检索结果-南通市图书馆

Acute and chronic toxicity of nickel to nitrifiers at different temperatures

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2019年第8期31卷 169-178页

作者： Xiaoguang Liu Mohammad M.I.Chowdhury Masuduz Zaman mingu kim George Nakhla Department of Civil and Environmental Engineering University of Western Ontario Department of Chemical and Biochemical Engineering University of Western Ontario

This study investigated the acute nickel toxicity on nitrification of low ammonia synthetic wastewater at 10, 23, and 35°C. The nickel inhibition half-velocity constants(K_(I,Ni)) for ammonia oxidizing bacteria(AOB) and nitrite oxidizing bacteria(NOB) based on Ni/MLSS ratio at 10, 23, and 35°C were 5.4 and 5.6 mg Ni/g MLSS, 4.6 and 3.5 mg Ni/g MLSS, and 9.1 and 2.7 mg Ni/g MLSS, respectively. In addition, chronic toxicity of nickel to nitrification of low ammonia synthetic wastewater was investigated at 10°C in two sequencing batch reactors(SBRs). Long-term SBRs operation and short-term batch tests were comparable with respect to the extent of inhibition and corresponding Ni/MLSS ratio. The μ_(max), b, and K_o of AOB were 0.16 day^(-1), 0.098 day^(-1) and 2.08 mg O_2/L after long-term acclimatization to nickel of 1 mg/L at 10°C, high dissolved oxygen(DO)(7 mg/L) and long solids retention time(SRT) of 63–70 days. Acute nickel toxicity of nitrifying bacteria was completely reversible.

关键词： Nickel inhibition Temperature Nitrifying culture Activated sludge Toxicity

Freezing and thawing effects of sand-silt mixtures on elastic waves

在线全文

学校读者我要写书评

暂无评论

Research in Cold and Arid Regions 2013年第4期5卷 418-424页

作者： mingu Kang JongChan kim Jung-Hee Park Jong-Sub Lee School of Civil Environmental and Architectural Engineering Korea University

Freezing and thawing during the winter season change soil properties such as density. The density change in the particulate media influences soil stiffness. In addition, freezing of partially or fully saturated soils changes the soil matrix from a particulate media to a continuum. The goal of this study is to investigate the cyclic freezing and thawing effects on elastic waves. Sand-silt mixtures with 10% silt fraction in weight and 40% saturation are prepared. The sand-silt mixtures are placed in a nylon cell, onto which a pair of bender elements and a pair of piezoelectric disk elements are installed for the measurement of shear and compressional waves, respectively. The temperature of the mixtures decreases from 20 ℃ to -10 ℃ to freezing. The frozen sample is gradually thawed at room temperature （20 ℃）, These freezing-thawing processes are repeated three times. The test result shows that the shear and compressional wave velocities significantly increase when the specimen is frozen. When the temperature is greater than 0 ℃, the elastic wave velocities are lower during thawing than during freezing due to soil structure change. This study demonstrates that soil strucre change during the winter season may be effectively estimated from elastic waves.

关键词： compressional waves freezing frozen soil shear stiffness shear waves thawing

在线全文

学校读者我要写书评

暂无评论

风吹过的发丝首尔GN美发沙龙

室内设计与装修 2022年第10期 84-87页

作者： [韩国]Seuk Hoon kim mingu Kang(摄影) 汉阳大学校室内建筑设计学首尔04763

美发沙龙是许多空间和功能元素交织在一起形成的一个非常复杂的空间,是为他或她进行头发护理的地方。美发沙龙既要有能高效完成工作流程的合理流线安排,有足够区域进行美发操作的工作场所,还必须是一个能够表达审美意向的空间。对于首... 详细信息

美发沙龙是许多空间和功能元素交织在一起形成的一个非常复杂的空间,是为他或她进行头发护理的地方。美发沙龙既要有能高效完成工作流程的合理流线安排,有足够区域进行美发操作的工作场所,还必须是一个能够表达审美意向的空间。对于首尔新的美发沙龙GNHair来说,设计团队的主要理念是把它打造成一个让顾客感到愉快的空间,同时在有限的空间里为美发师提供足够的工作空间。

关键词：美发功能元素审美意向头发护理工作流程设计团队首尔沙龙

Preparation and characteristics of ZnO:Al thin films by rf magnetron sputtering

在线全文

学校读者我要写书评

暂无评论

Preparation and characteristics of ZnO:Al thin films by rf m...