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| 1 | Effect of pitch angle on initial stage of a transport airplane ditching显示文摘Airworthiness regulations require that the transport airplane should be proved to ensure the survivability of the ditching for the passengers. The planned ditching of a transport airplane on the calm water is numerically simulated. The effect of pitch angle on the impact characteristics is especially investigated by a subscaled model. The Reynolds-averaged Navier-Stokes (RANS) equations of unsteady compressible flow are solved and the realizable j-e equations are employed to model the turbulence. The transformation of the air-water interface is tracked by volume of fluid (VOF) model. The motion of the rigid body is modeled by dynamic mesh method. The initial ditching stage of the transport airplane is analyzed in detail. The numerical results show that as the pitching angle increases, the maximal normal force decreases and the pitching motion becomes much gentler. The aft fuselage would be sucked down by the water and lead to pitching up, whereas the low horizontal tail prevents this trend. Consequently, the transport aircraft with low horizontal tail should ditch on the water at an angle between 10 and 12 as a recommendation. | Guo Baodong Liu Peiqing Qu Qiulin Wang Jiawen | 2013 | Chinese Journal of Aeronautics2013,26,1: | 18 |
| 2 | Increased expression of human T-cell immunoglobulin-and mucin-domain-containing molecule-4 in peripheral blood mononuclear cells from patients with system lupus erythematosus显示文摘全身的豺狼座 erythematosus (SLE ) 是 prototypic 自体免疫的疾病。天生、适应的免疫合作地贡献 SLE 的发展。介绍抗原的房间(APC ) 被建议了连接天生、适应的免疫。T 房间 immunoglobulin-domain-containing 和 mucin-domain-containing molecule-4 (Tim-4;另外作为 Timd4 知道) ,首先在 APC 的表面上表示了,是 TIM 家庭,的一个成员作为免疫系统的潜在的管理者收到了许多注意的分子的一个最近描述的组。在这研究,我们使用了量的即时反向的抄写聚合酶链反应从 SLE 病人在外部血 mononuclear 房间( PBMC )检验 Tim-4 的 mRNA 表示并且进一步在 PBMC 和浆液肿瘤坏死因素( TNF )分析了在 Tim-4 和 Tim-1 (为 Tim-4 的潜在的 ligand )的表示之间的关联-伪层次。结果证明在 PBMC 的那个 Tim-4 mRNA 表达式比在健康控制在 SLE 病人是显著地更高的,特别在疾病的活跃阶段的那些病人。而且, Tim-4 mRNA 层次密切在 SLE 病人然而并非在控制组在 PBMC 并且与浆液 TNF- 伪层次与 Tim-1 mRNA 层次被相关。一起拿,这些结果证明 Tim-4 可以涉及 SLE 的致病。 | Peiqing Zhao Liyun Xu Piming Wang Xiaohong Liang Jianni Qi Peng Liu Chun Guo Lining Zhang Chunhong Ma Lifen Gao | 2010 | Cellular & Molecular Immunology2010,7,2: | 11 |
| 3 | Aerodynamic optimization and mechanism design of flexible variable camber trailing-edge flap显示文摘Trailing-edge flap is traditionally used to improve the takeoff and landing aerodynamic performance of aircraft.In order to improve flight efficiency during takeoff,cruise and landing states,the flexible variable camber trailing-edge flap is introduced,capable of changing its shape smoothly from 50% flap chord to the rear of the flap.Using a numerical simulation method for the case of the GA(W)-2 airfoil,the multi-objective optimization of the overlap,gap,deflection angle,and bending angle of the flap under takeoff and landing configurations is studied.The optimization results show that under takeoff configuration,the variable camber trailing-edge flap can increase lift coefficient by about 8% and lift-to-drag ratio by about 7% compared with the traditional flap at a takeoff angle of 8°.Under landing configuration,the flap can improve the lift coefficient at a stall angle of attack about 1.3%.Under cruise state,the flap helps to improve the lift-todrag ratio over a wide range of lift coefficients,and the maximum increment is about 30%.Finally,a corrugated structure–eccentric beam combination bending mechanism is introduced in this paper to bend the flap by rotating the eccentric beam. | Weishuang LU Yun TIAN Peiqing LIU | 2017 | Chinese Journal of Aeronautics2017,30,3: | 9 |
| 4 | Chrysophanol protects against doxorubicin-induced cardiotoxicity by suppressing cellular PARylation显示文摘The clinical application of doxorubicin(DOX) in cancer chemotherapy is limited by its lifethreatening cardiotoxic effects. Chrysophanol(CHR), an anthraquinone compound isolated from the rhizome of Rheum palmatum L., is considered to play a broad role in a variety of biological processes.However, the effects of CHR’s cardioprotection in DOX-induced cardiomyopathy is poorly understood. In this study, we found that the cardiac apoptosis, mitochondrial injury and cellular PARylation levels were significantly increased in H9 C2 cells treated by Dox, while these effects were suppressed by CHR. Similar results were observed when PARP1 activity was suppressed by its inhibitors 3-aminobenzamide(3 AB)and ABT888. Ectopic expression of PARP1 effectively blocked this CHR’s cardioprotection against DOX-induced cardiomyocyte injury in H9 C2 cells. Furthermore, pre-administration with both CHR and 3 AB relieved DOX-induced cardiac apoptosis, mitochondrial impairment and heart dysfunction in Sprague–Dawley rat model. These results revealed that CHR protects against DOX-induced cardiotoxicity by suppressing cellular PARylation and provided critical evidence that PARylation may be a novel target for DOX-induced cardiomyopathy. | Jing Lu Jingyan Li Yuehuai Hu Zhen Guo Duanping Sun Panxia Wang Kaiteng Guo Dayue Darrel Duan Si Gao Jianmin Jiang Junjian Wang Peiqing Liu | 2019 | Acta Pharmaceutica Sinica B2019,9,4: | 8 |
| 5 | Controlling the effect of a distant extremely thick igneous rock in overlying strata on coal mine disasters显示文摘Based on theoretical analysis, similarity simulation tests, numerical simulation analysis and field observations, we analyzed rock collapse and rules of fraction evolution of overlying rocks and studied the rules in controlling the effect of an extremely thick igneous rock, found above a main mining coal seam in an area prone to coal mine disasters in the Haizi Coal Mine. The results show that this igneous rock, called a 'main key stratum', will not subside nor break for a long time, causing lower fractures and bed separations not to close. The presence of igneous rock plays an important role in rock bursts, mine floods, gas outburst and surface subsidence in coal mines. By analyzing the rules in controlling the effect of this igneous rock, we provide useful references for safety and high efficiency mining in coal mines under special geological conditions. | WANG Liang | 2010 | Mining Science and Technology2010,20,4: | 8 |
| 6 | Gentiopicroside targets PAQR3 to activate the PI3K/AKT signaling pathway and ameliorate disordered glucose and lipid metabolism显示文摘The obstruction of post-insulin receptor signaling is the main mechanism of insulin-resistant diabetes.Progestin and adipoQ receptor 3(PAQR3),a key regulator of inflammation and metabolism,can negatively regulate the PI3 K/AKT signaling pathway.Here,we report that gentiopicroside(GPS),the main bioactive secoiridoid glycoside of Gentiana manshurica Kitagawa,decreased lipid synthesis and increased glucose utilization in palmitic acid(PA) treated HepG2 cells.Additionally,GPS improved glycolipid metabolism in streptozotocin(STZ) treated high-fat diet(HFD)-induced diabetic mice.Our findings revealed that GPS promoted the activation of the PI3 K/AKT axis by facilitating DNA-binding protein 2(DDB2)-mediated PAQR3 ubiquitinated degradation.Moreover,results of surface plasmon resonance(SPR),microscale thermophoresis(MST) and thermal shift assay(TSA) indicated that GPS directly binds to PAQR3.Results of molecular docking and cellular thermal shift assay(CETSA) revealed that GPS directly bound to the amino acids of the PAQR3 NH2-terminus including Leu40,Asp42,Glu69,Tyr125 and Ser129,and spatially inhibited the interaction between PAQR3 and the PI3 K catalytic subunit(P110α) to restore the PI3 K/AKT signaling pathway.In summary,our study identified GPS,which inhibits PAQR3 expression and directly targets PAQR3 to restore insulin signaling pathway,as a potential drug candidate for the treatment of diabetes. | Haiming Xiao Xiaohong Sun Zeyuan Lin Yan Yang Meng Zhang Zhanchi Xu Peiqing Liu Zhongqiu Liu Heqing Huang | 2022 | Acta Pharmaceutica Sinica B2022,12,6: | 7 |
| 7 | Guiding T lymphopoiesis from pluripotent stem cells by defined transcription factors显示文摘Achievement of immunocompetent and therapeutic T lymphopoiesis from pluripotent stem cells(PSCs)is a central aim in T cell regenerative medicine.To date,preferentially reconstituting T lymphopoiesis in vivo from PSCs remains a practical challenge.Here we documented that synergistic and transient expression of Runx1 and Hoxa9 restricted in the time window of endothelial-to-hematopoietic transition and hematopoietic maturation stages in a PSC differentiation scheme(iR9-PSC)in vitro induced preferential generation of engraftable hematopoietic progenitors capable of homing to thymus and developing into mature T cells in primary and secondary immunodeficient recipients.Single-cell transcriptome and functional analyses illustrated the cellular trajectory of T lineage induction from PSCs,unveiling the T-lineage specification determined at as early as hemogenic endothelial cell stage and identifying the bona fide pre-thymic progenitors.The induced T cells distributed normally in central and peripheral lymphoid organs and exhibited abundant TCRαβrepertoire.The regenerative T lymphopoiesis restored immune surveillance in immunodeficient mice.Furthermore,gene-edited iR9-PSCs produced tumor-specific T cells in vivo that effectively eradicated tumor cells.This study provides insight into universal generation of functional and therapeutic T cells from the unlimited and editable PSC source. | Rongqun Guo Fangxiao Hu Qitong Weng Cui Lv Hongling Wu Lijuan Liu Zongcheng Li Yang Zeng Zhijie Bai Mengyun Zhang Yuting Liu Xiaofei Liu Chengxiang Xia Tongjie Wang Peiqing Zhou Kaitao Wang Yong Dong Yuxuan Luo Xiangzhong Zhang Yuxian Guan Yang Geng Juan Du Yangqiu Li Yu Lan Jiekai Chen Bing Liu Jinyong Wang | 2020 | Cell Research2020,30,1: | 7 |
| 8 | TGIF2 promotes the progression of lung adenocarcinoma by bridging EGFR/RAS/ERK signaling to cancer cell stemness显示文摘TGF-β-induced factor homeobox 2(TGIF2)is a transcription regulator that plays essential roles in the regulation of development and cell fate decisions.Aberrant expression of TGIF family proteins has been observed in several cancers,including ovarian,esophageal,and colorectal cancers.Here,we report that TGIF2 mediates the EGFR–RAS–ERK signaling pathway to enhance the stemness of lung adenocarcinoma(LUAD)cells and,therefore,promote the progression and metastasis of LUAD.We found that high TGIF2 expression was closely correlated with tumor growth,lymph node metastasis,and survival of patients with LUAD.Mice bearing TGIF2-silenced H1299 xenografts developed smaller tumors and fewer lung metastases.Importantly,silencing TGIF2 decreased the cancer stem cell(CSC)-like properties in A549 and H1299 cells.Furthermore,we identified that TGIF2 binding to the OCT4 promoter promotes its expression.In both LUAD cells and in vivo LUAD mouse models,we revealed that EGFR–RAS–ERK signaling phosphorylated TGIF2 and increased its stability,which was important for TGIF2-promoted LUAD stemness since phosphorylation-deficient TGIF2 mutants lost these functions.Thus,our study revealed that an important factor,TGIF2,bridges EGFR signaling to the CSC characteristics of LUAD cells,which can be utilized as an effective target for LUAD therapy. | Renle Du Wenzhi Shen Yi Liu Wenjuan Gao Wei Zhou Jun Li Shuangtao Zhao Chong Chen Yanan Chen Yanhua Liu Peiqing Sun Rong Xiang Yi Shi Yunping Luo | 2019 | Signal Transduction and Targeted Therapy2019,4,1: | 7 |
| 9 | Isorhapontigenin protects against doxorubicin-induced cardiotoxicity via increasing YAP1 expression显示文摘As an effective anticancer drug, the clinical limitation of doxorubicin(Dox) is the time-and dose-dependent cardiotoxicity. Yes-associated protein 1(YAP1) interacts with transcription factor TEA domain 1(TEAD1) and plays an important role in cell proliferation and survival. However, the role of YAP1 in Dox-induced cardiomyopathy has not been reported. In this study, the expression of YAP1 was reduced in clinical human failing hearts with dilated cardiomyopathy and Dox-induced in vivo and in vitro cardiotoxic model. Ectopic expression of Yap1 significantly blocked Dox-induced cardiomyocytes apoptosis in TEAD1 dependent manner. Isorhapontigenin(Isor) is a new derivative of stilbene and responsible for a wide range of biological processes. Here, we found that Isor effectively relieved Doxinduced cardiomyocytes apoptosis in a dose-dependent manner in vitro. Administration with Isor(30 mg/kg/day, intraperitoneally, 3 weeks) significantly protected against Dox-induced cardiotoxicity in mice. Interestingly, Isor increased Dox-caused repression in YAP1 and the expression of its target genes in vivo and in vitro. Knockout or inhibition of Yap1 blocked the protective effects of Isor on Dox-induced cardiotoxicity. In conclusion, YAP1 may be a novel target for Dox-induced cardiotoxicity and Isor might be a new compound to fight against Dox-induced cardiotoxicity by increasing YAP1 expression. | Panxia Wang Minghui Wang Yuehuai Hu Jianxing Chen Yanjun Cao Cui Liu Zhongkai Wu Juan Shen Jing Lu Peiqing Liu | 2021 | Acta Pharmaceutica Sinica B2021,11,3: | 7 |
| 10 | Three-dimensional Modeling for Predicting the Vibration Modes of Twin Ball Screw Driving Table显示文摘As a redundant drive mechanism,twin ball screw feed system has the advantage of high stiffness and little yaw vibration in the feeding process,while leads to increased difficulty with vibration characteristics analysis and structure optimization.Only low-dimensional structure and dynamics parameters are considered in the existing research,the complete and effective model for predicting the table’s vibrations is lacked.A three-dimensional(3D)mechanical model of twin ball screw driving table is proposed.In order to predict the vibration modes of the table quantitatively,an analytical formulation following a comprehensive approach is developed,where the drive system is modeled as a lumped mass-spring system,and the Lagrangian method is used to obtain the table’s independent and coupled axial,yaw,and pitch vibration modes.The frequency variation of each mode is studied for different heights of the center of gravity,nut positions and table masses by numerical simulations.Modal experiment is carried out on the Z-axis feed table of the horizontal machining center MCH63.The results show that for each mode,the error between the estimated and the measured frequencies is less than 13%.The independent and coupled vibration modes are in accordance with the experimental results,respectively.The proposed work can serve a better understanding of the table’s dynamics and be beneficial for optimizing the structure parameters of twin ball screw drive system in the design stage. | WANG Renche ZHAO Tong YE Peiqing LIU Yan | 2014 | Chinese Journal of Mechanical Engineering2014,27,1: | 5 |
| 11 | Wind tunnel tests of stratospheric airship counter rotating propellers显示文摘Aerodynamic performance of the high-altitude propeller,especially the counter rotation effects,is experimentally studied.Influences of different configurations on a stratospheric airship,included 2-blade counter-rotating propeller(CRP),dual 2-blade single rotation propellers(SRPs) and 4-blade SRP,are also indicated.This research indicates that the effect of counter rotation can greatly improve the efficiency.It shows that the CRP configuration results in a higher efficiency than the dual 2-blade SRPs configuration or4-blade SRP configuration under the same advance ratio,and the CRP configuration also gains the highest efficiency whether under the situation of providing the same trust or absorbing the same power.It concludes that,for a stratospheric airship,the CRP configuration is better than the multiple SRPs configuration or a multi-blade SRP one. | Yaxi Chen Peiqing Liu Zhihao Tang Hao Guo | 2015 | Theoretical & Applied Mechanics Letters2015,5,1: | 5 |
| 12 | Multi-objective optimization of shock control bump on a supercritical wing显示文摘Based on the supercritical'wing1'which was released in the DPW-III conference,multi-objective optimization has been done to increase the lift-drag ratio at cruise condition and improve transonic buffet boundary and drag-rise performance.Hicks-Henne shape functions are used to represent the bump shape.In the design optimization to increase lift-drag ratio,the objectives involve the cruise point and three other off-design points nearby.In the other optimization process to improve buffet and drag-rise performance,three buffet onset points near the cruise point and one drag-rise point are selected as the design points.Non-dominating sort genetic algorithm II(NSGA-II)is used in both processes.Additionally,individual analysis for every selected point on the Pareto frontier is conducted in order to avoid local convergence and achieve global optimum.Results of optimization for aerodynamic efficiency show a decrease of 11 counts in drag at the cruise point.Drag at nearby off-design points are also reduced to some extent.Similar approaches are made to improve buffet and drag-rise characteristics,resulting in significant improvements in both ways. | TIAN Yun LIU PeiQing LI Zhi | 2014 | Science China(Technological Sciences)2014,57,1: | 5 |
| 13 | Numerical simulation of Gurney flap on SFYT15thick airfoil显示文摘A two-dimensional steady Reynolds-averaged Navier–Stokes(RANS) equation was solved to investigate the effects of a Gurney flap on SFYT15 thick airfoil aerodynamic performance. This airfoil was designed for flight vehicle operating at 20 km altitude with freestream velocity of 25 m/s. The chord length(C) is5 m and the Reynolds number based on chord length is Re = 7.76 × 105. Gurney flaps with the heights ranging from 0.25%C to 3%C were investigated. The shear stress transport(SST) k-ω turbulence model was used to simulate the flow structure around the airfoil. It is showed that Gurney flap can enhance not only the prestall lift but also lift-to-drag ratio in a certain range of angles of attack. Specially, at cruise angle of attack(α = 3°), Gurney flap with 0.5%C height can increase lift-to-drag ratio by 2.7%, and lift coefficient by 12.9%, respectively. Furthermore, the surface pressure distribution, streamlines and trailing-edge flow structure around the airfoil are illustrated, which are helpful to understand the mechanisms of Gurney flap on airfoil aerodynamic performance. Moreover, it is found that the increase of airfoil drag with Gurney flap can be attributed to the increase of pressure drag between the windward and the leeward sides of Gurney flap itself. | Xi He Jinjun Wang Muqing Yang Dongli Ma Chao Yan Peiqing Liu | 2016 | Theoretical & Applied Mechanics Letters2016,6,6: | 5 |
| 14 | Numerical simulation of heat transfer of latent functionally thermal fluid in tubes with coaxially inserted cylindrical bars in laminar显示文摘The heat transfer of latent functionally thermal fluid in three kinds of tubes with coaxially inserted cylindrical bars is numerically researched using equivalent spe- cific heat model, and the flow fields are analyzed with field synergy field. It is found that in the tubes with coaxially inserted cylindrical bars, the heat transfer effects of functionally thermal fluid become more and more pronounced with the Ste de- creasing. This is similar to be case of functionally thermal fluid flowing in smooth straight tubes. Compared with the results receiving from smooth straight tubes, the heat transfer of functional thermal fluid in tubes with coaxially inserted cylindrical bars has been significantly enhanced. And this effect becomes more apparent as the diameter of coaxially inserted cylindrical bars increases meanwhile, however, energy consuming of the tubes shows the same trend. | JIN Jian LIU PeiQing LIN GuiPing | 2008 | Science China(Technological Sciences)2008,51,8: | 4 |
| 15 | Transonic buffet control research with two types of shock control bump based on RAE2822 airfoil显示文摘Current research shows that the traditional shock control bump(SCB) can weaken the intensity of shock and better the transonic buffet performance. The author finds that when SCB is placed downstream of the shock, it can decrease the adverse pressure gradient. This may prevent the shock foot separation bubble to merge with the trailing edge separation and finally improve the buffet performance. Based on RAE2822 airfoil, two types of SCB are designed according to the two different mechanisms. By using Reynolds-averaged Navier-Stokes(RANS) and unsteady Reynolds-averaged Navier-Stokes(URANS) methods to analyze the properties of RAE2822 airfoil with and without SCB, the results show that the downstream SCB can better the buffet performance under a wide range of freestream Mach number and the steady aerodynamics characteristic is similar to that of RAE2822 airfoil. The traditional SCB can only weaken the intensity of the shock under the design condition. Under the off-design conditions, the SCB does not do much to or even worsen the buffet performance. Indeed, the use of backward bump can flatten the leeward side of the airfoil, and this is similar to the mechanism that supercritical airfoil can weaken the recompression of shock wave. | Yun TIAN Shiqi GAO Peiqing LIU Jinjun WANG | 2017 | Chinese Journal of Aeronautics2017,30,5: | 4 |
| 16 | MicroRNA-34c-5p provokes isoprenaline-induced cardiac hypertrophy by modulating autophagy via targeting ATG4B显示文摘Pathological cardiac hypertrophy serves as a significant foundation for cardiac dysfunction and heart failure. Recently, growing evidence has revealed that microRNAs(miRNAs) play multiple roles in biological processes and participate in cardiovascular diseases. In the present research, we investigate the impact of miRNA-34 c-5 p on cardiac hypertrophy and the mechanism involved. The expression of miR-34 c-5 p was proved to be elevated in heart tissues from isoprenaline(ISO)-infused mice. ISO also promoted miR-34 c-5 p level in primary cultures of neonatal rat cardiomyocytes(NRCMs). Transfection with miR-34 c-5 p mimic enhanced cell surface area and expression levels of foetal-type genes atrial natriuretic factor(Anf) and β-myosin heavy chain(β-Mhc) in NRCMs. In contrast, treatment with miR-34 c-5 p inhibitor attenuated ISO-induced hypertrophic responses. Enforced expression of miR-34 c-5 p by tail intravenous injection of its agomir led to cardiac dysfunction and hypertrophy in mice, whereas inhibiting miR-34 c-5 p by specific antagomir could protect the animals against ISO-triggered hypertrophic abnormalities. Mechanistically, miR-34 c-5 p suppressed autophagic flux in cardiomyocytes, which contributed to the development of hypertrophy. Furthermore, the autophagy-related gene 4 B(ATG4 B) was identified as a direct target of miR-34 c-5 p, and miR-34 c-5 p was certified to interact with 3’untranslated region of Atg4 b mRNA by dual-luciferase reporter assay. miR-34 c-5 p reduced the expression of ATG4 B, thereby resulting in decreased autophagy activity and induction of hypertrophy. Inhibition of miR-34 c-5 p abolished the detrimental effects of ISO by restoring ATG4 B and increasing autophagy. In conclusion, our findings illuminate that miR-34 c-5 p participates in ISO-induced cardiac hypertrophy, at least partly through suppressing ATG4 B and autophagy. It suggests that regulation of miR-34 c-5 p may offer a new way for handling hypertrophy-related cardiac dysfunction. | Yuhong Zhang Yanqing Ding Min Li Jing Yuan Youhui Yu Xueying Bi Huiqi Hong Jiantao Ye Peiqing Liu | 2022 | Acta Pharmaceutica Sinica B2022,12,5: | 4 |
| 17 | Shock control bump parametric research on supercritical airfoil显示文摘High precision of CFD code was used to study supercritical Airfoil RAE2822 superimposed with different shock control bumps under the transonic conditions.A successful improvement was made to current widely used Hicks-Henne functions which describe shock control bumps.Based on improving the airfoil's lift-drag ratio,the study shows that,(1) the best bump crest position is at the position close to 50% of bump chord,which is almost independent of free stream or pre-shock Mach numbers,but the bump height is highly coupled with the crest position,which means that the higher the bump is,the more obviously the crest position affects the airfoil lift-drag ratio,and it becomes more evident with the increase of free stream or pre-shock Mach numbers;(2) in case that the lift-drag ratio of airfoil with bump is higher than basic airfoil,almost all the optimum distances between bump crest and shock wave are close to 30% of bump chord;(3) almost all the lift-drag ratios of airfoil with bump increase as bump chord length increases,of which this trend becomes more evident as bump height increases;(4) with the increase of the bump height,almost all the lift-drag ratios of airfoil with bump decrease at low free stream or pre-shock Mach numbers.When the Mach numbers are higher,the lift-drag ratio of airfoil increases as the increase of the bump height,and particularly,the trend tends to be visible when the Mach numbers are at a high level. | TIAN Yun LIU PeiQing FENG PeiHua | 2011 | Science China(Technological Sciences)2011,54,11: | 3 |
| 18 | Numerical simulation of gurney flaps lift-enhancement on a low reynolds number airfoil显示文摘Two-dimensional steady Reynolds-averaged Navier-Stokes(RANS) equations with transition shear stress transport(SST) model were solved to investigate the effects of Gurney flaps on the aerodynamic performance of a low Reynolds number airfoil. This airfoil was designed for flight vehicles operating at 20 km altitude with freestream velocity of 25 m/s. The chord length(C) of this airfoil is 5 m and the corresponding Reynolds number is 7.76×10~5. Gurney flaps with the heights ranging from 0.25%C to3%C were investigated. It has been shown that Gurney flaps can enhance not only the prestall lift but also lift-to-drag ratio in a certain range of angles of attack. Specially, at cruise angle of attack(3°), Gurney flap with the height of 0.5%C.can increase lift-to-drag ratio and lift coefficient by 1.6% and 12.8%, respectively. Furthermore, the mechanisms of Gurney flaps to improve the aerodynamic performance were illustrated by analyzing the surface pressure distribution, streamlines and trailing-edge flow structure for this low Reynolds number airfoil. Specially, distinguished from some other numerical researches, the flow details such as the laminar separation bubble and transition phenomena for low Reynolds number airfoil with Gurney flaps were investigated and it was found that Gurney flaps can delay the transition onset position at small angles of attack(≤2°). However, with the increase of angles of attack, Gurney flaps will promote the boundary layer transition. | HE Xi WANG JinJun YANG MuQing MA DongLi YAN Chao LIU PeiQing | 2017 | Science China(Technological Sciences)2017,60,10: | 3 |
| 19 | Tanshinone Ⅱ-A Attenuates and Stabilizes Atherosclerotic Plaques in Apolipoprotein E Knockout Mice Fed with High Cholesterol Diet显示文摘Objective TanshinoneⅡ-A(Tan),a bioactive diterpene isolated fromSalvia miltiorrhiza Bunge(Danshen),possesses anti-oxidant and anti-in-flammatory activities.The present study investigated whether Tan can reduce and stabilize atherosclerotic plaques in Apolipoprotein E knockout(ApoE-/-) mice maintained on a high cholesterol diet(HCD).Methods and Results Six week-old mice challenged with HCD were ran-domly assigned to 4 groups: C57BL/6J,ApoE-/-,ApoE-/-+30 mg/kg.d Tan and ApoE-/-+10 mg/kg.d Tan.After 16 weeks of inter-vention,Tan treated mice showed decreased atherosclerotic lesion size in the aortic sinus and face aorta.Furthermore,immunohistochemical a-nalysis revealed that Tan rendered the lesion composition a more stable phenotype as evidenced by reduced necrotic cores,decreased macrophageinfiltration,increased smooth muscle cell and collagen content.Tan also significantly reduced in situ superoxide anion production,aortic expres-sion of NF-κB,and matrix metalloproteinase-9(MMP-9).In vitro treatment of RAW264.7 macrophages with Tan significantly suppressed oxi-dized LDL-induced reactive oxygen species production,pro-inflammatory cytokine(IL-6,TNF-α,MCP-1) expression,and MMP-9 activity.Conclusions Tan attenuates the development of atherosclerotic lesions and promotes plaque stability in ApoE-/-mice by reducing vascular oxi-dative stress and inflammatory responses.Our findings highlightTan as a potential therapeutic agentto preventatherosclerotic cardiovascular dis-eases. | Suowen XU Yan Huang Peter J. Little Peiqing Liu | 2011 | 中国动脉硬化杂志2011,19,3: | 2 |
| 20 | Extraction and physicochemical characteristics of a red pigment produced by marine bacterium strain S - 9801显示文摘-- A red pigment that has better biological properties is produced by marine bacterium strain S- 9801. The extraction methods, physicochemical and toxicity of the pigment have been studied.Dissolubility of pigment in the five organic solvent has been tested, and ethanol is optimally chosen for extraction. Physicochemical characteristics of this pigment was stable. The absorbance of the pigment solution was no losing when put under natural light for 10 days or treated by UV for 30 minutes, color of the pigment unchanged after 100 ℃ hythere for 1 h or 80 ℃ xerother for 2 h. The median lethal dose (LD50) of the rat by celiac injection was 670.04 mg/kg and minimum lethal dose of oral was greater than 2 000 mg/kg. | Tian Li He Peiqing Liu Chenlin Bian Ji Miao Jinlai | 2002 | Acta Oceanologica Sinica2002,21,3: | 2 |