检索结果-南通市图书馆

Constitutive Behavior of the Interface between UHPC and Steel Plate without Shear Connector:From Experimental to Numerical Study

维普期刊数据库

同方期刊数据库评论

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8期140卷 1863-1888页

作者： Zihan wang Boshan Zhang Hui wang qing Ai Xingchun Huang School of Naval Architecture Ocean and Civil EngineeringShanghai Jiao Tong UniversityShanghai200240China Department of Bridge Engineering Tongji UniversityShanghai200092China

The application of ultra-high performance concrete(UHPC)as a covering layer for steel bridge decks has gained widespread *** employing a connection without a shear connector between the steel plate and UHPC,namely,the sandblasted interface and the epoxy adhesive with sprinkled basalt aggregate interface,the installation cannot only be simplified but also the stress concentration resulting from the welded shear connectors can be *** study develops constitutive models for these two interfaces without shear connectors,based on the interfacial pull-off and push-out *** validation,three-point bending tests on the steel-UHPC composite plates are *** results indicated that the proposed bilinear traction-separation model for the sandblasted interface and the trapezoidal traction-separation model for the epoxy adhesive with sprinkled basalt aggregate interface can generally calibrate the interfacial ***,the utilization of the experimentally determined pure shear strength underestimates the load-carrying capacity of the composite plates in the case of three-point bending *** recalling the Mohr-Coulomb criterion,this underestimation is attributed to the enhancement of the interface shear strength by the presence of normal stress.

关键词： Cohesive zone model interfacial behavior finite element simulation UHPC steel plate

Cut-off value of glycated hemoglobin A1c for detecting diabetic retinopathy in the Chinese population

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Diabetes 2024年第7期15卷 1531-1536页

作者： Yan Wen qing wang Department of Endocrinology China-Japan Union Hospital of Jilin UniversityChangchun 130033Jilin ProvinceChina

BACKGROUND Glycated hemoglobin A1c(HbA1c)is considered the most suitable for diabetes mellitus diagnosis due to its accuracy and ***,the effect of HbA1c on diabetic retinopathy(DR)in the Han and Korean populations in Jilin,China,remains *** To determine the best cut-off of HbA1c for diagnosing DR among the *** This cross-sectional study included 1933 participants from the Yanbian area of Jilin Province,*** investigators employed a questionnaire-based survey,physical examination,laboratory tests,and fundus photography for the *** best cut-off value for HbA1c was established via the receiver operating characteristic *** factors associated with HbA1c-associated risk factors were determined via linear *** The analysis included 887 eligible Chinese Han and Korean participants,591 of whom were assigned randomly to the training set and 296 to the validation *** prevalence of DR was 3.27% in the total ***1c of 6.2% was the best cut-off value in the training set,while it was 5.9% in the validation *** both Chinese Han and Korean populations,an HbA1c level of 6.2% was the best cut-off *** optimal cut-off values of fasting blood glucose(FBG)≥7 mmol/L and<7 mmol/L were 8.1% and 6.2% respectively in Han populations,while those in Korean populations were 6.9%and 5.3%,***,body mass index,and FBG were determined as the risk factors impacting HbA1c *** HbA1c may serve as a useful diagnostic indicator for *** HbA1c level of 6.2% may be an appropriate cut-off value for DR detection in the Chinese population.

关键词： Diabetic retinopathy Glycated hemoglobin A1c Cut-off value Age Body mass index Fasting blood glucose

Real-time arrival picking of rock microfracture signals based on convolutional-recurrent neural network and its engineering application

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 Rock Mechanics and Geotechnical Engineering 2024年第3期16卷 761-777页

作者： Bing-Rui Chen Xu wang Xinhao Zhu qing wang Houlin Xie State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan430071China University of Chinese Academy of Sciences Beijing100049China

Accurately picking P-and S-wave arrivals of microseismic(MS)signals in real-time directly influences the early warning of rock mass failure.A common contradiction between accuracy and computation exists in the current arrival picking ***,a real-time arrival picking method of MS signals is constructed based on a convolutional-recurrent neural network(CRNN).This method fully utilizes the advantages of convolutional layers and gated recurrent units(GRU)in extracting short-and long-term features,in order to create a precise and lightweight arrival picking ***,the synthetic signals with field noises are used to evaluate the hyperparameters of the CRNN model and obtain an optimal CRNN *** actual operation on various devices indicates that compared with the U-Net method,the CRNN method achieves faster arrival picking with less performance *** application of large underground caverns in the Yebatan hydropower station(YBT)project shows that compared with the short-term average/long-term average(STA/LTA),Akaike information criterion(AIC)and U-Net methods,the CRNN method has the highest accuracy within four sampling points,which is 87.44%for P-wave and 91.29%for S-wave,*** sum of mean absolute errors(MAESUM)of the CRNN method is 4.22 sampling points,which is lower than that of the other *** the four methods,the MS sources location calculated based on the CRNN method shows the best consistency with the actual failure,which occurs at the junction of the shaft and the second ***,the proposed method can pick up P-and S-arrival accurately and rapidly,providing a reference for rock failure analysis and evaluation in engineering applications.

关键词： Rock mass failure Microseismic event P-wave arrival S-wave arrival Deep learning

Model Parameters Identification and Backstepping Control of Lower Limb Exoskeleton Based on Enhanced Whale Algorithm

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 Mechanical Engineering 2024年第2期37卷 100-114页

作者： Yan Shi Jiange Kou Zhenlei Chen Yixuan wang qing Guo School of Automation Science and Electrical Engineering Beihang UniversityBeijing 100191China School of Aeronautics and Astronautics University of Electronic Science and Technology of ChinaChengdu 611731China

Exoskeletons generally require accurate dynamic models to design the model-based controller conveniently under the human-robot interaction ***,due to unknown model parameters such as the mass,moment of inertia and mechanical size,the dynamic model of exoskeletons is difficult to ***,an enhanced whale optimization algorithm(EWOA)is proposed to identify the exoskeleton model ***,the periodic excitation trajectories are designed by finite Fourier series to input the desired position demand of exoskeletons with mechanical physical *** a backstepping controller based on the identified model is adopted to improve the human-robot wearable comfortable performance under cooperative ***,the proposed Model parameters identification and control are verified by a two-DOF exoskeletons *** knee joint motion achieves a steady-state response after 0.5 ***,the position error of hip joint response is less than 0.03 rad after 0.9 *** addition,the steady-state human-robot interaction torque of the two joints is constrained within 15 N·*** research proposes a whale optimization algorithm to optimize the excitation trajectory and identify model ***,an enhanced mutation strategy is adopted to avoid whale evolution’s unsatisfactory local optimal value.

关键词： Parameter identification Enhanced whale optimization algorithm(EWOA) Backstepping Human-robot interaction Lower limb exoskeleton

Experimental investigation on the anisotropy of friction property for dry and water-saturated rock

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Friction 2024年第9期12卷 2064-2082页

作者： qing YANG Mingming HE Jinrui ZHAO Mingchen DING Jing wang State Key Laboratory of Eco-hydraulics in Northwest Arid Region Xi’an University of TechnologyXi’an 710048China China Communication Construction Company Mechanical and Electrical Engineering Co. Ltd.Beijing 100088China

Friction properties of rock are closely connected with the *** anisotropy of rock friction can provide a valuable assessment for geotechnical and geological *** this study,the rotary friction tests were conducted to analyze the water effect on the friction property and the friction anisotropy of the four types of *** drilling response model(DD-model)was employed to characterize the rotary friction behavior of the *** parameters of this model include the three types of friction parameters:1/ς,μ,and f,where 1/ςandμare constant,and f is a variable.A quantitative method is proposed for assessing the anisotropy of rock *** results of the rotary friction tests indicate that the relation between torque force and thrust force conforms to the *** changes of two friction constants 1/ςandμfrom dry state to water-saturated state suggest that the water effect on the friction strength of the rocks exhibits significant *** friction strength determined by the friction variable f increases first,then decreases,and finally stabilizes with the increasing of *** is an anisotropy index calculated by the proposed *** percentage difference of the average value of AIf between water-saturated and dry states shows the degree of the water effect on the friction anisotropy of the rocks,mudstone(MU)>granite(GR)>fine sandstone(FS)>argillaceous siltstone(AS).The quantitative model is hopefully constructed for characterizing the relation between the anisotropic friction strength of rock and the moisture state in future.

关键词： anisotropy rotary friction test drilling response model(DD-model) effective stress law

Influence of oxygen-rich hot air composite gas medium on sintering performance and function mechanism

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5期31卷 1071-1081页

作者： Min Gan Hao-xiang Zheng Xiao-hui Fan Zhi-yun Ji Qiang Li Ming Wu Yi-fan wang Xiao-long wang Yu-feng Wu Xu-ling Chen Zeng-qing Sun Xiao-xian Huang School of Minerals Processing and Bioengineering Central South UniversityChangsha410083HunanChina Shanxi Taigang Stainless Steel Co. Ltd.Taiyuan030003ShanxiChina

Hot air sintering technology is used to improve the quality and production efficiency of sintered ***,the current thick layer condition highlights the disadvantage of the low oxygen potential of the hot air sintering ***,it is considered to use oxygen enrichment sintering to improve the environment of hot air *** sintering,hot air sintering,and oxygen-rich hot air sintering were compared through sintering cup experiments,and the influence of hot air and oxygen-rich hot air on sintering indexes was *** air reduced the vertical sintering velocity,while improved the yield and tumbler ***-rich hot air sintering contributed to improving the vertical sintering velocity while ensuring the quality of sintered ore,thus comprehensively improving production *** the action of hot air,the highest temperature of the sintering layer increased and the high-temperature holding time was *** oxygen enrichment,the combustion efficiency of fuels in the upper layer of materials was promoted,which optimized heat distribution in the middle and lower layers of materials and increased the content of calcium ferrite in the sintered ore,thus strengthening the sintering process.

关键词： Iron ore sintering Hot air sintering Oxygen enrichment Function mechanism

Molecular mechanism of a coastal cyanobacterium Synechococcus *** 7002 adapting to changing phosphate concentrations

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Marine Life Science & Technology 2024年第3期6卷 562-575页

作者： Qiao-Wei Sun Yu Gao Jordan wang Fei-xue Fu Cheng-Wen Yong Shuang-qing Li Hai-long Huang Wei-Zhong Chen Xin-Wei wang Hai-Bo Jiang School of Marine Sciences Ningbo UniversityNingbo 315211China Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai) Zhuhai 519080China School of Life Sciences Central China Normal UniversityWuhan 430079China Department of Biological Sciences University of Southern CaliforniaLos AngelesCA 90089USA

Phosphorus concentration on the surface of seawater varies greatly with different environments,especially in *** molecular mechanism by which cyanobacteria adapt to fluctuating phosphorus bioavailability is still *** this study,transcriptomes and gene knockouts were used to investigate the adaptive molecular mechanism of a model coastal cyanobacterium Synechococcus *** 7002 during periods of phosphorus starvation and phosphorus recovery(adding sufficient phosphorus after phosphorus starvation).The findings indicated that phosphorus deficiency affected the photosynthesis,ribosome synthesis,and bacterial motility pathways,which recommenced after phosphorus was *** more,most of the metabolic pathways of cyanobacteria were enhanced after phosphorus recovery compared to the control which was kept in continuous phosphorus replete *** on transcriptome,54 genes potentially related to phosphorusdeficiency adaptation were selected and knocked out individually or in *** was found that five mutants showed weak growth phenotype under phosphorus deficiency,indicating the importance of the genes(A0076,A0549-50,A1094,A1320,A1895)in the adaptation of phosphorus *** mutants were found to grow better than the wild type under phosphorus deficiency,suggesting that the products of these genes(A0079,A0340,A2284–86)might influence the adaptation to phosphorus *** analysis revealed that cyanobacteria exposed to highly fluctuating phosphorus concentrations have more sophisticated phosphorus acquisition *** results elucidated that Synechococcus *** 7002 have variable phosphorus response mechanisms to adapt to fluctuating phosphorus concentration,providing a novel perspective of how cyanobacteria may respond to the complex and dynamic environments.

关键词： Synechococcus sp PCC 7002 Phosphorus fluctuation Cyanobacteria ・Gene knockout Molecular mechanism

Layered vanadium oxides:Promising cathode materials for calcium-ion batteries

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 Structural Chemistry 2024年第5期43卷 5-7页

作者： Yuhan Wu qing Zhao Zhijie wang School of Environmental and Chemical Engineering Shenyang University of TechnologyShenyang110870China Key Laboratory of Advanced Energy Materials Chemistry(Ministry of Education) Nankai UniversityTianjin300071China Key Laboratory of Semiconductor Materials Science Beijing Key Laboratory of Low Dimensional Semiconductor Materials and DevicesInstitute of SemiconductorsChinese Academy of SciencesBeijing100083China

Electric vehicles powered by lithium-ion batteries(LIBs)have been regarded as an effective way to reduce CO_(2)emissions,which is known as one of the main causes of global *** share of electric ve-hicles in total sales has increased rapidly,from around 4%in 2020 to 14%in 2022[1].In this case,LIBs have been mass-produced and consumed in the past few *** is estimated that LIBs will account for 65%of total lithium consumption by 2025[2].

关键词： lithium vanadium powered

Two thin middle-crust low-velocity zones imaged in the Chuan-Dian region of southeastern Tibetan Plateau and their tectonic implications

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 Earth Sciences 2024年第5期67卷 1675-1686页

作者： long LI Xin wang Guangbing HOU Yuan LING Yinshuang AI Key Laboratory of Earth and Planetary Physics Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049China Innovation Academy for Earth Science Chinese Academy of SciencesBeijing 100029China

Intracrustal low-velocity zones(LVZs)indicate a mechanically weak crust and are widely observed in the southeast margin of the Tibetan ***,their spatial distributions and formation mechanisms remain *** investigate their distribution and detailed morphology of the LVZs in the southeastern Tibetan Plateau,here we used teleseismic events and continuous waveform data recorded by 40 broadband seismic stations newly deployed in the Sichuan-Yunnan region from December 2018 to October 2020.A total of 12,924 high-quality P-wave receiver functions and 5–40 s fundamental Rayleigh surface wave phase velocity dispersion curves from ambient noise cross-correlation functions were *** Swave velocity model at a depth interval of 0–100 km in the study area was inverted by using the trans-dimensional Markov chain Monte Carlo strategy to jointly invert the complementary data of the receiver function waveform and Rayleigh surface wave phase velocity *** results show that there are two separate LVZs(~3.5 km/s)surrounding the rigid Daliangshan subblock at crustal depths of approximately 30–40 km,providing new constraints on the geometry of the LVZs in our study *** two LVZs obtained in this study may represent the middle crustal flow channels,through which the material in the center of the Tibetan Plateau extrudes to its southeast *** by the rigid Sichuan Basin and the spindle-like Daliangshan subblock,the material continues to flow southward through the mechanically weak middle crustal channels surrounding the Daliangshan *** addition,the existence of thin LVZs in the middle crust plays an important role in understanding the decoupling between the upper and lower crust in the study *** also provides new constraint on the complex tectonic deformation process of the southeastern margin of the Tibetan Plateau caused by the collision and compression of the Indian and the Eurasian plates.

关键词： Southeastern Tibetan Plateau Joint inversion Intracrustal low-velocity zone Mid-crustal channel flow