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Fault Diagnosis Model Based on Multi-level Information Fusion for CNC Machine Tools
Wen Yan,Tan Ji-wen,Zhan Hong,Sun Xian-bin 보안공학연구지원센터 2016 International Journal of Hybrid Information Techno Vol.9 No.8
The difficulty of CNC machine tools fault diagnosis is bigger than other general equipments because of the complex structure and the coupling among subsystems. The fault diagnosis model based on multi-level information fusion and hybrid intelligence is studied to improve reliability of fault diagnosis. Information from built-in sensors is used to monitor the status of CNC machine tools. The diagnosis principles of internal parameters-motor current, torque, temperature and following error are analyzed. Internal information and external sensors are two main sources which provide data to diagnosis. In order to detect effective fault signal, features of time domain, frequency domain and time-frequency domain are extracted. All these features constitute the feature set. The features are selected by the method of Kernel Principal Component Analysis (KCPA). Then the sensitive feature set is obtained. The method of multiple classifier fusion based on fuzzy comprehensive evaluation is researched. The determination method of weight based on information entropy is proposed. This diagnosis model has been tested feed system mechanical fault diagnosis of CNC machine tools and the results show which is effective and versatile.
Oxygen Limitation Improves Ganoderic Acid Biosynthesis in Submerged Cultivation of Ganoderma lucidum
Wen-Xian Zhang,Jian-Jiang Zhong 한국생물공학회 2013 Biotechnology and Bioprocess Engineering Vol.18 No.5
The effects of oxygen limitation on the production of ganoderic acid (GA), a secondary metabolite with antitumor activity, and on transcription levels of triterpene biosynthesis genes were investigated in liquid cultures of Ganoderma lucidum. A low oxygen supply level was beneficial to total GA biosynthesis, but negative to the cell growth. The higher GA production was obtained under micro-aerobic conditions (i.e. initial overall kLa values at 0.02 and 0.13/h). The maximum GA production of 272.3 ± 11.5 mg/L was obtained at an initial overall kLa of 0.13/h, which was 1.7-fold that at a normal cultivation condition (an initial kLa of 5.51/h). For four major individual GAs, the production level of GA-Mk, -T, -S, and -Me in the hypoxia-induced cells was increased by 50, 87,62, and 111%, compared with that of the control, respectively. Meanwhile, the transcriptions of four key genes encoding 3-hydroxy-3-methylglutaryl coenzyme A reductase, mevalonate-5-pyrophosphate decarboxylase, squalene synthase and squalene epoxidase in the triterpene biosynthetic pathway were up-regulated under the hypoxia condition (at an initial kLa of 0.13/h). Reactive oxygen species was generated in response to hypoxia, which seemed to be involved in the regulation of GA biosynthesis. The information obtained provides an insight into the role of oxygen limitation in the GA biosynthesis, and will be helpful for optimizing the fermentation process on a large scale.
Li Xian-Wen,Su Xing-Kang,Gu Long,Wang Xiang-Yang,Fan Da-Jun 한국원자력학회 2023 Nuclear Engineering and Technology Vol.55 No.5
Conjugate heat transfer between liquid metal and solid is a common phenomenon in a liquid-metalcooled fast reactor's fuel assembly and heat exchanger, dramatically affecting the reactor’s safety and economy. Therefore, comprehensively studying the sophisticated conjugate heat transfer in a liquidmetal-cooled fast reactor is profound. However, it has been evidenced that the traditional Simple Gradient Diffusion Hypothesis (SGDH), assuming a constant turbulent Prandtl number (Prt, usually 0.85 - 1.0), is inappropriate in the Computational Fluid Dynamics (CFD) simulations of liquid metal. In recent decades, numerous studies have been performed on the four-equation model, which is expected to improve the precision of liquid metal’s CFD simulations but has not been introduced into the conjugate heat transfer calculation between liquid metal and solid. Consequently, a four-equation model, consisting of the Abe k ε turbulence model and the Manservisi kq εq heat transfer model, is applied to study the conjugate heat transfer concerning liquid metal in the present work. To verify the numerical validity of the four-equation model used in the conjugate heat transfer simulations, we reproduce Johnson’s experiments of the liquid lead-bismuth-cooled turbulent pipe flow using the four-equation model and the traditional SGDH model. The simulation results obtained with different models are compared with the available experimental data, revealing that the relative errors of the local Nusselt number and mean heat transfer coefficient obtained with the four-equation model are considerably reduced compared with the SGDH model. Then, the thermal-hydraulic characteristics of liquid metal turbulent pipe flow obtained with the four-equation model are analyzed. Moreover, the impact of the turbulence model used in the four-equation model on overall simulation performance is investigated. At last, the effectiveness of the four-equation model in the CFD simulations of liquid sodium conjugate heat transfer is assessed. This paper mainly proves that it is feasible to use the four-equation model in the study of liquid metal conjugate heat transfer and provides a reference for the research of conjugate heat transfer in a liquidmetal-cooled fast reactor
Jing, Jie-Xian,Wang, Yan,Xu, Xiao-Qin,Sun, Ting,Tian, Bao-Guo,Du, Li-Li,Zhao, Xian-Wen,Han, Cun-Zhi Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.23
To evaluate the value of combined detection of serum CEA, CA19-9, CA24-2, AFP, CA72-4, SCC, TPA and TPS for the clinical diagnosis of upper gastrointestinal tract (GIT) cancer and to analyze the efficacy of these tumor markers (TMs) in evaluating curative effects and prognosis. A total of 573 patients with upper GIT cancer between January 2004 and December 2007 were enrolled in this study. Serum levels of CEA, CA19-9, CA24-2, AFP, CA72-4, SCC, TPA and TPS were examined preoperatively and every 3 months postoperatively by ELISA. The sensitivity of CEA, CA19-9, CA24-2, AFP, CA72-4, SCC, TPA and TPS were 26.8%, 36.2%, 42.9%, 2.84%, 25.4%, 34.6%, 34.2% and 30.9%, respectively. The combined detection of CEA+CA199+CA242+CA724 had higher sensitivity and specificity in gastric cancer (GC) and cardiac cancer, while CEA+CA199+CA242+SCC was the best combination of diagnosis for esophageal cancer (EC). Elevation of preoperative CEA, CA19-9 and CA24-2, SCC and CA72-4 was significantly associated with pathological types (p<0.05) and TNM staging (p<0.05). Correlation analysis showed that CA24-2 was significantly correlated with CA19-9 (r=0.810, p<0.001). The levels of CEA, CA19-9, CA24-2, CA72-4 and SCC decreased obviously 3 months after operations. When metastasis and recurrence occurred, the levels of TMs significantly increased. On multivariate analysis, high preoperative CA72-4, CA24-2 and SCC served as prognostic factors for cardiac carcinoma, GC and EC, respectively. combined detection of CEA+CA199+CA242+SCC proved to be the most economic and practical strategy in diagnosis of EC; CEA+CA199+CA242+CA724 proved to be a better evaluation indicator for cardiac cancer and GC. CEA and CA19-9, CA24-2, CA72-4 and SCC, examined postoperatively during follow-up, were useful to find early tumor recurrence and metastasis, and evaluate prognosis. AFP, TPA and TPS have no significant value in diagnosis of patients with upper GIT cancer.
Connectedness and compactness of weak efficient solutions for vector equilibrium problems
Xian Jun Long,Jian Wen Peng 대한수학회 2011 대한수학회보 Vol.48 No.6
In this paper, without assumption of monotonicity, we study the compactness and the connectedness of the weakly efficient solutions set to vector equilibrium problems by using scalarization method in locally convex spaces. Our results improve the corresponding results in [X. H. Gong, Connectedness of the solution sets and scalarization for vector equilibrium problems, J. Optim. Theory Appl. 133 (2007), 151-161].
( Wen Jing Yan ),( Ying Chun Tan ),( Ji Cheng Xu ),( Xian Ping Tang ),( Chong Zhang ),( Peng Bo Zhang ),( Ze Qiang Ren ) 한국응용약물학회 2015 Biomolecules & Therapeutics(구 응용약물학회지) Vol.23 No.3
Silibinin, a natural flavonoid antioxidant isolated from extracts of the milk thistle herb, has recently been identified as having antihepatotoxic and anticancer properties. In this paper, we investigated the effects of silibinin on behavior and neuroplasticity in mice subjected to chronic unpredictable mild stress (CUMS). After 5 consecutive weeks of CUMS, the mice were treated with silibinin (100 mg/kg, 200 mg/kg and 400 mg/kg by oral gavage) for 3 consecutive weeks. The results showed that silibinin administration significantly alleviated the CUMS-induced depressive-like behavior, including the total number of squares crossed and the frequency of rearing in the open field test, the immobility time in the tail suspension test and the forced swimming test. Furthermore, silibinin treatment increased the levels of brain-derived neurotrophic factor (BDNF), serotonin (5-HT) and norepinephrine (NE) in the prefrontal cortex and hippocampus. Our study provides new insight into the protective effects of silibinin on the depressive status of CUMS mice, specifically by improving neuroplasticity and neurotransmission.
Proper efficiency for set-valued optimization problems and vector variational-like inequalities
Xian Jun Long,Jing Quan,Dao-Jun Wen 대한수학회 2013 대한수학회보 Vol.50 No.3
The purpose of this paper is to establish some relationships between proper efficiency of set-valued optimization problems and proper efficiency of vector variational-like inequalities under the assumptions of generalized cone-preinvexity. Our results extend and improve the corresponding results in the literature.