共查询到20条相似文献,搜索用时 62 毫秒
1.
2.
3.
4.
5.
近年来,玩具的安全受到广泛的关注,欧美一些国家纷纷出台关于儿童玩具的法律法规,提高了儿童玩具的进入门槛。我国玩具出口以欧美地区为主,欧美的玩具政策和标准主导着世界各国政策的制定,通过研究欧美最近更新的法规,可以更好地掌握玩具标准法规的发展趋势。1.两个法规的相似点(1)两者都属于强制性法规。美国消费品安全改 相似文献
6.
7.
8.
四、发展同欧共体国家贸易的标准化对策 1.加强并保持与欧共体的密切联系,及时掌握欧共体的标准化政策、法规和标准等方面的信息 随着欧洲统一大市场的建立和欧洲一体化进程的加快,欧洲的标准化政策在调整,新出台的法规和指令也较多,欧洲标准的数量在迅速增加。我国政府有关部门应密切注视这些变化,及时收集和掌握这些信息,为我国制定对欧统一大市场的贸易政策和标准化政策,为我国企业生产出口欧共体国家的产品提供依据。 相似文献
9.
10.
11.
A method is proposed for estimating the parameters of a mixture of exponential and Weibull distributions for which the accuracy of preliminary estimates obtained by graphical analysis is refined in accordance with the criterion of maximum likelihood. The efficiency of the proposed method is supported by the results of statistical modeling. 相似文献
12.
An approximate analytical expression is derived for the velocity of the front of the wave of change of boiling modes on a
rod and on a plate. The impact of the Thomson effect and of the heater orientation in the gravity field is included. Adequate
agreement is demonstrated between the derived relations and experimental data. 相似文献
13.
Liebert A Wabnitz H Grosenick D Möller M Macdonald R Rinneberg H 《Applied optics》2003,42(28):5785-5792
A novel method for the determination of the optical properties of tissue from time-domain measurements is presented. The data analysis is based on the evaluation of the first moment and the second centralized moment, i.e., the mean time of flight and the variance of the measured distribution of times of flight (DTOF) of photons injected by short (picosecond) laser pulses. Analytical expressions are derived for calculation of absorption and of reduced scattering coefficients from these moments by application of diffusion theory for infinite and semi-infinite homogeneous media. The proposed method was tested on experimental data obtained with phantoms, and results for absorption and reduced scattering coefficients obtained by the proposed method are compared with those obtained by fitting of the same data with analytical solutions of the diffusion equation. Furthermore, the accuracy of the moment analysis was investigated for a range of integration limits of the DTOF. The moment analysis may serve as a comparatively fast method for evaluating optical properties with sufficient accuracy and can be used, e.g., for on-line monitoring of optical properties of biological tissue. 相似文献
14.
15.
16.
17.
水三相点是开尔文热力学温度的唯一基准点,也是ITS-90国际温标重要的定义固定点。因此,水三相点不确定度分析对整个温标的建立、温度量值传递起着至关重要的作用。近3年来,中国计量科学研究院研制出一系列高质量的水三相点容器,加强了水三相点的研究,为不确定度的分析提供了更为可靠的实验依据。同时,不确定度的分析也是客观评价新研制容器性能的一个重要指标。因此,根据实验结果对新研制容器所复现的水三相点进行了不确定度评定。评定结果表明,其扩展不确定度为0.16mK(k=2.69,P=0.99)。 相似文献
18.
19.
20.
Conventional methods for summation of direct measurement errors are considered. Conditions under which these methods provide consistent results are stated. It is proposed to utilize for characteristic of the total error, its interval estimator or the half-sum of the value obtained by adding up its arithmetic and geometric random errors.Translated from Izmeritel'naya Tekhnika, No. 4, pp. 10–12, April, 1995. 相似文献