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991.
根据锻锤基础及其地基土所承受的重复冲击载荷的特性,将连续损伤力学理论应用于锻锤基础系统的疲劳损伤问题,分析了地基土在重复冲击荷载作用下的疲劳损伤特性。通过研究发现,振幅随离基础中心距离增大而衰减,随离基础中心垂直深度的增大而衰减。同时,锻锤锻打引起的损伤增长对地基土表面或地基土深度上各点的最大振幅比都有极大影响。文中得出的结论具有一定的理论价值和工程实用意义。 相似文献
992.
洗衣机内桶专用料HHP1的生产 总被引:1,自引:0,他引:1
分析了聚丙烯洗衣机内桶专用料HHP1的性能及其与通用料的区别;介绍了HHP1生产工艺,从化验分析数据找出了影响性能的因素加以优化控制,生产合格的洗衣机内桶专用料。 相似文献
993.
Maldngdiamondfilmbydirectcurrentplasmajetisoneofhightechnologies.DevelopmenttrendofthetechnologyistOgetaIdleareafilmwithgoodqualitybyanequipmentwithhighpowerdirectcurrentplasmajetatPresent[l].However,duringthefilmgrowing,itsbasebodyhasvariabletempera... 相似文献
994.
水利工程与生态环境 总被引:1,自引:0,他引:1
李正霞 《电网与水力发电进展》2000,16(3):31-32
本文简述了水利工程对生态环境的影响 ,提出了加强水利工程环境影响评价的 4点建议 :1加强对工程价值的评价 ;2加强环境影响的经济评价 ;3进行风险分析评价 ;4长期跟踪评价。 相似文献
995.
Smith Dylan; Loewenstein George; Jepson Christopher; Jankovich Aleksandra; Feldman Harold; Ubel Peter 《Canadian Metallurgical Quarterly》2008,27(5):653
Objective: People tend to overestimate the impact that future events will have on their quality of life. In the case of a medical treatment like kidney transplant, this should result in biased predictions--overestimates of how much the transplant will benefit quality of life. The authors surveyed kidney transplant patients, both before and after transplant, to test whether they would overestimate the benefits of a successful transplant for their quality of life. Design: The authors interviewed 307 patients on a waiting list for cadaveric renal or renal-pancreatic transplant, and 195 patients one year after a successful transplant. A sub sample of patients were interviewed both before and after transplant. Main Outcome Measures: The survey included measures of quality of life, both in terms of an overall estimate (0-100), and across sub domains, including health, employment, and travel. Results: Cross-sectional results suggested that overall quality of life improved after transplant, but the predictions of pretransplant patients overestimated the magnitude of the improvement (p 相似文献
996.
É. A. Golubev 《Measurement Techniques》2008,51(2):130-135
Arguments are presented that show that it is ineffective to replace distribution propagation by uncertainty propagation in
estimating the uncertainty of measurements, which has a bearing on the accuracy and difficulty of estimating indirect-measurement
uncertainties with nonlinear transformations from input data.
__________
Translated from Izmeritel’naya Tekhnika, No. 2, pp. 15–18, February, 2008. 相似文献
997.
In the past decade, a major transition evolved in the Dutch fresh meat industry with ramifications for the entire meat business. In 1995, more than 95% of all fresh meat products for consumers were either sold loose or packed in the traditional way, i.e. on a white styrofoam tray with stretch wrap. Almost a decade later, about half of the meat industry has adapted the modified atmosphere packaging (MAP) technology. Strikingly, the first trials with this technology had already been conducted in The Netherlands in 1964, but it took four decades for the technology to conquer the Dutch meat industry. This paper argued that the partial adaptation of MAP diminished the product losses in fresh meat sales and hence the environmental impact of meat production and consumption. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
998.
R. P. Bernhard E. L. Christiansen J. H. Kerr 《International Journal of Impact Engineering》2001,26(1-10):33-38
Post-flight surveys of meteoroid and orbital debris (M&OD) impacts on the Space Shuttle Orbiter are conducted to identify damage caused by hypervelocity impacts from M&OD and to identify the source (i.e., whether meteoroid or orbital debris) of the projectiles responsible [1,2] This report provides data on Orbiter M&OD impacts for a five-year period and describes in detail the 39 most significant impacts. For the period 6/92 through 12/99 there were 49 Shuttle Transportation System (STS) missions (STS-50 through STS-103) of which 38 had post-flight inspections to identify M&OD impacts. Approximately 10% of the vehicle is surveyed in the M/OD inspections. The data for the 39 most significant impacts based on size found during the inspections are summarized in Table 1. This work contains estimates of impactor size which were determined using appropriate impact damage penetration equations that were derived by hypervelocity impact (HVI) test and analysis on relevant Orbiter materials. Although predictions for numbers of impacts are produced for each STS mission, we do not compare those predictions to the actual damage reported here as further efforts must be made to analyze the as-flown attitude timeline and adjust the predicted damage accordingly. 相似文献
999.
核壳粒子增韧工程塑料 总被引:2,自引:0,他引:2
讨论了具有橡胶核-硬塑料壳的核壳型冲击改性剂对工程塑料的增韧作用。应用多种橡胶增韧机理解释核壳粒子增韧工程塑料的原理,并比较详细地介绍了国内外采用核壳粒子增韧各类工程塑料的研究进展。 相似文献
1000.
针对套筒灌浆质量的检测与评定方法问题,利用冲击回波法对装配式剪力墙套筒灌浆缺陷开展了识别研究,分别建立了双层布置的直径为18、20、25 mm钢筋灌浆套筒的装配式剪力墙模型,进行了冲击回波有限元分析;开展了不同灌浆质量下的装配式剪力墙试件冲击回波试验,研究了不同冲击荷载下回波信号的频谱特征和时频特征。研究结果表明:不同的冲击荷载下回波信号频谱呈现不同的分布特征,5 mm钢球作用下灌浆区域和无灌浆区域的频谱图和时频图具有差异性,能够识别冲击点近侧的套筒内部的灌浆情况,试验结果与有限元分析结果相吻合。 相似文献