1,669 research outputs found
Invariant tori and Lagrange stability of pendulum-type equations
No full textAbstractIn this paper we prove that the pendulum-type equation x″ + g(t, x) = 0 possesses infinitely many invariant tori whenever g(t, x) has zero mean value on the torus T2, where g(t, x) belongs to C∞(T2). This yields the boundedness for solutions of the considered pendulum-type equation and thus leads to an answer to J. Moser's boundedness problem (1973, Ann. of Math. Stud. 77)
The charged and the spin-excitation gaps in the double-exchange model: a rigorous result
No full textWe extend a previous result of ours [G.S. Tian, Phys. Rev. B58 (1998) 7612] on the charged gap and the spin-excitation gap of the half-filled Kondo lattice model to the double-exchange model. In our original approach, this model cannot be dealt with since its localized spins have a large spin number S = 3/2. By following a construction argument due to Zener and rewriting the double-exchange Hamiltonian, we are able to overcome this difficulty and re-establish the same relation for this model.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000088659700004&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Physics, MultidisciplinarySCI(E)中国科学引文数据库(CSCD)3ARTICLE121-303
A 2-watt balanced power amplifier MMIC for Ku-band satellite communications
No full textA Ku-band power amplifier MMIC has been developed using 0.25-mum GaAs pHEMT technology. To achieve small chip size and simple drain-bias connection, a bus-bar power combiner is used. Also, balanced-power amplifier topology is used to obtain good input/ output return losses. The small-signal gain is about 15 dB and the gain variation is less than 1 dB from 12 to 17 GHz. Good input/output return losses are achieved at less than -15 dB due to the balanced topology. P-IdB of 32.6 dBm and PAE of 23.5% are achieved at 14 GHz. The effective chip area is 4.2 X 3.2 mm. Because the power amplifier is implemented using the balanced topology with the bus-bar power combiner, compact size, high output power, and good input/output return losses can be achieved simultaneously. (C) 2004 Wiley Periodicals, Inc.The author would like to thank Jeong-Ho Lee, Chung-Hwan Kim,
and Jae-Jin Lee at Teltron for their helpful discussions and encouragement.
This work was supported by KOSEF under the ERC
program through the MINT research center at Dongguk University
Flexicurity - Useful Oxymoron or Genuine Class Compromise?
No full textAuthor has checked copyrightDG 16/11/12Names JG 2012-11-1
Gesetzliche Mindestlöhne in Irland
No full textAuthor has checked copyrightDG 16/11/12Names JG 2012-11-1
The Dirichlet Problem for the Degenerate Elliptic Monge–Ampère Equation
No full textAbstractThe existence and uniqueness of the global C1,1/3 solution to the Dirichlet problem for the degenerate elliptic Monge–Ampère equation are proved, under mild conditions, and the application to the equation of the prescribed nonnegative Gauss curvature is also given
Diagnostic and clinical value of routine polymerase chain reaction analysis of intraocular fluid specimens in the diagnosis of suspected infectious posterior uveitis
No full textThe role of Plasmodium falciparum var genes in malaria in pregnancy
No full textSequestration of Plasmodium falciparum-infected erythrocytes in the placenta is responsible for many of the harmful effects of malaria during pregnancy. Sequestration occurs as a result of parasite adhesion molecules expressed on the surface of infected erythrocytes binding to host receptors in the placenta such as chondroitin sulphate A (CSA). Identification of the parasite ligand(s) responsible for placental adhesion could lead to the development of a vaccine to induce antibodies to prevent placental sequestration. Such a vaccine would reduce the maternal anaemia and infant deaths that are associated with malaria in pregnancy. Current research indicates that the parasite ligands mediating placental adhesion may be members of the P. falciparum variant surface antigen family PfEMP1, encoded by var genes. Two relatively well-conserved subfamilies of var genes have been implicated in placental adhesion, however, their role remains controversial. This review examines the evidence for and against the involvement of var genes in placental adhesion, and considers whether the most appropriate vaccine candidates have yet been identified
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