微视频在无机化学实验教学中的应用

To improve the students' autonomous learning ability and learning enthusiasm in practice course,we introduce micro video,which is short,fast,precise,easy,and fun,into inorganic chemistry laboratory teaching.As an important supplementary means of teaching,micro videos will solve the repeated problems,help students promote study efficiency,provide students with a good way for communication,and improve the students' study enthusiasm.     

Chaos in an Ar+ Composite Resonator Laser Using KNSBN;Cu Crystal Self-Pumped Phase-Conjugator

Observation of the dynamics in a single-mode Ar⁺ composite resonator laser using KNSBN;Cu crystal self-pumped phase-conjugator is reported. The sequence of instabilities occurring on gain change corresponds to the transition the chaos of the logistic equation. Period-doubling route to chaos, and period-5, -3,-3×2, and -2 together with -3 windows in the chaotic range were observed. The strange attractor which is similar to that of the forced Duffing equation is obtained by reconstructing phase-space pictures of the system.     

横向磁场导致CO2激光器混沌运转及其奇异吸引子的观测

在外加磁场的情况下,对单模均匀展宽CO₂激光器进行了实验研究。改变磁场的大小,观察到了自脉动和混沌现象,同时还获得了该系统的奇异吸引子,并对其物理机制进行了探讨。     

SYNTHESIS AND NMR CHARACTERIZATION OF PRECURSORS OF EPOXY NETWORK AS POLYMER HOST FOR SOLID ELECTROLYTE

To raise the room temperature ionic conductivity and improve the mechanical strength of a PEO-based polymer electrolyte, a noncrystalline two-component epoxy electrolyte system has been prepared. The diglycidyl ether of polyethylene glycols as precursors of the system were synthesized by a two-step process. The presumed structure of the product was characterized, by ~(13)C, ~1H NMR and IR spectroscopy. It was found that a side-reaction occurred between the secondary hydroxyl group of PEG-chlorohydrin and epichlorohydrin in some degree, resulting in a by- product containing—CH_2Cl side group. By selecting a characteristic signal, which is undistorted by the increase in the length of CH_2 CH_2—O segment, a ~1H NMR approach of determining the equivalent epoxy weight (EEW) was proposed. The method is valid to specimens even though the EEW is as high as 2,000. The examination of the specimens by DSC showed that epoxidation greatly depressed the crystallinity of the PEG's, whereas the T_g was raised.     

VISCOELASTICITY AND IONIC CONDUCTIVITY OF TWO-COMPONENT EPOXY NETWORK CONTAINING LITHIUM PERCHLORATE*

Polymeric solid electrolyte system composed of triglycidyl ether of glycerol (TGEG), diglycidyl ether of polyethylene glycol (DGEPEG)and LiClO_4 salt were synthesized. In this" system the electrolyte has a pecularity that not merely can the LiClO_4 provide ionic carriers, but also catalyze the crosslinking reaction without adding an usual curing agent. The effect of salt content and degree of crosslinking on the viscoelasticity and ionic conductivity were studied. Both WLF and VTF equations were used to treat the experimental data in order to elucidate the mechanism of ionic conduction. It was found that the ionic conductivity of the system is carded out through the segmental motion mechanism. However, the data must be treated with care. For example, in evaluating WLF parameters, the contribution concerned with ionic carrier generation with temperature to the conductivity must be differentiated from that concerned with segmental motion. Besides, the temperature range suitable to WLF equation must also be considered. For VTF equation, it might be inapplicable ff the temperature is too low and close to the glass transition temperature of the specimen. Further study is needed in order to have a quantitative information on the limitation of these equations.     

New Preparation Methodology of Functionalized Picolines

Under the organomagnesium complex n‐Bu₂CH₃MgLi conditions, picoline compounds provide a new entry to a broad range of polyfunctional picoline derivatives, after reaction with various electrophiles.     

碱土金属硫化物光激励材料在辐射剂量测量中的应用

采用碳还原法合成了掺杂两种稀土金属离子的碱土金属硫化物光激励发光材料,并对光激励发光材料的辐射剂量特性进行了研究。将材料做成PMMA剂量片在60Coγ源下接受辐照,然后用自己搭建的在线实时测试系统对剂量片发出的荧光信号进行测量。实验发现碱土金属硫化物光激励发光材料在0.01～1 000 Gy内,有很好的辐射剂量响应范围(5个剂量级),荧光信号峰值强度与辐照剂量线性关系良好,说明碱土金属硫化物光激励发光材料在辐射剂量测量中有着很好的应用前景。文章主要探讨了碱土金属硫化物光激励发光材料在辐射剂量测量中的应用。     

脉冲电流作用下LY12铝合金的微观结构和合金元素分布

研究了在凝固过程中施加脉冲电流对LY12铝合金微观结构和合金元素分布的影响.实验结果表明,在脉冲电流作用下,LY12合金的微观结构发生了明显变化,聚集在晶界和枝晶网的共晶组织大大减少,网络变得不连续,在晶内和晶界附近存在弥散的近似球状的共晶质点.另外,脉冲电流能有效地改善合金中Cu和Mg的成分偏析,其中对Cu在Al合金中的负偏析现象的改善更为显著,使Cu较均匀地分布于整个试样. 关键词： LY12铝合金 脉冲电流 显微结构 偏析