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71.
以常见塑料为原料,以有机物为溶剂,研究了塑料在有机溶剂中的溶解性能,提出了选择性分离混合塑料的方案。结果表明,实验所选用的塑料在有机溶剂中的溶解性能和溶解条件不同;可利用塑料与有机溶剂的相容性差别分离混合塑料。 相似文献
72.
Due to advances in medical research, more and more diseases can be cured nowadays, which largely increases the need for an easy-to-use software in calculating sample size of clinical trials with cure fractions. Current available sample size software, such as PROC POWER in SAS, Survival Analysis module in PASS, powerSurvEpi package in R are all based on the standard proportional hazards (PH) model which is not appropriate to design a clinical trial with cure fractions. Instead of the standard PH model, the PH mixture cure model is an important tool in handling the survival data with possible cure fractions. However, there are no tools available that can help design a trial with cure fractions. Therefore, we develop an R package NPHMC to determine the sample size needed for such study design. 相似文献
73.
The reaction between SO2 and calcined limestone particles has been studied in a fluidized bed combustor. Measurements of sorbent reactivity with SO2 were made for small batches of limestone injected into the combustor. Simultaneous continuous combustion of bituminous coal provided conditions like those of a boiler for study of the sulphation reaction. A semi-empirical rate model of the CaO-SO2 reaction has been developed. External mass transfer of SO2, diffusion within the particles and chemical reaction are taken into account. The limestone reactivity with SO2 is characterized by two parameters which are dependent on the temperature and sorbent particle size. A model for predicting the limestone requirements in a fluidized bed boiler has been developed. Parameters from the batch experiments are included. The predictions for sulfur retention agree with the experimental results. In addition, effects of operating conditions (gas velocity, recycle, limestone particle size) on the retention of SO2 were simulated using the model. 相似文献
74.
尾部烟气增湿活化脱硫原理性研究 总被引:1,自引:1,他引:1
论述应用大速差射流的尾部烟气脱硫增湿活化原理怀试验台架及其系统,试验结果及分析,在尾部烟气中SO2气体直接与固相脱硫剂(CaO粉及Ca(OH)2粉)反应能力很弱;SO2气体直接与水滴反应生成H2SO3的能力也能弱,它受到SO2气体在水中溶解能力的限制;增湿活化的机理在于水滴与脱硫剂粒子碰撞后在其表面生在液态Ca(OH)2离子膜,由它与SO2气体反应脱硫。因此,良好的活化反应器必须具有良好的水滴与脱 相似文献
75.
Dense blend membranes were prepared by blending hydrophilic polymers poly(vinyl alcohol) (PVA) and poly(ethyleneimine) (PEI), which were then crosslinked by glutaraldehyde (GA) in a mixture of solvents under the catalysis of hydrochloric acid (HCl) for the dehydration of tetrahydrofuran (THF) by pervaporation. The effect of experimental parameters such as feed water concentration, permeate pressure, and membrane thicknesses on permeate parameters, i.e., flux and selectivity were determined with feed water concentration less than 40 wt %. The membranes were found to have good potential for breaking the azeotrope of 94 wt % THF with a flux of 1.072 and 0.376 kg/m2 h for plane PVA/PEI and crosslinked PVA/PEI blend membrane, which exhibited high selectivity of 156 and 579 respectively. Selectivity was found to improve with decreasing feed water concentration and increasing membrane thickness, whereas flux decreased correspondingly. High permeate pressure causes a reduction in both flux and selectivity. These effects were clearly elucidated with the aid of the known relationship among plasticization effect, degree of swelling, permeate pressure, and feed water concentration. These blend membranes were also subjected to sorption studies to evaluate the extent of interaction and degree of swelling in pure as well as binary feed mixtures. Further ion exchange capacity studies were carried out for all the crosslinked and uncrosslinked membranes to determine the total number of interacting groups present in the membranes. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1152–1161, 2006 相似文献
76.
77.
针对低信噪比条件下的机动小目标实时检测与跟踪困难的问题, 提出一种基于混合估计多模粒子滤波的检测前跟踪改进算法. 首先根据前一时刻所采用的模型状态及其转移概率等先验信息实现当前时刻的模型采样; 然后在充分考虑当前量测下实现当前的粒子预测, 采用一种序贯重要性平滑重采样策略, 在不增加计算量的前提下, 改善了粒子多样性衰退的问题; 最后通过新的粒子集完成对模型和状态的合理估计与目标检测. 仿真结果验证了该方法的检测与跟踪性能优于传统的多模粒子滤波方法.
相似文献78.
本文所叙述的单氰乳剂,是一种新的复配农药制剂。它不仅增效作用显著,对为害农作物的蚜虫和红蜘蛛有很强的杀灭作用;而且其剂型独特,为国内尚不多见的水包油型的复配农药新制剂-微乳剂。该制剂生产工艺简单,产品性能稳定,常温贮存一年,有效成分分解率低于1.5%;在60℃至-5℃范围内,其产品均为均相透明的液体,且乳化性能十分优良。目前该品种已取得农药登记,正式投产。 相似文献
79.
80.
L. N. Bortnikov 《Combustion, Explosion, and Shock Waves》2007,43(4):378-383
This paper reports results of an analysis of experimental data on the combustion of a gasoline-hydrogen-air mixture in a reciprocating
internal combustion engine cylinder. The completeness of combustion of the mixture is shown to depend on the amount of hydrogen
in the fuel mixture and the composition and physicochemical properties of the mixture. In particular, the conditions of addition
of hydrogen to the gasoline-air mixture with active chemical action on the combustion process and the action of hydrogen as
an additional fuel component are determined. A dimensionless universal relation is proposed that allows one to uniquely determine
the initial composition of the fuel mixture (hydrogen to gasoline ratio) to accomplish combustion of the fuel mixture at the
lean combustion limit.
__________
Translated from Fizika Goreniya i Vzryva, Vol. 43, No. 4, pp. 8–14, July–August, 2007. 相似文献