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991.
制浆造纸工业生产过程中不可避免会产生泡沫,泡沫控制不当会严重影响制浆造纸工艺条件的执行以及设备的正常运转,导致产品产量和质量降低,而控制泡沫最直接有效的措施是添加合适的消泡剂.该文介绍了制浆造纸工业生产中泡沫的产生和稳定机理,泡沫对制浆造纸工业生产过程和产品质量的影响,并针对制浆造纸生产中制浆、抄纸、涂布和脱墨等工段泡沫特性和消泡要求,综述了制浆造纸用消泡剂的发展历程、各工段消泡剂种类和性质,介绍了消泡剂的研制开发和实际应用成本及使用效果等,并对制浆造纸用消泡剂的发展进行了展望. 相似文献
992.
993.
EPDM foam was prepared by dynamically vulcanizing EPDM compound in a HAAKE rheometer firstly, then mixing the partially precured EPDM compound with a blowing agent and a sulfur vulcanizing system on a two roll mill. The compound was extruded through a cold feed extruder, and the extrudate was foamed in a circulating hot air oven. EPDM compound was vulcanized partly in the HAAKE rheometer, the final torque increases with increasing sulfur content. Rheological measurement shows the dynamic storage modulus, the loss modulus, and the complex viscosity of precured EPDM compound increase with increasing sulfur content. Then the partially precured EPDM compound was compounded with a blowing agent and a sulfur vulcanizing systems, Rheometric measurement shows that the rate of vulcanization of partially precured EPDM compound is not affected by the precure. The blowing results show that the foam processibility could be improved and the expansion ratio increases in the same processing condition for optimum partially precured EPDM compound, which indicates the optimum crosslink density for EPDM could enhance the efficiency of blowing agent AC. SEM shows that the foam articles have a closed‐cell structure with few open cells, and the large cells inlay among the small cells. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3387–3394, 2006 相似文献
994.
Enhancement of combustion efficiency with mixing ratio during fluidized bed combustion of anthracite and bituminous blended coal 总被引:1,自引:0,他引:1
Jeong-Gook Jang Mi-Ran Kim Ki-Ho Lee Jea-Keun Lee 《Korean Journal of Chemical Engineering》2002,19(6):1059-1065
In order to investigate the effect of mixing ratio of bituminous coal to blended coal on the enhancement of combustion efficiency,
combustion experiments of blended coal with anthracite and bituminous are done in a laboratory scale fluidized bed combustor
(10.8 cm ID and 170 cm height). The gross heating values of anthracite and bituminous coal used in this study are 2,810 cal/g
and 6,572 cal/g, respectively. Experimental parameters are fuel feed rate, superficial gas velocity and mixing ratio of bituminous
coal to blended coal. The combustion efficiency increases with the mixing ratio of bituminous coal due to the lower unburned
carbon losses and higher burning velocity of bituminous coal. The rate of combustion in the combustor was increased with mixing
ratio resulted from a higher burning velocity of bituminous coal. The measured combustion efficiency experimentally is about
3.5-12.4% higher than that of the calculated value based on the individual combustion of anthracite and bituminous coal under
the same operating conditions. The optimum mixing ratio (MR) of bituminous coal determined is around 0.75 in this study.
This paper is dedicated to Professor Dong Sup Doh on the occasion of his retirement from Korea University. 相似文献
995.
Shu Liang Cheng Peng Zeng Liao Yong Wang 《International journal of systems science》2014,45(10):2203-2212
Approximations for general fractional order dynamic systems are of much theoretical and practical interest. In this paper, a new approximate method for fractional order integrator is proposed. The poles of the approximate model are unrelated to the order of integrator. This feature shows benefits on extending the algorithm to the systems containing various fractional orders. Then a unified approximate method is derived for general fractional order linear or nonlinear dynamic systems via combining the proposed new method with the distributed frequency model approach. Numerical examples are given to show the wide applicability of our method and to illustrate the acceptable accuracy for approximations as well. 相似文献
996.
We propose a face detection method based on skin color likelihood via a boosting algorithm which emphasizes skin color information while deemphasizing non-skin color information. A stochastic model is adapted to compute the similarity between a color region and the skin color. Both Haar-like features and Local Binary Pattern (LBP) features are utilized to build a cascaded classifier. The boosted classifier is implemented based on skin color emphasis to localize the face region from a color image. Based on our experiments, the proposed method shows good tolerance to face pose variation and complex background with significant improvements over classical boosting-based classifiers in terms of total error rate performance. 相似文献
997.
998.
This paper addresses a multi-supplier, multi-affected area, multi-relief, and multi-vehicle relief allocation problem in disaster relief logistics. A multi-objective optimisation model based on disaster scenario information updates is proposed in an attempt to coordinate efficiency and equity through timely and appropriate decisions regarding issues such as vehicle routing and relief allocation. An optimal stopping rule is also proposed to determine the optimum period of delay before responding to disaster, because decision making requires accurate disaster information. The main contribution of this paper is solving relief allocation problem in a novel way by correlating operational research with statistical decision making and Bayesian sequential analysis. Finally, a case is presented based on the post-disaster rescue in Eastern China after supertyphoon Saomai to test the applicability and show the potential advantages of the proposed model. 相似文献
999.
Pt-V2O5-WO3/TiO2 catalysts supported on SiC filter for NO reduction at low temperature 总被引:1,自引:0,他引:1
Joo-Hong Choi Jin-Hyun Kim Young-Cheoul Bak Rose Amal Jason Scott 《Korean Journal of Chemical Engineering》2005,22(6):844-851
The catalytic filter, V2O5-WO3-TiO2 supported on a ceramic filter, is known as a promising material for treating particulates and NO
x
simultaneously at optimum temperatures around 320°C. In order to improve its catalytic activity at low temperatures, the
effect of Pt addition on the catalytic filter has been investigated. Catalytic filters, Pt-V2O5-WO3-TiO2/SiC, were prepared by co-impregnation of Pt, V, and W precursors on TiO2 coated-SiC filter by vacuum aided-dip coating. The Pt-added catalytic filter shifted the optimum working temperature from
280–330°C (for the non Pt-impregnated filter) to 180–230°C, providing N
x
slip concentration less than 20 ppm for the treatment of 700 ppm NO at a face velocity of 2 cm/s with the same value over
the non Pt-added catalytic filters. The promotional effect following the addition of Pt is believed to result from electrical
modification of the catalyst maintaining a high electron transfer state. Ammonia oxidation was also observed to be dominant
above the optimal temperature for SCR. 相似文献
1000.