Recent Advances of Beta Zeolite in the Volatile Organic Compounds(VOCs) Elimination by the Catalytic Oxidations

Volatile organic compounds(VOCs) have become one of the most serious threats to human health and eco-environment due to their volatility, toxicity and diffusivity, etc. Catalytic completely oxidation had been regarded as a highly efficient strategy for the VOCs abatement. Metal or metal oxides supported on zeolite have been considered as superior catalysts for the treatment of VOCs. Among them, Beta zeolites have attracted many attentions due to their unique structure and consequently catalytic properties in the oxidation of VOCs. The progresses and developments made in the understanding and design of Beta zeolites-based catalysts in the completely oxidation of VOCs in the past two decades have been systematically summarized in this review.     

CONVERGENCE OF SIMPLIFIED AND STABILIZED MIXED ELEMENT FORMATS BASED ON BUBBLE FUNCTION FOR THE STOKES PROBLEM

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双机头电脑刺绣机横梁的模态分析

以GY902A型电脑刺绣机的主横梁作为研究对象，分别运用实验测试和有限元模拟方法分析了电脑刺绣机横梁弯曲振动的固有频率，并利用经过验证的有限元模型，在计算机上作了结构改进仿真设计，实现了在不改变电脑刺绣机重量的前提下，电脑刺绣机横梁的固有频率提高22％，使电脑刺绣机更不易发生共振．     

汶川八级地震滑坡高速远程特征分析

汶川地震触发的高速远程滑坡主要沿龙门山主中央断裂带汶川映秀—安县高川—北川县城—平武南坝—青川一线地震破裂带展布。由于获得了1.5g以上的抛掷加速度,具有明显的气垫效应,估计最大滑动速度一般大于70m•s-1,滑动距离一般为滑体启动时长度的数倍甚至10多倍,堆积成坝形成多处堰塞湖,最大滑行距离达3.2km。本文重点解剖了位于地震破裂带南西段(初始震中)的汶川映秀牛圈沟滑坡—碎屑流、位于地震破裂带中段的北川城西滑坡和位于地震破裂带北东段青川东河口滑坡—碎屑流3个典型实例,认为具有如下特征：(1）岩性条件：母岩遭受长期构造动力作用,呈碎裂岩体,后期被强烈风化,岩体极为破碎;(2）抛掷效应：位于汶川地震主断裂带或附近,垂直加速度大于水平加速度,强地面运动持时长,岩体发生振胀和抛掷;(3）碰撞效应：上部滑坡体发生高位剪出和高位撞击,致使岩体碎屑化;(4）铲刮效应：撞击作用导致下部山体被铲刮,形成次级滑坡,为碎屑流体提供了足够展翼和抛洒物源体积;(5）气垫效应：碎屑化岩体快速抛掷导致下部沟谷空气迅速谷状圈闭和向下紊流,形成气垫效应,或者,在下部地形开阔地带压缩空气呈层流状态致使滑体凌空飞行。     

平衡均匀水平试验确定挥发性有机化合物测量方法的精密度

挥发性有机化合物通常使用吹扫捕集色谱法检测。在7家协作实验室进行平衡均匀水平试验,测定了水中氯乙烯、1,1-二氯乙烯、二氯甲烷、反-1,2-二氯乙烯、1,1-二氯乙烷、氯仿、1,1,1-三氯乙烷等24种挥发性有机化合物。测量结果经一致性和离群值检验后,计算得重复性标准差范围为0.085～5.350μg/L,再现性标准差范围为0.096～7.737μg/L。对标准差和平均值拟合函数关系,得到精密度最终值。     

生物无机化学范式的转变:硅质海绵动物中二氧化硅的酶促缩聚反应(英文)

硅蛋白的发现导致了生物无机化学范式的转变,因为它是第一个可以催化无机单体合成无机聚合物分子的酶。分子生物学,生物化学和细胞生物学数据证实,两种硅质海绵动物,包括寻常海绵和六放海绵,它们的骨针都是由硅蛋白/酶催化合成的。这种酶不仅存在于硅质海绵骨针内部,而且也存在于硅质海绵骨针表面。在硅质海绵骨针生长过程中,它催化生物二氧化硅的合成而构建硅薄层,一层层的硅薄层逐步沉积从而形成硅质海绵骨针。寻常海绵动物Suberites domuncula体外实验获得的硅蛋白活性数据(催化生物二氧化硅的形成)反映了体内骨针生长所需的生物二氧化硅量。本文最后总结了在寻常海绵动物骨针生长和成熟过程中出现的生物熔合现象,即内部的硅薄层"烧结"在一起形成致密的硅棒。强壮的和坚硬的生物二氧化硅骨架的形成需要经历一个硬化过程,这个过程由海绵动物排水通道表面的细胞膜控制,排除生物二氧化硅缩聚反应过程中释放出的水分而使材料固化。     

Mechanically tunable broadband terahertz modulator based on high-aligned Ni nanowire arrays

We present a mechanically tunable broadband terahertz(THz) modulator based on the high-aligned Ni nanowire(NW)arrays. The modulator is a sandwich structure consisting of two polydimethylsiloxane layers and a central layer of highaligned Ni NW arrays. Our experimental measurements reveal the transmittance of THz wave can be effectively modulated by mechanical stretching. The NW density in arrays increases with the strain increasing, which induced an enhancement in the absorption of THz wave. When the strain increases from 0 to 6.5%, a linear relationship is observed for the variation of modulation depth(MD) of THz wave regarding the strain, and the modulated range is from 0 to 85% in a frequency range from 0.3 THz to 1.8 THz. Moreover, the detectable MD is about 15% regarding the 1% strain change resolution. This flexible Ni NW-based modulator can be promised many applications, such as remote strain sensing, and wearable devices.     

Lifting graph automorphisms along solvable regular covers

A solvable cover of a graph is a regular cover whose covering transformation group is solvable. In this paper, we show that a solvable cover of a graph can be decomposed into layers of abelian covers, and also, a lift of a given automorphism of the base graph of a solvable cover can be decomposed into layers of lifts of the automorphism in the layers of the abelian covers. This procedure is applied to classify metacyclic covers of the tetrahedron branched at face-centers.     

罗丹明类光学传感器在金属离子细胞成像中的应用

由于优良的光学性能和较宽的pH值适用范围,罗丹明类物质已经被广泛选作重金属与过渡金属离子细胞成像光学传感器的光学母体.对近年来罗丹明类光学传感器在重金属与过渡金属离子细胞成像中的应用进行了详细综述,包括设计思路、作用机理、应用范围等都进行了详细的比较分析.另外,提出了罗丹明类重金属和过渡金属细胞成像光学传感器目前存在的问题和今后的发展趋势.