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煤基Fe/AC去除废水中苯胺和吡啶的吸附行为和模型优化 被引量:1
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作者 李秉正 吴慧媛 +5 位作者 田晋平 杨颖超 鲍宇钢 秦丽娜 王莉霄 刘达 《煤炭转化》 CAS CSCD 北大核心 2020年第4期47-57,共11页
通过浸渍法制备煤基活性炭Fe系吸附剂(Fe/AC),并采用扫描电镜、N2吸附、元素分析和Boehm滴定法表征其结构及表面官能团。以批处理方式调变吸附条件(时间、初始质量浓度和温度)研究吸附剂对苯胺和吡啶的吸附行为,并分别采用Langmuir,Freu... 通过浸渍法制备煤基活性炭Fe系吸附剂(Fe/AC),并采用扫描电镜、N2吸附、元素分析和Boehm滴定法表征其结构及表面官能团。以批处理方式调变吸附条件(时间、初始质量浓度和温度)研究吸附剂对苯胺和吡啶的吸附行为,并分别采用Langmuir,Freundlich和Temkin模型拟合实验数据,同时用准一级、准二级和Elovich动力学方程分析吸附动力学行为,研究吸附剂吸附苯胺和吡啶的热力学行为。结果表明:当吸附100 mg/L的苯胺和吡啶时,硝酸铁处理对吸附剂的吸附量无显著影响,而当吸附2500 mg/L的苯胺和吡啶时,活性炭(AC),Fe3/AC(载铁活性炭,铁负载量为3%)和Fe5/AC(载铁活性炭,铁负载量为5%)的苯胺吸附量略有差别,分别为167 mg/g,166 mg/g和164 mg/g,AC,Fe3/AC和Fe5/AC的吡啶吸附量则分别为122 mg/g,102 mg/g和100 mg/g,说明硝酸铁处理可以降低吸附剂对苯胺和吡啶吸附量(吸附剂对吡啶吸附量降低得更为显著),这是由酸性含氧官能团的增加和吸附质亲水性叠加作用所致;吸附剂的吸附量随着温度升高而略下降;负载Fe具有催化氧化苯胺活性;Freundlich模型较好描述了AC和载铁活性炭(Fe/AC)对苯胺及吡啶吸附过程;准二级方程较好描述了Fe/AC对吡啶和低质量浓度苯胺吸附过程,Evolich动力学方程适用于高质量浓度苯胺吸附;吸附苯胺和吡啶是自发的和放热的。载铁活性炭适用于处理低质量浓度苯胺和吡啶废水。 展开更多
关键词 Fe/AC 吸附 苯胺 吡啶 模型优化
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Effects of HIV status notification on reducing the risk of sexual transmission of HIV in China 被引量:4
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作者 bao yugang Jing Jun +4 位作者 Zhang Yanhui Li Huasheng Feng Liangui Ning Zhen Tan Hongzhuan 《Chinese Medical Journal》 SCIE CAS CSCD 2014年第24期4177-4183,共7页
Background The risk of HIV sexual transmission is much higher among people unaware of their HIV status than among those aware. Only a few studies have indicated that the incidence of unsafe sex can be reduced when peo... Background The risk of HIV sexual transmission is much higher among people unaware of their HIV status than among those aware. Only a few studies have indicated that the incidence of unsafe sex can be reduced when people know their HIV status. This study was to investigate this effect in China. Methods A cohort study consisting of two surveys was conducted at two different times among a group of people living with HIV/AIDS, whose status was newly diagnosed with HIV via sexual contact, in Shanghai, Chongqing, and Kunming. The first survey was conducted among 823 people tested positive for HIV before notifying them of the HIV status. The second survey was conducted among 650 HIV-positive people at six months following the first survey (after notification of HIV status). The scope of survey covered unsafe sex practices, number of unsafe sexual partners, and frequency of unsafe sexual behaviors over the prior six months. Unsafe sex is defined as unprotected anal or vaginal sex with partners who are HIV positive or whose HIV status is unknown. Results The proportion of unsafe sex was reduced by about 85% after HIV status notification. The risk of HIV sexual transmission was 15 times higher among persons unaware of their HIV status than among those aware. Approximately 95% of new sexually transmitted HIV infections stemmed from 56% of the infected persons unaware of their HIV status in China. Conclusion Timely HIV status notification has the potential to significantly reduce unsafe sex among HIV-infected persons and reduce the risk for HIV transmission via unsafe sex. 展开更多
关键词 HIV/AIDS sexual transmission unsafe sex HIV status notification knowledge of HIV status
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鳀鱼蒸煮液的反渗透浓缩技术 被引量:3
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作者 张建友 包玉刚 +2 位作者 陈志明 费骁文 丁玉庭 《中国食品学报》 EI CAS CSCD 北大核心 2018年第4期169-175,共7页
以鳀鱼蒸煮液为原料,研究压力、温度、流速、蒸煮液浓度以及盐含量对反渗透膜通量、截留率、水溶性蛋白、氨基酸态氮等的影响。结果表明:提高温度、压力均能增大膜通量,且通量随温度的升高线性增加,随溶液盐含量的增加而降低。1.50 MPa... 以鳀鱼蒸煮液为原料,研究压力、温度、流速、蒸煮液浓度以及盐含量对反渗透膜通量、截留率、水溶性蛋白、氨基酸态氮等的影响。结果表明:提高温度、压力均能增大膜通量,且通量随温度的升高线性增加,随溶液盐含量的增加而降低。1.50 MPa时通量和溶质截留率的增长幅度均减小,截留效率降低;30℃时通量较大,挥发性盐基氮(TVB-N)、菌落总数相对于浓缩因子增长率最小,丙二醛(TBARS)受温度影响较大,其增长率大于相应的浓缩因子;增大流速对膜通量影响不显著(P>0.05);30℃,1.50 MPa,流速为1.60 m/s时进行反渗透浓缩,水溶性蛋白质、氨基酸态氮分别浓缩5.80倍和4.29倍;在降低盐含量的同时增大溶液浓度,可提高反渗透膜浓缩效率。多聚磷酸钠+SDS+EDTA复合清洗剂对反渗透膜的清洗效率高,30℃清洗30 min,膜通量恢复95.80%。 展开更多
关键词 鳀鱼蒸煮液 反渗透 浓缩 清洗方式
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