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AgPd双金属纳米空心球的合成及其催化性能

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无机化学学报 2024年第5期40卷 963-971页

作者：张桂敏马文娟丁文强傅正义武汉理工大学化学化工与生命科学学院武汉430070 武汉理工大学材料复合新技术国家重点实验室武汉430070

以Ag纳米颗粒为牺牲模板,H_(2)PdCl_(4)为前驱体,抗坏血酸为还原剂,聚乙烯吡咯烷酮为表面活性剂,在70℃下采用电偶置换法结合还原法制备出AgPd双金属纳米空心球。采用紫外可见光谱、粉末X射线衍射、透射电镜结合能量色散等手段对由不同... 详细信息

以Ag纳米颗粒为牺牲模板,H_(2)PdCl_(4)为前驱体,抗坏血酸为还原剂,聚乙烯吡咯烷酮为表面活性剂,在70℃下采用电偶置换法结合还原法制备出AgPd双金属纳米空心球。采用紫外可见光谱、粉末X射线衍射、透射电镜结合能量色散等手段对由不同体积的0.01 mol·L^(-1)H_(2)PdCl_(4)溶液制备的产物进行结构表征。结果表明,随着H_(2)PdCl_(4)溶液体积的增加,产物的空心化程度逐渐升高,晶粒的尺寸逐渐增大。当H_(2)PdCl_(4)溶液体积为120μL时,合成的AgPd双金属纳米空心球组成和结构较为均匀,其粒径约为25 nm,壳层厚度2~3 nm。双金属中,由于Ag和Pd电负性的差异,电子从Ag转移到了Pd,使Pd表面出现电子富集区,显著提高了其催化效率。将所合成的AgPd双金属以及纯金属Ag和Pd作为催化剂,分别用于硼氢化钠催化还原4-硝基苯酚的反应,发现AgPd双金属的催化性能远高于纯金属Ag和Pd,其中AgPd-120纳米空心球(H_(2)PdCl_(4)溶液体积120μL)作催化剂时的反应速率常数最高,是同等尺寸纯Ag纳米球的24.0倍,纯Pd纳米立方体的14.7倍。

关键词： AgPd双金属纳米空心球电偶置换 4-硝基苯酚催化还原

Selenium and human nervous system

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Chinese Chemical Letters 2023年第7期34卷 11-16页

作者： wenqiang ding Shuang Wang Jiaxiang Gu Lei Yu Institute of Translational Medicine Medical CollegeYangzhou UniversityYangzhou 225001China Department of Hand and Foot Clinical Medical CollegeYangzhou UniversityYangzhou 225001China School of Chemistry and Chemical Engineering Yangzhou UniversityYangzhou 225002China

Selenium plays various biological functions in the form of selenoprotein in human body. Brain is one of the most abundant organs of selenoprotein, which plays an important role in maintaining brain redox homeostasis, signal transduction pathway regulation and neuroimmune regulation. Yet, nano-selenium have attracted much attention for their high bioavailability and low toxicity. Nano-selenium are of great application potential in field of biomedical nervous system. Recently, investigation on selenoprotein and nano-selenium has gradually become a new hotspot for the important functions of selenium in human nervous system. In this article, we wish to review recent progresses and give a perspective.

关键词： Selenium Nervous system Selenoprotein Nano-selenium Plumbism Brain function

基于改进Canny边缘检测算法的导轨滑块尺寸在线视觉测量方法的研究

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计量与测试技术 2024年第4期51卷 40-41,46页

作者：丁文强蓝卉陈欢丽水市质量检验检测研究院浙江省计量科学研究院

本文提出了一种基于改进Canny边缘检测算法的导轨滑块尺寸测量方法。通过OpenCV机器视觉库,利用高斯平滑、自适应双阈值分割、霍夫变换等图像处理算法,对导轨滑块图像进行处理,实现滚动直线导轨滑块内滚道间距尺寸的在线精确测量。同时... 详细信息

本文提出了一种基于改进Canny边缘检测算法的导轨滑块尺寸测量方法。通过OpenCV机器视觉库,利用高斯平滑、自适应双阈值分割、霍夫变换等图像处理算法,对导轨滑块图像进行处理,实现滚动直线导轨滑块内滚道间距尺寸的在线精确测量。同时,对视觉测量法的可行性进行探讨和分析。

关键词：高斯平滑自适应阈值分割边缘检测尺寸测量

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地铁盾构隧道接缝渗漏风险分析

江苏建筑 2024年第2期 64-67页

作者：丁文强韦扣均赵进华设设计集团股份有限公司江苏南京210014

渗漏水是地铁盾构隧道中的一大主要病害。文章在对盾构隧道横纵向变形条件下接缝张开量进行分析的基础上,基于防水密封垫接触面的受力变形和服役性能发展规律,对接缝渗漏水的机理进行了研究,从而分别得出纵缝和环缝防水密封垫的接触压... 详细信息

渗漏水是地铁盾构隧道中的一大主要病害。文章在对盾构隧道横纵向变形条件下接缝张开量进行分析的基础上,基于防水密封垫接触面的受力变形和服役性能发展规律,对接缝渗漏水的机理进行了研究,从而分别得出纵缝和环缝防水密封垫的接触压力随横断面收敛变形和纵向沉降曲率半径及环缝错台的变化规律,对接缝渗漏的风险分析有一定的指导意义。

关键词：地铁盾构隧道接缝变形渗漏水风险

Whittle’s Index Based Sensor Scheduling for Multiprocess Systems Under DoS Attacks

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Journal of Systems Science & Complexity 2024年第1期37卷 329-350页

作者： CAI Zai ding Kemi Shenzhen Key Laboratory of Control Theory and Intelligent Systems Southern University of Science and TechnologyShenzhen 518055China.

In this paper,the authors consider how to design defensive countermeasures against DoS attacks for remote state estimation of multiprocess *** each system,a sensor will measure its state and transmits the data packets through an unreliable channel which is vulnerable to be jammed by an *** limited communication bandwidth,only a subset of sensors are allowed for data transmission,and how to select the optimal one to maximize the accuracy of remote state estimation is the focus of the proposed *** authors first formulate this problem as a Markov decision process and investigate the existence of optimal ***,the authors demonstrate the piecewise monotonicity structure of optimal *** the difficulty of obtaining an optimal policy of large-scale problems,the authors develop a suboptimal heuristic policy based on the aforementioned policy structure and Whittle’s ***,a closed form of the indices is derived in order to reduce implementation complexity of proposed scheduling policy and numerical examples are provided to illustrate the proposed developed results.

关键词： DoS attacks Kalman filter remote state estimation Whittle’s index.

A vertical track nonlinear energy sink

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Applied Mathematics and Mechanics(English Edition) 2024年第6期45卷 931-946页

作者： Meng LI Hu ding Shanghai Key Laboratory of Mechanics in Energy Engineering School of Mechanics and Engineering ScienceShanghai Frontier Science Center of MechanoinformaticsShanghai UniversityShanghai 200444China

Eliminating the effects of gravity and designing nonlinear energy sinks(NESs)that suppress vibration in the vertical direction is a challenging task with numerous damping *** this paper,the dynamic design of a vertical track nonlinear energy sink(VTNES)with zero linear stiffness in the vertical direction is proposed and realized for the first *** motion differential equations of the VTNES coupled with a linear oscillator(LO)are *** the strong nonlinearity considered of the VTNES,the steady-state response of the system is analyzed with the harmonic balance method(HBM),and the accuracy of the HBM is verified *** this basis,the VTNES prototype is manufactured,and its nonlinear stiffness is *** damping effect and dynamic characteristics of the VTNES are studied theoretically and *** results show that the VTNES has better damping effects when strong modulation responses(SMRs)***,even for small-amplitude vibration,the VTNES also has a good vibration suppression *** sum up,in order to suppress the vertical vibration,an NES is designed and developed,which can suppress the vertical vibration within certain ranges of the resonance frequency and the vibration intensity.

关键词： track nonlinear energy sink(TNES) vertical direction gravity nonlinear stiffness harmonic balance method(HBM) vibration control

Deep structure of the Southeast Asian curved subduction system and its dynamic process

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Journal of Oceanology and Limnology 2024年第3期42卷 701-704页

作者： Weiwei ding Key Laboratory of Submarine Geoscience&Second Institute of Oceanography Ministry of Natural ResourcesHangzhou 310012China School of Oceanography Shanghai Jiao Tong UniversityShanghai 200030China

The deep structure,material circulation,and dynamic processes in the Southeast Asia have long been an elusive scientific puzzle due to the lack of systematic scientific observations and recognized theoretical *** on the deep seismic tomography using long-period natural earthquake data,in this study,the deep structure and material circulation of the curved subduction system in Southeast Asia was studied,and the dynamic processes since 100 million years ago was *** is pointed out that challenges still exist in the precise reconstruction of deep mantle structures of the study area,the influence of multi-stage subduction on deep material exchange and shallow magma activity,as well as the spatiotemporal evolution and coupling mechanism of multi-plate *** work should focus on high-resolution land-sea joint 3-D seismic tomography imaging of the curved subduction system in the Southeast Asia,combined with geochemical analysis and geodynamic modelling works.

关键词： curved subduction system deep structure material recycling dynamic process Southeast Asia

New advances in the study of Tethyan Geodynamic System

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Science China Earth Sciences 2024年第3期67卷 874-878页

作者： Lin ding State Key Laboratory of Tibetan Plateau Earth System Science(LATPES) Institute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100101China

Tethyan Ocean was initially proposed by Austrian geologist Eduard Suess in 1893. The study of the Tethyan evolution by European geologists has led to the development of modern geology, but not to the establishment of plate tectonics theory(Trümpy, 2001). With the progress in various studies, the concept of Tethys has evolved from a Mesozoic ocean into three long-term evolving oceans:Proto-Tethys, Paleo-Tethys, and Neo-Tethys (Figure 1), and their life cycles cover the entire Phanerozoic era (Wu et al., 2020).

关键词： geology Mesozoic ocean

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Sensitivity of livelihood strategy to livestock production and marketization:An empirical analysis of grasslands in Inner Mongolia,China

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Regional Sustainability 2021年第4期2卷 363-374页

作者： Saheed Olaide JIMOH ding wenqiang DONG Haibin BAI Haihua YIN Yanting LIU Huihui HOU Xiangyang Grassland Research Institute Chinese Academy of Agricultural Sciences/Key Laboratory of Grassland Ecology and RestorationMinistry of AgricultureHohhot010010China Department of Pasture and Range Management College of Animal Science and Livestock ProductionFederal University of AgricultureAbeokuta23439Nigeria Agriculture Research Group Organization of African Academic Doctors(O-AAD)Nairobi25305-00100Kenya The Party School of the Communist Party of China Ningxia Hui Autonomous Region Party CommitteeNingxia Administration InstituteYinchuan750021China College of Pastoral Agricultural Science and Technology Lanzhou UniversityLanzhou730020China Grassland College Shanxi Agricultural UniversityTaigu030801China

Recent researches have primarily focused on the relationship between livelihood strategies and livelihood capital,with few empirical studies on the sensitivity of livelihood strategies to livestock production and marketization in Inner Mongolia Autonomous Region of *** study used an income distribution approach to categorize livelihood strategies of the respondents(n=394)into three types,i.e.,herder livelihood strategy(LS1),petty-herder livelihood strategy(LS2),and non-herder livelihood strategy(LS3).Using the multinomial logistic regression model,we compared livestock production and marketization across the three livelihood *** findings showed that(1)livestock production and marketization tended to favor LS1;(2)an increase in the land asset(contracted and rented grassland)and off-take rate increased the probability of households choosing LS1;(3)stocking rate was higher for LS1;and(4)the higher critical market-related risks perceived by herders were animal price and hay and corn ***,higher livestock price acted as a deterrent to diversifying into other livelihood strategies(LS2 and LS3).Finally,this study advocates for policies that will promote the land transfer market,adopt modern techniques in animal husbandry,improve the medium for disseminating market information to herders,and provide incentives for long-term livelihood transformation.

关键词： Livelihood strategy Livestock production Marketization Livelihood diversification Grassland Inner Mongolia Autonomous Region