CO2在p—SiC膜电极上的光电化学还原

近年来,CO_2的光电化学还原引起人们极大的兴趣,已有利用SiC粉末进行CO_2光催化还原的报道。本研究首次利用p-SiC膜光阴极还原CO_2,得到较高的CH_3OH产率。1 实验 在导电玻璃上采用水银光敏化CVD法制得微晶p-SiC膜,电极表面用4.6％HF溶液抛     

高温催化燃烧技术及其核催化剂的研制

高温催化燃烧技术作为一项环境友好的能源利用方式下得到世界各国的广泛重视,催化燃烧器设计与燃烧催华化剂研制领域不断取得新进展。本文通过考察负载型Pd催化剂和烧绿石型复氧化物催化剂的物化学特性与催化反应动力学特征,探讨了改良现有催化剂体系反应性能的有效途径。     

Heterogeneous reactions on the surface of fine particles in the atmosphere

Fine particles play an important role in the atmosphere. Research on heterogeneous reactions on the surface of fine particles is one of the frontier areas of atmospheric science. In this paper, physical and chemical characteristics of fine particles in the atmosphere and the interactions between trace gases and fine particles are described, methods used in heterogeneous reactions research are discussed in detail, progress in the study of heterogeneous reactions on the surface of fine particles in the atmosphere is summarized, existing important questions are pointed out and future research directions are suggested.     

A kinetic model for describing effect of the external surface concentration of TiO2 on the reactivity of eggshell activated carbon supported TiO2 photocatalyst

The porous support supported TiO2 is considered to be the promising photocatalyst due to the fact that it is easily recovered from water and has high capacity to mineralize pollutants. Obviously, the expected structure of this kind of photocatalyst is egg-shell, that is, TiO2 is mainly on the external surface of the porous support. The reactivity of the supported photocatalyst strongly depends on the concentration of TiO2 on the external surface of the porous support. In this study, a kinetic model was developed to describe the effect of the external surface concentration of TiO2 （CESC） on the reactivity of egg-shell activated carbon （AC） supported TiO2 photocatalysts. It was found that the obtained model precisely described the effect of CESC, on the reactivity of TiO2/AC photocatalysts. This study can be used to deeply understand the performance of TiO2/AC catalysts and to provide valuable information on designing efficient supported TiO2 photocatalysts.     

Sol-gel Method Synthesized Polyhedron SnO_2 Anode Material for Lithium Ion Battery

1 Introduction Tin-based oxides will be promising anode materials for lithium ion batteries due to its high specific capacity, low potential platform, and safety[1]. Many methods have been applied to synthesize SnO2 materials of different morphologies, such as chemical vapor deposition, spray, sol-gel method[2]. Triblock copolymer poly (ethylene oxide)-block-poly (propylene oxide)-block-poly (ethane oxide) (P123) has been used as surfactant to prepare nano-crystalline tin oxide particles[3]. In this pap...     

车辆荷载谱作用下简支T梁力学性能

由自编程序VLS(vehicle load spectrum--车辆荷载谱)构造随机车辆荷载谱,利用有限元程序将一般运行状态下的随机车辆荷载谱加载于简支T型钢筋混凝土梁上,模拟该梁在车辆荷载通过时的动力响应,得到了T梁位移时间历程曲线以及梁压区混凝土和拉区钢筋的应力时间历程曲线,并分析了压区混凝土和拉区钢筋的疲劳性能.结果表明车辆荷载谱作用下T梁动挠度大于汽车-20和挂车-100静荷载作用下的挠度;压区混凝土及拉区钢筋的最大应力均介于汽车-20和挂车-100静荷载作用下的应力值之间;T梁疲劳寿命可达到2×106,但不超过2×107;拉区钢筋不能够满足混凝土规范关于疲劳验算的规定,需要进行验算.     

乌鲁木齐二氧化硫污染成因分析及对策

文章通过对乌鲁木齐二氧化硫污染进行分析，得到乌鲁木齐市二氧化硫的城市中心区〉居民区、游憩区和文教区〉新市区的分布规律，乌鲁木齐特殊的地形地貌、气象气候条件和区域环境对二氧化硫污染的形成有重要作用.根据乌鲁木齐自身特殊的情况，提出相应的解决对策.     

攀枝花钒钛磁铁矿矿山遗迹资源特征及评价

攀枝花钒钛磁铁矿是我国西南地区最大的铁矿矿床之一,在生产过程中形成了类型丰富、数量众多的矿业遗迹景观。该矿业景观具有典型、系统及完整的特点,其科学价值和美学价值很高,与矿山遗迹相配套的自然与人文景观类型亦十分丰富。因此矿山遗迹资源具有十分巨大的开发价值,具备申报国家矿山公园的良好基础。     

生理盐水浸泡对Ti-6Al-4V钛合金超高周疲劳性能的影响

钛和钛合金可作为医用植入材料,有必要对其耐人体体液的侵蚀性能进行研究。用超声疲劳试验技术研究了室温下生理盐水中浸泡24 h后Ti-6A l-4V钛合金(TC4)的超高周疲劳性能,并与未经浸泡的同种材料的超声疲劳性能进行了对比分析。疲劳试验进行到109循环周次以上。结果显示,实验材料的S-N曲线均呈现缓慢下降趋势,材料不存在常规疲劳中的疲劳极限,经生理盐水浸泡24 h后对实验材料的超高周疲劳寿命无明显影响。用电子扫描电镜观测,实验材料表现为穿晶塑性断裂。     

含MR阻尼器的简支梁振动响应分析

基于由粘性阻尼和回滞阻尼组成的阻尼模型,对磁流变(MR)流体的动力学特性进行了研究.应用迭代摄动法讨论了含有MR阻尼器的振动系统的非线性频谱并且给出了带有MR流体阻尼器梁结构的计算结果,并应用Newm ark数值积分方法分析了带有MR阻尼器梁结构的多自由度振动系统在不同磁场强度和激励频率作用下的位移响应情况.结果表明,系统的刚度和响应的变化可以通过外加磁场强度来控制,随着磁场强度的增加,响应幅值减小,结构的刚度变大.