The advanced construction of science and technology with meta-synthetic wisdom proposed by Chinese scientist Qian Xuesen is introduced. Besides, from system construction of science and technology, the research and discussion of intelligent system as well as meta-synthetic wisdom are also given briefly.
The characteristics including position and function in state economy, technical requirement, economic ability, technical resource and output transformation of the state-owned companies were discussed, and the conclusion that the state-owned companies are able to lead by becoming the mainstay of spontaneous creation was proposed. To achieve the target, it needs to stimulate the enthusiasm of companies, technology managers and research and development staff of companies for technical creation. Combined the successful experience of the Shenhua Group, a new model of company spontaneous creation based on integration of technical resources was put forward.
The strut-and-tie model (STM) is an emerging procedure for the design of D-regions in concrete bridges. It is becoming one of the cutting edge research areas in structural engineering. Based on the concept and formation of strut-and-tie models, the typical D-regions existing in concrete bridges and their configurations are expounded. The criterion to develop appropriate strut-and-tie models and general procedures for dimensioning the D-region of structures are also discussed. According to AASHTO LRFD (2004), the application of the STM to design a typical anchorage blister is exemplified. At last, the origin and the state of the art are reviewed, and the current research areas are pointed out.
In Nanjing Yangtze river tunnel project, quantitative engineering was applied to identify and prevent the risk. The numerical simulation method and supercomputing were employed to model the tunneling process in key sections. These key sections including departure and reception of shield machine, crossing flood levee, tunneling through river bed with shallow cover, interaction between two working shield machines, tunneling through composite soil layers were modeled according to the real geological profile. Quantitative analysis of the numerical results forecasted the risks in ground settlements, behavior of shield machine, and stability of cutting face, etc. The causes and consequences of the risks were discussed. After that, methods to prevent the risks were proposed, evaluated, and validated.
Based on the analytical solutions of a spherical pressure vessel subjected to internal pressure, it points out that the results of membrane stress and bending stress are inaccurate obtained by the one-dimension integral along a line called assessment line in the direction of shell thickness recommended by some references and standards. Therefore, a more accurate method is presented in which the resorted stresses are obtained through two-dimension integral over a ring cross-section area called assessment area of the shell. As an example, an analysis based on the elastic analytical solutions of a thick-walled spherical shell bearing internal pressure shows that the method suggested by this paper can make analysis and design of pressure vessels more accurate.
The contribution level of cross modality to vibration response of structure is governed by damp and modality. The larger the damping and the denser the modality, the higher the contribution. In engineering vibration analysis' a system hypothesis with lightly damping and sparse modality is generally applied to solve approximately vibration response of structure where the contribution of cross modality is neglected due to the contribution small enough. Approximate solution of displacement response can satisfy engineering requirement with certain precision but the error between approximate response and exact one, maybe tiny, can heavily effect the peak frequency and irregular factors of spectral diagram in time domain vibration analysis and change the results of fatigue damage accumulation identification. With a simple supported beam in this paper the contribution of cross modality to fatigue damage accumulation is investigated. Random response is obtained by means of superposition methods and fatigue damage accumulation of structure under random vibration is analysised with Miner's linear damage ruler. Numerical simulation shows that the contribution of cross modality to fatigue damage accumulation of structure can not be neglected even if the structure is characterized with lightly damping and sparse modality.
The estimation for state of cable is significant to state of cable management. The famous methods for state estimation of cable are Weibull distribution model and Arrhenius method. The two methods are analyzed and researched. A method for measurement of Arrhenius model activation energy is presented. And the Weibull distribution model is used for state estimation of cable. The simulation based on overhaul data, test data and monitor data of the cables for Arrhenius model shows the effectiveness of the approach.
This article presents design theory for the strength of the cross-section of steel box concrete composite beam, based on the analysis of its mechanic behaviors, analyzes the influence of width- thickness ratio and confined effect on the strength, and puts forward the principles for rational design of its dimensions. The analysis shows that the bearing capacity of such new composite beam increases compared with that of empty steel box beam, and its mechanic behavior is obviously improved. Experimental study of 3 beams shows that steel box composite beam has good behavior of bending resist and flexibility and high bearing capacity. Such kind of beam has widely application prospect after further theoretical and experimental study.
A mathematical model of conventional design for the multi-effect two stage evaporation system with condensed water flash and solid separation was established. The equilibrium was correlated to equation and the model could be solved with computer easily. Then the complex manual calculating was avoided. Mass balance and energy balance equations of the system were expressed in matrix equation that has the advantage of clear structure and high modularization. By holding or omitting correlative block-smatrix in matrix equation, matrix equation could be used to describe the multi-effect two stage evaporation system without condensed water flash or solid separation. The model was solved by combining matrix method with iteration method. The practical example indicated that condensed water flash is an effective method to save energy. And the algorithm increases the convergence speed and stability.
Landfill leachate is a serious pollution with high COD and NH3-N. The MBR-NF process was adopted to treat the leachate. The results showed that the average removal efficiency of COD and NH3-N both reached 99.5 %, and the purified water could reach the first level of standard for pollution control on the landfill site for domestic waste. The total operation cost was 19.55 yuan/m3. Compared with the other leachate treatment processes, the MBR-NF has significant advantages on both technique and economic sides.
Real-time guidance system of traffic flow is information reconstruct in unit time. If events occut in short periodic time, these events will inflict the normal traffic guidance. In this paper, a new and simple solution scheme is proposed by analyzing status traffic situation. In this plan, systematic revision for read-time guidance in burst event is added to deduce reaction time. This scheme is imporved technology built on the current guidance system, therefore, this conclusion can be widly applied to traffic flow guidance system.
Stepped-frequency signal is a broad band signal which enhances range resolution of radar at the cost of increasing bandwidth. Baseband signal that is received in stepped-frequency radar can be thought of as the linear combination of exponential function which contains target information, while Prony algorithm is a mathematical mode which uses a linear combination of exponential function to describe equal space between sampling data. Extended Prony algorithm is applied to stepped-frequency radar, which can obtain more exact target information and overcome the shortcomings of using IDFT to synthesize high resolution range profiles. Corresponding modeling analysis and experiment simulation explain the advantages of Prony's method.
This paper investigated the interaction between water mist and smoke in experiments, revealing the variation trends of smoke temperature and species concentrations. Variation trends were also obtained under the same scenes by FDS(fire dynamic simulator) simulation. Experiment results were compared with simulation. The comparison comes out that with reasonable computation gird setting, FDS can predict the variation trends quite well. In practical water mist system design, FDS may be applied to predict the behavior of the designed system.
The Preissmann implicit scheme is used to discrete the one-dimensional Saint-Venant equation and the river-junction-river method is applied to resolve the hydrodynamic mathematical model for river networks. Based on the characteristics of river-junction-river method and the theory of WASP, the synthetic water quality model is set up for river networks, which includes many contamination variables and considers the transform and transplant of the contamination variables. This model is applied to simulate four river networks, the results of elevations and flows agree with the data, the result of contamination variables agree with the measured data. These results show this model is credible and it is a practical tool for forecast and management of water quality in river networks.
At present, the existing descriptions of trust by trust valuation models lack comprehensiveness. To solve this problem, this paper discusses the co-existence and integration of fuzziness and randomness of trust relation, analyzes the ways cloud models describe uncertain concepts and the algorithms cloud models transform between qualitative concepts and their quantitative expressions, and presents trust cloud, a trust evaluation model based on cloud theory. This model provides the algorithms of trust information transfer and combination described by digital characteristics. While describing accurate trust expectation, this model portrays the uncertainty through entropy and hyper entropy. Compared with traditional trust valuation models, trust values obtained in this model contains more semantic information, indicating that valuation results from the model are more suitable as evidence for decision-making on trust.
By discussing the drawbacks of a 2-dof robot arm remote control based on the point-to-point control, the continuous path control method is applied to the joint-coordinate-space-based serial robot remote control system. The condition needed to realize the continuous control is analyzed and the computation formula of the optimal synthesized velocity is given. The actual remote control experiment is implemented, and the continuous and smooth movement results are obtained within the desired time. It's verified that better accuracy in remote system can be obtained by means of continuous path control.