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Comparison of Thermal Performance between Annular Fins and Longitudinal Fins in Latent Heat Storage Unit

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Journal of Thermal Science 2023年第3期32卷 1227-1238页

作者： ZHU Yuxi qiu yan School of Energy and Power Engineering Shandong UniversityJi'nan 250061China

As a simple and effective method of heat transfer enhancement,fins are widely used in latent heat storage ***,the choice of annular fins and longitudinal fins has always been *** this paper,the melting process of phase change material(PCM)in annular fins and longitudinal fins latent heat storage units with the same volume is numerically *** ensure the same thermal penetration,three-dimensional spaces occupied with fins are specially controlled to be the *** with finned structures,the effects of natural convection(NC),placement mode and heat transfer fluid(HTF)inlet direction on the melting process are *** results show that the melting time in annular finned structure is always 10%less than that in longitudinal finned structure,which demonstrates the superior of the annular fins in the latent heat storage *** melting time is the shortest in vertical unit with annular fins and HTF inlet at the ***,the correlation formulas of the liquid fraction are proposed in the vertical unit with HTF inlet at the bottom.

关键词： latent heat storage annular fins longitudinal fins natural convection

Adaptation of Nitraria sphaerocarpa to wind-blown sand environments at the edge of a desert oasis

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Journal of Environmental Sciences 2007年第4期19卷 482-487页

作者： LI qiu-yan ZHAO Wen-zhi FANG Hai-yan Chinese Ecosystem Network Research Linze Inland River Basin Research Station Laboratory of Hydrology and Applied Ecology Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou 730000 China. Institute of Geographical Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China

This study addresses the adaptation of Nitraria sphaerocarpa to blown sand at the edge of a desert oasis with regard to the aspects of soil seed banks, seedlings, and population. Horizontally, the total number of seeds per unit area decreased from the shrub canopy center to intershrub areas, and most seeds were found under shrub canopies. Vertically, the highest proportion of seeds was found at depths of 5-10 cm. The emergence percentage, seedling mass, and seedling height, which were significantly affected by both burial depth and seed size, were highest at the optimal burial depth of 2 cm, and decreased with increasing burial depth in each seed size-class. Although seedling mass was usually greatest for large seeds and least for small seeds at each burial depth, little difference was observed in seedling height at shallow burial depths of 0-3 cm. The population shows a patchy and discontinuous distribution pattern. Population height increases with increasing sand depth. Also the density increases with increasing depth of sand in the desert; however, there is a steady decrease when the depth of sand is more than 100 cm. This result indicates that the depth of sand that is most suitable for the growth of Nitraria sphaerocarpa is 100 cm. The size of the population is significantly correlated with the sand depth, which increases with increasing depth in the desert.

关键词： Nitraria sphaerocarpa soil seed bank seedling growth sand burial adaptation

Two-sample Testing for Mean Functions with Incompletely Observed Functional Data

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Acta Mathematicae Applicatae Sinica 2020年第2期36卷 374-389页

作者： yan-qiu ZHOU yan-ling WAN Tao ZHANG School of Science Guangxi University of Science and TechnologyLiuzhou 545006China School of Social Science Guangxi University of Science and TechnologyLiuzhou 545006China

In functional data analysis,the collected data are often assumed to be fully observed on the ***,in dealing with real data(for example,environmental pollution data),we are often faced with the scenario that some functional data are fully observed on dense lattice while others are incompletely *** this paper,we propose a method for testing equivalence of mean functions of two samples under this *** asymptotic results of the proposed methods are *** proposed test is employed to analyze an environmental pollution study in Liuzhou City of *** show that the proposed test has a good control of the type-I error,and is more powerful than the complete case test in most cases.

关键词： functional data analysis significance test incompletely observed functional data mean function

Cyanuric chloride-catalyzed synthesis of 10-aryl-6,8-dimethyl-6,10-dihydro-5-oxa-6,8-diazaanthra[2,3-d][1,3]dioxole-7,9-diones

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Chinese Chemical Letters 2011年第7期22卷 811-814页

作者： Wei Lin Li qiu yan Luo Fu Lin yan School of Pharmacy Xinxiang Medical University Xinxiang 453003 China Department of Gynecological and Obstetric Third Affiliated Hospital to Xinxiang Medical University Xinxiang 453003 China

An environmentally friendly procedure for the preparation of 10-aryl-6,8-dimethyl-6,10-dihydro-5-oxa-6,8-diazaanthra[2,3- d] [ 1,3]dioxole-7,9-diones under thermal solvent-free conditions in the presence of cyanurie c... 详细信息

关键词： Bcnzodioxoles 3,4-Methylenedioxyphenol 1,3-Dimethylbarbituric acid Cyanuric chloride Solvent-free

Settlement patterns of mountainous half-filled and half-cut widened subgrade with retaining wall

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Journal of Mountain Science 2021年第10期18卷 2791-2802页

作者： FU Yong-guo JIANG Xin GU Han-yan qiu yan-jun School of Civil Engineering Southwest Jiaotong UniversityChengdu 610031China MOE Key Laboratory of High-speed Railway Engineering Southwest Jiaotong UniversityChengdu 610031China Highway Engineering Key Laboratory of Sichuan Province Southwest Jiaotong UniversityChengdu 610031China

The settlement of widened highway subgrade in mountainous area is not only affected by the interaction between new and existing subgrade, but also seriously restricted by the external retaining wall. Based on the practical engineering of half-filled and half-cut widened mountainous highway subgrade with external balance weight retaining wall(BWRW), a sophisticated finite element numerical model is established. The evolution law of subgrade settlement is revealed during the whole process of new subgrade filling and BWRW inclination after construction. The settlement component of subgrade is clarified considering whether the existing pavement continues to be used. The results show that the additional settlement caused by the BWRW inclination after construction cannot be ignored in the widening and reconstruction of mountainous highway subgrade. In addition, pursuant to the comprehensive design of subgrade and pavement, the component of subgrade settlement should be determined according to whether the existing pavement continues to be used, while considering the influence of BWRW inclination after construction. When the existing pavement continues to be used, the settlement of the existing subgrade is caused by the new subgrade filling and the BWRW inclination after construction. On the contrary, the settlement is only caused by the BWRW inclination after construction.

关键词： Mountain road widening Balance weight retaining wall Subgrade settlement Pavement utilization Retaining wall inclination

Clustering for Bivariate Functional Data

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Acta Mathematicae Applicatae Sinica 2024年第3期40卷 613-629页

作者： Shi-yun CAO yan-qiu ZHOU yan-ling WAN Tao ZHANG School of Science Guangxi University of Science and TechnologyLiuzhou 545006China School of Marxism Guangxi University of Science and TechnologyLiuzhou 545006China Key Laboratory of Intelligent Information Processing and Graph Processing Guangxi University of Science and TechnologyLiuzhou 545006China

In this paper,we consider the clustering of bivariate functional data where each random surface consists of a set of curves recorded repeatedly for each *** k-centres surface clustering method based on marginal functional principal component analysis is proposed for the bivariate functional data,and a novel clustering criterion is presented where both the random surface and its partial derivative function in two directions are *** addition,we also consider two other clustering methods,k-centres surface clustering methods based on product functional principal component analysis or double functional principal component *** results indicate that the proposed methods have a nice performance in terms of both the correct classification rate and the adjusted rand *** approaches are further illustrated through empirical analysis of human mortality data.

关键词： bivariate functional data -centres surface clustering functional principal component analysis partial derivative function

Optimal fusion rule for cooperative spectrum sensing in cognitive radio networks

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The Journal of China Universities of Posts and Telecommunications 2012年第5期19卷 58-65页

作者： WANG Qian YUE Dian-wu yan qiu-na College of Information Science and Technology Dalian Maritime University Dalian 116026 China National Mobile Communications Research Laboratory of Southeast University Nanjing 210096 China

In this paper, we analyze performance of cooperative spectrum sensing under counting rules when exponential model is utilized to characterize the burst nature of primary user （PU） link. Our objective is to minimize the average error probability （AEP） so that the link utilization in the considered link achieves its maximum. We derive a closed-form expression of AEP as well as the probability of interference （PoI） by classifying cognitive transmission into six events. Then, we consider the minimization of AEP over counting rules under the constraint of interference. As the solution, we develop an efficient algorithm to evaluate the optimal fusion rule. Finally, we verify our analysis in numerical results.

关键词： cooperative spectrum sensing cognitive radio network average error probability countering rule probability of interference,spectrum usage

Arbitrary-Order Fractance Approximation Circuits With High Order-Stability Characteristic and Wider Approximation Frequency Bandwidth

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IEEE/CAA Journal of Automatica Sinica 2020年第5期7卷 1425-1436页

作者： qiu-yan He Yi-Fei Pu Bo Yu Xiao Yuan College of Computer Science Sichuan UniversityChengdu 610065China College of Physics and Engineering Chengdu Normal UniversityChengdu 611130China College of Electronics and Information Engineering Sichuan UniversityChengdu 610065China

This paper discusses a novel rational approximation algorithm of arbitrary-order fractances,which has high orderstability characteristic and wider approximation frequency *** fractor has been exploited extensively in various scientific *** well-known shortcoming of the existing fractance approximation circuits,such as the oscillation phenomena,is still in great need of special research *** by this need,a novel algorithm with high orderstability characteristic and wider approximation frequency bandwidth is *** order to better understand the iterating process,the approximation principle of this algorithm is investigated at ***,features of the iterating function and frequency-domain characteristics of the impedance function calculated by this algorithm are researched,***,approximation performance comparisons have been made between the corresponding circuit and other types of fractance approximation ***,a fractance approximation circuit with the impedance function of negative2/3-order is *** high order-stability characteristic and wider approximation frequency bandwidth are fundamental important advantages,which make our proposed algorithm competitive in practical applications.

关键词： Fractal fractance fractional calculus fractional-order systems

Origin of a giant fuzzy reflection zone and its implication for natural gas exploration in the southwestern Qiongdongnan Basin of the South China Sea

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Journal of Oceanology and Limnology 2023年第2期41卷 710-728页

作者： Junhui YU Pin yan yanlin WANG yan qiu Guanghong TU Changliang CHEN Key Laboratory of Ocean and Marginal Sea Geology South China Sea Institute of OceanologyInnovation Academy of South China Sea Ecology and Environmental EngineeringChinese Academy of SciencesGuangzhou 510301China Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou) Guangzhou 511458China Key Laboratory of Marine Geology and Environment Institute of OceanologyChinese Academy of SciencesQingdao 266071China Key Laboratory of Marine Mineral Resources Guangzhou Marine Geological SurveyChina Geological SurveyMinistry of Natural ResourcesGuangzhou 511458China University of Chinese Academy of Sciences Beijing 100049China

The southwestern depression of the Qiongdongnan Basin(QDNB)hosts thick Cenozoic sediments and awaits major hydrocarbon *** seismic(MCS)profile CFT2011 across the southwestern QDNB reveals a~60-km-wide fuzzy reflection zone(FRZ)within the sediments,but its origin and distribution remain *** ocean bottom seismometer(OBS)data of Line CFT2011 are processed with focus on the velocity structures by traveltime tomography inversion and analyzed together with the coincident and adjacent MCS *** OBS velocity results show that the giant FRZ features lower velocity with difference up to 1.5 km/s and smaller vertical velocity gradient than the surrounding sedimentary sequences at the same depth,likely resulting from enhanced fluid *** MCS profile exhibits that the giant FRZ is about 3-9-km thick and extends from the Paleogene strata rich in organic matters upward to the lower Pleistocene *** the shallow overlying sediments,multiple bright spots with reverse polarity are imaged and their reflection amplitudes increase with offset,consistent with the features of gas-charged *** are probably shallow gas reservoirs with gases sourced from the deep ***,the FRZ is proposed to be a giant gas-charged zone,which probably contains lots of hydrocarbon gases migrated vertically from the deep Paleogene source rocks through the boundary faults of the depressions and the minor fractures generated under *** FRZ is also imaged on the adjacent MCS profiles MCS-L1 and MCS-L2 with the width of about 40 km and 68 km,*** is roughly estimated to cover an area of~1900 km2 and host a volume of~11400 km3 assuming an average thickness of 6 km,implying huge natural gas potential in the sedimentary depression of the southwestern QDNB of the South China Sea.

关键词： southwestern Qiongdongnan Basin fuzzy reflection zone low velocity gas charging natural gas potential