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211.
S. DAS S. C. PATNAIK H. K. SAHU A. CHAKRABORTY M. SUDARSHAN H. N. THATOI 《中国有色金属学会会刊》2013,23(2):484-493
分析了Sukinda铬铁矿采石场及其邻近区域水样的重金属污染及理化性质和微生物含量。铬铁矿的水样含有高浓度重金属,其浓度顺序为Cr>Fe>Zn>Ni>Co>Mn,然而该地区的地下水除了Fe以外并没有受到重金属污染。矿井水样的理化参数与正常水的有差别。与相邻矿水样相比,矿井水样含有一些低浓度的微生物种群,包括细菌、真菌和放线菌。金属浓度与相关的理化参数显示了他们之间有正、负响应,而金属浓度和微生物种群之间表现出了负的相关性。从铬铁矿废水中纯化出来的菌株对铬和其他的重金属以及抗生素表现出高的耐受性,可作为重金属污染的指示剂。 相似文献
212.
搅拌摩擦对接焊6061铝合金的高周疲劳行为 总被引:1,自引:0,他引:1
对6061铝合金进行搅拌摩擦对接焊,其焊接工艺参数为:旋转速度600、800、1000、1200 r/min,前进速度80、100 mm/min,探针插入深度1.85 mm。基于搅拌摩擦焊参数计算得到的能量输入结果表明,在输入能量为196~405 kJ的情况下,接头在297~354 kJ的输入能量范围内有最大的抗拉强度。在不同的应力比(R=0.5,0.3,0.1,-0.3,-0.5)下,将高强度、低强度2种焊接头进行疲劳测试。结果表明,对于这2种焊接头,显微组织特征明显影响其疲劳性能,比如搅拌区、热力影响区(TMAZ)和热影响区。从接头的显微组织、裂纹扩展路径和断裂表面观察等方面对其疲劳强度进行讨论。 相似文献
213.
ACCELERATED STORAGE, SHELF LIFE AND COLOR OF MANGO POWDER 总被引:2,自引:0,他引:2
Vacuum‐dried mango powder was produced from mango pulp through the addition of glycerol monostearate and tricalcium phosphate at 0.015 kg each per kg mango solids and maltodextrin at 0.62 kg per kg dry mango solids. The mango powder was packed in aluminum foil‐laminated pouches and stored in an accelerated storage environment maintained at 90% relative humidity (RH) and 38 ± 2C. The sticky‐point moisture content at 38 ± 2C was considered as the maximum moisture content to which the mango powder would remain stable. The shelf life of the powder predicted from this consideration and the Guggenheim‐Anderson‐de Boer (GAB) model for the water activity moisture content relationship was 114.68 days, whereas the actual shelf life was 105 days. The color change of the powder during storage followed first‐order reaction kinetics with a rate constant of 0.038 per day. 相似文献
214.
Hrishikesh Venkataraman Poornachand Kalyampudi Gabriel-Miro Muntean 《Wireless Personal Communications》2012,62(3):517-536
Multimedia streaming over heterogeneous wireless networks has attracted significant interest in recent years from both telecom
network operators and end users. However, the heterogeneity of the wireless network makes it very difficult to synchronize
real-time multimedia streaming to different types of end-user devices across different wireless networks. In addition, with
different delay and packet loss across different networks, multimedia delivery over the heterogeneous wireless networks cannot
provide good quality streaming video. This paper proposes CASHeW—a novel cluster-based design with an in-built feedback-based
adaptive mechanism that results in a higher video perceived quality in two-hop heterogeneous wireless network environments.
CASHeW employs a proxy-client-server mechanism between the base station (BS) and the end-user; and importantly uses a quality-oriented
adaptive scheme for efficient multimedia delivery. Simulation-based tests indicate that the performance of CASHeW not only
outperforms transport layer adaptive delivery protocols like the TCP-Friendly Rate Control Protocol (TFRCP) and Loss Delay
Adaptation (LDA+), but also is better than that of medium access control (MAC) layer protocols such as the Receiver Based
Auto Rate (RBAR) and Enhanced Distributed Channel Access (EDCA) in terms of average perceived quality, average bit rate and
loss rate. 相似文献
215.
A prepeeling dip was used to demonstrate that removal or modification of the cuticular waxes from the tomato fruit could be used to improve the tomato peeling process. the tomatoes were dipped at various temperatures for I min prior to regular lye peeling. the optimum temperature was found to be 45C. Several organic solvents including chloroform, ethyl acetate, ketones, and alcohols were used. These tomatoes were compared to tomatoes peeled using the lye without the dip. the prepeeling dip reduced the thickness of the cuticular wax layer and produced cracks in the cutin surface. This facilitated good penetration of lye into the tomato resulting in more complete peeling. Peeling after pretreatment produced 86% well peeled tomatoes as compared to 33% well peeled in the control run. 相似文献
216.