高电导率的a—SiHY合金的低温电导特性

用射央求地在硅单晶衬底上沉积出电导率高达６０Ｓ／ｃｍ的ａ－ＳｉＨＹ合金薄膜。在２０－３００Ｋ，对于钇含量高的样品，其电导仍是热激活的。ｌｇσ与１／Ｔ的关系曲线能够被拟合成斜率不同的两条直线，直线的斜率和两直线间拐点所地 温度依赖于膜中钇的含量。但对钇含量低的薄膜，电导对温度的依赖关系度为σ∝ｅｘｐ（－１／Ｔ＾１／４）。结果表明，这些钇含量不同的样品在没的温度范围内具有不同的导电机制。     

SOCP reformulation for the generalized trust region subproblem via a canonical form of two symmetric matrices

Mathematical Programming - We investigate in this paper the generalized trust region subproblem (GTRS) of minimizing a general quadratic objective function subject to a general quadratic inequality...     

Preparation and characterization of superfine ammonium perchlorate (AP) crystals through ceramic membrane anti-solvent crystallization

In this paper, a novel ceramic membrane anti-solvent crystallization (CMASC) method was proposed for the safe and rapid preparation ammonium perchlorate (AP) crystals, in which the acetone and ethyl acetate were chosen as solvent and anti-solvent, respectively. Comparing with the conventional liquid anti-solvent crystallization (LASC), CMASC which successfully introduces ceramic membrane with regular pore structure to the LASC as feeding medium, is favorable to control the rate of feeding rate and, therefore, to obtain size and morphology controllable AP. Several kinds of micro-sized AP particles with different morphology were obtained including polyhedral-like, quadrate-like to rod-like. The effect of processing parameters on the crystal size and shape of AP crystals such as volume ratio of anti-solvent to solvent, feeding pressure and crystallization temperature were investigated. It is found that higher volume ratio of anti-solvent to solvent, higher feeding pressure and higher temperature result in smaller particle size. Scaning electron microscopy (SEM) and X-ray diffraction (XRD) were used to characterize the resulting AP crystals. The nucleation and growth kinetic of the resulting AP crystals were also discussed.     

激光诱导等离子体干涉图相位信息的提取

分析了强激光在空气中产生等离子体干涉图的空间频谱特性，采用高阶契比雪夫数字递归滤波器和阈值自动调整的相位解包算法成功地撮了等离子体干涉图的相位信息。论述了对干涉图样进行数字滤波时的设计考虑，给出了实验结果。实验表明，这种方法可用于快速、瞬态光学干涉图样相位信息的提取。     

Local‐Curvature‐Controlled Non‐Epitaxial Growth of Hierarchical Nanostructures

Site‐selective growth on non‐spherical seeds provides an indispensable route to hierarchical complex nanostructures that are interesting for diverse applications. However, this has only been achieved through epitaxial growth, which is restricted to crystalline materials with similar crystal structures and physicochemical properties. A non‐epitaxial growth strategy is reported for hierarchical nanostructures, where site‐selective growth is controlled by the curvature of non‐spherical seeds. This strategy is effective for site‐selective growth of silica nanorods from non‐spherical seeds of different shapes and materials, such as α‐Fe₂O₃, NaYF₄, and ZnO. This growth strategy is not limited by the stringent requirements of epitaxy and is thus a versatile general method suitable for the preparation of hierarchical nanostructures with controlled morphologies and compositions to open up a verity of applications in self‐assembly, nanorobotics, catalysis, electronics, and biotechnology.     

紫外分光光度计标准溶液的制备及使用

介绍了紫外分光光度计标准溶液的特性及其用于检定紫外分光光度计准确度的优点和正确的使用方法。     

Cluster aggregation and fragmentation kinetics model for gelation

Gelation can occur in polymer, hydrogel, and colloid systems that undergo reversible aggregation-fragmentation (crosslinking accompanied by breakage). Gelation, characterized by rapid divergence of weight-average molecular weight and viscosity due to initial network formation, can be reversed if conditions change. In this paper, reversible aggregation and fragmentation in the pre-gelation time period are modeled with distribution kinetics. Moment equations are obtained from the population balance equation, and solved for eight different rate kernels. We identify the cases for which gelation is possible and obtain the critical values for the rate constants that allow gelation. The model provides a good simulation of published experimental data for aggregation and degradation of plasticized wheat gluten during thermo-mechanical treatments. We also evaluate two closure approximations based on Gamma and log-normal distributions, and conclude that log-normal closure predicts all five possible steady states, in agreement with the Vigil-Ziff criterion, and Gamma closure predicts only three. However, Gamma closure approximates the steady state either closely or exactly, whereas log-normal closure only poorly approximates the steady-state distribution.     

Simultaneous determination of ginsenoside Rg1, Re and notoginsenoside R1 in human plasma by LC‐MS/MS and its application in a pharmacokinetic study in Chinese volunteers

A rapid and sensitive liquid chromatography–tandem mass spectrometry (LC‐MS/MS) method has been developed and validated for simultaneous quantification of ginsenosides Rg₁, Re and notoginsenoside R₁ in human plasma. Chromatography was performed on Capcell Pak C₁₈ MG II column using a binary gradient using mobile phase A (5 mm ammonium formate solution) and B (methanol, containing 5 mm ammonium formate) at a flow rate of 0.3 mL/min. The entire chromatographic run time was 3.2 min. Quantification was achieved using multiple reaction monitoring in positive mode using API 3000. This method was validated in terms of specificity, linearity, precision, accuracy, matrix effect and stability. The calibration curves were linear in the concentration range of 0.020–5.00 ng/mL for ginsenosides Rg₁, Re and notoginsenoside R₁. The lower limit of quantification (LLOQ) of this method was 0.020 ng/mL. The intra‐run and inter‐run precision values were within 12.31% for ginsenoside Rg₁, 14.13% for ginsenoside Re and 11.46% for notoginsenoside R₁ at their LLOQ levels. The samples were stable under all tested conditions. This method was successfully applied to study the pharmacokinetics of ginsenoside Rg₁ and notoginsenoside R₁ in 24 healthy volunteers following oral administration of 200 mg Sanqi Tongshu Enteric‐Pellets Capsule.     

Analysis on strain transfer of a pasted FBG strain sensor

Optical fiber is not in direct contact with the material host in practice, so the strain measured by the Fiber-optic Bragg Grating (FBG) sensor is not the true strain. The transfer mechanism between the measured strain and the true strain depends on mechanical properties of fiber, protective layer, substrate, adhesive layer, and the material host. This paper analyzes the transfer mechanism of strain in detail, and proposes the shear stress distribution of polynomial form, and establishes the transfer function of strain. This paper also analyzes the influence on length of FBG sensor, adhesive layer thickness and elastic modulus on strain transfer coefficient in detail. The theoretical guidance for the practical application of the FBG sensor is given through the strain transfer analysis.     

An accelerated first-order method with complexity analysis for solving cubic regularization subproblems

Computational Optimization and Applications - We propose a first-order method to solve the cubic regularization subproblem (CRS) based on a novel reformulation. The reformulation is a constrained...