期刊文献+
共找到13篇文章
< 1 >
每页显示 20 50 100
Seasonal Dynamics of Biomass under Different Land Use Patterns 被引量:3
1
作者 徐霞 张智才 +1 位作者 张勇 田玉强 《Agricultural Science & Technology》 CAS 2010年第8期49-52,共4页
[Objective] The aim was to study seasonal dynamics of biomass under different land use patterns. [Methed] Aboveground biomass and underground biomass of plants under 3 different surface cover conditions of Stipa krylo... [Objective] The aim was to study seasonal dynamics of biomass under different land use patterns. [Methed] Aboveground biomass and underground biomass of plants under 3 different surface cover conditions of Stipa krylovii, Leymus chinensis and farmland were determined in growing season ( from May to October) of 2008. [ Result ] The aboveground biomass of Stipa krylovii, Leymus chinensis and farmland in August all reached the highest value, which of Stipa krylovii, Leymus chinensis and farmland was 287.91,117.05 and 193.59 g/m2, respectively. The total biomass of plant roots of the 3 plots in July all reached the highest value, which of Stipa krylovii, Leymus chinensis and farmland was 1 683.9, 1 601.9 and 513.9 g/m2, respectively. Leymus chinensis had the biggest biomass ratio of upper plant roots (0 - 15 cm) to lower plant roots (15 -30 cm), Stipa krylovii took second place, and farmland had the smallest one. ~ Conclusion The research provides theoretical basis for the ecological environment protection of ecological fragile area. 展开更多
关键词 Inner Mongolia grassland Land use patters BIOMASS Seasonal dynamics
在线阅读 下载PDF
Characterizing Rhizodegradation of the Insecticide Bifenthrin in Two Soil Types
2
作者 Xuan Le Dafeng Hui Emmanuel Kudjo Dzantor 《Journal of Environmental Protection》 2011年第7期940-946,共7页
Rhizodegradation is a process by which plant-supplied substrates stimulate microbial populations in plant root zones (rhizospheres) to cause removal of undesirable levels of contaminants in soil. This study characteri... Rhizodegradation is a process by which plant-supplied substrates stimulate microbial populations in plant root zones (rhizospheres) to cause removal of undesirable levels of contaminants in soil. This study characterized rhizodegradation of the insecticide bifenthrin in Armour silt loam and Sullivan fine sandy loam soils that were planted with switchgrass, big bluestem, and alfalfa. After six weeks in soils, plate dilution frequency assays (PDFA) of bacterial populations were higher in all planted soils than in unplanted ones. Planted Sullivan soils contained higher bacteria than corresponding Armour soils and alfalfa rhizospheres of both soil types contained highest bacteria. Bacterial populations generally increased between week 6 and week 10, before declining in each treatment at week 12. Carbon utilization patterns (CUP) of bacterial communities, measured as color development on BIOLOG plates, were higher in planted soils than in unplanted ones. Principal Component Analysis (PCA) constructed patterns based on different extents of color development;these patterns were used to relate microbial communities in the different treatments. Gas chromatography (GC-ECD) showed that significantly more bifenthrin dissipated in planted soils than unplanted ones. Different levels of bifenthrin were recovered in planted soils but the differences were generally not significant. Data are being evaluated further to provide a basis for the development of strategies for enhancing rhizodegradation of soils contaminated with bifenthrin. 展开更多
关键词 Rhizodegradation MICROBIAL Community Substrate Utilization patters BIOLOG BIFENTHRIN PESTICIDE DISSIPATION
暂未订购
Climate Patterns: Origin and Forcing
3
作者 Alexander Ruzmaikin 《American Journal of Climate Change》 2021年第2期204-236,共33页
This brief review described spatial-time climate patterns generated by the dynamics and thermodynamics of the Earth’s climate system and methods of identifying these patterns. Specifically, it does discuss the follow... This brief review described spatial-time climate patterns generated by the dynamics and thermodynamics of the Earth’s climate system and methods of identifying these patterns. Specifically, it does discuss the following major climate patterns: El Ni?o-Southern Oscillation (ENSO), Cold Ocean-Warm Land (COWL) pattern, Northern and Southern Annular Patterns (NAM and SAM), Atlantic Multidecadal Oscillation (AMO) and Atlantic Meridional Overturning Circulation (AMOC), Pacific North-American Pattern (PNA) and Pacific Decadal Oscillation Pattern (PDO). In view of an extensive number of publications on some climate patterns, such as the ENSO, which discussed in many hundred of publications, this review is not intended to cover all the details of individual climate patterns but intends only to give a general overview of their structure, mechanisms of their formation and response to external forcing. It is assumed that the climate patterns can be treated as attractors of dynamical systems allowing us to extract and predict some specific features of the patterns such as the origin and evolution of the climate patterns and their role in climate change. Thus the knowledge of patterns allows the climate prediction on long time scales and understanding of how an external forcing affects the frequency of occurrence of climate patterns and their magnitude but not the spatial structure. 展开更多
关键词 Spatial-Time patters Dynamics Climate Change Climate Prediction
在线阅读 下载PDF
Practical Model and Countermeasures for the Development of Ecological Circular Agriculture in Zhejiang Province,China 被引量:5
4
作者 ZHANG Qi1,ZHENG Shui-ming2,YE Xue-zhu1,ZHAO Shou-ping1,YU Guo-guang1 1.Institute of Quality and Standard for Agro-products,Zhejiang Academy of Agricultural Sciences,Hangzhou 310021,China 2.Department of Science and Education,Agricultural Bureau of Zhejiang Province,Hangzhou 310020,China 《Asian Agricultural Research》 2011年第2期58-60,64,共4页
Development status and five principal practice modes of ecological cycling agriculture are introduced,such as the quantitative reduction mode with the characteristics of fertilizer reduction and clean production,the e... Development status and five principal practice modes of ecological cycling agriculture are introduced,such as the quantitative reduction mode with the characteristics of fertilizer reduction and clean production,the ecological chain connection and conversion mode including the combination of farming and grazing and the new mode of farming,the agricultural waste recycling mode with biogas as a link and the comprehensive utilization of waste,quality enhancement mode of agricultural products,and eco-cycle mode of agricultural park.Based on the analysis of the socio-economic characteristic environment of these modes,corresponding policy suggestions are put forward in order to promote the development of circular agriculture,such as improving the macro-control mechanism led by the government,promoting the construction of technological innovation system of ecological circular agriculture,and creating the atmosphere for circular agriculture development. 展开更多
关键词 ECOLOGICAL CIRCULAR AGRICULTURE DEVELOPMENT patter
在线阅读 下载PDF
Weekly pattern of emergency room admissions for peptic ulcers:A population-based study 被引量:1
5
作者 Li-Ting Kao Ming-Chieh Tsai +2 位作者 Herng-Ching Lin Femi Pai Cha-Ze Lee 《World Journal of Gastroenterology》 SCIE CAS 2015年第11期3344-3350,共7页
AIM:To investigate variations in the incidence of peptic ulcers(PUs) in Taiwan by day of the week within age subgroups.METHODS:Ambulatory care data were retrieved from the Longitudinal Health Insurance Database 2000.T... AIM:To investigate variations in the incidence of peptic ulcers(PUs) in Taiwan by day of the week within age subgroups.METHODS:Ambulatory care data were retrieved from the Longitudinal Health Insurance Database 2000.There were 7204 subjects≥18 years-old with an emergency room admission claim for the treatment of PUs,resulting in a total of 9234 emergency room visits for PUs between 2009 and 2011.Data was divided into the seven days of the week and an additional variable for holidays.One-way analysis of variance was used to examine associations among the daily mean number of PU emergency room admissions and holidays/weekends/weekdays.RESULTS:One-way analysis of variance showed that there was a significant difference in emergency room admissions for PUs by the day of the week(P<0.001),with admission more likely to occur on Sundays or holidays than weekdays within the total and working populations.The weekday patterns of admission were similar for the patients aged 18-64 years and≥65years of age.Holidays,followed by Sundays,had higher PU admissions than the mean daily PU emergency room admissions.Furthermore,inclusion of only those treated for PUs with hemorrhage or perforation,Sundays and holidays had higher mean emergency room admissions than other days.Inclusion of patients who diagnosed with Helicobacter pylori infection,only holidays had higher mean emergency room admissions than other days.Inclusion of patients who had been prescribed non-steroidal anti-inflammatory drugs(NSAIDs)for over30 d,Sundays and holidays had higher mean PU ER admissions than other non-holiday weekdays.CONCLUSION:There is a higher incidence of emergency room admission for PUs on weekends than on weekdays for the total and working populations. 展开更多
关键词 CHRONOLOGY EPIDEMIOLOGY PEPTIC ULCER WEEKLY patter
暂未订购
Response of photosynthesis, morphology and growth of Hedysarum mongolicum seedlings to simulated precipitation change in Maowusu sandland 被引量:1
6
作者 XiaoCW JiaFP 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2002年第2期277-283,共7页
Response patters were investigated for seedlings of Hedysarum mongolicum, a dominant shrub in Maowusu sandland, to the simulated precipitation change by artificially controlling water supply at four levels. Plant ... Response patters were investigated for seedlings of Hedysarum mongolicum, a dominant shrub in Maowusu sandland, to the simulated precipitation change by artificially controlling water supply at four levels. Plant growth characters, in terms of branch number and length, leaf number and area, and biomass, increased while water supply increased. However, the effect of water supply on leaf photosynthetic rate was not significant. Root/shoot biomass ratio significantly decreased with the increase of water supply, which was considered adaptive distribution of biomass investments in the different water supply. Water supply obviously affected branching patter. Branch section number, branch number and length of the same section enhanced as water supply increased. Branch number and length were clearly positive correlation with total and aboveground biomass in four water supply treatments. Branch character fully showed plant growth. 展开更多
关键词 simulated precipitation Maowusu sandland semi arid area Hedysarum mongolicum branching patter
在线阅读 下载PDF
Basic Contrast of English, Chinese and the Shui language Sentences
7
作者 常迪 《海外英语》 2013年第2X期219-220,共2页
This paper is to explore the similar and different syntactic linear patterns and thought modals among English, Chinese and the Shui language, discussing this topic from microscopic, giving a much detailed contrast and... This paper is to explore the similar and different syntactic linear patterns and thought modals among English, Chinese and the Shui language, discussing this topic from microscopic, giving a much detailed contrast and comparison on microscopic English, Chinese and the Shui language syntactic. 展开更多
关键词 CONTRASTIVE study the Shui LANGUAGE THOUGHT patter
在线阅读 下载PDF
AN EFFICIENT LABELLING ALGORITHM FOR WOODPANELS SURFACE DEFECTS
8
作者 王克奇 《Journal of Northeast Forestry University》 SCIE CAS CSCD 1995年第4期54-57,共4页
This paper describes an efficient approach for labeling images using a combination of pipeline (Datacube) and (general purpose computer) processing. The output of the algorithm is coordinate list of labeled object pix... This paper describes an efficient approach for labeling images using a combination of pipeline (Datacube) and (general purpose computer) processing. The output of the algorithm is coordinate list of labeled object pixels that facilitates further high level operations. It is an efficient labeling algorithm for a automatic classification of surface defects on wood boards. 展开更多
关键词 Image modeling Patter recognition WOOD Surface defects
在线阅读 下载PDF
Canonical Shape Analysis of Hausa and Bole Ideophones
9
作者 Almustapha Wali Sambo 《宏观语言学》 2016年第2期65-79,共15页
Hausa and Bole are two languages from the same phylum i.e. Afro-asiatic. They have some common various linguistic features, most especially phonological and syntactic features. The main purpose of this paper is to com... Hausa and Bole are two languages from the same phylum i.e. Afro-asiatic. They have some common various linguistic features, most especially phonological and syntactic features. The main purpose of this paper is to come up with one of the phonological aspects of one of the word classes of Hausa and Bole. This means, we will analyse the syllable structure, which is canonical shape of ideophones of both languages using descriptive method of analysis adopted by Newman (2000). In Hausa, likewise in Bole, ideophones are numerous and several of them are commonly used syntactically. But, we will not deal with their syntactical use or function in this paper, what we focus on, is just their canonical shapes i.e. syllable structures. The paper is divided into four sections: sections one and four are introduction and conclusion respectively, while section two is descriptive analysis of canonical shape of Hausa ideophones, and section three, is of Bole ideophones. 展开更多
关键词 Hausa Bole ideophone SYLLABLE STRUCTURE TONE patter
在线阅读 下载PDF
Optimization of satellite searching strategy of the non-stationary antenna
10
作者 曹海青 王渝 姚志英 《Journal of Beijing Institute of Technology》 EI CAS 2015年第3期398-404,共7页
The tiny searching step length and the satellite distribution density are the major factors to influence the efficiency of the satellite finder,so a scientific and reasonable method to calculate the tiny searching ste... The tiny searching step length and the satellite distribution density are the major factors to influence the efficiency of the satellite finder,so a scientific and reasonable method to calculate the tiny searching step length is proposed to optimize the satellite searching strategy. The pattern clustering and BP neural network are applied to optimize the tiny searching step length. The calculated tiny searching step length is approximately equal to the theoretic value for each satellite. In application,the satellite searching results will be dynamically added to the training samples to re-train the network to improve the generalizability and the precision. Experiments validate that the optimization of the tiny searching step length can avoid the error of locating target satellite and improve the searching efficiency. 展开更多
关键词 tiny searching step length satellite finder patter clustering neural network
在线阅读 下载PDF
Selectively patterned TiO2 nanorods as electron transport pathway for high performance perovskite solar cells 被引量:2
11
作者 Daihong Huh KyoungSuk Oh +3 位作者 Minjin Kim Hak-Jong Choi Dong Suk Kim Heon Lee 《Nano Research》 SCIE EI CAS CSCD 2019年第3期601-606,共6页
Organic-inorganic hybrid perovskite solar cells (PSCs) are attracting tremendous attention for new-generation photovoltaic devices because of their excellent power conversion efficiency and simple fabrication process.... Organic-inorganic hybrid perovskite solar cells (PSCs) are attracting tremendous attention for new-generation photovoltaic devices because of their excellent power conversion efficiency and simple fabrication process. One of the various approaches to increase the efficiency of PSCs is to change the material or structure of the carrier transport layer. Here, optically long and electrically short structural concept is proposed to enhance the characteristics of a PSC by employing selectively grown single crystalline TiO2 nanorods. The approach has the merit of increasing the electro n-hole separati on effectively and en ables a thicker active layer to be coated without electrical loss by using TiO2 nano rods as an electr on pathway. Moreover, selectively grow n TiO2 nano rods in crease the optical path of the in cide nt light via scatteri ng effects and en able a smooth coati ng of the active layer. Nano imprint lithography and hydrothermal growth were employed to fabricate selectively grow n TiO2 nanorod substrates. The fabricated solar cell exhibits an efficiency of 19.86% with a current density, open-circuit voltage, and fill factor of 23.13 mA/cm^2, 1.120 V, and 76.69%, respectively. Time-resolved photoluminescence, ultraviolet-visible (UV-Vis) spectroscopy, and the incident phot on to current efficiency (IPCE) an alysis were conducted to understand the factors resp on sible for the improvement in characteristics of the fabricated PSCs. 展开更多
关键词 PEROVSKITE solar cells patter ned T1O2 NANORODS NANOIMPRINT LITHOGRAPHY
原文传递
Transfer characterization of sulfur from coal-burning emission to plant leaves by PIXE and XANES 被引量:1
12
作者 包良满 张桂林 +7 位作者 张元勋 李燕 林俊 刘卫 曹清晨 赵屹东 马陈燕 韩勇 《Chinese Physics C》 SCIE CAS CSCD 2009年第11期1010-1015,共6页
The impact of coal-burning emission on sulfur in camphor leaves was investigated using Proton Induced X-ray Emission (PIXE) and synchrotron radiation technique X-ray Absorption Near-Edge Structure (XANES) spectros... The impact of coal-burning emission on sulfur in camphor leaves was investigated using Proton Induced X-ray Emission (PIXE) and synchrotron radiation technique X-ray Absorption Near-Edge Structure (XANES) spectroscopy. The PIXE results show that the sulfur concentrations in the leaves collected at the polluted site are significantly higher than those in controls. The Sulfur XANES spectra show the presence of organic (disulfides, thiols, thioethers, sulfonates and sulfoxides) and inorganic sulfur (sulfates) in the leaves. The inorganic sulfur in the leaves of camphor tree polluted by coal combustion is 15% more than that of the control site. The results suggest that the long-term coal-burning pollution resulted in an enhanced content of the total sulfur and sulfate in the leaves, and the uptake of sulfur by leaves had exceeded the metabolic requirement of plants and the excess of sulfur was stored as SO4^2-. It can monitor the sulfur pollution in atmosphere. 展开更多
关键词 SULFUR PIXE XANES atmospheric particulate patter SO2 LEAF
原文传递
Pattern classification using fuzzy relation and genetic algorithm
13
作者 Kumar S.Ray 《International Journal of Intelligent Computing and Cybernetics》 EI 2012年第4期533-565,共33页
Purpose–This paper aims to consider a soft computing approach to pattern classification using the basic tools of fuzzy relational calculus(FRC)and genetic algorithm(GA).Design/methodology/approach–The paper introduc... Purpose–This paper aims to consider a soft computing approach to pattern classification using the basic tools of fuzzy relational calculus(FRC)and genetic algorithm(GA).Design/methodology/approach–The paper introduces a new interpretation of multidimensional fuzzy implication(MFI)to represent the author’s knowledge about the training data set.It also considers the notion of a fuzzy pattern vector(FPV)to handle the fuzzy information granules of the quantized pattern space and to represent a population of training patterns in the quantized pattern space.The construction of the pattern classifier is essentially based on the estimate of a fuzzy relation Ri between the antecedent clause and consequent clause of each one-dimensional fuzzy implication.For the estimation of Ri floating point representation of GA is used.Thus,a set of fuzzy relations is formed from the new interpretation of MFI.This set of fuzzy relations is termed as the core of the pattern classifier.Once the classifier is constructed the non-fuzzy features of a test pattern can be classified.Findings–The performance of the proposed scheme is tested on synthetic data.Subsequently,the paper uses the proposed scheme for the vowel classification problem of an Indian language.In all these case studies the recognition score of the proposed method is very good.Finally,a benchmark of performance is established by considering Multilayer Perceptron(MLP),Support Vector Machine(SVM)and the proposed method.The Abalone,Hosse colic and Pima Indians data sets,obtained from UCL database repository are used for the said benchmark study.The benchmark study also establishes the superiority of the proposed method.Originality/value–This new soft computing approach to pattern classification is based on a new interpretation of MFI and a novel notion of FPV.A set of fuzzy relations which is the core of the pattern classifier,is estimated using floating point GA and very effective classification of patterns under vague and imprecise environment is performed.This new approach to pattern classification avoids the curse of high dimensionality of feature vector.It can provide multiple classifications under overlapped classes. 展开更多
关键词 Pattern classifier Multidimensional fuzzy implication Fuzzy information granule Fuzzy patter vector Fuzzy relational calculus Genetic algorithms Fuzzy logic Pattern recognition
在线阅读 下载PDF
上一页 1 下一页 到第
使用帮助 返回顶部