不同矿物掺合料改良大坝碾压混凝土工程力学性能研究

为研究不同矿物掺合料对大坝碾压混凝土工程力学性能的影响,利用粉煤灰、矿粉和细石英砂等量部分替代水泥,制备了不同矿物掺合料、不同掺量条件下的混凝土试件并对其展开了单轴压缩、单轴劈裂及物质成分检测试验。研究发现:掺矿粉混凝土的力学性能明显优于普通混凝土,抗压强度提升在6%左右,抗拉强度提升在16%左右。掺矿粉混凝土的工程力学性能最佳,当矿粉掺量为10%时,其抗压强度为68.52MPa,较粉煤灰混凝土和石英砂混凝土分别高出3%和7%;抗拉强度为6.45MPa,较粉煤灰混凝土和石英砂混凝土分别高出11%和7%。     

大化水电站重力坝长龄期混凝土特性试验分析

对大化水电站大坝12－15年龄期混凝土芯样抗压强度、劈拉强度、静压弹性模量、密度、抗渗性、抗剪断等物理力学性能进行了综合试验和X—射线衍射、扫描电镜微观分析，证明大坝混凝土长龄期强度保证率高，混凝土芯样各项指标均符合设计要求，采用粉煤灰和缓凝减水剂“双掺”在降低工程造价、减少水化热的前提下混凝土强度和水化产物正常稳定。     

高粉煤灰碾压混凝土的特性研究

通过碾压混凝土强度、抗渗、碳化等性能试验研究及微观和理论分析手段，从宏观、微观上对高掺粉煤灰碾压混凝土的体性进行研究，提出粉煤灰掺量超过一定值会使碾压混凝土的物理力学性能乃至结构显著劣化，宜控制粉煤灰的最大掺量。研究表明，粉煤灰掺量应依工程设计的力学和耐久特性需要以及粉煤灰品质、龄期等综合性地优化选择，以满足最佳技术经济性。     

高掺量粉煤灰碾压混凝土在岩滩水电站的应用效果

结合岩滩水电站碾压混凝土施工质量监测及芯样物理性能检验结果,从碾压混凝土的施工性及抗压强度、抗渗标号、弹性模量及微观分析等不同角度评定高掺量粉煤灰碾压混凝土在岩滩水电站工程的应用效果,并详细分析了高掺量粉煤灰碾压混凝土在长龄期下的性能特征。     

田间装配式涵闸混凝土最佳配比试验研究

田间装配式涵闸具有施工方便、工期短等显著优势,但是使用标准混凝土时仍存在预制件笨重、装配不便的问题。文章通过正交试验方法,提出在混凝土掺入粉煤灰20%,掺入硅粉9%,掺入发泡剂1%的泡沫混凝土最佳配合比方案。检验结果显示,采用该配合比的试块,与标准混凝土相比,容重显著降低,抗压强度明显提升,具有重要的应用价值。     

混合粒化高炉矿渣再生骨料混凝土的抗冻融性研究

为了保证严寒地区建筑结构的冻融安全性,对水灰比(W/C)为47%的粒化高炉矿渣混合再生骨料混凝土进行研究,通过多组试验对混合混凝土的泌水性、抗压强度等进行评估,分析混合粒化高炉矿渣的再生骨料混凝土的抗冻融性。结果表明:1)当粒化高炉矿渣掺量小于50%时,其泌水性可保持在0.1 cm~3/cm~2以下;2)在混凝土的空隙通过性试验中,掺入粒化高炉矿渣后,混凝土的间隙通过性突出,抗压强度低于普通混凝土,但具有足够的抗冻融性能;3)在配合比设计为正常强度范围的混凝土中,利用粒化高炉矿渣取代50%以下的碎砂的再生骨料混凝土具有足够的泌水性、抗压强度,以及抗冻融性能。混合粒化高炉矿渣的再生骨料混凝土可用于在高寒地区进行的工程建设,研究成果可有效提高高寒地区建筑物的抗冻融性并延长其使用寿命,可为高寒地区工程项目中抗冻融混凝土的制备提供一定的参考。     

桥梁混凝土抗冻融性能的试验研究

混凝土的冻融破坏是寒冷地区经常与水接触混凝土结构物的常见破坏形式。本文采用快速冻融方法,对普通混凝土和高强混凝土的抗冻融性能进行了试验研究,测试了试件的质量、动弹性模量和抗压强度,通过试验研究了普通混凝土和高强混凝土的抗冻融和抗盐冻性能,并分析了普通混凝土和高强混凝土抗冻融性能与抗盐冻性能之间的差异。结果表明,在不引气的条件下,普通混凝土和高强混凝土的抗冻融和盐冻性能均很差;混凝土试件抗冻融和盐冻循环次数随着混凝土强度等级的提高而增加;普通混凝土试件抗冻融循环次数高于抗盐冻循环次数,高强混凝土试件抗冻融循环次数低于抗盐冻循环次数;仅以重量损失率和相对动弹性模量作为混凝土冻融或盐冻破坏的判断标准不够全面,还应考虑强度的损失率。     

降低防渗墙塑性混凝土的渗透性研究

为了增强大坝防渗能力，文章通过相关试验研究了硅灰对塑性混凝土抗渗性的改善程度。试验结果表明，掺入硅灰能够有效降低防渗墙的渗透性，当硅灰掺入量为15%时，渗透系数降低了80倍。与此同时，硅灰的使用提高了防渗墙的强度，弹性模量和抗渗性能，通过增加含硅灰塑性混凝土的水胶比，将强度和弹性模量保持在控制塑性混凝土的水平。研究结果丰富了高性能塑性混凝土的基本理论，为大坝的安全管理除险加固提供了理论依据。     

基于固废磷化渣的复合型防腐阻锈剂对混凝土性能的影响

为了提高严酷环境下建筑的耐久性,研究了防腐阻锈剂和防腐阻锈混凝土。以三乙醇胺、硝酸铝和Ca(OH)₂为原料,经化学反应,制备新型固体醇胺,再按一定质量分数将固体醇胺、固废磷化渣、石膏和苯甲酸钠混合、球磨,制得复合型防腐阻锈剂,将其掺入基准混凝土中,制得防腐阻锈混凝土,并研究其力学性能和防腐阻锈性能。结果表明：掺复合型防腐阻锈剂的防腐阻锈混凝土,抗压强度和抗折强度显著提高,抗渗等级达P12,碳化深度大幅降低,抗冷热干湿循环和抗冻融性能优异,用含防腐阻锈剂的海水混合液浸泡钢筋2年,钢筋无腐蚀行为。用复合型防腐阻锈剂制备的防腐阻锈混凝土能有效延缓建筑混凝土的腐蚀进程。利用固废磷化渣制备防腐阻锈剂,变废为宝,可为新型防腐阻锈剂的开发提供借鉴。     

高性能海工混凝土外加剂优选试验研究

为了大幅度提高混凝土的耐久性能,在设计配制C45强度等级的混凝土配合比基础上,研究了CPA与WG两种综合性外加剂及外涂的DPS永凝液对混凝土的强度及耐久性能的影响.采用不同外加剂组合进行配合比试验,通过测试其混凝土的工作性能、抗压强度、抗渗试验、电通量试验、氯离子扩散系数,对外加剂进行优选.试验结果表明,CPA型外加剂可以更好的提高混凝土的强度及耐久性能,WG型外加剂次之,通过外涂DPS使混凝土耐久性能有一定程度提高.要达到较高的耐久设计标准,需要综合运用外加剂内掺与外涂技术.     

Comparing FTTH access networks based on P2P and PMP fibre topologies

There is an ongoing discussion in the market which Next Generation Access (NGA) architecture best suits future needs and which investment and cost differences exist. The discussion can be subsumed as P2P vs. GPON, which is somewhat misleading as this article reveals. The discussion is driven by the fact that the high capital cost and the long asset life time of fibre mean that the technology choices made today will dominate the opportunities for telecommunication business of all market players, incumbents, competitors, content providers and business and residential users for many years in the future.The paper analyzes the cost and other differences between Fibre-to-the-Home (FTTH) access network architectures and their related different wholesale approaches by using the well-known and understood steady state approach applied in other NGA analyses in the past. In addition to the steady state analysis a dynamic cost evaluation is included taking into account the different investment behaviour of the FTTH architectures over time. The results describe investment and cost differences between architectures, incumbents and wholesale based competitive operators. The analysis has been performed for different geotypes (clusters) of decreasing population density in a representative European settlement structure.     

Indigenous peoples’ nutrition transition in a right to food perspective

In indigenous communities the nutrition transition characterized by a rapid westernization of diet and lifestyle is associated with rising prevalence of chronic disease. Field work and literature reviews from two different policy environments, Argentina (Jujuy) and Canada (Nunavut), identified factors that add to indigenous peoples’ disease risk. The analytical framework was the emerging human right to adequate food approach to policies and programmes. Indigenous peoples’ chronic disease risk tends to increase as a result of government policies that infringe on indigenous peoples’ livelihoods and territories, undermining their economic system, values and solidarity networks. Policies intended to increase food security, including food aid, may also fuel the nutrition transition. There is a need to explore further the connection between well-intended policies towards indigenous peoples and the development of chronic diseases, and to broaden the understanding of the role that different forms of discrimination play in the westernization of their lifestyles, values and food habits. Food policies that take due account of indigenous peoples’ human rights, including their right to enjoy their culture, may counteract the growth of chronic disease in these communities.     

面向对象的程序设计

用Ｃ＋ ＋ 语言阐述面向对象程序设计中封装和继承的概念以及在实际中怎样运用这些概念提高程序设计水平。     

A strategic skill based model of supplier integration and its effect on supply management performance

Supplier integration is a tool to help organizations gain competitive advantage. Strategic supply management skills and the supply management function's perceived status are hypothesized as antecedents to supplier integration leading to supply management performance. The sample for this study includes 152 executive level supply management professionals. The empirical results suggest that strategic skills and perceived status are essential antecedents to supplier integration and subsequent performance. Further, the relationship between strategic skills and performance is mediated by supplier integration. Results of a dominance analysis also suggest which strategic skills are most likely to explain status integration, and performance. These findings have significant implications for supply management theory and practice.     

Cost allocation of WCDMA and wholesale pricing for mVoIP and data services

This study estimates cost-based prices for wholesale voice and data services provided to 3G (WCDMA) MVNOs according to their distinct types. For estimation, 3G MVNOs are classified into different types, and the overall cost of WCDMA facilities are separated into voice and data components based on their subscriber rates, actual traffic rates, as well as efficiency consideration of traffic rates. The study then calculates cost-based wholesale prices of voice and data services for each of the 3G MVNO types. The result of this study shows that a cost-plus pricing scheme can help achieve the policy goals of the regulator, namely, lowering telecommunications tariffs and facilitating the introduction of new convergent-type services, far more effectively than the current retail-minus pricing scheme. The findings of this study may assist firms in developing business models based on 3G networks and telecom regulators in designing policies related to interconnection, mVoIP, prepaid calls, wholesale services, and network neutrality.     

Collectivism,individualism, and outgroup cooperation in a segmented China

A consistent theme in cross-cultural management research is that collectivists are more cooperative than individualists. We use Hofstede's measure for individualism–collectivism and combine it with an experimental measure of cooperation to test this relationship in China. In contrast to the established paradigm, we find that groups with higher individualistic scores are more cooperative than those groups with higher collectivistic scores. We attribute these results to groups being composed of outgroup members. In addition, we find that subjects from the more developed coastal area are more individualistic and cooperative than are subjects from inland China.

应用CGI技术创建CAI网页计数器

:CGI( Common Gateway Interface)是应用程序与 Web服务器交互的一个标准接口 ,利用该技术可以实现 HTML不具备的交互式主页功能。本文将通过“教育窗”主页的访问 (点击 )计算器的开发应用实例 ,提出了两种使用 CGI技术实现点击计数的方案     

钻井现场H2S气体的探测及防护

在钻井生产过程中，实施HSE管理体系，预防和控制H2S，保护每一位员工不受H2S气体危害，是钻井生产过程中HSE工作的重要一环。阐述了有害气体H2S的物理特性、毒性标准，介绍了几种常用的H2S气体探测器，以及具体操作方法。     

电子产品的电磁兼容性设计

首先介绍电磁兼容性的基本概念与研究领域,然后重点阐述电子产品的电磁兼容性设计与测量。     

SPYRO在烯烃原料生产方案测算中的应用

文章对SPYRO裂解模拟软件在石化企业烯烃生产原料优化方案测算中的应用进行了比较深度的概括分析.结合该软件在上海石化的实际应用,认为在劣质化原油加工份额不断增加的趋势下,SPYRO裂解模拟软件有助于石化企业在烯烃生产原料优化选择、生产计划合理安排、原油加工生产效益比较等方面为企业相关决策者提供有效地帮助.