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Journal of Iron and Steel Research International 2016年第3期23卷 281-288页

作者： Guang-hong WANG Sheng-guan QU Zhi-hua XIONG Fu-qiang LAI xiao-qiang li Mao-sheng YANG School of Mechanical and Automotive Engineering South China University of Technology Institute of Special Steel Central Iron and Steel Research Institute

Wear behavior and mechanism of plasma nitrided steel oscillating against a heat-treated and an untreated aluminum bronze alloy were investigated using an Optimol SRV *** influence of heat treatment on the mechanical properties of the alloy was ***,the wear debris was also examined to understand the wear *** results show that a 220-230μm nitrided layer,which was harder than the substrate,was obtained on the steel *** tensile strength and hardness of the alloy are found to be significantly improved by the heat treatment associated with low impact *** heat treatment of the alloy did not obviously decrease the friction coefficient of the nitrided steel-bronze ***,the wear loss of the nitrided steel increased when it mated with the treated bronze by a severe three-body *** nitrided steel was mainly damaged by fatigue *** plane contact conditions,the wear debris was mainly generated from the bronze part and can escape from the interface before being oxidized,leading to the phase structure of all the debris being copper rather than copper oxides.

关键词： steel plasma nitriding aluminum bronze sliding wear three-body abrasion

Microstructure and tribological properties of carburized 95W–3.5Ni–1.0Fe–0.5Co heavy alloy

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Rare Metals 2019年第2期38卷 165-172页

作者： Sheng-Guan Qu Guang-Hong Wang Zhang-Xuan Yang Fu-qiang Lai Zhi-Hua Xiong Hu Ke xiao-qiang li School of Mechanical and Automotive Engineering South China University of Technology

Tungsten heavy alloys(WHAs) produced by powder technology are widely used for the mechanical manufacturing, electronic and defense components, *** properties of these alloys need to be improved to meet the severe service conditions demanded. Carburization is a promising way to resolve this problem. In this work, microstructure and tribological properties of the carburized 95W–3.5Ni–1.0Fe–0.5Co heavy alloy were investigated in comparison with those of the untreated alloy. Results show that the carburized layer consists of a porous, outer WC layer and a modified W grain layer surrounded by Fe_6W_6C and Co_6W_6C at 970℃, regardless of the carburizing time. The depth of the carburized layer linearly increases in a relatively short time and slightly increases during the subsequent period. Surface roughness increases with carburizing time. Carburization can stabilize friction coefficient and effectively improve the wear resistance of the tungsten heavy alloy due to its significantly increased hardness and non-deformability, but the porous structure in the WC layer has a negative influence on its wear resistance. The carburized layer is damaged in the porous WC layer in the form of the spalling of WC particles where there are some microcracks and micropores, accompanied with peeling due to the solid tribofilm being pushed away.

关键词： Tungsten: Carburization Surface roughness Wear Spalling

In situ polymerization of aniline in electrospun microfibers

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Chinese Chemical Letters 2014年第1期25卷 83-86页

作者： xiao-qiang li Wan-Wan liu Shui-Ping liu Meng-Juan li Yong-Gui li Ming-Qiao Ge Key Laboratory of Eco-textiles Ministry of EducationJiangnan University College of Textile & Clothing Jiangnan University

Conductive microfibers with an average diameter of ca. 1.0 μm were prepared by in situ polymerization of aniline, in which poly（vinylchloride-acrylonitrile）（PVC-AN） was used as the filament-material in electrospinning to form precursor microfibers and carry the aniline monomers. Fourier-transform infrared （FTIR） results demonstrated that PANi was successfully polymerized in the microfibers. The morphology of the PVC-AN-PANi microfibers was observed by scanning electron microscopy （SEM）. Results of differential scanning calorimetry indicated that the polymer composite of PVC-AN-PANi formed via molecular interactions. Although the conductivity of PVC-AN-PANi microfibers was still limited （2.2 × 10^-8 S/cm）, this method provided an effective and convenient approach for preparing highly uniform and soft microfibrous electrodes.

关键词： Conductive microfibers Electrospinning Polymer composite Polyaniline

Vegetation and Environment History for the Past 14 000 yr BP from Dingnan, Jiangxi Province, South China

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Journal of Integrative Plant Biology 2006年第9期48卷 1018-1027页

作者： John Richard Dodson Shirene Hickson Rachel Khoo xiao-qiang li Jemina Toia Wei-Jian Zhou Institute for the Environment Brunel University Uxbridge UB8 3PH England School of Earth and Geographical Sciences University of Western Australia Perth WA 6009 Australia State Key Laboratory of Loess and Quaternary Institute for Earth Environment the Chinese Academy of Sciences Xi＇an 710075 China

A Late Pleistocene-Holocene pollen, phosphorus, and charcoal record was reconstructed from a peatland in southern Jiangxi Province in southern China. The area today has a mountainous and rolling landscape with villages, small towns, and agriculture dominated by rice paddies, vegetable, and fruit gardens, as well as areas of secondary forest and pine re-afforestation. The record opens before 14 300 yr BP, with Alnus woodland dominating the wetland areas and with an open Quercus woodland on the surrounding slopes. The forest area becomes more complex from approximately 12 800 yr BP and further from 9 000 yr BP. At approximately 6 000 yr BP, there is evidence of clearing and, by 4 500-4 000 yr BP, a complete collapse in the wetland Alnus and terrestrial forest as the low-lying areas are converted to rice production. For much of the record, the occurrence of fire around the site was low, although there is evidence of regional fires. Fire was used as a tool in clearing and then used in the annual cycles of stubble burning after rice harvest. Nutrient levels, as reflected by total phosphorus in the sediment, seem to be closely related to forest changes and high values in the surface layers probably result from land-management techniques associated with agriculture. Therefore, human impact greatly altered forest cover, fire frequency, and nutrient dynamics; this has been evident for approximately 6 000 yr BP and then intensities towards the present day.

关键词： development of rice agriculture nutrient and fire history South China vegetation history

Preparation,characterization and biocompatibility of aspartic acid modified CdTe quantum dots

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Chinese Chemical Letters 2014年第6期25卷 933-936页

作者： Shui-Ping liu Jia-Jia Fu Meng-Juan li lin lin xiao-qiang li Ming-Qiao Ge Key Laboratory of Eco-Textiles Ministry of Education(Jiangnan University) College of Textile & Clothing Jiangnan University School of Food & Biological Engineering Jiangsu University Technical University of Denmark DTU FoodSoltofts Plads B227.2800 Kgs.LyngbyDenmark

This study aims at preparing water soluble aspartic acid （ASP） modified CdTe quantum dots with tunable fluorescence emission controlled by reaction time. The size of the synthesized CdTe quantum dots was evaluated using transmission electron microscope （TEM） and also calculated based on their UV-vis spectra. The optical properties of TGA-CdTe quantum dots were characterized by UV-vis and fluorescence （FL） spectroscopy. The red-shift in the UV-vis absorption and FL emission with the increase of reaction time was observed. The biocompatibility examination indicated that the ASP modified CdTe QDs had low cytotoxicity.

关键词： Water-soluble quantum dots CdTe Surface modification Biocompatibility

Total endovascular repair of an intraoperative stent-graft deployed in the false lumen of Stanford type A aortic dissection: A case report

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World Journal of Clinical Cases 2020年第5期8卷 954-962页

作者： Xu-Ran li Yuan-Hao Tong xiao-qiang li Chang-Jian liu Chen liu Zhao liu Department of Vascular Surgery Nanjing Drum Tower Hospital The Affiliated Hospital of Nanjing University Medical School

BACKGROUND A 46-year-old male underwent ascending aortic replacement,total arch replacement,and descending aortic stent implantation for Stanford type A aortic dissection in ***,an intraoperative stent-graft was deployed in the false lumen *** caused severe iatrogenic thoracic and abdominal aortic dissection,and the dissection involved many visceral *** SUMMARY The patient had pain in the chest and back for 1 mo.A computed tomography scan showed that the patient had secondary thoracic and abdominal aortic *** ascending aortic replacement,total arch replacement,and descending aortic stent implantation for Stanford type A aortic dissection were performed 2 years *** intraoperative stent-graft was deployed in the false *** aneurysm repair was performed to address this intractable *** occluder was used to occlude the proximal end of the true lumen,and a covered stent was used to direct blood flow back to the true lumen.A three-dimensional printing technique was used in this operation to guide *** computed tomography scan at the 1stmo after surgery showed that the thoracic and abdominal aortic dissection was repaired,with all visceral arteries remaining *** patient did not develop renal failure or neurological complications after *** The total endovascular repair for false lumen stent-graft implantation was feasible and minimally *** procedures provided a new solution for stent-graft deployed in the false lumen,and other departments may be inspired by this case when they need to rescue a disastrous stent implantation.

关键词： Type A dissection False lumen stent graft implantation Endovascular repair 3D printing Thoracoabdominal aortic dissection Case report

Effect of short-time low-temperature austenitizing on microstructure and mechanical properties of DT300 ultra-high strength steel fabricated by laser powder bed fusion

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Journal of Iron and Steel Research International 2024年第7期31卷 1763-1777页

作者： Chen-yang Jiang xiao-qiang li Jin-tao Wang Hao Luo Sheng-qing Gao Sheng-guan Qu Chao Yang National Engineering Research Centre of Near-Net-Shape Forming for Metallic Materials South China University of TechnologyGuangzhou 510640GuangdongChina Institute of New Materials Guangdong Academy of ScienceGuangzhou 510650GuangdongChina

To address the inhomogeneous microstructure and improve the mechanical properties of DT300 ultra-high strength steel specimens fabricated by laser powder bed fusion,different post-heat treatment schedules are *** the increase in austenitizing temperature and time,the migration rate of austenite grain boundaries continuously increases with the dissolution of nano-carbides,and the formation of nano-oxides and twin martensite is also inhibited *** rapid growth in the size of prior austenite grains and martensite laths,as well as the decrease in the content of nano-oxides and twin martensite,led to a rapid decrease in the strength(yield strength and ultimate tensile strength)from HT2 to HTF *** HT1 specimens(austenitizing at 830℃for 30 min,then oil quenching and tempering at 300℃for 120 min and finally air cooling)display excellent mechanical properties of yield strength of 1572 MPa,ultimate tensile strength of 1847 MPa,elongation of 9.84%,and fracture toughness of 106 MPa m^(1/2),which are counterparts to those of conventional DT300 steel forgings after heat treatment.

关键词： DT300 ultra-high strength steel Laser powder bed fusion-Short-time low-temperature austenitizing Microstructure Mechanical property

Duality theorem for weak L-R smash products

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Applied Mathematics(A Journal of Chinese Universities) 2010年第4期25卷 481-488页

作者： ZHOU xiao-yan li qiang ZHANG liang-yun Department of Mathematics, Nanjing Agricultural University, Nanjing 210095, China Department of Mathematics Nanjing Agricultural University Nanjing China

This paper gives a duality theorem for weak L-R smash products, which extends the duality theorem for weak smash products given by Nikshych.

关键词： Weak Hopf algebras weak L-R smash products duality theorem.

Polymerization Mechanism of Methyl Methacrylate Initiated by Ethyl Acetate/t-BuP_4

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Chinese Journal of Polymer Science 2019年第6期37卷 598-603页

作者： De-Yong Xia Qi-Min Jiang Wen-Yan Huang Hong-Jun Yang xiao-qiang Xue li Jiang Bi-Biao Jiang Jiangsu Key Laboratory of Environmentally Friendly Polymeric Materials School of Materials Science and Engineering Jiangsu Collaborative Innovation Center of Photovoltaic Science and Engineering Changzhou University Changzhou University Huaide College

The anionic polymerization of methyl methacrylate(MMA) was carried out using phosphazene base t-BuP_4 and ethyl acetate(EA) as the catalyst and the initiator, respectively. Gas chromatography(GC), size exclusion chromatography(SEC) measurements, and nuclear magnetic resonance(NMR) analyses were used to reveal the polymerization mechanism and to confirm the polymer structure. The results confirmed the proposed polymerization mechanism and the polymer structure, while the initiator efficiency was low. Meanwhile,the initiation by methoxy anion coming from hydrolysis of the ester bond in MMA was also observed. As a result, there is a marked deviation between the theoretical molecular weight and the measured molecular weight, and it is essential to carry out the polymerization at excessive dosage of t-BuP_4 for preparing polymers with narrow molecular weight distribution.

关键词： Phosphazene base(t-BuP4) Methyl methacrylate Ethyl acetate Anionic polymerization

Treatment of Stanford type A aortic dissection with triple prefenestration, reduced diameter, and three-dimensional-printing techniques: A case report

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World Journal of Clinical Cases 2021年第1期9卷 183-189页

作者： Ming Zhang Yuan-Hao Tong Chen liu xiao-qiang li Chang-Jian liu Zhao liu Vascular Surgery Nanjing Drum Tower HospitalThe Affiliated Hospital of Nanjing University Medical SchoolNanjing 210008Jiangsu ProvinceChina Vascular Surgery Nanjing Drum Tower HospitalThe Affiliated Hospital of Nanjing University Medical SchoolNanjing 21008Jiangsu ProvinceChina

BACKGROUND A 63-year-old female was diagnosed with acute Stanford type A aortic *** patient had pain in the chest and back for 1 *** computed tomography angiography(CTA)showed Stanford type A aortic dissection(Myla type III aortic arch).The intimal tear was located at the top of the aortic arch and retrograded to the ascending *** SUMMARY Preoperatively,a three-dimensional(3D)-printed model of the aortic arch was made according to CTA ***,under the guidance of the 3D-printed aortic model,a pre-fenestrated stent-graft was customized,and the diameter of the stent-graft was reduced intraoperatively by surgeons.3D printing,triple prefenestration,and reduced diameter techniques were used during the *** CTA examinations were performed at the 3rd mo and 1st year after the surgery;the results showed that the aortic dissection was repaired without endoleak,and all three branches of the aortic arch remained *** Applying the triple pre-fenestration technique for aortic arch lesions was feasible and minimally invasive in our *** technique provides a new avenue for thoracic endovascular aortic repair of Stanford type A aortic dissection.

关键词： Type A aortic dissection Aortic arch Pre-fenestration 3D printing Endovascular repair Case report