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Scenario simulation and forecast of land use/cover in northern china

Chinese science Bulletin 2008年第9期53卷 1401-1412页

作者： LI YueChen 1,2,3 & HE ChunYang 3 1 college of Geographical science, Chongqing Normal university, Chongqing 400047, china 2.college of Resources and Environmental science, Chongqing university, Chongqing 400044, china 3 college of Resources science & Technology, Beijing Normal university, Beijing 100875, china college of Geographical science Chongqing Normal University Chongqing 400047 China college of Resources and Environmental science Chongqing University Chongqing 400044 China college of Resources science & Technology Beijing Normal University Beijing 100875 China

Modeling land use/cover scenario changes and its potential impacts on structure and functions of ecosystem in typical regions are helpful to understanding the interactive mechanism between land use/cover system and ecosystem. Based on the analysis of the existing land use/cover simulation and forecast models, a land use/cover scenario dynamics model by the integration of System Dynamics (SD) model, Back Propagation Neural Network (BPNN) and Cellular Automata (CA) model is developed with land use/cover scenario changes in northern china in the next 30 years and simulated in this paper. The model is to simulate the land use/cover scenario demands by using a SD model at first, and then allocating the land use scenario patterns at the local scale with the considerations of land use/cover suitability, inheritance ability and neighborhood effect by using BPNN-CA model to satisfy the balance between land use/cover scenario demands and supplies. It integrates the advantages of SD, BPNN and CA. Macro-driving factors and the micro-spatial pattern are also fully taken into account. The BPNN simplifies the identification of the factors’ weights used in CA model and improves the reliability of the simulation results. The simulation accuracy of the model developed in this paper was found to be about 74%. It suggests that the model has the ability to reflect the complexity of land use/cover system at different scales to some extent and it is a useful tool for assessing the potential impacts of land use system on ecosystem. The simulated results also indicate that the urban land, water area and forest will increase significantly, and farmland and unable land will decrease gradually. Obvious land use/cover changes will take place in the farming-pastoral zone and the southeast area of northern china.

关键词：土地利用中国北方细胞自动机系统动力学

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An improved method of support vector machine and its applications to financial time series forecasting

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Progress in Natural science:Materials International 2003年第9期 58-62页

作者： LIANG Yanchun and SUN Yanfeng (1. college of Computer science and Technology, jilin university, changchun 130012, china 2. college of Mathematics, jilin Univer sity, changchun 130012, china)

A novel method for kernel function of support vector machine is presented based on the information geometry *** kernel function is modified using a conformal mapping to make the kernel data-dependent so as to increase the ability of predicting highnoise data of the method. Numerical simulations demonstrate the effectiveness of the method. Simulated results on the prediction of thestock price show that the improved approach possesses better forecasting precision and ability of generalization than the conventional mod-els.

关键词： support vector machine (SVM) data-dependent information geometry con formal mapping financial time series stock price prediction.

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Motive force of Qinghai-Tibet Plateau moving to east

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Global Geology 2005年第Z1期 123-125页

作者： YANG Dong-hong YANG Xue-xiang, CHEN Dian-you college of Geo-Exploration science and Technology, jilin university, changchun 130026, jilin, china National Astronomical Observatories, Chinese Academy of science, Beijing 100012, changchun 130022, jilin, china college of Mathematics science, jilin university, changchun 130012, jilin, china

A calculation formula on spherical pattern of Qinghai-Tibet plateau moving model is established, Tibet massif moves norward by east in speed of 28 mm/a, Ganshu-Qinghai massif moves to northeast in speed of 15 mm/a, Qomolangma Feng moves northward by a few east in speed of 35 -42 mm/a. The low latitude perimeter is longer than the high latitude perimeter. When the Tibet massif moves northward, its latitude perimeter must be contracted and the Tibet massif must move eastward by Coriolis. Coriolis force is inertial in earth rotation. It makes the fall body turning to east and the rising block turning westward. In the Northern Hemisphere, it makes the northward body turning to east and the southward block turning to west. This is the reason why the tectonic zones of western Pacific are different from those of eastern Pacific.

关键词： Qinghai-Tibet Plateau GPS measurement crustal velocity eastward flow of crustal material

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Damage detection based on the propagation of longitudinal guided wave in a bimetal composite pipe

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Theoretical & Applied Mechanics Letters 2011年第2期1卷 20-24页

作者： Huixing Yun~(1,a) and Weiwei Zhang~2 1.college of Engineering Shanxi Agricultural university,Taigu 030801,china 2.college of science & Engineering,Jinan university,Guangzhou,china college of Engineering Shanxi Agricultural university Taigu 030801 China college of science & Engineering Jinan University Guangzhou China

This paper investigates the damage detection based on the propagation of guided wave in bimetal composite pipes,which can identify damage locations in both axial and circumferential *** feasibility of the method is showed by numerical simulations using FEM code ANSYS. Mode analysis is used to evaluate the guided wave mode and its structure,which can provide the basis of the mode selection in measurements *** guided wave propagation in a damaged pipe is computed by transient analysis.16 nodes around the pipe wall,as probes,are used to record the guided wave *** Pseudo Margenau-Hill distribution(PMHD)for each signal is carried out, three types of modes could be found,which are led mode,excited mode and lag mode in sequences. Based on the results,the arrival time of the excited mode could be used to locate damage in axial direction,and the energy distribution around the pipe of lag mode is consistent with the damage in circumferential *** simulation illustrated the possibility of detecting damage location in both axial and circumferential directions based on longitudinal ultrasonic guided waves only.

关键词： damage detection crack PMHD pipe

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Facile Synthesis of Nanocrystalline Cr_2O_3 Thin Film

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Journal of Wuhan university of Technology(Materials science) 2011年第6期26卷 1032-1035页

作者：杨明 School of Transportation Southeast University

A novel and facile synthesis route for the manufacture of transparent and uniform self-assembled nanocrystalline Cr2O3 （nc-Cr2O3） thin films with different morphology was reported, utilizing chromium nitrate as the inorganic source and triblock copolymer F127 as the morphology-directing agent by the evaporation-induced assembly （EIA） method. X-ray powder diffraction （XRD）, thermogravimetry-differential scanning calorimetry （TG-DSC）, N2-sorption, scanning electron microscopy （SEM） and transmission electron microscopy （TEM） were used to characterize the as-prepared nc-Cr2O3 thin films. The Cr2O3 thin film with different morphology was obtained by changing the relative humidity. The possible formation mechanism of the nc-Cr2O3 thin films with different morphologies was discussed.

关键词： microstrucmre Cr2O3 thin film

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Analysis of IGF2 mRNA expression and its methylation status between cattle yaks and their parents

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Progress in Natural science:Materials International 2009年第9期19卷 1063-1069页

作者： Zhenshan Liu a,b,1, Qifa Li a,1, Qingbo Zhang a, Xuguang Qu a, Liyan Dong a, Chamba Yang-zom c, Zhuang Xie a,*, Honglin Liu a a Laboratory of animal Reproductive Genetics and Molecular Evolution, college of animal science and Technology, Nanjing Agricultural university, Nanjing 210095, china b Institute of animal Husbandry and veterinary medicine, Shandong Academy of Agricultural sciences, Jinan 250100, china c college of Agriculture and animal Husbandry, Tibet university, Linzhi 860000, china Laboratory of animal Reproductive Genetics and Molecular Evolution College of Animal Science and Technology Nanjing Agricultural University Nanjing 210095 China Institute of animal Husbandry and veterinary medicine Shandong Academy of Agricultural Sciences Jinan 250100 China college of Agriculture and animal Husbandry Tibet University Linzhi 860000 China

Cattle yaks are an F1 hybrid between cattle and yaks and exhibit significant hybrid vigor. However, cattle yaks are sterile males. To study the epigenetic aspects of this reproductive isolation, IGF2 mRNA expression in cattle yaks and their parents and the patterns of the IGF2 differentially methylated regions (DMR) were examined in blood and testes. The results showed that IGF2 expression in cattle yaks’ testes was lower than in their parents (P 2 DMR was highly methylated (above 90%) in blood and testes of cattle yaks, yaks and cattle, with the highest level in cattle yaks (P > 0.05). Our study showed that IGF2 plays an important role in bovine spermato-genesis and might be involved in cattle-yak male sterility. The methylation level of the IGF2 DMR was irrelevant to the lower expression of IGF2 in cattle yaks; other factors perhaps play roles in its expression.

关键词： Cattle yak Male sterility IGF2 gene mRNA expression DNA methylation

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SHRIMP U-Pb dating and Hf isotopic analyses of Middle Ordovician meta-cumulate gabbro in central Qiangtang, northern Tibetan Plateau

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science china Earth sciences 2010年第5期53卷 657-664页

作者： ZHAI QingGuo1 WANG Jun1, LI Cai2 & SU Li3 1 Institute of Geology, Chinese Academy of Geological sciences, Beijing 100037, china 2.college of Earth sciences, jilin university, changchun 130061, china 3 The Geological Laboratory Center and State Key Laboratory of Geological Processes and Mineral Resources, china university of Geo- sciences, Beijing 100083, china Institute of Geology Chinese Academy of Geological Sciences Beijing China college of Earth sciences Jilin University Changchun China The Geological Laboratory Center and State Key Laboratory of Geological Processes and Mineral Resources China University of Geosciences Beijing China

Metabasites consisting of metamorphic ultra-mafic rocks, cumulate gabbro, gabbro (diabase), basalt, and plagiogranite are exposed at the Taoxinghu area in central Qiangtang, northern Tibetan Plateau. Zircon SHRIMP U-Pb dating for the cumulate gabbro yields a weighted mean age of 467±4 Ma, which is the oldest and most reliable magmatic age in this area. Zircon 176Hf/177Hf ratios range from 0.282615 to 0.282657, with εHf(t) values of 5.02±0.28, indicating that the cumulate gabbro was mainly derived from the depleted mantle. In addition, geochemical data of metabasites suggest that they have similar characteristics to those in the mid-ocean ridge basalts (MORB). The Taoxinghu metabasites may represent the fragment of Early Paleozoic ophiolite in the "Central Uplift" of the Qiangtang, northern Tibetan Plateau.

关键词： Qiangtang cumulate gabbro SHRIMP dating Hf isotope

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环五孔稀疏孔径系统成像性能研究

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光子学报 2024年第7期53卷 135-144页

作者：朱剑凯梁永辉刘冀林霍卓玺杨慧哲国防科技大学前沿交叉学科学院长沙410073 国防科技大学南湖之光实验室长沙410073 中国航天科技创新研究院北京100176 中国空间技术研究院钱学森空间技术实验室北京100081

稀疏孔径系统作为高分辨率成像解决方案,其成像性能却受子孔径之间活塞误差和各独立子孔径波前残差强烈影响。以均匀环五孔构型为研究对象,通过对点扩散函数和调制传递函数的表征,数值模拟得到了该构型的成像相关误差指标。从频域覆盖... 详细信息

稀疏孔径系统作为高分辨率成像解决方案,其成像性能却受子孔径之间活塞误差和各独立子孔径波前残差强烈影响。以均匀环五孔构型为研究对象,通过对点扩散函数和调制传递函数的表征,数值模拟得到了该构型的成像相关误差指标。从频域覆盖无截断的角度分析了环五孔构型的填充因子,选择范围为27.8%至68.5%。以斯特列尔比(大于0.80)为评价准则,填充因子为43.2%时的子孔径之间的活塞误差最大容忍度约为λ/6,含有独立自适应光学系统的各子孔径的波前残差均方根最大容忍度约为λ/14。填充因子的选择范围从根本上受到子孔径波前残差的限制,而子孔径之间的共相则需以一定的自适应光学校正水平为前提。

关键词：稀疏孔径系统环五孔构型干涉成像波前残差填充因子

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Cellulose nanocrystals as green fillers to improve crystallization and hydrophilic property of poly(3-hydroxybutyrate-co-3-hydroxyvalerate)

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Progress in Natural science:Materials International 2011年第6期21卷 478-484页

作者： Hou-yong YU~(1,2),Zong-yi QIN~1,Zhe ZHOU~2 1.State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Donghua university,Shanghai 201620,china 2.college of Material science and Engineering,Donghua university,Shanghai 201620,china State Key Laboratory for Modification of Chemical Fibers and Polymer Materials Donghua University Shanghai 201620 China college of Material science and Engineering Donghua University Shanghai 201620 China

The green nanocomposites of poly(3-hydroxybutyrate-co-3-hydroxyvalerate)(PHBV) with various cellulose nanocrystals (CNCs) contents were prepared by solution casting *** effects of CNCs on the crystallization behavior,spherulitic morphology,crystal structure and hydrophilic property of PHBV were studied by differential scanning calorimeter(DSC),polarized optical microscope(POM),wide-angle X-ray diffraction(WAXD) and static water contact angle *** is found that the CNCs act as an effective nucleation agent for crystallization of PHBV,inducing an increase in the melt crystallization temperature of the nanocomposites.A study of the non-isothermal crystallization kinetics further illustrated that overall crystallization rate of PHBV in the nanocomposites was faster than that of neat PHBV,but exhibited a decrease in the crystallinity and the spherulite size of PHBV. Furthermore,the contact angle decreased from 60.1°for neat PHBV to 32.5°for the nanocomposites with 10%CNCs(mass fraction).

关键词： nanocomposites poly(3-hydroxybutyrate-co-3-hydroxyvalerate) cellulose nanocrystals crystallization behavior hydrophilic property

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Investigation of 'chazi'(damaged-enamels)on Chenghua doucai Porcelains

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science china(Technological sciences) 2009年第6期52卷 1722-1729页

作者： DU Feng1 & SU BaoRu2 1 Institute of Chemistry & Molecular Engineering,Qingdao university of science & Technology,Qingdao,china 2.college of Information science & Technology,Qingdao university of science & Technology,Qingdao,china Institute of Chemistry & Molecular Engineering Qingdao University of Science & Technology college of Information science & Technology

At the end of the 1950s,Sun Yingzhou considered that the 'chazi'(damaged colour)on Chenghua doucai imperial porcelain as a defect was originally produced in firing process during Chenghua period(1465―1487).Researchers in china have accepted his *** any fragment with the 'chazi' has never been found in several tons of Chenghua imperial sherds excavated from Ming imperial kiln site in *** china,few scholars have questioned the formation of 'chazi',and further investigated *** researchers at the Research Laboratory in the British Museum,employing unde-structive EDXRF,have analyzed the chemical composition of the 'chazi'(damaged colour)on a Chen-ghua doucai stem cup in the museum,and they have confirmed that the 'chazi'(damaged colour)was caused by the fire of the Jianfu palace in the Forbidden City in *** on their research,the authors studied the colour chemical principle of the 'chazi's' formation *** to the ceramic technology principle,scientific reasoning for the 'chazi' was carried *** the help of the history of Qing court,the brainteaser of the 'chazi' was totally uncovered,the misunderstanding for the 'chazi' has also been *** research also suggests that employing modern science and technology is a direction to study Chinese ancient ceramic further.

关键词： Chenghua doucai porcelains court eunuchs the set on fire at the Jianfu palace ’chazi’(damaged-enamels) the British Museum colour chemical principle archaeology using science and technology

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