The great meaning of construction of the first high speed railway accelerated by the event of Beijing Olympic Games is discussed in this paper. The merits of rail transit and the key technologies of high-speed railway are specially introduced in detail. This paper acclaims the entering into high-speed railway age in China and calls for high quality building of the worldwide longest high-speed railway between Beijing and Shanghai. Contributions in developing railway network spreading all over the country are required.
Space structures are always preferred for Olympic stadiums and gymnasiums due to their great variety of forms, efficient mechanical behavior and the ability to cover large spans. The construction of 2008 Beijing Olympic stadiums and gymnasiums provides an enormous stage for space structures. It is advisable and useful for the further development of space structures to summarize the advanced design concepts, innovative structural forms as well as the new materials and techniques used in these stadiums and gymnasiums. A brief introduction to the 2008 Beijing Olympic stadiums and gymnasiums is presented first, then some representative Olympic stadiums and gymnasiums are discussed with respect to their novel architectural appearance, advanced structural forms and innovative techniques applied in design, construction and monitoring. By reviewing a number of classical Olympic stadiums and gymnasiums, their common characteristics are summarized as:perfect combination of novel architectural appearance, innovative structural form and satisfactory service performance;in accordance with the development of construction techniques, and hence promoting the progress of technology. Compared to the outstanding classical Olympic buildings, it is believed that some representative stadiums and gymnasiums of the 2008 Olympic Games do have the qualities to be recognized as the new members of this glorious list.
Reinforced concrete spatial grid structure includes planar open-web grid structure, open-web sandwich plate structure, open-web dual grid structure, cast-in-place concrete round eye hollow plate structure, these new structure systems have been applied in the plate of public buildings amount to more than 1 million square meters from the 1980s until now, and obtained the excellent social and economic efficiency. The corresponding technical specifications for some have been established. In recent years, we have developed the reinforced concrete open-web sandwich shell and arch structure through bending the reinforced concrete open-web sandwich plate structure by one direction,and the reinforced concrete open-web sandwich hyperbolic flat shell structure through bending the reinforced concrete open-web sandwich plate structure by the two directions These new spatial grid structure systems have the proprietary intellectual property rights of our country and have their own characteristic and the compatibility for the buildings. In the paper, we will introduce one by one successively according to the development time order. The security and rationality and efficiency and advancement of the structure will be analyzed through the project examples.
The Manual Mistake Operation Hazard and Operability Analysis Program for startup period and stop period of the hazard chemicals plants,which is discussed in this thesis,should provide a new analysis method and adequate technological grounds for preventing the mistake operation. The explosion which occurred in the nitrobenzene prefractionator's startup period in Jilin Petrochemical Corporation is taken as an example to analyze in this thesis.
The application of fiber reinforced plastics (FRP) in strengthening projects is one of the most popular fields in the studies in civil engineering. Practices and theories have testified that the technology of strengthening structures with prestressed FRP is feasible with obvious advantages. A concise state-of-the-art survey and new progress of the technology of strengthening structures with prestressed FRP are presented, including studies in terms of concrete structures strengthening with prestressed FRP, steel structures strengthening with prestressed FRP and the key problems in its practical application. Experimental studies revealed that strengthened with prestressed FRP, the cracking load, yielding load and ultimate capacity of RC beams increased obviously, behaviors of flexure members under long-term load were improved, and the fatigue life of concrete members were also increased.Strengthen steel beams with prestressed FRP, the yielding load and ultimate capacity increased obviously, with greater increase when more CFRP were used or at higher prestress level. Prestressed CFRP contributed to the rigidity of steel beam especially when strength of steel is relatively low. The key problems in practical application of the technology of strengthening with prestressed FRP include the studies on prestress applying system, prestress control value, prestress loss and end anchorage system.
In the analysis of the electromagnetic rail launch system.,this paper discusses the general developmental strategy of electromagnetic rail launch system based on the scenario planning theory. Through analyzing the world current situation and the key technical variables of electromagnetic orbit launch system, the paper conceives the three developmental strategy models of future electromagnetic rail launch system and proposes the focus of development strategy.
Competence set expansion is a process that decision-maker expands the obtained competence set to the competence set which is need to solve questions in decision process. This paper analyses the concept of competence set and its expansion and provides competence set expansion’s research methods under uncertainty, certainty, multiple criteria and dynamic state.
The security problem, such as network security, user data protection, authentication, mobile management and network services are becoming more and more important in Public WLAN. This paper focuses on the design research of the PWLAN security architecture. A security model based on access controller is proposed in this paper. Furthermore, a compound 802.1x and WEB authentication scheme is provided to ensures cryptographically protected access while preserving pre-existing public WLAN payment models.
The combinational evaluation method which combines TOPSIS with gray correlation degree analysis can improve validity of the evaluation result. In such method, a usual way to assign combinational weight of index is subjective weighting, to assign combinational preference coefficient and identification coefficient is manual weighting. The advantages of combinational evaluation method are not fully mined. Aim at this problem, a method uses projection pursuit algorithm to establish combinational evaluation model is presented. The real coded accelerating genetic algorithm is used to dispose those non-linear problems. The gained index weights are objective. In the same time, a new method of confirms combinational preference coefficients and identification coefficients of gray correlation degree is presented. The example shows the combinational evaluation method based on projection pursuit algorithm is scientific and objective.
he 60 rails on Shanghai Metro Line 1 from Jinjiang paradise station to Xinzhuang station have wounds of different degrees at the present time. Outer rails on curve railway have corner fine cracks on the inner flank, and some cracks evaluate down and lead to core wounds. Initially corner fine cracks expand slowly on the early stage, with the times of fatigue loads increasing crack depth expanding speed rate dh/dN breaks.The times of fatigue loads at turn over point is defined as the initial life of corner fine cracks.
In order to better understand the regularities of rockburst occurrence,Dongguashan Copper Mine has installed an ISSI seismic monitoring system, which can make a real-time monitoring of rock mass respond to mining. This paper briefly described the layout of the monitoring system in Dongguashan Copper Mine,then analyzed how to process various kinds of event waveforms. By contrasting the different locations resulting from the automatic processing and the artificial processing, it is confirmed that the accuracy of an event location has been improved greatly by the artificial processing, which will make the calculation of seismic source parameters even more accurate. Based on the corresponding relations between waveforms recorded and mining practice, the event waveforms are assorted, which can identify events quickly. According to the analysis results of a detecting blast and an identified seismic event,the waveform analysis method put forward in this paper is validated. It will establish a sound basis for subsequent analysis of the stress or strain status,delineation of hazardous areas of rock mass and adoption of reasonable measures.
Intelligent of building show intelligent application in building control. The reasonable control method more guarantees intellectualized building, at the same time, and bring personalized. In this paper, Distributed technique exchange theory has been main discussed in intelligent building control of remote control, and structed a high efficient distribuited control data exchange service end base on net.
The SLIM parameter has clear error to its real value on the base of the RIM parameter measurement method because it has larger air gap and edge effect. This paper proposes a new scheme suited for SLIM parameter detection. It only needs input total power, phase voltage, phase current, frequency, and then computes primary resistance, primary leakage induction, secondary resistance, secondary leakage induction, air induction and iron loss resistance. The performance analysis of SLIM indicates that this method is very effective and valuable.
This paper researches the electrons horizontal vibration when the electrons have high velocity. Its experimental method is using the characteristics that β-particles of 90Sr source in different magnetic fields by half circle-focus β- spectrum and in the same radius have different energy and momentum to study the functional relationship between the particle number (n) and the width of the copper narrow slot (δ) when the particles fly across the copper narrow slots with different widths (thickness is 8 mm)and find that the β-particles have the horizontal movement tendency no matter what energy and momentum the β-particles have, and when they fly across the copper narrow step there is the distribution of a flight of steps. The reason may be that β-particles have the horizontal amplitude A and the interaction of energy fluctuation in vacuum.
To solve the open problem of predicting intrusion in Reactive Intrusion Tolerance System, a hybrid Bayesian network method is presented in this paper. Firstly, an intrusion model is presented, which pays its emphasis on the influence of the intrusion upon the system and describes the intrusion as the state transition process of the attackers' capability. The intrusion model is appropriate to trig the reactive intrusion tolerance system. We proposed the constructing algorithm and the proof of its feasibility. Secondly, a hybrid Bayesian network model based on this intrusion model is presented to show the casual relation of the attack behavior and secure state. The model is divided into two layers: attack behavior layer and secure state layer, in which the attack edges and state nodes of intrusion model are used as nodes in behavior layer and state layer respectively. In this hybrid Bayesian network model, the connections of the same layer are continuous, but that of the different layer are converge. The algorithm for computing the joint probability distribution of the hybrid Bayesian network is presented. In the end, the efficiency of the intrusion model and hybrid Bayesian network in predicting intrusion is shown by the experiment with our belief propagation algorithm, and the advantages of this predicting method over the related work are shown by analysis and comparisons.