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1.
Site dynamic balance is a important element in installation and maintenance of heavy rotary mechanism. It's hard to discharge testing weights, and the remanent weights will effect the result of balance test. The paper presents a kind of dynamic balance algorithm which need not to discharge the test weights, basing on influence coefficient. The principle of the algorithm is to balance the sum of original unbalance weights and testing weights by the result balance weights. In the algorithm , the influence coefficient of last time can be used optionally for the same rotor. Then developing a dynamic balance system building on it. The site experimental results indicates that this algorithm has a high balance precision, predigests the steps and reduces the operation time.  相似文献   

2.
In this paper, a new method of researching; the site dupleface dynamic balance of machine rigid rotator, namely duple test weightmethod is presented. Weight the new method against the existing method,namely single test weight method [1], both the efficiency increasing and theenergy-consumming dicreasing would be forty percent and over, with thebasic points of vibration theory, the formula of calculating weight andposition of the duple face dynamic unbalance of a rotator by means ofapplying the duple test weight is developed in detail. The method in handll-ing distinct bearing form is also discussed. Rightness of the new method isproved out by the living example of the simulant contrast testing carried outn the dynamic balance test machine and the site balance for a rotatorsystem of motor.  相似文献   

3.
This paper describes the theory and research progress of dynamic structural damage identification technique of the last twenty years.The basic theory of dynamic structural damage identification techniques is introduced first.Next,three important aspects of damage identification are discussed: identification mechanisms,dynamic parameters,and identification algorithms.Finally,a review of the state-of-the-art and development trends in this field is presented.  相似文献   

4.
According to the proporties of mechanisms in different working orders,this pa-per provides the load-time function by dynamic view. The input excitation is useful for the study of tower crane dynamic-state,and true for selution of tower crane dynamic equation. The view andway in the paper have the meaning of theory and practice for other engineering machinery  相似文献   

5.
Being a kind of MWR, the orthogonal colloacation method can be conveniently used to reduce the initial-boundary value problems of the partial differential equations to initial value problems of ordinary differential equations. In this paper, the orthogonal collocation method is introduced in detail and by using it the dynamic characteristics of a steam-water heater are investigated.  相似文献   

6.
The wind load is a major load on tall buildings from side directions. It is of considerable necessity to building engineering that the static and dynamic wind load and the dynamic wind response can be achieved accurately. Therefore, the model of a tall building in Chongqing is made and tested in wind tunnel by using the high frequency balance used widely home and abroad at present. The characteristics of wind load are studied. This paper gives the coefficients of base force of the building produced by wind load in different wind directions, and offers reference for wind-resistant design of the building.  相似文献   

7.
As the domestic technology of selective catalytic reduction(SCR) has not been mature.A assembled-parameter dynamic mathematical model is established for the primary chemistry reaction process in SCR reactor.The mass balance equation of the NH3 adsorption-desorption on the catalyzer surface and six gas components,and total energy balance equation in SCR reactor are set up respectively.A dynamic simulation model has developed by using MATLAB simulation tool.The steady calculation for model is carried on.Based on the established dynamic simulation model,two dynamic simulation experiments have been done,which include the simulation experiment of step disturbance about NOx concentration and temperature.The simulation results current is correctl.The analyzed results indicate that the established dynamic mathematical model for SCR reactor is credible,and prove that the simulation model is practical.  相似文献   

8.
A lot of information needs processing in time in dynamic balance testing, but the current intelligent dynamic balance instruments and the controlling box of dynamic balance machines made up ofsinglemicrocontroller do not meet the request.A method isgioen that the DSP-Microcontroller will be useddiredtlyinthe system of the intelligent dynamic balance instrumentby using embedded design technique. A principal and subordinate control system compose of DSP and microcontroller. The Microcontroller the system as a principal controller and the DSP implements digital filtering and FFT in dynamic balanc by means of its fast operation. The system develoyed according tothe method can do more analysisin time areaand frequency area.  相似文献   

9.
There are three contrasting approaches to understanding the geography of production. The first approach emphasizes the importance of local agglomerations, the second intrafirm mechanisms, while the third highlights global relationships or global production networks (GPN) or global value chains. These explanations are partial, but complementary. This paper explores the restructuring of global production with a focus on the reshoring or repatriation of manufacturing production to the U.S. and UK. Our intention is to identify the drivers behind reshoring as the first stage toward developing a dynamic conceptual framework for understanding the global organization of production. Reshoring needs to be conceptualized by drawing on and combining approaches developed in GPN with micro‐approaches to understanding firms including the development of a geography of production tasks. The study is based on a theoretical mapping to inform an empirical analysis of reshoring in both countries to identify and conceptualize the quantitative and qualitative causal drivers behind this process. The evidence suggests that reshoring is sector‐dependent and is mainly driven by manufacturers’ cost‐management and quality strategies combined with the importance of manufacturing products close to market. This involves a “total manufacturing cost analysis” in which access to a set of tangible and intangible inputs are key drivers behind dynamics of GPN.  相似文献   

10.
In this paper, based on the actual need of production, a new technic method-ZS method on duple fact dynamic balance of machine rigid rotators is presented for small-scale production. The unbalanced weight and direction are obtained by adding duple test weight and measuring the bearing amplitude to the rotator system. The primary principle is developed in detail and the rightness of the new method is proved out by the simulant test and the applied real example. The outstanding advantage of the new method is that the investment cost is low and the adaptability is strong. There is a spacial application value for the great dajority of the mid and small enterprises that produce rotators in small-scale but usually the rotator standards need to be changed.  相似文献   

11.
Methods for satisfying the power balance requirement and the voltage magnitude costraint are developed and incorporated into the genetic algorithm method to form a constrained genetic algorithm for solving the load flow problem.The robustness of the load flow algorithm is enhanced by the dynamic population.the technique for accelerating the convergence of the optimisation process and the network node sequencing procedure described in the paper.The efficiency and feasibility of the developed CGALF algorithm have been tested using KK 11 node system under light load and heavy load conditions.  相似文献   

12.
李玲  陈胜华  宋莹  路婕 《中国农学通报》2006,22(11):512-512
目前,中国耕地平衡仅局限于数量平衡,而在现实中却出现了耕地的隐性失衡,已成为影响耕地总量动态平衡战略实施的焦点问题之一,而且对农民、农村和农业产生了许多直接的或者间接的影响。针对这一问题,笔者提出了耕地隐性失衡的主要形式,包括耕地实际数量减少,耕地社会功效有较大改变,耕地质量下降以及生态环境恶化;着重阐述了因耕地隐性失衡所导致的农民隐性失业、农业结构失衡、农村环境生态破坏等三农问题;并提出防治耕地隐性失衡的建议和对策,为真正实现耕地占补平衡,更好地进行耕地保护提供一些借鉴思路。  相似文献   

13.
Aiming at the free-riding problem in team incentive, this paper designs a dynamic incentive mechanism based on implicit side contract with dynamic game theory by introducing the reasonable assumption that there is horizontal monitor in team production. The theoretic analysis indicates that the dynamic incentive mechanism, in which a strict group incentive compatibility contract is taken at the first stage and an individual incentive compatibility contract is taken at the second stage, can implement team cooperation uniquely in the general condition of risk aversion and stochastic production by only two stage repeated game.  相似文献   

14.
上海远洋渔业产业规模和经济效益在中国远洋渔业产业中名列前茅,分析和总结上海远洋渔业产业发展动力因素对国内其他区域大力发展远洋渔业、推动渔业相关产业发展具有非常重要的借鉴意义。运用波特钻石理论模型,以上海远洋渔业产业发展历程为主线,从生产要素、市场要素和其他产业等方面总结、提炼了上海远洋渔业产业发展的基础动因,并结合当前新的经济形势,对上海远洋渔业产业优先发展的主导动力因素进行了探讨。研究指出:外部机会、政府行为、竞争压力和消费需求与消费方式的变化是推动产业发展的基础动因,而远洋渔业资源、技术资源、资金、深加工、物流、市场和专业人才的投入是产业发展的主导动力所在。  相似文献   

15.
管和  李人圭 《作物学报》1989,15(4):342-348
首先研究了苎麻嫩枝扦插繁殖的机理。阐明了水分动态平衡;光合作用和有机营养;内源激素和外源激素之间的关系;温度效应;扦插介质的理化性质和探索了苎麻嫩枝不定根发生的组织学变化。然后,按照这些试验结果建立了苎麻嫩枝喷雾全光照扦插繁殖技术。而且进一步发展为工厂化育苗。这是苎麻无性繁殖的新途径。  相似文献   

16.
To control the oil contamination, the mathematical model is set up on the lubrication and hydraulic system and simulated the dynamic proceed in the real circumstance. The contamination degree is contamination level to be controlled and change the oil when system is dynamic balance. It is validated by the test and this result is useful to the act.  相似文献   

17.
Through the overview of the development history of Tianjin Concession Parks, this paper analyzed the historical significance of Tianjin Concession Parks and put forward its existing problems, then summed up a series of strategies of sustainable development as follows: adhering to the Florence Charter; retaining the original form and texture of the Concession Parks; adopting a dynamic philosophy of protection and preservation; integrating with citizens' social life; supplementing and improving infrastructure facilities; and achieving environmental regeneration by planting. All these efforts are expected to contribute to making a balance between the development and construction of urban cities and the preservation of historical features, as well as provide lessons for inheriting urban history and culture in the future.  相似文献   

18.
基于信息熵和协整理论的新疆土地利用时空动态分析   总被引:4,自引:1,他引:3  
土地利用结构信息熵可以综合反映某区域在一定时段内各种土地利用类型的动态变化及其转换程度,对于具体区域的土地利用结构调整、优化利用土地具有一定的指导意义。土地利用动态变化研究是全球性的课题,土地利用结构变化是土地利用动态变化的结果,笔者应用信息熵理论和协整理论及Granger因果检验,探究新疆土地利用时空动态变化。结果表明:①土地利用结构信息熵反映了新疆土地利用的时空情况,其信息熵随着时间的推移缓慢上升,其变化幅度较小,总体上土地利用结构趋于稳定,但南北疆土地利用差异明显;②土地利用变化与经济发展密切相关。土地利用结构与经济发展是非平稳的时间序列,经济发展与土地利用结构之间存在协整关系,经济发展是土地利用变化的单向Granger原因。新疆经济发展是土地利用结构及类型变化的主要原因,其特殊的自然生态环境,应在保护生态环境的前提下,统筹安排各业各类用地,协调好经济发展与土地利用之间的关系。因此,必须对该区域的土地利用结构进行调整与优化,以维护区域系统的稳定。  相似文献   

19.
煤矿区多目标复垦模式是提高复垦综合效益的有效途径,但除新增耕地灌溉需水外,还需要解决水资源多目标供需平衡问题。笔者采用动态规划法(DP),对煤矿区多目标复垦的水资源供需平衡分析进行了研究;笔者以徐州九里矿区多目标复垦水资源供需平衡分析为例,通过建立目标函数,按照逆序法从末阶段开始对各个单阶段优化问题依次求解,得到需水和供水间的最优决策方案;该方法解决了多目标复垦的水资源供需平衡和效益最大化问题,有效推进了煤矿区多目标复垦的进行。  相似文献   

20.
土地利用平衡研究进展   总被引:1,自引:1,他引:0  
肖轶 《中国农学通报》2012,28(29):235-241
本文通过对土地利用平衡的内涵、困境、途径以及保障等方面研究的归纳总结,发现目前研究中存在的不足,对未来发展趋势和研究重点进行了展望。未来土地利用平衡研究应加强以下3个方面:(1)加强土地利用平衡影响因素的研究。特别是土地利用过程中相关利益主体的行为倾向和博弈行为分析。(2)加强土地利用平衡制度的研究。农村土地制度的改革是当前土地改革的核心,研究土地利用平衡制度,突破土地资源瓶颈,为区域经济社会发展提供更大的空间。(3)加强土地利用平衡创新途径研究。应该在提高耕地质量和土地利用效率的基础上,做好区域相关产业用地的梯度转移,实现城乡统筹的均衡发展与资源互补,发展基础设施,改善产业结构,改善生态环境等。研究结果和结论将对促进区域土地利用平衡研究具有重要科学意义。  相似文献   

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