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161.
高效液相色谱法测定蜂王浆中特有成分10—羟基—2—癸烯酸的研究 总被引:3,自引:0,他引:3
本文报道反相高效液相色谱法测定蜂王浆和蜂王浆制剂中的10-羟基-2-癸烯酸(10-HDA)的方法,用二氯甲烷从蜂王浆或蜂王浆制课题占萃取10-HDA,而后用HPLC测定,实验采用YWG-C18柱,35%乙醇水溶液为流动相,己二酸为内标,紫外检测器波长为212nm,加入法测回收率在95%以上。用此法测定了鲜蜂王浆和蜂王浆制剂中的10-HDA的含量。该法简单、快速,优于气相色谱法和薄层色谱法。 相似文献
162.
A novel TPPTS-Rh/SiO2 catalyst, prepared by directly modifying a heterogeneous high-surface-area Rh/SiO2 catalyst with water-soluble TPPTS ligands, could decrease the resistance of masstransfer in water/oil biphasic media for the hydroformylation of higher olefins. The catalytic performancefor hydroformylation on this biphasic TPPTS-Rh/SiO2 catalyst system was higher than those of thetraditional biphasic HRhCO(TPPTS)3 systems, owing to the chemical bonds between the highly dispersedRh metal particles and the TPPTS ligands. The catalyst system is applicable for hydroformylation ofhigher olefins such as 1-dodecene. 相似文献
163.
研究了Cu(Ⅱ)-胱氨酸络合物极谱波的性质;提出了一种用示波极谱法测定蛋白质中胱氨酸的新方法,可在8.0×10~(-4)mol/L Cu~(2+)+8.0×10~(-3)mol/L三乙醇胺的溶液中测定0.05~20mg/L的胱氨酸。 相似文献
164.
Anatase TiO2 nanocomposites for antimicrobial coatings 总被引:1,自引:0,他引:1
A sol-gel chemistry approach was used to fabricate nanoparticles of TiO(2) in its anatase form. The particle size is shown to be sensitive to the use of HClO(4) or HNO(3) as acid catalyst. The gold-capped TiO(2) nanocomposites were processed by the reduction of gold on the surface of the TiO(2) nanoparticles via a chemical reduction or a photoreduction method. Different percentages of vanadium-doped TiO(2) nanoparticles, which extended the TiO(2) absorption wavelength from the ultraviolet to the visible region, were successfully prepared. The synthesized nanocomposites have a size of about 12-18 nm and an anatase phase as characterized by XRD, TEM, AFM, and UV-vis spectroscopy. The TiO(2) nanocomposite coatings have been applied on glass slide substrates. The antibacterial activity of TiO(2) nanocomposites was investigated qualitatively and quantitatively. Two types of bacteria, Escherichia coli (DH 5alpha) and Bacillus megaterium (QM B1551), were used during the experiments. Good inhibition results were observed and demonstrated visually. The quantitative examination of bacterial activity for E. coli was estimated by the survival ratio as calculated from the number of viable cells, which form colonies on the nutrient agar plates. The antimicrobial efficiency and inhibition mechanisms are illustrated and discussed. 相似文献
165.
LBL分子沉积法制备葡萄糖氧化酶电极 总被引:1,自引:0,他引:1
采用以静电力为主的逐层分子交替沉积技术制备葡萄糖氧化酶(GOD)电极.通过带有正电荷的聚二甲基二烯丙基铵盐酸盐(PDDA)和带有负电荷的GOD交替沉积在修饰有3-巯基-1-丙基磺酸钠(MPS)的金电极表面.以甲酸二茂铁为电子媒介体,用循环伏安法检测GOD电极对葡萄糖的响应.结果表明,当GOD电极组装层数小于4时,电流响应随着层数的增加而增大,超过4层时电流响应减小.其中4层GOD修饰电极的线性范围为0.55~6.63 mmol•L-1,当pH为7.0时,响应最大.同时电极的检测重现性能良好,相对标准偏差为2.4%. 相似文献
166.
Kai Yang Xuan Zhang Enqin Fu Jingui Qin Minoru Kinoshita 《Journal of solid state chemistry》2004,177(11):4300-4304
Two new intercalation compounds were prepared by the reactions of Ni(II) cyclopolyamine complex cations with a preintercalate Mn1−xPS3K2x(H2O)y, respectively, through “ion exchange” process. Their structures were characterized by elemental analysis, X-ray powder diffraction and infrared spectroscopy. The lattice spacing increased 0.567 and 1.093 nm with respect to the pristine MnPS3. Ferrimagnetism of the intercalates was confirmed by SQUID experiment with Tc at 40 and 33 K, respectively. 相似文献
167.
脊髓小脑变性疾病病人血清铜,锌,铝,铁含量的研究 总被引:1,自引:0,他引:1
脊髓小脑变性疾病(SCD)的病因可能与遗传、神经生化紊乱、感染、微量元素平衡障碍及自由基损伤等因素有关,其中微量元素平衡障碍的研究具有重要意义。检测了SCD中发病率较高的橄榄桥小脑萎缩症(OPCA)及晚发性小脑皮质萎缩症(LCCA)病人15例血清中铜、锌、铝、铁等微量元素含量。发现病人比对照组铜明显降低,P〈0.01;锌明显降低,P〈0.01;铝明显升高,P〈0.01;铁无明显差别。 相似文献
168.
Yong Zhong DU Fu Qiang HU Hong YUAN Shinzo OMI 《中国化学快报》2006,17(4):553-556
Stable poly(styrene-co-sodium styrene sulfonate) (P(St-NaSS) nanoparticles with broader size distribution were synthesized by thermal emulsion polymerization without any conventional initiators and emulsifiers. The obtained polymer nanoparticles have higher ξ potential, and the particle sizes have broad distribution. The stability of polymer particles originated from the addition of small amounts of ionic comonomer, NaSS, which can act as an emulsifier in somewhat. The monomer conversion could reach up to about 28 wt% in 48 h, and did not increase by further polymerization when higher polymerization temperature (120 ℃) was employed. This polymerization system may be give some further understand for mechanism of emulsion polymerization. 相似文献
169.
Tianle Zhu Jiming Hao Lixin Fu Junhua Li Zhiming Liu 《Reaction Kinetics and Catalysis Letters》2005,84(1):61-67
Summary The cooperation effect of reducing species for selective reduction of NO over Ag/Al2O3 has been investigated in the presence of excess oxygen. When the combinations of propene or propane and ethanol or methanol were used as reducing agents, NO reduction took place over a wider temperature range, compared with a single hydrocarbon as reducing agent. 相似文献
170.
Rong-Qiang Fu Tong-Wen Xu Yi-Yun Cheng Wei-Hua Yang Zhong-Xiao Pan 《Journal of membrane science》2004,240(1-2):141-147
Starburst dendrimer polyamidoamine (PAMAM) with ellipsoidal or spheroidal shape is structure-regular and has much more amino groups than conventional polymers. This paper investigates the possibility of these amino groups on water dissociation in a bipolar membrane interface. To do this, a bipolar membrane is prepared by casting the solution of sulfonated poly(phenylene oxide) (SPPO) in dimethyl formamide (DMF) on a commercial anion exchange membrane that is immersed in PAMAM aqueous solution in advance. The existence of PAMAM adsorbed on the membrane is proved by X-ray photoelectron spectroscopy (XPS), and the adsorption amount is evaluated by weighting method. The junction thickness of the prepared bipolar membrane is determined by electrochemical impedance spectroscopy (EIS), and the performance is evaluated by current–voltage curves. The experiments show that both the generation and concentration of PAMAM would strongly affect the characteristics of the bipolar membranes. There exists a transitional concentration for various generations PAMAMs to catalyze effectively the water dissociation, and above or below the transitional concentration the performance of bipolar membranes is decreasing. The higher the generation, the lower the concentration. Moreover, at a fixed solution concentration, there is not the simple relation of monotone decreasing or increasing between the performance of bipolar membranes and the generations of PAMAMs. All these can be explained according to the characteristics of PAMAMs combined with available water dissociation theory. 相似文献