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Big Earth Data 2023年第4期7卷 1146-1168页

作者： Liang Zhang Yang Liu jingyun Zheng Zhixin Hao Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijingChina University of Chinese Academy of Sciences BeijingChina

Accurate reconstructed series are crucial for studying the differences in regional hydroclimatic variations in Europe over the past *** hierarchical clustering analysis and stepwise regression methods,we reconstructed yearly time series of the summer standardized precipitation evapotranspiration index(SPEl)for six European regions over the past *** analysis also revealed prominent regional hydroclimatic differences in multidecadal signals over the past 500 *** instance,in the 1500s-1570s(from the beginning of the 1500s to the end of the 1570s),drying trends were observed in northern and southeastern Europe,whereas southwestern Europe experienced a wetting ***,drying trends were observed in northern and central Europe in the ***,wetting trends were observed in western and central Europe during the 1830s-1850s,with drying trends in northern and southeastern ***,the hydroclimatic variations in most European regions showed drying trends in the 1920s-1950s,especially in southern *** utilizing large amounts of tree-ring samples and directly comparing regional hydroclimatic variations,our reconstructions provide a consistent and comprehensive dataset for further *** reconstructed dataset is available at https://***/10.57760/sciencedb.07215.

关键词： Europe hydroclimatic variations regional reconstruction tree-ring chronologies past millennium

Impacts of climate warming on plants phenophases in China for the last 40 years

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Chinese Science Bulletin 2002年第21期47卷 1826-1831页

作者： ZHENG jingyun GE Quansheng HAO Zhixin Institute of Geographic Sciences and Natural Resources Research Chinese Academy of SciencesBeijing 100101China

Based on plant phenology data from 26 stations of the Chinese Phenology Observation Network of the Chinese Academy of Sciences and the climate data, the change of plant phenophase in spring and the impact of climate warming on the plant phenophase in China for the last 40 years are analyzed. Furthermore, the geographical distribution models of phenophase in every decade are reconstructed, and the impact of climate warming on geographical distribution model of phenophase is studied as well. The results show that (i) the response of phenophase advance or delay to temperature change is nonlinear. Since the 1980s, at the same amplitude of temperature change, phenophase delay amplitude caused by temperature decrease is greater than phenophase advance amplitude caused by temperature increase; the rate of phenophase advance days decreases with temperature increase amplitude, and the rate of phenophase delay days increases with temperature decrease amplitude. (ii) The geographical distribution model between

关键词： climate warming phenophase change impact pheno-phase response to climate change China.

Rates of temperature change in China during the past 2000 years

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Science China Earth Sciences 2011年第11期54卷 1627-1634页

作者： GE QuanSheng ZHANG XueZhen HAO ZhiXin ZHENG jingyun Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China

Using 24 proxy temperature series, the rates of temperature change in China are analyzed at the 30- to 100-year scales for the past 2000 years and at the 10-year scale for the past 500 years. The results show that, at the 100-year scale, the warming rate for the whole of China in the 20th century was only 0.6±1.6℃/100 a （interval at the 95% confidence level, which is used here- after）, while the peak warming rate for the period from the Little Ice Age （LIA） to the 20th century reached 1.1_＋1.2~C/100 a, which was the greatest in the past 500 years and probably the past 2000 years. At the 30-year scale, warming in the 20th century was quite notable, but the peak rate was still less than rates for previous periods, such as the rapid warming from the LIA to the 20th century and from the 270s-290s to 300s-320s. At the 10-year scale, the warming in the late 20th century was very evident, but it might not be unusual in the context of warming over the past 500 years. The exact timing, duration and magnitude of the warming peaks varied from region to region at all scales. The peak rates of the 100-year scale warming in the AD 180s-350s in northeastern China as well as those in the 260s-410s and 500s-660s in Tibet were all greater than those from the mid-19th to 20th century. Meanwhile, the rates of the most rapid cooling at scales of 30 to 100 years in the LIA were promi-nent, but they were also not unprecedented in the last 2000 years. At the 10-year scale, for the whole of China, the most rapid decadal cooling in the 20th century was from the 1940s to 1950s with a rate of -0.3±0.6℃/10 a, which was similar to rates for periods before the 20th century. For all regions, the rates of most rapid cooling in the 20th century were all less than those for previous periods.

关键词： China past 2000 years rates of temperature change

Increasing terrestrial vegetation activity in China, 1982—1999

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Science China(Life Sciences) 2004年第3期47卷 229-240页

作者： FANG jingyun PIAO Shilong HE Jinsheng MA Wenhong Department of Ecology College of Environmental Sciences and Key Laboratory for Earth Surface Processes of the Ministry of Education Peking University Beijing 100871 China

Variations in vegetation activity during the past 18 years in China were investigated using the normalized difference vegetation index (NDVI) derived from the 3rd generation time series dataset of NOAA-AVHRR from 1982 to 1999. In order to eliminate the effects of non-vegetation factors, we characterized areas with NDVI tant factors. NDVI changes in China ex-hibited relatively large spatial heterogeneity; the eastern coastal regions experienced declining or indiscernibly rising trends, while agricultural regions and western China experienced marked increases. Such a pattern was due primarily to urbanization, agricultural activity, regional climate characteristics, and different vegetation responses to regional climate changes.

关键词： China NDVI vegetation activity climate change agricultural production urbanization.

Unprecedented Warming Revealed from Multi-proxy Reconstruction of Temperature in Southern China for the Past 160 Years

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Advances in Atmospheric Sciences 2017年第8期34卷 977-982页

作者： Yang LIU jingyun ZHENG Zhixin HAO Xuezhen ZHANG Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China University of Chinese Academy of Sciences Beijing 100049 China

Using the southern limit of snowfall recorded in Chinese documents, chronologies of tree-ring width, and tree-ring stable oxygen isotope（δ^（18）O）, the annual temperature anomaly in southern China during 1850–2009 is reconstructed using the method of signal decomposition and synthesis. The results show that the linear trend was 0.47℃（100 yr）^（-1）over 1871–2009,and the two most rapid warming intervals occurred in 1877–1938 and 1968–2007, at rates of 0.125℃（10 yr）^（-1）and 0.258℃（10 yr）^（-1）, respectively. The decadal variation shows that the temperature in the moderate warm interval of the 1910s–1930s was notably lower than that of the 1980s–2000s, which suggests that the warming since the 1980s was unprecedented for the past 160 years, though a warming hiatus existed in the 2000s. Additionally, there was a rapid cooling starting from the 1860s,followed by a cold interval until the early 1890s, with the coldest years in 1892 and 1893. A slight temperature decline was also found from the 1940s to the late 1960s. This study provides an independent case to validate the global warming for the past 160 years and its hiatus recently, because the proxy data are not affected by urbanization.

关键词： centennial warming temperature reconstruction multi-proxy southern China

Terrestrial vegetation carbon sinks in China,1981―2000

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Science China Earth Sciences 2007年第9期50卷 1341-1350页

作者： FANG jingyun GUO ZhaoDi PIAO ShiLong CHEN AnPing Department of Ecology College of Environmental Scienceand Key Laboratory for Earth Surface Processes of the Ministry of EducationPeking UniversityBeijing 100871China

Using China's ground observations,e.g.,forest inventory,grassland resource,agricultural statistics,climate,and satellite data,we estimate terrestrial vegetation carbon sinks for China's major biomes between 1981 and *** main results are in the following:(1)Forest area and forest biomass car-bon(C)stock increased from 116.5×10^(6) ha and 4.3 Pg C(1 Pg C=10^(15) g C)in the early 1980s to 142.8×10^(6) ha and 5.9 Pg C in the early 2000s,*** biomass carbon density increased form 36.9 Mg C/ha(1 Mg C=10^(6) g C)to 41.0 Mg C/ha,with an annual carbon sequestration rate of 0.075 Pg C/***,shrub,and crop biomass sequestrate carbon at annual rates of 0.007 Pg C/a,0.014―0.024 Pg C/a,and 0.0125―0.0143 Pg C/a,respectively.(2)The total terrestrial vegetation C sink in China is in a range of 0.096―0.106 Pg C/a between 1981 and 2000,accounting for 14.6%―16.1%of carbon dioxide(CO_(2))emitted by China's industry in the same *** addition,soil carbon sink is estimated at 0.04―0.07 Pg C/***,carbon sequestration by China's terrestrial ecosystems(vegetation and soil)offsets 20.8%―26.8%of its industrial CO_(2) emission for the study period.(3)Considerable uncertainties exist in the present study,especially in the estimation of soil carbon sinks,and need further intensive investigation in the future.

关键词： carbon sink China crops forests grasslands shrubs soils terrestrial ecosystems

UAV autonomous navigation system for GNSS invalidation 36

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UAV autonomous navigation system for GNSS invalidation

Recent advances in Cu-based nanocomposite photocatalysts for CO_2 conversion to solar fuels

第36届中国控制会议

作者： jingyun Duo Long Zhao School of automation science and electrical engineering Beihang University Science and Technology on Aircraft Control Laboratory Beihang University

ISBN: (纸本)9781538629185

The Global Navigation Satellite System（GNSS） and Strapdown Inertial Navigation System（SINS） integrated navigation system has been widely used on Unmanned Aerial Vehicles（UAVs） ***,the system cannot operates properly when GNSS is *** this paper we propose a systematic framework of visual aided inertial autonomous navigation system to solve this *** proposed system fuses the information of three sub navigation systems such as inertial navigation system,satellite navigation system and visual navigation system *** system gets video information from a monocular camera mounted on a *** the consecutive image frames are matched by detection and matching of oriented FAST and rotated BRIEF（ORB）.An algorithm of treble mismatching point pairs elimination is developed to eliminate outliers,and an optimizing method based on the evaluation of measurements using motion models is developed to reduce *** Kalman filter and multi-rate Kalman filter are both applied to effectuate the positioning of visual aided inertial navigation *** experiments were done based on an own-built multi-rotor *** obtained results show that the proposed system can operate normally and provide accurate navigation information when GNSS is shortly invalid.

关键词： UAV visual odometry integrated navigation Kalman filter

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Journal of Energy Chemistry 2017年第6期26卷 1039-1049页

作者： Huan Xie jingyun Wang Kemakorn Ithisuphalap Gang Wu Qing Li State Key Laboratory of Material Processing and Die & Mould Technology School of Materials Science and Engineering Huazhong University of Science and Technology Department of Chemical and Biological Engineering University at Buffalo The State University of New York

COconversion via photocatalysis is a potential solution to address global warming and energy *** can directly utilize the inexhaustible sunlight as an energy source to catalyze the reduction of COto useful solar fuels such as CO, CH, CHOH, and CHOH. Among studied formulations, Cubased photocatalysts are the most attractive for COconversion because the Cu-based photocatalysts are low-cost and abundance comparing noble metal-based catalysts. In this literature review, a comprehensive summary of recent progress on Cu-based photocatalysts for COconversion, which includes metallic copper, copper alloy nanoparticles（NPs）, copper oxides, and copper sulfides photocatalysts, can be found. This review also included a detailed discussion on the correlations of morphology, structure, and performance for each type of Cu-based catalysts. The reaction mechanisms and possible pathways for productions of various solar fuels were analyzed, which provide insight into the nature of potential active sites for the catalysts. Finally, the current challenges and perspective future research directions were outlined, holding promise to advance Cu-based photocatalysts for COconversion with much-enhanced energy conversion efficiency and production rates.

关键词： Cu-based photocatalyst CO_2 conversion Solar light Solar fuels Quantum efficiency

When will China achieve its carbon emission peak?

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National Science Review 2016年第1期3卷 8-12页

作者： Tianli Zheng Jiangling Zhu Shaopeng Wang jingyun Fang Department of Ecology College of Urban and Environmental Scienceand Key Laboratory for Earth Surface Processes of the Ministry of EducationPeking University Climate Change Research Center Academic Divisions of the Chinese Academy of Sciences and Peking University

Global warming is primarily attributed to the significant increase in atmospheric CO2 concentration,which is caused mainly by carbon emissions generated from fossil fuel combustion[1].Efficient measures are required t... 详细信息

关键词： CEI When will China achieve its carbon emission peak GDP will OECD

Carbon budgets of three temperate forest ecosystems in Dongling Mt.,Beijing,China

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Science China Earth Sciences 2007年第1期50卷 92-101页

作者： FANG jingyun LIU GuoHua ZHU Biao WANG XiaoKe LIU ShaoHui Department of Ecology College of Environmental Sciences and Key Laboratoryfor Earth Surface Processes of the Ministry of Education Peking University Beijing 100871 China

There is a general agreement that forest ecosystems in the NorthernHemisphere function as significant sinks for atmospheric CO_2; however, their magnitude anddistribution remain large uncertainties. In this paper, we report the carbon (C) stock and itschange of vegetation, forest floor detritus, and mineral soil, annual net biomass increment andlitterfall production, and respiration of vegetation and soils between 1992 to 1994, for threetemperate forest ecosystems, birch (Betula platyphylla) forest, oak (Ouercus liaotungensis) forestand pine (Pinus tabulaeformis) plantation in Mt. Dongling, Beijing, China. We then evaluate the Cbudgets of these forest ecosystems. Our results indicated that total C density (organic C perhectare) of these forests ranged from 250 to 300 t C ha^(-1), of which 35—54 t C ha^(-1) fromvegetation biomass C and 209-244 t C ha^(-1) from soil organic C (1 m depth, including forest floordetritus). Biomass C of all three forests showed a net increase, with 1.33—3.55 t C ha^(-1) a^(-1)during the study period. Litterfall production, vegetation autotrophic respiration, and soilheterotrophic respiration were estimated at 1.63—2.34,2.19—6.93, and 1.81 —3.49 t C ha^(-1)a^(-1), respectively. Ecosystem gross primary production fluctuated between 5.39 and 12.82 t Cha^(-1) a^(-1), about half of which (46%-59%, 3.20-5.89 t C ha^(-1) a^(-1)) was converted to netprimary production. Our results suggested that pine forest fixed C of 4.08 t ha^(-1) a^(-1), whereassecondary forests (birch and oak forest) were nearly in balance in CO_2 exchange between theatmosphere and ecosystems.

关键词： carbon budget carbon density carbon flux mountainous area temperate forest.