检索结果-南通市图书馆

A new family of windows——convolution windows and their applications

science china(Technological sciences) 2005年第4期48卷 468-480页

作者： zhang jieqiu1,2, liang changhong1 & chen yanpu3.1. department of applied math. & phys., college of science, airforce engineering university, xi’an 710051, china 2. National Key Laboratory of Antennas and Microwave Technology, xidian university, xi’an 710071, china 3. Computer Center, xi’an Communication college, xi’an 710106, china department of applied math. & phys. College of Science Airforce Engineering University Xi’an China National Key Laboratory of Antennas and Microwave Technology Xidian University Xi’an China Computer Center Xi’an Communication College Xi’an China

A new family of windows is constructed by convolutions via a few rectangular windows with same time width and is thus referred to as convolution windows. The expressions of the second-order up to the eighth-order convolution windows in both the time and frequency domains are derived. Their applications in high accuracy harmonic analysis of periodic signals are investigated. Comparisons between the proposed windows and some known windows with the same width shows that, when the synchronous deviation of data sampling is slight, the proposed ones have the least effect of spectral leakage. Therefore, the new windows are well suited for high accuracy harmonic analysis and parameter estimation for periodic signals. The error analysis and computer simulations show that the estimation errors, corresponding to frequency, amplitude and phase of every harmonic component of a signal, are proportional to the pth power of the relative frequency deviation in case of the pth-order convolution window is applied to windowing signal of approximately p cycles. By introducing real time adjustment in sampling interval, the proposed algorithm can adaptively trace signal frequency and lead to less sampling synchronous deviation. The proposed approach has the advantages of easy implementation and high measure precision and can be used in harmonic analysis of quasi-periodic signals whose fundamental frequency drifts slowly with time.

关键词： signal processing harmonic analysis window function convolution window synchronous error spoctral leakage

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Achieving structurally stable O3-type layered oxide cathodes through site-specific cation-anion co-substitution for sodium-ion batteries

引用

Journal of Energy Chemistry 2024年第6期93卷 411-418,I0011页

作者： Yihao Shen chen cheng xiao xia Lei Wang xi Zhou Pan Zeng Jianrong Zeng liang zhang Institute of Functional Nano&Soft Materials(FUNSOM) Soochow UniversitySuzhou 215123JiangsuChina Institute for Advanced Study School of Mechanical EngineeringChengdu UniversityChengdu 610106SichuanChina Shanghai Synchrotron Radiation Facility Shanghai Advanced Research InstituteChinese Academy of SciencesShanghai 201204China Shanghai Institute of applied phys.cs Chinese Academy of SciencesShanghai 201800China Jiangsu Key Laboratory of Advanced Negative Carbon Technologies Soochow UniversitySuzhou 215123JiangsuChina

O3-type layered oxides have garnered great attention as cathode materials for sodium-ion batteries because of their abundant reserves and high theoretical ***,challenges persist in the form of uncontrollable phase transitions and intricate Na^(+)diffusion pathways during cycling,resulting in compromised structural stability and reduced capacity over *** study introduces a special approach employing site-specific Ca/F co-substitution within the layered structure of O_(3)-NaNi_(0.5)Mn_(0.5)O_(2) to effectively address these ***,the strategically site-specific doping of Ca into Na sites and F into O sites not only expands the Na^(+)diffusion pathways but also orchestrates a mild phase transition by suppressing the Na^(+)/vacancy ordering and providing strong metal-oxygen bonding strength,*** as-synthesized Na_(0.95)Ca_(0.05)Ni_(0.5)Mn_(0.5)O_(1.95)F_(0.05)(NNMO-CaF)exhibits a mild O3→O3+O'3→P3 phase transition with minimized interlayer distance variation,leading to enhanced structural integrity and stability over extended *** a result,NNMO-CaF delivers a high specific capacity of 119.5 mA h g^(-1)at a current density of 120 mA g^(-1)with a capacity retention of 87.1%after 100 *** study presents a promising strategy to mitigate the challenges posed by multiple phase transitions and augment Na^(+)diffusion kinetics,thus paving the way for high-performance layered cathode materials in sodium-ion batteries.

关键词： Sodium-ion batteries O3-type layered oxides Site-specific co-doping Phase transition

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Efficient optimization of electron transfer pathway by constructing phosphide/ceria interface boosts seawater hydrogen production

引用

Journal of Energy Chemistry 2024年第8期95卷 490-498,I0011页

作者： Yifan Zhao Lingfeng Yang Youyu Long Min xi Anran chen Hua zhang School of Materials and Energy Yunnan UniversityKunming 650091YunnanChina Electron Microscopy Centre of Yunnan university Yunnan UniversityKunming 650091YunnanChina

Developing efficient and durable hydrogen evolution reaction(HER)electrocatalysts is one of the most important issues for the commercialization of seawater electrolysis,but it remains ***,we report a CeO_(2)-CoP nanoneedle array catalyst loaded on Ti mesh(CeO_(2)-CoP/TM)with workfunction-induced directional charge transport *** CeO_(2)-CoP/TM catalyst showed superior HER catalytic activity and stability,with over potentials of 41 and 60 mV to attain 10 mA cm^(-2),in 1 M KOH and 1 M KOH+seawater electrolyte,*** results and theoretical calculations reveal that the work function drives the charge transfer from CeO_(2)to CoP,which effectively balances the electronic density of CoP and CeO_(2),optimizes the d-band center,and accelerates the water activation kinetics,thus enhancing the HER *** solar-driven water electrolysis device displays a high and stable solar-to-hydrogen conversion efficiency of 19.6%.This study offers a work function-induced directional charge transport strategy to design efficient and durable catalysts for hydrogen production.

关键词： Work function Heterostructure Charge transport Seawater splitting Solar-to-hydrogen

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Non-destructive buffer enabling near-infrared-transparent inverted inorganic perovskite solar cells toward 1400 h light-soaking stable perovskite/Cu(In,Ga)Se_(2) tandem solar cells

引用

Journal of Energy Chemistry 2024年第10期97卷 622-629,I0013页

作者： Yu zhang Zhaoheng Tang Zhongyang zhang Jiahong Tang Minghua Li Siyuan Zhu Wenyan Tan xi Jin Tongsheng chen Jinsong Hu Chao Zhou Chunlei Yang Qijie liang Xugang Guo Weimin Li Weiqiang chen Yan Jiang MOE Key Laboratory of Laser Life science&Guangdong Provincial Key Laboratory of Laser Life science Guangzhou Key Laboratory of Spectral Analysis and Functional ProbesCollege of BiophotonicsSouth China Normal UniversityGuangzhou 510631GuangdongChina school of Materials science and engineering Beijing Institute of TechnologyBeijing 100081China Songshan Lake Materials Laboratory Dongguan 523429GuangdongChina department of Materials science and engineering Guangdong Provincial Key Laboratory of Functional Oxide Materials and DevicesSouthern University of Science and TechnologyShenzhen 518055GuangdongChina Beijing Advanced Innovation Center for Soft Matter science and engineering College of Chemical EngineeringCollege of Materials Science and EngineeringBeijing University of Chemical TechnologyBeijing 100029China department of phys.cs Liaoning UniversityShenyang 110036LiaoningChina Beijing National Laboratory for Molecular sciences(BNLMS) Institute of ChemistryChinese Academy of SciencesBeijing 100190China School of phys.cs and Materials science Guangzhou UniversityGuangzhou 510006GuangdongChina Shenzhen Institute of Advanced Technology Chinese Academy of SciencesShenzhen 18055GuangdongChina

Near-infrared(NIR)transparent inverted all-inorganic perovskite solar cells(PSCs)are excellent top cell candidates in tandem *** essential challenge is the replacement of metal contacts with transparent conductive oxide(TCO)electrodes,which requires the introduction of a buffer layer to prevent sputtering *** this study,we show that the conventional buffers(i.e.,small organic molecules and atomic layer deposited metal oxides)used for organic-inorganic hybrid perovskites are not applicable to all-inorganic perovskites,due to non-uniform coverage of the vulnerable layers underneath,deterioration upon ion bombardment and moisture induced perovskite phase transition,A thin film of metal oxide nanoparticles by the spin-coating method serves as a non-destructive buffer layer for inorganic ***-inorganic inverted near-infrared-transparent PSCs deliver a PCE of 17.46%and an average transmittance of 73.7%between 780 and 1200 *** combination with an 18.56%Cu(In,Ga)Se_(2) bottom cell,we further demonstrate the first all-inorganic perovskite/CIGS 4-T tandem solar cell with a PCE of 24.75%,which exhibits excellent illumination stability by maintaining 86.7%of its initial efficiency after 1400 *** non-destructive buffer lays the foundation for efficient and stable NIR-transparent inverted inorganic perovskite solar cells and perovskite-based tandems.

关键词： CsPbI_(3)perovskite Inverted perovskite solar cells Tandem solar cells Buffer layer Stability

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Enhanced red luminescence of Ca_(3)Si_(2−x)M_(x)O_(7):Eu^(3+)(M=Al,P)phosphors via partial substitution of Si^(4+) for applications in white light-emitting diodes

引用

Rare Metals 2024年第2期43卷 736-748页

作者： Yu-Hao Ma xi Gao Wen-Tao zhang Zhen-Rui Yang Zhou Zhao chen Qu college of Materials and Chemistry and Chemical engineering Chengdu University of TechnologyChengdu610059China State Key Laboratory of Geohazard Prevention and Geoenvironment Protection Chengdu University of TechnologyChengdu610059China International Advanced Energy science Research and Education Center Graduate School of Energy ScienceKyoto UniversityYoshida-HonmachiKyoto606-8501Japan

A red-emitting phosphor Ca_(2.91)Si_(2)O_(7):0.09Eu^(3+) with partial Al^(3+)/P^(5+) substitution on Si^(4+) was synthesized via a simple solid-state method,and the effects of the introduction of the M^(3+/5+)(M=Al,P)ions on the crystal structure and photoluminescence performance of Ca_(2.91)Si_(2−x)M_(x)O_(7):0.09Eu^(3+) phosphors were *** X-ray diffraction(XRD),energy-dispersive X-ray spectroscopy(EDS),and X-ray photoelectron spectroscopy(XPS)results revealed that the structure of Ca_(3)Si_(2)O_(7) remained the same after the introduction of Al^(3+) and P^(5+) *** characteristic emission of Eu^(3+)-doped Ca_(3)Si_(2−x)M_(x)O_(7) phosphors exhibited two main peaks at 617 nm(red)and 593 nm(orange)under excitation at 394 nm,which originated from the^(5)D_(0)→^(7)F_(2)and^(5)D_(0)→^(7)F_(1) electron transitions of Eu^(3+) *** the partial substitution of Al^(3+) and P^(5+),the red emission intensities of the Ca_(2.91)Si_(2)O_(7):0.09Eu^(3+) phosphors were significantly enhanced by 1.88-and 1.42-fold,respectively,which is attributed to the crystal-field effect around Eu^(3+).Meanwhile,the luminescence intensities of the Ca_(2.91)Si_(1.96)Al_(0.04)O_(7):0.09Eu^(3+) and Ca_(2.91)Si_(1.94)P_(0.06)O_(7):0.09Eu^(3+) phosphors at 210℃ were 79.36%and 77.53%of those at 30°C,respectively,indicating their excellent thermal ***,the as-prepared Ca_(2.91)Si_(1.96)Al_(0.04)O_(7):0.09Eu^(3+)and Ca_(2.91)Si_(1.94)P_(0.06)O_(7):0.09Eu^(3+) red-emitting phosphors were combined with a near-ultraviolet chip of 395 nm to fabricate red-light-emitting diode(LED)and white(w)-LED devices with excellent chromaticity *** summary,Al^(3+)/P^(5+)-substituted Ca_(2.91)Si_(2)O_(7):0.09Eu^(3+) can serve as red-emitting phosphors for applications in w-LEDs.

关键词： Ca_(3)Si_(2)O_(7) Red-emitting phosphor Structure substitution Luminescence enhancement Crystal-field effect White light-emitting diode

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A three-way electrolyte with ternary solvents for high-energy-density and long-cycling lithium-sulfur pouch cells

引用

SusMat 2024年第2期4卷 1-12页

作者： Zheng Li Legeng Yu chen-xi Bi xi-Yao Li JinMa xiang chen Xue-Qiang zhang Aibing chen Haoting chen Zuoru zhang Li-Zhen Fan Bo-Quan Li cheng Tang Qiang zhang Tsinghua Center for Green Chemical engineering Electrification Beijing Key Laboratory of Green Chemical Reaction Engineering and TechnologyDepartment of Chemical EngineeringTsinghua UniversityBeijingChina School of Materials science and engineering Beijing Institute of TechnologyBeijingChina Institute of Advanced Materials and Technology University of Science and TechnologyBeijingChina Shanxi Research Institute for Clean Energy Tsinghua UniversityTaiyuanChina Center for Next-Generation Energy Materials and School of Chemical engineering Sungkyunkwan UniversityJangan-GuSuwon-SiGyeonggi-DoRepublic of Korea college of Chemical and Pharmaceutical engineering Hebei University of Science and TechnologyShijiazhuangChina Ordos Carbon Neutral Research and Application Co. Ltd.Kangbashi DistrictOrdos CityInner MongoliaChina Institute for Carbon Neutrality Tsinghua UniversityBeijingChina

Lithium–sulfur(Li–S)batteries promise high-energy-density potential to exceed the commercialized lithiumion batteries but suffer from limited cycling lifespan due to the side reactions between lithium polysulfides(LiPSs)and Li metal ***,a three-way electrolyte with ternary solvents is proposed to enable high-energy-density and long-cycling Li–S pouch ***,ternary solvents composed of 1,2-dimethoxyethane,di-isopropyl sulfide,and 1,3,5-trioxane are employed to guarantee smooth cathode kinetics,inhibit the parasitic reactions,and construct a robust solid electrolyte interphase,*** cycling lifespan of Li–S coin cells with 50μm Li anodes and 4.0 mg cm^(−2) sulfur cathodes is prolonged from88 to 222 cycles using the three-way ***-heterogeneous solvation structure of LiPSs and organic-rich solid electrolyte interphase are identified to improve the cycling stability of Li metal ***,a 3.0 Ah-level Li–S pouch cell with the three-way electrolyte realizes a high energy density of 405 Wh kg^(−1) and undergoes 27 *** affords a three-way electrolyte recipe for suppressing the side reactions of LiPSs and inspires rational electrolyte design for practical high-energy-density and long-cycling Li–S batteries.

关键词： lithium metal anodes lithium-sulfur batteries pouch cells solid electrolyte interphase three-way electrolyte

来源：

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

Microstructure evolution of single crystal copper wires in cold drawing

引用

science china(Technological sciences) 2007年第6期50卷 736-748页

作者： chen Jian1,2, YAN Wen1,2, WANG XueYan2 & FAN xinHui2 1 department of applied phys.cs, Northwestern Polytechnical university, xi’an 710072, china 2 School of Material science and Chemical engineering, xi’an Technological university, xi’an 710032, china department of applied phys.cs Northwestern Polytechnical University Xi’an China School of Material science and Chemical engineering Xi’an Technological University Xi’an China

The deformation microstructure evolution of single crystal copper wires produced by OCC method has been studied with the help of TEM, EBSD; OM. The results show that there are a small number of dendrites; twins in the undeformed single crystal copper wires. However, it is difficult to observe these dendrites in deformed single crystal copper wires. The structure evolution of deformed single crystal copper wires during drawing process can be divided into three stages. When the true strain is lower than 0.94, macroscopic subdivision of grains is not evident,; the microscopic evolution of deformed structure is that the cells are formed; elongated in drawn direction. When the true strain is between 0.94; 1.96, macroscopic subdivision of grains takes place,; the number of microbands located on {111}; cell blocks is much more than that with the true strain lower than 0.94. When the true strain is larger than 1.96, the macroscopic subdivision of grains becomes more evident than that with the true strain between 0.94; 1.96,; S-bands structure; lamellar boundaries will be formed. From EBSD analysis, it is found that part of 100 texture resulting from solidifying is transformed into 111; 112 due to shear deformation, but 100 texture component is still kept in majority. When the true strain is 0.94, the misorientation angle of dislocation boundaries resulting from deformation is lower than 14°. However, when the true strain arrives at 1.96, the misorientation angle of some boundaries will be greater than 50°,; the peak of misorientation angle distribution produced by texture evolution is located in the range between 25°; 30°.

关键词： single crystal copper wires, deformation structure, electron backscattering diffraction, transmission electron microscopy

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Accelerated Sequential Deposition Reaction via Crystal Orientation engineering for Low-Temperature,High-Efficiency Carbon-Electrode CsPbBr_(3) Solar Cells

引用

Energy & Environmental Materials 2024年第1期7卷 168-175页

作者： Zeyang zhang Weidong Zhu Tianjiao Han Tianran Wang Wenming Chai Jiaduo Zhu He xi Dazheng chen Gang Lu Peng Dong Jincheng zhang Chunfu zhang Yue Hao State Key Discipline Laboratory of Wide Band Gap Semiconductor Technology&Shaanxi Joint Key Laboratory of Graphene School of MicroelectronicsXidian UniversityXi'an 710071China Guangzhou Wide Bandgap Semiconductor Innovation Center Guangzhou institute of technologyXidian UniversityGuangzhou 510555China Qinghai Huanghe Hydropower Development CO. LTD.Xining810008China

Low-temperature,ambient processing of high-quality CsPbBr_(3)films is demanded for scalable production of efficient,low-cost carbon-electrode perovskite solar cells(PSCs).Herein,we demonstrate a crystal orientation engineering strategy of PbBr_(2)precursor film to accelerate its reaction with CsBr precursor during two-step sequential deposition of CsPbBr_(3)*** a novel strategy is proceeded by adding CsBr species into PbBr_(2)precursor,which can tailor the preferred crystal orientation of PbBr_(2)film from[020]into[031],with CsBr additive staying in the film as CsPb_(2)Br_(5)*** calculations show that the reaction energy barrier of(031)planes of PbBr_(2)with CsBr is lower about 2.28 eV than that of(O2O)***,CsPbBr_(3)films with full coverage,high purity,high crystallinity,micro-sized grains can be obtained at a low temperature of 150℃.Carbon-electrode PSCs with these desired CsPbBr_(3)films yield the record-high efficiency of 10.27%coupled with excellent operation ***,the 1 cm^(2)area one with the superior efficiency of 8.00%as well as the flexible one with the champion efficiency of 8.27%and excellent mechanical bending characteristics are also achieved.

关键词： carbon-electrode perovskite solar cells crystal orientation engineering CsPbBr_(3) low temperature two-step sequential deposition

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Mitigating Lattice Distortion of High‑Voltage LiCoO_(2)via Core‑Shell Structure Induced by Cationic Heterogeneous Co‑Doping for Lithium‑Ion Batteries

引用

Nano-Micro Letters 2024年第3期16卷 169-182页

作者： Zezhou Lin Ke Fan Tiancheng Liu Zhihang Xu Gao chen Honglei zhang Hao Li Xuyun Guo xi zhang Ye Zhu Peiyu Hou Haitao Huang department of applied phys.cs and Research Institute for Smart Energy The Hong Kong Polytechnic UniversityHong KongPeople’s Republic of China department of applied phys.cs The Hong Kong Polytechnic UniversityHong KongPeople’s Republic of China Institute of Nanosurface science and engineering Guangdong Provincial Key Laboratory of Micro/Nano Optomechatronics EngineeringShenzhen UniversityShenzhenPeople’s Republic of China School of phys.cs and Technology University of JinanJinanShandongPeople’s Republic of China

Inactive elemental doping is commonly used to improve the structural stability of high-voltage layered transition-metal oxide ***,the one-step co-doping strategy usually results in small grain size since the low diffusivity ions such as Ti^(4+)will be concentrated on grain boundaries,which hinders the grain *** order to synthesize large single-crystal layered oxide cathodes,considering the different diffusivities of different dopant ions,we propose a simple two-step multi-element co-doping strategy to fabricate core–shell structured LiCoO_(2)(CS-LCO).In the current work,the high-diffusivity Al^(3+)/Mg^(2+)ions occupy the core of single-crystal grain while the low diffusivity Ti^(4+)ions enrich the shell *** Ti^(4+)-enriched shell layer(~12 nm)with Co/Ti substitution and stronger Ti–O bond gives rise to less oxygen ligand ***-situ XRD demonstrates the constrained contraction of c-axis lattice parameter and mitigated structural *** a high upper cut-off voltage of 4.6 V,the single-crystal CS-LCO maintains a reversible capacity of 159.8 mAh g^(−1)with a good retention of~89%after 300 cycles,and reaches a high specific capacity of 163.8 mAh g^(−1)at *** proposed strategy can be extended to other pairs of low-(Zr^(4+),Ta^(5+),and W6+,etc.)and high-diffusivity cations(Zn^(2+),Ni^(2+),and Fe^(3+),etc.)for rational design of advanced layered oxide core–shell structured cathodes for lithium-ion batteries.

关键词： Lithium-ion battery LiCoO_(2) Heterogeneous co-doping Core-shell structure High-voltage stability

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

The complex variable reproducing kernel particle method for elasto-plasticity problems

引用

science china(phys.cs,Mechanics & Astronomy) 2010年第5期53卷 954-965页

作者： chen Li1 & chenG YuMin2 1 department of engineering Mechanics,Chang’an university,xi’an 710064,china 2 Shanghai Institute of applied math.matics and Mechanics,Shanghai university,Shanghai 200072,china department of engineering Mechanics Chang’an University Xi’an China Shanghai Institute of applied math.matics and Mechanics Shanghai University Shanghai China

On the basis of reproducing kernel particle method(RKPM),using complex variable theory,the complex variable reproducing kernel particle method(CVRKPM) is discussed in this *** advantage of the CVRKPM is that the correction function of a two-dimensional problem is formed with one-dimensional basis function when the shape function is *** the CVRKPM is applied to solve two-dimensional elasto-plasticity *** Galerkin weak form is employed to obtain the discretized system equation,the penalty method is used to apply the essential boundary *** then,the CVRKPM for two-dimensional elasto-plasticity problems is formed,the corresponding formulae are obtained,and the Newton-Raphson method is used in the numerical *** numerical examples are given to show that this method in this paper is effective for elasto-plasticity analysis.

关键词： meshless method reproducing kernel particle method(RKPM) complex variable reproducing kernel particle method(CVRKPM) correction function elasto-plasticity

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：