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STUDY OF MECHANISM OF RQ EMBRITTlEMENT OF Fe_(73.5)Cu_1-Nb_3Si_(13.5)B_9 NANOCRYSTAllINE SOFT MAGNETIC AllOY

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Acta Metallurgica Sinica(English letters) 2002年第4期15卷 363-368页

作者： x.G.Cao,J.l.Huang,E.Sukedai,Y.G.Wang,W.Z.Chen and S.x.zhou Henan University of Science and Technology, luoyang 471003, China Okayama University of Science, Okayama 700, Japan Beijing laboratory of Electron Microscope, The Chinese Academy of Sciences, Beij Henan University of Science and Technology Luoyang 471003 China Okayama University of Science Okayama 700 Japan Beijing laboratory of Electron Microscope The Chinese Academy of Sciences Beijing 100080 China National Engineering Technology Research Center on Amorphous & Microcrystalline Alloys Beijing100081 China

Rapidly quenching embrittlement (RQE) sometimes appears in nanocrystalline soft magnetic alloy (FINEMET) during production process. As a re-sult of RQE the ductility of the as-quenched ribbon drops seriously. The mechanism of RQE has been elucidated in the recent works of current authors. R was believed that RQE is due to the structural relaxation but not related to α-Fe(Si) crystallization. In this paper, the high resolution TEM (HRTEM) method and image digital processing were applied to analyze the HRTEM images of two FINEMET rapidly quenched ribbons with different thicknesses in detail. In the thinner ductile sample, the ordering domains with the size of about 3nm are observed. In the thicker RQE sample, the metastable nanocrystalline domains with the size of 18nm are observed along with the structural relaxation. These domains seem to have Fe3B-like metastable phase struc-ture on nanometer scale. The result indicates that the local atomic ordering regions extend when RQE induced by structural relaxation occurs.

关键词： HRTEM FINEMET rapidly quenching embrittlement mecha-nism

xCO_2 satellite retrieval experiments in short-wave infrared spectrum and ground-based validation

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Science China Earth Sciences 2015年第6期58卷 1191-1197页

作者： zhou MinQiang ZHANG xingYing WANG PuCai WANG ShuPeng GUO lili HU lieQun Key laboratory of Middle Atmosphere and Global Environment Observation Institute of Atmospheric PhysicsChinese Academic Science College of Earth Science University of Chinese Academic Science National Satellite Meteorology Center China Meteorological Administration China Isotope and Radiation Corporation Urumqi Meteorological Satellite Ground Station China Meteorological Administration

Based on the optimal estimation method, a satellite xCO2 retrieval algorithm was constructed by combining lBlRTM with VlIDORT. One-year GOSAT/TANSO observations over four TCCON stations were tested by our algorithm, and retrieval results were compared with GOSAT l2 B products and ground-based FTS measurements. Meanwhile, the influence of CO2 line mixing effect on retrieval was estimated, and the research showed that neglecting CO2 line mixing effect could result in approximately 0.25% xCO2 underestimation. The accuracy of xCO2 retrievals was similar to GOSAT l2 B products at cloud-free footprints with aerosol optical depth less than 0.3, and 1% accuracy of xCO2 retrievals can be reached based on the validation result with TCCON measurements.

关键词： carbon dioxide retrieval experiments satellite high-spectral remote sensing ground-based validation

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Development and application of functional gene arrays for microbial community analysis

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中国有色金属学会会刊：英文版 2008年第6期18卷 1319-1327页

作者： Z. l. HE J. D. VAN NOSTRAND l.Y. WU J. Z. zhou Institute for Environmental Genomics Department of Botany and Microbiology University of Oklahoma Norman OK 73019 USA

功能的基因标记能关于功能的基因差异和微生物引起的社区的潜在的活动提供重要信息。尽管 microarray 技术成功地被使用了为纯文化学习基因表示，简单、人工的微生物引起的社区，改编如此的一种技术分析复杂微生物引起的社区仍然以设计... 详细信息

功能的基因标记能关于功能的基因差异和微生物引起的社区的潜在的活动提供重要信息。尽管 microarray 技术成功地被使用了为纯文化学习基因表示，简单、人工的微生物引起的社区，改编如此的一种技术分析复杂微生物引起的社区仍然以设计，样品准备，和数据分析提出很多挑战。这个工作集中于功能的基因数组(FGA ) 的开发和应用程序为微生物引起的社区研究指向关键功能的基因标记。一些与 FGA 有关明确地给问题调音，例如 oligonucleotide 探查设计， nucleic 酸抽取和纯化，数据分析，特性，敏感，和量的能力详细被讨论。最近的研究证明了 FGA 能从许多自然环境关于微生物引起的社区提供特定、敏感、潜在地量的信息并且控制生态系统。这种技术被期望革命化微生物引起的社区的分析，并且连接微生物引起的结构到生态系统工作。

关键词：微数列应用函数基因标记微生物种群

Cleaning Radio Frequency Interference in Pulsar-Folded Data Based on the Conditional Random Fields with an Adaptive Prior

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Research in Astronomy and Astrophysics 2023年第10期23卷 184-191页

作者： xue Chen J.l.Han W.Q.Su Z.l.Yang D.J.zhou National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China School of Astronomy and Space Science University of Chinese Academy of SciencesBeijing 100049China CAS Key laboratory of FAST NAOCChinese Academy of SciencesBeijing 100101China

Radio astronomy observations are frequently impacted by radio frequency interference(RFI).We propose a novel method,named 2σCRF,for cleaning RFI in the folded data of pulsar observations,utilizing a Bayesian-based model called conditional random fields(CRFs).This algorithm minimizes the“energy”of every pixel given an initial *** standard deviations(i.e.,rms values)of the folded pulsar data are utilized as pixels for all subintegrations and ***-RFI data without obvious interference is treated as“background noise,”while RFI-affected data have different classes due to their exceptional rms *** initial labeling can be automated and is adaptive to the actual *** CRF algorithm optimizes the label category for each pixel of the image with the prior initial *** demonstrate the efficacy of the proposed method on pulsar folded data obtained from Five-hundred-meter Aperture Spherical radio Telescope *** can effectively recognize and tag various categories of RFIs,including broadband or narrowband,constant or instantaneous,and even weak RFIs that are unrecognizable in some pixels but picked out based on their *** results are comparable to those obtained via manual labeling but without the need for human intervention,saving time and effort.

关键词： methods:data analysis techniques:image processing (stars:)pulsars:general

Study on the pyroelectric properties of PlT/P(VDF-TrFE) nanocomposites

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Chinese Science Bulletin 1998年第2期43卷 111-114页

作者： Qingqi Zhang H. l. W. Chan Qifa zhou C. l. Choy Hong Kong Polytech Univ Dept Appl Phys Hung Hom Hong Kong Hong Kong Polytech Univ Mat Res Ctr Hung Hom Hong Kong

lead lanthanum titanate (PlT) nanocrystalline powder prepared by the sol_gel process was incorporated into a polyvinylidene fluoride/trifluoroethylene (P(VDF_TrEF)) copolymer matrix to form PlT/P(VDF_TrFE) nanocomposites. The permittivities (ε) of the nanocomposites as a function of volume fraction of ceramic  were modeled using the Bruggeman model. The pyroelectric coefficients (p) and figure of merit (p/ε) were measured as functions of the poling field E. The nanocomposite has p and p/ε values higher than those of the copolymer, and has good potential in pyroelectric applications.

关键词： nanocomposites pyroelectric.

Many-body potential for simulating the self-assembly of polymer-grafted nanoparticles in a polymer matrix

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npj Computational Materials 2023年第1期9卷 71-84页

作者： Yilong zhou Sigbjørn løland Bore Andrea R.Tao Francesco Paesani Gaurav Arya Department of Mechanical Engineering and Materials Science Duke UniversityDurhamNC 27708USA Materials Science Division Lawrence Livermore National LaboratoryLivermoreCA 94550USA Department of Chemistry and Biochemistry University of CaliforniaSan DiegoLa JollaCA 92093USA Department of Chemical and NanoEngineering University of CaliforniaSan DiegoLa JollaCA 92023USA

Many-body interactions between polymer-grafted nanoparticles(NPs)play a key role in promoting their assembly into low-dimensional structures within polymer melts,even when the particles are spherical and isotropically ***,capturing such interactions in simulations of NP assembly is very challenging because explicit modeling of the polymer grafts and melt chains is highly computationally expensive,even using coarse-grained ***,we develop a many-body potential for describing the effective interactions between spherical polymer-grafted NPs in a polymer matrix through a machine-learning *** approach involves using permutationally invariant polynomials to fit two-and three-body interactions derived from the potential of mean force *** potential developed here reduces the computational cost by several orders of magnitude,thereby,allowing us to explore assembly behavior over large length and time *** show that the potential not only reproduces previously known assembled phases such as 1D strings and 2D hexagonal sheets,which generally cannot be achieved using isotropic two-body potentials,but can also help discover interesting phases such as networks,clusters,and *** demonstrate how each of these assembly morphologies intrinsically arises from a competition between two-and three-body *** approach for deriving many-body effective potentials can be readily extended to other colloidal systems,enabling researchers to make accurate predictions of their behavior and dissect the role of individual interaction energy terms of the overall potential in the observed behavior.

关键词： grafted polymer potential

Phase Transformation and Thermal Stability of Aged Ti-Ni-Hf High Temperature Shape Memory Alloys

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Journal of Materials Science & Technology 2006年第5期22卷 691-695页

作者： xianglong MENG Wei CAI K.T.lau l.M.zhou liancheng ZHAO School of Materials science ＆ Engineering Harbin Institute of Technology Harbin 150001 China Department of Mechanical Engineering The Hong Kong Polytechnic umversity Hung Horn KowloonHong Kong China

The use of Ni-rich TiNiHf alloys as high temperature shape memory alloys （SMAs） through aging has been presented. For Ni-rich Ti80-xNixHf20 alloys, their phase transformation temperatures are averagely increased more than 100 K by aging at 823 K for 2 h. Especially for the alloys with Ni-content of 50.4 at. pct and 50.6 at. pct, their martensitic transformation start temperatures （Ms） are more than 473 K after aging. TEM observation confirmed that some fine particles precipitate from the matrix during aging. The aged Ni-rich TiNiHf SMAs show the better thermal stability of phase transformation temperatures than the solutiontreated TiNiHf alloys. The fine particles precipitated during aging should be responsible for the increase of phase transformation temperatures and its high stability.

关键词： TiNiHf alloy High temperature shape memory alloy Aging Phase transformation

Critical Point of Ising Films with Different Growth Directions

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Chinese Physics letters 2000年第1期17卷 55-57页

作者： WANG Huai-yu zhou Yun-song D.l.lin Department of Physics Yantai UniversityYantai 264005 Department of Physics Capital Normal UniversityBeijing 100037 Department of Physics State University of New York at BuffaloBuffaloNY 14260-1500U.S.A.

The critical temperature Tc of a spin-1/2 Ising film of cubic structures is calculated by the variational cumulant expansion method for three directions of *** results from different growth directions are analysed and compared with each *** the present model,the Tc values depend largely on the number of nearest neighbors in a monolayer for films with the same number of monolayers but grown in different *** sc,bcc and fee structures,the highest Tc is found along the(100),(110),and(111)direction,respectively.

关键词： directions Ising variational

Valley-dependent transport in strain engineering graphene heterojunctions

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Chinese Physics B 2022年第7期31卷 509-515页

作者： Fei Wan x R Wang l H liao J Y Zhang M N Chen G H zhou Z B Siu Mansoor B.A.Jalil Yuan li Department of Physics Hangzhou Dianzi UniversityHangzhou 310018China Department of Physics and Key laboratory for low-Dimensional Quantum Structures and Manipulation(Ministry of Education) Hunan Normal UniversityChangsha 410081China Computational Nanoelectronics and Nano-device laboratory Electrical and Computer Engineering DepartmentNational University of SingaporeSingapore 117576Singapore

We study the effect of strain on band structure and valley-dependent transport properties of graphene *** is found that valley-dependent separation of electrons can be achieved by utilizing strain and on-site *** the presence of strain,the values of transmission can be effectively adjusted by changing the strengths of the strain,while the transport angle basically keeps *** an extra on-site energy is simultaneously applied to the central scattering region,not only are the electrons of valleys K and K'separated into two distinct transmission lobes in opposite transverse directions,but the transport angles of two valleys can be significantly ***,one can realize an effective modulation of valley-dependent transport by changing the strength and stretch angle of the strain and on-site energies,which can be exploited for graphene-based valleytronics devices.

关键词： strain engineering valley-dependent separation graphene on-site energy