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Preparation of Self-limiting Heating Cables with Excellent Processability, Mechanical Properties and PTC Effect via Thermal and Electrical Treatments

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Chinese Journal of Polymer Science 2024年第4期42卷 511-520页

作者： Tian-Hao yang Tong Wu Qiang fu State Key Laboratory of Polymer Materials Engineering College of Polymer Science and EngineeringSichuan UniversityChengdu610065China State Key Laboratory of Polymer Materials Engineering Polymer Research Institute of Sichuan UniversityChengdu610065China

Polymer/conductive filler composites have been widely used for the preparation of self-limiting heating cables with the positive temperature coefficient (PTC) effect. The control of conductive filler distribution and network in polymer matrix is the most critical for performance of PTC materials. In order to compensate for the destruction of the filler network structure caused by strong shearing during processing, an excessive conductive filler content is usually added into the polymer matrix, which in turn sacrifices its processability and mechanical properties. In this work, a facile post-treatment of the as-extruded cable, including thermal and electrical treatment to produce high-density polyethylene (HDPE)/carbon black (CB) cable with excellent PTC effect, is developed. It is found for the as-extruded sample, the strong shearing makes the CB particles disperse uniformly in HDPE matrix, and 25 wt% CB is needed for the formation of conductive paths. For the thermal-treated sample, a gradually aggregated CB filler structure is observed, which leads to the improvement of PTC effect and the notable reduction of CB content to 20 wt%. It is very interesting to see that for the sample with combined thermal and electrical treatment, CB particles are agglomerated and oriented along the electric field direction to create substantial conductive paths, which leads to a further decrease of CB content down to 15 wt%. In this way, self-limiting heating cables with excellent processability, mechanical properties and PTC effect have simultaneously been achieved.

关键词： Self-limiting heating cables Positive temperature coefficient Thermal treatment Electrical treatment

Influence of water coupling coefficient on the blasting effect of red sandstone specimens

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International Journal of Coal Science & Technology 2024年第1期11卷 148-166页

作者： yang Li Renshu yang Yanbing Wang Dairui fu School of Mechanics and Civil Engineering China University of Mining and Technology(Beijing)Beijing100083China School of Civil and Resource Engineering University of Science and Technology BeijingBeijing100083China

This study investigates the impact of different water coupling coefficients on the blasting effect of red *** analysis is based on the theories of detonation wave and elastic wave,focusing on the variation in wall pressure of the blasting *** DDNP explosive as the explosive load,blasting tests were conducted on red sandstone specimens with four different water coupling coefficients:1.20,1.33,1.50,and *** study examines the morphologies of the rock specimens after blasting under these different water coupling ***,the fractal dimensions of the surface cracks resulting from the blasting were calculated to provide a quantitative evaluation of the extent of rock *** scanning and 3D reconstruction were performed on the post-blasting specimens to visually depict the extent of damage and fractures within the ***,the volume fractal dimension and damage degree of the post-blasting specimens are *** findings are then combined with numerical simulation to facilitate auxiliary *** results demonstrate that an increase in the water coupling coefficient leads to a reduction in the peak pressure on the hole wall and the crushing zone,enabling more of the explosion energy to be utilized for crack propagation following the *** specimens exhibited distinct failure patterns,resulting in corresponding changes in fractal *** simulated pore wall pressure–time curve validated the derived theoretical results,whereas the stress cloud map and explosion energy-time curve demonstrated the buffering effect of the water *** the water coupling coefficient increases,the buffering effect of the water medium becomes increasingly prominent.

关键词： Water coupling coefficient Radial uncoupled charge Numerical simulation Fractal dimension

Electronic structure regulation and built-in electric field synergistically strengthen photocatalytic nitrogen fixation performance on Ti-BiOBr/TiO_(2)heterostructure

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Rare Metals 2024年第3期43卷 1125-1138页

作者： Ru-Qi Li Yu-Jie Bian chun-Ming yang Li Guo Tao-Xia Ma Chuan-Tao Wang Feng fu Dan-Jun Wang College of Chemistry and Chemical Engineering Yan’an UniversityYan’an Key Laboratory of Green Catalysis and Quality Improvement and Utilization of Low Rank CoalYan’an716000China

At present,industrial synthetic ammonia was still obtained through the Hubble-Bosch process,with large energy *** is a research hotspot to realize green synthetic ammonia by using solar *** difficulty of photocatalytic ammonia synthesis was that the photo-excited electrons have not enough energy to active N≡*** this study,Ti was doped into BiOBr by one-step hydrothermal method,which was oxidized into TiO_(2)when the doping amount reaches the maximum,in situ forming Ti_(0.31)B_(0.69)OB/TiO_(2)*** from the synergistic effect of Ti doping and S-scheme heterojunction,the synthetic ammonia efficiency of Ti_(0.31)B_(0.69)OB/TiO_(2)-11.96 reached 1.643 mmol·g_(cat)^(-1)at mild conditions and without hole scavenger for up to 7 h,the efficiency of synthetic ammonia is 115 times,10.5 times and 3.3 times of that of BiOBr,Ti_(0.31)B_(0.69)OB and TiO_(2),***,DFT calculation confirms that Ti doping accurately refine the electronic structure of BiOBr,facilitate nitrogen adsorption activation and reduce hydrogenation reaction energy barrier,thus accelerating the reaction kinetics of photocatalytic nitrogen reduction(NRR),Meanwhile,constructing S-scheme heterojunction boosts the separation and transfer of photogenerated electron-hole pairs,improving the reduction ability of electrons in the conduction band of TiO_(2)and the oxidation ability of holes in the valence band of Ti_(0.31)B_(0.69)OB.

关键词： S-scheme heterostructure Electronic structure regulation Built-in electric field Synergistical stren4gthening Photocatalytic nitrogen fixation

Remote sensing of air pollution incorporating integrated-path differential-absorption and coherent-Doppler lidar

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Defence Technology（防务技术） 2024年第1期31卷 594-601页

作者： Ze-hou yang Yong Chen chun-li Chen Yong-ke Zhang Ji-hui Dong Tao Peng Xiao-feng Li Ding-fu Zhou School of Physics Beijing Institute of TechnologyBeijing 100081China Southwest Institute of Technical Physics Chengdu 610041SichuanChina School of Optics and Photonics Beijing Institute of TechnologyBeijing 100081China

An innovative complex lidar system deployed on an airborne rotorcraft platform for remote sensing of atmospheric pollution is proposed and *** system incorporates integrated-path differential absorption lidar(DIAL) and coherent-doppler lidar(CDL) techniques using a dual tunable TEA CO_(2)laser in the 9—11 μm band and a 1.55 μm fiber *** combining the principles of differential absorption detection and pulsed coherent detection,the system enables agile and remote sensing of atmospheric *** static tests validate the system’s real-time detection capabilities,including the measurement of concentration-path-length product(CL),front distance,and path wind speed of air pollution plumes over long distances exceeding 4 *** experiments is conducted with the *** of the pollutant concentration and the wind field is carried out in an approximately 1 km slant range over scanning angle ranges from 45°to 65°,with a radial resolution of 30 m and10 *** test results demonstrate the system’s ability to spatially map atmospheric pollution plumes and predict their motion and dispersion patterns,thereby ensuring the protection of public safety.

关键词： Differential absorption LIDAR Coherent Doppler lidar Remoting sensing Atmospheric pollution

Trace formula of the integro-differential operator on a quantum graph

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Applied Mathematics(A Journal of Chinese Universities) 2024年第2期39卷 311-318页

作者： WEI Li-xiao yang Chuan-fu School of Mathematics and Statistics Nanjing University of Science and TechnologyNanjing 210094China.

In this paper we study the eigenvalue problem for integro-differential operators on a lasso *** trace formula of the operator is established by applying the residual technique in complex analysis.

关键词： integro-differential operators eigenvalue trace formula

Inactivation of TGF-βsignaling in CAR-T cells

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Cellular & Molecular Immunology 2024年第3期21卷 309-310页

作者： Zaopeng yang yang-Xin fu Changping Laboratory Beijing102206China Department of Basic Medical Sciences School of MedicineTsinghua UniversityBeijing100084China

Accumulating evidence suggests that the transforming growth factor(TGF)-βpathway might be an ideal target for optimizing chimeric antigen receptor(CAR)-T-cell therapy for solid *** Cellular&Molecular Immunology,Liang et al.(2024)reported that CAR-T cells expressing SMAD7 displayed favorable antitumor efficacy and a reduced risk of systemic toxicity.

关键词： CAR Immunology

Low-temperature NH_(3) abatement via selective oxidation over a supported copper catalyst with high Cu^(+) abundance

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Journal of Environmental Sciences 2024年第9期143卷 12-22页

作者： Zhiming yang Lin Peng Leneng yang Mingli fu Daiqi Ye Peirong Chen Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control National Engineering Laboratory for VOCs Pollution Control Technology and EquipmentSchool of Environment and EnergySouth China University of TechnologyGuangzhou 510006China Guangdong Chengyi Environmental Technology Corp. Shaoguan 512158China

Selective catalytic NH_(3)-to-N_(2) oxidation(NH_(3)-SCO)is highly promising for abating NH_(3) emissions slipped from stationary flue gas after-treatment *** practical application,however,is limited by the non-availability of low-cost catalysts with high activity and N_(2) ***,using defect-rich nitrogen-doped carbon nanotubes(NCNT-AW)as the support,we developed a highly active and durable copper-based NH_(3)-SCO catalyst with a high abundance of cuprous(Cu^(+))*** obtained Cu/NCNT-AW catalyst demonstrated outstanding activity with a T_(50)(*** temperature to reach 50% NH_(3) conversion)of 174℃ in the NH_(3)-SCO reaction,which outperformed not only the Cu catalyst supported on N-free O-functionalized CNTs(OCNTs)or NCNT with less surface defects,but also those most active Cu catalysts in open *** kinetics measurements and temperature-programmed surface reactions using NH_(3)as a probe molecule revealed that the NH_(3)-SCO reaction on Cu/NCNT-AW follows an internal selective catalytic reaction(i-SCR)route involving nitric oxide(NO)as a key *** to mechanistic investigations by X-ray photoelectron spectroscopy,Raman spectroscopy,and X-ray absorption spectroscopy,the superior NH_(3)-SCO performance of Cu/NCNT-AW originated from a synergy of surface defects and ***,surface defects promoted the anchoring of Cu O nanoparticles on N-containing sites and,thereby,enabled efficient electron transfer from N to Cu O,increasing significantly the fraction of SCR-active Cu^(+)sites in the *** study puts forward a new idea for manipulating and utilizing the interplay of defects and N-dopants on carbon surfaces to fabricate Cu^(+)-rich Cu catalysts for efficient abatement of slip NH_(3)emissions via selective oxidation.

关键词： NH_(3)-SCO XANES Localized etching N-doping N_(2) selectivity i-SCR

Composite Converter Combined APFC with Switched-capacitor Converter

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CSEE Journal of Power and Energy Systems 2024年第1期10卷 281-291页

作者： Qing fu Yishan Chen Yixing Su yang Hang School of Physics Sun Yat-Sen UniversityGuangzhou 510275China

To reduce switch numbers and voltage stress in semiconductor devices,this paper proposes a novel single-phase converter combined Active Power Factor Correction(APFC)with switched-capacitor *** addition,dynamic voltage regulation and voltage gain are improved by integrating the boost converter and switching capacitor *** interstage bulk capacitor is no longer *** average current control with redistribution of voltage in cells is proposed to obtain voltage lift ability of the switching capacitor cells and maintain a high-power *** study and verify the proposed converter preliminarily,theoretical analysis and simulation are presented in the ***,a 50o W prototype with two different configurations is built for experimental *** proposed converter can reach 95.62%of maximum efficiency,0.99 of power factor,and 3.55%of THD with 600 V output voltage,simultaneously.

关键词： AC-DC converter composite conveter power factor correction switched capacitor

Effect of Platelet-rich Plasma in Stimulating Macrophage Transformation into M2 Type under AMPK Signaling Pathway

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Chinese Journal of Biomedical Engineering 2024年第02期33卷 85-92页

作者： ZHONG Chang-rui fu chun-hua Longyan First Affiliated Hospital of fujian Medical University The Second Hospital of Longyan

Objective: To explore the effect of platelet-rich plasma(RPR) in stimulating the transformation of pro-inflammatory(M1) macrophages into antiinflammatory(M2) under the adenosine-monophosphate-dependent protein kinase(AMPK) signaling pathway. Methods: Rat peritoneal macrophages(RAW264.7) were cultured and randomly divided into 8 groups: blank control group, LPS group, RPR group A, RPR group B, LPS+RPR(12 h) group, LPS+RPR(24 h) group A, LPS+RPR(24 h)group B, LPS+RPR(24 h) group C. RPR was prepared based on blood donors. The expressions of AMPK signaling pathway-related proteins(AMPK, ULK1, m TOR) and macrophage markers(i NOS, Arg-1) in the blank control group, LPS group, LPS+RPR(12 h)group and LPS+RPR(24 h) group were observed and compared. The expressions of macrophage markers in LPS+RPR(24 h) B and C groups were compared, and the expressions of AMPK and TGF-β in RPR A and B groups were compared. Results: The gray values of AMPK and ULK1 in LPS cells decreased significantly, while those in LPS+RPR(12 h) and LPS+RPR(24 h) A cells increased significantly. The gray values of AMPK and ULK1 in LPS+RPR(24 h) A cells were higher than those in LPS+RPR(12 h)cells(P<0.05). The m TOR gray value of LPS cells was significantly higher than that of LPS+RPR(24 h) A cells, and the m TOR gray value of LPS+RPR(24 h) A cells was significantly lower than that of LPS+RPR(12 h) cells(P<0.05). The expression of i NOS in LPS cells was significantly decreased, the expression of i NOS in LPS+RPR(12 h) and LPS+RPR(24 h) cells was significantly increased, and the expression of i NOS in LPS+RPR(24 h) cells was higher than that in LPS+RPR(12 h) cells(P<0.05). The expression of Arg-1 in LPS cells was significantly decreased, the expression of Arg-1 in LPS+RPR(12 h) and LPS+RPR(24 h) A cells was significantly increased, and the expression of Arg-1 in LPS+RPR(24 h) A cells was higher than that in LPS+RPR(12 h)cells(P<0.05). The i NOS expression level of LPS+PRP(24 h) C cells was significantly higher

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