幂律型流体柱形渗透注浆机制

为进一步完善与丰富幂律型流体的渗透注浆理论,探讨了幂律型流体的柱形渗透注浆机制.采用理论分析与实验研究等方法,以幂律型流体流变方程及渗流运动方程为基础,推导了幂律型流体柱形渗透注浆扩散机制;分析它的适用范围及参数确定方法,并设计室内注浆试验对其进行验证.结果表明:实际测量计算的幂律型流体在被注砾(砂)石体中的等效扩散半径值与由幂律型流体柱形渗透注浆扩散机理公式计算出的扩散半径理论值间虽有30%35%的差异,但都处于可接受误差范围内.幂律型流体柱形渗透注浆扩散机理在整体上能较好地反映幂律型流体在被注介质中的柱形注浆渗透扩散规律,可为实际注浆施工提供理论支撑与指导作用.     

耦合试验与模型计算的表土渗透系数推求方法

针对黄土高原北部六道沟流域5种土地利用方式开展了表土渗透与比贯入阻力试验,并基于水量平衡原理及稳定渗透理论构建了表土非饱和渗透系数简易渗透模型,耦合两种试验和模型推求了表土非饱和渗透系数。研究结果表明:在研究区内,非饱和渗透系数和表土比贯入阻力的相关系数在0.93以上,表土非饱和渗透系数的数量级为10-5m/s,各种土地利用方式下表土非饱和渗透系数大小次序为:坡面苜蓿地坡面草地草地(淤地)农田(淤地)裸地(沙黄土)。研究结果可为土壤水力学特性研究及构建渗透模型提供理论与方法的借鉴。     

Search for cold fusion using Pd-D2O cells and Ti-D mixtures

We have searched for cold fusion produced in an electrolytic cell with Pd cathode and Pt anode. The electrolyte was 0.1 molar LiOD in 99.8% D₂O. A 2-mm rod of polycrystalline Pd and a 4-mm rod of single crystal Pd were used. No radiation was detected above background by a BF₃ neutron and Ge -X detector. The D₂ loading of the Pd was 0.8 D per Pd atom reaching saturation after 4 hours. We also attempted to duplicate the work of Scaramuzzi and co-workers on the Ti-D₂ system. Both powder and pieces of Ti were used. The material was cycled several times between 1100 K and 77 K. No neutron, - or x-ray emission above background was observed. The results of a barrier penetration calculation for H-like atoms are presented. The high fusion rates reported for PdD _x . are much larger than those expected from theoretical calculations on these systems.This work supported by USDOE under Contract nos. W-7405-ENG-82 and DE-FG02-87ER40371.     

Effect of rifle bullet parameters on the penetration into ballistic gelatin

To understand the effects of the rifle bullet parameters on the bullet-gelatin interaction quantitatively, a finite element model of bullet penetrating gelatin was set up and computational results are compared with experimental ones. The penetration of the rifle bullet into the gelatin was simulated by the nonlinear finite element method. The quantitative analysis of the changes in the gelatin interaction with the rifle bullet were conducted by changing the bullet parameters, such as attack angle on gelatin, initial velocity, warhead's tip and location of mass center of bullet. Results demonstrate that with the increase of the attack angle, instable moment of the bullet moves forward,the length of narrow wound channel shortens,and when penetration is completed diameters of temporary cavities increase, the gelatin energy and energy transmission ratio increases; With the increase of the impact velocity, instable moment of the bullet moves forward, the maximum forces acting on the gelatin and the gelatin energy increase remarkably; the length of narrow wound channel shortens, diameters of temporary cavities increase when penetration is completed, the gelatin energy and energy transmission ratio increase; The warhead's tip and location of mass center have a influence on the instable moment of the bullet and length of the narrow wound channel. The instable moment delays and narrow wound channel increases when the warhead's tip flattens. The instable moment moves forward a little and the narrow wound channel shortens a little when location of mass center moves back.     

Properties of supersulphated phosphogysumslag cement (SSC) concrete

Supersulphated phosphogysum-slag cement （SSC） is a newly developed non-burned cementitious material mainly composed of phosphogysum （PG） and ground granulated blast furnace slag （GGBFS）, with small amount of steel slag （SS） and clinker （CL）. SSC is a kind of environmentally-friendly cementitious material due to its energy-saving, low-carbon emission, and waste-utilization. We prepared concretes with supersulphated phosphogysum-slag cement, and studied the mechanical properties, micro- properties and resistance to chloride penetration of concrete in comparison with those of portland slag cement （PSC） and ordinary portland cement （OPC） concrete. The test results show that the compressive strength of SSC concrete can reach 38.6 MPa after 28 d, close to PSC concrete and OPC concrete. Microanalyses indicate that large quantities of ettringite and C-S-H, and little amount of Ca（OH）2 are generated during the hydration of SSC. The dense cement paste structure of SSC is formed by ettringite and C-S-H, surrounded unreacted phosphogysum. The property of resistance to chloride penetration of SSC concrete is better than PSC and OPC concrete due to the fact that SSC can form much more ettringite to solidify more Cl^-.     

双氯芬酸钾软膏的制备及其体外累积释药率的测定

制备双氯芬酸钾软膏并且应用Franz扩散池法测定其在不同测定温度和接收介质中的体外累积释药率,结果显示在测定温度为37℃、接收介质为磷酸盐缓冲液(pH=7.0)时软膏的累积释药率高达90%以上,透皮速率为2.08μg·cm-2·h-1,可以达到实验设计的目的.     

气体辅助注射成型中气道截面对气体穿透的影响

将各种不同气道截面等效于圆形,引入形状因子来衡量它们偏离圆形的程度。利用moldflow软件对气体在不同构型气道内的穿透过程进行了数值模拟。结果表明:形状因子越大则气体穿透深度越大,对气体辅助注射成型有利。但由于形状因子越大则气道截面偏离圆形越远,不利于形成均匀的熔体壁厚,因此在设计气道截面时,应合理选择形状因子以便获得恰当的气体穿透深度和熔体壁厚。最后还给出了气道设计的一般原则。     

叠层靶对低速弹丸的抗侵彻性分析

层间界面位置对由薄厚两层钢板组成的叠层靶的抗侵彻性具有重要影响.本文对低速弹丸侵彻叠层靶问题进行了量纲分析和数值模拟,对层问界面位置对叠层靶抗侵彻性的影响规律进行了研究.分析认为:弹丸低速侵彻中厚靶条件下,随着叠层靶界面位置沿弹丸侵彻方向的移动,叠层靶的抗侵彻性先增大后减小,并存在一个极大值.典型试验结果表明:在给定试验条件下,上下层厚度比为2.0的叠层靶,抗侵彻性明显好于上下层厚度比为0.5的叠层靶.     

循环流化床锅炉风帽射流深度实验研究

对包头第一电厂10#锅炉改造前后的两种风帽射流深度进行了理论分析和研究.根据动量定理和适当的物理简化,建立了风帽斜向下射流的物理模型,并推导出了关于射流深度的三次方程,因而可获得直接的理论解.根据密度相近的模化条件建立了射流运动的等效水模化试验台.最后,对改造前后两种风帽在循环流化床锅炉密相区的射流深度进行了对比.结果表明,实测的射流穿透深度和理论计算值吻合;采用侧箭头型风帽与7型风帽射流深度的变化不大,符合改造要求.     

不同级配类型沥青混合料抗剪性能研究

为了评价不同级配类型沥青混合料的抗剪性能,采用单轴贯入法对混合料进行抗剪试验。试验结果表明,级配对混合料的抗剪性能影响显著。对于密级配沥青混合料(AC),细级配混合料的抗剪性能优于粗级配混合料;随着公称最大粒径的增大,混合料的抗剪强度迅速降低。而对于间断级配沥青混合料(SAC),其抗剪强度则随公称最大粒径的增大而增加。所以从抗剪角度来说,悬浮密实的AC系列混合料适合采用小粒径,而骨架密实的SAC系列混合料则适合采用大粒径。同时试验结果还显示SBS改性沥青能有效的改善混合料的抗剪性能。据此,可以更加合理的选择混合料。