Nucleation Mechanism for Bainite

Based on the experimental results that solute-depleted zone was observed in Cu-28Zn-4AI (mass fraction) at 523 K, AG is calculated as a positive according to the thermodynamic criteria for the spinodal decomposition of a ternary systems. So, the solute-depleted zone cannot be formed by spinodal decomposition. Dislocation density required by the formation of solute-depleted zone is estimated greater than 7.89×109 cm-2, according to the segregation of solute atoms around dislocations, which is not consistent with the practical situation for the alloy at 523 K. Associated with the internal friction experimental fact that internal friction peaks appear within the incubation for bainitic transformation in Cu-Zn-AI alloy, the equilibrium temperature, TO, is evaluated as 433 K for solute-depleted Cu-25Zn-3.4AI, which is lower than the experimental temperature 523 K. Thus, nucleation by shear mechanism is impossible in this circumstance. Therefore, it is concluded that, like bainite in steels and Ag-Cd, bainite in     

大港白水头地区低阻油气层测井评价

在对白水头地区低阻油层的地质特征、物性特征及成因环境进行了分析研究后 ,应用测井曲线特征集法 ,把白水头油田常规油气层、低阻油气层、油水同层、水层等看成是独立的地质事件 ,建立了它们与测井曲线特征之间的对应关系 ,利用这种关系对未知地质事件进行了预测划分。最后根据所建模型定量计算储层各种参数 ,收到了良好的地质效果 ,表明测井曲线特征集法对于识别多成因的低阻油层是一种有效方法     

KZON-50/120空分设备的安装调试及设计改造

在KZON-50/120空分设备的安装调试和试运行过程中,对其机械和电器部分进行了多处改造,克服了原设计中存在的不足之处。改造后,机械和电器性能更加趋于合理,操作简单,便于维护,降低了制气费用,提高了制气纯度和经济效益,保证了空分设备更加安全可靠运行。     

Modeling and assimilation of root zone soil moisture using remote sensing observations in Walnut Gulch Watershed during SMEX04

Soil moisture status in the root zone is an important component of the water cycle at all spatial scales (e.g., point, field, catchment, watershed, and region). In this study, the spatio-temporal evolution of root zone soil moisture of the Walnut Gulch Experimental Watershed (WGEW) in Arizona was investigated during the Soil Moisture Experiment 2004 (SMEX04). Root zone soil moisture was estimated via assimilation of aircraft-based remotely sensed surface soil moisture into a distributed Soil-Water-Atmosphere-Plant (SWAP) model. An ensemble square root filter (EnSRF) based on a Kalman filtering scheme was used for assimilating the aircraft-based soil moisture observations at a spatial resolution of 800 m × 800 m. The SWAP model inputs were derived from the SSURGO soil database, LAI (Leaf Area Index) data from SMEX04 database, and data from meteorological stations/rain gauges at the WGEW. Model predictions are presented in terms of temporal evolution of soil moisture probability density function at various depths across the WGEW. The assimilation of the remotely sensed surface soil moisture observations had limited influence on the profile soil moisture. More specifically, root zone soil moisture depended mostly on the soil type. Modeled soil moisture profile estimates were compared to field measurements made periodically during the experiment at the ground based soil moisture stations in the watershed. Comparisons showed that the ground-based soil moisture observations at various depths were within ± 1 standard deviation of the modeled profile soil moisture. Density plots of root zone soil moisture at various depths in the WGEW exhibited multi-modal variations due to the uneven distribution of precipitation and the heterogeneity of soil types and soil layers across the watershed.     

三峡水电站ALSTOM机组低水头运行稳定性分析

混流式水轮机的水力稳定性与机组水力工况密切相关。以三峡电站左岸6号机组稳定性试验为例，分析了ALSTOM机组的低水头运行稳定性。根据试验分析结果，可将机组运行工况划分为小负荷区、涡带振动区、大负荷运行区。小负荷区机组效率较低，机组不宜在此区间运行；大负荷区机组运行稳定性最佳，但机组应避开强涡带工况区和特殊频率振动区运行。     

二滩水电站油、水、风系统设备运行与改造

水电站辅助设备的运行直接影响水电站运行的安全性和可靠性。二滩水电站投运初期，油、水、风系统先后出现了许多问题，通过应用新产品和新技术对其进行了改造。为水电厂辅助设备的设计、选型、安装提供了宝贵的经验，并对水电厂辅助设备的检修、调试和运行维护有一定的指导作用。     

湘钢80 t转炉工艺改进、产能提升的实践

介绍了湘潭钢铁集团有限公司3座80 t转炉通过改进装入制度、实行少渣量操作、控制炉型、优化生产工序等,实现了由日产7 000 t到10 000 t的产能提升,转炉作业率达84.22 %,冶炼品种钢比例达85.69 %.     

通信局房供电系统的谐波治理

本文在理论分析谐波产生及危害的基础上,针对某一通信局房,确定最终谐波治理方案并取得较好的治理效果,供同行在设计时参考。     

库车坳陷北带断裂输导天然气效率评价

在断裂输导天然气能力影响因素分析基础上,建立了断裂输导天然气能力评价参数.利用此评价参数对中国24个以断裂为主要输导通道的大中型气田断裂输导天然气能力进行了研究,并通过其天然气聚集效率和断裂输导天然气能力评价参数之间的关系研究得到:高效、中效和低效断裂输导天然气能力评价参数值应分别为大于250×10-4、250×10-4～25×10-4和小于25×10-4.根据库车坳陷北带断裂输导特征,对其下白垩统顶部断裂输导天然气效率进行了研究,得到库车坳陷北带下白垩统顶部高效断裂输导天然气区主要分布在大北1井周围、克拉1、2、3、4井周围和东秋5井-迪那2-依南2井周围3个地区,中、低效断裂输导天然气区围绕高效断裂输导天然气区分布.目前在该区发现的5个气田皆分布在高效断裂输导天然气分布区,表明高效断裂输导应是库车坳陷北带天然气成藏的重要条件.     

液化石油气磁力泵改造

对输送液化石油气磁力泵在运行1个月后出现的故障进行了分析,提出了在磁路、气路及安装等方面采取的一些改进措施。