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RATIONAL SPECTRAL COLLOCATION METHOD FOR A COUPLED SYSTEM OF SINGULARLY PERTURBED BOUNDARY VALUE PROBLEMS

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Journal of Computational Mathematics 2011年第4期29卷 458-473页

作者： Suqin chen Yingwei Wang Xionghua wu Department of Mathematics Tongji University Shanghai 200092 China

A, novel collocation method for a coupled system of singularly perturbed linear equations is presented. This method is based on rational spectral collocation method in barycentric form with sinh transform. By sinh transform, the original Chebyshev points are mapped into the transformed ones clustered near the singular points of the solution. The results from asymptotic analysis about the singularity solution are employed to determine the parameters in this sinh transform. Numerical experiments are carried out to demonstrate the high accuracy and efficiency of our method.

关键词： Singular perturbation Coupled system Rational spectral collocation method,Boundary layer Reaction-diffusion Convection-diffusion.

Modal and Fatigue Life Analysis on Beam with Multiple Cracks Subjected to Axial Force

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Transactions of Nanjing University of Aeronautics and Astronautics 2018年第5期35卷 874-882页

作者： Ma Yijiang chen Guoping wu Xinhai School of Naval Architecture and Ocean Engineering Jiangsu University of Science and Technology State Key Laboratory of Mechanics and Control for Mechanical Structures Nanjing University of Aeronautics and Astronautics

Based on the transfer matrix method and Forman equation,a new method is proposed to conduct the modal and fatigue life analysis of a beam with multiple transverse *** the modal analysis,the damping loss factor is introduced by the complex elastic modulus,bending springs without mass are used to replace the transverse cracks,and the characteristic transfer matrix of the whole cracked beam can be *** the fatigue life analysis,considering the interaction of the beam vibration and fatigue cracks growth,the fatigue life of the cracked beam is predicted by the timing analysis *** calculation shows that cracks have a significant influence on the modal and fatigue life of the beam.

关键词： beam cracks axial force natural frequency fatigue life

Novel approaches towards conquering hepatitis B virus infection

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World Journal of Gastroenterology 2007年第6期13卷 830-836页

作者： Guo-Yi wu Hong-Song chen Hepatology Institute People's Hospital Peking University Beijing 100044 China

Currently approved treatments for hepatitis B virus （HBV） infection include the immunomodulatory agent, IFN-α, and nucleos（t）ide analogues. Their efficacy is limited by their side effects, as well as the induction of viral mutations that render them less potent. It is thus necessary to develop drugs that target additional viral antigens. Chemicals and biomaterials by unique methods of preventing HBV replication are currently being developed, including novel nucleosides and newly synthesized compounds such as capsid assembling and mRNA transcription inhibitors. Molecular therapies that target different stages of the HBV life cycle will aid current methods to manage chronic hepatitis B （CriB） infection. The use of immunomodulators and gene therapy are also under consideration. This report summarizes the most recent treatment possibilities for CHB infection. Emerging therapies and their potential mechanisms, efficacy, and pitfalls are discussed.

关键词： Hepatitis B virus Antiviral drugs Drugevaluation Immunomodulatory agents Gene therapy

Anti-JPEG Compression Steganography Based on the High Tense Region Locating Method

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Computers, Materials & Continua 2019年第4期59卷 199-214页

作者： Yang wu Weiping Shang Jiahao chen State Key Laboratory of Mathematical Engineering and Advanced Computing Zhengzhou450002China School of Telecommunications Engineering Xidian UniversityXi’an710071China Zhuhai Campus of Beijing Normal University Zhuhai519000China

Robust data hiding techniques attempt to construct covert communication in a lossy public ***,the existing robust JPEG steganographic algorithms cannot overcome the side-information missing ***,this paper proposes a new robust JPEG steganographic algorithm based on the high tense region location method which needs no side-information of lossy ***,a tense region locating method is proposed based on the Harris-Laplacian feature ***,robust cover object generating processes are ***,the advanced embedding cost function is proposed.A series of experiments are conducted on various JPEG image sets and the results show that the proposed steganographic algorithm can resist JPEG compression efficiently with acceptable performance against steganalysis statistical detection libraries GFR(Gabor Filters Rich model)and DCTR(Discrete Cosine Transform Residual).

关键词： Robust data hiding steganography JPEG compression resistant Harris-Laplacian feature

Study on gust alleviation control and wind tunnel test

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Science China Technological Sciences 2013年第3期56卷 762-771页

作者： wu ZhiGang chen Lei YANG Chao School of Aeronautic Science and Engineering Beijing University of Aeronautics and Astronautics Division of Structural Strength Shanghai Aircraft Design and Research Institute

Aircraft are inevitably affected by gust during flight,which disturbs the regular operations of pilots and worsens the ride *** more grievous cases,flight mission cannot be completed and the flight safety may be *** order to improve the ride quality and the fatigue life of the plane structure under the affect of gust,it is necessary to explore and validate the gust alleviation *** the low-speed wind tunnel test,the gust alleviation active control technology applied to elastic aircraft is *** a large-type passenger plane configuration with high aspect ratio wing,a test system was designed and three gust alleviation control schemes with PID controllers were *** the gust alleviation control low-speed wind tunnel test was carried out in the FD-09 wind *** results showed that at certain speed and gust frequency,all of the 3 control schemes can alleviate the acceleration at fuselage and wing-tip to a certain extent,as well as the bending moment of *** gust alleviation control scheme,which uses aileron,elevator and canard as control surfaces synthetically,gives the most satisfying gust alleviation effect.

关键词： aeroelasticity aeroservoelasticity gust response gust alleviation active control wind tunnel test

激光增材制造网状结构金属基复合材料的研究进展

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中国有色金属学报 2024年第4期34卷 1052-1070页

作者：伍子纯刘阳李海尊谭振国唐楠宋宇峰刘筱陈宇强湖南科技大学机电工程学院湘潭411201 湖南科技大学高功效轻合金构件成形技术及耐损伤性能评价湖南省工程研究中心湘潭411201 湖南西交智造科技有限公司湘潭411100

相较于传统增强相呈均匀分布的金属基复合材料,网状结构金属基复合材料因其独特的“机械互锁”“位错钉扎”等组织结构特征,具有更优异的室温强度、高温强度、弹性模量和断裂韧性,在航天、航空等领域上具有广泛的应用前景。激光增材制... 详细信息

相较于传统增强相呈均匀分布的金属基复合材料,网状结构金属基复合材料因其独特的“机械互锁”“位错钉扎”等组织结构特征,具有更优异的室温强度、高温强度、弹性模量和断裂韧性,在航天、航空等领域上具有广泛的应用前景。激光增材制造技术可实现对网状结构的精细化调控,为网状结构金属基复合材料的进一步发展提供了新的途径。本文综述了高能量激光束诱导马兰戈尼对流作用下网状结构金属基复合材料的形成机理、影响网状结构形成的因素、不同类型网状结构的显微组织结构特征,分析了网状结构金属基复合材料的多段弯曲断裂、微孔聚集断裂等断裂机制,阐述了在霍尔−佩奇、奥罗万、泰勒、载荷传递等强化机制共同作用下的强化机理,以及独特的增强相贫、富区协同作用下的韧化机理,并对其未来的研究方向进行了展望。

关键词：网状结构激光增材制造金属基复合材料断裂机制强韧化机理

基于智慧生态链模式的资产数字化价值和信用值评估与交易增值

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深圳社会科学 2024年第3期7卷 65-82页

作者：陈水源吴晏卢明胜深圳市中城智慧城市研究院广东深圳518000

从技术流、业务流、物质流、信息流、财富流、货币流六大流转体系间扭曲的角度分析造成经济紧缩问题的成因,并基于资产数字化价值和数字化信用的角度提出相应解决办法。提出了资产数字化价值和数字化信用值评估的基本算法,认为基于智慧... 详细信息

从技术流、业务流、物质流、信息流、财富流、货币流六大流转体系间扭曲的角度分析造成经济紧缩问题的成因,并基于资产数字化价值和数字化信用的角度提出相应解决办法。提出了资产数字化价值和数字化信用值评估的基本算法,认为基于智慧生态链模式,在主权货币的支撑下,依托资产数字化价值及可交易流通普惠式数字化信用池,可进行再生产的策划、生产、交易和结算。通过智能交易、闭环项目增值、预设数字化信用值增配等方式,可实现资产数字化价值和数字化信用值持续增值。实现再生产活动由现行主权货币单一外在驱动,转化为由数字化信用值内在驱动与主权货币外在驱动相结合的双驱动数字经济模式。为确保这种模式有效开展,技术上需要建立由个人、企业、协会组织、政府共同参与的智慧生态链服务平台,组织上需要建立跨产业创新发展智慧生态联合体组织,从而实现十链融合、多方参与、互助共赢、生态发展新模式。这种智慧生态链下,基于资产数字化价值和数字化信用的智能交易和持续增值模式,将有望开启数字经济的全新时代。

关键词：智慧生态链资产数字化价值数字化信用值智能交易价值增值

Value of endoscopic methylene blue and Lugol's iodine double staining and detection of GST-n and telomerase in the early diagnosis of esophageal carcinoma

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World Journal of Gastroenterology 2005年第39期11卷 6090-6095页

作者： xuan Zhu Shuang-Hong Zhang Kun-He Zhang Bi-Ming Li Jiang chen Department of Gastroenterology the First Affiliated Hospital Jiangxi Medical College Nanchang 330006 Jiangxi Province China Department of Digestive Institution the First Affiliated Hospital Jiangxi Medical College Nanchang 330006 Jiangxi Province China

AIM：To explore the expressions of GST-π and telomerase activity in esophageal carcinoma and premalignant lesions and to investigate the value of endoscopic methylene blue （MB） and Lugol＇s iodine double staining. METHODS： Seventy-two patients with esophagopathy were sprayed endoscopically with MB and Lugol＇s iodine in proper order and the areas stained blue and brown, and the area between the blue and brown stains were obtained. Depending on the pattern of mucosal staining, biopsy specimen was obtained. GST-π and telomerase activity in specimens were examined by immunohistochemistry and PCR-based silver staining telomeric repeat amplification protocol, respectively. RESULTS： After MB and Lugol＇s iodine staining, the area between both the colors was obtained in 64 of the 72 patients and the areas were stained blue and brown in all of the 72 patients. Association test of two simultaneous ordinal categorical data showed a correlation between the esophageal mucosal staining and the esophageal histology （P〈0.005）. The expression of GST-π and telomerase activity in esophageal carcinoma and premalignant lesions increased. The expression of GST-π and telomerase activity in dysplasia and carcinoma was significantly higher than that in normal epithelium （P〈0.005）. The expression in hyperplasia was slightly higher than that in normal epithelium. With the lesions progressing from low- to moderate- to high-grade dysplasia, the positive rate increased （P〈0.025）. Expression of GST-π was correlated with that of telomerase activity in dysplasia and carcinoma （φ= 0.4831, P〈0.005;φ= 0.3031, P〈0.025, respectively）; but there was no correlation between them in normal epithelium and hyperplasia. CONCLUSION： The expression of GST-π and telomerase may be an early event in the carcinogenesis of esophagus. They may play an induced and synergistic role with each other in the carcinogenesis of esophagus. Endoscopic MB and Lugol＇s iodine double staining and detection of GST-π and telomerase acti

关键词： Esophageal carcinoma Endoscopy Glutathione S-transferases Telomerase

BASIC EQUATIONS AND WAVE THEORY OF GAS-LIQUID TWO-PHASE TRANSIENT FLOW

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Journal of Hydrodynamics 1992年第1期4卷 83-90页

作者： Yang, Jiandong wu, Rongqiao chen, Jiznzhi wuhan Univ of Hydraulic and Electric Engineering Wuhan China

This paper systematically discussed the equations for two-phase transient flow and pressure wave and interfacial wave. The behaviour of basic equations was analyzed. The formulas for the wave speed of the pressure wave and the interfacial wave were derived. It was proved that various mathematical models can be uniformed by the integrating model and various wave speed formulas can be uniformed by the universal formula derived. The basic equations for the separated flow model are ill-conditioned because of the unreasonable neglect of the pressure differences between the phases and interfaces. Drift flux model can improve the accuracy if some additional equations are provided. The basic equations for homogeneous flow model are well-conditioned and they can be used in two-phase transient flow, especially in the cases of no velocity slips between various phases fluid.

关键词： wave theory two-phase flow mathematical model