平均速度与速度平均

变速直线运动物体的位移跟发生该位移所用的时间之比定义为这段时间内的平均速度．即：v=s／t．它是矢量，其方向，与位移方向相同．物体在不同时间(或位移)内的平均速度一般是不相等的．其概念简单、清晰．     

关于匀变速直线运动实验装置的研究和改进

本文对测匀变速直线运动的实验装置进行了改进 ,采用了传感技术 ,演示效果好。     

由"测定匀变速直线运动的加速度"实验的数据处理方法引起的思考

"测定匀变速直线运动的加速度"实验是高中物理第一册(必修)课本中的一个学生实验,它要求学生用一次逐差法处理数据,本文就针对此实验的数据处理方法作一些思考和讨论.     

运用图象法研究匀变速运动的规律

依据新的高考考试说明的要求，“研究匀变速直线运动”是高考必考的19个学生实验之一．现行高中物理教材(必修本)是运用打点计时器所打出的纸带，依据匀变速运动的规律：△s=αT^2，求取运动小车的加速度α．笔者在教学实践中，依据同学们的实际能力，运用图象描点法求取运动小车的加速度α，其效果也不错．现介绍如下。     

方程式及变量的独立性

“匀变速直线运动”中 ,包含五个变量 ,即初速度ｖ0 ,末速度ｖ ,加速度ａ ,时间ｔ及路程ｓ.理论上讲这五个变量之间存在着无数的公式 ,但最有用的只有下面五个 :ｖ =ｖ0 ａｔ (1 )　ｓ =ｖ0 ｖ2 ｔ　(2 )ｓ=ｖ0 ｔ 12 ａｔ2 　 (3 )　ｓ =ｖ2 -ｖ202ａ 　(4 )ｓ=ｖｔ- 12 ａｔ2 (5)我们研究一下这五个公式 ,可看出 ,式中依次没有ｓ、ａ、ｖ、ｔ、和ｖ0 ,即式 (1 )到式 (5)各是ｖ0 、ｖ、ａ、ｔ;ｖ0 、ｖ、ｔ、ｓ;ｖ0 、ａ、ｔ、ｓ;ｖ0 、ｖ、ａ、ｓ;ｖ、ａ、ｔ、ｓ之间公式 ,每一个公式都只包括四个变量 .下面的问题是 ,这些公式之间有几…     

"自由落体运动"的难点突破

自由落体运动处于第二章的最后,其重点是自由落体运动是匀变速直线运动,而且加速度是g.难点是物体自由下落的快慢与物体的重量无关,即轻重不同的物体自由下落的加速度是相同的.(在学生的头脑中,重的物体落得快,轻的物体落得慢的想法根深蒂固,所以我认为本节的难点在这里)     

演示实验在自由落体运动教学中的巧妙应用

自由落体运动是学生了解匀变速直线运动的规律后接触的新知识．自由下落的物体学生在生活中常见，学生的思维定势是：重的物体下落快，轻的物体下落慢．如何既打破学生的思维定势，又能让学生从理论上顺利学到新知识呢？笔者认为讲好这节课的关键是做好演示实验．通过演示实验，让学生循序渐进地了解自由落体运动的确定过程，达到学习目的．     

谈谈打点纸带加速度的计算方法

在高中物理(必修)第一册研究匀变速直线运动的实验中，对实验所得纸带是这样处理的：从3条纸带中选择1条比较理想的，舍掉开头一些比较密集的点子，在后边便于测量的地方找一个开始计数的点，在该点下面标明A，以每打5次点的时间(即T=0．1s)作为一个时间     

气垫导轨实验的拓展

针对传统的气垫导轨实验起点低,过于简单的缺憾,补充了实验原理及实验方法,使其原有的实验内容得以拓展。     

一个奇妙的斜抛运动新规律

质点做斜抛运动的过程中, 瞬时速度与相对抛出点位移的夹角存在最大值, 该最大夹角只与初速度方向有关, 与初速度大小无关; 达到最大夹角所用时间, 只与初速度大小和重力加速度大小有关, 与初速度方向无关.证明了这条斜抛运动的奇妙规律, 并指出它对任意匀变速曲线运动均成立     

Ionisation energy values for the vibronic transitions from HCl X1 Σ+ (v″ = 0) to HCl+ ionic states X2 Π (v′ = 0

High-resolution Ne (I) (73.6 nm) photoelectron spectroscopic measurements provide values of the ionisation energies to the first 14 vibrational levels     

Rotational spectrum of molecules with C3v symmetry in an excited state vt = 2

The frequency expressions for pure rotational transitions of C_3v molecules are computed for the two components ℓ_t = 0 and |ℓ_t| = 2 of the vibrationally excited state v_t = 2. This computation is performed taking into account contributions to the vibration-rotation energy up to the sixth order of approximation. The validity of the obtained expressions is subject to conditions which result from hypotheses made in the course of the energy calculation and these hypotheses are specified. Finally, transitions are considered which can occur between the ℓ_t = 0 and |ℓ_t| = 2 components of the state v_t = 2 when the dipole moment induced by vibration is taken into account.     

The rotational spectrum and molecular parameters of ClO in the v=0 and v=1 states

The $\text{J =}\text{9}\text{2}\text{←}\text{7}\text{2}$, ${}^2\text{Π}{}_{\mathrm{<mtext>3</mtext><mtext>2</mtext>}}$ and ${}^2\text{Π}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$, ground vibrational state transitions of ³⁵ClO and ³⁷ClO and the ${}^2\text{Π}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$, excited vibrational state transitions of ³⁵ClO have been observed in the 164–167 GHz region. Additional measurements have also been made on the $\text{J =}\text{3}\text{2}\text{←}\text{1}\text{2}$ and $\text{J =}\text{5}\text{2}\text{←}\text{3}\text{2}$ transitions of both the ground and excited vibrational states. All measurements were made using millimeter oscillators which were phase locked to harmonics of a Hewlett-Packard microwave spectrometer's X-band source. Λ-doubling splitting of a few ${}^2\text{Π}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$ transitions was resolved.When magnetic and nuclear quadrupole hyperfine terms off-diagonal in J and $\text{Ω}$ in the Hund's case (a) representation were included in addition to the usual diagonal terms, an excellent fit to all of our observed transitions resulted. The most significant change from previously determined parameters is the centrifugal distortion constant D for which the values, D₀ = 0.03972(26) MHz for ³⁵ClO, D₀ = 0.03888(32) MHz for ³⁷ClO and D₁ = 0.0395(21) MHz for ³⁵ClO are obtained. Values of 1.56959(1) Å for the equilibrium bond length and 854(7) cm^?1 for the equilibrium vibrational frequency are derived from the measured spectra. In addition, values for the Λ-doubling constant β_p and the quadrupole coupling constant eQq₂ were derived from the measured spectra for the first time.     

Theoretical study of the dynamics for the H + Li H ( v = 0, j = 0) $\to$ H2 + Li reaction and its isotopic variants

Quasi-classical trajectory (QCT) method is carried out to calculate the dynamics of the H + LiH (v = 0, j = 0) ?\to H₂ + Li reaction and its isotopic variants based on the potential energy surface of the lowest ²A￠^2A' electronic state reported by Prudente et al. [Chem. Phys. Lett. 474, 18 (2009)]. The reaction cross-section, product rotational alignment parameter áP₂\langle P_2 ([(j￠)\vec]\vec{j'} ·\cdot [(k)\vec])?\vec{k})\rangle and one generalized polarization-dependent differential cross-section (2π/σ)(ds₀₀d\sigma_{00}/d w_t\omega_t) are calculated. We found that different collision energies and mass factors show driving influence on the process of the reactions and product molecules H₂ (HD, D₂) polarization distribution, and the trend of the isotopic effects in the high collision energy range is different to that in the low collision energy range. The calculations are also interpreted in relation to the features of the underlying potential energy surface. A comparison between the title reactions and a barrier-less reaction F + HBr ?\to FH + Br has been discussed in detail.     

Experimental Ro-Vibrational Line Intensities for the v1 + v2 and v2 + v3 Bands of the D234S Molecule

Russian Physics Journal - The study of the absolute line intensities in the high-resolution spectrum of the D234S molecule in the range of 2300–2900 cm–1 has been carried out for the...     

An indirect calculation of the triple-pomeron vertex at t = 0

By associating the triple-pomeron coupling gp(t) with the renormalization of the pomeron propagator and requiring the latter to correctly reproduce a dual f^o trajectory, as well as the magnitude and width of the ππ diffraction peak, we obtain gp(0) ≈ 1 GeV⁻¹.     

Experimental search for B = 2, T= 0 states in the d + d → d + X reaction

A search for isoscalar dibaryonic resonances by means of missing-mass spectra in the d + d → d + X reaction has been attempted using deuteron beams of T = 2.29,2.00 and 1.65 GeV. The results do not show any evidence for a narrow peak with a limit of $\text{30 nb}\text{GeV}{}^2$ for a 15 MeV width or a broad enhancement which could be unambiguously attributed to a dibaryonic resonance.     

Analysis of the (0 0 v(3)), v(3) = 1, 2, 3 Vibrotational States of HDSe

High-resolution Fourier transform spectra of HDSe in the region of the 2nu(3) and 3nu(3) bands were recorded and analyzed for five different (M)Se isotopic HDSe species. Energies obtained from rovibrational analyses of the (002) and (003) states, together with those taken of the (001) state from an earlier study [O. N. Ulenov, G. A. Onopenko, N. E. Tyabaeva, H. Bürger, and W. Jerzembeck, J. Mol. Spectrosc. 198, 27-39 (1999)], were used as input information for a "Global Fit" procedure. This fit provided 34 spectroscopic parameters for the HD(80)Se species which reproduced rotational-vibrational transitions of the (001), (002), and (003) states within experimental accuracy. Corresponding analyses were performed for the other (M)Se (M = 82, 78, 77, and 76) species. Copyright 2000 Academic Press.