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1.
A 70 MPa hydrogen environment fatigue test system has been designed and applied in the manufacture of a hydrogen storage vessel. Key equipment is the 80 MPa flat steel ribbon wound high pressure hydrogen storage vessel. A reasonable stress distribution has been realized, that is low stress in the liner of the pressure vessel and even stress in the flat ribbon layers. This optimal stress distribution is achieved through the adjustment of the prestress in flat steel ribbons. A control system for the fatigue test system has also been designed. It consists of a double control model, i.e. manual control and automatic control, to satisfy different experimental requirements. The system is the unique one that can be used in the real hydrogen environmental fatigue test system in China. An experiment for the 70 MPa onboard composite material hydrogen vessel has been carried out on the system. The experimental result from this test is in close agreement with the practical operating conditions.  相似文献   

2.
Market demand is positively affected by the investments in marketing and quality improvement. In a retailer dominated supply chain, the manufacturer takes charge of product quality improvement and the retailer focuses on marketing. The investments on cooperative marketing and product quality improvement in supply chains are known to be heterogeneous investment, where the manufacturer(he) is fairness sensitive and the retailer(she) is fairness insensitive. Due to the manufacturer's conservative investment resulting from this sensitivity of fairness, the retailer shares a proportion of the manufacturer's investment to increase his investment. It is found that the manufacturer's fairness negatively affects his investment and the manufacturer sometimes tends to be a ‘free rider' under decentralized decision patterns, which lead to a poor supply chain performance. This study also proves that both the manufacturer and the retailer are motivated to cooperate under centralized patterns,where the retailer's objective is additional expected profit and the manufacturer's objective is enlarging his utility.Based on the comparison of equilibrium solutions in decentralized and centralized patterns, this study suggests the range of cost-sharing proportion for supply chain coordination. The example shows the effectiveness of the provided supply chain coordination.  相似文献   

3.
In this paper, a dynamic model for an underwater snake-like robot is developed based on Kane's dynamic equations. This methodology allows construction of the dynamic model simply and incrementally. The partial velocity is deduced. The forces which contribute to dynamics are determined by Kane's approach. The generalized active forces and the generalized inertia forces are deduced. The model developed in this paper includes inertia force, inertia moment, gravity, control torques, and three major hydrodynamic forces: added mass, profile drag and buoyancy. The equations of hydrodynamic forces are deduced. Kane's method provides a direct approach for incorporating external environmental forces into the model. The dynamic model developed in this paper is obtained in a closed form which is well suited for control purposes. It is also computationally efficient and has physical insight into what forces really influence the system dynamics. The simulation result shows that the proposed method is feasible.  相似文献   

4.
Today‘s vehicles use electronic control units (ECU) to control engine/transmission, body and other amenities. All the vehicle performance depends on a lot of physical values and influence factors. This leads to a large number of control and regulation parameters in the ECU software. The ultimate objective of calibration work is the optimum determination of these parameters. Qualitatively excellent results can only be achieved in a shorter time by using a highly efficient calibration system. This paper provided an overview of a new calibration tool based on KWP2000 and gave an example calibration with this tool.  相似文献   

5.
This paper present an experimental study on the RC slab-colunm connections with nonrectangular colunms, namely cross-shaped column, T-shaped column and L-shaped column. The punching shear deformation and strength characteristics of slab-column connections with nonrectangular columns under punching shear load are investigated. Nine specimens with the three kinds of nonrectangular columns and two reference specimens with square columns are tested. The tested ultimate loads, deformations, and failur emodes of specimens are presented and discussed. Test results reveal that the punching shear strength and ductility of the connections with nonrectangular columns are higher than those of the corresponding connections with square columns, and also prove that the application of nonrectangular columns to flat-plate structure was feasible. Based on the test results, one method of calculating punching shear strength of connections with nonrectangular columns is proposed, which conforms with the current design practice of China. The test results on the punching shear strength are compared with the predictions of the formulas proposed by codes of several different countrie; and the predictions given by ACI code and China code are found to be conservative as the reinforcement ratio is increased.  相似文献   

6.
ABSTRACT     
《交通高教研究》2014,(3):101-104
This paper deals with the re-orientation of general education at the universities and colleges in Greater China in the twenty-first century. It is argued that the major challenge lies in the transformation of knowledge into wisdom so that it will facilitate improving students" life. It stresses that the methods of the merging of general education and life education lies in the self-transformation of teachers and the change of pedagogical approaches. This paper concludes that teaching is not only a profession, but also a mission. The teacher must always embrace a sense of gratitude while engaging in teaching and research work. This is where the deepest importance of our education lies.  相似文献   

7.
Mega-city region is the mainstream of global urban development and also the dominant model of the neo urbanization process in China. The Beijing-Tianjin-Hebei area, Yangtze River Delta area and Pearl River Delta area are China's three largest and most mature mega-city regions, the status of which represents the general level of the urban and regional development in China. Based on entire-array-polygon method, this paper makes a comprehensive evolution assessment of the three mega-city regions in terms of urban population index, urban economy index, urban life index, urban culture index and urban primacy index. In terms of general developing level, the three mega-city regions have progressed to optimize the structure. With their respective advantages and disadvantages, the three mega-city regions initially realize a "diversified" regional layout. The difference and gap among the three mega-city regions are obviously decreasing, which contributes to the regional balance of China metropolitan development. The rankings of the three mega-city regions will be in a continuous adjustment. The Beijing-Tianjin-Hebei area is possible to catch up and take the lead.  相似文献   

8.
This case study describes the effects of a grouting process developed to decrease groundwater flow exiting from a ruptured mine ventilation shaft lining in Luling coal mine at Huaibei, China. The primary purpose of grouting at this site is to prevent groundwater flow into the mine from adjacent aquifers. The study supports a transport perspective to describe the miscible grout movement, and provides an approximate analytical method to determine grout concentration based on Wilson and Miller's (1978) model. This study shows that the breakthrough curves (BTCs) established from the Wilson and Miller's model match the experimental BTCs obtained from test grouting performed at the site, and Rd a retardation factor of 1.1 is determined. The retardation factor and the BTC are subsequently used to guide the actual production grouting. The monitored result shows that the groundwater inflow at the disrupted ventilation well has been reduced by 47% after drilling and grouting just one borehole. The discharge rate was measured at no more than 4 m3/h after completion of four injection boreholes, which is about 13% of the 30 m3/h before grouting.  相似文献   

9.
A degradation model with a random failure threshold is presented for the assessment of reliability by the Bayesian approach. This model is different from others in that the degradation process is proceeding under pre-specified periodical calibrations. And here a random threshold distribution instead of a constant threshold which is difficult to determine in practice is used. The system reliability is defined as the probability that the degradation signals do not exceed the random threshold. Based on the posterior distribution estimates of degradation performance, two models for Bayesian reliability assessments are presented in terms of the degradation performance and the distribution of random failure threshold. The methods proposed in this paper are very useful and practical for multi-stage system with uncertain failure threshold. This study perfects the degradation modeling approaches and plays an important role in the remaining useful life estimation and maintenance decision making.  相似文献   

10.
This study investigates drivers' diversion decision behavior under expressway variable message signs that provide travel time of both an expressway route and a local street route. Both a conventional cross-sectional logit model and a mixed logit model are developed to model drivers' response to travel time information. It is based on the data collected from a stated preference survey in Shanghai, China. The mixed logit model captures the heterogeneity in the value of "travel time" and "number of traffic lights" and accounts for correlations among repeated choices of the same respondent. Results show that travel time saving and driving experience serve as positive factors, while the number of traffic lights on the arterial road, expressway use frequency, being a middle-aged driver, and being a driver of an employer-provided car serve as negative factors in diversion. The mixed logit model obviously outperforms the cross-sectional model in dealing with repeated choices and capturing heterogeneity regarding the goodness-of-fit criterion. The significance of standard deviations of random coefficients for travel time and number of traffic lights evidences the existence of hetero- geneity in the driver population. The findings of this study have implications for future efforts in driver behaviormodeling and advanced traveler information system assessment.  相似文献   

11.
As more and more Chinese and foreign-funded banks settle in the China (Shanghai) Pilot Free Trade Zone (CSPFTZ), it has become an imperative to enhance risk management of offshore banking. At the international level, the regulatory effort for offshore banking mainly focuses on tax evasion and money laundering. Existing regulatory frameworks have established standards to identify countries providing facilities for money laundering and developed punitive measures. In terms of strategy, it is suggested that, firstly, relevant regulatory measures should be improved in the short term, and it is necessary to define the scope of offshore banking and regulatory measures for Chinese banks and foreign-funded banks under a suitable legal framework. Secondly, it is necessary to establish risk exposure mechanism and risk evaluation system for the offshore banking in the CSPFTZ, while risk management measures are implemented based on on-site supervision. Thirdly, in the medium and long term, it is necessary to enhance management of potential risks which can be created by offshore banking due to deregulation. Fourthly, on the one hand, specific regulations should be formulated to provide a regulatory basis for taxation; on the other hand, tax informational exchange agreements (TIEAs) may be used as a reference for achieving effective tax regulation.  相似文献   

12.
互联网是一把“双刃剑”,它给我们的生活带来便利的同时也引发了不少社会问题。文章分析了近年来频繁出现在网络中的舆论暴力事件的含义及特征,全面探究了其产生的伦理根源,并针对其产生的原因提出了相应的伦理对策。  相似文献   

13.
根据入世承诺,我国从2006年12月11日起向外资全面开放金融业。作为规范外资银行的主要法规,新修订的《外资银行管理条例》及其实施细则对外资银行的本地注册、人民币零售业务和银行卡业务等方面作了相应的限制性规定。从法条层面看,这些限制规定似乎符合世贸组织有关服务贸易审慎监管的规定,但是从法理层面分析,特别是结合我国具体的入世承诺和其它的法律规定,这些限制措施的审慎理由并不充分,很容易受人诟病并招致其它世贸组织成员的挑战。  相似文献   

14.
文中阐述了我国商业银行内部控制制度的状况,并说明了完善我国商业银行内部控制制度的重要性。在此基础上,针对我国商业银行内部控制薄弱的状况,研究和分析我国商业银行内部控制对策理论。本文总结了对商业银行内部控制制度建设的对策及其建设思路,为进一步深化完善我国商业银行内部控制对策提供良好的理论依据和建设方向。  相似文献   

15.
This paper focuses on the situation in the cold region of China where the transportation safety management of road is passive and negative, the coordination between managements is poor, and the efficiency of emergency rescue is low in snow-icing weather. It also analyzes the characters of road transportation safety in snow-icing weather, and summarizes the national and foreign disposal strategies to deal with snow-icing traffic. Then three effective strategies that can reduce the impact on road transportation safety by snow-icing weather have been received, including the provision of information, traffic control, and dealing with the snow-icing. The paper also discusses the effect of each strategy from the perspective of road maintenance managers, emergency managers, traffic managers, and road users. It will be helpful to improve the operations of road transportation safety in snow-icing weather in the cold region of China.  相似文献   

16.
实践性欠缺是我国高等学校思想品德教育长期存在的一个实际问题。克服以往单纯的知识传授,增加德育的实践性环节,加强对青年学生的德育行为训练和实践磨练,是德育改革的趋向,也是增强学校德育实效性的重要途径。  相似文献   

17.
本文从德性伦理——伦理制度——制度伦理三个方面考察信用机制的生成条件,认为把信用作为个人品性准则、市场契约规则以及制度化伦理三个有机体相结合,将有利于社会信用体系的建构。  相似文献   

18.
针对目前我国寒冷地区冬季冰雪天气条件下道路交通安全管理被动、消极,部门间协调性差,紧急救援效率低的局面,对比分析了国内外寒冷地区冰雪天气条件下的道路交通安全特征,通过总结国内外冰雪天气条件下的道路交通安全处理策略,得出了三类有效降低冰雪天气对道路交通安全影响的管理措施——信息提供、交通控制、冰雪处理,并从道路维护管理者、紧急事件管理者、道路交通管理者和道路交通参与者四个方面就三种管理措施所能取得的安全效果进行了分析,期望能对我国寒冷地区的冰雪道路交通安全管理有所帮助。  相似文献   

19.
结合城市轨道交通建设的土地储备机制研究   总被引:4,自引:1,他引:4  
陈伟  范黎萍 《城市交通》2006,4(2):21-24
从加强政府调控土地一级市场的角度,分析了轨道交通建设投融资和土地储备机制相结合的重要性,结合轨道交通站点实施土地储备的量化分析,研究了结合市域轨道交通规划实施土地储备的储备范围、储备方式和储备时机等。同时,以上海市结合轨道交通实施土地储备的运作实例,提出了土地储备运作方案的策略。  相似文献   

20.
我国传统上是一个伦理本位的社会,伦理道德在社会生活中的影响巨大而深远。诚信是中国传统伦理道德体系中一个重要的范畴。诚信对社会主义市场经济伦理道德的建构具有十分重要的意义。诚信是维系市场经济良性发展的"内生变量",是一种特殊的经济资源。经济信用是从属于商品与货币关系中的一个微观经济范畴,是任何社会经济形态所共有的。它既是现代市场经济的重要资源,又是社会进步不可缺少的无形资本。从经济活动的微观、中观、宏观层面来看,诚信具有不可替代的作用。  相似文献   

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