期刊文献+
共找到154篇文章
< 1 2 8 >
每页显示 20 50 100
High Speed Regular Expression Matching Engine with Fast Pre-Processing 被引量:1
1
作者 Zhe Fu Jun Li 《China Communications》 SCIE CSCD 2019年第2期177-188,共12页
Regular expression matching is playing an important role in deep inspection. The rapid development of SDN and NFV makes the network more dynamic, bringing serious challenges to traditional deep inspection matching eng... Regular expression matching is playing an important role in deep inspection. The rapid development of SDN and NFV makes the network more dynamic, bringing serious challenges to traditional deep inspection matching engines. However, state-of-theart matching methods often require a significant amount of pre-processing time and hence are not suitable for this fast updating scenario. In this paper, a novel matching engine called BFA is proposed to achieve high-speed regular expression matching with fast pre-processing. Experiments demonstrate that BFA obtains 5 to 20 times more update abilities compared to existing regular expression matching methods, and scales well on multi-core platforms. 展开更多
关键词 deep inspection FINITE AUTOMATON REGULAR expression MATCHING pre-processing
在线阅读 下载PDF
Pre-processing and post-processing method for geostress simulation using seismic interpretation results 被引量:1
2
作者 ZHANG Li-hong 《Mining Science and Technology》 EI CAS 2009年第3期369-372,共4页
In order to carry out numerical simulation using geologic structural data obtained from Landmark(seismic interpretation system), underground geological structures are abstracted into mechanical models which can reflec... In order to carry out numerical simulation using geologic structural data obtained from Landmark(seismic interpretation system), underground geological structures are abstracted into mechanical models which can reflect actual situations and facilitate their computation and analyses.Given the importance of model building, further processing methods about traditional seismic interpretation results from Landmark should be studied and the processed result can then be directly used in numerical simulation computations.Through this data conversion procedure, Landmark and FLAC(the international general stress software) are seamlessly connected.Thus, the format conversion between the two systems and the pre-and post-processing in simulation computation is realized.A practical application indicates that this method has many advantages such as simple operation, high accuracy of the element subdivision and high speed, which may definitely satisfy the actual needs of floor grid cutting. 展开更多
关键词 seismic interpretation numerical simulation pre-processing POST-PROCESSING COUPLING
在线阅读 下载PDF
Concurrent multi-task pre-processing method for LEO mega-constellation based on dynamic spatio-temporal grids 被引量:1
3
作者 Xibin CAO Ning LI Shi QIU 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2023年第11期233-248,共16页
The Low Earth Orbit(LEO)remote sensing satellite mega-constellation has the characteristics of large quantity and various types which make it have unique superiority in the realization of concurrent multiple tasks.How... The Low Earth Orbit(LEO)remote sensing satellite mega-constellation has the characteristics of large quantity and various types which make it have unique superiority in the realization of concurrent multiple tasks.However,the complexity of resource allocation is increased because of the large number of tasks and satellites.Therefore,the primary problem of implementing concurrent multiple tasks via LEO mega-constellation is to pre-process tasks and observation re-sources.To address the challenge,we propose a pre-processing algorithm for the mega-constellation based on highly Dynamic Spatio-Temporal Grids(DSTG).In the first stage,this paper describes the management model of mega-constellation and the multiple tasks.Then,the coding method of DSTG is proposed,based on which the description of complex mega-constellation observation resources is realized.In the third part,the DSTG algorithm is used to realize the processing of concurrent multiple tasks at multiple levels,such as task space attribute,time attribute and grid task importance evaluation.Finally,the simulation result of the proposed method in the case of constellation has been given to verify the effectiveness of concurrent multi-task pre-processing based on DSTG.The autonomous processing process of task decomposition and task fusion and mapping to grids,and the convenient indexing process of time window are verified. 展开更多
关键词 LEO mega-constellation Concurrent multiple tasks Tasks pre-processing Highly dynamic spatiotemporal grids Multi-task fusion merging Importance evaluation
原文传递
Pre-processing filter design at transmitters for IBI mitigation in an OFDM system 被引量:1
4
作者 Xia Wang Lei Wang 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2013年第5期722-728,共7页
In order to meet the demands for high transmission rates and high service quality in broadband wireless communication systems, orthogonal frequency division multiplexing (OFDM) has been adopted in some standards. Ho... In order to meet the demands for high transmission rates and high service quality in broadband wireless communication systems, orthogonal frequency division multiplexing (OFDM) has been adopted in some standards. However, the inter-block interference (IBI) and inter-carrier interference (ICI) in an OFDM system affect the performance. To mitigate IBI and ICI, some pre-processing approaches have been proposed based on full channel state information (CSI), which improved the system performance. A pre-processing filter based on partial CSI at the transmitter is designed and investigated. The filter coefficient is given by the optimization processing, the symbol error rate (SER) is tested, and the computation complexity of the proposed scheme is analyzed. Computer simulation results show that the proposed pre-processing filter can effectively mitigate IBI and ICI and the performance can be improved. Compared with pre-processing approaches at the transmitter based on full CSI, the proposed scheme has high spectral efficiency, limited CSI feedback and low computation complexity. 展开更多
关键词 pre-processing filter inter-block interference (IBI) mitigation limited feedback orthogonal frequency division multiplexing (OFDM).
在线阅读 下载PDF
Scientific data products and the data pre-processing subsystem of the Chang'e-3 mission 被引量:1
5
作者 Xu Tan Jian-Jun Liu +7 位作者 Chun-Lai Li Jian-Qing Feng Xin Ren Fen-Fei Wang Wei Yan Wei Zuo Xiao-Qian Wang Zhou-Bin Zhang 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2014年第12期1682-1694,共13页
The Chang'e-3 (CE-3) mission is China's first exploration mission on the surface of the Moon that uses a lander and a rover. Eight instruments that form the scientific payloads have the following objectives: (1... The Chang'e-3 (CE-3) mission is China's first exploration mission on the surface of the Moon that uses a lander and a rover. Eight instruments that form the scientific payloads have the following objectives: (1) investigate the morphological features and geological structures at the landing site; (2) integrated in-situ analysis of minerals and chemical compositions; (3) integrated exploration of the structure of the lunar interior; (4) exploration of the lunar-terrestrial space environment, lunar sur- face environment and acquire Moon-based ultraviolet astronomical observations. The Ground Research and Application System (GRAS) is in charge of data acquisition and pre-processing, management of the payload in orbit, and managing the data products and their applications. The Data Pre-processing Subsystem (DPS) is a part of GRAS. The task of DPS is the pre-processing of raw data from the eight instruments that are part of CE-3, including channel processing, unpacking, package sorting, calibration and correction, identification of geographical location, calculation of probe azimuth angle, probe zenith angle, solar azimuth angle, and solar zenith angle and so on, and conducting quality checks. These processes produce Level 0, Level 1 and Level 2 data. The computing platform of this subsystem is comprised of a high-performance computing cluster, including a real-time subsystem used for processing Level 0 data and a post-time subsystem for generating Level 1 and Level 2 data. This paper de- scribes the CE-3 data pre-processing method, the data pre-processing subsystem, data classification, data validity and data products that are used for scientific studies. 展开更多
关键词 Moon: data products -- methods: data pre-processing -- space vehicles:instruments
在线阅读 下载PDF
Review of pre-processing technologies for ice cores
6
作者 DU Wen-tao KANG Shi-chang +4 位作者 QIN Xiang SUN Wei-jun ZHANG Yu-lan LIU Yu-shuo CHEN Ji-zu 《Journal of Mountain Science》 SCIE CSCD 2018年第9期1950-1960,共11页
High-resolution ice core records covering long time spans enable reconstruction of the past climatic and environmental conditions allowing the investigation of the earth system's evolution.Preprocessing of ice cor... High-resolution ice core records covering long time spans enable reconstruction of the past climatic and environmental conditions allowing the investigation of the earth system's evolution.Preprocessing of ice cores has direct impacts on the data quality control for further analysis since the conventional ice core processing is time-consuming,produces qualitative data,leads to ice mass loss,and leads to risks of potential secondary pollution.However,over the past several decades,preprocessing of ice cores has received less attention than the improvement of ice drilling,the analytical methodology of various indices,and the researches on the climatic and environmental significance of ice core records.Therefore,this papers reviews the development of the processing for ice cores including framework,design as well as materials,analyzes the technical advantages and disadvantages of the different systems.In the past,continuous flowanalysis(CFA)has been successfully applied to process the polar ice cores.However,it is not suitable for ice cores outside polar region because of high level of particles,the memory effect between samples,and the filtration before injection.Ice core processing is a subtle and professional operation due to the fragility of the nonmetallic materials and the random distribution of particles and air bubbles in ice cores,which aggravates uncertainty in the measurements.The future developments of CFA are discussed in preprocessing,memory effect,challenge for brittle ice,coupling with real-time analysis and optimization of CFA in the field.Furthermore,non-polluting cutters with many different configurations could be designed to cut and scrape in multiple directions and to separate inner and outer portions of the core.This system also needs to be coupled with streamlined operation of packaging,coding,and stacking that can be implemented at high resolution and rate,avoiding manual intervention.At the same time,information of the longitudinal sections could be scanned andidentified,and then classified to obtain quantitative data.In addition,irregular ice volume and weight can also be obtained accurately.These improvements are recorded automatically via user-friendly interfaces.These innovations may be applied to other paleomedias with similar features and needs. 展开更多
关键词 Ice core Alpine region Polar region pre-processing INNOVATION
原文传递
Image pre-processing research of coal level in underground coal pocket
7
作者 吴冰 高娜 《Journal of Coal Science & Engineering(China)》 2008年第1期162-164,共3页
Mathematical morphology is widely applicated in digital image procesing.Vari- ary morphology construction and algorithm being developed are used in deferent digital image processing.The basic idea of mathematical morp... Mathematical morphology is widely applicated in digital image procesing.Vari- ary morphology construction and algorithm being developed are used in deferent digital image processing.The basic idea of mathematical morphology is to use construction ele- ment measure image morphology for solving understand problem.The article presented advanced cellular neural network that forms mathematical morphological cellular neural network (MMCNN) equation to be suit for mathematical morphology filter.It gave the theo- ries of MMCNN dynamic extent and stable state.It is evidenced that arrived mathematical morphology filter through steady of dynamic process in definite condition. 展开更多
关键词 coal level pre-processing image stability neural network
在线阅读 下载PDF
Intelligent Data Pre-processing Model in Integrated Ocean Observing Network System
8
作者 韩华 丁永生 刘凤鸣 《Journal of Donghua University(English Edition)》 EI CAS 2009年第5期499-502,共4页
There are a number of dirty data in observation data set derived from integrated ocean observing network system. Thus, the data must be carefully and reasonably processed before they are used for forecasting or analys... There are a number of dirty data in observation data set derived from integrated ocean observing network system. Thus, the data must be carefully and reasonably processed before they are used for forecasting or analysis. This paper proposes a data pre-processing model based on intelligent algorithms. Firstly, we introduce the integrated network platform of ocean observation. Next, the preprocessing model of data is presemed, and an imelligent cleaning model of data is proposed. Based on fuzzy clustering, the Kohonen clustering network is improved to fulfill the parallel calculation of fuzzy c-means clustering. The proposed dynamic algorithm can automatically f'md the new clustering center with the updated sample data. The rapid and dynamic performance of the model makes it suitable for real time calculation, and the efficiency and accuracy of the model is proved by test results through observation data analysis. 展开更多
关键词 integrated ocean observing network intelligentdata pre-processing data cleaning fuzzy soft clustering
在线阅读 下载PDF
Signal pre-processing method and application design of edge nodes for distributed electromechanical system
9
作者 LIU Peijin ZHANG Xiangxiang +2 位作者 SUN Yu SHI Mengtao HE Ning 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2021年第3期272-280,共9页
A signal pre-processing method based on optimal variational mode decomposition(OVMD)is proposed to improve the efficiency and accuracy of local data filtering and analysis of edge nodes in distributed electromechanica... A signal pre-processing method based on optimal variational mode decomposition(OVMD)is proposed to improve the efficiency and accuracy of local data filtering and analysis of edge nodes in distributed electromechanical systems.Firstly,the singular points of original signals are eliminated effectively by using the first-order difference method.Then the OVMD method is applied for signal modal decomposition.Furthermore,correlation analysis is conducted to determine the degree of correlation between each mode and the original signal,so as to accurately separate the real operating signal from noise signal.On the basis of theoretical analysis and simulation,an edge node pre-processing system for distributed electromechanical system is designed.Finally,by virtue of the signal-to-noise ratio(SNR)and root-mean-square error(RMSE)indicators,the signal pre-processing effect is evaluated.The experimental results show that the OVMD-based edge node pre-processing system can extract signals with different characteristics and improve the SNR of reconstructed signals.Due to its high fidelity and reliability,this system can also provide data quality assurance for subsequent system health monitoring and fault diagnosis. 展开更多
关键词 distributed electromechanical system electromechanical signal edge node optimal variational mode decomposition(OVMD) signal pre-processing system
在线阅读 下载PDF
The Pre-processing Parallel Algorithm of A Sparse Linear Equation Group
10
作者 Cao Ying 《International English Education Research》 2015年第1期96-98,共3页
The solution of linear equation group can be applied to the oil exploration, the structure vibration analysis, the computational fluid dynamics, and other fields. When we make the in-depth analysis of some large or ve... The solution of linear equation group can be applied to the oil exploration, the structure vibration analysis, the computational fluid dynamics, and other fields. When we make the in-depth analysis of some large or very large complicated structures, we must use the parallel algorithm with the aid of high-performance computers to solve complex problems. This paper introduces the implementation process having the parallel with sparse linear equations from the perspective of sparse linear equation group. 展开更多
关键词 Sparse Linear Equations pre-processing Parallel Algorithm
在线阅读 下载PDF
The Role of Combined OSR and SDF Method for Pre-Processing of Microarray Data that Accounts for Effective Denoising and Quantification
11
作者 Jayakishan Meher Mukesh Kumar Raval +1 位作者 Pramod Kumar Meher Gananath Dash 《Journal of Signal and Information Processing》 2011年第3期190-195,共6页
Microarray data is inherently noisy due to the noise contaminated from various sources during the preparation of microarray slide and thus it greatly affects the accuracy of the gene expression. How to eliminate the e... Microarray data is inherently noisy due to the noise contaminated from various sources during the preparation of microarray slide and thus it greatly affects the accuracy of the gene expression. How to eliminate the effect of the noise constitutes a challenging problem in microarray analysis. Efficient denoising is often a necessary and the first step to be taken before the image data is analyzed to compensate for data corruption and for effective utilization for these data. Hence preprocessing of microarray image is an essential to eliminate the background noise in order to enhance the image quality and effective quantification. Existing denoising techniques based on transformed domain have been utilized for microarray noise reduction with their own limitations. The objective of this paper is to introduce novel preprocessing techniques such as optimized spatial resolution (OSR) and spatial domain filtering (SDF) for reduction of noise from microarray data and reduction of error during quantification process for estimating the microarray spots accurately to determine expression level of genes. Besides combined optimized spatial resolution and spatial filtering is proposed and found improved denoising of microarray data with effective quantification of spots. The proposed method has been validated in microarray images of gene expression profiles of Myeloid Leukemia using Stanford Microarray Database with various quality measures such as signal to noise ratio, peak signal to noise ratio, image fidelity, structural content, absolute average difference and correlation quality. It was observed by quantitative analysis that the proposed technique is more efficient for denoising the microarray image which enables to make it suitable for effective quantification. 展开更多
关键词 DENOISING MICROARRAY pre-processing Quantification SPATIAL Domain Filtering Optimized SPATIAL Resolution Quality Measures
暂未订购
Pre-process algorithm for satellite laser ranging data based on curve recognition from points cloud
12
作者 Liu Yanyu Zhao Dongming Wu Shan 《Geodesy and Geodynamics》 2012年第2期53-59,共7页
The satellite laser ranging (SLR) data quality from the COMPASS was analyzed, and the difference between curve recognition in computer vision and pre-process of SLR data finally proposed a new algorithm for SLR was ... The satellite laser ranging (SLR) data quality from the COMPASS was analyzed, and the difference between curve recognition in computer vision and pre-process of SLR data finally proposed a new algorithm for SLR was discussed data based on curve recognition from points cloud is proposed. The results obtained by the new algorithm are 85 % (or even higher) consistent with that of the screen displaying method, furthermore, the new method can process SLR data automatically, which makes it possible to be used in the development of the COMPASS navigation system. 展开更多
关键词 satellite laser ranging (SLR) curve recognition points cloud pre-process algorithm COM- PASS screen displaying
原文传递
工业博物馆藏品阐释的范式转型与路径创新——以加拿大巴塔鞋博物馆为例
13
作者 翁春萌 黄芷清 《创意设计源》 2025年第6期41-46,57,共7页
【目的】旨在探讨工业博物馆藏品阐释的范式转型与路径创新问题,以应对国内工业博物馆在藏品阐释中存在的互动性弱、行业特性不足、观众参与度低等现实困境。【方法】采用文献研究、实地观察与半结构化访谈等方法,系统剖析加拿大巴塔鞋... 【目的】旨在探讨工业博物馆藏品阐释的范式转型与路径创新问题,以应对国内工业博物馆在藏品阐释中存在的互动性弱、行业特性不足、观众参与度低等现实困境。【方法】采用文献研究、实地观察与半结构化访谈等方法,系统剖析加拿大巴塔鞋博物馆在藏品阐释方面的创新实践,重点围绕“观众参与”“情境沉浸”“寓教于乐”与“社区合作”四个维度展开分析。【结果】研究结果表明,巴塔鞋博物馆通过明确阐释核心、拓展阐释视角、创新阐释方式与空间,体现了“以观众为中心”阐释范式与创新路径。【结论】提出中国的工业博物馆应在服务理念、藏品开发、阐释方式及空间拓展等方面进行系统性创新,推动工业文化从静态展示转向动态参与、从“物本位”到“人本位”的阐释范式转型,从而增强博物馆的教育功能与文化传播力,实现工业文物的当代价值再生。 展开更多
关键词 工业博物馆 巴塔鞋博物馆 藏品阐释 范式
在线阅读 下载PDF
ISO 55013数据资产管理国际标准解读
14
作者 高昂 杨晓峰 +1 位作者 刘昱玮 石宇晨 《标准科学》 2025年第9期146-150,共5页
【目的】分析了ISO 55013:2024 Asset management—Guidance on the management of data assets国际标准的主要内容,该标准阐释了将数据视为资产予以有效管理的重要性,为数据资产管理体系建设提供系统性指导。【方法】通过阐述ISO 5501... 【目的】分析了ISO 55013:2024 Asset management—Guidance on the management of data assets国际标准的主要内容,该标准阐释了将数据视为资产予以有效管理的重要性,为数据资产管理体系建设提供系统性指导。【方法】通过阐述ISO 55013在资产数据管理、资产数据价值、识别数据资产、管理数据资产和数据治理等方面的核心要素,结合资产管理体系实践,提出数据资产密集型组织在管理实践方面的有效路径。【结果】ISO 55013为组织提供了数据资产管理指南,推动组织应用ISO 55001给出的资产管理体系管理数据。【结论】ISO 55013将为数据资产管理体系建设的规范化提供依据,推动组织在数字经济时代在数据资产管理中充分获取价值。 展开更多
关键词 数据资产管理 数据资产价值 资产管理体系 ISO 55013
在线阅读 下载PDF
Recognition and quality mapping of traditional herbal drugs:way forward towards artificial intelligence
15
作者 Sanyam Sharma Subh Naman Ashish Baldi 《Traditional Medicine Research》 2025年第1期12-26,共15页
The use of traditional herbal drugs derived from natural sources is on the rise due to their minimal side effects and numerous health benefits.However,a major limitation is the lack of standardized knowledge for ident... The use of traditional herbal drugs derived from natural sources is on the rise due to their minimal side effects and numerous health benefits.However,a major limitation is the lack of standardized knowledge for identifying and mapping the quality of these herbal medicines.This article aims to provide practical insights into the application of artificial intelligence for quality-based commercialization of raw herbal drugs.It focuses on feature extraction methods,image processing techniques,and the preparation of herbal images for compatibility with machine learning models.The article discusses commonly used image processing tools such as normalization,slicing,cropping,and augmentation to prepare images for artificial intelligence-based models.It also provides an overview of global herbal image databases and the models employed for herbal plant/drug identification.Readers will gain a comprehensive understanding of the potential application of various machine learning models,including artificial neural networks and convolutional neural networks.The article delves into suitable validation parameters like true positive rates,accuracy,precision,and more for the development of artificial intelligence-based identification and authentication techniques for herbal drugs.This article offers valuable insights and a conclusive platform for the further exploration of artificial intelligence in the field of herbal drugs,paving the way for smarter identification and authentication methods. 展开更多
关键词 artificial intelligence AYURVEDA machine learning models herbal drugs image pre-processing medicinal plants
在线阅读 下载PDF
End-to-end algorithm research in PACT—from signal processing to reconstruction solution to image processing:A review
16
作者 JinJin Cheng Shuilin Wang +12 位作者 Shirui Dong Yang Wang Xuyu Fu Jichao Zhang Wenkai Li Siyu Chen Silue Zeng Yaguang Ren Xiaohui Ma Jinhai Liu Mingjian Sun Rongkang Gao Chengbo Liu 《Journal of Innovative Optical Health Sciences》 2025年第4期19-61,共43页
Photoacoustic computed tomography(PACT)is an innovative biomedical imaging technique that has gained significant application in the field of biomedicine due to its ability to visualize optical contrast with high resol... Photoacoustic computed tomography(PACT)is an innovative biomedical imaging technique that has gained significant application in the field of biomedicine due to its ability to visualize optical contrast with high resolution and deep tissue penetration.However,the inherent challenges associated with photoacoustic signal excitation,propagation and detection often result in suboptimal image quality.To overcome these limitations,researchers have developed various advanced algorithms that span the entire image reconstruction pipeline.This review paper aims to present a detailed analysis of the latest advancements in PACT algorithms and synthesize these algorithms into a coherent framework.We provide tripartite analysis—from signal processing to reconstruction solution to image processing,covering a spectrum of techniques.The principles and methodologies,as well as their applicability and limitations,are thoroughly discussed.The primary objective of this study is to provide a thorough review of advanced algorithms applicable to PACT,offering both theoretical foundations and practical guidance for enhancing the imaging effect of PACT. 展开更多
关键词 Photoacoustic computed tomography pre-processing main transformation POSTPROCESSING deep learning
原文传递
人工智能技术在发电设备智慧运维体系优化中的应用
17
作者 林阳 何沛衡 《科技创新与应用》 2025年第35期45-48,共4页
发电设备运维体系对电力系统安全稳定运行具有重要意义,然而传统运维模式存在故障预测能力不足、响应时效低与数据利用率有限等问题,难以满足现代电力系统智慧化发展的需求。为此,该文探讨人工智能技术在发电设备智慧运维体系优化中的应... 发电设备运维体系对电力系统安全稳定运行具有重要意义,然而传统运维模式存在故障预测能力不足、响应时效低与数据利用率有限等问题,难以满足现代电力系统智慧化发展的需求。为此,该文探讨人工智能技术在发电设备智慧运维体系优化中的应用,构建基于数据驱动的智能运维流程,提升设备状态感知、故障预测与运维决策的效率与准确性。通过实验验证,所提出方法在隐患识别、运维响应速度与系统稳定性等方面均优于传统运维模式,体现出人工智能技术在发电设备运维体系优化中的应用价值。 展开更多
关键词 人工智能技术 发电设备 智慧运维 体系优化 大数据
在线阅读 下载PDF
红薯对农田杂草群落及其多样性的影响 被引量:8
18
作者 申时才 徐高峰 +2 位作者 张付斗 金桂梅 张玉华 《生物多样性》 CAS CSCD 北大核心 2014年第4期485-491,共7页
为了解红薯(Ipomoea batas)对农田杂草群落和生物多样性的影响,作者研究了云南省东南部红河州建水县5种不同覆盖度红薯田的杂草种类、密度、重要值及多样性。结果表明,5种红薯田共统计到25种杂草,隶属18科。其中4种入侵植物藿香蓟(Agera... 为了解红薯(Ipomoea batas)对农田杂草群落和生物多样性的影响,作者研究了云南省东南部红河州建水县5种不同覆盖度红薯田的杂草种类、密度、重要值及多样性。结果表明,5种红薯田共统计到25种杂草,隶属18科。其中4种入侵植物藿香蓟(Ageratum conyzoides)、鬼针草(Bidens pilosa)、牛膝菊(Galinsoga parviflora)、牛筋草(Eleusine indica)和2种本地植物马齿苋(Portulaca oleracea)、马唐(Digitaria sanguinalis)的密度较高,为红薯田杂草群落的优势物种。随红薯覆盖度增加,杂草优势物种的密度和重要值显著降低(P<0.05),然而2种本地物种打碗花(Calystegia hederacea)和早熟禾(Poa annua)密度却显著增加,2种本地物种铁苋菜(Acalypha australis)和稗(Echinochloa crusgalli)重要值与红薯覆盖度成正相关(P<0.05)。红薯覆盖度为1–25%和26–50%时,杂草群落的物种丰富度(23.5、24.5)、Simpson指数(0.89、0.85)、Shannon-Wiener指数(2.36、2.35)和Pielou均匀度指数(0.75、0.73)较高,说明中低水平的红薯覆盖度有利于提高群落的物种多样性。可以推断,红薯种植改变了农田杂草的群落结构,有利于限制优势杂草和入侵杂草的发生危害,中低水平的红薯覆盖度可作为一种有效的旱田替代化学除草剂的生态控草措施。 展开更多
关键词 IPOMOEA batas 杂草密度 重要值 农田多样性 生态控草 入侵杂草
原文传递
青钱柳组织培养的初步研究 被引量:34
19
作者 胡冬南 蒋艳 +2 位作者 吴少福 杨光耀 上官新晨 《江西农业大学学报》 CAS CSCD 北大核心 2005年第1期39-41,共3页
以MS为基本培养基,加入不同种类和浓度的激素,对青钱柳种子萌发芽、3年生植株和 15年生植株的一年生枝条进行组织培养试验。结果表明:BA对青钱柳愈伤组织的形成起至关重要的作用,所设 6种培养基,以MS+BA(1. 0mg/L)的愈伤组织形成率最高,... 以MS为基本培养基,加入不同种类和浓度的激素,对青钱柳种子萌发芽、3年生植株和 15年生植株的一年生枝条进行组织培养试验。结果表明:BA对青钱柳愈伤组织的形成起至关重要的作用,所设 6种培养基,以MS+BA(1. 0mg/L)的愈伤组织形成率最高,为 76. 3%。种子萌发芽的茎段没有形成愈伤组织, 3年生植株和15年生植株上的一年生枝条间愈伤组织形成率无明显差异。诱导过程中无褐化现象。 展开更多
关键词 愈伤组织 组织培养 枝条 发芽 植株 一年生 种子萌发 青钱柳 MS 初步研究
在线阅读 下载PDF
几种农药在烟草上的消解动态与复合效应 被引量:15
20
作者 花日茂 汤桂兰 +2 位作者 李学德 汤锋 岳永德 《中国环境科学》 EI CAS CSSCI CSCD 北大核心 2003年第4期440-443,共4页
采用室外盆栽试验方法,研究了吡虫啉、高效氯氰菊酯在烟草上的消解动态,同时研究了多菌灵、高效氯氰菊酯对吡虫啉及吡虫啉对高效氯氰菊酯降解速度的影响.结果表明,吡虫啉在烟叶中的消解半衰期为3.98d,喷药后15d,降解了94.60%;高效氯氰... 采用室外盆栽试验方法,研究了吡虫啉、高效氯氰菊酯在烟草上的消解动态,同时研究了多菌灵、高效氯氰菊酯对吡虫啉及吡虫啉对高效氯氰菊酯降解速度的影响.结果表明,吡虫啉在烟叶中的消解半衰期为3.98d,喷药后15d,降解了94.60%;高效氯氰菊酯对吡虫啉降解表现出延缓作用,而多菌灵对吡虫啉降解表现出加速作用.高效氯氰菊酯在烟草中消解半衰期为4.82d,喷药后15d,消解了88.32%;吡虫啉对高效氯氰菊酯的消解表现出延缓作用. 展开更多
关键词 烟草 吡虫啉 高效氯氟菊酯 消解动态 复合效应
在线阅读 下载PDF
上一页 1 2 8 下一页 到第
使用帮助 返回顶部