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61.
为了克服用极值法从白光干涉谱数据求解光程差存在的抗噪声能力差的缺点,提出了一种基于均方差最小意义下新的处理方法.该方法假定当光程差某个估计值与实际值最接近时,对应的干涉谱的均方差最小.首先对干涉谱测量值进行归一化处理,消除低频光强变化的影响,并用极值法求得光程差的初值,然后求归一化的干涉谱与基于初值的理想干涉谱之间的均方差,通过逼近法获得均方差最小时对应的估计值.数值仿真和实验结果表明,利用该方法处理白光干涉谱数据得到的光程差,不仅比极值法具有更高的数据精度,而且有效地提高了抗干扰能力. 相似文献
62.
G. E. Volovik 《Journal of Low Temperature Physics》2006,145(1-4):337-356
Ripplons—gravity-capillary waves on the free surface of a liquid or at the interfaces between two superfluids—are the most
favorable excitations for simulation of the general-relativistic effects related to horizons and ergoregions. The white-hole
horizon for the “relativistic” ripplons at the surface of the shallow liquid is easily simulated using the kitchen-bath hydraulic
jump. The same white-hole horizon is observed in quantum liquid—superfluid 4He. The ergoregion for the “non-relativistic” ripplons is generated in the experiments with two sliding 3He superfluids. The common property experienced by all these ripplons is the Miles instability inside the ergoregion or horizon.
Because of the universality of the Miles instability, one may expect that it could take place inside the horizon of the astrophysical
black holes, if there is a preferred reference frame which comes from the trans-Planckian physics. If this is the case, the
black hole would evapotate much faster than due to the Hawking radiation. Hawking radiation from the artificial black hole
in terms of the quantum tunneling of phonons and ripplons is also discussed.
相似文献
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H. Hofmann D. Mattissen T. W. Schaumann 《Materialwissenschaft und Werkstofftechnik》2006,37(9):716-723
Advanced multiphase steels offer a great potential for bodies‐in‐white through their combination of formability and achievable component strength levels. They are first choice for strength and crash‐relevant parts of challenging geometry. The intensive development of high‐strength multiphase steels by ThyssenKrupp has led to hot dip galvanizing concepts with an outstanding forming potential. Hot rolled, hot dip galvanized complex phase steels are currently produced in addition to cold rolled DP and RA steels. New continuously annealed grades with tensile strength levels of up to 1000 MPa in combination with sufficient ductility for applications mainly in the field of structural automobile elements make use of the classic advantages of microalloying as well as the principles of DP and TRIP steels. Further improvement of properties will be reached by the new class of high manganese alloyed steels. 相似文献
66.
鄂钢电炉炼钢厂在生产60Si2Mn弹簧圆钢时,发生较为严重的机械性能不合,主要表现为延伸率及断面收缩率低,试样呈脆性断口,断口及低倍试样中发现有白点缺陷.经分析,造成60Si2Mn弹簧圆钢机械性能不合的主要原因为钢中氢含量高,在工艺中提出改进措施,以改进其机械性能,提高产品质量. 相似文献
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Optimal bounded control of harmonically and stochastically excited strongly nonlinear oscillators 总被引:1,自引:0,他引:1
A procedure for designing optimal bounded control to minimize the response of harmonically and stochastically excited strongly nonlinear oscillators is proposed. First, the stochastic averaging method for controlled strongly nonlinear oscillators under combined harmonic and white noise excitations using generalized harmonic functions is introduced. Then, the dynamical programming equation for the control problem of minimizing response of the systems is formulated from the partially completed averaged Itô equations by using the dynamical programming principle. The optimal control law is derived from the dynamical programming equation and control constraint without solving the dynamical programming equation. Finally, the stationary probability density of the amplitude and mean amplitude of the optimally controlled systems are obtained from solving the reduced Fokker–Planck–Kolmogorov equation associated with fully completed averaged Itô equations. An example is given to illustrate the proposed procedure and the results obtained are verified by using those from digital simulation. 相似文献
69.
研究了日本酱油生产菌AspergillusoryzaeJP DQ 1,AspergillusoryzaeJP W和我国酱油生产菌AspergillusoryzaeAS3.951的酶系。结果表明:3种菌在浓酱油曲和白酱油曲培养基上均可产生α 淀粉酶、糖化酶、纤维素外切酶、果胶酶、酸性蛋白酶和中性蛋白酶;JP W是较好的白酱油生产菌,JP DQ 1是较好的浓酱油生产菌。还对酱油酵母的生理特性进行了部分研究,发现食盐浓度对酱油酵母生长影响较大,酱油发酵过程的盐浓度不宜超过3mol/L,低于2mol/L更佳。酱油酵母的较适生长pH为4.5~5.5。 相似文献
70.