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.     

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.     

Performance of an activated carbon made from waste palm shell in simultaneous adsorption of SO<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript> and NO<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript> of flue gas at low temperature

This study examined the individual and simultaneous adsorption of SO{in{itx}} (SO{in{it2}}) and NO{in{itx}} (NO-NO{in{it2}}) on activated carbon prepared from waste palm shell. The adsorption process was examined in a fixed bed reactor at low temperatures (100\2-300\dgC). For individual adsorption without any catalytic activation, SO{in{itx}} showed good adsorption whereas NO{in{itx}} was very much poor. In the simultaneous adsorption of SO{in{itx}} and NO{in{itx}}, SO{in{itx}} showed greater adsorption affinity than NO{itx}. For palm shell activated carbon (PSAC) impregnated with metal catalyst (Ni and Ce) the concentration adsorbed profile showed that the amount of SO{in{itx}} adsorbed decreased regularly, while the amount of the adsorbed NO{in{itx}} increased irregularly. The properties of the pure and impregnated PSAC were analyzed by BET, SEM and EDX. These investigations indicated that PSAC impregnated with metal catalyst is the determining factor in the adsorption of SO{in{itx}} and NO{in{itx}} simultaneously. Supported financially by Yayasan FELDA, Malaysia (Grant No. 6050075)     

Corrosion behavior and corrosion products of a low-alloy weathering steel in Qingdao and Wanning

A newly developed low-alloy weathering steel has been exposed in two coastal sites (Qingdao in the north,Wanning in the south) in China for one year.The samples in Wanning corroded far more seriously than those in Qingdao.The rust layer formed on the steel was analyzed by X-ray diffraction (XRD),scanning electron microscopy (SEM),N2 adsorption approach,polarization curves,and electrochemical impedance spectroscopy (EIS).The rust formed in Qingdao contains more X-ray amorphous compounds and is more compact than that formed in Wanning.Cr and Cu are enriched in the rust layer near the steel matrix,and the phenome-non is more obvious in Qingdao than in Wanning.The rust layer formed in Qingdao suppresses the anodic and cathodic reaction more remarkably than that formed in Wanning does.The rust layer formed in Qingdao possesses a higher ability to block the per-meation of chloride ions than that formed in Wanning does.     

可控气氛喷涂钛涂层及涂层电化学性能

为了研究在低度真空环境中所获得的钛涂层的组织和性能,以氩气为载气,在压力为0.4MPa、载气温度为室温、不同的喷涂条件下,用热喷涂方法在Q235钢基体上制备了钛金属涂层.经扫描电子显微镜（SEM）观察,发现在真空中用氩气为载气喷涂的钛涂层组织致密,缺陷与孔隙相对较少.x 射线衍射分析仪（XRD）分析表明,在空气中喷涂的钛涂层有较多的氧化物和氮化物;在真空中喷涂的钛涂层基本上没有氧化物和氮化物,其衍射图谱与纯钛十分接近;在空气中用氩气为载气喷涂的钛涂层含有一些氧化物,涂层中的缺陷和孔隙数量介于前两种状态之间.采用动电位极化法研究了在不同条件下热喷涂钛涂层的电化学腐蚀行为,并与纯钛试样进行比较.结果表明：在真空条件下喷涂的钛涂层腐蚀电位高于在空气中喷涂的钛涂层和在空气中用氩气为载气喷涂的钛涂层,但略低于纯钛的腐蚀电位.     

民国时期我国面点风味特色探究

民国时期的面点制作,从地域上看,基本形成了北、中、南三大面点风味流派,各地面点制作在吸收前代的基础上形成了明显的区域特征.与此同时,西方面点逐渐从我国大城市渗入到各地的饮食市场,出现了别样的局面.民国时期面点的发展,为新中国面点制作的壮大奠定了基础.     

限制卖空对证券市场收益偏度和波动性影响的实证研究

证券市场上对于是否应该允许卖空交易一直存在很大的争议，研究在全球市场范围内卖空交易对整个市场收益的影响，通过建立实证模型检验限制卖空交易对证券市场收益偏度和波动性的影响，结果证明限制卖空使市场收益的偏度向负向偏离，并加大了市场收益的波动程度。最后根据实证结果提出了引入卖空交易，解决我国证券市场风险不对称问题的对策。     

西大别石榴黑云斜长片麻岩中金红石的退变质演化

以取自大别山西段七里坪的石榴黑云斜长片麻岩为例,使用矿物热力学数据库和THER-MOCALC程序（3.33版）,计算了0.3~1.5GPa和450~650°C条件下的P-T视剖面相图,讨论了该类岩石中金红石、钛铁矿与榍石矿物稳定的P-T条件,分析了该岩石从高压条件近等温降压过程中金红石的退变质作用。研究表明,金红石具有较高的稳定压力,一般大于0.75GPa,压力低时稳定范围仅局限于较低温的小区域内;榍石具有小于565°C的较低温度和0.35~1.40GPa的压力范围,榍石可与金红石共生,但其P-T条件处于榍石稳定域边缘较狭窄的范围内;在温度大于475°C、压力低于0.75GPa的区域,金红石可与钛铁矿共生,钛铁矿则稳定于温度大于570°C、压力低于0.55GPa的范围。根据金红石向钛铁矿的转变及体系含水量,约束该片麻岩角闪岩相退变质P-T条件为压力0.55~0.75GPa且温度大于570°C。     

泄漏油品在不同颗粒直径土壤中扩散范围计算

针对油品在不同颗粒直径的土壤中渗透范围计算问题,借助CFD软件建立土壤多孔介质中油水两相流动的三维流动传质耦合模型。模拟结果表明,油品在0.5mm和0.221mm较大颗粒土壤中的泄漏范围是以U形区域扩散;在0.147mm和0.098mm较小颗粒土壤中以蛋状区域扩散;在0.021mm和0.002mm微小颗粒土壤中以鸭梨状区域扩散。油品泄漏1min内,在6种土壤中的扩散速率几乎相同;泄漏1～5min之间,颗粒在0.5mm至0.021mm依次减小的5种土壤中油品扩散速率逐渐增大,0.021mm比0.5mm土壤的扩散率高约12%;颗粒小于0.021mm时,其与0.002mm在相差近10倍的情况下,扩散速率几乎相同。     

混凝土中界面的某些力学特性

本文研究了砼中界面的一些力学特性，研究表明，砼中界面常常处于力学上最不利的位置，进而成为砼中最薄弱的部分。     

1961-2014年石家庄地区降水量的时空变化特征

利用石家庄地区5个代表站1961—2014年的逐日降水资料,采用多种统计分析方法,分析了石家庄地区降水量的时空变化特征,结果表明石家庄地区年降水量从20世纪70年代开始下降,80年代达到最低,90年代有所增加,但也没有明显的上升趋势,21世纪初又开始下降.20世纪70年代降水量的减少春季和秋季贡献最大,80年代降水量的减少和90年代降水量的增加主要是夏季的贡献.石家庄地区年降水量起伏较大,1963年降水量最多,为1 038.4 mm,2014年最少,仅为276.2 mm.近54年石家庄年降水量在波动中呈现下降趋势,线性趋势为-11.0 mm/(10 a),但下降趋势并不明显.石家庄北部年降水量呈上升趋势,市区及东部、南部和西部年降水量均呈下降趋势,变化趋势均不明显.近54年,石家庄春季降水量呈上升趋势,线性趋势为0.9 mm/(10 a),夏季、秋季和冬季降水量均呈下降趋势,线性趋势分别为-11.9,-1.1和-0.3 mm/(10 a),上升或下降趋势均不明显.夏季降水减少是导致石家庄年降水减少的主要原因.石家庄四季降水量变化趋势的空间分布具有明显的季节特征和区域特征.石家庄四季降水量均存在显著周期变化.     

面向21世纪加快高工专有机化学课程改革

针对国外近年来有机化学新教材的特点和教学内容改革的大趋势,根据国家教委《关于加强普通高等专科教育工作的意见》,结合目前国内普通高等专科学校的教学现状,提出了面向21世纪国内高工专有机化学课程教改的措施和对策。