酶促水解对大豆蛋白热凝结性的影响

酶促水解可以显著提高大豆分离蛋白的热凝结性。本课题采用微生物蛋白酶部分水解方法，使大豆分离蛋白的热凝结度从９．３％增加到３５．６％，酸性溶液中的氮溶解率从５．７％增加到４８．１％。拓宽了大豆分离蛋白的应用范围。

Laminar Forced Convection Heat and Mass Transfer of Humid Air across a Vertical Plate with Condensation

Condensation of humid air along a vertical plate was numerically investigated, with the mathematical model built on the full boundary layer equations and the film-wise condensation assumption. The velocity, heat and mass transfer characteristics at the gas-liquid interface were numerical analyzed and the results indicated that it was not reasonable to neglect the condensate film from the point of its thickness only. The condensate film thickness, interface temperature drop and the interface tangential velocity affect the physical fields weakly. However, the subcooling and the interface normal velocity were important factors to be considered before the simplification was made. For higher wall temperature, the advective mass transfer contributed much to the total mass transfer. Therefore, the boundary conditions were the key to judge the rationality of neglecting the condensate film for numerical solutions. The numerical results were checked by comparing with experiments and correlations.

Electrical resistance stability of high content carbon fiber reinforced cement composite

The influences of curing time, the content of free evaporable water in cement paste, environmental temperature, and alternative heating and cooling on the electrical resistance of high content carbon fiber reinforced cement (CFRC) paste are studied by experiments with specimens of Portland cement 42.5 with 10 mm PAN-based carbon fiber and methylcellulose. Experimental results indicate that the electrical resistance of CFRC increases relatively by 24% within a hydration time of 90 d and almost keeps constant after 14 d, changes hardly with the mass loss of free evaporable water in the concrete dried at 50 °C, increases relatively by 4% when ambient temperature decreases from 15 °C to ?20 °C, and decreases relatively by 13% with temperature increasing by 88 °C. It is suggested that the electric resistance of the CFRC is stable, which is testified by the stable power output obtained by electrifying the CFRC slab with a given voltage. This implies that such kind of high content carbon fiber reinforced cement composite is potentially a desirable electrothermal material for airfield runways and road surfaces deicing.

Analysis of 13Cr bloom solidification structure using CA-FE model

Solidification structure is critical in the control of the mechanical properties and quality during the continuous casting process. The thermo-physical properties of 13 Cr steel added some rare metals, such as Mo, V, Nb, are measured to better understand the solidification structure of 13 Cr bloom. A computational model using CA-FE(cellular automation-finite element) method coupled with heat transfer model is developed to describe the solidification structure in continuous casting process. It is found that the calculated solidification structure is in good agreement with the observed data. The influence of casting speed and superheat on the solidification structure of the bloom is studied in detail. In order to obtain more equiaxed crystal ratio and low degree of the segregation in the bloom, the optimized casting speed 0.6 m/min and superheat less than 25 °C are determined for the caster. Using the optimized manufacturing parameters, these samples are 60% with the equiaxed zone ratio of 8%–10% and below the degree of segregation 1.05.

Thermal Effects on Bond Properties of GFRP Rebars Embedded in Concrete

This paper presents the results of an experimental study on the thermal effects on glass fibre reinforced polymer （GFRP） bars embedded in concrete. The pullout test specimens were subjected to temperatures of 40℃, 60℃ and 80℃ during a continuous four months-period of time. The results were compared to the reference specimens （room temperature）. It was found that up to 60℃, the loss in bond strength due to the temperature is not significant, whereas for the 80℃-temperature a reduction of 14% in the bond strength is observed. Also, the bond-slip relationship was modelled using the CMR-model and new coefficients are proposed for the bond-slip behaviour of GFRP bars.

Thermal transfer experimental research of a horizontal tube evaporative condenser

The thermal resistances distribution in different wet-bulb temperatures, air velocities and spraying water densities were achieved by the experimental test. The fluctuation of the water film convection and the water-air interfacial thermal resistance were reviewed especially. In the distribution of thermal resistance, the rank of the thermal resistance proportion （from max to min） is air flow heat transfer resistance, heat transfer resistance between refrigerant and wall, water film convection resistance and wall heat transfer resistance. When the heat flux is constant, the total resistance lowers nearly along with the increasing of air flow and water spray density. But there are a best air flow value of 2.98 m/s and a best spray water density of 0.064 kg/（m ·s） respectively, if continue to increase them, condensation performance is not significantly improved any more. The test results are available to improve the evaporative condenser performance and the designing lever.

Study on the Influence of Structural Parameters of Multi-channel Cylinder Dryer on Heat Transfer Performance

An approach to design multi-channel cylinder dryer was proposed. The heat transfer performance and flow characteristic under various structural parameters were analyzed. First, an experiment was designed and set up to measure the condensing heat transfer coefficient and the pressure drop in order to ,~erify the applicability of the Cavallini＇s correlation. Then, the relationship among the count of channels, aspect ratio, spacing ratio, width, height and hydraulic diameter of a channel was given. Finally, the correlation of condensing heat transfer and the homogeneous model was introduced in order to observe the heat transfer performance and flow characteristic of the multi-channel cylinder dryer affected by different structures. The study reveals that the structural parameters including count of channels, aspect ratio, spacing ratio of a channel dramatically influence the condensation heat transfer coefficient and frictional resistance of the steam. Based on the selected paper machine, it is suggested that the overall performance of the multi-channel cylinder dryer is best if the count of channels is 150-200, the aspect ratio is 1 ： 3 and the spacing ratio is 1 ： 1-1 ： 3.

Experimental Investigation on Heat Transfer Coefficient during Upward Flow Condensation of R410A in Vertical Smooth Tubes

This paper presents an experimental investigation on condensation of R410 A upward flow in vertical tubes with the same inner diameter of 8.02 mm and different lengths of 300 mm, 400 mm, 500 mm and 600 mm. Condensation experiments were performed at mass fluxes of 103-490 kg m-2s-1. The saturation temperatures of experimental condition were 31℃, 38℃and 48℃, alternatively. The average vapor quality in the test section is between 0.91 and 0.98. The effects of tube length, mass flux and condensation temperature on condensation were discussed. Four correlations used for the upward flow condensation were compared with the experimental data obtained from various experimental conditions. A modified correlation was proposed within a ±15% deviation range.