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Characteristics of Nd：YGG Laser Operating at ^4F3/2-^4I9/2

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Chinese Physics Letters 2008年第11期25卷 3988-3990页

作者：张玲张春雨李德华魏志义张治国 hans j. eichler Stephan Strohmaier Beij.ng National Laboratory or Condensed Matter Physics Institute of Physics Chinese Academy of Sciences Beijing 100190 Optical Institute Technical University Berlin Strasse de 17 Juni 135 D-10623 Berlin Germany

The laser properties of the Nd：YGG crystal are investigated. The absorption spectrum from 500 to 90Onto and emission spectrum from 850 to 1400nm of Nd：YGG are measured. As much as 1.35 W output power of fundamental laser operating at 935 and 938nm with a slope efficiency of 15.7% and 105mW output power of frequency doubled blue laser are successfully obtained.

关键词： Characteristics of Nd:YGG Laser Operating ~4F_(3/2)-~4I_(9/2)

High-resolution Induan-Olenekian boundary sequence in Chaohu, Anhui Province

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Science China Earth Sciences 2005年第3期48卷 291-297页

作者： hans j. hansen Geological Institute Copenhagen University Oster Voldgade 10 DK-1350 Copenhage Denmark

The West Pingdingshan Section in Chaohu, Southeast China’s Anhui Province is one of the potential GSSP candidates for the Induan-Olenekian boundary. Extensive study has been done on the Induan-Olenekian boundary strata at the section to meet the requirements of defining the GSSP precisely. This paper focuses on the boundary strata at the section to present a review of the main results achieved in recent years. The Induan-Olenekian boundary strata here cover an interval of about four meters at the West Pingdingshan Section, in which the key indices of defining the boundary and the chief transitional processes of some parameters at the boundary are included. The relationship between the boundaries defined by ammonoids and by conodonts is well clarified at the section. The magnetic polarity analysis shows that the boundary interval belongs to a normal polarity zone. Both the carbonate and organic carbon isotopes com- positions experienced a significant conversion in the boundary interval.

关键词： Lower Triassic, Induan-Olenekian boundary, GSSP, candidate, Chaohu of China.

Micromechanical investigation of granular ratcheting using a discrete model of polygonal particles

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Particuology 2008年第6期6卷 390-403页

作者： Fernando Alonso-Marroquín hans B. Mhlhaus hans j. Herrmann Earth Systems Science Computational Centre & School of Physical Sciences The University of Queensland Earth Systems Science Computational Centre The University of Queensland Institut fr Baustoffe ETH-HenggerbergZrich

We use a two-dimensional model of polygonal particles to investigate granular ratcheting. Ratcheting is a long-term response of granular materials under cyclic loading, where the same amount of permanent deformation is accumulated after each cycle. We report on ratcheting for low frequencies and extremely small loading amplitudes. The evolution of the sub-network of sliding contacts allows us to understand the micromechanics of ratcheting. We show that the contact network evolves almost periodically under cyclic loading as the sub-network of the sliding contacts reaches different stages of anisotropy in each cycle. Sliding contacts lead to a monotonic accumulation of permanent deformation per cycle in each particle. The distribution of these deformations appears to be correlated in form of vortices inside the granular assembly.

关键词： Granular systems Dynamics and kinematics of rigid bodies Molecular dynamics methods

激光二极管端面抽运的多晶Nd∶YAG 1.06μm连续激光器

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中国激光 2004年第1期31卷 16-18页

作者：杨林黄维玲丘军林 Volker Gaebler hans j.eichler 华中科技大学激光技术国家重点实验室湖北武汉430074 Optical Institute Technical University Berlin

报道了激光二极管端面抽运的多晶Nd∶YAG(polycrystallineNd∶YAGceramic) 1 0 6 μm连续激光器的实验研究。在抽运功率为 0 3W时 ,激光达到阈值开始输出 ;在抽运功率为 9W时 ,输出功率达到 2W ,激光器光光转换效率为 2 2 2 %。

关键词：激光技术固体激光器激光二极管抽运多晶Nd:YAG 端面抽运连续激光器

Modeling slow deformation of polygonal particles using DEM

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Particuology 2008年第6期6卷 506-514页

作者： Andrés A. Pea Pedro G. Lind hans j. Herrmann Institute for Computational Physics Universitt Stuttgart Computational Physics IfB HIF E12 ETH Hnggerberg CH-8093 Zrich Switzerland Departamento de Física Universidade Federal do Ceará

We introduce two improvements in the numerical scheme to simulate collision and slow shearing of irregular particles. First, we propose an alternative approach based on simple relations to compute the frictional contact forces. The approach improves efficiency and accuracy of the Discrete Element Method （DEM） when modeling the dynamics of the granular packing. We determine the proper upper limit for the integration step in the standard numerical scheme using a wide range of material parameters. To this end, we study the kinetic energy decay in a stress controlled test between two particles. Second, we show that the usual way of defining the contact plane between two polygonal particles is, in general, not unique which leads to discontinuities in the direction of the contact plane while particles move. To solve this drawback, we introduce an accurate definition for the contact plane based on the shape of the overlap area between touching particles, which evolves continuously in time.

关键词： Granular media Discrete element method Slow deformation Contact forces

Achieving single-lobed far-field patterns of broad area laser diode with external cavity feedback

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Chinese Optics Letters 2003年第6期1卷 334-336页

作者：葛剑虹陈军 Andreas Hermerschmidt H.j.eichler The State Key Laboratory of Modern Optical Instrumentation Zhejiang University Hangzhou 310027 Optisches Institut Technische Univeisitat Berlin StraBe des 17. Juni 135 10623 Berlin Germany

We demonstrate a technique for single transverse mode operation of high-power broad area laser diode (BAL). In the experiment, the HR mirror is used as an external cavity mirror and the grating is used as a wavelength selective component. By tiling the HR mirror and the grating, the number of transverse modes oscillating in the cavity can be limited and the spectral bandwidth of the laser diode can be reduced. A single-lobed near diffraction-limited laser beam with the beam divergence (FWHM) of 0.43°, the spectral line-width of 0.7 nm and the output power of 350 mW are obtained. With the feedback, the power density of the output laser beam is increased 6 times in comparison with the free running.

关键词： Cavity resonators Diffraction gratings High power lasers Mirrors

Enhancing Immune Responses for Cancer Therapy

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Cellular & Molecular Immunology 2007年第3期4卷 173-184页

作者： hans j.Stauss Department of Immunology and Molecular Pathology University College London Hampstead Campus Royal Free Hospital Rowland Hill Street London NW3 2PF United Kingdom

Although the immune system possesses the means to respond to cancer, it often fails to control the spread of malignancy. Nonetheless, equipping endogenous immunity to release a strong antitumor response has significant advantages over conventional therapies. This review explores some of the options available to accomplish this, focusing first on vaccinations with tumor antigens to stimulate the immune system and empower stronger antitumor responses. We then compare and contrast the so-far limited clinical success of vaccination with the well-documented curative potential of adoptive therapy using T lymphocytes transfer. Finally, we highlight novel approaches using T call receptor （TCR） gene transfer strategy to exploit allogeneic T cell repertoires in conj.nction with receptors selected in vitro for defined MHC/peptide combinations, as a basis for antigen-specific gene therapy of cancers. Cellular ＆ Molecular Immunology.

关键词： tumor antigen vaccination adoptive immunotherapy T cell receptor gene transfer TCR gene therapy

Anisotropic plastic deformation behavior of as-extruded ZK60 magnesium alloy at room temperature

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Science China(Technological Sciences) 2009年第1期52卷 161-165页

作者： hans j.R Department of Materials Science and Engineering Norwegian University of Science and Technology

The anisotropic plastic deformation behavior of as-extruded ZK60 magnesium alloy at room tempera-ture (RT) was investigated by compressive and tensile testing in different directions, i.e. the loading axis oriented at 0°, 45° and 90° to the extrusion direction. The relationship between texture and plastic deformation behavior were examined. The results show that the extruded ZK60 alloy exhibits a strong ring fiber texture. The mechanical properties are strongly orientation dependent. In tension testing, the 0° specimen exhibited higher yield strength and lower elongation. In compression testing, however, ZK60 alloy exhibited almost the same yield strength in three directions. The anisotropic plastic defor-mation behavior is due to strong fiber texture and the lower symmetry of the hexagonal close packed (hcp) structure of ZK60 alloy. The correlation between texture and mechanical behaviour offers the possibility to improve the mechanical properties of magnesium alloy by optimization of the material production process.

关键词： anisotropic plastic deformation behavior ZK60 Mg alloy texture mechanical property

Recycling of automotive aluminum

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Transactions of Nonferrous Metals Society of China 2010年第11期20卷 2057-2063页

作者： j.rang CUI hans j.ROVEN Department of Materials Science and Engineering Norwegian University of Science and Technology(NTNU)

With the global warming of concern,the secondary aluminum stream is becoming an even more important component of aluminum production and is attractive because of its economic and environmental *** this work,recycling of automotive aluminum is reviewed to highlight environmental benefits of aluminum recycling,use of aluminum alloys in automotive applications,automotive recycling process,and new technologies in aluminum scrap *** survey shows that newly developed techniques such as laser induced breakdown spectroscopy(LIBS) and solid state recycling provide promising alternatives in aluminum scrap *** with conventional remelting and subsequent refinement,solid state recycling utilizing compression and extrusion at room or moderate temperature can result in significant energy savings and higher metal yield.

关键词： recycling automotive aluminum sorting mechanical separation solid state recycling