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991.
Huang Y Triscari JM Pasa-Tolic L Anderson GA Lipton MS Smith RD Wysocki VH 《Journal of the American Chemical Society》2004,126(10):3034-3035
Analysis of fragmentation patterns from 5654 unique doubly charged tryptic peptides is obtained. Great variability of average relative abundance of bond cleavage is found between different amino acid combinations. There exist similarities as well as differences between b and y ions. Strong enhancement or suppression of cleavage gives insight into possible chemical interactions at reactive conformations formed by preferred phi-psi angles. 相似文献
992.
Muzikar J Mechref Y Huang Y Novotny MV 《Rapid communications in mass spectrometry : RCM》2004,18(13):1513-1518
Post-source decay (PSD) fragmentation of chemically or enzymatically produced aminoglycans has been evaluated through matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry. Conversion of native glycans to their respective aminoglycan derivatives improved detection sensitivity of the usual fragments and promoted cross-ring fragmentation of linear oligosaccharides, facilitating linkage recognition. The cross-ring fragmentations for both dextrin and dextran oligosaccharides were not limited to the reducing-end glucose moiety, as they were extended throughout the entire molecule. When the amino group was generated for N-glycans derived from three different glycoproteins, an enhancement of PSD was observed, without a significant extent of cross-ring fragmentation. 相似文献
993.
Guihua Huang Yipeng Huang Wei Xu Qiuhong Yao Xiaofang Liu Caifeng Ding Xi Chen 《中国化学快报》2019,30(5):1021-1023
Using cesium lead halide perovskite nanocrystals, CsPb(Cl/Br)_3, as a light absorber, we report a highly effective UV and blue light blocking film. The CsPb(Cl/Br)_3 nanocrystals are well dispersed in the ethyl cellulose(EC) matrix to compose a UV and blue light shielding film, and the absorption edge of the film is tunable by adjusting Cl to Br ratio using anion exchange. The CsPbCl_2 Br-EC film exhibits a transmittance of 5% at 459 nm, 90% at 478 nm and 95% in the range of 500–800 nm, which makes it excellent for UV and blue light shielding. In addition, the as-prepared EC-CsPb(Cl/Br)_3 film shows excellent photostability under UV irradiation. Results demonstrate that this EC-CsPb(Cl/Br)_3 based materials with sharp absorbance edges, tunable blocking wavelength, and high photostability can be useful for the applications in UV and blue light blocking and optical filters 相似文献
994.
995.
顶空固相微萃取-气相色谱-质谱法测定废水中痕量挥发性烷基硫化物 总被引:3,自引:0,他引:3
建立了顶空固相微萃取(HS-SPME)和气相色谱/质谱(GC/MS)联用测定人工湿地废水中的痕量挥发性烷基硫化物的方法。针对废水中两种主要的挥发性烷基硫化物(二甲基硫、二甲基二硫),详细研究了萃取纤维头的种类、萃取时间、萃取温度、pH值、离子强度、样品量及解析条件对HS-SPME的影响。载气为高纯氦气,流速为1.0mL/min,色谱柱为DB-5ms毛细管柱(0.25μm,30m×0.32mm),柱温:25℃(5min)■40℃(1min)■60℃(5min);在优化的实验条件下,本法测定二甲基硫及二甲基二硫的线性范围分别为10~10000ng/L和1~10000ng/L;检出限(3σ)分别为1.9ng/L和1.8ng/L;相对标准偏差小于10%;回收率分别为81.0%~94.6%和84.0%~100.9%。用二乙基硫为内标物质,将本法用于人工湿地废水中主要的烷基硫化物二甲基硫和二甲基二硫的测定,获得满意结果。 相似文献
996.
采用共价接枝法, 以氨丙基-三乙氧基硅烷为氨源, 制备了一系列的NH2-SBA-15催化剂, 通过微量吸附量热技术定量地分析了该催化剂表面碱性中心的强度、数量和分布状态. 实验结果表明, SBA-15在 550 ℃焙烧6 h, 氨基硅源与SBA-15质量比为1.5, 是合成NH2-SBA-15催化剂最适宜的条件. 运用微量吸附量热技术实现了对NH2-SBA-15催化剂合成条件的优化. 相似文献
997.
The electroanalytical chemical properties of buspirone are reported in this paper. A sensitive single sweep voltammetric procedure for trace buspirone determination was developed. The detection limit is 5.0 x 10(-9)M. The method has been applied to the determination of buspirone in blood serum by simple dilution in a buffer. 相似文献
998.
999.
A new molecular model for 1,1,1,2,3,3,3-heptafluoropropane (R227ea) was developed on the basis of quantum chemical calculations and optimized using experimental vapor pressure and bubble density data. In combination with an existing model for ethanol, a molecular model for the binary mixture R227ea + ethanol was defined, using the Lorentz–Berthelot combining rule. It was validated at 283.17 K, where, considering the statistical uncertainties, it agrees to the experimental vapor pressure. The vapor–liquid equilibrium, comprising both bubble line and dew line data, was predicted at 343.13 K by molecular simulation. The Peng–Robinson equation of state fails for this system. 相似文献
1000.
Mingzhong Cai Yizheng Huang Rongli Zhang 《Journal of organometallic chemistry》2004,689(15):2436-2440
A silica-supported poly-γ-diphenylarsinopropylsiloxane palladium(0) complex has been prepared from γ-chloropropyltriethoxysilane via immobilization on fumed silica, followed by reacting with potassium diphenylarsenide and palladium chloride, and then the reduction with hydrazine hydrate. The palladium(0) complex has been found to catalyze the allylation of aldehydes via the formation of π-allylpalladium complexes, using allylic chlorides as allylating agent and SnCl2 as reducing agent. This polymeric palladium complex can be recovered and reused. 相似文献