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长三角区域一体化对城市群土地利用效率的空间协同效应

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地理研究 2024年第8期43卷 2104-2120页

作者：孙燕吴莉莉金晓斌符海月范业婷马国强南京财经大学公共管理学院南京210023 南京大学地理与海洋科学学院南京210023 南京农业大学公共管理学院南京210095 南京农业大学中国资源环境与发展研究院南京210095 自然资源部长三角国土生态与土地利用野外科学观测研究站南京210017 南京晓庄学院环境科学学院南京211171

随着城市群区域一体化的发展,城市之间是否可以借助空间邻近关系,实现土地利用效率的协同提升,目前仍缺乏经验证据。本文以长三角城市群为研究区域,以2003—2019年为研究期,利用改进的重力模型和SBM模型分别测度各城市的区域一体化水平... 详细信息

随着城市群区域一体化的发展,城市之间是否可以借助空间邻近关系,实现土地利用效率的协同提升,目前仍缺乏经验证据。本文以长三角城市群为研究区域,以2003—2019年为研究期,利用改进的重力模型和SBM模型分别测度各城市的区域一体化水平和城市土地利用效率,通过空间杜宾模型实证检验了长三角区域一体化对城市群土地利用效率的空间协同效应。结果表明:①长三角区域一体化对城市群土地利用效率产生了积极的显著的空间协同效应。城市区域一体化水平的提高,不仅可以直接地提升本地城市的土地利用效率,而且还可以借助空间邻近关系间接地提升邻近城市的土地利用效率。②基于地理距离、行政边界邻接和经济联系的空间邻近关系均有利于城市群土地利用效率的协同提升,且基于地理距离的空间协同效应最大。③异质性分析发现,相比地方政府主导,中央政府主导的区域一体化更有利于城市群土地利用效率的协同提升。本文的研究结论可为城市经济高质量发展与资源集约利用相关决策提供理论借鉴。

关键词：区域一体化城市土地利用效率协同效应空间杜宾模型长三角城市群

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压力钢管的应力与腐蚀监测系统设计与实现

科学技术创新 2024年第6期 43-46页

作者：马相马国强王大东国能四川东谷河流域水电开发有限公司四川丹巴

水电站压力钢管在腐蚀及泥沙环境中服役,会遭受严重的泥沙磨损和介质腐蚀。压力钢管球阀段的结构健康监测,能够有效避免发生结构致命安全隐患,状态预测预警以及延长设备运营寿命。对于结构健康监测包括材料腐蚀及荷载作用下的结构承力安... 详细信息

水电站压力钢管在腐蚀及泥沙环境中服役,会遭受严重的泥沙磨损和介质腐蚀。压力钢管球阀段的结构健康监测,能够有效避免发生结构致命安全隐患,状态预测预警以及延长设备运营寿命。对于结构健康监测包括材料腐蚀及荷载作用下的结构承力安全,进行应变等反映结构变化的参数和金属腐蚀的监测。

关键词：压力钢管磨损腐蚀结构健康监测

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印制线路板化学镍金镍腐蚀研究

印制电路信息 2024年第S1期32卷 183-194页

作者：沙雷马国强刘志平深南电路股份有限公司广东深圳518100

本文对印制线路板(PCB)化学镍金的镍腐蚀进行了研究,探讨了镍腐蚀的形成机理,结合以往的研究,通过本次研究实验发现金厚对镍腐蚀有一定的影响,但是镍槽的活性才是引起镍腐蚀最关键的影响因子。作者主要从镍缸活性探究镍腐蚀的问题,研究... 详细信息

本文对印制线路板(PCB)化学镍金的镍腐蚀进行了研究,探讨了镍腐蚀的形成机理,结合以往的研究,通过本次研究实验发现金厚对镍腐蚀有一定的影响,但是镍槽的活性才是引起镍腐蚀最关键的影响因子。作者主要从镍缸活性探究镍腐蚀的问题,研究了活化槽、镍缸药水稳定性(开缸剂M、药水添加)、有机物溶出对化学镍金镍腐蚀的影响,最后结合实际的生产经验给出镍腐蚀相应的控制方法。

关键词：印制线路板化学镍金镍腐蚀控制方法

THE DYNAMIC BUCKLING OF ELASTIC-PLASTIC COLUMN SUBJECTED TO AXIAL IMPACT BY A RIGID BODY

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Acta Mechanica Solida Sinica 2005年第3期18卷 256-264页

作者： Han Zhijun Wang Jingchao Cheng guoqiang ma Hongwei Zhang Shanyuan Institute of Applied Mechanics Taiyuan University of Technology Taiyuan 030024 China

The dynamic buckling of an elastic-plastic column subjected to axial impact by a rigid body has been discussed in this paper. The whole traveling process of elastic-plastic waves under impact action is analyzed with the characteristics method. The regularity of stress changes in both column ends and the first separating time of a rigid body and column are obtained. By using the energy principle and taking into account the propagation and reflection of stress waves the lateral disturbance equation is derived and the power series solution is given. In addition, the critical buckling condition can be obtained from the stability analysis of the solution. By numerical computation and analysis, the relationship among critical velocity and impact mass, hardening modulus, and buckling time is given.

关键词： dynamic buckling stress wave critical criteria power series solution

胺碘酮治疗急性心肌梗死并室上性心律失常的临床疗效

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临床合理用药杂志 2024年第6期17卷 9-12页

作者：马国强周臻臻杜永良山东省乳山市人民医院心内一科 264500 山东省乳山市人民医院神经内二科 264500

目的探讨胺碘酮治疗急性心肌梗死(AMI)并室上性心律失常的临床疗效。方法选取2021年6月—2022年6月乳山市人民医院收治的AMI并室上性心律失常患者90例作为研究对象,以双色球法分为利多卡因组(n=45)与胺碘酮组(n=45)。利多卡因组给予利... 详细信息

目的探讨胺碘酮治疗急性心肌梗死(AMI)并室上性心律失常的临床疗效。方法选取2021年6月—2022年6月乳山市人民医院收治的AMI并室上性心律失常患者90例作为研究对象,以双色球法分为利多卡因组(n=45)与胺碘酮组(n=45)。利多卡因组给予利多卡因治疗,胺碘酮组给予胺碘酮治疗,2组均于心率稳定后停药。比较2组临床疗效,治疗前与治疗结束后心功能指标[左心室射血分数(LVEF)、左心室舒张末期内径(LVEDD)、左心室收缩末期内径(LVESD)]、室上性心律失常发作次数及发作持续时间、心电图[心率、校正后QT间期(QTc)、QT间期离散度(QTd)]及不良反应。结果胺碘酮组总有效率高于利多卡因组(97.78%vs.82.22%,χ^(2)=4.444,P=0.035)。治疗结束后,2组LVEF高于治疗前,LVEDD、LVESD小于治疗前,且胺碘酮组升高/缩小幅度大于利多卡因组(P<0.01);2组室上性心律失常发作次数少于治疗前,室上性心律失常发作持续时间短于治疗前,且胺碘酮组变化幅度大于利多卡因组(P<0.01);2组心率、QTd低于治疗前,QTc高于治疗前,且胺碘酮组降低/升高幅度大于利多卡因组(P<0.05或P<0.01)。利多卡因组与胺碘酮组不良反应总发生率比较,差异无统计学意义(13.33%vs.4.44%,χ^(2)=1.235,P=0.266)。结论胺碘酮治疗AMI并室上性心律失常可较好地改善患者的心功能及心室肌复极离散程度,同时减少室上性心律失常发作次数,缩短发作持续时间,进而增强临床疗效,但不会增加不良反应发生风险,安全性较高。

关键词：急性心肌梗死室上性心律失常胺碘酮利多卡因心功能心电图安全性

Sulfur isotopic composition and source identification of atmospheric environment in central Zhejiang,China

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Science China Earth Sciences 2010年第11期53卷 1717-1725页

作者： Zhang MiaoYun Wang ShiJie ma guoqiang Zhou HuaiZhong Fu Jun Chinese Acad Sci Inst Geochem State Key Lab Environm Geochem Guiyang 550002 Peoples R China Jinhua Environm Monitoring Ctr Jinhua 321013 Peoples R China Environm Monitoring Ctr Zhejiang Prov Hangzhou 310012 Zhejiang Peoples R China

Sulfur dioxide and sulfate aerosols in the atmosphere are significant factors leading to acidification of the atmospheric environment and worsening the pollution of acid deposition. Because of the "fingerprint" characteristics of the stable sulfur isotopic composition, sulfur isotope has been widely adopted in environmental researches concerning sulfur cycle and source identification. In this study, the atmospheric environment of Jinhua City, central Zhejiang Province, was continuously monitored, and the sulfur isotopic composition of SO2 and sulfate aerosols in the atmosphere was analyzed. The results indicate that the variation of δ34S values for SO2 ranges from 1.0‰ to 7.5‰, and annual average is 4.7‰±2.3‰, whereas that of sulfate aerosols ranges from 6.4‰ to 9.8‰,and annual average is 8.1‰±1.0‰. The δ 34S values for SO2 have significant seasonal variations, which are 7.0‰ in winter and 3.3‰ in summer. These variations cannot be attributed to a single factor, and we suggest a temperature-dependent isotope equilibrium fractionation and elevated biogenic sulfur emissions of isotopically light S in summer may be the main controlling mechanisms. Furthermore, we also discuss the δ 34S model of atmospheric SO2 oxidation to form sulfate, and suggest that heterogeneous oxidation dominates in the oxidation reactions of atmospheric SO2 in the central Zhejiang Province. We further suggest that the relative humidity in the atmosphere plays an important role in the oxidation mechanism of atmospheric SO2.

关键词： sulfur isotope SO2 aerosol homogeneous oxidation heterogeneous oxidation

Behavioral Feature and Correlative Detection of Multiple Types of Node in the Internet of Vehicles

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Computers, materials & Continua 2020年第8期64卷 1127-1137页

作者： Pengshou Xie guoqiang ma Tao Feng Yan Yan Xueming Han School of Computer and Communications Lanzhou University of TechnologyLanzhou730050China Department of Computing Faculty of Science and EngineeringMacquarie UniversitySydneyNSW 2109Australia

Undoubtedly,uncooperative or malicious nodes threaten the safety of Internet of Vehicles(IoV)by destroying routing or *** this end,some researchers have designed some node detection mechanisms and trust calculating algorithms based on some different feature parameters of IoV such as communication,data,energy,etc.,to detect and evaluate vehicle ***,it is difficult to effectively assess the trust level of a vehicle node only by message forwarding,data consistency,and energy *** order to resolve these problems,a novel mechanism and a new trust calculating model is proposed in this ***,the four tuple method is adopted,to qualitatively describing various types of nodes of IoV;Second,analyzing the behavioral features and correlation of various nodes based on route forwarding rate,data forwarding rate and physical location;third,designing double layer detection feature parameters with the ability to detect uncooperative nodes and malicious nodes;fourth,establishing a node correlative detection model with a double layer structure by combining the network layer and the perception ***,we conducted simulation experiments to verify the accuracy and time of this detection method under different speed-rate topological conditions of *** results show that comparing with methods which only considers energy or communication parameters,the method proposed in this paper has obvious advantages in the detection of uncooperative and malicious nodes of IoV;especially,with the double detection feature parameters and node correlative detection model combined,detection accuracy is effectively improved,and the calculation time of node detection is largely reduced.

关键词： IoV behavioral feature double layer detection feature correlation analysis correlative detection model

Microstructure and strength of a tantalum-tungsten alloy after cold rolling from small to large strains

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Journal of materials Science & Technology 2021年第24期83卷 34-48页

作者： guoqiang ma Darcy A.Hughes Andrew W.Godfrey Qiang Chen Niels Hansena Guilin Wu College of materials Science and Engineering Chongqing UniversityChongqing400044China Department of Mechanical Engineering Technical University of DenmarkDK-2800KgsLyngbyDenmark Fremont CAUSA Laboratory of Advanced materials(MOE) School of Materials Science and EngineeringTsinghua UniversityBeijing100084China Southwest Technology and Engineering Research Institute Chongqing400039China Technical University of Denmark Risoe CampusDK-4000RoskildeDenmark Beijing Advanced Innovation Center for materials Genome Engineering University of Science and Technology BeijingBeijing100083China

Microstructural evolution of a refractory tantalum-tungsten alloy(Ta-4%W)after cold rolling from small to large von-Mises strains(0.12-2.7)was quantitatively studied using transmission electron *** subdivision was observed to take place at two *** necessary boundaries nearly paralleling to slip planes enclosed volumes further divided by diffuse cells and by remnants of Taylor *** increasing strain,the diffuse cells evolved into clear incidental dislocation boundaries enclosing cells,while the Taylor lattices *** subdivision was thus intermediate between those observed in cell forming and in non-cell forming ***,the average misorientation angle across all boundaries increased while the average boundary spacing *** of the microstructural parameters at each strain level were found to exhibit universal scaling *** microstructural evolution was found closely linking to the observed high strength and strain hardening of this *** on measured microstructural parameters,the flow stress was calculated utilizing linearly addition of the strengthening by solutes,incidental dislocation boundaries(Taylor strengthening)and geometrically necessary boundaries(Hall-Petch equation).The relative contribution of each strength mechanism evolved with increasing strain and with microstructural evolution:solutes and friction stress dominated at small strains while boundaries dominated at larger *** strengths were in close agreement with experimental tension tests and demonstrated an unexpectedly high and continuous parabolic hardening without transition across this large strain range.

关键词： Tantalum Deformation microstructure Geometrically necessary boundaries Taylor lattices Flow stress

场地短距离自行车不同专项爆发力训练方法比较

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体育科研 2024年第4期45卷 43-50页

作者：胡珂陆星辰梁效忠马国强上海市竞技体育训练管理中心上海202173 上海体育科学研究所(上海市反兴奋剂中心) 上海200030

目的:在东京奥运会赛前备战期间,针对场地自行车短距离项目采用的不同专项爆发力训练方法开展运动学和动力学变化特征的比较研究,为筛选更具针对性的训练方法提供科学依据。方法:以场地自行车国家队男子短组2名运动员为对象。专项安静... 详细信息

目的:在东京奥运会赛前备战期间,针对场地自行车短距离项目采用的不同专项爆发力训练方法开展运动学和动力学变化特征的比较研究,为筛选更具针对性的训练方法提供科学依据。方法:以场地自行车国家队男子短组2名运动员为对象。专项安静爆发力训练选择男子重点队员周某的训赛数据,比较比赛中原地起动250 m骑行与场地大齿轮比追击摩托、Wattbike Pro功率车(英国)静止离座起动、Cyclus 2练习台等动模式静止离座起动15 s 3项训练间差异;高速行进间爆发力训练选择男子重点队员徐某的训赛数据,比较了争先赛资格赛大坡俯冲200 m骑行与场地车大齿轮比摩托全程牵引、Wattbike Pro功率车大负荷行进间离座起动、场地车大齿轮比公路行进间冲坡10 s 3项训练间差异。采用SRM场地版无线功率测量计(德国)和Wattbike Pro功率车分别采集运动员场地、公路自行车,功率车训赛中的运动学参数。结果:①周某完成场地追击摩托训练(GR=3.93)中F_(max)和F_(avr)与比赛(GR=3.64)相比分别高5.5%和5.1%(Pmax)和F_(avr)与比赛(GR=4.50)相比分别高12.2%和19.2%(P<0.05),且两个5 s分段平均踏蹬力F_(avr-1st5s)和F_(avr-2nd5s)也分别较比赛高8.0%和35.6%(P<0.05),踏蹬力下降率(FD)与比赛相比低54.2%(P<0.05)。结论:大齿轮比的场地摩托拉开牵引静止出发15 s最大强度冲刺骑行是专项安静爆发力的有效训练方法;功率车大负荷等速方式行进间出发10 s最大强度冲刺骑行则在提高专项高速行进间爆发力方面更具针对性。

关键词：场地短距离自行车专项爆发力训练方法