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Correction to:Error Calculation of Large-Amplitude Internal Solitary Waves Within the Pycnocline Introduced by the Strong Stratification Approximation
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作者 Cunguo Xu Zhan Wang Masoud Hayatdavoodi 《哈尔滨工程大学学报(英文版)》 CSCD 2024年第1期247-247,共1页
In the original publication the third author name is published incorrectly as“Hayatdavoodi Masoud”.The correct author name should be read as“Masoud Hayatdavoodi”.The correct author name is available in this correc... In the original publication the third author name is published incorrectly as“Hayatdavoodi Masoud”.The correct author name should be read as“Masoud Hayatdavoodi”.The correct author name is available in this correction. 展开更多
关键词 STRONG Internal CORRECTION
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Microstructure and mechanical properties of curved AZ31 magnesium alloy profiles produced by differential velocity sideways extrusion
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作者 Wenbin Zhou Jianguo Lin Trevor A.Dean 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2023年第2期493-508,共16页
Lightweight curved profiles are widely utilised in the transportation industry considering the increasing need for improving aerodynamic efficiency,aesthetics and cutting emissions.In this paper,curved AZ31 Mg alloy p... Lightweight curved profiles are widely utilised in the transportation industry considering the increasing need for improving aerodynamic efficiency,aesthetics and cutting emissions.In this paper,curved AZ31 Mg alloy profiles were manufactured in one operation by a novel process,differential velocity sideways extrusion(DVSE),in which two opposed rams were used.Effects of extrusion temperature and velocity(strain rate) on curvature,microstructure,and mechanical properties of the formed profiles were examined.Profile curvature was found to be more readily controlled by the velocity ratio of the bottom ram v2to the top ram v1,whereas extrusion temperature(T=250,300,350℃)and extrusion velocity(v_(1)=0.1,1 mm/s) slightly affect curvature for a given velocity ratio.A homogeneous microstructure with equiaxed grains(~4.5 μm) resulted from dynamic recrystallisation(DRX),was observed after DVSE(v_(2)/v_(1)=1/2) at 300 ℃ and v_(1)=0.1 mm/s,where the initial billet had an average grain size of ~25 um.Increasing extrusion temperature leads to grain growth(~5 μm) at 350 ℃ and v_(1)=0.1 mm/s.DRX is incomplete at the relatively low temperature of 250℃(v_(1)=0.1 mm/s),and higher strain rate with v1=1mm/s(T=300℃),resulting in inhomogeneous bi-modal necklace pattern grains ranging in size around 1-25 μm for the former and 2-20μm for the latter.Grain refinement is attributed to DRX during the severe plastic deformation(SPD) arising in DVSE,and initiates at the prior boundaries of coarse grains in a necklace-like manner.Compared with the billet,micro-hardness and ultimate tensile strength of the profiles have been enhanced,which is compatible with grain refinement.Also,an obvious increase in tensile ductility was found.However,yield strength slightly decreases except for the complete DRXed case(300℃,v_(1)=0.1 mm/s),where a slightly higher value was found,indicating strengthening by grain refinement is greater than softening caused by texture modification.The initial billet had a strong basal texture wherein the {0002} basal plane is oriented parallel to the extrusion direction(’hard’ orientation),while DVSE results in the profiles having weak basal textures and the {0002} basal plane oriented ~5-10° to the extrusion direction(i.e.towards the orientation for easier slip).This significantly modified texture contributes to the softening of the profiles in the extrusion direction,in which tensile tests were performed,and the related elongation improvement. 展开更多
关键词 EXTRUSION Magnesium alloy AZ31 Curved profiles/sections BENDING Grain refinement Dynamic recrystallisation
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Identification and mapping of Rpi-blb4 in diploid wild potato species Solanum bulbocastanum
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作者 Jie Li Amanpreet Kaur +4 位作者 Brian Harrower Miles Armstrong Daolong Dou Xiaodan Wang Ingo Hein 《The Crop Journal》 SCIE CSCD 2023年第6期1828-1835,共8页
More than 170 years after causing the potato famine in Ireland,late blight is still considered one of the most devastating crop diseases.Commercial potato breeding efforts depend on natural sources of resistance to pr... More than 170 years after causing the potato famine in Ireland,late blight is still considered one of the most devastating crop diseases.Commercial potato breeding efforts depend on natural sources of resistance to protect crops from the rapidly evolving late blight pathogen,Phytophthora infestans.We have identified and mapped a novel broad-spectrum disease resistance gene effective against P.infestans from the wild,diploid potato species Solanum bulbocastanum.Diagnostic resistance gene enrichment sequencing(dRenSeq)was used to confirm the uniqueness of the identified resistance.RenSeq and GenSeq-based mapping of the resistance,referred to as Rpi-blb4,alongside recombinant screening,positioned the locus responsible for the resistance to potato chromosome 5.The interval spans approximately 2.3 Mb and corresponds to the DM reference genome positions of 11.25 and 13.56 Mb. 展开更多
关键词 Renseq Disease resistance Late blight Solanum bulbocastanum
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Two positive effects with one arrow:Modulating crystal and interfacial decoration towards high-potential cathode material
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作者 Xuexiu Gu Xuan-Wen Gao +5 位作者 Dongrun Yang Qinfen Gu YSong Hong Chen Tianzhen Ren Wen-Bin Luo 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第5期216-223,共8页
As the primary suppliers of cyclable sodium ions,O3-type layer-structured manganese-based oxides are recognized as highly competitive cathode candidates for sodium-ion batteries.To advance the development of high-ener... As the primary suppliers of cyclable sodium ions,O3-type layer-structured manganese-based oxides are recognized as highly competitive cathode candidates for sodium-ion batteries.To advance the development of high-energy sodium-ion batteries,it is crucial to explore cathode materials operating at high voltages while maintaining a stable cycling behavior.The orbital and electronic structure of the octahedral center metal element plays a crucial role in maintaining the octahedra structural integrity and improving Na^(+)ion diffusion by introducing heterogeneous chemical bonding.Inspired by the abundant configuration of extra nuclear electrons and large ion radius,we employed trace amounts of tungsten in this study.The obtained cathode material can promote the reversibility of oxygen redox reactions in the high-voltage region and inhibit the loss of lattice oxygen.Additionally,the formation of a Na_(2)WO_(4) coating on the material surface can improve the interfacial stability and interface ions diffusion.It demonstrates an initial Coulombic efficiency(ICE)of 94.6%along with 168.5 mA h g^(-1 )discharge capacity within the voltage range of 1.9-4.35 V.These findings contribute to the advancement of high-energy sodium-ion batteries by providing insights into the benefits of tungsten doping and Na_(2)WO_(4) coating on cathode materials. 展开更多
关键词 Sodium ion battery Layer-structured manganese-based oxides Cathodematerial Surface modification Elements doping
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Cholecystectomy and the risk of alimentary tract cancers:A systematic review 被引量:12
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作者 Maria Coats Sami M Shimi 《World Journal of Gastroenterology》 SCIE CAS 2015年第12期3679-3693,共15页
AIM: To investigate the association between cholecystectomy and gastro-intestinal tract(GIT) cancers.METHODS: We conducted a systematic review according to the PRISMA guidelines. A MEDLINE search was performed with pr... AIM: To investigate the association between cholecystectomy and gastro-intestinal tract(GIT) cancers.METHODS: We conducted a systematic review according to the PRISMA guidelines. A MEDLINE search was performed with predefined search criteria for English Language articles on the association between cholecystectomy and GIT cancers. Additional articles were retrieved by manual search of references. All relevant articles were accessed in full text. Data onstudy type; cases; controls; country; effect estimate; adjustments for confounders and quality of publication were extracted. The quality of the publications were scored by adherence to the STROBE checklist. The data for each part of the GIT were presented in separate tables.RESULTS: Seventy-five studies and 5 meta-analyses satisfied the predefined criteria for inclusion and were included in this review. There were inconsistent reports and no strong evidence of an association between cholecystectomy and cancers of the oesophagus(Adenocarcinoma), pancreas, small bowel and rightsided colon cancers. In squamous cancer of the oesophagus, cancers of the stomach, liver, bile ducts, small bowel and left sided colon cancers, good quality studies suggested a lack of association with cholecystectomy. Equally, distal colon and rectal cancers were found not to be associated with cholecystectomy. Several mechanisms for carcinogenesis/promotion of carcinogensis have been proposed. These have focused on a role for bile salts in carcinogenesis with several potential mutagenic molecular events and gut metabolic hormones signaling cell proliferation or initiation of carcinogenesis.CONCLUSION: This is a comprehensive review of the association between GIT cancers and cholecystectomy. This review found no clear association between cholecystectomy and GIT cancers. 展开更多
关键词 CHOLECYSTECTOMY Cancer Gastro-intestinal TRACT CAR
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Effects of bottom shear stresses on the wave-induced dynamic response in a porous seabed:PORO-WSSI (shear) model 被引量:7
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作者 J.Ye D.-S.Jeng 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2011年第6期898-910,共13页
When ocean waves propagate over the sea floor,dynamic wave pressures and bottom shear stresses exert on the surface of seabed.The bottom shear stresses provide a horizontal loading in the wave-seabed interaction syste... When ocean waves propagate over the sea floor,dynamic wave pressures and bottom shear stresses exert on the surface of seabed.The bottom shear stresses provide a horizontal loading in the wave-seabed interaction system,while dynamic wave pressures provide a vertical loading in the system.However,the bottom shear stresses have been ignored in most previous studies in the past.In this study,the effects of the bottom shear stresses on the dynamic response in a seabed of finite thickness under wave loading will be examined,based on Biot's dynamic poro-elastic theory.In the model,an "u-p" approximation will be adopted instead of quasi-static model that have been used in most previous studies.Numerical results indicate that the bottom shear stresses has certain influences on the wave-induced seabed dynamic response.Furthermore,wave and soil characteristics have considerable influences on the relative difference of seabed response between the previous model(without shear stresses) and the present model(with shear stresses).As shown in the parametric study,the relative differences between two models could up to 10% of p0,depending on the amplitude of bottom shear stresses. 展开更多
关键词 Bottom shear stresses Wave-induced dynamicresponse Porous seabed - "u-p" approximation - Biot's the-ory
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Experimental study of vortex-induced vibrations of a cylinder near a rigid plane boundary in steady flow 被引量:5
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作者 Bing Yang Fuping Gao +1 位作者 Dong-Sheng Jeng Yingxiang Wu 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2009年第1期51-63,共13页
In this study, the vortex-induced vibrations of a cylinder near a rigid plane boundary in a steady flow are studied experimentally. The phenomenon of vortex-induced vibrations of the cylinder near the rigid plane boun... In this study, the vortex-induced vibrations of a cylinder near a rigid plane boundary in a steady flow are studied experimentally. The phenomenon of vortex-induced vibrations of the cylinder near the rigid plane boundary is reproduced in the flume. The vortex shedding frequency and mode are also measured by the methods of hot film velocimeter and hydrogen bubbles. A parametric study is carded out to investigate the influences of reduced velocity, gap-to-diameter ratio, stability parameter and mass ratio on the amplitude and frequency responses of the cylinder. Experimental results indicate: (1) the Strouhal number (St) is around 0.2 for the stationary cylinder near a plane boundary in the sub-criti- cal flow regime; (2) with increasing gap-to-diameter ratio (eo/D), the amplitude ratio (A/D) gets larger but frequency ratio (f/fn) has a slight variation for the case of larger values of eo/D(eo/D 〉 0.66 in this study); (3) there is a clear difference of amplitude and frequency responses of the cylin- derbetween the larger gap-to-diameter ratios (e0/D 〉 0.66) and the smaller ones (e0/D 〈 0.3); (4) the vibration of the cylinder is easier to occur and the range of vibration in terms of Vr number becomes more extensive with decrease of the stability parameter, but the frequency response is affected slightly by the stability parameter; (5) with decreasing mass ratio, the width of the lock-in ranges in terms of Vr and the frequency ratio (f/fn) become larger. 展开更多
关键词 Vortex-induced vibration Cylinder near a plane boundary Steady flow Vortex shedding
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A Field Investigation on the Effects of Background Erosion on the Free Span Development of a Submarine Pipeline 被引量:4
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作者 WEN Shipeng XU Jishang +2 位作者 HU Guanghai DONG Ping SHEN Hong 《Journal of Ocean University of China》 SCIE CAS 2015年第4期621-628,共8页
The safety of submarine pipelines is largely influenced by free spans and corrosions. Previous studies on free spans caused by seabed scours are mainly based on the stable environment, where the background seabed scou... The safety of submarine pipelines is largely influenced by free spans and corrosions. Previous studies on free spans caused by seabed scours are mainly based on the stable environment, where the background seabed scour is in equilibrium and the soil is homogeneous. To study the effects of background erosion on the free span development of subsea pipelines, a submarine pipeline located at the abandoned Yellow River subaqueous delta lobe was investigated with an integrated surveying system which included a Multibeam bathymetric system, a dual-frequency side-scan sonar, a high resolution sub-bottom profiler, and a Magnetic Flux Leakage(MFL) sensor. We found that seabed homogeneity has a great influence on the free span development of the pipeline. More specifically, for homogeneous background scours, the morphology of scour hole below the pipeline is quite similar to that without the background scour, whereas for inhomogeneous background scour, the nature of spanning is mainly dependent on the evolution of seabed morphology near the pipeline. Magnetic Flux Leakage(MFL) detection results also reveal the possible connection between long free spans and accelerated corrosion of the pipeline. 展开更多
关键词 海底管道 自由 跨越发展 侵蚀 黄河水下三角洲 多波束测深系统 海底冲刷 加速腐蚀
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Diagnostic tools in male infertility--the question of sperm dysfunction 被引量:5
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作者 Christopher LR Barratt Steven Mansell +2 位作者 Catherine Beaton Steve Tardif Senga K Oxenham 《Asian Journal of Andrology》 SCIE CAS CSCD 2011年第1期53-58,共6页
Sperm dysfunction is the single most common cause of infertility, yet what is remarkable is that, there is no drug a man can take or add to his spermatozoa in vitroto improve fertility. One reason for the lack of prog... Sperm dysfunction is the single most common cause of infertility, yet what is remarkable is that, there is no drug a man can take or add to his spermatozoa in vitroto improve fertility. One reason for the lack of progress in this area is that our understanding of the cellular and molecular workings of the mature spermatazoon is limited. However, over the last few years there has been considerable progress in our knowledge base and in addressing new methods to diagnose sperm dysfunction. We review the current state of the field and provide insights for further development. We conclude that: (i) there is little to be gained from more studies identifying/categorizing various populations of men using a basic semen assessment, where an effort is required in making sure the analysis is performed in an appropriate high quality way; (ii) technological development is likely to bring the reality of sperm function testing closer to implementation into the clinical pathways. In doing this, these assays must be robust, cheap (or more appropriately termed cost effective), easy to use and clinically useful; and (iii) clinical necessity, e.g., the need to identify the highest quality spermatozoon for injection is driving basic research forward. This is an exciting time to be an andrologist and, likely, a fruitful one. 展开更多
关键词 gamete biomarker male fertility sperm biomarker sperm dysfunction
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Proteomic and genomic studies of non-alcoholic fatty liver disease-clues in the pathogenesis 被引量:3
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作者 Jun Wei Lim John Dillon Michael Miller 《World Journal of Gastroenterology》 SCIE CAS 2014年第26期8325-8340,共16页
Non-alcoholic fatty liver disease(NAFLD)is a widely prevalent hepatic disorder that covers wide spectrum of liver pathology.NAFLD is strongly associated with liver inflammation,metabolic hyperlipidaemia and insulin re... Non-alcoholic fatty liver disease(NAFLD)is a widely prevalent hepatic disorder that covers wide spectrum of liver pathology.NAFLD is strongly associated with liver inflammation,metabolic hyperlipidaemia and insulin resistance.Frequently,NAFLD has been considered as the hepatic manifestation of metabolic syndrome.The pathophysiology of NAFLD has not been fully elucidated.Some patients can remain in the stage of simple steatosis,which generally is a benign condition;whereas others can develop liver inflammation and progress into non-alcoholic steatohepatitis,fibrosis,cirrhosis and hepatocellular carcinoma.The mechanism behind the progression is still not fully understood.Much ongoing proteomic researches have focused on discovering the unbiased circulating biochemical markers to allow early detection and treatment of NAFLD.Comprehensive genomic studies have also begun to provide new insights into the gene polymorphism to understand patientdisease variations.Therefore,NAFLD is considered a complex and mutifactorial disease phenotype resulting from environmental exposures acting on a susceptible polygenic background.This paper reviewed the current status of proteomic and genomic studies that have contributed to the understanding of NAFLD pathogenesis.For proteomics section,this review highlighted functional proteins that involved in:(1)transportation;(2)metabolic pathway;(3)acute phase reaction;(4)antiinflammatory;(5)extracellular matrix;and(6)immune system.In the genomic studies,this review will discuss genes which involved in:(1)lipolysis;(2)adipokines;and(3)cytokines production. 展开更多
关键词 Non-alcoholic FATTY liver disease Proteomics Genom
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Simplified approach for design of raft foundations against fault rupture.Part II:soil-structure interaction 被引量:3
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作者 I. Anastasopoulos N. Gerolymos +1 位作者 G. Gazetas M. F. Bransby 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2008年第2期165-179,共15页
This is the second paper of two, which describe the results of an integrated research effort to develop a four-step simplified approach for design of raft foundations against dip-slip (normal and thrust) fault ruptu... This is the second paper of two, which describe the results of an integrated research effort to develop a four-step simplified approach for design of raft foundations against dip-slip (normal and thrust) fault rupture. The first two steps dealing with fault rupture propagation in the free-field were presented in the companion paper. This paper develops an approximate analytical method to analyze soil-foundation-structure interaction (SFSI), involving two additional phenomena: (i) fault rupture diversion (Step 3); and (ii) modification of the vertical displacement profile (Step 4). For the first phenomenon (Step 3), an approximate energy-based approach is developed to estimate the diversion of a fault rupture due to presence of a raft foundation. The normalized critical load for complete diversion is shown to be a function of soil strength, coefficient of earth pressure at rest, bedrock depth, and the horizontal position of the foundation relative to the outcropping fault rupture. For the second phenomenon (Step 4), a heuristic approach is proposed, which "scans" through possible equilibrium positions to detect the one that best satisfies force and moment equilibrium. Thus, we account for the strong geometric nonlinearities that govern this interaction, such as uplifting and second order (P-△) effects. Comparisons with centrifuge-validated finite element analyses demonstrate the efficacy of the method. Its simplicity makes possible its utilization for preliminary design. 展开更多
关键词 fault rupture analytical method raft foundation soil-structure interaction EARTHQUAKE
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Determining the role for uric acid in non-alcoholic steatohepatitis development and the utility of urate metabolites in diagnosis:An opinion review 被引量:2
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作者 Paul Brennan Kathleen Clare +1 位作者 Jacob George John F Dillon 《World Journal of Gastroenterology》 SCIE CAS 2020年第15期1683-1690,共8页
There has long been a recognised association between non-alcoholic fatty liver disease(NAFLD)and the composite aspects of the metabolic syndrome.Part of this association highlighted the supposed co-existence of elevat... There has long been a recognised association between non-alcoholic fatty liver disease(NAFLD)and the composite aspects of the metabolic syndrome.Part of this association highlighted the supposed co-existence of elevated uric acid levels in those with NAFLD.There is interest in exploitation of this as a putative diagnostic and prognostic biomarker in NAFLD.Given the increased economic and health burden associated with the NAFLD epidemic,improved methods of population-based,minimally-invasive methods and biomarkers are clearly highly sought and necessary.In this opinion review we review the proposed role of uric acid in the pathogenesis of NAFLD and its potential utilisation in the diagnosis and monitoring of the disease process. 展开更多
关键词 Non-alcoholic FATTY LIVER disease Non-alcoholic steatohepatitis Uric acid URATE Non-invasive fibrosis markers FATTY LIVER index
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Three-dimensional numerical simulation of wave interaction with perforated quasi-ellipse caisson 被引量:5
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作者 Yong-xue WANG Xiao-zhong REN +1 位作者 Ping DONG Guo-yu WANG 《Water Science and Engineering》 EI CAS 2011年第1期46-60,共15页
The finite difference method and the volume of fluid (VOF) method were used to develop a three-dimensional numerical model to study wave interaction with a perforated caisson. The partial cell method was adopted to ... The finite difference method and the volume of fluid (VOF) method were used to develop a three-dimensional numerical model to study wave interaction with a perforated caisson. The partial cell method was adopted to solve this type of problem for the first time. The validity of the present model, with and without the presence of caisson structures, was examined by comparing the model results with experimental data. Then, the numerical model was used to investigate the effects of various wave and structure parameters on the wave force and wave runup of the perforated quasi-ellipse caisson. Compared with the solid quasi-ellipse caisson, the wave force on the perforated quasi-ellipse caisson is significantly reduced with increasing porosity of the perforated quasi-ellipse caisson. Furthermore, the perforated quasi-ellipse caisson can also reduce the wave runup, and it tends to decrease with the increase of the porosity of the perforated quasi-ellipse caisson and the relative wave height. 展开更多
关键词 VOF method partial cell method perforated quasi-ellipse caisson wave pressure wave force wave runup
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Simplified approach for design of raft foundations against fault rupture.Part I:free-field 被引量:2
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作者 I. Anastasopoulos N. Gerolymos +1 位作者 G. Gazetas M. F. Bransb 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2008年第2期147-163,共17页
Over the past few decades, earthquake engineering research mainly focused on the effects of strong seismic shaking. After the 1999 earthquakes in Turkey and Taiwan, and thanks to numerous cases where fault rupture cau... Over the past few decades, earthquake engineering research mainly focused on the effects of strong seismic shaking. After the 1999 earthquakes in Turkey and Taiwan, and thanks to numerous cases where fault rupture caused substantial damage to structures, the importance of faulting-induced deformation has re-emerged. This paper, along with its companion (Part Ⅱ), exploits parametric results of finite element analyses and centrifuge model testing in developing a four-step semi-analytical approach for analysis of dip-slip (normal and thrust) fault rupture propagation through sand, its emergence on the ground surface, and its interaction with raft foundations. The present paper (Part Ⅰ) focuses on the effects of faulting in the absence of a structure (i.e., in the free-field). The semi-analytical approach comprises two-steps: the first deals with the rupture path and the estimation of the location of fault outcropping, and the second with the tectonically- induced displacement profile at the ground surface. In both cases, simple mechanical analogues are used to derive simplified semi-analytical expressions. Centrifuge model test data, in combination with parametric results from nonlinear finite element analyses, are utilized for model calibration. The derived semi-analytical expressions are shown to compare reasonably well with more rigorous experimental and theoretical data, thus providing a useful tool for a first estimation of near-fault seismic hazard. 展开更多
关键词 fault rupture semi-analytical expression soil-structure interaction EARTHQUAKE
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A flume test on erosion mechanism for an abandoned section of the Huanghe(Yellow)River Delta 被引量:1
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作者 高涛 李广雪 +2 位作者 史经昊 DONG Ping 刘杰 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2010年第3期684-692,共9页
The erosion mechanisms of abandoned coastal section are understood detailedly by flume experiment, which play an important role to the offshore engineering facilities. A movable-bed physical model has been used to inv... The erosion mechanisms of abandoned coastal section are understood detailedly by flume experiment, which play an important role to the offshore engineering facilities. A movable-bed physical model has been used to investigate the coastal erosion of an abandoned section of the Huanghe (Yellow) River Delta. The theory of physical scale models is discussed and a method for constructing the representative seabed section is developed. The results indicate that during the period initially after the abandonment of the delta the entire bed experienced rapid erosion because the seabed was steep and prone to liquefaction that resulted from storm wave action. After this initial period, a balance of erosion and accretion was established, and the beach profile equilibrated with a point of balance present on the profile. The experimental results indicate that the volume of deposition was about half that of the erosion. Wave action may also induce significant stratal changes through its interaction with the soft seabed. The major morphological features developed in the model delta section were found to be qualitatively comparable with those observed in the prototype. A distorted modeling law that maintains the similarity of the modeled and prototype equilibrium beach profiles is proposed. Experimental results show that the distorted modeling is able to reproduce the beach-face slope in nature, and the model also successfully reproduced three historical evolutionary stages of erosion. 展开更多
关键词 侵蚀机理 三角洲 黄河 水槽试验 物理模型 水槽实验 海岸侵蚀 冲淤平衡
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LED luminance measurement and development of low-cost computerized perimeter 被引量:1
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作者 Wang Zhigang Yang Li +2 位作者 Yang Dong Yin Zhiyong Zhou Qi 《仪器仪表学报》 EI CAS CSCD 北大核心 2007年第12期2138-2141,共4页
An accurate method has been developed to calculate and measure the luminance of light-emitting diode (LED). A novel, simple-structured and high-precision circuitry was designed, which has been applied to the developme... An accurate method has been developed to calculate and measure the luminance of light-emitting diode (LED). A novel, simple-structured and high-precision circuitry was designed, which has been applied to the development of a low-cost threshold static automated perimeter. Round LEDs of 2 mm in diameter were used as stimuli. A logarithmic scale is used to express the differential light sensitivity, where 0 dB represents the brightest stimulus that corresponds to 1 000 asb. The LED radiant power was measured and its equivalent luminance was calculated by the derived equations. The schematics of the system is given, together with a novel circuitry for selecting stimulus point and its luminance. Initial clinical trial results were promising,which led to a further development of a commercial product. 展开更多
关键词 LED 亮度测量 视野 视野计 成本
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Comparison of Turbulence Schemes for Prediction of Wave-Induced Near-Bed Sediment Suspension Above A Plane Bed 被引量:1
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作者 张弛 郑金海 +3 位作者 王义刚 张勐韬 郑东生 张继生 《China Ocean Engineering》 SCIE EI 2011年第3期395-412,共18页
Based on a wave bottom boundary layer model and a sediment advection-diffusion model, seven turbulence schemes are compared regarding their performances in prediction of near-bed sediment suspension beneath waves abov... Based on a wave bottom boundary layer model and a sediment advection-diffusion model, seven turbulence schemes are compared regarding their performances in prediction of near-bed sediment suspension beneath waves above a plane bed. These turbulence algorithm., include six empirical eddy viscosity schemes and one standard two-equation k-e model. In particular, different combinations of typical empirical formulas for the eddy viscosity profile and for the wave friction factor are examined. Numerical results are compared with four laboratory data sets, consisting of one wave boundary layer hydrodynamics experiment and three sediment suspension experiments under linear waves and the Stokes second-order waves. It is shown that predictions of near-bed sediment suspension are very sensitive to the choices of the empirical formulas in turbulence schemes. Simple empirical turbulence schemes are possible to perform equally well as the two-equation k-ε model. Among the empirical schemes, the turbulence scheme, combining the exponential formula for eddy viscosity and Swart formula for wave friction factor, is the most accurate. It maintains the simplicity and yields identically good predictions as the k-ε model does in terms of the wave-averaged sediment concentration. 展开更多
关键词 sediment transport wave boundary layer turbulence scheme
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The Performance of a Novel Latching-Type Electromagnetic Actuator for Single-Port Laparoscopic Surgery 被引量:1
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作者 Haochen Wang Ali El Wahed 《Journal of Modern Physics》 2019年第14期1659-1673,共15页
This paper reports on the performance evaluation of a novel latching-type electromagnetic actuator which is designed to be embedded at selected joints along single-port laparoscopic surgical instruments (SLS). The aim... This paper reports on the performance evaluation of a novel latching-type electromagnetic actuator which is designed to be embedded at selected joints along single-port laparoscopic surgical instruments (SLS). The aim of this actuator is to allow these instruments to become articulated with a push of a button in order to provide the optimum angulation required during SLS operations. This new actuator is comprised of electromagnetic coil elements, soft magnetic frames and a permanent magnet. Unlike conventional electromagnetic actuators, latching-type electromagnetic actuators could maintain their positions at either end of the actuation stroke without any power application requirement. In the current design, magnetic attraction forces initiated between the permanent magnet and the magnetic frame are utilised to lock the position of the actuator whilst a certain angulation position of the actuator is achieved as a result of the magnetic repulsion forces established between the permanent magnet and the coil elements. The performance of the new actuator in terms of the output force, maximum angulation and patient’s safety, was evaluated experimentally and the results were found to compare well with those acquired numerically using finite element methods. This actuator was seen to exhibit sufficient actuation forces and hence, it was capable of providing adaptable angulation characteristics for SLS tools. Finally, thermal evaluation of the actuator’s operation was conducted, which was found to be within safety limits specified by clinicians. 展开更多
关键词 Latching ELECTROMAGNETIC ACTUATOR LAPAROSCOPIC SURGICAL TOOLS Angulation
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An atypical ubiquitin ligase at the heart of neural development and programmed axon degeneration
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作者 Satpal Virdee 《Neural Regeneration Research》 SCIE CAS CSCD 2022年第11期2347-2350,共4页
The degeneration of nerve fibres following injury was first described by Augustus Waller over 170 years ago.Initially assumed to be a passive process,it is now evident that axons respond to insult via regulated cellul... The degeneration of nerve fibres following injury was first described by Augustus Waller over 170 years ago.Initially assumed to be a passive process,it is now evident that axons respond to insult via regulated cellular signaling events resulting in their programmed degeneration.Pro-survival and prodegenerative factors have been identified and their regulato ry mechanisms are beginning to emerge.The ubiquitin system has been implicated in the pro-degenerative process and a key component is the ubiquitin E3 ligase MYCBP2(also known as PHR1).Ubiquitin E3 ligases are tasked with the transfer of the small protein modifier ubiquitin to substrates and consist of hundreds of members.They can be classified as single subunit systems or as multi-subunit complexes.Their catalytic domains can also be assigned to three general architectures.Hints that MYCBP2 might not conform to these established formats came to light and it is now clear from biochemical and structural studies that MYCBP2 is indeed an outlier in terms of its modus operandi.Furthermore,the unconventional way in which MYCBP2 transfe rs ubiquitin to substrates has been linked to neurodevelopmental and pro-degenerative function.Herein,we will summarize these research developments relating to the unusual features of MYCBP2 and postulate therapeutic strategies that prevent Walle rian degeneration.These have exciting potential for providing relief from pathological neuropathies and neurodegenerative diseases. 展开更多
关键词 chemical biology E3 ligase MYCBP2 NEURODEGENERATION progammed axon death structural biology ubiqultin wallerian degeneration
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In-situ Monitoring the Setting Behavior of Foamed Concrete Using Ultrasonic Pulse Velocity Method
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作者 SHE Wei ZHANG Yunsheng +1 位作者 JONES MR GUO Panpan 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2013年第6期1146-1154,共9页
The applicability of ultrasonic pulse velocity (UPV) method to in-situ monitor setting and hardening process of foamed concrete (FC) was systematically investigated. The UPVs of various FC pastes were automaticall... The applicability of ultrasonic pulse velocity (UPV) method to in-situ monitor setting and hardening process of foamed concrete (FC) was systematically investigated. The UPVs of various FC pastes were automatically and continuously measured by a specially designed ultrasonic monitoring apparatus (UMA). Ultrasonic tests were performed on FC mixtures with different density (300, 500, 800 and 1 000 kg/m3), and different fly ash contents (0%, 20%, 40% and 60%). The influence of curing temperatures (20, 40, 60 and 80~C) was also studied. The experimental results show that three characteristic stages can be clearly identified during the setting process of an arbitrary FC paste: dormant stage, acceleration stage, and deceleration stage. Wet density, fly ash content, and curing temperature have great impact on setting behavior. A stepwise increase of the wet density results in shorter dormant stage and larger final UPV. Hydration reaction rate is obviously promoted with an increase in curing temperature. However, the addition fly ash retards the microstn,lcture formation. To aid in comparing with the ultrasonic results, the consistence spread test and Vicat needle test (VNT) were also conducted. A correlation between ultrasonic and VNT results was also established to evaluate the initial and final setting time of the FC mixtures. Finally, certain ranges of UPV with reasonable widths were suggested for the initial and final setting time, respectively. 展开更多
关键词 foamed concrete (FC) early age setting behavior ultrasonic monitoring setting time CONSISTENCE
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