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高混凝土面板堆石坝接缝止水试验研究和应用

岩土工程学报 2025年第1期47卷 30-37页

作者：郦能惠王立安任强张志韬张贤王新奇代巧枝南京水利科学研究院岩土工程研究所江苏南京210024 黄河勘测规划设计研究院有限公司河南郑州450031

混凝土面板堆石坝是当前最有竞争力的坝型,为保障高混凝土面板堆石坝的安全,坝体和面板的应力变形性状以及接缝位移成为研究的重点之一,通过止水材料开发、接缝止水结构设计和止水结构防渗模型试验研究提出了高混凝土面板堆石坝新型止... 详细信息

混凝土面板堆石坝是当前最有竞争力的坝型,为保障高混凝土面板堆石坝的安全,坝体和面板的应力变形性状以及接缝位移成为研究的重点之一,通过止水材料开发、接缝止水结构设计和止水结构防渗模型试验研究提出了高混凝土面板堆石坝新型止水结构,并应用于高混凝土面板堆石坝工程。在此基础上进行了高坝新型接缝止水结构力学特性试验研究,形成了试验方法,建立了高坝新型止水结构的劲度表达式,通过在某高坝工程的应用表明提出的接缝止水应力应变关系全面反映高坝新型止水结构各主要部件对于面板与趾板以及面板之间力的传递的贡献,更好地反映复杂地形地质条件下高坝设计布置的影响,具有一定的工程应用价值。

关键词：混凝土面板堆石坝接缝止水应力变形性状劲度表达式

A method for classifying orbits near asteroids

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Acta Mechanica Sinica 2014年第3期30卷 316-325页

作者： xian.yu Wang Sheng-Ping Gong Jun-Feng li Department of Aerospace Engineering Tsinghua University

A method for classifying orbits near asteroids under a polyhedral gravitational field is presented, and may serve as a valuable reference for spacecraft orbit design for asteroid exploration. The orbital dynamics near aster- oids are very complex. According to the variation in orbit characteristics after being affected by gravitational perturbation during the periapsis passage, orbits near an as- teroid can be classified into 9 categories：（1） surrounding- to-surrounding, （2） surrounding-to-surface, （3） surrounding- to-infinity, （4） infinity-to-infinity, （5） infinity-to-surface, （6） infinity-to-surrounding, （7） surface-to-surface, （8） surface- to-surrounding, and （9） surface-to- infinity. Assume that the orbital elements are constant near the periapsis, the gravitation potential is expanded into a harmonic series. Then, the influence of the gravitational perturbation on the orbit is studied analytically. The styles of orbits are dependent on the argument of periapsis, the periapsis radius, and the periapsis velocity. Given the argument of periapsis, the orbital energy before and after perturbation can be derived according to the periapsis radius and the periapsis velocity. Simulations have been performed for orbits in the gravitational field of 216 Kleopatra. The numerical results are well consistent with analytic predictions.

关键词： Asteroid. Orbital classification 216 Kleopatra-Orbit prediction Polyhedral gravitational field

Unveiling phosphofructokinase as the key target: an innovative strategy combining pull-down assays with optical imaging for snail-killing mechanism exploration

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Science China Chemistry 2025年

作者： yuxun Lu Weisi Wang Le yu yuqiang Zhao Ying Chen yunhai Guo Bingrong Luo yuhua liu Shizhu li liping Duan Ying Zhou yunnan Characteristic Plant Extraction Laboratory College of Chemical Science and Technology Yunnan University College of Biological and Chemical Engineering Guangxi University of Science and Technology National Institute of Parasitic Diseases Chinese Center for Disease Control and Prevention (Chinese Center for Tropical Diseases Research)NHC Key Laboratory of Parasite and Vector Biology WHO Collaborating Centre for Tropical Diseases National Center for International Research on Tropical Diseases School of Chemistry and Environment Yunnan Minzu University Dali Institute of Schistosomiasis Control

The Pomacea canaliculata, also known as apple snail, is an invasive species in China, posing a serious threat to agricultural production and public health. To prevent its rampant infestation, we developed a highly efficient snail-killing lead compound, 1-(4-chlorophenyl)-3-(pyridin-3-yl)urea (PBQ). However, the killing mechanism of PBQ remains unclear. To elucidate this, two novel compounds, B-PBQ and J-PBQ, were developed through structural modification of PBQ and were used, through both protein pull-down assay and confocal laser scanning microscopy imaging, to identify and confirm that phosphofructokinase(PFK) in the apple snail is the primary target protein of PBQ. Further studies revealed that PBQ successfully inhibits the activity,content, and expression of PFK in apple snail, disrupting the glycolysis pathway and leading to abnormal energy *** disruptions impair the snail’s tolerance to low oxygen, resulting in its efficient eradication. These findings offer a promising direction for developing next-generation PFK-targeted snail-killing pesticides. Furthermore, the strategy of combining pull-down assays with optical imaging used in this work provides a novel approach for the exploration of mechanisms of other pesticide candidates.

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Understanding micro-diffusion bonding from the fabrication of B_4C/Ni composites

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International Journal of Minerals,Metallurgy and Materials 2018年第3期25卷 365-374页

作者： Miao Wang Wen-xian Wang Hong-sheng Chen yu-li li College of Materials Science and Engineering Taiyuan University of Technology Key Laboratory of Interface Science and Engineering in Advanced Materials Ministry of Education Taiyuan University of Technology

A Ni-B_4C macroscopic diffusion welding couple and a Ni-15 wt% B_4C composite fabricated by spark plasma sintering(SPS) were used to understand the micro-scale diffusion bonding between metals and ceramics. In the Ni-B_4C macroscopic diffusion welding couple a perfect diffusion welding joint was achieved. In the Ni-15 wt% B_4C sample, microstructure analyses demonstrated that loose structures occurred around the B_4C particles. Energy dispersive X-ray spectroscopy analyses revealed that during the SPS process, the process of diffusion bonding between Ni and B_4C particles can be divided into three stages. By employing a nano-indentation test, the room-temperature fracture toughness of the Ni matrix was found to be higher than that of the interface. The micro-diffusion bonding between Ni and B_4C particles is quite different from the Ni-B_4C reaction couple.

关键词： B4C/Ni composites spark plasma sintering micro-diffusion welding microstructure nano-mechanical property

Palladium installed copper-organic framework for C–C coupling reactions

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Science China Chemistry 2025年

作者： yu-Mei Wang Mei-Xia Tao Kai-Ming Mo Xu Chen Shu-Hua Zhong Elena S Shubina Guo-Hong Ning Dan li College of Chemistry and Materials Science Guangdong Provincial Key Laboratory of Supramolecular Coordination ChemistryJinan University A.N.Nesmeyanov Institute of Organoelement Compounds Russian Academy of Sciences

The formation of C–C bonds is a crucial aspect of organic synthesis. Synthesists' long-term objective is to identify novel catalysts to optimize reaction systems based on traditional transition metal catalysis. This study explores the synthesis and catalytic potential of palladium-installed covalent metal-organic frameworks(CMOFs) based on copper cyclic trinuclear units(Cu-CTUs). By incorporating palladium ions into the imine-based framework JNM-7 through a straightforward immersion method, we achieved a notable enhancement in catalytic activity for critical C–C coupling reactions, including C–H arylation and Sonogashira cross-coupling. The resulting JNM-7-Pd demonstrated remarkable stability and recyclability, maintaining its efficiency over at least three cycles without any decline in efficiency.

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Hysteretic behavior of post-tensioned precast segmental CFT double-column piers

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Earthquake Engineering and Engineering Vibration 2023年第3期22卷 747-762页

作者： li xian Zhang Zilin Zhou Tao Xiao yu Sun yushun Jiangsu Key Laboratory of Environmental Impact and Structural Safety in Civil Engineering China University of Mining and TechnologyXuzhou 221116China Jiangsu Collaborative Innovation Center for Building Energy Saving and Construction Technology Xuzhou 221116China School of Transportation Southeast UniversityNanjing 211189China

Considering the desirable behavior of concrete filled steel tube(CFT)columns and the complicated behavior of segmental double-column piers under cyclic loads,three post-tensioned precast segmental CFT double-column pier specimens were tested to extend their application in moderate and high seismicity *** effects of the number of CFT segments and the steel endplates as energy dissipaters on the seismic behavior of the piers were *** experimental results show that the segmental piers exhibited stable hysteretic behavior with small residual displacements under cyclic *** the tested specimens achieved a drift ratio no less than 13%without significant damage and strength deterioration due to the desirable behavior of CFT *** the deformation of segmental columns was mainly concentrated at the column-footing interfaces,the increase of the segment numbers for each column had no obvious effects on the loading capacity but reduced the initial stiffness of the *** use of steel endplates improved the bearing capacity,stiffness and energy dissipation of segmental piers,but weakened their self-centering *** models were also proposed to simulate the hysteretic behavior of the tested specimens,and the influences of segment numbers and prestress levels on seismic behavior were further studied.

关键词： precast segmental piers cyclic loading test seismic behavior concrete filled tube column rockinganalysis

Effects of ultrasonic-assisted extraction on bioactive compounds,volatile flavors and antioxidant activities of vine tea water extracts

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Traditional Medicine Research 2025年第1期10卷 73-81页

作者： Xiao-Long Zhou Wei-Jin Jiang Ji yu Mao-Jun Yao yun-Tong li Hunan Provincial Key Laboratory of Research Resource Mining and High-valued Utilization on Edible&Medicinal PlantCollege of Chemistry and Chemical EngineeringJishou UniversityJishou 416000China Hunan Gaoge Dairy Co. Ltd.Changsha 410000China

Background:Ampelopsis grossedentata,vine tea,which is the tea alternative beverages in *** vine tea processing,a large amount of broken tea is produced,which has low commercial ***:This study investigates the influence of different extraction methods(room temperature water extraction,boiling water extraction,ultrasonic-assisted room temperature water extraction,and ultrasonic-assisted boiling water extraction,referred to as room temperature water extraction(RE),boiling water extraction(BE),ultrasonic assistance at room temperature water extraction(URE),and ultrasonic assistance in boiling water extraction(UBE))on the yield,dihydromyricetin(DMY)content,free amino acid composition,volatile aroma components,and antioxidant properties of vine tea ***:A notable influence of extraction temperature on the yield of vine tea extracts(P<0.05),with BE yielding the highest at 43.13±0.26%,higher than that of RE(34.29±0.81%).Ultrasound-assisted extraction significantly increased the DMY content of the extracts(P<0.05),whereas DMY content in the RE extracts was 59.94±1.70%,that of URE reached 66.14±2.78%.Analysis revealed 17 amino acids,with L-serine and aspartic acid being the most abundant in the extracts,nevertheless ultrasound-assisted extraction reduced total free amino acid *** chromatography-mass spectrometry analysis demonstrated an increase in the diversity and quantity of compounds in the vine tea water extracts obtained through ultrasonic-assisted ***,69 and 68 volatile compounds were found in URE and UBE extracts,which were higher than the number found in RE and BE *** vitro,antioxidant activity assessments revealed varying antioxidant capacities among different extraction methods,with RE exhibiting the highest DPPH scavenging rate,URE leading in ABTS•+free radical scavenging,and BE demonstrating superior ferric ion reducing antioxidant ***:The findings suggest that extraction methods signi

关键词： vine tea dihydromyricetin ultrasonic-assisted extraction volatile aroma components

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自激式电感耦合等离子体光源设计及光谱分析

光谱学与光谱分析 2025年第1期45卷 66-71页

作者：卢思贤龙开红詹陈锐李明北方工业大学电气与控制工程学院北京100144 益阳职业技术学院电子与信息工程学院湖南益阳413055

电感耦合等离子体(ICP)光谱仪是一种应用范围很广的元素分析仪,主要用于元素定性与定量的分析。ICP光源是光谱仪的核心部件,它在光谱仪中扮演着至关重要的角色。目前主流的ICP光源有两种:自激式和他激式,各自具有优缺点。他激式光源电... 详细信息

电感耦合等离子体(ICP)光谱仪是一种应用范围很广的元素分析仪,主要用于元素定性与定量的分析。ICP光源是光谱仪的核心部件,它在光谱仪中扮演着至关重要的角色。目前主流的ICP光源有两种:自激式和他激式,各自具有优缺点。他激式光源电路复杂、体积庞大、阻抗匹配速度较慢、最大输出功率有限。设计了一种基于镀金工艺的高功率MOSFET和变频实现阻抗匹配的自激式ICP光源,该光源采用射频放大和阻抗匹配一体化的设计,把从负载线圈采样的频率信号f_(1)以及功率放大电路放大后的频率相位f_(0)进行相位比较,再根据两者相位差的变化,进而控制频率的变化,实现阻抗匹配;设计上采用了镀金工艺的金属化硅N通道型高功率的MOSFET实现功率放大,具有更大的功率密度、更小的体积,最大输出功率超过2400 W。对研制的ICP光源进行了电学静态测试,给出了鉴相器、压控振荡器以及功率的输出特性,验证了各电路在相应工作状态下的性能表现;同时结合光谱仪进行了包含Ba、Na和li元素标准溶液的测试,获得了目标元素的光谱信号;另外,对获得的光谱信号进行了处理,使用了基于EEMD特征增强的方法对目标元素光谱信号进行有效增强,信号的线性决定系数(R^(2))从0.97降至0.99,相对标准偏差(RSD)从6.47%降至1.07%,增强了信号的准确性和可用性。本文所研制的自激式ICP光源,通过射频放大和阻抗匹配一体化设计缩小了体积,变频技术使阻抗匹配速度从毫秒级提升到纳秒级,镀金工艺的MOSFET技术使最大输出功率从原来的1800 W增加到2400 W,为ICP光源的进一步优化和应用奠定了基础,具有重要的科学研究和工程实践意义。

关键词：自激式ICP光源阻抗匹配光谱信号 EEMD算法

Droplet Bridging Effect in Polymer/Polymer/Filler Ternary Composites

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Chinese Journal of Polymer Science 2024年第12期42卷 1966-1975,I0010页

作者： Feng-Yi Hou li Peng Fei yu xian-Bo Huang Wei yu Advanced Rheology Institute Department of Polymer Science and EngineeringShanghai Jiao Tong UniversityShanghai200240China National Certified Enterprise Technology Center Kingfa Science and Technology Co.Ltd.Guangzhou510663China DPI P.O.Box 9025600 AXEindhovenThe Netherlands

In particle-filled polymer composites with selective distributions of fillers in one phase,much attention has been focused on the“volume exclusion effect”in reducing the percolation threshold of filler,while the role of dispersed polymer phase acting as bridges of fillers in the particle network has largely been ***,we studied industrially important ternary composites,polypropylene(PP)/ethylene-octene copolymer(a polyolefin elastomer,POE)/talc systems,and adopted rheology to reveal the bridging behavior of POE droplets in the network of talc *** is found that talc fillers concentrate in the PP phase using the“blend first”protocol,while more talc particles are located at the interface of PP and POE phases using the“filler first”*** the POE viscosity and talc size can affect the migration of talc from the POE phase to the PP phase in the“filler first”*** linear rheology behavior indicates that besides the“volume exclusion effect”,the talc-POE hybrid network can further contribute to the reinforcement ***,the POE droplet bridging structure can facilitate the rebuilding of the hybrid network after large amplitude oscillatory shear,in contrast to the un-recoverable structures in the PP/talc binary *** correlation between rheology and selective distribution of fillers in ternary composites may provide practical guidance for processing and designing advanced polymer composites with controlled selective location of fillers.

关键词： Polypropylene Filler selective localization Rheology Bridging