两种铝合金在3%NaCl溶液中的腐蚀特性

采用线性极化法和循环极化法,比较两种铝合金在不同pH值的3%NaCl溶液中的腐蚀速度、点蚀敏感性与蚀点发展趋势和它们的腐蚀特性.运用扫描电镜观察了铝合金的显微组织,比较铝合金的组织成分,分析杂质元素对耐蚀性能的影响.结果表明,除pH=9.5外,其它试验条件下铝合金ZL102(A)的腐蚀速度均小于铝合金LF6(B);铝合金A的点蚀敏感性较铝合金B小;铝合金B的蚀点发展趋势总体大于铝合金A;铝合金B中含多种杂质元素导致其耐点蚀性能较铝合金A差.     

机械合金化合成NiAl/HfB_2复合材料的组织与力学性能

球磨Ｎｉ,Ａｌ;Ｈｆ和Ｂ元素粉末反应合成ＮｉＡｌ／ＨｆＢ２复合材料,形成机制归结为机械碰撞诱发的自蔓延反应．采用 热压和热等静压工艺将纳米双相复合粉末压制成较密实的块体材料,进而研究其微观组织与力学性能．结果表明“反应球磨＋热 压”制备的ＮｉＡｌ／ＨｆＢ２复合材料基体晶粒细小,原位生成的弥散相颗粒主要分布于基体晶界,其强化效果显著而对塑性的削弱 作用较小;不同温度下的压缩屈服强度均远高于铸态ＮｉＡｌ,且压缩变形量均超过１０％;高温下材料的屈服强度依赖于应变速率, 用线性回归方法计算出的应力指数ｎ和变形激活能Ｑ高于单相ＮｉＡｌ,与含弥散相比例较高的ＸＤ ＮｉＡｌ－２０％ＴｉＢ２（体积分数） 复合材料相当．     

《电力需求侧管理》2007年选题方向

指导思想:以党的十六届六中全会精神和中央经济工作会议精神为指导,全面落实科学发展观,贯彻"十一五"规划纲要和国务院关于加强节能工作的决定,落实节约资源和保护环境的基本国策,努力实现"十一五"节能目标,促进经济和社会可持续发展.     

机电信息

中国电力可靠性指标发布会披露上海三大主机运行水平国内第一;上海轨道交通设备发展有限公司制订“十一五”发展规划;以新技术新装备为抓手迅速发展上海电气环保产业;开发新技术新装备加紧企业结构调整上海机电股份加快机电一体化产业发展;     

砂岩油藏酸化预处理技术研究与应用

针对酸化预处理技术不完善的现状,通过室内试验、数学模型、现场试验等进行了酸化处理的岩石损伤机理、损伤定量预测、破裂压力降低定量预测及现场试验分析等研究.通过电镜扫描和铸体薄片的对比,分析了砂岩酸化前后内部结构的变化；以有效承载面积的变化作为损伤变量,建立了岩石损伤定量预测模型,利用纵波波速变化计算不同酸处理阶段岩石损伤程度,验证了模型的可行性；考虑酸化岩石物性参数的变化,建立了酸化预处理降低破裂压力分析方法,现场试验验证了计算方法的可靠性,具有推广应用价值.     

新中国60年建筑回顾和建筑创作大奖——访中国建筑学会秘书长周畅

为迎接新中国成立60周年,中国建筑学会将举办建筑创作大奖.本刊记者(以下简称记)就大奖的有关问题专访了中国建筑学会秘书长周畅(以下简称周)先生,请他回答了记者的提问.     

Parameter identification and global sensitivity analysis of Xin’anjiang model using meta-modeling approach

Parameter identification, model calibration, and uncertainty quantification are important steps in the model-building process, and are necessary for obtaining credible results and valuable information. Sensitivity analysis of hydrological model is a key step in model uncertainty quantification, which can identify the dominant parameters, reduce the model calibration uncertainty, and enhance the model optimization efficiency. There are, however, some shortcomings in classical approaches, including the long duration of time and high computation cost required to quantitatively assess the sensitivity of a multiple-parameter hydrological model. For this reason, a two-step statistical evaluation framework using global techniques is presented. It is based on (1) a screening method (Morris) for qualitative ranking of parameters, and (2) a variance-based method integrated with a meta-model for quantitative sensitivity analysis, i.e., the Sobol method integrated with the response surface model (RSMSobol). First, the Morris screening method was used to qualitatively identify the parameters’ sensitivity, and then ten parameters were selected to quantify the sensitivity indices. Subsequently, the RSMSobol method was used to quantify the sensitivity, i.e., the first-order and total sensitivity indices based on the response surface model (RSM) were calculated. The RSMSobol method can not only quantify the sensitivity, but also reduce the computational cost, with good accuracy compared to the classical approaches. This approach will be effective and reliable in the global sensitivity analysis of a complex large-scale distributed hydrological model.     

Top 10 Technological Breakthroughs of CNPC in 2012

CNPC attaches great importance to technological research and development,and makes steady progress every year relying on the intelligence and diligence of its people. Major breakthrough in molecular geochemical tracing of complex oil/gas reservoir forming This important breakthrough addresses the difficulty in predicting hydrocarbon properties and understanding their enrichment levels and distribution laws in the key exploration areas of China,such as deep and ultra-deep,carbonate and unconventional reservoirs.It has provided a theoretical basis for quantitative evaluation of the potential of multi-source hydrocarbon accumulation,dynamic tracing of hydrocarbon generation-migrationaccumulation process and the related secondary changes,and effective prediction of the properties of major formations and hydrocarbon fluids.     

应用灰色方法提高预测精度再探

本文利用时间序列迭加可减少数据随机波动的特性,定义了滤波时间序列,并在此基础上,进行回归分析,提出了提高回归精度的一个新的方法。     

锌锰电池贮存前后的交流阻抗行为

本文应用交流阻抗技术研究了R20型Zn-MnO_2干电池在贮存前后的交流阻抗行为,建立了等效电路。对阻抗图谱的差别进行了分析和讨论,得出了一些对电池进行无损检测的结论。