Full Aero-elastic Bridge Model Design of Long Span Arch Bridge

Aero-elastic model design is the precondition of full bridge aero-elastic model tunnel tests. The full aero-elastic bridge model design of long span arch bridge is discussed. The effect on the model design of different transverse rod space and bend stiff is analyzed in detail. Different scheme need to be designed according to the transverse rod stiff. Considering the changing section dimensional arches, the method of projecting the spatial arches to the plane arches, then designing the plane arches, at last projecting the plane arches to the spatial arches is proposed at first. The results show that the method is effective.     

AN APPRONTMATE CALCULATING METHOD FOR WALL PLATES OF MAN'' S DRY GAS HOLDERS

The basic equations of wall plates of MAN' S dry gas holders are derived in this paper. According to the law of cylindrical bending given by the finite element results .we derive some approximate formula calculating the deflection and stresses of the wall plates from the basic equations. Compared with the known approximate calculating method.the method car. obviously increase the percision.     

Vibration Analysis and System Simulation for a Stalled Wind Turbine

The aerodynamic characteristic of wind turbine is calculated by applying the Blade Element Momentum(BEM) theory.Also finite element mode analysis is done for the tower and the rotor.Then the multi-dynamic model of the wind turbine is built in Adams.Also the drive chain is calculated by applying state space method and programmed in Matlab/ Simulink.With that the combined simulation of vibration characteristics is carried out on the base of MATLAB/Simulink and ADAMS,in which the transmission effects and aero-elasticity coupling is fully considered.The results show that the method is able to simulate the vibration characteristic almost the same as software Bladed,which is well-known for analyzing performance and loads for the design and certification of wind turbines.     

Approaches to enhance power density of gearboxes for wind turbines

Based on pitting strength, some approaches to enhance power density of gearboxes for wind turbines are discussed. The calculation load is greatly reduced by power division. Allowable stress numbers are effectively increased by improving property of quality materials, precision heat treatment or shot peening. Load capacities can be also obviously enhanced by improving the tooth shape of morphology optimization of tooth root, tooth correction or superfinishing of tooth surface. The center distance is effectively decreased by minishing minimum allowable safety factor or enlarging face width. The power density of gearbox can be further improved by means of structure optimization of planet carrier or uniform load of planetary gear transmission.     

The analysis of China wind power industry

The development course of China wind power industry is reviewed by six stages. National policies on wind power industry are elaborated from the aspects of laws & regulations, planning, finance & taxation and electrovalence policy. And these policies have played an important supporting and regulating role in the development of wind power industry. The development status of China wind power industry is analyzed based on wind turbine installed capacity, wind power output and their growth rate. It is explained that national wind turbine manufacturers have kept developing and become strong by the data of new global installed capacity share of mainland wind turbine manufacturers in 2013 and the new global market share of 8 domestic enterprises among the world top 15 wind turbine manufacturers. But there are still 5 key problems which influence the development of national wind turbine need to be solved, including lack of top-level design, abandon and restriction wind power seriously, lack of R&D abilities, some of the key parts relying on imports and wind turbine facing a quality guarantee dilemma. Taking Sinovel Wind Group Co. Ltd. and Xinjiang Goldwind Sci & Tech Co. Ltd., the two leading companies as an example, their performance is analyzed and it’s pointed out that the wind industry must keep vigilant after the overspeed development. The enterprises should try to avoid neglecting cultivating their inner core competitive ability, including technology advancements and products reliability. Occupying the market with low price competition and expanding blindly is also not desirable. At last, the development prospects of our country’s wind power industry are analyzed and three proposals are put forward.     

半粒稻米直链淀粉测定方法的研究及应用

本文提出一个简便易行的分析方法,用1粒稻米既可测出其中的直链淀粉含量,还可用以繁种,便于在育种早代选择优良个体、提高效率,加快进程。用本方法测得的直链淀粉含量与用中华人民共和国国标法GB_(7648-87),测得的结果经t检验,差异不显著。利用本法分析了F_1代种子及其亲本的直链淀粉含量,结果表明,在非糯品种与糯稻品种的两     

急、慢性冷应激对雏鸡腓肠肌及血清抗氧化功能的影响

【目的】探讨自由基在冷应激对禽类机体损伤中所起的作用,为探索促进动物冷适应的方法,提高动物的抗寒能力提供一定的理论依据;【方法】应用化学比色法检测了急、慢性冷应激对腓肠肌和血清中总抗氧化能力(T-AOC)、过氧化氢酶(CAT)活性、谷胱甘肽过氧化物酶(GSH-Px)活性、超氧化物歧化酶(SOD)活性及丙二醛(MDA)含量的影响;【结果】急性应激时,随应激时间的延长,腓肠肌T-AOC与SOD活性均逐渐降低,GSH-Px活性、CAT活性及MDA含量均逐渐升高,血清T-AOC逐渐降低,GSH-Px活性、CAT活性、SOD活性及MDA含量均逐渐升高;慢性应激时,随应激时间的延长,腓肠肌T-AOC、GSH-Px活性、CAT活性及SOD活性均逐渐升高,MDA含量逐渐降低,血清T-AOC、GSH-Px活性、CAT活性及MDA含量均逐渐升高,SOD活性逐渐降低;【结论】表明急、慢性冷应激均可使机体的抗氧化功能发生改变,诱发氧化胁迫,导致机体内自由基增多,对机体造成损伤。     

临界风速气力输送模糊控制仿真

基于MATLAB／Simulink软件环境，建立了临界风速气力输送模糊控制模型，并进行了仿真研究。仿真结果表明，模糊控制器能很好地达到预期控制效果，并具有快速、准确的优点，从而解决了气力输送过程中按动耗最低原则自动调节和控制风速的问题，为气力输送系统的性能改进提供了一条途径。     

直齿圆柱齿轮冷精锻成形过程数值模拟分析

对直齿圆柱齿轮冷精锻成形过程进行了三维大变形弹塑性有限元数值模拟。对闭式模锻预锻及以闭式模锻、孔分流及约束分流为终锻的两步成形过程的流动情况进行了数值分析。数值模拟结果及前期的工艺试验表明：终锻中采取分流、尤其是约束孔分流措施对于降低工作载荷、提高角隅充填能力十分有利，采用矩阵变换技术解决因引入边界摩擦及滑动约束带来的刚度阵非对称问题较为简单、合理、有效。