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991.
992.
以H2S和CS2作硫化剂,用PPS和TPDS方法研究了水煤气变换催化剂CoMoK/γ-Al2O3的硫化及反硫化过程。用H2S/H2硫化时,只发现H2S的消耗和H2O的生成,用CS2/H2硫化时,只发现H2S的消耗和H2O的生成。用CS2/H2硫化时,首先生成CO2,然后是CH4,H2O和H2S,TPG实验表明催化剂表面上积炭,造成催化剂和活性降低,但积炭在水煤变换反应进行了逐渐除法。TPDS实验表 相似文献
993.
以芳香基三唑类杀菌剂三唑酮为先导物设计并合成了5个含N,N-二烷基二硫代氨基甲酸酯的芳香三唑类化合物, 通过元素分析、红外光谱、核磁共振氢谱和质谱对其结构进行了表征. 用X射线单晶衍射测定了[α-(4-甲氧基苯甲酰基)-2-(1,2,4-三唑-1-基)]乙基-N,N-二甲基二硫代氨基甲酸酯的晶体结构, 晶体属于三斜晶系, 空间群, 晶胞参数为: a=0.73482(15) nm, b=1.1051(2) nm, c=1.1209(2) nm, α=90.32(3)°, β=101.97(3)°, γ=105.13(3)°, V=0.8578(3) nm3,
Z=2, Dc=1.357 g/cm3, F(000)=368, µ=0.324 mm-1. 生物测试结果显示这5种有机化合物都具有杀菌性和植物生长调节活性 相似文献
994.
Cd2+ complexes with antibiotics viz. neomycin, chlortetracycline, oxytetracycline, tetracycline, penicillin‐V and penicillin‐G as primary ligands and vitamin‐B5 as secondary ligand have been reported at pH = 7.30 ± 0.01 and μ = 1.0 M KNO3 at 298 K by polarographic technique.1 Cd2+ formed 1:1:1, 1:1:2, and 1:2:1 complexes with a stability constants trend of neomycin < chlortetracycline < oxytetracycline < tetracycline < penicillin‐V < penicillin‐G can be explained on the basis of the nature of ligands, bonding, and steric hindrance of these drugs. The nature of electrode processes were reversible and diffusion controlled. The values of stability constants showed that these drugs can be used to reduce the toxicity of Cd. 相似文献
995.
A strong chromatographic effect has been established during copper-managenese formate impregnation of γ-Al2O3. The samples obtained have been characterized by adsorption, IR, X-ray and magnetochemistry methods. 相似文献
996.
Dan Donescu Sever Serban Kristiana Gosa Cristian Petcu 《Central European Journal of Chemistry》2005,3(1):10-27
The possibility to prepare hybrids made by poly(vinyl acetate) (PVAc), poly(methyl methacrylate) (PMMA) and/or poly(ethyl
acrylate) (PEtA) with TiO2 was studied. The processes of polymer formation-radical polymerization and sol-gel process for inorganic network —were achieved
simultaneously. Due to a high reactivity of titanium isopropoxide (TIP) in the sol-gel process, a complexant comonomer, allyl
acetoacetate (AlAcAc), was used. Covalent bonds between polymer and inorganic chains were obtained by addition of trialkoxysilane
derivates with vinyl (VTES) or methacryloyl (MPTS) groups. The presence of TIP inhibits the radical polymerization of vinyl
acetate (VAc). The PVAc-TiO2 hybrids were produced by the sol-gel process of TIP in the presence of pre-obtained PVAc. Except for VTES and MPTS, trialkoxysilane
derivates with methyl (MeTES), octyl (OTES) and phenyl (PTES) groups were used. The thermal stability of hybrids is strongly
affected by TiO2 presence and by the type of trialkoxysilane derivates. The thermal stability of PVAc hybrids decreases in the presence of
TiO2 inorganic network. The glass transition temperature of polymers increases in the presence of the inorganic network. 相似文献
997.
Prostaglandin D2 synthase (PGDS) (beta-trace protein) is a highly abundant cerebrospinal fluid (CSF) glycoprotein. A number of studies have been performed to determine the potential value of this protein for the diagnosis of various neurological disorders. The measurement of total PGDS levels in CSF has proved marginally useful for this purpose, but promising results were obtained while investigating changes in the posttranslational modifications (PTM) pattern. Using 2-DE analysis, we previously showed that PGDS is differentially expressed in ante- and post mortem CSF samples. In the present study, we examined whether the PGDS isoforms may help to distinguish stroke and neurodegenerative disease patients from healthy subjects. The pattern of PGDS PTM was analyzed in CSF from patients with various neurological disorders (n = 44) using IEF/immunoblotting techniques. Strong alterations of this pattern were detected in patients with different forms of degenerative dementia. These findings are consistent with PGDS being altered in some neurological diseases and provide new opportunities for clinical applications. 相似文献
998.
A selective Spectrophotometric method has been developed for the trace determination of copper after adsorption of its 1-phenyl-4,4,6-trimethyl(1H, 4H)-pyrimidine-2-thiol (PTPT) complex onto microcrystalline naphthalene. The complex is quantitatively adsorbed on naphthalene in the pH range 7.5–11.5, separated by filtration, dissolved in dimethylformamide (DMF) and determined spectrophotometrically at 400 nm. Beer's law is obeyed in the concentration range 2.5–37.5 g of copper in 10 ml of DMF. The molar absorptivity and Sandell's sensitivity are 1.30 × 1041 · mol–1 · cm–1 and 0.0048g cm–2, respectively. Ten replicate analyses of a solution containing 20.0 g of copper gave a mean absorbance of 0.410 with a relative standard deviation of 0.91 %. The interferences of various ions have been studied and the method has been validated by the determination of copper in various standard reference materials, beers, wines, human hair, goat liver and environmental samples.On leave from St. Stephen's College, Delhi 110 007, India 相似文献
999.
1000.
本文用P204-兰113A-煤油组成的滤膜体系处理钒(Ⅳ)的溶液,并考察了表面活性剂、载体、外相pH值、内相酸度、起始钒(Ⅳ)浓度以及乳水比等因素对分离的影响。 相似文献