排序方式： 共有91条查询结果，搜索用时 15 毫秒
71.
Utilizing the self made unit body model test apparatus, the deformation laws of backfill grouting were studied under different grouting pressures, different soil conditions and different ground water pressures. It was shown that high grout pressures can accelerate the consolidation rate of grout drainage and increase final deformation amount. And soil permeability coefficient was an important factor to grout deformation. The ground water pressure was more important for sand soil while the grout pressure was for clay soil. The proposed apparatus can truly reflect stress status of grout injected to tail void. And grout deformation properties were helpful to clarify the stratum stress release and stratum deformation of backfill grouting. 相似文献
72.
DING Shi min LIU Yuan yuan WANG Li ao SHEN Yue hui JIANG Xue mei FENG Xiang hua HU Wu hong 《保鲜与加工》2009,(10):1197-1201
This study investigates the mercury distribution characteristics at different particle sizes, leaching characteristics with different impact factor such as the different time, the different ratio of liquid to solid and the different acidity, leaching toxicity and speciation of mercury in Municipal Solid Waste Incineration (MWSI) fly ash in Three Gorges area. The results show that the average content of mercury in the fly ash is 8.52 mg·kg1. The content of mercury in the fly ash is higher at the particle size of 100 μm, and which increases with the decreas of the ash particle size. Mercury leaching content closely relates to environmental conditions. The leaching content of mercury increases with the increase of pH and L/S, while it decreases with the leaching time. The content of mercury at oxidable form and the residue form are high, and whith at exchangeable form and reducible form is relatively low. 相似文献
73.
采用Isight软件中的优化拉丁方法设计了20组Realizable k ε湍流模型的经验系数，并在Fluent中采用这些经验系数对Ahmed模型的外流场进行了仿真分析.在此基础上，用Kriging模型建立近似面模型，以风洞试验结果为优化目标，采用多岛遗传算法对Realizable k ε湍流模型中的经验系数进行优化.最后，把优化的经验系数应用于某实车的研发，并做了风洞试验验证.结果表明，使用优化的经验系数进行计算，得到的速度场云图与实验更为接近，收敛速度快，阻力系数误差也减小了2.8%. 相似文献
74.
针对我国通货膨胀水平与不确定性的时变性特征，分别建立了随机波动均值模型和非对称随机波动均值模型，在MCMC稳态模拟的框架下研究了我国通货膨胀水平与不确定性的动态关系。研究结果表明：我国通货膨胀不确定性中具有明显的持续性特征，并且通胀水平中虽然不存在与金融资产价格运动类似的杠杆效应，但是正向冲击增加了经济行为主体对未来不确定性的预期，由此将导致明显的“示范效应”和“追涨效应”；特别是风险溢出系数的贝叶斯估计为正，反映了通胀不确定性对通胀水平的正向影响作用，说明我国目前的货币政策框架中含有相机抉择的成分因素。 相似文献
75.
在现代学校体育教学中开展民间体育活动不仅能促进学生的身心发展,而且对于传承中华民族的传统文化具有积极的意义。但大量研究表明：由于受各种因素影响,民族民间体育项目在中小学的开展还不是很普及,作者调查研究影响潮州中小学开展民间体育的各种因素,并得出初步结论：学校领导不够重视;师资缺乏;器材设施配备不齐;场地紧缺;信息资源薄弱。据此提出发展对策：应先提高民众对潮汕民俗民间体育文化的认知水平;要加强对地方特色传统项目的挖掘、收集、整理工作;应构建以学校教育为中心的传承机制, 多渠道开发和利用场地器材;各级教育行政部门、学校领导应充分重视民间体育项目进课堂的重要性,并在人力、物力、财力等方面给予支持。 相似文献
76.
This paper explored bending performance of tube gusset joint primarily according to experiment and finite element model. The method which is used to determine ultimate strength of the joint was proposed on the base of three joint types including /4 circle ribbed, half circle ribbed and circle ribbed stiffeners. Compared with the Japanese electricity transmitting steel tubular tower manufacture norm, a conclusion has been drawn that the ultimate strength has relationship with several different parameters. The result shows that the ultimate strength of the joint is related not only to the wall thickness t, diameter D, length of gusset plate B and the yield deflection δ at the top of the relevant section under the current status of the region, but also to the ribbed plate. The formula about ultimate strength has important application value for engineering design. 相似文献
77.
WAN Chao jun YUAN Qi tao LIU Li jun ZHANG Ting lei LIU Lian chuan LI You guang 《保鲜与加工》2008,(9):1012-1017
Four samples of waste concrete with crushed limestone as coarse aggregate were collected from four different demolition sites. Each sample was crushed into particles which were then screened by sieves to remove smaller particles of given size. The residue was retained for use. Most of the residue was the crushed limestone; it was used to replace natural limestone as the calcareous raw material to produce cement clinker. These four clinker samples were compared with the similar Chongqing Lafarge cement clinker and some selected Portland cements on the market. The comparison results of XRD indicated that the XRD characteristic apex of the four principal compounds in the usual cement clinkers, C3S, C2S, C3A and C4AF, are strong enough in the clinkers produced by the waste concretes. All the free CaO content in the clinkers produced by the waste concretes was less than 1%, meeting the requirement of a given Chinese standard. It can be used to prepare Portland cements with strength grade of 52.5. The experimental results offer theoretical and technological guidance for efficiently reusing waste concretes. 相似文献
78.
Because basic CMOS gates are widely employed in high performance VLSI chips, we designed completely customized high performance 52bit or gates and 108bit and gates. HSPICE tools were used to simulate the circuits in a CSM 0.13 μm process, under 1.2 V power voltage at 25℃. Based on the features of different circuits, the corresponding input stimuli of the theoretically maximal delay were used for simulation. The frequency of the input stimulus was 1.25 GHz, while the skew was set as 10% of the input stimulus cycle. The input delay was the interval from 50% of input voltage to 50% of output voltage per cycle, and the maximal delay was the maximum of the delays of all input data. According to the different logic types, five types of 52bit or gates and two types of and gates were designed. Comparing with the simulation results, we conclude that the fully customized gates we designed are superior in many aspects such as speed, power, and area. 相似文献
79.
The construction method of concreting layer by layer and segment by segment could reduce the use of steel and save construction cost, when concrete box arch ring was built cast in place with aid of arch centering. According to the simulation of large scal 相似文献
80.
The balance principle of the strain gauge arrays observation is analyzed in detail according to the first invariant of the stress. A partly damaged strain gauge arrays' strain conversion is discussed. The stress computation through the strain gauge arrays under different condition is confirmed. A method for determining the validity of the strain gauge arrays is studied and summarized. A collection procedure containing the strain gauge arrays' validity judgment, strain conversion, and stress computation is established based on the causal relation model. 相似文献