Effects of anions on rapid growth and growth habit of KDP crystals

The synthesis of KDP from its raw material has been found exist in the growth solution. In the crystal growth experiment, significant extension of specific faces was observed at low dopant concentration. At high doping concentration, the growth rate of the whole crystal decreased with no significant habit modification. The inhibiting effects of phosphite and other H-bonding anionic ions on the growth of pyramidal faces are discussed. Rapid growth rate experiments have been carried out with purified material and an averaged growth rate of 18.6mm/day was obtained.     

MDP－PROLOG~（＋＋）语言的实现

给出了ＭＤＰ－ＰＲＯＬＯＧ＋＋语言的预编译技术，详细论述了预编译程序ＰＰＰ的总体设计、数据结构、扫描处理以及进程文本创建．该语言已在多层分布并行处理系统Ｗｕｄｐ－９１上实现     

黏滞等离子体中双撕裂模不稳定性的数值模拟研究

本文采用磁流体力学模型,数值研究了平板位形下双撕裂模线性增长率关于等离子体电阻η和黏滞v的定标关系.结果表明,对于有理面间距较大的情况,线性增长率关于电阻和黏滞的指数定标率随着黏滞的增加逐渐由γ∝ η3/5v0的定标变化到γ∝η5/6v-1/6的定标;而对于有理面间距较小的情况,其指数定标率随着黏性的增加从γ∝η 1/3 v0的定标逐渐变化到γ∝η2/3v-1/3的定标.本文还给出了初始阶段对称的双撕裂模的非线性演化,发现在非线性阶段对称的双撕裂模将转化为反对称的双撕裂模,并解释了相应的物理机理.     

Origins of Intermediate Mass Fragments for 40Ar+natAg Reaction at 30 MeV/u

The energy spectra of intermediate-mass fragments (IMF) (3≤Z≤16) have been measured from 6° to 110° for ⁴⁰Ar+^natAg reachon at 30 MeV/u. The energy spectra were analyzed by the moving source model. The natUres of the projechle-like source, target-like source and mid-rapidity source as well as the evolution with angle and nuclear charge were discussed. Two intermediate mass fragments, measured by correlation method in forward angles, come from two sources. One comes from projectile-like source, and other one mainly comes from intermediate source respectively.     

掺钕微球的受激辐射激光和自受激拉曼散射

采用溶胶-凝胶法在SiO_2微球表面覆盖上一薄层Nd~(3+)掺杂SiO_2,并经电极放电熔融后形成表面光滑的高Q值微球.采用锥光纤将808 nm的抽运激光耦合入钕离子掺杂的高Q值微球形成回廊模,激发产生了1080—1097 nm波段受激辐射激光.由于所产生的激光有足够高的功率密度,在高Q SiO_2微球中激发产生了波长为1120—1143 nm一级自受激拉曼散射激光.推导了锥光纤掺钕微球组合的自受激拉曼散射的输出功率和阈值公式.描述了输出激光的特性:阈值、输出功率、线宽、边模抑制比.     

液滴撞击壁面铺展及换热过程数值模拟

基于喷雾冷却时液滴撞击壁面现象,本文采用CLSVOF(coupled level set and volume of fluid)方法对不同工况下单液滴撞壁过程进行数值模拟,获得了单液滴撞击热壁面动态特性;分析了初始速度、液滴直径等初始参数对液滴撞壁后的动态铺展规律以及壁面换热特性的影响规律,获得了上述参数变化时液滴铺...     

Isomeric effect in the self-assembly of pyridine-containing L-glutamic lipid: substituent position controlled morphology and supramolecular chirality

Three isomeric pyridine-containing L-glutamic lipids formed organogels in DMSO and self-assembled into different nanostructures of nanofiber, nanotwist and nanotube depending on the substituent position in the pyridine ring.     

Studies on the Nonisothermal Crystallization Behavior of Polypropylene/Multiwalled Carbon Nanotubes Nanocomposites

Polypropylene/multiwalled carbon nanotubes (PP/MWNTs) nanocomposites were prepared by a melt compounding process. The morphology and nonisothermal crystallization of these nanocomposites were investigated by means of optical microscopy, scanning electron microscopy, and differential scanning calorimetry. Scanning electron microscope micrographs of PP/MWNTs composite showed that the MWNTs were well dispersed in the PP matrix and displayed a clear nucleating effect on PP crystallization. Avrami theory, modified by Jeziorny and Mo's method, was used to analyze the kinetics of the nonisothermal crystallization process. It was found that the addition of MWNTs improved the crystallization rate and increased the peak crystallization temperature of the PP/MWNTs nanocomposites as compared with PP. The results show that the Jeziorny theory and Mo's method successfully describe the nonisothermal crystallization process of PP and PP/MWNTs nanocomposites.     

Sunlight-activated AlFeO3/TiO2 photocatalyst

A nanocomposite photocatalyst composed of AlFeO₃ and TiO₂ is prepared, and characterized through X-ray diffraction. Application of the nanocomposite for the photodegradations of eosin dye and methyl orange gives an improved photoactivity compared with TiO₂-only nanomaterials. The optimal concentration of AlFeO₃ in the composite is about 1.0 wt% under UV excitation, and 9.0 wt% under sunlight excitation for the improved photoactivity. Furthermore, this nanocomposite is more active for eosin photodegradation if natural sunlight rather than UV is used. This may be due to the reason that adding AlFeO₃ nanoparticles into TiO₂ matrix can promote the separation of photogener-ated charge carriers, and extend the photoresponse of TiO₂ toward visible region, which results in an increase in the solar energy utilization efficiency.     

自适应一致性高阶无单元伽辽金法

近来提出的一致性高阶无单元伽辽金法通过导数修正技术大幅度减少了所需积分点数目,并能够精确地通过线性和二次分片试验,显著改善标准无单元伽辽金法的计算效率、精度和收敛性.本文在此基础之上,充分利用无单元法易于在局部区域添加节点的优势,发展了一致性高阶无单元伽辽金法的h型自适应分析方法.根据应变能密度梯度该方法自适应地确定需节点加密的区域,基于背景积分网格的局部多层细化要求生成新的计算节点,同时考虑了节点分布由密到疏渐进过渡的情形.采用相邻两次计算的应变能的相对误差作为自适应过程的停止准则,将所发展自适应无网格法应用于由几何外形、边界外载和体力等因素造成的应力集中问题的计算分析.数值结果表明,所发展方法能够自适应地对高应力梯度区域进行节点加密,自动给出合理的计算节点分布.与已有的标准无网格法的自适应分析相比,所发展方法在计算效率、精度和应力场光滑性等方面均展现出显著优势.与采用节点均匀分布的一致性高阶无单元伽辽金法相比,它大幅度地减少了计算节点数目,有效提高了一致性高阶无单元伽辽金法在分析应力集中等存在局部高梯度问题时的计算效率和求解精度.