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Estimating surface evapotranspiration using combined MODIS and CBERS-02 data

Science china(Technological Sciences) 2005年第S2期48卷 145-160页

作者： XIN Xiaozhou1,2, LIU Qinhuo1, TANG Yong1,3, TIAN Guoliang1, GU Xingfa1, LI Xiaowen1,2, ZHENG Hongsheng4 & chen Jiayi4 1. State Key Laboratory of Remote Sensing Science, Institute of Remote Sensing Applications, Chinese Academy of Sciences, beijing 100101, china 2. Research Center for Remote Sensing and GIS, department of Geography, beijing normal university, beijing 100875. china 3. Graduate university of Chinese Academy of Sciences, beijing 100039, china 4. department of Atmospheric Physics, Peking university, beijing 100871, china 1. State Key Laboratory of Remote Sensing Science Institute of Remote Sensing Applications Chinese Academy of Sciences 100101 Beijing China2. Research Center for Remote Sensing and GIS Department of Geography Beijing Normal University 100875 Beijing China3. Graduate University of Chinese Academy of Sciences 100039 Beijing China4. Department of Atmospheric Physics Peking University 100871 Beijing China

Spatial scale error is one of the most serious problems in the estimates of land surface heat fluxes of sensible and latent from satellite-borne data such as MODIS 1km resolution reflectance and emissive data. One of the feasible and economic ways to decrease the spatial scale error is to use high resolution land use class data together with the MODIS data. CBERS-02 data were used to produce land use class of Baiyangdian area, Hebei Province, china in the autumn of 2004. The area ratio of each class in MODIS pixel was calculated, and used to derive the heat fluxes of the mixed pixel. The results showed that the estimated heat fluxes of soil, sensible and latent have been changed remarkably after using the high resolution land class data. It could be concluded from the comparison between simulated and ground-measured fluxes as well as the theoretical analysis that high resolution land class data are useful to diminishing the scale error of heat fluxes estimated from low resolution satellite data.

关键词： surface evapotranspiration spatial scale error MODIS CBERS land class.

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Synchronous estimation of DTM and fractional vegetation cover in forested area from airborne LIDAR height and intensity data

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Science china(Technological Sciences) 2008年第S2期51卷 176-187页

作者： BAO YunFei1,2,CAO ChunXiang1,ZHANG Hao1,chen ErXue3,HE QiSheng1,2,HUANG HuaBing1,LI ZengYuan3,LI XiaoWen1,4 & GONG Peng1 1 State Key Laboratory of Remote Sensing Science,jointly sponsored by the Institute for Remote Sensing Applications of Chinese Academy of Sciences and beijing normal university,beijing 100101,china 2 Graduate university of the Chinese Academy of Sciences,beijing 100049,china 3 Institute of Forest Resource Information Technique,the Chinese Academy of Forestry,beijing 100091,china 4 Research Center for Remote Sensing and GIS,department of Geography and beijing Key Laboratory for Remote Sensing of Environment and Digital Sites,beijing normal university,beijing 100875.china State Key Laboratory of Remote Sensing Science jointly sponsored by the Institute for Remote Sensing Applications of Chinese Academy of Sciences and Beijing Normal University Beijing 100101 China Graduate university of the Chinese Academy of Sciences Beijing 100049 China Institute of Forest Resource Information Technique the Chinese Academy of Forestry Beijing 100091 China Research Center for Remote Sensing and GIS Department of Geography and Beijing Key Laboratory for Remote Sensing of Environment and Digital Sites Beijing Normal University Beijing 100875 China

We proposed a method to separate ground points and vegetation points from discrete return,small footprint airborne laser scanner data,called skewness change *** method,which makes use of intensity of laser scanner data,is especially applicable in steep,and forested *** does not take slope of forested area into account,while other algorithms consider the change of slope in steep forested *** ground points and vegetation points can be used to estimate digital terrain model(DTM) and fractional vegetation cover,respectively.A few vegetation points which were classified into the ground points were removed as noise before the generation of *** method was tested in a test area of 10000 square meters.A LiteMapper -5600 laser system was used and a flight was carried out over a ground of 700―800 *** this tested area,a total number of 1546 field measurement ground points were measured with a total station TOPCON GTS-602 and TOPCON GTS -7002 for validation of DTM and the mean error value is -18.5 cm and the RMSE(root mean square error) is ±20.9 cm.A data trap sizes of 4m in diameter from airborne laser scanner data was selected to compute vegetation fraction *** of fractional vegetation cover was carried out using 15 hemispherical photographs,which are georeferenced to centimeter accuracy by differential *** gap fraction was computed over a range of zenith angles 10° using the gap light analyzer(GLA) from each hemispherical *** R2 for the regression of fractional vegetation cover from these ALS data and the respective field measurements is *** this study presents a method for synchronous estimation of DTM and fractional vegetation cover in forested area from airborne LIDAR height and intensity data.

关键词： LIDAR intensity skewness synchronous DTM fractional vegetation cover

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THE RETICAL STUDIES ON THE THERMOLYSIS OF THIETANE

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Chinese Chemical Letters 1991年第7期2卷 577-578页

作者： Guang Ju chen Xiao Yuan FU Ao Qing TANG Chemistry department,beijing normal university,beijing 100875

The mechanism of the thermolysis of thietane to form ethylene and thioformaldehyde has been studied by using ab initio SCF MO method at STO-3G* and 3-21G* *** has been found that there are two possible stepwise *** is to break C-C bond firstly,while the other is to break C-S bond at *** cleavage of C-S bond is pre- ferred over that of C-C bond.

关键词： STO THE RETICAL STUDIES ON THE THERMOLYSIS OF THIETANE

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Discrete nature of multivariate Paley-Wiener space

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Progress in Natural Science:Materials International 2003年第4期 62-65页

作者： chen Guanggui and FANG Gensun(department of Mathematlcs, beijing normal university, beijing 100875. china) department of mathematics Beijing Normal University Beijing 100875 China

Eoff proves that the univariate Paiey-Wiener space Bπ,p(R) is isomorphic to the discrete Hardy space Hp(Z), 0 详细信息

Eoff proves that the univariate Paiey-Wiener space Bπ,p(R) is isomorphic to the discrete Hardy space Hp(Z), 0

关键词： multivariate Paley-Wiener space discrete Hilbert transform discrete Hardy space.

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Microwave propagation in air drilling

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Petroleum Science 2010年第3期7卷 390-396页

作者： Meng Xiaofeng chen Yijian Zhou Jing Meng Yingfeng Physics department Beijing Normal University Beijing 100875 China State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Southwest Petroleum University Chengdu Sichuan 610500 China

This paper examines the feasibility in air drilling of transmitting down-hole signals by using microwaves. Firstly the basic theory of microwave propagation in the drill-pipe or casing was studied, including power loss, cutoff wavelength, and dust scattering. Theoretical analysis indicates that the microwave propagation distance in a cb214mm casing can easily reach 5,000 m. When the effect of dust particles is taken into account, the propagation distance decreases to 2,000 m. We conducted both laboratory experiments and field tests in casings commonly used in oil fields. The field tests show that the effective propagation distance of microwave in the casing is about 1,300 m. The experimental results do not match well with theoretical prediction, but are acceptable. In future commercial applications, by applying multiple relay amplifiers, the microwave propagation distance could be long enough for most drilling wells.

关键词： Microwave waveguide drill-pipe casing air drilling

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Speciation of the elements and compositions on the surfaces of dust storm particles:The evidence for the coupling of iron with sulfur in aerosol during the long-range transport

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Chinese Science Bulletin 2005年第8期50卷 738-744页

作者： ZHANG Xingying1,2, ZHUANG Guoshun1,2,3, chen Jianmin2 & XUE Huaxin2 1. Center for Atmospheric Environment Study, department of Chemistry, beijing normal university, beijing 100875. china 2. Center for Atmospheric Chemistry Study, department of Environ- mental Science and Engineering, Fudan university, Shanghai 200433, china 3. LAPC/NZC, Institute of Atmospheric Physics, NZC/LAPC, Chinese Academy of Sciences, beijing 100029, china Center for Atmospheric Environment Study Department of Chemistry Beijing Normal University Beijing 100875 China Center for Atmospheric Chemistry Study Department of Environmental Science and Engineering Fudan University Shanghai 200433 China LAPC/NZC Institute of Atmospheric Physics NZC/LAPC Chinese Academy of Sciences Beijing 100029 China

The speciation of the elements on the surface of the particles collected during dust storm and non-dust storm in beijing and Inner Mongolia was studied by XPS. The ma- jor species of iron on the surface were oxides, sulfate, silicate, FeOOH and minor part sorbed on SiO2/Al2O3. Sulfate is the dominant species of sulfur on the surface. SiO2 and Al2O3 are the main components of Si and Al on the surface respectively. One of the most important findings was that the Fe(II) (FeS and FeSO4) produced could account for up to 44.3% and 45.6% of the total Fe on the surface in the aerosol sample collected at that night and next day of the “peak” time of the dust storm occurring on March 20, 2002, while Fe2(SO4)3, one of the Fe(III) species on the surface decreased from 67.1% to 49.5% and 48.0% respectively. Both S and Fe en- riched on the surface of aerosol particles. Fe(II) accounted for 1.3%?5.3% of total Fe in bulk aerosol samples during dust storm. These results provided strong evidence to sup- port the hypothesis of the coupling between iron and sulfur in aerosols during the long-range transport, which would have important impact on the global biogeochemical cycle.

关键词：物种形成原理 XPS 大气悬浮物 Fe-S结合粒子集合

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AN EXPLORATION ON THE NATURE OF THE HYPERACTIVITY OF THE INSECT ANTIFREEZE PROTEIN CfAFP-501

AN EXPLORATION ON THE NATURE OF THE HYPERACTIVITY OF THE INS...

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40th IUPAC Congress

作者： Yanxia Zhou Hongwei Tan Guangju chen* department of Chemistry beijing normal university beijing 100875.china

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巴赫金对话理论的人文精神

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学术交流 2000年第1期 108-114页

作者：陈太胜北京师范大学中文系北京100875

本文企图在更为广阔和统一的思想语境里对话性地诠释巴赫金思想的精髓。多样性的巴赫金思想并非散沙一盘,对话理论及其人文精神是它的精髓。巴赫金终生徜徉在哲学、语言学、社会学和诗学各人文学科领域,而其中心工作就是建构自身的对话... 详细信息

本文企图在更为广阔和统一的思想语境里对话性地诠释巴赫金思想的精髓。多样性的巴赫金思想并非散沙一盘,对话理论及其人文精神是它的精髓。巴赫金终生徜徉在哲学、语言学、社会学和诗学各人文学科领域,而其中心工作就是建构自身的对话理论,他以之贯串于所有的人文学科各领域的研究中,而人文精神是巴赫金的对话理论体现出的核心精神,对话理论在其根底上是关于人的理论,是巴赫金终生为人而斗争的理论结晶,闪耀着人文精神的光辉,它以人为对象,关心人的主体建构,关心人的存在和命运,关心人的平等和自由。就诗学来说,巴赫金的杰出之处在于,在20世纪“语言论转向”的文化语境里,他既能以复调小说理论这种对话理论的变体来阐释陀思妥耶夫斯基小说的艺术形式。

关键词：巴赫金对话理论人文精神复调小说

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ONE SIDE ASYMPTOTIC EFFICIENCY IN UNIFORM DISTRIBUTIONS

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Journal of Systems Science & Complexity 2001年第2期14卷 159-164页

作者： SONG Weixing (mathematics department, beijing normal university, beijing 100875. china) 北京师范大学北京 100875

For the two side truncated distribution family: dPθ(x) = f(x;θ1θ2)I(θ≤ x≤θ2)dx, where θ=(θ1,θ2),θ < θ2,chen & Fu studied one side asymptotic efficiency of the estimator for parameter hation g(θ) = c1θ1 +... 详细信息

For the two side truncated distribution family: dPθ(x) = f(x;θ1θ2)I(θ≤ x≤θ2)dx, where θ=(θ1,θ2),θ chen & Fu studied one side asymptotic efficiency of the estimator for parameter hation g(θ) = c1θ1 + C2θ2, they pointed out that when c1c2≥0, there exist one side asymptotic efficient estimators for g(θ); when c1c2 < 0, the estimator they proposed is not asymptotically efficient. Then they put forward a question: Is there any other asymptotically efficient estimator for g(θ) when c1c2 <0? In this paper, we study this problem, we prove that when the distribution under consideration is uniform distribution with location and scale parameters, there does not exist one side asymptotically efficient estimators for the scale parameter.

关键词： AMU estimator asymptotic distribution asymptotically weak admissible estimate Neyman-Pearson Lemma.

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An united model and simulation of nitrogen transport, uptake and transformation in soil-crop system

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Journal of Environmental Sciences 1998年第1期10卷 89-99页

作者： Wang Hong qi, chen Jia jun State Key Laboratory of Environmental Simulation and Pollution Control, Institute of Environmental Science, beijing normal university,beijing 100875. china Li Yun zhu department of Soil and Water Science, Agricultu

Based on the simulation experiments of water and nitrogen transport, transformation and uptaking, under the condition of different cropping pattern of winter wheat in the greenhouse and the condition of different wastewater irrigation plan. An united computing model of crop growth, distribution of roots, water and nitrogen uptaking by roots and transformation in soil crop system was developed. Growth status of crops, root growth condition and water, nitrogen uptaking pattern by roots under different watering and N pollution conditions were simulated and analyzed due to the development of this mathematical model and the identification of parameters and boundary conditions in the greenhouse, so that it provided a primary computing method for selecting an efficient, productive watering and wastewater irrigating plan.

关键词： soil crop system nitrogen uptaking and movement mathematical model.

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