主要原因

In general, the design work with traditional measures is done by hand, which cannot meet the needs of the technology and manufacture. So the author has developed a CAD hydraulic design software fit for lower specific speed axial flow runner, which is easily operated by users.The main research work of this paper is as follows:1 Analyzing the main reason of axial flow power station cannot work well under littler volume of flow in some season and putting forward an improving scheme, pointing out the characters of design under abnormal factors.2 Combined with the development of the industry in our country, the abnormal hydraulic design method of propeller turbine is discussed based on present literature, data and experiment results.3 Guided by the design method of software engineering, a suit of hydraulic design software of Lower Specific Speed Axial Flow Runner is programmed by the object-oriented programming language Visual Basic and a straightforward, concise and standard Windows human-computer dialogue interface is designed for the system, which makes the operation of the system very convenient.4 ActiveX Automation technology is adopted as the interface with AutoCAD and the hydraulic drawings are edited, modified by AutoCAD until hydraulic model drawings according with the demand of engineering practice are output.5 To resolve practice problem, the author has designed a lower specific speed axial flow runner for Duowa Power Station through an example.

论文的主要内容有：1 深入分析很多轴流定桨式水电站枯水季节小流量下不能发电的主要原因，提出减容改造方案，并指出超常规条件下的改造设计特点。2 结合国情及行业发展需要，参考现有资料、文献和前人的研究成果，进行低比转速轴流式转轮叶片水力设计方法的研究，对轴流式转轮叶片的奇点分布法水力设计进行了全面的探索，结合现代计算机技术，找到了一种针对特殊条件的轴流式转轮叶片水力设计方法。3 仔细比较多种AutoCAD二次开发工具后，结合本课题的特点，选用Visual Basic语言，综合应用软件工程的设计思想，进行低比转速轴流式转轮叶片水力设计软件的编制，为系统设计了直观、简洁和标准的Windows人机对话界面，便于用户操作；编程时在考虑到设计条件特殊性的同时，尽量做到程序的通用性，使之可用于解决同一类问题；另外，大部分程序还可移植到普通轴流式转轮叶片水力设计中，具有良好的适应性。4 利用ActiveX Automation技术与AutoCAD接口，对AutoCAD进行二次开发，在AutoCAD下实现水力图的自动生成和编辑，直至输出符合实际工程要求的木模图。5 通过算例，为多哇水电站设计了一个低比转速轴流定桨式转轮，解决其在枯水期小流量下不能发电的问题。

The above differences are mainly caused by: Chinese is a language characterized by parataxis, while English is a typically hypotactic language.

5造成以上差异的主要原因是：汉语是以意合为主要特征的语言，而英语是以形合为特征的语言。

From on-site inspection of circumstance and the second-hand data control to see, one word a translation with neglect the idiomatic expression of outside text is to result in English use two not fitting main reason, use a foreign language mainly is for seeing to the foreigner, if appear so so of mistake, will influence exchanges, even produce to mislead of function.

从实地调查的情况以及所掌握的第二手资料来看，一字一字地翻译和忽略外文的习惯用法是造成英语使用不恰当的两个主要原因，使用外语主要是为了给外国人看的，如果出现这样那样的错误，就会影响交流，甚至产生误导的作用。

Families thought there were hygiene problems in familial banquets, such as dishwares disinfection, rural caterers operations and cold dishes cooking. 96.2% families expected some relevant supervisions to be carried out. The results above illuminate that rural familial banquets are popular in countryside, appropriate way is to improve the occasion.

而经济实惠是农村家庭选择自办家宴的最主要原因。45.2％的家庭认为自办家宴有卫生问题，且主要存在于餐饮具卫生、民间厨师加工操作卫生、凉菜制作卫生等环节。96.2％的家庭期望出台相应的管理措施。

RESULTS: Complications including cornea injury, iris injury, posterior capsule rupture, iris prolapse and hyphema, were mainly caused by inexpert skill and lacking of experience.

术中并发症主要是角膜损伤、后囊膜破裂、虹膜损伤、虹膜脱出、前房出血，主要原因是技术不熟练和操作经验不足。

Analyzing the relation between earthquake and structure distortion, main fault belt, crust, upper mantle, ground fracture, hotspring, geotherm, conductance frame, stress state in Guanzhong area is analyzed with earthquake mechanism, isoseismal line, crustal stress measure, fault displacement measure, and simulating test results. Earthquake formation mechanism is discussed with dynamics mechanism in Guanzhong base. There are 3 forces and a good medium environment, which are main reasons caused earthquake happened in Guanzhong area. The first force is NE and NEE level extrusion one which is parallel with long axis of Guanzhong base. The second one is level strain which is vertical with long axis of the base.

对地震与构造形变、主要断裂带、地壳及上地幔、地裂缝、温泉和地热、电性结构等关系进行了分析研究，通过震源机制解、地震等烈度线、地应力测量、断层位移测量及模拟试验等成果，分析了关中地区的地应力状态，从关中盆地的动力学机制，对该区的地震成因机制进行了探讨，认为与关中盆地长轴平行的NE和NEE向的水平挤压力、与盆地长轴方向垂直的水平张力及地幔上涌力三组力的作用，加之壳内高导层这一有利的介质环境，是导致关中地区地震发生的主要原因。

Crack is one of the most common damages in composite laminated plates,and it is the chief factor of causing failures.

裂纹是复合材料层合板的主要损伤类型之一，也是造成复合材料层合板失效的主要原因。

Fibrosis is the main cause of ligamentum flaum hypertrophy, and fibrosis is caused by the accumulation of mechanical stress with the aging process, especially along the dorsal aspect of the ligamentum flaum.

纤维化是黄韧带肥厚的主要原因，造成纤维化的主要因素是随着年龄的增长机械应力的积累，特别是在着黄韧带的背侧面。

It is found that the crystallinity and the orientation of macromolecule are the main reasons changing the mechanical properties and the great changes are happened during rolling.

结果发现，结晶度和大分子链的取向是影响材料力学性能的主要原因，力学性能的变化主要发生在轧制过程中。

Cerebral infarction is one of main complications of diabetes, and one of main lethal and maimed reasons impatient...

脑梗塞是糖尿病的主要并发症之一，也是糖尿病致死致残的主要原因之一，同年龄糖尿病患者发生脑梗塞的机率明显高于非糖尿病患者。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。