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3篇 您的检索式:作者名="Xiyan Ren"
    题名 作者 年代 出处 被引量
1Characterization of volatile organic compounds in the urban area of Beijing from 2000 to 2007显示文摘Beijing is one of the most polluted cities in the world.In this study,the long-term and continuous measurements of volatile organic compounds (VOCs) in the urban area of Beijing,specifically at Beijing 325 m Meteorological Tower,were conducted from 2000 to 2007.The annual record of VOC trends exhibited in two different phases was separated in 2003.Records show that VOC concentrations increased from 2000 to 2003 due to the abrupt increase in vehicle number.Contrarily,since 2003,there had been a decrease in VOCs concentrations as the policy on gasoline and air pollution was implemented.Toluene,benzene,and i-pentane are the chemicals that abound in and are directly related to vehicle activity,such as in vehicle exhaust and gasoline evaporation.Furthermore,records indicate that there had been seasonal variation in VOCs levels in that VOCs level in summer is higher than that in winter.As such,temperature is considered to significantly contribute to VOCs in Beijing.Records also show that VOCs level was high in the morning and during rush hours in the evening.In contrast,VOCs level was low during midday due to photochemical destruction with OH radical and dilution effect.In this study,a particular benzene to toluene ratio range (0.4-1.0) was used as the indicator of air propelled by vehicular exhaust.We also applied the correlation coefficients between BTEX and i-pentane to evaluate evaporation influence to ambient BTEX in the Beijing urban area.Yuesi Wang Xiyan Ren Dongsheng Ji Junqang Zhang Jie Sun Fankun Wu 2012Journal of Environmental Sciences2012,24,1:21
2Curative effect of acupuncture and moxibustion on insomnia: a randomized clinical trial显示文摘OBJECTIVE: To observe the effect of acupuncture and moxibustion on insomnia and explore its mechanism. METHODS: One hundred and twenty patients were randomly divided into an experiment group and a control group. Sixty patients in the experiment group were treated once a day with acupuncture at Baihui (GV 20), Sishencong (EX-HN 1), Shenmai (BL 62), and Zhaohai (KI 6) and with moxibustion at Baihui (GV 20) and Sishencong (EX-HN 1). Sixty patients in the control group were acupunctured once a day at Shenmen (HT 7), Neiguan (PC 6), and Sanyinjiao (SP 6).The Pittsburgh Sleep Quality Index (PSQI) was used to compare sleep improvement between the two groups. RESULTS: The total effective rate was 87.7% in the experiment group and 76.3% in the control group. The PSQI scores and the total score were lower after treatment than before treatment in bothgroups. However, the reduction in the experiment group was greater than that in the control group in sleeping quality, time to fall asleep, sleeping disorder, and daytime function (P<0.05). CONCLUSION: Acupuncture and moxibustion at Baihui (GV 20), Sishencong (EX-HN 1), Shenmai (BL 62), and Zhaohai (KI 6) significantly improved insomnia symptoms in the experiment group compared with the control group.Xiyan Gao Cuixiang Xu Peiyu Wang Shan Ren Yanli Zhou Xuguang Yang Ling Gao 2013Journal of Traditional Chinese Medicine2013,33,4:14
3Loss coefficient of nitrogenous non-point source pollution under various precipitation conditions显示文摘In this study,calibrations of non-point source(NPS)pollution models are performed based on Black River basin historical real-time runoff data,sedimentation record data,and NPS sources survey information.The concept of NPS loss coefficient for the watershed or the loss coefficients(LC)for simplicity is brought up by examining NPS build-up and migration processes along riverbanks in natural river systems.The historical data is used for determining the nitrogenous NPS loss coefficient for five land use types including farmland,urban land,grassland,shrub land,and forest under different precipitation conditions.The comparison of outputs from Soil and Water Assessment Tool(SWAT)model and coefficient export method showed that both methods could obtain reasonable LC.The high Pearson correlation coefficient(0.94722)between those two sets of calculation results justified the consistency of those two models.Another result in the study is that different combinations of precipitation condition and land use types could significantly affect the calculated loss coefficient.As for the adsorptive nitrogen,the order of impact on LC for different land use types can be sorted as:farm land.urban land.grassland.shrub land.forest while the order was farmland.grass land.shrub land.forest.urban land for soluble nitrogen.Hongguang CHENG Fanghua HAO Xiyan REN Shengtian YANG Wen XIONG Shaoping LEI 2008Frontiers of Environmental Science & Engineering2008,2,2:0
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