水洗法分离油砂工艺优化

对油砂水剂进行优化,以内蒙古图牧吉油砂为实验对象,考察水剂质量分数、剂砂质量比、搅拌时间及搅拌温度对尾砂残油率的影响。结果表明,在水剂质量分数为3.50%、剂砂质量比为0.4∶1.0、搅拌时间为25 min、搅拌温度为90 ℃条件下,内蒙古油砂尾砂残油率降至0.71%。改进后的水剂降低了水洗法分离油砂的剂耗与尾砂残油率。     

U肋加劲板焊接残余应力的一种简化计算方法

基于焊接残余应力数值模拟方法, 分析了U 肋加劲板各组成板件的板宽、板厚对焊接残余应力分布的影响, 揭示了U 肋与母板残余应力合力的分配规律, 提出了针对不同构造尺寸的U 肋加劲板焊接残余应力分布简化计算方法。研究结果表明:各组成板件的板宽变化对焊接残余拉应力的分布影响较小, 但对焊接残余压应力的大小影响较大;U 肋与母板的板厚比对U 肋与母板残余应力的分配比例影响较大。U 肋加劲板受压承载力计算时, 焊接残余应力分布可以采用简化方法计算, 其结果与根据数值模拟得到的焊接残余应力分布计算的结果基本一致。     

氘核中子反应截面的法捷耶夫方程理论计算

中子引起的轻核反应是核数据研究的重要内容。当前我国核数据库中氘核中子反应截面的计算结果局限于采用s 波可分离势,且入射能量在20 MeV以下。需要发展三体核反应的法捷耶夫方程理论方法,采用超出s 波的核子 核子相互作用,从而对更高能量范围内氘核全套中子反应截面做出准确的描述。本文介绍了利用法捷耶夫方程计算n+d三核子反应体系的弹性散射微分截面、破裂反应、破裂反应出射中子和质子的双微分截面的理论框架及数值计算结果,同时计算了弹性散射总截面和破裂反应总截面的激发函数。计算结果与实验数据及CENDL 32、ENDF/B Ⅷ.0、JENDL 5、JEFF 33等数据库中的评价数据符合较好。     

Strain Dependence of the Uniaxial Compression Response of Vegetable Shortening

Many soft food materials, including vegetable shortening, exhibit complex rheological behavior. For shortening, a precise determination of rheological behavior is necessary to understand its functionality as a food ingredient. Commercial vegetable shortening was subjected to monotonic and cyclic uniaxial compression tests at a wide range of loading rates. The elastic modulus determined from unloading was a function of strain, varying between 740 kPa in the shortening’s strain hardening region to 220 kPa at large strain where perfect plasticity had developed. Visual analysis of shortening specimens during the compression process showed that a rate-dependent stress overshoot was attributable to the development of a shear band following strain hardening. An elastoviscoplastic constitutive model was developed to define the complex rate-dependent compression response of vegetable shortening. Using the fundamental parameters obtained from the different types of compression tests, the proposed model accurately predicted the uniaxial compression response of vegetable shortening over a wide range (three decades) of compression rates. A model with predictive capabilities of large strain properties is desirable because shortening is subject to large strain in essentially all applications.     

基于反射波的剩余静校正技术在姬塬非纵资料处理中的应用

姬塬地区位于鄂尔多斯盆地中南部黄土塬区,地形起伏较大,低降速带厚度速度变化大,因此剩余静校正的好坏直接决定着剖面的成像精度。而非纵资料又因其缺少近偏移距信息,常规的剩余静校正方法有时会出现错位问题,本文利用CGG处理系统下新研发的基于反射波的剩余静校正模块,从原理出发,通过对实际资料的处理,分析成像效果,总结出适合于该工区的技术方法,提高成像精度。     

Viscous and elastic properties of poly(methyl methacrylate) melts filled with silica nanoparticles

In this paper it is shown that elastic properties of a poly(methyl methacrylate) melt in the linear range of deformation are more significantly influenced by the addition of silica nanoparticles than viscous ones. The effect is the strongest in the steady-state which is reached at several thousand seconds. That is the reason why the often used dynamic-mechanical experiments are not a very suitable method for investigations of that kind. Therefore, creep and creep-recovery tests were applied for the characterisation of the filled materials. The linear steady-state recoverable compliances following from the recovery experiments increase by a factor of 6 at the highest measured volume content of 2.1%. This finding is explained by the existence of long retardation times in the filled materials resulting from interactions between the fillers and matrix molecules attached to their surfaces which reduce their molecular mobility. Retardation spectra calculated from the recovery curves quantify these assumptions. The model is supported by the experimental finding that the recoverable compliance becomes smaller above a certain stress applied and approaches that of the matrix as such a behaviour could be explained by a detachment of the molecules from the particle surface. The paper demonstrates that investigations of elastic properties of nanoparticle filled polymers in the molten state at long experimental times are a very sensitive tool to get an insight into interactions between particles and macromolecules of such systems.     

气相色谱法测定牛奶屋顶包装中有机溶剂残留

建立了气相色谱分析方法测定牛奶屋顶包装中12种有机溶剂残留,即乙醇、丙酮、异丙醇、丁酮、乙酸乙酯、苯、乙酸异丙酯、正庚烷、正丁醇、乙酸丁酯、二甲苯等的方法。将样品剪至1cm×1cm碎片,于80℃下平衡30min后,抽取1mL气体于气相色谱仪检测。12种有机溶剂残留检出限为0.142～0.542mg/L;线性关系良好,相关系数均大于0.999;相对标准偏差RSD（n=6）在2%～3%之间;平均回收率在90%～110%之间。     

蒸压粉煤灰砖砌体性能试验研究

通过对蒸压粉煤灰砖砌体性能试验研究,表明蒸压粉煤灰砖满足国家规范要求．完全可以取代红砖。     

Instrumented Micro-indentation of Zirconia Ceramics

Instrumented micro-indentation experiments are conducted with Vickers and spherical indenters in Y-TZP and two different Mg-PSZ ceramics. The load ( P )–depth of penetration ( h ) curves from Vickers indentation can be fitted to P = Ch ⁿ with n ∼ 1.8. It is shown that within the micro-indentation range, measurements of Young's modulus ( E ) can be conducted in zirconia ceramics using sharp indenters, and that the results are consistent with those from spherical indentation. Quantification of piling-up and sinking-in is accomplished from P – h curves. Results from finite element computations are used to assess pressure-sensitivity and plastic-hardening coefficient from indentation experiments.     

Enhanced properties of pure alumina ceramics by oscillatory pressure sintering

A novel oscillatory pressure sintering (OPS) process to consolidate high-quality pure alumina ceramics is reported. The microstructure of the ceramics prepared by OPS develops into a higher final density, a smaller and a narrower distribution of grain sizes compared with those prepared by conventional pressureless sintering (PS) and hot-pressing (HP) processes. Enhanced mechanical properties of alumina ceramics were investigated by OPS process. The bending strength, hardness and elastic modulus of the OPS specimen reached about 546 MPa, 19.1 GPa and 374 GPa, respectively, i.e values significantly higher than that of the specimens by PS and HP. XRD analysis indicates the strengthening of atomic bonds aided by oscillatory pressure. The results suggest OPS to be an effective technique for preparing high-quality pure alumina ceramics.