共查询到20条相似文献,搜索用时 78 毫秒
1.
地球属于你,也属于我 总被引:1,自引:0,他引:1
世纪之交 ,我们看到、听到最多的词汇非“信息时代”和“环境保护”莫属。在本世纪的最后 2 0年 ,新产业革命在全球迅速兴起。1982年 ,全球信息产业的销售额是 2 370亿美元 ,1985年为40 0 0亿美元 ,到 1995年达到 6 40 0亿美元 ,预计到 2 0 0 0年将超过 1万亿美元 ,成为全球第一大产业。中国经济经过建国以后几十年 ,尤其是改革开放 2 0多年以来全国人民的奋起直追 ,逐步与世界潮流靠拢 ,中国的信息产业也得到突飞猛进的发展。 1998年 ,我国网络市场容量达 10 0亿元 ,信息产品总产值达 480 0亿元 ,比 1997年增长 2 6 %。目前全国有上网人数 … 相似文献
2.
3.
伊斯曼·柯达公司宣布,随着本公司绝大多数产品销售额的两位数增长,87年第三季度纯收入增长51%,达到3。961亿美元;而86年同期的纯收入为2.63亿美元。销售额从34.8亿元增加到39.1亿美元,上升12%。 相似文献
4.
2002年是我国加入WTO第一年,我国电子信息企业加快了改革和发展的步伐,进一步“做大、做精、做强”。在世界IT产业依然不景气的环境下,我国电子信息产业保持良好的发展态势,2002年全行业销售收入达到14000亿元,比2001年增长了20%左右,电子信息产品出口额突破925亿美元,比2001 相似文献
5.
6.
7.
8.
近几年,我国电子信息产业综合实力明显增强,消费类电子产品中的计算机、手机、彩电、空调、冰箱、洗衣机,以及微波炉等小家电产品的产量居世界首位.电子信息产品出口额以年均30%左右的速度增长.2006年电子信息产品出口完成3420亿美元,增长30%,占全国外贸出口总额的36%,为世界电子信息产品贸易总额的20%左右.2007年宏观目标出口额3900亿美元,同比增长14%,成为世界电子信息产品制造和出口大国.在我国电子信息产业继续保持平稳较快发展的同时,也为我国包装行业赢来了新的发展良机. 相似文献
9.
纳米材料在石油化工中的应用进展 总被引:3,自引:0,他引:3
纳米技术与信息技术、生物技术一起被并列为当代三大技术。纳米材料自从2 0世纪80年代开发问世之后,引起世界各国极大关注。1 全球纳米技术投资和市场美国1 999年制订了“国家纳米技术发展计划”,2 0 0 3年投资7 1 0亿美元,全面发展纳米科技,并成立了以发展纳米技术实用化为宗旨的行业协会。据美国咨询公司Freedoniar近期的《纳米材料》研究报告,2 0 0 2年美国纳米材料市场价值2亿美元,预计到2 0 0 7年将超过1 0亿美元,其中,无机物占6 1 %、聚合物和化学品占1 6 %、金属占1 4 %、新材料占9% ,2 0 1 2年将达到4 5亿美元。另据咨询资源公司(… 相似文献
10.
近年来,我国水产业发展突飞猛进,众多水产品不仅满足了国内市场需求,而且很多水产品出口到了国际市场。然而,我国出口的水产品等商品中,每年因包装不合格而导致的损失高达近70亿美元,这一数字在我国加入世贸组织后继续呈上升趋势。发达国家已将水产品等出口商品包装的检验标准从原先的几项、十几项现增加到几十项,中国出口水产品等商品贸易正受到日趋严重的“包装壁垒”。 相似文献
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.
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
13.
14.
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
15.
由于空压机进气侧轴承箱蜗壳温度探头密封效果不好,使空压机及其后续管道受到油污染。后将温度探头的O形圈密封改为骨架油封,杜绝了轴承箱漏油问题。文章简介空压机的结构和技术参数,详细介绍了骨架油封的制作和优点。 相似文献
16.
M. M. Gadenin 《Inorganic Materials》2013,49(15):1352-1356
It is shown that conditions of attainment of marginal states in the material of structural components are formulated on the basis of analysis of force and deformation criteria of formation and development of destruction. The parameters of these criteria are data on types of structural materials, standard and special characteristics of their mechanical properties, structural forms of considered elements of the equipment, and their operating stress loading. In this case, the construction of a system of state equations for describing interrelation of current damage, external actions, and responses to them is based on the concept of calculating variations in properties of materials at all stages of the design life cycle. 相似文献
17.
V. T. Kornienko 《Strength of Materials》1991,23(7):760-765
The article suggests a method of evaluating the microstructural inhomogeneity of deformation of metals by modeling. The method includes the measurement of deformations of metal according to meshes of a dividing grid with small base and the calculation of the distribution parameters of microdeformations in model representation. It is shown that the modeling method makes it possible objectively to evaluate the microinhomogeneity of deformation of metals independently of the chosen mesh size of the dividing grid. New structural characteristics are introduced: the base and wave of variation expressing the degree of crumbling or amalgamation of metal grains by inhomogeneity of deformation.Translated from Problemy Prochnosti, No. 7, pp. 40–44, July, 1991. 相似文献
18.
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
19.
20.
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