由联烯酸酯类化合物合成头孢克洛母核7-苯乙酰基3-氯-3-头孢烯4-羧酸对甲氧基苯甲醇酯

由青霉素G经扩环合成新的具有广谱抗菌作用的头孢类化合物一直是工业界和有机化学工作者感兴趣领域[1,2].我们课题组研究成功了由青霉素G的开环产物SOP化合物1,开始,经臭氧化、甲苯磺酰化合成联烯酸酯化合物3,再经过合环,合成了7-苯乙酰基3-氯-3-头孢烯4-羧酸对甲氧基苯甲醇酯(5),总收率为63.2%.具有广泛的应用前景.     

1-苯基-3-甲基-七氟丁酰吡唑酮-5(PMHFP)及邻菲咯啉(phen)希土混配配合物的合成及性质研究

本文在乙醇中合成了PMHFP及phen与希土离子的三元配合物Ln(PMHFP)₃·phen(Ln=La,Ce,Pr,Nd,Sm,Eu,Gd,Tb,Dy,Ho,Er,Tm,Yb,Lu,Y).通过化学分析,元素分析及电导分析确定了配合物的组成;研究了配合物的紫外、红光光谱;借助于差热-热重分析仪研究了所有配合物的挥发性质,测定了它们各自的起始挥发温度,探讨了用于希土分析的可能性.     

石英晶体微天平技术研究纳米TiO2表面Cu(Ⅱ)吸附与光化学还原过程

The adsorption and photochemical reduction process of Cu(Ⅱ) at the surface of nanocrystalline TiO₂ was investigated using in situ quartz crystal microbalance(QCM). It was found that the adsorption of Cu(Ⅱ) onto active sites of nanocrystalline fit the pseudo-second-order reaction better than the pseudo-first-order reaction, and that the rate constant of the reaction was estimated to be about 0.09 g·mmol₂·min₂. In addition, it was also found that the adsorption amount of Cu(Ⅱ) at the surface of TiO₂ was affected by pH、concentration and coexisting anions, and the saturated amount of adsorbed Cu(Ⅱ) was approximately 1.5 mmol·g^-1 at pH 4. During UV illumination, the frequency of QCM decreased gradually, which meant the photoreduction deposition of Cu(Ⅱ) from the solution, moreover, the rate of photodeposition of Cu(Ⅱ) increased with increasing pH of solution, and the rate of photoreduction enhanced obviously when the organics were introduced.     

Nonlinear theory of combustion stability in liquid rocket engine based on chemistry dynamics

Detailed models of combustion instability based on chemistry dynamics are developed. The results show that large activation energy goes against the combustion stability. The heat transfer coefficient between the wall and the combust gas is an important bifurcation parameter for the combustion instability. The acoustics modes of the chamber are in competition and cooperation with each other for limited vibration energy. Thermodynamics criterion of combustion stability can be deduced from the nonlinear thermodynamics. Correlations of the theoretical results and historical experiments indicate that chemical kinetics play a critical role in the combustion instability.     

以重铬酸钠—硫酸作氧化剂合成1,3—二氯丙酮

用重铬酸钠—硫酸作氧化剂,由1,3-二氯-2-丙醇氧化合成1,3-二氯丙酮。反应产物经乙醚萃取、正已烷重结晶,得白色针状或片状结晶,1,3-二氯丙酮收率81×10(-2),纯度>90×10(-2)。     

手性螺环配体的合成及其在不对称催化反应中的应用研究进展

手性螺环配体的合成及其在不对称催化反应中的应用是不对称合成和催化研究中重要的研究领域之一, 一些手性螺环配体被合成出来并成功地应用于不对称催化反应中. 综述了近十年来手性螺环配体的合成及在不对称催化反应中的应用研究进展.     

新生儿呼吸困难56例病因分析

对56例新生儿呼吸困难病因进行了分析。结果表明，该病多数由肺部疾病或颅内疾病引起，也有代谢性酸中毒或先天性疾病引起的。     

高分子专业毕业实习现状分析及措施研究

针对高分子材料科学与工程专业毕业实习存在的问题,结合国际工程认证要求以及学校对毕业生要求达到的毕业目标,提出了高分子专业毕业实习适合采取集中实习和分散实习相结合的方法。让毕业实习融入到毕业设计及毕业论文中,并使实习成为提前毕业设计和论文、就业、自谋出路的一部分,建立稳定的校外实习基地,提高学生毕业实习的质量,在巩固和深化他们自身专业理论水平的同时,提高其动手创造能力和思维创新能力,并使其综合工程素质得到提高。     

X射线荧光光谱法测定水样中的痕量元素

采用波长色散X射线荧光光谱仪测定了水样中痕量的A1、Cr、Ni、Zn、Sr、Ba、Tl、Pb。本法的测量结果与ICP和AAS的结果相近，对5．7μg/g Sr测量5次的RSD为1．2％，Sr的检出限(LLD)达到0．1μg/g。     

Laser photolysis of interaction of poly-guanylic acid (5′) with anthraquinone-2-sulfonate

The electron transfer reaction between triplet anthraquinone-2-sulfonate and poly- guanylic acid (5′) in CH3CN-H2O (97:3) has been investigated by 248 nm (KrF) laser flash photolysis. The transient absorption spectra and kinetics obtained from the interaction of triplet anthraquinone-2-sulfonate and poly[G] demonstrate that the primary ionic radical pair, radical cation of poly[G] and radical anion of anthraquinone-2-sulfonate have been detected simultaneously. The free energy changes in the process of the electron transfer were also calculated.