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A novel complex network-based deep learning method for characterizing gas-liquid two-phase flow

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Petroleum Science 2021年第1期18卷 259-268页

作者： Zhong-Ke Gao ming-xu liu Wei-Dong Dang Qing Cai School of Electrical and Information Engineering Tianjin UniversityTianjin 300072TianjinChina

Gas-liquid two-phase flow widely exits in production and transportation of petroleum *** gas-liquid flow and measuring flow parameters represent challenges of great importance,which contribute to the recognition of flow regime and the optimal design of industrial *** this paper,we propose a novel complex network-based deep learning method for characterizing gas-liquid ***,we map the multichannel measurements to multiple limited penetrable visibility graphs(LPVGs)and obtain their degree sequences as the graph *** on the degree distribution,we analyze the complicated flow behavior under different flow ***,we design a dual-input convolutional neural network to fuse the raw signals and the graph representation of LPVGs for the classification of flow structures and measurement of gas void *** implement the model with two parallel branches with the same structure,each corresponding to one *** branch consists of a channel-projection convolutional part,a spatial-temporal convolutional part,a dense block and an attention *** outputs of the two branches are concatenated and fed into several full connected layers for the classification and *** last,our method achieves an accuracy of 95.3%for the classification of flow structures,and a mean squared error of 0.0038 and a mean absolute percent error of 6.3%for the measurement of gas void *** method provides a promising solution for characterizing gas-liquid flow and measuring flow parameters.

关键词： Gas-liquid flow Gas void fraction Flow structure Limited penetrable visibility graph Deep learning

A cross-layer approach to enable multipacket transmission in MIMO-SDMA based WLAN

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2009年第2期10卷 271-278页

作者： Sheng-bo CHEN Wei CHEN Wei-lan HUANG Li-jun ZHAI xu-ming liu Department of Electronic Engineering. Tsinghua University Beijing 100084 China Nokia Research Center Beijing 100176 China

We propose a medium access control(MAC) protocol for uplink transmissions in wireless local area networks(WLANs),where both stations and access points(APs) are equipped with multiple antennas. The protocol solves some common problems in utilizing multiple input multiple output(MIMO) under the 802.11 protocol,e.g.,how to deploy preamble(training sequence) used for channel estimation and how to enable simultaneous data transmissions,and facilitates two simultaneous uplink data transmissions via a cross-layer approach. Furthermore,we develop a 3D discrete-time Markov model to analyze the per-formance of the proposed WLAN scheme. The analytical results are verified by simulation,and numerical results show that the system throughput can be significantly improved by our proposed scheme as compared with conventional schemes.

关键词： Multiple input multiple output (MIMO) Medium access control (MAC) Cross-layer design

A review of thickness-induced evolutions of microstructure and superconducting performance of REBa2Cu3O7-δ coated conductor

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Advances in Manufacturing 2017年第2期5卷 165-176页

作者： Jian-Xin Lin xu-ming liu Chuan-Wei Cui Chuan-Yi Bai Yu-ming Lu Feng Fan Yan-Qun Guo Zhi-Yong liu Chuan-Bing Cai Shanghai Key Laboratory of High Temperature Superconductors Shanghai University Shanghai 200444People's Republic of China

The research and development of high temperature superconducting （HTS） films, especially ReBa2Cu3- O7-δ （REBCO or RE123; RE=Y, Gd, or other rare earths） yttrium-based coated conductors, has generated widespread interest for the potential applications of the second generation superconducting films. In view of commercialization, however, the maximum superconducting currents for coated conductors should be increased further. Unfortunately, it has been frequently observed that the average critical current density Jc decreases with an increase in film thickness. The thickness effect is still a hurdle for largescale production, especially in pulsed laser deposition and metal organic deposition processes. An engineering current of more than 1 000 A/cm is desired owing to the high cost of 2G superconducting materials. The present work attempts to review the evolution of various issues subject to the thickness effect, including the microstructure, epitaxial texture, surface roughness, pinning force, oxygen deficiency, residual stress, copper-rich layers, and segregation of elements. Furthermore, recent progress in enhancing the performance of superconductors especially in terms of critical current density is illustrated, such as the use of heavy doping. Further understanding of the thickness effect is extremely important for large-scale commercial development of the second generation high temperature superconductors.

关键词： Thickness effect Superconducting film Critical current density Microstructure Epitaxial texture Pinning force

High RF power tests of the first 1.3 GHz fundamental power coupler prototypes for the SHINE project

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Nuclear Science and Techniques 2022年第1期33卷 107-119页

作者： Zhen-Yu Ma Shen-Jie Zhao xu-ming liu Yue-Chao Yu Hong-Ru Jiang Xiang Zheng Qiang Chang Zi-Gang Zhang Kai xu Yan Wang Yu-Bin Zhao Hong-Tao Hou Shanghai Advanced Research Institute Chinese Academy of SciencesShanghai 201204China

The Shanghai High Repetition Rate XFEL and Extreme Light Facility(SHINE)project will use 6001.3 GHz fundamental power couplers,which are modified based on TTF-Ⅲ power couplers,for continuous-wave operation with input power up to approximately 7 *** first batch of 20 sets of 1.3 GHz coupler prototypes was fabricated from three domestic manufacturers for the SHINE *** better characterize the radio frequency conditioning phenomena for validating the performance of power couplers,a room temperature test stand was designed,constructed,and commissioned for the SHINE 1.3 GHz power *** addition,a horizontal test cryostat was built to test the 1.3 GHz superconducting cavities,fundamental power couplers,tuners,and other components as a *** results of these tests indicate that the 1.3 GHz couplers are capable of handling up to 14 kW continuous ***,the main aspects of the radio frequency design and construction of the test stand,along with the test results of the high-power conditioning of the 1.3 GHz couplers,are described.

关键词： Superconducting accelerating cryomodule 1.3 GHz fundamental power coupler RF conditioning Test bench Horizontal test cryostat

Agent- oriented Software Engineering

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Journal of Systems Science and Systems Engineering 2001年第1期13卷 44-49页

作者： GUAN xu, CHENG ming, liu Bao School of Management, Tianjin University, Tianjin 300072, China School of Management Tianjin University Tianjin 300072 China

：An increasing number of computer systems are being viewed in terms of autonomous *** people believe that agent-oriented approach is well suited to design and build complex systems. Yet. todate, little effort had been devoted to discuss the advantages of agent-oriented approach as a mainstreamsoftware engineering paradigm. Here both of this issues and the relation between object-oriented and agent-oriented will be argued. we describe an agent-oriented methodology and provide a quote for designing anauction system.

关键词： agent-oriented approach software engineering multi-agent systems

Operational Modal Analysis of a Ship Model in the Presence of Harmonic Excitation

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Journal of Marine Science and Application 2013年第1期12卷 38-44页

作者： Junchen xu ming Hong Xiaobing liu State Key Laboratory of Structural Analysis for Industrial Equipment Dalian University of Technology Dalian 116024 China

A ship is operated under an extremely complex environment, and waves and winds are assumed to be the stochastic excitations. Moreover, the propeller, host and mechanical equipment can also induce the harmonic responses. In order to reduce structural vibration, it is important to obtain the modal parameters information of a ship. However, the traditional modal parameter identification methods are not suitable since the excitation information is difficult to obtain. Natural excitation technique-eigensystem realization algorithm （NExT-ERA） is an operational modal identification method which abstracts modal parameters only from the response signals, and it is based on the assumption that the input to the structure is pure white noise. Hence, it is necessary to study the influence of harmonic excitations while applying the NExT-ERA method to a ship structure. The results of this research paper indicate the practical experiences under ambient excitation, ship model experiments were successfully done in the modal parameters identification only when the harmonic frequencies were not too close to the modal frequencies.

关键词： natural excitation technique (NExT) eigensystem realization algorithm (ERA) ship structure harmonic excitation signal processing modal parameters identification ship model operational model analysis

Surgery for left ventricular aneurysm after myocardial infarction： techniques selection and results assessment

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Chinese Medical Journal 2012年第24期125卷 4373-4379页

作者： CHEN Xin QIU Zhi-bing xu ming liu Le-le JIANG Ying-shuo WANG Li-ming Department of Thoracic & Cardiovascular Surgery Nanjing First Hospital Nanjing Medical University Nanjing Heart Institute Nanjing Jiangsu 210006 China

Background The most appropriate surgical approach for patients with post-infarction left ventricular （LV） aneurysm remains undetermined. We compared the efficacy of the linear versus patch repair techniques, and investigated the mid-term changes of LV geometry and cardiac function, for repair of LV aneurysms. Methods We reviewed the records of 194 patients who had surgery for a post-infarction LV aneurysm between 1998 and 2010. Short-term and mid-term outcomes, including complications, cardiac function and mortality, were assessed. LV end-diastolic and systolic dimensions （LVEDD and LVESD）, LV end-diastolic and end-systolic volume indexes （LVEDVI and LVESVI） and LV ejection fraction （LVEF） were measured on pre-operative and follow-up echocardiography. Results Overall in-hospital mortality was 4.12%, and major morbidity showed no significant differences between the two groups. Multivariate analysis identified preoperative left ventricular end diastolic pressure 〉20 mmHg, low cardiac output and aortic clamping time 〉2 hours as risk factors for early mortality. Follow-up revealed that LVEF improved from 37% pre-operation to 45% 12 months post-operation in the patch group （P=0.008）, and from 44% pre-operation to 40% 12 months postoperation in the linear group （P=0.032）. In contrast, the LVEDVI and LVESVI in the linear group were significantly reduced immediately after the operation, and increased again at follow-up. However, in the patch group, the LVEDVI and LVESVI were significantly reduced at follow-up. And there were significant differences in the correct value changes of LVEF and left ventricular remodeling between linear repair and patch groups. Conclusions Persistent reduction of LV dimensions after the patch repair procedure seems to be a procedure-related problem. The choice of the technique should be tailored on an individual basis and surgeon＇s preference. The patch remodeling technique results in a better LVEF improvement, further significant reductions in L

关键词： left ventricular aneurysm post-infarction linear repair patch remodeling left ventricular remodeling

The Genetic Diversity and Phylogenetic Status of Luxi Cattle

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Agricultural Sciences in China 2006年第8期5卷 629-634页

作者： MAO Yong-jiang CHANG Hong YANG Zhang-ping xu ming ZHANG liu CHANG Guo-bin SONG Wei- tao WANG Dong-lei Animal Science and Technology College Yangzhou University Yangzhou 225009 P.R.China

A total of 87 individuals of Luxi cattle from Juanchen and Liangshan counties, Shangdong Province, China, were sampled by simple random sampling in typical colony. Twenty-one blood proteins and enzymes loci were detected by polyacrylamide gel electrophoresis （PAGE） and starch gel electrophoresis （SGE）. In the meantime, the data of 7 loci of 13 cattle populations in China and other countries were collected and phylogeny relationships were studied. The results indicated that 9 out of 21 loci showed polymorphism （42.86%）; the level of genetic variation in Luxi cattle population was relatively high, the mean heterozygosity was 0.1416. The Luxi cattle have a close phylogenetic relationship with the cattle populations of east and south of Asia, and this further confirmed the fact that Luxi cattle were the cross-breed between the Bos taurus and Bos indicus in China, but it is impossible that yellow cattle contained the blood of of Bali.

关键词： Luxi cattle genetic diversity cluster analysis

Effect of salvianolic acid B on Smad3 expression in hepatic stellate cells

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Hepatobiliary & Pancreatic Diseases International 2004年第1期3卷 102-105页

作者： Jun-Fang Zhao, Cheng-Hai liu, Yi-Yang Hu, Lie-ming xu, Ping liu and Cheng liu Shanghai, China Institute of Liver Diseases, Shanghai University of Tra- ditional Chinese Medicine, Shanghai 200023 , China Institute of Liver Diseases Shanghai University of Traditional Chinese Medicine Shanghai 200023 China.

BACKGROUND: Salvianolic acid B (SA-B), one of water soluble compounds derived from Radix salviae miltiorrhizae, had good action against liver fibrosis of patients with chro- nic hepatitis. Hepatic stellate cells (HSCs) is the cellular re- source for liver fibrogenesis, while transforming growth factor-β1 (TGF-β1) is most potent fibrogenic factor. In this study we investigated the mechanism of SA-B action against liver fibrosis relating to the interference with TGF- β1 signaling at HSC. METHODS: Hepatic stellate cells (HSCs) were isolated, cultured, and incubated with SA-B. The TGF-β1 content in the supernatant of subcultured HSCs was assayed with ELISA. Type I collagen and Smad3 protein in TGF-β1-sti- mulated primarily cultured HSCs for 4 days were detected by Western blot. RESULTS: TGF-β1 secreted in activated HSCs was more than in primary HSCs, and SA-B significantly decreased TGF-β1 secretion in activated HSCs. TGF-β1 increased the expression of type I collagen and Smad3 protein in d4 pri- mary HSCs, while SA-B inhibited their expression. CONCLUSIONS: SA-B inhibits TGF-β1 secretion in activa- ted HSCs and counteracts the expression of TGF-β1 stimu- lated type I collagen and Smad3. These actions are associat- ed with the effect of SA-B on liver fibrosis.

关键词： salvianolic acid B liver fibrosis transforming growth factor-β Smads