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Using Quantile regression Approach to Analyze Price Movements of Agricultural Products in China

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Journal of Integrative Agriculture 2012年第4期11卷 674-683页

作者： LI Gan-qiong XU Shi-wei LI Zhe-min SUN Yi-guo dONG Xiao-xia Agricultural Information Institute Chinese Academy of Agricultural Sciences/Key Laboratory of Agri-information Service Technology Ministry of Agriculture/Key Laboratory of Digital Agricultural Early Warning Technology and System Chinese Academy of Agricultural Sciences Beijing 100081 P.R. China department of Economics University of Guelph Ontario N1G2W1 Canada

This paper studies how the price movements of pork,chicken and egg respond to those of related cost factors in short terms in Chinese *** employ a linear quantile approach not only to explore potential data heteroscedasticity but also to generate confidence bands for the purpose of price stability *** then evaluate our models by comparing the prediction intervals generated from the quantile regression models with in-sample and out-of-sample *** monthly data from January 2000 to October 2010,we observed these findings：（i） the price changes of cost factors asymmetrically and unequally influence those of the livestock across different quantiles;（ii） the performance of our models is robust and consistent for both in-sample and out-of-sample forecasts;（iii） the confidence intervals generated from 0.05th and 0.95th quantile regression models are good methods to forecast livestock price fluctuation.

关键词： cost factors agricultural products forecasting price movements quantile regression model

Perforated nanocap array: Facile fabrication process and efficient surface enhanced raman scattering with fluorescence suppression

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Chinese Physics B 2013年第4期22卷 415-419页

作者：王军黄丽清童慧敏翟立鹏袁林赵丽华张薇薇单冬至郝爱文冯雪红 Non-equilibrium Condensed Matter and Quantum Engineering Laboratory School of Science Xi'an Jiaotong University

recently, individual reduced-symmetry metal nanostructures and their plasmonic properties have been studied extensively. However, little attention has been paid to the approach to fabricating ordered reduced-symmetry metal nanostructure arrays. In this paper, a novel perforated silver nanocap array with high surface-enhanced raman scattering （SErS） activity and fluorescence suppression is reported. The array is fabricated by electron beam evaporating Ag onto the perforated barrier layer side of a hard anodization （HA） anodic aluminum oxide （AAO） template. The morphology and optical property of the perforated silver nanocap array are characterized by an atomic force microscope （AFM）, a scanning electron microscope （SEM）, and absorption spectra. The results of SErS measurements reveal that the perforated silver nanocap array offers high SErS activity and fluorescence suppression compared with an imperforated silver nanocap array.

关键词： reduced-symmetry structures perforated nanocap array surface-enhanced raman scattering anodic aluminum oxide

A 3d Investigation of Geological Structure and Its relationship to Mineralization in the Nanling-Xuancheng Ore district,Middle-Lower Yangtze river Metallogenic Belt,China

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Journal of Earth Science 2022年第3期33卷 664-680页

作者： Sanming Lu Xueyi Lan Lili Zhao Zanzan Zhang Xiaoyong Yang Zhuang Zhao dong Guo Xiaochun Xu Yongsheng Wang Jianshe Li Huasheng Qi Public Geological Survey Management Center of Anhui Province Hefei 230091China Geological Exploration Technology Institute of Anhui Province Hefei 230031China School of resources and Environmental Engineering Hefei University of TechnologyHefei 230009China CAS Center for Excellence in Comparative Planetology University of Science and Technology of ChinaHefei 230026China

The Nanling-Xuancheng ore region of Anhui Province is located in the Middle-Lower Yangtze river metallogenic *** exploration and research have been carried out in this newly defined ore district,although the Chating large porphyry Cu-Au deposit and a few middle-sized skarntype Cu polymetallic deposits have been *** this study,we carried out high-resolution seismic reflection,magnetotelluric,gravity,and magnetic investigations,and constructed the 3 d geological structure of the uppermost crust in a depth range of 0-5 km using a comprehensive inversion of the new data constrained by previous deep-drilling *** hence proposed some new insights to understand the mineralization processes of this district.A system of alternating ridges and valleys is suggested as the major structure pattern,composed of“two-layer structure”of the basins and“three-layer structure”of ***,a conjugated fault system and its distribution features are revealed in our models,including the Jiangnan fault,Zhouwang fault,and Kunshan thrust *** Jiangnan and Kunshan faults are suggested to have controlled the diagenesis and *** deep concealed plutons located in Chating and Magushan are found,forming the Mesozoic diorite-felsic *** intrusions are believed to be the causes of hydrothermal deposits such as the Chating deposit and the Magushan deposit.

关键词： geophysical exploration 3d structure metallogenic mechanism Nanling-Xuancheng ore region Middle-Lower Yangtze river metallogenic belt ore deposits

Synthesis,Crystal Structure and dFT Calculation of 2-Methoxyimino Phenylacetate derivatives Containing 1,3,4-Oxadiazole ring

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Chinese Journal of Structural Chemistry 2021年第12期40卷 1647-1654,1554页

作者： rEN Hui-dong LI Kang-Ming YI Yang-Jie WANG Man YE Jiao HU Ai-Xi CHEN Yun OU Xiao-Ming LI Jian-Ming College of Chemistry and Chemical Engineering Hunan UniversityChangsha 410082China National Pesticide Creation Engineering Technology research Center Hunan Research Institute of Chemical Industry Co.Ltd.Changsha 410007China

Four novel 2-methoxyimino phenylacetate derivatives containing 1,3,4-oxadiazole ring were designed and synthesized from the key intermediate of Trifloxystrobin or Azoxystrobin via intermediate derivatization and active structure *** chemical structures of the target compounds were confirmed by]H NMr,13C NMr and elemental *** crystal structure of methyl(E)-2-(methoxyimino)-2-(2-(((5-((4-methoxyphenoxy)methyl)-1,3,4-oxadiazol-2-yl)thio)methyl)phenyl)acetate(Al)was determined by single-crystal X-ray *** A1 belongs to triclinic system,space group Pi with two molecules in each unit *** benzene ring plane C(2)-C(3)-C(4)-C(5)-C(6)-C(7)and oxazole ring plane are nearly parallel with the dihedral angle of 6.4°.The benzene ring plane C(12)-C(13)-C(14)-C(15)-C(16)-C(17)and oxazole ring plane are not perpendicular with the dihedral angle of 49.4°.The crystal of compound Al is stabilized by π-π stacking *** fungicidal activities of the target compounds against four plant pathogenic fungi in vitro were tested,and some of them had good *** dFT calculation was carried out to study the structure-activity relationship of the title derivatives using Gasian 09 and Multiwfii 3.6.

关键词： 2-methoxyimino phenylacetate derivatives synthesis crystal structure fungicidal activities dFT calculation

Influence Mechanism of the Trabecular and Chamfer radii on the Three-point Bending Properties of Trabecular Beetle Elytron Plates

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Journal of Bionic Engineering 2021年第2期18卷 409-418页

作者： Xiaoming Zhang Xindi Yu Jinxiang Chen Caiqi Zhao Sujun Guan Yaqin Fu School of Civil Engineering Southeast UniversityNanjing 211189China department of Physics Tokyo University of ScienceTokyo 1628601Japan College of Materials and Textiles Zhejiang Sci-Tech UniversityHangzhou 310018China

To improve the mechanical properties of Trabecular Beetle Elytron Plates(TBEPs,a type of biomimetic sandwich structure inspired by the beetle elytron)under transverse loads,three-point bending tests are performed to investigate the influence of the trabecular and chamfer radii of the core structure on the mechanical performance of TBEPs manufactured by 3d printing *** results show that the three-point bending performance of TBEPs can be improved by setting reasonable trabecular and chamfer radii;however,excessive increases in these radii can cause a decline in the mechanical *** the reason,these two structural parameters can enhance the deformation stiffness of the whole structure and the connection property between the core and skin,which is also the mechanical reason why Prosopocoilus inclinatus beetle elytra have thick,short trabeculae with a large chamfer ***,when these radii increase to a certain extent,the cracks are ultimately controlled between two adjacent trabeculae,and the failure of the plate is determined by the skin rather than the core ***,this study suggests a reasonable range for trabecular and chamfer radii,and indicates that TBEPs are better suited for engineering applications that have high compression requirements and general bending requirements.

关键词： beetle elytron bio-inspired structure sandwich structure honeycomb plate trabeculae bending properties

Comparison of 16S rrNA Gene Primers on Studying Microbial Community Composition in Bottom Water and Sediment of Artificial reefs in Laoshan Bay, China

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Journal of Ocean University of China 2022年第5期21卷 1313-1322页

作者： FANG Guangjie YU Haolin SHENG Huaxiang TANG Yanli LIANG Zhenlin Fisheries College Ocean University of ChinaQingdao 266003China Marine College Shandong UniversityWeihai 264200China

Marine microorganisms are indispensable regulators of nutrient cycling and energy flow,which are crucial for artificial reefs(Ars)***,little is known about the microbial communities in the bottom water and sediment of *** of microbial diversities have greatly advanced due to the development of high-throughput sequencing technologies,whereas the results may vary significantly due to the primers’*** study investigated the influences of two 16S ribosomal rNA gene primer choices(V4 and V3-V4)on microbial community compositions and *** results showed that the taxonomic assignment de-tected by primer V3-V4 was higher compared with that obtained by primer V4,whereas microbial community compositions had strong correlations between the two *** beta diversities of Ars can be uncovered by both primers,but the relation-ships between communities and environmental parameters were *** performances of the two primers for water samples were highly consistent,but the inconformity was evident for sediment *** the relatively lower taxonomic classification of primer V4 for sediment samples,primer V3-V4 was recommended for later *** the development and advancement of Ars in China,our findings provide a meaningful reference for ecologists focusing on the microbial diversities and ecological functions of these artificial habitats in the future.

关键词： 16S rrNA hypervariable region Ars bacteria archaea

Correlation Study on Grain Size Characteristics and Geotechnical Properties of Surface Sediments in Qingdao Offshore Area

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Journal of Ocean University of China 2024年第3期23卷 721-730页

作者： LI Anlong WANG Panpan GUO Xijun JI Xiangkun SHEN Kunming LIN Lin YAN Zhichao YUAN Lin key Laboratory of Submarine Geosciences and Prospecting Techniques Ministry of Education and College of Marine GeosciencesOcean University of ChinaQingdao 266100China College of Marine Geoscience Ocean University of ChinaQingdao 266100China China Construction Second Engineering Bureau Co. LTDYueyang 414000China Tianjin research Institute for Water Transport Engineering M.O.T.Tianjin 3000456China Lianyungang Xuwei Port Holding Group Co. Ltd.Lianyungang 222042China

The comprehension of sediment grain size parameters and the corresponding sedimentary environment holds paramount importance in elucidating the engineering geological attributes of the subaqueous *** study delineated the sedimentary environment zoning in the northern sea area of Qingdao through cluster analysis of grain size parameters derived from 123 surface sediment *** study analyzed the correlation between sediment geotechnical indices and grain size parameters across diverse sedimentary environments.A correlation equation was established for samples exhibiting a strong *** study found four distinct sedimentary environments in the study area:coastal,transitional,shallow sea,and *** the same sedimentary environment,the average grain size and sorting coefficient exhibit significant correlations with geotechnical indices such as water content,density,shear strength,plastic limit,liquid limit,and plastic ***,notable disparities in the correlation between grain size parameters and geotechnical indices emerge across different sedimentary environments.

关键词： grain size parameters cluster analysis sedimentary environment correlations geotechnical indexes

Comparison and quantitative assessment of two regional soil erosion survey approaches

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International Soil and Water Conservation research 2023年第4期11卷 660-668页

作者： Lixia dong Suhua Fu Baoyuan Liu Bing Yin Faculty of Geographical Science Beijing Normal UniversityBeijing100875PR ChinaFaculty of Geographical ScienceBeijing Normal UniversityBeijing100875PR China Advanced Institute of Natural Sciences Beijing Normal University at Zhuhai519087PR China State key Lab Soil Erosion and dryland Farming on the Loess Plateau Institute of Soil and Water ConservationNorthwest A&F UniversityPR China

regional soil erosion surveys are the first step of soil conservation *** and sampling ap-proaches are commonly used for soil erosion surveys at the regional *** the grid approach,the region is divided into grids(e.g.,1 km × 1 km),and the soil erosion rate of each grid was *** the sampling approach,a small portion of the area(typically 4%or less)was taken and then the soil erosion rate was *** on the above calculation,both approaches evaluated the soil erosion area(which is the area where the soil erosion rate is greater than the soil loss tolerance(t))and its distribution in the whole *** purpose of this paper is to compare the assessment results of the two approaches and analyse their practicality using Yunyang County,Chongqing,China(area is 3636 km^(2)).The soil erosion rate,percentage of soil erosion area(PSEA,which is the ratio of the area where the soil erosion rate is greater than the soil loss tolerance(t)to the area of the total study region)and its spatial distribution were compared between the two *** results showed that the grid approach overestimated the average soil erosion rate and PSEA overall for all 33 sample units and the whole region in comparison to the sampling *** sampling approach can yield a reasonable spatial distribution of the soil erosion rate in the whole *** addition,the soil erosion regions were more clustered than those using the grid approach,which can be more suitable for soil conservation ***,the sampling approach is an efficient and practical approach in regional soil erosion *** results can provide insights into regional soil erosion surveys.

关键词： regional soil erosion Soil erosion survey Grid approach Sampling approach CSLE

Effects of contents of Nb and C on hot deformation behaviors of high Nb X80 pipeline steels

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中国有色金属学会会刊：英文版 2009年第6期19卷 1395-1399页

作者：乔桂英肖福仁张晓兵曹雅斌廖波 School of Environmental and Chemical Engineering Yanshan University College of Materials Science and Engineering Yanshan University Shagang Group Corpoation

The behavior of the flow deformation and the effects of contents of Nb and C on deformation behaviors of high Nb X80 pipeline steels during hot compression deformation were studied by thermal simulation test. The content of solid solution Nb was quantificationally studied during the reheating and hot deformation process, and the effects of change of solid solution Nb in steels on hot deformation behaviors were discussed. The results show that the contents of Nb and C have great effects on the flow stress behaviors of high Nb X80 pipeline steels. When the C content in steels is constant, the recrystallization activation energy increases from 387 to 481 kJ/mol with increasing the Nb from 0.082% to 0.13% (mass fraction). However, the effect of Nb is correlative to the C content, i.e. w(Nb)/w(C). When w(Nb)/w(C) decreases from 3.61 to 2.18, the recrystallization activation energy decreases from 481 to 434 kJ/mol.

关键词： X80级管线钢热变形行为铌钢 Nb 流动应力热压缩变形热模拟试验质量分数