Nonlinearity of Electronic Throttle and Its Control     

DU Kai-ming  Qin Da-tong  LIU Zhen-jun  JIANG Feng-xiang  DING Rui 《保鲜与加工》2005,(4):14-18

This paper introduces the development of the electronic throttle control system (ETCS) , the structure and the principle of the system are also involved. After analyzing the nonlinearity problem existing in the mechanical structure of the system, a mathematical model of the ETCS is built up. Then three controllers (PID controller, Fuzzy controller, sliding mode controller) were designed and simulated in the matlab simulink. The result indicates that the PID controller has an overshoot,but the Fuzzy controller and the sliding mode controller can settle the nonlinearity problem better.  相似文献   

Discussion on Second-order Analysis of Variable-Section Beam-Column     

XIONG Xiao-li  LI kai-xi 《保鲜与加工》2004,(2):36-40

In this paper, based on the discussion of orthogonal decomposition method for the buckling mode of unsymmetrical structure, taking the variable-section beam-column as an example, a simple and direct method of the second order analysis is presented. In the new method, the conception of enlargement coefficient brought forward by Timoshenko is developed. To begin with the curvature of the variable-section beam-column, the linear equations are set up. With their solution, a group of orthogonal buckling mode can be obtained. The primary deflection can be decomposed to a group of homomorphic deflection similar to buckling mode. Then, the group of deflection is multiplied by corresponding enlargement coefficient and plus the result, finally, the second-order total deflection can be obtained.  相似文献   

Nonlinear Finite Element Analysis of RC Deep Flexural Simply Supported Beams Using Disturbed Stress Field Model     

ZHANG Chuan  JIANG Ning 《保鲜与加工》2006,(1):47

A nonlinear finite element analysis of 4 RC deep flexural simply supported beams with the program VT2 is presented. Crack development and failure modes , longitudinal reinforcement strain distributions and load -deflection curves were compared as a result in order to evaluate the validity of the disturbed stress field model to analyse such deep simply supported beam.  相似文献   

A Research of Life Cycle Integrated Management Pattern of Construction Project     

HE Qing hu  CHEN Fa biao 《保鲜与加工》2001,(4):75-80

Development Management (DM) in decision phase, Project Management on behalf of the owner (OPM) in implementation phase and Facility Management (FM) in operation phase are three isolated management tools during traditional life cycle management of construction project. As a result, a lot of potential disadvantages are aroused. In recent years, many research organizations try to reform the traditional method using different integration means. This paper tries to explore into integration of DM, OPM and FM to overcome the malpractice of traditional life cycle management of construction project. The research focuses on three aspects: 1.putting forward the concept of Life Cycle Integrated Management (LCIM), based on management integration theory; 2. Raising a new idea to owner's (operator's) management organization design, which emphasizes on the balance of life cycle objectives; 3. Analyzing an information module, level and method of system integration of Life Cycle Integrated Management Information System.  相似文献   

Virtual Shareholdings-Concept of Reform Mode for SOEs     

《保鲜与加工》2003,(2):93-98

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Problem in Mortgage Loan on Housing and Its Countermeasure     

《保鲜与加工》2003,(4):95-98

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Study on Application of ''Design and Build'' Contract Mode     

WANG Jun-cai~  HONG Hong~  LIAO Qi-yun~ 《保鲜与加工》2003,(6):108-114

The 'Design and Build' contract mode is a new contract and managerial approach, to which more and more attention has been paid. Now it becomes the contracting tendency in the international construction market. In this paper, the basic theories and method of the 'Design and Build' mode are widely and systematically studied. It specifies the intention of the 'Design and Build'contract mode, existing problems and corresponding countermeasures as well as its developing direction.  相似文献   

基于“数字流域”的水利信息服务   总被引：2，自引：1，他引：2  

代君  纪昌明 《中国农村水利水电》2005,(8):19-21

探讨了流域水利信息服务在随流域数字化进程发展过程中,为了满足各类信息用户的需要而采用的信息服务模式。基于“数字流域”的水利信息服务既不同于传统的手工检索服务模式,也不仅仅是基于WEB的信息服务模式,它是基于由多种前沿技术共同支撑所建立的、以水利信息为主体的流域信息资源网,面向全流域各类水利信息用户的复杂多变的信息需求的新的服务模式。  相似文献   

农机服务体系建设中的资源整合   总被引：1，自引：1，他引：1  

王咏源  汪波 《中国农机化》2005,(6):22-24,100

在农机化的快速发展过程中,农机资源本身也需要以更多的实现形式进行平衡的资源优化配置和整合,以更好的投入产出水平发挥它在农业生产、加工中的作用,适应未来农机服务市场的变化.  相似文献   

无土栽培技术的发展状况及趋势   总被引：3，自引：0，他引：3  

孙霞 《中国农机化》2005,(6):47-50

近年来无土栽培以其优质、高产、高品质的特点,深受人们的关注.介绍了国内外无土栽培的发展状况,着重介绍了国内外无土栽培的栽培方式、自动化程度、营养液的调控和管理技术,并分析了国内无土栽培存在的问题及今后的发展方向.  相似文献