Viscous Cosmology and Thermodynamics of Apparent Horizon

It is shown that the differential form of Friedmann equations of Friedman--Robertson--Walker (FRW) universe can be recast as a similar form of the first law T_hdS_h = dE + WdV of thermodynamics at the apparent horizon of FRW universe filled with the viscous fluid. It is also shown that by employing the general expression of temperature associated with the apparent horizon of an FRW universe and assumed that the temperature T_m of the energy inside the apparent horizon is proportional to the horizon temperature T_m= bT_h, we are able to show that the generalized second law of thermodynamics holds in the Einstein gravity provided T_h-T_m/r^~_A ≤(ρ+P^~).     

高速摄影技术在泥沙研究中的应用

本文应用高速摄影方法来观察明渠粗糙定床近床区域的泥沙颗粒运动,获得了近床区域内单颗泥沙在粗糙定床上的跳跃高度的变化规律为: 随机变量 服从Γ—分布: 同时,还获得了颗粒单步跃长的随机分市密度函数亦为Γ—分布:      

The confining behavior and asymptotic freedom for QCD( SU($\infty$)) - a constant-gauge-field path-integral analysis

We examine the Wilson confining-area behavior for QCD(SU( )) as described by a Witten effective reduced dynamics of constant-gauge fields. We show the model to be exactly soluble when dynamical quark fields are added, together with fermion asymptotic freedom behavior. Additionally, we give arguments for the triviality of the chiral-SU(N) non-abelian Thirring model at the t′Hooft limit of large number of colors in the context of these constant-gauge-field reduced dynamics. Received: 26 May 2004, Revised: 16 June 2005, Published online: 30 August 2005     

Measuring the top quark mass in the eµ channel: A study

We describe a simple method to measure the top quark mass in the channel that may be useful in Run II of D? detector. The method is validated by applying it to the Run Ib eμ data.     

Lowest- Q2 measurement of the γp → Δ reaction: Probing the pionic contribution

To determine nonspherical angular-momentum amplitudes in hadrons at long ranges (low Q²), data were taken for the p(ˉe, e'p)π⁰ reaction in the Δ region at Q ² = 0.060 (GeV/c)² utilizing the magnetic spectrometers of the A1 Collaboration at MAMI. The results for the dominant transition magnetic dipole amplitude and the quadrupole to dipole ratios at W = 1232 MeV are , Re( )%, and Re( )%. These disagree with predictions of constituent quark models but are in reasonable agreement with lattice calculations with nonlinear (chiral) pion mass extrapolations, with chiral effective field theory, and with dynamical models with pion cloud effects. These results confirm the dominance, and general Q² variation, of the pionic contribution at large distances.     

Using the e ± μ? + E Tmiss signature in the search for supersymmetry and lepton-flavor violation in neutralino decays

The LHC (CMS) discovery potential in the search for supersymmetry and lepton-flavor violation in neutralino decays using the e ^± μ^∓ + E _T ^miss signature is studied. A detailed study is done for the CMS test points LM1-LM9. It is shown that, for the point LM1, it is possible to detect lepton-flavor violation in neutralino decays with lepton-flavor-violating branching Br( → μ^± e ^∓ ) ≥ 0.04 Br( → e ⁺ e ⁻ , μ⁺ μ⁻ ) for an integral luminosity of 10 fb⁻¹. The discovery potential in the mSUGRA-SUSY scenario with tan β = 10, sgn(μ) = + in the (m ₀, m _1/2) plane using the e ^± μ^∓ + E _T ^miss signature is determined. The text was submitted by the authors in English.     

公告

●《物理学报》与“Chinese Physics”(中国物理)从2005年5月26日开始,作者必须在新网址上注册、登记投稿。《物理学报》新网址:http://wulixb.iphy.ac.cn,“Chinese Physics”新网址:http://cp.iphy.ac.cn,为了便于审稿,网上接受doc及pdf格式的电子文件,不再接受纸稿;收取稿件审理费、版面费及支付稿费也都在网上予以处理(国外作者不收审理费及支付稿费,只收版面费);有关稿件状况、审稿、处理及同行论文检索等事宜,可通过两刊网址分别查询。根据需要,由编辑部通知作者通过邮局寄一份核对无误的纸稿(隔行打印),如您在网上的最后修改稿是pd…     

A revised version of the program VEC （visual computing in electron crystallography）

The program package VEC (Visual computing in Electron Crystallography) has been revised such that (i) a program converting one-line symbols to two-line symbols of (3+1)-dimensional superspace groups has been incorporated into VEC so that the latter can interpret both kinds of symbols; (ii) a bug in calculating structure factors of one-dimensionally incommensurate modulated crystals has been fixed. The correction has been verified by successfully matching the experimental electron microscopy image of an incommensurate crystal with a series of simulated images. The precompiled revised version of VEC and relevant materials are available on the Web at http://cryst.iphy.ac.cn.     

公告

●《物理学报》与“Chinese Physics”(中国物理)从2005年5月26日开始,作者必须在新网址上注册、登记投稿。《物理学报》新网址:http://wulixb.iphy.ac.cn,“Chinese Physics”新网址:http://cp.iphy.ac.cn,为了便于审稿,网上接受doc及pdf格式的电子文件,不再接受纸稿;收取稿件审理费、版面费及支付稿费也都在网上予以处理(国外作者不收审理费及支付稿费,只收版面费);有关稿件状况、审稿、处理及同行论文检索等事宜,可通过两刊网址分别查询。根据需要,由编辑部通知作者通过邮局寄一份核对无误的纸稿(隔行打印),如您在网上的最后修改稿是pd…     

公告

●《物理学报》与“Chinese Physics”(中国物理)从2005年5月26日开始,作者必须在新网址上注册、登记投稿。《物理学报》新网址:http://wulixb.iphy.ac.cn,“Chinese Physics”新网址:http://cp.iphy.ac.cn,为了便于审稿,网上接受doc及pdf格式的电子文件,不再接受纸稿;收取稿件审理费、版面费及支付稿费也都在网上予以处理(国外作者不收审理费及支付稿费,只收版面费);有关稿件状况、审稿、处理及同行论文检索等事宜,可通过两刊网址分别查询。根据需要,由编辑部通知作者通过邮局寄一份核对无误的纸稿(隔行打印),如您在网上的最后修改稿是pd…     

消息

《物理学报》与“Chinese Physics”(中国物理)从2005年5月26日开始,作者必须在新网址上注册、登记投稿。《物理学报》新网址:http://wulixb.iphy.ac.cn,“Chinese Physics”新网址:http://cp.iphy.ac.cn,为了便于审稿,网上接受doc及pdf格式的电子文件,不再接受纸稿;收取稿件审理费、版面费及支付稿费也都在网上予以处理(国外作者不收审理费及支付稿费,只收版面费);有关稿件状况、审稿、处理及同行论文检索和收发费用时间等事宜,可通过两刊网址分别查询。根据需要,由编辑部通知作者通过邮局寄一份核对无误的纸稿(隔行打印),如您在网上的最…     

第Ⅰ种非对称两态叠加多模叠加态光场等阶N次方H压缩——1.腔模总数与压缩阶数两者之积取偶的情形

本文利用多模压缩态理论研究了第Ⅰ种非对称两态叠加多模叠加态光场|Ψ_Ⅰ^(ab)>_q的广义非线性等阶N次方H压缩特性.结果发现:在腔模总数q与压缩阶数N这两者之积qN为偶数亦即qN=2p的条件下,无论p=2m(m=1,2,3,…,…)还是p=2m+1(m=0,1,2,…,…),当两非对称态中各模的初始相位和 =φ_j^(a)、 =φ_j^(b)、态间的初始相位差(θ_pq^bI-θ_nq^aR),以及各单模相干态光场的光子干涉项之和 =[R_j^(a)R_j^(b)]cos(φ_j^(a)-φ_j^(b))]等满足一定条件时,态|Ψ_Ⅰ^(ab)>_q可分别呈现出周期性变化的奇数模-偶数阶、偶数模-奇数阶和偶数模-偶数阶的等阶N次方H压缩效应.     

铁族离子的双ζ型径函

本文给出了用3d电子的双ζ型Richardson径函计算光谱的Racah参量A,B,C和旋轨耦合参量ξ3d的一般数学表示式及其实用近似计算方法.用此方法计算了全部二价和三价铁族离子的这些参量,发现ξ3d的计算较用Slater径函有显著的改进;但C/B 3.6～3.8,比实验值小得较多,是此径函的一个局限.     

多原子极性晶体中表面激子的性质

本文研究多原子极性晶体中表面激子的性质.采用微扰法导出表面激子的有效哈密顿量.多支LO声子对表面激子的自陷能和有效势的影响是相互独立的.对于Wannier激子,电子、空穴间的相互作用的有效势仍是库仑型的,只是介电常数约化为 .多支LO声子的作用使激子的自陷能更低.并得到激子的自陷条件.