Si/C 复合材料是一种很有前途的高能量密度锂离子电池负极材料。然而,从微米/亚微米 Si 制备具有良好长循环性能(>400 次循环)的 Si/C 的报道很少。在本研究中,通过在稻壳基微米/亚微米 Si 上涂覆 N 掺杂多孔碳来制备 Si/C 复合材料;涂层是通过碳化前对硅、三聚氰胺和葡萄糖进行球磨来实现的。循环 800 次后,所得复合材料在 0.5 A/g 时的比容量为 1062.7 mAh/g。这种长周期性能在以前报道的微米/亚微米 Si 衍生的 Si/C 复合材料中是罕见的。良好的性能归因于表面 Si 与 N 掺杂多孔碳的充分覆盖。此外,微米/亚微米硅的转化过程相当简单,因为它不使用昂贵的原料、复杂的设备或复杂的合成步骤。该工艺在将微米/亚微米 Si 转化为具有良好长周期稳定性的 Si/C 复合材料方面具有工业前景。
A convenient, efficient protocol to prepare diverse spiroisoxazolino-diketopiperazines via a parallel solid-supported synthesis was developed. The key steps are (1) a coupling reaction of an amino acid; (2) tosylation with concomitant β-elimination to form an α, β-unsaturated ester; (3) a 1,3-dipolarcycloaddition with an oxime to form isoxazoline rings; and (4) cyclic cleavage to release the product
Highly Efficient Oxidative Coupling of Thiols and Oxidation of Sulfides in the Presence of MCM-41@Tryptophan-Cd and MCM-41@Tryptophan-Hg as Novel and Recoverable Nanocatalysts
stable nanocatalysts for Oxidation of sulfides to sulfoxides and oxidative coupling of thiols into their corresponding disulfides. These functionalized complexes were characterized by FT-IR spectroscopy, thermogravimetric analysis (TGA), powder X-ray diffraction (XRD) and N2 adsorption–desorption isotherms. The designed catalysts successfully oxidized a variety of sulfides and thiols with short reaction
摘要 通过将 Cd 或 Hg 配合物固定在 MCM-41 上合成了两种多相催化剂 MCM-41@Tryptophan-Cd 和 MCM-41@Tryptophan-Hg 作为新型、高效、可回收且稳定的纳米催化剂,用于硫化物氧化为亚砜和氧化反应。硫醇偶联成相应的二硫化物。这些功能化配合物通过 FT-IR 光谱、热重分析 (TGA)、粉末 X 射线衍射 (XRD) 和 N2 吸附-解吸等温线进行表征。所设计的催化剂在室温下以短反应时间以高产率成功氧化各种硫化物和硫醇,并在不显着损失其催化活性的情况下回收数次。图形摘要已提出在温和反应条件下合成固定在介孔 MCM-41 表面的 Cd 和 Hg 色氨酸复合物。在对这些催化剂进行表征后,研究了它们用于合成亚砜和二硫化物衍生物的催化活性。
Band-gap expansion of tungsten oxide quantum dots synthesized in sub-nano porous silica
The band-gap energy tuning of WO3 quantum dots was realized in the range of 2.6 eV (bulk) to 3.7 eV (sub-nano) by precise size control around one nanometer. Newly synthesized sub-nanoporous silicas act as excellent templates. In addition, single-electron reduction of oxygen under UV irradiation is now achievable with WO3.
Calcium salts of 1,5-benzodiazepine derivatives, process for producing the salts and drugs containing the same
申请人:——
公开号:US20030096809A1
公开(公告)日:2003-05-22
Provided are calcium salts of a 1,5-benzodiazepine derivative represented by the following formula (I):
1
(wherein, R
1
represents a lower alkyl group, R
2
represents a phenyl or cyclohexyl group, and Y represents a single bond or a lower alkylene group); a process for preparing the salts; and drugs containing the same as the active ingredient.
The compounds exhibit a potent inhibitory activity against the secretion of gastric acid and potent antagonism against gastrin and/or CCK-B receptor.
Stabilization of transition metals in nano-phyllosilicate phases generated by digestion of mesoporous silica is reported as an efficient route for the formation of highly dispersed metallic nanoparticles with outstanding catalytic activity.