The changing patterns of watersheds in a landscape, driven by human activities, play an important role in non-point source pollution processes. This paper aims to improve the location-weighted landscape contrast index...The changing patterns of watersheds in a landscape, driven by human activities, play an important role in non-point source pollution processes. This paper aims to improve the location-weighted landscape contrast index using remote sensing and GIS technology to account for the effects of scale and ecological processes. The hydrological response unit(HRU) with a single land use and soil type was used as the smallest unit. The relationship between the landscape index and typical ecological processes was established by describing the influence of the landscape pattern on non-point source pollution. To verify the research method, this paper used the Yanshi River basin as a study area. The results showed that the relative intensity of non-point source pollution in different regions of the watershed and the location-weighted landscape contrast index based on the minimum HRU can qualitatively reflect the risk of regional nutrient loss.展开更多
In order to enhance the robustness and contrast in the minimum variance(MV) beamformer, adaptive diagonal loading method was proposed. The conventional diagonal loading technique has already been used in the MV beamfo...In order to enhance the robustness and contrast in the minimum variance(MV) beamformer, adaptive diagonal loading method was proposed. The conventional diagonal loading technique has already been used in the MV beamformer, but has the drawback that its level is specified by predefined parameter and without consideration of input-data. To alleviate this problem, the level of diagonal loading was computed appropriately and automatically from the given data by shrinkage method in the proposed adaptive diagonal loaded beamformer. The performance of the proposed beamformer was tested on the simulated point target and cyst phantom was obtained using Field II. In the point target simulation, it is shown that the proposed method has higher lateral resolution than the conventional delay-and-sum beamformer and could be more robust in estimating the amplitude peak than the MV beamformer when acoustic velocity error exists. In the cyst phantom simulation, the proposed beamformer has shown that it achieves an improvement in contrast ratio and without distorting the edges of cyst.展开更多
功能负载(FL)原则预测高FL音位对比,例如/i:/和/?/,比低FL音位对比,例如/u:/和/?/,对发音的相互可懂度的影响更大。为了评估FL原则是否能准确预测英语作为通用语言(ELF)条件下的清晰度,本研究部分复制了由Munro和Derwing(2006)所做的第...功能负载(FL)原则预测高FL音位对比,例如/i:/和/?/,比低FL音位对比,例如/u:/和/?/,对发音的相互可懂度的影响更大。为了评估FL原则是否能准确预测英语作为通用语言(ELF)条件下的清晰度,本研究部分复制了由Munro和Derwing(2006)所做的第一项实证支持FL原则的研究。中国人录制了24个包含目标词的高低FL音素替换的英语句子,171名日本大学生听了这些句子并将目标词转写成书面英语。本研究的假设是,具有高FL音素替换的目标词比具有低FL音素替换的目标词更难理解。结果表明,具有高FL音素替换的目标词的清晰度确实低于具有低FL音素替换的目标词,而且多个高FL音素替换的叠加更加降低清晰度。本研究结果与Munro and Derwing (2006)的发现一致,即高FL音素替换比低FL音素替换更能降低清晰度,因此这项研究宣称在ELF条件下成功复制了该研究的一个方面。展开更多
基金Supported by the National Key R&D Programs of China(Nos.2017YFB0504201,2015BAJ02B)the National Natural Science Foundation of China(Nos.61473286,61375002)the Natural Science Foundation of Hainan Province(No.20164178)
文摘The changing patterns of watersheds in a landscape, driven by human activities, play an important role in non-point source pollution processes. This paper aims to improve the location-weighted landscape contrast index using remote sensing and GIS technology to account for the effects of scale and ecological processes. The hydrological response unit(HRU) with a single land use and soil type was used as the smallest unit. The relationship between the landscape index and typical ecological processes was established by describing the influence of the landscape pattern on non-point source pollution. To verify the research method, this paper used the Yanshi River basin as a study area. The results showed that the relative intensity of non-point source pollution in different regions of the watershed and the location-weighted landscape contrast index based on the minimum HRU can qualitatively reflect the risk of regional nutrient loss.
基金Project(2013GZX0147-3)supported by the Science and Technology Pillar Program of Sichuan Province,China
文摘In order to enhance the robustness and contrast in the minimum variance(MV) beamformer, adaptive diagonal loading method was proposed. The conventional diagonal loading technique has already been used in the MV beamformer, but has the drawback that its level is specified by predefined parameter and without consideration of input-data. To alleviate this problem, the level of diagonal loading was computed appropriately and automatically from the given data by shrinkage method in the proposed adaptive diagonal loaded beamformer. The performance of the proposed beamformer was tested on the simulated point target and cyst phantom was obtained using Field II. In the point target simulation, it is shown that the proposed method has higher lateral resolution than the conventional delay-and-sum beamformer and could be more robust in estimating the amplitude peak than the MV beamformer when acoustic velocity error exists. In the cyst phantom simulation, the proposed beamformer has shown that it achieves an improvement in contrast ratio and without distorting the edges of cyst.
文摘功能负载(FL)原则预测高FL音位对比,例如/i:/和/?/,比低FL音位对比,例如/u:/和/?/,对发音的相互可懂度的影响更大。为了评估FL原则是否能准确预测英语作为通用语言(ELF)条件下的清晰度,本研究部分复制了由Munro和Derwing(2006)所做的第一项实证支持FL原则的研究。中国人录制了24个包含目标词的高低FL音素替换的英语句子,171名日本大学生听了这些句子并将目标词转写成书面英语。本研究的假设是,具有高FL音素替换的目标词比具有低FL音素替换的目标词更难理解。结果表明,具有高FL音素替换的目标词的清晰度确实低于具有低FL音素替换的目标词,而且多个高FL音素替换的叠加更加降低清晰度。本研究结果与Munro and Derwing (2006)的发现一致,即高FL音素替换比低FL音素替换更能降低清晰度,因此这项研究宣称在ELF条件下成功复制了该研究的一个方面。
