超薄Ni(OH)2纳米片修饰Zn0.5Cd0.5S纳米颗粒作为二维/零维异质结构光催化剂可见光下光催化制氢

设计与制备高效的光解水催化剂是解决能源问题和环境问题的策略之一.硫化镉因其可在可见光引发下分解水制氢而受到广泛关注,然而光腐蚀严重,过电势高,载流子复合快速以及表面反应动力学缓慢等缺点极大地限制了其在光解水反应中的实际应用.本文采用简单液相法将均匀的Zn0.5Cd0.5S纳米颗粒锚定在超薄Ni(OH)2纳米薄片上,构建...     

Prediction of phase equilibrium behavior of quasibinary polymer solutions

A chronological review is given of typical contributions which played a role in approaching quantitative predictions of phase equilibria in binary and quasibinary polymer solutions. It describes step by step findings of the variables which govern phase separations in these systems. These variables are temperature, overall polymer concentration, and chain length distribution of the polymer mixture making up the solution. The last variable gives rise to a considerable difficulty in formulating the free energy of quasibinary solutions.     

SMP30-mediated synthesis of vitamin C activates the liver PPARα/FGF21 axis to regulate thermogenesis in mice

The vitamin-C-synthesizing enzyme senescent marker protein 30 (SMP30) is a cold resistance gene in Drosophila, and vitamin C concentration increases in brown adipose tissue post-cold exposure. However, the roles of SMP30 in thermogenesis are unknown. Here, we tested the molecular mechanism of thermogenesis using wild-type (WT) and vitamin C-deficient SMP30-knockout (KO) mice. SMP30-KO mice gained more weight than WT mice without a change in food intake in response to short-term high-fat diet feeding. Indirect calorimetry and cold-challenge experiments indicated that energy expenditure is lower in SMP30-KO mice, which is associated with decreased thermogenesis in adipose tissues. Therefore, SMP30-KO mice do not lose weight during cold exposure, whereas WT mice lose weight markedly. Mechanistically, the levels of serum FGF21 were notably lower in SMP30-KO mice, and vitamin C supplementation in SMP30-KO mice recovered FGF21 expression and thermogenesis, with a marked reduction in body weight during cold exposure. Further experiments revealed that vitamin C activates PPARα to upregulate FGF21. Our findings demonstrate that SMP30-mediated synthesis of vitamin C activates the PPARα/FGF21 axis, contributing to the maintenance of thermogenesis in mice.Subject terms: Transgenic organisms, Fat metabolism     

Ni和Mg对碳纳米管载Pt催化剂CO优先氧化催化性能的促进效应

采用共浸渍法制各了Ni和Mg促进的碳纳米管载Pt催化剂(Pt-Ni-Mg/CNT),考察了其对CO优先氧化的催化性能.结果表明,Pt-Ni和Mg在CNT表面发生了相互作用,可能存在合金纳米粒子,从而显著改善了催化剂CO优先氧化的催化性能.添加适量Ni可提高CO的转化率,而加入适量Mg则有助于改善CO2的选择性.当Pt,Ni和Mg同时负载时,优化后所得的催化剂5%Pt-5%Ni-5%Mg/CNT在100℃对富H2气体中CO选择氧化的转化率为100%,CO2的选择性为53.7%;该催化剂在140℃下连续反应24 h,催化活性稳定.