复合体系方法测量液体力学谱

本文介绍了采用复合体系，测量得到凝聚态物质从固态到液态连续变化力学谱的一种新的实验方法。以簧振动为例，给出了解析的计算公式，以及应用条件。通过进一步综合分析，得到具有更广应用范围的近似公式，可以近似应用于其他不同的振动模式，如低频扭摆。应用新的测量方法，给出了典型小分子玻璃材料甘油和碳酸丙稀从玻璃态到液态的力学谱，观察到甘油和碳酸丙稀玻璃化转变、碳酸丙稀的再结晶、熔化和挥发的过程；测量得到挥发过程中水的质量随时间精确变化的曲线。最后，本文给出了新方法的一些应用展望。     

回归曲线的加权正交级数估计

回归曲线的加权正交级数估计杨瑛（北京大学概率统计系，北京１００８７１）国家自然科学基金资助项目．１９８９年１２月３日收到．１９９０年１１月２２日收到第一次修改稿．１９９２年８月７日收到第二次修改稿．一、引论自１９６２年Ｃｅｎｃｏｖ［１］提出了密度函数...     

影响海洋微藻生产麻痹性贝类毒素的重要生态因素

麻痹性贝类毒素是有害赤潮海洋微藻生产的重要毒素种类，本文综述了影响该类毒素的主要生态因素有光，温度，盐度和营养盐4类；弱光对毒素合成有抑制作用。低温下PSP毒素产量高，通过对营养盐吸收机制的离子效应，盐度可影响毒素的生命合成，不同种类和株系对N、P限制的反应有极大差异。     

Strong limit-point classification of singular Hamiltonian expressions

Strong limit-point criteria for singular Hamiltonian differential expressions with complex coefficients are obtained. The main results are extensions of the previous results due to Everitt, Giertz, and Weidmann for scalar differential expressions.

     

Synthesis and crystal structure of a new one-dimensional system with end-to-end single dicyanamide bridges between nickel(II) centres

The complex [Ni(tn)₂{N(CN)₂}]ClO₄ (tn=trimethylenediamine) has been synthesized and the structure has been determined. The complex forms a one-dimensional chain structure via the bidentate bridging ligand dicyanamide. A two-dimensional networks is formed via interchain hydrogen bond interactions.     

Preparation and optical properties of Eu(III) complexes J-aggregate formed on the surface of silver nanoparticles

Ag colloidal nanoparticles coated with Eu(TTA)₃ · 2H₂O complexes were prepared, and it was found that Eu(TTA)₃ · 2H₂O complexes J-aggregate was formed on the surface of Ag nanoparticles according to a red shift (18.2 nm) in UV–Vis spectra. However, there had similar excitation wavelength, which was attributed to existence of Ag nanoparticles. Highly luminescent properties of Ag colloidal nanoparticles were observed, and it was believed to result from low energy transfer between Eu(III) complexes and Ag and the large electromagnetic field arising from the excitation of surface plasmon polariton of Ag nanoparticles.     

醋酸十二铵的吸附和SiO2悬浮液的稳定性

（1）测定了醋酸十二烷基铵（DAA）在CAB－O－SIL上的吸附，其等温线属双平台或LS型[1－3，5]；（2）NaCl的存在使DAA的吸附增加．但不影响其低浓度下第一平台的吸附量；HCl的存在则在全浓度范围内抑制了DAA的吸附，（3）测定了CAB－O－SIL颗粒在上述各溶液中的悬浮液的稳定性；（4）根据表面形成小胶团的吸附理论（即二步模型产）[2，3，5，]，并借助电导跟踪溶液中发生的变化，满意地解释了吸附和聚沉的实验结果．     

变温红外光谱研究多嵌段聚氨脂脲的微相分离行为

用傅里叶变换红外光谱方法研究了热处理对由聚环氧丙烷聚醚多元醇、３．５－二乙基甲苯二胺和４，４－二苯基甲烷二异氰酸酯组成的多嵌段聚氨酯脲（ＳＰＵＵ）的微相分离行为的影响．从室温逐步升温到３１０℃的过程中，氨基甲酸酯键（ＵＴ）之间形成的氢键大量解离，而脲键（ＵＡ）之间形成的、具有平面状双分叉结构的氢键在１３０～２００℃范围却大量生成；从３１０℃缓慢冷却到室温后，部分游离的ＵＴ重新形成氢键，而硬段之间形成的ＵＡ氢键的含量又有所增加．结果表明：高温热处理可以有效地提高ＳＰＵＵ的微相分离程度．     

Range-Renewal Processes: SLLNs and Power Laws*

Given n samples(viewed as an n-tuple) of a γ-regular discrete distribution π,in this article the authors concern with the weighted and unweighted graphs induced by the n samples. They first prove a series of SLLN results(of Dvoretzky-Erd¨os’ type). Then they show that the vertex weights of the graphs under investigation obey asymptotically power law distributions with exponent 1 + γ. They also give a conjecture that the degrees of unweighted graphs would exhibit asymptotically power law distribu...     

γ—Mo2N合成过程中的热变化及中间产物的研究

采用ＤＴＡ技术，通过改变升温速率研究了γ－Ｍｏ２Ｎ合成过程中的热变化，并经ＸＲＤ，ＢＥＴ及ＩＲ测试，对ＤＴＡ曲线中的谱峰进行归属，考察了中间产物，ＤＴＡ结果表明，在ＭｏＯ３和ＮＨ３程序升温反应过程中有放热峰及吸热峰出现，且随升温速率的长高，放热峰面积与吸热峰面积之比逐渐减小，结合ＸＲＤ及ＩＲ结果可知，ＤＴＡ曲线听放热峰可归属为由ＭｏＯ３变化为ＭｏＯ２的还原峰，吸热峰则归属为由ＭｏＯ２变化为Ｍｏ２Ｎ