带有电荷、磁荷的一类任意加速黑洞的瞬时辐射能通量

利用带有电荷、磁荷的一类任意加速黑洞视界面附近标量场的熵密度,研究黑洞的热辐射规律,导出了黑洞的瞬时辐射能通量,得到了黑洞的热辐射总是满足广义Stefan-Boltzmann定律的结论.导出的广义Stefan-Boltzmann系数不是常数,而是一个与黑洞参量(质量、所带的电荷与磁荷、加速度的大小、视界的变化率)有关的动比例系数.对于不同的动态黑洞,由于黑洞周围的引力场和电磁场不同,导出的广义Stefan-Boltzmann系数也不同.     

气液两相管流水力瞬变的数值计算及实验研究

由气液两相管流的基本方程出发,通过引入矢通量分裂,对传统的特征线差分做了较大的改进,形成了基于矢通量分裂的特征线差分解法。该法首先将控制方程组的特征值分解成正、负两部分,进而将控制方程中的矢通量雅可比矩阵分裂成两个亚矢量矩阵,对其按各自的迎风格式差分,从而建立了稳定的差分求解格式。该计算法适合于计算声速变化较大且计及液流速度的气液管流的瞬变。计算求解得到的各种不同初始空隙比的压力变化曲线、声速曲线、波速变化曲线、空隙比变化曲线及气体释放影响曲线,通过与不同初始空隙比时气液管流水力瞬变的实验结果对比分析,结果表明两者吻合较好,说明本文方法对于低空隙比的气液两相管流具有较普遍的适用性。     

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在HL-2A 装置上优化和发展了偏滤器靶板上的红外测温系统,并利用该系统分析了高约束模放电期间边缘局域模的热沉积分布特性。在高约束模式放电期间,超声分子束注入使边缘局域模所引起的偏滤器靶板上瞬间热通量峰值下降了~60%,并伴随着边缘局域模爆发频率增加了2~3 倍,而等离子体储能仅下降了~8%。分析结果表明,大幅度的丝状结构在超声分子束注入之后得到了有效抑制,沉积到偏滤器靶板上的瞬间热通量峰值也随之下降。此外,在超声分子束注入之后偏滤器室内的热辐射损失大幅度增加,从而耗散了热输运所携带的部分能量,进一步分散了沉积到偏滤器靶板上的能量,有效地保护了偏滤器靶板。     

Centrality Dependence of Flow in High—Energy Nucleus—Nucleus Collisions

Directed flow and elliptic flow of final state particles in high-energy nucleus-nucleus collisions in the EMU01 experiment have been studied.The dependences of directed flow and elliptic flow on incident energy and impact centrality of outgoing particles are presented.The results exhibit strong dependence of flow on centrality and energy.We also suggest a more reliable way to determine the event plane resolution here.     

Fluxes and Death Lines of Gamma-Ray Pulsars

We study the fluxes and the death lines of γ-ray emission of the pulsars with outer gaps.In a self-sustained outer gap,we derive that the fractional size of the outer gap is a function of period,period derivative,radial distance and magnetic inclination angle for a pulsar.Our results indicate that (i) averaged typical γ-ray energy and γ-ray flux of a pulsar with an outer gap increase with the magnetic inclination angle;we estimate the averaged γ-ray fluxes for observed canonical pulsars with outer gaps and compare them with the sensitivities of AGILE and GLAST,and (ii) if the fractional size of the outer gap at the inner boundary of the outer gap is not greater than unity,then an outer gap exists;such a condition gives the death lines of the pulsars with outer gaps.     

相应于随机自相似分形的记忆函数和分数次积分

For a physics system which exhibits memory, if memory is preserved only at points of random self-similar fractals, we define random memory functions and give the connection between the expectation of flux and the fractional integral. In particular, when memory sets degenerate to Cantor type fractals or non-random self-similar fractals our results coincide with that of Nigmatullin and Ren et al. .     

Lattice Boltzmann simulation of flows in bifurcate channel at rotating inflow boundary conditions and resulted different outflow fluxes

The Lattice Boltzmann method(LBM) is used to simulate the flow field in a bifurcate channel which is a simplified model of the draft tube of hydraulic turbine machine.According to the simulation results,some qualitative conclusions can be deduced.The reason of uneven flux in different branches of draft tube is given.Not only the vortex rope itself,but also the attenuation of the rotation strength is important in bringing on the uneven flux.The later leads to adverse pressure gradient,and changes the velocity profile.If the outlet contains more than one exit,the one that contains the vortex rope will lose flux because of this adverse pressure gradient.Several possible methods can be used to minimize the adverse pressure gradient domain in order to improve the efficiency of turbine machine.     

Hall电流对表面热通量均匀的竖直可渗透平板上MHD自然对流的影响

在横向磁场作用下,研究Hall电流对竖直可渗透平板上MHD自然对流的影响,平板具有均匀的热通量.和外部磁场相比,假设感应磁场可以忽略不计.利用自由变量公式化(FVF)和流函数公式化(SFF),将边界层方程简化为适当的形式.对局部蒸发系数ζ的整个取值范围,由FVF得到的抛物型方程,用简明的有限差分法进行数值积分;另一方面,由SFF得到的非相似方程,采用局部非相似法求解.有些区域,如局部蒸发系数ζ值足够大或足够小时,用正规的摄动法求解.对低值Prandtl数Pr,例如Pr=0.005,0.01,0.05时,用图形表示磁场参数M和Hall参数m,对局部表面摩擦因数和局部Nusselt数的影响.最后对不同的局部蒸发系数ζ值,给出流体的速度和温度分布.     

温度对功率LED光谱特性的影响

制备了两种1 w白光功率发光二极管(LED),这两种样品分别是对台湾和美国两家公司生产的蓝光芯片,涂敷相同荧光粉和透明硅胶封装而成.对制备好的LED进行了变温光学特性测试,温度变化范围为15～75℃,测试电流为350 mA.结果表明:温度变化对LED的峰值波长,辐射通量、色温等参数都有影响.通过对光谱曲线的数据处理,找...