长、短周期光纤光栅退火实验研究

光纤光栅技术是光纤通信领域继光纤放大器之后的一个里程碑 ,由此产生的全光纤光子线路及其集成将对光纤通信的发展产生巨大的推动作用。获得性能稳定的光纤光栅具有重要的意义。介绍了长、短周期光纤光栅的光学特性及退火特性     

铜(Ⅱ)与2-羰基丙酸水杨酰腙配合物的合成、晶体结构和抑菌活性

以2-羰基丙酸水杨酰腙作为配体与五水硫酸铜进行反应,制得配合物Cu(C₁₀H₈N₂O₄)(H₂O)₂(1)和Cu(C₁₀H₈N₂O₄)(CH₃OH)(H₂O)(2)(C₁₀H₈N₂O₄^2-为2-羰基丙酸水杨酰腙负离子),测试了配合物2的单晶结构.该单晶为墨绿色,属三斜晶系,P1空间群.晶胞参数a=0.7538(2)nm,b=1.1431(2)nm,c=0.7500(2)nm,α=93.26(2)^o,β=94.46(2)^o,γ=94.39(2)^o,V=0.6411(2)nm₃,μ=1.731mm^-1,Z=2,D_c=1.792g/cm³,F(000)=342.00,R=0.035,wR=0.048,GOF=1.78.在配合物2内,2-羰基丙酸水杨酰腙负离子中的2个氧原子和1个氮原子、甲醇中的氧原子以及配位水中的氧原子与铜原子配位,形成四方锥结构,其中来自甲醇的配位氧原子位于锥顶;此晶体为外消旋化合物,晶体中存在对映异构体,两者通过氢键连接,形成二聚体,成对出现在晶胞中.根据元素分析、红外和紫外光谱推测配合物1与2的结构相似;抑菌试验结果表明,配合物1对辣椒疫霉菌和烟草赤星菌分别有100%和66.02%的抑制作用.     

二维等离子体并行PIC模拟的性能分析及应用

通过区域分解法实现了二维等离子体粒子模拟程序并行化,并将此程序运行在由16个Pentium Ⅲ 1.6G CPU组成的微机机群上,对其性能进行了测试.结果表明,在计算规模一定的情况下,并行程序的并行效率随计算结点的增加而降低;而在计算节点不变的情况下,并行效率随计算规模的增加而增加,并行计算更适合于计算规模大的物理问题.利用此并行程序计算了等离子体中的束流不稳定性,结果表明,在波动激发的线性增长阶段,等离子体束流激发的Alfv啨n波基本上沿背景磁场方向传播,其波数满足共振条件ω-kV_b=-Ω_i,其中ω和k分别为Alfvén波的频率和波数,V_b为束流的速度,Ω_i为离子的回旋频率.     

稀土与水杨醛-1H-苯并三唑乙酰腙配合物的合成及抑菌实验

SBTH;生物活性;稀土与水杨醛-1H-苯并三唑乙酰腙配合物的合成及抑菌实验     

超细碳酸钙微晶结构与热分解特性

研究了不同晶粒粒径,不同团聚状态的3种超细碳酸钙样品的热分解状况.应用三维球对称相界面迁移机理和CoatsandRedfern方程与应用Kissinger非机理方程得到的动力学参数基本一致,与普通碳酸钙相比,超细碳酸钙显示出60～80kJ·mol^-1的表观活化能降.3种超细碳酸钙样品的X射线衍射的数据分析表明,超细碳酸钙样品晶格中存在较大的畸变应力.我们认为,这可能是导致其反常热分解特性的原因.同时,对样品的TEM,SEM的观察揭示了微结构的团聚状态对热分解活化能的影响.     

气质联用检测食品包装材料中的PAEs的教学实验探索

设计了一个综合性教学实验,采用超声萃取、化学浸出等前处理方法,并应用气相色谱质谱联用仪,对学生取样的六种有代表性的食品包装材料中的PAEs迁移值进行了检测。通过分析总离子流图中的丰度值和目标化合物的质谱图,确定了各包装材料中所含PAEs的种类和含量。本实验成功应用于学生的教学实验中,效果良好。     

Yalongenes A and B,Two New Cembranoids with Cytoprotective Effects from the Hainan Soft Coral Sarcophyton trocheliophorum Marenzeller

Two new cembranoids, yalongenes A ( 1 ) and B ( 2 ), were isolated from the South China Sea soft coral Sarcophyton trocheliophorum Marenzeller . Their structures were elucidated by detailed spectroscopic analysis (IR, MS, and NMR) and by comparison with a related model compound. Yalongenes 1 and 2 were evaluated for their cytoprotective effects on SH‐SY5Y cell injury induced by H₂O₂ in vitro, and the result showed that only compound 1 had a significant cytoprotective activity at the concentration of 1 μM .     

Diffusion mechanism during the swelling hidroxy-methyl cellulose membrane formation

The conduction properties of HMC polymer gel prepared by the phase inversion method were investigated through the diffusion coefficient in order to confirm the conduction mechanism. The solution introduced in the polymer is stored in the pores and then penetrates into the polymer chains. For swelling the polymer network. A model describing the swelling hidroxy-methyl cellulose is presented. The model is used to predict the type liquid–liquid phase separation (instantaneous or delayed) that occurs when HMC-PVPD-Solvent-Water casting solutions are immersed in a gelation bath. The model includes the thermodynamic interactions parameters and the transport parameters. The predictions of the model agree with the experimental observations.     

Homoclinic bifurcation at resonant eigenvalues

We consider a bifurcation of homoclinic orbits, which is an analogue of period doubling in the limit of infinite period. This bifurcation can occur in generic two parameter vector fields when a homoclinic orbit is attached to a stationary point with resonant eigenvalues. The resonance condition requires the eigenvalues with positive/negative real part closest to zero to be real, simple, and equidistant to zero. Under an additional global twist condition, an exponentially flat bifurcation of double homoclinic orbits from the primary homoclinic branch is established rigorously. Moreover, associated period doublings of periodic orbits with almost infinite period are detected. If the global twist condition is violated, a resonant side switching occurs. This corresponds to an exponentially flat bifurcation of periodic saddle-node orbits from the homoclinic branch.Partially supported by DARPA and NSF.Partially supported by the Deutsche Forschungsgemeinschaft and by Konrad-Zuse-Zentrum für Informationstechnik Berlin.