检索结果-南通市图书馆

Weight Analysis of Impact Factors of Interbedded Anti-Inclined Slopes Block-Flexure Toppling Based on Support Vector Regression

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Earth Science 2024年第2期35卷 568-582页

作者： Bocheng zhang huiming Tang Yibing Ning Kun Fang Ding Xia Department of Engineering Geology and Geotechnical Engineering Faculty of EngineeringChina University of GeosciencesWuhan430074China Badong National Observation and Research Station of Geohazards China University of GeosciencesWuhan430074China College of Geological Engineering and Geomatics Chang’an UniversityXi’an710054China

Block-flexure toppling failure is frequently encountered in interbedded anti-inclined rock(IAR)slopes,and seriously threatens the construction of hydropower infrastructure.In this study,we first investigated the Lean Reservoir area’s geological setting and the Linda landslide’s characteristics.Then,uniform design and random design were used to design 110 training datasets and 31 testing datasets,respectively.Afterwards,the toppling response was obtained by using the discrete element code.Finally,support vector regression was used to obtain the influence weights of 21 impact factors.The results show that the influence weight of the slope angle and rock formation dip angle on the toppling deformation among tertiary impact factors is 25.96%and 17.28%,respectively,which are much greater than the other 19 impact factors within the research range.For the primary impact factors,the influence weight is sorted from large to small as slope geometry parameters,joints parameters,and rock mechanics parameters.Joints parameters,especially the geometric parameters,cannot be ignored when evaluating the stability of IAR slopes.Through numerical simulation,it was qualitatively determined that failure surfaces of slopes were controlled by cross joints and that the rocks in the slope toe play a role in preventing slope deformation.

关键词： interbedded anti-inclined slopes block-flexure toppling impact factors numerical simulation support vector regression engineering geology

β-Carboline alkaloids from the roots of Peganum harmala L.

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Natural Medicines 2024年第2期22卷 171-177页

作者： LI Shengge zhang Qin WANG Yuetong LIN Bin LI Dahong HUA huiming HU Xu Henan Key Laboratory of zhang Zhongjing Formulate and Herbs for Immunoregulation Zhang Zhongjing Traditional School of Chinese MedicineNanyang Institute of TechnologyNanyang 473004China Key Laboratory of Structure-Based Drug Design&Discovery Ministry of EducationShenyang Pharmaceutical UniversityShenyang 110016China Wuya College of Innovation Shenyang Pharmaceutical UniversityShenyang 110016China School of Pharmaceutical Engineering Shenyang Pharmaceutical UniversityShenyang 110016China

This study reports the isolation of four newβ-carboline alkaloids(1−4)and six previously identified alkaloids(5−10)from the roots of Peganum harmala L.Among these compounds,1 and 2 were characterized as rareβ-carboline-quinazoline dimers exhibiting axial chirality.Compound 3 possessed a unique 6/5/6/7 tetracyclic ring system with an azepine ring,and compound 4 was a novel annomontineβ-carboline.The structures of these compounds were elucidated by spectroscopic data and quantum mechanical calculations.The biosynthetic pathways of 1−3 were proposed.Additionally,the cytotoxicity of some isolates against four cancer cell lines(HL-60,A549,MDA-MB-231,and DU145)was evaluated.Notably,compound 4 exhibited significant cytotoxicity against HL-60,A549,and DU145 cells with IC_(50) values of 12.39,12.80,and 30.65μmol·L^(−1),respectively.Furthermore,compound 2 demonstrated selective cytotoxicity against HL-60 cells with an IC_(50) value of 17.32μmol·L^(−1).

关键词： β-Carboline alkaloids Peganum harmala Structure elucidation Cytotoxic activity

Insight into the Permeability and Microstructure Evolution Mechanism of the Sliding Zone Soil: A Case Study from the Huangtupo Landslide, Three Gorges Reservoir, China

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Earth Science 2024年第3期35卷 941-954页

作者： Qianyun Wang huiming Tang Pengju An Kun Fang Junrong zhang Minghao Miao Qingwen Tan Lei Huang Shengming Hu Badong National Observation and Research Station of Geohazards China University of GeosciencesWuhan 430074China Faculty of Engineering China University of GeosciencesWuhan 430074China Institute of Rock Mechanics Ningbo UniversityNingbo 315211China National and Provincial Joint Engineering Laboratory for the Hydraulic Engineering Safety and Efficient Utilization of Water Resources of Poyang Lake Basin Nanchang Institute of TechnologyNanchang 330099China

A large number of laboratory investigations related to the permeability have been conducted on the sliding zones.Yet little attention has been paid to the particular sliding zones of the slideprone Badong Formation.Here,we experimentally investigate the permeability nature and the mechanism of seepage in the viscous sliding zone of the Huangtupo Landslide.Saturated seepage tests have been performed first with consideration of six dry densities and thirteen hydraulic gradients,in conjunction with the mercury intrusion porosimetry test and scanning electron microscopy test for the microstructure analysis after seepage.The results show that seepage in the sliding zone soil does not follow Darcy’s Law,since there is a threshold hydraulic gradient(i0)below which no flow is observed and a critical hydraulic gradient(icr)over which the hydraulic conductivity(K)tends to be stable.The percentage of bound water could be responsible for the occurrence of i0 and icr.Furthermore,pore size distributions(PSD)less than 0.6µm and between 10 and 90µm exhibit positive and negative correlations with the i0,respectively,indicating that the i0 is related to the PSD.The mechanism accounting for this result is that pore water pressure forces fine clay particles into the surrounding large pores and converts arranged particles to discretely distributed ones,thereby weakening the connectivity of pores.The seepages in the sliding zones behave differently from that in the sliding mass and sliding bed in response to the permeability.

关键词： reservoir landslides sliding zone soil permeability microstructure seepage.

Dual-band dynamic reconfigurable intelligent surface for signal enhancement in millimeter wave

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2024年第4期67卷 1133-1138页

作者： YAO huiming DU XinRun WANG HengBin GAO Song PANG YaChen ZHENG HaiRong GONG HuiWen LI Yi XU JianChun zhang JianHua BI Ke State Key Laboratory of Information Photonics and Optical Communications School of ScienceBeijing University of Posts and TelecommunicationsBeijing 100876China Beijing Key Laboratory of Intelligent Telecommunications Software and Multimedia Beijing University of Posts and TelecommunicationsBeijing 100876China State Key Laboratory of Networking and Switching Technology Beijing University of Posts and TelecommunicationsBeijing 100876China

Millimeter wave with large bandwidth,high transmission rate,and low delay is considered a reliable alternative to cope with the spectrum shortage.However,the fast attenuation and narrow beam characteristics make it difficult to achieve long-distance or wide-range applications.Here,a 1-bit dual-band reflective reconfigurable intelligent surface(RIS)for signal enhancement in millimeter wave with 16×16 elements is designed,fabricated,and measured.Different from most existent RIS,dynamic programming is realized at two separate frequency bands by integrating the PIN diodes and field-programmable gate array(FPGA).Particularly,the beam deflection,dual-beam,and multi-beam are created based on the coding theory and convolution operation,proving the effectiveness of wavefront manipulation.Moreover,the far-field patterns and signal power with different coding sequences are measured and compared.It is indicated that the received signal power is 6–7 dB stronger than that without coding,which shows good agreement with the desired expectations.The proposed reconfigurable metasurface exhibits great potential in beam forming,making it a promising candidate for progressive wireless communication applications.

关键词： dual-band millimeter wave reconfigurable intelligent surface signal enhancement

Impact of the Yellow River capture on the paleoenvironmental changes of Hongze Lake, China

在线全文

学校读者我要写书评

暂无评论

International Journal of Sediment Research 2023年第4期38卷 503-515页

作者： Hongwu Tang Ming Gao Saiyu Yuan huiming zhang Yang Xiao Fuxin zhang Kun zhang State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering Hohai University Key Laboratory of Hydrologic-Cycle and Hydrodynamic-System of Ministry of Water Resources Hohai University Institute of Water Science and Technology Hohai University

The Yellow River(YR) capture of the Huai River had a profound effect on the landscape evolution,ecology, and social development in China, disrupting the evolution of some vital shallow floodplain lakes.Because of the absence of lacustrine sediment provenance analysis, previous studies were inadequate in distinguishing the influence of YR capture on paleoenvironmental changes in these lakes, especially on landscape evolution, redox conditions, lake level changes, and organic productivity. The current study aims to use X-ray fluorescence-core scanning(XRF-CS) and multivariate statistics on a 9.8 m sediment core from Hongze Lake(HZL), China, to analyze the impact of the YR capture on the lake’s paleoenvironmental changes and the sediment provenance simultaneously. High-resolution images, magnetic susceptibility, and XRF-based multi-element data were obtained using a GEOTEK Multi-Sensor Core Logger. The calcium(Ca) content indicates the presence of YR sediment in HZL, given the high Ca content in YR sediment and the identification of mainly exogenous sources of Ca in HZL. The high values of Ca indicate that 48.7% of the sediment in the center of HZL is related to the YR’s incursion. Periods of higher Ca content coincide with periods of higher oxygenation levels of the lake(as indicated by the ratio of manganese to titanium) and lower organic content in the lake sediment(as indicated by the ratio of incoherent to coherent scatter). These analyses reveal that the YR’s capture of HZL significantly increased the lake’s oxygen level. Furthermore, the decrease in the organic content of sediment tends to be the result of the accelerated deposition caused by the YR. The decrease in Ca content coincides with an increase in lake levels(as indicated by magnetic susceptibility). Thus, it can be inferred that the embankment on the eastern side of HZL, built to increase lake storage, has reduced the incursion frequency of the YR.

关键词： Yellow River capture Paleoenvironmental reconstruction XRF-CS Hongze Lake

Microbial enhancement of plant nutrient acquisition

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Stress Biology 2022年第1期2卷 661-674页

作者： Sunil K.Singh Xiaoxuan Wu Chuyang Shao huiming zhang Shanghai Center for Plant Stress Biology Center for Excellence in Molecular Plant SciencesChinese Academy of SciencesShanghai 201602China University of Chinese Academy of Sciences Beijing 100049China

Nutrient availability is a determining factor for crop yield and quality.While fertilization is a major approach for improving plant nutrition,its efficacy can be limited and the production and application of fertilizers frequently bring problems to the environment.A large number of soil microbes are capable of enhancing plant nutrient acquisition and thereby offer environmentally benign solutions to meet the requirements of plant nutrition.Herein we provide summations of how beneficial microbes enhance plant acquisition of macronutrients and micronutrients.We also review recent studies on nutrition-dependent plant-microbe interactions,which highlight the plant’s initiative in establishing or deterring the plant-microbe association.By dissecting complex signaling interactions between microbes within the root microbiome,a greater understanding of microbe-enhanced plant nutrition under specific biotic and abiotic stresses will be possible.

关键词： Beneficial microbes Plant Macronutrient Micronutrient Plant-microbe interactions Volatile organic compounds Microbiome

Model-Assisted Estimators with Auxiliary Functional Data

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Communications in Mathematical Research 2022年第1期38卷 81-98页

作者： Chao Liu huiming zhang Jing Yan Department of Statistics and Data Science Southern University of Science and TechnologyShenzhen 518055China Pepartment of Mathematics Faculty of Science and TechmnologyUniversity of MacaoTaipa MacaoChina UMacao Zhuhai Research Institute ZhuhaiChina School of Mathematics and Statistics Beijing Institute of TechnologyBeijingChina

Few studies focus on the application of functional data to the field of design-based survey sampling.In this paper,the scalar-onunction regression model-assisted method is proposed to estimate the finite population means with auxiliary functional data information.The functional principal component method is used for the estimation of functional linear regression model.Our proposed functional linear regression model-assisted(FLR-assisted)estimator is asymptotically design-unbiased,consistent under mild conditions.Simulation experiments and real data analysis show that the FLR-assisted estimators are more efficient than the Horvitz-Thompson estimators under different sampling designs.

关键词： Survey sampling semi-supervised inference model-assisted estimator Horvitz-Thompson estimator functional linear regression

Long-term in-situ monitoring of anchoring system and preliminary analysis of monitoring data

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Earth Science 2024年

作者： Luobin Zheng huiming Tang Liangqing Wang Changdong Li Chengren Xiong Zongxing Zou Chenlu Wang Lingfeng Zhu Yifan zhang Faculty of Engineering China University of Geosciences Badong National Observation and Research Station of Geohazards China University of Geosciences

The geological environment in which the reservoir slope is situated is intricate， influenced by factors such as precipitation and fluctuations in reservoir water levels. Furthermore， the anchoring structure embedded within the rock mass of the slope undergoes corrosion and deterioration due to these factors， resulting in a highly complex interaction process between the slope rock mass and the anchoring structure. The long-term safety of rock-anchored structure systems is closely tied to the construction and safe operation of reservoirs， as both internal and external factors play a role in ensuring their stability. The present study aims to investigate this intricate issue by designing and establishing an on-site comprehensive multi-field information monitoring platform. The multi-site information monitoring platform comprises three components， namely the landslide monitoring system， anchor structure monitoring system， and data management system. The landslide monitoring system encompasses the surveillance of surface deformation， subsurface deformation， and environmental factors. The monitoring system for anchor structures includes the monitoring of prestress， anchor cable strain， and corrosion status of steel bars. The establishment of a preliminary system for data transmission and management has been accomplished. The current monitoring results indicate that the health condition of the tested anchor cables is satisfactory， and the strain and corrosion status are influenced by the design of the anchor cable structure. The platform is currently undergoing enhancements with the incorporation of cutting-edge anchoring structure design and monitoring equipment.

关键词：

Bacterial diacetyl suppresses abiotic stress-induced senescence in Arabidopsis

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Integrative Plant Biology 2022年第6期64卷 1135-1139页

作者： Sunil K.Singh Yazhou Sun Yu Yang Ziwei Zuo Xiaoxuan Wu Chuyang Shao Li Peng Paul W.Paré huiming zhang Shanghai Center for Plant Stress Biology Center for Excellence in Molecular Plant Sciencesthe Chinese Academy of SciencesShanghai 201602China University of Chinese Academy of Sciences Beijing 100049China Department of Chemistry and Biochemistry Texas Tech UniversityLubbock 79409TexasUSA

Premature plant senescence induced by abiotic stresses is a major cause of agricultural losses worldwide. Tools for suppressing stress-induced plant senescence are limited. Here, we report that diacetyl, a natural compound emitted by the plantbeneficial bacterium Bacillus amyloliquefaciens,suppresses abscisic acid-mediated foliar senescence in Arabidopsis thaliana under various abiotic stress conditions. Our results establish diacetyl as an effective protector against stressinduced plant senescence and reveal a molecular mechanism for bacteria-enhanced plant stress resistance.

关键词： ABA diacetyl microbial volatile leaf senescence