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191.
Zhang C Shephard NE Rhodes SM Chen Z 《Langmuir : the ACS journal of surfaces and colloids》2012,28(14):6052-6059
Sum frequency generation (SFG) vibrational spectroscopy was used to study the effect of silane headgroups on the molecular interactions that occur between poly(ethylene terephthalate) (PET) and various epoxy silanes at the PET/silane and PET/silicone interfaces. Three different silanes were investigated: (3-glycidoxypropyl) trimethoxysilane (γ-GPS), (3-glycidoxypropyl) methyl-dimethoxysilane (γ-GPMS), and (3-glycidoxypropyl) dimethyl-methoxysilane (γ-GPDMS). These silanes share the same backbone and epoxy end group but have different headgroups. SFG was used to examine the interfaces between PET and each of these silanes, as well as silanes mixed with methylvinylsiloxanol (MVS). We also examined the interfaces between PET and uncured or cured silicone with silanes or silane-MVS mixtures. Silanes with different headgroups were found to exhibit a variety of methoxy group interfacial segregation and ordering behaviors at various interfaces. The effect of MVS was also dependent upon silane headgroup choice, and the interfacial molecular structures of silane methoxy headgroups were found to differ at PET/silane and PET/silicone interfaces. Epoxy silanes have been widely used as adhesion promoters for polymer adhesives; therefore, the molecular structures probed using SFG were correlated to adhesion testing results to understand the molecular mechanisms of silicone-polymer adhesion. Our results demonstrated that silane methoxy headgroups play important roles in adhesion at the PET/silicone interfaces. The presence of MVS can change interfacial methoxy segregation and ordering, leading to different adhesion strengths. 相似文献
192.
Wang J Wang X Li Y Yan S Zhou Q Gao B Peng J DU J Fu Q Jia S Zhang J Zhan L 《Analytical sciences》2012,28(3):237-241
In the present study, we aimed to develop a nucleic acid lateral-flow method for the rapid and sensitive detection of multiple bacteria that contaminate platelet concentrations (PCs). Polymerase chain reaction (PCR) amplicons were produced by a set of board-range primers that recognize the conserved region of bacteria 16S rDNA, followed by hybridization with both an FITC (fluorescein isothiocyanate)-labelled probe and biotin-labelled probe, and then a nucleic acid lateral-flow dipstick (LFD) assay. The LFD accurately identified 7 species of bacteria, but had no cross-reactivity with human genomic DNA. The limit of detection (LOD) of the LFD assay was as low as 10(1) copies/μL of 16S rDNA for plasmid. In the case of spiked PCs without enrichment, the detection limit of LFD for K. pneumonia was 5 CFU/mL, 6.5 × 10(4) CFU/mL for the S. epidermidis and 35 CFU/mL for P. aeruginosa. 相似文献
193.
Cationic polymers and aptamers mediated aggregation of gold nanoparticles for the colorimetric detection of arsenic(III) in aqueous solution 总被引:4,自引:0,他引:4
Wu Y Zhan S Wang F He L Zhi W Zhou P 《Chemical communications (Cambridge, England)》2012,48(37):4459-4461
As(III) specifically interacts with an arsenic-binding aptamer to form an As(III)-aptamer complex, so that the following cationic polymer can aggregate gold nanoparticles (AuNPs) and cause a remarkable change in color, which enables the colorimetric detection of As(III) with high selectivity and a detection limit of 5.3 ppb. 相似文献
194.
Ge‐Fei Hao Sheng‐Gang Yang Guang‐Fu Yang Chang‐Guo Zhan 《Journal of computational chemistry》2013,34(24):2055-2064
Gibberellins (GAs) are phytohormones essential for many developmental processes in plants. In this work, fundamental mechanism of hormone perception by receptor GID1 has been studied by performing computational simulations, revealing a new GA‐binding channel of GID1 and a novel hormone perception mechanism involving only one conformational state of GID1. The novel hormone perception mechanism demonstrated here is remarkably different from the previously proposed/speculated mechanism [Murase et al., Nature 2008 , 456, 459] involving two conformational states (“OPEN” and “CLOSED”) of GID1. According to the new perception mechanism, GA acts as a “conformational stabilizer,” rather than the previously speculated “allosteric inducer,” to induce the recognition of protein DELLA by GID1. The novel mechanistic insights obtained in this study provide a new starting point for further studies on the detailed molecular mechanisms of GID1 interacting with DELLA and various hormones and for mechanism‐based rational design of novel, potent growth regulators that target crops and ornamental plants. © 2013 Wiley Periodicals, Inc. 相似文献
195.
The BiCl3‐catalyzed reaction of pyrroles with electron‐deficient olefins generated the corresponding Michael adducts in high yields. 相似文献
196.
Da Yan He Zhan Jiang Li Zhong Jun Li Yun Qi Liu Dong Xu Qiu Meng Shen Cai 《合成通讯》2013,43(18):2653-2658
Cabohydrates reacting with acetone in the presence of molecular sieve and p—toluene sulfonic acid provided a simple, convenient, high yield and good selective process for preparation of isopropylidene carbohydrates. 相似文献
197.
利用密度泛函理论研究了气体分子(NH3, H2O, H2S, NO2)吸附在二维M3(HIB)2(M=Ni, Cu; HIB为六亚氨基苯)薄膜上体系的几何结构和电子结构的变化. 结果表明, 2种薄膜对气体分子的响应不同. 其中NH3, H2O和H2S在M3(HIB)2薄膜表面的吸附较弱, 主要与薄膜的亚氨基形成氢键, 吸附能均小于-0.36 eV, 吸附对体系电子性质的影响很小. 但是 NO2分子在薄膜表面形成化学吸附, 吸附能在-0.65~-1.72 eV范围内. 吸附NO2分子使其电子结构发生明显改变, 如Cu3(HIB)2在费米能级处打开带隙, 由金属性质转变为半导体性质. 这是由于NO2分子的pz轨道与金属原子$d_{z}^{2}$ 轨道发生了强烈的轨道杂化. 此外, 研究发现高浓度的NO2分子吸附能够使Ni3(HIB)2薄膜由非磁性变为磁性体系, 由普通金属性质变为半金属性质; 而高浓度的NO2分子使Cu3(HIB)2薄膜由金属性质变为半导体性质, 薄膜电导率降低. 相似文献
198.
A novel ZnCo2O4/Bi2O3 heterojunction photocatalyst was prepared via balling method. The enhanced photocatalytic activity is mainly attributed to the broad photoabsorption and low recombination rate of photogenerated electron-hole pairs, which is driven by the photogenerated potential difference formed at the ZnCo2O4/Bi2O3 heterojunction interface. 相似文献
199.
测量了高氯酸钦(Ⅲ)和双(苯基亚砜)丙烷、双(苯基亚砜)丁烷配合物的溶液(甲醇-氯仿,二甲基甲酰胺)的电子光谱,计算了f-f跃迁的振子强度和强度参数,并讨论了“超灵敏”跃迁的强度和强度多数与配体性质的关系和溶剂的影响。 相似文献
200.