中国科学院机构知识库网格系统: 检索

Assessing Rangeland Sensitivity to Degradation in North Tibet 期刊论文 OAI收割
RANGELAND ECOLOGY & MANAGEMENT, 2022, 卷号: 84, 期号: 1, 页码: 86-97
作者: Duan, Cheng; Shi, Peili; Zong, Ning; Zhang, Xianzhou; Yu, Chengqun

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收藏 | 浏览/下载：36/0 | 提交时间：2022/11/09

Alpine rangelands Environmentally sensitive area index Geographic information system Random forest Tibet

Assessing Rangeland Sensitivity to Degradation in North Tibet 期刊论文 OAI收割
RANGELAND ECOLOGY & MANAGEMENT, 2022, 卷号: 84, 期号: 1, 页码: 86-97
作者: Duan, Cheng; Shi, Peili; Zong, Ning; Zhang, Xianzhou; Yu, Chengqun

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收藏 | 浏览/下载：30/0 | 提交时间：2022/11/09

Alpine rangelands Environmentally sensitive area index Geographic information system Random forest Tibet

食用蔬菜能吸收和积累微塑料 期刊论文 OAI收割
科学通报, 2019, 卷号: 64, 期号: 9, 页码: 928-934
作者: 李连祯; 周倩; 尹娜; 涂晨; 骆永明

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收藏 | 浏览/下载：150/0 | 提交时间：2020/06/17

微塑料生菜聚苯乙烯微球吸收积累健康风险 microplastics lettuce polystyrene microbeads uptake accumulation human health risk Microplastic (MP, 100 nm-5 mm) may present an attributable risk to ecosystem and human health, and its pollution has become a global environmental concern. Despite a wealth of information on the accumulation of MPs in aquatic species, there is no information on the uptake and accumulation of MPs by higher plants. Terrestrial edible plants are directly exposed to MPs when agricultural soil was applied with organic manure, sewage sludge as fertilizer or plastic mulching. In this paper, the uptake of two sizes of polystyrene (PS) microbeads (0.2 and 1.0 mum) and then their distribution and migration in an edible plant lettuce were firstly investigated based on laboratory experiments. We used fluorescent markers to track PS microbeads in plant tissues and found fluorescence to be a sensitive and reliable detection method. Sections from untreated control lettuce showed no autofluorescence. When roots were treated with fluorescently labeled PS microbeads, the microbeads could be identified by its fluorescence. Our main study investigated the uptake of 0.2 mum beads, as few luminescence signals were observed in lettuce roots for 1.0 mum beads in our experiment. We observed that 0.2 mum fluorescent microbeads were extracellularly trapped in the root cap mucilage (which is a highly hydrated polysaccharide) and a dark green tip (which was typical of lettuce roots exposed to label PS beads) was usually visible to the naked eye. Confocal images revealed that the PS luminescence signals were mainly located in the vascular system and on the cell walls of the cortex tissue of the roots, indicated that the beads passed through the intercellular space via the apoplastic transport system. Once inside the central cylinder, the 0.2 mum PS beads were transferred from the roots to the stems and leaves via the vascular system following the transpiration stream. We also observed that the PS beads adhered to one another and self-assembled systematically into grape-like and (chain) string-like clusters in the intercellular space of the root and stem vascular tissue of lettuce plant. In contrast to the root and stem, PS beads were dispersed in the leaf tissue. Here, for the first time we provide evidence of the adherence, uptake, accumulation, and translocation of submicrometer MPs within an edible plant. Our findings highlight the previously underappreciated human exposure pathway to MPs through the consumption of contaminated crops and emphasize the need for new management strategies to control the release of MPs waste products into the terrestrial environment. Ultimately, the potential impacts of low range sized MPs on food safety of crop plants and human health need to be urgently considered.

Location-Based Parallel Tag Completion for Geo-Tagged Social Image Retrieval 期刊论文 OAI收割
ACM TRANSACTIONS ON INTELLIGENT SYSTEMS AND TECHNOLOGY, 2017, 卷号: 8, 期号: 3, 页码: 21
作者: Zhang, Jiaming; Wang, Shuhui; Huang, Qingming

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收藏 | 浏览/下载：18/0 | 提交时间：2019/12/12

Tag matrix completion geo-location information social image retrieval asymmetric locality sensitive hashing

A New Strategy of Cost-Free Learning in the Class Imbalance Problem 期刊论文 OAI收割
IEEE TRANSACTIONS ON KNOWLEDGE AND DATA ENGINEERING, 2014, 卷号: 26, 期号: 12, 页码: 2872-2885
作者: Zhang, Xiaowan; Hu, Bao-Gang

收藏 | 浏览/下载：38/0 | 提交时间：2015/08/12

Classification class imbalance cost-free learning cost-sensitive learning abstaining mutual information ROC

基于互信息的代价缺失学习在不平衡数据中的研究 学位论文 OAI收割
工学博士, 中国科学院自动化研究所: 中国科学院大学, 2014
作者: 张晓晚

收藏 | 浏览/下载：47/0 | 提交时间：2015/09/02

不平衡数据代价缺失学习代价敏感学习互信息拒识图形化评估方法 Class Imbalance Cost-Free Learning Cost-Sensitive Learning Mutual Information Abstaining Graphical Evaluation Method

What Are the Differences Between Bayesian Classifiers and Mutual-Information Classifiers? 期刊论文 OAI收割
IEEE TRANSACTIONS ON NEURAL NETWORKS AND LEARNING SYSTEMS, 2014, 卷号: 25, 期号: 2, 页码: 249-264
作者: Hu, Bao-Gang

收藏 | 浏览/下载：32/0 | 提交时间：2015/08/12

Abstaining classifier Bayes cost-sensitive learning entropy error types mutual information reject types

Development situation and trend of domestic and international aerial mapping camera (EI CONFERENCE) 会议论文 OAI收割
2011 International Conference on Mechatronic Science, Electric Engineering and Computer, MEC 2011, August 19, 2011 - August 22, 2011, Jilin, China
Ming L. W.; Xue L.; Hui C. X.; Jun L. Q.

收藏 | 浏览/下载：32/0 | 提交时间：2013/03/25

In the modern military affairs especially in the complex field the acquirement of real-time battlefield information and intelligence is getting more and more important most of this work is completed by aerial reconnaissance or aerial mapping equipment. Aerial mapping camera with time-sensitive and flexible features is playing an increasingly important role in modern warfare. With the development of technology aerial mapping camera has also gone through several generations gradually from film-based type to transmission type. The theory and composition of domestic and international typical aerial mapping camera is introduced from the development situation and trend in this paper. Finally with the domestic research status the development trend of aerial mapping camera is proposed. 2011 IEEE.

Local variance based color image quality assessment method (EI CONFERENCE) 会议论文 OAI收割
2011 2nd International Conference on Advanced Measurement and Test, AMT 2011, June 24, 2011 - June 26, 2011, Nanchang, China
作者: Wang Y.; Wang Y.; Wang Y.; Wang Y.; Wang Y.

收藏 | 浏览/下载：31/0 | 提交时间：2013/03/25

In this paper local variance is used to describe the structural information of a color image in order to assess its quality. The representation method is different from conventional models in that some information that is sensitive to human eyes is enhanced by using local variance distribution. It encodes the local variance distribution of different channels of a color image into the three imaginary parts of a quaternion. The distance between the singular value feature vectors of the source image block and the distorted image block which are described by quaternion matrices is calculated. The experimental results show that the assessment results of the proposed assessment method are more consistent with the Human Visual System than those of the conventional assessment methods.

Color image quality assessment based on quaternion representation for the local variance distribution of RGB Channels (EI CONFERENCE) 会议论文 OAI收割
2009 2nd International Congress on Image and Signal Processing, CISP'09, October 17, 2009 - October 19, 2009, Tianjin, China
Yuqing W.; Ming Z.

收藏 | 浏览/下载：26/0 | 提交时间：2013/03/25

In this paper Quaternions are used to describe the structural information of a color image in order to assess its quality. The representation method is different from conventional models in that some information that is sensitive to human eyes is reinforced by using local variance. It encodes the local variance distribution of the RGB channels of a color image into the three imaginary parts of a quaternion. The luminance layer of the color image is taken as the real part of the quaternion. The distance between the singular value feature vectors of the source image block and the distorted image block which are described by quaternion matrices is calculated. The final assessment result is calculated by using the mid point of the distances. The experimental results show that the assessment results of the proposed assessment method are more consistent with the Human Visual System than those of the conventional assessment methods. 2009 IEEE.