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青藏高原西北部河流提取及季节变化差异分析 被引量:1
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作者 王国峰 王纪征 +2 位作者 肖逸 赵慧慧 乔宝晋 《遥感技术与应用》 CSCD 北大核心 2024年第2期447-458,共12页
河流是地球水循环的一个重要环节,准确获取山区河流信息对于区域内的水资源评价和生态修复方面都有重要作用。基于2019~2021年Sentinel-2影像,利用多光谱指数法自动区分河流、湖泊及冰川,结合随机森林方法,并以MERIT DEM为地形条件,自... 河流是地球水循环的一个重要环节,准确获取山区河流信息对于区域内的水资源评价和生态修复方面都有重要作用。基于2019~2021年Sentinel-2影像,利用多光谱指数法自动区分河流、湖泊及冰川,结合随机森林方法,并以MERIT DEM为地形条件,自动提取青藏高原西北部多时态、高分辨率的河网,结合第二次冰川编目划分了不同补给类型的集水区,进一步计算了河流面积和宽度的季节变化。结果表明,在这3 a内丰水期和枯水期的河流平均面积分别达到了7161.64±22.73 km2和4066.02±35.19 km2,Kappa系数和总体精度均达到了0.8以上,冰川补给类型和非冰川补给类型的河流平均面积季节变化率分别为0.34和0.23,冰川补给类型平均宽度季节变化大部分比非冰川补给类型变化大。冰川补给类型的河流宽度和面积变化比非冰川补给类型的河流变化整体更加明显,该研究表明冰川融水对河流径流的变化有重要的影响。 展开更多
关键词 河流提取 季节变化差异 冰川融水
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Improved multi-scale inverse bottleneck residual network based on triplet parallel attention for apple leaf disease identification
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作者 Lei Tang jizheng yi Xiaoyao Li 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2024年第3期901-922,共22页
Accurate diagnosis of apple leaf diseases is crucial for improving the quality of apple production and promoting the development of the apple industry. However, apple leaf diseases do not differ significantly from ima... Accurate diagnosis of apple leaf diseases is crucial for improving the quality of apple production and promoting the development of the apple industry. However, apple leaf diseases do not differ significantly from image texture and structural information. The difficulties in disease feature extraction in complex backgrounds slow the related research progress. To address the problems, this paper proposes an improved multi-scale inverse bottleneck residual network model based on a triplet parallel attention mechanism, which is built upon ResNet-50, while improving and combining the inception module and ResNext inverse bottleneck blocks, to recognize seven types of apple leaf(including six diseases of alternaria leaf spot, brown spot, grey spot, mosaic, rust, scab, and one healthy). First, the 3×3 convolutions in some of the residual modules are replaced by multi-scale residual convolutions, the convolution kernels of different sizes contained in each branch of the multi-scale convolution are applied to extract feature maps of different sizes, and the outputs of these branches are multi-scale fused by summing to enrich the output features of the images. Second, the global layer-wise dynamic coordinated inverse bottleneck structure is used to reduce the network feature loss. The inverse bottleneck structure makes the image information less lossy when transforming from different dimensional feature spaces. The fusion of multi-scale and layer-wise dynamic coordinated inverse bottlenecks makes the model effectively balances computational efficiency and feature representation capability, and more robust with a combination of horizontal and vertical features in the fine identification of apple leaf diseases. Finally, after each improved module, a triplet parallel attention module is integrated with cross-dimensional interactions among channels through rotations and residual transformations, which improves the parallel search efficiency of important features and the recognition rate of the network with relatively small co 展开更多
关键词 multi-scale module inverse bottleneck structure triplet parallel attention apple leaf disease
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手术切除联合博来霉素注射治疗耳廓瘢痕疙瘩的临床效果及对VSS评分、复发率的影响 被引量:3
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作者 陈铮 严继征 +1 位作者 曲毅 钱洪军 《临床医学研究与实践》 2022年第33期135-137,共3页
目的探讨手术切除联合博来霉素注射治疗耳廓瘢痕疙瘩的临床效果及对温哥华瘢痕量表(VSS)评分、复发率的影响。方法选取我院收治的56例耳郭瘢痕疙瘩患者作为研究对象,依据入院编号的奇偶性将其分为对照组(28例,手术切除+复方倍他米松)和... 目的探讨手术切除联合博来霉素注射治疗耳廓瘢痕疙瘩的临床效果及对温哥华瘢痕量表(VSS)评分、复发率的影响。方法选取我院收治的56例耳郭瘢痕疙瘩患者作为研究对象,依据入院编号的奇偶性将其分为对照组(28例,手术切除+复方倍他米松)和观察组(28例,手术切除+博来霉素)。比较两组的临床治疗效果。结果观察组的临床治疗总有效率显著高于对照组(P<0.05)。术后12周,观察组的血管内皮生长因子(VEGF)、表皮细胞生长因子(EGF)、转化生长因子-β_(1)(TGF-β_(1))水平显著低于对照组(P<0.05)。术后2、4、12、24周,观察组的VSS、十二项目瘙痒量表(12-PSS)评分均显著低于对照组(P<0.05)。观察组的不良反应总发生率及复发率均显著低于对照组(P<0.05)。结论手术切除联合博来霉素注射治疗耳廓瘢痕疙瘩的临床效果显著,可改善瘢痕情况,降低复发率。 展开更多
关键词 耳廓瘢痕疙瘩 博来霉素注射液 糖皮质激素
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Quantitative Estimation on Methane Storage Capacity of Organic-Rich Shales from the Lower Silurian Longmaxi Formation in the Eastern Sichuan Basin, China
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作者 Xiaowen Guo Tao Luo +6 位作者 Tian Dong Rui Yang Yuanjia Han jizheng yi Sheng He Zhiguo Shu Hanyong Bao 《Journal of Earth Science》 SCIE CAS CSCD 2023年第6期1851-1860,共10页
The assessment of gas storage capacity is crucial to furthering shale gas exploration and development in the eastern Sichuan Basin,China.Eleven organic-rich shale samples were selected to carry out the high pressure m... The assessment of gas storage capacity is crucial to furthering shale gas exploration and development in the eastern Sichuan Basin,China.Eleven organic-rich shale samples were selected to carry out the high pressure methane sorption,low-pressure N_(2)/CO_(2) gas adsorption,and bulk and skeletal density measurements to investigate the methane storage capacity(MSC).Based on the relative content of clay,carbonates,quartz+feldspar,we grouped the 11 samples into three lithofacies:silica-rich argillaceous shale(CM-1),argillaceous/siliceous mixed shale(M-2),and clay-rich siliceous shale(S-3).The total porosity of the shale samples varies from 3.4% to 5.6%,and gas saturation ranges from 47% to 89%.The measured total gas amount ranges from 1.84 mg/g to 4.22 mg/g with the ratio of free gas to total gas amount ranging from 52.7% to 70.8%.Free gas with high content in the eastern Sichuan Basin may be the key factor controlling amount of shale gas production.The TOC content critically controls the MSC of shales,because micropore,mesopore volumes and the specific surface areas associated with organic matter provide the storage sites for the free and adsorbed gas.The methane sorption capacities of samples from different lithofacies are also affected by clay minerals and moisture content.Clay minerals can provide additional surface areas for methane sorption,and water can cause a 7.1%-42.8% loss of methane sorption capacity.The total porosity,gas-bearing porosity,water saturation,free gas and adsorbed gas number of samples from different lithofacies show subtle differences if the shale samples had similar TOC contents.Our results suggest that,in the eastern Sichuan Basin,clay-rich shale lithofacies is also prospecting targets for shale gas production. 展开更多
关键词 METHANE shale gas Longmaxi Formation Sichuan Basin
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基于改进SLIC算法的电力设备故障区域分割方法 被引量:12
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作者 王季峥 尹丽菊 +3 位作者 咸日常 潘金凤 陈尧 于毅 《计算机应用与软件》 北大核心 2021年第1期222-226,237,共6页
在电力设备状态监测中,红外测温图像故障区域的分割是今后故障诊断智能化发展的关键环节。为了实现图像自动化处理,提高故障区域的分割精度,提出一种改进SLIC算法的故障区域分割方法。采用导向滤波器对红外测温图像进行预处理;在SLIC超... 在电力设备状态监测中,红外测温图像故障区域的分割是今后故障诊断智能化发展的关键环节。为了实现图像自动化处理,提高故障区域的分割精度,提出一种改进SLIC算法的故障区域分割方法。采用导向滤波器对红外测温图像进行预处理;在SLIC超像素迭代过程中增加亮度相似性限制条件,并将生成的超像素以种子点的色彩值匹配颜色;通过自动设置色调阈值,实现对电力设备故障区域的分割和标记。实验结果表明,改进的算法与原始SLIC算法相比,边缘召回率提高了4.10%,对故障区域的分割更具优势。 展开更多
关键词 图像分割 超像素 SLIC 导向滤波 故障诊断
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基于NSCT和改进Pal_King算法的电力设备红外图像增强方法 被引量:7
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作者 陈尧 尹丽菊 +3 位作者 咸日常 潘金凤 王季峥 于毅 《计算机应用与软件》 北大核心 2021年第11期236-241,287,共7页
针对电力设备红外图像存在对比度较低、噪声复杂、清晰度不优的问题,提出一种基于NSCT和改进PalKing算法的电力设备红外图像增强方法。采用直方图双向均衡化对红外测温图像进行预处理,对NSCT变换产生的低高频子带分别采用线性增强和改... 针对电力设备红外图像存在对比度较低、噪声复杂、清晰度不优的问题,提出一种基于NSCT和改进PalKing算法的电力设备红外图像增强方法。采用直方图双向均衡化对红外测温图像进行预处理,对NSCT变换产生的低高频子带分别采用线性增强和改进的自适应阈值函数进行系数修正,通过NSCT反变换重构图像,利用改进的PalKing算法进行图像增强处理。实验结果表明,该方法输出图像的平均梯度值、峰值信噪比值和熵值分别保持在5.9、25.4和6.8以上,提高了电力设备红外图像的对比度,有效抑制了噪声,使图像更加清晰。 展开更多
关键词 图像增强 NSCT变换 Pal_King 自适应阈值 电力设备
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4-硝基-1-萘基-β-D-半乳糖苷的合成研究 被引量:1
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作者 党济政 易莉 《中国当代医药》 CAS 2022年第11期16-19,共4页
目的设计合成4-硝基-1-萘基-β-D-半乳糖苷的方法。方法D-半乳糖与乙酸钠反应,酯化后得到β-D-半乳糖五乙酸酯。β-D-半乳糖五乙酸酯经过溴化氢的乙酸溶液溴代得到溴代糖、再用显色团4-硝基-1-萘酚取代端基溴、最终水解除去乙酰基,再重... 目的设计合成4-硝基-1-萘基-β-D-半乳糖苷的方法。方法D-半乳糖与乙酸钠反应,酯化后得到β-D-半乳糖五乙酸酯。β-D-半乳糖五乙酸酯经过溴化氢的乙酸溶液溴代得到溴代糖、再用显色团4-硝基-1-萘酚取代端基溴、最终水解除去乙酰基,再重结晶得到目标化合物。对该目标化合物进行核磁共振(^(1)H-NMR、^(13)C-NMR)和高分辨质谱(ESI-HRMS)表征确定结构。对溴代试剂选择、羟基乙酰化反应条件及重结晶条件进行优化筛选。结果表征结果显示,终产物即为化合物4-硝基-1-萘基-β-D-半乳糖苷。制备过程中溴代试剂应选择溴化氢的乙酸溶液,乙酰化反应条件应选择反应温度130℃,反应时间3 h,重结晶甲醇/水比例为3∶1。结论应用本法合成目标化合物4-硝基-1-萘基-β-D-半乳糖苷,建立的反应条件温和,操作简便可行。 展开更多
关键词 D-半乳糖 4-硝基-1-萘基-β-D-半乳糖苷 溴代 合成
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