检索结果-南通市图书馆

同方期刊数据库

Shear behavior of two-order morphology in rock joints

在线全文

学校读者我要写书评

暂无评论

Journal of Mountain Science 2023年第3期20卷 845-858页

作者： HUANG Man chen Xuan-nan hong chen-jie LIU Dan LUO Zhan-you DU Shi-gui WU Zao-sheng Dept.of Civil Engineering Shaoxing UniversityShaoxing 312000China State Key Laboratory for GeoMechanics and Deep Underground Engineering China University of Mining and Technology(Beijing)Beijing 100083China School of Civil and Environmental Engineering Ningbo UniversityNingbo 315000China Geological Survey Engineering Department Shaoxing Huahui Engineering Design Group Co.LTDShaoxing 312000China

Two-order morphology of rock joints named as waviness and unevenness can be separated by morphology classification method,which plays a decisive role in the evolution of shear stress during the shear *** joint morphology is obtained by using 3D printing and 3D laser scanning techniques and the joint model samples in two-order morphology are produced by cement ***,shear tests are performed under different normal *** shows that the waviness is dominant in the total morphology during the shear test,and the shear contribution of unevenness mainly occurs in the climbing phase of shearing *** the failure modes of two-order morphology,waviness mainly embodies shear dilation characteristics and unevenness mainly shows shear wear *** on this,a quantitative parameter is proposed to represent the ratio of the peak shear strength of the two-order morphology to that of total *** functional relationship between the peak shear strength of total and two-order morphologies is determined,providing a theoretical method for further in-depth study on the shear strength of the interaction with two-order morphology of rock joints.

关键词： Rock joints Two-order morphology Shearcharacteristics S hear strength Damage mechanism

维普期刊数据库

Evaluation of toppling rock slopes using a composite cloud model with DEMATEL–CRITIC method

在线全文

学校读者我要写书评

暂无评论

Water Science and Engineering 2023年第3期16卷 280-288页

作者： Huan-ling Wang Xu-fei Zhao hong-jie chen Kui Yi Wei-chau Xie Wei-ya Xu Research Institute of Geotechnical Engineering Hohai UniversityNanjing 210098China Huaneng Lancang River Hydropower Ltd. Technology R&D CenterKunming 650214China Department of Civil and Environmental Engineering University of WaterlooWaterlooOntario N2L 3G1Canada

Safety evaluation of toppling rock slopes developing in reservoir areas is crucial. To reduce the uncertainty of safety evaluation, this study developed a composite cloud model, which improved the combination weights of the decision-making trial and evaluation laboratory (DEMATEL) and criteria importance through intercriteria correlation (CRITIC) methods. A safety evaluation system was developed according to in situ monitoring data. The backward cloud generator was used to calculate the numerical characteristics of a cloud model of quantitative indices, and different virtual clouds were used to synthesize some clouds into a generalized one. The synthesized numerical characteristics were calculated to comprehensively evaluate the safety of toppling rock slopes. A case study of a toppling rock slope near the Huangdeng Hydropower Station in China was conducted using monitoring data collected since operation of the hydropower project began. The results indicated that the toppling rock slope was moderately safe with a low safety margin. The composite cloud model considers the fuzziness and randomness of safety evaluation and enables interchange between qualitative and quantitative knowledge. This study provides a new theoretical method for evaluating the safety of toppling rock slopes. It can aid in the predication, control, and even prevention of disasters.

关键词： Toppling rock slope Safety evaluation Composite cloud model DEMATEL CRITIC Huangdeng Hydropower Project

Prediction for permeability index of blast furnace based on VMD-PSO-BP model

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 Iron and Steel Research(International) 2024年第3期31卷 573-583页

作者： Xiao-jie Liu Yu-jie Zhang Xin Li Zhi-feng Zhang hong-yang Li Ran Liu Shu-jun chen School of Metallurgy and Energy North China University of Science and TechnologyTangshan 063210HebeiChina chengde Branch HBIS Group Co.Ltd.Chengde 067000HebeiChina

The permeability index is one of the important production indicators to monitor the operation of blast *** is crucial to grasp the trends of changes in the new permeability index in *** the complex vibration spectrum of the permeability index,a prediction model of the permeability index based on the VMD-PSO-BP(variational mode decomposition-particle swarm optimization-back propagation)method was ***,the key factors that affect the permeability index of blast furnace were studied from multiple ***,the permeability index was divided into multiple sub-modes based on the difference of frequency bands by the VMD algorithm,and a PSO-BP prediction model was established for each ***,the prediction results of each sub-mode were summed to obtain the final *** results show that the composite prediction accuracy by using the VMD algorithm is 3%higher than that of the traditional prediction method,which has better applicability.

关键词： Big data-Blast furnace Air permeability Variational mode decomposition Particle swarm optimization Back propagation Model prediction

Effect of different bottom blowing elements on stirring characteristics of molten bath in converter

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 Iron and Steel Research(International) 2024年第2期31卷 368-376页

作者： Ming Lv Shuang-ping chen hong-min Guo Yi-jie Hao Xiang-dong Xing School of Metallurgical Engineering Xi’an University of Architecture and TechnologyXi’an710055ShaanxiChina Shaanxi Longmen Steel Company Hancheng715405ShaanxiChina

The bottom blowing element is the key equipment to ensure the bottom blowing effect of the *** types of bottom blowing elements,dispersive type(D1),double circular seam(D2)and straight cylinder type(D3),were built,and the effects of bottom blowing element type on molten bath flow,wall erosion and furnace bottom erosion were *** was found that when the bottom blowing elements of dispersive type(D1)and double circular seam(D2)were used,the dead zone area in the lower part of the molten bath was smaller,and the high-speed zone area was larger;therefore,the stirring effect on the bottom melt was *** the straight cylinder type(D3)bottom blowing element was used,the gas penetrated the molten bath at a faster rate to reach the surface of molten bath and failed to disperse in the bottom molten bath,and the wall shear stress near the nozzle outlet was *** argon was blown by three different bottom blowing elements,the area of the wall shear stress greater than 3 Pa was 4.8,5.6 and 8.7 cm2,respectively,within 0.2 m of the bottom blowing nozzle outlet.

关键词： Converter steelmaking Bottom blowing element Molten bath stirring Wall erosion

Asymptomatic neurosyphilis may need early intervention in people living with HIV

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 Medical Journal 2020年第23期133卷 2877-2879页

作者： hong-jie chen Tao Yu jie Peng State Key Laboratory of Organ Failure Research Guangdong Provincial Key Laboratory of Viral Hepatitis ResearchDepartment of Infectious DiseasesNanfang HospitalSouthern Medical UniversityGuangzhouGuangdong 510515China

Syphilis is a sexually transmitted infection caused by the spirochete Treponema pallidum(***)and is of global and historic *** living with HIV(PLWH)infection are frequently coinfected with syphilis,because of the overlapping modes of pathogen *** can occur at any stage of syphilis infection,and PLWH are at a greater risk of developing neurosyphilis in early and late latent syphilis,including asymptomatic central nervous system(CNS)infection than those without HIV *** patients with neurosyphilis present neurological manifestations such as meningitis,stroke,cranial nerve dysfunction,auditory or ophthalmic abnormalities,and acute changes in mental ***,some neurosyphilis cases in PLWH lack signs or symptoms of CNS *** neurosyphilis is diagnosed in the absence of neurological signs or symptoms and can only be detected in the presence of cerebrospinal fluid(CSF)abnormalities indicative of CNS infection,including mononuclear pleocytosis,increased protein concentration,and/or a reactive CSF venereal disease research laboratory(VDRL)*** has raised concerns that a persistent reservoir of *** although asymptomatic in the CNS,may result in treatment failure and neurological sequelae in *** might lead to cranial nerve palsies,syphilitic meningitis,general paresis,and tabes dorsalis even several years after ***,early intervention may be needed for asymptomatic neurosyphilis in PLWH.

关键词： Asymptomatic auditory acute

维普期刊数据库

Spray pyrolysis-derived W-doped MoSe2/rGO paper-like microspheres:optimization of microstructure and mesostructure for enhanced lithium storage

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2024年第7期43卷 3019-3031页

作者： Wei Wang Jun-Yu chen jie Ouyang hong Yin Ao-jie Li Liang chen Jun-Lin Huang Yu-Can Zhu Gang-Yong Li Zhao-Hui Hou Key Laboratory of Hunan Province for Advanced Carbon-based Functional Materials Hunan Institute of Science and Technology School of Chemistry and Chemical Engineering Hunan Institute of Science and Technology Hunan Province Key Laboratory of Materials Surface & Interface Science and Technology Material Science and Engineering SchoolCentral South University of Forestry and Technology International Iberian Nanotechnology Laboratory (INL)

Two-dimensional MoSe2is a promising candidate for lithium-ion battery ***,its conductivity and lithium storage volumetric effect still need to be *** this work,W-doped MoSe2/rGO paper-like microspheres are successfully prepared through ultrasonic spray pyrolysis,achieving optimization at both the microstructure and mesostructure to enhance the lithium storage performance of the ***,by utilizing the similar two-dimensional structure between MoSe2and rGO,self-assembly is achieved through spray pyrolysis,resulting in a well-defined van der Waals heterostructure at the interface on the microscale,enhancing the electron and ion transfer capability of the ***,the mesoscale paper-like microsphere morphology provides additional volume expansion buffering ***,W-doping not only increases the interlayer spacing of MoSe2（0.73 nm）,thereby reducing the diffusion resistance of Li+,but also allow for the modulation of the energy band structure of the *** functional theory（DFT） calculations confirm that W-doped MoSe2/rGO exhibits the narrowest bandgap（0.892 eV）.Therefore,the composite demonstrates excellent lithium storage performance,maintaining a specific capacity of 732.9 mAh·g-1after 300 cycles at a current density of 1 A·g-1.

关键词： Molybdenum selenide Heterostructure Microspheres Li-ion batteries Kinetics

UAV-assisted data collection for wireless sensor networks with dynamic working modes

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Digital Communications and Networks 2024年第3期10卷 805-812页

作者： jie chen Jianhua Tang Shien-Ming Wu School of Intelligent Engineering South China University of TechnologyGuangzhou511442China

Wireless Sensor Network(WSN)is a cornerstone of Internet of Things(IoT)and has rich application *** this work,we consider a heterogeneous WSN whose sensor nodes have a diversity in their Residual Energy(RE).In this work,to protect the sensor nodes with low RE,we investigate dynamic working modes for sensor nodes which are determined by their RE and an introduced energy ***,we employ an Unmanned Aerial Vehicle(UAV)to collect the stored data from the heterogeneous *** aim to jointly optimize the cluster head selection,energy threshold and sensor nodes’working mode to minimize the weighted sum of energy con-sumption from the WSN and UAV,subject to the data collection rate *** this end,we propose an efficient search method to search for an optimal energy threshold,and develop a penalty-based successive convex approximation algorithm to select the cluster *** we present a low-complexity iterative approach to solve the joint optimization problem and discuss the implementation *** results justify that our proposed approach is able to reduce the energy consumption of the sensor nodes with low RE significantly and also saves energy for the whole WSN.

关键词： Unmanned aerial vehicle Wireless sensor networks Cluster heads Dynamic working modes

Eigenstate properties of the disordered Bose-Hubbard chain

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of physics 2024年第4期19卷 57-72页

作者： jie chen Chun chen Xiaoqun Wang Key Laboratory of Artificial Structures and Quantum Control(Ministry of Education) School of Physics and AstronomyShanghai Jiao Tong UniversityShanghai 200240China School of Physics Zhejiang UniversityHangzhou 310058China Collaborative Innovation Center of Advanced Microstructures Nanjing UniversityNanjing 210093China

Many-body localization(MBL)of a disordered interacting boson system in one dimension is studied numerically at the filling faction *** von Neumann entanglement entropy Svn is commonly used to detect the MBL phase transition but remains challenging to be directly *** on the U(1)symmetry from the particle number conservation,Svn can be decomposed into the particle number entropy S_(n) and the configuration entropy *** light of the tendency that the eigenstate's S_(c) nears zero in the localized phase,we introduce a quantity describing the deviation of S from the ideal thermalization distribution;finite-size scaling analysis illustrates that it shares the same phase transition point with Sv but displays the better critical *** observation hints that the phase transition to MBL might largely be determined by S and its fluctuations Notably,the recent experiments[***,et al.,Science 364,256(2019);***,et al.,***.19,481(2023)]demonstrated that this deviation can potentially be measured through the Sn ***,our investigations reveal that the thermalized states primarily occupy the low-energy section of the spectrum,as indicated by measures of localization length,gap ratio,and energy density *** low-energy spectrum of the Bose model closely resembles the entire spectrum of the Fermi(or spin XXZ)model,accommodating a transition from the thermalized to the localized ***,owing to the bosonic statistics,the high-energy spectrum of the model allows the formation of distinct clusters of bosons in the random potential *** analyze the resulting eigenstate properties and briefly summarize the associated *** distinguish between the phase regions at the low and high energies,a probing quantity based on the structure of S_(VN) is also *** work highlights the importance of symmetry combined with entanglement in the study of *** this regard,for the disordered Heisenberg XXZ

关键词： entanglement entropy decomposition U(1)symmetry thermalization-to-localization transition

Grain boundary engineering for enhancing intergranular damage resistance of ferritic/martensitic steel P92

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2024年第5期35卷 186-199页

作者： Lei Peng Shang-Ming chen Jing-Yi Shi Yong-jie Sun Yi-Fei Liu Yin-Zhong Shen hong-Ya He Hui-Juan Wang jie Tian State Key Laboratory of Particle Detection and Electronics University of Science and Technology of ChinaHefei 230026China School of Nuclear Science and Technology University of Science and Technology of ChinaHefei 230027China School of Materials Engineering Shanghai University of Engineering Science333 Long Teng RoadShanghai 201620China Experimental Center of Engineering and Material Science University of Science and Technology of ChinaHefei 230026China

Ferritic/martensitic(F/M)steel is widely used as a structural material in thermal and nuclear power ***,it is susceptible to intergranular damage,which is a critical issue,under service *** this study,to improve the resistance to intergranular damage of F/M steel,a thermomechanical process(TMP)was employed to achieve a grain boundary engineering(GBE)microstructure in F/M steel *** TMP,including cold-rolling thickness reduction of 6%,9%,and 12%,followed by austenitization at 1323 K for 40 min and tempering at 1053 K for 45 min,was applied to the as-received(AR)P92 *** prior austenite grain(PAG)size,prior austenite grain boundary character distribution(GBCD),and connectivity of prior austenite grain boundaries(PAGBs)were *** to the AR specimen,the PAG size did not change *** fraction of coincident site lattice boundaries(CSLBs,3≤Σ≤29)and Σ3^(n) boundaries along PAGBs decreased with increasing reduction ratio because the recrystallization fraction increased with increasing reduction *** PAGB connectivity of the 6%deformed specimen slightly deteriorated compared with that of the AR ***,potentiodynamic polarization studies revealed that the intergranular damage resistance of the studied steel could be improved by increasing the fraction of CSLBs along the PAGBs,indicating that the TMP,which involves low deformation,could enhance the intergranular damage resistance.

关键词： Grain boundary engineering Ferritic/martensitic steel Prior austenite grain boundary character distribution Grain boundary connectivity Intergranular damage resistance

维普期刊数据库