检索结果-南通市图书馆

Spatiotemporal Changes of Snow Depth in Western Jilin,China from 1987 to 2018

在线全文

学校读者我要写书评

暂无评论

Chinese Geographical Science 2024年第2期34卷 357-368页

作者： WEI Yanlin LI Xiaofeng GU Lingjia ZHENG Zhaojun ZHENG Xingming jiang tao Northeast Institute of Geography and Agroecology Chinese Academy of SciencesChangchun 130102China University of Chinese Academy of Sciences Beijing 100049China Changchun Jingyuetan Remote Sensing Experiment Site Chinese Academy of SciencesChangchun 130102China College of Electronic Science and Engineering Jilin UniversityChangchun 130012 National Meteorological Satellite Meteorological Center Beijing 100081China

Seasonal snow cover is a key global climate and hydrological system component drawing considerable attention due to glob-al warming conditions.However,the spatiotemporal snow cover patterns are challenging in western Jilin,China due to natural condi-tions and sparse observation.Hence,this study investigated the spatiotemporal patterns of snow cover using fine-resolution passive mi-crowave(PMW)snow depth(SD)data from 1987 to 2018,and revealed the potential influence of climate factors on SD variations.The results indicated that the interannual range of SD was between 2.90 cm and 9.60 cm during the snowy winter seasons and the annual mean SD showed a slightly increasing trend(P>0.05)at a rate of 0.009 cm/yr.In snowmelt periods,the snow cover contributed to an increase in volumetric soil water,and the change in SD was significantly affected by air temperature.The correlation between SD and air temperature was negative,while the correlation between SD and precipitation was positive during December and March.In March,the correlation coefficient exceeded 0.5 in Zhenlai,Da’an,Qianan,and Qianguo counties.However,the SD and precipitation were neg-atively correlated over western Jilin in October,and several subregions presented a negative correlation between SD and precipitation in November and April.

关键词： snow cover snow depth(SD) climate changes passive microwave(PMW) western Jilin,China

Analysis of Sea Surface Temperature Cooling in Typhoon Events Passing the Kuroshio Current

在线全文

学校读者我要写书评

暂无评论

Journal of Ocean University of China 2024年第2期23卷 287-303页

作者： HU Yuyi SHAO Weizeng SHEN Wei ZUO Juncheng jiang tao HU Song College of Marine Sciences Shanghai Ocean UniversityShanghai 201306China East China Sea Environment Monitoring Ministry of Natural ResourcesShanghai 201206China China Waterborne Transport Research Institute Ministry of TransportBeijing 100088China

The aim of this study is to investigate the sea surface temperature(SST) cooling as typhoons pass the Kuroshio Current.A numerical circulation model,denoted as the Stony Brook Parallel Ocean Model(sbPOM),was used to simulate the SST,which includes four wave-induced effect terms(i.e.,radiation stress,nonbreaking waves,Stokes drift,and breaking waves) simulated using the third-generation wave model,called WAVEWATCH-Ⅲ(WW3).The significant wave height(SWH) measurements from the Jason-2 altimeter were used to validate the WW3-simulated results,yielding a root mean square error(RMSE) of less than 0.50 m and a correlation coefficient(COR) of approximately 0.93.The water temperature measured from the Advanced Research and Global Observation Satellite was applied to validate the model simulation.Accordingly,the RMSE of the SST is 0.92℃ with a COR of approximately 0.99.As revealed in the sbPOM-simulated SST fields,a reduction in the SST at the Kuroshio Current region was observed as a typhoon passed,although the water temperature of the Kuroshio Current is relatively high.The variation of the SST is consistent with that of the current,whereas the maximum SST lagged behind the occurrence of the peak SWH.Moreover,the Stokes drift plays an important role in the SST cooling after analyzing four wave-induced terms in the background of the Kuroshio Current.The sensitivity experiment also showed that the accuracy of the water temperature was significantly reduced when including breaking waves,which play a negative role in the inside part of the ocean.The variation in the mean mixing layer depth(MLD) showed that a typhoon could enhance the mean MLD in the Kuroshio Current area in September and October,whereas a typhoon has little influence on the mean MLD in the Kuroshio Current area in May.Moreover,the mean MLD rapidly decreased with the weakening of the strong wind force and wave-induced effects when a typhoon crossed the Kuroshio Current.

关键词： typhoon wave sea surface temperature Kuroshio Current

Interfacial reaction between AZ91D magnesium alloy melt and mild steel under high temperature

在线全文

学校读者我要写书评

暂无评论

China Foundry 2024年第2期21卷 159-167页

作者： Jia-hong Dai Jian-yue Zhang Bin jiang Xiang-jun Xu Zhong-tao jiang Hong-mei Xie Qing-shan Yang Guo-qing Zhang College of Materials Science and Engineering Yangtze Normal UniversityChongqing 408100China National Engineering Research Center for Magnesium Alloys College of Materials Science and EngineeringChongqing UniversityChongqing 400044China Chongqing Jiulongyuan High-tech Industry Group Co. Ltd.Chongqing 400080China Loncin Industry Co. Ltd.Chongqing 400080China Department of Materials Science and Engineering The Ohio State UniversityColumbusOH 43210USA Chongqing Key Laboratory of Materials Surface&Interface Science Chongqing University of Arts and SciencesChongqing 402160China School of Metallurgy and Material Engineering Chongqing University of Science and TechnologyChongqing 401331China

The metallurgical quality control of magnesium(Mg)and Mg alloys in melting process is required to ensure a satisfied mechanical and corrosion performance,while the typical used steel crucible introduces impurities and interfacial interaction during melting process.Therefore,a systematic study about impurities diffusion and interfacial interaction between molten Mg and steel is necessary.In the present study,the interfacial reaction between molten AZ91D Mg alloy and mild steel during melting process was investigated with the melting temperatures of 700℃,750℃ and 800℃.The results show that Al(Fe,Mn)intermetallic layer is the intermetallic primarily formed at the interfaces of AZ91D melt and mild steel.Meanwhile,Al_(8)(Mn,Fe)5is indexed between Al(Fe,Mn)and AZ91D.AlFe_(3)C appears between the mild steel and Al(Fe,Mn)at 700℃ and 750℃,but absent at 800℃ due to the increased solubility of carbon in Mg matrix.It is found that the growth of the intermetallic layer is controlled by diffusion mechanism,and Al and Mn are the dominant diffusing species in the whole interfacial reaction process.By measuring the thickness of different layers,the growth constant was calculated.It increases from 1.89(±0.03)×10^(-12)m^(2)·s^(-1)at 700℃ to 3.05(±0.05)×10^(-12)m^(2)·s^(-1)at 750℃,and 5.18(±0.05)×10^(-12)m^(2)·s^(-1)at 800℃.Meanwhile,the content of Fe is linearly increased in AZ91D with the increase of holding time at 700℃ and 750℃,while it shows a significantly increment after holding for 8 h at 800℃,indicating holding temperature is more crucial to determine the Fe content of AZ91D than holding time.

关键词： AZ91D mild steel interface reaction intermetallic growth kinetics

Whole-brain Optical Imaging:A Powerful Tool for Precise Brain Mapping at the Mesoscopic Level

在线全文

学校读者我要写书评

暂无评论

Neuroscience Bulletin 2023年第12期39卷 1840-1858页

作者： tao jiang Hui Gong Jing Yuan Huazhong University of Science and Technology-Suzhou Institute for Brainsmatics Jiangsu Industrial Technology Research InstituteSuzhou215123China Wuhan National Laboratory for Optoelectronics Huazhong University of Science and TechnologyWuhan430074China

The mammalian brain is a highly complex network that consists of millions to billions of densely-interconnected neurons.Precise dissection of neural circuits at the mesoscopic level can provide important structural information for understanding the brain.Optical approaches can achieve submicron lateral resolution and achieve“optical sectioning”by a variety of means,which has the natural advantage of allowing the observation of neural circuits at the mesoscopic level.Automated whole-brain optical imaging methods based on tissue clearing or histological sectioning surpass the limitation of optical imaging depth in biological tissues and can provide delicate structural information in a large volume of tissues.Combined with various fluorescent labeling techniques,whole-brain optical imaging methods have shown great potential in the brain-wide quantitative profiling of cells,circuits,and blood vessels.In this review,we summarize the principles and implementations of various whole-brain optical imaging methods and provide some concepts regarding their future development.

关键词： Whole-brain optical imaging Optical sectioning Micrometer resolution Brain connectome Neural circuits Neuron

Relationship of depression and sleep quality,diseases and general characteristics

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

World Journal of Psychiatry 2022年第5期12卷 722-738页

作者： Yan jiang tao jiang Li-tao Xu Lan Ding Yuetan Community Health Service Center Fuxing Hospital Capital Medical UniversityBeijing 100045China Department of Medicine Innovation Research Chinese PLA General HospitalBeijing 100853China

BACKGROUND Depression is the most common type of depressive disorder.The most common sleep disorder associated with depression is insomnia.Insomnia and depression are closely related.AIM To investigate the relationship of designed questionnaire items and depression,and analyze the related factors with depression.METHODS Questionnaire included Patient Health Questionnaire-9(PHQ-9)and Pittsburgh sleep quality index(PSQI),12 kinds of diseases,8 general characteristics,and 20 insomnia characteristics,totally 56 items were filled out by 411 patients enrolled.RESULTS All the 9 items of PHQ-9,6 components of PSQI(except sleep duration),education,living situation,exercise,years of insomnia,western medicine treatment,Chinese medicine treatment,psychotherapy,kinds of insomnia,treatment expected to treat insomnia,psychological counseling,habit of 1 h before bed,habit of lunch break,diagnosed depression,coronary heart disease,mental illness showed significant difference between without and with depression group.By univariate analysis and multivariate analysis.The odds ratio of education,exercise,kinds of insomnia,habit of 1 h before bed,diagnosed depression,coronary heart disease(P=0.01)showed significant difference.Their odds ratios were 0.71(0.55,0.93),2.09(1.32,3.31),0.76(0.63,0.91),0.89(0.81,0.98),0.32(0.17,0.60),0.43(0.23,0.79).CONCLUSION We demonstrated that education,exercise,kinds of insomnia,habit of 1 h before bed,diagnosed depression and coronary heart disease affect the depression.

关键词： Depression Patient Health Questionnaire-9 Pittsburgh sleep quality index Sleep Insomnia

Formation mechanism of fault accommodation zones under combined stress in graben basin:Implications from geomechanical modeling

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

Petroleum Science 2024年第1期21卷 54-76页

作者： Qi-Qiang Ren Jin-Liang Gao Rong-tao jiang Jin Wang Meng-Ping Li Jian-Wei Feng Institute of Sedimentary Geology Chengdu University of TechnologyChengdu 610059SichuanChina PetroChina Research Institute of Petroleum Exploration and Development Beijing100083China jianghan Oilfield Oil and Gas Production Capacity Construction Management Center Chongqing408000China Sinopec Chongqing Fuling Shale Gas Exploration and Development Company Chongqing408000China College of Energy Chengdu University of TechnologyChengdu 610059SichuanChina School of Geoscience China University of Petroleum(East China)Qingdao 266580ShandongChina

A fault accommodation zone is a type of structure that is defined as regulating displacement and strain between faults structure.Increasing numbers of fault accommodation zones are being identified in graben basins,indicating the potential exploration target and petroleum accumulation areas.This study aims to analyze the formation mechanism and development of fault accommodation zones under combined stress by a numerical simulation method considering geomechanical modeling.Using three-dimensional(3-D)seismic interpretation and fractal dimension method,exampled with the Dongxin fault zone,the fault activity and fault combination pattern were conducted to quantitatively characterize the activity difference in fault accommodation zones.Combined with mechanical experiment test,a geomehcanical model was established for fault accommodation zones in a graben basin.Integrating the paleostress numerical simulations and structural physical simulation experiment,the developmental characteristics and genetic mechanism of fault accommodation zones were summarized.Influenced by multi movements and combined stresses,three significant tectonic evolution stages of the Dongxing Fault Zone(DXFZ)were distinguished:During the E_(s)^(3)sedimentary period,the large difference in the stress,strain,and rupture distribution in various faults were significant,and this stage was the key generation period for the prototype of the DXFZ,including the FAZ between large-scale faults.During the E_(s)^(2)sedimentary period,the EW-trending symmetric with opposite dipping normal faults and the NE-SW trending faults with large scale were furtherly developed.The junction area of two secondary normal faults were prone to be ruptured,performing significant period for inheriting and developing characteristics of fault accommodation zones.During the Es1 sedimentary period,the high-order faults in the DXFZ exhibited the obvious fault depressions and strike-slip activity,and the fault accommodation zones were furtherly inherited and developed.This stage was

关键词： Fault accommodation zone Graben basin Fault activity Tectonic physical simulation experiment Finite element numerical simulation Dongxin fault zone

The emerging technology of biohybrid micro-robots:a review

在线全文

学校读者我要写书评

暂无评论

Bio-Design and Manufacturing 2022年第1期5卷 107-132页

作者： Zening Lin tao jiang Jianzhong Shang Department of Intelligent Machinery and Instrument College of Intelligence Science and TechnologyNational University of Defense TechnologyChangsha 410073China

In the past few decades,robotics research has witnessed an increasingly high interest in miniaturized,intelligent,and integrated robots.The imperative component of a robot is the actuator that determines its performance.Although traditional rigid drives such as motors and gas engines have shown great prevalence in most macroscale circumstances,the reduction of these drives to the millimeter or even lower scale results in a significant increase in manufacturing difficulty accompanied by a remarkable performance decline.Biohybrid robots driven by living cells can be a potential solution to overcome these drawbacks by benefiting from the intrinsic microscale self-assembly of living tissues and high energy efficiency,which,among other unprecedented properties,also feature flexibility,self-repair,and even multiple degrees of freedom.This paper systematically reviews the development of biohybrid robots.First,the development of biological flexible drivers is introduced while emphasizing on their advantages over traditional drivers.Second,up-to-date works regarding biohybrid robots are reviewed in detail from three aspects:biological driving sources,actuator materials,and structures with associated control methodologies.Finally,the potential future applications and major challenges of biohybrid robots are explored.

关键词： Biohybrid robots Living cells Actuator materials Structure Control methodologies

Improved Multi-Bandwidth Mode Manifold for Enhanced Bearing Fault Diagnosis

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical Engineering 2022年第1期35卷 179-191页

作者： Guifu Du tao jiang Jun Wang Xingxing jiang Zhongkui Zhu School of Rail Transportation Soochow UniversitySuzhou 215131China

Variational mode decomposition(VMD) has been proved to be useful for extraction of fault-induced transients of rolling bearings. Multi-bandwidth mode manifold(Triple M, TM) is one variation of the VMD, which units multiple fault-related modes with different bandwidths by a nonlinear manifold learning algorithm named local tangent space alignment(LTSA). The merit of the TM method is that the bearing fault-induced transients extracted contain low level of in-band noise without optimization of the VMD parameters. However, the determination of the neighborhood size of the LTSA is time-consuming, and the extracted fault-induced transients may have the problem of asymmetry in the up-and-down direction. This paper aims to improve the efficiency and waveform symmetry of the TM method.Specifically, the multi-bandwidth modes consisting of the fault-related modes with different bandwidths are first obtained by repeating the recycling VMD(RVMD) method with different bandwidth balance parameters. Then, the LTSA algorithm is performed on the multi-bandwidth modes to extract their inherent manifold structure, in which the natural nearest neighbor(Triple N, TN) algorithm is adopted to efficiently and reasonably select the neighbors of each data point in the multi-bandwidth modes. Finally, a weight-based feature compensation strategy is designed to synthesize the low-dimensional manifold features to alleviate the asymmetry problem, resulting in a symmetric TM feature that can represent the real fault transient components. The major contribution of the improved TM method for bearing fault diagnosis is that the pure fault-induced transients are extracted efficiently and are symmetrical as the real. One simulation analysis and two experimental applications in bearing fault diagnosis validate the enhanced performance of the improved TM method over the traditional methods. This research proposes a bearing fault diagnosis method which has the advantages of high efficiency, good waveform symmetry and enhanced in-band noise removal capab

关键词： Variational mode decomposition Manifold learning Natural nearest neighbor algorithm Rolling bearing Fault diagnosis Time-frequency signal decomposition

High Speed Sintering:Assessing the Influence of Energy Input on Microstructure and Mechanical Properties of Polyether Block Amide(PEBA)Parts

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2024年第5期42卷 675-682,I0004,I0010页

作者： jiang-tao Sun Zhi-Yong Fan Yi-Wei Mao Wei Li Wei Zhu Dao-Sheng Cai Qing-Song Wei State Key Laboratory of Materials Processing and Die&Mould Technology Huazhong University of Science and TechnologyWuhan430074China State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan430074China National Engineering Research Centre for High Efficiency Grinding Hunan UniversityChangsha410082China Wuhan EasyMFG Technology CO. LTDWuhan430074China

High speed sintering,a new powder-bed fusion additive manufacturing technology,utilizes infrared lights(IR)to intensely heat and melt polymer powders.The presence of defects such as porosity,which is associated with particle coalescence,is highly dependdent on the level of energy input.This study investigate the influcence of energy input on porosity and its subsequent effects on the mechanical properties and microstructures of PEBA parts.The parts were manufactured with a variety of lamp powers,resulting in a range of energy input levels spanning from low to high.Subsequebtly,they underwent testing using Archimedes’method,followed by tensile testing.The porosity,mechanical characteristics,and energy input exhibit a strong correlation;inadequate energy input was the primary cause of pore formation.Using the reduced IR light power resulted in the following outcomes:porosity,ultimate tensile strength,and elongation of 1.37%,7.6 MPa,and 194.2%,respectively.When the energy input was further increased,the porosity was reduced to as low as 0.05%and the ultimate tensile strength and elongation were increased to their peak values of 233.8%and 9.1 MPa,respectively.

关键词： High speed sintering Additive manufacturing Energy input Powder bed fusion PEBA