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试谈构型式间的相互配合使用
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作者 万新军 《安庆师范学院学报(自然科学版)》 1996年第1期84-88,共5页
化合物的构型有种种表示方法,它们都是将具有三维空间结构的分子,采用各自的表现手法和表达功能描述于二维空间的平面上。本文讨论了这些构型式间的相互配合使用,以期对大家有所带助。
关键词 构型式 锯架式 立体化学 教学 楔形式
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Eleanor westney:《摹仿与创新:日本明治时期对西方国家机构型式的输入》
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作者 柯飞 《外语教学与研究》 CSSCI 北大核心 1990年第2期52-52,共1页
以往人们对近代日本社会变化的研究多集中于当时的社会、经济条件和明治思想家的动机上,该书作者Eleanor Westney则研究明治时代日本警察机构、邮政系统和大众传播媒介报纸这三种国家机构的建立和发展,试图从这方面揭示近代日本社会变... 以往人们对近代日本社会变化的研究多集中于当时的社会、经济条件和明治思想家的动机上,该书作者Eleanor Westney则研究明治时代日本警察机构、邮政系统和大众传播媒介报纸这三种国家机构的建立和发展,试图从这方面揭示近代日本社会变化的过程。 展开更多
关键词 日本明治时期 社会变化 大众传播媒介 构型式 西方国家 日本警察 明治时代 经济条件 邮政系统 日本传统
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关于圆柱螺旋弹簧强度计算列线图构绘型式的探讨 被引量:1
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作者 冯国大 《有色冶金设计与研究》 1998年第1期21-24,38,共5页
根据强度对弹簧进行选择计算,常需进行反复的试算。绘制出理想型式的列线图,利用图算法简化设计计算及选择最佳参数是方便、有效的。本文就国内外所见到的圆柱螺旋弹簧强度计算列线图的构绘型式进行分析讨论,并提出了一种更为合理的... 根据强度对弹簧进行选择计算,常需进行反复的试算。绘制出理想型式的列线图,利用图算法简化设计计算及选择最佳参数是方便、有效的。本文就国内外所见到的圆柱螺旋弹簧强度计算列线图的构绘型式进行分析讨论,并提出了一种更为合理的构绘型式。 展开更多
关键词 列线图 型式 弹簧 圆柱螺旋弹簧
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交—直—交电力机车主电路结构选择 被引量:2
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作者 张莹 张琳 《电力机车与城轨车辆》 2004年第4期57-58,60,共3页
主要阐述交—直—交电力机车主电路结构型式及特点,并从机车功率、可靠性要求、控制要求和经济性能比较等几个方面提出主电路的确定原则和方法。
关键词 交-直-交电力机车 主电路 构型式 确定原则 机车功率
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对汪小兰编《有机化学》第四版中结构式书写的建议
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作者 高智席 吴永平 《遵义师范学院学报》 2009年第3期77-78,共2页
一般有机化合物分子的构造式只能表示分子中各原子或基团间的连接方式和连接顺序而不能表示分子的空间构型。把构造式当作费歇尔投影式来对有机化合物分子进行构型判断是错误的。
关键词 造式 构型式 费歇尔投影式
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判别Fischer式构型的简易方法及其理论探讨 被引量:2
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作者 吕守茂 《湖北科技学院学报》 1989年第2期74-76,共3页
本文介绍判别Fischer式构型的一种简易方法,其特点是;不需要经平面结构式到立体构型式的变换便可直接在Fischer投影式上进行构型的判别。
关键词 Fischer式 平面结 立体构型式 手性碳原子 FISCHER投影式
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The preparation and properties of N-doped carbon materials and their use for sodium storage
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作者 YUAN Ren-lu HOU Ruo-yang +4 位作者 SHANG Lei LIU Xue-wei LI Ang CHEN Xiao-hong SONG Huai-he 《新型炭材料(中英文)》 SCIE EI CAS CSCD 北大核心 2024年第5期770-795,共26页
Defect engineering by heteroatom doping gives carbon materials some new characteristics such as a different electronic structure and a high electrochemical activity,making them suitable for high-performance applicatio... Defect engineering by heteroatom doping gives carbon materials some new characteristics such as a different electronic structure and a high electrochemical activity,making them suitable for high-performance applications.N-doping has been widely investigated because of its similar atom radius to carbon,high electronegativity as well as many different configurations.We summarize the preparation methods and properties of N-doped carbon materials,and discuss their possible use in sodium ion storage.The relationships between N content/configuration and crystallinity,electronic conductivity,wettability,chemical reactivity as well as sodium ion storage performance are discussed. 展开更多
关键词 N-doped carbon material N configuration Preparation method Performance Sodium storage
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葡萄糖构型测定的改进
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作者 李远军 《西昌师专学报》 1998年第1期42-44,38,共4页
前 言 国内高等学校现在使用的有机化学教科书及参考资料中,对葡萄糖的构型测定,都采用了三个步骤:即(1)由低级糖合成高级糖。把D—阿拉伯糖和D—萄萄糖、D—甘露糖联系起来推导。(2)由糖的氧化和还原决定出D—葡萄糖和D—甘露糖的构型... 前 言 国内高等学校现在使用的有机化学教科书及参考资料中,对葡萄糖的构型测定,都采用了三个步骤:即(1)由低级糖合成高级糖。把D—阿拉伯糖和D—萄萄糖、D—甘露糖联系起来推导。(2)由糖的氧化和还原决定出D—葡萄糖和D—甘露糖的构型及L—古罗糖的构型。(3)再通过糖的降级反应决定出D—阿拉伯糖的构型。 展开更多
关键词 葡萄糖 阿拉伯糖 构型式 甘露糖 差向异 低级糖 古罗糖 氧化和还原 糖二酸 高级糖
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混凝土泵车臂架连杆机构创新设计
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作者 郭承志 缪雄辉 +2 位作者 李建涛 夏益民 刘石坚 《机械研究与应用》 2012年第5期97-100,共4页
采用机构型综合的创新构思法,对现有混凝土泵车臂架系统连杆机构进行一般化处理,归纳出4种运动链型,通过不同构件的组合,得到13种新的非同构的机构型式,其中3种非同构型式对实际应用具有参考价值。
关键词 泵车 臂架 连杆 非同构型式 创新设计
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Application of discrete choice model in trip mode structure forecast:a case study of Bengbu
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作者 任刚 周竹萍 张浩然 《Journal of Southeast University(English Edition)》 EI CAS 2011年第1期83-87,共5页
In order to find the main factors that influence the urban traffic structure,a relational model between the travelers' characteristics and the trip mode choice is built.The data of urban residents' characteristics a... In order to find the main factors that influence the urban traffic structure,a relational model between the travelers' characteristics and the trip mode choice is built.The data of urban residents' characteristics are obtained from statistical data,while the trip mode split data is collected through a trip survey in Bengbu.In addition,the discrete choice model is adopted to build the functional relationship between the mode choice and the travelers' personal characteristics,as well as family characteristics and trip characteristics.The model shows that the relationship between the mode split and the personal,as well as family and trip characteristics is stable and changes little as the time changes.Deduced by the discrete model,the mode split result is relatively accurate and can be feasibly used for trip mode structure forecasts.Furthermore,the proposed model can also contribute to find the key influencing factors on trip mode choice,and restructure or optimize the urban trip mode structure. 展开更多
关键词 trip mode split trip mode structure discrete choice model forecasting
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Investigation on transformation process of trip mode choice for planned special events
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作者 吴娇蓉 王晨 +1 位作者 陈非 陈小鸿 《Journal of Southeast University(English Edition)》 EI CAS 2013年第2期199-206,共8页
This paper aims to provide a decision-making method for the transportation management strategies in guiding the transformation of trip mode choice during planned special events. The Expo 2010 Shanghai is taken as an e... This paper aims to provide a decision-making method for the transportation management strategies in guiding the transformation of trip mode choice during planned special events. The Expo 2010 Shanghai is taken as an example, and a structural equation model is employed to analyze the dynamic mechanism of trip mode choice behavior and the effectiveness of the transportation management measures at different stages. Based on the difference between the objective-oriented stated preference (SP) survey results and the objectives, together with the feedback from the previous stage survey, some adjustments on the transportation management measures are made in the next stage of the planning process until the objectives are eventually achieved. The results indicate that the adjustments on transportation management measures at different stages can effectively raise the transit share to 88.6%. Nonlocal visitors are inclined to choose nonstop modes of transportation and the companion attributes have the most significant effects on the trip mode choices of visitors. The research method is proved to be an effective way to support the decision making process of transportation management measures during planned special events in the future. 展开更多
关键词 planned special events trip mode choice structural equation model objective-oriented stated preferencesurvey
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A Survey of Steel Arch Bridges in China 被引量:4
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作者 Baochun Chen Kangming Chen +1 位作者 Shozo Nakamura Qiu Zhao 《Journal of Civil Engineering and Architecture》 2011年第9期799-808,共10页
A review of the current status and progress of steel arch bridges in China is presented in this paper. The existing steel arch bridges in China were analyzed in terms of steel material, span, structure type, main arch... A review of the current status and progress of steel arch bridges in China is presented in this paper. The existing steel arch bridges in China were analyzed in terms of steel material, span, structure type, main arch rib form and construction method. The comparison with CFST arch bridges and RC arch bridges is also conducted. It is shown that steel arch bridge has gain rapid development in China since 2000, characterized by long main spans. As for the span, most of the steel arch bridges have a span less than 250 m, while when the span exceeds 350 m, steel arch bridges are strongly competitive against CFST or RC arch bridges. Over 80% of the bridges are through and half-through bridge types, and the arch ribs are hingeless structures. The rise-to-span ratios of the arches are mainly between 1:4 and 1: 5. Most of the arches use solid box ribs, and a small portion of arches use truss ribs in which box sections are mostly adopted for the truss members. The cantilever method and scaffolding method are the two main construction methods used, but some other construction methods have also been developed. 展开更多
关键词 Steel arch bridge SURVEY bridge type RIB construction method China
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Time Domain Calculation of Connector Loads of a Very Large Floating Structure 被引量:3
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作者 Jiayang Gu Jie Wu +2 位作者 Enrong Qi Yifeng Guan Yubo Yuan 《Journal of Marine Science and Application》 CSCD 2015年第2期183-188,共6页
Loads generated after an air crash, ship collision, and other accidents may destroy very large floating structures (VLFSs) and create additional connector loads. In this study, the combined effects of ship collision... Loads generated after an air crash, ship collision, and other accidents may destroy very large floating structures (VLFSs) and create additional connector loads. In this study, the combined effects of ship collision and wave loads are considered to establish motion differential equations for a multi-body VLFS. A time domain calculation method is proposed to calculate the connector load of the VLFS in waves. The Longuet-Higgins model is employed to simulate the stochastic wave load. Fluid force and hydrodynamic coefficient are obtained with DNV Sesam software. The motion differential equation is calculated by applying the time domain method when the frequency domain hydrodynamic coefficient is converted into the memory function of the motion differential equation of the time domain. As a result of the combined action of wave and impact loads, high-frequency oscillation is observed in the time history curve of the connector load. At wave directions of 0° and 75°, the regularities of the time history curves of the connector loads in different directions are similar and the connector loads of C1 and C2 in the X direction are the largest. The oscillation load is observed in the connector in the Y direction at a wave direction of 75° and not at 0° This paper presents a time domain calculation method of connector load to provide a certain reference function for the future development of Chinese VLFS 展开更多
关键词 very large floating structures (VLFSs) time domainmotion differential equation COLLISION CONNECTOR impact load hydrodynamic coefficient oscillation load impact load
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Comparison of two types of twin-rotor piston engine mechanisms 被引量:6
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作者 邓豪 潘存云 +2 位作者 王晓聪 张雷 邓力 《Journal of Central South University》 SCIE EI CAS 2013年第2期363-371,共9页
A novel twin-rotor piston engine (TRPE) mechanism with high volumetric output and power density was introduced. This new engine comprises an energy conversion system and a differential velocity drive mechanism (DVD... A novel twin-rotor piston engine (TRPE) mechanism with high volumetric output and power density was introduced. This new engine comprises an energy conversion system and a differential velocity drive mechanism (DVDM). Two special geared four-bar mechanisms, DVDM-1 and DVDM-2, were utilized and compared. Based on the closed loop vector method, a mathematical model for position, velocity, and acceleration of the two mechanisms was established. Numerical examples illustrate that the kinematic characteristics were presented. Expression of the displacement and compression ratio of the two engine mechanisms were derived and compared. It is concluded that both DVDM-1 and DVDM-2 adopted in the proposed TRPE with six vane pistons create thirty-six power strokes per revolution of the output shaft, and the summation of two angles covered by each rocker is always 2x/N as the output shaft rotates an angle of x/N. In DVDM-1, the span angle of a vane piston should be designed to be 10.2°, and the compression ratio should be equal to 10; in DVDM-2, the span angle of a vane piston should be designed to be 10.6°, and the compression ratio should be equal to 4.3. 展开更多
关键词 ROTOR piston engine CRANK ROCKER power density
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Effect of pile-cap connection on behavior of torsionally loaded pile groups 被引量:2
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作者 Ling-gang KONG Li-min ZHANG 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2008年第3期303-312,共10页
To evaluate the responses of fixed and pinned pile groups under torsion, a method is presented to analyze the nonlinear behavior of free-standing pile groups with rigid pile caps. The method is capable of simulating t... To evaluate the responses of fixed and pinned pile groups under torsion, a method is presented to analyze the nonlinear behavior of free-standing pile groups with rigid pile caps. The method is capable of simulating the nonlinear soil response in the near field usingp-y and r-θ curves, the far-field interactions through Mindlin's and Randolph's elastic solutions, and the coupling effect of lateral resistance on torsional resistance of the individual piles using an empirical factor. Based on comparisons of the solutions for fixed- and pinned-head, 1×2, 2×2, and 3×3 pile groups subjected to torsion, it was found that pile-cap connection significantly influences the torsional capacity of pile groups and the assignment of applied torques in the pile groups. In this study, the applied torques for the pinned-head pile groups are only 44%-64% of those for the corresponding fixed-head pile groups at a twist angle of 2^o. Such a difference is mainly due to the change of the lateral resistances of individual piles in the groups. 展开更多
关键词 Pile group Pile foundations Torsional response Pile-cap connection Nonlinear analysis
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Vacuum deposited film growth,morphology and interfacial electronic structures of 2,7-dioctyl[1]benzothieno[3,2-b]benzothiophene(C8-BTBT)
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作者 WEI Jun-hua NIU Dong-mei GAO Yong-li 《Journal of Central South University》 SCIE EI CAS CSCD 2022年第4期1041-1061,共21页
Interfaces play critical roles in electronic devices and provide great diversity of film morphology and device performance.We retrospect the substrate mediated vacuum film growth of benchmark high mobility material 2,... Interfaces play critical roles in electronic devices and provide great diversity of film morphology and device performance.We retrospect the substrate mediated vacuum film growth of benchmark high mobility material 2,7-dioctyl[1]benzothieno[3,2-b]benzothiophene(C8-BTBT)and the interface electronic structures.The film growth of C8-BTBT molecules is diversified depending on the substrate-molecule and molecule-molecule interactions.On atomic smooth substrates C8-BTBT film grows in layer-by-layer mode while on coarse substrate it grows in islands mode.The initial molecular layer at dielectric,semiconductor and conductive substrates displays slight different lattice structure.The initial molecule orientation depends on the substrate and will gradually change to standing up configuration as in bulk phase.C8-BTBT behaves as electron donor when contacting with dielectric and stable conductive materials.This usually induces a dipole layer pointing to C8-BTBT and an upward bend bending in C8-BTBT side toward the interface.Although it is air stable,C8-BTBT is chemically reactive with some transition metals and compounds.The orientation change from lying down to standing up in the film usually leads to decrease of ionization potential.The article provides insights to the interface physical and chemical processes and suggestions for optimal design and fabrication of C8-BTBT based devices. 展开更多
关键词 interface film morphology packing configuration growth mode electronic structure chemical reaction interface dipole
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Research on Optimization wharf Structure Type of Triangle frame pier
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作者 ZHOU Yang 《International English Education Research》 2016年第4期97-98,共2页
Based on optimization wharf structure type of triangle flame pier proposed, namely" Spatial triangular flame pier + Big span bent which taking Slant supports" Simulating three-dimensional pier model of a variety of... Based on optimization wharf structure type of triangle flame pier proposed, namely" Spatial triangular flame pier + Big span bent which taking Slant supports" Simulating three-dimensional pier model of a variety of conditions in the actual loading by structural finite element software. Under the guidance of the three-dimensional structure of the most unfavorable load combination algorithm, three-dimensional combination algorithm is applied to the new structure by the MATLAB software programming. Search and calculate the most unfavorable combination of action effects and the corresponding intemal force of the main member, checking the feasibility of the three-dimensional algorithms, Calculating the new wharf structure structural features and stability, Providing numerical reference for the design of this sort of wharf. 展开更多
关键词 The triangle flame pier Slant supports Three-dimensional model Three-dimensional Algorithm
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Research on the Fragment Impact Resistance of a Composite Mast
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作者 Wei Zhang Chao Wu +2 位作者 Wenshan Yang Shanshan Xu Shaofei Ren 《Journal of Marine Science and Application》 2011年第3期300-305,共6页
Due to the unique structural mode and material property of a composite sandwich plate, related research such as fragment impact resistance of a composite mast is short of publication and urgent in this field. In this ... Due to the unique structural mode and material property of a composite sandwich plate, related research such as fragment impact resistance of a composite mast is short of publication and urgent in this field. In this paper, the commonly accepted sandwich core board theory was modified. Damage caused by a fragment attack was simulated onto a sandwich plate model built with solid and shell elements. It was shown that shear failure and vast matrix cracking are the main reasons for outer coat damage, and tension failure and partial matrix cracking are the cause for inner coat damage. Additionally, according to complexities in actual sea battles, different work conditions of missile attacks were set. Ballistic limit values of different fragment sizes were also obtained, which provides references for enhancing the fragment impact resistance of a composite mast. 展开更多
关键词 composite mast sandwich plate fragment impact ballistic limit
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Structure,expression,and developmental function of early divergent forms of metalloproteinases in Hydra
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作者 MICHAELPSARRASJR LIYAN 《Cell Research》 SCIE CAS CSCD 2002年第3期163-176,共14页
Metalloproteinases have a critical role in a broad spectrum of cellular processesranging from the break-down of extracellular matrix to the processing of signaltransduction-related proteins.These hydrolytic functions ... Metalloproteinases have a critical role in a broad spectrum of cellular processesranging from the break-down of extracellular matrix to the processing of signaltransduction-related proteins.These hydrolytic functions underlie a variety of mechanisms related to developmental processes as well as disease states.Structural analysis of metalloproteinases from both invertebrate and vertebrate species indicates that these enzymes are highly conserved and arose early during metazoan evolution.In this regard,studies from vari-ous laboratories have reported that a number of classes of metalloproteinases are found in hydra,a member of Cnidaria,the second oldest of existing animal phyla.These studies demonstrate that the hydra genome contains at least three classes of metalloproteinases to include members of the 1)astacin class,2)matrix met-alloproteinase class,and 3)neprilysin class.Functional studies indicate that these metalloproteinases play diverse and important roles in hydra morphogenesis and cell differentiation as well as specialized functions in adult polyps.This article will review the structure,expression,and function of these metalloproteinases in hydra. 展开更多
关键词 HYDRA METALLOPROTEINASES development astacin matrix metalloproteinases ENDOTHELIN
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Based on the ISM model embedded geriatric rehabilitation nursing facility development restriction factor analysis
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作者 XU YiJun 《International English Education Research》 2015年第12期62-64,共3页
This article through to new embedded geriatric rehabilitation care development present situation, pointed out that in the popularization of its restriction factors, and then asked a further analysis of various factors... This article through to new embedded geriatric rehabilitation care development present situation, pointed out that in the popularization of its restriction factors, and then asked a further analysis of various factors, constructed the obstacle factors explanation structure model (ISM).According to the result of classification model and find out the problem, the most direct factors and put forward the corresponding Suggestions, facilities for embedded geriatric rehabilitation nursing mode to find out the key points of development, provide a reference value to scientific basis. 展开更多
关键词 Embedded pattern Geriatric rehabilitation nursing facility ISM model
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