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151.
当网格剖分足够密时,采用差分解法可得到具有足够精度的有重土静力极限平衡数值解。根据大量计算分析,揭示了有效旁侧荷载宽度L、无量纲极限承载力 / 与内摩擦角 、无量纲参数λ的内在规律,据此将滑移线法数值解拟合为简洁的解析表达式,并在理论上证明了这一规律。通过与几种经典承载力公式的比较和分析,综合对该拟合公式的可靠度分析,论证了其正确性和可行性。 相似文献
152.
153.
According to the new requirement of sustainable development in the new stage, this paper puts forward the definition of the safeguarding capacity of regional sustainable development and uses some statistical methods of frequency statistics and principal component analysis to construct the index system of safeguarding capacity. Then it takes the data of the Three Gorges reservoir area for example to make empirical analysis, and provides efficient measurement tools to further measure the regional sustainability together with its safeguarding capacity, and therefore helps the government and the relevant organizations to establish more scientific policies of sustainable development. 相似文献
154.
A theoretical model is developed for the dropwise condensation heat transfer on the horizontal circular surface with radial gradient surface energy based on the heat transfer model of individual condensate drop and the size distribution model of condensate drop on homogeneous condensation surface.The effect of variation of contact angle on the gradient surface on condensation heat transfer and condensate drop size distribution is taken account of in this model.The theoretical calculation method was obtained to predict the dropwise condensation heat transfer coefficient on the horizontal circular surface with radial gradient surface energy under various wall subcooled temperature,contact angle profile on wall surface,and working fluid.The effects of surface energy gradient,wall subcooled temperature,and thermophysical properties of condensate on the condensation heat transfer are discussed respectively.The calculation results show that the condensation heat transfer coefficient increases slightly with the increase of wall subcooled temperature.As latent heat and surface tension increasing,the condensation heat transfer coefficient increases.A larger surface energy gradient induces a larger condensation heat transfer coefficient. 相似文献
155.
At present, in the evaluation process of the real estate value the material form is mainly concentrated on, while the value brought by the real estate brand are usually neglected. In this paper, considering the particularity of the real estate brand evaluation, the method of network analysis is adopted. In the evaluation process, the evaluation method of excess income law are developed by leading the thoughts and methods of the fuzzy set theory, and a systematic assess model is found. Then, an example is given as illustration. At last, the appraise about the application of the model is made. 相似文献
156.
It is difficult to measure the geometric quantity of small parts in finishing, assembling and measuring, because it's easy to break the workpieces' surface and alter their position by means of traditional contact measuring methods.There are some non contact measurers, such as,light feeler pin and interference microscope etc., because of it's high price and strict working conditions,so it's difficult to promote them in widely use. Precision measurement system based on machine vision has the advantages of non contact measuring as well as high performance and low price. Some problems, such as light source, algorithm of edge fitting, auto focusing,are discussed. 相似文献
157.
Both total irradiation and diffuse irradiation are necessary to building energy consumption analysis. At the most cases in China,only total irradiation is available. So some method is needed to estimate diffuse irradiation. Relationship between daily diffuse irradiation and daily total irradiation is analyzed, based on data form Beijing and Chengdu.Polynomial models for Beijing and Chengdu are established to estimate K d form K t . Validation tests show good performance of the models. Monthly means of predicted daily diffuse irradiation is not significantly different from that of the original daily diffuse irradiation. Also,the auto_correlation function of the predicted diffuse fraction, K d is coincident with that of the original K d . Beijing model can accurately predict the data of Chengdu,which is significantly different from Beijing as to the climate,so it is recommended as the general model. 相似文献
158.
The social evaluation theories of public project still have not been standardization today, and have effects on the process of the construction to city. One of the main reasons lays in that the index system, about the social evaluation theories of public project, connects with many fields, has many non-economic index and difficult in measuring the every index. This article is to mark off the main factors involved in social evaluation effectually, to set up index system of social evaluation practically, and to settle firm ground for methodology and theory of public project. 相似文献
159.
This paper ainalyses the size effect of the fracture energy of concrete tested bythree point bending. It is shown that positive errors of test results of fracture energy increase,ornegative errors decrease with increasing of the specimen ize. The phenomenon is one of main causesresulting in the size effect of fracture energy. 相似文献
160.
This paper analyzes the current situation of university students' credit evaluation and set up an evaluation index system of university students' credit to compensate a loan.Based on this index system,this paper sets up a matter-element evaluation model on the individual credit of university students loan by means of extensible engineering method.The grade of individual credit and the index for evaluating the level of individual credit are made as matter-element,meanwhile,the classical field,the segment field,the weight coefficient are obtained.Dependence function is established based on the grade of individual credit and then the grade is judged by calculating the synthetic dependence degree.Finally,this paper presents the evaluation method by giving an example.This method is simple in calculation,reasonable in evaluation with high applicability. 相似文献