单元

The above-described configuration of the zoom lens system allows appropriate setting of the imaging magnification of the fourth lens unit and the focal lengths of the third and fourth lens units.

变焦镜头系统的上述结构允许适当设定第四透镜单元的图像放大率以及第三和第四透镜单元的焦距。

From the industry to observe,the author discovers that the regional gap of the secondary industry was the primary contributor,but the rate of was descending.The third industry was becoming the important contributor.The industry structure adjusting and the agglomeration of the third industry and the secondary industry are the primary reason of the forming of the disparity of between the east and the rest areas.In the 1978 to 2005,the absolute convergence of economic growth didn't occur,the other way round,the club convergence of economic growth occurred in the east and in the middle.The speed of the economic growth in the east was higher about 1 centigrade than the middle and the developing west,and was higher about 2 centigrade than the west.

从以省区为单元的中国地区经济发展差距形成的产业构成来看，第二产业的地区差距长期以来都是中国地区经济发展差距的主要贡献者，居主导地位：但是随着第三产业产值比重的提高和第三产业地理集聚的非均衡性扩大(1990年以后)，第三产业的地区差距正逐渐演变为以省区为单元的中国地区经济发展差距形成的主要贡献者。1978-2005年期间，中国地区经济增长并没有出现绝对收敛趋势，而是表现为东中部地区内部的"俱乐部"收敛。1978-2005年东部地区经济增长速度比中西部地区更快，东部地区平均经济增长速度比中部地区高1个百分点左右，比西部地区高接近2个百分点，地区间经济增长速度存在显著的差异。

a kind of design project of multifunction electric power quality gauged instrument based on virtual instrument is put forward in this article.this system integrates virtual instrument programming and power electronics together,to realize diverse signals of current electric power quality field allin one.the integrated signal generator unit which carries out the collection of high speed digital data,d/ a conversion and analog output in four channels,unsymmetrical synchro control fifo etc.by fpga are introduced,the flow of electric power system various signal which generates by vc programming is elaborated,and the structural design of signal amplification unit is analysed.the experiment text result shows that this gauged instrument has attained current advanced high grade of accuracy and it will accelerate the steps of electric power quality calibration because of its accuracy and versatility.

摘 要：提出一种基于虚拟仪器技术的多功能电能质量标定仪的设计方案，采用虚拟仪器编程技术和电力电子技术相结合实现集目前电能质量领域的多样信号于一体。介绍采用fpga实现高速数字量采集、d/a转换及4通道模拟量输出、非对称同步控制fifo等的集成信号发生单元，阐述利用vc编程实现的电力系统多样信号的产生流程，分析信号放大单元的结构设计。实验测试结果表明该标定仪达到目前先进的高精度等级，由于其准确性和多功能性将加快电能质量标定的步伐。

Are there any explicit or implicit addressing problems if, on the machine being used, the units of memory allocation are smaller than the units of memory addressability?

是否存在隐式或显式寻址问题，即当在某台机器上运行程序时，内存分配单元小于内存地址单元时出现问题。

Are there any explicit or implicit addressing problemsif, on the machine being used, the units of memory allocation aresmaller than the units of memory addressability?

是否存在隐式或显式寻址问题，即当在某台机器上运行程序时，内存分配单元小于内存地址单元时出现问题。

All meshing elements except those are adjacent to edge and transition elements are equilateral triangle, which is very useful for finite element computation.

提出了一种可在平面内进行三角形有限元网格划分的方法，该方法可以在任意二维区域进行剖分；剖分单元除了边界和部分过度单元外，主要为等边三角形。

Outside, your main job is to clean the condenser coil. The fan inside the condenser coil sucks air through the fins, and as a result, pulls dirt and debris with it.

大多数中央空调是由两个基本部分组成的：一部分是室外单元，蒸发器位于中环附近的炉管是在主页和室内单元的旁边。

By default browsers center heading cells, and left align data cells.

浏览器默认将标题单元格居中，数据单元格左对齐。

Given that it's also useful to have the icons align with each other in each column, the ideal would seem to be for icons to align to the left or right of left or right aligned cells and automatically indent the cell contents to make space.

假设图标在每列中彼此对齐也有用处的话，理想状况是图标应该可以自动在左对齐或者右对齐的单元格中进行左对齐或者右对齐，并且，单元格内容自动缩进以确保空间。

The basic approach of protecting people from being hurt or killed in an accident is to improve crashworthiness of vehicles. This paper starts with discussing theories and methods for vehicle passive safety design, which included experiential methods, analytic methods, multi-body dynamics methods, crash test methods and the finite element method. Emphasis will be paid to the basic FEM theories and algorithms of impact problems. Topics discussed include the governing equation, element discretization, hourglass control, time integration, material model, shell element algorithms and contact-impact algorithms. For more reliable simulation results, this paper then conducts study on how to accurately get material model parameters by combining the FEM method with experimental method, and develops relevant material test machine and parameter calculating software. Based on that, basic typical impact simulation and test validation study are conducted. On the basis of the above work, the paper studies the thin-shell structures'crashworthiness, which was affected by the following factors: spot-weld features, shell thickness, cross-section and pre-deformation. As to vehicle parts'crashworthiness, the paper conducts simulation study of designing energy-absorbing steering system and adaptive airbag system. A practical energy-absorbing steering wheel is designed as an example. In further depth research, the paper suggests several inverse quantificational methods for vehicle crashworthiness design based on the ideal crash characteristics. The above theories and methods are applied with good results through several practical vehicles' crashworthiness design and improvement.

文中对汽车碰撞安全性的设计理论和方法进行了归类和总结，其中包括经验法、解析法、多刚体动力学法、试验法以及有限元方法等；重点介绍了碰撞有限元法的基本理论和有关算法，涉及到有限元求解控制方程、单元离散、沙漏模态控制、时间积分、材料模型和应力修正、薄壳单元算法以及接触碰撞界面算法等，探讨了有限元计算中的材料模型参数获取技术，开发了相应的材料试验装置及材料模型参数反求软件，在此基础上进行了基本的碰撞仿真算例和试验对比研究；文中通过应用有限元方法研究了薄壁构件的碰撞吸能特性，指出了设计薄壁吸能构件时需要考虑的几个主要影响因素，即焊点、壁厚、横截面和预变形等；在关于车辆部件的碰撞安全性能设计中进行了吸能转向机构和自适应安全气囊的仿真研究，提出了吸能转向机构和自适应安全气囊的仿真研究方法；文中最后探讨了整车碰撞性能的设计与改进方法，提出了以理想碰撞特性为目标，采用分段加速度或者根据碰撞时间进行设计的反推设计法、部件吸能仿真优化设计法等量化设计方法，并通过综合应用文中所讨论的相关技术进行了整车碰撞性能的设计与改进实例研究，所选定的车型是大众化的普通轿车和碰撞安全性基础较差的微型面包车，研究结果表明，本文所提出的设计与改进方法是适用而有效的，具有重要的工程实用意义和价值。

It has been put forward that there exists single Ball point and double Ball points on the symmetrical connecting-rod curves of equilateral mechanisms.

从鲍尔点的形成原理出发，分析对称连杆曲线上鲍尔点的产生条件，提出等边机构的对称连杆曲线上有单鲍尔点和双鲍尔点。

The factory affiliated to the Group primarily manufactures multiple-purpose pincers, baking kits, knives, scissors, kitchenware, gardening tools and beauty care kits as well as other hardware tools, the annual production value of which reaches US$ 30 million dollars.

集团所属工厂主要生产多用钳、烤具、刀具、剪刀、厨具、花园工具、美容套等五金产品，年生产总值3000万美元，产品价廉物美、选料上乘、质量保证，深受国内外客户的青睐