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Accelerated design of high-performance Mg-Mn-based magnesium alloys based on novel bayesian optimization 被引量:2
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作者 Xiaoxi Mi Lili Dai +4 位作者 Xuerui Jing Jia She Bjørn Holmedal Aitao Tang Fusheng Pan 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2024年第2期750-766,共17页
Magnesium(Mg),being the lightest structural metal,holds immense potential for widespread applications in various fields.The development of high-performance and cost-effective Mg alloys is crucial to further advancing ... Magnesium(Mg),being the lightest structural metal,holds immense potential for widespread applications in various fields.The development of high-performance and cost-effective Mg alloys is crucial to further advancing their commercial utilization.With the rapid advancement of machine learning(ML)technology in recent years,the“data-driven''approach for alloy design has provided new perspectives and opportunities for enhancing the performance of Mg alloys.This paper introduces a novel regression-based Bayesian optimization active learning model(RBOALM)for the development of high-performance Mg-Mn-based wrought alloys.RBOALM employs active learning to automatically explore optimal alloy compositions and process parameters within predefined ranges,facilitating the discovery of superior alloy combinations.This model further integrates pre-established regression models as surrogate functions in Bayesian optimization,significantly enhancing the precision of the design process.Leveraging RBOALM,several new high-performance alloys have been successfully designed and prepared.Notably,after mechanical property testing of the designed alloys,the Mg-2.1Zn-2.0Mn-0.5Sn-0.1Ca alloy demonstrates exceptional mechanical properties,including an ultimate tensile strength of 406 MPa,a yield strength of 287 MPa,and a 23%fracture elongation.Furthermore,the Mg-2.7Mn-0.5Al-0.1Ca alloy exhibits an ultimate tensile strength of 211 MPa,coupled with a remarkable 41%fracture elongation. 展开更多
关键词 Mg-Mn-based alloys high-performance Alloy design Machine learning Bayesian optimization
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Classification and Comprehension of Software Requirements Using Ensemble Learning
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作者 Jalil Abbas Arshad Ahmad +4 位作者 Syed Muqsit Shaheed Rubia Fatima Sajid Shah Mohammad Elaffendi Gauhar Ali 《Computers, Materials & Continua》 SCIE EI 2024年第8期2839-2855,共17页
The software development process mostly depends on accurately identifying both essential and optional features.Initially,user needs are typically expressed in free-form language,requiring significant time and human re... The software development process mostly depends on accurately identifying both essential and optional features.Initially,user needs are typically expressed in free-form language,requiring significant time and human resources to translate these into clear functional and non-functional requirements.To address this challenge,various machine learning(ML)methods have been explored to automate the understanding of these requirements,aiming to reduce time and human effort.However,existing techniques often struggle with complex instructions and large-scale projects.In our study,we introduce an innovative approach known as the Functional and Non-functional Requirements Classifier(FNRC).By combining the traditional random forest algorithm with the Accuracy Sliding Window(ASW)technique,we develop optimal sub-ensembles that surpass the initial classifier’s accuracy while using fewer trees.Experimental results demonstrate that our FNRC methodology performs robustly across different datasets,achieving a balanced Precision of 75%on the PROMISE dataset and an impressive Recall of 85%on the CCHIT dataset.Both datasets consistently maintain an F-measure around 64%,highlighting FNRC’s ability to effectively balance precision and recall in diverse scenarios.These findings contribute to more accurate and efficient software development processes,increasing the probability of achieving successful project outcomes. 展开更多
关键词 Ensemble learning machine learning non-functional requirements requirement engineering accuracy sliding window
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Simultaneous determination of 27 preservatives in toothpaste by high-performance liquid chromatography
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作者 Zhishan Wu Yanchao Wang +3 位作者 Chengjun Jiang Yuchen Long Shuai Yin Weicheng Yin 《日用化学工业(中英文)》 CAS 北大核心 2024年第12期1515-1523,共9页
A method of high-performance liquid chromatography(HPLC)was established for simultaneous determination of 27 preservatives in toothpaste.Toothpaste samples were extracted with 50%aqueous methanol solution,ultrasonicat... A method of high-performance liquid chromatography(HPLC)was established for simultaneous determination of 27 preservatives in toothpaste.Toothpaste samples were extracted with 50%aqueous methanol solution,ultrasonicated and then filtered.The target compounds were separated on a C_(18) column(250 mm×4.6μm,5μm)with the mobile phase consisting of acetonitrile and aqueous phosphoric acid solution,the column temperature was 30℃,the sample volume was 10μL,the flow rate was 1 mL/min,and diode array detector was used.Under the optimal experimental conditions,good linear relationship was obtained and the correlation coefficient(R^(2))was greater than 0.9995.This method was accurate and sensitive,which was suitable for the qualitative and quantitative analysis of 27 preservatives in toothpaste. 展开更多
关键词 TOOTHPASTE PRESERVATIVE high-performance liquid chromatography
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An Investigation on Open-RAN Specifications:Use Cases,Security Threats,Requirements,Discussions
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作者 Heejae Park Tri-HaiNguyen Laihyuk Park 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第10期13-41,共29页
The emergence of various technologies such as terahertz communications,Reconfigurable Intelligent Surfaces(RIS),and AI-powered communication services will burden network operators with rising infrastructure costs.Rece... The emergence of various technologies such as terahertz communications,Reconfigurable Intelligent Surfaces(RIS),and AI-powered communication services will burden network operators with rising infrastructure costs.Recently,the Open Radio Access Network(O-RAN)has been introduced as a solution for growing financial and operational burdens in Beyond 5G(B5G)and 6G networks.O-RAN promotes openness and intelligence to overcome the limitations of traditional RANs.By disaggregating conventional Base Band Units(BBUs)into O-RAN Distributed Units(O-DU)and O-RAN Centralized Units(O-CU),O-RAN offers greater flexibility for upgrades and network automation.However,this openness introduces new security challenges compared to traditional RANs.Many existing studies overlook these security requirements of the O-RAN networks.To gain deeper insights into the O-RAN system and security,this paper first provides an overview of the general O-RAN architecture and its diverse use cases relevant to B5G and 6G applications.We then delve into specifications of O-RAN security threats and requirements,aiming to mitigate security vulnerabilities effectively.By providing a comprehensive understanding of O-RAN architecture,use cases,and security considerations,thisworkserves as a valuable resource for future research in O-RAN and its security. 展开更多
关键词 O-RAN ARCHITECTURE use cases security issues security requirements security discussions
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Requirements ranking based on crowd-sourcing high-end product USs
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作者 MA Yufeng DOU Yajie +2 位作者 XU Xiangqian JIA Qingyang TAN Yuejin 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2024年第1期94-104,共11页
Based on the characteristics of high-end products,crowd-sourcing user stories can be seen as an effective means of gathering requirements,involving a large user base and generating a substantial amount of unstructured... Based on the characteristics of high-end products,crowd-sourcing user stories can be seen as an effective means of gathering requirements,involving a large user base and generating a substantial amount of unstructured feedback.The key challenge lies in transforming abstract user needs into specific ones,requiring integration and analysis.Therefore,we propose a topic mining-based approach to categorize,summarize,and rank product requirements from user stories.Specifically,after determining the number of story categories based on py LDAvis,we initially classify“I want to”phrases within user stories.Subsequently,classic topic models are applied to each category to generate their names,defining each post-classification user story category as a requirement.Furthermore,a weighted ranking function is devised to calculate the importance of each requirement.Finally,we validate the effectiveness and feasibility of the proposed method using 2966 crowd-sourced user stories related to smart home systems. 展开更多
关键词 high-end product complex system crowd-sourcing user stories topic mining requirements ranking
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Towards Improving the Quality of Requirement and Testing Process in Agile Software Development:An Empirical Study
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作者 Irum Ilays Yaser Hafeez +4 位作者 Nabil Almashfi Sadia Ali Mamoona Humayun Muhammad Aqib Ghadah Alwakid 《Computers, Materials & Continua》 SCIE EI 2024年第9期3761-3784,共24页
Software testing is a critical phase due to misconceptions about ambiguities in the requirements during specification,which affect the testing process.Therefore,it is difficult to identify all faults in software.As re... Software testing is a critical phase due to misconceptions about ambiguities in the requirements during specification,which affect the testing process.Therefore,it is difficult to identify all faults in software.As requirement changes continuously,it increases the irrelevancy and redundancy during testing.Due to these challenges;fault detection capability decreases and there arises a need to improve the testing process,which is based on changes in requirements specification.In this research,we have developed a model to resolve testing challenges through requirement prioritization and prediction in an agile-based environment.The research objective is to identify the most relevant and meaningful requirements through semantic analysis for correct change analysis.Then compute the similarity of requirements through case-based reasoning,which predicted the requirements for reuse and restricted to error-based requirements.Afterward,the apriori algorithm mapped out requirement frequency to select relevant test cases based on frequently reused or not reused test cases to increase the fault detection rate.Furthermore,the proposed model was evaluated by conducting experiments.The results showed that requirement redundancy and irrelevancy improved due to semantic analysis,which correctly predicted the requirements,increasing the fault detection rate and resulting in high user satisfaction.The predicted requirements are mapped into test cases,increasing the fault detection rate after changes to achieve higher user satisfaction.Therefore,the model improves the redundancy and irrelevancy of requirements by more than 90%compared to other clustering methods and the analytical hierarchical process,achieving an 80%fault detection rate at an earlier stage.Hence,it provides guidelines for practitioners and researchers in the modern era.In the future,we will provide the working prototype of this model for proof of concept. 展开更多
关键词 requirement prediction software testing agile software development semantic analysis case-based reasoning
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Autoantibodies against beta cells to predict early insulin requirements in pediatric patients with clinically diagnosed type 2 diabetes
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作者 Jorge M Molina Patricia G Medina +4 位作者 Rita A Gomez Julia R Herrera Nancy L Martínez Brenda Hernández Yesenia García 《World Journal of Diabetes》 SCIE 2024年第8期1717-1725,共9页
BACKGROUND Autoimmunity has emerged as a probable disease modifier in patients with clinically diagnosed type 2 diabetes mellitus(T2DM),that is,patients who have insulin resistance,obesity,and other cardiovascular ris... BACKGROUND Autoimmunity has emerged as a probable disease modifier in patients with clinically diagnosed type 2 diabetes mellitus(T2DM),that is,patients who have insulin resistance,obesity,and other cardiovascular risk factors,suggesting that the presence of glutamic acid decarboxylase(anti-GAD65),islet antigen 2(anti-IA2),and zinc transporter 8(anti-Zn8T)antibodies could have deleterious effects on beta cell function,causing failure and earlier requirement for insulin treatment.AIM To evaluate anti-GAD65,anti-IA2 and anti-Zn8T as predictors of early insulin requirement in adolescents with a clinical diagnosis of T2DM.METHODS This was a case–control study in patients with clinically diagnosed with T2DM(68 cases and 64 controls with and without early insulin dependence respectively),male and female,aged 12–18 years.Somatometry,blood pressure,glucose,insulin,C-peptide,glycated hemoglobin A1c,and lipid profiles were assessed.ELISA was used to measure anti-GAD65,anti-IA2,and anti-Zn8T antibodies.Descriptive statistics,Pearson'sχ2 test,Student's t test,and logistic regression was performed.P<0.05 was considered statistically significant.RESULTS There were 132 patients(53.8%female),with a mean age was 15.9±1.3 years,and there was a disease evolution time of 4.49±0.88 years.The presence of anti-GAD65,anti-IA2,and anti-Zn8T positivity was found in 29.5%,18.2%,and 15.9%,respectively.Dividing the groups by early or no insulin dependence showed that the group with insulin had a higher frequency of antibody positivity:anti-GAD65 odds ratio(OR):2.42(1.112–5.303,P=0.026);anti-IA2:OR:1.55(0.859–2.818,P=0.105);and anti-Zn8T:OR:7.32(2.039–26.279,P=0.002).CONCLUSION Anti-GAD65 positivity was high in our study.Anti-GAD65 and anti-Zn8T positivity showed a significantly depleted beta cell reserve phenotype,leading to an increased risk of early insulin dependence. 展开更多
关键词 DIABETES OBESITY Adolescents AUTOIMMUNITY Beta cell Insulin requirements
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How to implement a knowledge graph completeness assessment with the guidance of user requirements
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作者 ZHANG Ying XIAO Gang 《Journal of Systems Engineering and Electronics》 SCIE CSCD 2024年第3期679-688,共10页
In the context of big data, many large-scale knowledge graphs have emerged to effectively organize the explosive growth of web data on the Internet. To select suitable knowledge graphs for use from many knowledge grap... In the context of big data, many large-scale knowledge graphs have emerged to effectively organize the explosive growth of web data on the Internet. To select suitable knowledge graphs for use from many knowledge graphs, quality assessment is particularly important. As an important thing of quality assessment, completeness assessment generally refers to the ratio of the current data volume to the total data volume.When evaluating the completeness of a knowledge graph, it is often necessary to refine the completeness dimension by setting different completeness metrics to produce more complete and understandable evaluation results for the knowledge graph.However, lack of awareness of requirements is the most problematic quality issue. In the actual evaluation process, the existing completeness metrics need to consider the actual application. Therefore, to accurately recommend suitable knowledge graphs to many users, it is particularly important to develop relevant measurement metrics and formulate measurement schemes for completeness. In this paper, we will first clarify the concept of completeness, establish each metric of completeness, and finally design a measurement proposal for the completeness of knowledge graphs. 展开更多
关键词 knowledge graph completeness assessment relative completeness user requirement quality management
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Research Progress on Nutritional Requirements of Carp
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作者 Yina LU 《Asian Agricultural Research》 2024年第1期37-39,43,共4页
Carp is a temperate freshwater fish native to Asia,distributed in all regions of the world except Australia and South America.With the improvement of comprehensive and healthy breeding technology of carp,the unit yiel... Carp is a temperate freshwater fish native to Asia,distributed in all regions of the world except Australia and South America.With the improvement of comprehensive and healthy breeding technology of carp,the unit yield has been greatly increased mainly due to the exten-sive use of compound feed.In this study,the nutritional requirements of carp were summarized from the aspects of protein,amino acids,fat,carbohydrate,calcium and phosphorus,vitamins and taurine.This study provides a certain theoretical reference for scientific formula of carp feed. 展开更多
关键词 CARP Nutritional requirements Foreground
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Security and Privacy in Solar Insecticidal Lamps Internet of Things:Requirements and Challenges
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作者 Qingsong Zhao Lei Shu +3 位作者 Kailiang Li Mohamed Amine Ferrag Ximeng Liu Yanbin Li 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2024年第1期58-73,共16页
Solar insecticidal lamps(SIL) can effectively control pests and reduce the use of pesticides. Combining SIL and Internet of Things(IoT) has formed a new type of agricultural IoT,known as SIL-IoT, which can improve the... Solar insecticidal lamps(SIL) can effectively control pests and reduce the use of pesticides. Combining SIL and Internet of Things(IoT) has formed a new type of agricultural IoT,known as SIL-IoT, which can improve the effectiveness of migratory phototropic pest control. However, since the SIL is connected to the Internet, it is vulnerable to various security issues.These issues can lead to serious consequences, such as tampering with the parameters of SIL, illegally starting and stopping SIL,etc. In this paper, we describe the overall security requirements of SIL-IoT and present an extensive survey of security and privacy solutions for SIL-IoT. We investigate the background and logical architecture of SIL-IoT, discuss SIL-IoT security scenarios, and analyze potential attacks. Starting from the security requirements of SIL-IoT we divide them into six categories, namely privacy, authentication, confidentiality, access control, availability,and integrity. Next, we describe the SIL-IoT privacy and security solutions, as well as the blockchain-based solutions. Based on the current survey, we finally discuss the challenges and future research directions of SIL-IoT. 展开更多
关键词 CHALLENGES Internet of Things(IoT) privacy and security security requirements solar insecticidal lamps(SIL)
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Operational requirements analysis method based on question answering of WEKG
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作者 ZHANG Zhiwei DOU Yajie +3 位作者 XU Xiangqian MA Yufeng JIANG Jiang TAN Yuejin 《Journal of Systems Engineering and Electronics》 SCIE CSCD 2024年第2期386-395,共10页
The weapon and equipment operational requirement analysis(WEORA) is a necessary condition to win a future war,among which the acquisition of knowledge about weapons and equipment is a great challenge. The main challen... The weapon and equipment operational requirement analysis(WEORA) is a necessary condition to win a future war,among which the acquisition of knowledge about weapons and equipment is a great challenge. The main challenge is that the existing weapons and equipment data fails to carry out structured knowledge representation, and knowledge navigation based on natural language cannot efficiently support the WEORA. To solve above problem, this research proposes a method based on question answering(QA) of weapons and equipment knowledge graph(WEKG) to construct and navigate the knowledge related to weapons and equipment in the WEORA. This method firstly constructs the WEKG, and builds a neutral network-based QA system over the WEKG by means of semantic parsing for knowledge navigation. Finally, the method is evaluated and a chatbot on the QA system is developed for the WEORA. Our proposed method has good performance in the accuracy and efficiency of searching target knowledge, and can well assist the WEORA. 展开更多
关键词 operational requirement analysis weapons and equipment knowledge graph(WEKG) question answering(QA) neutral network
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Macroscopic Traversable Wormholes: Minimum Requirements
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作者 Peter K. F. Kuhfittig 《International Journal of Astronomy and Astrophysics》 2024年第3期230-243,共14页
While wormholes are just as good a prediction of Einstein’s theory as black holes, they are subject to severe restrictions from quantum field theory. To allow for the possibility of interstellar travel, a macroscopic... While wormholes are just as good a prediction of Einstein’s theory as black holes, they are subject to severe restrictions from quantum field theory. To allow for the possibility of interstellar travel, a macroscopic wormhole would need to maintain sufficiently low radial tidal forces. It is proposed in this paper that the assumption of zero tidal forces, i.e., the limiting case, is sufficient for overcoming the restrictions from quantum field theory. The feasibility of this approach is subsequently discussed by 1) introducing the additional conditions needed to ensure that the radial tidal forces can indeed be sufficiently low and 2) by viewing traversable wormholes as emergent phenomena, thereby increasing the likelihood of their existence. 展开更多
关键词 Morris-Thorne Wormholes Traversability Minimum requirements STABILITY Compatibility with Quantum Field Theory
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Optimization Techniques for GPU-Based Parallel Programming Models in High-Performance Computing
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作者 Shuntao Tang Wei Chen 《信息工程期刊(中英文版)》 2024年第1期7-11,共5页
This study embarks on a comprehensive examination of optimization techniques within GPU-based parallel programming models,pivotal for advancing high-performance computing(HPC).Emphasizing the transition of GPUs from g... This study embarks on a comprehensive examination of optimization techniques within GPU-based parallel programming models,pivotal for advancing high-performance computing(HPC).Emphasizing the transition of GPUs from graphic-centric processors to versatile computing units,it delves into the nuanced optimization of memory access,thread management,algorithmic design,and data structures.These optimizations are critical for exploiting the parallel processing capabilities of GPUs,addressingboth the theoretical frameworks and practical implementations.By integrating advanced strategies such as memory coalescing,dynamic scheduling,and parallel algorithmic transformations,this research aims to significantly elevate computational efficiency and throughput.The findings underscore the potential of optimized GPU programming to revolutionize computational tasks across various domains,highlighting a pathway towards achieving unparalleled processing power and efficiency in HPC environments.The paper not only contributes to the academic discourse on GPU optimization but also provides actionable insights for developers,fostering advancements in computational sciences and technology. 展开更多
关键词 Optimization Techniques GPU-Based Parallel Programming Models high-performance Computing
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The Customer Requirements Analysis Method of Engineering Products Based on Multiple Preference Information
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作者 Guo Mao 《Proceedings of Business and Economic Studies》 2024年第1期204-209,共6页
To effectively evaluate the fuzziness of the market environment in product planning,a customer requirements analysis method based on multiple preference information is proposed.Firstly,decision-makers use a preferred ... To effectively evaluate the fuzziness of the market environment in product planning,a customer requirements analysis method based on multiple preference information is proposed.Firstly,decision-makers use a preferred information form to evaluate the importance of each customer requirement.Secondly,a transfer function is employed to unify various forms of preference information into a fuzzy complementary judgment matrix.The ranking vector is then calculated using row and normalization methods,and the initial importance of customer requirements is obtained by aggregating the weights of decision members.Finally,the correction coefficients of initial importance and each demand are synthesized,and the importance of customer requirements is determined through normalization.The development example of the PE jaw crusher demonstrates the effectiveness and feasibility of the proposed method. 展开更多
关键词 Product planning Customer requirements Importance ratings Multi-format information
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A Study on Aligning Nursing Curriculum with Hospital Clinical Competency Requirements
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作者 Xuemei Li Jarrent Tayag 《Journal of Contemporary Educational Research》 2024年第9期283-289,共7页
The purpose of this study is to coordinate the alignment between the nursing curriculum and hospital clinical competencies,identify the reasons for the gaps,evaluate the impact of these gaps on the nursing profession,... The purpose of this study is to coordinate the alignment between the nursing curriculum and hospital clinical competencies,identify the reasons for the gaps,evaluate the impact of these gaps on the nursing profession,and propose strategies to bridge these gaps.This study will help strengthen nursing education,improve nursing students’skills,and help students adapt to complex clinical environments. 展开更多
关键词 Nursing education Clinical competency Hospital requirements Curriculum alignment Gap analysis
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Study of the Interior Design Based on Elderly People’s Psychological Behaviors and Requirements
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作者 Yu-xin Jiang Ai-li Wang 《Journal of Architectural Research and Development》 2024年第6期70-75,共6页
Nowadays,the elderly have become an increasingly large group of people in China,but still many problems exist in their living space.This paper explores the physiological and psychological behavioral changes of the eld... Nowadays,the elderly have become an increasingly large group of people in China,but still many problems exist in their living space.This paper explores the physiological and psychological behavioral changes of the elderly,studies their living space requirements,and tries to put forward targeted design strategies in response.Therefore,making a better and more reasonable living space for the elderly as well as improving their living quality,finally helping the development of elderly-friendly design in China. 展开更多
关键词 Interior design Elderly-friendly design Elderly’s requirement
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Measurement and analysis of defects in high-performance concrete with three-dimensional micro-computer tomography 被引量:8
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作者 郭丽萍 Andrea Carpinteri +1 位作者 孙伟 秦文超 《Journal of Southeast University(English Edition)》 EI CAS 2009年第1期83-88,共6页
In order to investigate the effects of two mineral admixtures (i. e., fly ash and ground slag)on initial defects existing in concrete microstructures, a high-resolution X-ray micro-CT( micro-focus computer tomogra... In order to investigate the effects of two mineral admixtures (i. e., fly ash and ground slag)on initial defects existing in concrete microstructures, a high-resolution X-ray micro-CT( micro-focus computer tomography)is employed to quantitatively analyze the initial defects in four series of highperformance concrete (HPC)specimens with additions of different mineral admixtures. The nigh-resolution 3D images of microstructures and filtered defects are reconstructed by micro- CT software. The size distribution and volume fractions of initial defects are analyzed based on 3D and 2D micro-CT images. The analysis results are verified by experimental results of watersuction tests. The results show that the additions of mineral admixtures in concrete as cementitious materials greatly change the geometrical properties of the microstructures and the spatial features of defects by physical-chemistry actions of these mineral admixtures. This is the major cause of the differences between the mechanical behaviors of HPC with and without mineral admixtures when the water-to-binder ratio and the size distribution of aggregates are constant. 展开更多
关键词 high-performance concrete DEFECT MICROSTRUCTURE X- ray micro-focus computer tomography mineral admixtures
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Sugarcane Requirement of Water and Effect of Fertigation on Sugarcane 被引量:1
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作者 谭宏伟 周柳强 +1 位作者 谢如林 黄美福 《Agricultural Science & Technology》 CAS 2009年第4期175-177,182,共4页
The sugarcane is a main sugar crop in China. The seasonal drying is one of the problems that influence the improvement of output and quality of sugarcane in China. The experimental results for the water requirement an... The sugarcane is a main sugar crop in China. The seasonal drying is one of the problems that influence the improvement of output and quality of sugarcane in China. The experimental results for the water requirement and fertigation of the sugarcane showed, that the distribution of the rainfall in spring, autumn and winter, all could not suit the requirements for sugarcane growth. Detailedly, it can suit that sugarcane requirement of 74.4%, 68.6% and 35.7% respectively at seedling emerging stage, tillering stage and mature stage according to sugarcane growth. The drought has already limited the yield of sugarcane. Application of fertigation can enhance the fertilizer use efficiency, and it is also a water saving technique in sugarcane production. 展开更多
关键词 Sugarcane planting area Distribution of rainfall Water requirement of sugarcane FERTIGATION
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Analysis of Test Methods for Parts to Follow Relative Requirements 被引量:2
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作者 潘淑清 《Journal of Beijing Institute of Technology》 EI CAS 2002年第1期71-74,共4页
Testing the parts of mechanical products and ensuring their accuracy to the design requirements are essential to products’ quality, market competitiveness and manufacturers’ maximum economical benefits from these pr... Testing the parts of mechanical products and ensuring their accuracy to the design requirements are essential to products’ quality, market competitiveness and manufacturers’ maximum economical benefits from these products. One of the latest subjects of study in the area of precision measurement is the testing of parts to follow the relative requirements, viz. design requirements for the size tolerance of size features and related geometrical tolerances of the central feature, including the envelope requirement, maximum material requirement and least material requirement. The article analyzes test methods for parts to follow the envelope requirement or maximum material requirement, as well as further requirements of geometrical tolerances for its central feature. The method is effective in improving product quality and rejecting unqualified parts. 展开更多
关键词 tolerancing principle envelope requirement maximum material requirement
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Preliminary Studies on High-performance Liquid Chro-matography Chemiluminescence Determination of theSaturated Fatty Acids(C_(16) C_(18))in Human Serum 被引量:1
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作者 段更利 中岛宪一郎 +1 位作者 黑田直敬 秋山修三 《Journal of Chinese Pharmaceutical Sciences》 CAS 1995年第1期22-29,共8页
The peroxyoxalate chemiluminescence(CL)detection of fatty acids in human se- rum combined with high-performance liquid chromatography (HPLC)is described.Some fatty acids in serum were extracted with a 1 :1(v/v)mixture... The peroxyoxalate chemiluminescence(CL)detection of fatty acids in human se- rum combined with high-performance liquid chromatography (HPLC)is described.Some fatty acids in serum were extracted with a 1 :1(v/v)mixture of chloroform-n-heptane.2-(4-Hydrazinocarbonyl- phenyl)-4,5-diphenylimidazole (HCPI) was used as a fluorescent labelling reagent of the fatty acids. The labelling reaction was carried out at 30℃ for 1 h at pH 6.5 and the resulting reaction mixture was sudjected to HPLC. The labelled fatty acid C_(17)(P-C_(17))was used as the internal standard. The la- belled fatty acids C_(16) and C_(18) were separated within 18 min on an ODS-8OTM column (150 mm× 6 mm ID,5μm,Tosoh Japan).The calibrlation curves of fatty acids from the spiked control serum were Y_1=-0.003 7 + 0.0028X_1,r=0.994 for FA C_( 16) and Y_2=0.00 1 2 + 0.00098X_2,r=0.999 for FA C_( 18),respectively.The average recoveries of facids from the spiked contrl serum were 107.2%(n=8,RSD=4.3%)for FA C_(16) and 97.35%(n=8, RSD=4.0%)for FA C_(18),respectively.The lower detection limits of fatty acids after reaction were 12μmol per 20μl injection for FA C_(16) and 18 μmol per 20μl injection for FA C_(18),respectively(signal to noise ratio, S/N=2).The HPLC/CL method was applied to the determination of FA C_(16) and FA C_(18) in normal human serum and the results showed that the concentrations of fatty acids in normal human serum were 0.134 ± 0.009 μ mol/ml serum(n=5) for FA C_(16) and 0.052±0.028 μmol/ml serum(n=5)for FA C_(18),respectively. 展开更多
关键词 Fatty acids high-performance Liquid Chromatography Peroxyoxalate chemi- luminescence detection Human serum
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