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1.
露石水泥混凝土路面关键技术研究   总被引:17,自引:2,他引:17  
研究了露石水泥混凝土路面铺筑过程中必然要遇到的材料选择、冲洗时间、成熟度、双层铺筑混凝土强度等关键技术问题,分析了冲洗时间、成熟度的主要影响因素,发现温度越高,冲洗时间越早,最早冲洗时间与最迟冲洗时间有较大的间隔,常温下可达十多个小时,温度升高,间隔减小,成熟度随温度的升高而增大,相隔一定时间分两层振捣的水泥混凝土试件强度与一次振捣的水泥混凝土试件强度基本相同。结果表明:成熟度指标、试验法是评价、检测露石工艺性质的有效手段,两层铺筑方法是降低此种路面成本的有效途径。  相似文献   
2.
对SBS改性沥青剪切发育过程的试验分析   总被引:2,自引:1,他引:2  
用不同类型的SBS与不同组分的基质沥青配伍,对改性过程中的取样用荧光显微镜进行微观观测和动态力学扫描及常规试验,发现微观观测和动态力学扫描均是判断聚合物是否稳定分散与发育的有效手段,而动态力学扫描具有更高的灵敏度,可以根据扫描结果独立判断剪切发育程度,而微观观测需与常规试验相结合方可得到较好结论。  相似文献   
3.
质量管理体系内审是组织进行质量体系管理自我完善的重要手段之一,一直以来通常采用符合性评价的方式,评价结束给的评价结论一般是定性的,如符合、基本符合和有效、基本有效;无法用一个量化的数据真实反映组织质量管理体系整体运行的成熟度。那么如何开发一套质量体系评价管理方法,采用量化的数据进行质量管理体系成熟度评价,全面掌握组织质量体系运行成熟度,针对性进行持续改进就尤为必要了。  相似文献   
4.
软件工程管理方法与实践   总被引:4,自引:0,他引:4  
概述了软件工程的概念、发展和近年来软件工程的新技术。介绍了开展软件工程化的方法和实践经验。  相似文献   
5.
采用化学结合水法、氯离子快速测定法(RCM法)和混凝土成熟度测定法研究了56 d龄期内混凝土氯离子扩散系数和混凝土成熟度的关系。结果表明:混凝土氯离子扩散系数不仅随养护龄期的延长而降低,还随养护温度的升高而降低,延长养护龄期或提高养护温度均可提高胶凝材料的水化程度;室内养护混凝土试件的氯离子扩散系数与混凝土成熟度值之间呈幂函数关系,二者具有很好的相关性(R2=0.976),利用室外养护混凝土试件的数据进行验证计算,其理论计算值与实测值具有较好的吻合性,可根据混凝土成熟度实测值预测出混凝土的氯离子扩散系数;在本工程中,沉管隧道接触海水时混凝土成熟度的推荐值为21064℃·h,控制边界值为13926℃·h,考虑外部养护温度和水化热对混凝土成熟度产生影响时,可对混凝土接触海水的龄期通过后计算进行适当的调整。  相似文献   
6.
This study evaluates the reproductive potential and condition of the red shrimp (Aristeus antennatus) population inhabiting the waters around the Balearic Islands (Northwestern Mediterranean Sea), between 1991 and 2004. Red shrimp is one of the most valuable exploited demersal fishery resources in the western Mediterranean. To assess the condition of this species, we use two indices based on weight and length data, one including the gonad weight and another excluding it. Different biological parameters of the population dynamics and reproductive biology, such as sex-ratio, maturity, gonadosomatic index and presence of the spermatophore in females have also been analysed. A negative relationship was found between the gonadosomatic index and the condition of red shrimp, indicating that energy reserves are transferred from the body to the gonad during the reproductive period. The condition of adults reached minimum values during the maturation and spawning period after mating, when the gonadosomatic index, the spermatophore presence in females and the proportion of females in the population were highest. The relationship between the condition of adults during the months prior to spawning and the number of recruits in the following year was significant and positive. This relationship was stronger when only male condition was considered, suggesting that males have an important role on the reproductive potential of this species. Overall, our results suggest that condition of red shrimp, particularly males, is an important aspect for the reproductive and recruitment success of this species. The observed decreasing trend in male condition over years may raise concern on the future reproductive potential of that population.  相似文献   
7.
目前国内关于无损预测水泥混凝土路面早期强度的研究成果较少.成熟度方法是一个预测水泥混凝土路面早期强度的无损试验方法,然而在我国公路行业未得到有效应用.通过室内试验建立水泥混凝土的成熟度-强度曲线,并通过该曲线预测水泥混凝土路面合适的切缝时机和开放交通时间.现场试验结果表明,成熟度方法可以较好地预测水泥混凝土路面的早期强度,且对于控制水泥混凝土路面的早期裂缝具有重要的工程实用价值.  相似文献   
8.
European hake (Merluccius merluccius) female size at maturity is estimated on an annual basis for Bay of Biscay and Galician coast, which are parts of the distribution of the Northern and Southern stocks, respectively. Clear trends in this reproductive parameter are observed along the time series and the potential factors affecting these trends have been investigated. Total biomass, different indexes of SSB, age diversity index, fishing mortality at age, NAO winter index, upwelling index and temperature were included in multiple regressions models to assess the relative importance of each of them on shifts in size at maturity.Bay of Biscay and Galician coast hake have followed different evolution in patterns of changes in size at maturity. In Bay of Biscay, a steadily decline of 15 cm has been observed from 1987 to 2004, which is well predicted by fishing mortality and age diversity, but also the environment may have played an important role. However, on the Galician coast a drastic decline of 16 cm from 1980 to 1988 was followed by a rapid increase in size at maturity during the next 10 years to original values and a stable period in the last 6 years. Decreasing biomass may explain the decline in size at maturity in the first period. However, total biomass and spawning biomass declined even during the period when size at maturity increased, which is contrary to compensatory theory. Shifts in environmental regime, NAO and upwelling, may have contributed to a decelerated growth during this period that might explain the later maturation.  相似文献   
9.
文章对高职院校项目成熟度模型进行了应用研究,提出了适合我国教育特点的具体的方法和步骤,为我国教学管理工作的改革与发展提供了参考。  相似文献   
10.
为优化我军对手部队装备建设程序和过程,提高我军对手部队装备建设质量和效益,分析了采用相似系统建模、系统相似性分析和成熟度分析等方法,解决对手部队装备建设中装备体系设计、逼真建设模拟装备、模拟装备建设途径选择等重难点问题的可行性,探讨了综合运用上述方法确定我军对手部队装备建设的基本流程和方法步骤。  相似文献   
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