K_0固结条件下花岗岩残积土三轴CU剪切试验研究

基于K0固结试验原理,将花岗岩残积土试样恢复到天然的K0应力状态,然后进行不排水剪切试验,同时进行三向等压固结状态下的不排水剪切平行试验。经试验结果分析,可知：花岗岩残积土静止侧压力系数K0试验值分布于0.38～0.40,与K0固结土样的K0计算值相近,K0固结试验测得的K0值比传统方式测得的数据稳定;花岗岩残积土CU...     

地下车库开挖的三维数值分析

通过计算已建楼房的地基承载力,对拟后开挖的主体旁地下车库运用太沙基理论进行分析、有限元软件数值模拟其开挖过程,得出开挖过程中主体楼房基础底部的沉降变形、坑底隆起和地表沉降的变形规律,为类似工程设计与施工提供了一定的参考。     

新型无线传感器网络启发式拓扑控制算法研究

提出了一种基于RNG图的启发式无线传感器网络拓扑控制算法HLRNG(Heuristic Local RelativeNeighbor Graph),采用RNG图和节点状态转化模型,建立从感应事件节点到sink节点间的局部多路径,以减少冗余路径并降低空闲节点的能耗。NS2仿真测试表明,HLRNG算法有效的延长了网络生命周期。     

松辽盆地北部西斜坡嫩江组一段S1砂组沉积体系分析

综合利用286口探井的岩心、录井及测井资料,通过详细的沉积学分析,查明了松辽盆地北部西斜坡嫩江组一段发育的砂体是湖底扇.嫩江组一段S1砂组沉积时期,湖岸线在盆缘坡折附近波动时,受盆缘陡坡的控制,在西部斜坡形成了分布较为广泛的湖底扇.这种湖底扇的沉积特征是砂岩层夹在厚层暗色泥岩中,上下均呈突变接触关系.单层厚度大于2m的...     

介孔分子筛K2O／SBA-15催化酯交换反应研究

以介孔分子筛SBA-15为载体,负载KNO,后经过焙烧,制得K2O／SBA-15固体碱催化剂。对K2O／SBA-15催化丙烯酸甲酯与正丁醇合成丙烯酸正丁酯的酯交换反应进行了研究。结果表明,当K2O负载量为2％,反应时间为6h,反应温度为180℃,n（正丁醇）／n（丙烯酸甲酯）为4,m（催化剂）／m,（原料）为0．1时,丙烯酸甲酯的转化率最大,为64．22％。     

纳米K2CO3/CaO催化大豆油制备生物柴油

以K2CO3、纳米CaCO3(自制)为原料,K2CO3的负载质量分数为50%,在750℃焙烧3 h得到纳米K2CO3/CaO固体碱催化剂,并通过XRD、FT-IR及TG-DSC等手段进行确认.再用该催化剂催化制备生物柴油,结果表明:制备生物柴油的最佳条件为温度70℃,质量分数3%的纳米K2CO3/CaO,醇油摩尔比12...     

Electrochemical Performance of Nd1.95NiO4+δ Cathode supported Microtubular Solid Oxide Fuel Cells

Nd_1.95NiO_4+δ (NNO) cathode supported microtubular cells were fabricated and characterized. This material presents superior oxygen transport properties in comparison with other commonly used cathode materials. The supporting tubes were fabricated by cold isostatic pressing (CIP) using NNO powders and corn starch as pore former. The electrolyte (GDC, gadolinia doped ceria based) was deposited by wet powder spraying (WPS) on top of pre‐sintered tubes and then co‐sintered. Finally, a NiO/GDC suspension was dip‐coated and sintered as the anode. Optimization of the cell fabrication process is shown. Power densities at 750 °C of ∼40 mWcm⁻² at 0.5V were achieved. These results are the first electrochemical measurements reported using NNO cathode‐supported microtubular cells. Further developments of the fabrication process are needed for this type of cells in order to compete with the standard microtubular solid oxide fuel cells (SOFC).     

蒙乃尔K500合金阀盖断裂分析

蒙乃尔K500合金阀盖在制造过程中成批开裂。分析表明,阀盖的化学成分和力学性能均符合要求,其开裂是由于锻造温度过高所致。     

Microstructure and mechanical properties of NZ30K alloy by semicontinuous direct chill and sand mould casting processes

The Mg-3.0Nd-0.2Zn-0.4Zr (NZ30K) alloys were prepared by direct-chill casting (DCC) and sand mould casting (SMC) processes,respectively and their microstructures and mechanical properties were investigated.The results indicate that casting method plays a remarkable influence on the microstructure and mechanical properties of as-cast NZ30K alloy.The grain size increases from 35-40μm in the billets made by the DCC to about 100-120μm in the billets by the SMC.The aggregation of Mg12Nd usually found at the trip...