1+1维含噪声Kuramoto-Sivashinsky方程表面宽度分布率的数值计算

通过对1+1维含噪声Kuramoto-Sivashinsky(KS)方程进行数值计算,得到其在饱和状态下的表面宽度分布率并与Kardar-Parisi-Zhang(KPZ)方程进行比较.结果表明,1+1维含噪声KS方程的表面宽度分布率标度函数受有限尺寸效应影响较小,并与KPZ方程具有相近的表面宽度分布率标度函数.     

Evidence for the anomalous scaling behaviour of the molecular-beam epitaxy growth equation

According to the scaling idea of local slope, we investigate numerically and analytically anomalous dynamic scaling behaviour of (1+1)-dimensional growth equation for molecular-beam epitaxy. The growth model includes the linear molecular-beam epitaxy (LMBE) and the nonlinear Lai--Das Sarma--Villain (LDV) equations. The anomalous scaling exponents in both the LMBE and the LDV equations are obtained, respectively. Numerical results are consistent with the corresponding analytical predictions.     

Surface structures of equilibrium restricted curvature model on two fractal substrates

With the aim to probe the effects of the microscopic details of fractal substrates on the scaling of discrete growth models, the surface structures of the equilibrium restricted curvature(ERC) model on Sierpinski arrowhead and crab substrates are analyzed by means of Monte Carlo simulations. These two fractal substrates have the same fractal dimension df, but possess different dynamic exponents of random walk zrw. The results show that the surface structure of the ERC model on fractal substrates are related to not only the fractal dimension df, but also to the microscopic structures of the substrates expressed by the dynamic exponent of random walk zrw. The ERC model growing on the two substrates follows the well-known Family–Vicsek scaling law and satisfies the scaling relations 2α + df≈ z ≈ 2zrw. In addition, the values of the scaling exponents are in good agreement with the analytical prediction of the fractional Mullins–Herring equation.     

沙漏流动过程中重力变化现象

对沙子流动过程中沙漏重力变化现象进行了理论与实验研究.通过将重力变化过程分为6个阶段,对各阶段沙粒与沙漏作用过程进行详细理论分析,并且从沙漏孔径、沙子粒度、沙漏高度三方面进行了实验探究,得到以上3个因素对沙漏重力变化的影响.     

非局域Sun-Guo-Grant方程的自洽模耦合理论

通过选取具有正确渐近行为的标度函数形式，将自洽的模耦合理论推广应用到对非局域的Sun-Guo-Grant方程的动力学标度性质的研究中.通过分析得到，在强耦合区基底维数d=1,2的情况下，动力学指数z随非局域参数ρ的变化关系.将这一结果与动力学重正化群理论和直接标度分析得到的结果进行了对比. 关键词： 表面粗糙生长动力学 动力学标度 自洽模耦合理论     

基于透射型几何相位编码超表面的太赫兹波束自由操控

为了实现太赫兹波束的自由操控,基于Pancharatnam-Berry几何相位理论,提出一种多层C型单元结构,实现在目标频率下0到2π的太赫兹波透射传输相位调控.基于广义斯涅耳定律,构建2-bit和3-bit编码超表面,在圆偏振入射条件下,实现透射型太赫兹波束的散射角度调控.采用数字信号处理理论中的傅里叶卷积运算,对不...     

考虑绿色技术投入的“农超对接”模式研究

将绿色技术投入引入由单个农户与单个超市组成的“农超对接”模式中,研究“农超对接”模式优势和农户与超市之间合约设计问题,分析不同“农超对接”模式下供应链主体预期效用,得出农户与超市最优决策。研究表明：农户风险厌恶度、消费者绿色偏好、绿色技术先进性均会影响农户绿色投入倾向,在毛收益佣金合同中,变动佣金比例影响农户绿色投入水平,而在净收益合同中,则不会有影响;比较不同合同发现,净收益佣金合同下“农户+农民合作社+超市”模式中的农户绿色技术投入水平最高;在所有模式下,农户风险厌恶均会在一定程度上降低最优绿色技术投入水平、超市和农户预期效用。     

On Equivalence of Two Realizations for a Nonlinear Lie Algebra

Recently,there are two independent approaches related to a class of nonlinear Lie algebras of three generators;and the realizations of these generators are achieved respectively in Schwinger-boson and position representation.However,by use of the representation transformation between these two representations,the equivalence of the two realizations is therefore proved.     

Effects of memory on scaling behaviour of Kardar--Parisi--Zhang equation

In order to describe the time delay in the surface roughing process the Kardar-Parisis-Zhang (KPZ) equation with memory effects is constructed and analysed using the dynamic renormalization group and the power counting mode coupling approach by Chattopadhyay [2009 Phys. Rev. E 80 011144]. In this paper, the scaling analysis and the classical self-consistent mode-coupling approximation are utilized to investigate the dynamic scaling behaviour of the KPZ equation with memory effects. The values of the scaling exponents depending on the memory parameter are calculated for the substrate dimensions being 1 and 2, respectively. The more detailed relationship between the scaling exponent and memory parameter reveals the significant influence of memory effects on the scaling properties of the KPZ equation.     

分散固相萃取净化/高效液相色谱法测定婴幼儿奶粉与米粉中15种多环芳烃

建立了高效液相色谱-荧光检测法同时测定婴幼儿奶粉和米粉中15种多环芳烃的检测方法。样品经乙腈提取,PSA分散固相萃取净化;乙腈-水梯度洗脱,Waters PAH专用柱分离,荧光检测器检测,外标法定量。在最优条件下,15种多环芳烃均得到有效分离,线性范围为1.0~50μg/L,相关系数均大于0.995,方法检出限(LODs,S/N=3)为0.05~0.3μg/kg,回收率为86.5%~106.8%,精密度(RSD,n=6)为0.7%~7.5%。该方法操作简单、灵敏度高,适用于婴幼儿奶粉和米粉中多环芳烃的检测。