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Storage and Density of Soil Organic Carbon in Urban Topsoil of Hilly Cities:A Case Study of Chongqing Municipality of China

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Chinese Geographical Science 2013年第1期23卷 26-34页

作者： LIU Yong WANG Cheng YUE Wenze hu Yanyan College of Resources and Environment Southwest University Institute of Land Science and Property Management Zhejiang University Chongqing Institute of Landscape Gardening

Rapid urbanization results in the conversion of natural soil to urban soil,and consequently,the storage and density of the soil carbon pools *** Chongqing Municipality of China as a study case,this investigation attempts to better understand soil carbon pools in hilly ***,the vegetated areas in the study area were derived from QuickBird ***,topsoil data from 220 soil samples(0-20 cm) in the vegetated areas were collected and their soil organic carbon(SOC) densities were *** the Kriging interpolation method,the spatial pattern of SOC was *** results show that the SOC density exhibited high spatial variability in the urban topsoil of ***,the SOC density in topsoil decreased according to slope in the order 2°-6° < 25°-90° < 0°-2° < 6°-15° < 15°-25°.Second,the newly developed areas during 2001-2010 had a lower SOC density than the areas built before ***,urban parks and gardens had a higher SOC density in topsoil,residential green land followed,and scattered street green land ranked *** hilly cities,the variability of terrain affects the distribution of *** Kriging results indicate that Kriging method combining slope with SOC density produced a high level of *** Kriging results show that the SOC density to the north of the Jialing River was higher than the *** vegetated areas were estimated to amount to 73.5 km2 across the study area with an SOC storage of 0.192 Tg and an average density of 2.61 kg/m2.

关键词： soil organic carbon (SOC) topsoil hilly city Kriging interpolation

Coexistence of Magnetism and Conductivity in Bis（ethylenediseleno） Tetrathiafulvalene （BEST） with Octahedral Anions Hexacyanoferrate （Ⅲ） and Nitroprusside

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Communications in Theoretical Physics 2005年第1期43卷 187-192页

作者： ZOUWei-Dong LIUZu—Li WUMing-hu YAOKai-Lun DepartmentofPhysics HuazhongUniversityofScienceandTechnologyWuhan430074，China／／DepartmentofPhysicsXianningTeachersCollegeXianning437005China DepartmentofPhysics HuazhongUniversityofScienceandTechnologyWuhan430074China DepartmentofPhysics XianningTeachersCollegeXianning437005China

Using an accurate density-function method, we explore the coexistence of the magnetism and conductivity in bis(ethylenediselena)-tetrathiafulvalene (BEST) with the paramagnetic hexacyanoferrate(Ⅲ) [Fe(CN)6]3-or the photochromic nitroprusside anion [Fe(CN)5NO]2-. The total and partial densities of states, and the atomic spin magnetic moments are calculated and discussed. It is found that the up- and down-spin total densities of states (DOS)are continuous in the vicinity of the Fermi level, there is overlap between the HOMO and LUMO in the up-spin subbands and the down-spin subbands, which reveals that these types of compounds have conductive properties. From the total and partial densities of states and atomic spin magnetic moments, it is shown that the spin magnetic moments of (BEST)4[Fe(CN)6] is mainly assembled at the iron atom and the cyanogen radical, and the spontaneous magnetic moments for (BEST)2[Fe(CN)5NO] come from iron atom, cyanogen and nitric oxide radical. To our best knowledge, it is the first theoretical study on the coexistence of the magnetism and conductivity of these compounds.

关键词： magnetic properties conductive properties first-principles method

The intrinsic γ-ray emissions of Fermi blazars

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Research in Astronomy and Astrophysics 2017年第7期17卷 25-38页

作者： Chao Lin Jun-hui Fan hu-Bing Xiao Center for Astrophysics Guangzhou University Astronomy Science and Technology Research Laboratory of Department of Education of Guangdong Province

The beaming effect is important for understanding the observational properties of *** this work, we collect 91 Fermi blazars with available radio Doppler factors. γ-ray Doppler factors are estimated and compared with radio Doppler factors for some sources. The intrinsic（de-beamed）γ-ray flux density（fγin）, intrinsic γ-ray luminosity（Lγin） and intrinsic synchrotron peak frequency（VPin）are calculated. Then we study the correlations between finγand redshift and find that they follow the theoretical relation： log f =-2.0 log z ＋ const. When the subclasses are considered, we find that stationary jets are perhaps dominant in low synchrotron peaked blazars. Sixty-three Fermi blazars with both available short variability time scales（？T） and Doppler factors are also collected. We find that the intrinsic relationship between Lγin and ？Tinobeys the Elliot ＆ Shapiro and Abramowicz ＆ Nobili relations. Strong positive correlation between fγinand VPinis found, suggesting that synchrotron emissions are highly correlated with γ-ray emissions.

关键词： galaxies active - BL Lacertae objects general - gamma-rays galaxies

Strain-mediated voltage-controlled switching of magnetic skyrmions in nanostructures

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npj Computational Materials 2018年第1期4卷 147-153页

作者： Jia-Mian hu Tiannan Yang Long-Qing Chen Department of Materials Science and Engineering The Pennsylvania State UniversityUniversity ParkPA 16802USA Department of Materials Science and Engineering University of Wisconsin–MadisonMadisonWI 53706USA

Magnetic skyrmions are swirling spin structures stabilized typically by the Dyzaloshinskii-Moriya *** existing control of magnetic skyrmions has often relied on the use of an electric current,which may cause overheating in densely packed *** we demonstrate,using phase-field simulations,that an isolated Néel skyrmion in a magnetic nanodisk can be repeatedly created and deleted by voltage-induced strains from a juxtaposed *** a skyrmion switching is non-volatile,and consumes only~0.5 fJ per switching which is about five orders of magnitude smaller than that by current-induced *** is found that the strain-mediated skyrmion creation occurs through an intermediate vortex-like spin structure,and that the skyrmion deletion occurs though a homogenous shrinkage during which the Néel wall is temporarily transformed to a *** findings are expected to stimulate experimental research into strain-mediated voltage control of skyrmions,as well as other chiral spin structures for low-power spintronics.

关键词： vortex magnetic repeatedly

The off-state gate isolation technique to improve ASET tolerance in differential analog design

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Science China(Technological Sciences) 2013年第10期56卷 2599-2605页

作者： hu ChunMei CHEN ShuMing CHEN JianJun QIN JunRui College of Computer National University of Defense Technology

A novel off-state gate RHBD technique to mitigate the single-event transient(SET)in the differential data path of analog circuit is demonstrated in this *** results present that this off-state gate technique could exploit charge sharing in differential circuits and reduce differential mode voltage perturbation *** is indicated that this technique is more effective to mitigate SET than the differential charge cancellation(DCC)technique with less penalty.

关键词： charge sharing ASET off-state gate layout mitigation technique

Field validation of the GLASS land surface broadband emissivitydatabase using pseudo-invariant sand dune sites in northern China

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International Journal of Digital Earth 2013年第S01期6卷 96-112页

作者： Lixin Dong Juyang hu Shihao Tang Min Min Key Laboratory of Radiometric Calibration and Validation for Environmental Satellites National Satellite Meteorological CenterBeijingChina

The land surface broadband emissivity (LSBE) is a key parameter for estimatingsurface radiation, and there have been many studies of the LSBE at global orlocal scales. However, few studies have validated the surface emissivity databasewith multi-point field measurement data using infrared radiometry, especially inChina. In this study, we focus on the validation of the emissivity product of theglobal land surface satellite (GLASS) LSBE database for northern China for theperiod from 2006 to 2011. Specifically, we have employed an eight-day averaged,gridded emissivity product in the 813.5 mm spectral range produced at a spatialresolution of 1000 m from the Moderate Resolution Imaging Spectrometeralbedo product using a new algorithm. The GLASS LSBE database was validatedover bare surfaces with field measurement data from sand samples collected atmany pseudo-invariant sand dune sites located in western and northwesternChina. By comparing measured emissivity for different land surface types atdifferent sites and different times, it was shown that the results were consistentand that the accuracy of the field measurements was reliable. The results of thevalidation of GLASS LSBE with these field emissivity data showed very goodagreement.

关键词： validation broadband emissivity field measurement emissivity GLASS northern China

Simulation study on fluctuant flow stress scale effect

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2006年第8期7卷 1343-1350页

作者： SHEN Yu YU hu-ping RUAN Xue-yu National die and Mold CAD Engmeering Research Center Shanghai Jiao Tong University Shanghai 200030 China

Crystal plasticity theory was used to simulate upsetting tests of different dimensions and grain size micro copper cylinders in this study on the fluctuant flow stress scale effect. Results showed that with the decrease of billet grain quantity, flow stress fluctuation is not always increased, but there is a maximum. Through this study, the fluctuant flow stress scale effect can be understood deeper, and relevant necessary information was obtained for further prediction and control of this scale effect and to design the microforming process and die.

关键词： Microforming Scale effect Numerical simulation Fluctuation

Updatable block-level deduplication of encrypted data with efficient auditing in cloud storage

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The Journal of China Universities of Posts and Telecommunications 2019年第3期26卷 56-72页

作者： Dang Qianlong Xie Ying Li Donghao hu Gongcheng School of Mathematics and Statistics Xidian University Xi'an 710071 China School of Natural and Applied Sciences Henan University of Technology Zhengzhou 450001 China

Updatable block-level message-locked encryption(MLE) can efficiently update encrypted data, and public auditing can verify the integrity of cloud storage data by utilizing a third party auditor(TPA). However, there are seldom schemes supporting both updatable block-level deduplication and public auditing. In this paper, an updatable block-level deduplication scheme with efficient auditing is proposed based on a tree-based authenticated structure. In the proposed scheme, the cloud server(CS) can perform block-level deduplication, and the TPA achieves integrity auditing tasks. When a data block is updated, the ciphertext and auditing tags could be updated efficiently. The security analysis demonstrates that the proposed scheme can achieve privacy under chosen distribution attacks in secure deduplication and resist uncheatable chosen distribution attacks(UNC-CDA) in proof of ownership(PoW). Furthermore, the integrity auditing process is proven secure under adaptive chosen-message attacks. Compared with previous relevant schemes, the proposed scheme achieves better functionality and higher efficiency.

关键词： data update operation block-level deduplication efficient auditing tree-based authenticated structure proof of ownership

Energy Efficient Resource Allocation in Timesharing Multiuser Systems with Hybrid Energy Harvesting Transmitter

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China Communications 2017年第8期14卷 83-92页

作者： Jinming hu Wei Heng Guodong Zhang Xiang Li National Mobile Communications Research Laboratory Southeast UniversityNanjing 210096China

An energy effi cient resource allocation scheme in timesharing multiuser system with a hybrid energy harvesting transmitter is studied in this paper. Specially, the operation energy of system is supplied by constant energy and energy harvesting, which harvests energy from external environment. Our goal is to maximize the energy effi ciency of timesharing multiuser systems by considering jointly allocation of transmission time and power control in an off-line manner. The original nonconvex objective function is transformed into convex optimization problem via the fractional programming approach. Then, we solve the convex problem by Lagrange dual decomposition method. Simulation results show that the proposed energy efficient resource allocation scheme has a better performance than the scheme which decomposes optimization problem into two parts(power allocation, time allocation) to solve iteratively.

关键词： energy harvesting energy efficient resource allocation fractional programming