作者机构：
[Wang, Qing] Beijing Radiat Ctr, Key Lab Beam Technol, Minist Educ, 12 Xueyuannan Rd, Beijing 100875, Peoples R China.;[Li, Yan] Liaoning Normal Univ, Sch Life Sci, South Liushu St 1, Dalian 116081, Liaoning, Peoples R China.;[Ferguson, David K.] Univ Vienna, Dept Palaeontol, Althanstr 14, A-1090 Vienna, Austria.;[Mo, Wen-Bo] Cent South Univ Forestry Sci & Technol, Coll Life Sci & Technol, Changsha 410004, Hunan, Peoples R China.;[Yang, Nan] Hunan City Univ, Coll Architecture & Urban Planning, Lab Key Technol Digital Urban Rural Spatial Plann, Yiyang 413000, Hunan, Peoples R China.
通讯机构：
[Wang, Q.] T;[Li, Y.] S;School of Life Science, South Liushu Street 1, China;The Key Laboratory of Beam Technology of Ministry of Education, 12 Xueyuannan Road, China
关键词：
Asian Monsoon;Climate evolution;Climate gradients;Co-existence approach;The Tibetan Plateau
摘要：
Many studies have suggested that the climate diversified in China during the Miocene, with the emergence of an arid region in north-western China, as the Asian Monsoon intensified with the rapid uplift of the Tibetan Plateau in the late Miocene. However, this opinion is not upheld by all geoscientists. Here Miocene fossil plant assemblages from 75 broadly scattered sites across China were investigated with the Co-existence Approach (CA) to exhibit trends in temperature and precipitation in time and space. Modern distributions and recorded climate data from China regarding the nearest living relatives of the fossil plant taxa were employed to pin-point the climatic parameters in which a maximum number of taxa could coexist. Evolution and climatic trends are presented in maps of China from the early, middle to late Miocene. These maps illustrate that the ranges of the temperature and precipitation in the Miocene were similar to or just a little larger than those in the Eocene but much smaller than those of the present. The whole of China still had low latitudinal climate gradients and was characterized by a subtropical climate without any arid region. The changing contours of temperature and precipitation may be ascribed to the initial stage of the Asian Monsoon. There was no abrupt elevation of the Tibetan Plateau, nor had the Plateau attained its present altitude or orography in the Miocene.
关键词：
Mining and manufacturing;Rock weathering;Fertilizer and pesticide use;Principal component analysis;Mixed metal pollution;Surface water pollution
摘要：
This study collected past sampling data on total concentrations of 12 heavy metals (Cd, Pb, Cr, Hg, Zn, Cu, Ni, Al, Fe, Mn, As, and Co) in surface water bodies, i.e., 168 rivers and 71 lakes, from 1972 to 2017. The intent was to investigate the levels and sources of heavy metal pollution across five decades and five continents. Mean heavy metal concentrations in global river and lake water, and the number of heavy metals with concentrations greater than the published threshold limits as per the standards of both the World Health Organization (WHO) and the United States Environmental Protection Agency (USEPA) were generally lower in the 1970s and 1980s than in the 1990s, 2000s, and 2010s. Over time, heavy metal pollution in surface water has changed from single metal pollution to mixed metal pollution. Heavy metal concentrations in water, and the number of heavy metals with concentrations above the threshold limits for both WHO and USEPA standards were lower in the developed countries of Europe and North America, and higher in the developing countries of Africa, Asia, and South America. Over time, the main sources of metal pollution have changed from mining and manufacturing to rock weathering and waste discharge. The main metal sources differed across the five continents, with fertilizer and pesticide use, along with rock weathering, being dominant in Africa. Mining and manufacturing, along with rock weathering, were dominant in Asia and Europe. Mining and manufacturing, along with fertilizer and pesticide use, were dominant sources in North America, while four sources (mining and manufacturing, fertilizer and pesticide use, rock weathering, and waste discharge) were responsible for the majority of heavy metal pollution in the river and lake water bodies of South America. Additionally, implementing rigorous standards on metal emissions and recycling metals from wastewater are effective for controlling heavy metal source pollution. (C) 2020 The Authors. Published by Elsevier B.V.
摘要：
In order to describe the movement process of air pollutants in high-rise buildings under the help of wind tunnel, an air pollutants' movement process experiment in high-rise buildings under the help of wind tunnel is designed. First, make a high-rise building model with height of 100 metres and 33 floors. The surface partial pressure coefficient of high-rise building model was measured by the wind pressure test program on the outer surface of the building. The concentration of air pollutants was detected by flame ionisation detector in building outer windows of different building floors using high-rise building model concentration test scheme. Pollutant concentration measurement and dimensionless representation method are given. Based on the coefficient distribution of wind pressure outside the building surface and the distribution of tracer gas concentration, the movement process of air pollutants in high-rise buildings under wind power is analysed, and the modelling analysis of motion process is completed. Experimental results show that the proposed method has high accuracy and application value in the process of air pollutant movement in high-rise buildings.
