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We demonstrate a 511 W laser diode pumped composite Nd:YAG ceramic laser. The optical pumping system is consisted of five laser diode stacked arrays arranged in a pentagonal shape around the ceramic rod whose size is φ6.35×144mm. When the pumping power is 1600 W, the cw laser output up to 511 W at 1064nm can be obtained with a linear piano-piano cavity, and the optical-to-optical efficiency is 31.9%. To our knowledge, this is the highest value of laser output by using a newly invented composite Nd:YAG ceramic rod as the gain medium.  相似文献
2.
We study the neutron star composition in the presence of a strong magnetic field. The effects of the anomalousmagnetic moments of both nucleons and electrons are investigated in relativistic mean field calculations for afl-equilibrium system. Since neutrons are fully spin polarized in a large field, generally speaking, the protonfraction can never exceed the field free case. An extremely strong magnetic field may lead to a pure neutronmatter instead of a proton-rich matter.  相似文献
3.
Under an external uniform electric field, the dielectric response of graded cylindrical composites having generalized dielectric profile inclusions is investigated. The generalized dielectric profile of graded cylindrical inclusion is expressed in the form, εi(r) = c(b + r)^keβr where r is the radial variable of the cylindrical inclusions and c, b, k and β are parameters. The local potential solution of generalized dielectric profile graded composites is derived by means of the power series method and the effective dielectric response is predicted in the dilute limit. Moreover, from the result of generalized profile, the analytical solutions of local potentials and the effective responses of graded composites having three cases of dielectric profiles, i.e., the exponential profile εi(r) = ce^βr, the general power law profile εi(r) = c(b + r)^k and the profile εi(r) = cr^keβr, are sorted out, respectively. In the dilute limit, our exact results are used to test the validity of differential effective dipole approximation (DEDA) for estimating the effective response of graded cylindrical composites, and it is shown that the DEDA is in excellent agreement with the exact result.  相似文献
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刘献铎 《应用声学》1987,6(1):47-47
七十年代后期,对于以过渡金属为基体的金属玻璃,熔旋制作技术有所发展,这导致对这些非晶金属系的磁性进行大量研究.通过测量加磁场下棒形样品的弹性谐振频率,最早观察到很高的磁弹耦合因数.这些材料现已发展为换能器的有效的原料. 金属玻璃是以熔化态投到旋转铜轮而进行快速淬火制成的,形成10—50μm厚的连续带.改变熔金属流的宽度可调节带的宽度,商业制品目前最宽可达6英寸(152.4cm).带的组成大约是80%的金属和20%的“玻璃形成”原素,如B、C、P和Si等.具有最好磁弹性质的合成物,是含有不同玻璃形成体组合的  相似文献
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