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Synthesis of benzoxazine-based phenolic resin containing furan groups

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Chinese Chemical Letters 2010年第7期21卷 868-871页

作者： Sheng Fang Li School of Chemical and Material Engineering,huangshi Institute of Technology,huangshi 435003,China School of Chemical and Material Engineering Huangshi Institute of Technology Huangshi 435003 China

A novel benzoxazine-based phenolic resin containing furan groups（PFB） was synthesized via simple two-step reactions and the structure of PFB was confirmed by FTIR and ~1H NMR *** scanning calorimetry（DSC） showed that the polybenzoxazine cured from PFB had good heat resistance and lower polymerization temperature compared with that of benzoxazine-based phenolic resins.

关键词： Benzoxazine Phenolic resin Furan Phenol-furfural Performance enhancement

Effects of adenovirus mediated vascular endothelial growth factor gene transfer on reconstitution of hematopoiesis in post-bone marrow transplantation mice

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Chinese Medical Journal 2005年第4期118卷 289-295页

作者： ZHONGZhao-dong ZOUPing HUXian-shi YOUYong CHENZhi-chao huangshi-ang InstituteofHematology UnionHospitalTongjiMedicalCollegeHuazhongUniversityofScienceandTechnologyWuhan430022China

Background Bone marrow transplantation ( BMT) conditioning procedure isconsidered as the cause of damage to bone marrow microvasculature and the delay of hematopoiesisrecovery. However, hematopoiesis regulation post BMT by vascular endothelial growth factor ( VEGF)has not yet been studied. In this study, adenovirus were used to investigate the effects of VEGFgene transfer on preventing damages to bone marrow microenvironment and its promotion ofhematopoiesis in post-BMT mice. Methods Recombinant adenovirus (Ad)-enhanced green fluorescentprotein (EGFP)/hVEGF_(165) was injected via tail vein into BALB/c mice undergoing syngeneic *** the different phases post BMT, the distribution of adenovirus and the plasma levels of hVEGFwere measured as well as the numbers of white blood cells (WBC) , platelet (PLT) and red blood cells(RBC) in peripheral blood. At the same time, the mice were injected with Chinese ink via tail vein,following which the tibias were separated and were used for analysis of bone marrowmicrovasculature surface area and cellularity. Results Significant expression of EGFP and hVEGF wasobserved in multiple organs at different phases post BMT, and the plasma level of hVEGF was up to(866. 67 ± 97. 13 ) pg/ml. The recovery of WBC, PLT and RBC of the group treated with recombinantadenovirus Ad-EGFP/hVEGF_(165) were significantly more rapid than those of other BMT groups (P 0. 05 ]. The restoration of hematopoiesis was retarded more than that of *** cellularity of bone marrow in each group was still lower than that of normal control [ ( 62. 3± 4. 0 ) % , P < 0. 05 ] at the 30th day post BMT, but the percentage in group treated with VEGF atthe 20th and 30th days post BMT [(46.5 ± 5.0)% and (55.1 ± 4.5)%] exceeded those of other BMTgroups (P <

关键词： vascular endothelial growth factor gene transfer bone marrowtranspbntation reconstitution of hematopoiesis

Projection Operator and Feynman Propagator for a Free Massive Particle of Arbitrary Spin

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Communications in Theoretical Physics 2004年第3期41卷 405-418页

作者： huangshi-Zhong ZHANGPeng-Fei RUANTu-Nan ZHUYu-Can ZHENGZhi-Peng DepartmentofPhysics AnhuiNormalUniversityWuhu241000China DepartmentofModernPhysicsandNationalSynchrotronRadiationLaboratory UniversityofScienceandTechnologyofChinaHefei230027China ChinaCenterofAdvancedScienceandTechnology（WorldLaboratory） Beijing100080China InstituteofHighEnergyPhysics theChineseAcadelnyofSciencesBeijing100039China

Based on the solution to the Bargmann Wigner equations, a direct derivation of the projection operator and Feynman propagator for a free massive particle of arbitrary spin is worked out. The projection operator constructed by Behrends and Fronsdal is re-deduced and confirmed, and simplified in the case of half-integral spin, the general commutation rules and Feynman propagator with additional non-covariant terms for a free massive particle with any spin are derived, and explicit expressions for the propagators for spins 3/2, 2, 5/2, 3, 7/2, and 4 are provided.

关键词：投影算子费曼分布函数随机旋转 Bargmann-Wigner方程数学物理方法

ON THE M_7C_3 IN Cr27 CAST IRON

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Acta Metallurgica Sinica(English Letters) 1992年第6期5卷 459-464页

作者： LI Yuqing WANG Cirong GU Zhaofeng Research Institute of Daye Steel Works,huangshi,China Senior Engineer,Research Institute of Daye Steel Works,huangshi 435001,China Research Inst of Daye Steel Works Huangshi China

Determination of(Fe,Cr)_7C_3 in Cr27 cast iron results about 30 v.-%.Minor Si and Mn are *** area of the M_7C_3 grains is 1—50μm^*** matrix analysis of elec- tron diffraction pattern with calculated angle between plane traces,{011}twins and also {013}twins producing local environment for Ru_7B_3 are observed in the orthorhombic M_7C_3. A crystallographic model for M_7C_3 is proposed.

关键词： cast iron M_7C_3 twin plane trace Cr 27

EFFECT OF Nb ON STRENGTHENING OF Fe-BASE SUPERALLOY AT INTERMEDIATE HIGH TEMPERATURES

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Acta Metallurgica Sinica(English Letters) 1993年第2期6卷 81-85页

作者： CHEN Guosheng WU Bohua ZHOU Lecheng LI Yuqing Research Institute of Daye Steel Works,huangshi,China Engineer,Research Institute of Daye Steel Works,huangshi 435001,China Research Inst of Die Steel Works Huangshi China

Because Nb accelerates the uniform distribution of MC phase and the grain refinement,as well as,increases the amount and stability of γ-phase,the tensile strength,ductility,stress rupture life and fatigue limit of Fe-30Ni-13Cr-1.2W-1.5Mo-2.5Ti-0.4AI superalloy at 650℃ can be improved with increase of Nb content up to 1.22 wt-%.The precipitation of small Laves phase particles dispersed along grain boundaries may be favourable to combined properties of the superalloy containing 1.22 wt-% *** will be worsened only that the pre- cipitation of Laves phase particles'dispersed along grain boundaries may be favourable for combined properties of the superalloy containing 1.22 wt-% *** will be worsened only that the precipitation of Laves phase is too more because of too high Nb content existhing.

关键词： Nb Fe-base superalloy strengthening

基于Mindlin解的隧道施工引发的附加荷载及接收井变形分析

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中南大学学报（自然科学版） 2022年第11期53卷 4300-4309页

作者：傅鹤林张凯源邓皇适陈足中南大学土木工程学院湖南长沙410075

对盾构机施工引起的接收井的受力和变形进行分析。首先,基于Mindlin解推导出盾构机临近接收井时各施工因素引起的附加应力和简化成竖向地基梁的围护结构变形计算公式;其次,计算分析某地铁盾构附加推力、盾壳摩阻力、盾尾注浆压力引起的... 详细信息

对盾构机施工引起的接收井的受力和变形进行分析。首先,基于Mindlin解推导出盾构机临近接收井时各施工因素引起的附加应力和简化成竖向地基梁的围护结构变形计算公式;其次,计算分析某地铁盾构附加推力、盾壳摩阻力、盾尾注浆压力引起的深度为13 m时刀盘平面和隧道轴线上的附加荷载、接收井墙面上的附加荷载、不同深度下盾构机距接收井5 m和10 m时围护结构的变形情况并通过数值模拟进行验证。研究结果表明:掌子面附加推力和盾壳摩阻力导致接收井围护结构变形在竖向分布为先增后减,附加注浆压力以刀盘为中心呈反对称分布;在对围护结构变形的影响因素中,盾壳摩阻力影响最大,掌子面附加推力的影响次之,盾尾附加注浆压力的影响可以忽略。

关键词： Mindlin解盾构施工接收井变形特征

PERIODIC SOLUTIONS FOR GENERALIZED PREDATOR-PREY SYSTEMS WITH TIME DELAY AND DIFFUSION

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Acta Mathematica Scientia 2004年第1期24卷 151-160页

作者：李必文 Department of Mathematics Hubei Narmal University Huangshi 435002 China

A set of easily verifiable sufficient conditions are derived for the existence of positive periodic solutions for delayed generalized predator-prey dispersion systemwhere ai(t),bi(t) and Di(t)(i = 1, 2) axe positive continuous T-periodic functions, gi(t,xi) (i = 1,2) and h(t,y) are continuous and T-periodic with respect to t and h(t,y) > 0 for y>0,t, y∈R,pi(x)(i=1,2) are continuous and monotonously increasing functions, and Pi(xi)>0 for xi>0.

关键词： Positive periodic solution continuation theorem of coincidence degree,predator-prey system diffusion delay

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分层土中盾构隧道掌子面极限推力研究

中南大学学报（自然科学版） 2023年第4期54卷 1370-1378页

作者：傅鹤林吴疆邓皇适陈足中南大学土木工程学院湖南长沙410075

在盾构隧道开挖过程中,掌子面受力十分复杂,盾构机对掌子面的推力对维持掌子面前方土体的稳定起着关键性作用,为此,基于筒仓理论和极限平衡法,改进传统楔形体模型,考虑盾构隧道掌子面处土体分层对掌子面极限推力的影响,建立折线型滑动模... 详细信息

在盾构隧道开挖过程中,掌子面受力十分复杂,盾构机对掌子面的推力对维持掌子面前方土体的稳定起着关键性作用,为此,基于筒仓理论和极限平衡法,改进传统楔形体模型,考虑盾构隧道掌子面处土体分层对掌子面极限推力的影响,建立折线型滑动模型,推导掌子面极限推力的计算公式。依据实际工程建立相应的数值模拟模型,并对计算公式中各参数敏感性进行分析。研究结果表明:考虑掌子面土体分层时极限推力的数值模拟解与由本文所得公式计算的理论解误差很小,验证了本文所述模型和计算方法的可靠性与准确性;掌子面极限推力随隧道埋深和直径增加而增大;分层土中引起极限推力变化的主要土体是上层软弱土;盾构直径越大,土体黏聚力和内摩擦角对极限推力的影响越大,且内摩擦角对极限推力的影响更显著;当盾构直径较小时,土体黏聚力和内摩擦角对极限推力的影响较小。

关键词：分层土极限推力筒仓理论极限平衡法折线型滑动模型

IMPROVED GAGLIARDO-NIRENBERG INEQUALITIES ON HEISENBERG TYPE GROUPS

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Acta Mathematica Scientia 2011年第4期31卷 1583-1590页

作者：罗光洲 School of Mathematics and Statistics Hubei Normal University

Motivated by the idea of M. Ledoux who brings out the connection between Sobolev embeddings and heat kernel bounds, we prove an analogous result for Kohn’s sub-Laplacian on the Heisenberg type groups. The main result... 详细信息

关键词： Heisenberg type group heat kernel Sobolev inequality Galiardo-Nirenberg inequality