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.     

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.     

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.     

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.     

Rheological characteristics of aged asphalt binder

Different aging levels(RTFOT,PAV-10h,PAV-20h and PAV-30 h) of asphalt binders with various mass ratios of mineral powder to asphalt(0,0.4,0.8,1.2,1.6,2.0) were used to investigate the rheological properties of aged asphalt binders with respect to their short and long terms aging characteristics.Viscosity test,dynamic shear test and creep test were conducted.The test results indicate that the viscosity of aged asphalt binder increases sharply with the extension of aging period.Complex shear modulus of aged asphalt increases,which indicates that the stiffness of asphalt binders can increase.The phase angle for aged asphalt binders reduces,which indicates that the elastic portion for viscoelastic property of asphalt binders increases.|G*|·sin δ increases after aging procedure which means that the fatigue resistance becomes poor.The creep test results show that creep strain curves varies remarkably for virgin and aged asphalt binders.The total strain during loading period and the permanent strain decreases significantly for aged asphalt binders,which implies that the elastic portion increases and the viscous portion decreases.     

浅析移动通信系统中的赋形权值优化算法

随着无线频谱资源的日益紧张,移动通信系统转向利用数字波束赋形技术来提高系统的容量。数字波束赋形技术的关键,是利用赋形权值优化算法对赋形权值进行寻优操作。常用的权值优化算法有遗传算法、粒子群优化算法和交叉熵算法。本文对三种优化算法应用时的关键步骤进行了总结,比较了三种算法的性能,最后对算法应用于时分移动通信系统存在的问题进行了分析。     

会话密钥分配协议的分析与设计

阐述并分析了通信网络中常用的两种会话密钥分配协议的安全性能，指出这两种密钥分配协议的不完善和不安全之处。提出了改进的措施，新的协议具有更好的安全性、可靠性和实用性。最后提出评价和设计会话密钥分配协议的几条原则。     

Dynamic characteristic analysis of intelligent beams structures based on the correlation of interval parameters

The problem of intelligent beam structural dynamic characteristic is studied under the condition that interval physical parameters are correlative. Firstly, the interval variables are turned into the product of the interval coefficients by the certain portion, and the interval coefficients are supposed to be of an allowable range, with the random variables obeying random rectangle distribution in the definition region. Secondly, The mean value and variance of interval eigenvalues equations are deduced by the Moment method for random variable function solutions under the condition that they are correlative each other. The bounds of eigenvalues are obtained by the mean value and variance of rectangle distribution. Finally, the feasibility and validity of this approach are verified by an engineering example. For comparisons, the corresponding eigenvalues ranges are obtained on the assumption that the interval variables are independent of each other and interval parameters are different in correlation.     

一类新的模糊控制算法

本文针对模糊控制器输入输出是确定量的特点,提出一类新的简单的推理决策算法。首先对隶属函数进行一般化的定义,然后用输入模式和规则模式表示过程测量值和用语言描述的人的控制规则。推理算法简化为在输入空间中两类模式的匹配度计算和最后的加权平均计算。在多维体积比和相对距离两种方法度量匹配度情况下,给出了4个具体算式。及算法的完整步骤,最后讨论了它的优点和局限。     

软件测试资源与成本管控和最优发布策略

为全面系统地了解软件测试过程中与可靠性相关的重要过程的研究现状和最新发展,对测试资源和成本的管理,以及最优发布技术问题进行了深入研究。首先将研究问题划分为4类,剖析了测试资源分配与控制,成本模型和最优发布基本内容,给出了其公式化的形式化描述和内在关系;然后从软件体系结构建模、测试过程建模、非线性最优化与仿真求解3个方面进行了技术分类评述。进一步将研究内容从5个方面进行归一化分类,并对选取的典型模型进行了归类比较总结。最后,指出了进一步研究发展的主要问题。研究分析表明,测试资源分配与成本管控和最优发布策略中,考虑到软件体系结构特征和不完美排错模型,向多目标融合方向发展,并与可靠性评估相关是后续研究的研究。     

基于等价鞅方法下认股权证的定价模型

分析了影响认股权证价值的主要因素以及认股权证与期权定价的主要区别,介绍了现行的几种认股权证的定价方式,并着重阐述了等价鞅方法,推导出了合适的类似Black-Scholes模型的认股权证公式,在对一些基本假设做出修正的基础上,推导出了一些应用于特殊情况的权证定价公式,可为同类研究参考.     

国外铁流体换能器的研究情况

本文简要评述了国外铁流体换能器的研究情况,分析了铁流体换能器研究背景以及它的工作原理,提供了美国海军研究所所研制的两种铁流体换能器的设计方案,讨论了铁流体换能器的特点.文章对我国研制铁流体换能器的可能性和必要性提出了看法,并提供了有关的参考文献.     

让教学成果在教学改革中发挥作用

就教学成果在实践教学中如何发挥作用做以阐述。在实践教学中,创造良好的教学环境,引入现代化手段,不断改进实验装置,优化调整实验内容,从而加 强对学生实验技能的培养,提 高学生的综合能力。     

NC机床伺服进给系统动态特性的测试方法

本文讨论了在数控机床、加工中心等实际机床上进行伺服进给系统动特性测试的可行性,提出了倒谱平均法等三种测试方法。通过JCS—018立式加工中心伺服进给系统动态特性的实测与计算机仿真的对比,证实了这些方法是有效的,得到的结果能相互引证,是令人满意的。     

食用海参的名称与种类鉴别

食用海参在中国和东南亚地区是一类运用历史悠久的烹饪原料 ,但对其种类资源情况一直缺乏系统的、比较准确的文献记录。由于食用海参的种类较多、学名历有更迭、中文名称杂乱 ,因此在已经出版的许多文献中 ,学名和俗名都很混乱。根据文献的零星记载和标本的鉴定情况 ,我国可供食用的海参大约有 2 1种 ,隶属于 3个目、4个科 ,并对其中主要的食用海参的名称进行了鉴别 ,对形态特征进行了描述