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51.
应用手性毛细管气相色谱法(酸性异丙醇、三氟乙酸酐为衍生试剂)、高效液相色谱法(邻苯二甲醛-N-乙酰-L-半胱氨酸为手性衍生试剂)同时测定人类第一磨牙牙本质中天冬氨酸的消旋化程度,结果表明,两者均可有效地用于天冬氨酸对映体的分离测定,但气相色谱检测限(0.2pmol)低于高效液相色谱(1.0pmol),而变异系数(7%)、总分析时间(100min)均高于高效液相色谱(分别对应为4%,31min)。  相似文献   
52.
Selective, high yield partial fluorination of p-bis-(trichloromethyl)benzene to p-bis-(chlorodifluoromethyl)benzene has been accomplished by warming a slurry of the p-bis-(trichloromethyl)benzene in anhydrous HF which also contains a small quantity of inert solvent, such as 1,2-dichloroethane.  相似文献   
53.
段玉峰 《化学通报》2002,65(7):492-496,491
本文是笔者在长期教学实践的基础上,对于化学专业生物化学课程教学内容和教学方法,研究的经济总结。其相关成果曾获陕西师范大学优秀教材一等奖及陕西省教学成果二等奖。  相似文献   
54.
铋(Ⅲ)-溴邻苯三酚红配合物吸附波及其应用*刘家欣段友构黄诚朱苗力(吉首大学化学系湖南吉首416000)匡向阳(永州市水文站湖南永州425000)关键词铋溴邻苯三酚红配合物吸附波中图分类号O657.14近年来,在某些有机试剂存在下用极谱法测定铋已有一...  相似文献   
55.
研究了偏氟乙烯的聚合条件与其聚合物的头-头链含量的关系。实验表明聚合物的头-头链的含量与聚合温度有关,而与引发剂的种类无关。因而,可以在较低的聚合温度下聚合制得带有低的头-头结构(约3%)的聚偏氟乙烯。将聚合物链的A结构含量对其熔点作图,得一直线,可表示为方程式A=24.8+0.362T_m(%)。  相似文献   
56.
The 4f-5d transition rates for rare-earth ions in crystals can be calculated with an effective transition operator acting between model 4f(N) and 4f(N-1)5d states calculated with effective Hamiltonian, such as semiempirical crystal Hamiltonian. The difference of the effective transition operator from the original transition operator is the corrections due to mixing in transition initial and final states of excited configurations from both the center ion and the ligand ions. These corrections are calculated using many-body perturbation theory. For free ions, there are important one-body and two-body corrections. The one-body correction is proportional to the original electric dipole operator with magnitude of approximately 40% of the uncorrected electric dipole moment. Its effect is equivalent to scaling down the radial integral (5d/r/4f) to about 60% of the uncorrected HF value. The two-body correction has magnitude of approximately 25% relative to the uncorrected electric dipole moment. For ions in crystals, there is an additional one-body correction due to ligand polarization, whose magnitude is shown to be about 10% of the uncorrected electric dipole moment.  相似文献   
57.
trans-RhCl(CO)(TPPTS)2 (TPPTS=tris(m-sulfonatophenyl)phosphine) has been intercalated into Zn-Al layered double hydroxides (LDHs) by the method of ion exchange. The structure, composition and thermal stability of the composite material have been characterized by powder X-ray diffraction, Fourier transform infrared and 31P solid-state magic-angle spinning nuclear magnetic resonance spectroscopy, elemental analysis, thermogravimetry, and differential thermal analysis. The geometry of trans-RhCl(CO)(TPPTS)2 was fully optimized using the PM3 semiempirical molecular orbital method, and a schematic model for the intercalated species has been proposed. The thermal stability of trans-RhCl(CO)(TPPTS)2 is significantly enhanced by intercalation, which suggests that such materials may have prospective application as the basis of a supported catalyst system for the hydroformylation of higher olefins.  相似文献   
58.
The equilibrium solubility of CsCl-CeCl3-HCl(11%)-H2O qua-ternary system at 25℃ has been determined by the physicchemical analysis method ,and the phase diagram was plotted, Two new double salts 3CsCl.CeCl3.3H2O and CsCl.CeCl3.4H2O obtained from the complicated system were identified and characterized by XRD,TG-DTA ,DSC,UV and fluorescence spectroscopy, Studies on the fluorescence excitation and emission show that 3CsCl.CeCl3.3H2O and CsCl.CeCl3.4H2O have upconversion luminescence of infrared-visible range,and the upconversion emission intensity increases with the increase of ratio of CeCl3 in CsCl.  相似文献   
59.
Liu X  Song D  Zhang Q  Tian Y  Zhang H 《Talanta》2004,62(4):773-779
Surface plasmon resonance (SPR) has been successfully applied for the simple, rapid, and label-free assay of various biomolecules. This assay evaluates a novel wavelength modulation SPR biosensor for the detection of tetanus toxin. The wavelength modulation SPR biosensor is designed based on fixing the incident angle of light and measuring the reflected intensities in the resonance wavelength range spanning 400-800 nm simultaneously. Tetanus toxin (TeNT), one of the most potent toxins known, is synthesized as a 150 kDa single polypeptide chain. The SPR biosensor has been shown to be capable of directly detecting concentration of tetanus toxin as low as 0.028 Lf ml−1. Under selected experimental conditions, the SPR biosensor has a good reproducibility, sensitivity and reversibility. The results illustrate how wavelength modulation SPR biosensor can be used to detect biomolecular interactions.  相似文献   
60.
层柱催化剂[Zn_2Al(OH)_2][SiW_(11)O_(39)Co(H_2O)]_(0.83)4H_2O的合成新途径及其对苯甲醛H_2O_2氧化的催化活性胡长文,贺庆林,张云峰,张继余,王恩波(东北师范大学化学系,长春130024)关键词层柱催化剂,苯?..  相似文献   
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