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Tree species classification in an extensive forest area using airborne hyperspectral data under varying light conditions

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Journal of Forestry Research 2023年第5期34卷 1359-1377页

作者： wen Jia yong Pang Institute of Forest Resource Information Techniques Chinese Academy of ForestryBeijing 100091People’s Republic of China Key Laboratory of Forestry Remote Sensing and Information System National Forestry and Grassland AdministrationBeijing 100091People’s Republic of China

Although airborne hyperspectral data with detailed spatial and spectral information has demonstrated significant potential for tree species classification,it has not been widely used over large areas.A comprehensive process based on multi-flightline airborne hyperspectral data is lacking over large,forested areas influenced by both the effects of bidirectional reflectance distribution function(BRDF)and cloud shadow *** this study,hyperspectral data were collected over the Mengjiagang Forest Farm in Northeast China in the summer of 2017 using the Chinese Academy of Forestry's LiDAR,CCD,and hyperspectral systems(CAF-LiCHy).After BRDF correction and cloud shadow detection processing,a tree species classification workflow was developed for sunlit and cloud-shaded forest areas with input features of minimum noise fraction reduced bands,spectral vegetation indices,and texture *** indicate that BRDF-corrected sunlit hyperspectral data can provide a stable and high classification accuracy based on representative training ***-shaded pixels also have good spectral separability for species *** red-edge spectral information and ratio-based spectral indices with high importance scores are recommended as input features for species classification under varying light *** to the classification accuracies through field survey data at multiple spatial scales,it was found that species classification within an extensive forest area using airborne hyperspectral data under various illuminations can be successfully carried out using the effective radiometric consistency process and feature selection strategy.

关键词： Tree species classification BRDF effects Cloud shadow Airborne hyperspectral data Random forest

Impacts of household income on beef at-home consumption:Evidence from urban China

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Journal of Integrative Agriculture 2021年第6期20卷 1701-1715页

作者： HU wen-bo CHEN yong-fu ZHAO Jing wu Bei-bei College of Economics and Management China Agricultural UniversityBeijing 100083P.R.China Appalachian Laboratory University of Maryland Center for Environmental ScienceMaryland 21532USA College of Economics and Management Nanjing Agricultural UniversityNanjing 210095P.R.China

Beef consumption in China has increased substantially from 5.0 million tons in 2000 to 7.7 million tons in 2019 thanks to rapid income growth,but still remains low compared to pork and poultry *** the understanding about the impacts of household income on beef consumption in China is necessary to forecast future beef demand and inform the domestic beef industry,especially in the context of unprecedented expansion of middle income class in *** on survey data of 32878 urban households collected by the National Bureau of Statistics of China,we employed the inverse hyperbolic sine(IHS)double-hurdle model to estimate income elasticities of beef demand across different income groups and simulated possible trends of future beef consumption of Chinese urban *** empirical results showed that the unconditional income elasticities of beef consumption at home vary between 0.169 for the lowincome group and 0.671 for the high-income *** simulated results indicated that beef consumption is expected to increase by 12.0 to 38.8%in 10 years and by 18.6 to 70.5%in 15 years under distinct income growth *** findings provide practical insights for policy makers and other stakeholders about future beef demand,such as potential opportunities embedded in rising beef demand for domestic producers and world beef exporters as well as the urgency of improving the supply chain resilience of beef in China.

关键词： beef consumption income elasticity income growth IHS double-hurdle model urban China

Theoretical Investigations on the Interaction Nature of Br_2 with HF, H_2O and NH_3

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Chinese Journal of Structural Chemistry 2007年第5期26卷 587-593页

作者： wu wen-Sheng WANG Zhao-Xu ZHENG Bai-Shu SHU Hua LI Xiang wu Jun-yong Department of Light Industry and Chemistry Zhaoqing University Zhaoqing Guangdong 526061 China School of Chemistry and Chemical Engineering Hunan University of Science and Technology Xiangtan Hunan 411201 China Institute of Modern Catalysis Beijing University of Chemical TechnologyState Key Laboratory of Chemical Resource Engineering Beijing 100029 China

The interactions of HF, H2O and NH3 with Br2 are investigated at the MP2（full）/ aug-cc-pVDZ level. It is found that two kinds of stable complexes, halogen-bonded and hydrogen-bonded complexes, exist between Br2 and HF and between Br2 and H2O. The interaction energy analysis and natural population analysis （NPA） are conducted to these two kinds of complexes, indicating the halogen-bonded complexes are more stable than the corresponding hydrogen-bonded ones, and the binding energies of the former increase in the order HFH2O for the latter.

关键词： MP2 intermolecular interaction halogen-bonded complex hydrogen-bondedcomplex NPA

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圈层化网络社群对青少年的伦理挑战及其应对

教学与管理 2025年第1期 34-38页

作者：刘昊琛冯永刚山东师范大学教育学部济南250014

青少年在网络空间构筑了基于共同兴趣和偏好的“新社群”。网络社群内部的圈层化趋势加强了青少年之间的联系与共鸣,在一定程度上重塑了他们的社会认知和伦理判断。然而,这种圈层化也带来了新型场域对伦理空间的冲击、圈层区隔对伦理关... 详细信息

青少年在网络空间构筑了基于共同兴趣和偏好的“新社群”。网络社群内部的圈层化趋势加强了青少年之间的联系与共鸣,在一定程度上重塑了他们的社会认知和伦理判断。然而,这种圈层化也带来了新型场域对伦理空间的冲击、圈层区隔对伦理关系的界分、特定惯习对伦理实践的影响和微观规训对伦理意识的裹挟等问题,将他们置于伦理挑战的情境中进行考量。鉴于此,创构主流舆论传播新格局、释放网络圈层整合共振力、激活多元话语互促生命力、注重外部治理和内部自律的统一性,对于网络社会治理和构建网络空间命运共同体具有重要意义。

关键词：圈层化网络社群青少年伦理挑战

Geochemical identification of a source rock affected by migrated hydrocarbons and its geological significance:Fengcheng Formation,southern Mahu Sag,Junggar Basin,NW China

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Petroleum Science 2024年第1期21卷 100-114页

作者： wen-Long Dang Gang Gao Xin-Cai You Ke-Ting Fan Jun wu De-wen Lei wen-Jun He yong Tang State Key Laboratory of Petroleum Resource and Prospecting China University of Petroleum(Beijing)Beijing102249China School of GeoSciences China University of Petroleum(Beijing)Beijing102249China Exploration&Development Institute Xinjiang Oil Field CompanyKaramay834000XinjiangChina

The Fengcheng Formation is a crucial source rock and the primary reservoir for oil accumulation in the Mahu *** oils are distributed throughout the Fengcheng Formation,ranging from the edge to the interior of the sag in the southern Mahu *** crude oils originate from in-situ source rocks in shallowly buried areas and the inner deep *** migration,the crude oil from the inner deep sag affects the source rocks close to carrier beds,leading to changes in the organic geochemical characteristics of the source *** changes might alter source rock evaluations and oil-source *** on data such as total organic carbon(TOC),Rock-Eval pyrolysis of source rocks,and gas chromatography-mass spectrometry(GC-MS)of the saturated fraction,and considering the geological characteristics of the study area,we define the identification characteristics of source rock affected by migrated hydrocarbons and establish the various patterns of influence that migrated hydrocarbons have on the source rock of the Fengcheng Formation in the southern Mahu *** source rocks of the Fengcheng Formation are mostly fair to good,containing mainly Type II organic matter and being thermally mature enough to generate *** rocks affected by migrated hydrocarbons exhibit relatively high hydrocarbon contents(S1/TOC>110 mg HC/g TOC,Extract/TOC>30%,HC:hydrocarbon),relatively low Rock-Eval Tmax values,and relatively high tricyclic terpane contents with a descending and mountain-shaped ***,biomarker composition parameters indicate a higher thermal maturity than in-situ source *** a comparison of the extract biomarker fingerprints of adjacent reservoirs and mudstones in different boreholes,three types of influence patterns of migrated hydrocarbons are identified:the edge-influence of thin sandstone-thick mudstone,the mixed-influence of sandstone-mudstone interbedded,and the full-influence of thick sandstone-thin *** finding reminds

关键词： Organic geochemistry Source rock Influence of migrated hydrocarbons Fengcheng Formation Southern Mahu Sag

Two-view attention-guided convolutional neural network for mammographic image classification

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CAAI Transactions on Intelligence Technology 2023年第2期8卷 453-467页

作者： Lilei Sun Jie wen Junqian Wang yong Zhao Bob Zhang Jian wu yong Xu College of Computer Science and Technology Guizhou UniversityGuiyangChina Shenzhen Key Laboratory of Visual Object Detection and Recognition Harbin Institute of TechnologyShenzhenChina Harbin Institute of Technology ShenzhenChina School of Electronic and Computer Engineering Shenzhen Graduate School of Peking UniversityShenzhenChina Department of Computer and Information Science University of MacaoTaipaChina Science for Life Laboratory KTH Royal Institute of TechnologyStockholmSweden

Deep learning has been widely used in the field of mammographic image classification owing to its superiority in automatic feature ***,general deep learning models cannot achieve very satisfactory classification results on mammographic images because these models are not specifically designed for mammographic images and do not take the specific traits of these images into *** exploit the essential discriminant information of mammographic images,we propose a novel classification method based on a convolutional neural ***,the proposed method designs two branches to extract the discriminative features from mammographic images from the mediolateral oblique and craniocaudal(CC)mammographic *** features extracted from the two-view mammographic images contain complementary information that enables breast cancer to be more easily ***,the attention block is introduced to capture the channel-wise information by adjusting the weight of each feature map,which is beneficial to emphasising the important features of mammographic ***,we add a penalty term based on the fuzzy cluster algorithm to the cross-entropy function,which improves the generalisation ability of the classification model by maximising the interclass distance and minimising the intraclass distance of the *** experimental results on The Digital database for Screening Mammography INbreast and MIAS mammography databases illustrate that the proposed method achieves the best classification performance and is more robust than the compared state-ofthe-art classification methods.

关键词： convolutional neural network deep learning medical image processing mammographic image

Advances in understanding the molecular mechanism of pancreatic cancer metastasis

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Hepatobiliary & Pancreatic Diseases International 2016年第4期15卷 361-370页

作者： yong-Xing Du Zi-wen Liu Lei You wen-Ming wu Yu-Pei Zhao Department of General Surgery Peking Union Medical College Hospital Chinese Academy of Medical Sciences and Peking Union Medical College

BACKGROUND： Pancreatic cancer（PC） is usually diagnosed at the late-stage and therefore, has widespread metastasis and a very high mortality rate. The mechanisms underlying PC metastasis are not well understood. Recent advances in genomic sequencing have identified groups of gene mutations that affect PC metastasis, but studies elucidating their roles are lacking. The present review was to investigate the molecular mechanisms of PC *** SOURCES： Relevant articles on PC metastasis were searched in MEDLINE via Pub Med prior to April 2015. The search was limited in English ***： PC metastatic cascades are multi-factorial events including both intrinsic and extrinsic elements. This review highlights the most important genetic alterations and other mechanisms that account for PC invasion and metastasis, with particular regard to epithelial-mesenchymal transition, inflammation, stress response, and circulating tumor ***： Analyses of relevant gene functions and signaling pathways are needed to establish the gene regulatory network and to define the pivotal modulators. Another promising area of study is the genotyping and phenotyping of circulating tumor cells, which could lead to a new era of personalized therapy by identifying specific markers and targets.

关键词： pancreatic cancer metastasis molecular mechanism targeted therapy

Low-dimensional chaos and fractal properties of long-term sunspot activity

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Research in Astronomy and Astrophysics 2014年第1期14卷 104-112页

作者： Shuang Zhou yong Feng wen-Yuan wu Yi Li Jiang Liu Chongqing Key Laboratory of Automated Reasoning and Cognition Chongqing Institute of Green and Intelligent TechnologyChinese Academy of Sciences University of Chinese Academy of Sciences

Two primary solar-activity indicators- sunspot numbers （SNs） and sunspot areas （SAs） in the time interval from November 1874 to December 2012 - are used to determine the chaotic and fractal properties of solar activity. The results show that （1） the long-term solar activity is governed by a low-dimensional chaotic strange attractor, and its fractal motion shows a long-term persistence on large scales; （2） both the fractal dimension and maximal Lyapunov exponent of SAs are larger than those of SNs, implying that the dynamical system of SAs is more chaotic and complex than SNs; （3） the predictions of solar activity should only be done for short- to mid-term behaviors due to its intrinsic complexity; moreover, the predictability time of SAs is obviously smaller than that of SNs and previous results.

关键词： methods: data analysis -- Sun: activity -- Sun: sunspots

Delamination process in cross-ply UHMWPE laminates under ballistic penetration

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Defence Technology（防务技术） 2021年第1期17卷 278-286页

作者： Gen-lin Mo Qian-wen Ma yong-xi Jin wen-min Yan Zhong-xin Li Zhi-lin wu Institute of Advanced Manufacturing Jiangsu UniversityZhenjiang212013China Key Laboratory of Transient Shock Beijing102202China Zhenjiang Hospital of Traditional Chinese Medicine 212013China School of Mechanical Engineering Nanjing University of Science and TechnologyNanjing210094China

Cross-ply unidirectional laminates made of ultra-high molecular weight polyethylene fibers are widely used as components of bullet-proof *** simulate the delamination process of the material under penetration,we constructed a numerical mechanical model,which was validated by tests using 7.6239 mm rifle bullets penetrating laminates of different *** results show that the delamination region is essentially *** simulated delamination region is in good agreement with the experimental *** is found that the delamination region increases with the compression modulus along the fiber *** delamination region increases when the shear strength between the fabric layers decreases;However,it is little influenced by the normal *** delamination region of the front face of the laminate is little influenced by the failure strain of the material and the initial velocity of the *** delamination region of the back face increases with the failure strain and decreases with the initial velocity.

关键词： proof process modulus