查询词典 mechanisms

The variable geometry truss mechanisms have been studied extensively and systematically by this project. The research plan has been completed all sidedly, and expected results have been obtained. Three new kinds of combination decahedrons and a new class of variable geometry truss mechanism, which is composed of an octahedron and three tetrahedrons connected in parallel form, are proposed. The position analyses for decahedrons, dodecahedrons, triple-octahedrons, combinations decahedron and a new type of structure of variable geometry truss mechanisms are presented by introducing additional extra linear displacement sensors and using resultant elimination and homotopy continuation algorithms. The method of kinematical analysis of variable geometry truss mechanisms is established.

课题组对变几何桁架机构进行了深入的研究，全面地完成了研究计划，取得了预期的成果；提出了三种新的十面体组合机构以及由一个八面体和三个四面体组成的新型变几何桁架机构的结构形式；应用结式消元、附加传感器和同伦方法等提出了十面体、十二面体、三重八面体、组合十面体和新型变几何桁架机构的位置分析方法；建立了变几何桁架机构运动分析的一般方法；建立了简洁的凯恩和拉格伦日动力学的模型；应用有限元和子结构方法，提出了变几何柞架机构弹性动力学模型，导出了逆动力学方程的显式形式；设计和研制了一台可折叠的八面体变几何杵架机构装置等。

First, it analyzes the background of the economy system and reform of the establishment of composite peasant households financing mechanism; defines the goal that build composite peasant households financing mechanism under the condition of uncertain market system; proposes a basic idea of innovation of peasants households financing mechanism at economy transition period, and outlines the frame content of composite peasant households financing mechanism. Composite peasant households financing mechanisms requests: peasant households which are enterprise management as financing main body, innovative financing means as a core, the market mechanism as a means. Our country must gradually establish a peasant household financing decision-making mechanisms and risk-control mechanisms, and create a favorable environment and conditions for peasant household.

首先分析了经济转型期复合型农户融资机制建立的经济体制背景和改革背景；明确了在市场体系还不够健全的条件下，构建复合型农户融资机制的目标定位；提出了经济转型期农户融资机制创新的基本思路，并勾勒出了复合型农户融资机制的框架内容；复合型农户融资机制应当以企业化经营的农户为融资主体，以创新融资方式为核心，以市场调节机制为手段，逐步建立农户融资决策机制和风险控制机制，并为农户融资创造一个良好的环境条件。

For inverse singularity, the parallel robot is divided into several series mechanisms, and the Jacobins matrix of these series mechanisms is solved by the exponential product equation and proved to be singular when the series mechanisms are singular.

对于逆奇异，将并联机构拆分成多个串联机构，由指数积方法求得其雅可比矩阵，并证明了机构逆奇异产生时的雅可比矩阵为奇异。

Comparisons between market performance under auction mechanisms and that under market maker mechanisms are made in terms of liquidity, stability, efficiency and transparency. The comparative results show that certain price formation mechanics integrated with specific market environment can affect market performance. The results of the test that is used to verify the liquidity of security market in China indicate that current price formation mechanics can provide the securities market with better liquidity. But the fixation of the minimum changing price lowers the liquidity of the market factitiously and close call auction mechanisms result in increased price fluctuation and price manipulation. Through the analysis on the competitive strategy of securities market, the objects and principles of the design of price formation mechanisms are established.

本文推导出了竞价机制和市商机制下证券市场的均衡价格，结果表明不同的价格形成机制对资产的真实价格有着不同的反映；从证券市场的流动性、稳定性、有效性和透明度等四个方面分别对竞价机制和做市商机制下的市场绩效进行了比较分析，结果表明一定的价格形成机制和特定的市场环境相结合就会对市场绩效产生不同的影响；通过对我国证券市场的流动性进行实证检验，发现当前我国证券市场价格形成机制能够为市场提供较好的流动性，但固定的最小变动价位人为地降低了市场流动性，并且封闭式的开盘集合竞价导致价格波动加大和市场操纵。

The journal covers the research advances of the dynamics and mechanisms of sexual processes in all plants, including meiotic mechanisms, male and female gametogenesis and their related gene expression, fertilization mechanisms, gamete recognition, control of early embryogenesis and biotechnological applications in sexual reproduction etc.

该杂志涵盖了所有植物有性繁殖过程的动力学与机制的研究进展，包括减数分裂机制、雌雄配子形成与它们相关的基因表达、授精机制、偶合子识别、早期胚胎形成控制以及生物技术在有性繁殖中的应用等等。

Latest advances in studies on mechanisms for hydroisomerizaton of n-alkane over bifunctional catalysts supported on zeolites,including monomolecular and bimolecular reaction mechanisms, pore mouth mechanism and key-lock mechanisms,were reviewed.

综述了近年来正构烷烃在分子筛为载体的双功能催化剂上加氢异构化反应机理的研究进展，介绍了单分子机理、双分子机理、孔口机理及锁匙机理，并展望了反应机理在制备新型催化剂领域的应用前景。

Because of the opposition and unitarity of serial mechanisms and parallel mechanisms in philosophy,the hybrid mechanisms can be built through the combination of parallel and serial mechanisms and play an important role in some specific application background.

本文以此为背景，深入研究了若干种空间三自由度并联/混联机构的新构型，提出了几种重要的性能指标的建模及优化方法，并就具体的应用领域进行了有益的探索和挖掘。

Nutrition solution culture, ICP-AES, the differential centrifugation technique and sequential chemical extraction method, suppression subtractive hybridization , RAPD were used in this thesis to study the mechanisms of copper tolerance and accumulation by Commelina communis grown in copper mine deposit which was reported to be a Cu hyperaccumulator, compared with C. communis grown in normal soil. Several aspects were examined, including: difference of copper tolerance and accumulation between C. communis grown in copper mine deposit and that grown in normal soil; difference of growth and nutrient accumunation between C. communis grown in copper mine deposit and that grown in normal soil under copper treatment; physiological differences between between C. communis grown in copper mine deposit and that grown in normal soil under copper treatment; subcellular distribution and chemical forms of Cu in C. communis; identification of cDNA fragments differentially expressed in C. communis grown in copper mine deposit; genetic diversity and copper tolerance of C. communis, tolerance mechanisms to copper in C. communis are discussed.

中文题名鸭跖草对铜的耐性机理和富集特征研究副题名外文题名 Mechanisms of Cu tolerance and accumulation by Commelina communis 论文作者廖斌导师蓝崇钰束文圣学科专业环境科学研究领域\研究方向学位级别博士学位授予单位中山大学学位授予日期2003 论文页码总数128页关键词重金属污染植物修复超富集植物土壤污染铜污染鸭跖草馆藏号BSLW /2003 /X53 /12 论文以本实验室报道的生长于矿山上的铜超富集植物鸭跖草和生长于正常土壤中的鸭跖草为试验材料，分别运用溶液培养法、ICP-AES元素测定技术、差速离心法和化学试剂逐步提取法、抑制消减杂交技术、RAPD技术研究了矿山和非矿山两种生境鸭跖草对铜的耐性和吸收积累的差异，两种生境鸭跖草在铜胁迫下养分吸收和积累的差异，两种生境鸭跖草在铜胁迫下生理反应的差异，以及铜在鸭跖草细胞内的分布及结合形态研究，矿山鸭跖草差异表达的cDNA克隆，铜对鸭跖草种群遗传分化的影响，从这几个方面探讨了矿山鸭跖草对铜的耐性机理。

Based on the simulation data, the effects of clearances, damping coefficient and the rotation speed on the dynamic behaviors are studied: compared with ideal mechanisms, mechanisms with clearances are less stable; as for mechanisms with clearances, when the crank rotates at the speed of 100rad/s, the actual clearances are always above the radium of clearances, axle pin and axle cover keep contact throught the rotation; when the crank rotates at the speed of 20rad/s, mechanisms are in an unstable state, at an angle of about 300, the actual clearances are below the radium of clearances, pairs lose contact, which results in collision between them; with the speed of 20rad/s, when damping coefficient is assumed 175Ns/m, distinct separation and collision happen between pairs; when damping coefficient is assumed 220Ns/m, separation and collision are controlled.

在含间隙机构中，当曲柄以100rad/s转动时，运动副间隙始终大於半径间隙，轴销与轴套始终保持连续接触；当曲柄以低速20rad/s转动时，系统处於极不稳定的震荡状态，在转至300°左右时，运动副间隙小於半径间隙，脱离接触，发生明显的分离碰撞现象。在含间隙机构中，曲柄以低速20rad/s转动，当取法向阻尼系数为175Ns/m时，副元素发生明显的分离碰撞现象；当取法向阻尼系数为220Ns/m时控制了副元素的分离，副元素一直处於连续接触状态。

In this project, the selection criteria of matrix and reinforcement for obtaining composites with high strength and toughness are determined. The as-cast and aged microstructures of composites reinforced with particles of different strength are observed, and their metallurgical conditions and stabilization mechanisms are analyzed. The aging precipitation behaviors and mechanisms are studied. Some characteristics of nano-materials (micro-distortion areas) are found in 150nm- Al2O3p/Al composites and their formation mechanisms are expatiated. The "flexible" restriction to the deformation of the matrix by low strength AlN particle is observed by in-situ TEM and SEM techniques, and the mechanisms of its resist on cracks propagation and its contribution to composite strength are revealed. The high temperature deformation behaviors of Al2O3p/Al composites are studied. A rare-earth coating is established on sub-micron Al2O3 particles, leading to an improvement in wettability between coated Al2O3 and liquid aluminum and a decrease in infiltration pressure. The strength and ductility of coated particles reinforced composite are also increased. The interfacial characteristics, bonding structures and their formation mechanisms are studied, and the crystal orientation relationships between reinforcement particles and aluminum matrix are investigated. Finally a lighter composite with better balance of strength and damping properties is reinforced with hollow ceramic microballoons of ultra-lower strength.

本项目发现了获得高强度和高韧性复合材料的基体、增强体选择依据；观察了各种强度质点增强复合材料的铸态和时效态微观组织，分析其微观结构形成的金属学条件及稳定性机理，研究了其时效析出规律和时效机制，发现了150nmAl2O3颗粒增强铝基复合材料基体中的纳米材料特征，并解释了其形成机理；利用TEM和SEM动态拉伸技术发现了低强度质点AlN颗粒对变形协调的&柔性强化&机制，揭示了其对裂纹扩展的阻碍作用和对复合材料高强度的贡献；研究了中强度质点的Al2O3颗粒增强铝基复合材料的高温变形行为，并对其进行了稀土界面层设计与制备，改善了颗粒与铝合金之间的界面润湿性，降低了复合材料铸造渗透压力，提高了复合材料的强、韧性；研究了多种复合材料界面结构及形成机理，确定了增强体与基体之间的界面结合机制，分析了复合材料界面处的晶体学位向关系；最后制备了含微孔的中空型陶瓷颗粒增强的特种复合材料，得到了强度和阻尼综合性能较好的轻质复合材料。

Do you know, i need you to come back

你知道吗，我需要你回来

Yang yinshu、Wang xiangsheng、Li decang,The first discovery of haemaphysalis conicinna.

1〕 杨银书，王祥生，李德昌。安徽省首次发现嗜群血蜱。