Escape of Brownian particles and stochastic resonance with low-temperature quantum fluctuations

In this paper, we investigate the escape of Brownian particles and stochastic resonance (SR) with low-temperatures quantum fluctuations by using the quantum Smoluchowski equations at low-temperature. Two specific examples have been considered: one is the example of bistable system, and the other is the example of metastable system. The explicit expressions of the mean-first passage time (MFPT) and signal-to-noise ratio (SNR) for both specific examples are obtained, respectively. Based on the numerical compu...     

Deflagration-to-detonation transition process for spherical aluminum dust/epoxypropane mist/air mixtures in a large-scale experimental tube

The deflagration-to-detonation transitions (DDTs) for clouds of spherical aluminum dust (SAD) mixed with air or epoxypropane mist (EPM) and air were investigated in a 29.6-m-long experimental tube of 199 mm in diameter. The clouds formed through the injection of SAD and SAD/liquid epoxypropane samples into the experimental tube. Explosions of the SAD/air mixture were initiated using a 7-m-long EPM/air cloud explosion ignited by a 40-J electric spark. Explosions in SAD/EPM/air clouds were initiated using a 1...     

Differential equation dynamical system based assessment model in GNSS interoperability

With the development of Global Navigation Satellite System (GNSS),the idea of GNSS interoperability is born and has become the focus of study in the field of satellite navigation.The popularity for GNSS to augment the interoperability with the existing ones necessitates the study of the assessment algorithm of this idea.In this paper,an assessment algorithm for interoperability comprehensive benefits based on the differential equation dynamical system is discussed.There are two important aspects in GNSS tha...     

Generation of Bell states via Lyapunov control on a two-qubit system with an anisotropic XY Heisenberg interaction

We demonstrate that an arbitrary Bell state can be achieved in a two qubit anisotropic Heisenberg XY chain via Lyapunov control. During the whole process, we only need to apply an external field along a given direction to a single qubit. This control strategy is effective for all initial states in the four-dimensional Hilbert space where the target state is asymptotically stable. The effects of imperfections on the fidelity for the target state such as Gaussian leakage of local control and localized dephasi...     

Combining GPS carrier phase and Doppler observations for precise velocity determination

The truncation error and propagation error are analyzed for velocity determination through differential GPS carrier phase observations,and an approach for the choice of the best number of points for the central difference method is developed.In order to overcome the disadvantages of existing GPS velocity determination methods,a new velocity determination algorithm is presented,based on combining carrier phase and Doppler observations.The basic idea is that two types of observation are combined by adding the...     

Connected cubic s-arc-regular Cayley graphs of finite nonabelian simple groups

A graph is said to be s-arc-regular if its full automorphism group acts regularly on the set of its s-arcs. In this paper, we investigate connected cubic s-arc-regular Cayley graphs of finite nonabelian simple groups. Two suffcient and necessary conditions for such graphs to be 1- or 2-arc-regular are given and based on the conditions, several infinite families of 1-or 2-arc-regular cubic Cayley graphs of alternating groups are constructed.     

New Advances in Catalytic Systems for Conversion of CH_4 and CO_2

One of the main goals for developing the C1 chemical industry is the direct conversion of methane and carbon dioxide to useful products. To realize this goal, researches on new catalytic systems are being globally focused. The exploration has been evolved from traditional heterogeneous catalysis into homogeneous catalysis. Coordinate complexes, biochemical and bionics, and photo- and electrochemical catalysis have been extensively studied in recent years. Tests in laboratories have verified for the direct conversion of CH4 to CH3OH that single-pass converstion of CH4 can reach over 70% in both Hg(II) salt and Pt(II) complex systems. The main problem of these systems is the obstacles involving reaction kinetics, so they must be solved before moving to pilot tests. Other catalytic systems discussed in the present article include explorations in the early stage. Among them, features of photo and enzymatic catalyst systems, such as mild reaction conditions, better selectivity and environmentally friendliness     

Spectroscopy Investigation on Conformational Transition of Tea Glycoconjugate from Green Tea

The conformational transition of a new glycoconjugate, tea glycoconjugate (TGC), was investigated by spectroscopy techniques including circular dichroism (CD) and ultraviolet (UV) spectroscopy. The solution behaviors of TGC in the mediums of different temperature, pH value, and ions were compared. Results showed that the native conformation of TGC was partially ordered. The CD value and UV absorbance of TGC altered with the change of pH value, temperature, the addition of ions, and also accompanied order-disorder transition. Especially the conditions with temperature higher than the glass transition temperature (Tg=62℃), higher pH value or lower pH value will have the most impact on the conformation of TGC, which will destroy the hydrogen bonds between the TGC molecules. The results indicated that the outside factors play important roles on the stability of the conformation of TGC.     

硼氢化钠水解制氢的研究

采用置换镀的方法在泡沫镍基体上获得不同载钌量的NaBH4水解制氢催化剂。实验结果表明，NaBH4水解制氢反应为零级反应，氢气生成速率随载钌量的增加而变快；当泡沫镍表面完全被钌覆盖时，载钌量为6%，相应的催化能力最强。与离子交换树脂载钌催化剂相比，泡沫镍载钌催化剂更稳定、耐用。实验还证实，30%比35%的NaBH4水溶液在相同的催化剂作用下更易发生水解反应；NaBH4水溶液中加入少量的NaOH有助于提高钌催化剂的催化性能。通过对NaBH4储氢体系的能量计算，说明采用该氢源体系的微型燃料电池的能量密度有望达到甚至超过锂离子电池的比能量水平。     

中心裂纹圆盘应力强度因子的测试误差分析

本文在中心裂纹圆盘应力强度因子解析解的基础上,利用一阶微分法则,给出了与裂纹相对长度和加载角相关的应力强度因子(K 和K )的4个误差传递函数。这4个误差传递函数关于裂纹相对长度和加载角均是非线性的,它们既是误差分析的基础,又是合理确定裂纹相对长度和加载角的基础。分析结果表明,加载角的误差Δθ除了对纯 型K 的误差几乎没有影响,对纯 型K 影响较小外,对复合型K 、K 的误差均有较大影响。最后,本文建议裂纹相对长度的取值范围为0.4～0.6;还建议在复合型断裂试验时,必须依据对K 、K 的总体精度要求来严格控制加载角的精度。