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System Identification of Controlled Pulse Keyhole Plasma Arc Welding Process

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Chinese Journal of Mechanical Engineering 2012年第6期25卷 1274-1280页

作者： JIA Chuanbao DU Yongpeng GUO Ning WANG Fang HAN Yanfei Shandong Provincial Key Laboratory of Special Welding Technology Institute of Oceanographic InstrumentationShandong Academy of SciencesQingdao 266001China

The development of closed-loop control systems is one of the most effective ways to improve the stability of the keyhole status during keyhole plasma arc welding （K-PAW）. Due to the disadvantages of the ＂one-pulse-one-keyhole＂ technology based on the conventional square current waveform, the controlled pulse welding current waveform is newly applied to control the keyhole open and close periodically. In order to realize the real-time control on the keyhole behavior with this advanced current waveform, welding experiments and system identification are conducted based on the classical control theory. One complete welding cycle can be divided into 3 periods. The keyhole establishing time is the most important time variable, which determines the keyhole behavior and welding process stability. At the same time, the averaged effiux plasma arc voltage during one pulse cycle can reflect the real keyhole dimension and status in a real-time manner. Therefore, two single-input-single-output （SISO） systems are proposed, in which keyhole establishing time and keyhole average dimension are taken as the system controlled variables respectively. Welding experiments are designed with the peak current varying randomly. Experiments show that the keyhole establishing time changes in an opposite direction to the varied peak current, and the averaged efflux plasma arc voltage varies with the same trend as the peak current. Based on the least squares technique and F test of classical system identification, second order difference equation for keyhole establishing time/peak current system and first order difference equation for keyhole average dimension/peak current system are obtained. It is proved that the calculated data by the two mathematical expressions are well matched with the measured data. The proposed research provides mathematical expressions and theoretical analysis to develop closed-loop systems for the controlled pulse K-PAW.

关键词： controlled pulse plasma arc welding keyhole system identification control

Current situation and trend of marine data buoy and monitoring network technology of China

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Acta Oceanologica Sinica 2016年第2期35卷 1-10页

作者： WANG Juncheng WANG Zhongqiu WANG Yiming LIU Shixuan LI Yunzhou Shandong Provincial Key Laboratory of Ocean Environment Monitoring Technology Qingdao 266001 China Institute of Oceanographic Instrumentation Shandong Academy of Science Qingdao 266001 China The First Institute of Oceanography State Oceanic Administrtion Qingdao 266061 China

Marine data buoy can provide a long-term, continuous, real-time, reliable data of ocean observation in a variety of complex marine environment. It is one of the most reliable, most effective and important means of ocean monitoring technology. In this paper, the classification, main theory and technology system of marine data buoy are summarized. The typical technological breakthrough of the development of marine data buoy in recent years is summarized. The composition and application of marine monitoring network in China was introduced, and the gap between the technology of China＇s marine data buoy and the international advanced countries is *** on the situation and demand of China＇s current situation and needs, the development trend of marine data buoy and buoy monitoring network are expected.

关键词： marine monitoring buoy marine observation monitoring network current situation and trend

Gonadal dysgenesis in Turner syndrome with Y-chromosome mosaicism:Two case reports

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World Journal of Clinical Cases 2020年第22期8卷 5737-5743页

作者： Xue-Fei Leng Ke Lei Yi Li Fei Tian Qin Yao Qing-Mei Zheng Zhi-Hong Chen Department of Pediatric Endocrinology Affiliated Hospital of Medical College Qingdao UniversityQingdao 266001Shandong ProvinceChina Department of Laboratory Medicine Affiliated Hospital of Medical College Qingdao UniversityQingdao 266001Shandong ProvinceChina Department of Gastrointestinal Surgery Affiliated Hospital of Medical College Qingdao UniversityQingdao 266001Shandong ProvinceChina Department of Gynecology Affiliated Hospital of Medical College Qingdao UniversityQingdao 266001Shandong ProvinceChina

BACKGROUND Turner syndrome(TS)has a variety of different karyotypes,with a wide range of phenotypic features,but the specific karyotype may not always predict the *** with Y chromosome mosaicism may have mixed gonadal dysgenesis,and the mosaicism is related to the potential for *** SUMMARY In this case report,we report two cases of TS with different karyotypes and gonadal *** 1 had obvious virilization,and was positive for the SRY gene,but her karyotype in peripheral blood lymphocytes was *** 2 had a mosaic karyotype,45X/46X,dic(Y:Y)(p11.3:p11.2),and the proportion of Y-bearing cells was 50%in peripheral blood lymphocytes,but the patient had normal female external genitalia and streaky gonads,with no genital *** tissues in the same TS individual may exhibit different ratios of *** gonadal determination and differentiation of mosaic TS are primarily dependent on the predominant cell line in the *** In TS patients with virilization,it is necessary to test at least two to three tissues to search for cryptic Y material.

关键词： Turner syndrome Gonadal dysgenesis Virilization Y chromosome mosaicism Gonadoblastoma Case report

Exosomal miR-320e through wnt2targeted inhibition of the Wnt/β-catenin pathway allevisate cerebral small vessel disease and cognitive impairment

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World Journal of Psychiatry 2023年第9期13卷 630-644页

作者： Zheng Wang Xue-Ning Li Shao-Nan Yang Yuan Wang Ke-Jin Gao Bin Han Ai-Jun Ma Department of Internal Medicine-Neurology Affiliated Hospital of Qingdao UniversityQingdao 266001Shandong ProvinceChina Department of Neurology The Affiliated Hospital of Qingdao UniversityQingdao 266001Shandong ProvinceChina

BACKGROUND Exosomal miRNAs play crucial roles in many central nervous system *** small vessel disease(CVSD)is a small vessel disease that is affected by various *** study aimed to investigate the role of exosomal miR-320e in the Wnt/β-catenin pathway stimulated by oxidative stress and assess its clinical correlation with psychiatric symptoms in patients with *** To explore whether exosomal miR-320e could suppress the Wnt/β-catenin pathway and play a protective role in CVSD progression,as well as examine its potential correlation with cognitive impairment and depression in patients with *** Differentially expressed exosomal miRNAs were filtered by sequencing plasma exosomes from patients with CVSD and healthy *** and dual luciferase analyses were used to confirm the binding of miR-320e to Wnt2,and the mRNA and protein levels of downstream components in the Wnt/β-catenin pathway were evaluated when overexpressed or with knockdown of miR-320e under H2O2-induced oxidative *** addition,Wnt2-targeting siRNA was used to confirm the role of miR-320e in the Wnt2-mediated inhibition of the Wnt/β-catenin pathway.A retrospective analysis was conducted among patients with CVSD to confirm the correlation between miR-320e expression and the severity of cognitive impairment and depression,which were quantified using the Montreal Cognitive Assessment(MoCA)/Executive Function Assessment(EFA),and the Hamilton Depression Scale(HAMD)/Beck Depression Inventory(BDI),*** High-throughput sequencing revealed that exosomal miR-320e was downregulated in patients with *** analysis and dual-luciferase reporter gene experiments showed that exosomal miR-320e inhibited the Wnt/β-catenin pathway in response to oxidative stress by targeting the 3'noncoding region of *** of exosomes carrying miR-320e into endothelial cells could also target Wnt2 and inhibit the Wnt2/β-catenin *** miR-32

关键词： Exosome Cerebral small vessel disease miRNA-320e Wnt2 Wnt/β-catenin pathway Depressed

A Single-server Discrete-time Retrial G-queue with Server Breakdowns and Repairs

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Acta Mathematicae Applicatae Sinica 2009年第4期25卷 675-684页

作者： Jin-ting Wang Peng Zhang Department of Mathematics Beijing Jiaotong University Beijing 100044 China Qingdao Branch The Bank of Communication Qingdao 266001 China

This paper concerns a discrete-time Geo/Geo/1 retrial queue with both positive and negative customers where the server is subject to breakdowns and repairs due to negative arrivals. The arrival of a negative customer causes one positive customer to be killed if any is present, and simultaneously breaks the server down. The server is sent to repair immediately and after repair it is as good as new. The negative customer also causes the server breakdown if the server is found idle, but has no effect on the system if the server is under repair. We analyze the Markov chain underlying the queueing system and obtain its ergodicity condition. The generating function of the number of customers in the orbit and in the system are also obtained, along with the marginal distributions of the orbit size when the server is idle, busy or down. Finally, we present some numerical examples to illustrate the influence of the parameters on several performance characteristics of the system.

关键词： Discrete-time retrial queue G-queue Markov chain unreliable server

Estimation of Nonlinear Roll Damping by Analytical Approximation of Experimental Free-Decay Amplitudes

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Journal of Ocean University of China 2019年第4期18卷 812-822页

作者： SUN Jinwei SHAO Meng College of Engineering Ocean University of China Qingdao 266100 China Key Laboratory of Ocean Engineering of Shandong Province Ocean University of China Qingdao 266100 China Institute of Oceanographic Instrumentation Qilu University of Technology (Shandong Academy of Sciences) Qingdao 266001 China Shandong Provincial Key Laboratory of Ocean Environmental Monitoring Technology Qingdao 266001 China National Engineering and Technological Research Center of Marine Monitoring Equipment Qingdao 266001 China

Damping is critical for the roll motion response of a ship in waves. A common method for the assessment of damping in a ship’s rolling motion is to perform a free-decay experiment in calm water. In this paper, we propose an approach for estimating nonlinear damping that involves a linear exponential analytical approximation of the experimental roll free-decay amplitudes, fol- lowed by parametric identification based on the asymptotic method. The restoring moment can be strongly nonlinear. To validate this method, we first analyzed numerically simulated roll free-decay data using rolling equations with two alternative parametric forms: linear-plus-quadratic and linear-plus-cubic damping. By doing so, we obtained accurate estimates of nonlinear damping coefficients, even for large initial roll amplitudes. Then, we applied the proposed method to real free-decay data obtained from a scale model of a bulk barrier, and found the simulated results to be in good agreement with the experimental data. Using only free-decay peak data, the proposed method can be used to estimate nonlinear roll-damping coefficients for conditions with a strongly nonlinear restoring moment and large initial roll amplitudes.

关键词： nonlinear roll damping parametric identification nonlinear restoring moment asymptotic method linear exponential approximation

A modified heat source model for rotating arc welding

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China Welding 2011年第3期20卷 57-62页

作者：郭宁韩焱飞张琳琳邹妍 Shandong Provincial Key Laboratory of Ocean Environment Monitoring Technology Institute of Oceanographic Instrumentation Shandong Academy of Sciences Qingdao 266001

A modified mathematical model of heat source for rotating arc welding （RAW） process was developed for investigating the heat and temperature distribution. The characteristics of temperature field based on the complex welding motion trajectory were studied. In this work, a transient three-dimensional （ 3D ） model was established and computed by a finite element analysis computer program MARC as well as its subroutine. In RA＇W process, the temperature changes in the style of stepladder. Moreover in the high temperature zone, there are multiple peak temperature points. These characteristics of temperature distribution are induced by the arc rotating which leads the repetitive heating or fasing during the welding process. In contrast with non-rotating arc （NRAW） process, the width of temperature distribution enlarges, and the peak temperature of weld pool decreases. Good agreement is shown between the computed results and experimental results of thermal cycle in RAW process.

关键词： rotating arc process temperature distribution finite element analysis

Controlled release behaviors of chitosan/α,β- glycerophosphate thermo-sensitive hydrogels

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Frontiers of Materials Science 2012年第3期6卷 250-258页

作者： Wei-Fang LIU Chuan-Zhen KANG Ming KONG Yang LI Jing SU An YI Xiao-Jie CHENG Xi-Guang CHEN College of Marine Life Science Ocean University of ChinaQingdao 266003China The Affiliated Hospital of Medical College Qingdao UniversityQingdao 266001China

Chitosan/α,β-glycerophosphate （CS/α,β-GP） thermo-sensitive hydrogels presented flowable solution state at low temperature and semisolid hydrogel when the ambient temperature increased. In this research, different concentrations of metronida- zole encapsulated, CS and α,β-GP, as well as different acid solvents, were chosen to evaluate their influences on the drug release behaviors from CS/α,β-GP hydrogels. It was found that there was a sustaining release during the first 3 h followed by a plateau. SEM images showed that drugs were located both on the surface and in the interior of hydrogels. The optimal preparation conditions of this hydrogel for drug release were as follows： 1.8% （w/v） CS in HAc solvent, 5.6% （w/v） a, 13-GP and 5g/L metronidazole encapsulation. Cytotoxicity evaluation found no toxic effect. In order to control the release rate, 2.5 g/L chitosan microspheres with spherical shape and smooth surface were incorporated, and it was found that the initial release process was alleviated, while drug concentration had no obvious effect on the release rate. It could be concluded that the metronidzole release behaviors could be optimized according to practical applica- tions.

关键词： chitosan (CS) glycerophosphate (GP) thermo-sensitive hydrogel con-trolled release microsphere

Rheumatologic manifestations of hepatic diseases

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Hepatobiliary & Pancreatic Diseases International 2003年第1期2卷 32-37页

作者： Zhao-Chun Chi Su-Zhen Ma the Division of Gastroenterologr, Department of Medicine, People’s Hospital, Qingdao 266001, China the Department of Infectious Diseases, Qingdao University College of Medicine, Qingdao 266012, China Division of Gastroenterology Department of Medicine People's Hospital Qingdao 266001 China.

A possible link is suggested between hepatic diseases and rheumatic disease. Polyarthralgia and polyarthritis may be seen during the prodromal period of acute viral hepatitis, especially in hepatitis B virus (HBV). The symptoms of arthritis, mild, localized or generalized, mostly involve the small joints of hands. Joint symptoms frequently precede the onset of jaundice, no residual joint deformities. Circulating immune complexes are believed to play a causative role in the development of vasculitis and arthritis. Hemochromatosis is an antosomal recessive disorder of iron. About 43%-81% of patients with hemochromatosis have arthritis. The common extrahepatic manifestations of autoimmune hepatitis are arthralgia and skin rash. The reported prevalence of symptomatic inflammatory arthropathy in patients with primary biliary cirrhosis ranges from 4% to 50%. Skeletal involvement with Wilson's disease is common. Such patients may complain of pain and stiffness, mainly in the knee, wrist, or other large joints. Shwachman's syndrome is a disorder of pancreatic exocrine. Symmetric bone lesions have been reported in 10% to 15% of patients. They are involved predominantly at the femoral neck. Rheumatic symptoms are seen in one third of adult patients with cystic fibrosis and arthritis in 2.5% to 12% of patients. The arthritis caused by pancreatic panniculitis is usually symmetrical and involves the small joints of the hand, wrist, and feet, but may involve such larger joints as the elbow, ankle, and knee.

关键词： hepatic diseases rheumatologic manifestation