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631.
The radical polymerization of maleic anhydride(MA),styrene(ST)with the vinyl groups introduced onto the surface of the nano-sized silica via solution polymerization method was developed.The methacryloxypropyl nano-sized silica(MPNS)was used as macromonomer and polymerized with maleic anhydride and styrene by initiating with BPO in toluene.The structure and properties of MPNS/SMA nano-composite were characterized by FT-IR spectra and TEM.Meanwhile,it was applied as tanning agent compared with the traditional styrene-maleic anhydride copolymer in leather.It was found that the applied leather had better quality characteristics with the addition of the nano-sized silica.  相似文献   
632.
In this paper,aliphatic amidediol was synthesized and mixed with glycerol used as a plasticizer for preparing thermoplastic starch(AGPTPS).The yield of aliphatic amidediol was 91%.FF-IR expressed that the mixture of aliphatic amidediol and glycerol formed stronger and stable hydrogen bond with starch molecules compared to the native cornstarch.By scanning electron microscope(SEM)native cornstarch granules were proved to transfer to a homogeneous continuous system.After being stored for a period time at room temperature,the mechanical properties of AGPTPS were also studied.As a mixed plasticizer,aliphatic amidediol and glycerol would be practical to extend TPS application scopes.  相似文献   
633.
Synthesis and cytotoxic activity of novel curcumin analogues   总被引:3,自引:0,他引:3  
Five novel curcumin analogues bearing different substituents at 4-position of phenyl group were synthesized. Their structures were confirmed by NMR and HRMS spectrum. Their cytotoxic activities against six tumor cell lines were tested by the standard MTT assay in vitro. The results indicated that four analogues (1A-1C, 1E) with solubilizing moieties showed selective potent cytotoxicity against HepG2, HeLa and CT26 cell lines, and analogue 1A and 1C exhibited more potent cytotoxicity than curcumin against CT26 cell line. It was suggested that introduction of appropriate substituents to 4-position of phenyl group might be a potential option for structural modification of curcumin.  相似文献   
634.
Novel chiral tetralin compounds were designed and synthesized, and their antifungal activities in vitro were tested. The results showed that all of target compounds had potent antifungal activities, and were stronger than that of control compounds tetrahydroisoquinolines. The binding model of lead molecules in the active site of CYP51 of Candida albicans showed that lead compound specifically interacted with the amino acids residues in the active site, without binding with the heme of CYP51, which was different from azole antifungal drugs. The present study might afford a novel lead molecule to develop non-azole CYP51 inhihitars of fungi.  相似文献   
635.
By the addition of rice wine koji,enhancement of the reactivity was observed for the baker's yeast reduction ofβ-keto esters into (S)-β-hydroxy esters with high enantiomeric purity (73-98%).  相似文献   
636.
Two species of N-arylpyrazoles containing active amino group were synthesized.And formylations of N-arylpyazoles containing amino in different position of pyrazole rings using Vilsmeier-Haack reaction gave a series of useful pyrazole intermediates.The important features of this protocol were cheap materials,easy process,mild reaction conditions and good yield of products.  相似文献   
637.
Synthesis of Cubic Mesoporous Silica MCM-48by Mixed Micellar Templates   总被引:2,自引:0,他引:2  
In 1992, Mobil researchers introduced a novel concept in the synthesis of mesoporous silicas (M41S)1,2 by using a self-assembled molecular array of surfactant molecules as structure-directing template. Depending on the shape of their templates and the respective resulting pore structure, the M41S family was identified : MCM-41(hexagonal), MCM-48(cubic), and other species. MCM-41 with honeycomb arrays of nonintersecting channels was shown to be the easiest to synthesize1. MCM-48 containin…  相似文献   
638.
The research of electrocatalytic oxidation of small organic molecules such as methanol, formaldehyde and formic acid has been fascinating electrochemists for more than thirty years, owing to its significance in energy conversion and reaction mechanisms. The surface adsorbed species involved in these electrocatalytic reactions, especially reactive and poisoning intermediates, have been investigated by electrochemical, spectroscopic and other physicochemical methods1. However, Raman spectrosco…  相似文献   
639.
张凤  方维海  罗毅  刘若庄 《中国科学B辑》2009,39(11):1430-1436
推导了通用的坐标空间多维蒙特卡罗微正则非绝热速率计算公式,并应用于计算异氰酸基5(S0)到第一激发三态(T1)的系间窜跃(ISC)速率.在CCSD水平上构建了一,二,三维势能面用于蒙特卡罗抽样.计算所得S0→T1 ISC速率与实验符合较好,因此可以预期多维蒙特卡罗微正则非绝热速率理论将成为计算多原子分子非绝热反应速率的有效手段之一.  相似文献   
640.
使用密度泛函理论B3LYP方法和二阶微扰理论MP2方法对由1-甲基尿嘧啶与N-甲基乙酰胺所形成的氢键复合物中的氢键强度进行了理论研究, 探讨了不同取代基取代氢键受体分子1-甲基尿嘧啶中的氢原子对氢键强度的影响和氢键的协同性. 研究表明: 供电子取代基使N-H…O=C氢键键长r(H…O)缩短, 氢键强度增强; 吸电子取代基使N-H…O=C氢键键长r(H…O)伸长, 氢键强度减弱. 自然键轨道(NBO)分析表明: 供电子基团使参与形成氢键的氢原子的正电荷增加, 使氧原子的负电荷增加, 使质子供体和受体分子间的电荷转移量增多; 吸电子基团则相反. 供电子基团使N-H…O=C氢键中氧原子的孤对电子轨道n(O)对N-H的反键轨道σ*(N-H)的二阶相互作用稳定化能增强, 吸电子基团使这种二阶相互作用稳定化能减弱. 取代基对与其相近的N-H…O=C氢键影响更大.  相似文献   
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