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排序方式: 共有8128条查询结果,搜索用时 15 毫秒
1.
绿色再生混凝土利用途径与评定思路 总被引:3,自引:0,他引:3
就再生混凝土骨料进行深入系统的研究 ,建立了一套与现行评价天然骨料标准相一致的评定方法 ,具有工程实际意义 ,为将来实际应用作好了基础理论研究 相似文献
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José M.V Gómez-Soberón 《Cement and Concrete Research》2002,32(8):1301-1311
In this paper, we present the experimental analysis of samples of recycled concrete (RC) with replacement of natural aggregate (NA) by recycled aggregate originating from concrete (RCA). The results of the tests of mechanical properties of RC were used for comparison with tests of mercury intrusion porosimetry (MIP), in which the distribution of the theoretical pore radius, critical pore ratio, the surface area of the concrete, threshold ratio and average pore radius were studied at ages of 7, 28 and 90 days. The results showed some variation in the properties of the RC with respect to ordinary concrete. Porosity increases considerably when NA is replaced by RCA. Additionally, a reduction in the mechanical properties of the RC is seen compared with ordinary concrete when porosity increases. 相似文献
5.
一个安全有效的身份鉴别协议与对应的数字签名方案 总被引:3,自引:0,他引:3
本文利用二元一次不定方程和Schnorr身份鉴别协议,构造出一个新的身份鉴别协议,该协议在RSA问题和离散对数问题是难解的假设下是安全的,同时给出了所对应的数字签名方案。 相似文献
6.
In this article we propose efficient scan path and BIST schemes for RAMs. Tools for automatic generation of these schemes have been implemented. They reduce the design effort and thus allow the designer to select the more appropriate scheme with respect to various constraints. 相似文献
7.
Signature analyzers are very efficient output response compactors for BIST design. The only limitation of signature analysis is the fault coverage reduction (aliasing) due to the information loss inherent to any data compaction. In this article, in order to increase the effectiveness of ROM BIST, we take advantage from the simplicity of the error patterns generated by ROMs and we show that aliasing free signature analysis can be achieved in ROM BIST.This work was performed when the author was on leave from Minsk Radio Engineering Institute, Computer Department, Belorus. 相似文献
8.
Pseudo-random testing techniques for mixed-signal circuits offer several advantages compared to explicit time-domain and frequency-domain test methods, especially in a BIST structure. To fully exploit these advantages a suitable choice of the pseudo-random input parameters should be done and an investigation on the accuracy of the circuit response samples needed to reduce the risk of misclassification should be carried out. Here these issues have been addressed for a testing scheme based on the estimation of the impulse response of the device under test (DUT) by means of input-output cross-correlation. Moreover, new acceptance criteria for the DUT are suggested which solve some ambiguity problems arising if the classification of the DUT as good or bad is based on a few samples of the cross-correlation function. Examples of application of the proposed techniques to real cases are also shown in order to assess the impact of the measurement system inaccuracies on the reliability of the test. 相似文献
9.
砖烟囱集团装药定向爆破拆除 总被引:1,自引:1,他引:0
对一座 40 m 高的砖烟囱,采用TNT集团装药实施定向倒塌拆除爆破.介绍了该烟囱拆除爆破工艺技术,爆破参数和施工方法. 相似文献
10.
H. S. Tripathi B. Mukherjee S. K. Das A. Ghosh G. Banerjee 《Bulletin of Materials Science》2003,26(2):217-220
Mullite was developed by reaction sintering of sillimanite beach sand and calcined alumina. Two varieties of sillimanite beach
sand viz. S and Z having different compositions were selected. Synthesis and properties of mullite were very much dependent
on the sillimanite beach sand composition. Presence of higher amount of impurities in the Z-variety of sillimanite sand favours
the densification by liquid phase formation. Presence of zircon in Z-variety increases the hardness and fracture toughness.
Alumina addition improves the mechanical/thermomechanical properties of the samples. Mullite retains the usual orthorhombic
habit of sillimanite. Rounded to sub rounded zirconia dispersed within the mullite matrix of the sample ZA is noticed. 相似文献