McMillan Tc公式的解析推导(Ⅲ)

本文把作者在前面两篇文章导出的T_c公式推广成下面形式:T_c=αω_log(ω_log/ω_c)^{(μ*/(λ-μ*))exp{-(1+λ)/(λ-μ*)},并从线性Eliashberg方程出发,导出了计算α的方程组。α一般是λ和μ*的函数。在弱耦合极限下,由上述方程组解得,α=2γ/π,其中lnγ=C=0.5772是Euler常数。这个结果表明了,前面两篇文章得到的T_c公式在弱耦合极限下是正确的。作者进而在Einstein谱和μ*=0情形,用数值计算方法从定α的方程组算出当λ=0.23,0.25,0.38和0.48时,a的数值。结果表明,至少在0.23≤λ≤0.45区间中,α变化很小,近似等于1/1.30。此时,本文的T_c公式实际上就是Allen及Dynes修改后的经验的McMillan T_c公式。 关键词：}     

Singular Points Near an X_0-breaking Double Singular Fold Point in Z_2-symmetric Nonlinear Equations

ＳｉｎｇｕｌａｒＰｏｉｎｔｓＮｅａｒａｎＸ_０－ｂｒｅａｋｉｎｇＤｏｕｂｌｅＳｉｎｇｕｌａｒＦｏｌｄＰｏｉｎｔｉｎＺ_２－ｓｙｍｍｅｔｒｉｃＮｏｎｌｉｎｅａｒＥｑｕａｔｉｏｎｓＳｕＹｉ（苏毅）ａｎｄＷｕｗｅｉ（吴微）（ＤｅｐａｒｔｍｅｎｔｏｆＭａｔｈｅ...     

靶丸支撑膜对ICF内爆性能影响的模拟研究

使用二维多群辐射扩散流体力学程序LARED-S,模拟研究靶丸支撑膜在惯性约束聚变氘氘（DD）气体靶内爆过程中的扰动演化过程及其对内爆性能的影响.二维模拟表明：靶丸支撑膜显著降低DD气体靶内爆的中子产额,二维模拟产额为一维结果的55.2%.内爆性能下降的主要物理机制是支撑膜使靶壳生成大幅度的尖钉深入DD气体区,使烧蚀层与DD气体之间物质界面处的电子热传导漏失功率显著增大,导致DD核反应速率显著降低,中子反应速率峰值时刻（bang-time时刻）提前.相比一维理想内爆的模拟结果,支撑膜引入的扰动显著降低bang-time时刻DD气体压强与内爆动能转化为DD气体内能的效率,壳层剩余动能相应大幅增加.     

Identity-Based Quantum Designated Verifier Signature

International Journal of Theoretical Physics - Designated verifier signatures are very useful in the applications such as e-voting and auction. In this paper, an identity-based quantum designated...     

利用可见-近红外-中红外超快光谱揭示离子交换法制备的少层MoS2中缺陷介导的载流子动力学

本文结合可见-近红外-中红外瞬态吸收光谱技术对离子交换法制备的少层MoS₂中缺陷介导的载流子动力学进行了详细的解析. 在近红外瞬态吸收光谱中观察到的宽带漂白信号表明少层MoS₂纳米片带隙中分布着大量的缺陷态. 实验结果明确揭示了载流子被缺陷态的快速捕获以及进一步的复合过程,证明带隙中的缺陷态对MoS₂光生载流子动力学过程起着至关重要的作用. 在中红外瞬态吸收光谱中观察到的正信号到负信号的转变进一步证实了在导带下小于0.24 eV处存在被载流子占据的缺陷态. 这些在少层MoS₂纳米片中存在的缺陷态可以作为有效的载流子捕获中心来辅助光生载流子在皮秒时间尺度内完成非辐射复合过程.     

Highly efficient perovskite solar cells by tuning electronic structures of thienothiophene-based as hole transport materials

The atomic substitutions were used to study the hole transport materials (HTM) properties of six thiophenothiophene molecules (HTM1-HTM6) to reveal the relationship between their core structures and photoelectric properties. To better investigate the difference between experimentally original and designed molecules, we calculated the hole mobility and some parameters (such as energy levels, stability, and optical properties, etc). The results showed that the molecular orbital levels of the original and designed molecules have well matched with perovskite and Ag electrode to ensure hole transport and inhibit the electron reflux. Among the designed HTMs, HTM5 has the smallest energy gap that results in the red-shifted absorption spectra. Furthermore, there is an obviously increased charge transfer integral V due to the introduction of the Si atom, which greatly improved the hole mobility. Therefore, atom substitution by introducing Si atoms (HTM5) will improve the energy levels and charge transport ability, and molecular design by means of atom substitution can be a potential way to tunable HTM performance in solar cells.     

V(001)表面上(4×1)-O,(2×2)-S两超结构的角分辨光电子谱

用角分辨紫外光电子谱详细研究了V(001)表面上,S和O偏析引起的(4×1)-O,(2×2)-S两超结构,确定了S,O各自引起的吸附态的峰位和对称性;得到了O占据V(001)表面上空位的实验证据。所得实验结果与理论计算相等。 关键词：     

激光驱动高压冲击波的实验观察

本文介绍能量约500J,脉宽约1.2ns的高功率激光脉冲聚焦辐照铝箔靶或铝台阶靶,用可见光超快速扫描相机观察靶背面冲击加热发光的情况。实验表明,采用特别的组合透镜聚焦,使激光冲击波的平面性得到明显的改善。实验测得铝台阶中的冲击波速度为17.6μm/ns,并推算出相应的冲击波压力达4.4Mbar。 关键词：     

THE U1 GAUGE FIELD IN A SUN GAUGE FIELD AND THE QUANTIZED VALUES OF DUAL CHARGES

Let F be a SU_N gauge field on the space-time manifold M₄, b_λ（x） （λ=0,1, 2, 3） the gauge potentials, the field strengths and Q（x） a Higgs field. All quantities b, f_λμ and Q（x） are SU_N'-valued, i.e. they are represented by N×N anti-hermitian traceless matrices.Let M₄' be the set of x such that Q（x）≠0 and define on M₄', where The following results are obtained:Theorem 1. The 1st set of Maxwell equations F_λμ,v+F_μv,λ+F_vλ,μ=0 are satisfied for arbitrary b_λ if and only if with Here s is an integer, 1≤s≤N-1.Suppose the conditions in theorem 1 are satisfied.Theorem 2. If s is a space-like two-dimensional surface, the value of dual charges contained in s defined by is equal to lq', where l is an integer and Theorem 3. The value of dual charges contained in S is equal to the integral which is independent of the gauge potentials.Theorem 4. The least positive value q' of dual charge can be attained by some Higgs fields.Remarks（a） When N=2, the results obtained are consistent with those of t Hooft, Arafune and Hou etc.（b） For N=3, we give an answer to the question of quantized values of dual charges which was discussed by Marciano and Pagels.（c） The Higgs field ø（x） is a mapping from M'₄ into the AⅢ type symmetric space SU_N/S(U_s X U_N-s) and the integral is an extension of Kronecker index for N=2.     

大鼠脑缺血再灌注后运动皮质细胞凋亡的体视学观察

用体视学方法分析大鼠脑缺血再灌注后大脑运动皮质细胞的凋亡情况。随机将24只SD大鼠分为缺血再灌注后6、12、24 h和对照组。采用结扎大鼠左侧颈总动脉和夹闭右侧颈总动脉15m in后放开的方法制备大鼠脑缺血再灌注模型。应用Hoechst33258荧光染色及免疫组化Bax蛋白表达来检测细