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61.
乌江流域茶园土壤理化性状对茶叶品质影响的研究   总被引:2,自引:1,他引:2  
对乌江流域主要茶场茶园土壤理化性状、茶叶生化成份测定结果表明:不同母岩发育的土壤理化性状各不相同,其对应的茶叶品质也不相同。土壤理化性状及茶叶品质优劣依序为硅质黄壤>砂页岩黄壤>第四纪粘质黄壤>小黄泥>黄棕壤  相似文献   
62.
(1甘肃农业大学经济管理学院,兰州 730070;2兰州资源环境职业技术学院,兰州 730020)  相似文献   
63.
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   
64.
Hydrodynamic models have been widely applied to river and coastal engineering projects. Understanding the hydrodynamic process is a prerequisite to modeling the pollution and sediment transport process. Hydrodynamic models of varying degrees of complexity should be selected appropriately according to the object of study, physical properties of the flow domain and hydrodynamic features. The essential procedure of hydrodynamic simulation is described in this paper. The main problems such as selection of model dimension in physical space, choice of variables, boundary conditions, initialization, design of computational grid, model resolution, parameterization of smaller scale fluctuations and sub-grid scale processes, model calibration and verification are investigated.  相似文献   
65.
The thesis introduces the origin of demonstrate item on the city water environment quality improvement-tao-hua river water environment competitive administer, analyzes the current situation and cause of taohua river valley pollute and ecological destroy, and summarizes the gain and loss in projects which have taken place in the domestic city water environment competitive administer. On the base, a collectivity idea is put forward that it should stress recovering and rebuilding ecosystem on the item. Due to the water environment in taohua river is representative, if the item can be favorably carried out, it not only improves GuiLin water environment, makes people life advantage and expands city tour, but also produces important affects to the other domestic cities in the condition of using marketable economy means to improve city water environment quality.  相似文献   
66.
Employing the standpoint of irrational investors in the behavior finance, the authors study the relation on the irrational behavior of medium and small Investors and underpricing of IPO in our country. The paper premises that a revenue-maximizing issuer will be regarded as the target function, and the rational institutional investors can be delegated the task of holding the stocks in the after-market for resale to the irrational medium and small investors--thereby extracting surplus from them, finally the issuer can maximize their expected revenue. We model the process mentioned above and find that the high underpricing of IPO in our country has the direct relation with numerous the irrational medium and small investors existing in our country who cause the underpricing.  相似文献   
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68.
The rural urbanization process in Chongqing is much slower than that in other metropolitans and most of the provinces in eastern China, which can't adapt to its important function as the economic and cultural center in southwestern China.It is urgent for Chongqing to accelerate the rural urbanization for improving its whole urbanization level and speeding up its economy development to catch up with other metropolitans and some advanced provinces.Compared with the urbanization in other metropolitans and some provinces, the authors demonstrated the rural urbanization situation and its characteristics in Chongqing in details, analyzed the reasons for the poor urbanization and its influences on the social-economic development especially that in the rural area.Inferior position of Chongqing's small towns in the market competition with those from other provinces is one of the results of its poor urbanization development.At last, the authors suggested a few practical countermeasures to improve the rural urbanization in order to get a rapid and sustainable rural development and to increase the whole economic effects of the metropolitan.  相似文献   
69.
70.
针对小水电站年发电量序列的特点,将最小二乘支持向量机(least squares support vector machine,LS-SVM)回归模型引入年发电量预测领域,并给出了相应的过程和算法。与常规基于人工神经网络(artificial neural net-works,ANN)的智能预测方法比较,该模型优点是明显的:①将神经网络迭代学习问题转化为直接求解多元线性方程;②整个训练过程中有且仅有一个全局极值点,确定了预测的稳定性。最后,一个实际的预测例子表明:该模型实现容易、预测准确,适用于小水电站预测。  相似文献   
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