检索结果-南通市图书馆

Advances in noble metal-modified g-C_(3)N_(4) heterostructures toward enhanced photocatalytic redox ability

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2024年第11期31卷 2368-2389页

作者： xiao zhang Ping Yang Faculty of Chemical Engineering and Technology Cracow University of TechnologyKrakow 31-155Poland School of Material Science&Engineering University of JinanJinan 250022China

The photocatalytic activity of catalysts depends on the energy-harvesting ability and the separation or transport of photogenerated *** light absorption capacity of graphitic carbon nitride(g-C_(3)N_(4))-based composites can be enhanced by adjusting the surface plasmon resonance(SPR)of noble metal nanoparticles(e.g.,Cu,Au,and Pd)in the entire visible *** can be carried out by varying the nanocomponents of the *** SPR of noble metals can enhance the local electromagnetic field and improve interband transition,and resonant energy transfer occurs from plasmonic dipoles to electron-hole pairs via near-field electromagnetic ***,noble metals have emerged as relevant nanocomponents for g-C_(3)N_(4) used in CO_(2) photoreduction and water ***,recent key advances in noble metals(either in single atom,cluster,or nanoparticle forms)and composite photocatalysts based on inorganic or organic nanocomponent-incorporated g-C_(3)N_(4) nanosheets are systematically discussed,including the applications of these photocatalysts,which exhibit improved photoinduced charge mobility in CO_(2) photoconversion and H2 *** related to the different types of multi-nanocomponent heterostructures(involving Schottky junctions,Z-/S-scheme heterostructures,noble metals,and additional semiconductor nanocomponents)and the adjustment of dimensionality of heterostructures(by incorporating noble metal nanoplates on g-C_(3)N_(4) forming 2D/2D heterostructures)are *** current prospects and possible challenges of g-C_(3)N_(4) composite photocatalysts incorporated with noble metals(e.g.,Au,Pt,Pd,and Cu),particularly in water splitting,CO_(2) reduction,pollution degradation,and chemical conversion applications,are summarized.

关键词： g-C_(3)N_(4) heterostructure noble metal photocatalysis H_(2)generation CO_(2)

Numerical simulation on sand sedimentation and erosion characteristics around HDPE sheet sand barrier under different wind angles

在线全文

学校读者我要写书评

暂无评论

Journal of Mountain Science 2024年第2期21卷 538-554页

作者： zhang Kai zhang Peili zhang Hailong TIAN Jianjin WANG Zhenghui xiao Jianhua College of Civil Engineering Lanzhou Jiaotong UniversityLanzhou 730000China Key Laboratory of Desert and Desertification Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China Key Laboratory of Ecological Safety and Sustainable Development in Arid Lands Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China

For the safety of railroad operations,sand barriers are utilized to mitigate wind-sand disaster *** disasters,characterized by multi-directional wind patterns,result in diverse angles among the *** this study,using numerical simulations,we examined the behavior of High Density Polyethylene(HDPE)sheet sand barriers under different wind angles,focusing on flow field distribution,windproof efficiency,and sedimentation erosion *** study discovered that at a steady wind speed,airflow velocity varies as the angle between the airflow and the HDPE barrier ***,a 90°angle results in the widest low-speed airflow area on the barrier’s downwind *** the airflow is not perpendicular to the barrier,it prompts a lateral airflow movement which decreases as the angle *** windproof efficiency correlates directly with this angle but inversely with the wind’s ***,with a wind angle of 90°,wind speed drops by 81%.The minimum wind speed is found at 5.1H(the sand barrier height)on the barrier’s downwind *** the angle grows,the barrier’s windproof efficiency improves,extending its protective *** is most prominent on the barrier’s downwind side,as the wind angle shifts from 30°to 90°,the sand sedimentation area on the barrier’s downwind side enlarges by *** the angle grows,sedimentation intensifies,eventually overtakes the forward erosion and enlarges the sedimentation area.

关键词： Multi-wind direction HDPE sheet sand barrier Numerical simulation Windproof efficiency Sedimentation erosion

Visible-light-induced organocatalyzed C（sp2）–H bond functionalization of 1,3-azoles with trifluoroacetylsilanes

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2024年第11期67卷 3662-3668页

作者： Zhengyu Li Zeguo zhang Zhihan zhang Gang Zhou Yizhi zhang Shanshan Liu xiao Shen The Institute for Advanced Studies Engineering Research Center of Organosilicon Compounds & Materials Ministry of EducationWuhan University College of Chemistry Central China Normal University

Previous carbene insertion to C–H bonds of 1,3-azoles relied on metal carbene species. Herein, we report a metal-free C（sp2）–H bond functionalization of 1,3-azoles with trifluoroacetylsilanes. The reaction features mild conditions, broad substrate scope and wide functional group tolerance. The mechanistic study supports that the success of the reaction is probably attributed to the dual roles of trifluoroacetylsilanes under the photocatalyzed conditions: generating carbenes which undergo cyclopropanation and generating biradicals which promote ring-opening aromatization of the in situ generated fused cyclopropanes.

关键词： C(sp2)–H bond functionalization carbenes biradicals cyclopropanation brook rearrangement

Research on blade tip clearance cavitation and turbulent kinetic energy characteristics of axial flow pump based on the partially-averaged Navier-Stokes model

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2024年第1期36卷 184-201页

作者： xiao-qi Jia Shuai-kang zhang Zu-chao Zhu Key Laboratory of Fluid Transmission Technology of Zhejiang Province Zhejiang Sci-Tech UniversityHangzhou310018China

To reveal the cavitation forms of tip leakage vortex(TLV)of the axial flow pump and the flow mechanism of the flow field,this research adopts the partially-averaged Navier-Stokes(PANS)model to simulate the cavitation values of an axial flow pump,followed by experimental *** experimental result shows that compared with the shear stress transport(SST)k-ωmodel,the PANS model significantly reduces the eddy viscosity of the flow field to make the vortex structure clearer and allow the turbulence scale to be more robustly *** cavitation area within the axial flow pump mainly comprises of TLV cavitation,clearance cavitation and tip leakage flows combined effect of triangular cloud cavitation *** formation and development of cavitation are accompanied by the formation and evolution of vortex,and variations in vortex structure also generate and promote the development of *** addition,an in-depth analysis of the relationship between the turbulent kinetic energy(TKE)transport equation and cavitation patterns was also conducted,finding that the regions with relatively high TKE are mainly distributed around gas/liquid boundaries with serious cavitation and evident gas-liquid *** phenomenon is mainly attributed to the combined effect of the pressure action term,stress diffusion term and TKE production term.

关键词： Cavitation axial flow pump tip leakage vortex(TLV) partially-averaged Navier-Stokes(PANS)model turbulent kinetic energy(TKE)

Asymmetric two-dimensional diffraction grating via a vortex field in an inverted-Ytype atomic system

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2024年第5期76卷 77-85页

作者： Duo zhang Ke Wang Kunpeng Zhao mei Wang Zhaoyu Sun School of Electrical and Electronic Engineering Wuhan Polytechnic UniversityWuhan 430023China

We propose a theoretical scheme to realize a two-dimensional(2D)diffraction grating in a four-level inverted-Y-type atomic system coupled by a standing-wave(SW)field and a Laguerre-Gaussian(LG)vortex *** to asymmetric spatial modulation of the LG vortex field,the incident probe field can be lopsidedly diffracted into four domains and an asymmetric 2D electromagnetically induced grating is *** adjusting the detunings of the probe field and the LG vortex field,the intensities of the LG vortex field and the coherent SW field,as well as the interaction length,the diffraction properties and efficiency,can be effectively *** addition,the effect of the azimuthal parameter on the Fraunhofer diffraction of the probe field is also *** asymmetric 2D diffraction grating scheme may provide a versatile platform for designing quantum devices that require asymmetric light transmission.

关键词： asymmetric diffraction grating standing-wave field Laguerre-Gaussian vortex field diffraction property

Understanding the failure mechanism towards developing high-voltage single-crystal Ni-rich Co-free cathodes

在线全文

学校读者我要写书评

暂无评论

Green Energy & Environment 2024年第6期9卷 1045-1057页

作者： Jixue Shen Bao zhang Changwang Hao xiao Li Zhiming xiao Xinyou He Xing Ou Engineering Research Center of the Ministry of Education for Advanced Battery Materials School of Metallurgy and EnvironmentCentral South UniversityChangsha410083China Zhejiang Power New Energy Co. Ltd.Zhuji311899China Material Science and Chemistry Engineering College China University of GeosciencesWuhan430074China

Benefited from its high process feasibility and controllable costs,binary-metal layered structured LiNi_(0.8)Mn_(0.2)O_(2)(NM)can effectively alleviate the cobalt supply crisis under the surge of global electric vehicles(EVs)sales,which is considered as the most promising nextgeneration cathode material for lithium-ion batteries(LIBs).However,the lack of deep understanding on the failure mechanism of NM has seriously hindered its application,especially under the harsh condition of high-voltage without sacrifices of reversible ***,singlecrystal LiNi_(0.8)Mn_(0.2)O_(2) is selected and compared with traditional LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM),mainly focusing on the failure mechanism of Cofree cathode and illuminating the significant effect of Co element on the Li/Ni antisite defect and dynamic ***,the presence of high Li/Ni antisite defect in NM cathode easily results in the extremely dramatic H2/H3 phase transition,which exacerbates the distortion of the lattice,mechanical strain changes and exhibits poor electrochemical performance,especially under the high cutoff ***,the reaction kinetic of NM is impaired due to the absence of Co element,especially at the single-crystal ***,the negative influence of Li/Ni antisite defect is controllable at low current densities,owing to the attenuated ***,Co-free NM can exhibit better safety performance than that of NCM *** findings are beneficial for understanding the fundamental reaction mechanism of single-crystal Ni-rich Co-free cathode materials,providing new insights and great encouragements to design and develop the next generation of LIBs with low-cost and high-safety performances.

关键词： Li/Ni antisite defect Dynamic characteristic High-voltage Single-crystal Ni-rich Co-free cathodes Lithium-ion batteries

Analysis of China's Electricity Price and Electricity Burden of Basic Industries under the Carbon Peak Target before 2030

在线全文

学校读者我要写书评

暂无评论

CSEE Journal of Power and Energy Systems 2024年第2期10卷 481-491页

作者： Yue Qiu Suyang Zhou Wei Gu xiao-Ping zhang School of Electrical Engineering Southeast UniversityNanjingChina School of Electronic Electrical and System EngineeringUniversity of BirminghamU.K.

The Chinese government is deepening reformation of electricity prices during the 14th Five Year Plan period and has set a carbon emission reduction target of reaching carbon peak before *** this context,will the carbon emission target influence electricity pricing and will electricity price influence competitiveness of Chinese main industries are two questions needing to be *** paper compares China's electricity price level with the selected major countries in the world,and four typical industries are selected to evaluate their electricity burden ***,the correlation between residential electricity price and industrial electricity price and the influencing factors is analyzed,from the perspectives of scale,structure and *** to the model obtained by regression analysis,the electricity price level and corresponding residential and industrial electricity burden in 2025 and 2030 are *** Terms-Electricity burden,industrial electricity price,regression analysis,residential electricity price.

关键词： Electricity burden industrial electricity price regression analysis residential electricity price

Variational Neural Inference Enhanced Text Semantic Communication System

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

China Communications 2024年第7期21卷 50-64页

作者： zhang Xi zhang Yiqian Li Congduan Ma xiao School of Electronics and Communication Engineering Sun Yat-Sen UniversityShenzhen 518107China Guizhou University State Key Laboratory of Public Big Data Guiyang 550025China Shenzhen Key Laboratory of Navigation and Communication Integration Shenzhen 518107China School of Computer Science and Engineering Sun Yat-Sen UniversityGuangzhou 510006China

Recently,deep learning-based semantic communication has garnered widespread attention,with numerous systems designed for transmitting diverse data sources,including text,image,and speech,*** efforts have been directed toward improving system performance,many studies have concentrated on enhancing the structure of the encoder and ***,this often overlooks the resulting increase in model complexity,imposing additional storage and computational burdens on smart ***,existing work tends to prioritize explicit semantics,neglecting the potential of implicit *** paper aims to easily and effectively enhance the receiver's decoding capability without modifying the encoder and decoder *** propose a novel semantic communication system with variational neural inference for text ***,we introduce a simple but effective variational neural inferer at the receiver to infer the latent semantic information within the received *** information is then utilized to assist in the decoding *** simulation results show a significant enhancement in system performance and improved robustness.

关键词： deep learning semantic communication variational neural inference

Vanadium oxide nanospheres encapsulated in N-doped carbon nanofibers with morphology and defect dual-engineering toward advanced aqueous zinc-ion batteries

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2024年第2期89卷 599-609,I0013页

作者： Yunfei Song Laiying Jing Rutian Wang Jiaxi Cui mei Li Yunqiang zhang School of Materials Science and Engineering Qilu University of Technology(Shandong Academy of Sciences)Jinan 250353ShandongChina Institute of Fundamental and Frontier Sciences University of Electronic Science and Technology of ChinaChengdu 610054SichuanChina

Vanadium-based electrodes are regarded as attractive cathode materials in aqueous zinc ion batteries(ZIBs)caused by their high capacity and unique layered ***,it is extremely challenging to acquire high electrochemical performance owing to the limited electronic conductivity,sluggish ion kinetics,and severe volume expansion during the insertion/extraction process of Zn^(2+).Herein,a series of V_(2)O_(3)nanospheres embedded N-doped carbon nanofiber structures with various V_(2)O_(3)spherical morphologies(solid,core-shell,hollow)have been designed for the first time by an electrospinning technique followed thermal *** N-doped carbon nanofibers not only improve the electrical conductivity and the structural stability,but also provides encapsulating shells to prevent the vanadium dissolution and aggregation of V_(2)O_(3)***,the varied morphological structures of V_(2)O_(3)with abundant oxygen vacancies can alleviate the volume change and increase the Zn^(2+)***,the phase transition between V_(2)O_(3)and Zn_XV_(2)O_(5-m)·n H_(2)O in the cycling was also *** a result,the as-obtained composite delivers excellent long-term cycle stability and enhanced rate performance for coin cells,which is also confirmed through density functional theory(DFT)*** assembled into flexible ZIBs,the sample still exhibits superior electrochemical performance,which may afford new design concept for flexible cathode materials of ZIBs.

关键词： Aqueous zinc ion batteries Vanadium trioxide Oxygen vacancy Structure evolution Phase optimization