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排序方式: 共有921条查询结果,搜索用时 15 毫秒
911.
Stuart B. Savage 《Journal of Engineering Mathematics》2008,60(2):221-240
The present paper extends the granular-flow constitutive model of Savage (1998 J Fluid Mech 377:1–26) to treat spherical particles.
Savage accounted for both quasi-static and collisional stresses by considering: (i) strain-rate fluctuations embodied in a
critical state plasticity model, as well as, (ii) individual particle velocity fluctuations modelled by granular-flow kinetic
theory. In the present work, the governing equations of the kinetic theory of Jenkins (1998 In: Hermann HJ, Luding S (eds)
Physics of Dry Granular Media. Kluwer Academic pp. 353–370) for identical spherical, smooth, inelastic particles are supplemented
with additional quasi-static terms that have forms patterned after the corresponding terms in the equations of Savage for
two-dimensional disk-like particles. The resulting equations along with side-wall and free-surface boundary conditions are
applied to examine free-surface granular flow down a heap contained between two frictional vertical side walls. Width-averaged
equations of motion are integrated to obtain depth profiles of mean velocity, granular temperature, solids fraction and the
Savage–Jeffrey parameter. Detailed comparisons are made with particle-tracking experiments. When the gap between the vertical
side walls is fairly narrow, good agreement is found between the predicted and the measured profiles of mean velocity and
granular temperature. 相似文献
912.
McKay Adam; Davis Chris; Savage Greg; Castles Anne 《Canadian Metallurgical Quarterly》2008,34(6):1495
The current research uses a novel methodology to examine the role of semantics in reading aloud. Participants were trained to read aloud 2 sets of novel words (i.e., nonwords such as bink): some with meanings (semantic) and some without (nonsemantic). A comparison of reading aloud performance between these 2 sets of novel words was used to provide an indicator of the importance of semantic information in reading aloud. In Experiment 1, in contrast to expectations, reading aloud performance was not better for novel words in the semantic condition. In Experiment 2, the training of novel words was modified to reflect more realistic steps of lexical acquisition: Reading aloud performance became faster and more accurate for novel words in the semantic condition, but only for novel words with inconsistent pronunciations. This semantic advantage for inconsistent novel words was again observed when a subset of participants from Experiment 2 was retested 6-12 months later (in Experiment 3). These findings provide support for a limited but significant role for semantics in the reading aloud process. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
913.
文章介绍了远程控制技术及控制软件pcAnywhere在液化气销售配送系统中的应用,解决了系统管理和技术维护中的实际问题,实现了对网点电脑及中心服务器的完全控制,确保公司信息系统的正常运行。 相似文献
914.
W.CO 《军民两用技术与产品》2014,(8):26-26
随着吊机将平台定位分段平稳地移入船坞,金海重工股份有限公司首制90m自升式海上作业平台正式进入该公司4号船坞进行搭载。 相似文献
915.
将空气雾化和机械雾化相结合,对硫磺喷枪进行改进.在Fluent软件环境下,基于气、液两相流模型进行了计算流体力学数值模拟.进口处以液硫、空气的实际速度为基准,出口处采用压力出口,焚硫炉内壁面选用标准无滑移壁面并假设其绝热,以简化焚硫炉内气液边界条件.以k-epsilon湍流模型为计算模型,采用压力-速度耦合方程求解,并选用压力修正算法.结果表明,在喷枪四周输入一定速度的空气后,喷枪附近形成一个涡流负压区,加速液硫向四周扩算,可增大雾化角及雾化行程,均匀雾滴分布.以某焚硫炉的工程实际参数,液硫速度5 m/s时,对比不同空气流速下的液硫雾化流场,在空气进口速度为4~6 m/s,雾化效果最佳. 相似文献
916.
Shahla Siabi Mohammadali Torbati Sodeif Azadmard-Damirchi Maryam Naebi Geoffrey P. Savage 《European Journal of Lipid Science and Technology》2023,125(1):2200071
Roman nettle (Urtica pilulifera L.) is an annual plant whose seeds are rich in oil and valuable phytochemicals. In this study, oil from Roman nettle seeds is extracted by cold pressing and its quality is evaluated during storage at room temperature for up to 90 days. The seed moisture content is adjusted to 0%, 2.5%, 5%, 7.5%, and 10% (g 100 g−1) to evaluate its effect on oil extraction yield. The highest oil yield (31.5%) is found in the seeds containing 5% moisture. Acid and peroxide values increase with both moisture content increase and during storage. Moreover, an increase in seed moisture content decreases the oxidative stability (from 8.1 to 6.3 h), carotenoids (from 25 to 14 mg kg−1), chlorophylls (from 742 to 486 mg kg−1), and phenolic contents (from 134 to 97 (mg caffeic acid per kg oil)) of the extracted oils. Fatty acid profile and phytosterols are not significantly influenced (p > 0.05) by the moisture content of the seeds and storage. Total phenol contents and γ-tocopherol levels increase during storage, but carotenoids, chlorophylls, and α-tocopherol levels decrease. Based on overall composition and quality parameters, Roman nettle seed oil may have potential food applications. 相似文献
917.
This study investigates closed-loop thermoset composite recycling through grinding and reincorporation. Contrary to many other studies, it is shown that by careful attention to the separation and reformulation procedure, the mechanical integrity of recycled composites can be improved, and the use of substantially larger volumes of recyclate is possible. Both factors are important aspects affecting the economic viability of regrinding as a possible future solution to the composites recycling problem. 相似文献
918.
本文介绍了攀钢高炉炉料结构特点及现状,分析了目前攀钢高炉炉料结构的几个热点问题,提出了目前市场条件下攀钢高炉炉料结构的优化方向及解决相关问题的措施。 相似文献
919.
Mycobacterium avium was isolated from 21 of 23 lymph nodes with lesions collected from 23 brood sows and from 17 lymph nodes with lesions of 17 pigs slaughtered at an abattoir in north central Iowa. Mycobacterium avium serotype 2 accounted for more than 65% of the isolations in sows and in pigs. Granulomas with acid-fast bacilli were found in 15 of 23 tissues from brood sows and in 13 of 17 lymph nodes from pigs. Similar microscopic lesions were observed in the sows and pigs. 相似文献
920.
Immunization is the most important single public health measure available to control many important infectious diseases. The childhood schedule of immunization consists of five injections of TA/CDT, five doses of Sabin vaccine, one injection of measles vaccine, and one injection of rubella vaccine. Even if TA/CDT and Sabin are given at the same time, this still means seven decisions to be made by the mother to take her child for immunization. Unless there is an effective health education programme, combined with cheap convenient effective immunization facilities, the herd immunity might drop to a level at which epidemics could occur. This article deals with the deterrents to immunization and suggests means of overcoming them. 相似文献