Statistical approach to light scattering from deformed textured heterogeneous polymer materials

A statistical theory of light scattering from deformed isotropic and textured heterogeneous polymer materials is formulated. Two types of textured structures are analyzed: assemblies of optically isotropic and anisotropic rods and a spatially anisotropic distribution of isotropic spherical inclusion centers. The small-angle H_v light-scattering patterns are calculated. The appearance of scattering from isotropic rods and spheres in deformed materials has been demonstrated. The changes of the H_v scattering patterns as a function of elongation and strucuture parameters are discussed. © 1993 John Wiley & Sons, Inc.     

Orientation and relaxation of polymer–clay solutions studied by rheology and small-angle neutron scattering

The influence of shear on viscoelastic solutions of poly(ethylene oxide) (PEO) and clay [montmorillonite, i.e., Cloisite NA+ (CNA)] was investigated with rheology and small-angle neutron scattering (SANS). The steady-state viscosity and SANS were used to measure the shear-induced orientation and relaxation of the polymer and clay platelets. Anisotropic scattering patterns developed at much lower shear rates than in pure clay solutions. The scattering anisotropy saturated at low shear rates, and the CNA clay platelets aligned with the flow, with the surface normal parallel to the gradient direction. The cessation of shear led to partial and slow randomization of the CNA platelets, whereas extremely fast relaxation was observed for laponite (LRD) platelets. These PEO–CNA networklike solutions were compared with previously reported PEO–LRD networks, and the differences and similarities, with respect to the shear orientation, relaxation, and polymer–clay interactions, were examined. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 3102–3112, 2004     

Acrylic acid level and adhesive performance and peel master‐curves of acrylic pressure‐sensitive adhesives

Three series of pressure‐sensitive adhesives were prepared with constant glass‐transition temperature, using emulsion polymerization. The monomers chosen were butyl acrylate, 2‐ethylhexyl acrylate (EHA), methyl methacrylate (MMA), and acrylic acid (AA). Within each polymer series, the proportion of AA monomer was held constant for each polymer preparation but acrylic ester monomer levels were varied. Adhesion performance was assessed by measurement of loop tack, static shear resistance, and through the construction of peel master‐curves. Peel master‐curves were generated through peel tests conducted over a range of temperatures and peel rates and through application of the time–temperature superposition principle. Bulk effects dominated by polymer zero shear viscosity change as AA and EHA levels were varied were attributed to the observed effect on static shear resistance and the horizontal displacements of peel master‐curves. Static shear resistance was found to strongly correlate with log(a_C), a parameter introduced to horizontally shift peel master‐curves to form a superposed, “super master‐curve”. An interfacial interaction was proposed to account for deviations observed when loop tack was correlated with log(a_C). Surface rearrangements via hydrogen bonding with the test substrate were suggested as responsible for the interfacial interaction. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 1237–1252, 2006     

STUDY ON THE DUCTILE DEFORMATION DOMAIN OF THE SIMPLE SHEAR IN ROCKS——TAKING BRITTLE FAULTS OF THE COVERING STRATA IN THE SOUTHERN JIANGSU AREA AS AN EXAMPLE

A study on the ductile deformation domain of the brittle fault in the shallow level ofthe crust is a new probe field for the modern structural geology. Taking the southern Jiang-su Province area as an example the orientation measurement of quartz crystals, the com-positional texture observation of three pressure sensitive minerals and the rheological param-eter determination of dislocation densities, etc. have been demonstrated and analysed basedon typical samples in the present paper. In addition, their generation mechanisms arealso discussed from the cataclastic rheology, the dynamic differentiation and the simpleshearing, specially, from the Ode strength theory. Finally, a generative relationship betweenthe ductile deformation domain of the brittle fault system, in the regional layer--slip andthe formation of the stratabound ore deposit is shown as well.     

Hydrophilic core-shell microspheres: a suitable support for controlled attachment of proteins and biomedical diagnostics

Functional hydrophilic microspheres (latex particles) have found various applications in life sciences and in medicine - particularly in latex diagnostic tests. This paper presents a comprehensive review of studies on latex particles with a hydrophilic interfacial layer composed of various hydrophilic polymers with reactive groups at the ends of macromolecules or at each monomeric unit along the chain. Typical examples of these hydrophilic polymers are poly(2-hydroxyethyl methyl methacrylate), poly(acrylic acid), poly(N,N-dimethylacrylamide), polysaccharides, poly(ethylene oxide) and polyglycidol. Hydrophilic microspheres with different morphologies (uniform or core-shell, see Figure) have been synthesized by emulsion and dispersion polymerizations. The chemical structure of polymers which constitute the interfacial layer of microspheres has been investigated using a variety of instrumental techniques (such as XPS, SSIMS and NMR) and analytical methods based on specific chemical reactions suitable for the determination of particular functional groups. Microspheres are exposed to contact with proteins in the majority of medical applications. This paper presents examples of studies on the attachment of these biomacromolecules to microspheres. The relation between the structure of the interfacial layer of microspheres and the ability of these particles for the covalent binding of proteins is discussed. Several examples of diagnostic tests, in which hydrophilic microspheres with adsorbed or covalently immobilized proteins were used as reagents, are presented. The paper also contains a short review of the application of magnetic hydrophilic particles for protein separation. Examples of hydrophilic latex particles used for hemoperfusion or heavy metal ion separation are presented. Hydrophilic microspheres with uniform or core-shell morphologies.     

Aging Process Effects on the Characteristics of Vacuum Residue Oxidation Products with the Addition of Crumb Rubber

This paper considers the effect of aging processes on viscoelastic characteristics of vacuum residue oxidation products modified with crumb rubber. Viscoelastic properties were compared to original bitumen raw material-vacuum residue and vacuum residue oxidation products during short-term and long-term aging. The complex shear modulus of the vacuum residue and its oxidation products decreased with an increase in temperature. Short-term aging resulted in increased shear modulus for all samples.The vacuum residue oxidation product modified with crumb rubber had the maximum values of the rutting parameter and fatigue parameter. There was an expansion of the temperature range of plasticity: for the vacuum residue oxidation product with crumb rubber, its value was 67.2 °C. The curves of the black diagram of the modified vacuum residue oxidation product are shifted towards smaller phase angles with the increase in the shear modulus, which indicates the increase in the stiffness and elasticity of the rubber bitumen binders. The vacuum residue oxidation product modified with crumb rubber corresponded to the rubber bitumen binder of the grade RBB 60/90, according to its physical and mechanical indicators.     

一类利用回归关系的计量指标抽样方案

在产品质量判定的抽样检验问题中,当目标指标需用破坏性试验才能得其值时,更为常用的是用非破坏性试验可得量值的协变指标量来预报它。但在产品抽样验收问题上,未能形成理论较为严密的方法,这是由于预报误差这个关键问题的处理尚未解决得好,即给不出抽样方案的功效计算的正确或是近似性较好的公式。本文通过建立合理的数学模型,把对目标指标的质量要求化为对协变指标量的统计要求,从而利用两者的回归关系,结合两种复杂的抽样方案,给出功效函数的计算公式和计算方法,并进行了分析。     

孔梯度陶瓷纤维复合膜管的制备及特性

陶瓷过滤管具有孔隙率高、耐腐蚀、耐高温、机械强度高、便于清洗、使用寿命长等优点,是高温烟尘处理用的高效过滤元件.本文研制了一种具有梯度孔结构堇青石陶瓷纤维复合膜过滤元件,该过滤元件是由多孔支撑体、过渡层和分离膜层组成.其中支撑体、过渡层和分离层的气孔率分别为35～40;、50～60;和60～70;.文中主要分析了孔梯度陶瓷纤维复合膜管的材料结构和抗热震性能,同时对复合膜管进行含尘气体过滤的冷态模拟试验.对于烟气中粒径大于或等于0.1μm的颗粒,复合膜管的截留率达到99.8;以上.     

Evaluation of Water Ammonium Ion Test Kit and Its Feasibility for the Analysis of Protein in Food

The traditional method for the determination of protein in food needs the operations of digestion, distillation, absorption, and titration; therefore, it is complicated and time-consuming and requires professional personnel. Is there a more convenient and faster detection method that can directly determine the ammonium ions in protein digestion solution to obtain the protein content of food and avoid the distillation–absorption–titration process? The feasibility of water ammonium ion test kits for food protein rapid detection was discussed here. After digestion, the protein in food transforms into ammonium ions in the digestion solution. Because of the variety of food, there are many different inorganic ions left in the food digestion solution, and at the same time, digestion agents are added in the digestion process and become potential interference factors in ammonium determination. Therefore, the detection accuracy of ammonium test kits needs to be evaluated first, including their anti-interference ability. The standard curve of ammonium was established by the test kit. When the ammonium concentration was 0.00–2.50 mg/L, the absorbance at 620 nm was linearly related to the ammonium concentration, the determination coefficient R² was 0.9995, and the detection limit of this method was 0.01 mg/L. The influences of temperature, pH value, and reaction time on the test kit method were discussed. The precision was 0.90–3.33%; the repeatability was 1.71–4.86%; and the recovery rate of tap water, river water, and sea water was controlled within 90–103%. The anti-interference ability of the evaluated test kit was better than that of the national standard detection method. The test kit, combined with sample pretreatment and protein conversion formula, was used to detect protein in different types of food (milk powder, rice flour, wheat flour, soy, banana, milk, fish food, chicken food, and dog food). The results showed that there were no significant differences (ρ > 0.05) between the national method and the test kit method. The ammonium ion test kit method shortened the determination time and had higher sensitivity, showing its potential for the rapid determination of food protein.     

HIGH-FREQUENCY VIBRATIONS OF CORRUGATED CYLINDRICAL PIEZOELECTRIC SHELLS

Coupled extensional and flexural cylindrical vibrations of a corrugated cylindrical piezoelectric shell consisting of multiple pieces of circular cylindrical surfaces smoothly connected along their generatrix are studied. To validate the results for the case of relatively thick shells or equivalently high-frequency modes with short wavelengths, existing analysis is extended by considering shear deformation and rotatory inertia. An analytical solution is obtained. Based on the solution, resonant frequencies and mode shapes are calculated.