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INSTABILITY OF GAS/LIQUID COAXIAL JET

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Journal of Hydrodynamics 2007年第5期19卷 542-550页

作者： LIU Kun sun de-jun YIN Xie-yuan department of Modem Mechanics University of Science and Technology of China Hefei 230026China

In this article the emphasis was given to the discussion of the effects of diameter ratio and swirling on instability character for the gas/liquid coaxial jet used by Liao, et al.[1], The results indicate that the finite diameter ratio markedly increases the maximum growth rate, the most unstable wavenumber, as well as the cutoff wavenumber. It implies that the finite diameter ratio will lead to the liquid jet breakup length shorter and the liquid drop size smaller. The effect of the swirling jets is much more complex： for the axisymmetric perturbation mode, the swirling enhances the flow stability, for helical perturbation, the dominant instability mode occurs at n〈0. And it is found that in long wave region there exists a new kind of instability modes at n=l that was not mentioned in Liao et al.＇s article. For this new mode, there appears a dominated swirling ratio at which the flow has the maximum growth rate.

关键词： gas/liquid coaxial jet instability character theeffects of diameter ratio and swirling ratio

THE OPTIMAL MOTION OF TWO-DIMENSIONAL UNDULATING PLATE SWIMMING IN FLUID FLOW

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Journal of Hydrodynamics 2011年第1期23卷 12-20页

作者： QIAN Qin-jian LIU Miao-qin sun Liang sun de-jun department of Modern Mechanics University of Science and Technology of China Hefei 230026 China School of Earth Sciences University of Science and Technology of China Hefei 230026 China

The optimum shape of a two-dimensional undulatory plate in its motion in fluid flow is analyzed and the physical parameters（the thrust and the power）are calculated by the boundary element *** the commonly used Lagrange multiplier method,only a saddle point of the optimum solution can be obtained,but not the solution itself due to the singularity of the *** eliminate the singularity,a method is proposed by adding an amplitude *** new method is a generalization of that proposed by Wu,and it can be applied to more complex *** optimum shape of the linearly varying amplitude motion is studied in *** is shown that both the maximum and the minimum solutions exist when the frequency is higher than a critical *** a high frequency,the maximum efficient motion with a large amplitude at the leading edge and a small amplitude at the trailing edge induces a large leading edge suction *** the frequency decreases,the leading edge suction force decreases to a minimum and then *** high wavenumbers,there exists an optimum frequency with the maximum *** efficiency holds over a large range of *** optimum efficiency increases as the wavenumber *** increase of the wavenumber can also reduce the leading edge suction *** optimization method can also be applied to a quadratically varying amplitude *** is found that the optimum efficiency is larger than that for the linearly varying amplitude ***,the additional efficiency is relatively small,especially as the original efficiency is already high enough.

关键词： two-dimensional undulating plate boundary element method optimization

Transient Growth of Perturbation Energy in the Taylor-Couette Problem with Radial Flow

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Chinese Physics Letters 2011年第5期28卷 176-179页

作者： CHEN Cheng GUO Zhi-Wei WANG Bo-Fu sun de-jun department of Modern Mechanics University of Science and Technology of ChinaHefei 230027

Transient growth of perturbation energy in the Taylor-Couette problem with radial flow is *** effects of radial flow on transient growth and structure of the optimal perturbation are mainly *** the wide gap case,strong radial flow,either inward or outward,shifts the peak of the amplitude of optimal perturbation towards the outer cylinder and the lift-up mechanism cannot be ***,for the narrow gap case,the optimal perturbation is almost unaffected by the radial flow and the lift-up mechanism still exists.

关键词： perturbation radial flow

Multiple Modes of Filament Flapping in a Uniform Flow

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Chinese Physics Letters 2012年第9期29卷 97-100页

作者： GAO Hao-Tian QIN Feng-Hua HUANG Wei-Xi sun de-jun department of Modern Mechanics University of Science and Technology of ChinaHefei 230026 department of Engineering Mechanics Tsinghua UniversityBeijing 100084

The instability of a flexible filament immersed in uniform flow is studied.A numerical simulation based on the immersed boundary method is conducted on a two-dimensional uniform flow past a flapping *** from the conventional bistability behavior,more regions of initial states of filament corresponding to different modes of motion are partitioned at each freestream velocity,and a new stable mode of motion with smaller flapping amplitude is *** selection highly depends on these initial states.

关键词： immersed Uniform partitioned

Pretreating and normalizing metabolomics data for statistical analysis

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Genes & Diseases 2024年第3期11卷 188-205页

作者： jun sun Yinglin Xia Division of Gastroenterology and Hepatology Department of MedicineDepartment of Microbiology/ImmunologyUIC Cancer CenterUniversity of Illinois ChicagoJesse Brown VA Medical Center Chicago(537)ChicagoIL 60612USA Division of Gastroenterology and Hepatology Department of MedicineUniversity of Illinois ChicagoChicagoIL 60612USA

Metabolomics as a research field and a set of techniques is to study the entire small molecules in biological *** is emerging as a powerful tool generally for pre-cision ***,integration of microbiome and metabolome has revealed the mechanism and functionality of microbiome in human health and ***,metabo-lomics data are very ***/pretreating and normalizing procedures on metabolomics data are usually required before statistical *** this review article,we comprehensively review various methods that are used to preprocess and pretreat metabolo-mics data,including MS-based data and NMR-based data preprocessing,dealing with zero and/or missing values and detecting outliers,data normalization,data centering and scaling,data *** discuss the advantages and limitations of each *** choice for a suitable preprocessing method is determined by the biological hypothesis,the characteristics of the data set,and the selected statistical data analysis *** then provide the perspective of their applications in the microbiome and metabolome research.

关键词： Data centering and scaling Data normalization Data transformation Missing values MS-Baseddata preprocessing NMRData preprocessing Outliers Preprocessing/pretreatment

Passivity-Based Stabilization for Switched Stochastic Nonlinear Systems

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IEEE/CAA Journal of Automatica Sinica 2024年第5期11卷 1307-1309页

作者： Yaowei sun jun Zhao School of Automation Zhengzhou University of AeronauticsZhengzhou 450046 Henan Key Laboratory of General Aviation Technology Zhengzhou University of AeronauticsZhengzhou 450046China College of Information Science and Engineering Northeastern UniversityShenyang 110819China

dear Editor,This letter addresses the passivity-based mean square exponential stabilization problem for switched stochastic nonlinear systems.A concept of generalized small-time norm-observability is presented and an appropriate test condition is also *** pre-given passivity rate and average dwell time,a set of feedback controllers is designed by use of the passivity property.

关键词： property letter stabilization

Metabolites and micronutrition in modulating amyotrophic lateral sclerosis

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Neural Regeneration Research 2024年第6期19卷 1183-1184页

作者： Katerina Claud jun sun department of Medicine University of Illinois Chicago Jesse Brown VA Medical Center Chicago

Amyotrophic lateral sclerosis(ALS) is a progressive neurodegenerative disease. The majority of ALS cases are sporadic with only about 20% of familial forms. Even in families with genetic predisposition, there is significant phenotypic variability, suggesting that ALS onset may be triggered by a combination of genetic factors, environmental factors(e.g., military service,

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Studies on Colloidal Properties of Mixed Metal Hydroxide－Clay Aqueous Suspension

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Chemical Research in Chinese Universities 1995年第4期11卷 316-322页

作者： NOU wan-guo ZHANG Chun-guang sun de-jun HAN Shu-hua and WANG Guo-ting(Institute of Colloid and Interface Chemistry,Shandong University,Jinan,250100) SHANDONG UNIV INST COLLOID & INTERFACE SCIJINAN 250100PEOPLES R CHINA

he electrical property,stability and rheological property of mixed metal hydroxide(MMH)-clay aqueous suspensions were studied via determining elec- trophoretic mobilities,heterocoagulation and rheological parameters. The suspen- sions of MMH-Na-montmorillonite and MMH-Kaolinite may be transformed from negatively charged systems into positively charged systems through changing the ratio of MMH to clav. The increase of MMH content makes the stability of dilute MMH-clay suspensions decreased in negatively chrged systems and increased in positively chrged systems. The complete coagulations at near neutral systems oc- curs. In the concentrated MMH-clay suspension,the steric network structures may be formed between MMH and clay particles,which cause the apparent viscosity(AV)and Bingham yield point(YP) of the suspentqion to increase. There is a suit- able ratio of MMH to clay at which the AV and YP of the suspension attain a maximum value,which in agreement with “bridging theory”of polymer flocculation.

关键词： Mixed metal hydroxide Clay Colloidal property Suspension

Characteristics of Hypertension death in Low-income Regions of Inner Mongolia, China

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Biomedical and Environmental Sciences 2020年第1期33卷 53-57页

作者： YU Di DU Mao Lin sun de jun QIAO Su Fang MA Yu Jia Wang Li GAO Yu Min CHEN Yong Sheng MENG Yong Liang sun Xiao Ling GUO Wen Fang WANG Qing Xia ZHANG Hai Rong LI Wu Yun Ta Na JIA Lei HAO Jing ZHAO Neng jun sun Juan Inner Mongolia Medical University Hohhot 010110Inner Mongolia Autonomous RegionChina Inner Mongolia People’s Hospital Hohhot 010017Inner Mongolia Autonomous RegionChina Xincheng District Hospital Hohhot 010010Inner Mongolia Autonomous RegionChina Inner Mongolia Normal University Hohhot 010022Inner Mongolia Autonomous RegionChina Inner Mongolia Autonomous Region Hospital of Traditional Chinese Medicine Hohhot 010020Inner Mongolia Autonomous RegionChina Affiliated People’s Hospital Inner Mongolia Medical UniversityHohhot 010050Inner Mongolia Autonomous RegionChina

Hypertension has been a major risk factor for cardiovascular disease[1].Hypertension overall prevalence in adults is 30%–45%,becoming>60%in people aged above 60 years[2],with a worldwide agestandardised prevalence of... 详细信息

关键词： Characteristics Hypertension death Low-income Regions Inner Mongolia China