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Unstable evolution of railway slope under the rainfall-vibration joint action

Journal of Mountain Science 2024年第4期21卷 1419-1431页

作者： DONG Haoyu WANG Jiading ZHANG dengfei li lin XU Yuanjun State Key Laboratory of Continental Dynamics Department of GeologyNorthwest UniversityXi’an 710069China

Understanding the unstable evolution of railway slopes is the premise for preventing slope failure and ensuring the safe operation of ***,as two major factors affecting the stability of railway slopes,few scholars have explored the unstable evolution of railway slopes under the joint action of *** on the model test of sandy soil slope,the unstable evolution process of slope under locomotive vibration,rainfall,and rainfall-vibration joint action conditions was simulated in this *** comparing and analyzing the variation trends of soil pressure and water content of slope under these conditions,the change laws of pore pressure under the influence of vibration and rainfall were *** main control factors affecting the stability of slope structure under the joint action conditions were further *** with the slope failure phenomena under these three conditions,the causes of slope instability resulting from each leading factor were ***,according to the above conclusions,the unstable evolution of the slope under the rainfall-vibration joint action was *** test results show that the unstable evolution process of sandy soil slope,under the rainfall-vibration joint action,can be divided into:rainfall erosion cracking,vibration promotion penetrating,and slope instability sliding three *** the process of slope unstable evolution,rainfall and vibration play the roles of inducing and promoting slide *** addition,the deep cracks,which are the premise for the formation of the sliding surface,and the violent irregular fluctuation of soil pressure,which reflects the near penetration of the sliding surface,constitute the instability characteristics of the railway slope *** paper reveals the unstable evolution of sandy soil slopes under the joint action of rainfall-vibration,hoping to provide the theoretical basis for the early warning and prevention technology of railway slopes.

关键词： Rainfall vibration joint action Small scale model tests Unstable evolution process Unstable characteristics Inducing sliding and promoting sliding

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The Analysis of Pingyao Ancient Town Street Spaces and View Spots Reachability by Space Syntax

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Journal of Data Analysis and Information Processing 2016年第4期4卷 177-186页

作者： dengfei li Xianchun Yan Yan Yu Key Laboratory of Southwest China Wildlife Resources Conservation China West Normal University Ministry of Education Nanchong China

The Pingyao ancient town is one of the four largest ancient cities in China. This study analyzes street spaces characteristic and view spots reachability of the Pingyao ancient town using space syntax. Then, it is concluded that the integration and reachability of street spaces are relatively higher in the northern ancient town;the accessibility among street spaces is relatively higher in the northeastern ancient town;and most of the ancient town street spaces are very open. Furthermore, the reachability of 14 view spots and their 4 corresponding street spaces is relatively higher in the 20 view spots and their 9 corresponding street spaces. Finally, some suggestions are presented to the tourism development of Pingyao ancient town based on the above conclusions.

关键词： Pingyao Ancient Town Space Syntax Reachability Street Space

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Study on Petal-Sepal Mutant of Sunflower (Helianthus annuus) after Space Mutation

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American Journal of Plant Sciences 2016年第17期7卷 2483-2497页

作者： Hao Feng Jun Yang dengfei li Key Laboratory of Southwest China Wildlife Resources Conservation China West Normal University Nanchong China

In this paper, we studied the morphological, histological and photosynthetic characteristics of the stably inherited sunflower petal-sepal mutant, and it was obtained by the space radiation-induced mutagenesis. Afterwards, we got following results: 1) The morphological characteristics represented that the inflorescence of petal-sepal mutant maintained the appearance and structure of capitulum, whereas no explicit tubular flower or ligulate flower was differentiated. 2) The histological characteristics revealed that the petal-sepal mutant only completed the inflorescence development and the differentiation of sepal primordia and inflorescence primordia, without entering the differentiation stage of tubular flower primordia, ligulate flower primordia, stamen primordia or pistil primordia. 3) The photosynthetic characteristics showed that the photosynthetic rate, transpiration and stomatal conductance of petal-sepal mutant were relatively weaker than the control plants. In the end, we concluded that the petal-sepal mutant of sunflower had only inflorescence differentiation, while several mutant genes were caused by radiation-induced mutation, which entered an infinitely recurrent development process rather than the floral differentiation stage. We also observed a few chloroplast structures in the paraffin section, combined with the results of photosynthetic characteristics of petal-sepal mutant, and then we believed that the inflorescence of petal-sepal mutant was involved in photosynthesis to accumulate energy for plant growth.

关键词： Space Mutation Helianthus annuus Petal-Sepal Mutant Sunflower Photosynthesis

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The Research on Land-Use Change and Ecological Environment Effect of Urban Landscape in China

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International Journal of Geosciences 2016年第7期7卷 956-961页

作者： dengfei li Youyou Huang Bo Qiao Xianchun Yan Wei He Key Laboratory of Southwest China Wildlife Resources Conservation (Ministry of Education) China West Normal University Nanchong China College of life Science China West Normal University Nanchong China State Key Laboratory of Geoenvironment Protection Chengdu University of Technology Chengdu China World Heritage Management Office of Ya’an City Sichuan Province Ya’an China

The rapid expansion of urban construction land has become the major characteristic of urban land-use change in China today. Meanwhile, the rapid urbanization process has led to the great changes of urban landscape in China, and it also has had certain impacts on environmental factors such as climate, soil, hydrology, biodiversity, etc., then it has made the overall ecological environment deteriorated. This study is based on the summary and analysis of research on land-use change and ecological environment effect of urban landscape in recent 20 years in China, and it aims at providing scientific bases and theoretical supports for the planning and construction of urban landscape, the sustainable land-use of city and the protection of ecological environment in China.

关键词： Urban Landscape Ecological Environment Effect Urbanization LUCC

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Study on Landscape Pattern Based on Landsat-8 in the Center of Chengdu City, China

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Journal of Environmental Protection 2016年第7期7卷 1050-1056页

作者： Wei He Youyou Huang Xin Dong Xianchun Yan dengfei li College of life Science China West Normal University Nanchong China Key Laboratory of Southwest China Wildlife Resources Conservation China West Normal University Ministry of Education Nanchong China State Key Laboratory of Geoenvironment Protection Chengdu University of Technology Chengdu China

Study on landscape spatial pattern in the center of Chengdu City is based on the Landsat-8 image by using 3S technique and spatial pattern analysis software Fragstats 3.3. The results showed that there covered an area of 193.92 km2 in the center of Chengdu City. 55.24% of the total area was made up of buildings, covering an area of 107.12 km2, and the overall landscape of impervious ground-based. There were 22,666 patches;29.67% of the patches were roads. The human interference of buildings, roads and green space was a maximum;fragmentation of the highest was green space. The fragmentation of overall urban landscape was high;the diversity was low;the value of Shannon’s diversity index was 0.63;the value of Shannon’s evenness index was 0.70. All kinds of landscape distribution were not balanced, and lack of connectivity. This research puts important reference for creating good urban landscape space and restoring the natural ecological environment in the western regions of China.

关键词： Chengdu City Landscape Pattern Urban Landscape 3S Technique Landscape Index

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Determination of Aromatic Components of Rosa davurica Pall. by Headspace Solid Phase Microextraction Combined with GC-MS

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Medicinal Plant 2018年第5期9卷 20-22,26页

作者： Yuan NIU Qiong XU Jian ZHUANG Yude WANG lilan DAI dengfei li Yalan ZHAO Lanzhou City Agricultural Technology Research and Extension Center

[Objectives] To determine the aromatic components of Rosa davurica Pall. [Methods] 42 kinds of aromatic components were identified from the flowers of R. davurica by headspace solid phase microextraction( HS-SPME) combined with gas chromatography-mass spectrometry( GC-MS). The main compounds were alcohols( 54. 88%) and aldehydes( 19. 55%). [Results] The top five components with the highest relative content were phenylethyl alcohol( 12. 69%),geraniol( 9. 85%),citronellol( 8. 80%),nerol( 7. 84%) and 2-n-pentylfuran( 7. 45%). [Conclusions] Headspace solid phase microextraction( HS-SPME) combined with gas chromatography-mass spectrometry( GC-MS) can provide basis for further development and utilization of R. davurica.

关键词： Rosa davurica Pall. Headspace solid phase microextraction (HS-SPME) Gas chromatography-mass spectrometry (GC-MS) Aromatic components

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改进迁移学习的双分支卷积神经网络图像去雾

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北京航空航天大学学报 2024年第1期50卷 30-38页

作者：李云红于惠康马登飞苏雪平段姣姣史含驰西安工程大学电子信息学院西安710048

针对现有图像去雾算法存在去雾不彻底和图像颜色失真的问题,提出一种迁移学习子网络和残差注意力子网络相结合的图像去雾模型。采用迁移学习子网络的预训练模型增强样本的特征属性;构建双分支网络结构,并利用残差注意力子网络辅助迁移... 详细信息

针对现有图像去雾算法存在去雾不彻底和图像颜色失真的问题,提出一种迁移学习子网络和残差注意力子网络相结合的图像去雾模型。采用迁移学习子网络的预训练模型增强样本的特征属性;构建双分支网络结构,并利用残差注意力子网络辅助迁移学习子网络训练网络模型的参数;利用尾部集成学习的方法融合双网络的特征,得到去雾图像的模型参数,完成图像恢复任务。实验结果表明:所提算法在RESIDE数据集和O-HAZE数据集上PSNR指标比GCANet分别提高了1.87 dB和4.22 dB,在O-HAZE数据集上SSIM指标比GCANet提高了6.7%。

关键词：图像去雾迁移学习卷积神经网络注意力机制集成学习

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ETHYLENE/PROPYLENE COPOLYMERIZATION BY NOVEL VANADIUM/TITANIUM BIMETALliC CATALYST

ETHYLENE/PROPYLENE COPOLYMERIZATION BY NOVEL VANADIUM/TITANI...

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5th International Symposium on High-Tech Polymer Materials

作者： Tao Jiang Wei Du dengfei Wang li Zhang Department of Chemistry and Chemical Engineering Daqing Petroleum Institute Daqing China

＜正＞Vanadium-based Ziegler-Natta catalysts are unique in their abilities to incorporate ethylene and propylene monomers in a random order.[l] But the low activity of vanadium catalyst limits its further ***,the traditional titanium-based Ziegler-Natta catalysts used in ethylene/propylene copolymerization had a high catalytic activity while produced copolymers with

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干湿循环作用下黄土厚度对其裂隙发育的影响

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西北大学学报（自然科学版） 2024年第1期54卷 1-10页

作者：焦少通王家鼎张登飞戚利荣李帅李琳李珊西北大学地质学系/大陆动力学国家重点实验室陕西西安710069

黄土体长期处于降雨和蒸发的湿热耦合环境,极易诱发土体裂隙产生,显著弱化土体的结构性和完整性,从而影响工程区域的建设。因此,对干湿循环作用下不同厚度的黄土开裂特性研究十分必要。该文通过室内干湿循环试验,记录试样的含水率变化... 详细信息

黄土体长期处于降雨和蒸发的湿热耦合环境,极易诱发土体裂隙产生,显著弱化土体的结构性和完整性,从而影响工程区域的建设。因此,对干湿循环作用下不同厚度的黄土开裂特性研究十分必要。该文通过室内干湿循环试验,记录试样的含水率变化和裂隙发育情况,利用数字图像处理技术,结合分形维数对裂隙网络进行分析。试验结果表明,蒸发路径和含水量的不同导致土体水分蒸发速度不同,土体越厚,水分蒸发速度越慢。界面摩擦力影响土体开裂过程,土体越厚,裂隙发育越慢,裂纹网络复杂性越低。随着干化的进行,界面摩擦力逐渐降低,土体收缩明显,干湿循环效应导致土体颗粒重新组合,加快水分蒸发过程,土体表面会不断劣化。研究结果可为地质灾害防治提供指导。

关键词：干湿循环土体厚度裂隙特征分形维数摩擦力

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古土壤层间富水对黄土场地湿陷性的影响

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西北大学学报（自然科学版） 2024年第1期54卷 72-83页

作者：李琳王家鼎谷琪张登飞焦少通西北大学地质学系/大陆动力学国家重点实验室陕西西安710069

黄土地层中往往交替分布着多层红色古土壤层,由于其硬度相对较高,遇水不易湿陷,对黄土地层湿陷量的测量结果有很大的影响。然而,对于古土壤对湿陷量的控制作用目前还缺乏相关研究,导致对湿陷地层湿陷量的科学取舍缺乏理论依据。为此该... 详细信息

黄土地层中往往交替分布着多层红色古土壤层,由于其硬度相对较高,遇水不易湿陷,对黄土地层湿陷量的测量结果有很大的影响。然而,对于古土壤对湿陷量的控制作用目前还缺乏相关研究,导致对湿陷地层湿陷量的科学取舍缺乏理论依据。为此该文统计了黄土高原区的浸水试验结果,分析了不同区域湿陷量室内外差异特征,并以西安地区两个试验场地的大型浸水试验为研究对象,进行了不同试验条件下土体中水分的扩散、含水率的变化、土压力变化以及累计湿陷量等测量工作。最终结果表明,古土壤层的存在阻碍湿陷进程,在阻止水分下渗的同时,阻碍深部地层湿陷量传递至地表,使得湿陷量实测值与计算值之间的差异与古土壤层数呈现正相关的趋势。该文将为普遍存在古土壤的黄土地层自重湿陷机理的研究提供参考。

关键词：古土壤浸水试验湿陷性湿陷系数黄土

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