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Bone marrow-derived mesenchymal stem cell-derived exosomeloaded miR-129-5p targets high-mobility group box 1 attenuates neurological-impairment after diabetic cerebral hemorrhage 被引量:2
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作者 Yue-Ying Wang Ke Li +5 位作者 Jia-Jun Wang Wei Hua Qi Liu Yu-Lan Sun Ji-Ping Qi Yue-Jia Song 《World Journal of Diabetes》 SCIE 2024年第9期1979-2001,共23页
BACKGROUND Diabetic intracerebral hemorrhage(ICH)is a serious complication of diabetes.The role and mechanism of bone marrow mesenchymal stem cell(BMSC)-derived exosomes(BMSC-exo)in neuroinflammation post-ICH in patie... BACKGROUND Diabetic intracerebral hemorrhage(ICH)is a serious complication of diabetes.The role and mechanism of bone marrow mesenchymal stem cell(BMSC)-derived exosomes(BMSC-exo)in neuroinflammation post-ICH in patients with diabetes are unknown.In this study,we investigated the regulation of BMSC-exo on hyperglycemia-induced neuroinflammation.AIM To study the mechanism of BMSC-exo on nerve function damage after diabetes complicated with cerebral hemorrhage.METHODS BMSC-exo were isolated from mouse BMSC media.This was followed by transfection with microRNA-129-5p(miR-129-5p).BMSC-exo or miR-129-5poverexpressing BMSC-exo were intravitreally injected into a diabetes mouse model with ICH for in vivo analyses and were cocultured with high glucoseaffected BV2 cells for in vitro analyses.The dual luciferase test and RNA immunoprecipitation test verified the targeted binding relationship between miR-129-5p and high-mobility group box 1(HMGB1).Quantitative polymerase chain reaction,western blotting,and enzyme-linked immunosorbent assay were conducted to assess the levels of some inflammation factors,such as HMGB1,interleukin 6,interleukin 1β,toll-like receptor 4,and tumor necrosis factorα.Brain water content,neural function deficit score,and Evans blue were used to measure the neural function of mice.RESULTS Our findings indicated that BMSC-exo can promote neuroinflammation and functional recovery.MicroRNA chip analysis of BMSC-exo identified miR-129-5p as the specific microRNA with a protective role in neuroinflammation.Overexpression of miR-129-5p in BMSC-exo reduced the inflammatory response and neurological impairment in comorbid diabetes and ICH cases.Furthermore,we found that miR-129-5p had a targeted binding relationship with HMGB1 mRNA.CONCLUSION We demonstrated that BMSC-exo can reduce the inflammatory response after ICH with diabetes,thereby improving the neurological function of the brain. 展开更多
关键词 Bone marrow mesenchymal stem cells Exosome Diabetic cerebral hemorrhage Neuroinflammation MicroRNA-129-5p high mobility group box 1
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A STUDY ON THE MECHANISM OF HIGH-LIFT GENERATION BY AN AIRFOIL IN UNSTEADY MOTION AT LOW REYNOLDS NUMBER 被引量:7
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作者 孙茂 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2001年第2期97-114,共18页
The aerodynamic force and flow structure of NACA 0012 airfoil performing an unsteady motion at low Reynolds number (Re = 100) are calculated by solving Navier-Stokes equations. The motion consists of three parts: the ... The aerodynamic force and flow structure of NACA 0012 airfoil performing an unsteady motion at low Reynolds number (Re = 100) are calculated by solving Navier-Stokes equations. The motion consists of three parts: the first translation, rotation and the second translation in the direction opposite to the first. The rotation and the second translation in this motion are expected to represent the rotation and translation of the wing-section of a hovering insect. The flow structure is used in combination with the theory of vorticity dynamics to explain the generation of unsteady aerodynamic force in the motion. During the rotation, due to the creation of strong vortices in short time, large aerodynamic force is produced and the force is almost normal to the airfoil chord. During the second translation, large lift coefficient can be maintained for certain time period and (C) over bar (L), the lift coefficient averaged over four chord lengths of travel, is larger than 2 (the corresponding steady-state lift coefficient is only 0.9). The large lift coefficient is due to two effects. The first is the delayed shedding of the stall vortex. The second is that the vortices created during the airfoil rotation and in the near wake left by previous translation form a short 'vortex street' in front of the airfoil and the 'vortex street' induces a 'wind'; against this 'wind' the airfoil translates, increasing its relative speed. The above results provide insights to the understanding of the mechanism of high-lift generation by a hovering insect. 展开更多
关键词 high-lift AIRFOIL flapping motion low Reynolds number
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Surface integral analogy approaches for predicting noise from 3D high-lift low-noise wings 被引量:1
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作者 Hua-Dong Yao Lars Davidson +3 位作者 Lars-Erik Eriksson Shia-Hui Peng Olof Grundestam Peter E.Eliasson 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2014年第3期326-338,共13页
Three surface integral approaches of the acoustic analogies are studied to predict the noise from three concep- tual configurations of three-dimensional high-lift low-noise wings. The approaches refer to the Kirchhoff... Three surface integral approaches of the acoustic analogies are studied to predict the noise from three concep- tual configurations of three-dimensional high-lift low-noise wings. The approaches refer to the Kirchhoff method, the Ffowcs Williams and Hawkings (FW-H) method of the permeable integral surface and the Curle method that is known as a special case of the FW-H method. The first two approaches are used to compute the noise generated by the core flow region where the energetic structures exist. The last approach is adopted to predict the noise specially from the pressure perturbation on the wall. A new way to con- struct the integral surface that encloses the core region is proposed for the first two methods. Considering the local properties of the flow around the complex object-the actual wing with high-lift devices-the integral surface based on the vorticity is constructed to follow the flow structures. The surface location is discussed for the Kirchhoff method and the FW-H method because a common surface is used for them. The noise from the core flow region is studied on the basis of the dependent integral quantities, which are indicated by the Kirchhoff formulation and by the FW-H formulation. The role of each wall component on noise contribution is analyzed using the Curle formulation. Effects of the volume integral terms of Lighthill's stress tensors on the noise pre-diction are then evaluated by comparing the results of the Curle method with the other two methods. 展开更多
关键词 AERO-ACOUSTICS high-lift facilities Surface integral approaches of acoustic analogy
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Numerical study of the influence of spoiler deflection on high-lift configuration
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作者 Wenhu Wang Peiqing Liu 《Theoretical & Applied Mechanics Letters》 CAS CSCD 2017年第3期159-163,共5页
This paper numerically studies the influence of the downward spoiler deflection on the boundary layer flow of a high-lift two-element airfoil consisting of a droop nose, a main wing, a downward deflecting spoiler and ... This paper numerically studies the influence of the downward spoiler deflection on the boundary layer flow of a high-lift two-element airfoil consisting of a droop nose, a main wing, a downward deflecting spoiler and a single slotted flap. Both of the boundary layer of the upper surface of the spoiler and the confluent boundary layer of the upper surface of the flap become thicker, as the downward spoiler deflection increases. Compared to the attached flow at the angle of attack of 10°, the flow of the upper surface of the spoiler becomes separated at the angle of attack of 16° when the spoiler deflection is large enough, which corresponds to the boundary layer flow reversal in velocity profiles. 展开更多
关键词 high-lift SPOILER Boundary layer Numerical simulation
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Use of High-Resolution Ultrasound (HRU) in the Assessment of Deep Injections of CHAP-Hyaluronic Acid (CHAP-HA) Fillers for Midface Lift 被引量:1
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作者 Hsiao-Tung Lee Haw-Yueh Thong 《Journal of Cosmetics, Dermatological Sciences and Applications》 2018年第3期126-132,共7页
High-resolution ultrasound (HRU) imaging is a useful tool to study hyaluronic acid (HA) filler injection in the face. It is noninvasive, quick, well-tolerated, and can provide in vivo and dynamic information. The form... High-resolution ultrasound (HRU) imaging is a useful tool to study hyaluronic acid (HA) filler injection in the face. It is noninvasive, quick, well-tolerated, and can provide in vivo and dynamic information. The formations of pools or pearls in HA fillers could be observed real time during injection. The plane of injection could be determined accurately, and there were no specimen manipulation artifacts. It was observed that HA gel fillers with differing production technologies showed distinct spread and distribution patterns in the periocular tissues on HRU examination. The authors used HRU to assess deep injections of CHAP-Hyaluronic Acid (CHAP-HA) fillers for midface lift. 10 patients who underwent bilateral midface deep injections using CHAP-HA filler were examined with HRU before and immediately after treatment, and in 2 weeks and one month later. The CHAP-HA appeared as hypoechoic densities within the preperiosteal plane in HRU. CHAP-HA adopted variable morphology within the tissue depending on individual tissue densities and the compliance of the tissues in the plane of injection. CHAP-HA was unidentifiable with surrounding tissue after one month in 13 of the 20 injection sites. HRU allows in vivo study of CHAP-HA injection behavior and could be a tool for further studies of HA-tissue reactions. 展开更多
关键词 CHAP-Hyaluronic Acid (CHAP-HA) FILLER high-Resolution Ultrasound (HRU) MIDFACE lift DEEP INJECTIONS Preperiosteal FILLER INJECTIONS
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Dynamic Stall on High-Lift Airfoil 30P30N in Ground Proximity
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作者 Mohamed Sereez Umayr Zaffar 《Open Journal of Fluid Dynamics》 2021年第3期135-152,共18页
Computational prediction of stall aerodynamics in free air and in close proximity to the ground considering the 30P30N three-element high-lift configuration is carried out based on CFD simulations using the OpenFOAM c... Computational prediction of stall aerodynamics in free air and in close proximity to the ground considering the 30P30N three-element high-lift configuration is carried out based on CFD simulations using the OpenFOAM code and Fluent software. Both the attached and separated flow regimes are simulated using the Reynolds Averaged Navier-Stokes (RANS) equations closed with the Spalart-Allamaras (SA) turbulence model for static conditions and pitch oscillations at Reynolds number, <em>Re</em> = 5 x 10<sup>6</sup> and Mach number, <em>M</em> = 0.2. The effects of closeness to the ground and dynamic stall are investigated and the reduction in the lift force in close proximity to the ground is discussed. 展开更多
关键词 Dynamic Stall high-lift Airfoil Ground Effect
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前列腺癌患者外周血中CD4^+CD25^(high)调节性T细胞及调节因子TGF-β1和COX-2的表达
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作者 夏桃林 刘涛 +5 位作者 吴振权 张海滨 杨明 刘绍远 何灼彬 李辽源 《中华男科学杂志》 CAS CSCD 北大核心 2011年第10期888-893,共6页
目的:通过检测前列腺癌患者以及健康志愿者外周血中CD4+CD25high调节性T细胞、TGF-β1及COX-2的表达,初步探讨CD4+CD25high调节性T细胞在前列腺癌发病机制中的作用及其与TGF-β1和COX-2的相关性。方法:应用流式细胞术检测30例前列腺癌... 目的:通过检测前列腺癌患者以及健康志愿者外周血中CD4+CD25high调节性T细胞、TGF-β1及COX-2的表达,初步探讨CD4+CD25high调节性T细胞在前列腺癌发病机制中的作用及其与TGF-β1和COX-2的相关性。方法:应用流式细胞术检测30例前列腺癌患者治疗前后(其中前列腺癌局限组11例,非局限组19例)及20例健康志愿者外周血单个核细胞(PBMC)中CD4+CD25high调节性T细胞占CD4+T细胞的比例;应用酶联免疫吸附试验(ELISA)检测其外周血清中TGF-β1和COX-2的表达。对前列腺癌患者上述指标进行术前术后对比分析,另对CD4+CD25high调节性T细胞与TGF-β1及COX-2的相关性进行分析;并探讨上述指标在前列腺癌患者局限组和非局限组间是否存在差异性。结果:流式细胞术检测显示,前列腺癌患者治疗前PBMC中CD4+CD25high调节性T细胞占CD4+T细胞的比例为(18.32±7.49)%,高于健康志愿者对照组(7.77±1.86)%(P<0.05)。前列腺癌患者治疗后其比值为(17.34±5.87)%,较治疗前稍减低,但两者相比无显著差异(P>0.05)。ELISA检测外周血清中TGF-β1和COX-2显示,前列腺癌组分别为(215.97±55.16)ng/ml和(6.88±5.14)ng/ml,对照组分别为(149.75±47.11)ng/ml和(5.65±2.69)ng/ml;前列腺癌患者外周血清中TGF-β1的表达水平高于健康志愿者对照组(P<0.05),COX-2的表达水平与对照组无显著差异(P>0.05)。通过多重线性回归分析表明,前列腺癌患者PBMC中CD4+CD25high调节性T细胞的表达与血清中TGF-β1和COX-2的表达无显著相关。前列腺癌局限组和非局限组外周血中CD4+CD25high调节性T细胞、TGF-β1及COX-2的表达均无显著性差异(P>0.05)。结论:前列腺癌患者PBMC中CD4+CD25high调节性T细胞可能参与前列腺癌的发生,其增殖机制与血清中TGF-β1和COX-2的表达无关,可能与肿瘤本身及肿瘤局部微环境相关。 展开更多
关键词 前列腺癌 CD4+CD25high调节性T细胞 转化生长因子Β1 环氧合酶-2
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YKJ-01型附着式升降脚手架在330m超高层建筑的应用
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作者 边广生 尚阳 张万 《建筑技术》 2024年第2期181-188,共8页
针对某330 m超高层项目,详细介绍了附着式升降脚手架在超高层的应用,主要包括:附着式升降脚手架施工平面布置,附着式升降脚手架参数设计,附着式升降脚手架直爬与斜爬部位处理,建筑结构凹槽位置防护设计,附着式升降脚手架斜爬角度变化,... 针对某330 m超高层项目,详细介绍了附着式升降脚手架在超高层的应用,主要包括:附着式升降脚手架施工平面布置,附着式升降脚手架参数设计,附着式升降脚手架直爬与斜爬部位处理,建筑结构凹槽位置防护设计,附着式升降脚手架斜爬角度变化,避难层位置附着式升降脚手架处理,高区大堂处格构柱设计,塔式起重机附墙处附着式升降脚手架处理措施,施工电梯处附着式升降脚手架处理措施,卸料平台处附着式升降脚手架处理措施,附着式升降脚手架分片提升断口位置处理,附着式升降脚手架安装、提升、拆除等。 展开更多
关键词 超高层建筑 附着式升降脚手架 斜爬 格构柱
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Unsteady Numerical Simulation of Flow around 2-D Circular Cylinder for High Reynolds Numbers 被引量:7
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作者 Yanhui Ai Dakui Feng +1 位作者 Hengkui Ye Lin Li 《Journal of Marine Science and Application》 2013年第2期180-184,共5页
In this paper, 2-D computational analyses were conducted for unsteady high Reynolds number flows around a smooth circular cylinder in the supercritical and upper-transition flow regimes, i.e. 8.21×104〈Re〈1.54&#... In this paper, 2-D computational analyses were conducted for unsteady high Reynolds number flows around a smooth circular cylinder in the supercritical and upper-transition flow regimes, i.e. 8.21×104〈Re〈1.54×106. The calculations were performed by means of solving the 2-D Unsteady Reynolds-Averaged Navier-Stokes (URANS) equations with a k-ε turbulence model. The calculated results, produced flow structure drag and lift coefficients, as well as Strouhal numbers. The findings were in good agreement with previous published data, which also supplied us with a good understanding of the flow across cylinders of different high Reynolds numbers. Meanwhile, an effective measure was presented to control the lift force on a cylinder, which points the way to decrease the vortex induced vibration of marine structure in future. 展开更多
关键词 circular cylinder vortex shedding high Reynolds number Strouhal numbers lift control measure marine structure unsteady numerical simulation
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Propeller Design for an Autonomous Underwater Vehicle by the Lifting-line Method based on OpenProp and CFD 被引量:2
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作者 Wencan Zhang Lihong Wu +4 位作者 Xiangwei Jiang Xisheng Feng Yiping Li Junbao Zeng Chongde Liu 《Journal of Marine Science and Application》 CSCD 2022年第2期106-114,共9页
A high-efficiency propeller can enable a long mission duration for autonomous underwater vehicles(AUVs).In this study,a new method with OpenProp coupled with computational fluid dynamics was developed to design a prop... A high-efficiency propeller can enable a long mission duration for autonomous underwater vehicles(AUVs).In this study,a new method with OpenProp coupled with computational fluid dynamics was developed to design a propeller for an Explorer100 AUV.The towed system simulation of the AUV was used to measure the nominal wake,and a self-propulsion simulation was used to measure the effective wake at the disc plane just in front of a propeller.Two propellers referring to the nominal wake(propeller 1)and effective wake(propeller 2)were designed with OpenProp and appended with the AUV for self-propulsion simulations,respectively.Through the numerical simulation of the AUV self-propulsion tests,the cruising velocity of AUV was obtained.The flow characteristics of the self-propulsion in pressure and velocity contours were also analyzed.The propeller designed with an effective wake improved the thrust,velocity,and efficiency by approximately 11.3%,6.7%,and 2.5%,respectively,as compared with those with a nominal wake.The cruising velocity of the final designed propeller for the Explorer100 AUV improved by 21.8%,as compared to that of the original propeller from the AUV free-running tests. 展开更多
关键词 Autonomous underwater vehicle high efficiency PROPELLER WAKE lifting line OpenProp
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Future Changes in Extreme High Temperature over China at 1.5℃-5℃ Global Warming Based on CMIP6 Simulations 被引量:13
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作者 Guwei ZHANG Gang ZENG +1 位作者 Xiaoye YANG Zhihong JIANG 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2021年第2期253-267,共15页
Extreme high temperature(EHT)events are among the most impact-related consequences related to climate change,especially for China,a nation with a large population that is vulnerable to the climate warming.Based on the... Extreme high temperature(EHT)events are among the most impact-related consequences related to climate change,especially for China,a nation with a large population that is vulnerable to the climate warming.Based on the latest Coupled Model Intercomparison Project Phase 6(CMIP6),this study assesses future EHT changes across China at five specific global warming thresholds(1.5℃-5℃).The results indicate that global mean temperature will increase by 1.5℃/2℃ before 2030/2050 relative to pre-industrial levels(1861-1900)under three future scenarios(SSP1-2.6,SSP2-4.5,and SSP5-8.5),and warming will occur faster under SSP5-8.5 compared to SSP1-2.6 and SSP2-4.5.Under SSP5-8.5,global warming will eventually exceed 5℃ by 2100,while under SSP1-2.6,it will stabilize around 2℃ after 2050.In China,most of the areas where warming exceeds global average levels will be located in Tibet and northern China(Northwest China,North China and Northeast China),covering 50%-70%of the country.Furthermore,about 0.19-0.44 billion people(accounting for 16%-41%of the national population)will experience warming above the global average.Compared to present-day(1995-2014),the warmest day(TXx)will increase most notably in northern China,while the number of warm days(TX90p)and warm spell duration indicator(WSDI)will increase most profoundly in southern China.For example,relative to the present-day,TXx will increase by 1℃-5℃ in northern China,and TX90p(WSDI)will increase by 25-150(10-80)days in southern China at 1.5℃-5℃ global warming.Compared to 2℃-5℃,limiting global warming to 1.5℃ will help avoid about 36%-87%of the EHT increases in China. 展开更多
关键词 extreme high temperature China CMIP6 1.5℃-5℃global warming
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High fat diet dysregulates microRNA-17-5p and triggers retinal inflammation:Role of endoplasmic-reticulum-stress 被引量:9
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作者 Maha Coucha Islam N Mohamed +3 位作者 Sally L Elshaer Osinakachuk Mbata Megan L Bartasis Azza B El-Remessy 《World Journal of Diabetes》 SCIE CAS 2017年第2期56-65,共10页
AIM To elucidate how high diet-induced endoplasmic reticulum-stress upregulates thioredoxin interacting protein expression in Müller cells leading to retinal inflammation. METHODS Male C57Bl/J mice were fed eithe... AIM To elucidate how high diet-induced endoplasmic reticulum-stress upregulates thioredoxin interacting protein expression in Müller cells leading to retinal inflammation. METHODS Male C57Bl/J mice were fed either normal diet or 60% high fat diet for 4-8 wk. During the 4 wk study, mice received phenyl-butyric acid(PBA); endoplasmic reticulum-stress inhibitor; for 2 wk. Insulin resistance was assessed by oral glucose tolerance. Effects of palmitate-bovine serum albumin(BSA)(400 μmol/L) were examined in retinal Müller glial cell line and primary Müller cells isolated from wild type and thioredoxin interacting protein knock-out mice. Expression of thioredoxin interacting protein, endoplasmic reticulum-stress markers, mi R-17-5p m RNA, as well as nucleotide-binding oligomerization domain-like receptor protein(NLRP3) and IL1β protein was determined.RESULTS High fat diet for 8 wk induced obesity and insulin resistance evident by increases in body weight and impaired glucose tolerance. By performing quantitative real-time polymerase chain reaction, we found that high fat diet triggered the expression of retinal endoplasmic reticulum-stress markers(P < 0.05). These effects were associated with increased thioredoxin interacting protein and decreased mi R-17-5p expression, whichwere restored by inhibiting endoplasmic reticulumstress with PBA(P < 0.05). In vitro, palmitate-BSA triggered endoplasmic reticulum-stress markers, which was accompanied with reduced mi R-17-5p and induced thioredoxin interacting protein m RNA in retinal Müller glial cell line(P < 0.05). Palmitate upregulated NLRP3 and IL1β expression in primary Müller cells isolated from wild type. However, using primary Müller cells isolated from thioredoxin interacting protein knock-out mice abolished palmitate-mediated increase in NLRP3 and IL1β.CONCLUSION Our work suggests that targeting endoplasmic reticulumstress or thioredoxin interacting protein are potential therapeutic strategies for early intervention of obesityinduced retinal inflammation. 展开更多
关键词 high fat diet PALMITATE Endoplasmic-reticulum-stress INFLAMMATION Thioredoxin-interacting protein Micro-RNA 17-5p
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LaSrNiO_(4-λ) with K_2NiF_4 Strcture──A Highly Active Catalyst for Direct Decomposition of Nitrogen Monoxide 被引量:3
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作者 ZHAO Zhen YANG Xiang-guang and WU Yue(Changchun Institute of Appl. Chem., Chin. Academy of Sciences, Changchun, 130022) 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 1996年第1期81-86,共6页
A series of perovskite-like mixed oxides La2-xSrxMO4±λ(M =Cu, Co,Ni; x=0,1 ) was prepared and characterized using X-ray powder diffraction. The catalytic properties of these catalysts in NO decompositiori were t... A series of perovskite-like mixed oxides La2-xSrxMO4±λ(M =Cu, Co,Ni; x=0,1 ) was prepared and characterized using X-ray powder diffraction. The catalytic properties of these catalysts in NO decompositiori were tested. The results showed that LaSrNiO4-λ with K2NiF4 structure is very active and stable for the decomposition of NO. 展开更多
关键词 LaSrNiO_(4-λ) highly activie catalyst Decomposition of nitrogen monoxide
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Process for improving the ladle free- opening rate for high aluminum steel in continuous casting 被引量:3
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作者 LIU Junzhan ZHOU Tongjun LUO Hui 《Baosteel Technical Research》 CAS 2015年第1期42-45,共4页
Steel 20Mn23AlV is a type of high aluminum steel with a very low ladle free-opening rate. The aluminum composition of 20Mn23AlV ranges from 1.6% to 2.45% ,which is significantly higher than other types of steel. Accor... Steel 20Mn23AlV is a type of high aluminum steel with a very low ladle free-opening rate. The aluminum composition of 20Mn23AlV ranges from 1.6% to 2.45% ,which is significantly higher than other types of steel. According to the real condition of 40 t ladle in steel-making plant of Baosteel Special Steel Company, previous works show that the key factors affecting the ladle free-opening rate of high aluminum steel in continuous casting are:sand material, accessories baking, ladle nozzle cleaning, the process and amount of adding sand, and the rate of argon stirring during refining. Therefore, improving the ladle filler sand quality, baking all of the raw materials, controlling the addition of ladle filler sand, cleaning the ladle nozzle, and optimizing argon stirring during the refining process can resolve the problem of a low ladle free-opening rate of high aluminum steel caused by the long ladle time of liquid steel. 展开更多
关键词 continuous casting high aluminum steel LADLE free - opening rate
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Layer regrouping for water-flooded commingled reservoirs at a high water-cut stage 被引量:2
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作者 Chuan-Zhi Cui Jian-Peng Xu +3 位作者 Duan-Ping Wang Zhi-Hong Liu Ying-song Huang Zheng-Ling Geng 《Petroleum Science》 SCIE CAS CSCD 2016年第2期272-279,共8页
Layer regrouping is to divide all the layers into several sets of production series according to the physical properties and recovery percent of layers at high water-cut stage, which is an important technique to impro... Layer regrouping is to divide all the layers into several sets of production series according to the physical properties and recovery percent of layers at high water-cut stage, which is an important technique to improve oil recovery for high water-cut multilayered reservoirs. Dif- ferent regroup scenarios may lead to different production performances. Based on unstable oil-water flow theory, a multilayer commingled reservoir simulator is established by modifying the production split method. Taking into account the differences of layer properties, including per- meability, oil viscosity, and remaining oil saturation, the pseudo flow resistance contrast is proposed to serve as a characteristic index of layer regrouping for high water-cut multilayered reservoirs. The production indices of multi- layered reservoirs with different pseudo flow resistances are predicted with the established model in which the data are taken from the Shengtuo Oilfield. Simulation results show that the pseudo flow resistance contrast should be less than 4 when the layer regrouping is implemented. The K-means clustering method, which is based on the objec- tive function, is used to automatically carry out the layer regrouping process according to pseudo flow resistances. The research result is applied to the IV-VI sand groups of the second member of the Shahejie Formation in the Shengtuo Oilfield, a favorable development performance is obtained, and the oil recovery is enhanced by 6.08 %. 展开更多
关键词 Water-flooded reservoirs Layer regrouping.Flow resistance - high water cut Reservoir simulation
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A Simple and Highly Efficient Enantioselective Synthesis of (<i>S</i>)-Rivastigmine 被引量:3
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作者 Veera R. Arava Laxminarasimhulu Gorentla Pramod K. Dubey 《International Journal of Organic Chemistry》 2011年第2期26-32,共7页
A highly efficient and convenient procedure for the enantioselective synthesis of (S)-Rivastigmine, a cholinergic agent for the treatment of mild to moderate dementia of the Alzheimer’s type and dementia due to Parki... A highly efficient and convenient procedure for the enantioselective synthesis of (S)-Rivastigmine, a cholinergic agent for the treatment of mild to moderate dementia of the Alzheimer’s type and dementia due to Parkinson’s disease, is accomplished by the treatment of versatile, readily accessible (S)-(-)-2-methyl-2-propanesulfinamide with 3-hydroxyacetophenone. This protocol provides high yield and excellent enantiomeric excess in short step synthesis. 展开更多
关键词 CHOLINERGIC Agent ENANTIOSELECTIVE highly Efficient (S)-(-)-2-Methyl-2-Propane Sulfina-mide (S)-Rivastigmine
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Plastic Flow Modeling of Ti-5 Al-2 Sn-2 Zr-4 Mo-4 Cr Alloy at Elevated Temperatures and High Strain Rates 被引量:1
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作者 王宝林 AI Xing +1 位作者 刘战强 LIU Jigang 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2015年第3期611-616,共6页
The true stress-sWain relationships of Ti-5A1-2Sn-2Zr-4Mo-4Cr(TC17) alloy with a wide range of strain rates were investigated by tmiaxial quasi-static and dynamic compression tests, respectively. Quasi- static compr... The true stress-sWain relationships of Ti-5A1-2Sn-2Zr-4Mo-4Cr(TC17) alloy with a wide range of strain rates were investigated by tmiaxial quasi-static and dynamic compression tests, respectively. Quasi- static compression tests were carried out with Instron 8874 test machine, while dynamic compression tests were performed with the split Hopkinson pressure bar (SHPB) which was installed with heating device and synchro- assembly system. The dynamic mechanical behaviors tests of TC17 were carded out from room temperature to 800 ℃ at intervals of 200 ℃ and at high sWain rates (5 500-1 9200 s-l). The stress-strain curves considering temperature-sWain rate coupling actions were obtained. The Johnson-Cook constitutive model was developed through data fitting of the stress-sWain curves. The material constants in the developed constitutive model can be determined using isothermal and adiabatic stress-strain curves at different strain rates. The Johnson-Cook constitutive model provided satisfied prediction of the plastic flow stress for TC17 alloy. 展开更多
关键词 Ti-5A1-2Sn-2Zr-4Mo-4Cr SHPB stress-strain curve high temperature high strain rate dynamic constitutive relationship
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Diffusion bonding behaviour of β-γTiAl alloys containing high niobium with Ti interlayer by spark plasma sintering 被引量:1
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作者 Qiang GAO Lai-qi ZHANG +1 位作者 Yi QIAO Jun-pin LIN 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2022年第12期3973-3984,共12页
High niobium β-γ TiAl alloy(HNBG) was diffusion bonded using spark plasma sintering with pure Ti as interlayer. The joint microstructural evolution, growth kinetics and mechanical properties were investigated. The j... High niobium β-γ TiAl alloy(HNBG) was diffusion bonded using spark plasma sintering with pure Ti as interlayer. The joint microstructural evolution, growth kinetics and mechanical properties were investigated. The joint included three diffusion zones. The β/B2 phase formed in the Zone Ⅰ, α_(2)phase in the Zone Ⅱ, and β-Ti and α-Ti phases in the Zone Ⅲ. The thickness of β/B2 phase, the average grain size of α_(2)phase and the amount of β-Ti phase increased with the increase of bonding temperature or bonding time. The growth activation energies of β/B2 and α_(2)phases were 582 and 253 kJ/mol, respectively. The joint acquired at 1000 °C, 10 min and 10 MPa showed the maximum shear strength of 308 MPa. Fracture mainly occurred along the interfaces between Zone Ⅰ and HNBG alloy, and between Zone I and Zone Ⅱ. Fracture mechanism of the joint was characterized by brittleness rupture along the phase boundary. 展开更多
关键词 high niobiumβ-γTiAl alloy diffusion bonding spark plasma sintering INTERLAYER microstructure evolution mechanical properties
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A COMPUTER SIMULATION OF HIGH-DOSE ION IMPLANTATION INTO AMORPHOUS MATERIALS
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作者 袁博 虞福春 《Nuclear Science and Techniques》 SCIE CAS CSCD 1990年第Z1期82-83,共2页
A computer program MACA was developed for simulating high-dose ion implantation into amorphous solids. The topology of amorphous solids was modelled by adjusting the free flight path distribution between collisions, s... A computer program MACA was developed for simulating high-dose ion implantation into amorphous solids. The topology of amorphous solids was modelled by adjusting the free flight path distribution between collisions, so that the radial distribution function will characterize the short - range order and long - range disorder of amorphous targets. A simulation example is given. 展开更多
关键词 Simulation of high - DOSE ion IMPLANTATION AMORPHOUS target TOPOLOGY modelling MACA code
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Manufacturing of Ultra-high Molecular Weight Polyethylene Fiber Reinforced Tape and the Loss of Strength
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作者 胡祖明 刘兆峰 《Journal of China Textile University(English Edition)》 EI CAS 1999年第4期92-94,共3页
Due to the low density and excellent mechanical proper-ties,high performance fiber reinforced materials have aconsiderable application in the area of high technologyand dally usage.In this paper,the Ultra-high Molecu-... Due to the low density and excellent mechanical proper-ties,high performance fiber reinforced materials have aconsiderable application in the area of high technologyand dally usage.In this paper,the Ultra-high Molecu-lar Weight Polyethylene(UHMWPE)fiber reinforcedPE tape prepared with the method of powder impregnat-ion was studied.The effect of impregnate length and thetensile force of the yarn on the fiber content as well as on the strength and modulus of the tape were discussed.Calculation shows that the strength and the modulus ofthe ULMWPE fiber can keep about 85% after it undergothe process. 展开更多
关键词 Ultra - high molecular WEIGHT POLYETHYLENE fiber REINFORCED material TAPE IMPREGNATION
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