噻唑型偶氮分散染料合成研究

本文以2-氨基-4-氯-5-醛基噻唑为重氮组分合成了一系列含醛基分散染料,进而与合活泼亚甲基的化合物缩合得到一系列含氰乙烯基的分散染料.对染料结构进行了表征,并测试了染料的吸收光谱.结果表明氰乙烯基的引入使得λmax和εmax都有所增大.     

Transport property measurements in sheared granular flows

Experiments were performed in a shear cell device under four different solid fractions. The glass spheres with a mean diameter of 3 mm were used as granular materials. The motions of the granular materials were recorded by a high-speed camera. By using image processing technology and a particle tracking method, the average and fluctuation velocities in the streamwise and the transverse directions could be successfully measured and analyzed. Three bi-directional stress gages were used to measure the normal and shear stresses along the upper boundary. The effective viscosity of the granular material flow can be calculated. By tracking the movements of particles continually, the curves of the mean-square diffusive displacements versus time were plotted and were used to determine the self-diffusion coefficients from the slopes of the curves. The fluctuations and the self-diffusion coefficients in the streamwise direction were much higher than those in the transverse direction. The fluctuations were found to increase with the solid fraction, but the diffusion coefficients were greater in a more dilute flow system.     

The dynamics of energy storage for paraffin wax in cylindrical containers

Heat transfer rates were measured to a commercial paraffin wax undergoing freezing and melting in vertical cylindrical containers. Circular, square and axially-partitioned cylinders were used. Natural convective motions were followed using tracer particles in a visual study of melting. Freezing fluxes were well predicted by a quasi-steady conduction model. Melting fluxes were enhanced by natural convection. A melting model employing an effective thermal conductivity predicted melting fluxes satisfactorily.     

Simple chemical syntheses of TAG monohydroperoxides

For the purpose of synthesizing standards to be used in the quantification of TAG hydroperoxides, three TAG (1,2-dioleoyl-3-palmitoylglycerol, 1-oleoyl-2-linoleoyl-3-palmitoylglycerol, and triolein) monohydroperoxides were chemically synthesized as authentic specimens. TAG were prepared by using a simple condensation in pyridine of glycerol and the corresponding acid chlorides. These TAG were then converted into monohydroperoxides by a photosensitized peroxidation. The synthesized monohydroperoxides were analyzed by normal-phase and RP-HPLC. The results of normal-phase HPLC analysis showed that monohydroperoxides from a corresponding TAG were a mixture of regioisomers. In RP-HPLC, however, the regioisomers of monohydroperoxides were not separated and gave a single peak, which may improve the sensitivity for the detection of TAG monohydroperoxides. In this study TAG monohydroperoxide standards were synthesized; these will be useful for the study of yet unknown biological and pathological roles of TAG hydroperoxides.     

Study of the preparation of a multiparticulate drug delivery system with a layering technique

The properties of a fully formulated enteric coating system were examined on a model multiparticulate formulation. Samples containing the model drug diltiazem hydrochloride were made in a fluid bed chamber with different amounts of Acryl-EZE, a ready-to-use coating dispersion. The effects of the film thickness on the dissolution profile were determined. While all samples yielded satisfactory release results in simulated intestinal fluid, the results in simulated gastric acid were worse than expected. The scanning electron microscopic images suggested that coating problems were not responsible for this behaviour.     

Preparation of macrocellular PU-PS interpenetrating networks

Macromolecular monoliths were synthesised from concentrated emulsions. Matrixes with only a polyurethane network were too soft and it was necessary to add to the formulation a rigid network such as polystyrene to obtain a material with a good dimensional stability. Either unconnected or interconnected interpenetrating networks were prepared, the later by using hydroxybutyl methacrylate as a comonomer that chemically links both networks. The modifications of the mechanical properties were evaluated by estimating the Young's modulus from compression tests.     

Color-emotion associations in interiors

Emotional reactions to red, green, blue, and gray colors in a living room were investigated using a self-report measure. Participants first watched a short video of a 3D model of a living room. Next, they were asked to match the living rooms with facial expressions of six basic emotions. The most stated emotions associated for the red room were disgust and happiness, while the least stated emotions were sadness, fear, anger, and surprise; for the green room, neutral and happiness were the most stated emotions, and anger, surprise, fear, and sadness were the least stated ones; for the blue room, neutral was the most stated emotion, while the least stated emotions were anger and surprise. Neutral, disgust, and sadness were the most stated emotions for the gray room. Gender differences were not found in human emotional reactions to living rooms with different wall colors.     

Interfacial shear strength studies using the single-filament-composite test. I: Experiments on graphite fibers in epoxy

The failure of the interface in a carbon fiber-epoxy system was studied for six different epoxy blends using the single-filament-composite technique. The blends were formulated to yield a wide range of stiffnesses, and their effect on interfacial failure was examined. Specimens were made from Hercules IM6-G carbon fiber and the different blends of epoxy, and then strained to obtain a distribution of fiber fragment lengths. Birefringence patterns near the fiber breaks were observed and recorded. Some of the specimens were strained until they failed and the resulting fracture surfaces were observed under a scanning electron microscope to determine fracture patterns and the existence of debonding. The fragment length distributions were interpreted using a Monte-Carlo simulation of a Poisson/Weibull model for fiber strength and flaw occurrence. The results were used to calculate an effective interfacial shear strength. From this analysis we conclude that one cannot accurately predict the interfacial properties of a composite based solely upon conventional single fiber and bulk matrix properties. Local matrix properties and fiber/matrix interactions, on a microscale, play a key role in composite strength.     

Application of ECT to solid concentration measurements during granular flow in a rectangular model silo

The paper presents results of concentration changes in cohesionless sand during dynamic mass flow in a rectangular model silo composed of a bin and hopper. Electrical capacitance tomography (ECT) was used. Sensors were located outside the silo along both the periphery and height. Local horizontal one-dimensional and cross-sectional two-dimensional evolutions of solid concentrations in dry sand during silo discharge were determined. The first ones were estimated from the raw data and the latter were obtained with the aid of the reconstructed data using a Linear Back Projection algorithm (LBP) to solve an inverse problem. Experiments in a model silo were carried out with two different initial sand densities and wall roughness grades. The measured results with ECT were compared with corresponding ones obtained with a Particle Image Velocimetry (PIV) method.     

喷动流化床流动形态变化的试验研究国家

在一个可视化的半圆柱喷动流化床试验台上研究了喷动流化床的流形变化规律。研究表明：随着喷动气量和流化气量的改变,床内会呈现不同的流动形态：固定床、带射流的流化床、喷动床、充气喷动床和喷动流化床。同时研究了量小喷动速度和最小喷动流化速度随喷动管内径、颗粒粒径、静止床高的变化规律,归纳了预测量小喷动速度和最小喷动流化速度的试验关联式,绘制了喷动流化床的流形划分相图。     

Short jute fiber-reinforced polypropylene composites: Effect of compatibilizer

Jute fibers were chopped to approximately 100 mm in length and then processed through a granulator having an 8-mm screen. Final fiber lengths were up to 10 mm maximum. These fibers along with polypropylene granules and a compatibilizer were mixed in a K-mixer at a fixed rpm, 5500, and dumped at a fixed temperature, 390°F, following single-stage procedure. The fiber loadings were 30, 40, 50, and 60 wt %, and at each fiber loading, compatibilizer doses were 0, 1, 2, 3 and 4 wt %. The K-mix samples were pressed and granulated. Finally, ASTM test specimens were molded using a Cincinnati injection molding machine. At 60% by weight of fiber loading, the use of the compatibilizer improved the flexural strength as high as 100%, tensile strength to 120%, and impact strength (unnotched) by 175%. Remarkable improvements were attained even with 1% compatibilizer only. Interface studies were carried out by SEM to investigate the fiber surface morphology, fiber pull-out, and fiber–polymer interface. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 329–338, 1998     

A mathematical description of the composition—Properties curve for fibres based on several aromatic copolyamides

Models describing the change in the properties of a fibre as a function of its composition were constructed with the results of a designed experiment. Adequacy testing showed that models for the breaking load and oxygen index are the most reliable. Computer programs were written for the IBM PS/AT for calculating the sections. Sections of equal outputs in a simplex for predicting the properties of a fibre as a function of the composition were constructed and the optimum compositions were sought.     

PRACTICAL PRODUCTION OF ONE-FIRE LUSTER GLAZED POTTERY*

Various metals in small quantities, singly and in various combinations, were ground in lead and leadless glazes. It was found that various colored lusters, transparent and opaque, could be reproduced under a fair degree of control in an ordinary downdraft gas-fired sagger kiln, which was fired from cones 010 to 1. After cooling to a dull red heat, the glazes were given a short reduction firing. Standard decorative processes were used with the luster glazes. Additional colors were produced by adding stains and metal oxides. Acid-resistant luster glazes were developed.     

Sintered Hydroxyapatite Latticework for Bone Substitute

Hydroxyapatite suspensions were extruded through a range of nozzles from 100 to 330 μm diameter from a stepper-driven syringe. Regular latticework scaffolds were built by fused deposition modeling (FDM), a solid freeforming method, on a three-axis table using 330 μm diameter filament. The scaffolds were sintered at 1250°C to 97% density retaining the hydroxyapatite crystal structure. The scaffolds were introduced to cultured human osteoblast cells and, after 48 h, the surfaces were thoroughly covered with active cells.     

Evidence for trace element forms of titanium and manganese in coal liquefaction extract solutions

The trace element contents of the insoluble portions of a filtered coal extract solution treated with pentane, toluene and THF were determined using atomic absorption spectroscopy (a.a.s.) and atomic emission spectroscopy (a.e.s.). In all cases a large proportion of the trace elements were found in the insoluble portion, but there were no significant differences between the individual trace elements. Further experiments were carried out in which TiO₂, MnCO₃ and low temperature ash were added to normal digestions of coal in hydrogenated anthracene oil (HAO), and were also digested in HAO only. The filter cakes produced in the latter experiments were redigested in fresh HAO a second and third time. The results strongly indicate that Ti passes through the filtration stage of the liquefaction process as finely-divided mineral matter. Mn, however, undergoes some change during the process which enables it to pass through the filtration stage.     

A unitized approach to regenerative solid polymer electrolyte fuel cells

In this work on regenerative fuel cells, the initial part deals with water electrolysis using a cell design that closely resembled that of a solid polymer fuel cell. The electrolytes were Nafion® 117 and the Dow experimental membrane. The electrodes were Pt-on-C and Pt/Ir-on-C gas diffusion electrodes on the oxygen side and Pt-on-C on the hydrogen side. Fuel cells were built with the above mentioned electrodes and membranes. These cells were run to obtain fuel cell and electrolysis data. Data for a maximum of five regenerative cycles were obtained. The current-potential data in the regenerative electrolysis were characterized by a gradual decay with time. The fuel cell data were very stable. The membrane-electrode assemblies were found in very good condition, and no visible corrosion of electrodes was evident.     

Fracture of glass fiber reinforced cement

Fracture patterns produced when a crack advancing from a notch in cement paste intersected a Cem FIL-2 glass fiber strand placed perpendicular to it were studied. The specimens were small notched compact tension specimens that could be wedge loaded in the scanning electron microscope chamber using a wet cell. Four distinct cracking patterns were identified. In most cases the fiber caused a shift in the crack path and in some specimens, microcracking and separation of the crack into 2 to 4 branches were observed. The filaments maintained their continuity and bridged over the track. Similar tests with E-glass fibers after accelerated curing revealed brittle behavior in which the crack path was straight and many filaments were broken.     

Effect of carbonation on the hydro-mechanical properties of Portland cements

We evaluate experimentally the effect of carbonation on the hydro-mechanical properties of Portland cement. Samples were carbonated at 90 °C and 28 MPa under wet supercritical CO₂. Two types of carbonation features were achieved, either the samples were homogeneously carbonated or they displayed sharp carbonation fronts. Using a tri-axial apparatus, the static elastic moduli and the mechanical strength were measured at in-situ pressure conditions (28 MPa) and showed a degradation of the mechanical properties of the samples where a carbonation front prevailed. Water and gas permeabilities were measured and showed that the samples with a carbonation front exhibit a stress sensitive permeability. P and S elastic wave velocities were measured to evaluate dynamic (ultrasonic range, 1 MHz) elastic moduli. The use of an effective medium theory approach enabled us to characterize the density and distribution of cracks within the samples. This approach outlines that the samples which developed a carbonation front were damaged.     

Effects of catalyst on the electrical properties of silicone rubber

Electrical properties, such as dissipation factor and electric conductivity, were studied for silicone rubber sheets. The specimens were prepared by the reaction of α,ω-dihydroxypolysiloxane with ethoxysilane, using dibutyltin dilaurate as a catalyst, at a relative humidity of about 100% at various temperatures and for various reaction times. It was found that the electrical properties were a function of the vulcanizing conditions; i.e., the further the vulcanization proceeded, the higher the dissipation factor and the electric conductivity. A reaction describing deterioration in electrical properties was then considered. Infrared spectroscopic studies on dibutyltin dilaurate showed that the dibutyltin dilaurates were partly hydrolyzed to lauric acid and dibutyltin dihydroxide. It was concluded that electrical property deteriorations, which were caused by changes in the vulcanizing conditions, were due to dibutyltin dilaurate hydrolysis. However, since the decomposed products were finally oxidized at elevated temperatures in an oxygen atmosphere, with a subsequent change to electrically inactive compounds, the initial electrical properties were recovered.     

气-固循环流化床的流动特性

循环流化床是一种新型高效无气泡气-固反应器,应用广泛。文章首先介绍了气-固循环流化床的特点,总结了循环流化床上部区域的流动特性,并讨论了循环流化床底部区域的流动特性,最后展望了循环流化床流动特性研究的发展趋势。