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Modified HDDR Process for Producing Anisotropic NdFeB Powders

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Journal of University of Science and Technology beijing 2001年第2期8卷 111-114页

作者： Xubo Liu, Yue Ming, Yaofu Xiao, Qi Zeng, Zhengyi Zhang, Run Wang (Material Science and Engineering School, University of Science and Technology beijing, beijing 100083, china) (beijing Institute of Aeronautical Materials, beijing 100095, china) Univ Sci & Technol beijing Mat Sci & Engn Sch Beijing 100083 Peoples R China Inst Aeronaut Mat Beijing 100095 Peoples R China

The effect of HDDR (hydrogenation-decomposition-desorption-recombination process) treating conditions on magnetic anisotropy of Nd13FebalCo17B7Ga1Zr0.1 powders has been studied. It is found that increasing recombination temperature is effective for magnetic anisotropy formation, but at the cost of reducing the coercive force. The microstructure analysis (TEM) indicates that the NdFeB recombination nucleation takes place markedly during the transition range from decomposition stage to recombination stage, in which both temperature and H-2 pressure change sharply. In order to create a more stable treatment condition for recombination nucleation, a modified HDDR process is established in which the conventional continuous transition range is divided into several stages. The experimental results have proved that such a process can effectively enhance the remanence of the magnet powders with high certainty, while only cause a little reduction in coercivity.

关键词： HDDR anisotropy NdFeB

Reduction of drosopterin content caused by a 45-nt insertion in Henna pre-mRNA of Drosophila melanogaster

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Science china(Life Sciences) 2008年第8期51卷 702-710页

作者： WANG Qin, ZHAO ChunJiang, BAI LiHua, DENG XueMei & WU ChangXin State Key Laboratory of Agrobiotechnology & Key laboratory of Animal Genetics and Breeding of the Ministry of Agriculture, College of Animal Science and Technology, china Agricultural University, beijing 100193, china 1. State Key Laboratory of Agrobiotechnology & Key laboratory of Animal Genetics and Breeding of the Ministry of Agriculture College of Animal Science and Technology China Agricultural University Beijing 100193 China

Phenylalanine hydroxylase is assumed to be a key enzyme in drosopterin metabolism, but direct in vivo evidence to support this hypothesis is still *** the present study, we found a new natural reces-sive purple eye mutant of Drosophila melanogaster, Hnbp, which was a 45-nt insertion mutant in the second exon of *** insertion resulted in a predicted protein with 15 additional amino acids as compared to the wild-type *** analysis of protein structure showed that the predicted mutant protein probably had two more β-sheets, which may cause instability of two α-helices near the catalytic centre of the enzyme in the Biopterin-Hydroxyl binding *** mutant showed eye color defect with decrease of mRNA level, as well as drosopterin content *** drosopterin defect could be fully rescued by expression of wild type Henna in the Hnbp background by GMR-GAL4 UAS-Henna/UAS-Henna:Hnbp/Hnbp transgenic *** taken together, it can be concluded that the mu-tation in Henna is responsible for drosopterin reduction in mutant Hnbp, which provides key in vivo evidence to support the hypothesis that Henna is involved in drosopterin synthesis.

关键词： Drosophila melanogaster Henna gene drosopterin phenylalanine hydroxylase Hnbp

Sol-gel Preparation and Infrared Radiation Property of Boron-substituted Cordierite Glass-ceramics

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Journal of Materials Science & Technology 2010年第5期26卷 445-448页

作者： Shuming Wang and Fenghua Kuang School of Materials Science and Engineering,University of Science & Technology beijing,beijing 100083,china [a] School of Materials Science and Engineering University of Science & Technology beijing beijing 100083 china

Boron for aluminum substitution in the cordierite structure has been examined by sol-gel preparation of different samples along the compositional junction Mg2Al4-xBxSi5O18 with x=0,0.5,1,*** increasing the x value from 0 to 1.5 the crystallization behavior changed *** amount B2O3 doping can promote the sintering of amorphous cordierite gel,effectively restrain the precipitation of μ-cordierite and enhance the crystallization of α-*** substitution of B3＋ for Al3＋ in cordierite crystal structure can effectively improve the near-infrared spectral emissivity of this cordierite based glass-ceramics.

关键词： Sol-gel Glass-ceramics Infrared radiation B3+ substitution Solid solution

DISTRIBUTION AND EFFECT OF Ce IN RE BEARING DUCTILE IRON

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Acta Metallurgica Sinica(English Letters) 1992年第6期5卷 419-424页

作者： ZHU Ruihui WANG Yu HAN Qiyong SONG Weixi University of Science and Technology beijing,beijing,china Engineer,Institute of Precise and Special New Materials,University of Science and Technology beijing,beijing 100083,china beijing Univ of Science and Technology Beijing China

The dependence of nodularization of graphite upon Ce content in RE bearing nodular cast iron,prepared by directional solidification,has been investigated by electrolytic extraction-radioisotope assay analysis of Ce in each phase of the iron together with measurement of nodulized *** show that the Ce occurs mainly as alloyed form. In the graphite phase,the Ce content is believed to be characterization of *** graphite would completely nodulized only the Ce is over a certain content in graphite phase.

关键词： RE nodular cast iron directional solidification graphite Ce

Development of SPM Quantitative Micromorphology Analysis Software

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International Journal of Minerals,Metallurgy and Materials 1999年第2期13卷 136-138页

作者： Suozai Li Libing Liao(School of Materials Science and Engineering, china University of Geosciences, beijing 100083, china) School of Materials Science and Engineering China University of Geosciences Beijing 100083 China

Scanning Probe Microscope (SPM) has great advantages in quantitative micromorphology analysis because of its conveniencein obtaining micromorphology information of materials on nanometer or atomic scale under control of a computer. Based on an established SPM quantitative micromorphology analysis model, an SPM image analysis software Which can calculate both two- and three-dimensional micromorphology parameters is developed.

关键词： SPM quantitative micromorphology analysis software

A novel aberrant splicing of G_(sa) transcript in human leukemia cell lines

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Chinese Science Bulletin 1999年第4期44卷 340-344页

作者： YE Qinong, YAO Xiao, WANG Hengliang, ZHANG Shu, LIU Huaitian, SU Guofu, HUANG Cuifen and ZHOU Tingchong beijing Institute of Biotechnology, beijing 100071, china Department of Biology, Shaanxi Normal College, Xi’an 710062, china beijing Medical University, School of Oncology, beijing 100036, china beijing Institute of Microbiology and Epidemiology, beijing 100071, china beijing Institute of Basic Medicine Sciences , beijing 100850, china beijing Institute of Biotechnology Beijing China Department of Biology Shaanxi Normal College Xi’an China School of Oncology Beijing Medical University Beijing China beijing Institute of Microbiology and Epidemiology Beijing China beijing Institute of Basic Medicine Sciences Beijing China

The α subunit of the stimulatory G protein, Gsα, is involved in the stimulation of adenylate cyclase pathway of signal transduction. The various Gsα mRNAs are generated either by alternative splicing or by using alternative promoter. A novel aberrant splicing of Gsα transcript in human leukemia cell lines is reported. The entire coding region of Gsα gene obtained, referred to as GsαLeu, was amplified by PCR with cDNA from Jurkat human leukemia cDNA library or the reverse-transcribed first strand cDNA from human leukemia cell line HL-60 as a template. The result of DNA sequencing indicated that,compared with originally reported Gsα, GsαLeu has two in-frame deletions, one in amino acid residues 23—249 and the other in amino acid residues 254—260, suggesting that G（sαLeu） may play an important role in leukemia. The complete coding region of GsαLu was inserted downstream of the thrombin site of pGEX-2T fusion protein expression vector and expressed in the form of GST/G(

关键词： Gsa splicing leukemia cloning and expression.

Multipliers and Herz type spaces

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Science china Mathematics 2008年第10期51卷 1919-1936页

作者： LU ShanZhen School of Mathematical Sciences, beijing Normal University, beijing 100875, china School of Mathematical Sciences Beijing Normal University Beijing 100875 China

Hrmander condition for boundedness of multiplier operators will be replaced by a weaker condition described by certain weighted or non-weighted Herz spaces. Some results on boundedness of multiplier operators are then established. As direct corollaries of main theorems in this paper, several celebrated results on boundedness of multiplier operators will be improved or deduced.

关键词： multiplier Herz space Herz type Hardy space 42B15 42B30 42B35

Hausdorff measures of the image, graph and level set of bifractional Brownian motion

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Science china Mathematics 2010年第11期53卷 2973-2992页

作者： LUAN NaNa School of Mathematical Sciences, beijing Normal University, beijing 100875, china 1. School of Mathematical Sciences Beijing Normal University Beijing 100875 China

Let BH,K = {BH,K(t), t ∈ R+} be a bifractional Brownian motion in Rd. This process is a selfsimilar Gaussian process depending on two parameters H and K and it constitutes a natural generalization of fractional Brownian motion (which is obtained for K = 1). The exact Hausdorff measures of the image, graph and the level set of BH,K are investigated. The results extend the corresponding results proved by Talagrand and Xiao for fractional Brownian motion.

关键词： bifractional Brownian motion self-similar Gaussian processes image graph level set local time Hausdorff dimension Hausdorff measure

The formation depth of coesite-bearing eclogite,Dabie UHPM zone,china,modified by tectono-original additional hydrostatic pressure

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Chinese Science Bulletin 1999年第5期44卷 398-411页

作者： LU Guxian, CHEN Jing, LIU Ruixun and LI Xiaobo Institute of Geomechanics , beijing 100081, china Electron Microscopy Laboratory, Peking University, beijing 100871, china Department of Geology, Peking University, beijing 100871, china Institute of Geological Information , beijing 100037, china Institute of Geomechanics Beijing China Electron Microscopy Laboratory Peking University Beijing China Department of Geology Peking University Beijing China Institute of Gelogical Information Beijing China

The knowledge that hydrostatic pressure is equal to the gravity value of the overlying rocks in studying a dynamic state of certain underground site is argued. It is suggested that the stress field T in the crust is a combination or superposition of total hydrostatic pressure P with differential stress σ,and the total hydrostatic pressure P at any point in the crust comprises two parts: one is spherical stress tensor PG caused by the gravity, and the other is spherical stress tensor Ps caused by tectonic stress; therefore P could not be attributed to the gravity of overlying rocks only. The results obtained by a finite-element simulation indicate that the tectono-original additional hydrostatic pressures Ps decrease gradually from the compressive zone （pcS） to the shear zone (PSHs)and to the tensile zone （PTs）, i.e.Pcs>PsHs>PTs in the same depth. On the basis of the above-mentioned research, the method of measurement and calculation of metallogenetic depth corrected by Ps is

关键词： formation depth tectonic additional hydrostatic pressure Dabie UHPM zone coesite-bearing eclogite expansion-cracking texture tectonic physicochemistry.