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Assembly and analysis of the Populus deltoides mitochondrial genome:the first report of a multicircular mitochondrial conformation for the genus Populus
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作者 Yanshu Qu Pengyan Zhou +2 位作者 Chunfa Tong Changwei Bi Li’an Xu 《Journal of Forestry Research》 SCIE CAS CSCD 2023年第3期717-733,共17页
Genomics research of Populus deltoides,an important timber species that is widely planted worldwide,is an important part of poplar breeding.Currently,the nuclear and chloroplast genome of P.deltoides have been sequenc... Genomics research of Populus deltoides,an important timber species that is widely planted worldwide,is an important part of poplar breeding.Currently,the nuclear and chloroplast genome of P.deltoides have been sequenced,but its mitochondrial genome(mitogenome)has not been reported.To further explore the evolution and phylogeny of P.deltoides,the mitogenome of P.deltoides I-69 was assembled using reads from Nanopore and Illumina sequencing platforms and found to consist of 802,637 bp and three circular chromosomes(336,205,280,841,and 185,591 bp)containing 58 genes(34 protein-coding genes,21 tRNA genes,and 3 rRNA genes).RNA analysis in combination with several species showed signifi cantly fewer RNA editingsites in the mitogenomes of poplar and other angiosperms than in gymnosperms.Sequence transfer analysis showed extensive mitogenome rearrangements in Populus species,and with evolution from lower to higher plants,tRNA transfer from chloroplasts to mitochondria became increasingly frequent.In a phylogenetic analysis,the evolutionary status of P.deltoides was determined,and the section Populus was supported.Our results based on the fi rst report of a multicircular conformation of the Populus mitogenome provide a basis for further study of the evolution and genetics of P.deltoides and other Populus species and for breeding programs. 展开更多
关键词 Mitochondrial genome Multi-circular Populus deltoids Comparative genomics PHYLOGENY
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Research and Application of Log Defect Detection and Visualization System Based on Dry Coupling Ultrasonic Method
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作者 Yongning Yuan Dong Zhang +4 位作者 Usama Sayed Hao Zhu Jun Wang Xiaojun Yang Zheng Wang 《Journal of Renewable Materials》 EI 2023年第11期3917-3932,共16页
In order to optimize the wood internal quality detection and evaluation system and improve the comprehensive utilization rate of wood,this paper invented a set of log internal defect detection and visualization system... In order to optimize the wood internal quality detection and evaluation system and improve the comprehensive utilization rate of wood,this paper invented a set of log internal defect detection and visualization system by using the ultrasonic dry coupling agent method.The detection and visualization analysis of internal log defects were realized through log specimen test.The main conclusions show that the accuracy,reliability and practicability of the system for detecting the internal defects of log specimens have been effectively verified.The system can make the edge of the detected image smooth by interpolation algorithm,and the edge detection algorithm can be used to detect and reflect the location of internal defects of logs accurately.The content mentioned above has good application value for meeting the requirement of increasing demand for wood resources and improving the automation level of wood nondestructive testing instruments. 展开更多
关键词 Ultrasonic method log defect detection visualization system dry coupling B-scan pulse transmission method bilinear image interpolation algorithm edge detection algorithm
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Reconcile the contradictory wettability requirements for the reduction and oxidation half-reactions in overall CO_(2) photoreduction via alternately hydrophobic surfaces
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作者 Hailing Huo Ting Hu +9 位作者 Chengxi Huang Fang Wu Tongyu Wang Xuan Liu Liang Zhang Qiang Ju Zhiqing Zhong Hongbin Xing Erjun Kan Ang Li 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第6期202-212,I0006,共12页
The overall photocatalytic CO_(2) reduction reaction(OPCRR)that can directly convert CO_(2) and H_(2)O into fuels represents a promising renewable energy conversion technology.As a typical redox reaction,the OPCRR inv... The overall photocatalytic CO_(2) reduction reaction(OPCRR)that can directly convert CO_(2) and H_(2)O into fuels represents a promising renewable energy conversion technology.As a typical redox reaction,the OPCRR involves two half-reactions:the CO_(2) reduction half-reaction(CRHR)and the water oxidation half-reaction(WOHR).Generally,both half-reactions can be promoted by adjusting the wettability of catalysts.However,there is a contradiction in wettability requirements for the two half-reactions.Specifically,CRHR prefers a hydrophobic surface that can accumulate more CO_(2) molecules on the active sites,ensuring the appropriate ratio of gas-phase(CO_(2))to liquid-phase(H_(2)O)reactants.Conversely,the WOHR prefers a hydrophilic surface that can promote the departure of the gaseous product(O_(2))from the catalyst surface,preventing isolation between active sites and the reactant(H_(2)O).Here,we successfully reconciled the contradictory wettability requirements for the CRHR and WOHR by creating an alternately hydrophobic catalyst.This was achieved through a selectively hydrophobic modification method and a charge-transfer-control strategy.Consequently,the collaboratively promoted CRHR and WOHR led to a significantly enhanced OPCRR with a solar-to-fuel conversion efficiency of 0.186%.Notably,in ethanol production,the catalyst exhibited a 10.64-fold increase in generation rate(271.44μmol g^(-1)h~(-1))and a 4-fold increase in selectivity(55.77%)compared to the benchmark catalyst.This innovative approach holds great potential for application in universal overall reactions involving gas participation. 展开更多
关键词 HYDROPHOBIC HYDROPHILIC Gas transport Overall CO_(2)photoreduction Z-scheme
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Morphological analysis for thermodynamics of cavitation collapse near fractal solid wall
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作者 单鸣雷 杨雨 +2 位作者 阚雪芬 殷澄 韩庆邦 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第6期422-432,共11页
A fractal geometric boundary with natural wall features is introduced into a hybrid lattice-Boltzmann-method(LBM)multiphase model. The physical model of cavitation bubble collapse near the irregular geometric wall is ... A fractal geometric boundary with natural wall features is introduced into a hybrid lattice-Boltzmann-method(LBM)multiphase model. The physical model of cavitation bubble collapse near the irregular geometric wall is established to study the thermodynamic characteristics of the bubble collapse. Due to the lack of periodicity, symmetry, spatial uniformity and obvious correlation in the LBM simulation of the bubble collapse near the fractal wall, the morphological analysis based on Minkowski functional is introduced into the thermodynamic investigation of cavitation bubble so as to analyze and obtain the effective information. The results show that the Minkowski functional method can employed to study the temperature information in complex physical fields hierarchically and quantitatively. The high/low temperature region of the cavitation flow is explored, and thermal effect between irregular and fractal geometric wall and cavitation bubble can be revealed. It illustrates that LBM and morphological analysis complement each other, and morphological analysis can also be used as an optional and potential tool in research field of complex multiphase flows. 展开更多
关键词 lattice Boltzmann method cavitation bubble morphological analysis
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The first mitogenome of Lauraceae(Cinnamomum chekiangense)
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作者 Changwei Bi Ning Sun +3 位作者 Fuchuan Han Kewang Xu Yong Yang David K.Ferguson 《Plant Diversity》 SCIE CAS CSCD 2024年第1期144-148,共5页
There are three distinct genetic systems in higher plants,the dominant nuclear genome and the semi-autonomous organelle genomes(plastids and mitochondria).In contrast to the conserved plastid genome(plastome),the plan... There are three distinct genetic systems in higher plants,the dominant nuclear genome and the semi-autonomous organelle genomes(plastids and mitochondria).In contrast to the conserved plastid genome(plastome),the plant mitochondrial genome(mitogenome)is characterized by an intriguing“evolutionary paradox”distinguished by a remarkably low mutation rate but with a significantly high rearrangement rate(Palmer and Herbon,1988;Lai et al.,2022). 展开更多
关键词 AUTONOMOUS distinguished Palmer
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Genome-wide identification and characterization of WUSCHEL-related homeobox(WOX) genes in Salix suchowensis 被引量:3
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作者 Xuelin Wang Changwei Bi +3 位作者 Chunyan Wang Qiaolin Ye Tongming Yin Ning Ye 《Journal of Forestry Research》 SCIE CAS CSCD 2019年第5期1811-1822,共12页
Members of the WUSCHEL-related homeobox(WOX)transcription factor family are essential for determining cell fate and regulating diverse developmental processes in plants.Many WOX genes have been systematically investig... Members of the WUSCHEL-related homeobox(WOX)transcription factor family are essential for determining cell fate and regulating diverse developmental processes in plants.Many WOX genes have been systematically investigated in woody plants such as Populus trichocarpa,but not in Salix suchowensis.Whole-genome sequence data for S.suchowensis is now available for comprehensive study of WOX genes in S.suchowensis.We thus surveyed the genome of S.suchowensis and demonstrated active expression of 15 WOX genes.In a phylogenetic analysis of WOX genes,the 15 SsWOX genes clustered among the modern/WUS,intermediate and ancient clades similar to the WOX genes of Arabidopsis thaliana.Based on the conserved intron/exon structure,SsWOX genes in the same subgroup had similar conserved exon–intron structures and motif domains.Furthermore,among several SsWOX subgroups,WUS(Wuschel)-box and EAR(the ERF-associated amphiphilic repression)-like motifs were conserved.Expression profiles of WOX genes in roots,stems and leaves indicate that SsWOX genes have various conserved roles in the tissues.Comparative analysis of the expression patterns in Salix suchowensis with that of Arabidopsis suggests that different shoot regeneration abilities are controlled by different WOX genes in plants.The analysis provide an overview of differentially expressed SsWOX genes during shoot regeneration,but also contribute to understanding the evolution of WOX genes in Salicaceae and the interrelations of WOX genes and other transcription factors,providing targets for further study. 展开更多
关键词 WOX family SALICACEAE Expression Evolution DUPLICATION
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Organellar genome assembly methods and comparative analysis of horticultural plants 被引量:4
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作者 Xuelin Wang Feng Cheng +7 位作者 Dekai Rohlsen Changwei Bi Chunyan Wang Yiqing Xu Suyun Wei Qiaolin Ye Tongming Yin Ning Ye 《Horticulture Research》 SCIE 2018年第1期918-930,共13页
Although organellar genomes(including chloroplast and mitochondrial genomes)are smaller than nuclear genomes in size and gene number,organellar genomes are very important for the investigation of plant evolution and m... Although organellar genomes(including chloroplast and mitochondrial genomes)are smaller than nuclear genomes in size and gene number,organellar genomes are very important for the investigation of plant evolution and molecular ecology mechanisms.Few studies have focused on the organellar genomes of horticultural plants.Approximately 1193 chloroplast genomes and 199 mitochondrial genomes of land plants are available in the National Center for Biotechnology Information(NCBI),of which only 39 are from horticultural plants.In this paper,we report an innovative and efficient method for high-quality horticultural organellar genome assembly from next-generation sequencing(NGS)data.Sequencing reads were first assembled by Newbler,Amos,and Minimus software with default parameters.The remaining gaps were then filled through BLASTN search and PCR.The complete DNA sequence was corrected based on Illumina sequencing data using BWA(Burrows–Wheeler Alignment tool)software.The advantage of this approach is that there is no need to isolate organellar DNA from total DNA during sample preparation.Using this procedure,the complete mitochondrial and chloroplast genomes of an ornamental plant,Salix suchowensis,and a fruit tree,Ziziphus jujuba,were identified.This study shows that horticultural plants have similar mitochondrial and chloroplast sequence organization to other seed plants.Most horticultural plants demonstrate a slight bias toward A+T rich features in the mitochondrial genome.In addition,a phylogenetic analysis of 39 horticultural plants based on 15 protein-coding genes showed that some mitochondrial genes are horizontally transferred from chloroplast DNA.Our study will provide an important reference for organellar genome assembly in other horticultural plants.Furthermore,phylogenetic analysis of the organellar genomes of horticultural plants could accurately clarify the unanticipated relationships among these plants. 展开更多
关键词 ANALYSIS DEFAULT TRANSFERRED
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Effect of volume fraction of ramie cloth on physical and mechanical properties of ramie cloth/UP resin composite 被引量:2
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作者 雷文 雷文广 任超 《中国有色金属学会会刊:英文版》 CSCD 2006年第B02期474-477,共4页
Ramie cloth/UP resin composite was formed at 0.2 MPa and cured at room temperature for 24 h and treated at 80℃for 2 h. The physical and mechanical properties of the composites with different volume fractions of ramie... Ramie cloth/UP resin composite was formed at 0.2 MPa and cured at room temperature for 24 h and treated at 80℃for 2 h. The physical and mechanical properties of the composites with different volume fractions of ramie cloth were studied. The results show that, with the increase of the volume fraction of the ramie cloth, densities of the composites become greater and greater, though all lower than the theoretical values, the linear shrinkage during the formation decreases from 1.20% of the original UP resin to 0.18% of the composite with 30% of ramie cloth in volume, all the composites also absorb more water than UP resin casting, greater volume fraction of the fiber, more water will be absorbed, but the increase in water absorption becomes smaller and smaller with time. As regards some mechanical properties, the tensile strength, flexural strength, flexural modulus and impact strength are all improved when more ramie fiber is added. Compared with those of pure UP resin casting, the mechanical properties are increased by 93.93%, 76.20%, 190.18% and 227.26% respectively when the volume fraction of the ramie cloth in the composite is 30%. The differential scanning calorimetry results show that only one peak will appear for the sample without or with less ramie fiber while two peaks will appear when more ramie cloth is added. 展开更多
关键词 苎麻布/UP树脂复合材料 苎麻布体积分数 物理性能 力学性能
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TESTING OF CORRELATION AND HETEROSCEDASTICITY IN NONLINEAR REGRESSION MODELS WITH DBL(p,q,1) RANDOM ERRORS
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作者 刘应安 韦博成 《Acta Mathematica Scientia》 SCIE CSCD 2008年第3期613-632,共20页
Chaos theory has taught us that a system which has both nonlinearity and random input will most likely produce irregular data. If random errors are irregular data, then random error process will raise nonlinearity (K... Chaos theory has taught us that a system which has both nonlinearity and random input will most likely produce irregular data. If random errors are irregular data, then random error process will raise nonlinearity (Kantz and Schreiber (1997)). Tsai (1986) introduced a composite test for autocorrelation and heteroscedasticity in linear models with AR(1) errors. Liu (2003) introduced a composite test for correlation and heteroscedasticity in nonlinear models with DBL(p, 0, 1) errors. Therefore, the important problems in regression model axe detections of bilinearity, correlation and heteroscedasticity. In this article, the authors discuss more general case of nonlinear models with DBL(p, q, 1) random errors by score test. Several statistics for the test of bilinearity, correlation, and heteroscedasticity are obtained, and expressed in simple matrix formulas. The results of regression models with linear errors are extended to those with bilinear errors. The simulation study is carried out to investigate the powers of the test statistics. All results of this article extend and develop results of Tsai (1986), Wei, et al (1995), and Liu, et al (2003). 展开更多
关键词 DBL(p Q 1) random errors nonlinear regression models score test HETEROSCEDASTICITY CORRELATION
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Transparent and Ultra-lightweight Design for Ultra-Broadband Asymmetric Transmission of Airborne Sound 被引量:1
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作者 Jie Hu Bin Liang Xiao-Jun Qiu 《Chinese Physics Letters》 SCIE CAS CSCD 2018年第2期34-37,共4页
Acoustic one-way manipulations have recently attracted significant attention due to the deep implications in many diverse fields such as biomedical imaging and treatment.However,the previous mechanisms of asymmetric m... Acoustic one-way manipulations have recently attracted significant attention due to the deep implications in many diverse fields such as biomedical imaging and treatment.However,the previous mechanisms of asymmetric manipulation of airborne sound need to use elaborate heavyweight structures and only work in certain frequency ranges.We propose a mechanism for designing an ultra-lightweight and optically transparent structure with asymmetric transmission property for normally incident plane waves.Instead of fabricating solids into complicated artificial structures with limited bandwidth and heavy asymmetric shape which allows the incident plane wave weight,we simply use xenon to fill a spatial region of to pass along one direction while reflecting the reversed wave regardless of frequency.We demonstrate both analytically and numerically its effectiveness of producing highly-asymmetric transmission within an ultra-broad band.Our design offers new possibility for the design of one-way devices and may have far-reaching impact on various scenarios such as noise control. 展开更多
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The chromosome-scale assembly of the willow genome provides insight into Salicaceae genome evolution 被引量:13
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作者 Suyun Wei Yonghua Yang Tongming Yin 《Horticulture Research》 SCIE 2020年第1期2140-2151,共12页
Salix suchowensis is an early-flowering shrub willow that provides a desirable system for studies on the basic biology of woody plants.The current reference genome of S.suchowensis was assembled with 454 sequencing re... Salix suchowensis is an early-flowering shrub willow that provides a desirable system for studies on the basic biology of woody plants.The current reference genome of S.suchowensis was assembled with 454 sequencing reads.Here,we report a chromosome-scale assembly of S.suchowensis generated by combining PacBio sequencing with Hi-C technologies.The obtained genome assemblies covered a total length of 356 Mb.The contig N50 of these assemblies was 263,908 bp,which was~65-fold higher than that reported previously.The contiguity and completeness of the genome were significantly improved.By applying Hi-C data,339.67 Mb(95.29%)of the assembled sequences were allocated to the 19 chromosomes of haploid willow.With the chromosome-scale assembly,we revealed a series of major chromosomal fissions and fusions that explain the genome divergence between the sister genera of Salix and Populus.The more complete and accurate willow reference genome obtained in this study provides a fundamental resource for studying many genetic and genomic characteristics of woody plants. 展开更多
关键词 evolution ASSEMBLY CHROMOSOME
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Maximum Network Throughput Based on Cross-Technology Communication for Sensor Networks 被引量:2
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作者 Demin Gao Zhihao Guan +1 位作者 Shuo Zhang Bin Hu 《China Communications》 SCIE CSCD 2021年第10期30-44,共15页
The exponentially increasing number of heterogeneous Internet of Things(Io T)devices(e.g.,Wi Fi and Zig Bee)crowed in the same ISM band(2.4 G)and recent advances in CrossTechnology Communications(CTC)motivate us to ex... The exponentially increasing number of heterogeneous Internet of Things(Io T)devices(e.g.,Wi Fi and Zig Bee)crowed in the same ISM band(2.4 G)and recent advances in CrossTechnology Communications(CTC)motivate us to explore more efficient data collection and maximize network throughput.CTC enables Wi Fi and Zig Bee devices to communicate directly without any hardware changes or gateway equipment,which sheds light on a more efficient data collection design.In this work,we propose a distributed algorithm,named Max Bee,to compute the maximum network throughput,which is formulated as a linear programming problem.Considering that the problem turns out to be non-convex and hard to solve exactly,we propose a distributed algorithm to solve nonlinear programming by using the dual decomposition method and gradient/subgradient algorithms.Through extensive simulations on different sets of deployed Zig Bee and Wi Fi devices,we observe that the proposed algorithm significantly increases the network throughput based on CTC for Sensor Networks. 展开更多
关键词 network throughput cross-technology communication sensor networks
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Maximum Data Generation Rate Routing Protocol Based on Data Flow Controlling Technology for Rechargeable Wireless Sensor Networks 被引量:2
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作者 Demin Gao Shuo Zhang +2 位作者 Fuquan Zhang Xijian Fan Jinchi Zhang 《Computers, Materials & Continua》 SCIE EI 2019年第5期649-667,共19页
For rechargeable wireless sensor networks,limited energy storage capacity,dynamic energy supply,low and dynamic duty cycles cause that it is unpractical to maintain a fixed routing path for packets delivery permanentl... For rechargeable wireless sensor networks,limited energy storage capacity,dynamic energy supply,low and dynamic duty cycles cause that it is unpractical to maintain a fixed routing path for packets delivery permanently from a source to destination in a distributed scenario.Therefore,before data delivery,a sensor has to update its waking schedule continuously and share them to its neighbors,which lead to high energy expenditure for reestablishing path links frequently and low efficiency of energy utilization for collecting packets.In this work,we propose the maximum data generation rate routing protocol based on data flow controlling technology.For a sensor,it does not share its waking schedule to its neighbors and cache any waking schedules of other sensors.Hence,the energy consumption for time synchronization,location information and waking schedule shared will be reduced significantly.The saving energy can be used for improving data collection rate.Simulation shows our scheme is efficient to improve packets generation rate in rechargeable wireless sensor networks. 展开更多
关键词 Wireless sensor networks maximum data generation rate rechargeable-WSNs
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Density cavities generated by plasma-field interactions in the far wake region of a space vehicle 被引量:2
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作者 胡涛平 罗青 李晓卿 《Chinese Physics B》 SCIE EI CAS CSCD 2007年第8期2449-2454,共6页
Under the consideration of non-steady case, a set of equations is derived, which describes the non-steady nonlinear interactions between plasma and field in the far wake region of a space vehicle. Numerical calculatio... Under the consideration of non-steady case, a set of equations is derived, which describes the non-steady nonlinear interactions between plasma and field in the far wake region of a space vehicle. Numerical calculations are also made and the numerical results show that density cavities and electromagnetic solitary waves are generated due to the modulation instability, if the envelope of high frequency modulation field is strong enough. This is of great significance to the detection of disguised space vehicles. 展开更多
关键词 PLASMAS modulation instability density cavity
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Non-steady interaction of plasma with aircraft in its near wake region 被引量:1
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作者 胡涛平 罗青 《Chinese Physics B》 SCIE EI CAS CSCD 2007年第1期179-185,共7页
Non-steady interactions between plasmas and aircraft in its near wake region are investigated in detail. Under the non-static limit, a set of equations that describe these interactions are obtained. The results of the... Non-steady interactions between plasmas and aircraft in its near wake region are investigated in detail. Under the non-static limit, a set of equations that describe these interactions are obtained. The results of the numerical simulation show that the cavitons of transverse plasmas are excited and density cavitons appear when the envelope of plasma becomes sufficiently intensive. This is very important for detecting the moving body that has a 'stealth' characteristic. 展开更多
关键词 IONOSPHERE plasma waves plasma interaction
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Mechanical properties of nano SiO_2 filled gypsum particleboard 被引量:1
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作者 雷文 邓玉和 +2 位作者 周梅 宣玲 冯谦 《中国有色金属学会会刊:英文版》 CSCD 2006年第B01期361-364,共4页
Nano SiO2 was filled into gypsum particleboard. Effect of the amount of nano SiO2 particles filled, ultrasonic dissipating duration and treating the nano particles with different coupling agents on the mechanical prop... Nano SiO2 was filled into gypsum particleboard. Effect of the amount of nano SiO2 particles filled, ultrasonic dissipating duration and treating the nano particles with different coupling agents on the mechanical properties of the board were studied respectively. The results show that nano SiO2 is helpful for the improvement of the properties. Adding 3%(mass fraction) nano SiO2 is the best for the improvement of both modulus of rupture(MOR) and modulus of elasticity(MOE) of the boards formed at 30 ℃ or 40 ℃. For the boards formed at 30 ℃, their MOR and MOE can be improved by 8.77% and 12.24%, and MOR and MOE of the boards formed at 40 ℃ can be improved by 44.44% and 108.38%.3% is also the best addition proportion to improve internal bond(IB) of the boards formed at 30 ℃, while 5% is the best for that of the boards formed at 40 ℃. At room temperature, dissipating nano SiO2 into flake by ultrasonic has better effect on the properties of the final products. Through ultrasonic treating for 1 h and the best treating duration, the MOR and MOE can be increased by 41.99% and 47.80%. In addition, different coupling agents have different effects on the final properties too, and silane coupling agent KH570 is better for the improvement of properties of the boards formed at room temperature. 展开更多
关键词 纳米级氧化硅 填充剂 石膏粒子板 力学性质 破裂摸量 弹性摸量 建筑材料
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Super energy flows in a waveguide filled with air and left-handed materials 被引量:1
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作者 余观夏 崔铁军 《Chinese Physics B》 SCIE EI CAS CSCD 2008年第1期164-169,共6页
The phenomena of super energy flows are studied theoretically and numerically in a parallel-plate waveguide which is filled with two layered equally-thick different media, i.e. air and specific left-handed materials ... The phenomena of super energy flows are studied theoretically and numerically in a parallel-plate waveguide which is filled with two layered equally-thick different media, i.e. air and specific left-handed materials (LHM) with εr1 = -1/(1 +δ) +iγ and μr1 = -(1 + δ) + iγ. In this special waveguide, two-directional super-energy flows are excited by a three-dimensional horizontal electric dipole at the same time, which has transmission patterns different from those of two-dimensional source and three-dimensional vertical electric dipole. We also show that the retardation and loss in LHM are sensitive to the amplitude of super power densities, and the dimensions of waveguide determine the propagating modes, which makes super energy flows more practical. 展开更多
关键词 super energy flows left-handed materials
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CONFIDENCE REGIONS IN TERMS OF STATISTICAL CURVATURE FOR AR(q) NONLINEAR REGRESSION MODELS
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作者 刘应安 韦博成 《Acta Mathematica Scientia》 SCIE CSCD 2004年第1期107-117,共11页
This paper constructs a set of confidence regions of parameters in terms of statistical curvatures for AR(q) nonlinear regression models. The geometric frameworks are proposed for the model. Then several confidence re... This paper constructs a set of confidence regions of parameters in terms of statistical curvatures for AR(q) nonlinear regression models. The geometric frameworks are proposed for the model. Then several confidence regions for parameters and parameter subsets in terms of statistical curvatures are given based on the likelihood ratio statistics and score statistics. Several previous results, such as [1] and [2] are extended to AR(q) nonlinear regression models. 展开更多
关键词 Nonlinear regression AR(q) errors confidence regions geometric framework statistical curvature
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Reduction of defect-induced ferromagnetic stability in passivated ZnO nanowires
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作者 吴芳 孟培雯 +2 位作者 罗康 刘云飞 阚二军 《Chinese Physics B》 SCIE EI CAS CSCD 2015年第3期349-352,共4页
First-principles calculations are performed to study the electronic structures and magnetic properties of ZnO nanowires(NM). Our results indicate that the single Zn defect can induce large local magnetic moment(~ ... First-principles calculations are performed to study the electronic structures and magnetic properties of ZnO nanowires(NM). Our results indicate that the single Zn defect can induce large local magnetic moment(~ 2μB) in the ZnO NWs, regardless of the surface modification. Interestingly, we find that local magnetic defects have strong spin interaction, and favor room-temperature ferromagnetism in bared ZnO NW. On the other hand, although H passivation does not destroy the local magnetic moment of Zn vacancy, it does greatly reduce the spin interaction between magnetic defects. Therefore, our results indicate that H passivation should be avoided in the process of experiments to maintain the room-temperature ferromagnetism. 展开更多
关键词 VACANCY magnetic interaction ZnO nanowires DFT calculations
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A Simple Model to Describe the Requirement of Realizing All-Optical Poling
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作者 郭斌 郭福全 +4 位作者 陈泳 朱丽珺 刘福生 张其锦 王恭明 《Chinese Physics Letters》 SCIE CAS CSCD 2006年第9期2458-2460,共3页
All-optical poling (AOP) of a crosslinkable polymer based on hexamethoxymethyl melamine (HMMM) and Disperse red 1 (DR-1) is investigated. It is'found that the saturation second harmonic generation (SHG) inten... All-optical poling (AOP) of a crosslinkable polymer based on hexamethoxymethyl melamine (HMMM) and Disperse red 1 (DR-1) is investigated. It is'found that the saturation second harmonic generation (SHG) intensity decreases significantly with the increase of the sample temperature from 33℃ to 63℃. From the perspective of energy equilibrium, the main factors of AOP are analysed, and by introducing the classical ideal gas model, a simple inequation is first deduced to describe the requirement of realizing AOP. 展开更多
关键词 2ND-HARMONIC GENERATION POLYMERIC MATERIALS NONLINEAR OPTICS EFFICIENCY
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