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1Gain self-scheduled H_∞ control for morphing aircraft in the wing transition process based on an LPV model显示文摘This article investigates gain self-scheduled H 1 robust control system design for a tailless fold- ing-wing morphing aircraft in the wing shape varying process. During the wing morphing phase, the aircraft's dynamic response will be governed by time-varying aerodynamic forces and moments. Nonlinear dynamic equations of the morphing aircraft are linearized by using Jacobian linearization approach, and a linear parameter varying (LPV) model of the morphing aircraft in wing folding is obtained. A multi-loop controller for the morphing aircraft is formulated to guarantee stability for the wing shape transition process. The proposed controller uses a set of inner-loop gains to provide stability using classical techniques, whereas a gain self-scheduled H 1 outer-loop controller is devised to guarantee a specific level of robust stability and performance for the time-varying dynamics. The closed-loop simulations show that speed and altitude vary slightly during the whole wing folding process, and they converge rapidly after the process ends. This proves that the gain self-scheduled H 1 robust controller can guarantee a satisfactory dynamic performance for the morphing aircraft during the whole wing shape transition process. Finally, the flight control system's robustness for the wing folding process is verified according to uncertainties of the aerodynamic parameters in the nonlinear model.Yue Ting Wang Lixin Ai Junqiang 2013Chinese Journal of Aeronautics2013,26,4:34
2Current status of diagnosis and treatment of bladder cancer in China-Analyses of Chinese Bladder Cancer Consortium database显示文摘Objective:To investigate current status of diagnosis and treatment of bladder cancer in China.Methods:A database was generated by Chinese Bladder Cancer Consortium(CBCC).From January 2007 to December 2012,14,260 cases from 44 CBCC centers were included.Data of diagnosis,treatment and pathology were collected.Results:The average age was 63.5 year-old and most patients were male(84.3%).The most common histologic types were urothelial carcinoma(91.4%),adenocarcinoma(1.8%),and squamous carcinoma(1.9%).According to 1973 and 2004 WHO grading system,42.0%,41.0%,and 17.0% of patients were grade 1,2,and 3,and 16.0%,48.7%,and 35.3% of patients were papillary urothelial neoplasms of low malignant potential,low,and high grade,respectively.Non-muscle invasive bladder cancer(NMIBC)and muscle invasive bladder cancer(MIBC)were 25.2% and 74.1%,respectively(0.8% not clear).Carcinoma in situ was only 2.4%.Most patients were diagnosed by white-light cystoscopy with biopsy(74.3%).Fluorescence and narrow band imaging cystoscopy had additional detection rate of 1.0% and 4.0%,respectively.Diagnostic transurethral resection(TUR)provided detection rate of 16.9%.Most NMIBCs were treated with TUR(89.2%).After initial TUR,2.6%accepted second TUR,and 45.7%,69.9%,and 58.7% accepted immediate,induced,and maintenance chemotherapy instillation,respectively.Most MIBCs were treated with radical cystectomy(RC,59.7%).Laparoscopic RCs were 35.1%,while open RC 63.4%.Extended and standard pelvic lymph node dissection were 7% and 66%,respectively.Three most common urinary diversions were orthotopic neobladder(44%),ileal conduit(31%),and ureterocutaneostomy(23%).Only 2.3% of patients accepted neo-adjuvant chemotherapy and only 18%of T3 and T4 patients accepted adjuvant chemotherapy.Conclusion:Disease characteristics are similar to international reports,while differences of diagnosis and treatment exist.This study can provide evidences for revisions of the guideline on bladder cancer in China.Kaiwen Li Tianxin Lin Wei Xue Xin Mu Enci Xu Xu Yang Fubao Chen Guangyong Li Lulin Ma Guoliang Wang Chaozhao Liang Haoqiang Shi Ming Li Mao Tang Xueyi Xue Yisong Lv Yaoliang Deng Chengyang Li Zhiwen Chen Xiaozhou Zhou Fengshuo Jin Xudong Liu Jinxin Wei Lei Shi Xin Gou Weiyang He Liqun Zhou Lin Cai Baiye Jin Guanghou Fu Xiangbo Kong Hongyan Sun Ye Tian Lang Feng Tiejun Pan Yiyi Wu Dongwen Wang Hailong Hao Benkang Shi Yaofeng Zhu Qiang Wei Ping Han Changli Wu Dawei Tian Zhangqun Ye Zheng Liu Zhiping Wang Junqiang Tian Lin Qi Minfeng Chen Wei Li Jinchun Qi Gongxian Wang Longlong Fu Zhaolin Sun Guangheng Luo Zhoujun Shen Zhaowei Zhu Jinchun Xing Zhun Wu Dong Wei Xin Chen Yanqun Na Hongfeng Guo Chunxi Wang Zhihua Lu Chuize Kong Yang Liu Jin Yang Jianyun Hu Xin Gao Jielin Li Changjun Yin Pu Li Shan Chen Zhen Du Jiongming Li Yongji Yan Xu Zhang Shuang Huang Fangjian Zhou Zhiling Zhang Yinghao Sun Shuxiong Zeng Song Cen Jiaquan Zhou Hanzhong Li Jin Wen Jian Huang 2015Asian Journal of Urology2015,2,2:21
3Prediction of recent bank retreat processes at typical sections in the Jingjiang Reach显示文摘The Jingjiang Reach is experiencing continuous channel degradation owing to operation of the Three Gorges Project(TGP)in2003.Significant retreat processes at composite riverbanks have occurred at local sites of this reach,which may influence the stability of the river regime and the effect of existing river training works.Therefore,bank retreat plays a key role in fluvial processes of the Jingjiang Reach,and it is necessary to predict the long-term processes of bank retreat at typical sections in the reach.In this study,various factors influencing bank retreat in the Jingjiang Reach are investigated,based on bank erosion processes at four sections and the corresponding flow and sediment conditions.It is discovered that fluvial erosion intensity is a dominant factor in controlling the processes of bank retreat in the reach,although other factors,such as bank soil properties,can also influence bank retreat.The bankfull width at a section with severe bank erosion since 2002 is defined as being equal to the sum of the bankfull width in 2002 and the accumulated bank retreat distance after 2002.The magnitude of the bankfull width can be expressed as an exponential function of the previous 5-year average fluvial erosion intensity during flood seasons.The accumulated distances of bank retreat at four sections over the period 2002–2012 are predicted using the proposed empirical relationships,with the calculated bank retreat processes agreeing well with observed data.XIA JunQiang ZONG QuanLi ZHANG Yi XU QuanXi LI XiaoJuan 2014Science China(Technological Sciences)2014,57,8:20
4Differential responses of short-term soil respiration dynamics to the experimental addition of nitrogen and water in the temperate semi-arid steppe of Inner Mongolia, China显示文摘We examined the effects of simulated rainfall and increasing N supply of different levels on CO2 pulse emission from typical Inner Mongolian steppe soil using the static opaque chamber technique, respectively in a dry June and a rainy August. The treatments included NH4NO3 additions at rates of 0, 5, 10, and 20 g N/(m2·year) with or without water. Immediately after the experimental simulated rainfall events, the CO2 effluxes in the watering plots without N addition(WCK) increased greatly and reached the maximum value at 2 hr. However, the efflux level reverted to the background level within 48 hr. The cumulative CO2 effluxes in the soil ranged from 5.60 to 6.49 g C/m2over 48 hr after a single water application, thus showing an increase of approximately 148.64% and 48.36% in the effluxes during both observation periods. By contrast, the addition of different N levels without water addition did not result in a significant change in soil respiration in the short term. Two-way ANOVA showed that the effects of the interaction between water and N addition were insignificant in short-term soil CO2 effluxes in the soil. The cumulative soil CO2fluxes of different treatments over 48 hr accounted for approximately 5.34% to 6.91% and 2.36% to 2.93% of annual C emission in both experimental periods. These results stress the need for improving the sampling frequency after rainfall in future studies to ensure more accurate evaluation of the grassland C emission contribution.Yuchun Qi Xinchao Liu Yunshe Dong Qin Peng Yating He Liangjie Sun Junqiang Jia Congcong Cao 2014Journal of Environmental Sciences2014,26,4:17
5Litter decomposition and C and N dynamics as affected by N additions in a semi-arid temperate steppe, Inner Mongolia of China显示文摘Litter decomposition is the fundamental process in nutrient cycling and soil carbon(C) sequestration in terrestrial ecosystems. The global-wide increase in nitrogen(N) inputs is expected to alter litter decomposition and,ultimately, affect ecosystem C storage and nutrient status. Temperate grassland ecosystems in China are usually N-deficient and particularly sensitive to the changes in exogenous N additions. In this paper, we conducted a 1,200-day in situ experiment in a typical semi-arid temperate steppe in Inner Mongolia to investigate the litter decomposition as well as the dynamics of litter C and N concentrations under three N addition levels(low N with 50 kg N/(hm2?a)(LN), medium N with 100 kg N/(hm2?a)(MN), and high N with 200 kg N/(hm2?a)(HN)) and three N addition forms(ammonium-N-based with 100 kg N/(hm2?a) as ammonium sulfate(AS), nitrate-N-based with 100 kg N/(hm2?a) as sodium nitrate(SN), and mixed-N-based with 100 kg N/(hm2?a) as calcium ammonium nitrate(CAN)) compared to control with no N addition(CK). The results indicated that the litter mass remaining in all N treatments exhibited a similar decomposition pattern: fast decomposition within the initial 120 days, followed by a relatively slow decomposition in the remaining observation period(120–1,200 days). The decomposition pattern in each treatment was fitted well in two split-phase models, namely, a single exponential decay model in phase I(<398 days) and a linear decay function in phase II(≥398 days). The three N addition levels exerted insignificant effects on litter decomposition in the early stages(<398 days, phase I; P>0.05). However, MN and HN treatments inhibited litter mass loss after 398 and 746 days, respectively(P<0.05). AS and SN treatments exerted similar effects on litter mass remaining during the entire decomposition period(P>0.05). The effects of these two N addition forms differed greatly from those of CAN after 746 and 1,053 days, respectively(P<0.05). During the decomposition period, N concentrations in the decomposing litter increased whereas C concentrations decreased, which also led to an exponential decrease in litter C:N ratios in all treatments. No significant effects were induced by N addition levels and forms on litter C and N concentrations(P>0.05). Our results indicated that exogenous N additions could exhibit neutral or inhibitory effects on litter decomposition, and the inhibitory effects of N additions on litter decomposition in the final decay stages are not caused by the changes in the chemical qualities of the litter, such as endogenous N and C concentrations. These results will provide an important data basis for the simulation and prediction of C cycle processes in future N-deposition scenarios.Qin PENG YuChun QI YunShe DONG YaTing HE ShengSheng XIAO XinChao LIU LiangJie SUN JunQiang JIA ShuFang GUO CongCong CAO 2014Journal of Arid Land2014,6,4:16
6Effects of polyphyllin I on growth inhibition of human non-small lung cancer cells and in xenograft显示文摘Polyphyllin 我(PPI ) ,从巴黎 polyphyllin 的根茎提取的小分子的单体,在以前的学习显示出强壮的 anticancer 效果。人的肺腺癌 A549 房间,人的肺有鳞的房间癌 SK-MES-1 房间,和人的肺大房间癌 H460 房间与 PPI 有教养然后对待。房间增长和 apoptosis 被 3- 测量[4,5-dimethylthiazol-2-yl ]-2,5-diphenyltetrazolium 溴化物试金,流动 cytometry,西方的污点分析,和 DNA 梯子。Athymic 裸体老鼠适用肿瘤与 PPI 被注射,并且肿瘤生长被记录。我们的结果证明 PPI 显著地禁止了房间衬里的三非小的房间肺癌症(NSCLC ) 的增长,与为 A549, H460,和 SK-MES-1 的 1.24, 2.40,和 2.33 g/ml 的禁止的集中(IC50 ) 房间分别地。在为 24 h 与 PPI 的 2.5 g/ml 被对待以后, A549 房间的 apoptotic 率是 39.68% ,它比控制的显著地高。肿瘤生长显著地与在裸体老鼠与 cisplatin (DDP ) 或 PBS 对待的组相比在对待 PPI 的组被禁止。在在 vitro 并且在 vivo 的 NSCLC 房间的 PPI 展览 antitumor 能力,它可能与 apoptosis 有关由 PPI 导致了。Minjian Kong Junqiang Fan Aiqiang Dong Haifeng Cheng Rongzhen Xu 2010Acta Biochimica et Biophysica Sinica2010,42,11:15
7Decision-Making in Driver-Automation Shared Control:A Review and Perspectives显示文摘Shared control schemes allow a human driver to work with an automated driving agent in driver-vehicle systems while retaining the driver’s abilities to control.The human driver,as an essential agent in the driver-vehicle shared control systems,should be precisely modeled regarding their cognitive processes,control strategies,and decision-making processes.The interactive strategy design between drivers and automated driving agents brings an excellent challenge for human-centric driver assistance systems due to the inherent characteristics of humans.Many open-ended questions arise,such as what proper role of human drivers should act in a shared control scheme?How to make an intelligent decision capable of balancing the benefits of agents in shared control systems?Due to the advent of these attentions and questions,it is desirable to present a survey on the decision making between human drivers and highly automated vehicles,to understand their architectures,human driver modeling,and interaction strategies under the driver-vehicle shared schemes.Finally,we give a further discussion on the key future challenges and opportunities.They are likely to shape new potential research directions.Wenshuo Wang Xiaoxiang Na Dongpu Cao Jianwei Gong Junqiang Xi Yang Xing Fei-Yue Wang 2020IEEE/CAA Journal of Automatica Sinica2020,7,5:14
8Effects of a conversion from grassland to cropland on the different soil organic carbon fractions in Inner Mongolia, China显示文摘耕作是除放牧以外影响草地生态系统的最重要的人的活动之一,但是它土壤上的影响总计器官的碳(C) ,特别在有倾向的器官的 C 部分上还充分没被理解。在这份报纸,在土壤收割不同部分的器官的 C 水池的角色在中国,和在不同 C 部分之间的关系的内部蒙古在一个草地大草原区域被调查也被讨论。结果显示在大草原和栽培土地的不同 C 部分的集中都与土壤深度日益增多地减少了。在到为 36 年的春天小麦地的从大草原的变换以后,在 0~100 厘米土壤深度的全部的器官的碳( TOC )集中在12.3%~28.2%减少了,并且表面土壤地平线的 TOC ,特别那些更显著地 030 厘米减少了( p < 0.01 )。溶解的器官的碳(文档) 和在 040 厘米的深度的微生物引起的生物资源碳(MBC ) 被发现分别地在 66.7% ~ 77.1% 和 36.5% ~ 42.4% 减少了。在 S。baicalensis 大草原,春天小麦地里的到 TOC 的文档在 0.52% 和 0.60% 之间改变了的土壤的比率,和那些仅仅在 0.18%0.20% 的范围。在春天小麦的微生物引起的商(qMBs ) 回答,从 1.11% ~ 1.40% 变化,也是比在 S 的那些低的。baicalensis 大草原,它在 1.50%1.63% 的范围。文档的变化对耕作骚乱更敏感。土壤 TOC,文档,和 MBC 是显著地积极的在 S 与对方一起相关。baicalensis 大草原,但是在春天小麦地里,在文档之间的相互关系和在文档和 MBC 之间的 TOC 和那没到达 0.05 的意义水平。QI Yuchun DONG Yunshe PENG Qin XIAO Shengsheng HE Yating LIU Xinchao SUN Liangjie JIA Junqiang YANG Zhijie 2012Journal of Geographical Sciences2012,22,2:13
9Numerical analysis and optimization of boundary layer suction on airfoils显示文摘Numerical approach of hybrid laminar flow control(HLFC) is investigated for the suction hole with a width between 0.5 mm and 7 mm. The accuracy of Menter and Langtry's transition model applied for simulating the flow with boundary layer suction is validated. The experiment data are compared with the computational results. The solutions show that this transition model can predict the transition position with suction control accurately. A well designed laminar airfoil is selected in the present research. For suction control with a single hole, the physical mechanism of suction control, including the impact of suction coefficient and the width and position of the suction hole on control results, is analyzed. The single hole simulation results indicate that it is favorable for transition delay and drag reduction to increase the suction coefficient and set the hole position closer to the trailing edge properly. The modified radial basis function(RBF) neural network and the modified differential evolution algorithm are used to optimize the design for suction control with three holes. The design variables are suction coefficient, hole width, hole position and hole spacing. The optimization target is to obtain the minimum drag coefficient. After optimization,the transition delay can be up to 17% and the aerodynamic drag coefficient can decrease by 12.1%.Shi Yayun Bai Junqiang Hua Jun Yang Tihao 2015Chinese Journal of Aeronautics2015,28,2:12
10An analysis of soil composition and mechanical properties of riverbanks in a braided reach of the Lower Yellow River显示文摘The channel adjustment in a braided reach is very prominent in the fluvial processes of the Lower Yel-low River, in which the process of bank erosion plays an important role, especially during the period of clear water scouring. The process of bank erosion is closely related to soil composition and mechani-cal properties of the riverbanks. In this paper, the recent bank erosion process in a braided reach be-tween Huayuankou and Gaocun was firstly investigated after the water impoundment and sediment detention of the Xiaolangdi Reservoir, and then a field observation and indoor soil tests were con-ducted at 10 typical riverbanks in the braided reach. Through analyzing the experimental results, changes of riverbank-soil composition and mechanical properties were found, and the two real reasons causing serious bank erosion in the braided reach were identified. The following conclusions were drawn from this study: (i) the majority of riverbanks are made up of cohesive soil, and can be charac-terized by obvious vertical stratification structures of soil composition; (ii) these riverbanks are very erodible due to the lower clay-content and weak erosion-resistant strength in the bank soil, with its critical shear stress value (0.1―0.3 Pa) being much less than that of the average near-bank flow shear stress (2.0―3.0 Pa), which is one important reason causing serious bank erosion; (iii) frequent occur-rence of bank failure during flood seasons usually results from the fact that the values of shear strength parameters such as the cohesion and internal friction angle decrease with the increase of water content in riverbank soil, and the value of cohesion reduces drastically from 34 to 4 kPa with the increase of water content, which is another important reason causing serious bank erosion in the braided reach.XlA JunQiang WU BaoSheng WANG YanPing ZHAO ShouGang 2008Chinese Science Bulletin2008,53,15:11
11Stationary flow fields prediction of variable physical domain based on proper orthogonal decomposition and kriging surrogate model显示文摘In this paper a new flow field prediction method which is independent of the governing equations, is developed to predict stationary flow fields of variable physical domain. Predicted flow fields come from linear superposition of selected basis modes generated by proper orthogonal decomposition(POD). Instead of traditional projection methods, kriging surrogate model is used to calculate the superposition coefficients through building approximate function relationships between profile geometry parameters of physical domain and these coefficients. In this context,the problem which troubles the traditional POD-projection method due to viscosity and compressibility has been avoided in the whole process. Moreover, there are no constraints for the inner product form, so two forms of simple ones are applied to improving computational efficiency and cope with variable physical domain problem. An iterative algorithm is developed to determine how many basis modes ranking front should be used in the prediction. Testing results prove the feasibility of this new method for subsonic flow field, but also prove that it is not proper for transonic flow field because of the poor predicted shock waves.Qiu Yasong Bai Junqiang 2015Chinese Journal of Aeronautics2015,28,1:10
12Suppression of Type 1 Insulin-like Growth Factor Receptor Expression by Small Interfering RNA Inhibits A549 Human Lung Cancer Cell Invasion in vitro and Metastasis in Xenograft Nude Mice显示文摘癌症侵略和转移,包含许多病理学的过程和 cytophysiological 变化,贡献肺癌症的高死亡。类型 1insulin-like 生长因素受体(IGF-1R ) ,把前进和侵略与癌症联系了,是在肺癌症的一个潜在的反侵略和反转移目标。禁止肺癌症房间的侵略性质,我们在由小介入 RNA ( siRNA )技术的 A549 人的肺癌症房间的成功地下面调整的 IGF-1R 基因表达,并且评估了它的效果oninvasion相关的基因表达,在 vitro 侵略的肿瘤房间,并且在有为 IGF-1R 表示发卡 siRNA 的一个原生质标志的异种皮移植 nudemice.A549 房间 transfected 的转移在 mRNA 水平以及蛋白质 level.Inbiological 试金显示出一个显著地减少的 IGF-1R 表达式, transfected A549 房间显示出 cell-matrixadhesion ,移植和侵略的重要减小。与这些结果一致,我们发现那条下面规定大减小附随地在侵略相关的基因表达伴随的 ofIGR-1R , includingMMP-2 , MMP-9 , u-PA ,并且为 IGF-1R 的 plasmidexpressing 发卡 siRNA 的 IGF-1R 特定的下游的 p-Akt.Direct 尾巴静脉注射显著地在结果显示出的 nudemice.Our 禁止了肺转移的形成是的 siRNA 的治疗学的潜力为在禁止肺癌症侵略和转移的基因治疗的一个方法。Jianfang QIAN~1 Aiqiang DONG~1 Minjian KONG~1 Zhiyuan MA~2 Junqiang FAN~1 and Guanyu JIANG~3 ~1Department of Cardiothoracic Surgery,Second Affiliated Hospital,School of Medicine,Zhejiang University,Hangzhou 310009,China ~2Department of Cardiovascular Surgery,Shanghai Jiaotong University Affiliated First People’s Hospital,Shanghai 200080,China ~3Department of Emergency,Second Affiliated Hospital School of Medicine,Zhejiang University,Hangzhou 310009,China 2007Acta Biochimica et Biophysica Sinica2007,39,2:9
13Investigation of dielectric barrier discharge plasma flow control显示文摘Effects of plasma flow control are researched on the basis of plasma exciting flow experiments and numerical simulations. Turbulent model is more effective than laminar model in plasma numerical simulation as results showed. Both plasma exciting effects of acceleration and flow separation suppression are investigated through experiments carried on the flat plate and the compressor cascades. The results demonstrate that boundary layer characteristic is modified by plasma exciting. Distributions of total pressure and velocity in the wake are improved notably for 20 m/s coming velocity and the effect of plasma can still be observed while velocity is increased to 50 m/s. For low velocity flow, plasma exciting is effective in flow separation suppression.NIE ChaoQun LI Gang ZHU JunQiang ZHANG Yi LI YuTong 2008Science China(Technological Sciences)2008,51,7:9
14MODELING OF THE DIVERSION CHANNEL CLOSURE FOR THE THIRD STAGE OF THE THREE GORGES PROJECT显示文摘The closure of third stage diversion channel for the Three Gorges Dam is characterized by large closure discharge, large drop in water surface, and high gap velocity. 1D and 2D flow mathematical models were used in this paper to simulate the hydraulic conditions during the closure. The variation of discharge in the diversion channel and the drops in water surface shared by the upstream and downstream cofferdams were computed using the 1D model, and the detailed hydraulic patterns in the diversion channel were simulated using the 2D model. The computed results indicate that the designed closure scheme for discharge of 9,010 m3/s was feasible for construction, while the designed closure scheme for discharge of 12,200 m3/s was inapplicable.Guangqian WANG , Baosheng WU and Junqiang XIA Professor, Department of Hydraulic Engineering, Tsinghua University, Beijing 100084, China E-mail: dhhwgq@tsinghua.edu.cnAssociate Professor, Department of Hydraulic Engineering, Tsinghua University, Beijing 100084, China E-mail: baosheng@tsinghua.edu.cnAssistant Professor, Department of Hydraulic Engineering, Tsinghua University, Beijing 100084, China E-mail: xiajq@tsinghua.edu.cn 2004International Journal of Sediment Research2004,19,1:9
15Remaining useful life prognostics for aeroengine based on superstatistics and information fusion显示文摘Remaining useful life(RUL) prognostics is a fundamental premise to perform conditionbased maintenance(CBM) for a system subject to performance degradation. Over the past decades,research has been conducted in RUL prognostics for aeroengine. However, most of the prognostics technologies and methods simply base on single parameter, making it hard to demonstrate the specific characteristics of its degradation. To solve such problems, this paper proposes a novel approach to predict RUL by means of superstatistics and information fusion. The performance degradation evolution of the engine is modeled by fusing multiple monitoring parameters, which manifest non-stationary characteristics while degrading. With the obtained degradation curve,prognostics model can be established by state-space method, and then RUL can be estimated when the time-varying parameters of the model are predicted and updated through Kalman filtering algorithm. By this method, the non-stationary degradation of each parameter is represented, and multiple monitoring parameters are incorporated, both contributing to the final prognostics. A case study shows that this approach enables satisfactory prediction evolution and achieves a markedly better prognosis of RUL.Liu Junqiang Zhang Malan Zuo Hongfu Xie Jiwei 2014Chinese Journal of Aeronautics2014,27,5:8
16Transition study of 3D aerodynamic configures using improved transport equations modeling显示文摘As boundary layer transition plays an important role in aerodynamic drag prediction,the proposal and study of transition prediction methods simulating the complex flow phenomena are prerequisite for aerodynamic design. In this paper, with the application of the linear stability theory based on amplification factor transport transition equations on the two-equation shear stress transport(SST) eddy-viscosity model, a new method, the SST-N TS-N CF model, is yielded. The new amplification factor transport equation for the crossflow instability induced transition is proposed to add to the N TS equation proposed by Coder, which simulates Tollmien–Schlichting wave transition. The turbulent kinetic energy equation is modified by introducing a new source term that simulates the transition process without the intermittency factor equation. Finally, coupled with these two amplification factor transport equations and SST turbulence model, a four-equation transition turbulence model is built. Comparisons between predictions using the new model and wind-tunnel experiments of NACA64(2)A015, NLF(2)-0415 and ONERA-D infinite swept wing and ONERAM6 swept wing validate the predictive quality of the new SST-N_(TS)-N_(CF) model.Xu Jiakuan Bai Junqiang Zhang Yang Qiao Lei 2016Chinese Journal of Aeronautics2016,29,4:8
17Improved local amplification factor transport equation for stationary crossflow instability in subsonic and transonic flows显示文摘Transition prediction is a hot research topic of fluid mechanics.For subsonic and transonic aerodynamic flows,e^(N) method based on Linear Stability Theory(LST)is usually adopted reliably to predict transition.In 2013,Coder and Maughmer established a transport equation for Tollmien-Schlichting(T-S)instability so that the e^(N) method can be applied to general Reynolds-Average-Navier-Stokes(RANS)solvers conveniently.However,this equation focuses on T-S instability,and is invalid for crossflow instability induced transition which plays a crucial role in flow instability of three-dimensional boundary layers.Subsequently,a transport equation for crossflow instability was developed in 2016,which is restricted to wing-like geometries.Then,in 2019,this model was extended to arbitrarily shaped geometries based on local variables.However,there are too many tedious functions and parameters in this version,and it can only be used for incompressible flows.Hence,in this paper,after a large amount of LST analyses and parameter optimization,an improved version for subsonic and transonic boundary layers is built.The present improved model is more robust and more concise,and it can be applied widely in aeronautical flows,which has great engineering application value and significance.An extensive validation study for this improved transition model will be performed.Jiakuan XU Lei QIAO Junqiang BAI 2020Chinese Journal of Aeronautics2020,33,12:7
18Global aerodynamic design optimization based on data dimensionality reduction显示文摘In aerodynamic optimization, global optimization methods such as genetic algorithms are preferred in many cases because of their advantage on reaching global optimum. However,for complex problems in which large number of design variables are needed, the computational cost becomes prohibitive, and thus original global optimization strategies are required. To address this need, data dimensionality reduction method is combined with global optimization methods, thus forming a new global optimization system, aiming to improve the efficiency of conventional global optimization. The new optimization system involves applying Proper Orthogonal Decomposition(POD) in dimensionality reduction of design space while maintaining the generality of original design space. Besides, an acceleration approach for samples calculation in surrogate modeling is applied to reduce the computational time while providing sufficient accuracy. The optimizations of a transonic airfoil RAE2822 and the transonic wing ONERA M6 are performed to demonstrate the effectiveness of the proposed new optimization system. In both cases, we manage to reduce the number of design variables from 20 to 10 and from 42 to 20 respectively. The new design optimization system converges faster and it takes 1/3 of the total time of traditional optimization to converge to a better design, thus significantly reducing the overall optimization time and improving the efficiency of conventional global design optimization method.Yasong QIU Junqiang BAI Nan LIU Chen WANG 2018Chinese Journal of Aeronautics2018,31,4:7
19Effect of electroacupuncture on chemotherapy-induced peripheral neuropathy in patients with malignant tumor:a single-blinded,randomized controlled trial显示文摘OBJECTIVE:To evaluate the effect of electroacupuncture on chemotherapy-induced peripheral neuropathy(CIPN), quality of life and immune status of patients with malignant tumors.METHODS:From Jan, 2013 to May, 2014, 37 patients with malignant tumors were included in this prospective single-blinded study, and randomized to receive either electroacupuncture or acupuncture treatment on basis of chemotherapy.The chemotherapy was continued for 2 courses as previous before the treatments, with 21 days as a course of treatment.Patients received acupuncture and electroacupuncture once per day starting at the day before chemotherapy for consecutive 7 days followed by 14 days off, with 21 days as a course of treatment, and continued for two courses of treatment.Then CIPN, traditional Chinese clinical symptoms,quality of life and immune status were all evaluated for each patient prior treatment and after two courses of treatment.RESULTS:The gender, age, cancer species as well as incidence(83.3% vs 84.2%) and grades of CIPN before treatments were all similar in patients receiving acupuncture or electroacupuncture(all P >0.05).After treatments, most patients with peripheral neuropathy were cured by two courses of electroacupuncture(84.2% vs 21.1%), whereas the other group of patients had similar incidences of peripheral neuropathy compared with prior-acupuncture(83.3% vs 72.2%).Besides, patients receiving electroacupuncture had lower incidence of peripheral neuropathy than those receiving acupuncture treatment(χ~2= 9.745, P = 0.002).The grades of peripheral neuropathy were significantly different in the two groups post-treatment(χ~2= 13.983, P =0.007).The total effective rates for traditional Chinese clinical symptoms were 16.7% and 84.2% in acupuncture and electroacupuncture groups, respectively(Z =-4.239, P < 0.001).The electroacupuncture treatment provided a more satisfactory life for patients compared with acupuncture(Z =-4.76, P < 0.001).Both electroacupuncture and acupuncture had no effects on immune function.CONCLUSION:Electroacupuncture could alleviate CIPN, and improve traditional Chinese clinical symptoms and quality of life, but did not affect immune function.Zhang Shiqiang Wu Tingting Zhang Haisheng Yang Yun Jiang Haiyan Cao Shengcheng Xie Fang Xia Xiaoting Lü Junqiang Zhong Yi 2017Journal of Traditional Chinese Medicine2017,37,2:7
20Evaluation on data assimilation of a global high resolution wave-tide-circulation coupled model using the tropical Pacific TAO buoy observations显示文摘In order to evaluate the assimilation results from a global high resolution ocean model, the buoy observations from tropical atmosphere ocean(TAO) during August 2014 to July 2015 are employed. The horizontal resolution of wave-tide-circulation coupled ocean model developed by The First Institute of Oceanography(FIOCOM model) is 0.1°×0.1°, and ensemble adjustment Kalman filter is used to assimilate the sea surface temperature(SST), sea level anomaly(SLA) and Argo temperature/salinity profiles. The simulation results with and without data assimilation are examined. First, the overall statistic errors of model results are analyzed. The scatter diagrams of model simulations versus observations and corresponding error probability density distribution show that the errors of all the observed variables, including the temperature, isotherm depth of 20°C(D20), salinity and two horizontal component of velocity are reduced to some extent with a maximum improvement of 54% after assimilation. Second, time-averaged variables are used to investigate the horizontal and vertical structures of the model results. Owing to the data assimilation, the biases of the time-averaged distribution are reduced more than70% for the temperature and D20 especially in the eastern Pacific. The obvious improvement of D20 which represents the upper mixed layer depth indicates that the structure of the temperature after the data assimilation becomes more close to the reality and the vertical structure of the upper ocean becomes more reasonable. At last,the physical processes of time series are compared with observations. The time evolution processes of all variables after the data assimilation are more consistent with the observations. The temperature bias and RMSE of D20 are reduced by 76% and 56% respectively with the data assimilation. More events during this period are also reproduced after the data assimilation. Under the condition of strong 2014/2016 El Ni?o, the Equatorial Undercurrent(EUC) from the TAO is gradually increased during August to November in 2014, and followed by a decreasing process. Since the improvement of the structure in the upper ocean, these events of the EUC can be clearly found in the assimilation results. In conclusion, the data assimilation in this global high resolution model has successfully reduced the model biases and improved the structures of the upper ocean, and the physical processes in reality can be well produced.SHI Junqiang YIN Xunqiang SHU Qi XIAO Bin QIAO Fangli 2018Acta Oceanologica Sinica2018,37,3:7
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