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The radial evolution of earthward BBFs during substorm

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Science China Earth Sciences 2010年第10期53卷 1542-1551页

作者： REmE H DANDOURAS i LUCEK E DUNLOP m Centre d'Etude Spatiale des Rayonnements Blackett Laboratory Imperial College London Rutherford Appleton Laboratory

We here study the occurrence rate,probability function of velocity and duration of earthward bursty bulk flows(BBFs) in the inner Plasma Sheet(iPS,β>0.5) using the data of Cluster in 2001 and *** occurrence rate of earthward BBFs increases with distance from the Earth up to ?19 RE,which is in agreement with the previous observations of the radial evolution of *** 54% of earthward BBFs in expansion phase have a velocity larger than 600 km/s,whereas only 38% of earthward BBFs in growth and recovery phases have a velocity larger than 600 km/*** average velocity of earthward BBFs in expansion phase is 732 km/s,larger than those in growth phase(631 km/s) and recovery phase(617 km/s).The durations of earthward BBFs decrease with the decrease of downtail distance from Earth due to the braking of earthward *** duration of earthward BBFs in expansion phase is larger than that in growth and recovery *** average durations in growth,expansion,and recovery phases are respectively 49.3,71.5,and 47.6 ***,the ratios of transports of energy of earthward BBFs in growth,expansion,and recovery phases can be estimated to be 0.51:1:***,the earthward BBFs in the expansion phase have the largest capability of the transport of energy and can produce the largest braking effects,such as inertial currents and auroral activities.

关键词： substorm growth expansion recovery duration energy transport

impulsive efects on global stability of models based on impulsive diferential equations with “supremum” and variable impulsive perturbations

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Applied mathematics and mechanics(English Edition) 2014年第1期35卷 85-96页

作者： i.m.STAmOVA T.G.STAmOV Department of mathematics The University of Texas at San Antonio Department of Engineering Design Faculty of Mechanical EngineeringTechnical University of Sofia

Sufficient conditions are investigated for the global stability of the solu tions to models based on nonlinear impulsive differential equations with ＂supremum＂ and variable impulsive perturbations. The main tools are the Lyapunov functions and Razu mikhin technique. Two illustrative examples are given to demonstrate the effectiveness of the obtained results.

关键词： global stability Lyapunov-Razumikhin function nonlinear impulsive dif-ferential equation with "supremum" variable impulsive perturbation

Review of research and application of evaporative cooling in preservation of fresh agricultural produce

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international Journal of Agricultural and Biological Engineering 2014年第5期7卷 85-102页

作者： m.C.Ndukwu S.i.manuwa Department of Agricultural and Bio-resources Engineering Michael Okpara University of AgricultureUmudike Umuahia Abia StateNigeria Department of Agricultural Engineering Federal University of Technology AkureP.M.B.704 AkureOndo StateNigeria

Extensive review of evaporative coolers for the preservation of fresh agricultural produce in some countries was *** of the designs employ mainly direct evaporative cooling methods which are simple but with lower thermal performance,and can only be used for short term storage of agricultural produce with moderate respiratory *** into novel technologies in evaporative cooling systems which can improve the cooling performances,such as membrane air treatments,dew point type and heat pipe type heat exchanger in indirect/direct evaporative cooling application,and their feasibilities in agricultural storage are either absent or *** kinds of materials especially agricultural residues have been used for air water contact in evaporative cooling in different climates,but most of the analyses focused on effect of air flow rate and pad thickness on the cooling effectiveness,and the energy efficiency and evaporation loss of these materials in most cases were not evaluated or *** paper highlights the prospects and constraints of commercialization and marketing of evaporative coolers in some developing countries,and the general weakness in researches and the ways forward in new area of research and development are concluded.

关键词： agricultural products evaporative cooling passive coolers active coolers pad materials

Optimal finite-dimensional spectral densities for the identification of continuous-time mimO systems

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Control Theory and Technology 2019年第3期17卷 276-296页

作者： i.m.miTHUN Shravan mOHAN Bharath BHiKKAJi Department of Electrical Engineering Indian Institute of Technology Madras Chennai 600036 India

This paper presents a method for designing in puts to identify linear con tinuous-time multiple-input multiple-output (mimO) systems. The goal here is to design a T-optimal band-limited spectrum satisfying certain input/output power constraints. The input power spectral density matrix is parametrized as the productφu(jω)= 1/2H(jω)H^H(jω),where H(jω) is a matrix polynomial. This parametrization transforms the T-optimal cost function and the constraints into a quadratically constrained quadratic program (QCQP). The QCQP turns out to be a non-convex semidefinite program with a rank one constraint. A convex relaxation of the problem is first solved. A rank one solution is constructed from the solution to the relaxed problem. This relaxation admits no gap between its solution and the original non-convex QCQP problem. The constructed rank one solution leads to a spectrum that is optimal. The proposed input design methodology is experimentally validated on a cantilever beam bonded with piezoelectric plates for sensing and actuation. Subspace identification algorithm is used to estimate the system from the input-output data.

关键词： System identification optimal input design fisher information matrix quadratically constrained quadratic program

Preserving fertility in the hypogonadal patient： an update

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Asian Journal of Andrology 2015年第2期17卷 197-200,I0006,I0007页

作者： Ranjith Ramasamy Joseph m Armstrong Larry i Lipshultz Department of Urology Baylor Collegesssss of Medicine Houston TX USA.

An increasing number of young and middle-aged men are seeking treatment for symptoms related to deficient levels of androgens （hypogonadism） including depression, loss of libido, erectile dysfunction, and fatigue. The increase in prevalence of testosterone supplementation in general and anabolic steroid-induced hypogonadism specifically among younger athletes is creating a population of young men who are uniquely impacted by the testicular end-organ negative consequences of exogenous steroid use. Exogenous testosterone therapy can alter the natural regulation of the hypothalamic-pituitary-gonadal axis leading to impaired spermatoganesis with azoospermia being a serious possible result, thus rendering the individual infertile. For men of reproductive age who suffer from hypogonadal symptoms, preservation of fertility is an important aspect of their treatment paradigm. Treatment with human chorionic gonadotropin （hCG） has shown the ability not only to reverse azoospermia brought on by testosterone supplementation therapy but also to help maintain elevated intratesticular testosterone levels. in addition, selective estrogen receptor modulators, often used with hCG have been shown both to elevate total testosterone levels and to maintain spermatogenesis in hypogonadal men.

关键词： human chorionic gonadotropin selective estrogen receptor modulators spermatogenesis testosterone supplementation therapy

Analysis of particulate behavior in porous media

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Applied mathematics and mechanics(English Edition) 2008年第4期29卷 511-516页

作者： Hani i.Siyyam m.H.Hamdan Department of mathematics and Physics College of Arts and SciencesQatar UniversityP.O.Box 2713DohaQatar Department of mathematical Sciences University of New BrunswickP.O.Box 5050Saint JohnNew BrunswickCanada

in this work, we analyze the behavior of the particle phase in the flow of a particle-laden mixture through a porous medium. An attempt is made to model the diffusion and dispersion processes, and to quantify the devi... 详细信息

关键词： porous media dusty gases particle behavior

Transfusion transmitted virus: A review on its molecular characteristics and role in medicine

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World Journal of Gastroenterology 2006年第32期12卷 5122-5134页

作者： m irshad YK Joshi Y Sharma i Dhar Clinical Biochemistry Division Department of Laboratory medicine All India Institute of Medical SciencesNew Delhi-110029India Department of Gastroenterology and Human Nutrition All india institute of medical Sciences New Delhi-110029India

The present review gives an updated overview of transfusion transmitted virus （TTV）, a novel agent, in relation to its molecular characteristics, epidemiological features, modes of transmission, tissue tropism, pathogenesis, role in various diseases and its eradication from the body. TTV, a DNA virus, is a single stranded, non-enveloped, 3.8 kb long DNA virus with a small and covalently closed circular genome comprising 3852 bases. it was tentatively designated Cirdnoviridae *** genome sequence is heterogeneous and reveals the existence of six different genotypes and several subtypes. TTV has been reported to transmit not only via parenteral routes, but also via alternate routes. This virus has been detected in different non-human primates as well. At present, TTV is detected by polymerase chain reaction （PCR） with no other available diagnostic assays. it shows its presence globally and was detected in high percent populations of healthy persons as well as in various disease groups. initially it was supposed to have strong association with liver disease; however, there is little evidence to show its liver tropism and contribution in causing liver diseases. it shows high prevalence in hemodialysis patients, pointing towards its significance in renal diseases. in addition,TTV is associated with several infectious and non-infectious diseases. Though, its exact pathogenesis is not yet clear, TTV virus possibly resides and multiplies in bone marrow cells and peripheral blood mononuclear cells （PBmCs）. Recently, attempts have been made to eradicate this virus with interferon treatment. more information is still needed to extricate various mysteries related to TTV.

关键词： Transfusion transmitted virus DNA Virus Hepatitis Transfusion

Hybridization between microstructure and magnetization improvement in lead and RE co-doped BiFeO_3

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Journal of Rare Earths 2016年第5期34卷 495-506页

作者： m.A.Ahmed S.F.mansour S.i.El-Dek m.m.Karamany materials Science Lab.(1) Physics Dept.Faculty of ScienceCairo University Physics Department Faculty of ScienceZagazig University materials Science and Nanotechnology Dept. Faculty of Post Graduate Studies for Advanced SciencesBeni-Suef University Basic Science Dept. Faculty of EngineeringBritish University in Egypt

The crystal structure,magnetic and electrical properties of Bi（0.96）Pb（0.04） FeO3 and Bi（0.92）Pb（0.04）RE（0.04）FeO3（RE=La,Sm,Dy and Yb）polycrystalline samples were prepared by the flash autocombustion technique.X-ray diffraction（XRD）measurements show that the rare-earth doped compositions crystallized in rhombohedral symmetry of space group R3 *** undoped sample consisted needle shape particles while rare earth substitution preferred platelet like particles as clarified from high resolution transmission electron microscopy（HRTEm）.morphological features were examined using field emission scanning electron microscopy（FESEm）.magnetization measurements showed that Yb^3＋ samples possessed the highest room temperature saturation magnetization while when Bi^3＋ ions were substituted by La^3＋ ions,a smaller mS（0.28 emu/g）was *** coexistence of ferroelectric and magnetic transitions was detected using DSC and χm,indicating the multiferroic characteristics of Bi（0.92）Pb（0.04）RE（0.04）FeO3 *** Néel temperature shifted upwards with decreasing the ionic radius of rare earth *** correlation was established between microstructure,morphology and magnetic properties in view of the contribution of magnetocrystalline and shape anisotropy in the magnetic parameters values.

关键词： BiFeO3 multiferroic rare earths anisotropy dielectric conductivity Neel temperature

Thermal Spray Coating of Tungsten for Tokamak Device

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Plasma Science and Technology 2006年第2期8卷 164-167页

作者：蒋显亮 F. GiTZHOFER m.i. BOULOS institute of Surface and Coatings Technology Central South University Changsha 410083 China Plasma Technology Research Center University of Sherbrooke Sherbrooke J1K 2R1Canada

Thermal spray, such as direct current （d.c.） plasma spray or radio frequency induced plasma spray, was used to deposit tungsten coatings on the copper electrodes of a tokamak device. The tungsten coating on the outer surface of one copper electrode was formed directly through d.c. plasma spraying of fine tungsten powder. The tungsten coating/lining on the inner surface of another copper electrode could be formed indirectly through induced plasma spraying of coarse tungsten powder. Scanning electron microscopy （SEm） was used to examine the cross section and the interface of the tungsten coating. Energy Dispersive Analysis of X-ray （EDAX） was used to analyze the metallic elements attached to a separated interface. The influence of the particle size of the tungsten powder on the density, cracking behavior and adhesion of the coating is discussed. it is found that the coarse tungsten powder with the particle size of 45-75μm can be melted and the coating can be formed only by using induced plasma. The coating deposited from the coarse powder has much higher cohesive strength, adhesive strength and crack resistance than the coating made from the fine powder with a particle size of 5μm.

关键词： tokamak device copper electrode thermal spray tungsten coating tungsten/copper interface