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Comparative analysis of metabolite changes in two contrasting rice genotypes in response to low-nitrogen stress

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The Crop Journal 2018年第5期6卷 464-474页

作者： Xiuqin Zhao Wensheng Wang Ziyan Xie Yongming Gao Chunchao Wang Muhammed Mahbubur Rashid Mohammad Rafiqul Islam Binying Fu Zhikang Li Institute of Crop Sciences National Key Facility for Crop Gene Resources and Genetic Improvement Chinese Academy of Agricultural Sciences Shenzhen Institute for Innovative Breeding Chinese Academy of Agricultural Sciences

Identification of metabolites responsible for tolerance to low nitrogen availability(low-N)will aid in the genetic improvement of rice yield under nitrogen *** this study,a backcross introgression line(G9)and its recurrent parent Shuhui 527(SH527),which show differential responses to low-N stress,were used to identify metabolites associated with lowN tolerance in *** in metabolite contents in the leaves of G9 and SH527 at three growth stages under low-N stress were assessed by gas chromatography–mass *** metabolites,including amino acids and derivatives,were highly enriched in G9 compared with SH527 under the control condition,suggesting that the two genotypes had basal metabolite ***-N stress induced genotype-specific as well as growth stagedependent metabolite *** induced specifically in G9 that were involved in glycolysis and tricarboxylic acid metabolism were enriched at the tillering and grain filling stages,and metabolites involved in nitrogen and proline metabolism were enriched at the booting *** of pyroglutamate,glutamate,2-oxoglutarate,sorbose,glycerate-2-P,and phosphoenolpyruvic acid in G9 suggests that these metabolites could be involved in low-N stress *** results presented here provide valuable information for further elucidation of the molecular mechanisms of low-N tolerance in crops.

关键词： Rice Low-nitrogen stress Metabolite Nitrogen metabolism

Correcting for the solar wind in pulsar timing observations: the role of simultaneous and low-frequency observations

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Research in Astronomy and Astrophysics 2017年第10期17卷 33-40页

作者： Ze-Xi Niu George Hobbs Jing-Bo Wang Shi Dai Department of Astronomy Beijing Normal University Australia Telescope National facility CSIRO Xinjiang Astronomical Observatory Chinese Academy of Sciences Key Laboratory of Radio Astronomy Chinese Academy of Sciences

The primary goal of pulsar timing array projects is to detect ultra-low-frequency gravitational waves. Pulsar data sets are affected by numerous noise processes including varying dispersive delays in the interstellar medium and from the solar wind. The solar wind can lead to rapidly changing variations that, with existing telescopes, can be hard to measure and then remove. In this paper we study the possibility of using a low frequency telescope to aid in such correction for the Parkes Pulsar Timing Array （PPTA） and also discuss whether the ultra-wide-bandwidth receiver for the FAST telescope is sufficient to model solar wind variations. Our key result is that a single wide-bandwidth receiver can be used to model and remove the effect of the solar wind. However, for pulsars that pass close to the Sun such as PSR J1022＋ 1022, the solar wind is so variable that observations at two telescopes separated by a day are insufficient to correct the solar wind effect.

关键词： stars: pulsars -- gravitational waves

Control of Secondary Phases by Solution Treatment in a N-Alloyed High-Mn Cryogenic Steel

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Acta Metallurgica Sinica(English Letters) 2018年第10期31卷 1059-1072页

作者： Xiao-Jiang Wang Xin-Jun Sun Cheng Song Shuai Tong Luo-Jin Liu Huan Chen Wei Han Feng Pan Department of Materials Science and Engineering Tsinghua University Department of Structural Steels Central Iron and Steel Research Institute

The secondary phases of the steels have significant effects on the microstructure and mechanical properties, making controlling these secondary phases important. The control of MnS inclusions and A1N precipitates in a N-alloyed high-Mn twin-induced plastic cryogenic steel via solution treatment was investigated with several different techniques including microstructural characterization, 298 K tensile testing, and 77 K impact testing. The solutionizing temperature （ST） increased from 1323 to 1573 K, where the elongated MnS inclusions and large-sized AlN precipitates became spheroidized and dissolved. The aspect ratio of the MnS inclusions decreased as the ST increased and the number density increased. The impact toughness of the steels showed anisotropy and low impact energy values, due to the elongated MnS inclusions and large-sized AIN precipitates. The anisotropy was eliminated by spheroidizing the MnS inclusions. The impact energy was improved by dissolving the large-sized AlN precipitates during the solution treatment. The austenite grain size increased when the dissolution of the AlN precipitate increased, but the effect of the grain size on the yield strength, toughness, and the strength--ductility balance was weak.

关键词： Cryogenic Solutionizing temperature Low-temperature toughness Spheroidize Dissolution

Pretreatment with Baicalin Attenuates Hypoxia and Glucose Deprivation-Induced Injury in SH-SY5Y Cells

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Chinese Journal of Integrative Medicine 2016年第3期22卷 201-206页

作者：周庆博鞠小宁王晓云王美红孔峰孙超毕建忠 Department of Neurology the Second Hospital of Shandong University central Laboratory the Second Hospital of Shandong University

Objective： To explore the neuroprotective effects of baicalin against hypoxia and glucose deprivation- reperfusion （OGD/RO）-induced injury in SH-SY5Y cells. Methods： SH-SY5Y cells were divided into a control group, a OGD/RO group, which was subject to OGD/RO induction; and 3 baicalin groups subject to baicalin （1, 5, 25 μmol/L） for 2 h before induction of OGD/RO （low-, medium-, and high-dose baicalin groups）. Cell viability was detected by thiazolyl blue tetrazoliurn bromide （MTT） assay and flow cytometric analysis was used to detect cell apoptosis. Real-time polymerase chain reaction was performed to determine the mRNA expression of caspase-3 gene. Westem blot analysis was conducted to determine the expression of nuclear factor （NF）- κB and N-methyl-d- aspartic acid receptor-1 （NMDAR1）. Results： Baicalin could significantly attenuate OGD/RO mediated apoptotic cell death in SH-SY5Y cells; the apoptosis rates in the low-, medium- and high-dose groups were 12.1%, 7.9%, and 5.4%, respectively. Western blot and real-time PCR analysis revealed that significant decrease in caspase-3 expression in the baicalin group compared with the OGD/RO group （P〈0.01）. Additionally, down-regulation of NF-K B and NMDAR1 was observed in the baicalin group compared with those obtained from the OGD/RO group. Compared with the low-dose baicalin group, remarkable decrease was noted in the medium- and high-dose groups （P〈0.01）. Conclusion： Baicalin pre-treatment attenuates brain ischemia reperfusion injury by suppressing cellular apoptosis.

关键词： baicalin neuroprotection apoptosis caspase-3 nuclear factor-κB N-methyl-d-aspartic acid receptor-1 hypoxia and glucose deptivation-reperfusion

General Admissibility for Linear Estimators of Multivariate Random Regression Coefficients and Parameters with Respect to a Restricted Parameter Set

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Journal of Shanghai Jiaotong university(Science) 2009年第6期14卷 742-746页

作者：肖爱玲王志忠 School of Info-physics and Geometics Engineering Central South University School of Informeties Guangdong University of Foreign Studies School of Mathematica Science and Computing Technology Central South University

This paper considers the linear model effected by random disturbance,Y=XB+ε,where [~B_ε]～([^(AΘ)_0],VΣ),and ΘTATX TN XAΘΣ.It gives a definition for general admissible estimator of a linear function SΘ + GB of random regression coefficients and *** necessary and sufficient conditions for LY and LY + C to be general admissible estimators of SΘ + GB in the class of both homogenous and non-homogenous linear estimators are *** conclusion is not dependent of whether or not SΘ + GB is estimable.

关键词： parametric matrix linear estimator general optimality general admissibility

Adsorption of Ag(Ⅰ) on H_2TiO_3 from aqueous solutions

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中国有色金属学会会刊：英文版 2007年第4期17卷 832-835页

作者：柴立元韦顺文彭兵李竹英 School of Metallurgical Science and Engineering Central South University Yiwu Bureau of Quality and Techni cal Supervision

Adsorption of silver ions from aqueous solution onto H2TiO3 was studied. Equilibrium experimental studies were performed to determine the adsorption capacity of H2TiO3 for silver ion at various pH values. Batch experiments were conducted in the range of pH value 3?7 and silver ions concentration 10?200 mg/L. The results show that the adsorption is strongly dependent on pH value. The equilibrium absorption capacity of H2TiO3 increases significantly with the increase of pH value from 3 to 7. The adsorption of silver ion obeys the Langmuir isothermal equation well in the concentration range studied, the adsorption constant is 0.054 7, 0.052 4, 0.088 1 at pH 5, 6 and 7, respectively, and the maximum adsorption capacities are 23.64, 29.76 and 40.82 mg/g.

关键词：银离子吸附水合氧化钛 H2TiO3

Microstructure and Mechanical Properties of Unidirectional W Filament Reinforced Al-6 Ti-6 Nb and SiCp-Al-6 Ti-6 Nb Matrix Composites

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Rare Metals 2000年第4期19卷 312-318页

作者：贾德昌郭书苞韩欢庆周玉李新林 Harbin Institute of Technology Harbin 150001 Central Iron & Steel Research InstituteBeijing 100081

Unidirectional Tungsten filament (W_f) reinforced pure Al,Al-6Ti-6Nb and SiC_p-Al-6Ti-6Nb matrix composites were prepared by hot-pressing in vacuum atmosphere,their microstructure and room temperature mechanical properties were investigated. It was indicated that no reaction products appeared at W_f/Al interfaces in pure Al matrix composites. While, in W_f/Al-6Ti-6Nb and W_f/SiCp-Al-6Ti-6Nb,intermetallic WAl_4 interfacial reaction products formed. Much better strengthening effect from W filament was shown in the W_f/Al-6Ti-6Nb and W_f/SiCp-Al-6Ti-6Nb composites than in the pure Al matrix composite. Their strength reached 319 and 339MPa, respectively, with only a small content of W_f(<5Vol.%). The excellent reinforcement effects could be predominantly attributed to the strong W_f/Al interfacial bonding strength due to the interfacial reaction.

关键词： Tungsten filament Al-6Ti-6Nb SiCp-Al-6Ti-6Nb Composite Microstructure Mechanical properties

Effect of boron addition on the microstructure and stress-rupture properties of directionally solidified superalloys

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International Journal of Minerals,Metallurgy and Materials 2014年第11期21卷 1120-1126页

作者： Bao-ping Wu Lin-han Li Jian-tao Wu Zhen Wang Yan-bin Wang Xing-fu Chen Jian-xin Dong Jun-tao Li School of Materials Science and Engineering University of Science and Technology Beijing central Iron & Steel Material Research Institute

This study is focused on the effect of boron addition, in the range of 0.0007wt% to 0.03wt%, on the microstructure and stress-rupture properties of a directionally solidified superalloy. With increasing boron content in the as-cast alloys, there is an increase in the fraction of the γ′/γ eutectic and block borides precipitate around the γ′/γ eutectic. At a high boron content of 0.03wt%, there is precipitation of lamellar borides. Upon heat treatment, fine block borides tend to precipitate at grain boundaries with increasing boron content. Overall, the rupture life of the directionally solidified superalloy is significantly improved with the addition of nominal content of boron. However, the rupture life decreases when the boron content exceeds 0.03wt%.

关键词： superalloys directional solidification microstructure boron stress-rupture properties

Atom exchange of martensite in Cu-13Zn-15Al alloy during non-isothermal aging

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中国有色金属学会会刊：英文版 2006年第5期16卷 1064-1068页

作者：李周肖柱保吉庆徐根应郑峰 School of Materials Science and Engineering Central South University College of Biology and Chemical Engineering Jiaxing University

The bulk specimens with preferable orientation were utilized to investigate atom exchange of martensite in Cu-13Zn-15Al alloy during non-isothermal aging by in-situ X-ray diffraction. It is found that the exchange of Zn atoms at position Ⅲ and Cu atoms at Ⅱ and the exchange of Zn atoms at position Ⅲ and Al atoms atⅠon the basal plane of martensite occur during heating at a heating rate of 5 ℃/min. 13% (2/25 ) of Al atoms transfer from positionⅠto position Ⅲ when temperature goes up to 160 ℃.

关键词： Cu-Zn-Al 形状记忆合金铜合金马氏体原子交换非等温时效