Influence of Steam Turbine System on Low Frequency Oscillation

Low frequency oscillation of electric power system is a problem which electric workers always care about. The influences of prime mover characteristics were ignored in the past research. The paper introduces the models of steam turbine system and each part of electric power system, and calculates the corresponding eigenvalues, then analyzes the influences of steam turbine system on low frequency oscillation.     

Analysis of thermal stress in a water pipe of blast furnace copper stave

To solve the general problem that copper staves experience water pipe failure in blast furnace,the effects of constraints on the thermal stress distribution of copper stave water pipe are investigated by thermal-structural coupling analysis.In this study,a mathematical model of thermal stress of copper stave is established to analyze the thermal deformation and stress distribution of water pipe under subject to different types of constraints.The results show that the thermal stress on the root of water pipe is larger than others as the terminal of water pipe is free or being fixed.But the equivalent stress on the root of water pipe is just 45 MPa as the terminal of water pipe is free,which is lower than the yield strength of pure copper.The equivalent stress on the root of water pipe is about 272 MPa as the terminal of water pipe is being fixed,and exceeds the yield strength of pure copper.The water pipes should be flexible.The maximum equivalent stress is about 600 MPa as the water pipe is subjected to the constraint of shell,which is far beyond the yield strength of pure copper.The maximum displacement is located at the end of water pipe and is about 1.73 mm.Then the diameter of the hole should be 120 mm with taking installation error into consideration.     

Dynamics of Actin Polymerization

The process of actin polymerization and depolymerization have some relation with its function,the activation of such process is compatible to its functions. The polymerization progress is divided into four steps: The first step is the activation of the monomer actin. The nucleation of actin nucleus forms in the second step which limits the polymerization speed. The elongation of the F-actin filaments happens in the following step. In the last step, a steady-state is attained, the length of the filament does not change because the polymerizing rate in the barbed end is the same with the depolymerizing rate in the pointed end. Some factors which affect the polymerizing process, such as nucleotide, actin related proteins are discussed. The aim is to know more about how to assemble the complicated system with biomacromolecule and what to function.     

Adaptive Intrusion Detection System Based on Agent and Data Mining

Intrusion detection system is an essential component of network security protection mechanisms. Most intrusion detection system can not adapt the variation of network environment. Aiming at this problem, an adaptive strategy that composed of condition space and strategy space is proposed. The condition space describes the network environment and the strategy space describes the strategy. There is an exclusive strategy corresponds to a certain environment state in condition space. On the base of the adaptive strategy, an adaptive intrusion detection system based on agent and data mining is designed. The simulation experiments indicate that the adaptive strategy is effective.     

Water model study on flow optimization of five streams L-type tundish

In this paper, the water model method is used to optimize the flow behavior of asymmetrical five streams L-type tundish in a steelmaking plant. The results show that the optimization plan is set up with turbulence suppressor T+ vice guide wall D2+ main guide wall with three holes (D1a) which consists of top two holes with 25° inclination and one hole with 30° inclination below. With this plan, the time which the colorants reach to the outlets increases, the difference of response time in all outlets decreases, the peak concentration of the RTD reduces, the existence time of high concentration liquid steel extends, and the ratio of dead zone in each streams reduces.     

Behavior and Design of High-strength Bolt in Tensile Connection

The tensile strength of high strength bolt is affected by many factors, including prying force. The prying force can result in the increment of bolt force, for which the connection failed ahead of time. Several methods are presented for calculating the prying force. In the China's "Code for Design of Steel Structure" (GB50017), there is no formula for calculation of prying force and a factor of 0.8 is considered in formula for tensile strength of bolt for taking the prying force into account. It is proposed that the design value of tensile resistance for high strength bolt should be increased.     

Stability Contrast of Landslide Disaster After Repeating Control

Xiang-jiapo landslide,which consists of shallow layer,middle layer and deep layer,is a multi-landslide with several layers.Influenced by geological condition and rainfall,it have not obtained good effect even after three-time control.Because the distortion of landslide increase so fast, the government planed to control the landslide for the forth time.Based on monitoring data of the landslide movement,the paper make a constrast analysis of 3D numerical simulation's calculating between the formal control and the forth time control by a non-linear finite elements programm ABAQUS.Both results of numerical simulation and monitoring indicate that the forth time control have achieved good effect.     

Exploring Harmonious Protection of Land Resources in City Construction

Urbanization in China is at an essential point in its transformation from the initial stage to accelerating stage. With quick expansion of city scale and large occupation of land for urban construction, the contradiction between land resource shortage and people's living needs becomes more and more prominent. It has great affection on the grand plan of China's sustainable development of economy and society. How to adjust the relations between the development of urban construction and protect the land resource, promote the rational use of urban land, perfect and complete the protection system of land resource for improving the efficiency of urban land use. In order to conserve land resource and find a sustainable way for development of people's living and environment construction, the above mentioned problems are the most important issue for urban construction and important subject of this paper.