非均匀可激发介质中的稀密螺旋波

在非均匀可激发介质中,采用Barkley模型数值模拟了稀螺旋波和密螺旋波, 并对二者的动力学行为随参数的变化进行了研究. 结果发现:稀螺旋波的旋转频率随参数b的增加迅速减小,之后趋于饱和, 显示出不同于密螺旋波的行为;两种螺旋波的周期和波长随参数ε 和非均匀区域尺寸R的增加而增加,相对稀螺旋波而言,密螺旋波的性质对R的依赖更为敏感; 稀螺旋波端点的波速随R的增加而减小,与密螺旋波波速变化趋势相反. 另外,由于非均匀区域的影响,当ε 或b 超过某一临界值时,螺旋波臂上出现缺陷点.     

烟尘簇团粒子光学截面和散射矩阵的数值计算

用离散偶极子近似方法,计算了单个烟尘簇团粒子的光学特性,得到了簇团粒子的散射截面、吸收截面及不对称因子随入射角的变化关系,为研究波在烟尘粒子中的传输特性提供了有效的计算方法;给出了不同入射角情况下烟尘簇团粒子散射矩阵元素的角分布,为研究散射体的散射特性、极化特性以及散射体结构特性提供了一种理论方法. 关键词：烟尘簇团粒子散射矩阵光学截面DDA     

非线性薛定谔方程的新多级包络周期解

基于Lamé方程和新的Lamé函数,应用摄动方法和Jacobi椭圆函数展开法求解了非线性薛定谔方程,获得多种新的多级准确解。这些解对应着不同的形式的包络周期解。这些解在极限条件下可以退化为各种形式的包络孤波解。     

树状分形结构形成过程的实验研究

对大量金属小球在强电场作用下运动形态的演化全过程用联机摄像装置进行了实时拍摄,通过用Sandbox方法计算其稳定状态的分维数,系统地研究了分维数随电压的变化关系.结果表明：在一定电压范围内金属小球聚集体通过自组织过程形成稳定的树状分形结构,其分维数随外加电压的增加而减小.该结果对研究耗散结构的形成机理和外界动力对耗散结构的形貌影响具有参考价值.关键词：分形生长自组织过程树状结构分维数     

Dynamics of Front Driven by Convection Field in Bistable Media

The front dynamics driven by a convection field in a model of FitzHugh-Nagumo type is studied both analytieMly and numerically. Saddle-node bifurcation induced by the convection field is found by using a singular perturbation analysis of front solutions. Convection field accelerates the B1och front propagating opposite the direction of convection field, but inhibits the Bloch front propagating along the direction of convection field. In addition convection field drives Ising front to travel opposite the direction of convection field.     

Superlattice Patterns in Coupled Turing Systems

In this paper, superlattice patterns have been investigated by using a two linearly coupled Brusselator model. It is found that superlattice patterns can only be induced in the sub-system with the short wavelength. Three different coupling methods have been used in order to investigate the mode interaction between the two Turing modes. It is proved in the simulations that interaction between activators in the two sub-systems leads to spontaneous formation of black eye pattern and/or white eye patterns while interaction between inhibitors leads to spontaneous formation of super-hexagonal pattern. It is also demonstrated that the same symmetries of the two modes and suitable wavelength ratio of the two modes should also be satisfied to form superlattice patterns.     

一维链状配位聚合物[Cu(en)2]2[Cu(en)2α-AsⅢ8VⅣ14O42(HPO4)]·8H2O的合成与晶体结构

钒氧化合物由于其有趣的阴离子结构和在催化反应、药物化学以及材料科学等领域中的应用而受到人们的关注[1,2].     

Synthesis, Characterization and Structural Determination of Ferrocene Derivatives Linked with Benzo[b]pyrans ——2-Amino-7,7-dimethyl-4-ferrocenyl-5-oxo-5,6, 7,8-tetrohydro-4H-chromene-3-carbonitrile

The title compound (C22H22N2O2Fe·CH3OH) was synthesized via a one-pot proce- dure from ferrocenylaldehyde, malononitrile and 5,5-dimethyl-1,3-cyclohexanedione using room temperature ionic liquid and pyridine as the catalysts, and characterized by elemental analysis, IR and 1H NMR. The structure was determined by X-ray single-crystal diffraction. The crystal belongs to monoclinic system, space group P21/n, with a = 9.7085(15), b = 22.951(4), c = 9.987(2) A, β = 112.494(3)°, V = 2055.9(6) A3, Z = 4, Mr = 402.28, Dc = 1.403 g/cm3, μ = 0.759 mm-1, F(000) = 868, the final R = 0.0536 and wR = 0.1449 for 4202 observed reflections with I > 2σ(I). The supramolecular single-helix chain of the title compound is formed by linking the building units with the hydrogen bond between N1 and N2. The adjacent chains are connected to a 2D layer by the hydrogen bond between N1 and O1. The adjacent layers are further linked by van der waals’ force. The CH3OH molecule is trapped in the interlayer.     

微波辅助提取GC-MS分析莪术挥发油成分

1引言 莪术是我国传统中药材,是一种有效的抗癌中药,在防治恶性肿瘤特别是早期宫颈癌方面有较好的疗效.据<本草纲目>记载:莪术辛、苦、温,归肝、脾经,具有行气破血、消积止痛之功效,被称为血中之气药.莪术根茎中含挥发油约1%～2.5%,为多种倍半萜类,其中莪术醇和榄香烯以及莪术酮和莪术二酮具有抗肿瘤、抗病毒的疗效.微波辅助提取具有设备简单、适用范围广、萃取效率高、节省时间和溶剂、污染小等诸多优点,应用范围已从最初的环境样品分析迅速扩展到食品、化工和农业等领域.本研究以莪术为原料,采用微波萃取法提取挥发油,通过紫外分光光度法监测其含量变化,用气相色谱-质谱法(GC-MS)分析最优提取工艺条件下所得挥发油成分,为进一步开发莪术药用价值提供依据.     

Application of methyl parathion hydrolase (MPH) as a labeling enzyme

Methyl parathion hydrolase (MPH) is an enzyme that catalyzes the degradation of methyl parathion, generating a yellow product with specific absorption at 405 nm. The application of MPH as a new labeling enzyme was illustrated in this study. The key advantages of using MPH as a labeling enzyme are as follows: (1) unlike alkaline phosphatase (AP), horseradish peroxidase (HRP), and glucose oxidase (GOD), MPH is rarely found in animal cells, and it therefore produces less background noise; (2) its active form in solution is the monomer, with a molecular weight of 37 kDa; (3) its turnover number is 114.70 ± 13.19 s⁻¹, which is sufficiently high to yield a significant signal for sensitive detection; and (4) its 3D structure is known and its C-terminal that is exposed to the surface can be easily subjected to the construction of genetic engineering monocloning antibody–enzyme fusion for enzyme-linked immunosorbent assay (ELISA). To demonstrate its utility, MPH was ligated to an single-chain variable fragment (scFv), known as A1E, against a white spot syndrome virus (WSSV) with the insertion of a [–(Gly–Ser)₅–] linker peptide. The resulting fusion protein MPH-A1E possessed both the binding specificity of the scFv segment and the catalytic activity of the MPH segment. When MPH-A1E was used as an ELISA reagent, 25 ng purified WSSV was detected; this was similar to the detection sensitivity obtained using A1E scFv and the HRP/Anti-E Tag Conjugate protocol. The fusion protein also recognized the WSSV in 1 μL hemolymph from an infected shrimp and differentiated it from a healthy shrimp. Figure The 3-D structure of MPH. (a) monomer showing C- and N-terminals; (b) the crystal structure of the dimer W. Yang and Y.-F. Zhou contributed equally to this work.