对羟基苯甲酸与对苯二甲酸乙二酯的共聚物研究

对羟基苯甲酸与对苯二甲酸乙二酯的共聚物研究张广利，阎丰琪，李勇，王震，潘景岐，张鸿志（北京大学化学系北京１００８７１）关键词液晶共聚酯，ＰＥＴ／ＰＨＢ共聚脂，序列分布Ｊａｃｂｏｎ和ＫｕｈｆｕＪ’ｌ于７０年代报道了对羟基苯甲酸（ＰＨＢ）一对苯二甲酸乙二...     

基于ZigBee的特种装备贮运状态监测系统设计

设计了一种基于ZigBee技术的实时贮运状态监测系统。系统通过MEMS传感器实现特种装备贮运状态的采集,采用CC2530模块实现数据的无线传输,以ARM微处理器STM32F407为核心实现数据的实时存储、分析与显示,并应用数字滤波算法对数据进行滤波处理,提高了检测数据的精确度。系统测试结果表明该系统对于节点信息的采集和无线传输具有较高的可靠性和稳定性,具有推广应用价值。     

An atomic force microscopic investigation of electro-sensitive polymer surface

An electro-sensitive poly(2-acrylamide-2-methylpropane sulfonic acid) (PAMPS) film was fabricated by surface-initiated atom transfer radical polymerization (ATRP) method on silicon substrate. Atomic force microscopy (AFM) experiments in contact mode show that friction force and the adhesion force between the AFM tip and the film may change regularly with the alteration of the applied negative bias voltage between them, indicating that the microscopic wettability of the film can be adjusted by external electric field. On the other hand, the AFM experiments in tapping mode reveal that the film may take corresponding phase change under the electric field. These effects were considered to result from the conformational overturn of the sulfonic groups and the adjacent alkyl chains in the electric field.     

Experimental observation of nanojets formed by heating PbO-coated Pb clusters

We are reporting the first experimental observation of nanojets formed by heating PbO-coated Pb clusters, which has been predicted theoretically by Moseler and Landman. During heating, the hot liquid is ejected through the broken orifice into a vacuum and forms a condensed trail in the shape of a tadpole, as shown in the transmission electron micrographs. The temperature-variable Raman spectra indicate that nanojet formation is closely related to the heating temperature and thus essentially to the pressure in the coated clusters. The pressure inside the shell rises from the inner core's melting and its confined volume expansion. It then drops after the final explosion, dominating the whole nanojetting process.     

Parameters concerning the preparation and performance of a magnetic microparticle antibody

We have described Magnetic Microparticle Antibodies and Their Application to RIAs in a recently published paper¹. In this article operative parameters for the preparation of a magnetic second antibody (MSA-II) including results of purification of donky anti-rabbit (DxR) serum by an (NH₄)₂SO₄ precipitation method, rates of recovery of products in preparation of magnetic nucleus (MN, Fe₃O₄ microparticle), in distillation of acrolein (AL) and in preparation of polyacrolein magnetic particle (PAMP), change in pH value of suspension irradiated before and after⁶⁰Co -irradiation and volume of wet sediment in separation of magnetic particles by a magnetic separator, etc., as well as correlation of levels of quality control (QC) sera obtained with liquid-phase double antibody assay (LDA) and MSA-II assay during four years were supplementarily summarized. These operative parameters would be helpful to mastering the procedures for preparation and/or use of the magnetic particles. The better correlation of levels of QC sera for both the assays showed the reliability of the magnetic antibody.This paper is a progress report of the Technical Contract No. 8955/R0/Deferred Programme Acrivities (DPA) 1994 from 1996-02-15 to 1997-02-14, supported by Intemational Atomic Energy Agency.     

Estimation of Critical Temperature of Thermal Explosion for Nitrosubstituted Azetidines Using Non-isothermal DSC

Based on reasonable hypothesis, two general expressions and their six derived formulae for estimating the critical temperature (T_b) of thermal explosion for energetic materials (EM) were derived from the Semenov's thermal explosion theory and eight non‐isothermal kinetic equations. We can easily obtain the values of the initial temperature (T_0i) at which DSC curve deviates from the baseline of the non‐isothermal DSC curve of EM, the onset temperature (T_ei), the exothermic decomposition reaction kinetic parameters and the values of T₀₀ and T_e0 from the equation T_{0i or ei}=T_{00 or e0}+a₁β_i+a₂β_i²+···+a_L?2β_i^L?2, i=1, 2, ;···, L and then calculate the values of T_b by the six derived formulae. The T_b values for seven nitrosubstituted azetidines, 3,3‐dinitroazetidinium nitrate ( 1 ), 3,3‐dinitroazetidinium picrate ( 2 ), 3,3‐dinitroazetidinium‐3‐nitro‐1,2,4‐triazol‐5‐onate ( 3 ), 1,3‐bis(3′,3′‐dinitroazetidine group)‐2,2‐dinitropropane ( 4 ), 1‐(2′,2′,2′‐trinitroethyl)‐3,3‐dinitroazetidine ( 5 ), 3,3‐dinitroazetidinium perchlorate ( 6 ) and 1‐(3′,3′‐dinitroazetidineyl)‐2,2‐dinitropropane ( 7 ), obtained with the six derived formulae are agreeable to each other, whose differences are within 1.5%. The results indicate that the heat‐resistance stability of the seven nitrosubstituted azetidines decreases in the order 6 > 7 > 5 > 4 > 3 > 2 > 1 .     

配位驱动组装单组分白光发光金属-有机配合物材料的研究进展

金属-有机配合物材料基于其结构种类多样性及发光性能可调控的特点，被广泛应用于安全防伪、信息存储、智能传感、显示装置、白光照明等领域。本综述详细介绍了单组分金属-有机配合物在白光发光领域内的研究进展。按照Au(Ⅰ)/Ag(Ⅰ)/Cu(Ⅰ)配合物、Zn(Ⅱ)/Cd(Ⅱ)配合物、Eu(Ⅲ)和Tb(Ⅲ)共掺杂Ln(Ⅲ)配合物、染料掺杂配合物、其他主族元素/过渡元素/镧系元素掺杂/多元素掺杂配合物5个类别对配合物结构特点、发光机理、白光发光组成、白光性能指标进行分析，归纳不同类别配合物白光发光材料的构筑策略，总结金属-有机配合物材料作为白光候选材料具备的优势，并从理论研究和实际应用2个方面提出待进一步解决的问题，以期早日实现金属-有机配合物发光材料的工业化生产及应用。