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Effect of soft reduction process on segregation of a 400 mm thick high-alloy steel slab

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Journal of Iron and Steel Research International 2021年第3期28卷 272-278页

作者： Ren-sheng Chu Zhan-jun Li jin-gang liu Yong Fan Yang liu Chang-wen Ma Research Institute of Technology Shougang Group Co.Ltd.Beijing100043China Beijing Engineering Research Center of Energy Steel Beijing100043China Beijing Key Laboratory of Green Recyclable Process for Iron and Steel Production Technology Beijing100043China Institute of Iron and Steel Technology TU Bergakademie FreibergFreiberg09599SachsenGermany

During the solidification of high-alloy steel(0.4C–1.5Mn–2Cr–0.35Mo–1.5Ni),the high temperature gradient of solidified shell as well as the columnar crystal development would contribute to the centre segregation and cracking due to the high carbon and alloy *** effect of soft reduction process on the segregation of a 400 mm thick high-alloy steel slab was *** trials in a steel mill were performed combining with segregation *** inner quality of the high-alloy steel slab produced through the optimised soft reduction procedures and had a significant improvement in centre *** reduction amount is increased from 20%of solid phase fraction,to avoid the segregation due to the long liquid core,and the reduction rate is deceased from 1.35 to 0.88 mm/m as *** operation would contribute to the symmetrical distribution of solute element and decrease the segregation to avoid the *** obvious improvement in centre segregation to mainly 1.0 class of high-alloy slab after procedure optimization was *** quality improvement of slab would ensure the quality of downstream forging.

关键词： Continuous casting Soft reduction High-alloy steel Segregation Cracking

FLUORENE-BRIDGED POLYPHENYLQUINOXALINES WITH HIGH SOLUBILITY AND GOOD THERMAL STABILITY:SYNTHESIS AND PROPERTIES

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Chinese Journal of Polymer Science 2010年第6期28卷 971-980页

作者： Cheng Li Zhuo Li jin-gang liu Hai-xia Yang Shi-yong Yang Laboratory of Advanced Polymer Materials Institute of ChemistryChinese Academy of SciencesBeijing 100190China

A novel fluorene-bridged tetraketone monomer,9,9-bis[(4-benzilyloxy)phenyl]fluorene(FLTK) was synthesized and *** tetraketone was polymerized with various aromatic tetraamines to afford a series of polyphenylquinoxalines(PPQs).The obtained polymers were found to be soluble in common organic solvents such as N-methyl-2-pyrrolidone(NMP),chloroform and *** and tough PPQ films obtained by spin-casting their NMP solutions exhibited tensile strengths higher than 60 *** films also demonstrated good thermal stability up to 500℃in nitrogen and glass transition temperatures higher than 280℃.In addition,the PPQ films exhibited good hydrolytic stability. High surface and volume resistivity retentions were achieved for the films after immersion or boiling in water for 24 h.

关键词： Polyphenylquinoxaline Fluorene Solubility Thermal stability Hydrolytic stability

Novel phosphorus-silicon synergistic flame retardants:Synthesis and characterization

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Chinese Chemical Letters 2012年第7期23卷 793-796页

作者： Tao Song Zhi Sheng Li jin gang liu Shi Yong Yang Laboratory of Advanced Polymer Materials Institute of ChemistryChinese Academy of SciencesBeijing 100190China

Three novel flame retardants containing both phosphorus and silicon elements in their structures,including[（1,1,3,3- tetramethyl-1,3-disiloxanediyl）di-2,1-ethanediyl]bis（diphenylphosphine oxide）（FR-1）,[（2,4,6,8-tetramethylcyclotetra-siloxane -2,4,6,8-tetrayl）tetra-2,1-ethanediyl]tetrakis[diphenylphosphine oxide]（FR-2） and 1,3,5,7,9,11,13,15-octakis（di-phenylphosphine oxide-2,1-ethanediyl）pentacyclo[9.***.1.1^（3,9）.l^（5,15）.1^（7,13）]octasiloxane（FR-3） were synthesized by a convenient pathway from the reaction of diphenylphosphine oxide（DPPO） and vinyl-terminated siloxanes under the catalysis of triethylborane. The chemical structures of the target compounds were confirmed by nuclear magnetic resonance（^1H NMR,^13C NMR,^29Si NMR and ^31P NMR）,matrix-assisted laser desorption/ionization time-of-flight mass spectrometry（MALDI-TOF-MS） and Fourier transform infrared（FT IR） *** analysis（TGA） results indicated that the new flame retardants possessed good thermal stability both in nitrogen and in ***-3 containing polyhedral oligosilsesquioxanes（POSS） moiety exhibited the best thermal properties with a 10%weight loss temperature〉400℃ and a residual weight ratio〉39%at 700℃ .

关键词： Phosphorous-containing siloxanes POSS Flame retardant Synergistic effect

Residual stress in the cylindrical drawing cup of SUS304 stainless steel evaluated by split-ring test

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Acta Mechanica Sinica 2016年第1期32卷 125-134页

作者： Liang-Hong Xiao Dao-He Yuan Jun-Zhong Xiang jin-gang liu Yi-Chun Zhou School of Mechanical Engineering Xiangtan University Key Laboratory of Low Dimensional Materials & Application Technology Xiangtan University Ministry of Education

The residual stresses in the wall of a SUS304 stainless steel cylindrical drawing cup were evaluated by split-ring tests, and the influences of stamping die parame- ters on the residual stress were investigated. A new theoretical model of a split-ring test was developed to evaluate the resid- ual stress in a ring, which was verified to be reasonable and reliable by numerical simulations with ABAQUS code and by nanoindentation tests. Seven groups of split-ring tests were completed, and the residual stresses were calculated according to the theoretical model. The split-ring test results showed that the circumferential residual stress in the wall of the SUS304 stainless steel cylindrical drawing cup was very large and did not change with the different die comer radius. The circumferential residual stress first increased with the increase of drawing punch-die clearance, then was almost unchanged when the clearance increased greater than blank thickness 1 mm. Thus, a smaller clearance was suggested to be chosen to reduce the residual stress in the wall of the SUS304 stainless steel drawing cup.

关键词： Residual stress Split-ring test FEM numericalsimulation SUS304 stainless steel Nanoindentation

Synergistic Enhancement of Electrocatalytic Activity toward Oxygen Reduction Reaction in Alkaline Electrolytes with Pentabasic （Fe, B, N, S, P）-Doped Reduced Graphene Oxide

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Chinese Journal of Chemistry 2016年第9期34卷 878-886页

作者： Wei Chen Munil Sin Ping-Jie Wei Qian-Ling Zhang jin-gang liu Department of Chemistry East China University of Science and Technology Shanghai 200237 China Shenzhen Key Laboratory of Functional Polymer College of Chemistry and Environmental Engineering Shenzhen University Shenzhen Guangdong 518060 China

As alternatives to Pt-based electrocatalysts, the development of nonprecious metal catalysts with high performance in the cathodic oxygen reduction reaction （ORR） is highly desirable for widespread use in fuel cells. Here we report a simple approach for preparing pentabasic （Fe, B, N, S, P）-doped reduced graphene oxide （rGO） via a two-step doping method of adding boric acid and ferric chloride to ternary （N, S, P）-doped rGO （NSPG）. Electro- chemical investigation of the composites for the ORR revealed that simultaneously doping appropriate amounts of Fe and B into the NSPG produced a synergistic effect that endowed the prepared catalyst with both a positively shifted ORR half-wave potential and high selectivity for the 4e^-reduction of O2. The optimized Fe2B-NSPG catalyst approached a 4e^- process for the ORR with a half-wave potential （E1/2=0.90 V vs. RHE） even 30 mV higher than that of the commercial Pt/C catalyst in alkaline solution. Furthermore, relative to the Pt/C catalyst, the Fe2B-NSPG demonstrated superior stability and excellent tolerance of the methanol cross-over effect. This simple method afforded pentabasic （Fe, B, N, S, P）-doped rGO as a promising nonpreeious metal catalyst used for alkaline fuel cells.

关键词： oxygen reduction reaction reduced graphene oxide multiple dopant electrocatalysis

HETEROAROMATIC POLYMERS—HIGH TEMPERATURE POLYPYRROLONES DERIVED FROM 2,6-BIS(3',4'-DIAMINOPHENYL)-4-BIPHENYLPYRIDINE AND VARIOUS AROMATIC DIANHYDRIDES

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Chinese Journal of Polymer Science 2005年第5期23卷 521-529页

作者： Hai-xia Yang jin-gang liu Xiao-juan Zhao Yan-feng Li Lin Fan Shi-yong Yang School of Chemistry and Chemical Engineering Lanzhou University Lanzhou 730000 China Laboratory of Advanced Polymer Materials Institute of Chemistry Chinese Academy of Sciences Beijing 100080 China

A new type of aromatic tetraarnine containing biphenyl moiety in the side chain was synthesized via a modified Chichibabin＇s reaction. 3-Nitro-4-acetamidoacetophenone was reacted with 4-phenyl benzaldehyde in the presence of ammonium acetate to obtain 2,6-bis（3＇,4＇-diaminophenyl）-4-biphenyl pyridine （DPPA）. A series of polypyrrolones （PPys） were prepared using tetraamine and various aromatic dianhydrides via a two-step cyclization procedure. All the PPys show excellent high temperature stabilities with the initial decomposition temperatures of 530-549℃ and residual weight ratio of 49%-80% at 750℃ in nitrogen. The polymers exhibit no apparent glass transition temperatures （Tgs） except PPy-1 （Tg= 327℃）, which is derived from tetraamine DPPA and 2,2-bis[4-（3＇,4＇-dicarboxyphenoxy）-phenyl]propane dianhydride （BPADA）. In addition, the polymers have acceptable mechanical properties with the tensile strength of 65-94 MPa. The PPy films show excellent hydrolysis-resistance in alkaline aqueous medium and could maintain most of the properties even after boiling in 10% aqueous sodium hydroxide solution for a week.

关键词： Tetraamine Polypyrrolone Pyridine High temperature polymers Film Hydrolysis-resistance.

piggyBac-mediated germline transformation of the malaria mosquito Anopheles sinensis (Diptera:Culicidae)

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Insect Science 2021年第4期28卷 1202-1206页

作者： jin-gang liu Liang Qiao Jia-Jun Zhang Bin Chen Zheng-Bo He Chongqing Key Laboratory of Vector Insects Institute of Entomology and Molecular BiologyCollege of Life SciencesChongqing Normal UniversityChongqingChina

Dear Editor,Anopheles sinensis is the primary vector of vivax malaria in *** the risks posed by ***,many methods have been used to control this vector,most commonly chemical ***,the extensive use of insecticides has subjected mosquitoes to intense selection pressure,resulting in the development of resistance,variations in mosquito behavior.

关键词： malaria behavior. China.

Multiple perforations and fistula formation following corticosteroid administration: A case report

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World Journal of Clinical Cases 2017年第2期5卷 67-72页

作者： jing-Ni He Zhong Tian Xu Yao Hang-Yu Li Yun Yu Yuan liu jin-gang liu Department of General surgery Shengjing Hospital Affiliated to China Medical University Department of General surgery the 4~(th) Hospital Affiliated to China Medical University

Eosinophilic granulomatosis with polyangiitis(Eg PA) is a rare systemic small- and medium-sized-vessel vasculitis. The literature contains only a few reports of gastrointestinal perforation with this condition. We report a patient with EPgA treated with high-dose steroid who underwent emergency surgery for intestinal perforations. We performed a simple repair of the 11 perforations. Intestinal fistulas developed 8 d postoperatively; they healed well after 60 d of continuous washing and negative pressure suction. The clinical data of 14 additional patients with EgP A or Churg-Strauss syndrome complicated with gastrointestinal perforation, which were reported from 1996 to 2014, were also collected and compared. The formation of multiple perforations and fistulas following high dosage steroid administration can have a good outcome with appropriate management. Meticulous attention to abdominal symptoms and appropriate interventions can result in timely management. Corticosteroid administration remains a very important perioperative procedure for EPgA.

关键词： vasculitis Eosinophilic granulomatosis with polyangiitis Churg-Strauss syndrome gastrointestinal perforation surgery

NUMERICAL MODELLING OF FREE-SURFACE FLOWS WITH BOTTOM AND SURFACE-LAYER PRESSURE TREATMENT

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Journal of Hydrodynamics 2009年第3期21卷 352-359页

作者： WANG Kun State Key Laboratory of Coastal and Offshore Engineering Dalian University of Technology Dalian 116024 China

A new non-hydrostatic numerical model with the three-dimensional Navier-Stokes equations on structured grids was constructed and discussed. The algorithm is based upon a staggered finite difference Crank-Nicholson scheme on a Cartesian grid. The eddy viscosity coefficient was calculated by the efficient k-ε turbulence model. A new surface-layer non-hydrostatic treatment and a local cell bottom treatment were introduced so that the three-dimensional model is fully non-hydrostatic and is free of any hydrostatic assumption. The developed model is second-order accuracy in both time and space when semi-implicit coefficient is set to 0.5. The validity of the present solution algorithm was demonstrated from its application to the three-dimension channel flow and the wave propagation over a submerged bar problems.

关键词： Navier-Stokes equations implicit k -ε turbulence model surface-layer non-hydrostatic treatment local cell bottom treatment