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Microwave Behavior of α-Fe/Fe_3B/y_2O_3 Nanocomposites in GHz Range Prepared by Melt-Spun Technique

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Journal of Rare Earths 2004年第1期22卷 13-16页

作者： Masahiro Itoh ken-ichi Machida Collaborative Research Center for Advanced Science and Technology Collaborative Research Center for Advanced Science and Technology Osaka University 2-1 Yamadaoka Suita Osaka 565-0871 JapanOsaka University 2-1 Yamadaoka Suita Osaka 565-0871 Japan

Nanocomposites α-Fe/Fe 3B/y 2O 3 were prepared by a melt-spun technique, and the electromagnetic wave absorption properties were measured in the 0 05～20 05 GHz range. Compared with α-Fe/y 2O 3 composites, the resonance frequency (f r) of α-Fe/Fe 3B/y 2O 3 shifted to a higher frequency range due to the large anisotropy field (H A) of tetragonal Fe 3B (～0 4 mA·m -1). The relative permittivity (ε r=ε r′-jε r″) was constantly low over the 0 5～10 GHz region, which indicates that the composite powders have a high resistivity (ρ=～100 Ωm). The effective electromagnetic wave absorption (RLy range of 2.7～6.5 GHz on resin composites of 80% (mass fraction) α-Fe/Fe 3B/y 2O 3 powders, with thickness of 6～3 mm respectively. A minimum reflection loss of -33 dB was observed at 4.5 GHz with an absorber thickness of 4 mm.

关键词： melt-spun nanocomposites electromagnetic wave absorption anisotropy field matching frequency

Effects of uniaxial compressive strain on the electronic- transport properties of zigzag carbon nanotubes

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Nano Research 2016年第5期9卷 1267-1275页

作者： Masato Ohnishi ken Suzuki Hideo Miura Fracture and Reliability Research Institute Graduate School of Engineering Tohoku University Sendai 980-8579 Japan

Recently, substantial attention has been paid to the strain sensitivity of the carbon nanotubes＇（CNTs＇） electronic properties. In this study, the relationships between the geometric structures and electronic states of zigzag CNTs under uniaxial compressive strain were investigated. We found that different factors dominate the electronic states of zigzag CNTs depending on the strain regions： the initial stage of the strain loading, which lasts until column-buckling deformation begins, and the strain regions corresponding to column- and shell-buckling deformations. Because shell-buckling deformation significantly increases the re-orbital angle, the angle between the π orbital axis vectors of adjacent atoms, strong localization of the density of states （LDOS） occurs in the buckled area. We also analyzed the current able to pass through deformed CNTs using a tight-binding-based Green＇s function approach and determined that the current can be significantly suppressed by applying uniaxial compressive strain. Our method of predicting the electronic state of a deformed CNT based on the π-orbital angle is expected to be useful for predicting the electronic properties of CNT-based electronic devices and sensors.

关键词： carbon nanotube strain buckling deformation Green's function method electronic-transport property

Hepatitis B:Who should be treated?-managing patients with chronic hepatitis B during the immune-tolerant and immunoactive phases

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World Journal of Gastroenterology 2021年第43期27卷 7497-7508页

作者： Miwa Kawanaka ken Nishino Hirofumi Kawamoto ken Haruma Department of General Internal Medicine 2 General Medical CenterKawasaki Medical SchoolOkayama 700-8505Japan

New hepatitis B virus(HBV)infections are decreasing owing to improved antiviral therapy and increased HBV vaccination worldwide;however,the number of HBV infections remains a major cause of liver *** triggers cytotoxic immunity to eliminate HBV-infected ***,the HBV pathophysiology changes in persistently infected individuals depending on host immune responses and HBV DNA proliferation *** prevent liver cirrhosis and carcinogenesis caused by HBV,it is important to treat HBV infection at an early *** treatment is recommended for the immunoactive hepatitis B surface-antigen-positive and-negative phase,but not during the immune-inactive phase or immune-tolerant phase;instead,follow-up is ***,these patients should be monitored through regular blood tests to accurately diagnose the immune-inactive or-tolerant *** treatment regimen should be determined based on the age,sex,family history of liver cancer,and liver fibrosis status of *** treatment is often recommended due to various problems during the immune-tolerant *** review compares the four major international practice guidelines,including those from the Japanese Society of Hepatology,and discusses strategies for chronic hepatitis B treatment during the immune-tolerant,immune-inactive,and resolved ***,recommended hepatitis B antiviral therapy and follow-up protocols are discussed.

关键词： Hepatitis B Immune tolerance Immune-inactive Anti-viral therapy Hepatocellular carcinoma Cirrhosis

REKF and RUKF for pico satellite attitude estimation in the presence of measurement faults

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Journal of Systems Engineering and Electronics 2014年第2期25卷 288-297页

作者： Halil Ersin Sken Chingiz Hajiyev Department of Space and Astronautical Science The Graduate University for Advanced Studies (Sokendai) Aeronautics and Astronautics Faculty Istanbul Technical University

When a pico satellite is under normal operational condi- tions, whether it is extended or unscented, a conventional Kalman filter gives sufficiently good estimation results. However, if the measurements are not reliable because of any kind of malfunc- tions in the estimation system, the Kalman filter gives inaccurate results and diverges by time. This study compares two different robust Kalman filtering algorithms, robust extended Kalman filter （REKF） and robust unscented Kalman filter （RUKF）, for the case of measurement malfunctions. In both filters, by the use of de- fined variables named as the measurement noise scale factor, the faulty measurements are taken into the consideration with a small weight, and the estimations are corrected without affecting the characteristic of the accurate ones. The proposed robust Kalman filters are applied for the attitude estimation process of a pico satel- lite, and the results are compared.

关键词： pico satellite attitude estimation robust Kalman filter-ing extended Kalman filter (EKF) unscented Kalman filter (UKF).

STRUCTURE AND DyNAMICS OF POLyMERIC MATERIALS IN NANO-SCALE

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Chinese Journal of Polymer Science 2011年第1期29卷 43-52页

作者： Toshio Nishi So Fujinami ken Nakajima WPI Advanced Institute for Materials Research Tohoku University

The nano-palpation technique, i.e., nanometer-scale elastic and viscoelastic measurements based on atomic force microscope, is introduced. It is demonstrated to be very useful in analyzing nanometer-scale materials properties for the surfaces and interfaces of various types of soft materials. It enables us to obtain not only structural information but also mechanical information about a material at the same place and at the same time.

关键词： Nano-palpation Atomic force microscope Soft material young's modulus Viscoelasticity.

Optimal Parallel Algorithm for the Knapsack Problem Without Memory Conflicts

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Journal of Computer Science & Technology 2004年第6期19卷 760-768页

作者： ken-LiLi Ren-FaLi Qing-HuaLi SchoolofComputerandCommunication HunanUniversityChangsha410082P.R.China SchoolofComputerScienceandTechnology HuazhongUniversityofScienceandTechnologyWuhan430074P.R.China

The knapsack problem is well known to be NP-complete. Due to its importance in cryptosystem and in number theory, in the past two decades, much effort has been made in order to find techniques that could lead to practical algorithms with reasonable running time. This paper proposes a new parallel algorithm for the knapsack problem where the optimal merging algorithm is adopted. The proposed algorithm is based on anEREW-SIMD machine with shared memory. It is proved that the proposed algorithm is both optimal and the first without memory conflicts algorithm for the knapsack problem. The comparisons of algorithm performance show that it is an improvement over the past researches. Keywords knapsack problem - NP-complete - parallel algorithm - optimal algorithm - memory conflict Supported by the National Natural Science Foundation of China under Grant No.60273075, the National High Technology Development 863 Program of China under Grant No.863-306-ZD-11-01-06.ken-Li Li received his B.S. and M.S. degrees in mathematics from National University of Defense Technology and Central South University in 1995 and 2000 respectively and he is now a Ph.D. candidate in computer software and theory at Huazhong University of Science and Technology. His main research interests include parallel computing and combinatorial optimization.Ren-Fa Li received his Ph.D. degree in computer software and theory at Huazhong University of Science and Technology, and he is concurrently a professor and Ph.D. supervisor in School of Computer and Communication, Human University. His main research interests include network computing.Qing-Hua Li received his M.S. degree in computer science from Huazhong University of Science and Technology in 1981, and he is concurrently a professor and Ph.D. supervisor in School of Computer Science and Technology, Huazhong University of Science and Technology. His current research interests include parallel processing, combinatorial optimization, and grid comp

关键词： knapsack problem NP-complete parallel algorithm optimal algorithm memory conflict

Transition Gibbs free energy level cross section and formulation of carrier SRH recombination rate

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Journal of Semiconductors 2013年第12期34卷 9-12页

作者： ken K.Chin Department of Physics and CNBM New Energy Materials Research Center New Jersey Institute of Technology

The transition among multiple charging states of a semiconductor＇s localized intrinsic/impurity defects is considered as phase transitions, and the concept of transition Gibbs free energy level （TGFEL） is proposed. Dependence of the cross section of TGFEL on its charge state is discussed. Introduction of TGFEL to replace acti- vation energy has fundamentally important consequences for semiconductor physics and devices. TGFEL involves entropy. What is to be included and not included in the entropy term consistently for all defect levels is an unre- solved open question, related to correct interpretation of various experimental data associated with various defect levels. This work is a first step towards resolving this question.

关键词： transition Gibbs free energy level Shockley-Read-Hall single level defects

Aligning Fe_(2)O_(3)photo-sheets on TiO_(2)nanofibers with hydrophilic and aerophobic surface for boosting photoelectrochemical performance

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Nano Research 2023年第3期16卷 4178-4187页

作者： Xiangyu Meng Qi Zhan yanan Wu Mengmeng Zhu ken Liu Na wang Kuibo yin yueming Sun Shuai Dong yunqian Dai School of Chemistry and Chemical Engineering Southeast UniversityNanjing 211189China School of Physics Southeast UniversityNanjing 211189China SEU-FEI Nano-Pico Center Key Laboratory of MEMS of Ministry of EducationSoutheast UniversityNanjing 210096China

Photoelectrochemical(PEC)nanomaterials are critical to producing clean oxygenation or value-added chemical production by utilizing sustainable solar energy,but are always limited by simultaneous integration of architectural engineering and electronic regulation in one *** by density functional theory(DFT)calculations and finite element analysis(FEA),the bioinspired ivy-like Fe_(2)O_(3)heterostructures with enriched oxygen defects on TiO_(2)nanofibers are designed for boosting PEC ***-like Fe_(2)O_(3)photo-sheets remarkably enhanced the light harvesting by multiple light-mater *** oxygen vacancies on Fe_(2)O_(3)photo-sheets could aid the photons catching and promote the reactivity at active *** importantly,demonstrated by a well-designed dynamic observation,the abundant tip-edges within ivy-like Fe_(2)O_(3)photo-sheets enabled the surface of heterostructure with hydrophilic and aerophobic *** functionalized surface allowed the rapid desorption of produced bubbles and thus ensured a high density of unoccupied active sites for electrolyte *** by these attributes,the Fe_(2)O_(3)@TiO_(2)nanofibers delivered an excellent photocurrent of 40.8 mA/mg,high donor density(1.2×10^(18)cm^(−3)),and rapid oxygen production rate(1 mmol/(L∙h)).This work demonstrates a new strategy on nano-structural design for enhancing light-harvesting and making a hydrophilic/aerophobic surface on low-dimensional oxide nanomaterial,holding great potential on designing high-performance PEC devices for producing survival source gas,carbon-neutral fuel,and valuedchemicals.

关键词： electrospinning nanofibers TiO2 Fe2O3 light harvesting photoelectrochemical

A new cascade-less engine operated from subsonic to hypersonic conditions: designed by computational fluid dynamics of compressible turbulence with chemical reactions

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Journal of Thermal Science 2010年第6期19卷 481-485页

作者： ken Naitoh Kazushi Nakamura Takehiro Emoto Waseda University Faculty of Science and Engineering

By using our computational fluid dynamic models, a new type of single engine capable of operating over a wide range of Mach numbers from subsonic to hypersonic regimes is proposed for airplanes, whereas traditional piston engines, turbojet engines, and scram engines work only under a narrower range of operating conditions. The new engine has no compressors or turbines such as those used in conventional turbojet engines. An important point is its system of super multijets that collide to compress gas for the transonic regime. Computational fluid dynamics is applied to clarify the potential of this engine. The peak pressure at the combustion center is over 2.5 MPa, while that just before ignition is over 1.0 MPa. The maximum power of this engine will be sufficient for actual use. Under the conditions of higher Mach numbers, the main intake passage located in front of the super multijet nozzles, takes in air more. That results in a ram or scramjet engine for supersonic and hypersonic conditions.

关键词： Aircraft engine multijets twister system compressible flow