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Environmentally friendly solders 3-4 beyond Pb-based systems

Rare Metals 2006年第Z2期25卷 95-100页

作者： GAO Yuan liu Peng guo Fu xia Zhidong LEI Yongping SHI Yaowu College of Materials Science and Engineering Beijing University of Technology Beijing 100022 China College of Materials Science and Engineering Beijing University of Technology Beijing 100022 China College of Materials Science and Engineering Beijing University of Technology Beijing 100022 China College of Materials Science and Engineering Beijing University of Technology Beijing 100022 China College of Materials Science and Engineering Beijing University of Technology Beijing 100022 China College of Materials Science and Engineering Beijing University of Technology Beijing 100022 China

Based on environmental considerations, global economic pressures, enacted by legislations in several countries, have warranted the elimination of lead from solders used in electronic applications. Sn3.5Ag, SnAgCu, and Sn0.7Cu have emerged among various lead-free candidates as the most promising solder alloys to be utilized in microelectronic industries. However, with the vast development and miniaturization of modern electronic packaging, new requirements such as superior service capabilities have been posed on lead-free solders. In order to improve the comprehensive property of the solder alloys, two possible approaches were adopted in the current research and new materials developed were patented. One approach was involved with the addition of alloying elements to make new ternary or quaternary solder alloys. Proper addition of rare earth element such as La and Ce have rendered solder alloys with improved mechanical properties, especially creep rupture lives of their joints. Another approach, the composite approach, was developed mainly to improve the service temperature capability of the solder alloys. Composite solders fabricated by mechanically incorporating various reinforcement particles to the solder paste have again exhibited enhanced properties without altering the existing processing characteristics. The recent progress and research efforts carried out on lead-free solder materials in Beijing University of Technology were reported. The effects of rare earth addition on the microstructure, processing properties, and mechanical properties were presented. The behaviors of various Sn-3.5Ag based composite solders were also explicated in terms of the roles of reinforcement particles on intermetallic growth, steady-state creep rate, the onset of tertiary creep, as well as the overall creep deformation in the solder joints. Thermomechanical fatigue (TMF) behavior of the solder alloys and composite solders were investigated with different parameters such as ramp

关键词： lead-free solder composite solder no-clean flux creep mechanical properties thermomechanical fatigue

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响应面法优化硅藻土负载纳米零价铁去除水中Cr(Ⅵ)

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离子交换与吸附 2024年第1期40卷 91-98页

作者：刘下国周安益吴事典李嘉诚李凯江苏省环保集团苏州有限公司江苏省汾湖高新技术产业开发区安全生产监督管理和环境保护局

近年来，纳米零价铁(Nanoscale zerovalent iron, NZVI)因高还原性、高比表面积等优点被广泛应用于去除水中Cr(Ⅵ)的研究。本文采用壳聚糖改性后的硅藻土(CDt)对NZVI进行负载制备了硅藻土负载型纳米零价铁(NZVI-CDt)，并对其去除水中Cr(... 详细信息

近年来，纳米零价铁(Nanoscale zerovalent iron, NZVI)因高还原性、高比表面积等优点被广泛应用于去除水中Cr(Ⅵ)的研究。本文采用壳聚糖改性后的硅藻土(CDt)对NZVI进行负载制备了硅藻土负载型纳米零价铁(NZVI-CDt)，并对其去除水中Cr(Ⅵ)的条件进行了响应面法优化。以负载比(CDt与NZVI的质量比)、温度、反应时间以及反应溶液pH值为4个响应因素，以水中Cr(Ⅵ)的去除率为响应值进行了四因素三水平的响应面实验设计(Box-Behnken Design, BBD)，建立了响应面模型。分析结果表明：模型在整个回归区域内拟合度好，4个因素对Cr(Ⅵ)去除率的影响是显著的(F值为146.83)，影响顺序为溶液p H值>负载比>反应时间>温度。通过模型优化得到最佳去除条件为：负载比3∶1，温度30℃，反应时间35 min,pH=4，且预测的Cr(Ⅵ)最高去除率为97.81%。通过3组平行实验对模型的预测结果进行验证，得到预测值高于实际值且绝对误差为1.93%，说明预测值与实际值的拟合度较好。通过该研究优化了NZVI-CDt去除水中Cr(Ⅵ)的反应条件，为NZVI-CDt的实际应用提供了数据支持和理论依据。

关键词：纳米零价铁 Cr(Ⅵ) 硅藻土响应面法

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Single-atom catalysis for advanced oxidation and reduction systems in water decontamination

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Rare Metals 2024年第8期43卷 3576-3606页

作者： Jie Teng Jin-Hui Xu Wen-Xin Sun Xue-Feng liu xia Xu guo-Shuai liu School of Urban Construction Changzhou UniversityChangzhou 213164China School of Environmental and Civil Engineering Jiangnan UniversityWuxi 214122China

Water scarcity is an escalating global crisis,posing a severe threat to populations ***,exploring various materials to remove emerging contaminants from freshwater sources has garnered significant *** this regard,single-atom catalysis(SACs) has emerged as a catalyst of scientific progress in water purification and treatment methodologies during recent *** exhibit exceptional catalytic activity,selectivity and stability,due to their near-perfect atom utilization,highly unsaturated coordination environment and uniform reaction ***,a comprehensive and critical review encompassing the successful integration of SACs into water purification processes needs to be *** review aims to accentuate recent trends by presenting the synthesis,structure,and environment and energy application-relevant properties of *** results show that a comprehensive and multi-perspective summary of the advantages of SACs in environmental remediation can have significant benefits,such as fast kinetics,costeffectiveness,*** oxidation and reduction processes of SACs and functional SACs materials in water purification were ***,the last section is devoted to the current research gaps and further perspectives on the application of SACs in water treatment,which are summarized and analyzed.

关键词： Single-atom catalysis Water treatment Oxidation Reduction

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Genetic Differentiation of Different Geographical Populations of Bemisia tabaci (Gennadius) Complex

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Agricultural Sciences in China 2007年第6期6卷 696-705页

作者： CHU Dong liu guo-xia FAN Zhong-xue TAO Yun-li ZHANG You-jun High-Tech Research Center Shandong Academy of Agricultural Sciences Jinan 250100 P.R.China Institute of Vegetables and Flowers Chinese Academy of Agricultural Sciences Beijing 100081 P.R.China

Bemisia tabaci （Gennadius） is a species complex, which includes different geographical populations with genetic differentiation. The recent progress on the genetic differentiation of various geographical populations of B. tabaci complex was introduced. The genetic differentiation was further analyzed on the basis of the sequences of mtDNA COI and rDNA ITS1 recorded in the world＇s GenBank. Five groups are defined on the basis of mtDNA COI and rDNA ITS1, including the Asia group, America group, Africa group, Australia group, and Biotype B/Mediterranean/Middle East/ Northern Africa/Biotype Ms group. There are several ungrouped geographical classifications, such as the Uganda population, Ivory Coast population, and Taiwan population. Geographical isolation may be the most important factor that contributed to the genetic differentiation of various geographical populations of B. tabaci. Many populations with biological advantages invaded new regions and caused severe economic losses within human activity. It is necessary to strengthen the research of B. tabaci biotype to prevent the spread of invaded populations and the invasion of potentially dangerous populations.

关键词： Bemisia tabaci (Gennadius) geographical populations mtDNA COI rDNA ITS 1 genetic differentiation

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Configuration Synthesis and Grasping Performance Analysis of Multi-Loop Coupling Capture Mechanism for Launch and Recovery of Torpedo-Shaped Autonomous Underwater Vehicle

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China Ocean Engineering 2024年第3期38卷 453-466页

作者： ZHANG guo-xing xia Xin-lu guo Jin-wei School of Mechanical Engineering Jiangsu University of Science and TechnologyZhenjiang 212100China

Research of capture mechanisms with strong capture adaptability and stable grasp is important to solve the problem of launch and recovery of torpedo-shaped autonomous underwater vehicles(AUVs).A multi-loop coupling capture mechanism with strong adaptability and high retraction rate has been proposed for the launch and recovery of torpedo-shaped AUVs with different morphological ***,the principle of capturing motion retraction is described based on the appearance characteristics of torpedo-shaped AUVs,and the configuration synthesis of the capture mechanism is carried out using the method of constrained chain ***,the screw theory is employed to analyze the degree of freedom(DoF)of the capture ***,the 3D model of the capture mechanism is established,and the kinematics and dynamics simulations are carried *** with the capture orientation requirements of the capture mechanism,the statics and vibration characteristics analyses are carried ***,considering the capture process and the underwater working environment,the motion characteristics and hydraulics characteristics of the capture mechanism are ***,a principle prototype is developed and the torpedo-shaped AUVs capture experiment is *** work provides technical reserves for the research and development of AUV capture special equipment.

关键词： capture mechanism torpedo-shaped AUVs configuration synthesis launch and recovery grasping performance analysis

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Nuclei-rich galvanizing strategy for suppressing zinc dendrite growth

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Rare Metals 2024年第8期43卷 4016-4018页

作者： Hai-xia Wu Kai-Lu guo College of Chemistry and Chemical Engineering Henan Key Laboratory of Function-Oriented Porous MaterialsLuoyang Normal UniversityLuoyang 471934China

The uncontrolled growth of zinc dendrites on zinc anode hinders the application of zinc ion *** solve this problem,Lu's group proposed a nuclei-rich galvanizing strategy for suppressing the zinc dendrite *** allows the nuclei-rich zinc electrode to cycle steadily for1200 h and have a high Coulombic efficiency of 99.7%at15 mA·cm^(-2)with a deposited amount of 10 mAh·cm^(-2).Moreover,the Zn-MnO_(2) battery with a low N/P ratio of 1.9exhibited sustained cycling life.

关键词： cycling sustained battery

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Zeolite polymer membrane as protective interface for Mg battery

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Rare Metals 2024年第9期43卷 4636-4638页

作者： Hai-xia Wu Kai-Lu guo College of Chemistry and Chemical Engineering Henan Key Laboratory of Function-Oriented Porous MaterialsLuoyang Normal UniversityLuoyang 471934China

Excessive electrolyte decomposition seriously determines the performance of high-voltage Mg batteries. In Nazar's work, the strategy using a zeolite polymer membrane as a protective interface was proposed to restrain the electrolyte decomposition. This strategy could boost Mg plating/stripping performance up to 6000 h in zeolite/Mg|zeolite/Mg symmetric cells and 91%capacity retention in zeolite/Mg||Mo_(3)S_(4)battery after 200 *** storage devices have been intensively explored because of their important roles in our daily lives [1D3].

关键词： zeolite interface electrolyte

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Arbitrary High-Order Fully-Decoupled Numerical Schemes for Phase-Field Models of Two-Phase Incompressible Flows

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Communications on Applied Mathematics and Computation 2024年第1期6卷 625-657页

作者： Ruihan guo Yinhua xia School of Mathematics and Statistics Zhengzhou UniversityZhengzhou450001HenanChina School of Mathematical Sciences University of Science and Technology of ChinaHefei230026AnhuiChina

Due to the coupling between the hydrodynamic equation and the phase-field equation in two-phase incompressible flows,it is desirable to develop efficient and high-order accurate numerical schemes that can decouple these two *** popular and efficient strategy is to add an explicit stabilizing term to the convective velocity in the phase-field equation to decouple *** resulting schemes are only first-order accurate in time,and it seems extremely difficult to generalize the idea of stabilization to the second-order or higher *** this paper,we employ the spectral deferred correction method to improve the temporal accuracy,based on the first-order decoupled and energy-stable scheme constructed by the stabilization *** novelty lies in how the decoupling and linear implicit properties are maintained to improve the *** the framework of the spatially discretized local discontinuous Galerkin method,the resulting numerical schemes are fully decoupled,efficient,and high-order accurate in both time and *** experiments are performed to validate the high-order accuracy and efficiency of the methods for solving phase-field models of two-phase incompressible flows.

关键词： Two-phase incompressible flows Fully-decoupled High-order accurate Linear implicit Spectral deferred correction method Local discontinuous Galerkin method

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Control Strategies for Digital Twin Systems

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IEEE/CAA Journal of Automatica Sinica 2024年第1期11卷 170-180页

作者： guo-Ping liu IEEE the Center for Control Science and Technology Southern University of Science and TechnologyShenzhen 518055China

With the continuous breakthrough in information technology and its integration into practical applications, industrial digital twins are expected to accelerate their development in the near future. This paper studies various control strategies for digital twin systems from the viewpoint of practical *** make full use of advantages of digital twins for control systems, an architecture of digital twin control systems, adaptive model tracking scheme, performance prediction scheme, performance retention scheme, and fault tolerant control scheme are proposed. Those schemes are detailed to deal with different issues on model tracking, performance prediction, performance retention, and fault tolerant control of digital twin systems. Also, the stability of digital twin control systems is analysed. The proposed schemes for digital twin control systems are illustrated by examples.

关键词： Digital twin control systems fault tolerant control model tracking performance prediction performance retention

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Morphological Classification of Infrared Galaxies Based on WISE

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Research in Astronomy and Astrophysics 2024年第4期24卷 222-236页

作者： Zhi-Ren Pan Bo Qiu Cui-xiang liu A-Li Luo xia Jiang xiao-Yu guo School of Electronic and Information Engineering Hebei University of TechnologyTianjin 300401China Key Laboratory of Optical Astronomy National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China

This study introduces a novel convolutional neural network,the WISE Galaxy Classification Network(WGC),for classifying spiral and elliptical galaxies using Wide-field Infrared Survey Explorer(WISE)*** attains an accuracy of 89.03%,surpassing the combined use of K-means or SVM with the Color-Color method in more accurately identifying galaxy *** enhanced variant,WGC_mag,integrates magnitude parameters with image features,further boosting the accuracy to 89.89%.The research also delves into the criteria for galaxy classification,discovering that WGC primarily categorizes dust-rich images as elliptical galaxies,corresponding to their lower star formation rates,and classifies less dusty images as spiral *** paper explores the consistency and complementarity of WISE infrared images with SDSS optical images in galaxy morphology *** SDSS Galaxy Classification Network(SGC),trained on SDSS images,achieved an accuracy of 94.64%.The accuracy reached 99.30% when predictions from SGC and WGC were *** the complementarity of features in WISE and SDSS images,a novel variant of a classifier,namely the Multi-band Galaxy Morphology Integrated Classifier,has been *** classifier elevates the overall prediction accuracy to 95.39%.Lastly,the versatility of WGC was validated in other data *** the HyperLEDA data set,the distinction between elliptical galaxies and Sc,Scd and Sd spiral galaxies was most pronounced,achieving an accuracy of 90%,surpassing the classification results of the Galaxy Zoo 2 labeled WISE data *** research not only demonstrates the effectiveness of WISE images in galaxy morphology classification but also represents an attempt to integrate multi-band astronomical data to enhance understanding of galaxy structures and evolution.

关键词： methods:data analysis infrared:galaxies galaxies:spiral galaxies:elliptical and lenticular cD

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