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1.
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.  相似文献   

2.
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.  相似文献   

3.
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.  相似文献   

4.
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.  相似文献   

5.
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.  相似文献   

6.
科技期刊版式设计略谈   总被引:1,自引:0,他引:1  
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.  相似文献   

7.
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.  相似文献   

8.
玉米中转基因成分的定性PCR检测   总被引:1,自引:0,他引:1  
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.  相似文献   

9.
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.  相似文献   

10.
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.  相似文献   

11.
齿轮—五杆机构的轨迹特性研究   总被引:4,自引:0,他引:4  
采用计算机机构动画仿真的方法,对齿轮五杆机构的轨迹特性进行了研究。分析了该机构双曲柄存在的条件,两连杆铰接点C的轨迹曲线可到达的区域及该轨迹曲线形状随机构结构参数的不同而变化的规律,从而为齿轮五杆机构的轨迹综合提供了重要依据。  相似文献   

12.
数学优化方法在新安江模型参数率定中的应用分析   总被引:3,自引:0,他引:3  
以3种数学优化方法及新安江(三水源)模型的理论为依据,介绍了优化方法在新安江三水源模型参数率定中的应用.将率定成果与API模型进行了对比,说明这3种优化方法在大宁河流域参数率定中应用效果良好,具有很好的参考和推广价值.  相似文献   

13.
扬声器的自滤波特性与D类功放失真的改善   总被引:1,自引:0,他引:1  
应用动圈式扬声器的电—力—声类比等效线路对动圈式扬声器的频率特性进行了初步的研究,提出了利用扬声器的自滤波性能改善因D类功放移相网络引起信号相位失真的方法。同时,采用比较、反馈的方法对音频信号的谐波加以抑制,使得数字功放的总体失真指数下降。  相似文献   

14.
物联网演进路线的探究   总被引:1,自引:1,他引:0  
分析研究物联网的起源及发展路线,并从人和物二个角度探讨网络的技术特征,给出物联网的演进模型。分析结果显示,虚拟世界与物理世界对信息通信的探索将会融合,物联网发展的终极目标是网络的泛在化。据此结论,从公共物联网和系统应用角度对我国物联网的发展与研究提出两点建议。  相似文献   

15.
长江三角洲区域是我国沿海三大经济区之一。当前,该区际经济一体化正处于快速发展阶段。分析了区域经济的形成机制和长三角区域经济一体化的内在要求、整合条件及存在问题,从市场和政府这两个层面提出进一步加强长江三角洲区域经济一体化的策略。  相似文献   

16.
旅游地环境的可持续发展问题   总被引:4,自引:0,他引:4  
对旅游业的资源型特点,当前旅游业发展对旅游地环境的影响程度,以及不断强化旅游地环境保护的重意义作了精辟地分析.提出了以人为本、突出特色、塑造形象、科学规划和管理的旅游地环境可持续发展的思想和方法.  相似文献   

17.
采用不同浓度的纤维索酶和果胶酶混合液对红豆杉种子的胚进行了处理,采用3% 0.5%(m/v)的纤维索酶 果胶酶混合液效果好.得到了红豆杉胚原生质体;同时采用了B5、V-KM、MS3种培养基对所得到的原生质体进行了初步培养;实验结果表明.采用V-KM附加椰子汁(含天然植物激素)培养基培养胚性原生质体效果较好,并研究了植物激素的浓度和光照强度等对愈伤组织的诱导的影响,表明采用IAA和NAA对愈伤组织生长效果较好,光照强度在1000lx生长效果较好.  相似文献   

18.
蒸汽发生器炉管剩余寿命可靠性分析   总被引:1,自引:0,他引:1  
通过对炉管材料高温性能分析,结合蒸汽发生器工况条件,综合考虑影响其寿命的腐蚀、温度、损伤等不确定因素,利用可靠性理论和方法,建立炉管剩余寿命的预测模型,对炉管剩余寿命进行可靠性分析。计算分析表明,腐蚀速率是影响蒸汽发生器炉管寿命的重要因素,提高蒸汽发生器炉管运行寿命首要工作是减少炉管的腐蚀。以油田多台在役蒸汽发生器为例进行计算,结果表明,该预测模型是正确的,符合实际的。计算软件的应用为蒸汽发生器的维修决策提供了科学依据,并大大地提高了油田生产效率。  相似文献   

19.
完善装备采购信息发布工作,对安全、平等、高效地传递装备采购信息,打破军工行业垄断,加快装备竞争性采购进程具有十分重要的意义。揭示了装备采购信息发布工作存在的问题及成因,分析了完善装备采购信息发布工作的必要性,提出了完善装备采购信息发布工作的4点对策。  相似文献   

20.
确定盘形凸轮曲率半径的相对加速度法及其应用   总被引:2,自引:0,他引:2  
提出了一种确定盘形凸轮曲率半径的新方法。该方法基于在世界坐标系中,质点沿空间曲线运动时,其速度,法向(向心)加速度和空间曲线曲率半径之间的关系,利用凸轮与从动件的相对速度和相对加速度来确定凸轮的曲率半径。应用从动件和支承绕凸轮轴线反转的模型,将凸轮与从动件的相对速度和相对加速度转变成绝对速度和绝对加速度,凸轮的曲率半径或理论曲率半径转变为凸轮与从动件接触线或者滚子轴线轨迹的曲率半径;利用复数向量结合从动件坐标系中的分量表达位移,速度和加速度,导出了4种常用凸轮机构的凸轮曲率半径解析表达式。该方法推导凸轮曲率半径解析表达式过程简单,意义明确,适用范围较广。  相似文献   

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