检索结果-南通市图书馆

Contribution of point defects and nano-grains to thermal transport behaviours of oxide-based thermoelectrics

在线全文

学校读者我要写书评

暂无评论

npj Computational Materials 2016年第1期2卷 84-92页

作者： Guang-Kun Ren Jin-Le Lan Kyle J Ventura Xing Tan Yuan-Hua Lin Ce-Wen Nan state Key Laboratory of New Ceramics and Fine Processing Department of Materials Science and EngineeringTsinghua UniversityBeijingChina state Key Laboratory of Organic-inorganic Composite College of Materials Science and EngineeringBeijing University of Chemical TechnologyBeijingChina School of Engineering Clarkson UniversityPotsdamNYUSA

Point defects and nano-grains are very effective ways to control the thermal conductivity in oxide-based *** we use the optimised Debye–Callaway model to understand how the effect of point defects and nano-grains to reduce the thermal conductivity by inducing normal process and oxygen vacancy in oxide-based *** results reveal that this model can be effective to fit the experimental data of thermal conductivity in ZnO-,CaMnO_(3)-,BiCuSeO-,SrTiO_(3)^(-)and In_(2)O_(3)-based systems,which indicate that the normal scattering process and the oxygen vacancy will make obvious contribution to the thermal conductivity as compared with alloy compounds *** calculations also propose that it could be desirable to obtain higher ZT by controlling the concentration of oxygen vacancy in the nano-grained thermoelectric oxides.

关键词： alloy grain thermal

Temperature effects of dark solitons on the self-deflection of bright solitons in a separate bright-dark soliton pair

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese science Bulletin 2007年第6期52卷 725-731页

作者： ZHANG GuangYong LIU JinSong ZHANG HuiLan WANG Cheng LIU ShiXiong Institute of Optoelectronics science and Engineering State Key Laboratory of Laser Technology Huazhong University of Science and Technology Wuhan 430074 China department of Physics China University of Geosciences Wuhan 430074 China

Based on the theory of one-dimensional separate soliton pairs formed in a serial photorefractive crystal circuit, we investigated the temperature effects of the dark soliton on the self-deflection of the bright soliton in a bright-dark soliton pair. The numerical results obtained by solving the nonlinear propaga-tion equation showed that the bright soliton moves on a parabolic trajectory in the crystal and its spa-tial shift changed with the temperature of the dark soliton. The higher the temperature of the dark soli-ton was, the smaller the spatial shift of the bright soliton was. The self-bending process was further studied by the perturbation technique, and the results were found to be in good agreement with that obtained by the numerical method.

关键词：暗孤子明孤子自偏转明暗孤子对温度效应

Comparative Effect of City Finished Compost and NPK Fertilizer on Growth and Availability of Phosphorus to Radish (<i>Raphanus sativus</i>L.)

在线全文

学校读者我要写书评

暂无评论

Open Journal of soil science 2012年第2期2卷 146-154页

作者： Ashoka Sarker Md. Abul Kashem Khan Towhid Osman department of soil science University of Chittagong Chittagong Bangladesh.

A pot experiment was carried out to investigate the comparative effect of city finished compost and NPK fertilizer on the growth and availability of phosphorus to radish (Raphanus sativus L.). An air dried sandy loam soil was mixed with five rates of city finished compost (CFC) equivalent to 0, 5, 10, 20, 40 ton ha–1 and three rates of NPK fertilizer equivalent to 50% (N-P-K = 69-16-35 kg ha–1), 100% (N-P-K = 137-32-70 kg ha–1 K) and 150% (N-P-K = 206-48-105 kg ha–1). Four plants were harvested at 45 days of growth and remaining one plant was harvested at 90 days of growth and separated into leaves and bulbs. After harvest, soil samples were collected from each pot to measure soil pH and available P extracted by Olsen, Mehlich-3, Kelowna and Bray & Kurtz-1 extractants. The growth parameters (length of leaves and bulbs, fresh and dry weight of leaves and bulbs), relative dry matter yield, plant P concentrations, P uptake by radish, soil pH, and available P increased by the rates of CFC and NPK fertilizer treatments. Among the treatments, growth performance of radish was better with the highest rate of 40 t ha–1 CFC treatments. The results obtained from the 5 and 10 t ha–1 CFC treatment were comparable with the results of 50% and 100% NPK fertilizer treatments respectively. Similar effects of amendments were obtained in the case of plant P concentration, uptake of P by plant, soil pH and available soil P concentration. Available P and soil pH showed very strong and positive correlation (P –1 city finished compost could be used instead of 100% to obtain similar yield and to improve soil conditions.

关键词： Compost soil Extraction Methods Growth Phosphorus Radish

Multi-scaling hierarchical structure analysis on the sequence of *** complete genome

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese science Bulletin 2001年第23期46卷 1988-1992页

作者： WANG Jin ZHANG Qidong REN Kui SHE Zhensu state Key Laboratory of Pharmaceutical Biotechnology School of Life ScienceNanjing UniversityNanjing 210093China state Key Laboratory for Studies of Turbulence and Complex Systems Department of Mechanics and Engineering SciencePeking UniversityBeijing 100871China department of Geophysics Peking UniversityBeijing 100871China

We have applied the newly developed hierarchical structure theory for complex systems to analyze the multi-scaling structures of the nucleotide density distribution along a linear DNA sequence from the complete Escherichia coli genome. The hierarchical symmetry in the nucleotide density distribution was demonstrated. In particular, we have shown that the G, C density distribution that represents a strong H-bonding between the two DNA chains is more coherent with smaller similarity parameter compared to that of A, T density distribution, indicating a better organized multi-scaling fluctuation field for G, C density distributionalong the genome sequence. The biological significance of these findings is under investigation.

关键词： complexity hierarchical structure genome nucleotide Escherichia coli.

Effects of defect states on the performance of CuInGaSe_2 solar cells

在线全文

学校读者我要写书评

暂无评论

Journal of Semiconductors 2014年第2期35卷 76-81页

作者：万福成汤富领薛红涛路文江冯煜东芮执元 state Key Laboratory of Gansu Advanced Non-ferrous Metal Materials Department of Materials Science and EngineeringLanzhou University of Technology science and Technology on Surface Engineering Laboratory Lanzhou Institute of Physics

Device modeling has been carried out to investigate the effects of defect states on the performance of ideal CulnGaSe2 （CIGS） thin film solar cells theoretically. The varieties of defect states （location in the band gap and densities） in absorption layer CIGS and in buffer layer CdS were examined. The performance parameters： open-circuit voltage, short-circuit current, fill factor, and photoelectric conversion efficiency for different defect states were quantitatively analyzed. We found that defect states always harm the performance of CIGS solar cells, but when defect state density is less than 10 14 cm-3 in CIGS or less than 10 18 cm-3 in CdS, defect states have little effect on the performances. When defect states are located in the middle of the band gap, they are more harmful. The effects of temperature and thickness are also considered. We found that CIGS solar cells have optimal performance at about 170 K and 2 μm of CIGS is enough for solar light absorption.

关键词： device modeling defect states solar cell conversion efficiency

Seashore paspalum (Paspalum vaginatum Sw.) performance under shade in multi-environment trials

在线全文

学校读者我要写书评

暂无评论

Grass Research 2021年第1期1卷 42-49页

作者： Beatriz Tome Gouveia Paul Raymer Brian M.Schwartz Esteban F.Rios Kevin E.Kenworthy J.Bryan Unruh Charles Fontanier Esdras M.Carbajal Jason Kruse Natasha K.Restuccia Susana R.Milla-Lewis department of Crop and soil sciences North Carolina State UniversityCampus Box 7620RaleighNC 27695USA department of Crop and soil sciences University of GeorgiaGriffin Campus1109 Experiment StreetGriffinGA 30223USA department of Crop and soil sciences University of GeorgiaTifton Campus2360 Rainwater RoadTiftonGA 31793USA Agronomy department University of Florida2005 SW 23rd Street Bldg 350GainesvilleFL 32608USA Environmental Horticulture department University of FloridaWest Florida Research and Education Center4253 Experiment RoadHwy 182JayFL 32565USA department of Horticulture and Landscape Architecture Oklahoma State UniversityOklahomaOK 74078USA department of Environmental Horticulture University of Florida1541 Fifield HallGainesvilleFL 32611USA

Shade caused by trees or buildings can affect the quality and growth of ***,breeding for shade tolerance is an essential component of most turfgrass improvement *** objective of this study was to evaluate the performance of seashore paspalum(Paspalum vaginatum Sw.)breeding lines under shade in multi-environment *** sources were 20 lines from the university of Georgia seashore paspalum breeding program and two checks,the cultivars'SeaDwarf'and'SeaStar'.Field trials were conducted from 2016 to 2019 under shade structures designed to reduce ambient sunlight at three locations:Citra(FL),Tifton(GA),and Raleigh(NC).The response variables evaluated were percent living ground cover(%GC),dark green color index(DGCI),canopy height(CH)and turfgrass quality(TQ).Data were analyzed by mixed model approaches using ASReml-R,and the t-statistics were used to group the *** genetic variances were observed in the single-location-repeated-measures analysis for CH and DGCI at Citra and Tifton,%GC at Citra,and TQ at *** correlations of the predicted values for entries between locations ranged from low to moderate,with the exception of between Citra and Tifton(0.76)for *** were a few breeding lines with superior performance to the entry average for all traits for which the entry variance was *** conclusion,genetic variability was observed for all traits and superior seashore paspalum breeding lines for multiple traits were identified under shade.

关键词： breeding cultivar measures

Synthesis and photoluminescent properties of Sr_2Si_5N_8:Eu^(2+) red phosphors for white light-emitting diodes

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Rare Earths 2014年第8期32卷 691-695页

作者：刘畅张壁郝绿原徐鑫 Key Laboratory of Materials for Energy Conversion Chinese Academy of Science department of Materials science and Engineering University of Science and Technology of China

Highly efficient Sr2Si5N8：Eu^2＋red emitting phosphor was successfully synthesized by a cost-effective direct silicon nitrida-tion and gas-reduction method. The effects of synthesis parameters, including reaction temperature, heating rate and gas species, on the crystal structure and photoluminescence of the prepared phosphors were studied. Single-phase Sr2Si5N8：Eu^2＋phosphor was ob-tained at 1500℃ with a heating rate of 300℃/h under NH3-1 vol.%CH4 atmosphere using starting silicon and oxide powders. Silicon powder and high heating rate favored the achievement of the pure Sr2Si5N8 phase. Under near-UV to blue light excitation, the obtained Sr2Si5N8：Eu2＋phosphor showed a board red emission band centered at about 625 nm, which agreed well with the phosphors prepared by the conventional solid-state reaction. The possible reaction mechanism was also proposed based on the experimental observations.

关键词： Sr2SisNs:Eu^2+ phosphor direct silicon nitridation photoluminescence rare earths

Pole Analysis of Unitarized One Loop χ PT Amplitudes——A Triple Channel Study

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2012年第9期58卷 410-414页

作者：戴凌云王轩弓郑汉青 department of Physics and state Key Laboratory of Nuclear Physics and Technology Peking University Institute of High Energy Physics Chinese Academy of Science

In a previous paper [Commun. Theor. Phys., [arxiv：hep-ph/11081451]], guish poles of different dynamical origin, in unitarized amplitudes of ππ, K K system. that ＂A Breit-wigner resonance should exhibit two poles on different Riemann sheets axis when Nc = ∞＂. In this paper, we extend our previous work [Commun. Theor. to the ππ-KK=ηη three channel system. We reconfirm most of the predictions in our Phys., [arxiv：hep-ph/11081451]]. Especially the fo（980） is of KK molecule nature. 0 Breit-WJgner type. we proposed a method to distinThat is based on the observation which meet each other on the real phys,[arXiv：hep,ph/11081451]]*** work ： Theor. ther poles, including the σ,are of Breit-wigner type.

关键词： Meson-Meson scattering unitarity Hadron resonance

Electron-deficient core fused-ring based non-fullerene acceptor enables over 15% efficiency in single junction organic solar cells

在线全文

学校读者我要写书评

暂无评论

science China Chemistry 2019年第4期62卷 403-404页

作者： Hongzheng Chen state Key Laboratory of Silicon Materials MOE Key Laboratory of Macromolecular Synthesis and Functionalization Department of Polymer Science and Engineering Zhejiang University

Organic solar cells(OSCs)are promising to access flexible,light weight and semi-transparent photovoltaic devices by low-cost solution ***,the fused-ring nonfullerene acceptors play an important role in promoting the research progress of the *** power conversion efficiencies(PCEs)have been rapidly boosted to over 14%in single junction OSCs with the development of new nonfullerene acceptors and the related devices[1-3].Although the PCEs of OSCs are still inferior to their inorganic counterparts,further improvement of the PCEs could be expected by the development of new photovoltaic materials.

关键词： Electron-deficient core single junction non-fullerene acceptor