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Simulation of freezing and melting of soil on the northeast Tibetan Plateau

Chinese science Bulletin 2011年第20期56卷 2145-2155页

作者： XIA Kun 1,2,3,LUO Yong 2,4,5 & LI WeiPing 2 1 Institute of Atmospheric Physics,Chinese academy of sciences,Beijing 100029,china 2National Climate center,china Meteorological Administration,Beijing 100081,china 3Graduate University of Chinese academy of sciences,Beijing 100049,china 4 center for earth System science,Tsinghua University,Beijing 100084,china 5Key Laboratory of earth System Numerical Simulation,Ministry of Education,Beijing 100084,china Institute of Atmospheric Physics Chinese Academy of Sciences Beijing China National Climate center China Meteorological Administration Beijing China Graduate University of Chinese academy of sciences Beijing China center for earth System science Tsinghua University Beijing China Key Laboratory of earth System Numerical Simulation Ministry of Education Beijing China

Using observational data spanning the period from February to December 2009 and recorded at the Suli station in Qinghai Province,the land-surface model CLM3.0 was employed to simulate the freezing and melting of *** results indicate that the simulated soil temperature is higher than the observed soil temperature and the ultimate thawing date is earlier than the observed date during the melting *** the freezing period,the simulated soil temperature is lower than the observed soil temperature and the ultimate freezing of the deep soil is earlier than that ***,the simulation of freezing is better than that of melting,and the simulation of a shallow layer is better than that of a deeper *** the original CLM3.0,it is assumed that frozen soil begins to melt when the soil temperature exceeds 0C,which is inconsistent with *** critical freeze-thaw temperature was calculated according to thermodynamics equations and the freeze-thaw condition was *** this work,the melting rate for frozen soil was reduced using the modified scheme,and the simulated soil temperature was lowered. Meanwhile,the refreezing of soil during the melting season was well simulated and more closely matched ***,it was found that the rates of melting and freezing differ,with the former being slower than the latter,but refreezing during the melting season is rather quick.

关键词：土壤温度冻结期青藏高原东北部模拟融化观测数据热力学方程表面模型

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Study on rare earth/alkaline earth oxide-doped CeO_2 solid electrolyte

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Rare Metals 2007年第4期26卷 311-316页

作者： YAN Kai ZHEN Qiang Song Xiwen School of Materials science and Engineering Shanghai University Shanghai 200072 China research center of Nanoscience and Nanotechnology Shanghai Univeesity Shanghai 200444 China School of Materials science and Engineering Inner Mongolia University of Science and Technology B aotou 014010 China

Five types of rare earth/alkaline earth oxide-doped CeO2 superfine-powders were synthesized by a low-temperature combustion technique. The relevant solid electrolyte materials were also sintered by pressureless sintering at different temperatures. The results of X-ray diffraction and transmission electron microscopy showed that the grain size of the powders was approximately 20-30 nm, and rare earth/alkaline earth oxides were completely dissolved into ceria-based solid solution with fluorite structure. The electrical conductivities of the SmzO3-CeO2 system were measured by the ac impedance technique in air at temperatures ranging from 513-900℃. The results indicated that the ionic conductivities of Srno.2oCe0.8Ol.875 solid electrolyte increase with increasing sintering temperature, and the relationship between the conductivities and measuring temperature obeys the An＇henius equation. Then the SmzO3-CeO2 material was further doped with other rare earth/alkaline earth oxide, and the conductivities improve with the effective index.

关键词： doped ceria rare earth/alkaline earth oxide solid electrolyte conductivity effective index

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Multiple time scale evaluation of the energy balance during the maize growing season,and a new reason for energy imbalance

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science china earth sciences 2009年第1期52卷 108-117页

作者： GUO JianXia1,2,BIAN LinGen3 & DAI YongJiu2 1 Meteorological Observation center of china Meteorological Administration,Beijing 100081,china 2 State Key Laboratory of Remote Sensing science,School of Geography and Remote Sensing science,Beijing Normal University,Beijing 100875,china 3 Chinese academy of Meteorological sciences,Beijing 100081,china Meteorological Observation center of china Meteorological Administration Beijing China State Key Laboratory of Remote Sensing science School of Geography and Remote Sensing Science Beijing Normal University Beijing China Chinese academy of Meteorological sciences Beijing China

Energy imbalance is a common problem associated with the measurement of surface energy using the eddy covariance *** the evaluation of the energy balance,people usually pay more attention to the statistical result that the effective energy(the sum of sensible and latent heat) is systematically lower than the available energy(the difference of net radiation and ground heat flux).However,little attention has been paid to the existence of the reversed situation when the effective energy is larger than the available energy or their contribution to the overall energy closure *** this paper,based on the analysis of the energy balance on multiple time scales across the maize growth season,we conclude that the non-synchronization of energy components is the main reason for the existence of the reversed *** shifting the phase of the effective energy components half an hour ahead,the rates of energy closure over all time scales are improved and dramatically reduce the number of the half-hourly samples when the energy ratio exceeds 1 or is below *** to the characteristics of the energy distribution and transformation over multiple time scales,latent heat is always the main type of energy cost,and the residual of the energy balance increases with the growth of the maize plant surpassing the sensible heat for seventy *** is suggested that the heat storage and photosynthetic energy play an important role in the energy balance during the growing period of maize.

关键词： maize energy balance multiple time scale energy hysteresis

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Control of atmospheric CO_2 concentrations by 2050: A calculation on the emission rights of different countries

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science china earth sciences 2009年第10期52卷 1447-1469页

作者： DING ZhongLi1, DUAN XiaoNan2, GE QuanSheng3 & ZHANG ZhiQiang4 1 Institute of Geology and Geophysics, Chinese academy of sciences, Beijing 100029, china 2 The General Office of Chinese academy of sciences, Beijing 100864, china 3 Institute of Geographic sciences and Natural Resources research, Chinese academy of sciences, Beijing 100101, china 4 The Lanzhou Branch of the National science Library, the Scientific Information center for Resources and Environment, Lanzhou 730000, china Institute of Geology and Geophysics Chinese Academy of Sciences Beijing China The General Office of Chinese academy of sciences Beijing China Institute of Geographic sciences and Natural Resources research Chinese Academy of Sciences Beijing China The Lanzhou Branch of the National science Library the Scientific Information Center for Resources and Environment Lanzhou China

This paper is to provide quantitative data on some critical issues in anticipation of the forthcoming international negotiations in Denmark on the control of atmospheric CO2 concentrations. Instead of letting only a small number of countries dominate a few controversial dialogues about emissions reductions, a comprehensive global system must be established based on emissions allowances for different countries, to realize the long-term goal of controlling global atmospheric CO2 concentrations. That a system rooted in "cumulative emissions per capita," the best conception of the "common but differentiated responsibilities" principle affirmed by the Kyoto Protocol according to fundamental standards of fairness and justice, was demonstrated. Based on calculations of various countries' cumulative emissions per capita, estimates of their cumulative emissions from 1900 to 2005, and their annual emissions allowances into the future (2006―2050), a 470 ppmv atmospheric CO2 concentration target was set. According to the following four objective indicators―total emissions allowance from 1900 to 2050, actual emissions from 1900 to 2005, emissions levels in 2005, and the average growth rate of emissions from 1996 to 2005―all countries and regions whose population was more than 300000 in 2005 were divided into four main groups: countries with emissions deficits, countries and regions needing to reduce their gross emissions, countries and regions needing to reduce their emissions growth rates, and countries that can maintain the current emissions growth rates. Based on this proposal, most G8 countries by 2005 had already expended their 2050 emissions allowances. The accu-mulated financial value based on emissions has reached more than 5.5 trillion US dollars (20 dollars per ton of CO2). Even if these countries could achieve their ambitious emissions reduction targets in the future, their per capita emissions from 2006 to 2050 would still be much higher than those of developing coun

关键词： international negotiations on climate change cumulative emissions per capita emission allowance

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Distribution and origin of biologically available phosphorus in the water of the Meiliang Bay in summer

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science china earth sciences 2006年第Z1期49卷 146-153页

作者： HUANG Qinghui, WANG Zijian, WANG Donghong, MA Mei & WANG Chunxia State Key Laboratory of Environmental Aquatic Chemistry, research center for Eco-Environmental sciences, Chinese academy of sciences, Beijing 100085, china Key Laboratory of Yangtze Aquatic Environment (Ministry of Education), College of Environmental science and Engineering, Tongji University, Shanghai 200092, china State Key Laboratory of Environmental Aquatic Chemistry Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing China Key Laboratory of Yangtze Aquatic Environment (Ministry of Education) College of Environmental Science and Engineering Tongji University Shanghai China

The investigation and continuous monitoring with an innovative iron oxide embedded cellulose acetate membrane (FeO/CAM) on the concentrations of biologically available phosphorus (BAP) were conducted in the Meiliang Bay of the Taihu Lake during summer in 2004. The results showed that the concentrations of dissolved (FeO-DP), particulate (FeO-PP) and total bioavailable phosphorus (FeO-P) had similar horizontal distribution. The BAP concentrations were the highest in those estuaries in the northern bay. With the decrease of the distance to the estuary or long shore,there was little difference between BAP concentrations in an open lake area. During the observation period, algal blooms occurred in most waters of the northern bay, which was reflected from the high concentrations of chlorophyll a (Chl-a). While they were not highest in the estuarine waters of those major rivers, this is the case for the BAP concentrations. The concentrations of Chl-a had a significantly positive correlation with those of bioavailable phosphorus in the open area of the Meiliang *** the sediment resuspension induced by wind and wave, BAP concentrations increased in a short-term, indicating that the riverine P inputs mainly contribute to the concentrations of BAP in the estuarine water while internal P release was the major source of BAP in the open lake area. In the eutrophic shallow lake, the blooms of alga may cause pH increase and further result in internal P release. The above results showed that the new membrane of FeO/CAM can be used to monitor the concentrations of BAP and provide the scientific justifications for the control strategy of the lake eutrophication.

关键词： phosphorus, bioavailability, eutrophication, resuspension, Taihu Lake.

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Quantitative estimation of the shrub canopy LAI from atmosphere-corrected HJ-1 CCD data in Mu Us Sandland

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science china earth sciences 2010年第S1期53卷 26-33页

作者： CHEN Wei1,2,CAO ChunXiang1,HE QiSheng1,2,GUO HuaDong3,ZHANG Hao1,2,LI RenQiang4,ZHENG Sheng1,2,XU Min1,2,GAO MengXu1,2,ZHAO Jian1,2,LI Sha1,NI XiLiang1,2,JIA HuiCong1,JI Wei1,TIAN Rong1,2,LIU Cheng1,2,ZHAO YuXing5 & LI JingLu6 1 State Key Laboratory of Remote Sensing science,Jointly Sponsored by the Institute of Remote Sensing Applications of Chinese academy of sciences and Beijing Normal University,Beijing 100101,china 2 Graduate University of Chinese academy of sciences,Beijing 100049,china 3 center for earth Observation and Digital earth,Chinese academy of sciences,Beijing 100190,china 4 china Key Laboratory of Ecological Network Observation and Modeling,Institute of Geographical sciences and Natural Resources research,Chinese academy of sciences,Beijing 100101,china 5 Ordos Forestry Sand Control science Institute,Dongsheng 017000,china 6 Inner Mongolia Biomass Thermoelectricity Limited Company,Wushen 017300,china State Key Laboratory of Remote Sensing science Jointly Sponsored by the Institute of Remote Sensing Applications of Chinese Academy of Sciences and Beijing Normal University Beijing China Graduate University of Chinese academy of sciences Beijing China center for earth Observation and Digital earth Chinese Academy of Sciences Beijing China china Key Laboratory of Ecological Network Observation and Modeling Institute of Geographical Sciences and Natural Resources Research Chinese Academy of Sciences Beijing China Ordos Forestry Sand Control science Institute Dongsheng China Inner Mongolia Biomass Thermoelectricity Limited Company Wushen China

The leaf area index(LAI) is an important ecological parameter that characterizes the interface between vegetation canopy and the *** addition,it is used by most process-oriented ecosystem *** paper investigates the potential of HJ-1 CCD data combined with linear spectral unmixing and an inverted geometric-optical model for the retrieval of the shrub LAI in Wushen Banner of Inner Mongolia in the Mu Us ***(Moderate Resolution Atmospheric Radiance and Transmittance Model) was used for atmospheric *** was extracted using the threshold of the normalized difference vegetation index,with which water bodies and farmland were separated,in combination with a vegetation map of the People's Republic of china(1:1000000).Using the geometric-optical model,we derive the per-pixel reflectance as a simple linear combination of two components,namely sunlit background and *** fraction of sunlit background is related to the shrub *** the support of HJ-1 CCD data,we employ linear spectral unmixing to obtain the fraction of sunlit background in an atmospherically corrected HJ *** addition,we use the measured shrub canopy structural parameters for shrub communities to invert the geometric-optical model and retrieve the pixel-based shrub *** total,18 sample plots collected in Wushen Banner of Inner Mongolia are used for *** results of the shrub LAI show good agreement with R2 of 0.817 and a root-mean-squared error of 0.173.

关键词： shrub leaf area index inversion HJ-1 data geometric-optical model MODTRAN Mu Us Sandland

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Design and Expression of a Synthetic phyC Gene Encoding the Neutral Phytase in Pichia pastoris

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Acta Biochimica et Biophysica Sinica 2006年第11期38卷 803-811页

作者： Li-Kou ZOU~(1,3) Hong-Ning WANG~(2,1*) Xin PAN~4 Tao XIE~1 Qi WU~5 Zi-Wen XIE~1 Wan-Rong ZHOU~1 1 Laboratory of Veterinary and Biotechnology,Sichuan Agricultural University,Ya'an 625014,china 2 Sichuan University Bioengineering research center for Animal Disease Prevention and Control,Chengdu 610065,china 3 Faculty of Environment and Resource of Dujiangyan Campus,Sichuan Agricultural University,Dujiangyan 611830,china 4 College of earth science,Chengd University of Technology,Chengdu 610059,china 5 College of Life science,Sichuan Agricultural University,Ya'an 625014,china Laboratory of Veterinary and Biotechnology Sichuan Agricultural UniversityYa'an 625014 China Faculty of Environment and Resource of Dujiangyan Campus Sichuan Agricultural UniversityDujiangyan 611830 China Sichuan University Bioengineering research center for Animal Disease Prevention and Control Chengdu 610065 China College of earth science Chengdu University of TechnologyChengdu 610059 China College of Life science Sichuan Agricultural UniversityYa'an 625014 China

The 1074-bp phyCs gene （optimized phyC gene） encoding neutral phytase was designed andsynthesized according to the methylotrophic yeast Pichia pastoris codon usage bias without altering theprotein *** expression vector,pP9K-phyCs,was linearized and transformed in *** of total extracellular phytase activity was 17.6 U/ml induced in Buffered Methanol-complex Medium（BMMY） and 18.5 U/ml in Wheat Bran Extract Induction （WBEI） medium at the flask scale,respectively,improving over 90 folds compared with the wild-type *** enzyme showed temperature optimumof 70℃ and pH optimum of *** enzyme activity retained 97% of the relative activity afterincubation at 80℃ for 5 *** of the heavy glycosylation the expressed phytase had a molecularsize of approximately 51 *** deglycosylation by endoglycosylase H （EndoH_f）,the enzyme had anapparent molecular size of 42 *** property and thermostability was affected by the glycosylation.

关键词： design expression synthetic phyC gene neutral phytase Pichia pastoris

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Principle of small target detection for hyperspectral imagery

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science china earth sciences 2007年第8期50卷 1225-1231页

作者： GENG XiuRui1,2,3 & ZHAO YongChao2,3,4 1 research center for Remote Sensing and GIS, Department of Geography, Beijing Normal University, Beijing 100875, china 2 State Key Laboratory of Remote Sensing science, Chinese academy of sciences, Beijing 100101, china 3 Institute of Erectronics, Chinese academy of sciences, Beijing 100080, china 4 center for for Assessment and Monitoring of Forest and Environmental Resources and Division of Ecosystem sciences University of California Berkeley, CA 94720-3114, USA research center for Remote Sensing and GIS Department of Geography Beijing Normal University Beijing China State Key Laboratory of Remote Sensing science Chinese Academy of Sciences Beijing China Institute of Erectronics Chinese Academy of Sciences Beijing China center for for Assessment and Monitoring of Forest and Environmental Resources and Division of Ecosystem sciences University of California Berkeley USA

This paper generalizes the progress of algorithms in small target detection for hyperspectral imaging, and finds that whitening the image is the key point of many methods in small target detection. An al-gorithm is presented to detect desired targets by converting large targets into small ones based on the weighted sample autocorrelation matrix.

关键词： hyperspectral whiten target detection

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Helium isotope investigation on magnetic reversal boundaries of loess-paleosol sequence at Luochuan, central Chinese Loess Plateau

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Chinese science Bulletin 2007年第17期52卷 2407-2412页

作者： DU XueQing1,6, WANG YongHong2, REN JianGuo3, YE XianRen4 & LU HuaYu5,1 1 State Key Laboratory of Loess and Quaternary Geology, Institute of earth Environment, Chinese academy of sciences, Xi’an 710075, china 2 College of Marine Geosciences, Ocean University of china, Qingdao 266003, china 3 National Natural science Foundation of china, Beijing 100085, china 4 Lanzhou research center for Petroleum and Natural Gas Resources, Institute of Geology and Geophysics, Chinese academy of sciences, Lanzhou 730000, china 5 Key Laboratory of Coast and Island Development, School of Geographic and Oceanographic sciences, Nanjing University, Nanjing 210093, china 6 Graduate University of Chinese academy of sciences, Beijing 100049, china State Key Laboratory of Loess and Quaternary Geology Institute of Earth Environment Chinese Academy of Sciences Xi’an China Graduate University of Chinese academy of sciences Beijing China College of Marine Geosciences Ocean University of China Qingdao China National Natural science Foundation of china Beijing China Lanzhou research center for Petroleum and Natural Gas Resources Institute of Geology and Geophysics Chinese Academy of Sciences Lanzhou China Key Laboratory of Coast and Island Development School of Geographic and Oceanographic Sciences Nanjing University Nanjing China

Extraterrestrial particles have higher 3He/4He ratios than those of terrestrial sediments ( > 100 Ra versus < 0.03 Ra, where Ra is the 3He/4He ratio normalized to the atmospheric value of 1.4×10?6). The inter- planet... 详细信息

Extraterrestrial particles have higher 3He/4He ratios than those of terrestrial sediments ( > 100 Ra versus earth and can accumulate in deposits. IDPs sedimentation rate changes can significantly influence 3He concentration in the earth surface sediments. Since IDPs are not easy to detect in terrestrial deposits, measuring helium isotopes is a helpful approach to examine changes in IDPs. Helium concentration and helium isotopic composition magnetic substances and the quartz particles were examined for helium concen- tration and helium isotopic ratio. Results show that the 3He/4He ratio and the 3He concentrations of the magnetic substances are clearly higher than those of the bulk samples and the quartz particles, and, the 3He/4He ratio of the extracted magnetic substances is also higher than that of the average level of the earth’s crust. The higher helium content in the magnetic fractions can be explained by an influx of IDPs.

关键词：中国黄土高原古土壤氦同位素行星际尘埃颗粒反方向磁化

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Natural gas origins of large and medium-scale gas fields in china sedimentary basins

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science china earth sciences 2008年第S1期51卷 1-13页

作者： ZHANG ShuiChang &ZHU GuangYou research center of research Institutes of Petrochina Exploration and Development,Beijing 100083,china research center of research Institutes of Petrochina Exploration and Development Beijing China

china sedimentary basins present abundant natural gas resource thanks to its unique geological *** highly-matured hydrocarbon source rocks,widespread coal-measure strata and low temperature Quaternary saline strata,etc.,indicate the wide foreground of china natural gas resources. Up to now,most of the petroliferous basins have been discovered to have wholesale natural gas accumulation from Precambrian,Paleozoic,Mesozoic to Cenozoic in the east,the central,the west and the coast of *** large and medium-scale gas reservoirs are mainly composed of hydrocarbon gas with big dry coefficient,tiny non-hydrocarbon,wide carbon isotope distribution and varying origin types,the hydrocarbon gas includes coal-formed gas,oil-formed gas,biogenic gas and inorganic gas, ***-formed gas is the main type of china natural gas resources,in particular several explored large-scale gas fields(>100 billion cubic meter)of Kela 2,Sulige and Daniudi,etc.,they all belong to coal-formed gas fields or the gas fields consisting mostly of coal-formed ***-formed gas is also abundant in china marine basins,for example marine natural gas of Sichuan Basin generated from crude oil cracking *** and secondary biogenic gas fields were discovered respectively in the Qaidam Basin and Western Slope of Songliao *** addition,inorganic gases are mainly distributed in the eastern china,in particular the Songliao Basin with abundant carbon dioxide accumulation,indicating that the eastern china present large exploration potential of inorganic gas.

关键词： natural gas origin sedimentary basin large and medium-scale gas field

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