日本地震简介和日建设计的抗震设计

为更好地帮助读者理解本刊各篇论文的内容,本文简要介绍日本的地震状况,日建设计对地震设计的考虑方法,以及日建设计的设计用人工模拟地震波。     

天津独流减河工程监控系统现地通信单元设计

提出一种配电网电容电流测量的新方法，在零序电压互感器的开口三角侧串联一个可调电感，通过注入一个变频恒流信号寻找配电网的谐振频率，改变可调电感的数值后寻找另一谐振频率，联立2个谐振方程求解电容电流，该方法消除了电压互感器漏抗对测量的影响。开发了配电网电容电流测量仪，经模拟试验和现场测试表明，该方法具有安全、快捷、准确等特点，适用于中性点不接地或经随调式消弧线圈接地配电网。     

济钢105m^2带冷机综合密封节能降耗提高冷却效率的实践

由于烧结机扩容同时工艺优化去掉热筛后，使烧结矿的料层提高，热返矿进入带冷机超负荷运行料温持续偏高，并且带来台车漏风漏料扬尘，冷却风量效率低，烧损成品皮带等问题。通过采取综合密封及改进相关冷却方式，解决了以上存在的问题，并达到节能降耗的目的。     

介孔氧化铁对正辛醇乙氧基化反应的催化性能

以十二烷基磺酸钠为模板剂、乙二胺为碱性介质,将水热法合成的氧化铁/十二烷基磺酸钠复合中孔材料在550℃、空气气氛中煅烧10h,除去模板剂,得到介孔氧化铁。通过X射线衍射、氮气吸附-脱附方法对介孔氧化铁的晶体结构和表面物性进行表征。表征结果显示,煅烧后的介孔氧化铁具有典型的六方介孔的结构特征,平均孔径为5.4nm。将介孔氧化铁用于催化正辛醇乙氧基化反应,研究结果表明,升高反应温度和初始压力、增加催化剂用量,可加快环氧乙烷的反应速率,同时产物的相对分子质量分布较窄。当平均聚合度为6.5时,正辛醇聚氧乙烯醚相对分子质量分布的选择性系数达到21.1。     

Investigations of water inrushes from aquifers under coal seams

In many coal mines, limestone-confined aquifers underlie coal seams. During coal extraction from these mines, water inrushes occur frequently with disastrous consequences. This paper introduces the hydrogeological conditions of the coal mines and the potential water inrush disasters from aquifers under coal seams. It then presents the water inrush mechanism. The main factors which control water inrushes include strata pressure, mining size, geologic structures and the water pressure in the underlying aquifer. Analysis shows that reduction of confinement due to mining is the major cause of the water-conducting failure in the floor strata. The depth of the failure zone is strongly dependent on the mining width. This paper also presents field observation results of the water-conducting failure in the floor strata, and applies the finite element method coupled with stress-dependent permeability to analyze hydraulic conductivity enhancement due to coal extraction. Finally, theoretical and empirical methods to predict water inrushes are given, and technical measures for improving mine design and safety for coal extraction over aquifers are presented. These measures include fault and fracture grouting and mining method modification such as changing long-wall to short-wall mining.     

海底管道系统失效故障树的建立及定性分析

受自然环境、管道腐蚀、第三方破坏及管理不善等因素的影响,海底管道系统在铺设及运行过程中常常会失效。文中以海底管道穿孔、凝管、断裂和设备故障等主要失效形式为顶事件建立了海底管道系统失效故障树,通过系统的定性分析得到了海底管道系统失效故障树的37个一阶最小割集,进而确定了影响海底管道系统失效的4项主要因素,并针对这些主要因素提出了相应的解决问题的措施。     

大坝洪水漫顶风险评估

洪水漫顶是导致大坝溃坝的主要原因之一,大坝洪水漫顶风险评估是大坝风险评估的重要组成部分。为此,简要介绍了大坝洪水漫顶的风险模型,并通过实例详细地讨论了模型中各有关参数的不确定性处理方法,探讨了入库洪水的不确定性对洪水漫顶风险率的影响以及按规范设计的大坝的防洪能力问题。     

18臂机械井径与磁法井径组合测井仪原理及应用

文章主要介绍了18臂机械井径与磁法井径组合测井仪的仪器结构、主要技术特性、测量原理及测井资料在油田中的应用。通过对测井资料的分析，阐述了该仪器在套损检测、补贴效果检查、射孔工程作业效果评价等方面的应用，为油田套管分析提供了可靠的保证。     

Predicting Acute Renal Failure after Cardiac Surgery: Validation and Re‐definition of a Risk‐Stratification Algorithm

Background:  Acute renal failure (ARF) after cardiac surgery is associated with significant morbidity and mortality, irrespective of the need for dialysis. Previous studies have attempted to identify predictors of ARF and develop risk stratification algorithms. This study aims to validate the algorithm in an independent cohort of patients that includes a significant proportion of female and black patients and compares two different definitions of renal outcome.
Methods:  A large single center cardiac surgery database was examined (n, 24,660; 1993–2000) which included 29.9% females and 3.7% black patients. Post‐operative ARF was defined as: a) ARF requiring dialysis, b) > 50% reduction in creatinine clearance relative to baseline or requiring dialysis. Clinical variables related to baseline renal function and cardiovascular disease were used in recursive partitioning analysis for both outcome definitions. Chi‐square goodness of fit analysis was performed to validate the algorithm.
Results:  The frequency of post‐operative ARF requiring dialysis ranged between 0.5 and 15.5% based on the risk categories with the area under the receiver operating characteristic (ROC) curve of 0.78. Using the more inclusive definition of ARF, the frequency was significantly higher ranging from 2.6 to 25%(P < 0.001) with an area under ROC curve of 0.65.
Conclusions:  The renal risk stratification algorithm is valid in predicting post‐operative ARF in an independent cohort of patients, well represented by differences in gender and race. Since the need for dialysis remains subjective, a more objective and inclusive definition of ARF may help in identifying a larger number of patients 'at‐risk'.     

Calculation of the Thermodynamic Properties of Diatomic Substances Based on the Ornstein-Zernike Equation

The new method of calculation of intermolecular distribution functions is used to calculate various thermodynamic properties of diatomic substances (oxygen, nitrogen, ethane). Good agreement is demonstrated between the calculation and experimental data.