PEG型酸性温控离子液体中芳香酸和醇的酯化反应

报道了该催化体系在芳香酸和醇酯化反应中的应用. 研究发现, 该离子液体具有优良的催化性能, 产品易分离, 催化剂可循环使用且活性不降低, 催化剂不易流失, 实现了均相催化剂的高效回收和再利用.     

广义模糊熵及其诱导的区别度

广义模糊熵是模糊熵在广义模糊补意义下的推广,本文给出广义模糊熵的公理化定义 ,基于σ-广义模糊熵,讨论了广义模糊熵和区别度的相互诱导关系.     

动点的牵连运动分析与运动合成定理推证

点的合成运动分析中,复杂运动合理地分解和合成的关键在于牵连点的运动分析,牵连点是动系上与动点瞬时相重合的点,由于动点在动系上不断变迁,故牵连点随时间变动。本文指出,任一瞬时,牵连点均是动系上的某一“固定”点,仅随动系一起运动,采用解析方法提出了牵连点速度和加速度的一种表示方法,并推导了点的速度和加速度合成定理。本方法无需引入相对导数,易于学生理解。     

树状大分子接枝型聚合物色谱分离材料研究进展

随着色谱固定相制备技术和材料科学领域的不断发展,目前已经有大量修饰方法和新型材料被用于固相萃取、高效液相色谱以及离子色谱聚合物固定相填料的功能化修饰。其中聚酰胺-胺(PAMAM)树状大分子由于其独特的结构和性质,在色谱分离材料结构完善和性能提升中也发挥了重要的作用。该文主要综述了PAMAM树状大分子在以聚合物为基质的色谱分离材料修饰中的应用,并对其今后的发展进行了展望。     

基于x~ly~m形积分因子解一类非恰当方程

选取xlym形状积分因子,对非恰当方程xayb(cydx+exdy)+xfyh(kydx+pxdy)=0推导出了l,m的计算公式,并给出了具体实例.     

Modification of Montmorillonite through Intercalative Polymerization

Montmorillonite(MMT) was modified through intercalative polymerization of phenol and formaldehyde catalyzed by oxalic acid.The modified montmorillonite was delaminated at large,as demonstrated by XRD and TEM studies,It can disperse easily in epoxy resion to from exfoliated nanocomposites.The nanoscale silicate platelets dispersed in water can be metallized by silver deposition.     

共軛高分子的研究——Ⅳ.以丁基锂与四氯化钛组合的催化剂的苯乙炔聚合

利用Ziegler型催化剂进行炔烃聚合的研究在近年来受到了注意。最近,Watson等以丁基锂与四氯化钛组合的催化剂进行乙炔、丙炔、丁炔-1的聚合,得到不溶性的聚合物,不过产率很低。我們利用丁基锂与四氯化钛组合的催化剂进行了苯乙炔的聚合,发现这个聚合反应很容易进行,得到可溶于苯的低聚物及不溶于苯的高聚物。現将結果简报于后。     

一种新颖1D链状聚合物[Ni(acac)2(dadpm)]∞的合成与晶体结构

The title compound [Ni(acac)₂(dadpm)]_∞ (acac=acetylacetonate, dadpm=4,4′-diaminodiphenylmethane) was synthesized from Ni(acac)₂·2H₂O with dadpm in DMF. The structure was characterized by elemental analysis, IR spectroscopy, thermal analysis and single-crystal X-ray diffraction. X-ray analysis revealed that the central Ni atom is at a center of symmetry, and is octahedrally coordinated by four O atoms from two acac anions and two N atoms from two dadpm ligands. Each dadpm ligand, which has a two-fold axis passing through its methylene C atom, bridges two Ni atoms to form a 1D polymeric chain. Neighboring chains connect via H bonding interactions to generate a 2D network. It crystallizes in the monoclinic system, space group P2/c with a=0.556 79(7), b=0.896 06(12), c=2.187 3(3) nm, β=94.942(3)°, V=1.087 2(3) nm³, Z=2, D_c=1.390 g·cm^-3, F(000)=480, M_r=455.17, μ(Mo Kα)=0.924 mm^-1, R(F)=0.036 0, wR(F²)=0.101 0, S=1.013. CCDC: 254565.     

氧瓶-离子色谱法测定树脂中的卤素和硫元素

含有卤素和硫元素的树脂样品经氧瓶法燃烧分解，用含H2O2的去离子水溶液吸收，离子色谱法分离测定．本法简便、快速，特别适于测定树脂中不活泼的卤族元素，且可同时测定。CI、S的相对标准偏差分别为0．22%,0．36％，最大绝对误差分别为0．43％和0．80％。树脂中CI、S的含量在0．28mmol/g～14mmol／g内可用此法准确测定，其最低检测限为0．05mmol／g。     

四苯硼钠在活性炭表面吸附过程的疏水相互作用

In this paper, the adsorption characteristics of sodium tetraphenylborate(NaBPh4) on activated carbon at 298.2,303.2,308.2,313..2 and 323.2 K was studied.The results show that the adsorption isotherm of NaBPh4 on activated carbon at different temperatures could be described using Langrnuir equation. Furthermore, the standard Gibbs energy, enthalpy, entropy and hydrophobic interaction Gibbs energy for the adsorption of NaBPh4 on activated carbon were studied, and the result shows that the hydrophobic interaction of BPh4^- ion plays the most important role for the transfer of NaBPh4 from water to activated carbon surface.