The forming time of the Yangtze River Three Gorges is considered as one of keys in the research on the Yangtze River,also is one of the most disputed hotspots.In order to solve the difficult problem,the authors adopt ...The forming time of the Yangtze River Three Gorges is considered as one of keys in the research on the Yangtze River,also is one of the most disputed hotspots.In order to solve the difficult problem,the authors adopt the internationally recognized thoughts and methods of substance tracing from source to sink.The lithologic characteristics,magnetic parameters and magnetic mineral characteristics of deposits in 2 bores are analyzed,which are both sampled from the sedimentary center of the Jianghan Plain.The results are as follows:At about 110 m depth of the core,the contents of coarse materials and stable magnetic mineral both increase significantly.Meanwhile,the magnetic susceptibility of sediment,saturation isothermal remanent magnetization and magnetic susceptibility values of anhysteretic remanent magnetism increase suddenly,which all reflect that at about 110 m depth,the important adjustment has appeared in water system of the Jianghan Plain,and the sedimentary environment and material composition have changed greatly.And it may be the horizon where the Yangtze River Three Gorges formed,its forming time reflected by the paleomagnetic dating is between 1.17 and 1.12Ma B.P.展开更多
Integrated gravitational, electrical-magnetic surveys and data processing carried out in the Sanshandao-Jiaojia area, Eastern Shandong Province, northeast China, aim to illuminate the geological characteristics of thi...Integrated gravitational, electrical-magnetic surveys and data processing carried out in the Sanshandao-Jiaojia area, Eastern Shandong Province, northeast China, aim to illuminate the geological characteristics of this shallow-covered area and delineate deep-seated gold prospecting targets. In this region, altogether 12 faults exert critical control on distribution of three types of Early Precambrian metamorphic rock series, i.e. those in the metamorphic rock area, in the granitic rock area underlying the metamorphic rock, and in the remnant metamorphic rock area in granites, respectively. Additionally, the faults have major effects on distribution of four Mesozoic Linglong rock bodies of granite, i.e. the Cangshang, Liangguo, Zhuqiao-Miaojia and Jincheng granites. The Sanshandao and Jiaojia Faults are two well-known regional ore-controlling faults; they have opposite dip direction, and intersect at a depth of 4500 m. Fracture alteration zones have striking geophysical differences relative to the surrounding county rocks. The two faults extend down along dip direction in a gentle wave form, and appear at some steps with different dips. These steps comprise favorable gold prospecting areas, consistent with a step metallogenic model. Six deep-seated gold-prospecting targets are delineated, i.e. Jincheng-Qianchenjia, Xiaoxizhuang-Zhaoxian, Xiyou-Wujiazhuangzi, Xiangyangling-Xinlicun, Panjiawuzi and Miaojia-Pinglidian.展开更多
Salinity is a major abiotic stress factor that seriously affects plant growth. Many genes are involved in the response to salt stress with various metabolism pathways. A number of plant transcription factor family gen...Salinity is a major abiotic stress factor that seriously affects plant growth. Many genes are involved in the response to salt stress with various metabolism pathways. A number of plant transcription factor family genes have been found to be involved in the salt stress response, and NAM, ATAF and CUC(NAC) transcription factors are thought to act as active regulators during abiotic stress, especially salt stress. In this study, we detected a rice NAC transcription factor coding gene, OsNAC041, and confirmed that it influenced the germination of seeds under salt stress and salt tolerance of plants. OsNAC041 was primarily expressed in the leaves and located in the nucleus. Furthermore, the CRISPR/Cas9 method was used to obtain a targeted osnac041 mutant, of which the plant height was higher than that of the wild-type, showing increased salt sensitivity. Moreover, RNA-seq analysis revealed a number of differentially expressed genes(DEGs) involved in several important signaling pathways in the osnac041 mutant. Subsequently, Kyoto Encyclopedia of Genes and Genomes annotation also revealed differential expression of DEGs associated with mitogen-activated protein kinase signaling, peroxisome, eukaryotictype ABC transporters, photosynthesis and plant hormones, which are involved in stress-related signaling pathways. Overall, our study suggested that OsNAC041 was involved in the salt stress response in rice. These findings not only provide empirical evidence of OsNAC041 function, but also provide new insight into its potential application in rice resistance breeding.展开更多
Cauliflower is an important variety of Brassica oleracea and is planted worldwide.Here,the high-quality genome sequence of cauliflower was reported.The assembled cauliflower genome was 584.60 Mb in size,with a contig ...Cauliflower is an important variety of Brassica oleracea and is planted worldwide.Here,the high-quality genome sequence of cauliflower was reported.The assembled cauliflower genome was 584.60 Mb in size,with a contig N50 of 2.11 Mb,and contained 47,772 genes;56.65%of the genome was composed of repetitive sequences.Among these sequences,long terminal repeats(LTRs)were the most abundant(32.71%of the genome),followed by transposable elements(TEs)(12.62%).Comparative genomic analysis confirmed that after an ancient paleohexaploidy(γ)event,cauliflower underwent two whole-genome duplication(WGD)events shared with Arabidopsis and an additional whole-genome triplication(WGT)event shared with other Brassica species.The present cultivated cauliflower diverged from the ancestral B.oleracea species~3.0 million years ago(Mya).The speciation of cauliflower(~2.0 Mya)was later than that of B.oleracea L.var.capitata(approximately 2.6 Mya)and other Brassica species(over 2.0 Mya).Chromosome no.03 of cauliflower shared the most syntenic blocks with the A,B,and C genomes of Brassica species and its eight other chromosomes,implying that chromosome no.03 might be the most ancient one in the cauliflower genome,which was consistent with the chromosome being inherited from the common ancestor of Brassica species.In addition,2,718 specific genes,228 expanded genes,2 contracted genes,and 1,065 positively selected genes in cauliflower were identified and functionally annotated.These findings provide new insights into the genomic diversity of Brassica species and serve as a valuable reference for molecular breeding of cauliflower.展开更多
With the discoveries of a series of large gas fields in the northeast of Sichuan Basin, such as Puguang and Longgang gas fields, the formation mechanism of the gas reservoir containing high H2S in the ancient marine c...With the discoveries of a series of large gas fields in the northeast of Sichuan Basin, such as Puguang and Longgang gas fields, the formation mechanism of the gas reservoir containing high H2S in the ancient marine carbonate formation in superposition-basin becomes a hot topic in the field of petroleum geology. Based on the structure inversion, numerical simulation, and geochemical research, we show at least two intervals of fluid transfer in Puguang paleo-oil reservoir, one in the forepart of late Indo-Chinese epoch to early Yanshan epoch and the other in the metaphase of early Yanshan epoch. Oil and gas accumulation occurred at Puguang structure through Puguang-Dongyuezhai faults and dolomite beds in reef and shoal facies in Changxing Formation (P2ch) - Feixianguan Formation (T1f) in the northwest and southwest directions along three main migration pathways, to form Puguang paleo-oil reservoir. Since crude oil is pyrolysised in the early stage of middle Yanshan epoch, Puguang gas reservoir has experienced fluid adjusting process controlled by tectonic movement and geochemical reconstruction process controlled by thermochemical sulfate reduction (TSR). Middle Yan-shan epoch is the main period during which the Puguang gas reservoir experienced the geochemical reaction of TSR. On one hand, TSR can recreate the fluid in gas reservoir, which makes the gas drying index larger and carbon isotope heavier. On the other hand, the reciprocity between fluid regarding TSR (hydrocarbon, H2S, and water) and reservoir rock induces erosion of the reservoir rocks and anhydrite alteration, which improves reservoir petrophysical properties. Superimposed by later tectonic movement, the fluid in Puguang reservoir has twice experienced adjustment, one in the late Yanshan epoch to the early Himalayan epoch and the other time in late Himalayan epoch, after which Puguang gas reservoir is finally developed.展开更多
In this paper, a novel unmanned aerial vehicle(UAV)-enabled full duplex decode-and-forward(DF) technique is used in mobile relaying system. Compared with conventional static relaying, mobile relaying provides more deg...In this paper, a novel unmanned aerial vehicle(UAV)-enabled full duplex decode-and-forward(DF) technique is used in mobile relaying system. Compared with conventional static relaying, mobile relaying provides more degree of freedom for experiencing better channel conditions and further improving the system reliable performance. The source and relay transmit power as well as relay trajectory are jointly optimized for sum outage probability minimization in mobile relaying system. Due to the non-convex nature of the original problem, block coordinate decent optimization techniques are employed to decompose it into two sub-problems, which leads to an efficient iterative algorithm. Specifically, for the pre-determined relay trajectory, the optimal transmit power of source and relay are obtained by solving Karush-Kuhn-Tucker(KKT) conditions. For the given source/relay power allocation, the optimal UAV trajectory is obtained by solving dual problem. Based on the two steps, an iterative algorithm is proposed to jointly optimize source/relay power allocation and UAV trajectory alternately. Numerical results show the performance gain of our proposed scheme.展开更多
Due to the multitudinous structural types of glycosylated components,accurate identification of glycosylation modifications and secondary metabolite structures in herbs remains a challenge for natural drug analysis an...Due to the multitudinous structural types of glycosylated components,accurate identification of glycosylation modifications and secondary metabolite structures in herbs remains a challenge for natural drug analysis and new drug discovery[1].To solve this problem,we developed an auxiliary spectral analysis strategy based on Glyco-GNN machine learning techniques(Fig.1).It is named as“Glycomol”,an auxiliary tool for the identification of glycoside molecules.In Glycomol,the structure of glycosylated components was analyzed in terms of parent nucleus,glycan modification sites,and glycan types.Saponins were taken as representative glycosylated components due to their high structural complexity.To estimate the likelihood of results from this modularization strategy,first we extracted the liquid phase and mass spectrum information of 96 structure-known saponins from multi-stage mass spectrometry data.Then,24 standard saponins were applied for analysis and a 95.8%hit rate was achieved.展开更多
The Yangtze River is one of the most important components of the East Asia river system. In this study, sediments in the Jianghan Basin, middle Yangtze River, were selected for trace element and rare earth element （...The Yangtze River is one of the most important components of the East Asia river system. In this study, sediments in the Jianghan Basin, middle Yangtze River, were selected for trace element and rare earth element （REE） measurements, in order to decipher information on the change of sediment provenance and evolution of the Yangtze River. According to the elemental variations, the late Cenozoic sediments of the Jianghan Basin could be divided into four parts. During 2.68-2,28 Ma and 1.25-0 Ma, proveJ nance of the sediments was consistent, whereas sediments were derived from variable sources during 2.28-1.25 Ma. Comparison of the elemental compositions between the Pliocene and Quaternary sediments revealed a change in sediment source from a more felsic source area to a more basic source area around the Pliocene--Quaternary boundary. Input from the Emeishan LIP should account for this provenance change, Based on the provenance analysis of sediments in the Jianghan Basin, we infer that the Yangtze River developed into a large river with its drainage basin extended to the Emeishan LIP no later than the Pliocene-Quaternary boundary.展开更多
AIM: To explore a safe and efficient strategy of tumortherapy using anti-angiogenetic agents.METHODS: Endostatin gene with a signal sequence ofhuman IgG y chain was amplified by PCR and cloned intopVAXl plasmid which ...AIM: To explore a safe and efficient strategy of tumortherapy using anti-angiogenetic agents.METHODS: Endostatin gene with a signal sequence ofhuman IgG y chain was amplified by PCR and cloned intopVAXl plasmid which was the only vector authorized byFDA in clinical trial to construct a recombinant plasmidnamed as pVAX-sEN. The recombinant plasmid wasdetected with EcoRI/KpnI and DNA sequencing. BALB/c micebearing hepatocarcinoma cell line H22 were treated withnaked pVAX-sEN or liposome-DNA complex in which thedose of DNA and the ratio of DNA and liposome weredifferent from each other. To compare the efficiency ofgene transfection, expression of endostatin at the treatedtumor site was assayed with ELISA. To investigate the effectof pVAXI-sEN on hepatocellular carcinoma, pVAX-sENeither naked or in liposome-DNA complex was injectedinto BALB/c mice bearing H22, then the diameter of tumorswas measured, microvessel density was detected byimmunohistochemistry, endostatin expression in vivo wasassayed at different time points.RESULTS: DNA sequencing showed the endostatin genewith the signal peptide was correctly cloned. In situ geneexpression assay indicated that both the ratio of DNAand liposome and the dose of DNA could affect the genetransfection efficiency. Interestingly, naked pVAX-sEN hada similar in situ endostatin expression to pVAX-sEN withliposome. Animal experiments showed that pVAX-sENtogether with pVAX-sEN-liposome complex could efficientlysuppress the growth of mouse hepatoma cells.CONCLUSION: Naked endostatin plasmid intratumoralinjection can get a similar gene transfection efficiency toliposome-DNA complex when used in situ.展开更多
On September 5,2019,a moderate earthquake of Mw5.4 unexpectedly occurred in the apparently quiescent central basin of the South China Sea.We immediately carried out a seismicity monitoring experiment around the epicen...On September 5,2019,a moderate earthquake of Mw5.4 unexpectedly occurred in the apparently quiescent central basin of the South China Sea.We immediately carried out a seismicity monitoring experiment around the epicenter by using broadband ocean bottom seismometers(OBS)for the following three scientific targets.The first is knowing the earthquake seismogenic mechanism,fault structure and further development.The second is finding the role of the residual spreading ridge playing in earthquake processes and further revealing the deep structures of the ridge directional turning area.The third is confirming the existence and significance of the so called“Zhongnan fault”.This paper reports the preliminary results of the first phase experiment.Five OBSs were deployed for seismicity monitoring with a duration of 288 days,but only three were recovered.Micro-earthquakes were firstly detected by an automatic seismic phase picking algorithm and then were verified by analyzing their seismic phases and time-frequency characteristics in detail.A total of 21,68 and 89 microearthquakes were picked out from the three OBSs respectively within the distance of 30 km.The dominant frequency of these micro-earthquakes is 12-15 Hz,indicating tectonic fracturing.During the first two months after the mainshock the seismicity was relatively stronger,and micro-earthquakes were still occurring occasionally till the end of observation,indicating the epicenter area is active.We used Match&Locate method to locate 57 micro-earthquakes preliminarily.Their spatial distribution shows that the seismicity is developed mainly along the NE direction roughly parallel to the residual ridge with depth variations between 10-20 km.展开更多
The phase structure and magnetic properties of high-Co containing permanent magnets with high thermal stability have been systematically studied in this work.It is abnormal that the coercivity of annealed samples was ...The phase structure and magnetic properties of high-Co containing permanent magnets with high thermal stability have been systematically studied in this work.It is abnormal that the coercivity of annealed samples was slightly lower than that of sintered samples,while the coercivity was usually enhanced after annealing in conventional Nd–Fe–B samples.Further analysis showed that in addition to RE2(Fe,Co)14B main phase and RE-rich grain boundary phase,there were also new Co-rich magnetic phases located in the grain boundary.During annealing,the phase structures of high-Co containing magnets were readjusted,especially the increasing Co-rich magnetic phase and emerging RE-rich particles precipitated from the main phase.Eventually,the isolated RE-rich particles would act as the pinning center of the domain wall movement in demagnetization process.It was confirmed that the coercivity of annealed high-Co containing magnets was controlled by both nucleation and pinning.Pinning mechanism can partially compensate for the weakening of magnetic isolation due to increased Co-rich magnetic phase,which explained the moderate decrease in coercivity of annealed high-Co containing magnets.The discovery of new coercivity mechanism contributed to in-depth understanding of high-Co containing magnets.展开更多
Solid bitumens were found throughout the carbonate reservoirs in the Puguang gas field, the largest gas field so far found in marine carbonates in China, confirming that the Puguang gas field evolved from a paleo-oil ...Solid bitumens were found throughout the carbonate reservoirs in the Puguang gas field, the largest gas field so far found in marine carbonates in China, confirming that the Puguang gas field evolved from a paleo-oil reservoir. The fluid conduit system at the time of intensive oil accumulation in the field was reconstructed, and petroleum migration pathways were modeled using a 3-D model and traced by geochemical parameters. The forward modeling and inversion tracing coincided with each other and both indicated that oils accumulated in the Puguang-Dongyuezhai structure originated from a generative kitchen to the northwest of the Puguang gas field. The deposition of organic-rich Upper Permian source rocks dominated by sapropelic organic matter in the Northeast Sichuan Basin, the development of fluid conduit system that was vertically near-source rock and laterally near-generative kitchen, and the focusing of oils originated from a large area of the generative kitchen, were the three requirements for the formation of the giant paleo-oil reservoir from which the giant Puguang gas field evolved. The Puguang gas field had experienced a three-stage evolution. The post-accumulation processes, especially the organic-inorganic interaction in the hydrocarbon-water-rock system, had not only profoundly altered the composition and characteristics of the petroleum fluids, but also obviously changed the physicochemical conditions in the reservoir and resulted in complicated precipitation and solution of carbonate minerals.展开更多
Numerical simulation are conducted to explore the characteristics of the axial inflow and related aerodynamic noise for a large-scale adjustable fan with the installation angle changing from−12°to 12°.In suc...Numerical simulation are conducted to explore the characteristics of the axial inflow and related aerodynamic noise for a large-scale adjustable fan with the installation angle changing from−12°to 12°.In such a range the maximum static(gauge)pressure at the inlet changes from−2280 Pa to 382 Pa,and the minimum static pressure decreases from−3389 Pa to−8000 Pa.As for the axial intermediate flow surface,one low pressure zone is located at the junction of the suction surface and the hub,another is located at the suction surface close to the casing position.At the outlet boundary,the low pressure is negative and decreases from−1716 Pa to−4589 Pa.The sound pressure level of the inlet and outlet noise tends to increase monotonously by 11.6 dB and 7.3 dB,respectively.The acoustic energy of discrete noise is always higher than that of broadband noise regardless of whether the inlet or outlet flow surfaces are considered.The acoustic energy ratio of discrete noise at the inlet tends to increase from 0.78 to 0.93,while at the outlet it first decreases from 0.79 to 0.73 and then increases to 0.84.展开更多
Objective:Yiqi Huoxue Decoction (YQHX) has been widely used for clinical treatment of ischemic heart disease.While oxidative stress plays a key role in the pathogenesis of ischemic heart disease,the function and molec...Objective:Yiqi Huoxue Decoction (YQHX) has been widely used for clinical treatment of ischemic heart disease.While oxidative stress plays a key role in the pathogenesis of ischemic heart disease,the function and molecular mechanism underlying antioxidative protective effects of YQHX on H9c2 cardiomyocytes against ischemia/hypoxia (I/H) have yet to be well clarified.Methods:H9c2 cells were subjected to 12 h of hypoxia with serum-free conditions and then treated with or without YQHX (100-400 μg/mL).Cell viability was examined using a CCK-8 assay.Maleic dialdehyde (MDA) and superoxide dismutase (SOD) activity were detected using commercial kits.Intracellular reactive oxygen species (ROS) levels and mitochondrial membrane potential were measured using fluorescence microscopy and confocal laser-scanning microscopy,respectively.Ultrastructural details of mitochondria in H9c2 cells were observed using transmission electron microscopy.The antioxidative protective pathway was assessed by measuring mRNA and protein expression of Nrf2 and HO-1,as well as AMPK activation.Results:I/H injury gradually induced oxidative stress.Treatment with YQHX significantly increased cell viability and reversed I/H-induced oxidative stress,including reducing the production of oxidative stress products (ROS and MDA),increasing SOD levels,improving mitochondrial morphology,and increasing mitochondrial membrane potential.YQHX was also observed to increase I/H-induced expression of Nrf2 and HO-1,and the activation effects of YQHX were blocked by an AMPK inhibitor.In addition,HPLC analysis showed that YQHX contained two active antioxidative constituents (calycosin and ferulic acid).Conclusion:The results suggest that anti-oxidative effects exerted by YQHX in H9c2 cardiomyocytes may be linked to upregulation of the AMPK-mediated Nrf2/HO-1 pathway.展开更多
The hollow parts formed with cross-wedge rolling (CWR) have a wide application in many fields, such as architecture and automobile, etc. But the finished configuration of part’s cross section was always ellipse and i...The hollow parts formed with cross-wedge rolling (CWR) have a wide application in many fields, such as architecture and automobile, etc. But the finished configuration of part’s cross section was always ellipse and it was hard to make it satisfied with traditional forming process. This paper proposed a FEM model of hollow workpiece of CWR in the sizing process, and simulated the deformation condition using the ANSYS program. Three kinds of parts with different wall thickness were calculated. Some stress and strain fields of the deformed hollow parts at various conditions are gained. The influence of wall thickness on the distribution of stress and strain was analyzed. The paper also found two phenomena, which never have been seen at traditional experiment, and author tried to give some explanations. The ANSYS program provided the relationship between the tolerance of the deformed workpiece and the deforming parameter. It is helpful to design the sizing dies of a new precise forming process of hollow parts on the CWR. The new process that designed through the information of FEM improved the accuracy of hollow parts on CWR. It proved the validity and practicability of numerical simulation.展开更多
Objective The 2014 Ludian Mw6.1 earthquake in Yunnan occurred in a mountainous area with complex tectonics and topography, which caused serious damage as well as co-seismic landslides of an unusual large scale. Becau...Objective The 2014 Ludian Mw6.1 earthquake in Yunnan occurred in a mountainous area with complex tectonics and topography, which caused serious damage as well as co-seismic landslides of an unusual large scale. Because the suspected seismogenic faults on the surface, distribution of aftershocks and focal mechanism solutions are not consistent, it remains difficult to determine what is the real causal fault or seismogenic structure for this event. Actually, it may imply the complicity of the seismic source at depth. In addition, the distribution of the co- seismic landslides also exhibits some diffusion that is different from general eases, likely associated with the seismic focus structure.展开更多
On the basis of field observations, microscopic thin-sections and laboratory data analysis of ten faults in Xuanhan County area, northeastern Sichuan Basin, central China, the internal and megascopic structures and te...On the basis of field observations, microscopic thin-sections and laboratory data analysis of ten faults in Xuanhan County area, northeastern Sichuan Basin, central China, the internal and megascopic structures and tectonite development characteristics are mainly controlled by the geomechanical quality in brittle formation of the Changxing-Feixianguan Formation. The fluid transportation performance difference between the faults formed by different geomechanics or different structural parts of the same fault are controlled by the mcgascopic structure and tectonite development characteristics. For instance, the extension fault structure consists of a tectonite breccia zone and an extension fracture zone. Good fluid transportation performance zones are the extension fracture zone adjacent to the tectonite breccia zone and the breccia zone formed at the early evolutionary stage. The typical compression fault structure consists of a boulder-clay zone or zones of grinding gravel rock, compression foliation, tectonite lens, and dense fracture development. The dense fracture development zone is the best fluid transporting area at a certain scale of the compression fault, and then the lens, grinding gravel rock zone and compression foliation zones are the worst areas for hydrocarbon migration. The typical tensor-shear fault with a certain scale can be divided into boulder-clay or grinding gravel rock zones of the fault, as well as a pinnate fractures zone and a derivative fractures zone. The grinding gravel rock zone is the worst one for fluid transportation. Because of the fracture mesh connectivity and better penetration ability, the pinnate fractures zone provides the dominant pathway for hydrocarbon vertical migration along the tensor-shear fault.展开更多
In this paper,we investigate the end-to-end performance of intelligent reflecting surface(IRS)-assisted wireless communication systems.We consider a system in which an IRS is deployed on a uniform planar array(UPA)con...In this paper,we investigate the end-to-end performance of intelligent reflecting surface(IRS)-assisted wireless communication systems.We consider a system in which an IRS is deployed on a uniform planar array(UPA)configuration,including a large number of reflecting elements,where the transmitters and receivers are only equipped with a single antenna.Our objective is to analytically obtain the achievable ergodic rate,outage probability,and bit error rate(BER)of the system.Furthermore,to maximize the system’s signal-to-noise ratio(SNR),we design the phase shift of each reflecting element and derive the optimal reflection phase of the IRS based on the channel state information(CSI).We also derive the exact expression of the SNR probability density function(p.d.f.)and show that it follows a non-central Chi-square distribution.Using the p.d.f.,we then derive the theoretical results of the achievable rate,outage probability,and BER.The accuracy of the obtained theoretical results is also verified through numerical simulation.Itwas shown that the achievable rate,outage probability,and BER could be improved by increasing the number of reflecting elements and choosing an appropriate SNR regime.Furthermore,we also find that the IRS-assisted communication system achieves better performance than the existing end-to-end wireless communication.展开更多
Background:Alzheimer’s disease(AD)is a neurodegenerative disease that primarily manifests as progressive memory loss and cognitive impairment.Traditional herbal medicines may be helpful in the discovery of new anti-A...Background:Alzheimer’s disease(AD)is a neurodegenerative disease that primarily manifests as progressive memory loss and cognitive impairment.Traditional herbal medicines may be helpful in the discovery of new anti-AD drugs.Studies have shown that Ferula assafoetida has neuroprotective and memory-enhancing effects,which may be beneficial for the treatment of AD.However,the combination of active ingredients and their mechanisms remain unclear.Therefore,we aimed to identify potential active ingredients in F.assafoetida and their mechanisms of action against AD by using network pharmacology.Methods:In our study,an integrated network pharmacological approach,that included adsorption,distribution,metabolism and excretion screening,target identification,network construction,topological analysis,gene ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis,and molecular docking,was used to predict the pharmacological material basis and potential mechanisms through which these ingredients may treat and prevent AD.Results:The results indicated that 12 key active ingredients,obtained by topological analysis(including farnesiferol a,conferol,farnesiferol b,ferulic acid,etc.),may be the primary pharmacological components that may ameliorate AD.The 2 key significant pathways identified are the cholinergic synapse signaling pathway(critical targets include ACHE,CHRM1,CHRM2,MAPK1,PIK3CA,PIK3CB,PIK3CD,and PIK3CG)and the AD signaling pathway(critical targets include APP,BACE1,GSK3B,MAPK1,NCSTN,NOS1,PSEN1).These critical targets are closely related to the regulation of three typical pathological features of AD[central nervous system(CNS)cholinergic hypofunction,amyloid-β(Aβ)plaques,and hyperphosphorylated tau proteins].Finally,14 critical targets in the 2 key significant pathways were validated by molecular docking analysis.Conclusion:F.assafoetida may be effective for alleviating AD symptoms,through multi-component,multi-target,and multi-pathway synergistic effects,associated with the multiple pathogen展开更多
The technology actuality and development trend of variable thrust rocket engines at home and abroad are summarized. Key technologies of developing variable thrust rocket engines are analyzed. Development advices on de...The technology actuality and development trend of variable thrust rocket engines at home and abroad are summarized. Key technologies of developing variable thrust rocket engines are analyzed. Development advices on developing variable thrust rocket engines that are adapted to the situation of our country are brought forward.展开更多
基金Supported by the National Natural Science Foundation of China (Grant Nos. 90411005,40472151and40672206)the National Basic Research Program of China (Grant No. 2004CB720204)
文摘The forming time of the Yangtze River Three Gorges is considered as one of keys in the research on the Yangtze River,also is one of the most disputed hotspots.In order to solve the difficult problem,the authors adopt the internationally recognized thoughts and methods of substance tracing from source to sink.The lithologic characteristics,magnetic parameters and magnetic mineral characteristics of deposits in 2 bores are analyzed,which are both sampled from the sedimentary center of the Jianghan Plain.The results are as follows:At about 110 m depth of the core,the contents of coarse materials and stable magnetic mineral both increase significantly.Meanwhile,the magnetic susceptibility of sediment,saturation isothermal remanent magnetization and magnetic susceptibility values of anhysteretic remanent magnetism increase suddenly,which all reflect that at about 110 m depth,the important adjustment has appeared in water system of the Jianghan Plain,and the sedimentary environment and material composition have changed greatly.And it may be the horizon where the Yangtze River Three Gorges formed,its forming time reflected by the paleomagnetic dating is between 1.17 and 1.12Ma B.P.
基金the Geological Science and technology foundation of Shandong Provincial Bureau of Geology and Mineral Resources (Grant No. 20080037)
文摘Integrated gravitational, electrical-magnetic surveys and data processing carried out in the Sanshandao-Jiaojia area, Eastern Shandong Province, northeast China, aim to illuminate the geological characteristics of this shallow-covered area and delineate deep-seated gold prospecting targets. In this region, altogether 12 faults exert critical control on distribution of three types of Early Precambrian metamorphic rock series, i.e. those in the metamorphic rock area, in the granitic rock area underlying the metamorphic rock, and in the remnant metamorphic rock area in granites, respectively. Additionally, the faults have major effects on distribution of four Mesozoic Linglong rock bodies of granite, i.e. the Cangshang, Liangguo, Zhuqiao-Miaojia and Jincheng granites. The Sanshandao and Jiaojia Faults are two well-known regional ore-controlling faults; they have opposite dip direction, and intersect at a depth of 4500 m. Fracture alteration zones have striking geophysical differences relative to the surrounding county rocks. The two faults extend down along dip direction in a gentle wave form, and appear at some steps with different dips. These steps comprise favorable gold prospecting areas, consistent with a step metallogenic model. Six deep-seated gold-prospecting targets are delineated, i.e. Jincheng-Qianchenjia, Xiaoxizhuang-Zhaoxian, Xiyou-Wujiazhuangzi, Xiangyangling-Xinlicun, Panjiawuzi and Miaojia-Pinglidian.
基金supported by the National Science Foundation of China (Grant No. 31771486)the Sichuan Youth Science and Technology Foundation (Grant No. 2017JQ0005)+1 种基金the National Key Research and Development Program of China (Grant No. 2017YFD01005050102)the National Transgenic Major Project (Grant No. SQ2018ZD08019-001-003)
文摘Salinity is a major abiotic stress factor that seriously affects plant growth. Many genes are involved in the response to salt stress with various metabolism pathways. A number of plant transcription factor family genes have been found to be involved in the salt stress response, and NAM, ATAF and CUC(NAC) transcription factors are thought to act as active regulators during abiotic stress, especially salt stress. In this study, we detected a rice NAC transcription factor coding gene, OsNAC041, and confirmed that it influenced the germination of seeds under salt stress and salt tolerance of plants. OsNAC041 was primarily expressed in the leaves and located in the nucleus. Furthermore, the CRISPR/Cas9 method was used to obtain a targeted osnac041 mutant, of which the plant height was higher than that of the wild-type, showing increased salt sensitivity. Moreover, RNA-seq analysis revealed a number of differentially expressed genes(DEGs) involved in several important signaling pathways in the osnac041 mutant. Subsequently, Kyoto Encyclopedia of Genes and Genomes annotation also revealed differential expression of DEGs associated with mitogen-activated protein kinase signaling, peroxisome, eukaryotictype ABC transporters, photosynthesis and plant hormones, which are involved in stress-related signaling pathways. Overall, our study suggested that OsNAC041 was involved in the salt stress response in rice. These findings not only provide empirical evidence of OsNAC041 function, but also provide new insight into its potential application in rice resistance breeding.
基金supported by grants from the National Key Research and Development Program of China(2017YFD0101805)the Modern Agro-Industry Technology Research System,China(CARS-23-A-07)+1 种基金the Vegetable Modern Agro-Industry Technology Research System,Tianjin(ITTVRS2017004)the Natural Science Foundation of China(No.31872115).
文摘Cauliflower is an important variety of Brassica oleracea and is planted worldwide.Here,the high-quality genome sequence of cauliflower was reported.The assembled cauliflower genome was 584.60 Mb in size,with a contig N50 of 2.11 Mb,and contained 47,772 genes;56.65%of the genome was composed of repetitive sequences.Among these sequences,long terminal repeats(LTRs)were the most abundant(32.71%of the genome),followed by transposable elements(TEs)(12.62%).Comparative genomic analysis confirmed that after an ancient paleohexaploidy(γ)event,cauliflower underwent two whole-genome duplication(WGD)events shared with Arabidopsis and an additional whole-genome triplication(WGT)event shared with other Brassica species.The present cultivated cauliflower diverged from the ancestral B.oleracea species~3.0 million years ago(Mya).The speciation of cauliflower(~2.0 Mya)was later than that of B.oleracea L.var.capitata(approximately 2.6 Mya)and other Brassica species(over 2.0 Mya).Chromosome no.03 of cauliflower shared the most syntenic blocks with the A,B,and C genomes of Brassica species and its eight other chromosomes,implying that chromosome no.03 might be the most ancient one in the cauliflower genome,which was consistent with the chromosome being inherited from the common ancestor of Brassica species.In addition,2,718 specific genes,228 expanded genes,2 contracted genes,and 1,065 positively selected genes in cauliflower were identified and functionally annotated.These findings provide new insights into the genomic diversity of Brassica species and serve as a valuable reference for molecular breeding of cauliflower.
基金Supported by National Basic Research Program of China (Grant No. 2005CB422105)
文摘With the discoveries of a series of large gas fields in the northeast of Sichuan Basin, such as Puguang and Longgang gas fields, the formation mechanism of the gas reservoir containing high H2S in the ancient marine carbonate formation in superposition-basin becomes a hot topic in the field of petroleum geology. Based on the structure inversion, numerical simulation, and geochemical research, we show at least two intervals of fluid transfer in Puguang paleo-oil reservoir, one in the forepart of late Indo-Chinese epoch to early Yanshan epoch and the other in the metaphase of early Yanshan epoch. Oil and gas accumulation occurred at Puguang structure through Puguang-Dongyuezhai faults and dolomite beds in reef and shoal facies in Changxing Formation (P2ch) - Feixianguan Formation (T1f) in the northwest and southwest directions along three main migration pathways, to form Puguang paleo-oil reservoir. Since crude oil is pyrolysised in the early stage of middle Yanshan epoch, Puguang gas reservoir has experienced fluid adjusting process controlled by tectonic movement and geochemical reconstruction process controlled by thermochemical sulfate reduction (TSR). Middle Yan-shan epoch is the main period during which the Puguang gas reservoir experienced the geochemical reaction of TSR. On one hand, TSR can recreate the fluid in gas reservoir, which makes the gas drying index larger and carbon isotope heavier. On the other hand, the reciprocity between fluid regarding TSR (hydrocarbon, H2S, and water) and reservoir rock induces erosion of the reservoir rocks and anhydrite alteration, which improves reservoir petrophysical properties. Superimposed by later tectonic movement, the fluid in Puguang reservoir has twice experienced adjustment, one in the late Yanshan epoch to the early Himalayan epoch and the other time in late Himalayan epoch, after which Puguang gas reservoir is finally developed.
基金supported by National High Technology Project of China 2015AA01A703Scientific and Technological Key Project of Henan Province under Grant 182102210449the National Natural Science Foundation of China under Grants 61372101 and 61671144
文摘In this paper, a novel unmanned aerial vehicle(UAV)-enabled full duplex decode-and-forward(DF) technique is used in mobile relaying system. Compared with conventional static relaying, mobile relaying provides more degree of freedom for experiencing better channel conditions and further improving the system reliable performance. The source and relay transmit power as well as relay trajectory are jointly optimized for sum outage probability minimization in mobile relaying system. Due to the non-convex nature of the original problem, block coordinate decent optimization techniques are employed to decompose it into two sub-problems, which leads to an efficient iterative algorithm. Specifically, for the pre-determined relay trajectory, the optimal transmit power of source and relay are obtained by solving Karush-Kuhn-Tucker(KKT) conditions. For the given source/relay power allocation, the optimal UAV trajectory is obtained by solving dual problem. Based on the two steps, an iterative algorithm is proposed to jointly optimize source/relay power allocation and UAV trajectory alternately. Numerical results show the performance gain of our proposed scheme.
基金funded by the National Natural Science Foundation of China(Grant Nos.:82374076,and 82174354)National Key R&D Program of China(Grant No.:2023YFC3504100)+3 种基金Natural Science Foundation of Beijing(Grant No.:7244493)NSFC Cultivating Project of Institute of Chinese Materia Medica,China Academy of Chinese Medical Sciences(Grant No.:ZXKT23003)Young Elite Cultivating Project of Institute of Chinese Materia Medica,China Academy of Chinese Medical Sciences(Grant No.:ZZ17-YQ-023)Start-up Fund for New Scientific Researchers of China Academy of Chinese Medical Sciences(Grant No.:ZZ16-XRZ071).
文摘Due to the multitudinous structural types of glycosylated components,accurate identification of glycosylation modifications and secondary metabolite structures in herbs remains a challenge for natural drug analysis and new drug discovery[1].To solve this problem,we developed an auxiliary spectral analysis strategy based on Glyco-GNN machine learning techniques(Fig.1).It is named as“Glycomol”,an auxiliary tool for the identification of glycoside molecules.In Glycomol,the structure of glycosylated components was analyzed in terms of parent nucleus,glycan modification sites,and glycan types.Saponins were taken as representative glycosylated components due to their high structural complexity.To estimate the likelihood of results from this modularization strategy,first we extracted the liquid phase and mass spectrum information of 96 structure-known saponins from multi-stage mass spectrometry data.Then,24 standard saponins were applied for analysis and a 95.8%hit rate was achieved.
基金supported by the National Natural Science Foundation of China(Grants Nos.40971008 and 40771213)the Open Research Program of State Key Laboratory of Loess and Quaternary Geology(Grant No.SKLLQG0908)
文摘The Yangtze River is one of the most important components of the East Asia river system. In this study, sediments in the Jianghan Basin, middle Yangtze River, were selected for trace element and rare earth element （REE） measurements, in order to decipher information on the change of sediment provenance and evolution of the Yangtze River. According to the elemental variations, the late Cenozoic sediments of the Jianghan Basin could be divided into four parts. During 2.68-2,28 Ma and 1.25-0 Ma, proveJ nance of the sediments was consistent, whereas sediments were derived from variable sources during 2.28-1.25 Ma. Comparison of the elemental compositions between the Pliocene and Quaternary sediments revealed a change in sediment source from a more felsic source area to a more basic source area around the Pliocene--Quaternary boundary. Input from the Emeishan LIP should account for this provenance change, Based on the provenance analysis of sediments in the Jianghan Basin, we infer that the Yangtze River developed into a large river with its drainage basin extended to the Emeishan LIP no later than the Pliocene-Quaternary boundary.
基金Supported by the National Natural Science Foundation of China,No.30100078 and Huo Yingdong Educational Fund,No.81035
文摘AIM: To explore a safe and efficient strategy of tumortherapy using anti-angiogenetic agents.METHODS: Endostatin gene with a signal sequence ofhuman IgG y chain was amplified by PCR and cloned intopVAXl plasmid which was the only vector authorized byFDA in clinical trial to construct a recombinant plasmidnamed as pVAX-sEN. The recombinant plasmid wasdetected with EcoRI/KpnI and DNA sequencing. BALB/c micebearing hepatocarcinoma cell line H22 were treated withnaked pVAX-sEN or liposome-DNA complex in which thedose of DNA and the ratio of DNA and liposome weredifferent from each other. To compare the efficiency ofgene transfection, expression of endostatin at the treatedtumor site was assayed with ELISA. To investigate the effectof pVAXI-sEN on hepatocellular carcinoma, pVAX-sENeither naked or in liposome-DNA complex was injectedinto BALB/c mice bearing H22, then the diameter of tumorswas measured, microvessel density was detected byimmunohistochemistry, endostatin expression in vivo wasassayed at different time points.RESULTS: DNA sequencing showed the endostatin genewith the signal peptide was correctly cloned. In situ geneexpression assay indicated that both the ratio of DNAand liposome and the dose of DNA could affect the genetransfection efficiency. Interestingly, naked pVAX-sEN hada similar in situ endostatin expression to pVAX-sEN withliposome. Animal experiments showed that pVAX-sENtogether with pVAX-sEN-liposome complex could efficientlysuppress the growth of mouse hepatoma cells.CONCLUSION: Naked endostatin plasmid intratumoralinjection can get a similar gene transfection efficiency toliposome-DNA complex when used in situ.
基金jointly supported by the National Natural Science Foundation of China(Nos.42076047,41890811)。
文摘On September 5,2019,a moderate earthquake of Mw5.4 unexpectedly occurred in the apparently quiescent central basin of the South China Sea.We immediately carried out a seismicity monitoring experiment around the epicenter by using broadband ocean bottom seismometers(OBS)for the following three scientific targets.The first is knowing the earthquake seismogenic mechanism,fault structure and further development.The second is finding the role of the residual spreading ridge playing in earthquake processes and further revealing the deep structures of the ridge directional turning area.The third is confirming the existence and significance of the so called“Zhongnan fault”.This paper reports the preliminary results of the first phase experiment.Five OBSs were deployed for seismicity monitoring with a duration of 288 days,but only three were recovered.Micro-earthquakes were firstly detected by an automatic seismic phase picking algorithm and then were verified by analyzing their seismic phases and time-frequency characteristics in detail.A total of 21,68 and 89 microearthquakes were picked out from the three OBSs respectively within the distance of 30 km.The dominant frequency of these micro-earthquakes is 12-15 Hz,indicating tectonic fracturing.During the first two months after the mainshock the seismicity was relatively stronger,and micro-earthquakes were still occurring occasionally till the end of observation,indicating the epicenter area is active.We used Match&Locate method to locate 57 micro-earthquakes preliminarily.Their spatial distribution shows that the seismicity is developed mainly along the NE direction roughly parallel to the residual ridge with depth variations between 10-20 km.
基金Project supported by National Key R&D Program of China(Grant No.2021YFB3803003)Youth Innovation Promotion Association CAS(Grant No.2023311).
文摘The phase structure and magnetic properties of high-Co containing permanent magnets with high thermal stability have been systematically studied in this work.It is abnormal that the coercivity of annealed samples was slightly lower than that of sintered samples,while the coercivity was usually enhanced after annealing in conventional Nd–Fe–B samples.Further analysis showed that in addition to RE2(Fe,Co)14B main phase and RE-rich grain boundary phase,there were also new Co-rich magnetic phases located in the grain boundary.During annealing,the phase structures of high-Co containing magnets were readjusted,especially the increasing Co-rich magnetic phase and emerging RE-rich particles precipitated from the main phase.Eventually,the isolated RE-rich particles would act as the pinning center of the domain wall movement in demagnetization process.It was confirmed that the coercivity of annealed high-Co containing magnets was controlled by both nucleation and pinning.Pinning mechanism can partially compensate for the weakening of magnetic isolation due to increased Co-rich magnetic phase,which explained the moderate decrease in coercivity of annealed high-Co containing magnets.The discovery of new coercivity mechanism contributed to in-depth understanding of high-Co containing magnets.
基金supported by the"973"Project (2005CB422105)the Program for Changjiang Scholars and Innovative Research Team at the University (PCSIRT IRT0658).
文摘Solid bitumens were found throughout the carbonate reservoirs in the Puguang gas field, the largest gas field so far found in marine carbonates in China, confirming that the Puguang gas field evolved from a paleo-oil reservoir. The fluid conduit system at the time of intensive oil accumulation in the field was reconstructed, and petroleum migration pathways were modeled using a 3-D model and traced by geochemical parameters. The forward modeling and inversion tracing coincided with each other and both indicated that oils accumulated in the Puguang-Dongyuezhai structure originated from a generative kitchen to the northwest of the Puguang gas field. The deposition of organic-rich Upper Permian source rocks dominated by sapropelic organic matter in the Northeast Sichuan Basin, the development of fluid conduit system that was vertically near-source rock and laterally near-generative kitchen, and the focusing of oils originated from a large area of the generative kitchen, were the three requirements for the formation of the giant paleo-oil reservoir from which the giant Puguang gas field evolved. The Puguang gas field had experienced a three-stage evolution. The post-accumulation processes, especially the organic-inorganic interaction in the hydrocarbon-water-rock system, had not only profoundly altered the composition and characteristics of the petroleum fluids, but also obviously changed the physicochemical conditions in the reservoir and resulted in complicated precipitation and solution of carbonate minerals.
基金supported by Key Research and Development Project of Shandong Province[2019GSF109084]Young Scholars Program of Shandong University[2018WLJH73].
文摘Numerical simulation are conducted to explore the characteristics of the axial inflow and related aerodynamic noise for a large-scale adjustable fan with the installation angle changing from−12°to 12°.In such a range the maximum static(gauge)pressure at the inlet changes from−2280 Pa to 382 Pa,and the minimum static pressure decreases from−3389 Pa to−8000 Pa.As for the axial intermediate flow surface,one low pressure zone is located at the junction of the suction surface and the hub,another is located at the suction surface close to the casing position.At the outlet boundary,the low pressure is negative and decreases from−1716 Pa to−4589 Pa.The sound pressure level of the inlet and outlet noise tends to increase monotonously by 11.6 dB and 7.3 dB,respectively.The acoustic energy of discrete noise is always higher than that of broadband noise regardless of whether the inlet or outlet flow surfaces are considered.The acoustic energy ratio of discrete noise at the inlet tends to increase from 0.78 to 0.93,while at the outlet it first decreases from 0.79 to 0.73 and then increases to 0.84.
基金the National Natural Science Foundation of China:Study of Influence of Supplementing Qi and Activating Blood Circulation Herbs on Mitochondrial Energy Metabolism and Signal Transduction of Myocardial Ischemia Rats(No.81473552).
文摘Objective:Yiqi Huoxue Decoction (YQHX) has been widely used for clinical treatment of ischemic heart disease.While oxidative stress plays a key role in the pathogenesis of ischemic heart disease,the function and molecular mechanism underlying antioxidative protective effects of YQHX on H9c2 cardiomyocytes against ischemia/hypoxia (I/H) have yet to be well clarified.Methods:H9c2 cells were subjected to 12 h of hypoxia with serum-free conditions and then treated with or without YQHX (100-400 μg/mL).Cell viability was examined using a CCK-8 assay.Maleic dialdehyde (MDA) and superoxide dismutase (SOD) activity were detected using commercial kits.Intracellular reactive oxygen species (ROS) levels and mitochondrial membrane potential were measured using fluorescence microscopy and confocal laser-scanning microscopy,respectively.Ultrastructural details of mitochondria in H9c2 cells were observed using transmission electron microscopy.The antioxidative protective pathway was assessed by measuring mRNA and protein expression of Nrf2 and HO-1,as well as AMPK activation.Results:I/H injury gradually induced oxidative stress.Treatment with YQHX significantly increased cell viability and reversed I/H-induced oxidative stress,including reducing the production of oxidative stress products (ROS and MDA),increasing SOD levels,improving mitochondrial morphology,and increasing mitochondrial membrane potential.YQHX was also observed to increase I/H-induced expression of Nrf2 and HO-1,and the activation effects of YQHX were blocked by an AMPK inhibitor.In addition,HPLC analysis showed that YQHX contained two active antioxidative constituents (calycosin and ferulic acid).Conclusion:The results suggest that anti-oxidative effects exerted by YQHX in H9c2 cardiomyocytes may be linked to upregulation of the AMPK-mediated Nrf2/HO-1 pathway.
文摘The hollow parts formed with cross-wedge rolling (CWR) have a wide application in many fields, such as architecture and automobile, etc. But the finished configuration of part’s cross section was always ellipse and it was hard to make it satisfied with traditional forming process. This paper proposed a FEM model of hollow workpiece of CWR in the sizing process, and simulated the deformation condition using the ANSYS program. Three kinds of parts with different wall thickness were calculated. Some stress and strain fields of the deformed hollow parts at various conditions are gained. The influence of wall thickness on the distribution of stress and strain was analyzed. The paper also found two phenomena, which never have been seen at traditional experiment, and author tried to give some explanations. The ANSYS program provided the relationship between the tolerance of the deformed workpiece and the deforming parameter. It is helpful to design the sizing dies of a new precise forming process of hollow parts on the CWR. The new process that designed through the information of FEM improved the accuracy of hollow parts on CWR. It proved the validity and practicability of numerical simulation.
基金supported by the National Natural Science Foundation of China(grant No.41572194)the Institute of Geology,China Earthquake Administration(grant No.IGCEA1604)the National Key Basic Research Program of China(grant No.2013CB733205)
文摘Objective The 2014 Ludian Mw6.1 earthquake in Yunnan occurred in a mountainous area with complex tectonics and topography, which caused serious damage as well as co-seismic landslides of an unusual large scale. Because the suspected seismogenic faults on the surface, distribution of aftershocks and focal mechanism solutions are not consistent, it remains difficult to determine what is the real causal fault or seismogenic structure for this event. Actually, it may imply the complicity of the seismic source at depth. In addition, the distribution of the co- seismic landslides also exhibits some diffusion that is different from general eases, likely associated with the seismic focus structure.
文摘On the basis of field observations, microscopic thin-sections and laboratory data analysis of ten faults in Xuanhan County area, northeastern Sichuan Basin, central China, the internal and megascopic structures and tectonite development characteristics are mainly controlled by the geomechanical quality in brittle formation of the Changxing-Feixianguan Formation. The fluid transportation performance difference between the faults formed by different geomechanics or different structural parts of the same fault are controlled by the mcgascopic structure and tectonite development characteristics. For instance, the extension fault structure consists of a tectonite breccia zone and an extension fracture zone. Good fluid transportation performance zones are the extension fracture zone adjacent to the tectonite breccia zone and the breccia zone formed at the early evolutionary stage. The typical compression fault structure consists of a boulder-clay zone or zones of grinding gravel rock, compression foliation, tectonite lens, and dense fracture development. The dense fracture development zone is the best fluid transporting area at a certain scale of the compression fault, and then the lens, grinding gravel rock zone and compression foliation zones are the worst areas for hydrocarbon migration. The typical tensor-shear fault with a certain scale can be divided into boulder-clay or grinding gravel rock zones of the fault, as well as a pinnate fractures zone and a derivative fractures zone. The grinding gravel rock zone is the worst one for fluid transportation. Because of the fracture mesh connectivity and better penetration ability, the pinnate fractures zone provides the dominant pathway for hydrocarbon vertical migration along the tensor-shear fault.
基金supported in part by the Joint Research Fund for Guangzhou University and Hong Kong University of Science and Technology under Grant No.YH202203the Guangzhou Basic Research Program Municipal School(College)Joint Funding Project,the Research Project of Guizhou University for Talent Introduction under Grant No.[2020]61+7 种基金the Cultivation Project of Guizhou University under Grant No.[2019]56the Open Fund of Key Laboratory of Advanced Manufacturing Technology,Ministry of Education under Grant No.GZUAMT2021KF[01]the National Natural Science Foundation of China under Grant Nos.51978089 and 62171119the Key R&D Plan of Sichuan Science and Technology Department under Grant No.22ZDYF2726the Chengdu Normal University Scientific Research and Innovation Team under Grant Nos.CSCXTD2020B09,ZZBS201907,CS21ZC01the Open Project of Intelligent Manufacturing Industry Technology Research Institute under Grant No.ZNZZ2208the National Key Research and Development Program of China under Grant No.2020YFB1807201Key research and development plan of Jiangsu Province under Grant No.BE2021013-3.
文摘In this paper,we investigate the end-to-end performance of intelligent reflecting surface(IRS)-assisted wireless communication systems.We consider a system in which an IRS is deployed on a uniform planar array(UPA)configuration,including a large number of reflecting elements,where the transmitters and receivers are only equipped with a single antenna.Our objective is to analytically obtain the achievable ergodic rate,outage probability,and bit error rate(BER)of the system.Furthermore,to maximize the system’s signal-to-noise ratio(SNR),we design the phase shift of each reflecting element and derive the optimal reflection phase of the IRS based on the channel state information(CSI).We also derive the exact expression of the SNR probability density function(p.d.f.)and show that it follows a non-central Chi-square distribution.Using the p.d.f.,we then derive the theoretical results of the achievable rate,outage probability,and BER.The accuracy of the obtained theoretical results is also verified through numerical simulation.Itwas shown that the achievable rate,outage probability,and BER could be improved by increasing the number of reflecting elements and choosing an appropriate SNR regime.Furthermore,we also find that the IRS-assisted communication system achieves better performance than the existing end-to-end wireless communication.
基金the National Key Research and Development Program of China(2019YFC1710105).
文摘Background:Alzheimer’s disease(AD)is a neurodegenerative disease that primarily manifests as progressive memory loss and cognitive impairment.Traditional herbal medicines may be helpful in the discovery of new anti-AD drugs.Studies have shown that Ferula assafoetida has neuroprotective and memory-enhancing effects,which may be beneficial for the treatment of AD.However,the combination of active ingredients and their mechanisms remain unclear.Therefore,we aimed to identify potential active ingredients in F.assafoetida and their mechanisms of action against AD by using network pharmacology.Methods:In our study,an integrated network pharmacological approach,that included adsorption,distribution,metabolism and excretion screening,target identification,network construction,topological analysis,gene ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis,and molecular docking,was used to predict the pharmacological material basis and potential mechanisms through which these ingredients may treat and prevent AD.Results:The results indicated that 12 key active ingredients,obtained by topological analysis(including farnesiferol a,conferol,farnesiferol b,ferulic acid,etc.),may be the primary pharmacological components that may ameliorate AD.The 2 key significant pathways identified are the cholinergic synapse signaling pathway(critical targets include ACHE,CHRM1,CHRM2,MAPK1,PIK3CA,PIK3CB,PIK3CD,and PIK3CG)and the AD signaling pathway(critical targets include APP,BACE1,GSK3B,MAPK1,NCSTN,NOS1,PSEN1).These critical targets are closely related to the regulation of three typical pathological features of AD[central nervous system(CNS)cholinergic hypofunction,amyloid-β(Aβ)plaques,and hyperphosphorylated tau proteins].Finally,14 critical targets in the 2 key significant pathways were validated by molecular docking analysis.Conclusion:F.assafoetida may be effective for alleviating AD symptoms,through multi-component,multi-target,and multi-pathway synergistic effects,associated with the multiple pathogen
文摘The technology actuality and development trend of variable thrust rocket engines at home and abroad are summarized. Key technologies of developing variable thrust rocket engines are analyzed. Development advices on developing variable thrust rocket engines that are adapted to the situation of our country are brought forward.
