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101.
We investigated the structure of liquid SnTe at high pressures up to 8.2 GPa by energy-dispersive x-ray diffraction. On melting at low pressures, the crystalline B1 structure changed into not B1-like but distorted-B1-like local structure. We also found that the structure changes at around 1.6-3.3 GPa. At high pressures, the bond angle and coordination number approached those for B2-based structure, but still showed clear deviations from B2-like local structure. 相似文献
102.
This contribution describes a concise synthesis to ethyl trans-[(4S)-methoxy-(2S)-pyrrolidinylmethoxy]cyclohexanecarboxylate (2b) as a key intermediate of very late antigen-4 (VLA-4) antagonist trans-4-[1-[[2,5-dichloro-4-(1-methyl-3-indolylcarboxyamide)phenyl]acetyl]-(4S)-methoxy-(2S)-pyrrolidinylmethoxy]cyclohexanecarboxylic acid (1). The synthesis employs a reductive etherification as a key reaction using (2S,4S)-1-benzyloxycarbonyl-4-methoxypyrrolidine-2-carboxyaldehyde (12) and trans-4-triethylsilyloxycyclohexanecarboxilic acid ethyl ester (13b). This synthesis provides 2b in 6 steps with 38% overall yield from commercially available starting material. 相似文献
103.
104.
Ryoichi Chiba Masaaki Izumi Yoshihiro Sugano 《Archive of Applied Mechanics (Ingenieur Archiv)》2008,78(1):61-74
Forced convection heat transfer in a non-Newtonian fluid flow inside a pipe whose external surface is subjected to non-axisymmetric
heat loads is investigated analytically. Fully developed laminar velocity distributions obtained by a power-law fluid rheology
model are used, and viscous dissipation is taken into account. The effect of axial heat conduction is considered negligible.
The physical properties are assumed to be constant. We consider that the smooth change in the velocity distribution inside
the pipe is piecewise constant. The theoretical analysis of the heat transfer is performed by using an integral transform
technique – Vodicka’s method. An important feature of this approach is that it permits an arbitrary distribution of the surrounding
medium temperature and an arbitrary velocity distribution of the fluid. This technique is verified by a comparison with the
existing results. The effects of the Brinkman number and rheological properties on the distribution of the local Nusselt number
are shown. 相似文献
105.
采用无皂乳液聚合合成的聚苯乙烯(PS)微球为模板、氨水/三乙醇胺为催化体系, 通过溶胶-凝胶方法合成了PS/TiO2(核/壳)复合微球, 然后通过煅烧制备了N掺杂、锐钛型空心TiO2微球. 在反应体系中三乙醇胺扮演双重角色, 既是TiO2生成及包覆过程的抑制剂又是空心TiO2微球的N掺杂剂. 改变氨水、三乙醇胺和钛酸正丁酯用量可控制TiO2壳的形态和尺寸. 氨水用量增加, PS/TiO2复合微球的壳表面变得粗糙|三乙醇胺用量增加, 壳表面变得光滑|钛酸正丁酯用量提高导致壳层变厚. 改变三乙醇胺用量可调节空心TiO2微球中的N掺杂量|N掺杂空心TiO2微球具有可见光响应和光催化作用. 相似文献
106.
Summary A set of hydrophilicity parameters in a normal-phase liquid chromatography of peptides is presented in order to clarify the
contribution of individual amino acid residues to peptide retention and to predict retention times. The retention of 100 peptides
was studied using normal-phase liquid chromatography on amide, diol and silica columns. An acetonitrile-water mixed solution
containing 0.2% trifluoroacetic acid +0.2% triethylamine was used as the mobile phase in a linear gradient elution system.
The contribution of each residue upon retention was calculated by linear multiple regression analysis. This paper described
the contribution values as “hydrophilicity retention coefficients”. Using these hydrophilicity retention coefficients, retention
times could be predicted for peptides of known amino acid content and sequence. A set of hydrophilicity retention coefficients
on each column was successfully explained by contributions to the degree of retention. 相似文献
107.
Yazhou SUN Yixuan ZHAO Shuya JIN Shitao WANG Zhiyu SUN Xueheng ZHANG Duo YAN Shuwen TANG Peng MA Yuhong YU Ke YUE Limin DUAN Herun YANG Chengui LU Fang FANG Hong SU 《原子核物理评论》2020,37(3):742-748
开发了HIRFL-CSR外靶实验装置的大型数据分析程序(ANAETF),并成功应用于核物理实验数据分析。详细阐述了该程序中的数据分析流程、漂移室寻迹算法、粒子鉴别方法和反应截面提取技术。利用本程序分析了240 MeV/u能量下12C次级束流打碳靶的实验数据,实现了清楚的碳和硼剩余核的粒子鉴别,总探测效率达到 ~90%,本工作提取的反应截面与已有的实验结果符合较好。 相似文献
108.
The discovery that supporting electrolytes can be effectively confined in typical organic solvents in a c-Hex-based multiphase electrolyte solution has led to the development of a novel heterogeneous continuous flow synthetic system. PTFE fiber functions as a separation filter that can efficiently isolate the c-Hex phase from multiphase electrolyte solutions. This system has demonstrated both electrochemical solvating and carbon-carbon bond forming reactions. Hydrophobic substrates can be introduced into the reactor as c-Hex solutions, which are then electrochemically transformed into the target hydrophobic products that pass through the PTFE fiber as c-Hex solutions. 相似文献
109.
Bin Wang Derek Yiren Ong Yihang Li Jia Hao Pang Kohei Watanabe Ryo Takita Shunsuke Chiba 《Chemical science》2020,11(20):5267
A concise protocol for anti-hydromagnesiation of aryl alkynes was established using 1 : 1 molar combination of sodium hydride (NaH) and magnesium iodide (MgI2) without the aid of any transition metal catalysts. The resulting alkenylmagnesium intermediates could be trapped with a series of electrophiles, thus providing facile accesses to stereochemically well-defined functionalized alkenes. Mechanistic studies by experimental and theoretical approaches imply that polar hydride addition from magnesium hydride (MgH2) is responsible for the process. Anti-hydromagnesiation of aryl alkynes was facilitated solely by magnesium hydride. The resulting alkenylmagnesium intermediates were functionalized with various electrophiles to afford stereochemically defined tri-substituted alkenes. 相似文献
110.
Cheng Conghui Xie Jingxi Zhu Qiqi Chen Luyao Guo Kexin Li Shanshan He Shuya Xiao Fangzhu 《Journal of Radioanalytical and Nuclear Chemistry》2021,330(3):1075-1090
Journal of Radioanalytical and Nuclear Chemistry - Deinococcus radiodurans (DR) is highly resistant to ionizing radiation. This study aims to convert dsrA gene into DR to construct... 相似文献