006)
文摘Next-generation sequencing(NGS) technology is capable of sequencing millions or billions of DNA molecules simultaneously.Therefore, it represents a promising tool for the analysis of molecular targets for the initial diagnosis of disease, monitoring of disease progression, and identifying the mechanism of drug resistance. On behalf of the Tumor Biomarker Committee of the Chinese Society of Clinical Oncology(CSCO) and the China Actionable Genome Consortium(CAGC), the present expert group hereby proposes advisory guidelines on clinical applications of NGS technology for the analysis of cancer driver genes for precision cancer therapy. This group comprises an assembly of laboratory cancer geneticists, clinical oncologists, bioinformaticians,pathologists, and other professionals. After multiple rounds of discussions and revisions, the expert group has reached a preliminary consensus on the need of NGS in clinical diagnosis, its regulation, and compliance standards in clinical sample collection. Moreover, it has prepared NGS criteria, the sequencing standard operation procedure(SOP), data analysis, report, and NGS platform certification and validation.
基金financial support by the National Natural Science Foundation of China(52073212,51772205,and 51772208)General Program of Municipal Natural Science Foundation of Tianjin(17JCYBJC17000,17JCYBJC22700)。
文摘Three-dimensional(3D)printing technology is becoming a promising method for fabricating highly complex ceramics owing to the arbitrary design and the infinite combination of materials.Insufficient density is one of the main problems with 3D printed ceramics,but concentrated descriptions of making dense ceramics are scarce.This review specifically introduces the principles of the four 3D printing technologies and focuses on the parameters of each technology that affect the densification of 3D printed ceramics,such as the performance of raw materials and the interaction between energy and materials.The technical challenges and suggestions about how to achieve higher ceramic density are presented subsequently.The goal of the presented work is to comprehend the roles of critical parameters in the subsequent 3D printing process to prepare dense ceramics that can meet the practical applications.
基金This work was supported by the National Natu-ral Science Foundation of China (Grant Nos. 49732080, 40003003,40234041).
文摘The existence and subduction of the eastern Mianl oceanic basin in the south Qinling belt are keys to understand the Qinling orogen. Based on geological mapping, several volcanic slices have been identified in Tumen, Zhoujiawan, Xiaofu and Yuantan areas, which distribute in the northern margin of the Dahong Mountains (DHM), and thrust into the Sanli-gang-Sanyang fault. These slices consist mainly of diabases, basaltic-andesitic lavas, pyroclastic rocks and a minor tuff. The geochemistry of the basalts, andesites,and diabases is characterized by depleting in Nb and Ta, enriching in Th and LILE (e.g.K, Rb, Ba), and undifferentiating in HFSE. These geochemical characteristics suggest that the original magma of these rocks was derived from a mantle wedge above a subduction zone, and formed in an island-arc setting in Carboniferous-early Triassic. Comparing with the ophiolites and island-arc volcanic rocks in Mianxian-Leyang area to the west, it is reasonable to consider that there had been an oceanic basin connecting with the Mianle ancient ocean to the westward, distributing along the south edge of the Tongbai-Dabie block. In view of the ophiolite in Huashan area and these island-arc volcanic rocks along the north of the Dahong Mountains, it is suggested that there had been a plate tectonic evolutionary history with oceanic basin rifting and subduction in this region.
基金supported by the National Basic Research Program of China (No.2006CB202200)the Ministry of Education Innovation Team Project (No. IRT0656)+2 种基金the Central University Basic Research Special Fund Operating Expense (No.2009QL06)the New Century Excellent Talents Support Projects of Ministry of Education (No.NCET-08-0833)the National Natural Science Foundation of China (No.41040027)
文摘Geomechanics in deep mines becomes more complex and structural support in soft rock can be very difficult.Highly stressed soft rock subject to expansion deformation is particularly difficult to control.The Tiefa Coal Industry Group Daqiang Coal Mine is used as an example.A ventilation shaft,à550 horsehead,is located in tertiary soft rock.Analysis of the reasons for deformation shows an intumescent rock,which is easily damaged.Field observations and theoretical analysis led to a design capable of stabilizing the rock.A combination of spray,anchors,anchor bolts,and soft corner coupled truss supports allowed the deformation to be controlled.This provides a model for similar designs when support of a horsehead roadway is required.
基金Project supported by National Key Research and Development Program(2017YFB0404301)
文摘Wide color gamut(WCG) backlight for liquid crystal display(LCD) utilizing white light-emitting diodes(LED) has attracted considerable attention for their high efficiency and color reduction.In this review,recent developments in crystal structure,luminescence and applications of phosphors for wide color gamut LED backlight are introduced.As novel red phosphors,Mn4+activate fluoride and aluminate phosphors are advanced in quantum efficiency,thermal quenching and color saturation for their characteristic spectrum with broad excitation band and linear emission.The crystal structure and fluorescence properties of Mn4+doped fluosilicate,fluorogermanate,fluotitanate,as well as Sr4 Al14O25,CaAl12O19 and BaMgAl10O17 phosphors are discussed in detail.A serial of narrow-band red-emitting Eu2+,Eu3+and Pr3+-doped nitride silicates and molybdate phosphors are also introduced.Rare-earth-doped oxynitride and silicate green-emitting phosphors have attracted more and more attention because of the wide excitation,narrow emission,high quenching temperature,high quantum efficiency,such as β-sialon:Eu2+,Ba3Si6O12N2:Eu2+,MSi2O2N2:Eu2+(M=Ca,Sr,Ba),y-AlON:Mn2+and Ca3Sc2Si3O12:Ce3+.All above phosphors demonstrate their adaptability in wide color gamut LCD display.Especially for Mn4+doped fluosilicate red phosphor and β-sialon:Eu2+green phosphor.To achieve an ultra-high color gamut in white LED backlight and against the OLED,innovative narrow-band-emission red and green phosphor materials with independent intellectual property rights are continuously pursed.
文摘Background:Bone metastases are common in patients with advanced cancer.Bisphosphonates(BPs) could prevent or delay the development of skeleton-related events(SREs).The present study aimed to identify the clinical features of and treatment strategies for Chinese patients with bone metastases.Methods:Consecutive cancer patients who had bone metastases and received BP treatment were enrolled.A questionnaire was developed to collect the patients' clinical data,as well as information on the diagnosis and management of bone metastases.Physicians' awareness of the guidelines and knowledge of the application of BP were also assessed.Results:A total of 3223 patients with lung cancer(36.5%),breast cancer(30.9%),prostate cancer(8.5%),and gastrointestinal cancer(5.7%) were included in this study.The sites of bone metastases were the thoracic spine(56.0%),lumbar spine(47.1%),ribs(32.6%),and pelvis(23.2%).The SRE frequency was the highest in patients with multiple myeloma(36.6%),followed by those with lung cancer(25.9%),breast cancer(20.2%),prostate cancer(18.2%),and gastrointestinal cancer(17.3%).Irradiation to the bone was the most frequent SRE(58%in lung cancer patients,45%in breast cancer patients,and 48%in prostate cancer patients).Our survey also showed that 45.5%of patients received BP within 3 months after their diagnosis of bone metastases,whereas the remaining 54.5%of patients did not receive BP treatment until at least 3 months after their diagnosis of bone metastases.The SRE frequency in the former group was significantly lower than that in the latter group(4.0%vs.42.3%,P < 0.05).In patients with more than 6 months of continuous BP treatment,the mean time to the first SRE was significantly longer than that in patients with less than 6 months of continuous BP treatment(7.2 vs.3.4 months,P < 0.05).In addition,12.2%of the physicians were not aware of the efficacy of BP in preventing and delaying SRE.Only half(52.3%) of the physicians agreed that the BP treatment should persist for at least 6 months unless it was intol
文摘Alzheimer's disease(AD)is the most common cognitive disorder in the elderly.Its main clinical manifestations are cognitive decline(C),behavioral and psychological symptoms(B),and a decline in the activities of daily living(A),also known as ABC symptoms.Early identification and evaluation of ABC symptoms are helpful for establishing the accurate diagnosis,comprehensive treatment,and prognosis of AD.To guide Chinese clinical practice for optimization of the comprehensive management of AD,in 2018,The Academy of Cognitive Disorder of China gathered 22 neurologists and gerontologists in China to build a consensus on the comprehensive management of AD.Based on a review of the evidence,the consensus summarizes the pathogenesis,pathological changes,clinical manifestations,evaluation,diagnosis,drug and non-drug treatment,and patient care for AD.Focus group discussion was used to establish a flowchart of comprehensive ABC management for AD patients.The new consensus provides a feasible AD management process for clinicians.
基金supported by the National Natural Science Foundation of China (91333204, 91633301, 51673201)the Ministry of Science and Technology of China (2014CB643501)the Chinese Academy of Sciences (XDB12030200, KJZD-EW-J01)
文摘Halogenation is a very efficient chemical modification method to tune the molecular energy levels, absorption spectra and molecular packing of organic semiconductors. Recently, in the field of organic solar cells(OSCs), both fluorine-and chlorinesubstituted photovoltaic materials, including donors and acceptors, demonstrated their great potentials in achieving high power conversion efficiencies(PCEs), raising a question that how to make a decision between fluorination and chlorination when designing materials. Herein, we systemically studied the impact of fluorination and chlorination on the properties of resulting donors(PBDB-T-2 F and PBDB-T-2 Cl) and acceptors(IT-4 F and IT-4 Cl). The results suggest that all the OSCs based on different donor and acceptor combinations can deliver good PCEs around 13%–14%. Chlorination is more effective than fluorination in downshifting the molecular energy levels and broadening the absorption spectra. The influence of chlorination and fluorination on the crystallinity of the resulting materials is dependent on their introduction positions. As chlorination has the advantage of easy synthesis, it is more attractive in designing low-cost photovoltaic materials and therefore may have more potential in largescale applications.
