检索结果-南通市图书馆

Comparison of irradiation-induced void formations in tungsten with equiaxed and columnar structures

在线全文

学校读者我要写书评

暂无评论

Tungsten 2024年第4期6卷 794-805页

作者： Liu Xi jia-Jun zhao ji-Jun zhao Yuan-Yuan Wang Key Laboratory of Materials Modification by Laser Ion and Electron Beams(Ministry of Education) Dalian University of Technology

Tungsten(W) has been received much attention,since it is regarded as one of the most promising plasma facing materials for fusion *** are two typical morphologies of unirradiated polycrystalline W,which have the equiaxed and columnar grains,***,the role of arrangement of grain boundary(GB) in absorbing irradiation-generated point defects is still waiting to be *** current investigation,irradiation-induced void formations in W with equiaxed and columnar microstructures are predicted,respectively,using the developed phase-field *** significant kinetic behavior,such as the generation and annihilation of point defects and the interaction between point defects and GB,is reasonably *** density,size and porosity of void formed in these two microstructures are examined and analyzed according to the effects of GB ratio,temperature and damage *** analytical results show that higher GB ratio can effectively reduce void porosity,and the columnar-grained structure has better irradiation resistance than that of the equiaxed one in the case of small grain *** importantly,the predicted void sizes changed with temperature and damage rate agree well with the experimentally measured *** work has a more beneficial contribution to the microstructural improvement of International Thermonuclear Experimental Reactor-grade W.

关键词： Grain morphology Irradiation-induced void Phase-field Tungsten

Ceramic-based meta-material absorber with high-temperature stability

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Rare Metals 2024年第9期43卷 4433-4440页

作者： Xing-Cong Chen Wei-jia Luo Run-Ni zhao Yong-Zheng Wen ji Zhou State Key Laboratory of New Ceramics and Fine Processing School of Materials Science and EngineeringTsinghua University

With the continuous exploration of uncharted and extreme environments,enhanced temperature robustness of passive devices has become particularly *** this study,a ceramic-based meta-material absorber with exceptional temperature stability is developed using a fusion design approach that combines rare metal-based tungsten bronze structural ceramics and ***,the absorbance of the meta-material array based on Mie resonance exceeds 49.0%in both waveguides and free space,approaching the theoretical *** to impedance analysis,the absorption performance can be distinctly correlated with the dielectric loss （Q_f）.Notably,the high-temperature robustness is verified to still be effective at 400℃.These advancements in our design allow for the use of monolithic materials in fabricating temperature-stable perfect absorbers,providing greater freedom in the dielectric performance and expanding their potential applications,including in space exploration and 5G millimeter-wave scenarios.

关键词： Meta-material absorber Microwave absorption Miniaturization Rare metal-based ceramics Temperature robustness

Perenniality:From model plants to applications in agriculture

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Molecular Plant 2024年第1期17卷 141-157页

作者： Bo zhao jia-Wei Wang National Key Laboratory of Plant Molecular Genetics CAS Center for Excellence in Molecular Plant Sciences(CEMPS)Institute of Plant Physiology and Ecology(SIPPE)Chinese Academy of Sciences(CAS)Shanghai 200032China School of Life Science and Technology ShanghaiTech UniversityShanghai 201210China Key Laboratory of Plant Carbon Capture CASShanghai 200032China New Cornerstone Science Laboratory Shanghai 200032China

To compensate for their sessile nature,plants have evolved sophisticated mechanisms enabling them to adapt to ever-changing *** such prominent feature is the evolution of diverse life history strategies,particularly such that annuals reproduce once followed by seasonal death,while perennials live longer by cycling growth *** intrinsic phenology is primarily genetic and can be altered by environmental *** evolutionary transitions between annual and perennial life history strategies are common,perennials account for most species in nature because they survive well under year-round *** proportion,however,is reversed in ***,perennial crops promise to likewise protect and enhance the resilience of agricultural ecosystems in response to climate *** significant endeavors that have been made to generate perennial crops,progress is slow because of barriers in studying perennials,and many developed species await further *** findings in model species have illustrated that simply rewiring existing genetic networks can lead to lifestyle *** implies that engineering plant life history strategy can be achieved by manipulating only a few key *** this review,we summarize our current understanding of genetic basis of perenniality and discuss major questions and challenges that remain to be addressed.

关键词： perenniality developmental plasticity flowering time poplar Arabis alpina perennial crops life history strategy

Stacking MoS_(2) flower-like microspheres on pomelo peels-derived porous carbon nanosheets for high-efficient X-band electromagnetic wave absorption

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

Nano Research 2024年第3期17卷 1607-1615页

作者： jia zhao Zhe Gu Qingguo Zhang College of Chemistry and Materials Engineering Bohai UniversityJinzhou 121013China

The key to solve increasingly severe electromagnetic(EM)pollution is to explore sustainable,easily prepared,and cost-effective EM wave absorption materials with exceptional absorption ***,instead of anchoring on carbon materials in single layer,MoS_(2) flower-like microspheres were stacked on the surface of pomelo peels-derived porous carbon nanosheets(C)to fabricate MoS_(2)@C nanocomposites by a facile solvothermal *** wave absorption performances of MoS_(2)@C nanocomposites in X-band were systematically investigated,indicating the minimum reflection loss(RLmin)of-62.3 dB(thickness of 2.88 mm)and effective absorption bandwidth(EAB)almost covering the whole X-band(thickness of 2.63 mm)with the filler loading of only 20 wt.%.Superior EM wave absorption performances of MoS_(2)@C nanocomposites could be attributed to the excellent impedance matching characteristic and dielectric loss capacity(conduction loss and polarization loss).This study revealed that the as-prepared MoS_(2)@C nanocomposites would be a novel prospective candidate for the sustainable EM absorbents with superior EM wave absorption performances.

关键词： pomelo peels-derived porous carbon nanosheets(C) MoS_(2)@C nanocomposites stacked structure electromagnetic(EM)wave absorption

Barrier Option Pricing in Regime Switching Models with Rebates

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

Acta Mathematicae Applicatae Sinica 2024年第3期40卷 849-861页

作者： Yue-xu zhao jia-yong BAO School of Economics Hangzhou Dianzi UniversityHangzhou 310018China School of Sciences Hangzhou Dianzi UniversityHangzhou 310018China

This paper is concerned with the valuation of single and double barrier knock-out call options in a Markovian regime switching model with specific *** integral formulas of the rebates are derived via matrix Wiener-Hopf factorizations and Fourier transform techniques,also,the integral representations of the option prices are ***,the first-passage time density functions in two-state regime model are *** applications,several numerical algorithms and numerical examples are presented.

关键词： option pricing Markovian regime switching Wiener-Hopf factorization Fourier transform

Parsing Objects at a Finer Granularity: A Survey

在线全文

学校读者我要写书评

暂无评论

Machine Intelligence Research 2024年第3期21卷 431-451页

作者： Yifan zhao jia Li Yonghong Tian School of Computer Science Peking UniversityBeijing100871China State Key Laboratory of Virtual Reality Technology and Systems School of Computer Science and EngineeringBeihang UniversityBeijing100191China

Fine-grained visual parsing, including fine-grained part segmentation and fine-grained object recognition, has attracted considerable critical attention due to its importance in many real-world applications, e.g., agriculture, remote sensing, and space technologies. Predominant research efforts tackle these fine-grained sub-tasks following different paradigms, while the inherent relations between these tasks are neglected. Moreover, given most of the research remains fragmented, we conduct an in-depth study of the advanced work from a new perspective of learning the part relationship. In this perspective, we first consolidate recent research and benchmark syntheses with new taxonomies. Based on this consolidation, we revisit the universal challenges in fine-grained part segmentation and recognition tasks and propose new solutions by part relationship learning for these important challenges. Furthermore, we conclude several promising lines of research in fine-grained visual parsing for future research.

关键词： Finer granularity visual parsing part segmentation fine-grained object recognition part relationship

Rapid chemical recycling of waste polyester plastics catalyzed by recyclable catalyst

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

Green Chemical Engineering 2024年第2期5卷 257-265页

作者： Yu-ji Luo jia-Yin Sun Zhi Li School of Physical Science and Technology ShanghaiTech UniversityShanghai201210China

Waste plastics are serious environmental threats due to their low degradability and low recycling *** and efficient waste plastics recycling technologies are urgently demanded for a sustainable ***,we report a rapid,closed-loop,and streamlined process to convert polyesters such as poly(ethylene terephthalate)(PET)back to its purified *** trifluoromethanesulfonic acid or metal triflates as the recyclable catalyst,polyesters such as PET can be completely depolymerized by simple carboxylic acids within 1 *** coupling this acidolysis with a subsequent hydrogenolysis process,the consumed carboxylic acid was recovered and the closed-loop of PET depolymerization could be *** catalysts and depolymerization agents are fully recycled while only PET and hydrogen are consumed.

关键词： Chemical recycling Waste polyester plastics Acidolysis Recyclable catalyst

Identifying and localizing of seismogenic electromagnetic anomalies from data observed by permanent MT stations

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2024年第5期67卷 1698-1713页

作者： Bing HAN Wenbao HU Guoze zhao ji TANG State Key Laboratory of Earthquake Dynamics Institute of GeologyBeijing 100029China Key Laboratory of Exploration Technologies for Oil and Gas Resources of Ministry of Education Yangtze UniversityWuhan 430100China

In this research, an arbitrarily oriented electric dipole at subsurface is used to simulate Seismogenic Electromagnetic(SEM) radiation emanating from a seismic zone during its gestation phase. Analytical synthesis of responses at the Lijiang magnetotelluric(MT) station has revealed that SEM radiation could induce identifiable anomalies in the electromagnetic(EM)spectrum, apparent resistivity and phase within specific frequency bands. Background variations were extracted from long-term observation data of Dali and Lijiang MT stations, enabling the identification of SEM anomalies related to the Yunlong and Yangbi earthquakes. Multiple parameters of dipole sources at subsurface were obtained by applying the Differential Ant Colony Optimization(DACO) algorithm to anomalous data of two stations with multi-frequencies and various response functions. The spatial distribution of these predicted dipoles is predominantly clustered in or around the seismogenic area, with their azimuthal orientation aligning towards the seismogenic fault in general. This study has demonstrated the potential of using subsurface electric dipole simulations for SEM radiation analysis, offering a feasible approach for the prediction and understanding of seismogenic zones.

关键词： MT responses Identifying SEM anomaly Vector electric dipole responses Localizing SEM sources by inversion

Threshold Selection and Resource Allocation for Quantized Identification

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Science & Complexity 2024年第1期37卷 204-229页

作者： WANG Ying LI Xin zhao Yanlong ZHANG ji-Feng Key Laboratory of Systems and Control Institute of Systems ScienceAcademy of Mathematics and Systems ScienceChinese Academy of SciencesBeijing 100190China School of Mathematical Sciences University of Chinese Academy of SciencesBeijing 100049China

This paper is concerned with the optimal threshold selection and resource allocation problems of quantized identification, whose aims are improving identification efficiency under limited resources. Firstly, the first-order asymptotically optimal quantized identification theory is extended to the weak persistent excitation condition. Secondly, the characteristics of time and space complexities are established based on the Cramér-Rao lower bound of quantized systems. On these basis, the optimal selection methods of fixed thresholds and adaptive thresholds are established under aperiodic signals, which answer how to achieve the best efficiency of quantized identification under the same time and space complexity. In addition, based on the principle of maximizing the identification efficiency under a given resource, the optimal resource allocation methods of quantized identification are given for the cases of fixed thresholds and adaptive thresholds, respectively, which show how to balance time and space complexity to realize the best identification efficiency of quantized identification.

关键词： Quantized output resource allocation system identification threshold selection.