RC剪力墙在不同轴压比下抗震性能的数值模拟分析

利用Ansys有限元分析软件,对不同轴压比下的RC剪力墙进行数值模拟分析,采用荷载步文件进行低周反复荷载的模拟加载,研究轴压比分别为0.20,0.25,0.30的3片剪力墙的抗震性能,包括抗震承载力、延性、耗能能力、裂缝开展模式等的变化规律。研究表明,模拟结果与轴压比为0.25的实体墙的试验结果相吻合。     

Defects production and mechanical properties of typical metal engineering materials under neutron irradiation

Maintaining the safety and reliability of nuclear engineering materials under a neutron irradiation environment is significant. Atomic-scale simulations are conducted to investigate the mechanism of irradiation-induced vacancy formation in CLAM, F82 H and α-Fe with different neutron energies and objective laws of the effect of vacancy concentration on mechanical properties of α-Fe. Damage of these typical metal engineering materials caused by neutrons is mainly displacement damage, while the displacement damage rate and the non-ionizing effect of neutrons decrease with the increase of neutron energy. The elastic modulus, yield strength, and ultimate strength of α-Fe are in the order of magnitude of GPa. However, the elastic modulus is not constant but decreases with the increase of strain at the elastic deformation stage. The ultimate strength reaches its maximum value when vacancy concentration in α-Fe is 0.2%. On this basis, decreasing or increasing the number of vacancies reduces the ultimate strength.     

A Novel Fluorescence Probe 9-（4-（1,2-diamine）benzeneN 1-phenyl）acridine for Nitric Oxide Determination

A novel fluorescent probe 9-(4-(1,2-diamine)benzene-N1-phenyl)acridine(DABPA) was synthesized for the detection of nitric oxide(NO) and characterized by IR, 1H-NMR and EI-MS spectroscopy. Based on a photoelectron transfer mechanism, the fl uorescence intensities of DABPA were investigated with the different concentrations of NO. Under the optimal experimental conditions, the fl uorescence intensity of DABPA had a good linear relationship(R2=0.9977) with NO concentration in the range from 1×10-7 to 1.5×10-6 mol/L with a detection limit of 1×10-8 mol/L. The cytotoxicity induced by DABPA was evaluated by the MTT(3-(4,5-dimethylthiazol-2-yl)-2,5diphenyl tetrazolium bromide) assay for biological application. Furthermore, the probe DABPA had also been successfully applied to real-time image NO produced in PC12 cells in the presence of L-arginine.     

Calculation of thermodynamic parameters of Mg-Al-Y alloy

By means of Miedema formation enthalpy model with Toop model, the excess free-energy, enthalpies of formation, excess entropies and activity values of all components of Mg-Al-Y ternary alloy were calculated with computer programming. The experimental results show that enthalpies of formation, excess freeenergy and excess entropies of the ternary alloy are negative in the whole content range, the minimum values at 1 123 K are all obtained at x Al=55%, x Y=45%, x Mg=0%, which are-37.969, –30.961 kJ/mol and-6.24 J/(mol·k) respectively. Activity curves show that the activity values of Al and Y in Mg-Al-Y ternary alloy rapidly decrease with the decrease of molar fraction, the values of which are very small when the molar fraction decreases to 0.4. It means that there is a strong interaction between Al and Y and stable compounds can be form in the Mg-Al-Y ternary alloy system.     

Preparation and spectral analysis of gold nanoparticles using magnetron sputtering and thermal annealing

Gold(Au) nanoparticles were prepared on Au-fi lm-coated K9 glass and silicon substrates by direct current(DC) magnetron sputtering and thermal annealing treatment. The effects of substrate material, annealing temperature, and time on morphologies of Au nanoparticles were investigated, and the formation mechanism of Au nanoparticles was discussed. The experimental results indicate that silicon substrate is more suitable for the formation of Au nanoparticles. On a silicon substrate, Au nanoparticles formed with good spherical shapes at temperature over 700 ℃. It was also found by spectral analysis that the fi eld enhancement factor of the island-shaped Au particles was smaller than that of the granular Au particles; the better the spherical shape as well as the smaller the size and spacing of Au particles, the higher the light absorption rate; the absorption peak had a red shift with increasing particle size and spacing.     

基于机械臂运动的组合航天器惯性参数在轨辨识

随着空间技术发展,交会对接任务越来越多,服务航天器与目标航天器对接形成组合航天器后惯性参数会发生明显变化。因此,提出一种基于机械臂运动的组合航天器惯性参数在轨辨识方法。该方法可以分为2步:第一步辨识组合航天器的质量和质心;第二步辨识组合航天器的惯性张量。该方法优点是实现了质量、质心与惯性张量等辨识参数的相互解耦,不需要消耗航天器上宝贵的喷气燃料,仅需要测量航天器的速度,而不是加速度和力。仿真结果验证了方法的有效性。     

基于地图Mashup的水质实时监测系统软件开发

该文介绍了基于地图Mashup的水质实时监测系统的设计,实现了对监测站点各项数据的查询和报表输出,与现场视频信号动态连接进行直观监测,并且能够对监测站信息进行设置,同时系统设计兼顾了良好的用户界面交互性。     

门票经济转型问题分析--以江西为例

目前我国景区门票价格一路高歌,这反映了我国旅游业的经济主要是靠门票经济为主导的经济模式。居高不下的门票价格让许多游客闻风丧胆,这样不利于旅游业长期的发展。短期的利益牺牲了许多游客对景区的第一印象,再加上我国景区里的娱乐开发单一,并且还存在小景点收费现象,这与可持续发展的理念相违背。本文揭示了当前旅游业目前实行的门票经济的现状,以江西景点为例,分析了目前存在的问题,并对存在的问题提出相应地解决对策。     

浅谈子程序在数控铣教学中的应用

子程序是数控编程过程中的一种常用功能,灵活使用子程序技术,可以减少编程时的程序量,增强数控机床的功能。本文针对子程序调用技术在数控铣床教学中的几种常用方法进行探讨与研究,希望对同行起一个抛砖引玉的作用。     

美国社区学院汽车维修专业课程开发的特点及启示

研究了美国社区学院汽车维修专业人才培养的特点。美国社区学院汽车维修专业人才培养是由行业主导,根据技术领域和职业岗位的技能需求,按照行业职业资格标准开发课程体系和教学内容,建立适应行业职业资格标准和岗位技能培养的课程标准,从而规范课程教学的基本要求,对中国高职院校汽车维修专业人才培养有一定的启示意义。