共查询到20条相似文献,搜索用时 146 毫秒
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本文就中国和巴基斯坦现行LED灯具性能标准中LED灯具分类、试验条件、性能要求、输入功率、光通量、色坐标和显色性、LED灯具寿命试验要求、型式试验试样量等差异性条款进行比对分析,以期为中巴标准互认及中国产品“走出去”提供参考。 相似文献
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公路整体施工质量的基础和保障,对于提高道路的使用性能、增加路面使用寿命是至关重要的。公路路基填筑工作量大、压实标准高,用重型压实机械容易达到要求的压实度,而用小型压实机械就比较困难了。采用重型击实试验标准,以土最大密实度作为标准密实度,使路基强度与稳定性大幅度提高,具有十分重要的意义。 相似文献
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参照国内外对夜视(NIVS)兼容机外照明灯具的辐射强度设计要求标准,比较了有关夜视(NIVS)兼容机外照明灯具辐射强度的测量原理及方法.提出了使用带余弦修正器快速光谱辐射计测试系统,基于标准灯方法对快速光谱辐射计进行NVIS A类和B类的辐射强度定标校准,从而实现夜视(NIVS)兼容机外照明灯具辐射强度的准确测试.结果表明:带余弦修正器快速光谱辐射计测试系统在机外照明灯具的辐射强度测试方面具有较为广阔的应用前景. 相似文献
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《中国新技术新产品》2021,(3)
目前,对土方机械产品照明灯的评价方法还不够规范,往往在生产出样机后才能对产品照明灯的质量进行试验。而样机的灯光试验又受天气和环境等因素的影响;一旦在样机试验阶段发现问题,如果需要对该设计进行更改,就需要投入很高的成本。该文结合实际应用案例,阐述了应用3DMax软件对土方机械照明灯的灯光照度、灯光照射范围等进行虚拟仿真的方法。实践表明,该方法能够直观地展示出照明灯设计的好坏,为灯具的选型、位置的摆放、灯罩的设计以及设计方案的更改提供了可靠的依据。 相似文献
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本文针对现代化家庭中灯具开关位置较为固定的问题,设计了一套能够自由控制室内灯具亮灭的无线遥控开关。它是以电力电子技术、电源电路为基础,利用PT2262/PT2272无线发收模块和MOC3021光可控硅隔离器设计的一种照明开关,代替了传统的机械开关,解决了开关损耗和开关噪声问题。 相似文献
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白洪金 《中国新技术新产品》2009,(24):129-129
传统机械机械零部件设计的特点是以长期经验积累为基础,通过力学、数学建模及试验等所形成的经验公式、图表、标准及规范作为依据,运用条件性计算或类比等方法进行设计。文章针对传统机械零部件的设计局限性,提出了现代产设计思想。 相似文献
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照明灯具产品强制性认证所适用的标准GB7000.1-2007<灯具第1部分:一般要求与试验> (以下简称新版标准)于2009年1月1日起实施,新版标准代替GB7000.1-2002(以下简称原版标准). 相似文献
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Abstract: The purpose of this paper is to provide a comparison between embedding tests covered by the EN383 and ASTM D5764 standards, highlighting some difficulties regarding the application of the referred standards. These embedding tests are essential to evaluate the embedding strength of wood, which is required for the assessment of joints strength. The proposed comparison is based either on experimental data and numerical simulations through the finite element (FE) method. Tests were performed on maritime pine wood (Pinus pinaster Ait. species) according to the longitudinal and radial directions, allowing the comparison of the embedding strength and elastic foundation modulus. Three dimensional FE models of the tests were built using contact elements technology and assuming the steel dowel and wood as linear elastic isotropic and orthotropic materials, respectively. The contact modelling is a challenging topic for which this paper also proposes some guidance. The test configuration proposed in the EN383 standard for assessment of the embedment strength in compression is more susceptible to the dowel bending than the half‐hole test configuration proposed in the ASTM D5764 standard. The numerical simulation of the EN383 embedding test raises some additional difficulties regarding the dowel boundary conditions. 相似文献
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Takizawa K Fujii T Fujikake H Hirabayashi T Tanaka Y Hara K Takano S Asakawa H Kita H 《Applied optics》1999,38(12):2570-2578
We made a liquid-crystal (LC) luminaire for the first time to our knowledge by combining a metal halide lamp and an optical shutter composed of a compound of a very high nematic-isotropic point (172 degrees C) LC and a polymer (CLCP). The shutter can modulate high-power light independently of the state of polarization because the CLCP film becomes transparent or opalescent when either sufficiently high or no voltage is applied to it. To solve the problem, which is peculiar to CLCP films, that the color temperature of light modulated by the film changes with the film's transmittance, a pulse-width modulation method that varies the time ratio of the on and off states of the shutter was developed. The performance characteristics of the luminaire were as follows: illuminance range, 192 to 10,400 lx at a distance of 5 m from the luminaire; rise and decay times, 1.4 and 1.5 ms; color temperature, 4060-5600 K; operation room temperature, ~150 degrees C; stable operation time, more than 2000 h. Experimental results show the feasibility of applications of this luminaire in various fields, including television, movie, and stage lighting. 相似文献
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A study has been carried out on the effect of strength mismatch in weld metal and penetration ratio on the ultimate strength capacity of fillet welds and their failure modes. The ultimate strength capacity evaluated with nonlinear Finite Element Analysis (FEA) and testing is compared with the ultimate strength capacity predicted by standards: Eurocode3, BSK 07 (Boverkets handbok om StålKonstruktioner) and AWS (American Welding Society) D1.1 Structural welding code-Steel. Test results are used to establish correct material properties, to be input into the finite element model. A criterion for selection of consumables has been developed, when two different grades of high strength steels are to be joined. The results show that fully penetrated joint with under-matched filler material is more ductile and the ultimate strength capacity of base plate can be achieved. It is observed that joints with under-matched filler material are more sensitive to penetration ratio. The test data correlates reasonably well to the results predicted by FEA software and design codes. It is also concluded that joint preparation has an effect on the ultimate strength capacity of the joint. 相似文献
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分析了输送管管体横向拉伸试样弯曲度对屈服强度测试值的影响,从理论上初步阐明了管体横向拉伸试样的弯曲会引起屈服强度测试值的降低,并提出在相关的标准中应对管体横向试样的展平程度作出规定. 相似文献
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知识产权成为了全球关注的热点,标准也成为了各国争夺国际市场的主要手段之一。标准与知识产权的结合已经带来了全球竞争模式的重大改变。面对激烈的国际竞争,2008年我国发布了《国家知识产权战略纲要》,其中对标准与知识产权结合的问题做出了战略指导,文章从技术创新和标准战略实施的角度,就纲要中知识产权和技术标准结合的战略重点做了分析和解读,并提出了具体的实施建议。 相似文献
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Wang Yiyi 《中国标准化(英文版)》2009,(3):19-23
Inclusion of intellectual property in standards brings important changes to the global competition model.Based on the furious international circumstances, Outline of the National Intellectual Property Strategy was published in 2008,indicating the strategic direction of intellectual property involved in standards. This article analyzes relative items from innovation and standard strategy implemen- tation aspects,and makes some suggestions. 相似文献
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Evaluation of the quality of historic brickwork / Die Ermittlung der Mauerwerksgüte von Bestandsmauerwerk aus kleinformatigen Ziegeln
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Dipl.‐Ing. Jonny Henkel 《Mauerwerk》2016,20(5):391-406
The quality of historic brickwork is a significant matter for structural engineers for modernisation, also due to its concentration in public areas. One substantial issue for structural inspection is the characteristic masonry strength or allowable masonry stress, which are defined by the compressive strength. There are several ways of assessing the compressive strength of brickwork or its components, but most of these test methods are not described in engineering standards or are only based on standards for new buildings. This article provides information about the various testing methods and gives recommendations for the selection of applicable test procedures and the experimental scope. 相似文献