检索结果-南通市图书馆

维普期刊数据库

Efficient ammonia production over e_(g)-occupancy-optimized perovskite electrocatalysts

在线全文

学校读者我要写书评

暂无评论

Nano Research 2024年第6期17卷 4682-4686页

作者： Mingfa Chen Yu zhang Fulong Liu Zhenbao zhang Yuming Dong yongfa Zhu Heqing Jiang Jiawei Zhu Key Laboratory of Synthetic and Biological Colloids Ministry of EducationSchool of Chemical and Material EngineeringJiangnan UniversityWuxi 214122China Qingdao Institute of Bioenergy and Bioprocess Technology Chinese Academy of SciencesQingdao 266101China School of Chemistry and Chemical Engineering Linyi UniversityLinyi 276005China Department of Chemistry Tsinghua UniversityBeijing 100084China

Renewable-energy-driven nitrate(NO_(3)^(−))electroreduction to ammonia(NH_(3))(NERA)has been an attractive technology for decarbonizing NH_(3)production and wastewater treatment.Improving NERA efficiency requires electrocatalysts that are earth-abundant and show fantastic performance.Here we report a semiempirical activity descriptor of eg occupancy(of surface B-site cations)for identifying inexpensive perovskite oxides with extremely high efficacy toward NERA.We establish the descriptor by systematic investigations of more than 10 perovskite oxides.These investigations demonstrate that their intrinsic NERA activities display a volcano-shaped dependence on eg occupancy and the optimized intrinsic activities are accessible at near-1 eg occupancies.This could plausibly be attributed to the favorable overlaps between surface adsorbates and vertically-oriented eg orbitals.More importantly,utilizing this descriptor,we predict a highly active,selective,and durable NERA electrocatalyst with a composition of Ba_(0.5)Sr_(0.5)Co_(0.8)Fe_(0.2)O_(3−δ)(BSCF).Because of its close-to-1 e_(g)occupancy(i.e.~1.2),the BSCF features a superior NH_(3)production rate of 0.12 g·h^(−1)·mg_(cat.)^(−1)(Faradaic efficiency of 97.8%)that is at top of the volcano plot,and substantially outperforms most NERA electrocatalysts reported in literature.

关键词： perovskite oxide nitrate electroreduction ammonia electrosynthesis eg occupancy

Unraveling the role of iron on Ni-Fe alloy nanoparticles during the electrocatalytic ethanol-to-acetate process

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2024年第4期17卷 2328-2336页

作者： Junshan Li Luming Li Xinyu Ma Jun Wang Jun Zhao Yu zhang Ren He Yaoyue Yang Andreu Cabot yongfa Zhu Institute for Advanced Study Chengdu University610106 ChengduChina State Key Laboratory of Environmental-Friendly Energy Materials Southwest University of Science and TechnologyMianyang 621010China College of Food and Biological Engineering Chengdu UniversityChengdu 610106China School of Chemistry and Environment Southwest Minzu UniversityChengdu 610041China Hebei Key Laboratory of Photoelectric Control on Surface and Interface College of ScienceHebei University of Science and TechnologyShijiazhuang 050018China Catalonia Institute for Energy Research-IREC Sant Adriàde BesòsBarcelona 08930CataloniaSpain ICREA Pg.Lluís Companys 23Barcelona 08010CataloniaSpain Department of Chemistry Tsinghua UniversityBeijing 100084China

The anodic electrooxidation of ethanol to value-added acetate is an excellent example of replacing the oxygen evolution reaction to promote the cathodic hydrogen evolution reaction and save energy.Herein,we present a colloidal strategy to produce Ni-Fe bimetallic alloy nanoparticles(NPs)as efficient electrocatalysts for the electrooxidation of ethanol in alkaline media.Ni-Fe alloy NPs deliver a current density of 100 mA·cm^(-2) in a 1.0 M KOH solution containing 1.0 M ethanol merely at 1.5 V vs.reversible hydrogen electrode(RHE),well above the performance of other electrocatalysts in a similar system.Within continuous 10 h testing at this external potential,this electrode is able to produce an average of 0.49 mmol·cm^(-2)·h^(-1) of acetate with an ethanol-to-acetate Faradaic efficiency of 80%.A series of spectroscopy techniques are used to probe the electrocatalytic process and analyze the electrolyte.Additionally,density functional theory(DFT)calculations demonstrate that the iron in the alloy NPs significantly enhances the electroconductivity and electron transfer,shifts the rate-limiting step,and lowers the energy barrier during the ethanol-to-acetate reaction pathway.

关键词： electrocatalysis ethanol oxidation reaction alloy nanoparticle acetate biorefinery

Numerical Study on Effect of Suction Slot Geometric Parameters on Airflow Field in Compact Spinning

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Shanghai Jiaotong university(Science) 2024年第2期29卷 245-251页

作者：林惠婷汪军张永法 College of Textiles Donghua UniversityShanghai 201600China College of Textiles and Apparel Quanzhou Normal UniversityQuanzhou 362000FujianChina Zhejiang Shuangdun Textile Technology Co. Ltd.Ningbo 315000ZhejiangChina

The airflow field in the condensing zone is crucial as it affects the fiber condensing,additional twists,and consequently yarn properties.Parameters of spinning and suction slot geometric were found to be key factors influencing the airflow characteristics.To develop a better understanding of the complex airflow field within the pneumatic compact spinning system with lattice apron,a 3D numerical simulation model was built and the influence of negative pressure and geometric of suction slot was investigated.The results reveal that the accelerating air from the top of the suction slot generates transverse condensing force and downward pressure on the fiber strand.The inclination angle has a small effect on airflow velocity.The absolute z-velocity and c-velocity in the positive a-axis were both increased with increasing the slot width from 1.0mm to 1.5 mm.An arc suction slot increased the absolute z-velocity and a-velocity compared with a linear one,thus benefiting fiber condensing.By decreasing the outlet negative pressure to-3kPa,the airflow velocity increased significantly.

关键词： suction slot airflow compact spinning simulation

Mutual impact of true triaxial stress, borehole orientation and bedding inclination on laboratory hydraulic fracturing of Lushan shale

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Rock Mechanics and Geotechnical Engineering 2023年第12期15卷 3131-3147页

作者： yongfa zhang Anfa Long Yu Zhao Arno Zang Chaolin Wang College of Civil Engineering Guizhou UniversityGuiyang550025China Helmholtz Centre Potsdam GFZ German Research Centre for GeosciencesPotsdam14473Germany

Unconventional resources like shale gas has been the focus of intense research and development for two decades. Apart from intrinsic geologic factors that control the gas shale productivity (e.g. organic matter content, bedding planes, natural fractures, porosity and stress regime among others), external factors like wellbore orientation and stimulation design play a role. In this study, we present a series of true triaxial hydraulic fracturing experiments conducted on Lushan shale to investigate the interplay of internal factors (bedding, natural fractures and in situ stress) and external factors (wellbore orientation) on the growth process of fracture networks in cubic specimens of 200 mm in length. We observe relatively low breakdown pressure and fracture propagation pressure as the wellbore orientation and/or the maximum in situ stress is subparallel to the shale bedding plane. The wellbore orientation has a more prominent effect on the breakdown pressure, but its effect is tapered with increasing angle of bedding inclination. The shale breakdown is followed by an abrupt response in sample displacement, which reflects the stimulated fracture volume. Based on fluid tracer analysis, the morphology of hydraulic fractures (HF) is divided into four categories. Among the categories, activation of bedding planes (bedding failure, BF) and natural fractures (NF) significantly increase bifurcation and fractured areas. Under the same stress regime, a horizontal wellbore is more favorable to enhance the complexity of hydraulic fracture networks. This is attributed to the relatively large surface area in contact with the bedding plane for the horizontal borehole compared to the case with a vertical wellbore. These findings provide important references for hydraulic fracturing design in shale reservoirs.

关键词： True triaxial hydraulic fracturing experiment In situ stress state Bedding planes Natural fractures Wellbore orientation Shale reservoirs

Tailoring Texture to Highly Strengthen AZ31 Alloy Plate in the Thickness Direction via Pre-tension and Rolling-Annealing

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2023年第2期36卷 266-280页

作者： Tianjiao Li Jiang Zheng Lihong Xia Haoge Shou yongfa zhang Rong Shi Liuyong He Wenkai Li International Joint Laboratory for Light Alloys(Ministry of Education) College of Materials Science and EngineeringChongqing UniversityChongqing400044China Shenyang National Laboratory for Materials Science Chongqing UniversityChongqing400044China College of Mechanical Engineering Chongqing Technology and Business UniversityChongqing400067China Zhejiang Provincial Engineering Center of Integrated Manufacturing Technology and Intelligent Equipment Zhejiang University City CollegeHangzhou310015China

Conventional wrought Mg alloys,such as AZ31 and ZK60 rolled plates,usually exhibit significantly low tensile yield strength in the thickness direction.This can be attributed to the high activity of{10-12}tension twinning due to the strong basal texture(//ND,normal direction).In this work,the tensile yield strength in the ND of the as-rolled(AR)AZ31 plate increased from 50 to 150 MPa(increased by 200%)via simple processing,i.e.,pre-tension and rolling-annealing(PTRA)treatment.The strong basal texture(//ND)of the AR plate was changed into a weakened fiber texture(⊥ND).The evolution of microstructures during PTRA treatment and the activated deformation modes during uniaxial tension were studied quantitatively and statistically by the means of intergranular misorientation(IM)and in-grain misorientation axes(IGMA)analysis.The results indicate that various twin variants,as well as{10-12}-{10-12}secondary twins,were activated during pre-tension and rolling,and most residual matrix was consumed by twins after annealing.The dominated deformation modes in tension changed from{10-12}tension twinning(the AR sample)to prismatic slip(the PTRA sample)in the early tensile deformation.The underlying formation mechanism of the fiber texture and corresponding strengthening mechanism were discussed.

关键词： Pre-tension Annealing Tailoring texture Texture strengthening Deformation modes

Anisotropic cyclic deformation behavior of an extruded Mg-3Y alloy sheet with rare earth texture

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Magnesium and Alloys 2022年第6期10卷 1581-1597页

作者： Tianjiao Li Jinsong Rao Jiang Zheng Dongdi Yin Haoge Shou yongfa zhang Rong Shi Weichao Jing Lihong Xia International Joint Laboratory for Light Alloys(Ministry of Education) College of Materials Science and EngineeringChongqing University174 Shazhengjie StreetShapingba DistrictChongqing 400044China Shenyang National Laboratory for Materials Science Chongqing UniversityChongqing 400044China Key Laboratory of Advanced Technologies of Materials Ministry of EducationSchool of Materials Science and EngineeringSouthwest Jiaotong UniversityChengduSichuan 610031China College of Mechanical Engineering Chongqing Technology and Business UniversityChongqing 400067China

Mg-RE(magnesium-rare earth)alloys exhibit pronounced in-plane anisotropy of mechanical response under quasi-static monotonic loading resulting from the RE texture,as extensively reported.In this work,an obvious in-plane anisotropy of cyclic deformation behavior was observed in an extruded Mg-3Y alloy sheet during strain-controlled tension-compression low-cycle fatigue(LCF)at room temperature.The extrusion direction(ED)samples displayed better fatigue resistance with almost symmetrical hysteresis loops and longer fatigue life compared with the transverse direction(TD)samples.The influences of texture on the deformation modes,cracking modes,and mechanical behavior of Mg-Y alloy sheets under cyclic loading were studied quantitatively and statistically.The activation of various slip/twinning-detwinning systems was measured at desired fatigue stages via EBSD observations together with in-grain misorientation axes(IGMA)analysis.The results indicate that the activation of deformation modes in the TD sample was featured by the cyclic transition,i.e.,prismatic slip(at the tensile interval)→{10–12}tension twinning(at the compressive reversal)→detwinning+prismatic slip(at the re-tensile reversal).In the case of the ED sample,the cyclic deformation was dominated by the basal slip throughout the fatigue life.For cracking modes,intergranular cracking and persistent slip bands(PSB)cracking were the primary cracking modes in the ED sample while the TD sample showed a high tendency of{10–12}tension twinning cracking(TTW cracking).The underlying mechanisms influencing the activation of various slip/twinning-detwinning systems,as well as cracking modes and cyclic mechanical behavior,were discussed.

关键词： Anisotropic cyclic deformation Dislocation slip Twinning-detwinning Cracking modes Mechanical behavior

维普期刊数据库

The catalytic effect of both oxygen-bearing functional group and ash in carbonaceous catalyst on CH_(4)-CO_(2) reforming

在线全文

学校读者我要写书评

暂无评论

Frontiers of Chemical Science and Engineering 2010年第2期4卷 147-152页

作者： Weidong zhang yongfa zhang Key Laboratory of Coal Science and Technology of Shanxi Province and Ministry of Education Taiyuan University of TechnologyTaiyuan 030024China

A kind of new catalyst-carbonaceous catalyst-for CH_(4)-CO_(2) reformation has been developed in our laboratory.The effect of both oxygen-bearing functional group such as phenolic hydroxyl,carbonyl,carboxyl,and lactonic,and ash such as Fe_(2)O_(3),Na_(2)CO_(3),and K_(2)CO_(3) in the carbonaceous catalyst on the CH_(4)-CO_(2) reforming has been investigated with a fixed-bed reactor.It has been found that the carbonaceous catalyst is an efficient catalyst on CO_(2)-CH_(4) reforming.With the decrease of oxygen-bearing functional group,the catalytic activity of carbonaceous catalyst decreases quickly.The oxygen-bearing functional groups play a significant role in the carbonaceous-catalyzed CO_(2)-CH_(4) reforming;the ash components in carbonaceous catalyst also have an important influence on the CO_(2)-CH_(4) reforming.Fe_(2)O_(3),Na_(2)CO_(3),and K_(2)CO_(3) in the ash can catalyze the CO_(2)-CH_(4) reforming reaction;CaO has little effect on CO_(2)-CH_(4) reforming reaction.CaO can catalyze the gasification between carbonaceous catalyst and CO_(2);Al_(2)O_(3) and MgO inhibit the CO_(2)-CH_(4) reforming.

关键词： carbonaceous catalyst CH_(4)-CO_(2)eforming oxygen-bearing functional group ash

Road map for, and technical challenges of, carbon-nanotube integrated circuit technology

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

National Science Review 2024年第3期11卷 14-16页

作者： Jia Si Panpan zhang Zhiyong zhang Key Laboratory for the Physics and Chemistry of Nanodevices and Center for Carbon-based Electronics School of Electronics Peking University State Key Laboratory of Information Photonics and Optical Communications Beijing University of Posts and Telecommunications

The past decade has witnessed an explosion of research on carbon-nanotube(CNT) electronics due to their outstanding properties, including an ultrathin body, a high carrier mobility and a high saturation velocity.

关键词： TRANSISTORS

New structure transistors for advanced technology node CMOS ICs

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

National Science Review 2024年第3期11卷 24-41页

作者： Qingzhu zhang Yongkui zhang Yanna Luo Huaxiang Yin Integrated Circuit Advanced Process R&D Center Institute of Microelectronics of Chinese Academy of Sciences(IMECAS) State key Lab of Fabrication Technologies for Integrated Circuits Institute of Microelectronics of Chinese Academy of Sciences School of Integrated Circuits University of Chinese Academy of Sciences

Over recent decades, advancements in complementary metal-oxide-semiconductor integrated circuits(ICs)have mainly relied on structural innovations in transistors. From planar transistors to the fin field-effect transistor(FinFET) and gate-all-around FET(GAAFET), more gate electrodes have been added to three-dimensional(3D) channels with enhanced control and carrier conductance to provide higher electrostatic integrity and higher operating currents within the same device footprint. Beyond the 1-nm node, Moore's law scaling is no longer expected to be applicable to geometrical shrinkage. Vertical transistor stacking, e.g. in complementary FETs(CFET), 3D stack(3DS) FETs and vertical-channel transistors(VFET), for enhanced density and variable circuit or system design represents a revolutionary scaling approach for sustained IC development. Herein, innovative works on specific structures, key process breakthroughs, shrinking cell sizes and design methodologies for transistor structure research and development are reviewed. Perspectives on future innovations in advanced transistors with new channel materials and operating theories are also discussed.

关键词： transistor CMOS GAAFET CFET 3DS FET