双水杨醛亚胺双核镍(Ⅱ)配合物降冰片烯加成聚合的研究

降冰片烯加成均聚产物具有好的热稳定性好和光学透明性,表现了优异的各向同性电性能,对金属具有很好的粘连附着性,可用于微电子器件的封装材料和液晶显示屏的保护涂层等领域,亦可作为耐高温工程材料使用,因而其制备和材料性能的研究备受学术界和企业界的青睐．降冰片烯加成聚合与传统的烯烃聚合具有许多相似     

Study on the preparation and adsorption thermodynamics of chitosan microsphere resins

The aim of this research is to study the thermodynamic behavior of resins of chitosan microspheres (RCM) in adsorbing Cu²⁺, so that the theoretical basis of the application of RCM to eliminate metal ions in wastewater or fruit and vegetable juice can be obtained. First, RCM were prepared from chitosan as a raw material by using reverse phase suspension cross-linking polymerization, and some physicochemical properties of RCM were characterized. Second, the adsorption behavior of Cu²⁺ onto RCM was investigated by the batch method. The results show that the diameter of the microspheres was relatively uniform and the surface of microspheres was compacted with pores. The physical properties of the RCM were as follows: water content 51.982%, skeletal density 1.212 g · cm⁻³, pileup density 0.862 g·L⁻¹, porosity was in 0.554 and crosslinking degree was in 13.581%. The saturated adsorption capacity of RCM for Cu²⁺ was 0.993 mmol·g⁻¹. At the same time, the results also indicated that the adsorption of RCM for Cu²⁺ followed the Langmuir isotherm equation: C _e/Q = 11.614 + 1.0075C _e at 313 K and the adsorption appeared to be of the monomolecular type. The adsorption was found through thermodynamic study to be a spontaneous endothermic process of increased entropy. The adsorption potential decreased gradually as Cu²⁺ concentration increased at the same temperature and it increased as temperature increased at the same initial concentration of Cu²⁺. __________ Translated from Periodical of Ocean University of China, 2008, 38(1) (in Chinese)     

Structures and properties of the polyacrylonitrile fabric coated with ZnO-Ag composites

The polyacrylonitrile (PAN) fabric coated with ZnO-Ag composite was achieved by hydrothermal synthesis techniques and photochemical method. The PAN fabrics coated with ZnO-Ag composite were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared (FT-IR), UV-vis spectrophotometer and fabric induced static tester, respectively. The SEM images revealed the formation of the coating aggregates on the fiber surface. The FT-IR spectra and XRD patterns revealed the chemical structures of the coatings on the PAN fabrics. The results of UV-vis test showed that there was an obvious increase in ultraviolet resistant properties after coating. The antistatic properties results revealed the improvement in the antistatic performance of coated fabrics, attributed to the superior electrical and optical properties of ZnO and Ag.     

中子中子碰撞产生超高能中子问题模拟

ICF的聚变靶丸中,高能中子相互之间发生碰撞将导致超高能中子的产生,推导中子中子碰撞与超高能中子产生的关系,研究利用蒙特卡罗方法确定碰撞后中子速度的方法,通过求解非线性中子输运方程及对DT聚变小球中的中子输运问题进行数值模拟,研究中子与中子碰撞产生超高能中子及其与聚变中子源强的关系问题.     

An optical spectroscopy study of defects in lithium tantalate single crystals

The congruent, stoichiometric, and Mg doped stoichiometric LiTaO₃ single crystals have been successfully grown by the Czochralski technique. The evolution of defect structures caused by varying composition and post-growth processing has been evaluated from the optical absorption and photoluminescence measurements. Optical absorption studies showed that the UV absorption edge is very sensitive to the composition of LiTaO₃ crystals. Photoluminescence of various LiTaO₃ single crystals at room temperature was observed. The emission bands centered at 360, 430, and 530 nm were assigned to different defects, which can well show the defect information in LiTaO₃ crystals.     

电感耦合等离子体原子发射光谱(ICP-AES)法测定水-乙二醇型难燃液压液中Ca、Mg、Zn元素含量

通过基体匹配法消除光谱干扰,采取降低雾化气流量、提高冷却器流量和降低蠕动泵泵速以减少进样量的措施直接进样,建立了电感耦合等离子体原子发射光谱(ICP-AES)法测定水-乙二醇型难燃液压液中Ca、Mg、Zn添加剂元素含量的分析方法。实验结果表明:所测各元素的相对标准偏差均小于5%,线性相关系数大于0.999,加标回收率在97%～105%,方法的检出限均小于0.15mg/L。方法无需对样品进行预处理,直接进样检测,具有分析速度快、操作简单、测定结果可靠等特点,可以实现水-乙二醇型难燃液压液中Ca、Mg、Zn元素的含量分析。     

非线性中子输运问题的蒙特卡罗模拟

针对考虑中子之间相互碰撞的非线性中子输运方程,提出一种线性化近似处理方法,导出相应的积分输运方程,利用蒙特卡罗方法求解此方程,数值实验表明算法的有效性,为研究超高能中子产生与输运问题提供了必要的模拟工具.     

NdxEr5-xSi3系列化合物晶体结构和磁性研究

利用电弧熔炼制备了NdxEr5-xSi3(x=0~5)系列化合物样品。通过X射线粉末衍射分析和磁性测量研究了Nd替代Er对Er5Si3化合物结构和磁性的影响。研究结果表明:随着Nd替代量的增加,其晶体结构、相组成及磁性能发生了明显变化。低Nd含量时(x≤3),样品具有Mn5Si3型六角结构,空间群为P63/mcm,样品具有反铁磁性。虽然奈尔温度不遵循De Gennes定律,但能被RKKY理论完美解释。高Nd含量时(x=5),样品具有Cr5B3型四方结构,空间群为I4/mcm,对外显示铁磁性。Nd含量为x=4时,两种结构共存,Rietveld精修表明Mn5Si3型结构占58(1)%,Cr5B3型结构占42(1)%。其磁化率温度曲线在50~100 K具有铁磁性特征,但随着温度的进一步下降,又显示出反铁磁性的特征,暗示其内部存在着铁磁相和反铁磁相的耦合。     

A Novel Heterocyclic Ring System: Synthesis and Spectral Data of 4,8,9b-Triazacyclopenta[c,d]phenalene

The synthesis and ¹H-NMR and electronic absorption spectra of 4,8,9b-triazacyclopenta[c, d]phenalene and several of its derivatives are described.     

High-resolution sorption studies of argon and nitrogen on large crystals of microporous zeolite ZSM-5

Summary High resolution adsorption (HRADS) with argon and nitrogen at 77 K were performed on large crystals of zeolite ZSM-5 using a novel volumetric device. Multi-step isotherms for both adsorptives could be observed for the first time. The micropore filling was followed by low temperature microcalorimetry. Exothermic heats of adsorption were found to be correlated with steps in the adsorption isotherms. Based on results from atom-atom potential energy calculations (AAP) as well as from independent model building it is shown that 24 kinetic adsorbate molecules can be situated in a ZSM-5 unit cell. Localized adsorption is presented as possible filling mechanisms. Experimental results are reasonably interpreted assuming primary filling of narrow channels and secondary adsorption in the wider channel intersections. At least for nitrogen there is evidence for a transition of fluid-like to a solid-like adsorbate phase.Compared to argon, Henry's constants and the initial isosteric heat of adsorption indicate a stronger adsorption of nitrogen which is thought to be due to additional interactions of the nitrogen quadrupole moment with the zeolite framework.

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Sorptionsuntersuchungen zur Hochauflösung von Argon und Stickstoff an großen Kristallen von mikroporösem Zeolit ZSM-5