粗粒土的本构模型研究

本文结合云南天生桥面板堆石坝的试验研究,提出了一个非线性应力应变模型,即K-G模型。建议了一种用三轴试验直接求取残余强度的方法。预测表明:该模型能较好地模拟土的剪胀性和预测不同应力路径,在一定程度上能考虑中主应力σ_2对破坏的影响及应变软化性。所选的模型拟合曲线均为大家所熟知,旦参数易于用常规三轴试验(σ_3=c)确定,因而是一个具有实用价值的模型。     

弹性地基梁理论在挑梁计算中的应用

本文把弹性地基梁理论运用到挑梁计算中,得到了挑梁的弯矩,剪力,梁下应力计算公式。通过进一步简化。提出了更为实用的挑梁计算公式。与实验结果相比吻合较好,可供设计挑梁时参考。     

Specific UV absorbance of Aldrich humic acid: changes during transport in aquifer sediment

This study examined the transport behavior of Aldrich humic acid (AHA) in low natural organic carbon content sediment contaminated with tetrachloroethene (PCE), for comparison to a nonionic surfactant mixture previously examined in the same system. Tracking of individual molecular weight (MW) fractions of AHA was attempted by UV absorbance, followed by conversion to mass of carbon using specific ultraviolet absorbance (SUVA) (UV absorbance per mass of carbon) measurements. The analysis required determination of variations of SUVA with MW, which showed a maximum at 10 000 Daltons. Furthermore, SUVAs of AHA MW fractions greater than about 10 000 Daltons increased following AHA interaction with sediment in batch experiments, and this was associated with AHA-driven leaching of cations from the sediment. AHA transport was examined in a series of three columns representing the up-gradient, residual-zone, and down-gradient portions of a DNAPL contaminated site. SUVAs of larger MW AHA fractions cycled through decreased, increased, and eventual return to influent values during the early, intermediate, and final stages of breakthrough, respectively. These variations were attributable to a combination of preferential adsorption of low MW fractions of the AHA during early breakthrough and AHA-driven leaching of sediment cations during intermediate breakthrough, with eventual exhaustion of sediment cation complexation during the final stage of breakthrough. The complex variations in SUVA precluded accurate conversion of measured UV absorbance to carbon mass. However, the effect of AHA loss to sediment on the solubilizing capacity of the AHA solution was indicated by the breakthrough behavior of AHA-solubilized PCE, which showed that AHA loss from the aqueous phase during transport in this system did not decrease the solubilizing capacity of the AHA mixture.     

兰州电网输电线路外力破坏情况分析及对策

根据兰州电网输电线路近年来发生的外力破坏情况,对其规律及特点进行分析,提出相应的预防对策.     

A Large Deformation Model for the Elastic Moduli of Two-dimensional Cellular Materials

1Introduction Themechanicalbehaviorofcellularmaterialsde pendsontheirrelativedensity,cellgeometryandthema terialpropertiesofthesolidfromwhichtheyaremade.Theelasticmoduliofcellularmaterialscanbederived fromananalysisofthedeformationmechanismofthecell members.Thesimplegeometryofanidealizedunitcell allowsthederivationofrelationsbetweenmicro structural featuresandeffectivemechanicalproperties.Manytheoreticalmodelshavebeendevelopedtopre dicttheelasticmoduliofcellularmaterials[14].AbdEl Sayedetal[…     

千瓦级熔融碳酸盐燃料电池组

论述了千瓦级熔融碳酸盐燃料电池组制备及组装工艺中双极板组合件、高温粘结剂、隔膜原位制备、制紧力、热量管理等技术。采用高温粘结技术制备双极板组合件 ,并在电池组启动时原位制备隔膜。由 5 2个单电池串联组成的电池组在65 0℃操作温度 ,0 .5MPa压力下 ,最大输出功率达到 10 2 5 .48W。用此高温粘结技术与湿密封相结合 ,使电池组的操作压力可达到 0 .5MPa。     

特殊类型二阶变系数齐次线性微分方程通解公式

本文给出了二阶变系数齐次线性微分方程的系数满足某些条件时的通解公式。     

东－松超镁铁岩体铬铁矿成因地质现象分析

通过与铬铁矿形成有关的宏观和微观地质现象分析，得出铬铁矿矿体是地幔岩高度熔融形成的富铬和镁的极端部分。     

一种用于相控阵AEW雷达杂波抑制的新方法

提出了一种用于相控阵机载预警(AEW)雷达杂波抑制的简化辅助通道法,这种方法与Klemm提出的辅助通道法相比,采用的辅助通道数从N+K-1个[N为天线阵元(或列子阵)数,K为相干处理脉冲数]减少到4～6个。其性能与Klemm方法基本相同,而运算量大大减少,使实现成为可能。     

整函数与亚纯函数的复合增长性的性质

本文得到如下结果: 1)设g是超越整函数,且T(r,g)=O(logr)~2),则■T(r,g)/logM(r,g)=1 2)设f是级为λ_f(0<λ_f<∞)的超越亚纯函效,g为超越整函数,且T(r,g)=O(logr)~2),则■logT(r,f(g))/T(r,g)=λ_f。