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Flow field reconstruction and shock train leading edge position detection of scramjet isolation section based on a small amount of CFD data

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Advances in Aerodynamics 2022年第1期4卷 599-613页

作者： Hao Chen Ye Tian Mingming Guo Jialing le Yuan Ji Yi Zhang Hua Zhang Chenlin Zhang Southwest University of Science and Technology Mianyang621000China China Aerodynamics Research and Development Center Mianyang621000China Shanghai Jiao Tong University Shanghai200240China Shenyang Aircraft Design and Research Institute Shenyang110035China

Scramjet is the main power device of hypersonic vehicles. With the gradual expansion of wide velocity domain, shock wave/shock wave and shock wave/boundary layer are the main phenomena in scramjet isolator. When the leading edge of the shock train is pushed out from the inlet of the isolator, the engine will not start. Therefore, it is very important to detect the flow field structure in the isolator and the leading edge position of the shock train. The traditional shock train detection methods have low detection accuracy and slow detection speed. this paper describes a method based on deep learning to reconstruct the flow field in the isolator and detect the leading edge of the shock train. Under various back pressure conditions, the flow field images of computational fluid dynamics (CFD) data and the corresponding upper and lower wall pressure data were obtained, and a data set corresponding to pressure and flow field was constructed. By constructing and training convolutional neural networks, a mapping model with pressure information as input and flow field image as output is obtained, and then the leading edge position of shock train is detected on the output flow field image. The experimental results show that the average structure similarity (SSIM) between the reconstructed flow field image and the CFD flow field image is 0.902, the average peak signal-to-noise ratio (PSNR) is 25.289, the average correlation coefficient (CORR) is 0.956, and the root mean square error of shock train leading edge detection is 3.28 mm. Moreover, if the total pressure input is appropriately reduced, the accuracy of flow field reconstruction does not decline significantly, which means that the model has a certain robustness. Finally, in order to improve the detection accuracy of the leading edge position, we fine tuned the model and obtained another detection method, which reduced the root mean square error of the detection results to 1.87 mm.

关键词： Scramjet Shock train CFD Convolutional neural network Reconstruction

Yangzhou Uses Food as Medium for Foreign Communication

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Voice of Friendship 2016年第2期 53-56页

作者： Yang le

Huaiyang cuisine,regarded by many as the best food in southeastern China,is one of the four major traditional Chinese *** the 2,500th anniversary of the founding of the city of Yangzhou,Jiangsu province,the World Association of Chinese Cuisine named it an International Gourmet Food *** years,Yangzhou has served foreign communications along

关键词： southeastern Medium Jiangsu founding municipal ceremony distinguished president chairman ASEAN

Difference Equation for N-body Type Problem

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Communications in Mathematical Research 2009年第5期25卷 411-417页

作者： Xu le-SHUN HAN YUE-CAI LIU BAI-FENG College of Mathematics and Computer Science Nanjing Normal University Nanjing 210097 Department of Applied Mathematics Northwest A ＆ F University Yangling Shanxi 712100 School of Mathematics Jilin University Changchun 130012 Department of Mathematics and Information Science Shandong Institute

In this paper, the difference equation for N-body type problem is established, which can be used to find the generalized solutions by computing the critical points numerically. And its validity is testified by an exam... 详细信息

关键词： Difference equation N-bodytype problem critical point

Research on ＂intelligent＂ old-age Road

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International English Education Research 2018年第4期 81-83页

作者： ZHANG le Shanghai University of Engineering Science songjiang district of Shanghaichina

The wisdom of the aged has become a direction that can＇t be ignored in the development of the old-age industry. It can be combined with traditional home care, institutional pension and community pension, and can improve the efficiency of these old-age models, and can also connect the transformation of old-age service and medical service to the combination of medical support, and there are many advantages. this article will analyze the realization basis of intelligent endowment, the advantages and disadvantages of intelligent endowment, and explore how to effectively promote the development of intelligent pension industry.

关键词： the organizational efficiency of the intelligent pension model

Origin of the Ecological Crisis:Common Meaning behind "Four-cause Theory"

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Meteorological and Environmental Research 2013年第11期4卷 25-27,31页

作者： le Zhang School of Philosophy and Sociology Beijing Normal University

At present, the increasingly severe ecological problem disperses in the world, showing the sign of crisis everywhere. There are many factors leading global ecological crisis, such as dominant idea, population overload, excess consumption and technology alienation. However, vari- ous reasons commonly point toward the capital logic actually. Society controlled under the capital pursuits surplus value and profit growth blindly, ig- nores the nature law and environmental justice, which is the archcriminal leading ecological collapse. Therefore, only abandoning the capital logic, stipulating the economic rationality, we can eliminate environmental woes gradually, thus ultimately achieving harmony and common prosperity of man and nature.

关键词： Ecological crisis "Four-cause theory" Capital logic China

Wang Xiaoling and the Winglaiyuen Brand

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China Today 2014年第2期63卷 56-59页

作者： XIE le

SINCE its establishment in 1947, the Winglaiyuen restaurant has become a well-known Hong Kong brand with an international reputation. Its development and expansion is largely due to one woman’s single-minded *** is Wang Xiaoling."Running a successful restaurant is lucrative, but also hard work, because it demands whole-hearted devotion. Many brands

关键词：中国经济建设经济发展国民收入幸福指数

Clinical significance of melatonin concentrations in predicting the severity of acute pancreatitis

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World Journal of Gastroenterology 2013年第25期19卷 4066-4071页

作者： Yin Jin Chun-Jing Lin le-Mei Dong Meng-Jun Chen Qiong Zhou Jian-Sheng Wu Department of Gastroenterology First Affiliated Hospital of Wenzhou Medical College

AIM: To assess the value of plasma melatonin in predicting acute pancreatitis when combined with the acute physiology and chronic health evaluation?II?(APACHEII) and bedside index for severity in acute pancreatitis (BISAP) scoring systems.METHODS: APACHEII and BISAP scores were calculated for 55 patients with acute physiology (AP) in the first 24 h of admission to the hospital. Additionally, morning (6:00 AM) serum melatonin concentrations were measured on the first day after admission. According to the diagnosis and treatment guidelines for acute pancreatitis in China, 42 patients suffered mild AP (MAP). The other 13 patients developed severe AP (SAP). A total of 45 healthy volunteers were used in this study as controls. The ability of melatonin and the APACHEII and BISAP scoring systems to predict SAP was evaluated using a receiver operating characteristic (ROC) curve. The optimal melatonin cutoff concentration for SAP patients, based on the ROC curve, was used to classify the patients into either a high concentration group (34 cases) or a low concentration group (21 cases). Differences in the incidence of high scores, according to the APACHEII and BISAP scoring systems, were compared between the two groups.RESULTS: The MAP patients had increased melatonin levels compared to the SAP (38.34 ng/L vs 26.77 ng/L) (P = 0.021) and control patients (38.34 ng/L vs 30.73 ng/L) (P = 0.003). There was no significant difference inmelatoninconcentrations between the SAP group and the control group. The accuracy of determining SAP based on the melatonin level, the APACHEII score and the BISAP score was 0.758, 0.872, and 0.906, respectively, according to the ROC curve. A melatonin concentration ≤ 28.74 ng/L was associated with an increased risk of developing SAP. The incidence of high scores (≥ 3) using the BISAP system was significantly higher in patients with low melatonin concentration (≤ 28.74 ng/L) compared to patients with high melatonin concentration (> 28.74 ng/L) (4

关键词： Pancreatitis Melatonin concentrations Predict Cutoff Bedside index for severity in acute pancreatitis Acute physiology and chronic health evaluation?II

Optimization of aero-engine combustion chambers with the assistance of Hierarchical-Kriging surrogate model based on POD downscaling method

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Advances in Aerodynamics 2023年第1期5卷 403-427页

作者： Shuhong Tong Yue Ma Mingming Guo Ye Tian Wenyan Song Heng Wang Jialing le Hua Zhang Southwest University of Science and Technology Mianyang 621000China China Aerodynamics Research and Development Center Mianyang 621000China Northwestern Polytechnical University Xi’an 710072China

In view of the long calculation cycle,high processing test and cost of the traditional aero-engine combustion chamber design process,which restricts the engine optimization design cycle,this paper innovatively proposes a surrogate model for the performance of aero-engine combustion chambers based on the POD-Hierarchical-Kriging *** experiments,the predicted results of the POD-Hierarchical-Kriging model are compared and analyzed with the calculated results of the one-dimensional program,and the root mean square error of the predicted values of combustion efficiency and total pressure loss is 0.0064%and 0.1995%,*** accuracy of the POD-Hierarchical-Kriging model is compared with the cubic polynomial model,the basic Kriging model and the Hierarchical-Kriging *** verifies the feasibility and accuracy of the POD-Hierarchical-Kriging model for the prediction of performance of aero-engine combustion *** global sensitivity analysis method is applied to obtain the influence effect of design variables on the ***,a multi-objective optimization method based on the NSGA-II algorithm is studied,and finally the optimal set of Pareto solutions is obtained and analyzed,which can be used to guide the optimal design of aero-engine combustion chambers and accelerate the progress of aero-engine development.

关键词： Aero-engine combustion chamber Surrogate model POD-Hierarchical-Kriging Multi-objective optimization

Results of Testing Maize Hybrids on Lands Shifting from Rice-Growing Areas of less Efficiency in the Mekong Delta

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Journal of Agricultural Science and Technology(B) 2015年第4期5卷 241-246页

作者： le Quy Kha Institute of Agricultural Sciences for Southern Vietnam 121 Nguyen Binh Khiem Street District 1 Ho Chi Minh City Vietnam

Forecasters predict that by 2020 there will be 4.5 or 5 million tons per annum maize supply deficiency in Vietnam. As a result of this projection, the government responded by shifting 80,000 ha of low-efficiency rice production areas into maize production （2014-2015） and this area of production for maize is expected to increase to 150,000 ha by 2016-2020. Nevertheless, not all commercial maize hybrids could be suitable for rice-growing land in the Mekong Delta and a national project of hybrid maize development for Mekong Delta has been conducted since early 2014. In the project, yield trials of 20 maize hybrids, sourced from Vietnamese institutions and the private sector including Syngenta （NK67） and Dekalb （DK9901）, were sown in Dong Thap, Hau Giang and Long An provinces situated in the Mekong Delta, in minor acid sulphate soils with a pH of 5.0-5.5. The trial included three replications in an Alpha lattice design conducted during spring-summer in 2014. The hybrids flowered at 50-52 d after planting and physiologically matured between 93-97 d after planting. this suggested they would be suitable for cropping systems, which was comprised of three seasons per year. To determine which hybrid is best suited for the region, researchers evaluated yield and ear characteristics. The average yield of the genotypes across locations was 52.03, 54.92 and 57.60 quintals/ha, respectively, and the heritability of genotypes in each location was 0.51, 0.81 and 0.61, respectively. The mean yield of DK9901 was 58.19 quintals/ha, ranking the 7th among 20 hybrids, and NK67 was 47.58 quintals/ha, ranking the 19th. The grand mean was 54.92 quintals/ha and heritability for all genotypes was 0.79. The highest yield was produced by the Southern seed company hybrid SSC474 （69.39 quintals/ha）, which yielded significantly more maize than DK9901 （58.19 quintals/ha） at P 〈 0.05, followed by VS71 from National Maize Research Institute （NMRI） at 63.52 quintals/ha, and LCH9A from NMRI at 63.39 quin

关键词： Maize (Zea mays L.) hybrid Mekong Delta rice-growing land yield trials.