检索结果-南通市图书馆

Low-permittivity LiLn(PO_(3))_(4)(Ln=La,Sm,Eu)dielectric ceramics for microwave/millimeter-wave communication

Journal of Advanced Ceramics 2024年第5期13卷 602-620页

作者： huanrong Tian Xiaohan zhang Zidong zhang Yao Liu haitao Wu Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials(Ministry of Education) Shandong UniversityJinan 250061China School of Materials Science and Engineering Shandong UniversityJinan 250061China School of Environmental and Material Engineering Yantai UniversityYantai 264005China

The development of dielectric materials with low permittivity and low loss is a great challenge in wireless *** this study,LiLn(PO_(3))_(4)(Ln=La,Sm,Eu)ceramic systems were successfully prepared using the traditional solid-state method.X-ray diffraction analysis indicated that the LiLn(PO_(3))_(4)ceramics crystallized in a monoclinic structure when sintered at 850–940℃.The characteristic peak shifted to higher angles with variations in the Ln element,which was ascribed to a reduction in the cell *** analysis by structure refinement revealed that the reduction in the cell volume resulted from the decrease in chemical bond lengths and the compression of[LiO_(4)]and[PO_(4)]***,the LiLn(PO_(3))_(4)ceramic system displayed exceptional performance at low sintering temperatures(910–925℃),including a high quality factor(q·f)of 41,607–75,968 Ghz,low temperature coefficient of resonant frequency(τ_(f))ranging from−19.64 to−47.49 ppm/℃,low permittivity(ε_(r))between 5.04 and 5.26,and low density(3.04–3.26 g/cm^(3)).The application of Phillips–van Vechten–Levine(P–V–L)theory revealed that the increased q·f value of the LiLn(PO_(3))_(4)systems can be attributed to the enhanced packing fraction,bond covalency,and lattice energy,and the stability of τ_(f) was associated with the increase in the bond ***,a prototype microstrip patch antenna using LiEu(PO_(3))_(4) ceramics was *** measurement results demonstrated excellent antenna performance with a bandwidth of 360 Mhz and a peak gain of 5.11 dB at a central frequency of 5.08 ***,low-εr LiLn(PO_(3))_(4)ceramic systems are promising candidates for microwave/millimeter-wave communication.

关键词： low permittivity LiLn(PO_(3))_(4) microwave dielectric properties Phillips-van Vechten-Levine(P-V-L)theory microstrip patch antenna

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

Performance and environmental impacts of deep foundation excavation in soft soils:A field and modeling-based case study in Nanjing,China

引用

Underground Space 2024年第5期18卷 218-238页

作者： Chenhe Ge Meng Yang Pengfei Li Mingju zhang Zhonghao zhang Key Laboratory of Urban Security and Disaster Engineering Ministry of EducationBeijing University of TechnologyBeijing 100124China China Construction Second Engineering Bureau Ltd. Beijing 100070China The Third Construction Engineering Company Ltd.of China Construction Second Engineering Bureau Beijing 100070China

This paper focuses on the performance of a braced deep excavation in soft soil based on field monitoring and numerical *** tests were conducted to determine the soil parameters used in the modified Cam–Clay(MCC)*** field monitoring means were adopted and a three-dimensional model was *** and temporal effects induced by the excavation are investigated for the deep-large foundation pit in soft *** characteristics of the enclosure structure and the surrounding environment throughout the excavation process are *** behaviors of diaphragm walls,columns,the maximum wall deflection rate,ground surface settlement,and utility pipelines were focused on and investigated during the whole excavation ***,the axial forces of the internal supports are *** on the measured and simulated data,the following main conclusions were obtained:the numerical simulation results are in good agreement with the measured values,which proves the accuracy of the model parameters;the wall and the ground surface showed the maximum displacement increment at stage 9,which was a coupled product of the"creep effect"of the soft soil in Nanjing,China and the"depth effect"of the excavation;as the excavation progressed,the ground settlement changed from a"rising"to a"spoon-shaped"trend,dvm was measured betweenδ_(vm)=0.0686%h andδ_(vm)=0.1488%h;the rebound deformation curve of the pit bottom was corrugated,and the depth of disturbance of the pit bottom after the completion of soil unloading was 2–3 times the excavation depth;the closer the pipeline is to the corner of the pit,the less the excavation process will affect the settlement of the pipeline and the less the obvious pit corner effect will occur;the support strength of the buttress and the longest corner brace should be strengthened during the actual construction process to ensure the stability of the foundation deformation.

关键词： Deep excavation Modified Cam-Clay Deformation characteristics Creep effect Corner effect

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

Resource Allocation for Cognitive Network Slicing in PD-SCMA System Based on Two-Way Deep Reinforcement Learning

引用

China Communications 2024年第6期21卷 53-68页

作者： zhang Zhenyu zhang Yong Yuan Siyu Cheng Zhenjie School of Electronic Engineering Beijing University of Posts and TelecommunicationsBeijing 100876China Beijing Key Laboratory of Work Safety Intelligent Monitoring(Beijing University of Posts and Telecommunications) Beijing 100876China

In this paper,we propose the Two-way Deep Reinforcement Learning(DRL)-Based resource allocation algorithm,which solves the problem of resource allocation in the cognitive downlink network based on the underlay *** users(SUs)in the cognitive network are multiplexed by a new Power Domain Sparse Code Multiple Access(PD-SCMA)scheme,and the physical resources of the cognitive base station are virtualized into two types of slices:enhanced mobile broadband(eMBB)slice and ultrareliable low latency communication(URLLC)*** design the Double Deep q Network(DDqN)network output the optimal codebook assignment scheme and simultaneously use the Deep Deterministic Policy Gradient(DDPG)network output the optimal power allocation *** objective is to jointly optimize the spectral efficiency of the system and the quality of Service(qoS)of *** results show that the proposed algorithm outperforms the CNDDqN algorithm and modified JEERA algorithm in terms of spectral efficiency and qoS ***,compared with the Power Domain Non-orthogonal Multiple Access(PD-NOMA)slices and the Sparse Code Multiple Access(SCMA)slices,the PD-SCMA slices can dramatically enhance spectral efficiency and increase the number of accessible users.

关键词： cognitive radio deep reinforcement learning network slicing power-domain non-orthogonal multiple access resource allocation

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

Privacy-Preserving Frank-Wolfe on Shuffle Model

引用

Acta Mathematicae Applicatae Sinica 2024年第4期40卷 887-907页

作者： Ling-jie zhang Shi-song WU hai zhang School of Mathematics Northwest UniversityXi’an 710127China School of Mathematics and Information Science Baoji University of Arts and SciencesBaoji 721013China China Southern Power Grid Artificial Intelligence Technology Company Limited Guangzhou 510700China

In this paper,we design the differentially private variants of the classical Frank-Wolfe algorithm with shuffle model in the optimization of machine *** weak assumptions and the generalized linear loss(GLL)structure,we propose a noisy Frank-Wolfe with shuffle model algorithm(NoisyFWS)and a noisy variance-reduced Frank-Wolfe with the shuffle model algorithm(NoisyVRFWS)by adding calibrated laplace noise under shuffling scheme in thel_(p)(p∈[1,2])-case,and study their privacy as well as utility guarantees for the h?lder smoothness *** particular,the privacy guarantees are mainly achieved by using advanced composition and privacy amplification by *** utility bounds of the Noisy FWS and NoisyVRFWS are analyzed and obtained the optimal excess population risksO(n-(1+α/4α+log(d)√log(1/δ)/n∈and O(n-1+α/4α+log(d)√log1(+δ)/n^(2)∈with gradient complexity O(n(1+α)^(2)/4α^(2)forα∈[1/√3,1].It turns out that the risk rates under shuffling scheme are a nearly-dimension independent rate,which is consistent with the previous work in some *** addition,there is a vital tradeoff between(α,L)-holder smoothness GLL and the gradient *** linear gradient complexity O(n)is showed by the parameterα=1.

关键词： differential privacy Frank-Wolfe algorithm privacy amplification shuffle model

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

Recent advances in photochemistry for positron emission tomography imaging

引用

Chinese Chemical Letters 2024年第8期35卷 149-162页

作者： Jing-Jing zhang Lujun Lou Rui Lv Jiahui Chen Yinlong Li Guangwei Wu Lingchao Cai Steven h.Liang Zhen Chen Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources Jiangsu Provincial Key Lab for the Chemistry and Utilization of Agro-Forest BiomassJiangsu Key Lab of Biomass-Based Green Fuels and ChemicalsInternational Innovation Center for Forest Chemicals and MaterialsCollege of Chemical EngineeringNanjing Forestry UniversityNanjing 210037China Department of Radiology and Imaging Sciences Emory UniversityAtlantaGA 30322United States

As a powerful noninvasive imaging technology,positron emission tomography(PET)has been playing an important role in disease theranostics and drug *** successful application of PET relies on not only the biological properties of PET tracers but also the availability of facile and efficient radiochemical reactions to enable practical production and widespread use of PET *** recently,photochemistry is emerging as a novel,mild and efficient approach to generating PET *** this review,we focus on the recent advances in newly developed photocatalytic radiochemical reactions,innovation on automated photochemical radiosynthesis modules,as well as implementation in late-stage radiolabeling and radio-pharmaceutical synthesis for PET *** believe that this review will inspire the development of more promising radiolabeling protocols for the preparation of clinically useful PET agents.

关键词： Positron emission tomography(PET) Fluorine-18 Carbon-11 Photocatalysis Automation Late-stage functionalization

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

Magnetic Topological Dirac Semimetal Transition Driven by SOC in EuMg_(2)Bi_(2)

引用

Chinese Physics Letters 2024年第1期41卷 63-67页

作者：王佳萌钱浩吉姜琦乔山叶茂 State Key Laboratory of Functional Materials for Informatics Shanghai Institute of Microsystem and Information TechnologyChinese Academy of SciencesShanghai 200050China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China Research Center for Intelligent Chips and Devices Zhejiang LabHangzhou 311121China Center for Transformative Science ShanghaiTech UniversityShanghai 201210China School of Physical Science and Technology ShanghaiTech UniversityShanghai 201210China Shanghai Synchrotron Radiation Facility Shanghai Advanced Research InstituteChinese Academy of SciencesShanghai 201204China

Magnetic topological semimetals have been at the forefront of condensed matter physics due to their ability to exhibit exotic transport *** the interplay between magnetic and topological orders in systems with broken time-reversal symmetry is crucial for realizing non-trivial quantum *** delve into the electronic structure of the rare-earth-based antiferromagnetic Dirac semimetal EuMg_(2)Bi_(2) using first-principles calculations and angle-resolved photoemission *** calculations reveal that the spin-orbit coupling(SOC)in EuMg_(2)Bi_(2) prompts an insulator to topological semimetal transition,with the Dirac bands protected by crystal *** linearly dispersive states near the Fermi level,primarily originating from Bi 6p orbitals,are observed on both the(001)and(100)surfaces,confirming that EuMg_(2)Bi_(2) is a three-dimensional topological Dirac *** research offers pivotal insights into the interplay between magnetism,SOC and topological phase transitions in spintronics applications.

关键词： spectroscopy topological Dirac

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 sponge-based iron-tannic-acid hydrogel interface evaporator designed for clean water production

引用

Science China(Technological Sciences) 2024年第5期67卷 1579-1591页

作者： zhang ZeKun LI ChengLong TAO huaYu GE Bo zhang YongLe ZhAO LiMin LIU JunChang REN GuiNa zhang ZhaoZhu School of Materials Science and Engineering Liaocheng UniversityLiaocheng252059China School of Environmental and Material Engineering Yantai UniversityYantai264405China State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou730000China

Due to the rapid advancement of technologies,there has been a significant increase in the discharge of industrial wastewater,and freshwater is becoming a scarce ***,research on solar evaporators is mainly focused on the efficient production of clean water,with less emphasis on the removal of residual pollutants remaining in the original *** this study,problems,including the difficult recovery of catalyst powder and the difficult removal of floating organic matter are solved by co-depositing low-surface-tension zirconia particles and bismuth tungstate onto the floating *** and melamine sponges were combined to solve the problem that traditional hydrogels lack mechanical *** excellent water-repellent effect can be seen from the contact angle between the liquid globule and canvas/felt,which is greater than 155°.The steam generation rate of the assembled evaporation system is 1.78 kg m^(-2)h^(-1),and its purification efficiency for methyl orange and rhodamine B exceeds 99%.This study presents a novel strategy for treating wastewater contaminated with organic dyes,aiming to solve problems including environmental damage,water pollution,and water scarcity.

关键词： oil removal non-wetting interface

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

Construction of Phosphorus-Functionalized Multichannel Carbon Interlayers for Dendrite-Free Metallic Zn Anodes

引用

Energy & Environmental Materials 2024年第5期7卷 99-107页

作者： Liang he qingyin zhang he Li Shiping Liu Ting Cheng Ruoxuan zhang Yujia Wang Peng zhang Zhiqiang Shi Tianjin Key Laboratory of Advanced Fibers and Energy Storage School of Materials Science and Engineering Tiangong University Cangzhou Institute of Tiangong University School of Chemical Engineering and Technology Tiangong University Tianjin Lishen Battery Joint-Stock CO. LTD

Zn metal anodes are usually subject to grave dendrite growth during platting/stripping, which dramatically curtails the lifespan of aqueous Zn-ion batteries and capacitors. To address above problems, in our work, a novel phosphorus-functionalized multichannel carbon interlayer was designed and covered on Zn anodes. The results demonstrated that the multichannel structure combined with the three-dimensional meshy skeleton can provide more sufficient space for Zn deposition, thereby effectively inhibiting the growth of zinc dendrites. Meanwhile, theoretical calculations also confirmed that the P–C and P=O functional groups from phosphorus-functionalized multichannel carbon interlayer have the decisive influence in reducing the zinc nucleation potential and depositing uniformly zinc. Concretely, the symmetrical battery assembled with phosphorus-functionalized multichannel carbon interlayer-covered Zn anodes possessed a long lifetime of 3300 h at2 mA cm-2with 1 mAh cm-2. Furthermore, the full cell with activated carbon cathodes exhibited a high specific capacity of 80.5 mAh g-1and outstanding cycling stability without capacity decay after 15 000 cycles at a high current density of 5 A g-1. The superior electrochemical performance exceeded that of most reported papers. Consequently, our synthesized zincophilic interlayer with the unique structure has superior prospects for application in stabilizing zinc anodes and prolonging the lifespan of batteries.

关键词： aqueous Zn-ion supercapacitors multichannel carbon fiber phosphorus functionalized Zn dendrite Zn metal anode

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Dilute Aqueous-Aprotic Electrolyte Towards Robust Zn-Ion hybrid Supercapacitor with high Operation Voltage and Long Lifespan

引用

Nano-Micro Letters 2024年第9期16卷 1-12页

作者： Shuilin Wu Yibing Yang Mingzi Sun Tian zhang Shaozhuan huang Daohong zhang Bolong huang Pengfei Wang Wenjun zhang Key Laboratory of Catalysis and Energy Materials Chemistry of Ministry of Education&hubei Key Laboratory of Catalysis and Materials Science South-Central Minzu UniversityWuhan 430074People’s Republic of China Department of Materials Science and Engineering and Center of Super‑Diamond and Advanced FilmsCity University of Hong Kong83 Tat Chee AvenueKowloon TongHong Kong SARPeople’s Republic of China Department of Applied Biology and Chemical Technology The Hong Kong Polytechnic UniversityHung HomKowloonHong Kong SARPeople’s Republic of China Key Laboratory of Photochemical Conversion and Optoelectronic Materials Technical Institute of Physics and ChemistryChinese Academy of SciencesBeijingPeople’s Republic of China

With the merits of the high energy density of batteries and power density of supercapacitors,the aqueous Zn-ion hybrid supercapacitors emerge as a promising candidate for applications where both rapid energy delivery and moderate energy storage are ***,the narrow electrochemical window of aqueous electrolytes induces severe side reactions on the Zn metal anode and shortens its *** also limits the operation voltage and energy density of the Zn-ion hybrid ***'water in salt'electrolytes can effectively broaden their electrochemical windows,but this is at the expense of high cost,low ionic conductivity,and narrow temperature compatibility,compromising the electrochemical performance of the Zn-ion hybrid ***,designing a new electrolyte to balance these factors towards high-performance Zn-ion hybrid supercapacitors is urgent and *** developed a dilute water/acetonitrile electrolyte(0.5 m Zn(CF_(3)SO_(3))_(2)+1 m LiTFSI-h_(2)O/AN)for Zn-ion hybrid supercapacitors,which simultaneously exhibited expanded electrochemical window,decent ionic conductivity,and broad temperature *** this electrolyte,the hydration shells and hydrogen bonds are significantly modulated by the acetonitrile and *** a result,a Zn-ion hybrid supercapacitor with such an electrolyte demonstrates a high operating voltage up to 2.2 V and long lifespan beyond 120,000 cycles.

关键词： Zn-ion supercapacitors Zn metal anode Electrolyte engineering hydrogen bonds Solvation structures

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

Modified NiFe-MOF with defects induced by-Nh_(2)and-Sh for enhanced adsorption and photocatalytic reduction of CO_(2)

引用

Journal of Materials Science & Technology 2024年第3期170卷 167-176页

作者： Ruting huang Yeyin zhang Wenqiang Li Wanxia zhang Yong Fang Wenrui zhang Anqi Cui Yu Ying Xianyang Shi Information Materials and Intelligent Sensing Laboratory of Anhui Province Anhui Province Key Laboratory of Wetland Ecosystem Protection and RestorationSchool of Resource and Environmental EngineeringAnhui UniversityHefei230601China Key Laboratory of Nutrient Cycling Resources and Environment of Anhui Institute of Soil and FertilizerAnhui Academy of Agricultural SciencesHefei230001China

In this study,a Ni-Fe metal-organic framework modified by-Nh_(2)and-Sh was synthesized using a sim-ple hydrothermal process for enhancing photocatalytic CO_(2)*** expected,the N2S-NiFe(Nh_(2)-BDC/h_(4)DSBDC,2:1)displayed excellent photocatalytic CO_(2)reduction activity and high CO selectivity(12,412.23μmol g^(−1)h^(−1))under visible light irradiation(λ≥420 nm),which is 5 times that of ***,the excellent photocatalytic performance of N2S-NiFe can benefit from the rich defect trap site caused by the introduction of amino and sulfhydryl groups,accelerating charge transfer and promoting space charge separation,as supported by the photo-electrochemical *** better understand the CO_(2)adsorption mechanism,density functional theory calculations were performed,which revealed that the Niov site has more negative adsorption energy compared with the Feov *** study provides a simple strategy to establish efficient photocatalysts for CO_(2)reduction through the modification of organic ligands.

关键词： NiFe-MOF CO_(2)reduction Defect structure Photocatalytic

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

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：