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61.
土质边坡稳定安全系数的计算值主要与采用的简化计算方法和土工参数有关。采用正交试验法计算分析了不同的计算方法、材料参数、水位及其相关荷载、地震作用等对边坡安全系数计算值的影响,进而对设计中的计算方法和材料参数提出了一些有益的建议,并提出了在工程运行管理中应尽量避免低水位或水位骤降情况的意见,为土石坝类工程的设计与运行管理提供了重要参考。  相似文献   
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63.
The cavity induced by top-blow gas jets impinging on the bath surface is one of most important parameters, which has overwhelming influence on the rate of slag formation and metallurgical performance. Water model experiments are conducted through a 1/10 scaled-down top-blown convertor. Effects of lance height and gas flow rate on penetration behavior are studied, and also the influence mechanism of liquid surface tension on penetration depth is addressed based on the experiments and theory analysis. An energy utilization index (EUI) is defined to reflect how much the impinging kinetic energy of gas jets are transferred into bath for formation of cavity, and an improved model is proposed to predict penetration depth of jets. The results show that penetration depth increases with lowering lance height and increasing gas flow rate, and impact diameter increases with increasing lance height, but is little affected by gas flow rate. Influence of liquid surface tension on penetration depth is enhanced with increasing surface tension and penetration depth. The EUI increases with increasing lance height, and a function relationship of it with lance height is obtained based on the experiments.  相似文献   
64.
The electrocardiogram (ECG) signal is a recording of the electrical activity on the body surface generated by the heart frequency of which is weak and low. Many researchers devote themselves to get more perfect ECG in many ways. This article introduces the characterize of an ECG signal , then discusses the requirements for the sampling circuit of an ECG. Since there are some shortcoming in common design means, the authors give an effective circuit. The system is composed of a low-cost , low-power and high-performance MCU C8051F020 , amplifier AD620 , right-leg drive circuit ,communication circuit and power management circuit. Then software design is given which is used to sampling and filtering ECG signal. Levkov filter arithmetic and smooth filter arithmetics are used in this design. In the end , the authors advance a distributing and networking ECG monitor system.  相似文献   
65.
Dong village is very valuable for research work because of its special regional and national character and rich cultural implication. In this paper, some information about the location, form and features of Dong village is given. Then, the relationship between the culture and the settlement is analyzed, which provides a clue for understanding Dong village and will be beneficial to creating modern human settlements.  相似文献   
66.
Pushover analysis is a tool to study the inelastic behavior of structures under strong seismic action. The 3D-pushover analysis was performed to analyze the inelastic lateral-torsional coupled response of multistory asymmetric structures. The symmetric frame and frame-wall systems were studied in this paper, and the capability curve of the top displacement and base shear,the story drift and the position of rotation center were compared with reference to corresponding symmetric structures. The characters of inelastic response of multistory asymmetric structures were found. The conclusion provides reference for performance-based seismic design of asymmetric structures.  相似文献   
67.
In accordance with the deficient elongation of the Stretching-bending Rectifier, as well as the severe wear and slipping of V-belt , the driving system velocity ratio of rectifier and the calculation formula of the theoretical elongation are deduced, which are based on the analysis of its structure and reeling principle. The carrying capacity of the driving system is also analyzed and it reaches the main reason for the elongation of the stretching-bending rectifier that cannot reach request, which is caused by the step less torsion of fixed output of the continuously variable transmission. The improvement measure which can be achieved by increasing the stiffness of the spring to increase the output torsion of the continuously variable transmission is proposed. Thus it makes the actual coefficient of elongation,which can satisfiy the producing request.  相似文献   
68.
云粳29号是云南省农业科学院粮食作物研究所选育的常规粳稻香软米新品种,2011年3月通过云南省农作物品种审定委员会审定。该品种早熟、米质优、产量高、抗倒伏、抗稻瘟病和白叶枯病,其米饭香浓,柔软可口、外观油润光泽、冷不回生、商品性好。为进一步促进该品种推广应用,保持其优质、高产特性,防止混杂、退化,经过不断探索和研究,提出了优质种子提纯复壮与繁育技术。  相似文献   
69.
基于圆盘渗透仪常用计算模型的比较和分析   总被引:1,自引:0,他引:1  
圆盘渗透仪已成为一种常用的田问测定土壤导水参数的仪器,基于圆盘渗透仪在某一选定点测量的入渗时间以及与入渗时间相对应的入渗量,利用一些常用的计算模型来计算低基模吸力土壤表层的导水参数,如吸水系数、导水率和宏观毛管上升高度等。本研究在总结一些常用的计算模型的基础上,并结合实验和模拟的数据对其进行比较和分析,为利用圆盘渗透仪进行土壤水力特性的估算提供了一定的参考作用。  相似文献   
70.
以弧形钢闸门自重、静水压力、闸墩及护坡自重、闸墩基础与地基间的摩擦系数和基底粘着力等因素作为随机变量,探讨了弧形钢闸门抗滑稳定可靠性分析方法,建立了抗滑稳定极限状态方程。结合工程实例对弧形钢闸门抗滑稳定可靠性进行了定量分析,可靠性指标b为4.1688,失效概率Pf为6.717×10-5,并与传统的容许应力法作了比较。结果表明,该方法更科学、更合理、更具有实际意义。  相似文献   
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