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DTAIS:Distributed trusted active identity resolution systems for the Industrial Internet
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作者 Tao Huang Renchao Xie +7 位作者 Yuzheng Ren F.Richard Yu Zhuang Zou Lu Han Yunjie Liu Demin Cheng Yinan Li Tian Liu 《Digital Communications and Networks》 SCIE CSCD 2024年第4期853-862,共10页
In recent years,the Industrial Internet and Industry 4.0 came into being.With the development of modern industrial intelligent manufacturing technology,digital twins,Web3 and many other digital entity applications are... In recent years,the Industrial Internet and Industry 4.0 came into being.With the development of modern industrial intelligent manufacturing technology,digital twins,Web3 and many other digital entity applications are also proposed.These applications apply architectures such as distributed learning,resource sharing,and arithmetic trading,which make high demands on identity authentication,asset authentication,resource addressing,and service location.Therefore,an efficient,secure,and trustworthy Industrial Internet identity resolution system is needed.However,most of the traditional identity resolution systems follow DNS architecture or tree structure,which has the risk of a single point of failure and DDoS attack.And they cannot guarantee the security and privacy of digital identity,personal assets,and device information.So we consider a decentralized approach for identity management,identity authentication,and asset verification.In this paper,we propose a distributed trusted active identity resolution system based on the inter-planetary file system(IPFS)and non-fungible token(NFT),which can provide distributed identity resolution services.And we have designed the system architecture,identity service process,load balancing strategy and smart contract service.In addition,we use Jmeter to verify the performance of the system,and the results show that the system has good high concurrent performance and robustness. 展开更多
关键词 Industrial Internet NFT IPFS TRUST Identity resolution system
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Impact of increasing one-carbon metabolites on traumatic brain injury outcome using pre-clinical models
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作者 Sanika M.Joshi Theresa Currier Thomas Nafisa M.Jadavji 《Neural Regeneration Research》 SCIE CAS CSCD 2024年第8期1728-1733,共6页
Traumatic brain injury is a major cause of death and disability worldwide,affecting over 69 million individuals yearly.One-carbon metabolism has been shown to have beneficial effects after brain damage,such as ischemi... Traumatic brain injury is a major cause of death and disability worldwide,affecting over 69 million individuals yearly.One-carbon metabolism has been shown to have beneficial effects after brain damage,such as ischemic stroke.However,whether increasing one-carbon metabolite vitamins impacts traumatic brain injury outcomes in patients requires more investigation.The aim of this review is to evaluate how one-carbon metabolites impact outcomes after the onset of traumatic brain injury.PubMed,Web of Science,and Google Scholar databases were searched for studies that examined the impact of B-vitamin supplementation on traumatic brain injury outcomes.The search terms included combinations of the following words:traumatic brain injury,dietary supplementation,one-carbon metabolism,and B-vitamins.The focus of each literature search was basic science data.The year of publication in the literature searches was not limited.Our analysis of the literature has shown that dietary supplementation of B-vitamins has significantly improved the functional and behavioral recove ry of animals with traumatic brain injury compared to controls.Howeve r,this improvement is dosage-dependent and is contingent upon the onset of supplementation and whether there is a sustained or continuous delive ry of vitamin supplementation post-traumatic brain injury.The details of supplementation post-traumatic brain injury need to be further investigated.Overall,we conclude that B-vitamin supplementation improves behavioral outcomes and reduces cognitive impairment post-traumatic brain injury in animal model systems.Further investigation in a clinical setting should be stro ngly considered in co njunction with current medical treatments for traumatic brain injury-affected individuals. 展开更多
关键词 folic acid NICOTINAMIDE one-carbon metabolism RIBOFLAVIN traumatic brain injury vitamin B12 vitamin B2 vitamin B3
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Surviving winter on the Qinghai-Xizang Plateau:Extensive reversible protein phosphorylation plays a dominant role in regulating hypometabolism in hibernating Nanorana parkeri
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作者 Yong-Gang Niu Deng-Bang Wei +6 位作者 Xue-Jing Zhang Ti-Sen Xu Xiang-Yong Li Hai-Ying Zhang Zhi-Fang An Kenneth B.Storey Qiang Chen 《Zoological Research》 SCIE CSCD 2024年第1期1-12,共12页
Changes in protein abundance and reversible protein phosphorylation(RPP)play important roles in regulating hypometabolism but have never been documented in overwintering frogs at high altitudes.To test the hypothesis ... Changes in protein abundance and reversible protein phosphorylation(RPP)play important roles in regulating hypometabolism but have never been documented in overwintering frogs at high altitudes.To test the hypothesis that protein abundance and phosphorylation change in response to winter hibernation,we conducted a comprehensive and quantitative proteomic and phosphoproteomic analysis of the liver of the Xizang plateau frog,Nanorana parkeri,living on the Qinghai-Xizang Plateau.In total,5170 proteins and 5695 phosphorylation sites in 1938 proteins were quantified.Based on proteomic analysis,674 differentially expressed proteins(438 up-regulated,236 down-regulated)were screened in hibernating N.parkeri versus summer individuals.Functional enrichment analysis revealed that higher expressed proteins in winter were significantly enriched in immune-related signaling pathways,whereas lower expressed proteins were mainly involved in metabolic processes.A total of 4251 modified sites(4147 up-regulated,104 down-regulated)belonging to 1638 phosphoproteins(1555 up-regulated,83 down-regulated)were significantly changed in the liver.During hibernation,RPP regulated a diverse array of proteins involved in multiple functions,including metabolic enzymatic activity,ion transport,protein turnover,signal transduction,and alternative splicing.These changes contribute to enhancing protection,suppressing energy-consuming processes,and inducing metabolic depression.Moreover,the activities of phosphofructokinase,glutamate dehydrogenase,and ATPase were all significantly lower in winter compared to summer.In conclusion,our results support the hypothesis and demonstrate the importance of RPP as a regulatory mechanism when animals transition into a hypometabolic state. 展开更多
关键词 Nanorana parkeri PROTEOMIC Phosphoproteomic HIBERNATION Reversible protein phosphorylation Metabolism
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6G New Multiple Access Technology
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作者 Yifei Yuan Yongpeng Wu +3 位作者 Lei Wang Zhifeng Yuan Wei Bai Yuanwei Liu 《China Communications》 SCIE CSCD 2024年第1期I0002-I0005,共4页
As a basic technology at physical layer of mobile communications,non-orthogonal multiple access has been attracting wide attention across the academia and the industry.During the standardization of the fifth-generatio... As a basic technology at physical layer of mobile communications,non-orthogonal multiple access has been attracting wide attention across the academia and the industry.During the standardization of the fifth-generation(5G)of mobile communications,3GPP conducted preliminary study on non-orthogonal multiple access without reaching the consensus to standardize the technology. 展开更多
关键词 TECHNOLOGY ACCESS attracting
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Underestimated Methane Emissions from Solid Waste Disposal Sites Reveal Missed Greenhouse Gas Mitigation Opportunities
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作者 Yao Wang Chuanbin Zhou +6 位作者 Ziyang Lou Houhu Zhang Abid Hussain Liangtong Zhan Ke Yin Mingliang Fang Xunchang Fei 《Engineering》 SCIE EI CAS CSCD 2024年第5期12-15,共4页
1.Introduction Cities are responsible for approximately 70%of all anthropogenic greenhouse gas(GHG)emissions and about 60%of all anthropogenic methane(CH4)emissions[1,2].Solid waste disposal sites(including landfills ... 1.Introduction Cities are responsible for approximately 70%of all anthropogenic greenhouse gas(GHG)emissions and about 60%of all anthropogenic methane(CH4)emissions[1,2].Solid waste disposal sites(including landfills and dumpsites),which are prevalent in global cities,emit CH4 generated from the anaerobic biodegradation of municipal solid waste(MSW).Notably,the proportions of CH4 emissions from disposal sites surpass 50%of the total CH4 emissions in some megalopolises[3].CH4 has a high global warming potential(GWP),being 28 times stronger than carbon dioxide(CO_(2))over a 100-year period and 80 times stronger over a 20-year period[4].Understanding and mitigating CH4 emissions from solid waste disposal sites is particularly pertinent and pressing,considering that the latest Synthesis Report from the Intergovernmental Panel on Climate Change(IPCC)emphasizes that the current pace of mitigation and adaptation policies and measures falls short of restraining global temperature rise to under 1.5℃ within the 21st century[4].More than 150 countries signed the Global Methane Pledge at the United Nations Climate Change Conference in Glasgow(COP26),which aims to reduce global annual CH4 emissions by 30%by 2030,compared with emissions in 2020[5]. 展开更多
关键词 LANDFILL SOLID restrain
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Global prevalence and gender inequalities in at least 60 min of self-reported moderate-to-vigorous physical activity 1 or more days per week:An analysis with 707,616 adolescents
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作者 Raphael H.O.Araujo AndrúO.Werneck +13 位作者 Clarice L.Martins Luciana L.Barboza Rafael M.Tassitano Nicolas Aguilar-Farias Gilmar M.Jesus Robinson Ramírez-Véelez Riki Tesler Adewale L.Oyeyemi Ellen C.M.Silva Robert G.Weaver Mark S.Tremblay Javier Brazo-Sayavera Grégore I.Mielke Danilo R.P.Silva 《Journal of Sport and Health Science》 SCIE CAS CSCD 2024年第5期709-716,共8页
Background:Guidelines recommend that adolescents should accumulate an average of 60 min per day of moderate-to-vigorous physical activity(MVPA).However,using only this cut-off could hide important information.For inst... Background:Guidelines recommend that adolescents should accumulate an average of 60 min per day of moderate-to-vigorous physical activity(MVPA).However,using only this cut-off could hide important information.For instance,from a population-level point of view,increasing physical activity for those with no or low physical activity could provide more health benefits than increasing physical activity for those with intermediate levels.Also,including a more sensitive cut-point of≥1 days per week could be an additional strategy for identifying those with low access/opportunities for physical activity practice.Thus,the current study aims to estimate the prevalence of≥60 min of MVPA≥1 days per week among adolescents globally,and to describe any relevant gender inequalities.Methods:We used representative datasets from 146 countries/territories collected between 2003 and 2019.MVPA was self-reported.Participants were grouped into younger(≤14 years old)and older(>14 years old)adolescents.Crude Poisson regression models were used to identify the relative differences in≥60 min of MVPA≥1 days per week between boys and girls,and random-effects meta-analysis models were used to identify the pooled estimates.Analyses were stratified by country and region.Results:Approximately 80%of both younger and older adolescents reported≥60 min of MVPA≥1 days per week.This prevalence was≥94%in Europe and Central Asia and North America,while the estimates for the other regions were<77%.The prevalence of≥60 min of MVPA≥1 days per week was higher among boys than girls,with the largest differences occurring among the oldest adolescents(Prevalence ratio_(≤14y)=1.04(95%confidence interval(95%CI)):1.03-1.04)vs.Prevalence ratio_(>14y)=1.09(95%CI:1.08-1.10)).Conclusion:Approximately 8 out of 10 adolescents reported accumulating≥60 min of MVPA≥1 days per week,with notable differences between regions.Gender differences were observed in several countries,especially among the oldest adolescents.Priorities for physical activity promotion among adolescents should include increasing access/opportunities for physical activity among those who do not achieve≥60 min of MVPA≥1 days per week and reducing gender inequalities. 展开更多
关键词 Global School-based Student Health Survey Health Behaviour Among School-aged Children survey Inequality Surveillance Youth
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Preparation of Peanut Shell Cellulose Double-Network Hydrogel and Its Adsorption Capacity for Methylene Blue
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作者 Yalin Li Lei Liu +4 位作者 Wenbao Huang Junpu Xie Zhaoxia Song Shuna Guo Enci Wang 《Journal of Renewable Materials》 EI 2023年第7期3001-3023,共23页
To achieve optimal recovery and value-added utilisation of cellulose in peanut shells,the cellulose in peanut shells was first extracted using the sodium hydroxide-sodium chlorite method.Then,cellulose hydrogel was pr... To achieve optimal recovery and value-added utilisation of cellulose in peanut shells,the cellulose in peanut shells was first extracted using the sodium hydroxide-sodium chlorite method.Then,cellulose hydrogel was prepared by graft copolymerisation using N,N’-methylenebisacrylamide as the cross-linking agent,sodium persulfate as the initiator,and acrylic acid as the monomer.Orthogonal optimisation experiments were designed to obtain optimal process parameters for hydrogel preparation with the cellulose dosage of 0.40 g,initiator dosage of 0.20 g,polymerisation temperature of 70°C,cross-linking agent of 0.25 g,and monomer dosage of 3.0 mL.The effect of initiator dosage on hydrogel synthesis was the most significant,followed by monomer dosage and reaction temperature.Characterisation using X-ray diffraction analysis and scanning electron microscopy revealed that the hydrogel was amorphous and exhibited a distinct three-dimensional double network structure.Hydrogel swelling kinetic analysis showed that the hydrogel swelling process was divided into three stages,and fitted the Schott secondary swelling kinetic model.The prepared hydrogel had a good adsorption effect on methylene blue;the adsorption of methylene blue by the hydrogel was 1.259 mg/g at 25°C when the initial concentration of methylene blue was 5 mg/L.The adsorption kinetics of the hydrogel fit the pseudo-first-order kinetic model,pseudo-secondorder kinetic model,Eovich model and particle diffusion model.The best fitting effect was obtained with the pseudo-second-order kinetic model.The adsorption isotherm analysis of methylene blue on hydrogel showed that the adsorption process was consistent with Langmuir and Freundlich models.The correlation coefficient of the Freundlich isotherm model was higher,indicating that the adsorption of methylene blue on hydrogel was mainly chemisorption. 展开更多
关键词 CELLULOSE HYDROGEL graft copolymerisation cross-linking polymerisation swelling property
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A deep learning based misbehavior classification scheme for intrusion detection in cooperative intelligent transportation systems
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作者 Tejasvi Alladi Varun Kohli +1 位作者 Vinay Chamola F.Richard Yu 《Digital Communications and Networks》 SCIE CSCD 2023年第5期1113-1122,共10页
With the rise of the Internet of Vehicles(IoV)and the number of connected vehicles increasing on the roads,Cooperative Intelligent Transportation Systems(C-ITSs)have become an important area of research.As the number ... With the rise of the Internet of Vehicles(IoV)and the number of connected vehicles increasing on the roads,Cooperative Intelligent Transportation Systems(C-ITSs)have become an important area of research.As the number of Vehicle to Vehicle(V2V)and Vehicle to Interface(V2I)communication links increases,the amount of data received and processed in the network also increases.In addition,networking interfaces need to be made more secure for which existing cryptography-based security schemes may not be sufficient.Thus,there is a need to augment them with intelligent network intrusion detection techniques.Some machine learning-based intrusion detection and anomaly detection techniques for vehicular networks have been proposed in recent times.However,given the expected large network size,there is a necessity for extensive data processing for use in such anomaly detection methods.Deep learning solutions are lucrative options as they remove the necessity for feature selection.Therefore,with the amount of vehicular network traffic increasing at an unprecedented rate in the C-ITS scenario,the need for deep learning-based techniques is all the more heightened.This work presents three deep learning-based misbehavior classification schemes for intrusion detection in IoV networks using Long Short Term Memory(LSTM)and Convolutional Neural Networks(CNNs).The proposed Deep Learning Classification Engines(DCLE)comprise of single or multi-step classification done by deep learning models that are deployed on the vehicular edge servers.Vehicular data received by the Road Side Units(RSUs)is pre-processed and forwarded to the edge server for classifications following the three classification schemes proposed in this paper.The proposed classifiers identify 18 different vehicular behavior types,the F1-scores ranging from 95.58%to 96.75%,much higher than the existing works.By running the classifiers on testbeds emulating edge servers,the prediction performance and prediction time comparison of the proposed scheme is compared with those of the existing studies. 展开更多
关键词 Vehicular Ad-hoc Networks(VANETs) Intelligent Transportation Systems(ITS) Artificial Intelligence(AI) Deep Learning Internet of Things(IoT)
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All-fiber ellipsometer for nanoscale dielectric coatings
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作者 Jose Javier Imas Ignacio R.Matías +3 位作者 Ignacio Del Villar Aritz Ozcáriz Carlos Ruiz Zamarreño Jacques Albert 《Opto-Electronic Advances》 SCIE EI CAS CSCD 2023年第10期31-43,共13页
Multiple mode resonance shifts in tilted fiber Bragg gratings(TFBGs)are used to simultaneously measure the thickness and the refractive index of TiO_(2) thin films formed by Atomic Layer Deposition(ALD)on optical fibe... Multiple mode resonance shifts in tilted fiber Bragg gratings(TFBGs)are used to simultaneously measure the thickness and the refractive index of TiO_(2) thin films formed by Atomic Layer Deposition(ALD)on optical fibers.This is achieved by comparing the experimental wavelength shifts of 8 TFBG resonances during the deposition process with simulated shifts from a range of thicknesses(T)and values of the real part of the refractive index(n).The minimization of an error function computed for each(n,T)pair then provides a solution for the thickness and refractive index of the deposited film and,a posteriori,to verify the deposition rate throughout the process from the time evolution of the wavelength shift data.Validations of the results were carried out with a conventional ellipsometer on flat witness samples deposited simultaneously with the fiber and with scanning electron measurements on cut pieces of the fiber itself.The final values obtained by the TFBG(n=2.25,final thickness of 185 nm)were both within 4%of the validation measurements.This approach provides a method to measure the formation of nanoscale dielectric coatings on fibers in situ for applications that require precise thicknesses and refractive indices,such as the optical fiber sensor field.Furthermore,the TFBG can also be used as a process monitor for deposition on other substrates for deposition methods that produce uniform coatings on dissimilar shaped substrates,such as ALD. 展开更多
关键词 tilted fiber Bragg grating(TFBG) mode transition ELLIPSOMETER
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Maternal dietary deficiencies in folic acid or choline worsen stroke outcomes in adult male and female mouse offspring
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作者 McCoy Clementson Lauren Hurley +9 位作者 Sarah Coonrod Calli Bennett Purvaja Marella Agnes S.Pascual Kasey Pull Brandi Wasek Teodoro Bottiglieri Olga Malysheva Marie A.Caudill Nafisa M.Jadavji 《Neural Regeneration Research》 SCIE CAS CSCD 2023年第11期2443-2448,共6页
Maternal one-carbon metabolism plays an important role in early life programming.There is a well-established connection between the fetal environment and the health status of the offspring.Howeve r,there is a knowledg... Maternal one-carbon metabolism plays an important role in early life programming.There is a well-established connection between the fetal environment and the health status of the offspring.Howeve r,there is a knowledge gap on how maternal nutrition impacts stro ke outcomes in offspring.The aim of our study was to investigate the role of maternal dietary deficiencies in folic acid or choline on stroke outcomes in 3-month-old offspring.Adult female mice were fed a folic acid-deficient diet,choline-deficient diet,or control diet 4 weeks before pregnancy.They we re continued on diets during pregnancy and la ctation.Male and female offspring were weaned onto a control diet and at 2 months of age were subjected to ischemic stroke within the sensorimotor cortex via photothrombotic damage.Mothers maintained on either a folic acid-deficient diet or choline-deficient diet had reduced levels of S-adenosylm ethionine in the liver and S-adenosylhomocysteine in the plasma.After ischemic stro ke,motor function was impaired in 3-month-old offspring from mothers receiving either a folic acid-deficient diet or choline-deficient diet compared to the animals receiving a control diet.In brain tissue,there was no difference in ischemic damage volume.When protein levels were assessed in ischemic brain tissue,there were lower levels of active caspase-3 and hypoxia-inducible factor 1α in males compared to females and betaine levels were reduced in offspring from the mothers receiving a choline-deficient diet.Our results demonstrate that a deficient maternal diet at critical time points in neurodevelopment results in worse stro ke outcomes.This study emphasizes the importance of maternal diet and the impact it can have on offspring health. 展开更多
关键词 APOPTOSIS choline metabolism folic acid ischemic stroke maternal diet motor function one-carbon metabolism stroke outcome
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基于LBP值对空间统计特征的纹理描述符 被引量:19
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作者 徐少平 刘小平 +2 位作者 李春泉 胡凌燕 杨晓辉 《模式识别与人工智能》 EI CSCD 北大核心 2013年第8期769-776,共8页
针对基于内容图像检索应用背景下局部二值模式(LBP)描述符缺乏空间描述能力及所需特征矢量维数较长的不足,提出一种基于LBP值对空间统计特征构建的改进纹理描述符(ILBP).ILBP描述符首先利用LBP微模式编码方法将原始图像转换为LBP伪灰度... 针对基于内容图像检索应用背景下局部二值模式(LBP)描述符缺乏空间描述能力及所需特征矢量维数较长的不足,提出一种基于LBP值对空间统计特征构建的改进纹理描述符(ILBP).ILBP描述符首先利用LBP微模式编码方法将原始图像转换为LBP伪灰度图像,然后再提取出多个关于LBP值对空间分布关系统计值构成描述图像特征的特征矢量.在基于内容的图像检索原型测试平台上完成大量实验.实验结果表明,与LBP及其各类变种描述符相比,ILBP描述符在进一步增强LBP描述符描述能力的同时大幅度压缩特征矢量维数,具有更好的查询正确率和查询效率. 展开更多
关键词 基于内容的图像检索 局部二值模式(LBP) 局部二值模式伪图像 统计特征 查询正确率
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学前儿童害羞与社会适应:师幼关系的调节作用 被引量:14
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作者 朱晶晶 李燕 +2 位作者 张云 Robert J.Coplan 刘田田 《心理科学》 CSSCI CSCD 北大核心 2018年第5期1130-1137,共8页
本研究对360名幼儿进行为期一年半的追踪,探讨害羞幼儿的社会适应和师幼关系在害羞与社会适应之间的调节作用。幼儿母亲完成儿童社会偏好量表,幼儿教师完成师幼关系量表和对儿童社会适应的评价。结果表明,害羞与儿童人际技能和口头主张... 本研究对360名幼儿进行为期一年半的追踪,探讨害羞幼儿的社会适应和师幼关系在害羞与社会适应之间的调节作用。幼儿母亲完成儿童社会偏好量表,幼儿教师完成师幼关系量表和对儿童社会适应的评价。结果表明,害羞与儿童人际技能和口头主张显著负相关,与内化问题、不合群行为和同伴排斥显著正相关;师幼关系与儿童社会适应相关,并在害羞与儿童社会适应之间具有调节作用。 展开更多
关键词 学前儿童 害羞 社会适应 师幼关系
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青藏工程走廊热融湖塘水理化特性分析 被引量:7
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作者 林战举 牛富俊 +3 位作者 罗京 尹国安 刘明浩 CHRIS Burrn 《水科学进展》 EI CAS CSCD 北大核心 2014年第2期217-224,共8页
为查明青藏工程走廊热融湖塘水理化特性及其理化特性与湖塘分布之间的关系,选取青藏工程走廊楚玛尔河至风火山段为研究区域,沿青藏公路从北向南依次选取19个热融湖塘进行水深、面积等几何特征调研并取水样,进行阴阳离子等理化参数测定... 为查明青藏工程走廊热融湖塘水理化特性及其理化特性与湖塘分布之间的关系,选取青藏工程走廊楚玛尔河至风火山段为研究区域,沿青藏公路从北向南依次选取19个热融湖塘进行水深、面积等几何特征调研并取水样,进行阴阳离子等理化参数测定。分析了热融湖塘水的理化特性,并结合调研资料探讨了热融湖塘理化特性与区域环境及湖塘分布之间的相关性。结果表明在3个研究亚区湖的水理化特性有较大差别,楚玛尔河高平原从北向南湖水矿化度逐渐升高,水质由淡水向咸水再到强咸水过渡,主要与该区域"碟"状湖的分布特征和寒旱多风及蒸发量大有关;可可西里山区和北麓河盆地的湖水矿化度较低,水质以弱咸水或淡水为主。这两个亚区湖较深,地形以丘陵盆地为主,降低了湖面的蒸发量。 展开更多
关键词 青藏工程走廊 多年冻土 热融湖塘 理化特性
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人群健康与健康决定因素 被引量:11
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作者 周雷 李枫 +1 位作者 詹永红 Huhg Armstrong 《中国健康教育》 2004年第2期142-144,共3页
关键词 人群健康 健康决定因素 健康促进 社会支持 健康发展
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钻孔摄像技术的发展与现状 被引量:117
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作者 王川婴 LAWK Tim 《岩石力学与工程学报》 EI CAS CSCD 北大核心 2005年第19期3440-3448,共9页
基于光学技术的钻孔摄像设备能以照相胶片或视频图像的方式直接提供钻孔孔壁的图像。全景技术的实现使同时观测360°钻孔孔壁成为可能,而数字技术的应用则提供了形成、显示和处理这些图像的能力。所有的图像不仅可用于定性地识别钻... 基于光学技术的钻孔摄像设备能以照相胶片或视频图像的方式直接提供钻孔孔壁的图像。全景技术的实现使同时观测360°钻孔孔壁成为可能,而数字技术的应用则提供了形成、显示和处理这些图像的能力。所有的图像不仅可用于定性地识别钻孔内的情况,而且还可准确地获得相关的数据并进一步从事定量分析。钻孔摄像技术具有广阔的应用,主要包括岩土工程、工程地质、土木工程、石油工业、采矿工程、冰川研究等诸多方面。据此,全面地回顾了钻孔摄像技术的发展历史和当前的现状,描述了在各个阶段出现的设备技术特征,对数字光学成像系统的原理、光源设计、图像处理和精度进行了对比,给出了以单环技术和图幅技术为定义的数字光学成像系统,最后讨论了钻孔摄像技术将来的发展方向。 展开更多
关键词 钻孔摄像 地质勘探 数字式光学成像 全景图像 石油勘探
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细菌生存优化在非线性模型辨识中的应用 被引量:2
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作者 林卫星 Peter X.Liu +2 位作者 李文磊 陈炎海 欧超 《系统仿真学报》 CAS CSCD 北大核心 2009年第10期3100-3104,共5页
提出了一种新的基于细菌生存优化(Bacterial Foraging Optimization BFO)的非线性模型辨识方法。它是利用群集智能仿生BFO算法对一类Hammerstein系统进行辨识,从而估计出它的参数模型。通过对这类输入非线性模型进行辨识,并用仿真实验说... 提出了一种新的基于细菌生存优化(Bacterial Foraging Optimization BFO)的非线性模型辨识方法。它是利用群集智能仿生BFO算法对一类Hammerstein系统进行辨识,从而估计出它的参数模型。通过对这类输入非线性模型进行辨识,并用仿真实验说明BFO算法的参数设置与选择方法。比较基于粒子群优化(Particle Swarm Optimization PSO)的非线性模型辨识算法,特别是对有色噪声的鲁棒性、模型的辨识精度、辨识收敛速度进行对比分析,以得出BFO辨识算法的优缺点及其有效性。 展开更多
关键词 系统辨识 HAMMERSTEIN模型 细菌生存优化 粒子群优化
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用于互联网遥操作的基于速率的点对点传输协议的研究 被引量:1
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作者 叶秀芬 Liu Peter Xiaoping +1 位作者 冯伟兴 李国斌 《哈尔滨工程大学学报》 EI CAS CSCD 2003年第3期273-277,共5页
互联网的传输时延、时延抖动、带宽限制和带宽变化都对遥操作不利,但互联网的这种通信条件常作为给定条件,很少有人专门研究.互联网传输层的两个协议TCP和UDP以及其他新开发的实时应用协议都不适合于基于互联网的遥操作系统的数据传输,... 互联网的传输时延、时延抖动、带宽限制和带宽变化都对遥操作不利,但互联网的这种通信条件常作为给定条件,很少有人专门研究.互联网传输层的两个协议TCP和UDP以及其他新开发的实时应用协议都不适合于基于互联网的遥操作系统的数据传输,为此,本文首先为基于互联网的遥操作系统提出了一种新的拥塞控制算法,开发了基于速率的点对点三项式传输协议.然后,从理论上说明该协议能够探测网络状态变化,并对这种网络带宽变化是易响应的;另外,该协议也是协议内部公平、协议间公平和有效收敛的.最后,通过仿真比较可以推知,该协议能最小化时延和时延抖动及丢包率. 展开更多
关键词 遥操作 拥塞控制算法 互联网传输协议
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中国信息系统(IS)研究的多样性研究 被引量:4
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作者 季绍波 韩维贺 闵庆飞 《情报学报》 CSSCI 北大核心 2005年第2期142-150,共9页
本文对1999年至2003年中国管理类18种重要期刊中的604篇信息系统(IS)领域文章进行了实证研究,目的在于分析国内IS研究的多样性.本文从研究题目、参考学科、研究方法、分析层次4个角度,对中国IS研究的多样性进行了描述和时间序列分析.通... 本文对1999年至2003年中国管理类18种重要期刊中的604篇信息系统(IS)领域文章进行了实证研究,目的在于分析国内IS研究的多样性.本文从研究题目、参考学科、研究方法、分析层次4个角度,对中国IS研究的多样性进行了描述和时间序列分析.通过与国外IS研究多样性的比较,本文阐释了中国IS研究多样性的特征.最后分析了IS研究多样性对于中国IS学科发展可能产生的正、负面影响,并提出了相应措施. 展开更多
关键词 中国 信息系统 IS 研究方法 参考学科
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聚酰亚胺多层膜的制备及其在非线性光学中的应用 被引量:4
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作者 宋乃恒 王植源 《高分子学报》 SCIE CAS CSCD 北大核心 2008年第4期394-398,共5页
报道了一种通过旋涂制备NLO聚合物多层膜的方法。紫外一可见吸收光谱及膜的厚度表征说明,在所得多层膜的结构中,聚合物单层膜的厚度可以较好地控制在100~200nm之间,所得含有5个双层的NLO多层膜(厚度1.6μm)具有良好的结构均一性... 报道了一种通过旋涂制备NLO聚合物多层膜的方法。紫外一可见吸收光谱及膜的厚度表征说明,在所得多层膜的结构中,聚合物单层膜的厚度可以较好地控制在100~200nm之间,所得含有5个双层的NLO多层膜(厚度1.6μm)具有良好的结构均一性,光学显微镜下没有观察到明显的结构缺陷。与单层具有较大厚度的NLO聚合物薄膜(如2~4μm)相比,所得聚合物多层膜可以允许掺杂更多的发色团而不发生相分离。 展开更多
关键词 聚酰亚胺多层膜 非线性光学 制备 光学性质
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Role of behavioral training in reducing functional impairments after stroke 被引量:4
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作者 Mahira Moftah Nafisa M.Jadavji 《Neural Regeneration Research》 SCIE CAS CSCD 2019年第9期1507-1508,共2页
Stroke is the leading cause of long-term disability worldwide.There are two main types of stroke,hemorrhagic and ischemic.A hemorrhagic stroke is when there a bleed in the brain,whereas an ischemic stroke is the resul... Stroke is the leading cause of long-term disability worldwide.There are two main types of stroke,hemorrhagic and ischemic.A hemorrhagic stroke is when there a bleed in the brain,whereas an ischemic stroke is the result of blockage of blood flow to the brain,which leads to degeneration,neurotoxicity,inflammation,and apoptosis.This damage not only affects the ischemic core,but also neuronal,astrocyte,and synaptic survival in the peri-infarct region and connected areas(Kerr et al.,2011;Jadavji et al.,2018).The prevalence of ischemic stroke is predicted to increase as the global population ages(Mukherjee and Patil,2011).Between 1970 and 2008 there has been a 100%increase in stroke incidence in low income countries.For example,the estimated losses in gross domestic product,as the result of vascular diseases,including stroke,have ranged from$20 million in Ethiopia to$1 billion in China and India(Mukherjee and Patil,2011). 展开更多
关键词 STROKE is the LEADING DISABILITY WORLDWIDE China and INDIA
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