期刊文献+
共找到4篇文章
< 1 >
每页显示 20 50 100
Effect of Cultivation on Soil Organic Matter and Aggregate Stability 被引量:32
1
作者 A.WILLIAMS XINGBao-Shan P.VENEMAN 《Pedosphere》 SCIE CAS CSCD 2005年第2期255-262,共8页
Agricultural sustainability relates directly to maintaining or enhancing soil quality. Soil quality studies in Canada during the 1980 s showed that loss of soil organic matter (SOM) and soil aggregate stability was st... Agricultural sustainability relates directly to maintaining or enhancing soil quality. Soil quality studies in Canada during the 1980 s showed that loss of soil organic matter (SOM) and soil aggregate stability was standard features of non-sustainable land management in agroecosystems. In this study total soil organic carbon (SOC), particulate organic matter (POM), POM-C as a percentage of total SOC, and aggregate stability were determined for three cultivated fields and three adjacent grassland fields to a… 展开更多
关键词 aggregate stability CULTIVATION NMR particulate organic matter soil organic matter
下载PDF
Synthetically Evaluation System for Multi-source Image Fusion and Experimental Analysis 被引量:2
2
作者 肖刚 敬忠良 +1 位作者 吴建民 刘从义 《Journal of Shanghai Jiaotong university(Science)》 EI 2006年第3期263-270,共8页
Study on the evaluation system for multi-source image fusion is an important and necessary part of image fusion. Qualitative evaluation indexes and quantitative evaluation indexes were studied. A series of new concept... Study on the evaluation system for multi-source image fusion is an important and necessary part of image fusion. Qualitative evaluation indexes and quantitative evaluation indexes were studied. A series of new concepts, such as independent single evaluation index, union single evaluation index, synthetic evaluation index were proposed. Based on these concepts, synthetic evaluation system for digital image fusion was formed. The experiments with the wavelet fusion method, which was applied to fuse the multi-spectral image and panchromatic remote sensing image, the IR image and visible image, the CT and MRI image, and the multi-focus images show that it is an objective, uniform and effective quantitative method for image fusion evaluation. 展开更多
关键词 image fusion independent single evaluation union single evaluation synthetic evaluation evaluation system
下载PDF
母语为英语和泰语的汉语高级学习者有定范畴习得研究——以单句内光杆NP标记“们”为例 被引量:3
3
作者 姜有顺 《语言教学与研究》 CSSCI 北大核心 2017年第4期36-47,共12页
为了探查汉语本族语者对"们"的标记规律的语感以及二语学习者对"们"的标记规律的习得情况,本文采用图片诱导的句子完型填空任务,考察了汉语高级水平的泰语母语者和英语母语者以及汉语本族语者为单句内部5个句法位... 为了探查汉语本族语者对"们"的标记规律的语感以及二语学习者对"们"的标记规律的习得情况,本文采用图片诱导的句子完型填空任务,考察了汉语高级水平的泰语母语者和英语母语者以及汉语本族语者为单句内部5个句法位置的光杆普通NP标记"们"的语感倾向。结果发现,本族语者有给谓语前位的NP加"们"的显著倾向。二语者对"们"的标记规律的习得受到汉语表达有定性的语序手段(即有定效应)与母语的有定标记的强制性这两个因素的共同影响。谓语前位的NP标记"们"的规律首先被二语者习得。以"们"的标记的习得为个案,本文进而探讨了汉语作为二语的有定范畴习得的一般规律。 展开更多
关键词 有定范畴 有定效应 句法位置
原文传递
Finite sample breakdown point of Tukey's halfspace median 被引量:3
4
作者 LIU XiaoHui ZUO YiJuna WANG QiHua 《Science China Mathematics》 SCIE CSCD 2017年第5期861-874,共14页
Tukey's halfspace median(HM), servicing as the multivariate counterpart of the univariate median,has been introduced and extensively studied in the literature. It is supposed and expected to preserve robustness pr... Tukey's halfspace median(HM), servicing as the multivariate counterpart of the univariate median,has been introduced and extensively studied in the literature. It is supposed and expected to preserve robustness property(the most outstanding property) of the univariate median. One of prevalent quantitative assessments of robustness is finite sample breakdown point(FSBP). Indeed, the FSBP of many multivariate medians have been identified, except for the most prevailing one—the Tukey's halfspace median. This paper presents a precise result on FSBP for Tukey's halfspace median. The result here depicts the complete prospect of the global robustness of HM in the finite sample practical scenario, revealing the dimension effect on the breakdown point robustness and complimenting the existing asymptotic breakdown point result. 展开更多
关键词 Tukey depth Tukey median breakdown point in general position
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部