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Effects of nitrogen addition on plant biomass and tissue elemental content in different degradation stages of temperate steppe in northern China

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Journal of Plant Ecology 2018年第5期11卷 730-739页

作者： jin-bin Chen Cheng-Cheng Dong Xiao-Dong Yao Wei Wang Department of Ecology College of Urban and Environmental Sciences and Key Laboratory for Earth Surface ProcessesPeking UniversityNo.5 Yiheyuan RoadHaidian DistrictBeijing 100871China School of Urban Planning and Design Peking University Shenzhen Graduate SchoolLishui RoadXili TownNanshan DistrictShenzhen 518055China

Aims Grassland degradation has become a common problem *** studies have analyzed the effects of nitrogen(N)addition on plant growth in grasslands,but few have considered its effects on plant growth in degraded *** aim of this study was to evaluate the effects of N addition on plant growth in grasslands with different levels of degradation in Inner Mongolia,*** A 2-year field experiment was conducted to evaluate plant growth response to N addition in degraded grasslands on the Inner Mongolian *** with four levels of degradation were selected for N-addition treatments(0,10,20,30,40,50 g N m−2 year−1).Important Findings Aboveground biomass was increased by N fertilization in degraded grasslands,and N addition was significantly related to increased biomass in grasslands with severe ***,N fertilization did not significantly affect belowground *** effects of N addition on foliar nutrient concentrations in the same species differed among grasslands with different degradation *** was an inconsistent response to N addition between Sanguisorba officinalis and Vicia sepium in non-degraded *** was a significant positive correlation between foliar N content and aboveground biomass in grasslands with different levels of *** results indicate that the effects of N addition on plant growth in grasslands differ according to the severity of *** conclude that N fertilization may be an effective management technique for degraded grasslands in this area and may improve for-age productivity in the short term.

关键词： nitrogen addition degraded grassland aboveground biomass belowground biomass foliar nitrogen concentrations root nitrogen concentrations

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Association of neonatal blood levels of brain-derived neurotrophic factor with development of autism spectrum disorder:a systematic review and meta-analysis

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World Journal of Pediatrics 2021年第2期17卷 164-170页

作者： Ya-Kun Liu Hua Gao Shao-bin jin Wen-Jun Tu Ya-Jun Chen Department of General Surgery Beijing Children’s HospitalCapital Medical UniversityNo.56 Nanlishi St.Beijing 100045China Department of Pediatric Surgery Qilu Hospital of Shandong UniversityNo.107 West Wenhua StJinan 250000China Institute of Radiation Medicine Chinese Academy of Medical SciencePeking Union Medical CollegeNo.238 Baidi StTianjin 300192China Key Lab of Cerebral Microcirculation in Universities of Shandong Shandong First Medical UniversityShandong Academy of Medical SciencesNo.619 Changcheng St.Taian 271000China

Background Our goal was to evaluate the association between neonatal blood brain-derived neurotrophic factor(BDNF)level and autism spectrum disorder(ASD)diagnosis later in *** MEDLINE and Web of Science databases were searched from inception until September 16,*** lists of all relevant articles also were *** blood BDNF concentrations,standard deviations,sample sizes,and other data needed for calculation of effect sizes were extracted by two independent *** quality of the included studies was appraised using the Newcastle-Ottawa Scale for case-control *** were pooled using the random-effects *** Five case-control studies involving 1341 cases and 3395 controls were included in the *** meta-analysis of all included studies showed no significant difference in blood BDNF levels between neonates diagnosed with ASD later in life and healthy controls[standardized mean difference(SMD)=0.261;95%confidence interval(CI)-0.052 to 0.573;P=0.102],with high level of heterogeneity(Q=64.346;I2=93.784;P<0.001).A subgroup analysis by assay type showed decreased blood BDNF levels in ASDs compared to controls(SMD=—0.070;95%CI-0.114 to-0.026;P=0.002),with high level of homogeneity(Q=0.894;I2=0.000;P=0.827).No evidence of publication bias was *** Neonates diagnosed with ASD later in life have decreased blood levels of BDNF measured by double-antibody *** studies are warranted to facilitate a more robust conclusion.

关键词： Autism spectrum disorder Autistic disorder Brain-derived neurotrophic factor Neonates Neurotrophins

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A Bulk‑Heterostructure Nanocomposite Electrolyte of Ce_(0.8)Sm_(0.2)O_(2‑δ)-SrTiO_(3) for Low‑Temperature Solid Oxide Fuel Cells

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Nano-Micro Letters 2021年第3期13卷 66-79页

作者： Yixiao Cai Yang Chen Muhammad Akbar bin jin Zhengwen Tu Naveed Mushtaq Baoyuan Wang Xiangyang Qu Chen Xia Yizhong Huang State Key Laboratory for Modification of Chemical Fibers and Polymer Materials Key Laboratory of High Performance Fibers and ProductsEngineering Research Center of Technical TextilesMinistry of EducationCollege of Materials Science and EngineeringDonghua University201620 ShanghaiPeople’s Republic of China Key Laboratory of Ferro and Piezoelectric Materials and Devices of Hubei Province Faculty of Physics and Electronic ScienceHubei UniversityWuhan 430062HubeiPeople’s Republic of China School of Materials Science and Engineering Nanyang Technological UniversitySingapore 639798Republic of Singapore

Since colossal ionic conductivity was detected in the planar heterostructures consisting of fluorite and perovskite,heterostructures have drawn great research interest as potential electrolytes for solid oxide fuel cells(SOFCs).However,so far,the practical uses of such promising material have failed to materialize in SOFCs due to the short circuit risk caused by *** this study,a series of fluorite/perovskite heterostructures made of Sm-doped CeO2 and SrTiO3(SDC–STO)are developed in a new bulk-heterostructure form and evaluated as *** prepared cells exhibit a peak power density of 892 mW cm−2 along with open circuit voltage of 1.1 V at 550°C for the optimal composition of 4SDC–*** electrical studies reveal a high ionic conductivity of 0.05–0.14 S cm^−1 at 450–550°C,which shows remarkable enhancement compared to that of simplex *** AC impedance analysis,it has been shown that the small grain-boundary and electrode polarization resistances play the major roles in resulting in the superior ***,a Schottky junction effect is proposed by considering the work functions and electronic affinities to interpret the avoidance of short circuit in the SDC–STO *** findings thus indicate a new insight to design electrolytes for low-temperature SOFCs.

关键词： Bulk-heterostructure SOFC electrolyte Ionic conductivity Schottky junction Work function

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Effects of alternating magnetic field on the corrosion rate and corrosion products of copper

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Rare Metals 2008年第3期27卷 324-328页

作者： GUO bin ZHANG Peng jin Yongping CHENG Shukang School of Materials Science and Engineering Harbin Institute of Technology Harbin 150001 China Institute of Electromagnetic and Electronic Technology Harbin Institute of Technology Harbin 150001 China

The effects of alternating magnetic field on the corrosion morphologies, corrosion rate, and corrosion products of copper in 3.5% NaCl solution, sea water, and magnetized sea water were investigated using electrochemical test, scanning electron microscopy/energy dispersive analysis system of X-ray （SEM/EDAX）, and X-ray diffraction （XRD）. The results show that the corrosion rate of copper in magnetized sea water is minimal. Moreover, the surface of the specimen in magnetized sea water is uniform and compact as compared with those in 3.5% NaCl solution and sea water. The corrosion products of copper in magnetized sea water are mainly Cu2O and CuCl2. However, the corrosion products in sea water are CuCl, Cu2Cl（OH）3, and FeCl3-6H2O. The electrochemical corrosion mechanisms of copper in the three media were also discussed.

关键词： corrosion sea water alternating magnetic field copper corrosion products

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Size effects on springback behavior of H80 foils

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Rare Metals 2018年第12期37卷 1082-1090页

作者： Zhen-Wu Ma Zi-Yang Cao jin-bin Lu Yuan-jing Zhang Wei Liu Zhen Yin College of Mechanical Engineering Suzhou University of Science and TechnologySuzhou 215009China Suzhou Key Laboratory of Precision and Efficient Machining Technology Suzhou 215009China

Size effects make traditional bending theories infeasible in analyzing the springback behavior of H80 foils in the similarity bending experiment. It is observed that there is a certain critical thickness value, which divides the change trend of springback amount of foils into two opposite parts. In order to reveal the reason for size effects on the springback behavior of H80 foils, the method of hardness increment characterization was applied to describe the deformation distribution of foils. The competition between strengthening effect of geometrically necessary dislocations and weakening effect of surface grains determines the change trend of springback amount with foil thickness. When the thickness of foils is large, the weakening effects dominate the material behavior, resulting in that the springback amount decreases with the decrease in foil thickness. However, when the foil thickness is small, the strengthening effects dominate the springback tendency, leading to a sharp increase in the springback amount. Furthermore, the deformation distribution is disturbed due to the enhanced effects of individual grain heterogeneity with the decrease in the thickness of foils, leading to the large scatter of springback angle after unloading.

关键词： Foil bending Springback behavior Size effects Hardness increment characterization

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Particle Simulations for Electron Beam-Plasma Interactions

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Chinese Physics Letters 1998年第12期15卷 895-897页

作者： ZHOU Guo-cheng LI Yang CAO jin-bin WANG Xue-yi Center for Space Science and Applied Research Chinese Academy of SciencesBeijing 100080

The computer simulations of high-frequency instabilities excited by the high density electron beam and their nonlinear effect are ***-dimensional electromagnetic particle simulations are performed with different values of the electron beam-to-plasma density *** results show that for the high electron beam-to-background plasma density ratio,all the Langmuir waves and two electromagnetic waves with left-hand and right-hand circular polarizations(i.e.,the“L-O mode”and the“R-X mode”)propagating parallel to the magnetic field can be generated and the maximum values of wave electric fields are nearly the *** electron beam and background plasma are diffused and a part of energetic background electrons are obviously accelerated by the wave-particle *** heating of the beam and background plasma is mainly due to the electrostatic(Langmuir)wave-particle interactions,but the accelerations of a part of energetic background electrons may be mainly due to the electromagnetic wave-particle interactions.

关键词： beam Electron electrostatic

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Nonadiabatic acceleration of plasma sheet ions related to ion cyclotron waves

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Science China(Technological Sciences) 2014年第12期57卷 2434-2440页

作者： WANG Zhi Qiang CAO jin bin RME Henri DANDOURAS Iannis MA Yu Duan Department of Space Science and Application College of Astronautics Nanjing University of Aeronautics and Astronautics University of Toulouse UPS-OMP IRAP Toulouse 31082 France The French National Centre for Scientific Research The Research Institute in Astrophysics and Planetology Space Science Institute School of Astronautics Beihang University

The nonadiabatic acceleration of plasma sheet ions is important to the understanding of substorm energetic injections and the formation of ring current. Previous studies show that nonadiabatic acceleration of protons by magnetic field dipolarization is hard to occur at X>–10 RE because the time-scale of dipolarization(several minutes) is much larger than the gyroperiod of protons there(several seconds). In this paper, we present a case of nonadiabatic acceleration of plasma sheet ions observed by Cluster on October 30, 2006 at(XGSM, YGSM)=(-7.7, 4.7) RE. The nonadiabatic acceleration of ions is caused not by previously reported magnetospheric dipolarization but by the ultra low frequency(ULF) waves during magnetospheric dipolarization. The nonadiabatic acceleration of ions generates a new energy flux structure of ions, which is characterized by the usual energy flux increase of ions(28–80 ke V) and a concurrent energy flux decrease of ions in a lower energy range(10 e V–20 ke V). These new observations constitute a complete physical picture: The lower energy ions absorb the wave energy, and thus get accelerated to higher energy. We use a nonadiabatic model to interpret the ion energy flux variations. Both analytic and simulation results are in good agreement with the observations. This indicates that the nonadiabatic acceleration associated with ULF waves superposed on dipolarized magnetic field is an effective mechanism for ion energization in the near-Earth plasma sheet. The presented energy flux structures can be used as a proxy to identify the similar dynamic process.

关键词： nonadiabatic acceleration ion cyclotron waves wave-particle interaction

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Preliminary design and parametric study of 1400 m partially earth-anchored cable-stayed bridge

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Science China(Technological Sciences) 2010年第2期53卷 502-511页

作者： SUN bin, CHENG jin & XIAO RuCheng Department of Bridge Engineering, Tongji University, Shanghai 200092, China 1. Department of Bridge Engineering Tongji University Shanghai 200092 China

The preliminary design and parametric study of 1400 m partially earth-anchored cable-stayed bridge are described. Static per-formance of this new type of bridge is discussed. Compared with fully self-anchored cable-stayed bridge, its advantages in fin-ished state are summarized. Based on numerical calculation, effects of several structural parameters on static performance are presented.

关键词： partially earth-anchored cable-stayed bridge preliminary design parametric study

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Optical property and spectroscopy studies on the selected lubricating oil in the terahertz range

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Science China(Physics,Mechanics & Astronomy) 2009年第12期52卷 1938-1943页

作者： TIAN Lu ZHOU QingLi jin bin ZHAO Kun ZHAO SongQing SHI YuLei ZHANG CunLin Department of Materials Science and Engineering China University of PetroleumBeijing 102249China Beijing Key Laboratory for Terahertz Spectroscopy and Imaging Key Laboratory of Terahertz OptoelectronicsMinistry of EducationDepartment of PhysicsCapital Normal UniversityBeijing 100048China State Key Laboratory of Heavy Oil Processing China University of PetroleumBeijing 102249China Department of Mathematics and Physics China University of PetroleumBeijing 102249China

The optical property and spectroscopy of selected kinds of lubricating oil are studied based on the terahertz time-domain spectroscopy (THz-TDS) in the spectral range of 0.3-1.6 THz. The samples are classified by their characteristics via the near-infrared spectrum. The experimental results reveal that lubricating oil is more sensitive in the range of terahertz than in the near-infrared,and the specific kinds of lubricating oil can be identified according to their different spectral features in the terahertz range. The THz-TDS technology applied to lubricating oil analysis has potentially significant impact on the petroleum field.

关键词： terahertz near-infrared transform spectrum lubricating oil

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Application of ultrasonic in strength measurement of similar materials of limestone

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Journal of Central South University of Technology 2005年第z1期12卷 157-161页

作者： LIU Tie-xiong PENG Zhen-bin HAN jin-tian School of Geoscience and Environmental Engineering Central South University Changsha 410083 China Guangdong Provincial Academy of Building Research Guangzhou 510500 China School of Geoscience and Environmental Engineering Central South University Changsha 410083 China Guangdong Provincial Academy of Building Research Guangzhou 510500 China

Similar materials such as cement, gypsum and sand are options for simulating limestone characteristic.A series of reasonable proportions are chosen to do similar experiments of Karst roof based on the proportions testing of small samples indoors. Applying on ultrasonic, the velocities of transverse wave and vertical wave of similar samples have been inspected with the sound wave instrument. Dynamic modulus of elasticity and Poisson's ratio of the samples have been educed. According to the testing data, the relationship between the transverse wave and vertical wave velocity, compressive strength and anti-bend strength are analyzed. It has been proved that the vertical wave velocity is better for reflecting compressive strength and anti-bend strength of similar materials than the transverse wave velocity. The vertical wave velocity increases with the strengthand dynamic modulus of elasticity.

关键词： ultrasonic similar materials similar theory modulus of elasticity Poisson's ratio

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