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91.
Takahiro Nakae Ryuji Ohnishi Yoshiharu Kitahata Tatsuya Soukawa Hisako Sato Shigeki Mori Tetsuo Okujima Hidemitsu Uno Hiroshi Sakaguchi 《Tetrahedron letters》2012,53(13):1617-1619
6,13-Diiododibenzo[a,h]anthracene and 5,8-diiodopicene were synthesized by AuCl-catalyzed double cyclization. The highly selective reaction yielded a new class of peri-halogenated fused aromatics. 相似文献
92.
93.
Shigeki Habaue Soichiro Murakami Hideyuki Higashimura 《Journal of polymer science. Part A, Polymer chemistry》2005,43(23):5872-5878
Novel oxovanadium(IV)–bisoxazoline catalysts, such as vanadyl sulfate (VOSO4)–(R)‐2,2′‐isopropylidenebis(4‐phenyl‐2‐oxazoline) [(R)Phbox], for the asymmetric oxidative coupling polymerization (AOCP) of 2,3‐dihydroxynaphthalene were developed. For example, the AOCP with VOSO4–(R)Phbox in CH2Cl2–MeOH [7/1 (v/v)] at room temperature for 24 h under an O2 atmosphere, followed by acetylation of the hydroxyl groups, afforded a polymer in a 58% yield with a specific rotation of [α]D = ?147. The enantioselectivity during the polymerization was estimated to be 80% enantiomeric excess (S), a value much higher than that observed for the polymerizations with the copper(I)‐based catalyst systems and the typical oxovanadium(IV) catalysts reported for the asymmetric oxidative coupling producing the 1,1′‐bi‐2‐naphthol derivatives. © 2005 Wiley Periodicals, Inc., Inc. J Polym Sci Part A: Polym Chem 43: 5872–5878, 2005 相似文献
94.
Silicon dioxide (SiO2) layers with a thickness more than 10 nm can be formed at ∼120 °C by direct Si oxidation with nitric acid (HNO3). Si is initially immersed in 40 wt.% HNO3 at the boiling temperature of 108 °C, which forms a ∼1 nm SiO2 layer, and the immersion is continued after reaching the azeotropic point (i.e., 68 wt.% HNO3 at 121 °C), resulting in an increase in the SiO2 thickness. The nitric acid oxidation rates are the same for (1 1 1) and (1 0 0) orientations, and n-type and p-type Si wafers. The oxidation rate is constant at least up to 15 nm SiO2 thickness (i.e., 1.5 nm/h for single crystalline Si and 3.4 nm/h for polycrystalline Si (poly-Si)), indicating that the interfacial reaction is the rate-determining step. SiO2 layers with a uniform thickness are formed even on a rough surface of poly-Si thin film. 相似文献
95.
Discrimination Between 8‐Oxo‐2′‐Deoxyguanosine and 2′‐Deoxyguanosine in DNA by the Single Nucleotide Primer Extension Reaction with Adap Triphosphate 下载免费PDF全文
Dr. Yosuke Taniguchi Yoshiya Kikukawa Prof. Dr. Shigeki Sasaki 《Angewandte Chemie (International ed. in English)》2015,54(17):5147-5151
The adenosine derivative of 2‐oxo‐1,3‐diazaphenoxazine (Adap) exhibits a superb ability to recognize and form base pairs with 8‐oxo‐2′‐deoxyguanosine (8‐oxo‐dG) in duplex DNA. In this study, the triphosphate of Adap (dAdapTP) was synthesized and tested for single nucleotide incorporation into primer strands using the Klenow Fragment. The efficiency of dAdapTP incorporation into 8‐oxo‐dG‐containing templates was more than 36‐fold higher than with dG‐containing templates, and provides better discrimination than does the incorporation of natural 2′‐deoxyadenosine triphosphate (dATP). The selective incorporation of dAdapTP into 8‐oxo‐dG templates was therefore applied to the detection of 8‐oxo‐dG in human telomeric DNA sequences extracted from H2O2‐treated HeLa cells. The enzymatic incorporation of dAdapTP into 8‐oxo‐dG‐containing templates may provide a novel basis for sequencing oxidative DNA damage in the genome. 相似文献
96.
Effect of Acid Treatment of Montmorillonite on “Support‐Activator” Performance to Support Metallocene for Propylene Polymerization Catalyst 下载免费PDF全文
Takao Tayano Hideshi Uchino Takehiro Sagae Katsuyuki Yokomizo Koji Nakayama Shigeki Ohta Hiroshi Nakano Masahide Murata 《大分子反应工程》2017,11(2)
This work is focused on montmorillonite (MMT)‐based “support‐activators” (S‐As) for the metallocene‐catalyzed propylene polymerization. This catalyst was previously industrialized; however, for further technological advances, the activation mechanism is investigated. The chemical and morphological requirements of the S‐A are surveyed using both commercially available raw clay minerals (non‐acid‐treated) and acid‐treated clay minerals. The S‐A possessing strong‐acid sites (pK a < ?8.2) gives a highly active catalyst. Acid treatment of MMT induces morphological changes as well as the formation of strong acid sites. Based on pore size distribution analysis and atomic force microscopy observations, it is concluded that the strong acid sites are located in the small pores around the edge of the clay mineral (not in the interlayer), where the structure is disordered by the acid treatment.
97.
98.
Genki Odahara Shigeki Otani Chuhei Oshima Masahiko Suzuki Tsuneo Yasue Takanori Koshikawa 《Surface and interface analysis : SIA》2011,43(12):1491-1493
We observed in situ growth of a single graphene sheet on Ni(111) by low‐energy electron microscopy. The sheet was grown epitaxially beyond the steps on the substrate. The crystalline shapes of graphene islands were clearly seen; the straight edges of the island are crossed at either 60 or 120°, and the linear edges shifted perpendicular to the edge keeping the equilibrium shape. Graphene islands were united to form a single sheet without any grain boundaries and any wrinkles. The Ni substrate of several centimeters in size was covered with a single‐domain graphene sheet. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
99.
This Minireview provides an overview of the chemistry of pyrazole and N‐heterocyclic carbene (NHC) complexes bearing an NH group at the β‐position to the metal. The synthesis and structures as well as the Brønsted acidic nature of the β‐NH group are described in detail. These complexes are attractive candidates for novel metal–ligand cooperative bifunctional catalysts, which would benefit highly effective molecular and energy transformations. 相似文献
100.
应用电化学法聚合酚藏花红(PPS)功能化的单壁碳纳米管,以其作为烟酰胺辅酶(NADH)氧化的电化学催化剂(电极),构建基于乙醇脱氢酶的安培型乙醇生物电化学传感器.该电极于0.0 V时,对NADH具有很好的催化性能.而单体酚藏花红则由于其电位过低(-0.48 V),不能显示催化性能.循环伏安和计时安培法测试表明:该传感器... 相似文献