Research advances of un-symmetric constitutive theory of anisotropic viscoelastic liquids and its hydrodynamic behavior

Research advances of un-symmetric constitutive equation of anisotropic fluid,influence of un-symmetric stress tensor on material functions,vibrational shear flow of the fluid with small amplitudes and rheology of anisotropic suspension were reported.A new concept of simple anisotropic fluid was introduced.On the basis of anisotropic principle,the simple fluid stress behaviour was described by velocity gradient tensor F and spin tensor W instead of velocity gradient tensor D in the classic Leslie-Ericksen continuum theory.Two relaxation times analyzing rheological nature of the fluid and using tensor analysis a general form of the constitutive equation of co-rotational type was introduced.More general model LCP-H for the fluid was developed.The unsymmetry of the shear stress was predicted by the present continuum theory for anisotropic viscoelastic fluid-LC polymer liquids.The influence of the relaxation times on material functions was specially studied.It is important to study the unsteady vibrational rotating flow with small amplitudes,as it is a best way to obtain knowledge of elasticity of the LC polymer,i.e.dynamic viscoelasticity.For the shear-unsymmetric stresses,two shear stresses were obtained thus two complex viscosities and two complex shear modulus(i.e.first and second one) were introduced by the constitutive equation which was defined by rotating shear rate introduced by author.For the two stability problems of fluid,such as stability of hydrodynamic flow and orientational motion,were discussed.The results show that the polymer suspension systems exhibit anisotropic character.The PNC systems can exhibit significant shear-thinning effects.For more concentrated polymer nano-suspensions,the first normal stress difference change from positive to negative,which is similar to LC polymer behavior.     

当前民办高校融资难的成因及对策

针对民办高校所需办学经费无国家财政拨款,全部为自筹资金的现状,分析了形成当前民办高校融资难的原因,既有信贷政策、银行方面的因素,也有民办高校自身的因素.提出民办高校要生存,要发展,光靠举办者投入或捐赠以及每年的学费收入是不够的,还需要积极拓展更多融资渠道解决办校融资难的问题.     

脉冲振动预磁器的研究和设计

根据细粒磁性物回收工艺中需要使用预磁器的要求,研究预磁器的工作时序、充放电回路的电器元件特性和电路电压、电流特征.设计的电磁预磁器磁场强度高,能耗低,性价比高.对预磁化电路展开理论计算和推导.首次提出脉冲振动预磁器系统结构,将RLC电路振荡波形转变为振动波形,形成"脉振"高场强,延长了线圈的使用寿命.经实际运行检验,该装置性能稳定,效果好,能耗低,每小时耗电仅0.8 kW,在预磁器领域是一项创新的实用技术.     

城市污水热能资源化的基础研究

作为城市污水热能资源化的基础研究,根据理论分析方法,对有效利用城市污水所赋存的热能时,其节能效果和对减轻大气污染的作用进行了若干分析和探讨.分别计算了流量为1 m3/s时城市污水赋存的热量,以及采暖面积为1万m2时所需的城市污水及赋存的热量,与空调、锅炉相比产生相同热量时的一次能和二次能的消减量,以及相应条件下的污染物年间(采暖期)消减量等.     

Vibrational shear flow of anisotropic viscoelastic fluid with small amplitudes

Using the constitutive equation of co-rotational derivative type for anisotropic viscoelastic fluid-liquid crystalline(LC),polymer liquids was developed.Two relaxation times are introduced in the equation:λn represents relaxation of the normal-symmetric stress components;λs represents relaxation of the shear-unsymmetric stress components.A vibrational rotating flow in gap between cylinders with small amplitudes is studied for the anisotropic viscoelastic fluid-liquid crystalline polymer.The time-dependent constitutive equation are linearized with respect to parameter of small amplitude.For the normal-symmetric part of stress tensor analytical expression of the shear stress is obtained by the constitutive equation.The complex viscosity,complex shear modulus,dynamic and imaginary viscosities,storage modulus and loss modulus are obtained for the normal-symmetric stress case which are defined by the common shear rate.For the shear-unsymmetric stress part,two shear stresses are obtained thus two complex viscosities and two complex shear modulus(i.e.first and second one) are given by the constitutive equation which are defined by rotating shear rate introduced by author.The dynamic and imaginary viscosities,storage modulus and loss modulus are given for each complex viscosities and complex shear modulus.Using the constituive equation the rotating flow with small amplitudes in gap between two coaxial cylinders is studied.     

科技期刊版式设计略谈

对科技期刊版式设计中的标题、插图与空白的处置进行了分析探讨,认为科技期刊版式设计在总体上应是追求格式一致与节奏变化的统一,整体性与连贯性的统一.布局合理的版式设计带给期刊的是整体的和谐美,别具风格的版式设计标志着期刊的个性特征.     

玉米中转基因成分的定性PCR检测

利用改良 CTAB 法提取玉米产品的基因组 DNA,应用 PCR 检测方法,并以玉米特异性内源基因 IVR 为内参,花椰菜花叶病毒 35S 启动子(CaMV35S 启动子)、农杆茵胭脂碱合成酶终止子(NOS终止子)为靶基因检测玉米中是否存在转基因成分.实验结果表明,有些玉米样品中存在转基因成分,表明市场上存在未经标识的转基因玉米及其加工品.     

利用双折射晶体实现双偏振光叠加的教学研究

利用晶体的双折射现象和它的基本性质,采用现代光纤和CCD摄像放大技术手段研究了双偏振光的叠加和干涉现象,讨论了学生在教学中不易理解的难点问题.     

单极世界军备竞赛微分方程稳定性的研究

对一国或多国军备竞赛的数学模型进行了研究.单独一国的经济增长服从Horrod-Domer模型,但当多国一起竞争时,弱国将遭受前所未有的严重挑战.通过研究超级大国、另一大国和弱国这三个国家之间军备竞赛稳定性问题,得到了军备竞赛稳定性的条件.     

Effect of sediment on vertical dynamic impedance of rock-socketed pile with large diameter

Based on the fictitious soil pile model, the effect of sediment on the vertical dynamic impedance of rock-socketed pile with large diameter was theoretically studied by means of Laplace transform technique and impedance function transfer method. Firstly, the sediment under rock-socketed pile was assumed to be fictitious soil pile with the same sectional area. The Rayleigh-Love rode model was used to simulate the rock-socketed pile and the fictitious soil pile with the consideration of the lateral inertial effect of large-diameter pile. The layered surrounding soils and bedrock were modeled by the plane strain model. Then, by virtue of the initial conditions and boundary conditions of the soil pile system, the analytical solution of the vertical dynamic impedance at the head of rock-socketed pile was derived for the arbitrary excitation acting on the pile head. Lastly, based on the presented analytical solution, the effect of sediment properties, bedrock property and lateral inertial effect on the vertical dynamic impedance at rock-socketed pile head were investigated in detail. It is shown that the sediment properties have significant effect on the vertical dynamic impedance at the rock-socketed pile head. The ability of soil-pile system to resist dynamic vertical deformation is weakened with the increase of sediment thickness, but amplified with the increase of shear wave velocity of sediment. The ability of soil pile system to resist dynamic vertical deformation is amplified with the bedrock property improving, but the ability of soil-pile system to resist vertical vibration is weakened with the improvement of bedrock property.     

泥水盾构开挖面前泥浆渗透距离预测算法

为了计算泥水盾构开挖面前泥浆渗透地层的距离,基于泥浆渗透不伴生泥膜的假设,提出改进模型来分析不同泥浆的渗透距离. 结果表明：在泥浆渗透时间小于20 s的情况下,与Xu模型相比,改进模型的最大精度提高6%,且无须泥浆渗透试验. 在不考虑泥膜的情况下,纯膨润土泥浆的最大渗透距离为5.8~6.3 m;添加高分子材料的膨润土泥浆最大渗透距离为0.3~1.6 m,是纯膨润土泥浆的5%~25%;羧甲基纤维素钠对泥浆的改性效果最好. 微透水泥膜的形成时间为3.2~5.0 s. 考虑泥浆渗透伴生泥膜的情况,得到改进模型的修正系数为0.72~0.92. 预测常用的泥浆渗透距离,当盾构刀盘切削周期为10 s时,泥浆渗透距离为2.3~6.3 cm,最大的渗透距离是一般盾构直径（6 m）的1.05%.     

HP-β-CD对脂质体和真核细胞通透性的影响

以薄膜水化法制备的阴离子脂质体的平均粒径为（180±2.3）nm．Zeta电位为-33．9mV．分别以脂质体中钙黄绿素的泄露量和紫外分光光度法测定蛋白含量,以表征羟丙基书-环糊精（HP-β-CD）对脂质体和真核微生物蓝色犁头霉（Absidiacoerulea）细胞通透性的影响．结果表明：在HP-f1．CD作用下,两者的通透性变化趋势一致．分析比较HP-β-CD作用下的甾体化合物17a,21-二羟基孕甾-4-烯-3,20-二酮（RS）在脂质体和菌体细胞中的通量变化的相关性,表明脂质体与细胞通量变化的拟合度达到97．9％,相关性显著（P〈0．05）．由此说明,本研究建立的脂质体制备方法以及获得的脂质体能够模拟真核细胞,应用于真核微生物的生物学研究．     

矿物掺合料对混凝土抗氯离子渗透性影响研究

氯离子渗透腐蚀是引起钢筋混凝土腐蚀的主要原因,然而氯离子渗透性和矿物掺合料有直接关联。主要通过实验研究了掺入矿物掺合料后混凝土中孔结构的特征,进而分析了矿物掺合料对混凝土抗氯离子渗透性的影响。     

微网高渗透对电网稳定性的影响分析

微网对电网的渗透改变了电网中能量传递的单向性,对现有电网的稳定性产生较大影响．分析不同渗透率下微网对电网电压稳定和功角稳定的影响,通过标准EPRI 36节点测试平台进行数字仿真验证,得出允许的最大渗透率,并进一步讨论了影响渗透率的主要因素,为微网中各分布式发电的最优能量匹配和提高微网并网时电网的可靠性、稳定性提供一定的理论依据．     

弹丸侵彻混凝土靶的MSC.Dytran数值模拟

采用嵌入高压状态方程的Johnson-Cook混凝土本构模型,利用有限元程序MSC.Dytran,对动能弹以200～1000m/s的速度侵彻混凝土靶板进行数值计算,得到弹体的速度曲线、加速度曲线及不同弹体初速度下的最大侵彻深度;并结合弹体几何相似准则,给出弹体无量纲初速度和无量纲最大侵彻深度间的关系.     

松花江漫滩地区静压PHC管桩沉桩阻力理论估算与数值分析

目的给出松花江漫滩地区采用综合调节系数法估算静压PHC管桩沉桩阻力所需要的综合修正系数;找出数值分析的静压PHC管桩沉桩阻力与估算的沉桩阻力及实测压桩力之间的关系．方法根据松花江漫滩地区具有代表性工程的静力触探数据和实测压桩力,对采用综合调节系数法估算的静压PHC管桩沉桩阻力与实测压桩力进行对比分析;采用有限元分析软件ANSYS对代表性工程的静压PHC管桩的桩土相互作用进行数值分析．结果松花江漫滩地区采用综合调节系数法估算静压PHC管桩沉桩阻力所需要的综合修正系数为α为0．5—1．0、β为0．6～1．0;数值分析的静压PHC管桩沉桩阻力与估算的沉桩阻力及实测压桩力之间存在一定误差,但变化趋势是一致的．结论静压PHC管桩沉桩过程与静力触探过程之间存在着内在的、本质的联系,采用静力触探数据估算静压管桩的沉桩阻力是可行的;针对松花江漫滩地区相似性质的土层,采用给出的综合修正系数,得到静压管桩的沉桩阻力,从而合理地选择施工设备,降低工程造价．     

两种添加剂对石蜡针入度的影响

对于一般的 q- 1维正规单纯形利益区域和多重线性多项式模型 ,利用n(≤ q)阶多重线性多项式的最优设计 ,采用了极端顶点设计及棱中心设计方案 ,选用 16个实验数据 ,建立石蜡在两种添加剂的作用下针入度性质的 3阶多重线性多项式的针入度拟合方程 :f(x1,x2 ,x3 ) =- 172 .5 9+5 96 8.91x1- 5 830 .5 7x21+2 5 0 4 .4 4x3 1- 32 .4 9x2 。并对其协同效应、对抗效应和可加效应以及变化趋势进行了研究 ,结果表明 :动物蜡添加剂对石蜡针入度的影响不显著 ,而植物蜡添加剂对石蜡针入度的影响显著 ,并可以利用拟合方程对添加剂作用于石蜡的针入度的物理特性进行预测。这一结果对石蜡新产品的研究具有参考价值。     

石油沥青针入度与温度的关联研究

针入度是表征沥青产品软硬程度和中温抗疲劳的技术指标,也是针入度分级体系的分级指标。相关文献都得出针入度的对数与摄氏温度具有非常高的相关性。但是所有文献均未涉及针入度的对数或针入度的双对数与摄氏温度、绝对温度的倒数之间的关联研究。为了探索针入度分级体系、黏度分级体系和Performance Grade分级体系之间的相关性,采用两种原油生产的10个沥青产品研究了15、25、30 ℃的针入度的对数和双对数分别与摄氏温度、绝对温度的倒数之间的线性相关性以及这些线性相关性的斜率和截距之间的线性相关性。通过相关系数的对比发现,国内外检索到的文献中存在将近80年的针入度的对数与摄氏温度之间的线性关系并不是表征针入度与温度之间的最优线性关系,针入度的对数与绝对温度倒数的线性相关性高于针入度的对数与摄氏温度的相关性。针入度的对数与绝对温度的倒数的线性方程中斜率和截距之间也具有很高的线性相关性。研究发现,文中所有沥青的针入度与温度之间的关系均可以用一个方程来表达。     

湿陷性黄土地区公路地基承载力的评价

通过西北黄土代表性区域兰州、介休、阎良等地湿陷性黄土原状地基和强夯冲击碾压处理后地基进行的室内土工试验和原位测试,对载荷试验、旁压试验、静力触探、动力触探和标准贯入等试验在公路工程地基承载力评价时的可行性进行探讨,并对强夯和冲击碾压处理黄土地基的处理效果进行分析.试验结果表明,湿陷性黄土地区公路工程地基承载力评价时,旁压试验在一定程度上可以取代浅层的载荷试验,并作为地基处理后承载力评价的主要测试方法;240 t.m强夯处理湿陷性黄土地基的有效加固深度为4 m,有效影响深度为5~6 m;冲击碾压的有效加固深度为0.5~1.0 m,有效影响深度为1~2 m.     

建筑钢结构熔透对接焊缝缺陷对焊缝抗拉承载力影响的研究

超声波探伤计算建筑钢结构熔透对接焊缝的缺陷率,对含有不同位置缺陷及缺陷率的焊缝进行拉力试验,用缺陷率-焊缝强度关系图分析焊缝抗拉承载力达到:母材强度,GB50017-2003一、二、三级熔透对接焊缝设计值,母材屈服强度标准值时,建筑钢结构熔透对接焊缝可允许存在的体积性缺陷率限值.研究结果表明:存在于熔透对接焊缝中部的缺...