期刊文献+
共找到3篇文章
< 1 >
每页显示 20 50 100
让多媒体在品德与社会教学中发挥有效功用
1
作者 王艳仲 《天天爱科学》 2016年第16期104-104,共1页
在品德与社会教学中运用多媒体技术,面向了学生的生活实际,加强课程内容与学生生活实际的密切联系。更创设了学生乐于接受的学习情景。着实凸显了多媒体在教学中直观形象、新颖生动、感染力强的教学功用。
关键词 品德与社会教学 多媒体 有效功用
原文传递
Soil Removal Efficacy of Catholyte on Polyamide 6.6 Fabric
2
作者 Natasha van Heerden Hester JH Steyn Robert Schall 《Chinese Business Review》 2012年第7期682-689,共8页
This study determined the detergency properties of Catholyte, an electrochemically activated medium, on polyamide 6.6 as a possible alternative to conventional laundering detergents. Undyed polyamide 6.6 was used and ... This study determined the detergency properties of Catholyte, an electrochemically activated medium, on polyamide 6.6 as a possible alternative to conventional laundering detergents. Undyed polyamide 6.6 was used and soiled with keltex, corn starch, mineral oil, oleic acid, morpholine, vegetable fat, butanol, solvesso 150 and water. Some soiled fabric was retained as control and not laundered. Soiled fabric was laundered at 30 ~C as well as 40 ~C with either, distilled water, Catholyte, non-phosphate detergent, a 50/50 solution of Catholyte and non-phosphate detergent, or a 50/50 solution of Catholyte and phosphate detergent. Data were analyzed descriptively by using analysis of variance (ANOVA), which fitted the factors of treatment and temperature, as well as all two-factor interactions between these variables. A probability value of 0.05 or less indicated significance. Catholyte was effective in removing soil and reached a/XE* value of 59.30, but was statistically different from the phosphate detergent. Temperature did not have a significant effect on soil removal from the fabric, but the interaction with a treatment had significant effects. Treatment alone had a significant soil removal effect on the fabric. Thus, the temperature was dependent on an interaction with the treatment. The non-phosphate detergent was efficient in removing soil from the fabric and slightly more efficient than either 50/50 Catholyte solution. The 50/50 Catholyte/non-phosphate detergent solution was slightly less effective than its phosphate containing counterpart. When considering the interaction between treatment and temperature, the 50/50 Catholyte/phosphate and 50/50 Catholyte/non-phosphate solutions were more efficient at 40 ~C. Thus the interaction between the solution and higher temperature proved to be a better combination. This was also the case for the Catholyte and the non-phosphate wash liquors. Catholyte, an environmentally friendly washing agent, is an attractive alternative to conventional laundry detergents because it removes soil efficiently from polyamide 6.6 fabric. 展开更多
关键词 electrochemical activation CATHOLYTE soil removal polyamide 6.6
下载PDF
Achieving Efficient Channel Utilization for Data Communications in IEEE 802.11 WLAN
3
作者 张亮 舒炎泰 《Transactions of Tianjin University》 EI CAS 2005年第6期422-427,共6页
In the IEEE g02. 11 protocol, the adoption of the exponential backoff technique leads to throughput performance strongly dependent on the initial contention window size and, most importantly, on the number of contendi... In the IEEE g02. 11 protocol, the adoption of the exponential backoff technique leads to throughput performance strongly dependent on the initial contention window size and, most importantly, on the number of contending stations considered in the network. This paper proposes a simple but accurate method to dynamically estimate the number of contending stations in a wireless local area network ( WLAN ). Based on estimation, all the mobile stations dynamically adjust the initial contention window in medium access control ( MAC ) layer to avoid collisions. The simulation results show that the proposed algorithm can achieve efficient channel utilization, higher system throughput, and better fairness performance. 展开更多
关键词 IEEE 802.11 wireless local area network( WLAN distributed coordination function DCF
下载PDF
上一页 1 下一页 到第
使用帮助 返回顶部