检索结果-南通市图书馆

Fatigue properties and damage constitutive model of salt rock based on CT scanning

在线全文

学校读者我要写书评

暂无评论

International Journal of Mining Science and Technology 2024年第2期34卷 245-259页

作者： Junbao Wang Xiao Liu Qiang Zhang Xinrong Liu Zhanping Song Shijin Feng College of Civil engineering Xi’an University of Architecture and TechnologyXi’an 710055China Shaanxi Key lab of Geotechnical and Underground Space engineering Xi’an 710055China School of Civil engineering Chongqing UniversityChongqing 400045China Department of Geotechnical engineering Tongji UniversityShanghai 200092China

To investigate the macroscopic fatigue properties and the mesoscopic pore evolution characteristics of salt rock under cyclic loading,fatigue tests under different upper-limit stresses were carried out on salt rock,and the mesoscopic pore structures of salt rock before and after fatigue tests and under different cycle numbers were measured using CT scanning *** on the test results,the effects of the cycle number and the upper-limit stress on the evolution of cracks,pore morphology,pore number,pore volume,pore size,plane porosity,and volume porosity of salt rock were *** failure path of salt rock specimens under cyclic loading was analyzed using the distribution law of plane *** damage variable of salt rock under cyclic loading was defined on basis of the variation of volume porosity with cycle *** order to describe the fatigue deformation behavior of salt rock under cyclic loading,the nonlinear Burgers damage constitutive model was further *** results show that the model established can better reflect the whole development process of fatigue deformation of salt rock under cyclic loading.

关键词： Salt rock Cyclic loading CT scanning Mesoscopic pore evolution Constitutive model

Traffic engineering and Quality of Service in Hybrid Software Defined Networks

在线全文

学校读者我要写书评

暂无评论

China Communications 2024年第2期21卷 96-121页

作者： Samiullah Mehraban Rajesh Kumar Yadav IOT lab Department of Computer Science&EngineeringDelhi Technological UniversityDelhi 110042India

For Future networks, many research projects have proposed different architectures around the globe;Software Defined Network(SDN) architectures, through separating Data and Control Layers, offer a crucial structure for it. With a worldwide view and centralized Control, the SDN network provides flexible and reliable network management that improves network throughput and increases link utilization. In addition, it supports an innovative flow scheduling system to help advance Traffic engineering(TE). For Medium and large-scale networks migrating directly from a legacy network to an SDN Network seems more complicated & even impossible, as there are High potential challenges, including technical, financial, security, shortage of standards, and quality of service degradation challenges. These challenges cause the birth and pave the ground for Hybrid SDN networks, where SDN devices coexist with traditional network devices. This study explores a Hybrid SDN network’s Traffic engineering and Quality of Services Issues. Quality of service is described by network characteristics such as latency, jitter, loss, bandwidth,and network link utilization, using industry standards and mechanisms in a Hybrid SDN Network. We have organized the related studies in a way that the Quality of Service may gain the most benefit from the concept of Hybrid SDN networks using different algorithms and mechanisms: Deep Reinforcement Learning(DRL), Heuristic algorithm, K path partition algorithm, Genetic algorithm, SOTE algorithm, ROAR method, and Routing Optimization with different optimization mechanisms that help to ensure high-quality performance in a Hybrid SDN Network.

关键词： DRL hSDN QoE QoS SDN TE

Construct a 3D microsphere of HMX/B/Al/PTFE to obtain the high energy and combustion reactivity

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2024年第2期32卷 45-54页

作者： Jian Wang Jie Chen Yaofeng Mao Yongjun Deng Wei Cao Fude Nie Jun Wang Institute of Chemical Materials China Academy of Engineering PhysicsMianyang 621999PR China Shock and Vibration of engineering Materials and Structures Key lab of Sichuan Province Mianyang 621010PR China

Metal(aluminum and boron)based energetic materials have been wildly applied in various fields including aerospace,explosives and micro-devices due to their high energy ***,the low combustion efficiency and reactivity of metal fuels,especially boron(B),severely limit their practical ***,multi-component 3D microspheres of HMX/B/Al/PTFE(HBA)have been designed and successfully prepared by emulsion and solvent evaporation method to achieve superior energy and combustion *** reactivity and energy output of HBA are systematically measured by ignitionburning test,constant-volume explosion vessel system and bomb *** to the increased interfacial contact and reaction area,HBA shows higher flame propagation rate,faster pressurization rate and larger combustion heat of 29.95 cm/s,1077 kPa/s,and 6164.43 J/g,which is 1.5 times,3.5 times,and 1.03 times of the physical mixed counterpart(HBA-P).Meanwhile,HBA also shows enhanced energy output and reactivity than 3D microspheres of HMX/B/PTFE(HB)resulting from the high reactivity of *** reaction mechanism of 3D microspheres is comprehensively investigated through combustion emission spectral and thermal analysis(TG-DSC-MS).The superior reactivity and energy of HBA originate from the surface etching of fluorine to the inert shell(Al_(2)O_(3) and B_(2)O_(3))and the initiation effect of Al to *** work offers a promising approach to design and prepare high-performance energetic materials for the practical applications.

关键词： HMX/B/Al/PTFE 3D microspheres Surface etching Reaction mechanism

Grain size refinement of additive manufactured Ce-TZP ceramics by coupled two-step pre-sintering and HIP

在线全文

学校读者我要写书评

暂无评论

Journal of Advanced Ceramics 2024年第5期13卷 621-629页

作者： Ruoshi Zhao Hongbing Yang Xintong Liu Hezhen Li Chang-An Wang Jing Ma Yanhao Dong State Key lab of New Ceramics and Fine Processing School of Materials Science and EngineeringTsinghua UniversityBeijing 100084China

Ceria-stabilized tetragonal zirconia polycrystal(Ce-TZP)has exceptional fracture toughness and flaw tolerance due to facile t‒m phase transformation ***,its wider-range applications are limited by its relatively low strength due to its large grain size and low transformation stress,which results in yield-like ***,we combined additive manufacturing(AM),pressureless two-step sintering,and hot isostatic pressing(HIP),and addressed the challenging grain size refinement problem in *** successfully produced dense ultrafine-grained Ce-TZP ceramics with an average grain size below 500 nm,a three-point bending strength above 800 MPa,and a single-edge-notch-beam fracture toughness in the range of 11‒12 MPa·m^(1/2).The critical roles of processing design,mixed Ce valences,and ***-stabilization of tetragonal polymorphs were *** work offers insights and strategies for the future development of stronger and tougher Ce-TZP ceramics that can compete with tetragonal yttria-stabilized zirconia in various applications,including additive manufacturing.

关键词： zirconia additive manufacturing(AM) two-step sintering hot isostatic pressing(HIP) grain size refinement

Efficient elimination of carbamazepine using polyacrylonitrile-supported pyridine bridged iron phthalocyanine nanofibers by activating peroxymonosulfate in dark condition

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

Journal of Environmental Sciences 2024年第3期137卷 224-236页

作者： Zhexin Zhu Wenjie Qian Zhiguo Shang Xiaoji Ma Zhendong Wang Wangyang Lu Wenxing Chen National engineering lab for Textile Fiber Materials and Processing Technology(Zhejiang) Zhejiang Sci-Tech UniversityHangzhou 310018China

The monoaminotrinitro iron phthalocyanine(FeMATNPc)is used to connect with isonicotinic acid(INA)for amide bonding and axial coordination to synthetic a unique catalyst FeMATNPc-INA,which is loaded in polyacrylonitrile(PAN)nanofibers by *** introduction of INA destroys theπ-πconjugated stack structure in phthalocyanine molecules and exposes more active *** FeMATNPc-INA structure is characterized by X-ray photoelectron spectroscopy and UV-visible absorption spectrum,and the FeMATNPcINA/PAN structure is characterized by Fourier transform infrared spectroscopy and X-ray *** FeMATNPc-INA/PAN can effectively activate peroxymonosulfate(PMS)to eliminate carbamazepine(CBZ)within 40 minutes(PMS 1.5 mmol/L)in the *** effects of catalyst dosage,PMS concentration,pH and inorganic anion on the degradation of CBZ are *** has been confirmed by electron paramagnetic resonance,gas chromatography–mass spectroscopy and free radical capture experiments that the catalytic system is degraded by·OH,SO4^(·-)and Fe(IV)=O are the major active species,the singlet oxygen(^(1)O_(2))is the secondary active *** degradation process of CBZ is analyzed by ultra-high performance liquid chromatography-mass spectrometry and the aromatic compounds have been degraded to small molecular acids.

关键词： Pyridine bridged iron phthalocyanine Isonicotinic chloride hydrochloride Efficient elimination Peroxymonosulfate activation Degradation pathway

A survey on dynamic graph processing on GPUs: concepts, terminologies and systems

在线全文

学校读者我要写书评

暂无评论

Frontiers of Computer Science 2024年第4期18卷 1-23页

作者： Hongru GAO Xiaofei LIAO Zhiyuan SHAO Kexin LI Jiajie CHEN Hai JIN National engineering Research Center for Big Data Technology and System/Services Computing Technology and System lab/Cluster and Grid Computing lab School of Computer Science and TechnologyHuazhong University of Science and TechnologyWuhan 430074China Zhejiang lab Hangzhou 311121China

Graphs that are used to model real-world entities with vertices and relationships among entities with edges,have proven to be a powerful tool for describing real-world problems in *** most real-world scenarios,entities and their relationships are subject to constant *** that record such changes are called dynamic *** recent years,the widespread application scenarios of dynamic graphs have stimulated extensive research on dynamic graph processing systems that continuously ingest graph updates and produce up-to-date graph analytics *** the scale of dynamic graphs becomes larger,higher performance requirements are demanded to dynamic graph processing *** the massive parallel processing power and high memory bandwidth,GPUs become mainstream vehicles to accelerate dynamic graph processing ***-based dynamic graph processing systems mainly address two challenges:maintaining the graph data when updates occur(i.e.,graph updating)and producing analytics results in time(i.e.,graph computing).In this paper,we survey GPU-based dynamic graph processing systems and review their methods on addressing both graph updating and graph *** comprehensively discuss existing dynamic graph processing systems on GPUs,we first introduce the terminologies of dynamic graph processing and then develop a taxonomy to describe the methods employed for graph updating and graph *** addition,we discuss the challenges and future research directions of dynamic graph processing on GPUs.

关键词： dynamic graphs graph processing graph algorithms GPUs

Nano-alumina@cellulose-coated separators with the reinforcedconcrete-like structure for high-safety lithium-ion 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

Chinese Journal of Chemical engineering 2024年第4期68卷 83-93页

作者： Zhihao Yang Li Chen Jian Xue Miaomiao Su Fangdan Zhang Liangxin Ding Suqing Wang Haihui Wang Guangdong Provincial Key lab of Green Chemical Product Technology School of Chemistry and Chemical EngineeringSouth China University of TechnologyGuangzhou 510640China Beijing Key laboratory of Membrane Materials and engineering Department of Chemical EngineeringTsinghua UniversityBeijing 100084China

Separators play a critical role in the safety and performance of lithium-ion ***,commercial polyolefin separators are limited by their poor affinity with electrolytes and low melting *** this work,we constructed a reinforced-concrete-like structure by homogeneously dispersing nano-Al_(2)O_(3) and cellulose on the separators to improve their stability and *** this reinforcedconcrete-like structure,the cellulose is a reinforcing mesh,and the nano-Al_(2)O_(3) acts as concrete to support the *** constructing the reinforced-concrete-like structure,the separators exhibit good stability even at 200℃(thermal shrinkage of 0.3%),enhanced tensile strain(tensile stress of 133.4 MPa and tensile strains of 62%),and better electrolyte wettability(a contact angle of 6.5°).Combining these advantages,the cells with nano-Al_(2)O_(3)@cellulose-coated separators exhibit stable cycling performance and good rate ***,the construction of the reinforced-concretelike structure is a promising technology to promote the application of lithium-ion batteries in extreme environments.

关键词： Alumina Nanomaterials Lithium-ion batteries Membranes Cellulose Reinforced-concrete-like structure

Bimolecular reduction of carbon dioxide: double synthons for alkynes trifunctionalization

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2024年第3期67卷 841-847页

作者： Wenfang Xiong Xiaobin Tan Hongjian Liu Baiyao Zhu Jinwu Zhao Jianxiao Li Chaorong Qi Huanfeng Jiang School of Pharmacy Guangdong Medical UniversityDongguan 523808China Key lab of Functional Molecular engineering of Guangdong Province School of Chemistry and Chemical EngineeringSouth China University of TechnologyGuangzhou 510640China

Carbon dioxide reduction, as a sustainable and versatile strategy for the access of chemical fuels, has attracted increasing attention and enormous efforts have been devoted to it in recent years. However, employing carbon dioxide as double synthons via bimolecular reduction remains challenging. Here, by leveraging the bimolecular reduction of carbon dioxide to carbonyl and methyl respectively, we describe a Pd-catalyzed trifunctionalization of alkynes with aryl iodide for the first time and showcase its advantages on the formation of various β-diketones and their application in the constructing of heterocyclic compounds with important biological activity, including pyrimidine, oxazole, pyrazole.

关键词： carbon dioxide bimolecular reduction trifunctionalization double synthons

Numerical simulation of liquid sloshing in a spherical tank by MPS method

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2024年第2期36卷 232-240页

作者： Cong-yi Huang Ji-fei Wang Wei-wen Zhao De-cheng Wan Computational Marine Hydrodynamic lab(CMHL) School of Naval ArchitectureOcean and Civil EngineeringShanghai Jiao Tong UniversityShanghai200240China Shanghai Aerospace System engineering Institute Shanghai201109China

This paper investigates the sloshing phenomena in a spherical liquid tank using the moving particle semi-implicit(MPS)method,a crucial study in fluid *** from previous research focused on rectangular or LNG tanks,this work explores the unique motion patterns inherent to spherical *** accuracy of our in-house MPS solver MLParticle-SJTU is validated against experimental data and finite volume method(FVM).And the MPS method reveals a closer alignment with experimental outcomes,which suggests that MPS method is particularly effective for modeling complex,non-linear fluid *** the fluid’s response to excitation at its natural frequency is simulated,showcasing vigorous sloshing and rotational *** analyses of the fluid motion are conducted by drawing streamline diagrams,velocity vector diagrams,and vorticity *** fluid’s motion response is explored using both time-domain and frequency-domain curves of the fluid centroid,as well as the sloshing force.

关键词： Moving particle semi-implicit(MPS)method spherical tank liquid sloshing model experiment