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| 1 | Accuracy assessment of global historical cropland datasets based on regional reconstructed historical data——A case study in Northeast China显示文摘Historical cropland datasets are fundamental for quantifying the effects of human land use activities on climatic change and the carbon cycle. Two representative global land-use datasets, the Global Land Use Database (termed SAGE dataset) and the Historical Database of the Global Environment (termed HYDE dataset) have been established and used widely. Despite improvement of data quality and methodologies for extracting historical land use information, certain dataset limitations exist that need to be quantified and communicated to users so that they can make informed decisions on whether and how these land-use products should be used. The Cropland data of Northeast China (CNEC) is based on calibrated historical data and a multi-sourced data conversion model, and reconstructs cropland cover change in Northeast China over the last 300 years. Us- ing the CNEC as a reference, we evaluated the accuracy of cropland cover for SAGE and HYDE in Northeast China at spatial scales ranging from the entire Northeast China to provinces and even individual raster grid cells. Neither SAGE nor HYDE reflects real historical land reclamation. Cropland areas in SAGE are overestimated by 20.98 times in 1700 to 1.6 times in 1990. Although HYDE is better, there are significant disagreements in cropland area and distribution between HYDE and CNEC, especially in the 18th and 19th centuries. The proportion of total grid cells whose relative error was greater than 100% was 63.55% in 1700 and 53.27% in 1780. Global cropland dataset errors over Northeast China originate mainly from both the reverse calculation method for historical cropland data based on modern spatial patterns, and modern land-use outputs from satellite data. | Li BeiBei Fang XiuQi Ye Yu Zhang XueZhen | 2010 | Science China Earth Sciences2010，53，11： | 31 |
| 2 | Cropland cover change in Northeast China during the past 300 years显示文摘Land use/cover change induced by human activities has emerged as a 'global' phenomenon with Earth system consequences. Northeast China is an area where the largest land cultivation activities by migrants have happened in China during the past 300 years. In this paper, methods including documentary data calibration and multi-sourced data conversion model are used to reconstruct historical cropland cover change in Northeast China during the past 300 years. It is concluded that human beings have remarkably changed the natural landscape of the region by land cultivation in the past 300 years. Cropland area has increased almost exponentially during the past 300 years, especially during the past 100 years when the ratio of cropland cover changed from 10% to 20%. Until the middle of the 19th century, the agricultural area was still mainly restricted in Liaoning Province. From the late 19th century to the early 20th century, dramatic changes took place when the northern boundary of cultivation had extended to the middle of Heilongjiang Province. During the 20th century, three agricultural regions with high ratio of cropland cover were formed after the two phases of spatial expansion of cropland area in 1900s—1930s and 1950s—1980s. Since 1930s—1940s, the expansion of new cultivated area have invaded the forest lands especially in Jilin and Heilongjiang Provinces. | YE Yu FANG XiuQi REN YuYu ZHANG XueZhen CHEN Li | 2009 | Science China Earth Sciences2009，52，8： | 21 |
| 3 | Social impacts of the climatic shift around the turn of the 19th century on the North China Plain显示文摘Historical case studies of climate change impacts and the resulting social responses can provide analogies for better understanding the impacts of current and future climate changes.Around the turn of the 19th century,the climate of the North China Plain experienced a shift from a relatively warm stage in the 18th century to a colder stage in the 19th century,which was characterised by a much colder climate and more frequent and severe floods and droughts.Historical information about refugees,social disorder,grain transportation,and disaster relief on the North China Plain in 1780-1819 is collected from the Veritable Records of the Qing Dynasty(a collection of official records).The mechanism of climate change affecting the food security of the society,as indicated by the development of a refugee problem around the turn of the 19th century,is analyzed by examining the social vulnerability.There are four basic findings:(1) In the 40 years from 1780-1819,the society on the North China Plain was unstable and characterised by a significant deterioration of the refugee situation.The number of refugees increased markedly,and their behaviour became increasingly violent.In the 1780s,most of the disaster victims chose to stay at their residences waiting for relief.From 1790 to 1800,hundreds of thousands of refugees migrated to northeast China.In the 1810s,the frequency of farmer rebellions increased sharply.(2) The increase in instability corresponded to the climatic cooling over the same time period.The increased instability was a result of the negative impacts of climate change accumulating and transmitting to the social level.(3) For food security,a precondition for the negative impacts of climate change on human society was the vulnerability of the regional socioeconomic system,which had a high sensitivity and low capacity to respond.This vulnerability could be described by the following three observations:① The regional balance of supply and demand for food was in a critical state,which led to a high sensitivity and dramatic reduction in yield that was caused by climate change;② the capacity for disaster relief efforts by the government was too low to meet the needs of crisis management;③ the capacity for refugees' resettlement in eastern Inner Mongolia and northeast China,which both border the North China Plain,was severely restricted by climatic conditions or the quarantine policy.(4) It is estimated that climate change caused the social vulnerability to reach a critical level approximately 20 years earlier on the North China Plain. | FANG XiuQi XIAO LingBo WEI ZhuDeng | 2013 | Science China Earth Sciences2013，56，6： | 19 |
| 4 | Agriculture Development-induced Surface Albedo Changes and Climatic Implications Across Northeastern China显示文摘To improve the understandings on regional climatic effects of past human-induced land cover changes,the surface albedo changes caused by conversions from natural vegetation to cropland were estimated across northeastern China over the last 300 years,and its climatic effects were simulated by using the Weather Research and Forecasting (WRF) model.Essential natural vegetation records compiled from historical documents and regional optimal surface albedo dataset were used.The results show that the surface albedo decreased by 0.01-0.03 due to conversions from grassland to cropland in the Northeast China Plain and it increased by 0.005-0.015 due to conversions from forests to cropland in the surrounding mountains.As a consequence,in the Northeast China Plain,the surface net radiation increased by 4-8 W/m 2,2-5 W/m 2,and 1-3 W/m 2,and the climate was therefore warmed by 0.1℃-0.2℃、0.1℃-0.2℃、 0.1℃-0.3 ℃ in the spring,autumn and winter,respectively.In the surrounding mountain area,the net radiation decreased by less than 1.5 W/m 2,and the climate was therefore cooled too slight to be detected.In summer,effects of surface albedo changes on climate were closely associated with moisture dynamics,such as evapotranspiration and cloud,instead of being merely determined by surface radiation budget.The simulated summer climatic effects have large uncertainties.These findings demonstrate that surface albedo changes resulted in warming climate effects in the non-rainy seasons in Northeast China Plain through surface radiation processes while the climatic effects in summer could hardly be concluded so far. | ZHANG Xuezhen WANG Wei-Chyung FANG Xiuqi YE Yu ZHENG Jingyun | 2012 | Chinese Geographical Science2012，22，3： | 15 |
| 5 | Societal response to challenges of global change and human sustainable development显示文摘It is now widely accepted that carbon emission from human activities is an important driving force in global warming, and global change has a deep impact on sustainable development of human society. To meet the challenges of global change, the international community has reached a consensus that developed countries take strict actions in emission reduction, whereas developing countries take spontaneous efforts in reducing emissions under the guiding principle of common but differentiated responsibilities, with an agreed goal to restrict global surface temperature increase due to human activities to within 2℃ of pre-industrial levels. However, there is no clear pathway to reach this goal. A number of related questions must be addressed on principles to be followed, research emphasis and policy measures. Here we argue that response policies to address global change issues must be based on balanced development at regional and international levels, and on advancements in science and technology. This requires consideration of harmony not only between humans and nature but also within human societies, to properly deal with the relationship between global change and sustainable development. We must make equal efforts toward carbon emission reduction and carbon sequestration, and toward mitigation and adaptation. There should be more research support to reduce uncertainties in our understanding of global change. Addressing the challenges of global change creates great opportunities for the development of human society. This will facilitate transformation of energy use structure, improve and restore ecological functioning of the earth environment, transform production modes and ways of living in human society, and promote harmonic and balanced development at regional and international levels. | XU GuanHua GE QuanSheng GONG Peng FANG XiuQi CHENG BangBo HE Bin LUO Yong XU Bing | 2013 | Chinese Science Bulletin2013，58，25： | 15 |
| 6 | Transmission of climate change impacts from temperature change to grain harvests, famines and peasant uprisings in the historical China显示文摘Because of the complexity of social responses to climate change,as well as limitations of proxy data concerning interactions between climate change and human responses,the social impacts of past climate change and associated response mechanisms,thus,require further investigation.To shed light on the transmission of climate change impacts within historical Chinese society,we selected 30-year resolution sequences of temperature anomalies in eastern China and 10-year resolution sequences of grain harvest grades,famine indices,and frequencies of peasant uprisings in China over the past 2000 years.Using a food security perspective,we analyzed the impacts of temperature changes historically transmitted through Chinese production,population,and social subsystems,and differences in transmission characteristics between cold and warm units.Our results were as follows.(1)From 210 BC to 1910 AD,temperature changes in China were significantly positively correlated with grain harvest grades(correlation coefficient,0.338),and significantly negatively correlated with famine indices,and frequencies of peasant uprisings(correlation coefficients,-0.301 and-0.277,respectively).The correlation coefficients between famine indices and grain harvest grades or frequencies of peasant uprisings were very low.(2)There was a higher proportion of bumper or normal harvests(86.5%of the total decades),more moderate and mild famines(76%),and a lower proportion of peasant uprisings(33.3%)in the 30-year warm units.Conversely,there was a higher proportion of poor or normal harvests(70.7%),a greater proportion of moderate and severe famines(77.6%),and more peasant uprisings(51.7%)in the 30-year cold units.(3)Of the 23 main transmission pathways extending from temperature change to the social subsystem,13 occurred in cold units,of which 7 had an endpoint of peasant uprisings,and 10 occurred in warm units of which 3 had an endpoint of peasant uprisings.The main transmission pathways that were more likely to be associated with the impacts of temperature change were:Cold→poor harvests→severe famines→more uprisings;cold→poor harvests→moderate famines→more uprisings;warm→bumper harvests→mild famines→no uprisings;warm→bumper harvests→moderate harvests→no uprisings;warm→normal harvests→mild famines→no uprisings;and warm→normal harvests→moderate famines→no uprisings.(4)The transmission of the impacts of temperature change was a complex process.Within this process,famine was most prone to being modulated by human society.In the transmission pathways from the production to the social subsystem,there was a stepwise decrease in the occurrence rate of decades that were probably affected by climate change.In all cold units,10.4%of decades ending in more uprisings were most likely to be associated with the impacts of temperature change.In all warm units,47.9%of decades ending in no uprisings were most likely to be associated with the impacts of temperature change.This research can contribute a better understanding on the past interaction mechanisms and processes within the human-climate-ecosystem complex,as well as a better response to the impacts of the ongoing climate change. | FANG XiuQi SU Yun YIN Jun TENG JingChao | 2015 | Science China Earth Sciences2015，58，8： | 15 |
| 7 | Reconstruction of typhoons in the Yangtze River Delta during 1644-1949AD based on historical chorographies显示文摘在到 1949AD 的从 1644 的长江三角洲的台风上的代理记录在 Qing 王朝和中华民国时期从历史的地图被提取。在为识别历史的台风的基本原则的参考,在 306 年的一个时期上的长江三角洲上的时间系列被开发。结论如下。(1 ) 有从 1644 的 241 台风的一个总数到 1949AD。用到 1949AD 的从 1884 的历史的地图,台风的数字是 65,到 87.8% 的平等者由气象学的观察记录了。活动重建了仅仅使用二个方法一次的有在台风的差别的年的数字是 55,在到 1949AD 的从 1884 的时期到达 83.3% 。这结果意味着使用历史的地图重建能代表的历史的台风的系列在年的台风活动的变化。(2 ) 台风活动的平均数字每从 1644 的年是 0.79 次到 1949AD,并且他们显示出一个增加的趋势。这 306 年能被台风活动的平均数字划分成三个时期:它从 1644 是低的到 1784AD,并且更多的台风活动从 1785 被发现到 1904AD。台风活动的数字在最后时期到达顶点,是值得注意的,它每从 1905 的年是 1.2 次到 1949AD。(3 ) 在第 20 世纪前,在温暖的时期的台风活动的数字是不到冷时期的数字。然而,台风活动的数字戏剧性地增加了在早第 20 世纪。把台风活动与 El Ni 作比较 ? o 事件,当时,台风活动的数字没增加的数据表演 El Ni ? o 发生了。 | ZHANG Xiangping YE Yu FANG Xiuqi | 2012 | Journal of Geographical Sciences2012，22，5： | 13 |
| 8 | Impact of climate change on fluctuations of grain harvests in China from the Western Han Dynasty to the Five Dynasties(206 BC–960 AD)显示文摘The occurrence of bumper or poor grain harvests in ancient China plays an important role in explaining how past climate changes affected the economy.Because of the lack of long-term continuous and high-resolution quantitative data for reconstructing the series of grain harvests in ancient China,understanding of the impacts and mechanisms involved in climate change is limited.This study presents a method designed for reconstructing grain harvest series by quantifying grain output levels based on the descriptions in historical documents.The method involves setting the grain output level for each year based on very specific meanings of different words,calculating a yield index based on the structure of each level and assessing grain yields(bumper or poor harvests)every 10 years.First,1636 records related to grain yields(including crop yields,food security,agricultural disasters,grain prices,grain storage and people's livelihoods)for each year were retrieved from history books called the Twenty-Four Histories.Second,using this method,a 10-year resolution graded grain harvest series from the Western Han Dynasty to the Five Dynasties(206 BC–960 AD)is reconstructed.Finally,the relationship between the variations in temperature and precipitation and the fluctuation of grain yields is examined.The results show that from the Western Han Dynasty to the Five Dynasties,bumper,average and poor harvest decades accounted for 33.3%,39.3%and 27.4%of the 1,166-year period,respectively.The grain yields during 206 BC–960 AD can be divided into three stages:a period of bumper harvests during 206–51 BC,poor harvests during 50 BC–590 AD and bumper harvests during 591–960 AD.Bumper harvest decades typically experienced a warm climate with normal or high levels of precipitation,while poor harvest decades had a cold and dry climate.A positive correlation was found between temperature and grain yield because a warm climate allows a full use of resources.The observed relationship between precipitation and grain yield indicated that both flooding and droughts cause poor harvests,which confirms that agricultural production in the monsoon climate of eastern China is greatly impacted by conditions of limited heat and extreme precipitation. | SU Yun FANG XiuQi YIN Jun | 2014 | Science China Earth Sciences2014，57，7： | 13 |
| 9 | Extreme climate events,migration for cultivation and policies:A case study in the early Qing Dynasty of China显示文摘Based on the historical records of the annual increase in the workforce (men older than 16 years of age), the annual new taxed cropland in the Shengjing area (Northeast China), the extreme climate events in North China, and related management policies in Northeast China during 1661―1680, a case study has been conducted to investigate the relationship between the extreme climate events in North China and the migration to Northeast China for cultivation. This study has found that the migration to Northeast China for cultivation from 1661 to 1680 was a response to the drought events that occurred in North China. The upsurge of migration, which occurred in 1665―1680, was a response to the drought period during 1664―1680 in North China while the fewer disasters period in Northeast China. There were three migratory peaks during the upsurge of migration, which corresponded to the three drought events. The peaks of migration, however, often lagged behind the drought events about 1―2 years. The encourag-ing-migration policy, which was adopted to encourage cultivation in Northeast China, did not produce much migration into the region in the early Qing Dynasty. It did, however, provide a policy background, which ensured more than 10000 migrants per year to Northeast China when North China suffered from drought/flood disasters. As a response to the highest peak of migration induced by the severe droughts in North China during 1664―1667, a prohibiting-migration policy restricted further migration to Northeast China was carried out in 1668. Although the prohibiting-migration policy could not entirely stop the migrants fleeing from famine in North China to Northeast China, the migrants and cultivation were significantly reduced under the policy. The frequent changes of the policy on the years when taxation started after the land was cultivated were also related to climate events. The extreme climate events in North China, migration to Northeast China for cultivation, and the related management poli-cies showed an impact-response chain, which reflected the interaction among extreme climate events, human behavior, and policies. | FANG XiuQi YE Yu ZENG ZaoZao | 2007 | Science China Earth Sciences2007，50，3： | 8 |
| 10 | Plant phenology and climate change显示文摘Plant phenology is regarded as an important natural indicator of climate change because plants are finely tuned to the seasonality of their climate.In response to the impacts of climate change,the observed shifting of phenophases at multiple scales since the 20th century,ranging from individual plants to whole ecosystems,is consistent with cli- | FANG XiuQi CHEN FaHu | 2015 | Science China Earth Sciences2015，58，6： | 8 |
| 11 | The changing regional distribution of grain production in China in the 21st century显示文摘This paper examines the changing regional distribution of grain production in China. Based on the analysis of data from county statistics for the period 2000–2003, major differences in the main grain-output regions in China can be observed. The main grain-producing areas have shifted from the south to the north of China. New grain production regions have been also added to western China since the late 1990s. The per capita grain consumption in one third of China’s main grain-producing counties has fallen below 400 kg; most of these areas are located in southern China. In the new millennium, Northeast China, the central-south North China, and the arid and semi-arid regions of Northwest China produced three quarters of the surplus grains. Most of these areas are located in regions susceptible to environmental change. The amount of grain production in these regions shows high fluctuations. It is argued here that further studies of recent environmental changes as well as a risk assessment of China’s food security in main grain-output regions are needed. | YIN Peihong FANG Xiuqi TIAN Qing MA Yuling | 2006 | Journal of Geographical Sciences2006，16，4： | 8 |
| 12 | Carbon emissions induced by cropland expansion in Northeast China during the past 300 years显示文摘Assessments of the impacts of land use and land cover changes(LUCC) on the terrestrial carbon budget, atmospheric CO2 concentration, and CO2-related climatic change are important to understand the environmental effects of LUCC and provide information about the effects of historical carbon emissions. Using regional land cover reconstructions from historical records, with a bookkeeping model, we estimated the carbon sink changes caused by historical cropland expansion in Northeast China during the past 300 years. The conclusions are as follows:(1) There was a dramatic land reclamation of cropland during the past 300 years in Northeast China. Approximately 26% of the natural land was cultivated, and 38% of the grassland and 20% of the forest and shrubland were converted to cropland.(2) The carbon emission induced by cropland expansion between 1683 and 1980 was 1.06–2.55 Pg C, and the estimation from the moderate scenario was 1.45 Pg C. The carbon emissions of the soil carbon pool was larger than that from the vegetation carbon pool and comprised more than 2/3 of the total carbon emissions.(3) The carbon emissions of the three provinces in Northeast China were different. Heilongjiang Province had the largest carbon emissions, and Jilin Province had the second largest emissions.(4) The primary source of carbon emissions was forest reclamation(taking 60% of the total emissions in the moderate scenario), the secondary source was grassland cultivation(taking 27%), and the tertiary sources were shrubland and wetland reclamation(taking 13%). Examination on the data accuracy revealed that the high-resolution regional land cover data allowed the carbon budget to be evaluated at the county level and improved the precision of the results. The carbon emission estimation in this study was lower than those in previous studies because of the improved land use data quality and various types of land use change considered. | LI BeiBei FANG XiuQi YE Yu ZHANG XueZhen | 2014 | Science China Earth Sciences2014，57，9： | 8 |
| 13 | Impacts of climate warming on heating energy consumption and southern boundaries of severe cold and cold regions in China显示文摘Impacts of climate warming on heating energy consumption and southern boundaries of severe cold and cold regions of China in the past 20 years are analyzed by using daily and monthly average tem- perature data from 590 weather stations in China and based on regulations of Heating Ventilation and Air Conditioning Design Rules (GB50019-2003) and Thermal Design Rules for Civil Building (GB50175-93) (China National Standard). The contribution of climate warming to coal saving for heating during cold seasons in major cities is calculated according to indices of coal consumption for heating in major cities during cold seasons defined in Energy Conservation Design Standard for New Heating Residential Buildings (JCJ26-95). Comparing with the period before 1980, southern boundaries of se- vere cold and cold regions shift toward north up to 2 degrees in latitude since the mid-1980s. Theo- retically, climate warming could contribute to 5%―10% coal savings for heating since the mid-1980s in major cities, and even more since the mid-1990s. | CHEN Li FANG XiuQi LI Shuai | 2007 | Chinese Science Bulletin2007，52，20： | 7 |
| 14 | The effects of international trade on Chinese carbon emissions: An empirical analysis显示文摘国际贸易是到一个国家的碳排出物的一个重要影响因素。作为中国外贸的快速的发展自从它进在 2002 的 WTO 的入口,中国的碳排出物上的国际贸易的效果是越来越重要的。用中国和精力消费数据的最近的可得到的输入产量表格,这研究由分析在在 2002 和 2007 之间的贸易表达的排出物在碳排出物和效果的变化上估计了中国外贸的效果。结果在中国国际贸易显示出表达的碳排出物的越来越重要的出口行为。从 2002 ~ 2007,网的比例出口了排出物,在国内排出物的国内出口排出物分别地从 18.32% ~ 29.79% 并且从 23.97% ~ 34.76% 增加了。另外,大约 22.10% 总数和 32.29% 进口排出物在分别地,在 2002 和 2007 处理贸易被产生它被进口并且以后出口了排出物。尽管,大多数扇区在 imported and exported 排出物显示出一个生长趋势,电子设备,化学工业,和纺织品仍然是的电的机械和通讯的扇区最大的排放出口商,网络出口了哪个也最大的排出物。为中国和另外的发展中的国家,技术改进可以是减少排出物目前上演的碳的最有利、可接受的方法。在排出物减小的未来协商,当时,包括在国际贸易表达的碳排出物将是公平、合理的更多财务经济的全部的排出物。 | WEI Benyong FANG Xiuqi WANG Yuan | 2011 | Journal of Geographical Sciences2011，21，2： | 6 |
| 15 | Who will win the future of display technologies?显示文摘In recent years,China and other countries have invested heavily in the research and manufacturing capacity of display technology.Meanwhile,different display technology scenarios,ranging from traditional LCD (liquid crystal display) to rapidly expanding OLED (organic light-emitting diode) and emerging QLED (quantum-dot light-emitting diode),are competing for market dominance.Amidst the trivium strife,OLED,backed by | hepeng jia Xiuqi Huang Liangsheng Liao Xiaogang Peng Jun Xu Dongyuan Zha | 2018 | National Science Review2018，5，3： | 5 |
| 16 | Accuracy Comparison of Gridded Historical Cultivated Land Data in Jiangsu and Anhui Provinces显示文摘The spatial resolution of source data, the impact factor selection on the grid model and the size of the grid might be the main limitations of global land datasets applied on a regional scale. Quantitative studies of the impacts of rasterization on data accuracy can help improve data resolution and regional data accuracy. Through a case study of cropland data for Jiangsu and Anhui provinces in China, this research compared data accuracy with different data sources, rasterization methods, and grid sizes. First, we investigated the influence of different data sources on gridded data accuracy. The temporal trends of the History Database of the Global Environment(HYDE), Chinese Historical Cropland Data(CHCD), and Suwan Cropland Data(SWCD) datasets were more similar. However, different spatial resolutions of cropland source data in the CHCD and SWCD datasets revealed an average difference of 16.61% when provincial and county data were downscaled to a 10 × 10 km^2 grid for comparison. Second, the influence of selection of the potential arable land reclamation rate and temperature factors, as well as the different processing methods for water factors, on accuracy of gridded datasets was investigated. Applying the reclamation rate of potential cropland to grid-processing increased the diversity of spatial distribution but resulted in only a slightly greater standard deviation, which increased by 4.05. Temperature factors only produced relative disparities within 10% and absolute disparities within 2 km^2 over more than 90% of grid cells. For the different processing methods for water factors, the HYDE dataset distributed 70% more cropland in grid cells along riverbanks, at the abandoned Yellow River Estuary(located in Binhai County, Yancheng City, Jiangsu Province), and around Hongze Lake, than did the SWCD dataset. Finally, we explored the influence of different grid sizes. Absolute accuracy disparities by unit area for the year 2000 were within 0.1 km^2 at a 1 km^2 grid size, a 25% improvement over the 10 km^2 grid size. Compared to the outcomes of other similar studies, this demonstrates that some model hypotheses and grid-processing methods in international land datasets are truly incongruent with actual land reclamation processes, at least in China. Combining the model-based methods with historical empirical data may be a better way to improve the accuracy of regional scale datasets. Exploring methods for the above aspects improved the accuracy of historical cropland gridded datasets for finer regional scales. | YUAN Cun YE Yu TANG Chanchan FANG Xiuqi | 2017 | Chinese Geographical Science2017，27，2： | 5 |
| 17 | Temporal variability of iron concentrations and fractions in wetland waters in Sanjiang Plain, Northeast China显示文摘Chemical forms, reactivities and transformation of iron fractions in marshy waters were investigated with cross-flow filtration technique to study the iron environmental behavior. Iron fractions were divided into four parts: acid-labile iron (pre-acidification of unfiltered marshy water samples, > 0.7 μm), high-molecular-weight iron (0.7-0.05 μm), medium-molecular-weight iron (0.05-0.01 μm), and low-molecular-weight iron (< 0.01 μm). The cross-flow filtration suggested that iron primarily exist in both the > 0.7 μm and < 0.01 μm size fractions in marshy waters. Rainfall is the key for rain-fed wetland to determine fate of iron by changing the aquatic biochemical conditions. By monitoring the variation of iron concentrations and fractions over three years, it was found that dissolved iron and acid-labile iron concentrations exhibit a large variation extent under different annual rainfalls from 2006 to 2008. The seasonal variation for iron species proved that the surface temperature could control some conversion reactions of iron in marshy waters. Low- molecular-weight iron would convert to acid-labile iron gradually with temperature decreasing. The photochemical reactions of iron fractions, especially low-molecular-weight iron had occurred under solar irradiation. The relative proportion of low-molecular-weight in total dissolved iron ranging from 28.3% to 43.2% were found during the day time, which proved that the observed decreasing concentration of acid lability iron was caused by its degradation to low molecular weight iron. | Xiaofeng Pan Baixing Yan Muneoki Yoh Lixia Wang Xiuqi Liu | 2010 | Journal of Environmental Sciences2010，22，7： | 4 |
| 18 | Methodology for credibility assessment of historical global LUCC datasets显示文摘Land use-induced land cover change(LUCC)is an important anthropogenic driving force of global change that has influenced,and is still influencing,many aspects of regional and global environments.Accurate historical global land use/cover datasets are essential for a better understanding of the impacts of LUCC on global change.However,there are not only evident inconsistencies in current historical global land use/cover datasets,but inaccuracies in the data in these global dataset revealed by historical record-based reconstructed regional data throughout the world.A focus in historical LUCC and global change research relates to how the accuracy of historical global land cover datasets can be improved.A methodology for assessing the credibility of existing historical global land cover datasets that addresses temporal as well as spatial changes in the amount and distribution of land cover is therefore needed.Theoretically,the credibility of a global land cover dataset could be assessed by comparing similarities or differences in the data according to actual land cover data(the'true value').However,it is extremely difficult to obtain historical evidence for assessing the credibility of historical global land cover datasets,which cannot be verified through field sampling like contemporary global land cover datasets.We proposed a methodological framework for assessing the credibility of global land cover datasets.Considering the types and characteristics of the available evidence used for assessments,we outlined four methodological approaches:(1)accuracy assessment based on regional quantitative reconstructed land cover data,(2)rationality assessment based on regional historical facts,(3)rationality assessment based on expertise,and(4)likelihood assessment based on the consistency of multiple datasets.These methods were illustrated through five case studies of credibility assessments of historical cropland cover data.This framework can also be applied in assessments of other land cover types,such as forest and grassland. | Xiuqi FANG Wanyi ZHAO Chengpeng ZHANG Diyang ZHANG Xueqiong WEI Weili QIU Yu YE | 2020 | Science China Earth Sciences2020，63，7： | 4 |
| 19 | Establishment of a new acute-on-chronic liver failure model显示文摘To establish an animal model of acute-on-chronic liver failure(ACLF) that would replicate the pathological process of ACLF in humans, rats were administered porcine serum(PS) for 11 weeks. Liver fibrosis was determined by pathological and biochemical assessments. The animals then were injected with D-galactosamine(D-gal) and lipopolysaccharide(LPS). The survival times of animals with cirrhosis and ACLF were determined over 48 h. Other animals were killed at 0, 4, 8 and 12 h after administration of D-gal/LPS. Liver injury was assessed by histopathological analysis and biochemical indices, and apoptosis was detected by Western blot and TUNEL analysis. After PS administration for 11 weeks the serum levels of hyaluronic acid and N-procollagen type III peptide increased significantly, and serious fibrosis and cirrhosis was observed at weeks 10 and 11. Cirrhotic rats were injected with D-gal/LPS to induced ACLF; the rate of mortality over 48 h was 80%. ALT and AST levels increased markedly at 4 h, but decreased significantly at8 and 12 h post-treatment. The total bilirubin, direct bilirubin, and total bile acids levels increased markedly at 8 and 12 h. Clotting times, TNF-α and IL-6 levels increased significantly, except for 12 h post-treatment.Apoptosis, inflammation and necrosis were elevated as determined by hematoxylin-eosin staining and TUNEL assays. BCL-2 levels decreased significantly, While BAX levels increased significantly.Cytochrome c expression peaked at 8 h postD-gal/LPS treatment. In conclusion, an ACLF model induced by PS and D-gal/LPS was established and the underlying mechanisms of ACLF development were explored. | Fangfang Li Luyang Miao Hua Sun Yuyang Zhang Xiuqi Bao Dan Zhang | 2017 | Acta Pharmaceutica Sinica B2017，7，3： | 4 |
| 20 | Relationships between tree-ring cell features of Pinus koraiensis and climate factors in the Changbai Mountains,Northeastern China显示文摘Anatomical characteristics have been proven useful for extracting climatic signals. To examine the climatic signals recorded by tree-ring cell features in the Changbai Mountains, we measured cell number and cell lumen diameter, in addition to ring widths, of Korean pine(Pinus koraiensis) tree rings at sites of varied elevation,and we developed chronologies of cell number(CN), mean lumen diameter(MLD), maximum lumen diameter(MAXLD) and tree-ring width(TRW). The chronologies were correlated with climatic factors monthly mean temperature and the sum of precipitation. As shown by our analysis, the cell parameter chronologies were suitable for dendroclimatology studies. CN and TRW shared relatively similar climatic signals which differed from MLD andMAXLD, and growth-climate relationships were elevationdependent, as shown by the following findings:(1) at each elevation, MLD and MAXLD recorded different monthly climatic signals from those recorded by TRW for the same climatic factors; and(2) MLD and MAXLD recorded climatic factors that were absent from TRW at lower and middle elevations. Cell lumen diameter proved to be an effective archive for improving the climate reconstruction for this study area. | Hui Wang Xuemei Shao Xiuqi Fang Yuan Jiang Chunlan Liu Qing Qiao | 2017 | Journal of Forestry Research2017，28，1： | 3 |
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