Anchoring single Pt atoms on hollow Ag3VO4 spheres for improved activity towards photocatalytic H2 evolution reaction

The high cost of noble metal catalysts has been a great bottleneck for the catalyst industry. Using the noble metal at a single-atom level for catalytic applications could dramatically decrease the cost. The impacts of single Pt atoms on the photocatalytic performance of Ag₃VO₄ have been investigated and reported. In this report, single Pt atoms were anchored on the surface of Ag₃VO₄ (AVO) as a cocatalyst, and the resultant composite photocatalyst has been studied for photocatalytic H₂ production from water driven by visible light. The as-prepared AVO particles are hollow nanospheres in the monoclinic phase with a bandgap of 2.20 eV. The light absorption edge of AVO/Pt is slightly red-shifted compared to that of the pristine AVO, indicating more visible light absorption of AVO/Pt. The XPS peaks of Ag, V, and Pt exhibit a significant shift after AVO and Pt get into contact, suggesting the strong interaction between the surface Ag and V atoms, and single Pt atoms. After 3-h illumination, the photocatalytic H₂ evolution amount from AVO/Pt is improved up to 1400 μmol, which is 2.8 times that on the bare AVO. Such efficient photocatalytic H₂ evolution on AVO/Pt is still maintained after five reaction cycles. The better photocatalytic performance of AVO/Pt has been attributed to the more efficient visible light utilization and the lower interfacial charge transfer resistance, as demonstrated in the DRS and EIS spectra. The presence of the surface Pt atoms also leads to a higher amount of reactive radicals, which could efficiently promote the surface redox reactions.     

中国大陆PCB产业自动化的现况与未来

从中国大陆PCB发展的现况分析实行设备自动化连线为企业所创造的价值。设备自动化连线是中国大陆PCB必须面临的改革出路。     

BaxSr（1—x）TiO3多层膜椭偏光谱研究

用溶胶－凝胶技术在Bi(100）衬底上制备了单层和渐变型多层的BaxSr(1-X)TiO3薄膜，其膜层组分分别为：Ba0.7Sr0.3TiO3,Ba0.8Sr0.2TiO,Ba0.9Sr0.1TiO3,BaTiO3，对生长制备出的多层BaxSr(1-X)TiO3薄膜进行了变角度椭偏光谱测量，通过椭偏光谱解谱分析研究，首次得到了BaxSr(1-X)TiO3多层膜结构不同膜层的膜厚和光学常数，其结果显示：椭偏光谱分析得到的不同膜层的膜厚与卢瑟福背向散射测量得到的结果基本相符；渐变型多层膜中BaTiO3薄膜的折射率比单层BaTiO3薄膜折射率大许多，与体BaTiO3的折射率相接近，这说明渐变型多层膜中BaTiO3薄膜的光学性质与体材料的光学性质接近。     

油气管道完整性评价与管理软件

作为保障油气管道安全运行的重大举措，管道的完整性管理已经受到了国内外油气管道业界的高度重视，并处在不断地推广应用之中。为方便管道完整性管理技术的实际应用，研制开发了适用于工程实用目的的油气管道完整性评价与管理软件(PIAMS)， 并包含了管道风险评价与剩余强度评价的功能模块。为此，介绍了该软件的结构、模块、特点、主要功能和用户界面；该软件由数据库、管道风险分析、腐蚀缺陷评价、用户管理4个模块组成；可以运用该软件管理油气管道的完整性数据信息，进行管道的风险计算、风险分析以及对含缺陷管道的剩余强度评价；此外，该软件还具有可扩展性强的特点。     

The geometric nature of plasticity laws

This paper concerns the plasticity constitutive laws in small strain. In the thermodynamic approach developed here, the key concept is that of internal variables. The differential nature of plasticity law has been pointed out for a long time. If we unite the invariance condition of these laws in a state variable transformation, this involves, ultimately, that the natural mathematic frame of plasticity theory is Differential Geometry. The system state is defined as a point of a differentiable manifold. The state variable are the local coordinates of this point in a chart. The internal stresses are the components of a covariant vector of the cotangent bundle to internal state manifold and the elastic domain is a convex part of cotangent vector space. The plastic yield criteria such as von Mises condition define a Riemannian structure over the manifold. The metric element is identified with the internal dissipation element. Constitutive laws link the covariant derivatives of the thermodynamic stress with the state variable. Hardening modulus splits up in two parts, kinematic hardening and metric hardening. This last is defined by Christoffel connection coefficients. Applied to von Mises isotropic yield condition, the metric hardening is identified with isotropic hardening. The Baltov-Sawczuk model is also analysed. The use of appropriate polar coordinates simplifies significantly the computations. Generalization to a significant category of non-differentiable yield criteria, such as Tresca condition, is considered by introducting a metric tensor family. The adaptation of Drucker's postulate to the proposed model requires the introduction of parallel transport of the internal stress covector. Generally, this transport is different over distinctive paths joining two points. This fact expresses internal state manifold curvature. The Riemann-Christoffel tensor is computed for von Mises, Baltov-Sawczuk and Tresca models.     

柴达木盆地北缘的右行走滑冲断系统及其动力学

通过对于断裂系统分析和地球物理资料的解释,证实了柴达木盆地北缘西段的主要构造形成时间为上新世以后,变形样式为一系列右行走滑冲断构造。走滑冲断构造带内部的断层在平面上呈分支复合,剖面上表现为正花状构造,断层上、下盘地层层序无法直接对比。右行走滑冲断构造形成于南祁连由北向南的斜向推覆作用,而主要应力来源于柴达木地块北缘由南向北的陆内俯冲作用。用一个运动学模型解释了柴北缘的右行走滑冲断作用机制。