检索结果-南通市图书馆

Atomically self-healing of structural defects in monolayer WSe_(2)

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2024年第9期33卷 49-55页

作者： Kangshu li junxian li Xiaocang Han Wu Zhou Xiaoxu Zhao School of Materials Science and Engineering Peking UniversityBeijing 100871China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100049China AI for Science Institute Beijing 100084China

Minimizing disorder and defects is crucial for realizing the full potential of two-dimensional transition metal dichalcogenides(TMDs) materials and improving device performance to desired properties. However, the methods in defect controlcurrently face challenges with overly large operational areas and a lack of precision in targeting specific defects. Therefore,we propose a new method for the precise and universal defect healing of TMD materials, integrating real-time imaging withscanning transmission electron microscopy (STEM). This method employs electron beam irradiation to stimulate the diffusionmigration of surface-adsorbed adatoms on TMD materials grown by low-temperature molecular beam epitaxy (MBE),and heal defects within the diffusion range. This approach covers defect repairs ranging from zero-dimensional vacancydefects to two-dimensional grain orientation alignment, demonstrating its universality in terms of the types of samples anddefects. These findings offer insights into the use of atomic-level focused electron beams at appropriate voltages in STEMfor defect healing, providing valuable experience for achieving atomic-level precise fabrication of TMD materials.

关键词： scanning transmission electron microscopy(STEM) atom manipulation nanoscale materials and structures:fabrication and characterization new materials:theory design fabrication

Querying linked Data Based on Hierarchical Multi-Hop Ranking Model

在线全文

学校读者我要写书评

暂无评论

Journal of Shanghai Jiaotong university(Science) 2018年第4期23卷 568-576页

作者： li junxian WANG Wei WANG dingjing School of Computer Jiangsu University of Science and Technology Zhenjiang 212003 Jiangsu China School of Computer Science Fudan University Shanghai 200433 China Yangzhou Polytechnic College Yangzhou 225009 Jiangsu China

How to query linked Data effectively is a challenge due to its heterogeneous *** are three types of heterogeneities,i.e.,different structures representing entities,different predicates with the same meaning and different literal formats used in *** based on ontology mapping or Information Retrieval(IR) cannot deal with all types of *** these limitations,we propose a hierarchical multi-hop language model(HMPM).It discriminates among three types of predicates,descriptive predicates,out-associated predicates and in-associated predicates,and generates multi-hop models for them *** predicates' similarities between the query and entity are organized into a hierarchy,with predicate types on the first level and predicates of this type on the second *** candidates are ranked in ascending *** evaluated HMPM in three datasets,DBpedia,linked MDB and *** results of experiments show that the effectiveness and generality of HMPM outperform the existing approaches.

关键词： hierarchical multi-hop ranking model(HMPM) linked Data language model

lightweight Dual‑Functional Segregated Nanocomposite Foams for Integrated Infrared Stealth and Absorption‑Dominant Electromagnetic Interference Shielding

在线全文

学校读者我要写书评

暂无评论

Nano-Micro Letters 2024年第11期16卷 38-55页

作者： Zhonglei Ma Ruochu Jiang Jiayao Jing Songlei Kang li Ma Kefan Zhang junxian li Yu Zhang Jianbin Qin Shuhuan Yun Guangcheng Zhang MOE Key Laboratory of Material Physics and Chemistry Under Extraordinary Conditions Shaanxi Key Laboratory of Macromolecular Science and TechnologySchool of Chemistry and Chemical EngineeringNorthwestern Polytechnical UniversityXi’an 710072People’s Republic of China College of Chemistry and Chemical Engineering Key Laboratory of Auxiliary Chemistry and Technology for Chemical IndustryMinistry of EducationShaanxi University of Science and TechnologyXi’an 710072People’s Republic of China Department of Mechanical and Industrial Engineering University of Toronto5 King’s College RoadTorontoON M5S 3G8Canada Chongqing Innovation Center Northwestern Polytechnical UniversityChongqing 401135People’s Republic of China

lightweight infrared stealth and absorption-dominant electromagnetic interference(EMI)shielding materials are highly desirable in areas of aerospace,weapons,military and wearable ***,lightweight and high-efficiency dual-functional segregated nanocomposite foams with microcellular structures are developed for integrated infrared stealth and absorption-dominant EMI shielding via the efficient and scalable supercritical CO_(2)(SC-CO_(2))foaming combined with hydrogen bonding assembly and compression molding *** obtained lightweight segregated nanocomposite foams exhibit superior infrared stealth performances benefitting from the synergistic effect of highly effective thermal insulation and low infrared emissivity,and outstanding absorption-dominant EMI shielding performances attributed to the synchronous construction of microcellular structures and segregated ***,the segregated nanocomposite foams present a large radiation temperature reduction of 70.2℃ at the object temperature of 100℃,and a significantly improved EM wave absorptivity/reflectivity(A/R)ratio of 2.15 at an ultralow Ti_(3)C_(2)T_(x) content of 1.7 vol%.Moreover,the segregated nanocomposite foams exhibit outstanding working reliability and stability upon dynamic compression *** results demonstrate that the lightweight and high-efficiency dual-functional segregated nanocomposite foams have excellent potentials for infrared stealth and absorption-dominant EMI shielding applications in aerospace,weapons,military and wearable electronics.

关键词： Segregated nanocomposite foams Microcellular structures Infrared stealth EMI shielding Low infrared emissivity

A quality evaluation strategy for Rhizoma coptidis from a variety of different sources using chromatographic fingerprinting combined with biological fingerprinting

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2013年第33期58卷 4092-4100页

作者： li junxian YAN Dan MA liNa XIONG Yin YAN ChunXia li BaoCai PENG Cheng XIAO XiaoHe College of life Science and Technology Kunming University of Science and Technology Military Institute of Chinese Materia Medica 302th Military Hospital of China College of Pharmacy Chengdu University of Traditional Chinese Medicine College of Traditional Chinese Pharmacy Beijing University of Chinese Medicine

Most of herbal medicines of different sources are used for the same treatment goal in clinic despite their tremendous differences of the *** the clinical efficacy is closely related to the quality of medicines,the implementation of an effective quality control(QC)process is *** methods based on content determination and chromatographic fingerprints(CFs)have been recommended as powerful *** spite of advances in QC,it is still difficult to determine that which of the chemical compositions can best reflect the correlation with the desired biological ***,we have focused on the biological activities of multi-source herbal medicines to establish an analytical *** looking for correlations between the biological activities and their chemical compositions,the method can identify reasonable chemical indicators or chemical methods with biological activity *** this study,high-performance liquid chromatography(HPLC)and microcalorimetry are combined as a useful method for evaluating the quality of Rhizoma coptidis from different *** results of biological fingerprints(BFs)showed that the antibacterial activity sequence of *** of different sources was Coptis teeta Wall.(CT)>Coptis chinensis Franch.(CC)>Coptis deltoidea *** et Hsiao(CD).The"spectrum-activity"relationships between CFs and BFs were investigated using the canonical correlation analysis(CCA).Compared with the CCA result of CFs and BFs,the canonical correlation coefficient r1and r2were 0.9974 and 0.9752,*** revealed that there are a close correlation between the spectrum-activity relationships and several of the major anti-bacterial components in the CFs,including jatrorrhizine,coptisine,palmatine,and *** course,*** was only a representative of multisource medical *** result of the current study will provide an effective reference for evaluating the quality of multisource herbal medicines.

关键词：中药材质量色谱指纹图谱生物学活性指纹识别黄连评价策略生物活性高效液相色谱

A Characterization of Besov Spaces of Para-Accretive Type and Its Application

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics 2017年第4期8卷 590-606页

作者： junxian li Kunchuan Wang Department of Applied Mathematics National Dong Hwa University Taiwan

There are two folds in this article. One fold is to characterize the Besov spaces of para-accretive type , which reduces to the classical Besov spaces when the para-accretive function is constant, by using a discrete Calderón-type reproducing formula and Plancherel-P?lya-type inequality associated to a para-accretive function b in Rn. The other is to show that a generalized singular integral operator T with extends to be bounded from for and , where ε is the regularity exponent of the kernel of T.

关键词： Besov Space Calderón Reproducing Formula Para-Accretive Function Tb Theorem Triebel-lizorkin Space

SONG PRODUCTION AND HEARING IN THE BUSHCRICKET DERACANTHA ONOS (ORTHOPTERA, TETTIGONIIDAE)

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

Chinese Journal of Acoustics 1988年第1期7卷 83-89页

作者：沈钧贤关力 Inst of Biophysics China

The basic features of song pattern,stridulatory mechanism and auditory sensitivity in thebushcricket species Deracantha onos were studied with sond analysis and *** bushcricket uses an elytro-elytral mechanism of sound production:a denticulatedvein(file)on the under-surface of the left elytron is rubbed by the inside edge(plectrum)of the rightelytron at the rate of 30—33/*** a few teeth does not influence the rhythm of the motorneurons innervating the *** file-train of pulses is the element of calling song of ***-train of pulses is composed of one elytra-opening pulse and 11 to 13 elytra-closing tooth *** tooth impact of the file at the plectrum elicts a damped oscillation called'tooth pulse'.The rateof tooth pulses is about 450/*** frequency spectrum of the song covers a wide frequency bandmainly between 6 and 30 kHz with a predominant peak at 12 to 14 *** intensity is about 110 dBat 10cm from the *** best sensitivity of heari

关键词： SONG PRODUCTION AND HEARING IN THE BUSHCRICKET DERACANTHA ONOS ORTHOPTERA,TETTIGONIIDAE

Progress on Transition Metal Ions Dissolution Suppression Strategies in Prussian Blue Analogs for Aqueous Sodium-/Potassium-Ion Batteries

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Nano-Micro Letters 2024年第7期16卷 142-168页

作者： Wenli Shu junxian li Guangwan Zhang Jiashen Meng Xuanpeng Wang liqiang Mai Department of Physical Science and Technology School of ScienceWuhan University of TechnologyWuhan 430070People’s Republic of China School of Materials Science and Engineering State Key Laboratory of Advanced Technology for Materials SynthesisWuhan University of TechnologyWuhan 430070People’s Republic of China Sanya Science and Education Innovation Park Wuhan University of TechnologySanya 572000People’s Republic of China Hubei Longzhong Laboratory Wuhan University of TechnologyXiangyang Demonstration ZoneXiangyang 441000People’s Republic of China

Aqueous sodium-ion batteries(ASIBs)and aqueous potassium-ion batteries(APIBs)present significant potential for large-scale energy storage due to their cost-effectiveness,safety,and environmental ***,the intricate energy storage mechanisms in aqueous electrolytes place stringent require-ments on the host *** blue analogs(PBAs),with their open three-dimensional framework and facile synthesis,stand out as leading candidates for aqueous energy ***,PBAs possess a swift capacity fade and limited cycle longevity,for their structural integrity is compromised by the pronounced dis-solution of transition metal(TM)ions in the aqueous *** manuscript provides an exhaustive review of the recent advancements concerning PBAs in ASIBs and *** dissolution mechanisms of TM ions in PBAs,informed by their structural attributes and redox processes,are thoroughly ***,this study delves into innovative design tactics to alleviate the dissolution issue of TM *** conclusion,the paper consolidates various strategies for suppressing the dissolution of TM ions in PBAs and posits avenues for prospective exploration of high-safety aqueous sodium-/potassium-ion batteries.

关键词： Prussian blue analogs Transition metal ions dissolution Suppression strategies Aqueous sodium-ion batteries Aqueous potassium-ion batteries

The Nonlinear Filter Boolean Function of lili-128 Stream Cipher Generator Is Successfully Broken Based on the Complexity of Nonlinear 0 1 Symbol Sequence

在线全文

学校读者我要写书评

暂无评论

Circuits and Systems 2013年第2期4卷 165-168页

作者： Xiangao Huang Chao Wang Wei Huang junxian li Beijing Institute of Technology Zhuhai Campus Zhuhai China Computer Center Chang’an University Xi’an China Research Institute of Electronics Xi’an China

The nonlinear filter Boolean function of lili-128 stream cipher generator is studied in this paper. First we measure the complexity of the stream ciphers sequence of lili-128 stream cipher generator and obtain the shortest bit stream sequence reconstructed Boolean function of nonlinear filter in lili-128 stream cipher generator. Then the least nonlinear Boolean function of generating stream cipher sequence is reconstructed by clusterig, nonlinear predictive and nonlinear synchronization from shortest bit stream sequence. We have verified the correctness of our reconstruction result by simulating the block diagram of lili-128 keystream generator using our getting Boolean function and implement designers’ reference module of lili-128 stream cipher public online, and two methods produce the same synchronous keystream sequence under same initial state, so that our research work proves that the nonlinear Boolean function of lili-128 stream cipher generator is successfully broken.

关键词： lili-128 Stream Cipher Clock Control Boolean Function Complexity Attack

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

地层出砂井测试工艺优化

油气井测试 2018年第2期27卷 47-52页

作者：李军贤中国石油大庆油田有限责任公司试油试采分公司黑龙江大庆163412

为减小地层出砂砂粒、钻屑、高冲蚀性固相杂质冲蚀测试工具,避免地层塌陷及工具卡堵等,分析了地层出砂的自然因素和人为因素,提出了地层出砂的力学机理,阐明了地层出砂对地面测试工作造成的设备损坏、套管损坏及测试数据不准确等不良影... 详细信息

为减小地层出砂砂粒、钻屑、高冲蚀性固相杂质冲蚀测试工具,避免地层塌陷及工具卡堵等,分析了地层出砂的自然因素和人为因素,提出了地层出砂的力学机理,阐明了地层出砂对地面测试工作造成的设备损坏、套管损坏及测试数据不准确等不良影响。通过采取井下工具结合填砾滤砂及地面测试增加滤砂工艺等方式对常规测试工艺进行防砂滤砂优化,从而除去流体中携带的砂粒。通过A区块T#3探井测试,选用井下工具结合填砾滤砂在井下通道中进行第一道滤砂;地面流程中采用除砂器依靠离心力和重力作用进行第二道除砂,过滤后的流体通过滤网和除砂筒之间的环形空间进入下游测试流程,除砂后流体中砂比达到0.02%以下,保证了测试工作的连续性。该工艺能减少砂粒对套管和测试设备的损害,提高了测试施工成功率,在地层出砂井的测试施工中取得了较好效果。

关键词：测试工艺地层出砂出砂机理防砂工艺优化除砂器