对2010年高考江苏卷第5题的一点疑问

[题目] 2010年高考江苏卷第5题 空间有一沿x轴对称分布的电场,其电场强度E随x变化的图像如图1所示.下列说法正确的是     

再谈2010年高考江苏卷第5题电场特点

文献[1]和文献[2]都对2010年高考江苏卷第5题做了分析,笔者对两文中一些观点不敢苟同,现分析如下．     

判断的依据是什么——再议2009年高考江苏卷物理第9题

《物理通报》2010年第1期第62页刊登了南京外国语学校姚小琴老师的一篇关于2009年高考江苏卷物理第9题的文章,笔者看了受益匪浅．但笔者也发现了一些问题,现分析如下．如有不当之处还请各位物理同仁批评指正．     

一道高考试题带来的启示——谈"基本模型"在解题和命题中的作用

探讨了2010年高考江苏卷物理第9题解题方法和命题者的命题思路,以及对今后教学工作的启示.     

巧设疑问引导学生掌握伏安法测电阻

在中学物理实验教学中对电阻阻值的测定是电学实验的重点,在历届高考中屡见不鲜(2003年江苏卷第13题,2004年渝、川、吉理科综合第22题,2004年北京理科综合第22题,2005年全国理科综合1卷第22题,2007年全国理科综合Ⅱ卷第22题及上海、海南等在高考电学实验中均考查了电阻的测定).     

正确构建模型是解答问题的关键

文献[1]分析了2010高考江苏物理卷第5题,然后采用构建电场图线的电荷模型,化抽象为具体,对题目进行解答．最后作者对该题图像提出质疑,并对图像进行修正．通读全文,笔者认为对该题的解答和研究方法非常可取,这道试题应该是没有疑义的;但作者建立的物理模型却值得商榷．     

2010年高考江苏卷物理第9题的微瑕——兼谈附加磁场边界形状的确定

1前言 2010年高考江苏卷物理试题第9题是一道选择题,考查带电粒子在磁场中的运动.题目设计新颖独到,富有创意,能综合考查相关知识的运用[1],但笔者认为这道题目本身有值得商榷的地方.     

用几何画板动态演示2 0 1 7年高考江苏物理卷第1 5题

用几何画板动态演示了2 0 1 7年高考江苏物理卷第1 5题的物理过程, 帮助学生建立清晰的几何图像, 理 清解题思路, 在解决问题的过程中锻炼思维能力     

对2010年高考全国卷Ⅰ第21题答案的质疑

题目:(2010年高考全国卷Ⅰ第21题)一简谐振子沿x轴振动,平衡位置在坐标原点.t=0时刻振子的位移x=-0.1m;t=4/3s时刻x=0.1m;t=4s时刻x=0.1m.该振子的振幅和周期可能为     

对2014年高考江苏物理卷第7题的深度思考

对2014年高考江苏卷第7题进行了研究,通过理论分析和实验验证确定该题没有正确选项,并对命题失误的原因进行了分析.     

X‐ray‐Raman‐scattering‐based EXAFS beyond the dipole limit

X‐ray Raman scattering (XRS) provides a bulk‐sensitive method of measuring the extended X‐ray absorption fine structure (EXAFS) of soft X‐ray absorption edges. Accurate measurements and data analysis procedures for the determination of XRS‐EXAFS of polycrystalline diamond are described. The contributions of various angular‐momentum components beyond the dipole limit to the atomic background and the EXAFS oscillations are incorporated using self‐consistent real‐space multiple‐scattering calculations. The properly extracted XRS‐EXAFS oscillations are in good agreement with calculations and earlier soft X‐ray EXAFS results. It is shown, however, that under certain conditions multiple‐scattering contributions to XRS‐EXAFS deviate from those in standard EXAFS, leading to noticeable changes in the real‐space signal at higher momentum transfers owing to non‐dipole contributions. These results pave the way for the accurate application of XRS‐EXAFS to previously inaccessible light‐element systems.     

Resonance Raman intensity analysisof the excited‐state photochemical dynamicsof dimethyl 1,3‐dithiole‐2‐thione‐4,5‐dicarboxylate in the A‐band absorption

Dimethyl 1,3‐dithiole‐2‐thione‐4,5‐dicarboxylate (DDTD) was synthesized and characterized using NMR, Fourier transform (FT)‐Raman, Fourier transform‐infrared (FT‐IR) and UV spectroscopies. Resonance Raman spectra (RRs) were obtained with 341.5, 354.7 and 368.9 nm excitation wavelengths and density functional calculations were carried out to elucidate the π (S C S) →π* (S C S) electronic transitions and the RRs of DDTD in cyclohexane solution. The RRs indicate that the Franck–Condon region photo dynamics have a multidimensional character with motion predominantly along the CS stretch and the C S symmetric stretch modes in the five‐member heterocycle. A preliminary resonance Raman intensity analysis was carried out and the results for DDTD were compared with previously reported results for 1,3‐dithiole‐2‐thione (DTT). Differences and similarities of the spectra in terms of molecular symmetry and electron density are also discussed. Copyright © 2010 John Wiley & Sons, Ltd.     

A deep insight into the mechanism of the acid‐catalyzed rearrangement of the Z‐phenylhydrazone of 5‐amino‐3‐benzoyl‐1,2,4‐oxadiazole in a non‐polar solvent

The conversion of the Z‐phenylhydrazone of 5‐amino‐3‐benzoyl‐1,2,4‐oxadiazole ( 1a ) into the relevant 1,2,3‐triazole ( 2a) has been quantitatively studied in toluene in the presence of several halogenoacetic acids ( HAA s, 3a – h ). Again, the occurrence of two reaction pathways has been pointed out: they require one or two moles of acid, respectively, thus repeating the situation previously observed in the presence of trichloroacetic acid. The observed rate constant ratios (k_III/k_II) are only slightly affected by the nature of the acid used. To gain a deeper insight into the action of the acids used we have measured the association constants of the HAA s ( 3a – h) with 4‐nitroaniline ( 4 ) in toluene. Also in this case, the formation of two complexes requiring one (K₂) or two (K₃) moles of acid has been evidenced, but now the K₃/K₂ ratios are significantly affected by the strength of the acid examined. The variation of the K₃/K₂ ratios larger than those concerning the k_III/k_II ratios appears useful to enlighten the very nature of the acid‐catalyzed pathways in toluene, which has been elucidated also carrying out the rearrangement in the presence of mixtures of tribromo‐ and trichloro‐acetic acids at different concentrations. Copyright © 2010 John Wiley & Sons, Ltd.     

Exact solution of the Klein‐Gordon equation for the PT‐symmetric generalized Woods‐Saxon potential by the Nikiforov‐Uvarov method

The exact solution of the one‐dimensional Klein‐Gordon equation of the ????‐symmetric generalized Woods‐Saxon potential is obtained. The exact energy eigenvalues and wavefunctions are derived analytically by using the Nikiforov and Uvarov method. In addition, the positive and negative exact bound states of the s‐states are also investigated for different types of complex generalized Woods‐Saxon potentials.     

Catalysis by hydrogen chloride in the gas‐phase elimination kinetics of 2‐phenyl‐2‐propanol and 3‐methyl‐1‐buten‐3‐ol

A homogeneous, molecular, gas‐phase elimination kinetics of 2‐phenyl‐2‐propanol and 3‐methyl‐1‐ buten‐3‐ol catalyzed by hydrogen chloride in the temperature range 325–386 °C and pressure range 34–149 torr are described. The rate coefficients are given by the following Arrhenius equations: for 2‐phenyl‐2‐propanol log k₁ (s^?1) = (11.01 ± 0.31) ? (109.5 ± 2.8) kJ mol^?1 (2.303 RT)^?1 and for 3‐methyl‐1‐buten‐3‐ol log k₁ (s^?1) = (11.50 ± 0.18) ? (116.5 ± 1.4) kJ mol^?1 (2.303 RT)^?1. Electron delocalization of the CH₂?CH and C₆H₅ appears to be an important effect in the rate enhancement of acid catalyzed tertiary alcohols in the gas phase. A concerted six‐member cyclic transition state type of mechanism appears to be, as described before, a rational interpretation for the dehydration process of these substrates. Copyright © 2007 John Wiley & Sons, Ltd.     

Kinetic study of the formation reaction of N‐chloro‐2‐oxazolidinone

The chlorination reactions of 2‐oxazolidinone with hypochlorous acid (HOCl), tert‐butyl hypochlorite (^tBuOCl) and N‐chlorosuccinimide (NCS) were studied at 25 °C, constant ionic strength, and under isolation conditions. The kinetic results obtained in the formation processes of the N‐chloro‐2‐oxazolidinone are summarized in this paper. The kinetics studied showed a first order with respect to the concentration of the each reactant and a complex dependence of the pH on the rate constant. The reactivity order with respect to the chlorinating agent found is k(HOCl) > k(^tBuOCl) > k(NCS). Copyright © 2015 John Wiley & Sons, Ltd.     

Non‐interacting single‐impurity Anderson model: solution without using the equation‐of‐motion method

Ground‐state properties of the non‐interacting symmetric single‐impurity Anderson model (SIAM) are derived from the corresponding eigenenergy equation. Explicit formulae are given for the ground‐state energy, the hybridization, and the momentum distribution that are essential quantities for variational approaches to the interacting model. Various spectral functions, e.g., the total density of states, the phase shift function, and the impurity spectral function, are shown to agree with those obtained from the equation‐of‐motion method (see supplementary material). For a constant hybridization strength and a semi‐elliptic host density of states it is seen that the impurity spectral function builds up weight at the band edges.

     

Augmentation of the step‐by‐step Energy‐Scanning EXAFS beamline BL‐09 to continuous‐scan EXAFS mode at INDUS‐2 SRS

An innovative scheme to carry out continuous‐scan X‐ray absorption spectroscopy (XAS) measurements similar to quick‐EXAFS mode at the Energy‐Scanning EXAFS beamline BL‐09 at INDUS‐2 synchrotron source (Indore, India), which is generally operated in step‐by‐step scanning mode, is presented. The continuous XAS mode has been implemented by adopting a continuous‐scan scheme of the double‐crystal monochromator and on‐the‐fly measurement of incident and transmitted intensities. This enabled a high signal‐to‐noise ratio to be maintained and the acquisition time was reduced to a few seconds from tens of minutes or hours. The quality of the spectra (signal‐to‐noise level, resolution and energy calibration) was checked by measuring and analysing XAS spectra of standard metal foils. To demonstrate the energy range covered in a single scan, a continuous‐mode XAS spectrum of copper nickel alloy covering both Cu and Ni K‐edges was recorded. The implementation of continuous‐scan XAS mode at BL‐09 would expand the use of this beamline in in situ time‐resolved XAS studies of various important systems of current technological importance. The feasibility of employing this mode of measurement for time‐resolved probing of reaction kinetics has been demonstrated by in situ XAS measurement on the growth of Ag nanoparticles from a solution phase.