氧化钨（WO3）薄膜光电催化性能的改善及应用

半导体WO₃具有较小的禁带宽度和良好的稳定性，对可见光具有较强的吸收，在光催化和光电催化领域具有广泛的用途。然而，单一WO₃薄膜仍然存在着光生电子-空穴复合率高、光电催化活性与能量转换效率偏低等问题。本文从WO₃薄膜光电催化性能的改善及应用两个方面对近年来的研究进行了综述。在WO₃薄膜光电催化性能的改善方面，分别从有序纳米结构的构建、离子掺杂与表面修饰进行总结。同时，也归纳总结了WO₃薄膜作为光电极在分解水制氢、光电催化还原CO₂和降解有机污染物等方面的应用，并提出了WO₃薄膜在光电催化过程中存在的问题，指出WO₃有序纳米异质结的构建是提高WO₃薄膜光电催化活性的有效方法。WO₃薄膜光电极的规模制备、廉价助催化剂的使用、光电极的稳定性与耐蚀性是其实际应用过程中需要解决的问题。     

内蒙古某排岩矿铁资源回收试验

内蒙古某矿堆置在排土场的排岩矿总量巨大，由于其铁元素含量较低，长期以来未能得到有效利用，不仅占用了大量的土地，还造成了严重的资源浪费。为有效回收利用排岩矿中的铁资源，该排岩矿通过采用破碎—干选—磨矿—弱磁选工艺最终得到了全铁品位62%以上的铁精矿，有效回收了排岩矿中的铁资源，经济效益和社会效益显著。     

Contamination of some foodstuffs marketed in Italy by fatty acid esters of monochloropropanediols and glycidol

ABSTRACT

Fatty acid esters of 3-monochloropropanediol (3-MCPD), 2-MCPD and glycidol (Gly) are food-processing contaminants that cause concerns about possible adverse health effects. The present study evaluates the contamination levels of the three ester classes in 130 samples of foodstuffs marketed in Italy covering 10 food categories, namely margarines, oils, roasted coffee, breakfast cereals, salted crackers, cookies, infant biscuits, rusks, breads and potato crisps. The analytical method employed is a so-called indirect method that entails MCPD/glycidol cleavage from their esterified forms, cleanup, derivatisation and GC-MS analysis. The MCPDs and glycidol concentrations (from esters) were found to be equal or a little higher than the levels reported in previous studies conducted in other European countries and described in the literature. 3-MCPD was the predominant compound in all foodstuffs analysed with the exception for rusks where Gly levels were slightly higher. Considering the sum of MCPD and Gly esters, the most contaminated foodstuffs were seed oils, followed by margarines and cookies, whereas roasted coffee, bread, rusks, cornflakes and infant biscuits were less contaminated with MCPDs and Gly concentrations often below LOQ or LOD values. Refined olive oil, potato chips and salted crackers showed contamination levels intermediate between the two above groups. The results of this study also confirm that the use of palm oil as an ingredient or frying medium is an important cause of increase of the levels of MCPD and Gly esters, especially in salted crackers, rusks and potato crisps. Finally, the Italian intake of 3-MCPD due to the various foods analysed has been calculated and related to TDI. The MoE for Gly was also estimated.     

A Dual Inhibitor of DYRK1A and GSK3β for β-Cell Proliferation: Aminopyrazine Derivative GNF4877

Loss of β-cell mass and function can lead to insufficient insulin levels and ultimately to hyperglycemia and diabetes mellitus. The mainstream treatment approach involves regulation of insulin levels; however, approaches intended to increase β-cell mass are less developed. Promoting β-cell proliferation with low-molecular-weight inhibitors of dual-specificity tyrosine-regulated kinase 1A (DYRK1A) offers the potential to treat diabetes with oral therapies by restoring β-cell mass, insulin content and glycemic control. GNF4877, a potent dual inhibitor of DYRK1A and glycogen synthase kinase 3β (GSK3β) was previously reported to induce primary human β-cell proliferation in vitro and in vivo. Herein, we describe the lead optimization that lead to the identification of GNF4877 from an aminopyrazine hit identified in a phenotypic high-throughput screening campaign measuring β-cell proliferation.     

The Critical Role of Passive Permeability in Designing Successful Drugs

Passive permeability is a key property in drug disposition and delivery. It is critical for gastrointestinal absorption, brain penetration, renal reabsorption, defining clearance mechanisms and drug-drug interactions. Passive diffusion rate is translatable across tissues and animal species, while the extent of absorption is dependent on drug properties, as well as in vivo physiology/pathophysiology. Design principles have been developed to guide medicinal chemistry to enhance absorption, which combine the balance of aqueous solubility, permeability and the sometimes unfavorable compound characteristic demanded by the target. Permeability assays have been implemented that enable rapid development of structure-permeability relationships for absorption improvement. Future advances in assay development to reduce nonspecific binding and improve mass balance will enable more accurately measurement of passive permeability. Design principles that integrate potency, selectivity, passive permeability and other ADMET properties facilitate rapid advancement of successful drug candidates to patients.     

预压力对压电驱动履带移动系统的性能影响

为了提高夹心式压电驱动移动系统的机械输出性能，提出了一种U型预压力调节机构，并开展了预压力对夹心式压电驱动履带移动系统输出性能影响关系的实验研究。首先，针对U型预压力调节机构的安装对夹心式压电振子的振动特性影响关系开展了有限元仿真分析，发现U型预压力调节机构始终处在夹心式压电振子的两相工作模态振动节点位置；其次，开展了夹心式压电驱动履带移动系统的原理样机的预压力调节测试实验，确定了系统的最大输出牵引力及其所对应的最佳预压力；最后，在最佳预压力工作状态下，开展了原理样机的牵引力特性、越障性能以及模拟月壤环境下的运动特性实验。研究结果表明，在最佳预压力工作状态下，夹心式压电驱动履带移动系统的机械输出性能最佳，为其进一步在月面巡视器上的应用提供了技术支持和试验基础。     

基于流固耦合的柱面气膜密封支撑结构性能研究

利用流固耦合分析方法,研究一种波箔结构柔性支撑柱面气膜密封,探讨气膜厚度、浮环与转子的偏心率以及柔性支撑结构的泊松比、弹性模量、波箔数量等参数对支撑结构等效应力及变形量的影响。结果表明:柔性支承结构满足柱面气膜密封的正常运作,不会造成因为气膜刚度过大而使得浮环与波箔发生破坏性变形,并且变形量远小于波箔高度;柔性支撑的等效应力和变形量随平均气膜厚度的增大而减小,随偏心率的增加而增大,随支撑材料泊松比的增大而增大;弹性模量的增加并不影响柔性支撑结构的等效应力,但是会使变形量减小;增加波箔数量,柔性支撑的等效应力略有减小,变形量显著减小。     

污水处理中小球藻的自絮凝特性

以BG11(+N)培养基和模拟生活污水为底物,考察了污水处理小球藻(Chlorella vulgaris)的自絮凝特性,探究了自絮凝机理。结果表明:以短沉淀时间运行,小球藻在模拟生活污水中自然形成絮体,沉降性良好;藻细胞表面粗糙,含有丝状、胶状胞外聚合物;絮体内部含有大量短杆菌、球菌;絮体具有相对较高的Na、P、Fe、Ca、Mg元素含量,无机物中主要物质形态为Ca4O(PO4)2。污水处理小球藻的絮凝机理为:基质条件及反应器运行参数等促使藻细胞生理过程发生改变,藻细胞分泌更多絮凝性胞外聚合物增强黏附,生化过程富集P、Fe、Ca、Mg元素改善沉降性,絮凝性细菌大量繁殖促进菌藻共絮凝。     

垂直轴风力机两种翼型气动性能比较研究

叶片是风力机最重要的组成部分,在不同的风能资源情况下,翼型的选择对垂直轴风力机气动特性有着重要的影响。文章分别以NACA0018翼型(对称翼型)和NACA4418翼型(非对称翼型)建立3叶片H型垂直轴风力机二维仿真模型。应用数值模拟的研究方法,从功率系数、单个叶片切向力系数等方面比较两种风力机模型在不同叶尖速比下的气动特性,并采用风洞实验数据验证了流场计算的准确性。CFD计算结果表明:在低叶尖速比下,NACA4418翼型风力机气动特性优于NACA0018翼型风力机,适用于低风速区域;在高叶尖速比下,NACA0018翼型风力机气动特性较好,适用于高风速地区。而且在高叶尖速比时,NACA0018翼型在上风区时,切向力系数平均值要高于NACA4418翼型,在下风区时,NACA418翼型切向力系数平均值高。该研究可为小型垂直轴风力机翼型的选择提供参考。     

打印层厚度对FDM薄板固有特性的影响

针对不同打印层厚度对熔融沉积成型(fused deposition modeling,简称FDM)薄板固有特性的影响规律及相应的机理进行了研究。首先,以悬臂边界条件下的FDM薄板为研究对象,创建了固有特性理论模型;其次,完成了薄板样件的制备,同时搭建了样件的动力学测试系统,实验研究了样件的固有特性参数;最后,对比分析理论与实验结果,以验证理论模型的正确性。研究结果表明,所建模型可以准确预测FDM薄板结构的固有特征参数;打印层越厚,样件的固有频率越高,但其模态振型不会随着打印层厚度的变化而变化。该研究为提高FDM产品动力学性能提供了理论基础和技术支持。