A practical reliability assessment approach and its application for pile-stabilized slopes using FORM and support vector machine

Bulletin of Engineering Geology and the Environment - Many uncertainties exist in pile-stabilized slopes which make their design substantially complicated. In this paper, a first-order reliability...     

海底电缆交叉鬼波化双检合并技术改进及应用

双检合并技术在海底电缆地震资料处理中被广泛应用,可衰减电缆鬼波的影响。传统方式以水、陆检记录的波场记录相同为假设,电缆鬼波压制效果差,合并效果并不理想。在分析交叉鬼波化双检合并技术基本原理的基础上,综合利用水检资料与陆检鬼波褶积的结果和陆检资料与水检鬼波褶积的结果求取刻度算子,同时在地震资料处理中利用陆检资料标定水检资料,从而优化了交叉鬼波化双检合并技术。实际资料处理结果表明,改进后的技术可有效衰减电缆鬼波,分离出上行波场,大幅度拓宽地震资料频带,提高地震资料分辨率,从而提供更丰富的构造细节信息。     

Triphenylphosphonium (TPP)-Based Antioxidants: A New Perspective on Antioxidant Design

Mitochondrial oxidative damage and dysfunction contribute to a wide range of human diseases. Considering the limitation of conventional antioxidants and that mitochondria are the main source of reactive oxygen species (ROS) which induce oxidative damage, mitochondria-targeted antioxidants which can selectively block mitochondrial oxidative damage and prevent various types of cell death have been widely developed. As a lipophilic cation, triphenylphosphonium (TPP) has been commonly used in designing mitochondria-targeted antioxidants. Conjugated with the TPP moiety, antioxidants can achieve more than 1000-fold higher mitochondrial concentration depending on cell membrane potentials and mitochondrial membrane potentials. Herein we discuss the deficiencies of conventional antioxidants and the advantages of mitochondrial targeting, and review various types of TPP-based mitochondria-targeted antioxidants. These provide theoretical and background support for the design of new anti-oxidant.     

新型超润湿性自吸聚合物在压裂液体系中的应用

研制了一种具有润湿性的新型压裂液体系,并对聚合物进行XRD和TGA分析.流变学和扫描电镜实验表明,压裂液具有致密的网状结构.通过SEM测试得到破胶液的微观结构,表明交联作用更加明显.NFW压裂液在90℃时具有良好的流变性能,破胶液的表面张力较低,为20 mN·m-1.因此,这种具有润湿性的压裂液可作为致密油气藏开发的替代品.     

采用八叉树和OSG分页结点的海量点云三维可视化

针对现有海量点云可视化方法存在索引构建时间长、内存占用大等问题，研究一种八叉树索引结合OSG分页结点的快速可视化方法，可在占用较小内存的基础上快速建立点云索引并实时调度。采用八叉树索引结构对海量点云进行数据组织，建立各层级的八叉树结点并以文件映射的方式分块保存，对结点文件重组织转换为支持OSG渲染引擎的多分辨率点云数据。采用基于OSG分页结点的实时调度技术，对海量点云进行高质量可视化。与目前两款主流的点云数据处理商业软件进行实验对比分析，结果表明所提方法具有索引建立速度快、内存占用小等优点，同时可视化交互更加流畅，适用于各种配置计算机下海量点云数据的调度管理与实时可视化。     

Rapid screening of DON contamination in whole wheat meals by Vis/NIR spectroscopy and computer vision coupling technology

This work intends to develop an online experimental system for screening of deoxynivalenol (DON) contamination in whole wheat meals by visible/near-infrared (Vis/NIR) spectroscopy and computer vision coupling technology. Spectral and image information of samples with various DON levels was collected at speed of 0.15 m s⁻¹ on a conveyor belt. The two-type data were then integrated and subjected to chemometric analysis. Discriminant analysis showed that samples could be classified by setting 1000 μg kg⁻¹ as the cut-off value. The best correct classified rate obtained in prediction was 93.55% based on fusion of spectral and image features, with reduced prediction uncertainty as compared to single feature. However, quantification of DON by quantitative analysis was not successful due to poor model performance. These results indicate that, although not accurate enough to provide conclusive result, this coupling technology could be adopted for rapid screening of DON contamination in cereals and feeds during processing.     

In situ Raman spectroscopic study towards the growth and excellent HER catalysis of Ni/Ni(OH)2 heterostructure

The electrochemical water splitting to produce H₂ in high efficiency with earth-abundant-metal catalysts remains a challenge. Here, we describe a simple “cyclic voltammetry + ageing” protocol at room temperature to activate Ni electrode (AC-Ni/NF) for hydrogen evolution reaction (HER), by which Ni/Ni(OH)₂ heterostructure is formed at the surface. In situ Raman spectroscopy reveals the gradual growth of Ni/Ni(OH)₂ heterostructure during the first 30 min of the aging treatment and combined with polarization measurements, it suggests a positive relation between the Ni/Ni(OH)₂ amount and HER performance of the electrode. The obtained AC-Ni/NF catalyst, with plentiful Ni–Ni(OH)₂ interfaces, exhibits remarkable performance towards HER, with the low overpotential of only 30 mV at a H₂-evolving current density of 10 mA/cm² and 153 mV at 100 mA/cm², as well as a small Tafel slope of 46.8 mV/dec in 1 M KOH electrolyte at ambient temperature. The excellent HER performance of the AC-Ni/NF could be maintained for at least 24 h without obvious decay. Ex situ experiments and in situ electrochemical-Raman spectroscopy along with density functional theory (DFT) calculations reveal that Ni/Ni(OH)₂ heterostructure, although partially reduced, can still persist during HER catalysis and it is the Ni–Ni(OH)₂ interface reducing the energy barrier of H1 adsorption thus promoting the HER performance.     

Adaptive compensation of persistent actuator failures of nonlinear systems

In this article, adaptive compensation designs are developed for nonlinear systems with uncertainties from the system functions and persistent actuator failures of characterizations that (i) some unknown system inputs are stuck at some unknown fixed or varying values at unknown time instants and (ii) the failure pattern always switches from one to another and the switching does not stop. Such a controlled plant is described by an uncertain time-varying nonlinear system, and some robust adaptive feedback linearization based failure compensation results are studied for closed-loop system stabilization and bounded output tracking for some specific conditions. To improve the tracking performance in the presence of persistent actuator failures, a new adaptive control scheme is developed, using the failure indicator function which contains the failure pattern and failure time in the formulation. Detailed stability and tracking performance are shown. Simulation results are shown to verify the effectiveness of the proposed adaptive actuator failure compensation method.     

Structural,optical and electrical properties of indium doped Cu2ZnSn(S,Se)4 thin films synthesized by the DC and RF reactive magnetron cosputtering

Element doping into the Cu₂ZnSn(S,Se)₄ (CZTSSe) absorber is an effective method to optimize the performance of thin film solar cells. In this study, the Cu₂In_xZn_1-xSn(S,Se)₄ (CIZTSSe) precursor film was deposited by magnetron cosputtering technique using indium (In) and quaternary Cu₂ZnSnS₄ (CZTS) as targets. Meanwhile, the In content was controlled using the direct current (DC) power on In target (P_In). A single kesterite CIZTSSe alloy was formed by successfully doping a small number of In³⁺ into the main lattice of CZTSSe. The partial Zn²⁺ cations were substituted by In³⁺ ions, resulting in improving properties of CZTSSe films. Morphological analysis showed that large grain CIZTSSe films could be obtained by doping In. The well-distributed, smooth, and dense film was obtained when the P_In was 30 W. The band gap of CIZTSSe could be continuously adjusted from 1.27 to 1.05 eV as P_In increased from 0 to 40 W. In addition, the CIZTSSe alloy thin film at P_In = 30 W exhibited the best p-type conductivity with Hall mobility of 6.87 cm²V^?1s^?1, which is a potential material as the absorption layer of high-performance solar cells.     

基于局部分型面的电器外壳注塑模具设计

电器外壳制品形状结构复杂,有两处侧凸(孔)较难处理。通过对矩形孔内侧凸的结构分析,在其局部设计了分型面,避免了使用侧向抽芯机构;对侧孔部位设计了斜顶杆侧向抽芯机构,其结构简单、紧凑。模具采用一模二腔、平衡式布局,采用经扁推杆由制品内部进料的潜伏式浇口,S型流道。在NX 8.0中完成了模具结构设计。经实践证明,该模具结构合理,产品合格。