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A novel semi-active TMD with folding variable stiffness spring

Earthquake Engineering and Engineering Vibration 2014年第3期13卷 509-518页

作者： M.H.rafi eipour A.K.Ghorbani-Tanha M.rahimian r.Mohammadi-Ghazi Department of Civil Engineering Science and Research Branch Islamic Azad University Tehran 39187-97717 Iran School of Civil Engineering College of Engineering University of Tehran P.O.Box 11155-4563 Tehran Iran Department of Civil and Environmental Engineering Massachusetts Institute of Technology Cambridge MA USA Formerly with School of Civil Engineering College of Engineering University of Tehran P.O.Box 11155-4563 Tehran Iran

An innovative variable stiffness device is proposed and investigated based on numerical simulations. The device, called a folding variable stiffness spring （FVSS）, can be widely used, especially in tuned mass dampers （TMDs） with adaptive stiffness. An important characteristic of FVSS is its capability to change the stiffness between lower and upper bounds through a small change of distance between its supports. This special feature results in lower time-lag errors and readjustment in shorter time intervals. The governing equations of the device are derived and simplified for a symmetrical FVSS with similar elements. This device is then used to control a single-degree-of-freedom （SDOF） structure as well as a multi-degree-of-freedom （MDOF） structure via a semi-active TMD. Numerical simulations are conducted to compare several control cases for these structures. To make it more realistic, a real direct current motor with its own limitations is simulated in addition to an ideal control case with no limitations and both the results are compared. It is shown that the proposed device can be effectively used to suppress undesirable vibrations of a structure and considerably improves the performance of the controller compared to a passive device.

关键词： semi-active tuned mass damper variable stiffness folding variable stiffness spring

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Electron states and electron raman scattering in semiconductor double cylindrical quantum well wire

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Chinese Physics B 2016年第11期25卷 453-460页

作者： M Munguía-rodríguez ri Betancourt-riera re Betancourt-riera r riera J M Nieto Jalil Departamento de Investigación en Física Universidad de Sonora Apartado Postal 5-88 83190 Hermosillo Sonora México Instituto Tecnológico de Hermosillo. Avenida Tecnologico S/N Col. Sahuaro 83170 Hermosillo Sonora México Tecnológico de Monterrey-Campus Sonora Norte. Bulevar Enrique Mazón Lopez No. 965 83000 Hermosillo Sonora México

The differential cross section for an electron raman scattering process in a semiconductor GaAs/AlGaAs double quantum well wire is calculated,and expressions for the electronic states are *** system is modeled by considering T = 0 K and also with a single parabolic conduction band,which is split into a subband system due to the *** gain and differential cross-section for an electron raman scattering process are *** addition,the emission spectra for several scattering configurations are discussed,and interpretations of the singularities found in the spectra are *** electron raman scattering studied here can be used to provide direct information about the efficiency of the lasers.

关键词： Electron cylindrical confinement conduction radius decoupling AlGaAs parabolic modeled resonant

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In vitro Safety Evaluation and Anticlastogenic Effect of BacoMind^(TM) on Human Lymphocytes

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Biomedical and Environmental Sciences 2008年第1期21卷 7-23页

作者： DIPANWITA DUTTA DEB PrEETI KAPOOr r. P. DIGHE r. PADMAJA M. S. ANAND P. D'SOUZA M. DEEPAK B. MUrALI AMIT AGArWAL Natural remedies Pvt. Ltd 19 K. M. Stone Hosur Road Plot No. 5B Veerasandra Indl. Area Bangalore 560100 India

Objective BacoMind^TM （BM） is a standardized extract of Bacopa monnieri, which belongs to the family Scrophulariaceae and is a creeping annual plant found throughout the Indian subcontinent. It has been used by Ayurvedic medicinal practitioners in India for almost 3000 years and is classified as a medharasayana, a substance which improves memory and intellect. With the widespread traditional use as well as scientific validation of Bacopa monnieri for nootropic activity, a bioactive-rich unique phytochemical composition-BacoMind^TM was developed from B. monnieri for use as a cognition and memory enhancing agent. The present study aimed to investigate the in vitro toxicity of this formulation of BacoMind^TM on human lymphocytes and to rule out its possible contribution to mutagenicity. Methods In the present investigation the active ingredients present in BM were identified and quantified by high performance liquid chromatography （HPLC） and high performance thin-layer chromatography （HPTLC）. Antioxidant and anticlastogenic properties of BM were studied in vitro with and without metabolic activation. Doses of BM were chosen on the basis of mitotic index （MI） and cytokinesis-block proliferation index （CBPI）. Clastogenicity assays were performed at 31.2 μg/mL, 62.5 μg/mL, and 125 μg/mL, while the Salmonella reverse mutation assay （Ames test） was performed at doses of 61.72, 185.18, 555.55, 1666.67, and 5000.00 μg/plate. results HPLC and HPTLC analysis of BM revealed the presence of bacoside A3. bacopaside Ⅰ, bacopaside Ⅱ, jujubogenin isomer of bacopasaponin C, bacosine, luteolin, apigenin, bacosine, and β-sitosterol D glucoside. BM demonstrated significant antioxidant activity. The number of chromosomal aberrations and the frequency of micronuclei induced by BM were not statistically significant up to a dose of 62.5 μg/mL. A subsequent dose of 125 μg/mL prior to metabolic activation induced mild clastogenicity, but it was found to be biologically insignificant as this ef

关键词： BacoMind^TM Cytotoxicity Chromosomal aberration Ames test Micronucleus, Clastogens Antioxidant High performance liquid chromatography High performance thin-layer chromatography (HPTLC)

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Numerical Study of U-beam Inertial Separator

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Journal of Thermal Science 2001年第3期10卷 264-268页

作者： L.H.Chen J.r.Fan 等 CollegeofMechanicalandEnergyEngineering ZhejiangUniversityHangzhouChina310027 CollegeofMechanicalan

A detailed parametric study is conducted on three-dimensional gas-solid multiphase flow characteristics in inertial separators via numerical simulation. The carrier phase is treated in the Eulerian frame, the particles are tracked in the Lagrangian frame, and particle-wall collision and particle-particle collision are considered. The inertial separators are made out of U-beam tube, arranged staggered .The separator has good performance for large particles and its compact structures make it easy to manufacture and install. The simulation is carried out in different inflow rate and provide the pressure losses in the separators, velocity field of gas phase, the trajectories of particles and the separation efficiency of separators. The result from this study not only shows the multiphase flow-dynamic characteristics of the separators, but also gives the relationship among the efficiency, structure and pressure losses of the separator. The comparison between the numerical simulation result and experimental data demonstrate the reliability of the numerical simulation.

关键词： gas-solid inertial separator numerical simulation dynamic characteristics separation efficiency.

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Effects of rare Earth Elements on the Characteristics of Low Temperature Plasma Nitrocarburized Martensitic Stainless Steel

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Journal of Materials Science & Technology 2012年第11期28卷 1046-1052页

作者： r.L.Lju Y.J.Qiao M.F.Yan Y.D.Fu College of Materials Science and Chemical Engineering Harbin Engineering UniversityHarbin 150001China School of Materials Science and Engineering Harbin Institute of TechnologyHarbin 150001China

Low temperature plasma nitrocarburizing of 17-4PH martensitic stainless steel was conducted at 430 ℃ with and without rare earth （rE） addition. The microstructure, kinetics, microhardness, wear behavior as well as corrosion resistance of the modified layer were studied by optical microscopy, X-ray diffraction, Vickers microhardness tester, pin-on-disc tribometer and potentiodynamic polarization tests. The results show that the thickness of plasma rE nitrocarburized layer is much thicker than that formed by nitrocarburizing without rE addition. The incorporation of rE does not change the kind of the phases and the nitrocarburized layer consists mainly of nitrogen and carbon expanded martensite （aN）, γ-Fe4N and a-Fe with a trace of CrN phases. The surface microhardness of plasma nitrocarburized layer can be increased by 100 HV after rE addition. Wear resistance of the specimen can be apparently improved by low temperature plasma nitrocarburizing with and without rE addition and without sacrificing its corrosion resistance. Wear reduction effect of low temperature plasma nitrocarburizing with rE addition is better than that of the conventional one.

关键词： Stainless steel Low temperature Plasma nitrocarburizing rare earth (rE) Wear and friction

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气-液半间歇反应器中甘油氯化:用于生产氯代醇的新型催化剂(英)

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催化学报 2014年第5期35卷 663-669页

作者： r.Vitiello V.russo r.Turco r.Tesser M.Di Serio E.Santacesaria Department of Chemicals Sciences University of Study of Naples "Federico Ⅱ"

Glycerol from biodiesel production can be an important industrial feedstock for chemical commodities as it can be used in the food,cosmetic,pharmaceutical and tobacco ***,crude glycerol derived from biodiesel production has a low value because of *** purification of this glycerol into a high grade involves high costs and is not economically feasible for small and medium size *** glycerol conversion into chlorohydrins was studied using new homogeneous catalysts and hydrochloric acid as chlorination *** is an interesting alternative route to epichlorohydrin and then to epoxy *** behavior of two series of homologous catalysts,glycolic acid series(glycolic acid,di-glycolic acid and thio-glycolic acid) and amminoacid series(glutamic acid,aspartic acid and cysteine),were investigated for their activity and *** acids were more active than *** pK_a values had a strong influence on selectivity(mono-chlorohydrins/di-chlorohydrins) for the amminoacid series,which was not observed for the glycolic acids.A kinetic model and reaction mechanism developed in a previous work were used for interpreting the kinetic runs.

关键词：粗甘油催化剂氯化剂氯代醇间歇反应器生产硫代乙醇酸生物柴油

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TWO-GrID METHOD FOr CHArACTErISTICS FINITE-ELEMENT SOLUTION OF 2D NONLINEAr CONVECTION-DOMINATED DIFFUSION PrOBLEM

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Applied Mathematics and Mechanics(English Edition) 2005年第11期26卷 1506-1514页

作者：秦新强School of Sciences Xi’an Jiaotong University Xi’an 710049 P.r.China School of Sciences Xi’an University of Technology Xi’an 710048 P.r.China) 马逸尘章胤 School of Sciences Xi’an Jiaotong UniversityXi’an 710049 P.R.China School of Sciences Xi’an University of TechnologyXi’an 710048 P.R.China

For two-dimension nonlinear convection diffusion equation, a two-grid method of characteristics finite-element solution was constructed. In this method the nonlinear iterations is only to execute on the coarse grid and the fine-grid solution can be obtained in a single linear step. For the nonlinear convection-dominated diffusion equation, this method can not only stabilize the numerical oscillation but also accelerate the convergence and improve the computational efficiency. The error analysis demonstrates if the mesh sizes between coarse-grid and fine-grid satisfy the certain relationship, the two-grid solution and the characteristics finite-element solution have the same order of accuracy. The numerical is more efficient than that of characteristics example confirms that the two-grid method finite-element method.

关键词： convection-diffusion equation characteristics finite-element two-grid method convergence

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ESTIMATION OF rELATIVE BLOOD VOLUME IN HEAD AND NECK TUMOrS

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波谱学杂志 2002年第1期19卷 101-102页

作者： r.H.WU r.Bruening J.MA C.BErCHTENBrEITHEr r.JUND H.B.rAO X.H.XU M.rEISEr Shantou University Medical College China Klinikum GrosshadernUniversity of MunichGermany Klinikum Grosshadern University of MunichGermany Dalian Medical University China Shantou University Medical College China

Introduction: The calculation of relative blood volume in head and neck tumor with Mr imaging is anew approach that may provide additional hemodynamic information relevant to both untreated and treated tumors. This hemodynamic information is especially useful for the differentiation between viable tumor and postsurgical changes or radiation induced scar, and is also beneficial for tumor staging and tumor biopsy.

关键词： maps ESTIMATION OF rELATIVE BLOOD VOLUME IN HEAD AND NECK TUMOrS

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Uniformity of TiN Films Fabricated by Hollow Cathode Discharge

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Plasma Science and Technology 2010年第2期12卷 212-217页

作者：姜海富巩春志田修波杨士勤 r.K.Y.FU P.K.CHU State Key Lab.of Advanced Welding Production & Technology School of Material Science and Engineering Harbin Institute of Technology Department of Physics and Materials Science City University of Hong Kong

Titanium nitride （TIN） films were deposited on AISI 304 stainless steel substrates using hollow cathode plasma physical vapor deposition （HC-PVD）. Titanium was introduced by eroding the Ti cathode nozzle and TiN was formed in the presence of a nitrogen plasma excited by radio frequency （rF）. The substrate bias voltage was varied from 0 to -300 V and the uniformity in film thickness, surface roughness, crystal size, microhardness and wear resistance for the film with a diameter of 20 mm was evaluated. Although the central zone of the plasma had the highest ion density, the film thickness did not vary appreciably across the sample. The results from atomic force microscopy （AFM） revealed a low surface roughness dominated by an island-like morphology with a similar crystal size on the entire surface. Higher microhardness was measured at the central zone of the sample. The sample treated at -200 V had excellent tribological properties and uniformity.

关键词： hollow cathode TiN film uniformity

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Particulate matter emissions and gaseous air toxic pollutants from commercial meat cooking operations

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Journal of Environmental Sciences 2018年第3期30卷 162-170页

作者： Nicholas Gysel William A.Welch Chia-Li Chen Poornima Dixit David r.Cocker Ⅲ Georgios Karavalakis Department of Chemical and Environmental Engineering University of CaliforniaRiverside Center for Environmental research and Technology University of CaliforniaRiverside

This study assessed the effectiveness of three novel control technologies for particulate matter（PM） and volatile organic compound（VOC） removal from commercial meat cooking operations. All experiments were conducted using standardized procedures at University of California, riverside＇s commercial test cooking facility. PM mass emissions collected using South Coast Air Quality Management District（SCAQMD） Method 5.1, as well as a dilution tunnel-based PM method showed statistically significantly reductions for each control technology when compared to baseline testing（i.e., without a catalyst）. Overall, particle number emissions decreased with the use of control technologies, with the exception of control technology 2（CT2）, which is a grease removal technology based on boundary layer momentum transfer（BLMT） theory. Particle size distributions were unimodal with CT2 resulting in higher particle number populations at lower particle diameters. Organic carbon was the dominant PM component（ 99%） for all experiments. Formaldehyde and acetaldehyde were the most abundant carbonyl compounds and showed reductions with the application of the control technologies. Some reductions in mono-aromatic VOCs were also observed with CT2 and the electrostatic precipitator（ESP） CT3 compared to the baseline testing.

关键词： Charbroiled meat cooking Particulate emissions Particle number Carbonyl compounds VOCs

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