2012年北京市高中新课程高考物理试卷评析

对2012年北京市新课程高中物理试卷做了比较全面、深刻的评析.对试卷形成的特色做了阐述.对试卷的正确导向作用做了说明.对高考命题提出了一些建议.     

2-D Fiber-optic Sensing Probe

给出了一种新颖的二维强度调制反射式光纤传感探头.导出了二维传感探头的调制函数.给出了特性调制曲线.设计并实现了5光纤传感探头.获得了与理论符合较好的实验结果.     

内耗研究的历史评述

通过介绍几位在内耗领域的先驱研究者:C.Zener,葛庭燧,P.G.Bordoni ,J.L.Snoek,评述了内耗研究的进展.也介绍了日本研究者的相关工作.     

聚合物湍流减阻流动的直接数值模拟研究

采用离散弹性元素.珠簧哑铃模型方程模拟了聚合物减阻流动.模拟出了高分子聚合物浓度的空间分布.得到了减阻率与粘弹性应力,雷诺应力等的定量关系.分析了聚合物湍流结构和离散弹性元素模型中弹性系数的关系.     

威耳逊对云室的实验研究

介绍了C.T.R.威耳逊的主要贡献和发明云室的过程.他由研究水滴的凝结规律入手,不断改进实验装置,拍摄了带电粒子的径迹照片,从而证明了康普顿效应;还分析了威耳逊取得成功的几个重要因素.     

某空间望远镜相关跟踪系统摆镜随机振动分析

介绍了基础激励下机构随机振动响应的理论与分析方法.利用有限元分析软件ANSYS建立了某空间望远镜相关跟踪系统摆镜的有限元模型,并进行了随机振动响应分析.通过分析考察了其承受动力学环境的能力.对计算结果进行了分析.指出了现有结构中的薄弱环节,提出了改进方案,为摆镜的设计提供了重要参考依据.     

在线同位素分离器激光离子源的元素选择性和激光技术

分析了目前在线同位素分离器改进的必要性和可能性.介绍了激光多步共振电离原理和激光离子源原理.具体分析了热毛细管式激光离子源元素选择性的产生及其影响的因素.描述了所使用的激光器和激光技术.对热毛细管式的激光离子源作了元素选择性实验,结果表明该离子源的元素选择性达到了50─10000.     

LaNi5氚老化效应的实验研究

测定了老化LaNi5料的解吸等温线及去氘化热力学参数.评价了氚老化对LaNi5贮氢性能的影响.结果表明,氚老化使LaNi5解吸等温线形貌发生重大改变.与新鲜材料相比,老化2140天后,在373 K下,坪台压力降低了约50%,坪斜由0.033到0.130,可逆吸氢容量减少了约1.3 mmol.g-1.老化LaNi5料去氘化反应热力学焓变ΔH和熵变ΔS分别由30.1 kJ.mol-1和105 J.mol-1.K-1增加到44.5 kJ.mol-1和128 J.mol-1.K-1.     

我是怎样喜欢上物理的

 我从小学起,就比较喜欢数学,上初中以后,有了物理课,也就自然而然地对物理产生了浓厚的兴趣.而我真正迷上物理,还是高二的事.高二时,我们开设了选修课,我选学了物理实验.虽然每周只有一个下午的选修课,但它却使我一下发现了一个新天地.主持选修课的刘滨生老师很重视对实验设计的训练,特别突出了实验中严谨、细致作风的培养.也许正是这种严谨、细致的要求,恰恰与我沉稳、耐心的性格相符.因此,我在实验中能够比较得心应手,从中获得了很大的乐趣.这时,我才真正领会到了学物理的快乐.     

单个量子态的操纵和测量:2012年诺贝尔物理学奖述评

塞尔日.阿罗什和大卫.维因兰德获得了2012年诺贝尔物理学奖.他们独立地发展了突破性的实验方法,成功地实现了对单个量子态的测量和控制,由此展示了量子世界的基本特性.同时促进了基于量子技术的量子信息和原子钟的发展.     

Minority opinion spreading in random geometry

The dynamics of spreading of the minority opinion in public debates (a reform proposal, a behavior change, a military retaliation) is studied using a diffusion reaction model. People move by discrete step on a landscape of random geometry shaped by social life (offices, houses, bars, and restaurants). A perfect world is considered with no advantage to the minority. A one person-one argument principle is applied to determine locally individual mind changes. In case of equality, a collective doubt is evoked which in turn favors the Status Quo. Starting from a large in favor of the proposal initial majority, repeated random size local discussions are found to drive the majority reversal along the minority hostile view. Total opinion refusal is completed within few days. Recent national collective issues are revisited. The model may apply to rumor and fear propagation. Received 23 January 2002     

用染料激光增益降低二元混合物中少量化合物的受激拉曼散射可探测浓度

在二元混合物构成的圆形谐振腔中,用染料的激光增益增强了少量化合物(乙醇溶液中的甲醇、水溶液中的乙醇)的受激拉曼散射（SRS）光谱,将少量化合物在悬垂液滴中的瞬态SRS探测极限提高了近一个数量级. 用受激拉曼散射理论,解释了增强少量化合物SRS的机理. 关键词： 受激拉曼散射 染料激光增益 二元混合物 最小可探测浓度     

Effect of Au film and absorption groups on minority carrier life of porous silicon

In this paper, the samples were prepared with or without metal assistance in different time. The effect of Au film and absorption groups on minority carrier life of porous silicon was studied by using μ-PCD measurements, and the result was further proved by FTIR spectra and SEM images. The results were showed that the existed hydrogen-related groups on the surface of porous silicon would decrease the minority carrier life and the grid Au film also can decrease the minority carrier life. The minority carrier life may be controlled by the more effective factor, metal elements or absorption groups.     

电子辐照下GaAs/Ge太阳电池载流子输运机理研究

通过地面模拟辐照试验获得不同能量电子辐照下GaAs/Ge太阳电池电学参数退化的基本规律, 在此基础上使用PC1 D模拟程序分析太阳电池内部的载流子输运机理, 建立不同能量的电子辐照下GaAs/Ge太阳电池中多数载流子浓度和少数载流子扩散长度随辐照粒子注量变化的基本规律. 研究结果表明: 多数载流子浓度和少数载流子扩散长度均随入射电子注量的增大而减小, 多数载流子去除率和少数载流子扩散长度损伤系数均随电子能量的增高而增大, 多数载流子去除效应和少数载流子扩散长度缩短分别是电池开路电压和短路电流退化的主要原因.     

The origin of enhanced magnetization in strained gadolinium

From combined spin-resolved photoemission and spin-polarized inverse photoemission, the experimental spin-resolved band structure of gadolinium on Mo(112) has been constructed. The occupied spin dependent electronic structure near the Fermi level is dominated by shallow dispersion of a spin minority band with considerable surface weight. There is an occupied spin majority bulk band straddling the Fermi level whose spin minority counterpart remains largely on the unoccupied side of the Fermi level. This results in large spin majority weight in the occupied band structure relative to spin minority.     

低温退火磷吸杂工艺对低少子寿命铸造多晶硅电性能的影响

本文针对低少子寿命铸造多晶硅片进行试验, 通过一种将多温度梯度磷扩散吸杂工艺与低温退火工艺结合的新型低温退火吸杂工艺, 去除低少子寿命多晶硅片中影响其电性能的Fe杂质及部分晶体缺陷, 提高低少子寿命多晶硅所生产的太阳电池各项电性能. 通过低温退火磷扩散吸杂工艺与其他磷扩散吸杂工艺的比较, 证明了低温退火吸杂工艺具有更好的磷吸杂和修复晶体缺陷的作用. IV-measurement发现经过低温退火工艺处理后的低少子寿命多晶硅, 制备的太阳电池光电转换效率比其他实验组高0.2%, 表明该工艺能有效地提高低少子寿命多晶硅太阳电池各项电性能参数及电池质量. 本研究结果表明新型低温退火磷吸杂工艺可将低少子寿命硅片应用于大规模太阳电池生产中, 提高铸造多晶硅材料在太阳能领域的利用率, 节约铸造多晶硅的生产成本. 关键词： 低温退火 磷吸杂 低少子寿命多晶硅 太阳电池     

半导体深能级瞬态谱中多子脉冲下的少子陷阱响应

在一个Si中掺Aup⁺n结的多子脉冲下深能级瞬态谱(DLTS)中,发现了一个少子峰信号。给出了这一现象的主要实验结果,并做了系统的物理分析。这是p⁺n结中高掺杂一侧的自由少数载流子尾在自建势所张开的空间电荷区中被少子陷阱俘获后,再发射的结果。 关键词：     

The influence of a minority magnetic phase on the field dependence of the magnetocaloric effect

The field dependence of the magnetic entropy change can be used to detect the existence of a minority magnetic phase without experimentally reaching its Curie temperature. In this work, we present results that could suggest a breakdown of the recently proposed universal behaviour of the magnetocaloric effect in materials with a second-order magnetic phase transition in some La-containing samples. The behaviour of the outlier La-containing materials is an evidence of the existence of minority phases, preventing the construction of the universal curve with a single reference temperature. However, the use of two reference temperatures avoids this difficulty and allows applying the universal curve for practical purposes even with the presence of the minority phase.     

金融市场中经纪人相互竞争和适应性行为的物理模型

金融物理中的争当少数者博奕模型,是一个用来模拟金融市场动力学行为的最简单的模型,可以尝试利用它来对实际金融市场中许多现象提供物理的理解.文章介绍了关于金融物理的争当少数者博奕模型的一些主要研究结果和若干最新的发展方向.     

Electronic structure of half-metallic ferromagnet Co<Subscript>2</Subscript>MnSi at high-pressure

In this study, first principles calculation results of the half-metallic ferromagnetic Heusler compound Co₂MnSi are presented. All calculations are based on the spin-polarized generalized gradient approximation (σ-GGA) of the density functional theory and ultrasoft pseudopotentials with plane wave basis. Electronic structure of related compound in cubic L2₁ structure is investigated up to 95 GPa uniform hydrostatic pressure. The half-metal to metal transition was observed around ~70 GPa together with downward shift of the conduction band minimum (CBM) and a linear increase of direct band gap of minority spins at Γ-point with increasing pressure. The electronic density of states of minority spins at Fermi level, which are mainly due to the cobalt atoms, become remarkable with increasing pressure resulting a sharp decrease in spin polarization ratio. It can be stated that the pressure affects minority spin states rather than that of majority spins and lead to a slight reconstruction of minority spin states which lie below the Fermi level. In particular, energy band gap of minority spin states in equilibrium structure is obviously not destroyed, but the Fermi level is shifted outside the gap.