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Effect of SACMA and QMW test methods on Compressive Properties of Composite Laminates after Low Velocity Impact

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Chinese Journal of Aeronautics 2002年第2期15卷 90-97页

作者：程小全张子龙益小苏吴学仁 Aircraft Design and Research Institute Beijing University of Aeronautics and Astronautics Beijing 100083 China Beijing Institute of Aeronautical Materials Beijing 100095 China

Experimental studies on the compressive behavior of composite laminates after low velocity impact was carried out with two test methods. One is SACMA Standard, and the other is a small dimensional specimen test method. Impact damage distributions, compressive failure process after impact, quasi static indentation and compression of laminates with a hole were brought into comparison between these two test methods. The results showed that there is a great difference between these two test methods. Compressive behavior of laminates after impact varies with different test methods. Residual compressive strength of laminates after low velocity impact measured with SACMA Standard can reflect stiffness properties of composite resins more wholely than that measured with the other method can do. Small dimensional specimen test method should be improved on as an experimental standard of compressive strength after impact. \{

关键词： composite\} laminates test methods low velocity impact damage residual compressive strength

A REVISIT TO THE FEATURES OF BEC AS REFLECTED IN THE LISTENING SECTION — FROM THE PERSPECTIVE OF test methods

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Chinese Journal of Applied Linguistics 2006年第5期29卷 75-80,128页

作者：张艳陶伟中国科学技术大学

From the perspective of test methods, this paper revisits the communicative testing features reflected in the Revised Syllabus of the BEC Handbook (2002) by carrying out detailed analyses of the Sample Listening of BEC Vantage. A table of the Sample Listening is then constructed by using Bachman's framework of test methods (1999). From the table and a layout of its components, this paper explicates the five communicative testing features embodied in the Revised BEC: authenticity, contextualization, communicativeness, overall ability and holistic, qualitative scoring method.

关键词： BEC communicative testing features test methods

Comparative study of flexural strength test methods on CAD/CAM Y-TZP dental ceramics

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Regenerative Biomaterials 2015年第4期2卷 239-244页

作者： Yongxiang Xu Jianmin Han Hong Lin Linan An Department of Dental Materials Peking University School and Hospital of StomatologyBeijing 100081China National Engineering Laboratory for Digital and Material Technology of Stomatology Peking University School and Hospital of StomatologyBeijing 100081China Department of Materials Science and Engineering Advanced Materials Processing and Analysis CenterUniversity of Central FloridaOrlandoFL 32816USA

Clinically,fractures are the main cause of computer-aided design and computer-aided manufacturing(CAD/CAM)3 mol%-yttria-stabilized tetragonal zirconia polycrystal(Y-TZP)all-ceramic dental restorations failure because of repetitive occlusal *** goal of this work is to study the effect of test methods and specimen’s size on the flexural strength of five ceramic *** biaxial flexure test(BI)and uni-axial flexure tests(UNI),including three-point flexure test(3PF)and four-point flexure test(4PF),are used in this *** all five products,the flexural strength is as follows:BI>3PF>***,specimens with smaller size(3PF-s)have higher values than the bigger ones(3PF).The difference between BI and UNI resulted from the edge flaws in ceramic *** relationship between different UNI(including 3PF-s,3PF and 4PF)can be explained according to Weibull statistical fracture *** is recommended to evaluate the flexural strength of CAD/CAM Y-TZP dental ceramics.

关键词： CAD/CAM Y-TZP dental ceramics flexural strength test methods

A review of the development of asphalt foaming technology

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Journal of Road Engineering 2024年第3期4卷 334-347页

作者： Qiang Li Shijie Song Jiaqing Wang Ning Wang Shuai Zhang College of Civil Engineering Nanjing Forestry UniversityNanjing 210037China Jiangsu Zhongxing Maintainance Co. Ltd.Nantong 226015China

To comprehensively assess the current state-of-art in asphalt foaming technology, the following four key aspectshave been reviewed systematically: foaming principles, test methods, evaluation indicators, and influencing *** findings reveal that asphalt foaming was primarily driven by the vaporization of water, with deteriorationprocesses including bubble collapse and liquid film drainage. However, the current understanding of asphaltfoaming principles remains limited, primarily due to difficulties in capturing and precisely measuring its microscopic behaviors during asphalt foaming process. Volume changes provided an intuitive means to evaluate theexpansion capacity of asphalt and its foaming stability. Bubble evolution characteristics of foamed asphalt offeredpromising insights into its foaming performance. Traditional ruler and stopwatch-based assessments were beingsuperseded by automated techniques like laser and ultrasonic ranging. Nevertheless, the current measuringequipment still lacks the capability to comprehensively evaluate the foaming effect of asphalt across various dimensions. Asphalt temperature and foaming water consumption significantly affected asphalt foaming performance, and the inclusion of foaming agents typically led to a notable increase in the half life of foamed ***, the interaction between foaming agents and asphalt, as well as the underlying mechanisms affecting thefoaming effect, are still unclear and require further exploration. Future research should primarily focus on thecorrelation between asphalt foaming effect and mixture performance, aiming to guide the practical engineeringapplication of foamed asphalt mixtures and enlarge the advantages of such low-emission and sustainable mixtures.

关键词： Foamed asphalt Foaming mechanism test methods Evaluation indicators Influencing factors

tests to evaluate the ecological impact of treated ballast water on three Chinese marine species

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Chinese Journal of Oceanology and Limnology 2014年第5期32卷 1105-1117页

作者：张亚楠王子羲蔡磊明蔡翔孙文俊马立青 Environmental Engineering Institute Dalian Maritime University Department of Mechanical Engineering Tsinghua University Ecological Monitoring Training and Research Center Zhejiang Academy of Agricultural Sciences (ZAAS) Shanghai Academy of Environmental Sciences Department of Chemical and Biochemical Engineering Western University

Ballast water has been a topic of concern for some time because of its potential to introduce invasive species to new habitats. To comply with the International Convention for the Control and Management of Ships' Ballast Water and Sediments, members of the International Maritime Organization(IMO) must equip their ships with on-board treatment systems to eliminate organism release with ballast water. There are many challenges associated with the implementation of this IMO guideline, one of which is the selection of species for testing the ecological impacts of the treated ballast water. In the United States, ballast water toxicity test methods have been defined by the United States Environmental Protection Agency. However, the test methods had not been finalized in China until the toxicity test methods for ballast water were established in 2008. The Chinese methods have been based on species from three trophic levels: Skeletonema costatum, Neomysis awatschensis, and Ctenogobius gymnauchen. All three species live in broad estuarine and open sea areas of China; they are sensitive to reference toxicants and acclimatize easily to different conditions. In this paper, the biological characteristics, test processes and statistical analysis methods are presented for the three species. Results indicate that the methods for evaluating these three organisms can be included in the ecological toxicity tests for treated ballast water in China.

关键词： treated ballast water ecological impact marine species toxicity test methods

Variation-aware fault modeling

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Science China(Information Sciences) 2011年第9期54卷 1813-1826页

作者： HOPSCH Fabian BECKER Bernd HELLEBRAND Sybille POLIAN Ilia STRAUBE Bernd VERMEIREN Wolfgang WUNDERLICH Hans-Joachim Fraunhofer IIS/EAS University of Freiburg University of Paderborn University of Passau University of Stuttgart

To achieve a high product quality for nano-scale systems,both realistic defect mechanisms and process variations must be taken into *** existing approaches for variation-aware digital testing either restrict themselves to special classes of defects or assume given probability distributions to model variabilities,the proposed approach combines defect-oriented testing with statistical library *** uses Monte Carlo simulations at electrical level to extract delay distributions of cells in the presence of defects and for the defect-free *** allows distinguishing the effects of process variations on the cell delay from defect-induced cell delays under process *** provide a suitable interface for test algorithms at higher levels of abstraction,the distributions are represented as histograms and stored in a histogram data base (HDB).Thus,the computationally expensive defect analysis needs to be performed only once as a preprocessing step for library characterization,and statistical test algorithms do not require any low level information beyond the *** generation of the HDB is demonstrated for primitive cells in 45 nm technology.

关键词： process variations test methods statistical test histogram data base

Study on Reliability for Automatic Transfer Switching Equipment

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Study on Reliability for Automatic Transfer Switching Equipm...

挤包高压直流电缆的质量控制:采用低频耐压试验检测电缆的关键缺陷(英文)

The 26th International Conference on Electrical contacts and the 4th International Conference on Reliability of Electrical Products & Electrical Contacts

作者： Lu Jianguo Luo Yanyan li Wenhua Zhao Sheng Province-Ministry Joint Key Laboratory of Electromagnetic Field and Electrical Apparatus Reliability Hebei University of Technology The key Laboratory of Low-Voltage Apparatus Intellectual Technology of Zhejiang Wenzhou University

ISBN: (纸本)9781622763139;1622763130

As the automatic transfer switching equipments (ATSE) are widely used on distribution *** are mainly used to switch the load automatically and ensure the security and reliability of power ***,the reliability of ATSE is extremely *** paper mainly includes:1) to analyze the failure modes of ATSE;2)to establish the reliability characteristic parameters of ATSE;3) to discuss the test methods of reliability demonstration test in details.

关键词： reliability test methods ATSE

来源： cnki会议评论

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高电压技术 2011年第11期37卷 2664-2671页

作者： Erling Ildstad Frank Mauseth Mildrid Selsjord Rolf Hegerberg Department of Electric Power Engineering NTNUTrondheimNorway SINTEF Energy Research.Trondheim Norway

The main purpose of the work presented here is to evaluate different methods for quality control of polymeric insulated HVDC *** insight gained can be used to evaluate proposed test methods for quality assurance of long lengths of polymer insulated power *** experiments were performed using both Rogowski shaped test objects and model cables,insulated with XLPE containing imbedded spherically shaped *** were performed by stressing the test object with AC(50 Hz),VLF(0.1 Hz) and DC voltages and measuring time to breakdown at the different *** slope of the voltage-time curve for 0.1 and 50 Hz were found to be parallel showing higher breakdown strength for 0.1 Hz than 50 *** number of periods to breakdown is somewhat higher for 0.1 Hz than for 50 *** breakdown strength for DC was much higher than for both AC 50 Hz and 0.1 *** results indicate that the VLF test voltage needs to be 2 to 3 times higher than at 50 Hz power frequency in order to eliminate the same defects within a comparable time.

关键词： HVDC VLF power cables quality control test methods extruded insulation

Importance,Organization and Evaluation of Interlaboratory tests

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China's Refractories 2018年第2期27卷 1-6页

作者： Gerhard URBANEK Steffen UHLIG RHI AG Leoben A-8700Austria QuoData GmbH Freising D-85356Germany

The importance of ＂precise＂ test values and their verification is growing in every industry throughout the world, lnterlaboratory studies constitute a basis for this. The high expenses and mathematical work required to carry out proper interlaboratory studies are frequently considered reasons not to conduct such studies. This makes it all the more important to emphasize the various advantages of an accurate interlaboratory study. In addition to providing precision data for the test method, it is also possible to carry out laboratory evaluations, which is important for accredited test laboratories. Furthermore, existing test methods can be optimized, refer- ence material can be obtained, and test methods can be compared. Optimized test instructions can also be generated using the findings and precision data. These advantages will be described in detail by means of examples below.

关键词： interlaboratory study round Robin tests test methods precision of test methods ISO 5725 standards