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| 1 | Analysis of pressure characteristics under laminar and turbulent flow states inside the pilot stage of a deflection flapper servo-valve:Mathematical modeling with CFD study and experimental validation显示文摘Electro-hydraulic servo-valves are widely used components in the mechanical industry,aerospace and aerodynamic devices which precisely control the airplane or missile wings.Due to the small size and complex structure in the pilot stage of deflection flapper servo-valves,accurate mathematical models for the flow and pressure characteristics have always been very difficult to be built.In this paper,mathematical models for the pilot stage of deflection flapper servo-valve are investigated to overcome some gaps between the theoretical formulation and overall performance of the valve by considering different flow states.Here,a mathematical model of the velocity distribution at the flapper groove exit is established by using Schlichting velocity equations for incompressible laminar fluid flow.Moreover,when the flow becomes turbulent,a mathematical model of pressure characteristics in the receiving ports is built on the basis of the assumption of the collision between the liquid and the jet as the impact of the jet on a moving block of fluid particles.To verify the analytical models for both laminar and turbulent flows,the pressure characteristics of the deflection flapper pilot stage are calculated and tested by using numerical simulation and experiment.Experimental verification of the theory is also presented.The computed numerical and analytical results show a good agreement with experimental data. | Bijan Krishna SAHA Songjing LI Xinbei LV | 2020 | Chinese Journal of Aeronautics2020，33，3： | 6 |
| 2 | Thermodynamic Characteristic Study of a High-temperature Flow-rate Control Valve for Fuel Supply of Scramjet Engines显示文摘Thermodynamic characteristics are of great importance for the performance of a high-temperature flow-rate control valve,as high-temperature environment may bring problems,such as blocking of spool and increasing of leakage,to the valve.In this paper,a high-temperature flow-rate control valve,pilot-controlled by a pneumatic servo system is developed to control the fuel supply for scramjet engines.After introducing the construction and working principle,the thermodynamic mathematical models of the valve are built based on the heat transfer methods inside the valve.By using different boundary conditions,different methods of simulations are carried out and compared.The steady-state and transient temperature field distribution inside the valve body are predicted and temperatures at five interested points are measured.By comparing the simulation and experimental results,a reasonable 3D finite element analysis method is suggested to predict the thermodynamic characteristics of the high-temperature flow-rate control valve. | ZENG Wen TONG Zhizhong LI Songjing LI Hongzhou ZHANG Liang | 2012 | Chinese Journal of Aeronautics2012，25，4： | 6 |
| 3 | Vascular endothelial growth factor expression and significance in different grades of the Breast Imaging Reporting and Data System显示文摘Objective Mammography is the only modality proven to reduce mortality in breast cancer,and ultrasonography is a well-known adjunct to mammography screening.The Breast Imaging Reporting and Data System(BI-RADS) classification is a practical tool and is correlated with histopathology and combined use with triple assessment(examination,imaging,and biopsy) of palpable diagnostic cases.This study aimed to investigate the relationship between vascular endothelial growth factor(VEGF) expression and different grades of BI-RADS in breast cancer.Methods Ninety-six patients with breast carcinoma were evaluated using BI-RADS by ultrasonography,mammography,and a combination of both modalities.In the combined imaging assessment,BI-RADS 1-4a grade was considered when the score of ultrasonography and mammography was lower than 4a,and BI-RADS 4b-5a grade was considered when the score of ultrasonography and mammography was higher than 4a.Immunohistochemical Ultra SensitiveTM S-P method was employed to evaluate the expression of VEGF in 96 patients.Fifty patients with benign breast disease were selected as the control group.The relationship between VEGF expression and different grades of BI-RADS and that between VEGF expression and other standard prognostic parameters associated with invasive breast cancer,such as size,grade,cancer stage,and metastasis were analyzed.Results The sensitivities of ultrasonography and mammography alone was 74.0% and 84.4%,respectively;However,the sensitivity of their combination increased to 90.6%.The positive rates of VEGF in invasive breast cancer BI-RADS 4b-5(59/87,67.8%) were higher than those in BI-RADS 4a(3/9,33.3%,P<0.05) and benign breast disease tissues(BI-RADS 1-4a,11/50,22.0%)(P<0.05).There was a positive correlation between VEGF overexpression and BI-RADS 4b-5,histological grade(Ⅲ),lymph node metastasis,and distant metastasis of invasive breast cancer.VEGF expression was not related to the age and size of the tumor in each group(P>0.05).Conclusion There was a positive correlation between VEGF overexpression and BI-RADS 4b-5 grade.The overexpression of VEGF might be an important biological marker for the invasion and metastasis of breast cancer. | Gangping Wang Jingjing Li Shuguang Yang Zuofeng Zhang Songjing Lei | 2019 | Oncology and Translational Medicine2019，5，6： | 1 |
| 4 | Adenovirus-mediated HSV-TK gene therapy using the human telomerase promoter induced apoptosis of small cell lung cancer cell line显示文摘 | SongJS Kim HP | 2004 | Oncol Rep2004，12，2： | 1 |
| 5 | Self-assemb- ling molecular trees containing octa-p-phenylene: from nanocrystals to nanocapsules显示文摘 | Yoo Y S ChoiJ H SongJ H | 2004 | J Am Chem Soc2004，126，： | 1 |
| 6 | Compensatory base changes in ITS2 secondary structures correlate with the biological species concept despite intragenomic variability in ITS2 sequences- A proof of concept显示文摘 | WOLF M CHEN S L SONGJ Y | 2013 | P LoS One2013，8，66： | 1 |
| 7 | suicide gene therapy using the human telomerase catalytic subunit (hTERT) gene promoter induced apoptosis of ovarian cancer cell line显示文摘 | SongJS Kim HP Yoon WS | 2003 | Biosci Biotechnol Biochem2003，67，11： | 1 |
| 8 | BrainexpressionofCrerecombinasedrivenbypancreasspecificpromoters显示文摘 | SongJ XuY HuX ChoiB TongQ | 2010 | Genesis2010，48，62： | 1 |
| 9 | The crystal structure of the Argonaute2 PAZ domain reveals an RNA binding motif in RNAi effector complexes显示文摘 | SongJ J Liu J Tolia N H | 2003 | Nat Struct Biol2003，10，12： | 1 |
| 10 | High-accuracy de novo assembly and SNP detection of chloroplast genomes using a SMRT circular consensus sequencing strategy显示文摘 | LI Q H LI Y SONGJ Y | 2014 | New Phytologist2014，204，4： | 1 |
| 11 | Adenovirus-mediated HSV-TK geneherapy using the human telomerase promoter induced apoptosis of small cell lung cancer cell line显示文摘 | SongJS Kim HP | 2004 | Oncol Rep2004，12，2： | 1 |
| 12 | Dual-energy Computed Tomography Characterization of Solitary Pulmonary Nodules显示文摘 | Chae SongJ W Krauss B | 2010 | J Thorac Imaging2010，25，4： | 1 |
| 13 | Clinical utility of dual-energy CT in the evaluation of solitary pulmonary nodules: initial experience显示文摘 | Chae SongJ W SeoJB | 2008 | Radiology2008，249，2： | 1 |
| 14 | Piezoelectric mnagenerators based on zinc oxide nanowire arrays显示文摘 | Wag Z L SongJ H | 2006 | Science2006，312，： | 1 |
| 15 | The effects of obstructive jaundice on the pharmacodynamics of propofol: does the sensitivity of intravenous anesthetics change among icteric patients? 显示文摘 | SONGJ C ZHANG M Z LU Z J | 2009 | Acta Anaesthesiol Seand2009，53，10： | 1 |
| 16 | Electroresponsive Behavior of 2- Hydroxypropyltrimethyl Ammonium Chloride Chitosan Hydrogel Under DC Electric Field显示文摘 | SongJ Lin G Yang S | 2010 | Journal of Macromolecular Science Part A2010，48，2： | 1 |
| 17 | Foil gas bearing with compression springs: analyses and experiments显示文摘 | SongJ Kim D | 2007 | Journal of Tribology Transactions of the ASME2007，129，3： | 1 |
| 18 | A Numerical Study of Cavitation Phenomenon in a Flappernozzle Pilot Stage of an Electrohydraulic Servovalve with an Innovative Flapper Shape显示文摘 | AUNG N LI Songjing | 2014 | Energy Conversion and Management2014，77，1： | 1 |
| 19 | Terpenoid mosquito repellents: A combined DFT and QSAR study显示文摘 | SONGJ WANG Z FIND LATERA et at | 2013 | Bioorg Med Chem Lett2013，23，5： | 1 |
| 20 | Experimental and Numerical Investigation of Cavitation Phenomenon in Flappernozzle Pilot Stage of an Electrohydraulic Servovalve显示文摘 | LI Songjing AUNG N ZHANG Shengzhuo | 2013 | Computers & Fluids2013，88，12： | 1 |
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