检索结果-南通市图书馆

Rare Metals 2015年第8期34卷 590-594页

作者： zhen-xiong ma Qi-Tao Zhang Jun-Liang Liu Chang-Hao Yan Ming Zhang Teruhisa Ohno School of Chemistry and Chemical Engineering Yangzhou University Department of Applied Chemistry Faculty of EngineeringKyushu Institute of Technology School of Chemical Engineering Yangzhou Polytechnic Institute

Luminescent polystyrene microspheres were easily fabricated from poly(styrene-co-methacrylic acid)and aqueous RE(III) chloride solution(RE=Eu, Tb) in the presence of 2,20-bipyridine as second ligand. The negative charges of carboxyl groups on the surface of microspheres coordinated with rare earth ions at first, such as complexes covalently linked to 2,20-bipyridine, resulting in strong photoluminescence. Various methods, including transmission electron microscope(TEM), scanning electron microscope(SEM), energy dispersive spectroscopy(EDS),Fourier transform infrared spectroscopy(FT-IR), and fluorescence spectrophotometer, were used to characterize the resultant polystyrene composite microspheres. This work highlights the idea that it is facile to synthesis luminescent microspheres by surface-modified method directly.

关键词： Luminescent Polystyrene Terbium Europium 2,2’-bipy

A new gravitational theory and dark matter problem

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2024年第6期76卷 129-136页

作者： xiong Zhao Yongge ma Department of Physics Beijing Normal UniversityBeijing 100875China

We propose a new gravitational theory with torsion based on Riemann-Cartan geometry,in which all physical quantities are *** addition to the spacetime metric,the gravitational degrees of freedom in this theory also include the torsion and two scalar *** energy-momentum tensor of the matter fields in this theory is also proposed.A spherically symmetric static vacuum solution of the theory is *** turns out that this solution can fit the observational data of the rotation curve outside the stellar disk in the Milky ***,the galactic dark matter may just be the gravitational effect of the theory with torsion.

关键词： gravity torsion dark matter

Amino acids TORC(talk)to anabolism through uncharged tRNA

在线全文

学校读者我要写书评

暂无评论

Science China(Life Sciences) 2024年第8期67卷 1775-1776页

作者： zhen-zhen ma Shi-Min Zhao The Obstetrics&Gynecology Hospital of Fudan University State Key Laboratory of Genetic EngineeringShanghai Key Laboratory of Metabolic Remodelling and HealthFudan UniversityShanghai 200090China

Anabolism is essential for proliferation as well as to replenish dysfunctional macromolecules in *** to that both substantial building blocks and energy are required for anabolism,cells must double check whether these prerequisites are met before deciding to start *** acids are building blocks of protein synthesis,their sufficiency in cells is closely monitored by several mechanisms,which all are linked to protein synthesis.

关键词： synthesis. synthesis deciding

Identifying malicious traffic under concept drift based on intraclass consistency enhanced variational autoencoder

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2024年第8期67卷 238-252页

作者： Xiang LUO Chang LIU Gaopeng GOU Gang xiong zhen LI Binxing FANG Institute of Information Engineering Chinese Academy of Sciences School of Cyber Security University of Chinese Academy of Sciences School of Computer Science and Technology Harbin Institute of Technology (Shenzhen)

Accurate identification of malicious traffic is crucial for implementing effective defense countermeasures and has led to extensive research efforts. However, the continuously evolving techniques employed by adversaries have introduced the issues of concept drift, which significantly affects the performance of existing methods. To tackle this challenge, some researchers have focused on improving the separability of malicious traffic representation and designing drift detectors to reduce the number of false ***, these methods often overlook the importance of enhancing the generalization and intraclass consistency in the representation. Additionally, the detectors are not sufficiently sensitive to the variations among different malicious traffic classes, which results in poor performance and limited robustness. In this paper, we propose intraclass consistency enhanced variational autoencoder with Class-Perception detector(ICE-CP) to identify malicious traffic under concept drift. It comprises two key modules during training:intraclass consistency enhanced(ICE) representation learning and Class-Perception(CP) detector construction. In the first module, we employ a variational autoencoder(VAE) in conjunction with Kullback-Leibler(KL)-divergence and cross-entropy loss to model the distribution of each input malicious traffic flow. This approach simultaneously enhances the generalization, interclass consistency, and intraclass differences in the learned representation. Consequently, we obtain a compact representation and a trained classifier for nondrifting malicious traffic. In the second module, we design the CP detector, which generates a centroid and threshold for each malicious traffic class separately based on the learned representation, depicting the boundaries between drifting and non-drifting malicious traffic. During testing, we utilize the trained classifier to predict malicious traffic classes for the testing samples. Then, we use the CP det

关键词： concept drift cyberspace security intrusion detection malicious traffic identification variational autoencoder

同方期刊数据库

A Survey of Knowledge Graph Construction Using machine Learning

在线全文

学校读者我要写书评

暂无评论

Computer Modeling in Engineering & Sciences 2024年第4期139卷 225-257页

作者： Zhigang Zhao xiong Luo maojian Chen Ling ma School of Computer and Communication Engineering University of Science and Technology BeijingBeijing100083China Shunde Innovation School University of Science and Technology BeijingFoshan528399China Beijing Key Laboratory of Knowledge Engineering for materials Science Beijing100083China

Knowledge graph(KG)serves as a specialized semantic network that encapsulates intricate relationships among real-world entities within a structured *** framework facilitates a transformation in information retrieval,transitioning it from mere string matching to far more sophisticated entity *** this transformative process,the advancement of artificial intelligence and intelligent information services is ***,the role ofmachine learningmethod in the construction of KG is important,and these techniques have already achieved initial *** article embarks on a comprehensive journey through the last strides in the field of KG via machine *** a profound amalgamation of cutting-edge research in machine learning,this article undertakes a systematical exploration of KG construction methods in three distinct phases:entity learning,ontology learning,and knowledge ***,a meticulous dissection of machine learningdriven algorithms is conducted,spotlighting their contributions to critical facets such as entity extraction,relation extraction,entity linking,and link ***,this article also provides an analysis of the unresolved challenges and emerging trajectories that beckon within the expansive application of machine learning-fueled,large-scale KG construction.

关键词： Knowledge graph(KG) semantic network relation extraction entity linking knowledge reasoning

Monophase-homointerface electrodes intrinsically stabilize high-voltage all-solid-state batteries

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

Science China Chemistry 2024年第5期67卷 1729-1739页

作者： Xiaolin xiong Xianguo ma Tianshi Lv Liquan Chen Liumin Suo Beijing National Laboratory for Condensed matter Physics Institute of PhysicsChinese Academy of ScienceBeijing 100190China Center of materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China

The electrochemical stability and contact reliability of heterointerfaces between the solid electrolyte(SE) and electrode are critical for all-solid-state batteries(ASSBs), particularly much more challenging for high-voltage ASSBs, owing to the limited thermodynamically electrochemical window and mechanical inflexibility of SE, aggravating interfacial side reactions and contact failure. Considering all those issues originating from intrinsic heterogeneity in physicochemical features between the cathode material and SE, we are thinking about simplifying the heterointerfaces into a homointerface as a permanent cure to solve all electrochemical-mechanical interfacial failure. Herein, we propose monophase cathodes to construct thermodynamically stable all-in-one homointerfaces in ASS electrodes, removing unstable heterointerfaces by excluding SEs and intrinsically eliminating the Li chemical potential gap to avoid the formation of lithium-depleted space-charge layer and highly resistive mixed ion–electron conductor interphase. Our conception is successfully validated in the layered transition-metal oxide cathodes, which display outstanding stability no matter the MH-LiCoO_(2) cathode charging to 4.7 V or MH-Li_(1.2)Mn_(0.54)Ni_(0.13)-Co_(0.13)O_(2) cathode charging to 5.3 V. It is undeniable that our current version of above-illustrated MH-cathodes would bring out some new challenges for the practical application due to abandoning the SE. However, we believe our work also offers a brandnew direction to ultimately address the electrochemical–mechanical interfacial issues that would be promising for high-energy ASSBs with more discoveries of advanced monophase cathodes in the future.

关键词： monophase-homointerface electrode high-voltage all-solid-state batteries electrochemical-mechanical interfacial issue

Research status and perspectives of MXene-based materials for aqueous zinc-ion batteries

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2024年第5期43卷 1867-1885页

作者： Xiao-Yu Wang Qi-Hang Yang Xin-Yan Meng Meng-Meng zhen zhen-Zhong Hu Bo-xiong Shen School of Energy and Environmental Engineering Hebei University of TechnologyTianjin 300071China

Aqueous zinc-ion batteries(AZIBs)as green battery systems have attracted widespread attention in large-scale electrochemical energy storage devices,owing to their high safety,abundant Zn materials,high theoretica specific capacity and low redox *** there are some thorny issues in AZIBs that hinder their practical application,such as low intrinsic electron conductivity,slow ion migration kinetics,zinc dendrites and side ***-based materials with superior conductivity,large polar surface and abundant active sites can simultaneously serve as cathode materials,electrolyte additive and protection layer of anode to regulate redox reactions of *** various materials have been used to improve electrochemical performances of AZIBs there is a lack of in-depth discussion on the regulation mechanism of MXene-based materials for *** this review,we elaborate the research progress of MXenebased materials in AZIBs,including their application in cathode materials and inhibition of zinc *** the future prospects and development directions of MXenebased materials that may improve performance of AZIBs are prospected.

关键词： MXene Aqueous zinc-ion batteries Composite materials Zinc dendrites

SDCC: software-defined collective communication for distributed training

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2024年第9期67卷 105-125页

作者： Xin JIN zhen ZHANG Yunshan JIA Yun ma Xuanzhe LIU School of Computer Science Peking University Department of Computer Science and Technology Johns Hopkins University

Communication is crucial to the performance of distributed training. Today's solutions tightly couple the control and data planes and lack flexibility, generality, and performance. In this study, we present SDCC, a software-defined collective communication framework for distributed training. SDCC is based on the principle of modern systems design to effectively decouple the control plane from the data *** abstracts the operations for collective communication in distributed training with dataflow operations and unifies computing and communication with a single dataflow graph. The abstraction, together with the unification, is powerful: it enables users to easily express new and existing collective communication algorithms and optimizations, simplifies the integration with different computing engines(e.g., Py Torch and Tensor Flow) and network transports(e.g., Linux TCP and kernel bypass), and allows the system to improve performance by exploiting parallelism exposed by the dataflow graph. We further demonstrate the benefits of SDCC in four use cases.

关键词： machine learning systems distributed training deep learning collective communication software-defined networking

同方期刊数据库

Novel process for facile preparation of mesoporous silica-based materials with controllable pore structure from coal fly ash Author links open overlay panel

在线全文

学校读者我要写书评

暂无评论

Particuology 2024年第8期91卷 128-137页

作者： Jian-ming Gao zhen Li Shujia ma Yuanyuan Zhang Fangqin Cheng Institute of Resources and Environment Engineering State Environmental Protection Key Laboratory of Efficient Utilization Technology of Coal Waste ResourcesShanxi Collaborative Innovation Center of High Value-added Utilization of Coal-related WastesShanxi UniversityTaiyuan 030006China

Extraction of silica from fly ash to produce mesoporous silica materials is one of the most important utilization *** silica could not be synthesized on a large-scale by conventional sol-gel *** this paper,facile preparation of mesoporous silica with controllable pore structure from fly ash by the template-free process via two steps of mineral phase transformation and selective acid etching was *** influence of crystalline structure and acid etching degree on structure of as-synthesized mesoporous silica materials was revealed,as well as mechanism of crystalline structure transformation and pore structure *** results show that mullite and quartz could be transformed into acid-soluble kaliophilite when fly ash reacted with K_(2)CO_(3)at temperature of 800-1100℃.The hexagonal kaliophilite would be transformed into orthorhombic KAlSiO_(4)-O1 phase when the temperature is controlled at 1100℃.Mesoporous silica with specific surface area of 475.93 m^(2)/g and 642.57 m^(2)/g could be synthesized from activated fly ash with kaliophilite and KAlSiO_(4)-O1 phase crystalline *** controlling the degree of acid etching,mesoporous silica materials with different pore structures can be *** paper provides a cost-effective and large-scale process for the preparation of mesoporous silica materials with controllable pore structure from solid waste fly ash.

关键词： Fly ash Mesoporous silica Crystal transformation Acid etching Controllable pore structure

Roughness characterization and shearing dislocation failure for rock-backfill interface

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

International Journal of Minerals,Metallurgy and materials 2024年第6期31卷 1167-1176页

作者： Meifeng Cai Zhilou Feng Qifeng Guo xiong Yin Minghui ma Xun Xi Key Laboratory of High-Efficient Mine and Safety of Metal Mines of Ministry of Education Beijing 100083China Key Laboratory of Urban and Underground Space Engineering University of Science and Technology BeijingBeijing 100083China Shandong Gold Group Co LtdJinan 250102China

Shearing dislocation is a common failure type for rock–backfill interfaces because of backfill sedimentation and rock strata movement in backfill mining *** paper designed a test method for rock–backfill shearing *** digital image techno-logy and three-dimensional(3D)laser morphology scanning techniques,a set of 3D models with rough joint surfaces was ***,the mechanical behavior of rock–backfill shearing dislocation was investigated using a direct shear *** effects of interface roughness on the shear–displacement curve and failure characteristics of rock–backfill specimens were *** 3D fractal dimen-sion,profile line joint roughness coefficient(JRC),profile line two-dimensional fractal dimension,and the surface curvature of the frac-tures were *** correlation characterization of surface roughness was then analyzed,and the shear strength could be measured and calculated using *** results showed the following:there were three failure threshold value points in rock–backfill shearing dis-location:30%–50%displacement before the peak,70%–90%displacement before the peak,and 100%displacement before the peak to post-peak,which could be a sign for rock–backfill shearing dislocation *** surface JRC could be used to judge the rock–backfill shearing dislocation failure,including post-peak sliding,uniform variations,and gradient change,corresponding to rock–backfill disloca-tion failure on the field *** research reveals the damage mechanism for rock–backfill complexes based on the free joint surface,fills the gap of existing shearing theoretical systems for isomerism complexes,and provides a theoretical basis for the prevention and control of possible disasters in backfill mining.

关键词： rock–backfill roughness correlation characterization shearing dislocation interface failure