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Ultrasonic Vibration Electrical Discharge Machining in Gas

厦门大学学报（自然科学版） 2002年第S1期41卷 10-11页

作者： ZHANG qin-he, ZHANG jian-hua, DENG jian-xin, qin yong, NIU Zong-wei (College of Mechanical Engineering, Shandong University, Jinan 250061, China)

A new method of ultrasonic vibration electrical discharge machining(UEDM) in gas is proposed in this paper. In UEDM in gas, the gap between tool electrode and workpiece is small(about 0.01mm), and the voltage between them is higher than EDM in liquid, so short circuit is easy to take place. It is very important for improving the MRR to avoid short circuit. Therefore, some measures have been taken, a rotation and a planetary motion are superimposed upon the tool electrode. During UEDM in gas, workpiece is vibrating with ultrasonic frequency, which can have the molten workpiece material ejected out from base body of workpiece without being reattached to it again, it is very useful to increase MRR. The electrode is formed to be thin-walled pipe, the high pressure gas is supplied through the internal hole and flow over the machining gap with a high velocity. It can enhance the removal of molten and evaporated workpiece material. The gas with a high velocity also cools and solidifies the removed material and prevents them from adhering onto the surface of the tool electrode. Furthermore, during the pulse interval, the gas with a high velocity blows off the plasma formed by the previous discharge and decreases the temperatures of the discharge spots on the tool electrode and the workpiece due to heat transfer, thus guaranteeing the recovery of the dielectric strength of the gap. The experiments were performed on an electrical discharge small hole machine DK730(made in China, modified by author). The worktable of the machine was especially designed to accept an ultrasonic vibration unit, and the clamp of the machine was designed to accept high pressure gas when it turning. 45# steel and copper were selected as workpiece and tool electrode respectively. Air and oxygen gas were selected as gas mediums. Five sets of experiments were carried out to show the effects of open voltage, pulse duration, wall thickness of pipe electrode, amplitude of ultrasonic vibration and gas medi

关键词： UEDM gas medium MRR tool electrode wear

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DKP-SLAM:A Visual SLAM for Dynamic Indoor Scenes Based on Object Detection and Region Probability

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Computers, Materials & Continua 2025年第1期82卷 1329-1347页

作者： Menglin Yin yong qin jiansheng Peng College of Automation Guangxi University of Science and TechnologyLiuzhou545000China Department of Artificial Intelligence and Manufacturing Hechi UniversityHechi546300China Key Laboratory of AI and Information Processing Education Department of Guangxi Zhuang Autonomous RegionHechi546300China Guangxi Key Laboratory of Sericulture Ecology and Applied Intelligent Technology School of Chemistry and BioengineeringHechi UniversityHechi546300China

In dynamic scenarios,visual simultaneous localization and mapping(SLAM)algorithms often incorrectly incorporate dynamic points during camera pose computation,leading to reduced accuracy and *** paper presents a dynamic SLAM algorithm that leverages object detection and regional dynamic ***,a parallel thread employs the YOLOX object detectionmodel to gather 2D semantic information and compensate for missed ***,an improved K-means++clustering algorithm clusters bounding box regions,adaptively determining the threshold for extracting dynamic object contours as dynamic points *** process divides the image into low dynamic,suspicious dynamic,and high dynamic *** the tracking thread,the dynamic point removal module assigns dynamic probability weights to the feature points in these *** with geometric methods,it detects and removes the dynamic *** final evaluation on the public TUM RGB-D dataset shows that the proposed dynamic SLAM algorithm surpasses most existing SLAM algorithms,providing better pose estimation accuracy and robustness in dynamic environments.

关键词： Visual SLAM dynamic scene YOLOX K-means++clustering dynamic probability

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Enhancing m^(6)A modification in the motor cortex facilitates corticospinal tract remodeling after spinal cord injury

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Neural Regeneration Research 2025年第6期20卷 1749-1763页

作者： Tian qin Yuxin Jin Yiming qin Feifei Yuan Hongbin Lu jianzhong Hu yong Cao Chengjun Li Department of Spine Surgery and Orthopedics Xiangya HospitalCentral South UniversityChangshaHunan ProvinceChina Key Laboratory of Organ Injury Aging and Regenerative Medicine of Hunan ProvinceChangshaHunan ProvinceChina National Clinical Research Center for Geriatric Disorders Xiangya HospitalCentral South UniversityChangshaHunan ProvinceChina Department of Sports Medicine Xiangya HospitalCentral South UniversityChangshaHunan ProvinceChina

Spinal cord injury typically causes corticospinal tract disruption. Although the disrupted corticospinal tract can self-regenerate to a certain degree, the underlying mechanism of this process is still unclear. N6-methyladenosine(m^(6)A) modifications are the most common form of epigenetic regulation at the RNA level and play an essential role in biological processes. However, whether m^(6)A modifications participate in corticospinal tract regeneration after spinal cord injury remains unknown. We found that expression of methyltransferase 14 protein(METTL14) in the locomotor cortex was high after spinal cord injury and accompanied by elevated m^(6)A levels. Knockdown of Mettl14 in the locomotor cortex was not favorable for corticospinal tract regeneration and neurological recovery after spinal cord injury. Through bioinformatics analysis and methylated RNA immunoprecipitation-quantitative polymerase chain reaction, we found that METTL14 regulated Trib2 expression in an m^(6)A-regulated manner, thereby activating the mitogen-activated protein kinase pathway and promoting corticospinal tract regeneration. Finally, we administered syringin, a stabilizer of METTL14, using molecular docking. Results confirmed that syringin can promote corticospinal tract regeneration and facilitate neurological recovery by stabilizing METTL14. Findings from this study reveal that m^(6)A modification is involved in the regulation of corticospinal tract regeneration after spinal cord injury.

关键词： corticospinal tract remodeling epigenetic regulations locomotor cortex m^(6)A modification methyltransferase 14 protein(METTL14) mitogen-activated protein kinase neural regeneration spinal cord injury syringin TRIB2

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Structural designs and mechanism insights into electrocatalytic oxidation of 5-hydroxymethylfurfural

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Journal of Energy Chemistry 2025年第1期100卷 792-814页

作者： Jing Lei Huijie Zhang jian Yang Jia Ran Jiqiang Ning Haiyan Wang yong Hu Key Laboratory of the Ministry of Education for Advanced Catalysis Materials Department of Chemistry Zhejiang Normal University Jinhua Advanced Research Institute Department of Optical Science and Engineering Fudan University College of Chemistry and Materials Engineering Zhejiang A&F University

Biomass conversion offers an efficient approach to alleviate the energy and environmental *** oxidation of 5-hydroxymethylfurfural(HMF) has attracted tremendous attention in the latest few years for the mild synthesis conditions and high conversion efficiency to obtain 2,5-furan dicarboxylic acid(FDCA), but there still remain problems such as limited yield, short cycle life,and ambiguous reaction mechanism. Despite many reviews highlighting a variety of electrocatalysts for electrochemical oxidation of HMF, a detailed discussion of the structural modulation of catalyst and the underlying catalytic mechanism is still lacking. We herein provide a comprehensive summary of the recent development of electrochemical oxidation of HMF to FDCA, particularly focusing on the mechanism studies as well as the advanced strategies developed to regulate the structure and optimize the performance of the electrocatalysts, including heterointerface construction, defect engineering,single-atom engineering, and in situ reconstruction. Experimental characterization techniques and theoretical calculation methods for mechanism and active site studies are elaborated, and challenges and future directions of electrochemical oxidation of HMF are also prospected. This review will provide guidance for designing advanced catalysts and deepening the understanding of the reaction mechanism beneath electrochemical oxidation of HMF to FDCA.

关键词： Structural design

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Recent Advances in Fibrous Materials for Hydroelectricity Generation

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Nano-Micro Letters 2025年第2期17卷 109-133页

作者： Can Ge Duo Xu Xiao Feng Xing Yang Zheheng Song Yuhang Song Jingyu Chen Yingcun Liu Chong Gao yong Du Zhe Sun Weilin Xu jian Fang College of Textile and Clothing Engineering Soochow UniversitySuzhou 215123People’s Republic of China National Engineering Laboratory for Modern Silk Soochow UniversitySuzhou 215123People’s Republic of China State Key Laboratory of New Textile Materials and Advanced Processing Technologies Wuhan Textile UniversityWuhan 430200People’s Republic of China Institute of Functional Nano&Soft Materials(FUNSOM) Soochow UniversitySuzhou 215123People’s Republic of China Department of Electrical and Computer Engineering University of MassachusettsAmherstMA 01003USA Department of Materials Imperial College LondonSouth Kensington CampusLondon SW72AZUK College of Textile Science and Engineering Zhejiang Sci-Tech UniversityHangzhou 310018People’s Republic of China School of Materials Science and Engineering Shanghai Institute of Technology100 Haiquan RoadShanghai 201418People’s Republic of China

Depleting fossil energy sources and conventional polluting power generation pose a threat to sustainable *** generation from ubiquitous and spontaneous phase transitions between liquid and gaseous water has been considered a promising strategy for mitigating the energy *** materials with unique flexibility,processability,multifunctionality,and practicability have been widely applied for fibrous materials-based hydroelectricity generation(FHG).In this review,the power generation mechanisms,design principles,and electricity enhancement factors of FHG are first ***,the fabrication strategies and characteristics of varied constructions including 1D fiber,1D yarn,2D fabric,2D membrane,3D fibrous framework,and 3D fibrous gel are ***,the advanced functions of FHG during water harvesting,proton dissociation,ion separation,and charge accumulation processes are analyzed in ***,the potential applications including power supply,energy storage,electrical sensor,and information expression are also ***,some existing challenges are considered and prospects for future development are sincerely proposed.

关键词： Hydroelectricity Fibrous material Streaming potential Ion diffusion

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Stable copper boron–imidazolate cage as Cu-riched enzyme for highly efficient electrocatalytic CO2 reduction to ethylene

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Science China Chemistry 2025年

作者： Jun-Qiang Chen Qiao-Hong Li qin-Long Hong Ping Shao Hai-Xia Zhang jian Zhang State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of Matter Chinese Academy of Sciences

Single-atom catalyst has garnered widespread attention to mimic mature enzymes due to its well-defined atomic structure and coordination environments. However, since the carbon–carbon（C–C） coupling reactions require synergistic catalysis of multiple sites, single-atom catalysts suffer from insufficient active sites and unclear reaction mechanisms. Controlling the reaction intermediates in a precisely targeted pocket through careful metal–organic cage design is therefore crucial. Here, we prepare a tetrahedral [Cu6L4]-type boron–imidazolate cage integrating highly active Cu sites and optimized cavity, which exhibits enzyme like specific catalytic performance in electrochemical CO2reduction reaction（CO2RR） to enhance the selectivity of *** analyses and computational calculations suggest that the single Cu site together with neighboring boron–imidazolate ligands provides suitably synergistic effects that enable the energetically favorable formation of an *COCHO intermediate, a key step determining selectivity. As a result, the [Cu6L4]-type cage of BIC-145 achieves a Faradaic efficiency of 28% for C2H4maintaining an average current density of -3.54 mA cm-2over a 5-hour electrolysis period. This work represents the first example for studying single-metal site catalysts with ultra-low coordination numbers through the rational design of metal–organic cages.

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Impact of depressed left ventricular function on outcomes in patients with three-vessel coronary disease undergoing percutaneous coronary intervention

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Chinese Medical Journal 2013年第4期126卷 609-614页

作者： GAO Zhan XU Bo Ajay J. Kirtane YANG Yue-jin YUAN Jin-qing CHEN Ji-lin QIAO Shu-bin WU yong-jian qin Xue-wen YAN Hong-bin YAO Min LIU Hai-bo CHEN Jue YOU Shi-jie GAO Run-lin Cardiovascular Institute & Fu Wai Hospital Chinese Academy of Medical Sciences Peking Union Medical College Beijing100037 China

Background Patients with multivessel coronary artery disease and depressed left ventricular ejection fraction （LVEF） represent a high risk group of patients for coronary revascularization. There are limited data on percutaneous coronary intervention treatment in this population. Methods Among a cohort of 4335 patients with three-vessel disease with or without left main disease undergoing percutaneous coronary intervention, 191 patients had LVEF 〈40% （low ejection fraction （EF）） and 4144 patients had LVEF _〉40%. In-hospital and long-term outcomes were examined according to LVEF. Results The estimated two-year rates of major adverse cardiac events, cardiac death, and myocardial infarction were significantly higher in the low EF group （19.64% vs. 8.73%, Log-rank test： P 〈0.01; 10.30% vs. 1.33%, Log-rank test： P 〈0.01, and 10.32% vs. 2.28%, Log-rank test： P 〈0.01 respectively）, but there was no difference in the rates of target vessel revascularization （6.18% vs. 6.11%, Log-rank test： P=0.96）. Using the Cox proportional hazard models, LVEF 〈40% was a significant risk factor for cardiac death, myocardial infarction, and major adverse cardiac events （OR （95% CI）： 4.779 （2.369-9.637）, 2.673 （1.353-5.282）, and 1.827 （1.187-2.813） respectively）, but was not a statistically significant risk factor for target vessel revascularization （OR （95% CI）： 1.094 （0.558-2.147））. Conclusion Among patients undergoing percutaneous coronary intervention for multivessel coronary artery disease, left ventricular dysfunction remains associated with further risk of cardiac death in-hospital and during long-term follow-up.

关键词： three-vessel coronary disease left ventricular dysfunction percutaneous coronary intervention

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Stepwise assembly to construct stable copper(I) cluster-based circularly polarized luminescent MOFs

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Science China Chemistry 2025年

作者： Jing-Wen Xie Meng-Ting Wang Yan Jin Si Li jian-Hua qin Shuang-Quan Zang Tomas C.W.Mak College of Chemistry Henan Key Laboratory of Crystalline Molecular Functional Materials Zhengzhou University College of Chemistry and Chemical Engineering Luoyang Normal University Department of Chemistry The Chinese University of Hong Kong

Circularly polarized luminescence （CPL） materials have been extensively studied in recent years owing to their widespread applications in 3D display,optical storage,optical anti-counterfeiting,and biological imaging,***（I） clusters have emerged as a promising candidate for CPL materials,driven by their cost-effectiveness,superior luminescent properties,precise structure,and low ***,the poor environmental stability of copper（I） clusters renders their synthesis and preservation challenging,thereby significantly impeding their ***,we have designed and synthesised a chiral double-coordinated ligand in order to construct copper（I） cluster nodes that can be further *** anticipated,by utilizing stepwise assembly strategy,a Cu4cluster node co-modified by chiral alkynyl ligands and triphenylphosphine was further assembled with Cd2+ions to obtain 2D layers structure,L/*** L/D-Cu4-Cd exhibits excellent stability and optical properties,including bright yellow emission,solvent-responsive luminescence,and CPL activity with a maximum glumup to 2.0×10-3,which shows potential applications in the WLED and *** interestingly,the material also exhibits deflection ability towards different wavelengths of linearly polarized light,showing certain potential in the preparation of circular polarizer.

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Positive effect of Mo on mechanical properties of a Ni-42W-10Co-x Mo medium heavy alloy

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China Foundry 2025年

作者： Guo-xin Cao jian-xin Dong yong-sheng He He jiang Fang Hao Zhi-hua Nie Teng-fei Ma Bao-quan Fu School of Materials Science and Engineering University of Science and Technology Beijing Xi'an Superalloy Technology Co. Ltd. School of Materials Science and Engineering Beijing Institute of Technology Key Laboratory of Air-driven Equipment Technology of Zhejiang Province Quzhou University

In this study,a novel Ni-W-Co-Mo medium heavy alloy (MHA) was designed to improve its mechanical strength via Mo *** the Ni-42W-10Co-xM o alloy series,where x represents the weight percent of Mo and varies between 0,1,2,5,and 10,the microstructure transitions from a dendritic structure to a hypoeutectic structure as the Mo content increases from 0 to 5wt.%.Moreover,as the Mo content increases from 0to 10wt.%,the distribution of theμ-phase shifts from being individually dispersed to forming aggregates,and its volume fraction rises from 0.5%to 7.9%.Notably,theμ-phase evolves into an eutectic microstructure,which helps in minimizing the segregation of *** change is accompanied by a substantial enhancement in mechanical properties;specifically,the compressive yield strength at room temperature increases from 350 MPa to 646 MPa,indicating a significant 85%***,the microhardness increases from 230 HV to 304 *** dynamics simulations further reveal that the strengthening mechanism of Ni-42W-10Co-xM o alloys is Mo-induced solid solution strengthening and precipitation strengthening.

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Bluetooth-based authentication system for ambient intelligence

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2008年第6期9卷 770-775页

作者： jian HE Hui LI yong ZHANG Zhang-qin HUANG School of Software Engineering Beo＇ing University of Technology Beo＇ing 100022 China College of Computer Science Beijing University of Technology Beijing 100022 China College of Electronic Information and Automation Tianjin University of Science and Technology Tianjin 300222 China

According to the requirement of natural human-computer interaction for Ambient Intelligence （Aml）, a Bluetoothbased authentication technique is provided. An authentication network combining advantages of Bluetooth ad hoc network with the Ethernet is introduced first in detail. Then we propose a Bluetooth badge for storing the user＇s identification information. Finally, the authentication system based on Bluetooth badge and authentication network is introduced. It is demonstrated experimentally that the Bluetooth-based authentication technique can authenticate the user automatically.

关键词： Bluetooth Ambient Intelligence (Aml) Authentication

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