The paper introduces the work proceeding of consulting engineer in managing civil engineering abroad in detail, then discusses the fact that there are some thing to be improved in drawing up of civil engineering bid documents, compiling operation technical specification, opening sealed tenders and testing of materials and workmanship during construction in China. Finally the paper suggests that in all of the contracts for work of civil engineering construction the imported terms of contract for work of civil engineering construction and the operation technical specification compiled by design engineers should be included, so as to eliminate corruption in the civil engineering field and ensure the engineering quality.
In this paper the structure characteristics of surprised rain gust and storm in Beijing and Shanghai and heavy rain gust in NE Sichuan are analyzed, and the surprised severe weather is discussed by V - 3θchard. The results showed that the surprised weather can be forecast. Facilities for water drainage water storage and windbreak should be allocated.
The profound influence of economy globalization on the progress of the world, especially the impact on the development of China is described. It proposes that the globalization of R&D is a new stage of economy globalization. The rapid development of TNCs’ R&D in China is presented. The opportunities and challenges of R&D globalization for both developed and developing countries are discussed. The measures for encouraging globalization of R&D for developed, developing countries and UN are suggested.
The application of externally bonded fiber reinforced polymer (FRP) laminates to the exposed faces of concrete members provides an innovative and efficient rehabilitation method for strengthening and upgrading structurally inadequate or functionally obsolete concrete structures. However, FRP laminates unlike the cold worked steel exhibit elastic-rupture behavior and also the limited bond capacity of FRP-concrete interface often fails the retrofitted system in an undesirable brittle manner, which leaves FRP material unused with more reserves. Moreover, enhancements in cracking and yield load due to FRP bonding are not significant. To take full advantage of FRP laminates, more gains can be achieved by prestressing the fibers prior to bonding them. Traditional practice is to pretension fiber sheets impregnated with adhesive or FRP plate, which is time-consuming, difficult to apply in the field and ensure a perfect bond at the interface. A newly-developed PBO fiber possesses high modulus, high strength and higher energy absorption capability as compared to carbon and aramid fibers, and PBO fiber sheet can be pretensioned to over 70% of its tensile strength without being impregnated with adhesive. All these make such material suitable to be prestressed for strengthening concrete structures. Based on the experiments and theoretical studies, a comprehensive strengthening method with prestressed PBO sheet is established including concept, working principle and corresponding countermeasures, whose strengthening effect is validated by both laboratory and field experiments.
This paper surveys the development history and the relative key technology of the control and manipulating system in the huge transporter and construction machinery, and proposes a new kind of scheme to realize the transmission of power, motion control and synthesis based on network control by field-bus control. Taking the computer control system of the engineering machinery applied in the transporting of the railroad bridge in the Shanghai suspension magnetic railway as example, the design method and control strategy of the network control system based on the configuration of the field bus control system and PC104 airborne industrial control computer are discussed. The research conclusions provide the new approach to realize the control and manipulation of the huge transporter and construction machinery.
To improve dynamic performance’s optimization efficiency of hydraulic excavator’s work device, the dynamic modification simulation of the structure was investigated by dual modal space method based on modal analysis. The results show that the mass modification remarkably influences the first and second order natural frequency and damp ratio, and has little effect on high order modal frequency and damp ratio. The stiffness modification influences the first five modal frequency and damp ratio remarkably; high order modal frequency and damp ratio are sensitive to stiffness modification. The investigating results reveal the relationship between modal parameter modification and dynamic characteristic of the structure, and lay the foundation for improving overall quality of mechanical products.
Virtual prototyping technology has been used to analyze the dynamic characteristics of rubber spring suspension of AD250 articulated dump truck. Multi-body dynamics simulation of the ride comfort has been performed under different velocity and different load. The results of analysis are consistent with experiment results, which shows the correctness of the model. Results indicate that the good and constant ride comfort can be satisfied under different load because of the nonlinear properties of rubber springs of front suspension. Rear suspension system under light load has higher supporting frequency than under deadweight. The results provide a basis for the parameter optimization of rubber spring suspension.
The time-triggered architecture for CAN is analyzed. The implementation issue of time- triggered architecture based on 8052 single-chip processor and CAN controller SJA1000 is designed. The maximum number of transmission messages in basic cycle is given. And the scheduling capability is analyzed. The experiment is based on the automotive engine management, the result proves that using time-triggered architecture can not only manage the message transmission but also improve the bandwidth utilization.
In this paper, firstly, the connotation and the solution of down knock-out option and the basic principle of real option are dissertated, then, the method applied in project investment decision based on down knock-out option and game theory is put forward. And the project pricing in duopoly market structure is mainly analyzed. At last, example is provided.
Based on the theories, methods, technologies and tools of contemporary integrated manufacturing, the Complex System (Product) Integrated Manufacturing Engineering (COSIME) is presented and researched, aiming to improve the T (Time to market), Q (Quality), C (Cost), S (Service) of the complex product development. The connotation, system framework and technology system of COSIME are given. Furthermore, the phased research results of six key technologies are introduced： (1) the management mode of the complex product integrated manufacturing system based on the theory of the ” management of person with ability and institution” and the advanced manufacture patterns; (2) the concurrent engineering methods and techniques for the enterprises dispersed at different sites based on the theory of the project management; (3) the means and technologies of the virtual prototyping engineering for complex product; (4) the concept design and performance evaluation system for complex product based on the advanced distributed interactive simulation technology; (5) the quality control and management system for complex product; (6) the two integrated manufacturing infrastructures for the all lifecycle activities of complex product based on PLM and the grid computing technologies.
Cooling pipe made of 20# seamless tube is widely used to cool liquid zinc in zinc smelting industry. Since its life is especially short, the consumption of cooling pipe is very high. By using finite element analysis method, the thermal stress distribution is obtained and the site of the maximum thermal stress lies in the joint of bent section and straight section and inclines to the bent section. The residual stress is measured by using the cut method. Liquid zinc has low surface tension and high permeability and corrosivity. It can form Fe~ Zn alloy with steel in the cooling pipe and can dissolve C and Si in cooling pipe. Liquid zinc is not compatible with cooling pipe. Therefore, the compatibility is a decisive factor on the life of cooling pipe in liquid zinc. The damage of the cooling pipe in liquid zinc is caused by high temperature corrosion and stress corrosion. Thermal stress plays an important role between the thermal stress and the residual stress in determine the position of the damaged site of the cooling pipe in liquid zinc.
The liquefied petroleum gas (LPG) has multifarious risks associated with fire or explosion in the traffic and storage process. The leak of LPG can induce disasters including flash fire, unconfined vapor cloud explosion (UVCE), boiling liquid expanding vapor explosion (BLEVE), etc. In this paper, occuring condition and risk of those disasters are analyzed. Quantified risk analysis (QRA) is used in consequence assessment. The assessment method for the hazards to the environment by UVCE and BLEVE is researched.
With the wireless LAN technologies being widely applied, new WLAN security standards have been proposed to enhance the WLAN security. In this paper, through discussing the technology characteristic and the basic framework of the WAPI standard, the detail of the application of the WAPI authentication procedure on the WLAN access point was given. Furthermore, the performance of the authentication procedure was discussed.
By using ISO9705 Room/Corner Fire Test Rig, thin steel tubes were tested. The response behaviors of steel element under thermal-mechanical coupling effect in a simulated corner fire were studied. In the experiment, the heat release rate and temperature field of the fire, temperature and deflection of the steel element and the temperature of the gas close to steel surface were measured. Effects of the temperature elevation and distribution of the steel element under corner fire conditions along with the fire growth on the deflection were analyzed. Results show that there exists significant temperature difference along the longitude of the steel and an unsymmetrical deflection variation. These indicate that assumptions of the uniform temperature distribution along the longitude direction in previous studies were improper. Under this non-uniform temperature distribution, failure resulted from the local yield of the higher temperature zone of the element is more inclined to occur. Indeed, this non-uniform temperature distribution caused by the corner fire is more dangerous to the fire safety of steel elements than the even case under same fire size.
The traditional book issue corporation management mode is not adaptable to the developing situation and competitive demand. Chained operation is the key method to improve its management performance. Based on chained operation and information system programming theories, this paper designed a set of information system, including the design thought, system function frame and information relationship graphic analysis, as well as some key technologies to analyze, design, and develop this system.
Element content, chemical composition, stability, viscosity and heat value of bio-oil are analyzed based on many literatures in this paper. Some new technologies to refine and to utilize bio-oil are introduced such as directly catalyzing bio-oil vapor, and adding surfactants into bio-oil,so that it can be used directly in diesel engine. The catalysts and their effects on the refining and utilization of bio-oil are discussed.
The agriculture informationization is supported by related information technique. The paper expatiates on general characters of agriculture informationization, introduces current development of agriculture informationization supporting system,and analyses the subsistent problems of the agriculture informationization. It brings forward that the pivots of quickening the construction of agriculture informationization are to manage the research of the preservation technique of agriculture information, develop agriculture information application technique and build the network for agriculture information spreading.