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Retrieving Soil Water Contents from Soil Temperature Measurements by Using Linear Regression

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Advances in Atmospheric Sciences 2003年第6期20卷 849-858页

作者： qin xu Binbin ZHOU NOAA NationalSevereStormsLaboratoryNormanOklahomaUSA NOAAJNWSflNationalCentersforEnvironmentalPrediction CampSpringsMarylandUSA

A simple linear regression method is developed to retrieve daily averaged soil water content from diurnal variations of soil temperature measured at three or more depths. The method is applied to Oklahoma Mesonet soil temperature data collected at the depths of 5, 10, and 30 cm during 11–20 June 1995. The retrieved bulk soil water contents are compared with direct measurements for one pair of nearly collocated Mesonet and ARM stations and also compared with the retrievals of a previous method at 14 enhanced Oklahoma Mesonet stations. The results show that the current method gives more persistent retrievals than the previous method. The method is also applied to Oklahoma Mesonet soil temperature data collected at the depths of 5, 25, 60, and 75 cm from the Norman site during 20–30 July 1998 and 1–31 July 2000. The retrieved soil water contents are verified by collocated soil water content measurements with rms differences smaller than the soil water observation error (0.05 m3 m−3). The retrievals are found to be moderately sensitive to random errors (±0.1 K) in the soil temperature observations and errors in the soil type specifications.

关键词： retrieval soil water content

Cusp points and assembly changing motions in the PRR-PR-PRR planar parallel manipulator

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Frontiers of Mechanical Engineering 2023年第2期18卷 177-187页

作者： Chengwei SHEN Jingjun YU xu pei School of Mechanical Engineering&Automation Beihang UniversityBeijing 100191China

Most parallel manipulators have multiple solutions to the direct kinematic *** ability to perform assembly changing motions has received the attention of a few *** points play an important role in the kinematic *** study investigates the cusp points and assembly changing motions in a two degrees of freedom planar parallel *** direct kinematic problem of the manipulator yields a quartic polynomial *** root in the equation determines the assembly configuration,and four solutions are obtained for a given set of actuated joint *** regarding the discriminant of the repeated roots of the quartic equation as an implicit function of two actuated joint coordinates,the direct kinematic singularity loci in the joint space are determined by the implicit *** points are then obtained by the intersection of a quadratic curve and a cubic *** assembly changing motions by encircling different cusp points are highlighted,for each pair of solutions with the same sign of the determinants of the direct Jacobian matrices.

关键词： planar parallel manipulator assembly changing motions cusp points quartic polynomial discriminant of repeated roots

Understanding the effects of the impervious surfaces pattern on land surface temperature in an urban area

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Frontiers of Earth Science 2015年第2期9卷 276-285页

作者： qin NIE Jianhua xu Department of Spatial Information Science and Engineering Xiamen University of Technology Xiamen 361024 China The Research Center for East-West Cooperation in China The-Key Laboratory of GIScience of the Minis-try of Education of China East China Normal University Shanghai 200241 China

It is well known that urban impervious surface （IS） has a warming effect on urban land surface temperature （LST）. However, the influence of an IS＇s structure, components, and spatial distribution on LST has rarely been quantitatively studied within strictly urban areas. Using ETM＋ remote sensing images from the downtown area of Shanghai, China in 2010, this study characterized and quantified the influence of the IS spatial pattern on LST by selecting the percent cover of each IS cover feature and ten configuration metrics. The IS fraction was estimated by linear spectral mixture analysis （LSMA）, and LST was retrieved using a mono-window algorithm. The results indicate that high fraction IS cover features account for the majority of the study area. The high fraction IS cover features are widely distributed and concentrated in groups, which is similar with that of high temperature zones. Both the percent composition and the configuration of IS cover features greatly affect the magnitude of LST, but the percent composition is a more important factor in determining LST than the configuration of those features. The significances and effects of the given configuration variables on LST vary greatly among IS cover features.

关键词： urban impervious surfaces land surfacetemperature spatial pattern Shanghai city

Solitons in Bose-Einstein Condensates with Time-Dependent Atomic Scattering Length in a Harmonic Trap

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Communications in Theoretical Physics 2008年第12期50卷 1323-1326页

作者： ZHANG Xiao-Fei ZHANG pei YANG qin Beijing National Laboratory for Condensed Matter Physics Institute of Physics Chinese Academy of Sciences Beijing 100190 China Department of Physics Honghe University Mengzi 661100 China College of Science Honghe University Mengzi 661100 China School of Electrical and Mechanical Engineering Jinxing University Jinxing 314001 China

We obtain the integrable relation for the one-dimensional nonlinear Schrodinger equations which describes the dynamics of a Bos-Einstein Condensates with time-dependent scattering length in a harmonic potential. The exact one- and two-soliton solutions are constructed analytically by using the Hirota method. Then we further discuss the dynamics of the one soliton and the interactions between two solitons in currently experimental conditions.

关键词： Bose-Einstein condensate nonlinear equation the time-dependent scattering length soliton

The total column densities and fractional abundances of CH_3CN,CH_3OH,HCOOCH_3 and^(13)CS in W51 cores

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Science China(Physics,Mechanics & Astronomy) 2005年第2期48卷 158-167页

作者： pei Chunchuan MA Hongjun ZENG qin LI Bo Purple Mountain Observatory Chinese Academy of Sciences Nanjing 210008 China Purple Mountain Observatory Chinese Academy of Sciences Nanjing 210008 China Purple Mountain Observatory Chinese Academy of Sciences Nanjing 210008 China Purple Mountain Observatory Chinese Academy of Sciences Nanjing 210008 China

We present interferometric observations of the W51 region at 2.7 mm and 3.3 mm with the Berkeley-Illinois-Maryland Association Array. The lines of CH3CN (J = 6 – 5, K = 0,1,2,3,4), CH3OH (15-2 ?151 E), HCOOCH3-A (71,6 – 61,5), HCOOCH3 -E (71,6 – 61,5) and 13CS (2-1) as well as the 2.7 mm continuum toward W51 have been observed. The derived total beam-averaged column densities NT and fractional abundances of CH3CN, CH3OH, HCOOCH3 and 13CS in W51 cores have been obtained.

关键词： massive star formation, interstellar molecular lines, column density, fractional abundance.

Low Complexity SOVA for Turbo Codes

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China Communications 2017年第8期14卷 33-40页

作者： Ruilin pei Zulin Wang qin Huang Jiaqing Wang School of Electronic and Information Engineering Beihang UniversityBeijing100191China Collaborative Innovation Center of Geospatial Technology Wuhan430079China State Key Laboratory of Wireless Mobile Communications(CATT) Beijing100191China

Recently, trimming Soft-output Viterbi algorithm(T-SOVA) has been proposed to reduce the complexity of SOVA for Turbo codes. In its fi rst stage, a dynamic algorithm, lazy Viterbi algorithm, is used to indicate the minimal metric differences which brings obstacle on hardware implementation. This paper proposes a Viterbi algorithm(VA) based T-SOVA to facilitate hardware implementation. In the first stage of our scheme, a modified VA with regular structure is used to fi nd the maximum likelihood(ML) path and calculate the metric differences. Further, local sorting is introduced to trim the metric differences, which reduces the complexity of trimming operation. Simulation results and complexity analysis show that VA based T-SOVA performs as well as lazy VA based T-SOVA and is easier to be applied to hardware implementation.

关键词： VA SOVA local sorting hardware implementation

Application of sustained delivery microsphere of cyclosporine A for preventing posterior capsular opacification in rabbits

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International Journal of Ophthalmology(English edition) 2013年第1期6卷 1-7页

作者： Cheng pei Yi xu Jean Xin.Jiang Li-Jun Cui Li Li Li qin Department of Ophthalmology the First Affiliated Hospitalof Xi'an Jiaotong University Disease Control Center of Shaanxi Province University of Texas Health Science Center at San Antonio

AIM:To explore the inhibitory effect of a sustained cyclosporin A (CsA) delivery microsphere (CsA-MS) on posterior capsular opacification (PCO) in rabbit eyes after cataract extraction. ·METHODS:Twenty New Zealand white rabbits accepted cataract extraction plus intraocular lens implantation and their left eyes were intraoperatively injected CsA-MS prepared using polymer polylactioglycolic acid (PLGA) as a carrier and their right eyes were injected with empty MS. The changes in cornea, anterior chamber reaction, intraocular pressure, PCO and CsA concentration in aqueous humor were examined postoperatively and all the eyes were enucleated 3 months after surgery for histopathological and morphological examination with light microscopy and electron microscopy. · RESULTS:Conjunctival hyperemia, corneal edema, intraocular pressure and anterior chamber response of experimental and control eyes were similar, while PCO in CsA MS injected eyes was greatly improved compared with that in control eyes. Posterior capsules in CsA-MS injected eyes were smooth and lens epithelial cells (LEC) did not proliferate significantly (P >0.05), while LEC in posterior capsule of control eyes had different degrees of proliferation and cortical regeneration. LEC in CsA-MS injected eyes were not functionally active and underwent apoptosis, whereas LEC in control eyes were functionally active (F-test, P =0.025). In addition, the cornealultrastructure showed no differences between CsA-MS and MS injected eyes. CONCLUSION:CsA-MS has high bioavailability in rabbit eyes and could inhibit postoperative PCO occurrence and development during the study period, suggesting that CsA-MS may be a promising, effective and safe administration route to prevent PCO in clinic.

关键词： sustained cyclosporine A delivery microsphere posterior capsular opacification rabbit eyes

The runoff characteristics under simulated rainfall on purple soil sloping cropland

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Chinese Journal Of Geochemistry 2011年第3期30卷 317-322页

作者： xu pei FU Bin Key Laboratory of Mountain Surface Process and Hazards Chinese Academy of Sciences Chengdu 610041 China Institute of Mountain Hazards and Environment Chinese Academy of Sciences Chengdu 610041 China

Rainfall runoff is a critical hydrological process related to soil erosion and agricultural non-point pollu-tion. In this study, 25 simulation experiments on rainfall were carried out in five runoff plots. Rape (Brassica campestris) was planted on the downslope of the plots. Experiments were conducted when the vegetation coverage reached 80%. Each plot was subjected to five rainfall events differing in intensity. The results showed: (1) the runoff coefficients of overland flow and subsurface flow were less than 0.6 and 0.005, respectively; (2) the discharge of overland flow was the quadratic function of time; (3) runoff coefficient was the function of slope gradient and rain-fall intensity. When the slope gradient increased from 8.7% to 46.6%, the runoff coefficient of overland flow first increased and then decreased. The runoff coefficient reached the maximum when the slope gradient was within the range of 17.6%-36.4%; and (4) the process of subsurface flow generation included the increasing phase and reces-sion phase. Discharge was a logarithm function of time in the increasing phase, and an exponential function in the recession phase. Runoff coefficient of subsurface flow decreased first and then increased when the slope gradient varied from 8.7% to 46.6% and was not correlated with rainfall intensity.

关键词：模拟降雨径流特性紫色土坡耕地农业非点源污染径流系数降雨强度径流小区

Effect of glucose on the soil bacterial diversity and function in the rhizosphere of Cerasus sachalinensis

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Horticultural Plant Journal 2021年第4期7卷 307-317页

作者： Wenjie Zhou xu qin Deguo Lyu Sijun qin College of Horticulture Shenyang Agricultural UniversityShenyang 110866China Small Fruit Institute Eastern Liaoning University/Key Laboratory of Blueberry Breeding and Postharvest HandlingLiaoning ProvinceDandongLiaoning 118003China School of Garden Science and Engineering Shandong Agriculture and Engineering UniversityJinanShandong 250100China

Most cherry orchards in China have low organic carbon content,though carbon is very important for plant *** changes in soil carbon and bacterial diversity were determined after different amounts of 12C-glucose were added to the rhizosphere of Cerasus *** bacteria diversity was measured using high throughput sequencing,and bacteria containing 13C-glucose were identified using DNA-SIP *** results demonstrated that soil microbial biomass carbon(MBC)content and the soil respiratory rate were increased at 3 and 7 days after adding *** soil organic carbon(SOC)content was decreased on the 7th day in the treatment where the added glucose-C was equivalent to the MBC *** content was decreased on the 15th day after adding glucose-C equivalent to five times that of the soil *** to the controls,the relative abundance of taxa at the phylum level displayed no significant change in the treatments with glucose-C added as 10%and equal amount of soil MBC 3–30 days after ***,the relative abundance of Proteobacteria increased significantly in the treatment with the addition of glucose-C equivalent to five times of soil *** main changes were observed in the bacteria in several genera including A4,Flavisolibacter,Aquicella,and Candidatus ***-SIP results indicated that the relative abundance of the Proteobacteria and Pseudomonas was the highest;these were the primary bacteria phylum and genus,respectively,from day 3 to day *** conclusion,the changing pattern demonstrated that with the addition of more glucose,the range of the bacterial communities changed *** and Pseudomonas may be the bacteria promoting priming effect.

关键词： Cerasus sachalinensis Soil respiration Soil organic carbon High throughput sequencing DNA-SIP Priming effect