电磁感应习题分类例析

电磁感应是高中物理中的一个重要知识点，也是高考的热点，本文对这类综合题进行分类例析．     

基于萘基新型冠醚的合成、晶体结构及其对联吡啶盐的络合性能研究

以2,7-二羟基萘为起始原料,经与8-(对甲苯磺酰氧基)-3,6-二氧-1-辛醇醚化,再与对甲苯磺酰氯酯化得7,7最后与2,7-二羟基萘在碳酸铯为碱作用下得基于2,7-二羟基萘基块新型的冠醚,三步总收率为35%.利用单晶X衍射研究其结构,晶体为三斜晶系,P-1空间群,a=8.165(3),b=13.435(4),c=14.083(3),γ=64.11(2)°,β=80.40(3)°,γ=88.19(3)°,V=1368.9(7)3,Z=2,Dc=1.331 g/cm3,λ=0.071070 nm,μ(Mo Kα)=1.331 mm-1,Mr=353.22,F(000)=584.在1的晶体结构中,两个萘基块通过二缩三乙二醇醚键相连形成1个二萘并[30]-冠-8大环结构,空腔大小为8.2×12.0,分子呈Z型结构.通过核磁研究了主体分子1对联吡啶盐在溶液中的相互络合作用.     

火焰原子吸收光谱法测定齿科烤瓷修复用金基和钯基合金中银的不确定度评定

探讨了火焰原子吸收光谱法测定齿科烤瓷修复用金基和钯基合金中银的不确定度的评价方法。分析了不确定度的重要来源,包括称样质量、标准溶液的配制、工作曲线拟合、试液定容体积及测量重复性等引入的不确定度分量组成。对各不确定度分量进行分析计算,求得标准不确定度为0.023%,扩展不确定度为0.046%。     

确定"曲线运动速度的方向"实验的改进

1原教材中实验 曲线运动速度的方向可通过实验现象笼统地来说明，如砂轮打磨物体产生的火星、飞出的链球、由转动的雨伞边缘飞出的雨滴，等等．如何通过实验确定做曲线运动的物体在某一时刻的速度方向？按照人教版教材“演示”的实验思想，在教学过程中，老师们多用“管”作轨道进行实验设计，有两种常见情况．一是软管喷墨实验，把弯曲的软管置于水平面内，用注射器使墨水沿软管做曲线运动，并从管口喷出，喷出的墨迹显示出喷出点瞬时速度方向；     

利用连续准相位匹配光学参量振荡器实验强度差压缩态的实验研究

我们利用激光二级管泵浦的全固化单频Nd:YVO4激光器输出1.06μm激光泵浦准相位匹配铌酸锂三共振连续光学参量振荡器,在晶体温度改变8℃的情况下,得到波长范围为1988nm-2293nm的下转换光输出,最低泵浦阈值仅有1.8mW,最高转换效率达16%.并在信号光和闲置光的波长有较大分离(约200nm)的情况下,观察到信号光和闲置光的起伏的关联(0.4dB).     

2,6-二甲基哌啶+水体系临界性质的氘代同位素影响

用等体积法分别确定2,6-二甲基哌啶+水和2,6-二甲基哌啶+重水体系的临界组成, 并测定各自的临界温度. 采用折射率法在较宽温度范围内测定两个体系的温度-折射率(T-n)共存曲线, 利用标φ曲线法将其转化为温度-摩尔分数(T-x)和温度-体积分数(T-φ)共存曲线, 求得临界指数β、指前因子B、Wegner校正项因子B1及与共存曲线直径ρd相关的参数. 研究结果表明, 氘代后, 体系低临界温度下降了约3.2 K, 临界组成和共存曲线形状不变, 在近临界点临界指数β仍符合三维伊辛模型(3D-Ising)的理论值(0.327).     

Au5Si2/Si Heterojunction Nanowires Formed by Combining SiO Evaporation with Vapour--Liquid--Solid Mechanism

Crystalline AusSi2/Si heterojunetion nanowires （AusSi2/SiNWs） are obtained by thermal evaporating SiO pow- ders on thick gold-coated silicon substrates in a low vacuum system. Structure analysis of the produced AusSh/Si heterojunetions is performed by employing a transmission electron microscope （TEM） and a selected area electric diffraetometer. The chemical compositions axe studied by a energy-dispersive x-ray spectroscope attached to the TEM. A two-step growth model is proposed to describe the formation of the AusSi2/SiNWs. During the first step, crystalline SiNWs are formed via a growth mechanism combining the oxide-assisted growth process with the vapour-liquid-solid model at relatively high temperature. In the second step, the temperature decreases and one segment of the preformed SiNWs reacts with the remnant Au to form single crystalline AusSi2 nanowires by a solid-liquid-solid process. The present work should be useful for the future synthesis and research of high-quality gold silicide nanowires and microelectronic devices based on the nanowires.     

Application of the HKS in the identification of kaons produced in the reaction （e,e＇K^＋）

At Jefferson Laboratory the experiment E02-017 was carried out to investigate the fission associated with kaons in the hypernuclei-producing interaction p（e,K^＋e＇）A. The newly installed high resolution kaon spectrometer （HKS） in Hall C was used as a key instrument to identify kaons. This paper introduces the HKS hardware and describes the way the kaons are identified. Maintaining most of the kaons （nearly 100%） in the data, HKS identifies kaons with a purity of -67% in this experiment. The resolution of the kaon target time reconstructed by HKS reaches 0.42 ns.     

实验制备光通信波段1.34μm高纯度的压缩态

本文利用周期极化磷酸氧钛钾晶体构成的光学参量振荡器实验制备了光通信波段1.34μm纯度为0.993的真空压缩态光场,压缩态光场的压缩度为2.98dB、反压缩度为3.04dB。高纯度的真空压缩态光场可为制备光通信波段高保真度的薛定谔猫态提供量子光源。     

Precisely tuning Ge substitution for efficient solution-processed Cu_2ZnSn(S,Se)_4 solar cells

The kesterite Cu_2ZnSn(S,Se)_4(CZTSSe) solar cells have yielded a prospective conversion efficiency among all thinfilm photovoltaic technology. However, its further development is still hindered by the lower open-circuit voltage(Voc), and the non-ideal bandgap of the absorber is an important factor affecting this issue. The substitution of Sn with Ge provides a unique ability to engineer the bandgap of the absorber film. Herein, a simple precursor solution approach was successfully developed to fabricate Cu_2Zn(SnyGe_(1-y))(SxSe_(1-x))_4(CZTGSSe) solar cells. By precisely adjusting the Ge content in a small range, the V_(oc) and J_(sc) are enhanced simultaneously. Benefitting from the optimized bandgap and the maintained spike structure and light absorption, the 10% Ge/(Ge+Sn) content device with a bandgap of approximately 1.1 eV yields the highest efficiency of 9.36%. This further indicates that a precisely controlled Ge content could further improve the cell performance for efficient CZTGSSe solar cells.