写做实验的英语作文Title: Exploring the Phenomenon of Electric Conductivity: An Experimental Investigation。
Electric conductivity is a fundamental concept in physics with broad applications in various fields, from electronics to materials science. Understanding the factors that influence conductivity and exploring its behavior under different conditions is crucial for advancing technological innovations. In this experiment, we aimed to investigate the factors affecting electric conductivity and analyze the relationship between conductivity and temperature.To conduct the experiment, we assembled a simplecircuit consisting of a power supply, wires, a resistor, and a voltmeter to measure voltage across the resistor. We chose a variety of materials with different properties to test their conductivity, including metals like copper and aluminum, as well as non-metals like graphite and silicon.Firstly, we measured the conductivity of each material at room temperature. By applying a constant voltage across the resistor and measuring the resulting current, we were able to calculate the conductivity using Ohm's law. The results showed that metals generally exhibited higher conductivity compared to non-metals, which was consistent with theoretical expectations.Next, we investigated the effect of temperature on conductivity by gradually heating the materials while measuring their conductivity. We observed that for most materials, conductivity increased as temperature rose. This phenomenon can be explained by the fact that at higher temperatures, atoms vibrate more vigorously, leading to greater electron mobility and thus higher conductivity. However, this trend was not universal, as some materials exhibited a decrease in conductivity at very high temperatures due to other competing effects such as phonon scattering.Furthermore, we explored the influence of materialproperties such as purity and crystalline structure on conductivity. We compared the conductivity of pure metals with that of their alloys and observed that impurities and defects in the crystal lattice tended to decrease conductivity by disrupting the flow of electrons. Additionally, we examined the effect of varying the length and cross-sectional area of the conductor on conductivity, confirming the expected inverse relationship between resistance and cross-sectional area, and directrelationship between resistance and length.Overall, our experiment provided valuable insights into the factors affecting electric conductivity and demonstrated the importance of temperature, material properties, and geometric factors in determining conductivity. These findings have implications for various technological applications, such as designing efficient electrical conductors and optimizing semiconductor devices.In conclusion, this experimental investigation shed light on the complex behavior of electric conductivity and highlighted the interplay between various factors. Bysystematically analyzing the conductivity of different materials under controlled conditions, we deepened our understanding of this fundamental physical phenomenon and laid the groundwork for further research in this area.。
1.荷载短期荷载short-time load 临界荷载critical load 持续荷载sustained loads恒载dead load 活载live load 峰值荷载peak load 冲击荷载impact load 2.专业名词力矩面等横截面cross section 隔离体 a free body 轴力axial forces 带肩梁ledger beam正应力the normal stress 剪应力the shear stress 固定铰支座 a pin support 可动铰支座 a roller support 平面内弯矩in-plane bending 平面外弯矩out-of-plane bending简支梁a simple beam 悬臂梁 a cantilever beam 分布力distributed load 均布力uniformly distributed load 静定结构statically determinate structure 超静定结构statically indeterminate structure 角焊缝fillet weld 对接焊缝groove weld外缘outer edges 中性轴the neutral axis 形心矩centroidal distance沙石混凝土sand-and-stone concrete 预应力混凝土pre stressed concrete复合应力combined stress 极限应变limiting tensile strain 平均正应力mean normal stress名义抗剪强度nominal shear strength 惯性力inertia force 地震作用seismic action广义位移generalized displacement 扭矩torsion 预加应力pre stress托梁corbel3.材料平面顶deck 屋面防水层water proof roofing 金属箔层压板foil-laminated钢筋steel 涂料paint 木条板lath 灰泥plaster 楔子wedge基础footing 横向钢筋transverse reinforcement 纵筋longitudinal reinforcement 弯起纵筋bent-up longitudinal steel 单向板one-way slabs 腹筋the web steel 楼梯踏步stair tread 顶棚抹灰plastered ceilings 承重墙bearing wall第 1 页/共 4 页轻质幕墙light weight curtain walls 桁架truss 构件member 谷仓grain elevator桥墩bridge pier 大型结构heavy structure 梯井stair shaft高层写字楼high-rise office 预埋构件metal insert 作业平台work plat form企口木板tongue-and-groove plank 施工架constructed yoke 走道脚手架 a walkway scaffold铅垂线the plumb line 喷雾器fog sprays 型钢structural steel 剪力墙shear wall平板flat slab 合成薄板synthetic film 防护墙板endosing wall panels人字起重机derrick crane 卫生间设施bathroom groups 服务竖井the service shaft隔气层vapor barriers 隔热层insulation 结露点dew point 空心板hollow plank竖向剪力墙shear-resistant vertical wall 预制构件pre cast member 隔板wall panel4.其他1应力等值线 a stress contour 数值分析numerical analysis 悬索基础cable structures实验研究experimental investigation 超静定次数degree of statical indeterminaly叠加法method of superposition 基本结构released structure高跨比span-depth ratio弯矩图bending moment diagram 附着deposit 弹性模量modulus of elasticity水化hydrate 硬化harden 变量variables 环境相对湿度ambient relative humidity蒸发evaporate 定向立方体单元oriented elementary cube初步结论tentative conclusion斜向拉力diagonal tension 微分长度单元 a differential length 应力迹线stress trajectory骨料咬合作用aggregate interlock 销栓作用dowel action 延性ductility扭转力偶twisting couple 力臂lever arm 分数fraction 取代in lieu of地震高发区zones of high earthquake probability 平立面in plan elevation平动translation 转动rotation 凹部depressions 凸起projection 凸口recess 在现场on the site 误差error 通用规范applicable codes滑模施工slip form operations 养护care 锚固be anchored in 挠度deflection5.其他2侧向支持sway bracing 先张法pre tensioning technique 后张法post tensioning technique安全系数safety factor 安全储备margin of safety 附属cust-in fittings防火等级fire ratings 不匀称沉降differential settlement 深基础deep foundation扩展式基础spread foundation 符合基础combined footings 条形基础strap footings垂直于at right angles to 类似于analogous to 单位力法unit-load method大小相等方向相反be equal in magnitude and opposite in direction静力平衡方程equations of static equilibrium 与……有关pertain to求合力from a summation of force 一组联立方程 a set of simultaneous equations协调方程equations of compatibility 经验方程empirical equation大一个数量级an order of magnitude longer 第二面积积分the second moment-area thorea·b dot product a*b cross product 位移互等定理reciprocal displacement theorem第 3 页/共 4 页液压控制系统hydraulic master control system 功的互等定理…………work ……与……成正比in direct proportion to 与……一致be geared to。
CHN-T1标模大型低速风洞试验结果相关性分析张晖;范利涛【摘要】为满足型号研制的试验数据质量需求,进一步开展CFD验证与确认工作,中国空气动力研究与发展中心建立了大展弦比运输机高低速统一标模体系.为获得可靠风洞试验数据,使用设计加工的第一个运输机标模CHN-T1(1:6.4,翼展4.667m)在FL-13风洞和DNW-LLF风洞进行了试验.同一构型下,前者试验雷诺数为1.4×106～2.5×106,后者试验雷诺数为1.4×106～3.2×106.模型在FL-13风洞中通过TG1801A内式六分量天平与大迎角支撑机构相连,在DNW-LLF风洞中则通过W616天平与尾撑机构相连.两风洞均测量了模型力和力矩.风洞试验数据差异评估包括重复性、气动特性和雷诺数影响.结果对比表明:标模在不同风洞试验中的升力线斜率相差很小;设计升力点附近(Ma=0.78,C L=0.5)阻力系数相差0.0004,试验数据一致性较好;雷诺数对标模气动特性影响符合预期.【期刊名称】《实验流体力学》【年(卷),期】2019(033)003【总页数】6页(P106-111)【关键词】标模;风洞试验;相关性;试验精度;支架干扰;天平【作者】张晖;范利涛【作者单位】中国空气动力研究与发展中心低速空气动力研究所,四川绵阳621000;中国空气动力研究与发展中心低速空气动力研究所,四川绵阳 621000【正文语种】中文【中图分类】V211.740 引言风洞标模最初是检验风洞试验数据长期稳定性指标(如气流偏角、数据重复性、数据不确定度等)的重要工具[1,2]。
随着CFD(Computational Fluid Dynamics)技术不断发展，标模更多被用于验证先进的CFD算法[3-8]。
NASA(National Aeronautics and Space Administration)先后研发了DLR-F4[3]、DLR-F6[9]、CRM[10]等标模,并在风洞中进行试验，利用试验数据验证CFD算法在阻力预测中的实用性。
重载列车缓冲器特性研究综述孙树磊;李芾;黄运华;周张义;丁军君【摘要】介绍和总结了国内外货车缓冲器的发展概况,概述了钢弹簧摩擦缓冲器、摩擦橡胶式缓冲器、黏性阻尼缓冲器以及摩擦胶泥缓冲器的工作原理,分析研究了其阻抗特性.就缓冲器动力学计算模型的建立、缓冲器特性间断点的处理及其列车动力学模型的建立3个方面提出了今后研究的重点和难点,为缓冲器的选型设计以及纵向动力学的研究提供了一定的理论支撑.【期刊名称】《铁道机车车辆》【年(卷),期】2012(032)002【总页数】5页(P5-9)【关键词】重载列车;缓冲器;动力学计算模型;特性【作者】孙树磊;李芾;黄运华;周张义;丁军君【作者单位】西南交通大学机械工程学院,四川成都610031;西南交通大学机械工程学院,四川成都610031;西南交通大学机械工程学院,四川成都610031;西南交通大学机械工程学院,四川成都610031;西南交通大学机械工程学院,四川成都610031【正文语种】中文【中图分类】U260.34+2铁路运输作为我国货物运输的重要手段之一，目前承担着全国货物运输的55%左右［1］。
据预测，2015年全国铁路货运量将达到45亿t，换算周转量将达到5.1亿万t·km，较2010年分别增长32.2%和41.7%［2］。
可见，铁路货运在国民经济的发展中起着不可替代的作用。
而重载列车作为我国铁路货运发展的重要方向，是解决铁路大宗货物运输的关键技术之一。
随着列车载重的增加、运行速度的提高，列车的纵向冲动成非线性增长［3］。
尤其是近几年来，大秦铁路成功开通2万t级的重载组合列车，暴露出了一系列的问题，如由于车钩力显著增大，车钩、钩舌以及钩尾框等出现故障及裂纹的比例增大，缓冲器裂损严重等，这就为列车纵向动力学的研究提供了前提。
而缓冲器作为重载列车缓和冲击和耗散振动能量的关键部件，很大程度上决定了列车的纵向动力学性能。
缓冲器的性能指标也直接影响了列车的牵引质量、车辆总质量、编组作业效率、货物的完好率等涉及铁路运输效能的主要技术经济指标［1］。
