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Effect of tungsten carbide particles on microstructure and mechanical properties of Cu alloy composite bit matrix

Journal of Iron and Steel Research International 2024年第2期31卷 519-530页

作者： Ding-qian Dong feng-yuan he Xin-hui Chen Hui Li Kai-hua Shi Hui-wen Xiong Xin Xiang Li Zhang College of Mechanical Engineering Sichuan University of Science and EngineeringZigong643000SichuanChina State Key Laboratory of Powder Metallurgy Central South UniversityChangsha410083HunanChina Zigong Cemented Carbide Co. Ltd.Zigong643011SichuanChina Material Corrosion and Protection Key Laboratory of Sichuan Province Sichuan University of Science and EngineeringZigong643000SichuanChina

Copper alloy composite bit matrix was prepared by pressureless vacuum infiltration,using at least one of the three kinds of tungsten carbide particles,for example,irregular cast tungsten carbide,monocrystalline tungsten carbide and sintered reduced tungsten carbide *** effects of powder particle morphology,particle size and mass fraction of tungsten carbide on the microstructure and mechanical properties of copper alloy composite were investigated by means of scanning electron microscopy,X-ray diffraction and abrasive wear test in *** results show that tungsten carbide morphology and particle size have obvious effects on the mechanical properties of copper alloy *** tungsten carbide partially dissolved in the copper alloy binding phase,and layers of Cu_(0.3)W_(0.5)Ni_(0.1)Mn_(0.1)C phase with a thickness of around 8–15μm were formed on the edge of the cast tungsten *** 45%irregular crushed fine cast tungsten carbide and 15%monocrystalline cast tungsten carbide were used as the skeleton,satisfactory comprehensive performance of the reinforced copper alloy composite bit matrix was obtained,with the bending strength,impact toughness and hardness reaching 1048 MPa,4.95 J/cm^(2) and 43.6 HRC,*** main wear mechanism was that the tungsten carbide particles firstly protruded from the friction surface after the copper alloy matrix was worn,and then peeled off from the matrix when further wear occurred.

关键词： Polycrystalline diamond compact Pressureless vacuum infiltration Copper alloy composite bit matrix Microstructure characterization Abrasive wear behavior

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Geometry Services Construction Based on Ontology towards Cooperative Design in Cloud Environment

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Computer Aided Drafting,Design and Manufacturing 2011年第1期21卷 39-45页

作者： CAI Hong-ming BU feng-lin he yuan-jun Shanghai Jiao Tong University Shanghai 200240 China

APIs of CAD system could be encapsulated to construct web services so as to provide standard access interfaces for web-based cooperative design. However, lack of semantic supporting make integration of heterogeneous modelling system limited to operational level. On the purpose of carrying out cooperative design in a flexible cloud environment, an intelligent and effective support mechanism is needed for mass and complex interaction in cooperative work. Therefore, Ontology-based Geometry Modeling Services Environment （OGMSE） is provided to realize a knowledge-level geometry modeling so as to supported semantic 3D model management and intelligent operation support. First, CAD APIs are encapsulated into web service for web invocation. Then, ontology contained structural semantic and operational semantic is built for management of models and modeling process. Lastly, conception-driven modeling mechanism is built to invocate service according to interaction requirement, thus to realize conception-level cooperative design. Based on an open geometry engine, a prototype system has been developed. The result shows that the approach provides a reference direction for large-scale application on the network.

关键词： cooperative design geometry service domain ontology operational semantic

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Impact of temperature and salinity on fines detachment: AFM measurements and XDLVO theory

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Petroleum Science 2025年第1期22卷 338-347页

作者： Wei-feng yuan Yu-Long Yang Lu yuan Ji-Rui Hou State Key Laboratory of Petroleum Resources and Engineering China University of Petroleum Unconventional Petroleum Research Institute China University of Petroleum

Fine particle detachment and subsequent migration can lead to severe pore plugging and consequent permeability decline. Therefore, it is crucial to quantify the critical condition when fine particle detachment occurs. The frequently observed deviations or even contradictions between experimental results and theoretical predictions of fines detachment arise from an insufficient understanding of adhesion force that can be highly influenced by salinity and temperature. To clarify the intrinsic influence of salinity and temperature on fines detachment, adhesion forces between carboxyl microspheres and hydrophilic silica substrates in an aqueous medium were measured at various salinities and temperatures using atomic force microscopy(AFM). The AFM-measured adhesion force decreases with increasing salinity or temperature. Trends of mean measured adhesion forces with temperature and salinity were compared with the DLVO and XDLVO theories. DLVO theory captured the trend with temperature via the impact of temperature on electric double layer interactions, whereas XDLVO theory captured the observed trend with salinity via the impact of salinity on the repulsive hydration force. Our results highlight the significance of hydration force in accurately predicting the fate of fines in porous media.

关键词： Adhesion force AFM Temperature Salinity XDLVO Hydration force

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Glaucomatous retinal ganglion cells:death and protection

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International Journal of Ophthalmology(English edition) 2025年第1期18卷 160-167页

作者： Na Cui Jun Jia yuan he Department of Ophthalmology the Second Affiliated Hospital of Xi’an Medical UniversityXi’an 710038Shaanxi ProvinceChina Xi’an Key Laboratory for the Prevention and Treatment of Eye and Brain Neurological Related Diseases Xi’an 710038Shaanxi ProvinceChina

Glaucoma is a group of diseases characterized by progressive optic nerve degeneration,with the characteristic pathological change being death of retinal ganglion cells(RGCs),which ultimately causes visual field loss and irreversible *** intraocular pressure(IOP)remains the most important risk factor for glaucoma,but the exact mechanism responsible for the death of RGCs is currently *** factor deficiency,impaired mitochondrial structure and function,disrupted axonal transport,disturbed Ca2+homeostasis,and activation of apoptotic and autophagic pathways play important roles in RGC death in *** review was conducted using Web of Science,PubMed,Project,and other databases to summarize the relevant mechanisms of death of RGCs in glaucoma,in addition to outlining protective treatments to improve the degradation of RGCs.

关键词： glaucoma retinal ganglion cells neuroprotection progressive death axonal deletion

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Support electron inductive effect of Pd-Mn/Ni foam catalyst for robust electrocatalytic hydrodechlorination

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Journal of Environmental Sciences 2025年第3期149卷 288-300页

作者： Junxi Li Chao feng Chong Chen yuan Pan Yunqi Liu State Key Laboratory of heavy Oil Processing China University of Petroleum(East China)Qingdao 266580China Key Laboratory of Biofuels Qingdao Institute of Bioenergy and Bioprocess TechnologyChinese Academy of SciencesQingdao 266101China

Structural regulation of Pd-based electrocatalytic hydrodechlorination(EHDC)catalyst for constructing high-efficient cathode materials with low noble metal content and high atom utilization is crucial but still ***,a support electron inductive effect of Pd-Mn/Ni foam catalyst was proposed via in-situ Mn doping to optimize the electronic structure of the Ni foam(NF),which can inductive regulation of Pd for improving the EHDC *** mass activity and current efficiency of Pd-Mn/NF catalyst are 2.91 and 1.34 times superior to that of Pd/NF with 2,4-dichlorophenol as model compound,*** Mn-doped interlayer optimized the electronic structure of Pd by bringing the d-state closer to the Fermi level than Pd on the NF surface,which optimizied the binding of EHDC ***,the Mn-doped interlayer acted as a promoter for generating H∗and accelerating the EHDC *** work presents a simple and effective regulation strategy for constructing high-efficient cathode catalyst for the EHDC of chlorinated organic compounds.

关键词： Palladium Structural Regulation Electrocatalytic hydrodechlorination Support electron inductive effect

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Tetraphenylethylene-derived organic cages with persistent photogenic radicaloids and efficient photothermal conversion

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Science China Chemistry 2025年第2期68卷 661-669页

作者： Suqiong Yan Bo Yang Fanda feng yuan Zhang Shirong Ban Hui Ma Wei Huang State Key Laboratory of Coordination Chemistry School of Chemistry and Chemical EngineeringNanjing UniversityNanjing 210093China Shenzhen Research Institute of Nanjing University Shenzhen 518057China

Transformation of the electronic spin states has received significant interest in recent years because of its applications in the magnetic information storage materials and optical response ***,it can be formidably challenging to use ultraviolet(UV)light as a contactless stimulus to alter the electronic spin states of the supramolecular *** by the approach on the radical cation mechanism of the Scholl reaction and the photocyclization reactivity of tetraphenylethylene(TPE)derivatives,we report two photochromic cages(cage-TPE-1 and cage-TPE-2)that can be photochemically transformed from electron paramagnetic resonance(EPR)-silent to EPR-active form via UV irradiation due to the photo-induced electron transfer process at the TPE *** provided a strong single-electron signal with a g value of 2.003 in cage-TPE-1 and cage-TPE-2 but no signal was detected for the pristine samples without the *** transformation can be monitored by ultraviolet–visible–near-infrared(UV–vis–NIR)and photoluminescence(PL)*** photogenic radical cage intermediate was unstable in solution resulting in the degradation and intramolecular cyclization of the reactive species,while the radicals were found to be stable and persistent in the solid state due to the spin delocalization,the steric protection of confined cavities,and the oxygen *** theoretical calculations and spectral measurements suggest that the photogenic radical cage-TPE-2(•+)experiences photocyclization on the TPE *** with the close-shell cage,the radical cage-TPE-1(•+)and cage-TPE-2(•+)exhibit better photothermal conversion performance due to the incubated infrared absorption from open-shell electron feature and reduced band gap.

关键词： supramolecular cage photogenic radical photocyclization photothermal conversion

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Spatiotemporal characteristics and influencing factors of vegetation water use efficiency on the Tibetan Plateau in 2001–2020

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Journal of Geographical Sciences 2025年第1期35卷 39-64页

作者： he Chenyang WANG Yanjiao YAN feng LU Qi School of Ecological and Environmental Science East China Normal UniversityShanghai200241China Institute of Ecological Conservation and Restoration Chinese Academy of ForestryBeijing100091China National Climate Center China Meteorological AdministrationBeijing100081China

Water use efficiency(WUE),as a pivotal indicator of the coupling degree within the carbon–water cycle of ecosystems,holds considerable importance in assessment of the carbon–water balance within terrestrial ***,in the context of global warming,WUE evolution and its primary drivers on the Tibetan Plateau remain *** study employed the ensemble empirical mode decomposition method and the random forest algorithm to decipher the nonlinear trends and drivers of WUE on the Tibetan Plateau in 2001–*** indicated an annual mean WUE of 0.8088 gC/mm·m^(2)across the plateau,with a spatial gradient reflecting decrease from the southeast toward the *** manifesting monotonous trends of increase or decrease in WUE accounted for 23.64%and 9.69%of the total,***,66.67%of the region exhibited trend reversals,i.e.,39.94%of the area of the Tibetan Plateau showed transition from a trend of increase to a trend of decrease,and 26.73%of the area demonstrated a shift from a trend of decrease to a trend of *** factors accounted for 70.79%of the variability in *** leaf area index and temperature served as the major driving forces of WUE variation.

关键词： water use efficiency spatiotemporal characteristic influencing factor Tibetan Plateau

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Unsupervised multiplex graph diffusion networks with multi-level canonical correlation analysis for multiplex graph representation learning

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Science China(Information Sciences) 2025年第03期68卷 66-79页

作者： Sichao FU Qinmu PENG Yange he Baokun DU Bin ZOU Xiao-yuan JING Xinge YOU School of Electronic Information and Communications Huazhong University of Science and Technology Platform Operation and Marketing Center JD Retail Faculty of Mathematics and Statistics Hubei Key Laboratory of Applied Mathematics Hubei University School of Computer Science Wuhan University

In recent years, unsupervised multiplex graph representation learning(UMGRL) has received increasing research interest, which aims to learn discriminative node features from the multiplex graphs supervised by data without the guidance of labels. Although these designed UMGRL methods have obtained great success in various graph-related tasks, most existing UMGRL models still have the following issues: highly depending on complex self-supervised strategies(i.e., data augmentation,pretext tasks, and negative pairs sampling), restricted receptive fields, and only aggregating low-frequency information between nodes. In this paper, we propose a simple unsupervised multiplex graph diffusion network(UMGDN) with the aid of multi-level canonical correlation analysis to solve the above issues. Specifically, we first decouple the feature transform and propagation processes of the graph convolution layer to further improve the generalization of the learnable parameters. And then, we propose adaptive diffusion propagation to capture long-range dependency relationships between nodes, not the local neighborhood interactions. Finally, a multi-level canonical correlation analysis loss on both the feature transform and propagation processes is proposed to maximize the correlation of the same node features from multiple graphs for guiding model optimization. Compared to the existing UMGRL models, our proposed UMGDN does not need to introduce any data augmentation, negative pairs sampling techniques, complex pretext tasks, and also adaptively aggregates the optimal frequency information between nodes to generate more robust node embeddings. Extensive experiments on four popular datasets and two graph-related tasks demonstrate the effectiveness of the proposed method.

关键词： unsupervised multiplex graph representation learning graph neural networks node classification node clustering

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Failure mechanisms of AlGaN/GaN heMTs irradiated by high-energy heavy ions with and without bias

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Nuclear Science and Techniques 2025年第1期36卷 49-58页

作者： Pei-Pei Hu Li-Jun Xu Sheng-Xia Zhang Peng-Fei Zhai Ling Lv Xiao-Yu Yan Zong-Zhen Li Yan-Rong Cao Xue-feng Zheng Jian Zeng yuan he Jie Liu Institute of Modern Physics Chinese Academy of Sciences(CAS)Lanzhou 730000China Key Laboratory of Wide Band‑gap Semiconductor Materials Ministry of EducationXidian UniversityXi’an 710071China University of Chinese Academy of Sciences(UCAS) Beijing 100049China

Gallium nitride(GaN)-based devices have significant potential for space ***,the mechanisms of radiation damage to the device,particularly from strong ionizing radiation,remains *** study investigates the effects of radiation on p-gate AlGaN/GaN high-electron-mobility transistors(heMTs).Under a high voltage,the heMT leakage current increased sharply and was accompanied by a rapid increase in power density that caused"thermal burnout"of the *** addition,a burnout signature appeared on the surface of the burned devices,proving that a single-event burnout effect ***,degradation,including an increase in the on-resistance and a decrease in the breakdown voltage,was observed in devices irradiated with high-energy heavy ions and without *** latent tracks induced by heavy ions penetrated the heterojunction interface and extended into the GaN ***,a new type of N_(2)bubble defect was discovered inside the tracks using Fresnel *** accumulation of N_(2)bubbles in the heterojunction and buffer layers is more likely to cause leakage and *** study indicates that electrical stress accelerates the failure rate and that improving heat dissipation is an effective reinforcement method for GaN-based devices.

关键词： GaN heMTs heavy ions Single-event burnout Latent tracks Degradation

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Efficient magnetic capture of PE microplastic from water by PEG modified Fe_(3)O_(4)nanoparticles:Performance,kinetics,isotherms and influence factors

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Journal of Environmental Sciences 2025年第1期147卷 677-687页

作者： Yifan Zhang Jingjing Duan Ruiqian Liu Evangelos Petropoulos Yanfang feng Lihong Xue Linzhang Yang Shiying he College of Resources and Environmental Sciences Nanjing Agricultural UniversityNanjing 210095China Key Laboratory of Agro-Environment in Downstream of Yangze Plain Ministry of Agriculture and Rural AffairsInstitute of Agricultural Resources and EnvironmentJiangsu Academy of Agricultural SciencesNanjing 210014China School of Engineering Newcastle UniversityNewcastle upon Tyne NE17RUUK Stantec UK Newcastle upon Tyne NE13DYUK

Due to their resistance to degradation,wide distribution,easy diffusion and potential uptake by organisms,microplastics(MPs)pollution has become a major environmental *** this study,PEG-modified Fe_(3)O_(4)magnetic nanoparticles demonstrated superior adsorption efficiency against polyethylene(PE)microspheres compared to other adsorbents(bare Fe_(3)O_(4),PEI/Fe_(3)O_(4)and CA/Fe_(3)O_(4)).Themaximumadsorption capacity of PEwas found to be 2203 mg/g by adsorption isotherm ***/Fe_(3)O_(4)maintained a high adsorption capacity even at low temperature(5℃,2163 mg/g),while neutral pH was favorable for MP *** presence of anions(Cl^(-),SO_(4)^(2-),HCO_(3)^(-),NO_(3)^(-))and of humic acids inhibited the adsorption of *** is proposed that the adsorption process was mainly driven by intermolecular hydrogen ***,the study demonstrated that PEG/Fe_(3)O_(4)can potentially be used as an efficient control against MPs,thus improving the quality of the aquatic environment and of our water resources.

关键词： Microplastic removal Adsorption Magnetic nanoparticles Wastewater Surface modification

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