Studies on Syntheses and Biological Activities of Novel Triazole Compounds Containing Phosphorodithioate Groups

Sixteen new triazole organic phosphorus compounds were synthesized. Their structures were confirmed with IR, IH NMR, elemental analysis and MS. The primary biological tests show that the titled compounds have the fungicidal activities, which are influenced by R groups and the substituents attached to the P atom.     

Studies on Synthesis and Biological Activities of Novel Triazole compounds Containing Thiophene Groups

Fifteen new triazole compounds containing thiophene groups were synthesized and their structures were confirmed by means of 1H NMR, IR, MS spectroscopies and elemental analyses. The preliminary biological tests show that the titled compounds exhibit some activities of fungicides and plant growth regulators.     

生物界面上的化学过程——关于化学生物学研究前沿的讨论

在细胞和固体表面建立的生物界面上发生的化学-生物学过程是一个医学、环境、农业和生物技术共同面对的问题.以破骨细胞介导的骨再吸收过程为例阐述过程中的生物事件顺序,提出有待解决的化学问题.     

纤维加强金属基复合材料热机械疲劳模型的研究进展

纤维增强金属基复合材料的热机械疲劳(thermomechanical fatigue 简称TMF)特性的研究在近年受到高度重视.本文根据国内外近期进行的理论研究以及获得的主要成果作一概要介绍.对于热机械循环特性,主要介绍基于细观力学方法的轴向性质模型,以及基于断裂与损伤理论的横向性质模型.对于热机械疲劳性能研究,结合横向性质导出两种热机械疲劳模型,然后分析基体的细观结构对疲劳寿命的影响.      

Influences of nonlinear interactions of polaritons in uniaxial crystals

We have analysed theoretically the polarization and dielectric constant of uniaxial ionic crystals,including the effect of the nonlinear interactions between ions.The spectrum of polaritons(coupling modes of photons and optical phonons) under nonlinear interactions was developed.A new branch of dispersion relations emerges in the original frequency gap.     

基于DSP实现的数字化闭环光纤陀螺

提出一种基于高速数字信号处理专用DSP芯片使用的数字化闭环光纤陀螺系统方案,并着重讨论其数字快速算法的实现。这种快速算法采用多抽样率数字信号系统中抽取的高效结构实现,能够在保证系统的实时性和精度的条件下,极大地减少了DSP系统的运算量和存储量。     

可满足性（SAT）问题的概率研究

本文首先构造了随机均匀产生的d-SAT问题的概率模型,然后给出了SAT问题的解的个数的均值的计算公式,使用矩方法研究了解空间的元素满足方程的概率以及在临界点方程有解的概率和极限性质,最后确定n/m=Td=ln(2)/(ln2^d/2^d-1)是其解的平均个数的临界点,并且当n/m=rd时,方程有解的概率随着m→∞而趋于0。     

广义幂级数环的PP性质

作为幂级数环的推广,Ｒｉｂｅｎｂｏｉｍ引入了广义幂级数环的概念．设Ｒ是有单位元的交换环,（Ｊ,≤）是严格全序半群．本文中我们证明了如下结果：（１）广义幂级数环 ［［Ｒｓ］］是ＰＰ－环当且仅当Ｒ是ＰＰ－环且Ｂ（Ｒ）的任意 Ｓ－可标子集Ｃ在Ｂ（Ｒ）中有最小上界;（２）如果对任意ｓ∈Ｓ都有０≤ｓ,则［［Ｒｓ,≤］］是弱ＰＰ－环当且仅当Ｒ是弱ＰＰ－环．我们还给出了一个例子说明交换的弱ＰＰ－环可以不是ＰＰ－环．     

O‐Ethyl and O‐methyl N‐(2,3,4,6‐tetra‐O‐acetyl‐β‐d‐glucopyranosyl)thiocarbamate

In both the title structures, O‐ethyl N‐(2,3,4,6‐tetra‐O‐acetyl‐β‐d ‐gluco­pyran­osyl)­thio­carbam­ate, C₁₇H₂₅NO₁₀S, and O‐methyl N‐(2,3,4,6‐tetra‐O‐acetyl‐β‐d ‐gluco­pyran­osyl)­thiocar­bam­ate, C₁₆H₂₃NO₁₀S, the hexo­pyran­osyl ring adopts the ⁴C₁ conformation. All the ring substituents are in equatorial positions. The acetoxy­methyl group is in a gauche–gauche conformation. The S atom is in a synperi­planar conformation, while the C—N—C—O linkage is antiperiplanar. N—H?O intermolecular hydrogen bonds link the mol­ecules into infinite chains and these are connected by C—H?O interactions.     

Unusual Normal and Superconducting State Properties Observed in Hydrothermal Fe_(1-δ)Se Flakes

The electronic and superconducting properties of Fe_(1-δ)Se single-crystal flakes grown hydrothermally are studied by the transport measurements under zero and high magnetic fields up to 38.5 T. The results contrast sharply with those previously reported for nematically ordered Fe Se by chemical-vapor-transport(CVT) growth. No signature of the electronic nematicity, but an evident metal-to-nonmetal crossover with increasing temperature,is detected in the normal state of the present hydrothermal samples. Interestingly, a higher superconducting critical temperature T_c of 13.2 K is observed compared to a suppressed T_c of 9 K in the presence of the nematicity in the CVT Fe Se. Moreover, the upper critical field in the zero-temperature limit is found to be isotropic with respect to the field direction and to reach a higher value of ~42 T, which breaks the Pauli limit by a factor of 1.8.