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International Journal of Minerals,Metallurgy and Materials 2014年第9期21卷 919-924页

作者： Yuan-Zhi Zhu ya-feng zhang Chao-Qi Zhao feng Zhou College of Mechanical and Electrical Engineering North China University of Technology Key Laboratory for Ferrous Metallurgy and Resources Utilization of the Ministry of Education Wuhan University of Science and Technology

The effect of the microstructure of plates fabricated both in the traditional process, involving casting, hot rolling and cold rolling （HR）, and in the novel twin roll casting ＋ cold rolling （TRC） process on the surface quality of presensitized （PS） plates was analyzed by optical microscopy （OM）, scanning electron microscopy （SEM）, and energy-dispersive X-ray spectroscopy （EDXS）. The formation of pores on the surface of the electrolyzed HR plate could be attributed to the presence of approximately 1-μm-sized large Al-Fe precipitates in the HR plate compared to the smaller precipitates in the TRC plate. Moreover, residual graphite lubricants used during the TRC process were entrapped on the surface of the TRC plate during the subsequent rolling process. The entrapped pollutants tended to further deteriorate the formation of pores on the surface of the TRC plate, and no residual carbon was detected on the surface of the HR plate. Furthermore, the surface quality of the TRC plate can be improved by surface cleaning before the cold rolling process, which could dramatically lower the residual graphite on the surface.

关键词： aluminum plates microstructure presensitizing surface quality

rhe Mitochondrion-Targeted PENTATRICOPEPTIDE REPEAT78 Protein Is Required for nad5 Mature mRNA Stability and Development in Maize

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Molecular Plant 2017年第10期10卷 1321-1333页

作者： ya-feng zhang Masaharu Suzuki feng Sun Bao-Cai Tan Key Laboratory of Plant Cell Engineering and Germplasm Innovation Ministry of Education School of Life Sciences Shandong University Jinan 250100 China Guangdong Provincial Key Laboratory of Plant Molecular Breeding College of Agriculture South China Agricultural University Guangzhou 510642 China Plant Molecular and Cellular Biology Program University of Florida Gainesville Florida 32611 USA

Pentatricopepetide repeat （PPR） proteins are a large family of RNA-binding proteins involved in RNA meta- bolism in plant organelles. Although many PPR proteins have been functionally studied, few of them are identified with a function in mitochondrial RNA stability. By using a reverse genetic approach, we characterized the role of the mitochondrion-targeted PPR78 protein in nad5 mature mRNA stability and maize （Zea mays） seed development. Loss of PPR78 function leads to a dramatic reduction in the steady-state level of mitochondrial nad5 mature mRNA, blocks the assembly of complex I in the electron transport chain, and causes an arrest in embryogenesis and endosperm development. Characterization of a second strong allele confirms the function of PPR78 in nad5 mRNA accumulation and maize seed development. The generation of mature nad5 requires the assembly of three distinct precursor RNAs via transsplicing reactions, and the accumulation ofnad5T1 precursor is reduced in the ppr78 mutants. However, it is the instability of mature nad5 rather than nad5T1 causing loss of the full-length nad5 transcript, and degradation of nad5 losing both translation start and stop codons is enriched in the mutant. Our data imply the assembly of mature nad5 mRNA precedes the protection of PPR78.

关键词： PPR nad5 mitochondrial RNA stability complex I seed development maize

Aluminum matrix composites reinforced by molybdenum-coated carbon nanotubes

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International Journal of Minerals,Metallurgy and Materials 2011年第6期18卷 695-702页

作者： Jun-hui Nie Cheng-chang Jia Na Shi ya-feng zhang Yi Li XianJia School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China

To extend the application of carbon nanotubes （CNTs） and explore novel aluminum matrix composites,CNTs were coated by molybdenum layers using metal organic chemical vapor deposition,and then Mo-coated CNT （Mo-CNT）/Al composites were prepared by the combination processes of powder mixing and spark plasma *** influences of powder mixing and Mo-CNT content on the mechanical properties and electrical conductivity of the composites were *** results show that magnetic stirring is better than mechanical milling for mixing the Mo-CNTs and Al *** electrical conductivity of the composites decreases with increasing Mo-CNT *** the Mo-CNT content is 0.5wt%,the tensile strength and hardness of Mo-CNT/Al reach their maximum *** tensile strength of 0.5wt% Mo-CNT/Al increases by 29.9%,while the electrical conductivity only decreases by 7.1%,relative to sintered pure *** phase analysis of Mo-CNT/Al composites reveals that there is no formation of Al carbide in the composites.

关键词： carbon nanotubes aluminum matrix composites molybdenum layer mechanical properties electrical conductivity

Improved Cd determination in glasses by laser ablation inductively coupled plasma mass spectrometry using nitrogen as a matrix modifier

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Chinese Chemical Letters 2009年第1期20卷 92-95页

作者： Qian Ni Zhao Chu Hu Zheng Yu Bao ya feng zhang State Key Laboratory of Geological Processes and Mineral Resources China University of Geosciences Wuhan 430074 China Laboratory of No. 9 Gold Detachment Chinese People's Arming Police Unit Hainan 570216 China

The addition of 5-10 mL min^-1 nitrogen to the central channel of plasma in Laser ablation Inductively Coupled Plasma Mass Spectrometry （LA-ICP-MS） increases the sensitivities of Cd by a factor of 3 and decreases oxide interferences by one order of magnitude, which allows the direct analysis of trace levels of Cd in glass samples. This simple method shows a great potential for the direct determination of Cd in various kinds of samples.

关键词： LA-ICP-MS Cd MPI-DING glass

Fabrication and thermal conductivity of copper matrix composites reinforced by tungsten-coated carbon nanotubes

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International Journal of Minerals,Metallurgy and Materials 2012年第5期19卷 446-452页

作者： Jun-hui Nie Cheng-chang Jia XianJia Yi Li ya-feng zhang Xue-bing Liang School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China China Iron ＆ Steel Research Institute Group Beijing 100081 China

Carbon nanotubes （CNTs） were coated by tungsten using metal organic chemical vapor deposition. Magnetic stirring was employed to disperse the W-coated CNTs （W-CNTs） in a Cu matrix, and then, the mixed powders were consolidated by spark plasma sintering. The W-CNTs obtained a uniform dispersion within the Cu matrix when the W-CNT content was less than 5.0vo1%, but high content of W-CNTs （10vol%） resulted in the presence of clusters. The W-CNT/Cu composites containing low content of W-CNTs （〈5.0vol%） exhibited a higher thermal conductivity than the sintered pure Cu, while the CNT/Cu composites exhibited no increase in thermal conductivity after the incorporation of uncoated CNTs. The W-CNT content was found to play a crucial role in determining the thermal conductivity of the W-CNT/Cu composites. The thermal conductivity of the W-CNT/Cu composites increased first and then decreased with the W-CNT content increasing. When the W-CNT content was 2.5vo1%, the W-CNT/Cu composite obtained the maximum value of thermal conductivity. The thermal resistance of the （W-CNT）-Cu interface was predicted in terms of Maxwell-Gamett effective medium approximation, and its calculated value was about 3.0× 10-9 m2.K.W-l.

关键词： metallic matrix composites (MMCs) carbon nanotubes tungsten copper spark plasma sintering thermal conductivity

A pH-sensitive Modified Polyacrylamide Hydrogel

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Chinese Chemical Letters 2006年第3期17卷 399-402页

作者： Ping An SONG ya feng zhang Jian Zheng KUANG Guangzhou Institute of Chemistry Chinese Academy of Sciences Guangzhou 510650 Guangdong Research and Development Center of Chemical Grouting Engineering Technology Guangzhou 510650

A pH-sensitive modified polyacrylamide hydrogel was prepared by two steps and the modified polyacrylamide was characterized by ^1HNMR spectrum. The surface morphology and swelling behavior of the hydrogels were invest... 详细信息

关键词： Polyacrylamide hydrogel pH-sensitive.

Assessment of coastal vulnerability to environmental change in Jiangsu coastal plain

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Journal of Geographical Sciences 2001年第1期11卷 24-33页

作者： yaNG Gui-shan, SHI ya-feng, zhang Chen, LIANG Hai-tang (Nanjing Institute of Geography and Limnology, CAS, Nanjing 210008, China) CAS Nanjing Institute of Geography and Limnology Nanjing China (GRID:grid.9227.e) (ISNI:***)

Assessment of coastal vulnerability to future environmental change has been emphasized in coastal nations or regions. The Jiangsu coastal plain, located to the north of the yangtze River Delta in China, is most vulnerable to sea level rise and exacerbating coastal hazards. This paper develops the method of delimiting vulnerable scope and assessing coastal vulnerability through field observations and sampling and by applying remote sensing and GIS, which are suitable for great river delta and coastal plains with large area, relative complex micro-geomorphology and the protection of seawall. Applying this method, the coastal vulnerability of the Jiangsu coastal plain to relative sea level rise (approximately 50 cm up to the year 2050) and exacerbating storm surges have been assessed. The results show that, up to the year 2050, the Jiangsu coastal plain will probably lose 12.8 % of tidal flats (about 5.8x104 hm2) and 7.9 % of cultivated land (about 7.2x104 hm2). Meanwhile, 2.0 % of population, 3.8 % of original value of fixed assets, 3.2% of GDP (Gross Domestic Product), 40.3 % of salt industry and 5.8 % of aquiculture respectively will be affected due to coastal environmental change.

关键词： coastal vulnerability assessment vulnerable scope coastal environmental change Jiangsu coastal plain

Theoretical study of stereodynamics for the D'+ DS(v=0,j=0) → D'D + S abstraction reaction

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Chinese Physics B 2013年第5期22卷 279-284页

作者：郭雅慧张凤昀马红章 College of Science China University of Petroleum

Quasiclassical trajectory （QCT） calculations have been performed for the abstraction reaction, Dt＋ DS（v = 0, j = 0） → D＇D ＋ S on a new LZHH potential energy surface （PES） of the adiabatic 3A＇＇ electronic state [Lü et al. 2012 J. Chem. Phys. 136 094308]. The collision energy effect on the integral cross section and product polarization are studied over a wide collision energy range from 0.1 to 2.0 eV. The cross sections calculated by the QCT procedure are in good accordance with previous quantum wave packet results. The three angular distribution functions, P（θr）, P（φr）, and P（θr,φr）, together with the four commonly used polarization-dependent differential cross sections （（2 π/σ）（ d σ00 / d ω1）, （2π/σ）（d σ20 / d ω1）, （2π/σ）（dσ22＋/dω1）, （2π/σ）（dσ21-/dω1）） are obtained to gain insight into the chemical stereodynamics of the title reaction. Influences of the collision energy on the product polarization are exhibited and discussed.

关键词： quasi-classical trajectory integral cross section stereodynamics product polarization

AT1 receptor in rostral ventrolateral medulla mediating blunted baroreceptor reflex in spontaneously hypertensive rats

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Acta Pharmacologica Sinica 2004年第11期 49-54页

作者： Xin-ya GAO, feng zhang, Ying HAN, Han-jun WANG, Ying zhang, Rui GUO, Guo-qing ZHUDepartment of Physiology, Nanjing Medical University, Nanjing 210029, China

AIM: To determine the role of AT 1 receptor in the rostral ventrolateral medulla (RVLM) in mediating the blunted baroreceptor reflex in spontaneously hypertensive rats (SHR). METHODS: Intravenous injections of graded doses of phenylephrine (1, 5, 10, 20, and 40 μg/kg) increased the blood pressure to elicit the baroreceptor reflex in both SHR and normotensive Wistar rats anesthetized with urethane. The baroreceptor reflex sensitivity (BRS) was determined before and after microinjection of Ang Ⅱ, losartan, or AT1 receptor antisense oligodeoxynucleotides into the RVLM. AT1 receptor protein level in the RVLM was measured by Western blotting. RESULTS: The BRS was significantly decreased in SHR compared with normal rats. Bilateral microinjection of AT1 receptor antagonist losartan (250 nmol/h) into the RVLM partly reversed the blunted BRS in SHR, but had no significant effect on the BRS in normal rats. Ang Ⅱ (1.5 nmol/h) significantly inhibited the BRS in normal rats, which was completely abolished by pretr

关键词： angiotensin Ⅱ antisense oligodeoxynucleotide hypertension baroreceptor reflex rostral ventrolat-eral medulla

Nogo-A expression dynamically varies after spinal cord injury

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Neural Regeneration Research 2015年第2期10卷 225-229页

作者： Jian-wei Wang Jun-feng yang Yong Ma Zhen Hua yang Guo Xiao-lin Gu ya-feng zhang Wuxi Hospital of Traditional Chinese Medicine Institute of Orthopedics and Traumatology of Nanjing University of Chinese Medicine Nanjing University of Chinese Medicine

The mechanism involved in neural regeneration after spinal cord injury is unclear. The my-elin-derived protein Nogo-A, which is speciifc to the central nervous system, has been identiifed to negatively affect the cytoskeleton and growth program of axotomized neurons. Studies have shown that Nogo-A exerts immediate and chronic inhibitory effects on neurite *** vivo, inhibitors of Nogo-A have been shown to lead to a marked enhancement of regenerative axon extension. We established a spinal cord injury model in rats using a free-falling weight drop device to subsequently investigate Nogo-A expression. Nogo-A mRNA and protein expression and immunoreactivity were detected in spinal cord tissue using real-time quantitative PCR, immu-nohistochemistry and western blot analysis. At 24 hours after spinal cord injury, Nogo-A protein and mRNA expression was low in the injured group compared with control and sham-operated groups. The levels then continued to drop further and were at their lowest at 3 days, rapidly rose to a peak after 7 days, and then gradually declined again after 14 days. These changes were observed at both the mRNA and protein level. The transient decrease observed early after injury followed by high levels for a few days indicates Nogo-A expression is time dependent. This may contribute to the lack of regeneration in the central nervous system after spinal cord injury. The dynamic varia-tion of Nogo-A should be taken into account in the treatment of spinal cord injury.

关键词： nerve regeneration spinal cord injury contusion Nogo-A axon growth immunohisto-chemistry fluorescent quantitative PCR neural regeneration