检索结果-南通市图书馆

Analysis of Comprehensive Benefits of Transforming Slope Farmland to Terraces on the Loess Plateau:A Case Study of the Yangou Watershed in Northern Shaanxi province,china

在线全文

学校读者我要写书评

暂无评论

Journal of Mountain Science 2011年第3期8卷 448-457页

作者： XU Yong YANG Bo TANG Qing LIU Guobin LIU Puling Institute of Geographic Sciences and Natural Resources Research CAS Beijing 100101 China Graduate University of Chinese Academy of Sciences Beijing 100049 China Institute of Soil and Water Conservation CAS Yangling Shaanxi 712100 China

De-farming slope farmland has been an effective measure in recent years to improve environment and prevent soil and water loss on the Loess *** are different views about the defarming method,and also various de-farming patterns have been put into *** paper takes the Yangou Watershed in Shaanxi province of china as a case for studying the comprehensive benefits of transforming slope farmland to *** on the day-by-day meteorological data of the Yan'an station in 2005 and the data of terrain features,soil and land use data of the Yangou Watershed,the impact of transforming slope farmland on terraces were simulated and analyzed in aspects of yield increase and water-soil conservation under different topographic conditions with the aid of software ***,an empirical analysis was applied to study the effects of transforming slope farmland to terraces in the Yangou *** results show that:(1) The bigger the topographic gradient is,the more remarkable benefits it has in yield increase and water-soil conservation.(2) Farmland with slope below 5° could be retained,but farmland with slope above 15° should be converted to forest or grassland as soon as possible.(3. Transforming slope farmland to terraces has the same remarkable effects as the current policy of "Relieving and de-farming" in improving agricultural production conditions,safeguarding food security,raising permanent vegetation coverage rate,and preventing soil and water ***,it is more cost-effective than the policy of "Relieving and de-farming".It's strongly suggested that the policy of transforming slope farmland to terraces be carried out on the Loess Plateau without delay.

关键词： Slope farmland Terrace Comprehensive benefits Yangou Watershed Loess Plateau

Study of coastal water zone ecosystem health in Zhejiang province based on remote sensing data and GIS

在线全文

学校读者我要写书评

暂无评论

Acta Oceanologica Sinica 2010年第5期29卷 27-34页

作者： CHEN Zhenghua PAN Delu BAI Yan School of the Environment Gangxi University Nanning 530004 China State Environmental Protection Key Laboratory of Satellite Remote Sensing Ministry of Environmental Protection Institute of Remote Sensing Applications Chinese Academy of Sciences Beijing 100101 China State Key Laboratory of Satellite Ocean Environment Dynamics Second Institute of Oceanography State Oceanic Administration Hangzhou 310012 China

The coastal ecosystem health assessment is a field of increasing *** this paper,a preliminary assessment of ecosystem health in Zhejiang coastal water zone was made,mainly based on remote sensing data and GIS *** spatial and quantitative evaluation was facilitated by the progress of remote sensing and GIS technique ***,human activities,hydrology and ecosystem problems in the study area were discussed and ***,from 4 aspects of human stress,physical,chemical and biological responses to anthropogenic activities and natural stress,several indicators such as water transparency（Secchi Disk Depth,SDD）,suspended substance concentration,dissolved inorganic nitrogen,active phosphate,chlorophyll,harmful algae bloom,as well as distribution of sewage,sea lanes and port were ***,the Analytic Hierarchical Process was used for indicator weight calculation,and the ecosystem health criteria were established according to the integrative analysis of national water quality criteria,similar coastal ecosystem health research in other places or data inherent *** results indicated that from 2005 to 2007 the coastal water ecosystem health value in Zhejiang province was unhealthy and needs ecological restoration by human intervention.

关键词： coastal water zone ecosystem health indicator remote sensing GIS

Multi-spectral image fusion method based on two channels non-separable wavelets

在线全文

学校读者我要写书评

暂无评论

Science in china(Series F) 2008年第12期51卷 2022-2032页

作者： LIU Bin1,2 & PENG JiaXiong3.1 School of Mathematics and Computer Science, Hubei University, Wuhan 43.062, china 2 Key Laboratory of Applied Mathematics of Hubei {3., Wuhan 43.062, china 3.Institute of Image Recognition and Artificial Intelligence, Huazhong University of Science and Technology, Wuhan 43.074, china 1. School of Mathematics and Computer Science Hubei University Wuhan 430062 China 2. Key Laboratory of Applied Mathematics of Hubei province Wuhan 430062 China 3. Institute of Image Recognition and Artificial Intelligence Huazhong University of Science and Technology Wuhan 430074 China

A construction method of two channels non-separable wavelets filter bank which dilation matrix is [1, 1; 1,-1] and its application in the fusion of multi-spectral image are presented. Many 4×4 filter banks are designed. The multi-spectral image fusion algorithm based on this kind of wavelet is proposed. Using this filter bank, multi-resolution wavelet decomposition of the intensity of multi-spectral image and panchromatic image is performed, and the two low-frequency components of the intensity and the panchromatic image are merged by using a tradeoff parameter. The experiment results show that this method is good in the preservation of spectral quality and high spatial resolution information. Its performance in preserving spectral quality and high spatial information is better than the fusion method based on DWFT and IHS. When the parameter t is closed to 1, the fused image can obtain rich spectral information from the original MS image. The amount of computation reduced to only half of the fusion method based on four channels wavelet transform.

关键词： image fusion non-separable wavelets multi-spectral image panchromatic image

Statistical Research on the Seismic Quiescence Before the 1988 Lancang-Gengma Earthquakes with M=7.6 and 7.2 in Yunnan province,china

在线全文

学校读者我要写书评

暂无评论

Earthquake Research in china 1996年第3期10卷 75-83页

作者： Liu ZuyinSeismological Bureau of Yunnan province,Kunming 650041,china

In this paper,the temporal and spatial variation process of seismicity in areas from Lancang to Tengchong before the 1988 Lancang-Gengma earthquakes(M=7.6,7.2),January 1980 to October 1988,is studied in detail according to the theory that the whole process of earthquake sequence in the time stage of anomalous seismicity before a strong event may be considered as the non-homogeneous Poisson *** results demonstrate that(1)from April 1985 to April 1988,there existed an obvious difference of seismicity in spatial distribution in the whole region; to the north of Lancang,there occurred two seismic quiescent belts:one is 210 km long for M≥3.5 events and anotheris 160 km long for M≥3.0 events; therefore,this may be classified into four sub-regions from south to north,that is,the south region,the mid-region,the mid’-region,and the north region.(2)Before the mainshocks,there existed anomalous seismic quiescence for as Song as 42 months in the mid-region(M≥3.5)and 3..5 months in the mid’-region(M≥3.0)

关键词： Anomalous seismicity Non-homogeneous Poisson process Statistical research

Sol-gel preparation and spectroscopic study of the pyrophanite MnTiO_3.nanoparticles

在线全文

学校读者我要写书评

暂无评论

Science china Chemistry 2005年第3期48卷 210-215页

作者： ZHOU Guowei1, KANG Youngsoo2, LI Tianduo1 & XU Guiying3.1. School of Light Chemicals and Environmental Engineering, Shandong Institute of Light Industry, Jinan 250100, china 2. Department of Chemistry, Pukyong National University, Daeyeon-3.dong, Nam-gu, Pusan 608-73., Korea 3. Key Laboratory for Colloid and Interface of Ministry of Education of china, Shandong University, Jinan 250100, china 1. School of Light Chemicals and Environmental Engineering Shandong Institute of Light Industry 250100 Jinan China 2. Department of Chemistry Pukyong National University Daeyeon-3-dong Nam-gu 608-737 Pusan Korea 3. Key Laboratory for Colloid and Interface of Ministry of Education of china Shandong University 250100 Jinan China

The nanosized xerogel of titanium dioxide (TiO2) and manganese oxides (MnO2, Mn2O3. Mn3.4) was prepared by the sol-gel method using manganese chloride (MnCl2·4H2O) and titanium isopropoxide (Ti(O-iPr)4) as precursors in cetyltrimethylammonium bromide (CTAB)/ ethanol/H2O/HCl micelle solutions, following the calcinations of the produced powders at differ-ence temperatures. The nanostructure and phase composition of these nanoparticles were characterized with X-ray powder diffraction (XRD), transmission electron microscopy (TEM), en-ergy dispersive X-ray spectroscopy (EDX) and X-ray photoelectron spectroscopy (XPS). The spectroscopic characterizations of these nanoparticles were also done with UV-Vis spectroscopy and laser Raman spectroscopy (LRS). XRD patterns show that the pyrophanite MnTiO3.phase was formed at the calcinations temperature of 900℃. The TEM images show that the nanoparti-cles are almost spherical or slight ellipose and the sizes are 50 nm on average. The UV-Vis spectra show that the nanosized MnTiO3.have significant absorption bands in the visible region. There are new absorption peaks of MnTiO3.nanoparticles in LRS compared with the pure TiO2 powder.

关键词： pyrophanite MnTiO3. nanoparticles, spectroscopy, CTAB micelle, sol-gel.

In situ synthesis of DNA micro-arrays using typography technique

在线全文

学校读者我要写书评

暂无评论

Science china Chemistry 2007年第1期50卷 75-83页

作者： TANG JianXin 1,2 ,HE NongYue 1,2,3.&LI Song 1 1State Key Laboratory of Bioelectronics,Southeast University,Nanjing 210096,china 2Key Laboratory of Green Packaging and Application of Biological Nanotechnology of Hunan province,Hunan University of Tech- nology,Zhuzhou 412008,china 3.hongshan Huoju Polytechnic,Zhongshan 52843.,china 1. State Key Laboratory of Bioelectronics Southeast University Nanjing 210096 China 2. Key Laboratory of Green Packaging and Application of Biological Nanotechnology of Hunan province Hunan University of Technology Zhuzhou 412008 China 3. Zhongshan Huoju Polytechnic Zhongshan 528436 China

A novel typography technique was developed to in situ synthesize oligonucleotide arrays on glass slide,which has the celerity,high spatial resolution,lower cost,reliable operation,and high synthetic *** principle and process of the typography technique for fabricating gene-chips have been described in detail.A suit of poly(terafluoroethylene)devices for synthesizing oligonucleotide arrays were designed and prepared,and the fiber tubes with a number of nano-or micron-channels were em- *** oligonucleotide arrays of 16 and 160 features with four different probes were synthesized using the typography *** four specific oligonucleotide probes including the matched and the mismatched by the fluorescent target sequence gave obviously different hybridization fluorescent *** was indicated that the gene-chip fabricated by the typography method could be used to rapidly screen single-nucleotide polymorphisms(SNP)and to detect mutations.

关键词： typography oligonucleotide in situ synthesis DNA microarrays

Contourlet HMT model with directional feature

在线全文

学校读者我要写书评

暂无评论

Science china(Information Sciences) 2012年第7期55卷 1563-1578页

作者： WANG XiangHai 1,2,3.,CHEN MingYing 1 ,SONG ChuanMing 1,2 ,XU MengChun 1 & FANG LingLing 3.1 College of Computer and Information Technology,liaoning Normal University,Dalian 116029,{3. 2 State Key Laboratory for Novel Software Technology,Nanjing University,Nanjing 210093.{3. 3.Provincial Key Laboratory for Computer Information Processing Technology,Soochow University,Suzhou 215006,{3. 1. College of Computer and Information Technology Liaoning Normal University Dalian 116029 China2. State Key Laboratory for Novel Software Technology Nanjing University Nanjing 210093 China3. Provincial Key Laboratory for Computer Information Processing Technology Soochow University Suzhou 215006 China

According to Shanno's information theory,the directional feature of texture is defined as the value of directional variable when an image signal attains a singularity of random *** terms of this definition,we calculate the texture's directional features using Tamura's method and study the directional probability distribution of Contourlet *** we find that the directional features tend to be conveyed across parent and child *** on this conclusion,we establish a novel probability distribution model of hidden direction variables under the condition of hidden state variable's distribution,named Contourlet HMT model with directional *** structure and training method of the model are presented as ***,an unsupervised context-based image segmentation algorithm is proposed on the basis of the proposed *** effectiveness is verified via extensive experiments carried out on several synthesized images and remote sensing images.

关键词： directional feature Contourlet HMT Contourlet HMT with directional feature unsupervised texture segmentation

Robust adaptive fuzzy backstepping output feedback tracking control for nonlinear system with dynamic uncertainties

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science china(Information Sciences) 2010年第2期53卷 307-324页

作者： TONG ShaoCheng & LI YongMing Department of Basic Mathematics, liaoning University of Technology, Jinzhou 121001, china 1. Department of Basic Mathematics Liaoning University of Technology Jinzhou 121001 China

In this paper, an adaptive fuzzy output feedback control approach based on backstepping design is proposed for a class of SISO strict feedback nonlinear systems with unmeasured states, nonlinear uncertainties, unmodeled dynamics, and dynamical disturbances. Fuzzy logic systems are employed to approximate the nonlinear uncertainties, and an adaptive fuzzy state observer is designed for the states estimation. By combining backstepping technique with the fuzzy adaptive control approach, a stable adaptive fuzzy output feedback robust control is constructed recursively, in which nonlinear damping terms and a dynamical signal are introduced to counteract the nonlinear uncertainties and dominate the dynamic disturbances, respectively. It is proved that the proposed adaptive fuzzy control approach guarantees that all the signals of the closed-loop system are semi-globally uniformly bounded, and the tracking error converges to a small neighborhood of the origin. Simulation studies are included to illustrate the effectiveness of the proposed approach.

关键词： nonlinear systems fuzzy control adaptive control backstepping technique adaptive state observer stability analysis

Development of ancestors' cultivation revealed in phytolith assemblages from Guangfulin relics

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2003年第3期48卷 287-290页

作者： ZHANG Yulan1,2, ZHANG Minbin1 & SONG Jian3.1. Key Laboratory of Marine Geology of the Ministry of Education, Tongji University, Shanghai 200092, china 2. State Key Laboratory of Estuarine and Coastal Research, East china Normal University, Shanghai 200062, china 3. Shanghai Museum, Shanghai 200003. china Key Laboratory of Marine Geology of the Ministry of Education Tongji University Shanghai 200092 China State Key Laboratory of Estuarine and Coastal Research East China Normal University Shanghai 200062 China Shanghai Museum Shanghai 200003 China

Shanghai Museum has got great achievements in re-excavating Guangfulin relics. It is the first time that the cultural remains of Wangyoufang type is found above the Liangzhu cultural remains which comes from East Henan province, providing previous materials for researching cul-ture evolution around Taihu Lake. Samples were taken from the immature soil layer and cultural layers of Guangfulin relics for phytolith analysis. According to the systemic re-search for the archaeological remains and phytolith fossil, the phytoliths in Guangfulin relics can be divided into four zones. The development of rice agriculture and living condi-tion of Guangfulin ancestors was discussed based on the ex-isting rice fan-shaped phytolith, rice shell phytolith, diatom fossil and archaeology evidence in the same layer. The Guangfulin relics has gradually developed since a high sea level 5000 years ago, and the broad rice agriculture has si-multaneously developed. The newly re-excavated relics pro-vides valuable materials for the research of ancestors and ancient culture in Shanghai.

关键词：上海 Guangfulin遗址远古农作物植物化石