期刊文献+
共找到443篇文章
< 1 2 23 >
每页显示 20 50 100
Effect of No Tillage and Conventional Tillage on Wheat Grain Yield Variability: A Review
1
作者 Kenza Kadiri Hassani Moussadek Rachid +4 位作者 Baghdad Bouamar Zouahri Abdelmjid Dakak Houria Maher Hassnae Bouabdli Abdelhak 《Journal of Environmental & Earth Sciences》 CAS 2024年第1期57-70,共14页
Conservation Agriculture(CA)covers more than 205 million hectares in the world.This made it possible to face and mitigate the challenges of climate change,reducing soil erosion and providing multiple ecosystem service... Conservation Agriculture(CA)covers more than 205 million hectares in the world.This made it possible to face and mitigate the challenges of climate change,reducing soil erosion and providing multiple ecosystem services.The first elementary factor influenced is the yield evaluation.It has a direct effect on farmers’choices for sustainable production.The present article records a review focused on wheat yield average positive change compared between conventional tillage(CT)and no tillage(NT)systems.The international database collected showed that NT is adaptable everywhere.The results of wheat yield differentiation showed the influence of crop rotation depending on stations located in different climatic zones.In more than 40 years of research,specialists have succeeded in demonstrating the importance of crop productivity like wheat.The whole integrates also experimentations where the initiation starts more than ten years. 展开更多
关键词 Climate change No tillage Crop rotation WHEAT YIELD
下载PDF
Prevalence and Associated Factors of Diabetes Mellitus in Benin
2
作者 Alphonse Kpozehouen Francois Djrolo +6 位作者 Charles J.Sossa Akpa R.Gbary Yessito Chouehanou Dieudonné Fambo Yessouf Tchabi Roger Salamon Dismand S. Houinato 《Open Journal of Epidemiology》 2015年第3期163-171,共9页
Background: Data on diabetes mellitus in general population in Benin is scarce. This study aimed therefore to assess prevalence and risk factors of diabetes mellitus in Benin. Methods: The study consisted of a cross-s... Background: Data on diabetes mellitus in general population in Benin is scarce. This study aimed therefore to assess prevalence and risk factors of diabetes mellitus in Benin. Methods: The study consisted of a cross-sectional survey, using the World Health Organisation (WHO)’s instrument for stepwise surveillance (STEPS) of non-communicable diseases risk factors. A five-stage random sample of 25 to 64 years old male and female adults living in Benin participated in structured interviews and their size, weight and blood pressure were measured according to standardized procedures. Glycaemia was measured using ACCUTREND? test strips for capillary blood glucose. Prevalence and means were computed with their 95% confidence interval and standard error respectively, taking into account the sampling design. Prevalence was compared by Khi2 and means by Student’s t test. Univariate and multivariate logistic regressions were performed to identify socio-demographic diabetes’s risk factors. Results: A total of 3772 adults participated in the study. The average age of respondents was 44.2 years. Overall, 68.3% of subjects were illiterate, 82.4% lived in rural areas, 82.57% were self-employed, 20% overweight, 7.51% obese and the prevalence of hypertension was 29.5 p.100. The prevalence of diabetes mellitus was 1.4 p.100 [CI95% = (0.94:2.05)]. This prevalence was higher in men than in women (2.1% vs. 0.8%, p = 0.0031). This prevalence was higher in urban areas than in rural areas. The Littoral department had the highest prevalence (3.4%), followed by the Collines department (2.7%), Donga (2.4%) and Borgou (2.3%). As many as 49.3% of subjects diagnosed with diabetes mellitus were not aware of their status. The age group of 56 - 64 years had the highest risk [OR = 6.6, IC95% = (1.6;22.4)]. The risk of diabetes was higher in people living in urban areas than in people living in rural areas [OR = 3.04 CI95% = (1.6;6.0)]. After controlling for confounding factors, risk factors of diabetes were gender, men being more at risk than women (p = 0.002) age from 55 to 64 years (p = 0.009), overweight (p < 0.0001) and obesity (p = 0.002). Conclusion: Our findings suggested that diabetes mellitus was common in Benin. The prevalence of diabetes is more likely to increase in regard to the nutritional transitions (diet) and the accelerating urbanization of Benin. Communication campaigns for behavioral change are needed to slow down or even reverse this trend. 展开更多
关键词 PREVALENCE Risk Factors Diabetes Mellitus BENIN
下载PDF
WOA-DNN for Intelligent Intrusion Detection and Classification in MANET Services 被引量:1
3
作者 C.Edwin Singh S.Maria Celestin Vigila 《Intelligent Automation & Soft Computing》 SCIE 2023年第2期1737-1751,共15页
Mobile ad-hoc networks(MANET)are garnering a lot of attention because of their potential to provide low-cost solutions to real-world communica-tions.MANETs are more vulnerable to security threats.Changes in nodes,band... Mobile ad-hoc networks(MANET)are garnering a lot of attention because of their potential to provide low-cost solutions to real-world communica-tions.MANETs are more vulnerable to security threats.Changes in nodes,band-width limits,and centralized control and management are some of the characteristics.IDS(Intrusion Detection System)are the aid for detection,deter-mination,and identification of illegal system activity such as use,copying,mod-ification,and destruction of data.To address the identified issues,academics have begun to concentrate on building IDS-based machine learning algorithms.Deep learning is a type of machine learning that can produce exceptional outcomes.This study proposes that WOA-DNN be used to detect and classify incursions in MANET(Whale Optimized Deep Neural Network Model)WOA(Whale Opti-mization Algorithm)and DNN(Deep Neural Network)are used to optimize the preprocessed data to construct a system for classifying and predicting unantici-pated cyber-attacks that are both effective and efficient.As a result,secure data transport to other nodes is provided,preventing intruder attacks.The invaders are found using the(Machine Learning)ML-IDS and WOA-DNN methods.The data is reduced in dimensionality using Principal Component Analysis(PCA),which improves the accuracy of the outputs.A classifier is used in forward propagation to predict whether a result is normal or malicious.To compare the traditional and proposed models’effectiveness,the accuracy of classification,detection of the attack rate,precision rate,and F-Measure,Recall are utilized.The proposed WOA-DNN model has higher assessment metrics and a 99.1%accuracy rate.WOA-DNN also has a greater assault detection rate than others,resulting in fewer false alarms.The classification accuracy of the proposed WOA-DNN model is 99.1%. 展开更多
关键词 Intrusion detection system whale optimization algorithm deep neural network mobile ad-hoc networks forward and back propagation
下载PDF
Fault Recognition of Multilevel Inverter Using Artificial Neural Network Approach
4
作者 Aravind Athimoolam Karthik Balasubramanian 《Intelligent Automation & Soft Computing》 SCIE 2023年第5期1331-1347,共17页
This paper focuses on the development of a diagnostic tool for detect-ing insulated gate bipolar transistor power electronic switchflaws caused by both open and short circuit faults in multi-level inverter time-frequen... This paper focuses on the development of a diagnostic tool for detect-ing insulated gate bipolar transistor power electronic switchflaws caused by both open and short circuit faults in multi-level inverter time-frequency output voltage specifications.High-resolution laboratory virtual instrument engineering work-bench software testing tool with a sample rate data collection system,as well as specialized signal processing and soft computing technologies,are used in this proposed method.On a single-phase cascaded H-bridge multilevel inverter,simu-lation and experimental investigations of both open and short issues of the insu-lated gate bipolar transistor components are performed out.In all conceivable switch issues,the output voltage signals are evaluated for different modulation index values.Fast fourier transform and discrete wavelet transform methods are used to investigate the frequency domain properties of output voltage signals.In the artificial neural network,the back propagation training technique was employed,and the generated neural parameter values were used in the Laboratory Virtual Instrumentation Engineering Workbench real-time fault diagnosis model. 展开更多
关键词 Back propagation learning DWT cascaded H-bridge MLI FFT sinusoidal PWM THD
下载PDF
A Review of Haptic Technology Applications in Healthcare
5
作者 Ilman Shazhaev Dimitry Mihaylov Abdulla Shafeeg 《Open Journal of Applied Sciences》 CAS 2023年第2期163-174,共12页
Regaining lost abilities via the formation of new neural pathways as a result of extensive practice and retraining is a key feature of the rehabilitation process. However, patient boredom is a big issue in rehabilitat... Regaining lost abilities via the formation of new neural pathways as a result of extensive practice and retraining is a key feature of the rehabilitation process. However, patient boredom is a big issue in rehabilitation owing to the extensive practice that is necessary. Awareness of the value of haptic (touch-enabled) interfaces in computer applications has grown because to the emergence of games with buzzing joysticks and consumer electronics with touchpads. Some forms of haptics, however, are paving the way for cutting-edge computer-based rehabilitation solutions, such as “serious games,” which are only one use of haptics’ potential to enhance clinical treatment. In this paper, we aim to review the methods and technologies of haptic feedback that are used for medical treatment and rehabilitation. Developing and innovating better haptic feedback technology has the potential to expand and improve access to virtual healthcare such as the doctor being able to “feel” a patient’s tumor from miles away by being paired with robotic devices. 展开更多
关键词 HAPTIC Healthcare Virtual Reality Videogame Serios Games TECHNOLOGY
下载PDF
Assessing the Factors Influencing Effective Municipal Solid Waste Management System in Barishal Metropolitan Areas
6
作者 Tareq Mahamud Abir Mallika Datta Sumi Rani Saha 《Journal of Geoscience and Environment Protection》 2023年第1期49-66,共18页
Unorganized municipal solid waste (MSW) disposal system leads to stress on ecosystems and disturbs various nature cycles and human health. Solid waste management all over world is looked as a major challenge to civil ... Unorganized municipal solid waste (MSW) disposal system leads to stress on ecosystems and disturbs various nature cycles and human health. Solid waste management all over world is looked as a major challenge to civil bodies, especially in developing countries like Bangladesh. The proper management system of municipal solid waste depends on various factors like social, cultural, financial, political, environmental, physical and institutional and so on. The purpose of this study is to explore the leading factors that affect the solid waste management in Barishal city. For achieving this purpose, this research first has identified the socio-economic, cultural, physical and technical, institutional and environmental factors and then analyzed the factors which affect the solid waste management system in the study area. To achieve the purpose of the study, quantitative method has been used in this research. As a sample of this study, 150 household heads from total household members of the city have been selected randomly by using lottery method. A structured questionnaire has been constructed for collecting quantitative data. The quantitative data have been analyzed in this study by using SPSS Program, and Microsoft Excel. The findings of the study show that all city people know solid waste and solid waste management stakeholders present in the city and waste pickers collect all types of waste in the city and socio-economic, cultural, physical and technical, institutional factors affect the effective solid waste management in the study area where environmental factors have no influence on effective solid waste management in the study area. The study people have a bad impression of the current existing management system of the solid waste and they express their expectations where they mention that if municipal authorities improve the condition of the infrastructure, roads and vehicles;allow more budgets to manage waste;take proper strategies and planning to manage waste smartly like imposing fines, set up rules, then the municipal authorities will be able to manage solid waste properly. Finally, this research has proposed some recommendations that might be helpful for the policy-makers in the study area for making policies and further research regarding solid waste management. 展开更多
关键词 ECOSYSTEM Solid Waste Management Municipal Solid Waste Management
下载PDF
Effect of Health Education Program on Self-Efficacy and Functional Capacity of Patients with Coronary Artery Bypass Surgery in Khartoum State-Sudan, 2015-2019
7
作者 Mohamed Idriss Yahya Musa Egbal Abbashar Algamar +4 位作者 Manal Elzein Musa Ismail Osama Mohamed Elsanousi Amair Siddig Alhussein Zeinab Abaker Ahmed Omer Abdalgabar Musa Hassan 《World Journal of Cardiovascular Surgery》 2023年第12期167-180,共14页
Coronary heart disease is among the most prevalent and costly of all global health problems. Coronary artery bypass grafting (CABG) has been increasingly used since the 1960s. Coronary heart disease is a leading cause... Coronary heart disease is among the most prevalent and costly of all global health problems. Coronary artery bypass grafting (CABG) has been increasingly used since the 1960s. Coronary heart disease is a leading cause of death worldwide, including Sudan. Self-efficacy and functional capacity is a critical factor for quality of life in patients who has undergone CABG as well as for their caregivers from their families. Aim of the Study: To explore the effects of an educational program on self-efficacy and functional capacity of patients after CABG. 1) There will be no significant difference between the intervention group and control group concerning knowledge regarding Self-efficacy and functional capacity post CABG surgery. 2) The application of our educational program for the patients will enhance the patients with CABG surgery and improve knowledge about Self-efficacy and functional capacity post CABG surgery. 3) There are some socio demographic factors that affect the response to the educational program. Methods: This was a quasi-experimental, interventional and hospital-based study, including pre-test, a post-test and follow-up test, with a control group, conducted during the period from September 2014 to June 2019. Patients were recruited consecutively to the cases and control group using convenience sampling. The sample consisted of 76 patients;41 as cases and 35 as control group. The sample included those who had undergone CABG in Khartoum State. Relevant data were collected using a checklist to monitor the effect of a health education program on self-efficacy and functional capacity of the patients. Result: The results showed marked improvement in patients’ self-efficacy and functional capacity between pretest and posttest for the study group;p-value = (0.001) in the health status of cases in comparison to the control group. The indices were observed to be higher for patients who received a nursing educational program throughout the study period;p-value = (0.002). 展开更多
关键词 Education Program SELF-EFFICACY Functional Capacity Coronary Artery Bypass Surgery
下载PDF
Bridging the gap between data mining and medical applications
8
作者 Simon James Fong 《Medical Data Mining》 2023年第2期60-61,共2页
Artificial Intelligence(AI)is one of the most promising and rapidly evolving fields in modern science.It is increasingly being applied to a wide range of domains,including medicine,where it holds enormous potential fo... Artificial Intelligence(AI)is one of the most promising and rapidly evolving fields in modern science.It is increasingly being applied to a wide range of domains,including medicine,where it holds enormous potential for improving patient care,reducing costs,and enhancing clinical decision-making.One area of AI that has shown great promise in the medical domain is data mining,which is the process of extracting useful information and knowledge from large data sets. 展开更多
关键词 CLINICAL MINING holds
下载PDF
基于LabVIEW的苹果擦伤分级系统设计 被引量:9
9
作者 高晓阳 Paul H Heinemann Joseph Irudayaraj 《农业机械学报》 EI CAS CSCD 北大核心 2006年第4期152-154,共3页
基于美国USDA苹果分级标准研制了苹果擦伤检测分级系统样机。系统依据所研究的苹果表面擦伤拉曼光谱PLS/CVA处理和UNEQ模型分类,通过设计的LabVIEW虚拟仪器控制系统实时完成苹果分级。对48个预先分级的美国红元帅苹果(reddelicious#4167... 基于美国USDA苹果分级标准研制了苹果擦伤检测分级系统样机。系统依据所研究的苹果表面擦伤拉曼光谱PLS/CVA处理和UNEQ模型分类,通过设计的LabVIEW虚拟仪器控制系统实时完成苹果分级。对48个预先分级的美国红元帅苹果(reddelicious#4167)分别进行两轮实际分级实验来评估该系统的性能。实验结果表明该分级检测系统对无擦伤、轻擦伤和重擦伤苹果组的分级平均准确率分别为100%、99%、97%。分级系统每分钟可分级苹果3~6个,对运动苹果分级误判率较低,是实施苹果自动检测分级生产线的基本模块。 展开更多
关键词 苹果 分级系统 擦伤 拉曼光谱 虚拟仪器
下载PDF
佛罗里达州柑桔投资的远景展望——GAMS仿真的案例(英文)
10
作者 陈秉钧 Spreen Tom H Moss Charles B 《农业工程学报》 EI CAS CSCD 北大核心 1995年第2期42-47,共6页
运用GAMS仿真展示了美国佛罗里达州柑桔生产投资的经济远景。仿真动态地、定量地回答了长期投资决策中的五个关键因素:期望净投资回收率、最低竞争价格、最大可接受的贷款利率、新建桔园的最优种植计划、最早获得盈利的年份(以净现值为... 运用GAMS仿真展示了美国佛罗里达州柑桔生产投资的经济远景。仿真动态地、定量地回答了长期投资决策中的五个关键因素:期望净投资回收率、最低竞争价格、最大可接受的贷款利率、新建桔园的最优种植计划、最早获得盈利的年份(以净现值为表征)。该项研究有助于投资者作出正确的投资决策。 展开更多
关键词 GAMS仿真 投资 净现值 回收率 柑桔类果树 美国
下载PDF
Stroke Rehabilitation In The United States 被引量:2
11
作者 Richard D.Zorowitz 周景升 宋为群 《中国康复医学杂志》 CAS CSCD 北大核心 2008年第1期5-7,共3页
I have attempted to present you with many of the ways that in the United States we are addressing the issue of motor deficits in stroke survivors. Many of these techniques show promise. However,there is much work to b... I have attempted to present you with many of the ways that in the United States we are addressing the issue of motor deficits in stroke survivors. Many of these techniques show promise. However,there is much work to be done in order to determine which techniques may be the most effective for cer-tain patients. It is also need to figure out the timing of many of these techniques in order to maximize their benefit. As this last slide shows,stroke survivors need to be "involved with their own rescue." Without their motivation and practice,stroke survivors will never reach their maximal functional capacity. With new techniques and technologies,rehabilitation professionals can provide stroke survivors with the means to intensify their therapies to facilitate functional recovery,reorganize the brain and return them to a fulfilling quality of life. 展开更多
关键词 美国 中风 康复治疗 临床医学 康复效果
下载PDF
避孕 被引量:2
12
作者 Mindy A.Smith Leslie A.Shimp Pharm +1 位作者 梁万年 曹红霞 《中国全科医学》 CAS CSCD 2002年第7期511-514,共4页
关键词 避孕 意外妊娠 生物医学 家庭评价 影响因素
下载PDF
Editorial statement 被引量:44
13
作者 Salvatore Gruttadauria Bruno G Gridelli 《World Journal of Gastroenterology》 SCIE CAS CSCD 2009年第6期647-647,共1页
In the following four articles,we will provide an overview of the current clinical work in different areas of liver transplantation.For many decades,this transplantation has been the treatment choice for patients suff... In the following four articles,we will provide an overview of the current clinical work in different areas of liver transplantation.For many decades,this transplantation has been the treatment choice for patients suffering from chronic 展开更多
关键词 肝疾病 肝移植 治疗方法 临床研究
下载PDF
Influence of Gaps Between Multiple Floating Bodies on Wave Forces 被引量:25
14
作者 缪国平 H. Ishida T. Saitoh 《China Ocean Engineering》 SCIE EI 2000年第4期407-422,共16页
The present study aims to give general hints about hydrodynamic interactions for water wave diffraction on a super large floating structure composed of a large number of box-shaped modules with many small gaps in betw... The present study aims to give general hints about hydrodynamic interactions for water wave diffraction on a super large floating structure composed of a large number of box-shaped modules with many small gaps in between. And meanwhile, it also aims to seek for an effective way to take the gap influence into consideration without numerical difficulties existing in conventional methods. An asymptotic matching technique is exploited by virtue of the smallness of gaps. Formal potential solutions are established for the near field around the gap ends and the far field away from gap ends, respectively, and the unknowns in those solutions are uniquely determined by asymptotic matching. The eigen-function expansion method is used for the outer far field and a series of pulsating sources at each gap end is introduced to simulate the gap influence. Strong hydrodynamic interaction is observed and a new resonant phenomenon, the mechanism of which differs absolutely from any known ones, is revealed in the present study. Sharp peak responses for both vertical and horizontal wave-exciting forces on each block are found around some special resonance frequencies, which depend on the draft of the structure and the gap width. The present results are of practical significance to the design of links (connectors) of modules for super large floating structures. And the importance is also closely related to the hydro-elasticity analysis for super large floating structures, in which local loads may be as important as the integrated loads. 展开更多
关键词 super large floating structure wave interaction RESONANCE gap influence
下载PDF
endoscopic 以后后退 cholangiopancreatography 复杂并发症: 他们怎么能被避免? 被引量:21
15
作者 Juan J Vila Everson LA Artifon Jose Pinhata Otoch 《World Journal of Gastrointestinal Endoscopy》 CAS 2012年第6期241-246,共6页
Endoscopic retrograde cholangiopancreatography(ERCP) has a significant complication rate which can be lowered by adopting technical variations of proven beneficial effect and prophylactic maneuvers such as pancreatic ... Endoscopic retrograde cholangiopancreatography(ERCP) has a significant complication rate which can be lowered by adopting technical variations of proven beneficial effect and prophylactic maneuvers such as pancreatic stenting during ERCP or periprocedural non-steroidal anti-inflammatory drug administration.However,adoption of these prophylactic maneuvers by endoscopists is not uniform.In this editorial we discuss the beneficial effects of the aforementioned maneuvers. 展开更多
关键词 Acute NECROTIZING Anti-inflammatory Agents CATHETERIZATION CHOLANGIOPANCREATOGRAPHY Complications ENDOSCOPIC retrograde NON-STEROIDAL Pancreatitis STENTS
下载PDF
An evaluation of force-based design vs.direct displacement-based design of jointed precast post-tensioned wall systems 被引量:10
16
作者 M. Ataur Rahman Sri Sritharan 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2006年第2期285-296,共12页
The unique features of jointed post-tensioned wall systems, which include minimum structural damage and re-centering capability when subjected to earthquake lateral loads, are the result of using unbonded post-tension... The unique features of jointed post-tensioned wall systems, which include minimum structural damage and re-centering capability when subjected to earthquake lateral loads, are the result of using unbonded post-tensioning to attach the walls to the foundation, along with employing energy dissipating shear connectors between the walls. Using acceptance criteria defined in terms of inter-story drift, residual drift, and floor acceleration, this study presents a multiplelevel performance-based seismic evaluation of two five-story unbonded post-tensioned jointed precast wall systems. The design and analysis of these two wall systems, established as the direct displacement-based and force-based solutions for a prototype building used in the PREcast Seismic Structural Systems (PRESSS) program, were performed at 60% scale so that the analysis model could be validated using the PRESSS test data. Both buildings satisfied the performance criteria at four levels of earthquake motions although the design base shear of the direct displacement-based jointed wall system was 50% of that demanded by the force-based design method. The study also investigated the feasibility of controlling the maximum transient inter-story drift in a jointed wall system by increasing the number of energy dissipating shear connectors between the walls but without significantly affecting its re-centering capability. 展开更多
关键词 CONCRETE PRECAST unbonded post-tensioning WALL building code performance-based evaluation force-baseddesign direct-displacement based design
下载PDF
Characterization of cytotoxic compound from marine sediment derived actinomycete Streptomyces avidinii strain SU4 被引量:3
17
作者 Sudha S Masilamani Selvam M 《Asian Pacific Journal of Tropical Biomedicine》 SCIE CAS 2012年第10期770-773,共4页
Objective:To investigate the cytotoxic activity of actinomycete isolated from marine sediment.Methods:In the present study the DNA was isolated and the ITS region of 16s rRNA was amplified by polymerase chain reaction... Objective:To investigate the cytotoxic activity of actinomycete isolated from marine sediment.Methods:In the present study the DNA was isolated and the ITS region of 16s rRNA was amplified by polymerase chain reaction,using two universal bacterial primers,1492K(5'-GGTTACCTTG'TTAC GACTT-3')and Eubac27F(5'-AGAGTTTGATCCTGGCTC AG-3').The amplified products were purified using TIANgel mini purification kit,ligated to MD18-T simple vector(TaKaRa),and transformed into competent cells of Escherichia coli DH5α.16S rRNA gene fragment was sequenced using forward primer M13F(-47)and reverse primer M13R(-48).Blast search sequence similarity was found against the existing non-redundanl nucleotide sequence database thus,identified as Streptomyces sp SU,Streptomyces rubralavandulae strain SU1,Streptomyces cacaoi strain SU2,Streptomyces cavourensis strain SU3,Streptomyces avidinii strain SU4,Streptomyces globisporus strain SU5,Streptomyces variabilis strain SU6,Streptomyces coelicolor strain SU 7.Among the eight identified isolates,one actinomycete Streptomyces avidinii strain SU4 was selected for further study.Results:Crude extract of the actinomycete isolate exhibited IC_(50)in 64.5μg against Hep-2 cell line,250μg in VERO cell line.This value is very close to the criteria of cytotoxicity activity for the crude extracts,as established by the American National Cancer Institute(NCI)is in IC_(50)<30μg/mL.The CC MS analysis showed that the active principle might be 1,2-benzenedicarboxylic acid,bis(2-methylpropyl)ester(12.17%),isooctyl phthalate(15.29%)with the retention time 15.642 and 21.612,respectively.Conclusions:This study clearly proves that the marine sediment derived actinomycetes with bioactive metabolites can be expected to provide high quality biological material for high throughout biochemical and anticancer screening programs.These results help us to conclude that the potential of using metabolic engineering and post genomic approaches to isolate more bioactive compounds and make their possible commercial application is not far off. 展开更多
关键词 ACTINOMYCETES Cytotoxicity ITS sequencing GC MS STREPTOMYCES avidinii CHARACTERIZATION CYTOTOXIC COMPOUND Extra cellular metabolite
下载PDF
Lateral load pattern in pushover analysis 被引量:9
18
作者 孙景江 Tetsuro Ono +1 位作者 赵衍刚 王威 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2003年第1期99-108,共10页
The seismic capacity curves of three types of buildings including frame,frame-shear wall and shear wall ob- tained by pushover analysis under different lateral load patterns are compared with those from nonlinear time... The seismic capacity curves of three types of buildings including frame,frame-shear wall and shear wall ob- tained by pushover analysis under different lateral load patterns are compared with those from nonlinear time history analy- sis.Based on the numerical results obtained a two-phase load pattern:an inverted triangle(first mode)load pattern until the base shear force reaches β times its maximum value,V_(max)followed by a(x/H)~α form,here β and α being some coeffi- cients depending on the type of the structures considered,is proposed in the paper,which can provide excellent approxima- tion of the seismic capacity curve for low-to-mid-rise shear type buildings.Furthermore,it is shown both the two-phase load pattern proposed and the invariant uniform pattern can be used for low-to-mid-rise shear-bending type and low-rise bending type of buildings.No suitable load patterns have been found for high-rise buildings. 展开更多
关键词 pushover analysis performance-based seismic design lateral load pattern nonlinear time history analysis
下载PDF
Antiplane SH-deformations near a surface rigid foundation above a subsurface rigid circular tunnel 被引量:4
19
作者 V.W.Lee M.E.Manoogian S.Chen 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2002年第1期27-35,共9页
The problem on the dynamic response of a rigid embedded foundation in the presence of an underground rigid tunnel and subjected to excitation of incident anti-plane SH waves is analyzed.By using the exact analytical s... The problem on the dynamic response of a rigid embedded foundation in the presence of an underground rigid tunnel and subjected to excitation of incident anti-plane SH waves is analyzed.By using the exact analytical solution for the two-dimensional SH-wave propagation in and around both the surface rigid foundation and subsurface rigid tunnel,those aspects of the resulting ground motions that are of special interest and importance for seismic resistant design in earthquake analyses have been examined.The computed amplitudes of the resulting periodic ground motions display a very complicated wave-interference between the surface foundation and underground tunnel that lead to observed standing wave patterns, together with abrupt changes in the wave amplitudes and large amplification of the incident motions. 展开更多
关键词 SH waves wave-interference embedded foundation underground tunnel analytical solution
下载PDF
Implementation of configuration dependent stiffness proportional damping for the dynamics of rigid multi-block systems 被引量:4
20
作者 Yun Byeong Chae Jae Kwan Kim 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2003年第1期87-98,共12页
The distinct element method(DEM)has been used successfully for the dynamic analysis of rigid block sys- tems.One of many difficulties associated with DEM is modeling of damping.In this paper,new procedures are propose... The distinct element method(DEM)has been used successfully for the dynamic analysis of rigid block sys- tems.One of many difficulties associated with DEM is modeling of damping.In this paper,new procedures are proposed for the damping modeling and its numerical implementation in distinct element analysis of rigid muhi-block systems.The stiff- ness proportional damping is constructed for the prescribed damping ratio,based on the non-zero fundamental frequency ef- fective during the time interval while the boundary conditions remain essentially constant.At this time interval,the funda- mental frequency can be estimated without complete eigenvalue analysis.The damping coefficients will vary while the damp- ing ratio remains the same throughout the entire analysis.A new numerical procedure is developed to prevent unnecessary energy loss that can occur during the separation phases.These procedures were implemented in the development of the dis- tinet element method for the dynamic analyses of piled multi-block systems.The analysis results |or the single-block and two-block systems were in a good agreement with the analytic predictions.Applications to the seismic analyses of piled four- block systems revealed that the new procedures can make a significant difference and may lead to much-improved results. 展开更多
关键词 multi-block systems stiffness proportional damping ROCKING impact distinet element method rigid body dynamics
下载PDF
上一页 1 2 23 下一页 到第
使用帮助 返回顶部