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161.
162.
以中英2国高中化学教材中的有机化学模块为切入点,对英国CIE A-level化学教材与人教版高中《化学2(必修)》及《有机化学基础(选修5)》在该模块中的课程标准、结构体系、内容选取及组织呈现、栏目设计、典型知识点的编排等方面进行比较,分析英国CIE A-level化学教材的特色和优势。 相似文献
163.
《Tetrahedron: Asymmetry》2006,17(11):1693-1699
A convenient synthetic method for the synthesis of substituted cyclohex-2-en-1-ones by the direct alkylation of phenols has been developed. Furthermore, enantiomerically enriched 2,6-dimethyl-6-(3-methylbut-2-enyl)-cyclohexa-2,4-dienone was prepared by the deprotonation of 2,6-dimethylphenol with a sparteine–lithium complex followed by alkylation with 1-chloro-3-methylbut-2-ene. 2,6-Dimethyl-6-(3-methyl-but-2-enyl)-cyclohex-2-enone was prepared from the corresponding cyclohexa-2,4-dien-1-one by selective hydrogenation of the 4,5-double bond. The method was extended to 2-methyl-naphthalen-1-ol and 1-methyl-naphthalen-2-ol resulting in 2-(R)-methyl-2-(3-methylbut-2-enyl)-2H-naphthalen-1-one and 1-(S)-methyl-1-(3-methylbut-2-enyl)-1H-naphthalen-2-one, respectively. 相似文献
164.
《中国化学快报》2020,31(5):1281-1287
Extensive structure-activity relationships (SARs) study of JND3229 was conducted to yield a series of new reversible 2-oxo-3,4-dihydropyrimido[4,5-d]pyrimidine privileged scaffold as EGFRC797S inhibitors. One of the most potent compound 6i potently suppressed EGFRL858R/T790M/C797S kinase with an IC50 value of 3.1 nmol/L, and inhibited the proliferation of BaF3 cells harboring EGFRL858R/T790M/C797S and EGFR19D/T790M/C797S mutants with IC50 values of 290 nmol/L and 316 nmol/L, respectively. Further, 6i dose-dependently induced suppression of the phosphorylation of EGFRL858R/T790M/C797S and EGFR19D/T790M/C797S in BaF3 cells. Compound 6i may serve as a promising lead compound for further drug discovery overcoming the acquired resistance of non-small cell lung cancer (NSCLC) patients. 相似文献
165.
A synthesized 24-mer single-stranded deoxyribonucleic acid (ssDNA) was covalently immobilized onto a self-assembled aminoethanethiol monolayer modified gold electrode, using water-soluble 1-ethyl-3(3-dimethylaminopropyl)-carbodiimide (EDC). The covalently immobilized ssDNAs were hybridized with complementary ssDNA (cDNA) or yAL(3) gene in solution, forming double-stranded DNAs (dsDNA). Meanwhile, daunomycin as an electrochemical active intercalator in the hybridization buffer solution was intercalated into the dsDNA to form a dsDNA/daunomycin system on the gold electrode surface, which was used for DNA electrochemical sensor. The cathodic waves of daunomycin bound to the double-stranded DNA (dsDNA) by linear sweep voltammetry were utilized to detect the cDNA. The cathodic peak current (i(pc)) of duanomycin was linearly related to the concentrations of cDNA between 0.1 mug ml(-1) and 0.1 ng ml(-1). The detection limit was about 30 pg ml(-1). 相似文献
166.
The determination of individual light rare-earth metals in monazite sand is described, based on TLC with a mixture of di-isopropyl ether, diethyl ether, di(2-ethylhexyl)phosphate and nitric acid (8:8:0.4:0.07 v v ) as eluent. Linear densitometric calibration graphs are obtained for individual light rare-earths in the range 0.015-0.60 mug. The minimum detectable quantities of La. Ce, Pr, Nd and Sm are 9, 10, 20, 13 and 12 ng, respectively. The relative standard deviations for the determination of La, Ce, Pr, Nd and Sm in monazite sand were 1.8, 1.1, 5.9, 1.9 and 6.5%, respectively. Results were in good agreement with those obtained by spectrophotometry. 相似文献
167.
Xu-Ni Cao Jin-Hua Li Hai-Hong Xu Jia-Rong Zhan Li Lin Katsunobu Yamamoto Li-Tong Jin 《Chromatographia》2004,59(3-4):167-172
Liquid chromatography with amperometric detection (LC-AD) is developed and applied to simultaneously determine five aromatic amines. In the LC-AD, a new carbon nanotubes/poly(3-methylthiophene) modified dual-electrode is fabricated and then used as the working electrode. It is found that this chemically modified electrode (CME) exhibits efficiently electrocatalytic oxidation for aromatic amines with relatively high sensitivity, stability and long-life. Thus, lower detection in LC-AD can be achieved, which are 4.0 × 10–8 mol L–1 for aniline, 1.6 ×10–7 mol L–1 for 4-nitroaniline, 1.0 × 10–7 mol L–1 for 4-chloroaniline, 1.5 × 10–7 mol L–1 for 1-naphthylamine, 1.7 × 10–7 mol L–1 for 2-bromoaniline. The recoveries of the five analytes are also determined, which range between 0.95 and 1.05 for drinking water, 0.86 and 1.10 for the LiWa River water. 相似文献
168.
Palladium-benzimidazolium salt catalyst systems have been studied for the Suzuki coupling. A different substitutent effect has been uncovered with respect to nitrogen substituents in the benzimidazolium salts from the palladium-imidazolium salt analogs. A practical and highly active palladium catalyst system, PdCl2/N,N′-dibenzylbenzimidazolium chloride 2, has been identified for the Suzuki coupling of aromatic halides with arylboronic acids. The coupling of a wide array of aromatic halides with arylboronic acids with the PdCl2-2 catalyst system gave good to excellent yields. The effective palladium loading could be as low as 0.0001 mol% and 0.01-0.1 mol% for iodide and bromide substrates, respectively. The coupling of unactivated aromatic chlorides with arylboronic acids also gave good results using Cs2CO3 as base with a 2 mol% palladium loading. The electronic factors from aromatic halides exert a significant influence on the Suzuki coupling catalyzed by the PdCl2-2 system while the electronic effect from the arylboronic counterparts is negligible. The aromatic halides with modest steric hindrance could also couple smoothly with phenylboronic acids using the PdCl2-2 catalyst system. 相似文献
169.
在低压条件下以酞菁铁为原料, 采用独立双温控加热系统在石英玻璃基底上气相沉积制备了大面积准直性好和管径均匀的碳纳米管. 利用扫描电子显微镜(SEM/FESEM)和透射电子显微镜(TEM)研究了定向碳纳米管的生长形态和结构. 详细讨论了系统真空度、反应温度、气体流速及氢气和氩气的体积比例等参数对碳纳米管生长的影响, 并测试了该碳纳米管的场发射性能及超电容性能. 相似文献
170.
金复合介孔SBA-15吸附血红蛋白在H2O2电催化反应中的应用 总被引:2,自引:0,他引:2
以P123嵌段共聚物表面活性剂为模板剂制备介孔氧化硅SBA-15,并用沉积-沉淀(DP)法在SBA-15介孔表面负载纳米Au颗粒制备得到金复合介孔SBA-15材料(Au-SBA-15).再以Au-SBA-15材料制备玻碳修饰电极,将血红蛋白固定于修饰电极上用循环伏安法考察其对不同浓度H2O2溶液的电催化反应.在固定了血红蛋白的Hb/Au-SBA-15/GC修饰电极上,H2O2在+0.95
V处出现了氧化峰,且随着H2O2浓度的增大峰电流不断增加,说明金复合介孔氧化硅材料具有良好的生物兼容性,有利于血红蛋白的固定,其修饰电极对H2O2溶液具有一定的电催化作用. 相似文献