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Microstructural evolution and mechanical behavior of metastable β-type Ti-25Nb-2Mo-4Sn alloy with high strength and low modulus

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Progress in Natural Science:Materials International 2013年第2期23卷 174-182页

作者： Shun Guo Qingkun Meng Guangyue liao Liang hu Xinqing Zhao School of Materials Science and Engineering Beihang University

This paper presents a systematic study of newly developed metastable β-type Ti-25Nb-2Mo-4Sn (wt%) alloy with high strength and low elastic modulus, with focus on the microstructural evolution and mechanical behavior associated with aging. The pre-treatment (solution treatment or cold rolling) prior to aging exerts substantial influence on the subsequent aging response including microstructural evolution and mechanical behavior. Even under the same aging treatment, the aging products could be (β+ω), or alternatively (β+α), depending on the pre-treatments. This interesting aging response was discussed on the basis of the mechanism for ω formation. High-density dislocation tangles and grain boundaries induced by severe cold rolling play a key role in hindering the transition from β to isothermal ω, favoring the precipitation of α phase on aging. By aging cold-rolled specimen for short time, superior mechanical properties, i.e. high ultimate strength of ～1113 MPa and low elastic modulus of ～65 GPa, achieved in Ti-25Nb-2Mo-4Sn alloy. The characterization of microstructural evolution and compositional change indicated that the precipitation of fine α does not cause the enrichment of β-stabilizers in β matrix upon a short-time aging, guaranteeing low elastic modulus of the short-time aged specimen. Meanwhile, fine α precipitates as well as dislocations play a crucial part in strengthening, giving rise to its high yield strength and high ultimate tensile strength.

关键词： Metastable β Ti alloy Microstructural evolution ω Phase Low modulus High strength

A general and efficient Lewis acid catalysed Mukaiyama-aldol reaction of difluoroenoxysilanes and ketones

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Science Bulletin 2017年第22期62卷 1504-1509页

作者： Fu-Min liao Xiao-Tong Gao Xiao-Si hu Shi-Liang Xie Jian Zhou Shanghai Key Laboratory of Green Chemistry and Chemical Processes School of Chemistry and Molecular Engineering East China Normal University Shanghai 200062 China State Key Laboratory of Elemento-organic Chemistry Nankai University Tianjin 300071 China Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development School of Chemistry and Chemical Engineering East China Normal University Shanghai 200062 China

We report a general and highly efficient Mukaiyama-aldol reaction of ketones and *** the reaction of aryl ketones worked efficiently in the presence of Bi(OTf)_3, that of aliphatic ketones required the use of Sc(OTf_)3. In addition, Sc(OTf)_3 was capable of achieving excellent 1,2-selectivity in the corresponding reaction of α,β-unsaturated ketones. This method provides a facile access to differently substituted β-hydroxy α,α-difluoro ketones, versatile synthons for difluomethylated tertiary alcohols.

关键词： Lewis acid catalysed Mukaiyama-aldol reaction Ketones Difluoroenoxysilanes β-Hydroxy α,α-difluoro ketones

Impact of Initial Storm Intensity and Size on the Simulation of Tropical Cyclone Track and Western Pacific Subtropical High Extent

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Journal of Meteorological Research 2017年第5期31卷 946-954页

作者： Yuxing WANG Yuan SUN Qianfeng liao Zhong ZHONG Yijia hu Kefeng LIU College of Meteorology and Oceanography National University of Defense Technology Jiangsu Collaborative Innovation Center for Climate Change Nanjing University

Typhoon Megi, the 13th typhoon of the 2010 typhoon season, was selected for case study by utilizing the Weather Research and Forecasting （WRF） model. Twelve sensitivity experiments with various initial tropical cyclone （TC） in- tensities and sizes were conducted to investigate their impacts on the simulation of typhoon track. Interaction between TC and the western Pacific subtropical high （WPSH） was also analyzed to explore the mechanism for the impact on TC track of the initial TC intensity and size. Numerical results indicate that the simulated TC size and TC track are sensitive to initial TC intensity and size. Stronger initial TC intensity and larger initial TC size often lead to larger simulated TC size and make TC turn northward earlier. Further analysis suggests that, with the increase of ini- tial TC intensity and size, more air mass enters into the TC region, which subsequently reduces the extent of WPSH. As a result, the steering flow changes significantly and eventually causes the TC to turn northward earlier. The present study confirms that the initial TC intensity and size have certain influences on the TC track simulation, which demonstrates the importance of accurate initial condition for successful simulation of the TC intensity and TC track. Moreover, it also deepens our understanding of the interaction between TC and WPSH, provides helpful clues for the TC track change study, and discusses the future directions for improvement of TC track forecast.

关键词： tropical cyclone size subtropical high tropical cyclone track WRF model

Stable isotope(δ^(13)C_(ker),δ^(13)C_(carb),δ^(18)O_(carb)) distribution along a Cambrian outcrop section in the eastern Tarim Basin,NW China and its geochemical significance

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Geoscience Frontiers 2017年第1期8卷 163-170页

作者： hu Liu Zewen liao Haizu Zhang Yankuan Tian Bin Cheng Shan Yang State Key Laboratory of Organic Geochemistry Guangzhou Institute of GeochemistryChinese Academy of SciencesGuangzhou 510640China Sichuan Key Laboratory of Shale Gas Evaluation and Exploitation Chengdu 610091China Research Institute of Petroleum Exploration and Development PetroChina Yarim Oilfield CompanyKorla 841000XinjiangChina

This study investigated the geochemical features of the lower Paleozoic strata of Yaerdang Mountain outcrop along with the core samples from well TD2∈ in the eastern Tarim Basin,NW *** total organic carbon abundance,hydrocarbon-generating precursor biospecies,and stable isotope ratios of organics and carbonate（δ13Cker,δ13Ccarb and δ18Ocarb） were comprehensively studied for their possible correlative constraints during sedimentary *** results revealed that the δ13Cker（VPDB） of Cambrian kerogens along the outcrop section varied from-34.6‰ to-28.4‰,indicating an increasing tendency from the lower Cambrian to the upper *** was on the whole accompanied by the variation in the δ13Ccarb and δ18Ocarb along the profile,which might be associated with the changes in the sea level and also in the compositional variation of benthic and planktonic *** large variation in the stable carbon isotope ratios up to 6‰ along the outcrop section reflected the heterogeneity of the Cambrian source rocks from the eastern Tarim ***,the 13C-enriched crude oils from well TD2∈might have been derived from a localized stratum of Cambrian source *** results from this study showed the possibility of multiple source kitchens in the Cambrian-lower Ordovician portion of Tarim Basin.

关键词： Kerogen Heterogeneity Tarim Basin Stable isotope geochemistry

Comprehensive diag”nostic review of the (13)~C-enriched crude oils exemplified by TD2∈ and TZ62S in Tarim Basin, NW China

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Chinese Journal Of Geochemistry 2015年第1期34卷 62-68页

作者： hu Liu Zewen liao Haizu Zhang Yankuan Tian Bin Cheng Xiaohong Chang State Key Laboratory of Organic Geochemistry Guangzhou Institute of Geochemistry Chinese Academy of Sciences University of Chinese Academy of Sciences Research Institute of Petroleum Exploration & Development Petro China Tarim Oilfield Company

The crude oils typically from the CambrianLower Ordovician source rocks of Tarim Basin, NW"China, such as TD2 and TZ62S, are13C-enriched with the stable carbon isotopic ratios(VPDB) approaching-28 %.In this paper, the main research viewpoints on this issue are summarized, and combined with results from organic and inorganic carbon isotope stratum curves of the outcrop at the Ya'erdang Mountain in Tarim Basin. In addition, more alternative interpretations are discussed. On one hand, the inverse fractionation features of stable carbon and hydrogen isotopes of these crude oils may imply their protogenous nature. On the other hand, the anisotropy of source rocks and contribution from older stratum source rocks need verifying as well. For the sake of the final resolution of this issue, some further study topics are recommended.

关键词：塔里木盆地综合诊断原油中国富集碳同位素比值同位素地层审查

Current susceptibilities of brown planthopper Nilaparvata lugens to triflumezopyrim and other frequently used insecticides in China

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Insect Science 2021年第1期28卷 115-126页

作者： Xun liao Peng-Fei Xu Pei-Pan Gong hu Wan Jian-Hong Li nstitute of Crop Protection Guizhou UniversityGuiyangChina hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory College of Plant Science and TechnologyHuazhong Agricultural UniversityWuhanChina

The brown planthopper is a notorious rice pest in many areas of *** evolution of insecticide resistance in Nilaparvata lugens has become a serious problem in the effective control of this pest in the paddy *** this article,the current susceptibility of *** field populations to novel mesoionic insecticide triflumezopyrim and major classes of chemical insecticides was determined and *** monitoring results indicated that field populations of *** had developed low resistance to triflumezopyrim(resistance ratio,RR:1.3-7.3-fold)during 2015-2018 in China,and the median lethal concentration values varied from 0.05 to 0.29 mg/***,during 2017 to 2018,field populations of *** showed high resistance levels to thiamethoxam(RR:456.1-1025.6-fold),imidacloprid(RR:2195.3-6899.0-fold)and buprofezin(RR:1241.57521.7-fold),moderate to high resistance levels to dinotefuran(RR:97.6-320.1-fold),clothianidin(RR:69.4-230.1-fold)and isoprocarb(RR:44.1-108.0-fold),and low to moderate levels of resistance to chlorpyrifos(RR:12.0-29.7-fold)and nitenpyram(RR:6.9-24.1-fold).In contrast,*** just showed low resistance to sulfoxaflor(RR:3.3-8.5-fold)and etofenprox(RR:5.0-9.1-fold)in the ***,the P450 gene CYP6ER1 was found to be significantly overexpressed in all five field populations of *** collected in 2018 when compared with a laboratory susceptible *** findings will provide useful information to delay the evolution of insecticide resistance in ***.

关键词： Nilaparvata lugens(Stal) P450 gene susceptibility triflumezopyrim

Structural characterization and anti-inflammatory activities of novel polysaccharides obtained from Pleurotus eryngii

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Food Science and human Wellness 2024年第5期13卷 3031-3042页

作者： Han Wang sai Ma Alfred Mugambi Mariga Qiuhui hu Qian Xu Anxiang Su Ning Ma Gaoxing Ma College of Food Science and Engineering Nanjing University of Finance and Economics/Collaborative Innovation Center for Modern Grain Circulation and SafetyNanjing 210023China School of Agriculture and Food Science Meru University of Science and TechnologyMeru 972-60200Kenya

Natural polysaccharides named PEP-0.1-1,PEP-0-1 and PEP-0-2 from edible mushroom species Pleurotus eryngii were obtained in the present *** showed that molecular weights of these polysaccharides were 3235,2041 and 23933 Da,***,structural characterization revealed that PEP-0.1-1 had a→4-α-D-Glcp-1→backbone and contained→4)-α-D-Glcp and→4)-β-D-Glcp reducing end ***-0-1 backbone contained→4-α-D-Glcp-1→and→6-α-3-O-Me-D-Galp-1→,and the side chains containedα-D-Glcp,β-D-Manp-1→andα-D-Glcp-3→.However,PEP-0-2 backbone consisted of→4-α-DGlcp-1→and→6-α-3-O-Me-D-Galp-(1→6)-α-D-Galp-1→while the side chains containedα-D-Glcp andβ-D-Manp-1→.Biological activity analysis was then carried out and found that all these polysaccharides could significantly suppress the relative mRNA expression of toll-like receptor 4,nitric oxide(NO),tumor necrosis factor-α,interleukin(IL)-1βand IL-6 in lipopolysaccharide(LPS)-induced inflammation of RAW264.7 cells,as well as the over secretion of the above cell ***,Western blotting analysis revealed that all these purified fractions displayed significant inhibition effects on the expression of c-Jun N-terminal kinases protein induced by LPS in mitogen activated protein kinase pathway,along with the relieving on the inhibition effect of LPS on IκB-αprotein *** summary,the information generated by the present study could provide a theoretical basis for the exploration of novel healthy food materials from edible mushroom with antiinflammation activities.

关键词： Pleurotus eryngii Polysaccharides Structural characterization Anti-inflammatory activity

Stereoselective Synthesis of cis-2,5-Disubstituted Pyrrolidines via Copper-Catalyzed Cyclization of Alkenes

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Chinese Journal of Chemistry 2016年第11期34卷 1076-1080页

作者： sai-hu Cai Bing-Chao Da Jia-hui Zhou Yun-He Xu Teck-Peng Loh Department of Chemistry University of Science and Technology of China Hefei Anhui 230026 China DiVision of Chemistry and Biological Chemistry School of Physical and Mathematical Sciences Nanyang Technological University 637371 Singapore

An efficient methodology for the stereoselective synthesis of cis-2,5-disubstituted pyrrolidines using copper catalyst was developed. The corresponding cis-2,5-disubstituted pyrrolidines could be obtained in reasonable yields and with good stereoselectivities in the presence of 4,4＇-di-tert-butyl-2,2＇-bipyridine as ligand and l-methyl-2-pyrrolidinone as solvent.

关键词： stereoselectivity pyrrolidines copper-catalyzed cyclization

Interfacial characteristics and mechanical properties of additive manufacturing martensite stainless steel on the Cu-Cr alloy substrate by directed energy deposition

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Journal of Materials Science & Technology 2021年第31期90卷 121-132页

作者： Wenqi Zhang Hailong liao Zhiheng hu Shasha Zhang Baijin Chen huanqing Yang Yun Wang Haihong Zhu Wuhan National Laboratory for Optoelectronics Huazhong University of Science and TechnologyWuhan 430074China State Key Laboratory of Material Processing and Die&Mould Technology School of Material Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074China XI’AN Space Engine Company Limited Xi’an710100China

Copper/steel is a typical bimetal functional material,combining the excellent electrical and thermal conductivity of copper alloy and the high strength and hardness of stainless *** has been recent interest in manufacturing copper/steel bimetal by directed energy deposition(DED)due to its layer-bylayer ***,cracks tend to form on the copper/steel interface because of the great difference in thermal expansion coefficient and crystal structure between copper and *** this work,interfacial characteristics and mechanical properties of the copper/steel bimetal were studied from one layer to *** laser power has a great influence on the Cu element distribution of the molten pool,affecting the crack formation dramatically on the solidification *** tend to form along columnar grain boundaries because of the Cu-rich liquid films and spherical particles in the ***-free and good metallurgical bonding copper/steel interface is formed at a scanning velocity of 800 mm/min and the laser power of 3000 *** ultimate tensile strength(UTS)and the break elongation(EL)of the vertically combined crack-free copper/steel bimetal are 238.2±4.4 MPa and 20.6±0.7%,*** fracture occurs on the copper side instead of the copper/steel interface,indicating that the bonding strength is higher than that of the Cu-Cr *** UTS of the horizontally combined crack-free copper/steel bimetal is 746.7±22.6 MPa,which is 200%higher than that of the Cu-Cr alloy *** microhardness is 398.6±5.4 HV at the steel side and is 235.3±64.1 HV at the interface,which is400%higher than that of the Cu-Cr alloy *** paper advances the understanding of the interfacial characteristics of heterogeneous materials and provides guidance and reference for the fabrication of multi-material components by DED.

关键词： Directed energy deposition Additive manufacturing Bimetal Interfacial characteristics Crack