Synthesis of New 13-O-Acylavermectin Bl Aglycones

Six new 13-O-acylavermectin Bl aglycones(3-8) were synthesized from avermectin B1 aglycone and their bioactivities were evaluated against Spodoptera exigua, Spodoptera eridania, Tetranychus urticae and Aphis fabae.     

Isolation of 2-Chloro-5-methylpyridine from its Isomer 2-Chloro-3-methylpyridine by Formation of its Copper(II) Complex

2-Chloro-5-methylpyridine is an important intermediate for the preparation of biological active compounds, especially insecticides1, e.g. imidacloprid2, and is usually manufac- tured from 3-methylpyridine N-oxide. However, the manufacturing process also forms the by-products: 3-methylpyridine and its isomer 2-chloro-3-methylpyridine3. The pro- perties of the isomers are similar, it is difficult to separate by ordinary methods, such as distillation. Scheme 1 79.4%13.6%5.2%NClCH3NCH3ClNC…     

Synthesis and Photocytotoxicity of Mono-functionalised Porphyrin with Valine Moiety

A mono-funtionalised tetraphenylporphyrin (TPP) bearing valine moiety at the phenyl ring was synthesized for photocytotoxicity examination in four steps, starting from regiospecific mono-nitration of TPP at the phenyl ring. The in vitro photocytotoxicitic effect against SPC-Al adenocarcinona cell line was tested.     

两相同部件温贮备可修的人机系统解的性质分析

本文首先用强连续算子半群理论证明了两相同部件温贮备可修的人机系统动态非负解的存在唯一性 ,然后证明了 0是系统主算子的本征值 ,并得到 0本征值对应的本征向量是正的 ,从而系统存在稳态正解 .     

硅基两维光子晶体的制备和光子带隙特性

利用反应离子束刻蚀设备制备了硅基的两维空气柱光子晶体，并用红外显微镜测试了样品的 反射谱. 理论上用时域有限差分(FDTD)方法计算了样品的光子带隙，从测试结果看光子带隙 和理论计算的光子带隙符合得很好.  关键词： 光子晶体 光子带隙 反射谱 时域有限差方法     

BIFURCATIONS OF ROUGH 3—POINT—LOOP WITH HIGHER DIMENSIONS

The authors study the bifurcation problems of rough heteroclinic loop connecting three saddle points for the case β1 > 1, β2 > 1, β3 < 1 and β1β2β3 < 1. The existence, number, coexistence and incoexistence of 2-point-loop, 1-homoclinic orbit and 1-periodic orbit are studied. Meanwhile, the bifurcation surfaces and existence regions are given.     

不可压缩流的集中消失现象

分别对二维和三维不可压缩流体给出了一个较为直观的集中消失现象的充分条件,即若与近似解序列相应的弱*亏损测度所集中的集合在位置空间上的投影的Hausdorff维数小于1,则近似解序列在L²中的弱极限是Euler方程的经典弱解.利用这个充分条件,验证了一个集中的例子.     

与q形变玻色算符逆算符相关的相干态及其量子统计性质

讨论了ｑ形变玻色算符的广义逆算符作用于ｑ－相干态所得到的两类量子态的数学及量子统计性质。结果表明，ｑ－相干态的光子激发态不存在压缩但呈现反聚束效应，而ｑ－相干态的光子湮灭态却存在压缩但不呈现反聚束效应。     

计算机辅助电子线路实验的思考与探索

本文介绍了EltctronicWorkbench软件和计算机虚拟仪器系统，采用计算机模拟仿真技术对电子线路实验加以辅助设计和探索。     

多复变数的Schwarz导数(IV)

从2个不同的Lie群出发 ,定义与讨论了2种互不等价的Cⁿ中域上的全纯映照的Schwarz导数，给出了这2种Schwarz导数为零的充要条件 .