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.     

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.     

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.     

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.     

复合型镁质胶凝材料的水化相及其硬化体显微结构

将菱苦土与苛性白云石按一定比例混合构成复合型镁质胶凝材料,将其与氯化镁水溶液按n（MgO）/n（MgCl2）=5拌和后形成氯氧镁水泥硬化体,研究了该复合型镁质胶凝材料的水化相及其硬化体显微结构。该硬化体的强度随着菱苦土在苛性白云石中含量的增加,其不同养护时间的抗折和抗压强度均随之增加,24 h的最高抗折强度为9.07 MPa,28 d的最高抗压强度为183.50 MPa,说明将复合型镁质胶凝材料与氯化镁溶液拌和后,形成了具有一定强度的水泥石或氯氧镁水泥硬化体。XRD和IR测试结果证明形成的硬化体为5型相结晶体,其显微特征主要是大量的凝胶体形貌而非针（棒）状结晶结构,呈放射状的针（棒）状晶体仅在孔洞中存在。认为凝胶体是复合型镁质胶凝材料硬化体具有很高强度的来源。     

阻燃木材的燃烧特性分析（二）

根据木材阻燃机理,以磷-氮体系阻燃剂为主进行复配,获得3组配方（质量比）：三聚氰胺∶磷酸∶硼酸=2∶2∶3;聚磷酸铵∶双氰胺=2∶1;尿素∶双氰胺∶磷酸=1∶3∶4。每组配方分别配制浓度为5%,10%,15%的阻燃液,采用浸渍法在恒温80℃下,浸渍24 h处理白杨木材试样。利用锥形量热仪在热辐射功率为50 kW/m2的条件下,对阻燃处理后的木材试样以及空白试样进行燃烧特性分析。实验结果表明,三聚氰胺、磷酸、硼酸组成的配方在增强木材试样的耐火性、抑制试样产烟量和一氧化碳生成率方面效果显著;聚磷酸铵APP、双氰胺组成的配方在控制木材试样燃烧速度和降低总热释放量方面效果显著;尿素、双氰胺、磷酸组成的配方在提高载药量、降低热释放速率、延长点燃时间、抑制二氧化碳生成率方面效果显著;3组配方在降低木材试样的质量损失率和有效燃烧热方面效果相近。综合各项分析结果,确定尿素、双氰胺、磷酸按1∶3∶4的比例（质量比）配制浓度为15%的阻燃液为最佳配方。     

不同晶貌磷酸锌化合物的制备与表征

在n[Zn(OAc)2]∶n[(NH4)2HPO4]=1∶2.2,180℃,5d的最佳反应条件下,通过变化体系中的不同溶剂(无溶剂、离子液体、水、乙二醇等),均可以制备出Zn(H3O)PO4化合物。采用XRD、SEM等分析手段系统地研究了不同溶剂对Zn(H3O)PO4晶体形貌的影响。实验结果表明,溶剂的变化对产物晶体的形貌产生了较大的影响,其中溶剂自身存在极性可能是导致产物晶体形貌不同的重要原因之一。同时还研究了体系当中添加其他物质,如NH4Cl等对Zn(H3O)PO4晶体形貌的影响。NH4Cl在晶体生长过程中起到了良好的促进作用。     

添加剂对稻草灰熔融特性影响的实验研究

为了给生物质热化学转化中灰结渣和聚团问题的解决提供参考和依据,在小型实验装置上对稻草、稻草与添加剂混合物进行了燃烧试验.通过热力平衡计算软件选出合适的添加剂,添加剂包括Al粉、Si粉、Al2O3、SiO2、Ca3(PO4)2、CaSiO3、CaCO3、Al2(SO4)318H2O、CaSO4、CaO、(NH4)H2PO4等,通过对样品燃烧生成的底灰进行观测分析,选择较理想的添加剂(NH4)H2PO4,Al2(SO4)318H2O,CaSO4,CaO,CaCO3.理想添加剂样品底灰的XRD测试结果表明,(NH4)H2PO4可将稻草中钾转化为高熔点的K2CaP2O7;CaSO4和Al2(SO4)318H2O则可将碱金属钾以K2SO4形式固定在底灰中;CaO,CaCO3不直接与碱金属反应,但可与系统中的其它元素进行反应,促进稻草中熔融态钾的转化析出.实验结果表明,添加剂是解决由碱金属引起的秸秆灰熔融问题的有效途径之一.     

磷酸－铵脱水缩聚动力学

本文研究了化学纯ＮＨ４Ｈ２ＰＯ４、农用磷铵及在二者中添加ＺｎＳＯ４·７Ｈ２Ｏ的脱水缩聚动力学，并用纸色谱法分析出了缩聚产物中聚磷酸盐的组成。实验结果表明，农用磷铵的脱水缩聚较纯磷铵的脱水缩聚容易进行。     

松口蘑菌丝体生长的最适培养基的选择

松口蘑是专一性很强的菌根菌,难以人工培养。不同的培养基对松口蘑菌丝体的生长有明显的影响。本文报道通过松口蘑菌丝得率为指标的实验,确定松口蘑菌丝体液体发酵培养基。结果表明最适培养基为:蔗糖70 g/L、硝酸铵5 g/L、KH2PO41 g/L、MgSO4.7H2O 0.5 g/L和酵母膏8 g/L。     

Preparation and Composition—Structure—Thermal Stability Relation of a Novel Open—framework Vanadium Phosphate （H3NCH2CH2NH3）3[（VO）4（PO4）2（HPO4）4]

A novel open-franmework vanadium(IV) phosphate (H3NCH2CH2NH3)3[(VO)4(PO4)2(HPO4)4](short for V2P3-en)has been prepared.It is synthesized hydrothermally in the presence of ethylenediamine(en)at 170℃ for 5 days by self-assembly form sturcturally simple precursors V2O5,H3PO4and H2O.The compound is characterized by means of Fourier transform-infrared spectroscopy(FT-IR),Thermogravimetry-differenti8al thermal analysis(TG-DTA),X-ray powder diffraction analysis(XRD) and Scanning electron microscopy (SEM) \.Furthermore,the composition-structure-thermal stability relation of V2P3-en is exploed in terms of crystal chemistry,and the potential approach to the enhancement of its thermal stability is proposed.     

Investigation of Phosphate Cement-based Binder with Super High Early Strength for Repair of Concrete

Magnesium phosphate cement- based binder ( MPB ) for repair of concrete was prepared by proportionally mixing over burned MgO powder ( M) with NHH2 PO4 powder ( P) and set modifying admixtures . It is characteristic by excellent properties such as rapid setting, high strength and high bond strength to old concrete .. The study is focused on the key factors influencing the setting time and strength of MPB, the bond property of MPB to old concrete and the kinetic feature of the hydration of MPB,     

Investigation of Phosphate Cement-based Binder with Super High Early

Magnesium phosphate cement-based binder (MPB) for repair ofconcrete was prepared by proportionally mixing over burned MgO powder (M) with NHH2PO4 powder (P) and set modifying admixtures. It is characteristic by excellent properties such as rapid setting,high strength and high bond strength to old concrete.. The study is focused on the key factors influencing the setting time and strength of MPB, the bond property of MPB to old concrete and the kinetic feature of the hydration of MPB.     

THE ROLE OF MgO-CeO_2 IN THE DENSIFICATION OF Si_3N_4

An investigation of the pressureless sinteringof Si_3N_4 with MgO-CeO_2 reveals that Mgo-CeO_2 is a muchmore effective sintering aid for silicon nitride than eitherMgO or CeO_2.The amount of MgO-CeO_2 and MgO/CeO_2weight ratio has a strong influence on the densification be-haviour and mechanical properties of the sintered materials.The Silicon nitride pressureless sintered with MgO-CeO_2 re-tains a relative density of 98.5%,a bending strength of 950MPa.The Si-Mg-Ce-O-N system is of great value for appli-cation and theoretical study.