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Phase Transformations in ZrO_2 after Shock Loading
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作者 Sergey N.Kulkov Alexander G.Melnikov 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 1993年第1期32-36,共5页
The effects of shock loading on the morphology,grain growth during heating and phase transforma- tion of ZrO_2 have been investigated.It is shown that shock loading may be efficiently used to modify submicron ceramic ... The effects of shock loading on the morphology,grain growth during heating and phase transforma- tion of ZrO_2 have been investigated.It is shown that shock loading may be efficiently used to modify submicron ceramic powders with nanocrystalline structure.After shock loading,the critical diameter of ZrO_2 particles transformed from tetragonal to monoclinic decreased due to stored strain energy. Annealing of powders resulted in reversible transformation to the tetragonal without considerable grain growth up to 1200℃. 展开更多
关键词 submicron ceramics NANOCRYSTALLINE shock loading phase transformation
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Redistribution of Trace Elements During Shock-inducd Melting and Phase Tranzition of Minerals in the Suizhou l6 Chondrite
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作者 XIE Xiande ZHANG Hong WANG Chunyun 《矿物学报》 CAS CSCD 北大核心 2013年第S1期116-116,共1页
The Suizhou meteorite is an L6 chondrite. This meteorite is consisted of olivine, low-Ca pyroxene, plagioclase, FeNi metal, troilite, whitlockite, chlorapatite, chromite and ilmenite. Olivine and pyroxene grains displ... The Suizhou meteorite is an L6 chondrite. This meteorite is consisted of olivine, low-Ca pyroxene, plagioclase, FeNi metal, troilite, whitlockite, chlorapatite, chromite and ilmenite. Olivine and pyroxene grains display shock-induced mosaic texture, and most plagioclase grains were melted and transformed to maskelynite. This meteorite contains a few very thin shock-produced melt veins ranging from 20 to 100 μm in width. They are chondritic in composition and contain abundant high-pressure minerals in two assemblages. One is the coarse-grained assemblage of ringwoodite, majorite, lingunite with minor amount of tuite, xieite, the CF-phase, akimotoite and amorphized perovskite, and the fine-grained assemblage (the melt vein matrix) composed of majorite-pyrope garnet, magnesiowüstite. FeNi metal and troilite in the Suizhou shock veins were molten and occur as small intergrowth grains or veinlets filling the interstices of garnet crystals or cracks in the vein matrix. It was revealed that olivine, pyroxene and plagioclase in the Suizhou shock veins have transformed in solid state to their high-pressure polymorphs ringwoodite, majorite, and lingunite, respectively, without change in their chemical compositions. 展开更多
关键词 trace element shock MELTING phase transition LA-ICP-MS Suizhou METEORITE
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Numerical study of dynamic phase transitions in shock tube
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作者 王平 唐少强 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2007年第7期921-929,共9页
Shock tube problem of a van der Waals fluid with a relaxation model was investigated. In the limit of relaxation parameter tending towards zero, this model yields a specific Riemann solver. Relaxing and relaxed scheme... Shock tube problem of a van der Waals fluid with a relaxation model was investigated. In the limit of relaxation parameter tending towards zero, this model yields a specific Riemann solver. Relaxing and relaxed schemes were derived. For an incident shock in a fixed tube, numerical simulations show convergence toward the Riemann solution in one space dimension. Impact of parameters was studied theoretically and numerically. For certain initial shock profiles, nonclassical reflecting wave was observed. In two space dimensions, the effect of curved wave fronts was studied, and some interesting wave patterns were exposed. 展开更多
关键词 phase transition shock RELAXATION
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射流参数对双孔液态CO_(2)相变冲击岩石裂纹扩展的影响
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作者 于建新 王云蒙 +1 位作者 王金星 陈晨 《工程爆破》 CSCD 北大核心 2024年第2期98-109,158,共13页
液态CO_(2)相变作用时的射流形状与冲击方向影响着破岩效果。基于自行构建的试验系统,结合LS-DYNA数值模拟,研究了双孔液态CO_(2)在不同气流释放方向组合下的岩石裂纹扩展规律。结果表明:双孔X方向相背冲击时,岩石裂纹并不能在两孔之间... 液态CO_(2)相变作用时的射流形状与冲击方向影响着破岩效果。基于自行构建的试验系统,结合LS-DYNA数值模拟,研究了双孔液态CO_(2)在不同气流释放方向组合下的岩石裂纹扩展规律。结果表明:双孔X方向相背冲击时,岩石裂纹并不能在两孔之间扩展贯通。双孔X方向相对冲击时,两孔之间形成贯穿裂纹。双孔Y方向同向冲击时,裂纹沿初始冲击方向扩展,并在孔周围扩展形成多条裂纹。数值模拟结果表明:在不同释放口组合冲击作用下,X方向相对冲击时裂纹在两孔之间形成贯穿,初始裂纹继续扩展贯穿至前后侧面。X方向相背冲击下的试样裂隙主要向预留孔四周扩展。Y方向同向冲击下试样内部裂隙沿初始气流冲击方向的反方向扩展,并未形成贯穿裂纹。从裂纹定向扩展效果而言,双孔X方向相对冲击效果最好,Y方向同向冲击次之,X方向相背冲击最差。从顶面主裂纹扩展数量而言,X方向相背冲击最多,Y方向同向冲击次之,X方向相对冲击最少。研究结果可为CO_(2)冲击致裂技术应用提供指导。 展开更多
关键词 液态CO_(2) 相变冲击 裂纹扩展 损伤分析 数值模拟
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重度烧伤患者非休克期两种输血治疗策略的对比研究
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作者 张冰 巴芳芳 宋小彦 《临床研究》 2024年第5期56-58,共3页
目的浅析重度烧伤患者(非休克期)应用两种输血治疗方案的临床效果。方法选择2020年4月至2023年4月郑州市第一人民医院收治的重度烧伤患者88例进行回顾性分析,依据输血策略的不同分为A组(限制性输血)与B组(开放性输血),各44例,就两组患... 目的浅析重度烧伤患者(非休克期)应用两种输血治疗方案的临床效果。方法选择2020年4月至2023年4月郑州市第一人民医院收治的重度烧伤患者88例进行回顾性分析,依据输血策略的不同分为A组(限制性输血)与B组(开放性输血),各44例,就两组患者输血量,输血有效性[输血前后计算每单位红细胞输注前后的变化量,Δ红细胞(RBC)、Δ血红蛋白(Hb)和Δ红细胞压积(HCT)],电解质变化,凝血功能,不良反应风险进行组间比较。结果A组患者输入RBC、血浆及总血量均低于B组,差异有统计学意义(P<0.05);A组输血有效性ΔRBC、ΔHb指标均高于B组,差异有统计学意义(P<0.05);A组治疗后钠离子(Na^(+))、钙离子(Ca^(2+))指标均高于于B组,且钾离子(K^(+))指标低于B组,差异有统计学意义(P<0.05);A组治疗后凝血酶原时间(PT)、凝血酶时间(TT)、活化部分凝血活酶时间(APTT)指标高于B组,纤维蛋白原浓度(FIB)指标低于B组,差异有统计学意义(P<0.05);A组不良反应风险(9.09%)与B组(20.45%)比较,差异无统计学意义(P>0.05)。结论在治疗重度烧伤患者的非休克期输血过程中,采取限制性输血与开放性输血两种治疗策略均可达到良好的治疗效果,但限制性输血治疗可减少输血的频率,从而降低输血可能带来的风险,并节约血液资源,这对于临床合理安全使用血液具有重要意义。 展开更多
关键词 烧伤 限制性输血 开放性输血 非休克期
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应用于新型环路热管的两相引射器数值模拟
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作者 周尧 杨小平 +3 位作者 倪一程 刘继平 魏进家 严俊杰 《化工学报》 EI CSCD 北大核心 2024年第1期268-278,共11页
环路热管是一种高效被动式相变传热装置,广泛应用于高热流电子器件散热等领域。前期研究发现将小型两相引射器与平板式环路热管耦合,可大幅提高传热性能。然而,小型两相引射器内部流动及传热机理尚不清晰,难以对新型环路热管进行正向设... 环路热管是一种高效被动式相变传热装置,广泛应用于高热流电子器件散热等领域。前期研究发现将小型两相引射器与平板式环路热管耦合,可大幅提高传热性能。然而,小型两相引射器内部流动及传热机理尚不清晰,难以对新型环路热管进行正向设计与理论建模。通过数值模拟研究了汽水参数和混合腔结构对两相引射器性能及内部流场分布的影响。结果表明,喉部下游存在凝结激波,随着背压增加,其位置逐渐向喉部移动;其强度与背压、蒸汽产量、混合腔长度呈正相关,与水温呈负相关。引射器最大工作背压在40~125 kPa,与蒸汽产量和水温呈正相关,与混合腔长度呈负相关。通过大量模拟,得到了设计功率下水温和混合腔长度对引射器工作模式和压比的影响规律。 展开更多
关键词 环路热管 引射器 传热 两相流 凝结 激波 数值模拟
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Analysis of Culture Shock In Intercultural Communication 被引量:1
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作者 周培蕊 《海外英语》 2012年第15期214-215,共2页
Culture shock can be easily encountered in intercultural communication.This paper illustrates the causes of culture shock,and also provides solutions to deal with culture shock and try to reduce its influence.
关键词 CULTURE shock CAUSE phase STRATEGY
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霍尔辛赫煤矿可控冲击波强化增透试验研究
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作者 许起 《煤炭与化工》 CAS 2024年第6期120-124,共5页
为了改善CO_(2)气爆致裂对煤层的增透效果,本文以霍尔辛赫煤矿五盘区集中回风大巷为研究背景,应用可控冲击波增透技术对使用过CO_(2)气爆致裂的煤层进行了强化增透试验研究。在五盘区集中回风大巷共布置7个强化增透钻孔。通过增透孔、... 为了改善CO_(2)气爆致裂对煤层的增透效果,本文以霍尔辛赫煤矿五盘区集中回风大巷为研究背景,应用可控冲击波增透技术对使用过CO_(2)气爆致裂的煤层进行了强化增透试验研究。在五盘区集中回风大巷共布置7个强化增透钻孔。通过增透孔、观测孔抽采效果的观察分析,表明在已实施CO_(2)措施的区域,可控冲击波增透可以在一定程度上提高钻孔瓦斯流量,具有二次强化增透效果。 展开更多
关键词 可控冲击波 瓦斯抽采 相变致裂
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A Phase-Dependent Hypothesis for Locomotor Functions of Human Foot Complex 被引量:2
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作者 Lei Ren David Howard +2 位作者 Lu-quan Ren Chris Nester Li-mei Tian 《Journal of Bionic Engineering》 SCIE EI CSCD 2008年第3期175-180,共6页
The human foot is a very complex structure comprising numerous bones, muscles, ligaments and synovial joints. As the only component in contact with the ground, the foot complex delivers a variety of biomechanical func... The human foot is a very complex structure comprising numerous bones, muscles, ligaments and synovial joints. As the only component in contact with the ground, the foot complex delivers a variety of biomechanical functions during human locomotion, e.g. body support and propulsion, stability maintenance and impact absorption. These need the human foot to be rigid and damped to transmit ground reaction forces to the upper body and maintain body stability, and also to be compliant and resilient to moderate risky impacts and save energy. How does the human foot achieve these apparent conflicting functions? In this study, we propose a phase-dependent hypothesis for the overall locomotor functions of the human foot complex based on in-vivo measurements of human natural gait and simulation results of a mathematical foot model. We propse that foot functions are highly dependent on gait phase, which is a major characteristics of human locomotion. In early stance just after heel strike, the foot mainly works as a shock absorber by moderating high impacts using the viscouselastic heel pad in both vertical and horizontal directions. In mid-stance phase (-80% of stance phase), the foot complex can be considered as a springy rocker, reserving external mechanical work using the foot arch whilst moving ground contact point forward along a curved path to maintain body stability. In late stance after heel off, the foot complex mainly serves as a force modulator like a gear box, modulating effective mechanical advantages of ankle plantiflexor muscles using metatarsal-phalangeal joints. A sound under- standing of how diverse functions are implemented in a simple foot segment during human locomotion might be useful to gain insight into the overall foot locomotor functions and hence to facilitate clinical diagnosis, rehabilitation product design and humanoid robot development. 展开更多
关键词 BIOMECHANICS human foot locomotion rollover model shock absorber SPRING phase-dependent
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On some problems of seismic crustal phase
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作者 葛焕称 《Acta Seismologica Sinica(English Edition)》 CSCD 1995年第1期57-63,共7页
In this paper, some practical problems in seismological observations are discussed on the identification of seismiccrustal phase, such as: “whether P (Pg) and S(Sg) are direct waves or not?”; “whether S(Sg) and Lg ... In this paper, some practical problems in seismological observations are discussed on the identification of seismiccrustal phase, such as: “whether P (Pg) and S(Sg) are direct waves or not?”; “whether S(Sg) and Lg as well asng and P (Pg) are two kinds of waves or identical wave?”;“on seismoiogicai phases in regional travel-timetable”;“on the symbols and identifications of phases in seismological observation repors”;“on the relation between mLg and ML”, and so on. Some confused ideas on these problems are clarified. 展开更多
关键词 seismological observation near shock seismic phase MAGNITUDE
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Global structure stability of impact-induced tensile waves in phase-transforming materials
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作者 黄守军 王静静 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2013年第9期1155-1166,共12页
The global structure stability of the impact-induced tensile waves mentioned by Huang (Huang, S. J. Impact-induced tensile waves in a kind of phase-transforming materials. IMA Journal of Applied Mathematics, 76, 847-... The global structure stability of the impact-induced tensile waves mentioned by Huang (Huang, S. J. Impact-induced tensile waves in a kind of phase-transforming materials. IMA Journal of Applied Mathematics, 76, 847-858 (2011)) is considered. By introducing Riemann invariants, the governing equations of motion are reduced into a 2 ~ 2 diagonally strictly hyperbolic system. Then, with the aid of the theory on the typical free boundary problem and maximally dissipative kinetics, the global structure stability of the impact-induced tensile waves propagating in a phase-transforming material is proved. 展开更多
关键词 global structure stability impact-induced tensile wave phase boundary shock wave rarefaction wave
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Shock-induced migration of asymmetry tilt grain boundary in iron bicrystal: A case study of Σ3 [110] 被引量:1
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作者 Xueyang Zhang Kun Wang +5 位作者 Jun Chen Wangyu Hu Wenjun Zhu Shifang Xiao Huiqiu Deng Mengqiu Cai 《Chinese Physics B》 SCIE EI CAS CSCD 2019年第12期273-279,共7页
Many of our previous studies have discussed the shock response of symmetrical grain boundaries in iron bicrystals.In this paper, the molecular dynamics simulation of an iron bicrystal containing Σ3 [110] asymmetry ti... Many of our previous studies have discussed the shock response of symmetrical grain boundaries in iron bicrystals.In this paper, the molecular dynamics simulation of an iron bicrystal containing Σ3 [110] asymmetry tilt grain boundary(ATGB) under shock-loading is performed. We find that the shock response of asymmetric grain boundaries is quite different from that of symmetric grain boundaries. Especially, our simulation proves that shock can induce migration of asymmetric grain boundary in iron. We also find that the shape and local structure of grain boundary(GB) would not be changed during shock-induced migration of Σ3 [110] ATGB, while the phase transformation near the GB could affect migration of GB. The most important discovery is that the shock-induced shear stress difference between two sides of GB is the key factor leading to GB migration. Our simulation involves a variety of piston velocities, and the migration of GB seems to be less sensitive to the piston velocity. Finally, the kinetics of GB migration at lattice level is discussed. Our work firstly reports the simulation of shock-induced grain boundary migration in iron. It is of great significance to the theory of GB migration and material engineering. 展开更多
关键词 shock-loading grain boundary migration IRON phase transition
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Effect of metallic phase content on mechanical properties of (85Cu-15Ni)/(10NiO-NiFe_2O_4) cermet inert anode for aluminum electrolysis 被引量:7
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作者 张刚 李劼 +1 位作者 赖延清 田忠良 《中国有色金属学会会刊:英文版》 EI CSCD 2007年第5期1063-1068,共6页
(85Cu-15Ni)/(10NiO-NiFe2O4) cermets were prepared with Cu-Ni mixed powders as toughening metallic phase and 10NiO-NiFe2O4 as ceramic matrix. The phase composition, microstructure of composite and the effect of metalli... (85Cu-15Ni)/(10NiO-NiFe2O4) cermets were prepared with Cu-Ni mixed powders as toughening metallic phase and 10NiO-NiFe2O4 as ceramic matrix. The phase composition, microstructure of composite and the effect of metallic phase content on bending strength, hardness, fracture toughness and thermal shock resistance were studied. X-ray diffraction analysis indicates the coexistence of (Cu-Ni), NiO and NiFe2O4 phases in the cermets. Within the content range of metallic phase from 0% to 20% (mass fraction), the maximal bending strength (176.4 MPa) and the minimal porosity (3.9%) of composite appear at the metallic phase content of 5%. The fracture toughness increases and Vickers’ hardness decreases with increasing metal content. When the thermal shock temperature difference (△t) is below 200 ℃, the loss rate of residual strength for 10NiO-NiFe2O4 ceramic is only 8%, but about 40% for (85Cu-15Ni)/(10NiO-NiFe2O4) cermets. As △t is above 200 ℃, the residual strength sharply decreases for sample CN0 and falls slowly for samples CN5-CN20. 展开更多
关键词 NIFE2O4 金属陶瓷 铝电解 阻抗
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High Order Relaxation Schemes on Phase Transition Equations
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作者 叶茂 《Journal of Electronic Science and Technology of China》 2004年第2期48-52,共5页
Formal analysis of the bubble phenomena of the second order relaxation scheme is presented when this method is applied to phase transition equations. The reason of oscillations is that the second order scheme can’t f... Formal analysis of the bubble phenomena of the second order relaxation scheme is presented when this method is applied to phase transition equations. The reason of oscillations is that the second order scheme can’t find the discontinuities on the phase boundary. Based on this realization, a second order relaxation scheme is derived to eliminate it. This new method finds all components and characteristic discontinuities, thus the phase boundary is found exactly. The difference of presented new method and the well-known Nessyahu-Tadmor(NT) scheme is also studied. From the numerical experiment, the new derived scheme is shown much better to compute the phase transition equations. 展开更多
关键词 phase transition shock phase boundary relaxation scheme NT scheme
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Structure Transformations in the Polycrystalline (Ti,Nb)<sub>3</sub>Al Alloy under Shock-Wave Loading
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作者 Nataliya V. Kazantseva Evgenii V. Shorokhov 《Journal of Modern Physics》 2011年第10期1141-1145,共5页
Structure transformations in the two-phase (Ti, Nb)3Al alloy, induced by shock-wave loading, were studied. The samples were subjected to an impact of a steel plate. The maximum pressure on the samples’ surfaces was 1... Structure transformations in the two-phase (Ti, Nb)3Al alloy, induced by shock-wave loading, were studied. The samples were subjected to an impact of a steel plate. The maximum pressure on the samples’ surfaces was 100 GPa, while the maximum temperature was 573 K. The β0→α2 phase transformation occurred during strong deformations. High temperature rectilinear dislocations (such types of dislocations usually could arise at 1073 K) with the c-component, which occasionally formed slip bands, were located at the α2-phase grains after the shock. The deformation α2-phase twins were not observed. 展开更多
关键词 TI3AL phase Transformation shock Waves
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THE FLOW STRUCTURE OF DILUTE GAS-PARTICLE SUSPENSIONS BEHIND A SHOCK WAVE MOVING ALONG A FLAT SURFACE
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作者 A.N.Osiptsov S.L.Veselyi +1 位作者 V.A.Kulikovskii 王柏懿 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 1991年第6期531-538,共8页
The asymptotic and numerical investigations of shock-induced boundary layers in gas-particle mixtures are presented. The Saffman lift force acting on a particle in a shear flow is taken into account. It is shown that ... The asymptotic and numerical investigations of shock-induced boundary layers in gas-particle mixtures are presented. The Saffman lift force acting on a particle in a shear flow is taken into account. It is shown that particle migration across the boundary layer leads to intersections of particle trajectories. The corresponding modification of dusty gas model is proposed in this paper.The equations of two-phase sidewall boundary layer behind a shock wave moving at a constant speed are obtained by using the method of matched asymptotic expansions. The method of the calculation of particle phase parameters in Lagrangian coordinates is described in detail. Some numerical results for the case of small particle concentration are given. 展开更多
关键词 gas-particle suspension shock-induced flow two-phase boundary layer
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Two-way coupling model for shock-induced laminar boundary-layer flows of a dusty gas
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作者 Boyi Wang Yi Xiong A.N. Osiptsov 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2005年第6期557-563,共7页
The present paper describes a numerical two-way coupling model for shock-induced laminar boundary-layer flows of a dust-laden gas and studies the transverse migration of fine particles under the action of Saffman lift... The present paper describes a numerical two-way coupling model for shock-induced laminar boundary-layer flows of a dust-laden gas and studies the transverse migration of fine particles under the action of Saffman lift force. The governing equations are formulated in the dilute twophase continuum framework with consideration of the finiteness of the particle Reynolds and Knudsen numbers. The full Lagrangian method is explored for calculating the dispersedphase flow fields (including the number density of particles) in the regions of intersecting particle trajectories. The computation results show a significant reaction of the particles on the two-phase boundary-layer structure when the mass loading ratio of particles takes finite values. 展开更多
关键词 shock wave Dusty gas Two-phase boundary layer Two-way coupling Numerical modeling
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健康冲击对中老年农户生计策略变迁的影响——来自CHARLS面板数据的证据 被引量:1
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作者 王晓轩 胡梓君 《云南农业大学学报(社会科学版)》 CAS 2023年第5期144-153,共10页
基于可持续生计分析框架,使用CHARLS数据及多期双重差分方法分析健康冲击对中老年农户生计策略选择的影响与作用机制。研究发现:当中老年农户遭受健康冲击后,其更倾向选择农业型生计策略,而非农业兼业型及非农型生计策略;异质性分析得出... 基于可持续生计分析框架,使用CHARLS数据及多期双重差分方法分析健康冲击对中老年农户生计策略选择的影响与作用机制。研究发现:当中老年农户遭受健康冲击后,其更倾向选择农业型生计策略,而非农业兼业型及非农型生计策略;异质性分析得出,健康冲击更为显著地促进男性农户选择农业型生计策略,而非农业兼业型。而健康冲击则抑制女性农户从事非农生计活动,并且健康冲击对低学历农户影响更为显著,导致其更倾向选择农业型生计策略,而放弃从事农业兼业型及非农型生计活动;机制检验证明,中老年农户生计资本水平越低,其生计策略选择越易因健康冲击发生变化。据此,提出政府应加大健康扶贫力度等建议,为推动中老年农户生计策略多样化发展提供理论参考。 展开更多
关键词 健康冲击 生计策略 多期双重差分法 PSM-DID 生计资本
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热冲击环境下涂层/基底界面的微观形貌及元素扩散规律研究
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作者 杨来侠 高伟 +2 位作者 赵晋超 高扬 徐超 《航空制造技术》 CSCD 北大核心 2023年第19期14-21,共8页
针对热障涂层在高温环境中长期服役的需求,研究热障涂层在热冲击环境下涂层/基底界面形貌演变及元素扩散规律。通过自主搭建的石英灯加热平台对热障涂层进行热冲击试验。利用SEM和EDS对热冲击后涂层/基底界面的微观形貌及元素分布进行分... 针对热障涂层在高温环境中长期服役的需求,研究热障涂层在热冲击环境下涂层/基底界面形貌演变及元素扩散规律。通过自主搭建的石英灯加热平台对热障涂层进行热冲击试验。利用SEM和EDS对热冲击后涂层/基底界面的微观形貌及元素分布进行分析,利用Boltzmann-Matano扩散模型计算了涂层/基底界面Al元素的扩散系数。结果表明,沉积态的热障涂层中黏结层(BC)主要由β和γ相组成,并且在涂层/基底界面已经出现扩散区;随着热冲击试验的进行,Al元素快速消耗致使BC层和基底间Al元素浓度梯度转变,Al元素开始向外扩散,部分拓扑密堆(TCP)相中富集的难熔元素可以重新固溶到基底中,最终各元素在界面区的分布逐渐均匀;Al元素的扩散系数在热冲击试验开始前为正值,到600次热冲击循环后为负值,且扩散系数的最大值均出现在涂层/基底界面处,距离界面越大,扩散系数就越低。 展开更多
关键词 热障涂层(TBCs) 热冲击 元素扩散 扩散系数 拓扑密堆相(TCP)
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煤与瓦斯突出冲击动力效应及致灾特征模拟实验系统研制与应用 被引量:2
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作者 杨雪林 文光才 +4 位作者 孙海涛 曹偈 王波 戴林超 鲁俊 《煤炭学报》 EI CAS CSCD 北大核心 2023年第10期3731-3749,共19页
由于对煤与瓦斯突出激发后致灾特征及其诱导矿井风流灾变机制不清,现场常根据经验布设风门、布置自救系统等设施,尚不能有效地布置安全防护措施和制定科学合理的应急预案。为了准确掌握突出冲击动力效应及致灾特征,基于相似理论,研发了... 由于对煤与瓦斯突出激发后致灾特征及其诱导矿井风流灾变机制不清,现场常根据经验布设风门、布置自救系统等设施,尚不能有效地布置安全防护措施和制定科学合理的应急预案。为了准确掌握突出冲击动力效应及致灾特征,基于相似理论,研发了一套考虑突出孔洞周围卸压区煤体瓦斯补给作用的突出模拟实验系统,并基于突出模型和瓦斯渗流理论通过严格计算确定了补气装置的关键参数。该实验系统主要包括:突出孔洞动力系统、突出激发装置、巷道模拟系统和数据采集与控制中心4个模块,能够模拟巷道内突出冲击波形成和传播、突出煤-瓦斯两相流运移及瓦斯逆流等突出动力现象。开展了瓦斯压力为0.8 MPa的突出灾变模拟实验,利用高速摄像机直接观测到突出冲击波形成过程。结果表明:突出发生瞬间,在管道内瞬间形成空气冲击波,后面依次出现的是冲击气流、突出瓦斯气流和煤-瓦斯两相流。且空气冲击波速度>冲击气流速度>突出瓦斯气流速度>突出煤-瓦斯两相流阵面速度,4者最大速度分别为546.5、496.7、112.6、51.5 m/s,并沿管道逐渐衰减。突出过程中高压瓦斯从突出孔洞涌入巷道空间,造成瓦斯逆流现象。突出过程中突出孔洞内瓦斯压力呈指数下降。突出发生后巷道内瓦斯体积分数随时间变化存在“骤升期”和“缓慢下降期”,突出瓦斯在巷道内运移方式主要包括“驱替”和“扩散”。突出煤沿主巷堆积高度与堆积质量呈现出一致性。突出煤与原煤粒径分布差异主要集中于0~500μm,而粒径分布最大差异主要集中于150~200μm。此外,粒径分布于150~200μm的煤粉占比随距突出口距离的增加而增加,表现出较强的分选性。 展开更多
关键词 煤与瓦斯突出 煤-瓦斯两相流 突出冲击波 瓦斯涌出 突出强度
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