检索结果-南通市图书馆

Chinese Journal of Mechanical Engineering 2024年第4期37卷 290-305页

作者： Chao Wang Tao zhu Bing Yang Shoune xiao Guangwu Yang State Key Laboratory of Rail Transit Vehicle System Southwest Jiao tong UniversityChengdu 610031China

The current research on the integrity of critical structures of rail vehicles mainly focuses on the design stage,which needs an effective method for assessing the service *** paper proposes a framework for predicting the remaining useful life(RUL)of in-service structures with and without visible *** hypothetical distribution and delay time models were used to apply the equivalent crack growth life data of heavy-duty railway cast steel knuckles,which revealed the evolution characteristics of the crack length and life scores of the knuckle under different fracture failure *** results indicate that the method effectively predicts the RUL of service knuckles in different failure modes based on the cumulative failure probability curves for different locations and surface crack *** study proposes an RUL prediction framework that supports the dynamic overhaul and state maintenance of knuckle fatigue cracks.

关键词： Heavy-duty railway Cast steel knuckle Remaining useful life Fatigue crack growth Hypothetical distribution

Research on Restoration of Murals Based on Diffusion Model and Transformer

在线全文

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2024年第9期80卷 4433-4449页

作者： Yaoyao Wang Mansheng xiao Yuqing Hu Jin Yan Zeyu zhu School of Computing Hunan University of TechnologyZhuzhou412000China School of Computing Hunan Software Vocational and Technical UniversityXiangtan411100China

Due to the limitations of a priori knowledge and convolution operation,the existing image restoration techniques cannot be directly applied to the cultural relics mural restoration,in order to more accurately restore the original appearance of the cultural relics mural images,an image restoration based on the denoising diffusion probability model(Denoising Diffusion Probability Model(DDPM))and the Transformer *** process involves two steps:in the first step,the damaged mural image is firstly utilized as the condition to generate the noise image,using the time,condition and noise image patch as the inputs to the noise prediction network,capturing the global dependencies in the input sequence through the multi-attentionmechanismof the input sequence and feedforward neural network processing,and designing a long skip connection between the shallow and deep layers in the Transformer blocks between the shallow and deep layers using long skip connections to fuse the feature information of global and local outputs to maintain the overall consistency of the restoration results;In the second step,taking the noisy image as a condition to direct the diffusion model to back sample to generate the restored *** results show that the PSNR and SSIM of the proposedmethod are improved by 2%to 9%and 1%to 3.3%,respectively,which are compared to the comparison *** study proposed synthesizes the advantages of the diffusionmodel and deep learningmodel to make themural restoration results more accurate.

关键词： Transformer deep learning noise estimation network diffusion model mural restoration

Two-stage aging treatment to accelerate aging kinetics without impairing strength in B_4C/7A04Al composite

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(Technological Sciences) 2024年第8期67卷 2485-2492页

作者： CHEN yunTao MA GuoNan zhu ShiZe WANG Dong xiao BoLv MA ZongYi Shi-Changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China Centre of Excellence for Advanced Materials Dongguan 523808China

Aging treatments are the key process to obtain satisfactory strength for 7xxxAl alloys and their composites. However, traditional single-stage(SS) aging is time-consuming to reach a peak strength condition. In this study, an efficient 120℃ + 160℃ two-stage(TS) aging treatment was proposed on a B_4C/7A04Al composite fabricated via powder metallurgy(PM) technology, which could acquire similar peak-aging strength but only took about 15% of the time compared to traditional 120℃ SS aging. The evolution of precipitation during the TS aging was investigated, as well as those of the 7A04Al alloys for comparison. In the second stage aging process, the higher aging temperature accelerated the nucleation of η′ phases inside the grains and thus increased the density of precipitates. Moreover, the short aging time limited the coarsening of precipitates and the broadening of precipitatefree zones. The above factors were beneficial for quickly obtaining satisfactory precipitation strengthening effects. The B_4C/7A04Al composite exhibited slower aging kinetics than the 7A04Al alloy in the TS aging. Mg elements consumption by the chemical reaction between B impurities introduced by B_4C particles and the Al matrix was considered to potentially retard the aging kinetics of the B_4C/7A04Al composite. Nevertheless, the precipitation sequence was not affected.

关键词： aluminum matrix composites aging treatment powder metallurgy mechanical properties precipitation

Large-scale manufacturing of functional single-atom ink for convenient glucose sensing

在线全文

学校读者我要写书评

暂无评论

Nano Research 2024年第8期17卷 7256-7263页

作者： Muyu Yan xiaofei zhu Can Xiong xiao Han Zhenggang Xue Yuen Wu Department of Endocrinology Institute of Endocrine and Metabolic DiseasesThe First Affiliated Hospital of USTCDivision of Life Sciences and MedicineUniversity of Science and Technology of ChinaHefei 230001China Deep Space Exploration Laboratory University of Science and Technology of ChinaHefei 230026China NEST Laboratory Department of PhysicsDepartment of ChemistryCollege of ScienceShanghai UniversityShanghai 200444China Center of Advanced Nanocatalysis(CAN) Department of Applied ChemistryUniversity of Science and Technology of ChinaHefei 230026China

Printing techniques hold great potential in the manufacture of electronics such as sensors,micro-supercapacitors,and flexible ***,developing large-scale functional conductive inks with appropriate rheological properties and active components still remains a ***,through optimizing the formulations of ink,iron single sites supported N-doped carbon black(Fe_(1)-NC)inks can serve as both conductive electrodes and high-reactive catalysts to realize convenient glucose detection,which pronouncedly reduces the dosage of enzyme and simplifies the sensors *** detail,utilizing in-situ pyrolysis method,Fe_(1)-NC single-atom catalysts(SACs)are prepared in bulk(dekagram-level).The batched Fe_(1)-NC SACs materials can be uniformly mixed with modulated ink to realize the screen printing with high resolution and ***,the whole scalable preparation and ink-functional process can be extended to various metals(including Co,Ni,Cu,and Mn).The introduction of highly active Fe_(1)-NC sites reduces the amount of enzyme used in glucose detection by at least 50%,contributing to the cost reduction of *** strategy in harnessing the SACs onto the carbon inks thus provides a broad prospect for the low-cost and large-scale printing of sensitive sensing devices.

关键词： large-scale manufacturing single-atom inks screen printing glucose sensing low enzyme dosage

Synthesis of highly stable Ni nanoparticles via electrostatic self-assembly for enhanced hydrogen storage of MgH_(2)

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

Rare Metals 2024年第9期43卷 4356-4366页

作者： Qin-Ke Tang Jiang-Chuan Liu Rui Shi yun-Feng zhu Ji-Guang Zhang Ya-Na Liu Jun Wang Yao Zhang xiao-Hui Hu Zhi-Bin Liu Li-Quan Li College of Materials Science and Engineering Jiangsu Collaborative Innovation Centre for Advanced Inorganic Function CompositesNanjing Tech UniversityNanjing 211816China School of Materials Science and Engineering Southeast UniversityNanjing 211189China

Magnesium-based hydrides have been widely recognized as an appropriate choice for solid-state hydrogen ***,its undesirable thermodynamics and sluggish hydrogenation/dehydrogenation kinetics are major bottlenecks for its ***,a highly stable and highly dispersed Ni-based catalyst(Ni/Al_(2)O_(3)/GN)was fabricated to promote the hydrogen storage performance of MgH_(2)via the electrostatic effect of NiAl-LDH/GN precursor with a co-calcination reduction ***_(2)-5wt%Ni/Al_(2)O_(3)/GN exhibits excellent hydrogen storage performance,releasing about 5.7 wt%hydrogen in 3500 s at 250℃,and can reach a saturation hydrogen absorption of about 6.15 wt%in 3000 s at 100℃.Furthermore,it also shows low dehydrogenation apparent activation energy of 89.1 and 118.2 kJ·mol^(-1).Impressively,the catalyst ensures the stability of both the physical phase and structure during ball milling and cycling *** role of each phase in Ni/Al_(2)O_(3)/GN on the hydrogen storage performance of MgH_(2)was also discussed through experiments and theoretical calculation,and the synergistic catalytic mechanism of Ni/Al_(2)O_(3)/GN was clearly *** work provides a unique perspective for the preparation of highly stable and highly dispersible catalysts.

关键词： Magnesium hydride Ni/Al_(2)O_(3)/GN Hydrogen storage performance Catalytic mechanism

Space/Air Covert Communications:Potentials,Scenarios,and Key Technologies

在线全文

学校读者我要写书评

暂无评论

China Communications 2024年第3期21卷 1-18页

作者： Mao Haobin Liu Yanming zhu Lipeng Mao Tianqi xiao Zhenyu Zhang Rui Han zhu Xia Xianggen School of Electronic and Information Engineering Beihang UniversityBeijing 100191China Department of Electrical and Computer Engineering National University of SingaporeSingapore 117583Singapore School of Science and Engineering Shenzhen Research Institute of Big Datathe Chinese University of Hong KongShenzhenGuangdong 518172China Department of Electrical and Computer Engineering University of HoustonHoustonTX 77004USA Department of Computer Science and Engineering Kyung Hee UniversitySeoulSouth Korea446-701 Department of Electrical and Computer Engineering University of DelawareNewarkDE 19716USA

Space/air communications have been envisioned as an essential part of the next-generation mobile communication networks for providing highquality global connectivity. However, the inherent broadcasting nature of wireless propagation environment and the broad coverage pose severe threats to the protection of private data. Emerging covert communications provides a promising solution to achieve robust communication security. Aiming at facilitating the practical implementation of covert communications in space/air networks, we present a tutorial overview of its potentials, scenarios, and key technologies. Specifically, first, the commonly used covertness constraint model, covert performance metrics, and potential application scenarios are briefly introduced. Then, several efficient methods that introduce uncertainty into the covert system are thoroughly summarized, followed by several critical enabling technologies, including joint resource allocation and deployment/trajectory design, multi-antenna and beamforming techniques, reconfigurable intelligent surface(RIS), and artificial intelligence algorithms. Finally, we highlight some open issues for future investigation.

关键词： artificial intelligence(AI) sixth generation(6G) space-air-ground integrated networks(SAGINs) space/air covert communications

Assessment of the triglyceride glucose index in adult patients with chronic diarrhea and constipation

在线全文

学校读者我要写书评

暂无评论

World Journal of Clinical Cases 2024年第6期12卷 1094-1103页

作者： Jing-Yi zhu Mu-yun Liu Chang Sun Department of Gastroenterology The First Affiliated Hospital of Naval Medical UniversityShanghai 200433China Department of Gastroenterology Navy No.905 HospitalNaval Medical UniversityShanghai 200433China

BACKGROUND Accumulating evidence suggests that the gut microbiome is involved in the pathogenesis of insulin resistance(IR).However,the link between two of the most prevalent bowel disorders,chronic diarrhea and constipation,and the triglyceride glucose(TyG)index,a marker of IR,has not yet been *** To investigate the potential association between TyG and the incidence of chronic diarrhea and *** This cross-sectional study enrolled 2400 participants from the National Health and Nutrition Examination Survey database from *** was used as an exposure variable,with chronic diarrhea and constipation as determined by the Bristol Stool Form Scale used as the outcome variables.A demographic investigation based on TyG quartile subgroups was *** application of multivariate logistic regression models and weighted generalized additive models revealed potential correlations between TyG,chronic diarrhea,and *** analyses were performed to examine the stability of any potential *** In the chosen sample,chronic diarrhea had a prevalence of 8.00%,while chronic constipation had a prevalence of 8.04%.In multiple logistic regression,a more prominent positive association was found between TyG and chronic diarrhea,particularly in model 1(OR=1.45;95%CI:1.17-1.79,P=0.0007)and model 2(OR=1.40;95%CI:1.12-1.76,P=0.0033).No definite association was observed between the TyG levels and chronic *** weighted generalized additive model findings suggested a more substantial positive association with chronic diarrhea when TyG was less than 9.63(OR=1.89;95%CI:1.05-3.41,P=0.0344),and another positive association with chronic constipation when it was greater than 8.2(OR=1.74;95%CI:1.02-2.95,P=0.0415).The results of the subgroup analyses further strengthen the extrapolation of these results to a wide range of *** Higher TyG levels were positively associated with abnormal bowel health.

关键词： Triglyceride glucose index National Health and Nutrition Examination Survey Chronic diarrhea Chronic constipation Cross-sectional study Bowel health

A novel Effective Panicle Number per Plant 4 haplotype enhances grain yield by coordinating panicle number and grain number in rice

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

The Crop Journal 2024年第1期12卷 202-212页

作者： yun Wang xiaoqian Wang Laiyuan Zhai Sundus Zafar Congcong Shen Shuangbing zhu Kai Chen yun Wang Jianlong Xu State Key Laboratory of Crop Gene Resources and Breeding Institute of Crop SciencesChinese Academy of Agricultural SciencesBeijing 100081China State Key Laboratory of Crop Biology College of AgronomyShandong Agricultural UniversityTai’an 271018ShandongChina Shenzhen Branch Guangdong Laboratory for Lingnan Modern AgricultureAgricultural Genomics Institute at ShenzhenChinese Academy of Agricultural SciencesShenzhen 518120GuangdongChina Rice Research Institute Shenyang Agricultural UniversityShenyang 110866LiaoningChina National Nanfan Research Institute(Sanya) Chinese Academy of Agricultural SciencesSanya 572024HainanChina

Increasing effective panicle number per plant(EPN)is one approach to increase yield potential in ***,molecular mechanisms underlying EPN remain *** this study,we integrated mapbased cloning and genome-wide association analysis to identify the EPN4 gene,which is allelic to NARROW LEAF1(NAL1).Overexpression lines containing the Teqing allele(TQ)of EPN4 had significantly increased ***-EPN4^(TQ) in japonica(geng)cultivar Lemont(LT)exhibited significantly improved EPN but decreased grain number and flag leaf size relative to *** analysis indicated that accessions with EPN4-1 had medium EPN,medium grain number,and medium grain weight,but had the highest grain yield among seven haplotypes,indicating that EPN4-1 is an elite haplotype of EPN4 for positive coordination of the three components of grain ***,accessions carrying the combination of EPN4-1 and haplotype GNP1-6 of GNP1 for grain number per panicle showed higher grain yield than those with other allele ***,pyramiding of EPN4-1 and GNP1-6 could be a preferred approach to obtain high yield potential in breeding.

关键词： Rice Effective panicle number per plant Grain number per panicle Haplotype Grain yield potential

Acoustic characterization of hydrate formation and decomposition in clay-bearing sediments

在线全文

学校读者我要写书评

暂无评论

Petroleum Science 2024年第4期21卷 2830-2838页

作者： Yi-Jian zhu xiao-Mei Yang Xing Huang Hao Li xiao-Hui Wang Yi-Fei Sun Peng xiao Chang-Yu Sun Guang-Jin Chen State Key Laboratory of Heavy Oil Processing College of Chemical Engineering and Environment China University of Petroleum

Understanding the acoustic characteristics of hydrates in various sediments is crucial for hydrate resource detection and safe and efficient exploitation, as hydrate occurrence patterns vary greatly in different sediments. In this work, sediments with different bentonite contents, water saturations, and types were prepared to investigate the characteristics of P-wave velocity(reflecting the magnitude of hydrate saturation in the sediment) and amplitude(reflecting the degree of hydrate-sediment cementation) during hydrate formation and depressurization. During hydrate formation, the P-wave velocity and amplitude have similar trends. As clay content increases, the P-wave velocity increase rates quickened. On the other hand, the increased rate of P-wave velocity slows down with the increase of water saturation in the clay-bearing sediments. Comparing various types of sediment shows that the water absorption and swelling of bentonite reduce the pore space, speeding up the cementation of the hydrate with the sediment and increasing P-wave velocity at a faster rate. Correspondence between P-wave velocity and hydrate saturation is strongly related to sediment type, clay content, and water *** rapidly decreasing amplitude in the early stage of hydrate depressurization indicates that hydrate in clay-bearing sediments is weakly cemented to the sediments, which is prone to stratigraphic *** findings of this study offer guidance for hydrate resource assessments in clay-bearing sediments as well as geologic risk estimations during hydrate mining.

关键词： Gas hydrate Bentonite Illite P-wave velocity Amplitude

‘Super-stable' interlayer organic carbon in soil clay minerals and its impact on soil carbon sequestration

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science China Earth Sciences 2024年第11期67卷 3626-3630页

作者： Dong LIU Chuanqin HUANG Keqing xiao Yongguan zhu Wenfeng TAN CAS Key Laboratory of Mineralogy and Metallogeny/Guangdong Provincial Key Laboratory of Mineral Physics and Materials Guangzhou Institute of Geochemistry Chinese Academy of Sciences CAS Center for Excellence in Deep Earth Science University of Chinese Academy of Sciences College of Resources & Environment Huazhong Agricultural University State Key Laboratory of Urban and Regional Ecology Research Centre for Eco-Environmental Sciences Chinese Academy of Sciences

Soils play a significant role in the global carbon cycle, acting as both sinks and sources of terrestrial carbon. They exert substantial influence on climate change by regulating the atmospheric concentrations of greenhouse gases, including carbon dioxide, through processes of carbon fixation and release (Lehmann et al., 2020). Soil organic carbon represents a key carbon reservoir within terrestrial ***, enhancing soil organic carbon levels is a crucial strategy for augmenting terrestrial carbon sinks and mitigating global climate change.

关键词： MECHANISMS