Crystallization of Poly(ethylene adipate) within γ-Phase Poly(vinylidene fluoride) Matrix

The effects of PEA on the γ-phase PVDF crystal structure and the crystallization of PEA within the pre-existing γ-phase PVDF spherulites have been investigated by optical microscopy(OM), infrared spectroscopy(IR) and scanning electron microscopy(SEM). The results demonstrate that the γ-phase PVDF spherulites consist of the lamellae exhibiting a highly curved scroll-like morphology and develop preferentially in PEA-rich blend. With increasing PEA concentration, the scroll diameter increases and the scrolls are better separated from each other. PEA crystallizes first in the interspherulitic region and transcrystalline layer develops. Subsequently, the transcrystalline layer of PEA continues to grow within the γ-phase PVDF spherulites, e.g., in the region between the scrolls, until impinging on other PEA transcrystalline layers or spherulites. The crystallization kinetics results indicate that the growth rate of PEA crystals in the intraspherulitic region of γ-phase PVDF shows a positive correlation with content of PEA, but a negative one with the crystallization temperature of γ-phase PVDF.     

EDTA快速滴定法测定矿石中的氧化铝

介绍一种利用二乙基二硫代氨基甲酸钠分离后以EDTA滴定测定矿石中铝的新方法。锰矿样品用Na OH,Na_3PO_4和Na_2O_2混合熔剂熔融,消除Ca,Mg,Ti的干扰,用含无水乙醇的热水浸取,其中的Mn变为Mn O2沉淀析出,干过滤,定容。将滤液中和至弱酸性,加入二乙基二硫代氨基甲酸钠,一些金属阳离子形成难溶水的络合物而分离,再次过滤,一定量的滤液与过量的EDTA标准溶液反应,用锌标准溶液滴定剩余的EDTA,即得氧化铝的含量。该法采用二甲酚橙为指示剂,同时加入少量氯化十六烷基吡啶,滴定终点颜色突变明显,改善了测量精密度,操作易于掌握。样品测定结果的相对标准偏差为0.42%~1.08%(n=5),加标回收率为97.39%~99.94%。分析过程只需滴定一次,且不使用含铅、铜、氟溶液,方法便捷环保。     

金化学物相分析的准确测定与进展

介绍了用I2–KI(NH4I)法测定金物相时应注意的事项,同时综述了近几年来金化学物相分析的研究进展,包括不同价态金的测定、"不可见金"在矿物中尤其是在硫化矿中的存在形式以及难处理金矿的化学物相分析技术的研究等。     

激光钝化对熔石英修复后损伤性能影响的实验研究

采用10.6 μupm 的 CO₂激光, 对单次激光脉冲辐照修复熔石英存在的烧蚀采用大光斑钝化去除. 经过辐照修复的区域置于前表面测试初始损伤阈值, 结果表明调制造成的损伤得到了一定程度的抑制; 辐照区域置于后表面修复后 熔石英的初始损伤阈值超过了基底的初始损伤阈值. 实验观察到了应力分布外扩, 同时明显减弱. 对损伤增长的测试说明, 经过激光熔融辐照后的损伤点, 当应力释放以后, 损伤扩展初期表现出指数增长趋势, 后期随着辐照次数的增加, 损伤增长不再明显, 并且趋于恒定值.     

Two localized CO2 laser treatment methods for mitigation of UV damage growth in fused silica

Two methods：high-power,short-time,single-shot irradiation（Method A） and low-power,long-time,multi-shot irradiation（Method B） are investigated to mitigate the UV damage growth in fused silica by using a 10.6-μm CO2 laser.To verify the mitigation effect of the two methods,the laser induced damage thresholds（LIDTs） of the mitigated sites are tested with a 355-nm,6.4-ns Nd：YAG laser,and the light modulation of the mitigation sites are tested with a 351-nm continuous Nd：YLF laser.The mitigated damaged sites treated with the two methods have almost the same LIDTs,which can recover to the level of pristine material.Compared with Method A,Method B produces mitigated sites with low crater depth and weak light modulation.In addition,there is no raised rim or re-deposited debris formed around the crater edge for Method B.Theoretical calculation is utilized to evaluate the central temperature of the CO2 laser beam irradiated zone and the radius of the crater.It is indicated that the calculated results are consistent with the experimental results.     

一个基于Keeping Up with the Joneses的随机内生增长模型

本文建立了一个基于Keeping up with the Joneses的随机内生增长模型,利用"伪双状态变量"法得到了均衡时的最优消费、最优经济增长率和最优福利,讨论了相对消费对它们的影响.     

CO_2激光光栅式扫描修复熔石英表面缺陷的实验研究与数值模拟

基于熔石英材料对波长为10.6μm的CO2激光具有强吸收作用这一特点,提出采用CO2激光光栅式多次扫描修复熔石英光学元件表面密集分布的划痕和抛光点等缺陷的方法.实验结果表明,在合理的扫描参数下,元件表面的划痕和抛光点等缺陷可被充分地消除.损伤阈值测试结果表明,表面划痕和抛光点等缺陷被完全消除的元件的损伤阈值可回复到或超过基底的损伤阈值.同时结合有限元软件Ansys的模拟结果分析了CO2激光扫描修复及消除元件表面划痕和抛光点等缺陷的过程.本文为消除元件表面划痕和抛光点等缺陷提供了非常有意义的参考.     

非线性Af—Bg型自由基交替共聚反应的固化理论

利用高分子反应统计理论,给出了非线性Ａｆ－Ｂｇ型自由基交替共聚反应的溶胶－凝胶分配方程和反应体系的凝凝胶化条件,这些结果是进一步研究与凝胶网络性能相关的网络结构参数的基础。     

非线性A_f-B_g型自由基交替共聚反应的固化理论

利用高分子反应统计理论 ,给出了非线性Af-Bg 型自由基交替共聚反应的溶胶 -凝胶分配方程和反应体系的凝胶化条件 ,这些结果是进一步研究与凝胶网络性能相关的网络结构参数的基础     

光滑化牛顿法求解广义绝对值方程

本文研究了广义绝对值方程Ax-|Bx-c|=b的求解问题.利用一个光滑的NCP函数将广义绝对值方程转化为等价的光滑方程组,获得了算法全局超线性收敛性的结果.并给出数值实验验证了理论分析及算法的有效性.