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1.
对称配筋小偏心受压构件的截面设计   总被引:4,自引:1,他引:3  
对小偏心受压构件在对称配筋情况下的截面配筋计算,提出用最佳一次逼近多项式简化基本公式,直接按二次方程求解ξ的近似方法,具有精度高,相对误差小,计算方便等优点,可供工程设计人员参考。  相似文献   
2.
3.
Constraints on small graphitic helices   总被引:1,自引:0,他引:1  
  相似文献   
4.
窄带中频数字接收机高速信号处理技术   总被引:1,自引:0,他引:1  
窄带中频数字接收机在雷达对抗侦察中得到了广泛应用,其高速信号处理技术是目前研究的重点。本文详细介绍了数字雷达告警接收机高速信号处理技术的发展现状和关键技术,最后通过对该技术的全面分析指出了值得深入研究的领域。  相似文献   
5.
简单回顾了国内外在火电机组运行优化领域的研究历程,列举了目前国内外市场上针对火电机组的各种主流运行优化产品的功能特点和应用情况,分析了国外引进产品和国内自主研发产品在中国当前市场环境下各自的优势和劣势。介绍了当前运行优化系统在国内电站机组的应用现状,阐述了国内外运行优化系统在实际应用中存在的问题,并提出了相应的改进意见。对机组运行优化系统的未来发展进行了展望,指出机组运行优化系统将利用先进技术设备和信息平台,与电站管理紧密结合,在日益规范的市场中不断发展完善,为提高电站经济性发挥更大的作用。  相似文献   
6.
Way Kuo 《IIE Transactions》1985,17(2):132-140
Classical statistical estimation techniques have limited usage in predicting system availability when a system, e.g., a computer or telecommunications system, is highly reliable. A Bayesian solution is suggested in this paper. Gamma priors, which are rich in shapes, are assigned to the scale parameters of a gamma distributed component on-time and off-time. Estimation of the gamma priors follows engineer's past experiences for reliability modeling. Both steady-state and instantaneous availabilities are derived using Bayes Theorem. An illustration highlights the assessment and evaluation of the proposed availability measure.  相似文献   
7.
Solid solutions of the GdFeO3–GdInO3 system were prepared at 1550 °C by ceramic powder processing. The formulated composition was Gd(Fe1−xInx)O3 (GFI) with the indium contents at x = 0, 0.25, 0.5, 0.75, and 1.0. A stable phase of Gd(Fe1/3In2/3)O3 in our system was identified by X-ray diffraction and phase composition analysis. Multi-phase morphologies were observed for GFI bulks with x = 0.5 and 0.75. Dielectric and electrical properties of the GFI bulks were investigated. The addition of 25% In3+ in GdFeO3 had an obvious enhancement in polarization and led to an elevated resonance frequency. Dielectric properties of GFI bulks except GdInO3 were strongly dependent upon the test frequency, which corresponded to the response of polarization mechanism. GdInO3 displayed as a stable dielectric, which was frequency- and temperature-insensitive. GdInO3 was thermally activated and became leaky until above 600 °C.  相似文献   
8.
The water bamboo husk is one of major agricultural wastes in Taiwan. In this study, the powder obtained from the water bamboo husk was added to poly(lactic acid) (PLA) to form novel reinforced biodegradable composites. Morphologies, mechanical properties, and heat resistance of these water bamboo powder reinforced composites were investigated. The results indicate that the char yields were increased as plant powder was incorporated to PLA. In addition, the mechanical properties were also enhanced due to the addition of powders. The increments of storage moduli of PLA were about 50–200%. Moreover, the increments of loss moduli of PLA were about 70–200%. On the other hand, the Tg of PLA was slightly decreased by the addition of powder, and this may improve the brittle characteristics of PLA. Furthermore, this type of reinforced PLA would be more environmental friendly than the artificial additive‐reinforced one. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers  相似文献   
9.
The purpose of the study was to describe how three generations of mothers have reacted to their pregnancies and deliveries and also how they feel about their maternity. Furthermore, the purpose was to illustrate the transfer of knowledge from one generation to another. Interviews have been made with three triads of generations, in all nine mothers. A phenomenological-hermeneutic onset has been chosen in order to analyse the narratives of the mothers. In the structural analyses the following themes came to hand: positive experiences/feelings, negative experiences/feelings, internal and external network and knowledge. The life-experiences of the maternity of the mothers were chiefly positive while experiences from pregnancy and childbirth were positive as well as negative. The knowledge of the mothers regarding childbirth and the bringing up of children were mostly conveyed in the everyday-contact during their early years, amongst mother-daughter-granddaughter. For the feeling of a successful experience during pregnancy, delivery and maternity, the internal network as well as the external turned out to be of great importance. In order to even better be able to provide for the needs of the expectant mothers or of those who have recently become mothers, an individual planning of care of both in- and out-patients within maternity- and childwelfare can be valuable.  相似文献   
10.
This review reports the different genetic factors that have been identified either as risk factor for Alzheimer's disease (AD) or directly causing the disease. First are reviewed epidemiological data and biological mechanisms about the apoplipoprotein E gene allele epsilon 4 that is a major risk factor for Alzheimer's disease. The second part describes the mutations responsible for early-onset autosomal dominant AD found in three different genes. The gene located on chromosome 21 encodes the amyloid precusor protein (APP). The presenilin 1 and presenilin 2 genes, located on chromosome 14 and 1 respectively, encode not yet known membrane proteins.  相似文献   
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