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《中国光学快报(英文版)》2014,(9):F0003-F0003
正Chinese Optics Letters is a short-article journal for the rapid dissemination of new,i mportant results in all branches of optical science and technology and related fields,published monthly by Chinese Laser Press and distributed abroad by the Optical Society(OSA).Submission of Papers 相似文献
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Mark J. Kaiser 《Computational Geometry》1999,12(3-4):177-217
The mixed volume optimization problem is to determine the point of duality Q for a given convex set K that minimizes the “mixed volume” of the associated polar set (K*;Q). In the plane, the mixed volumes translate as the area and length; in space, the mixed volumes include the volume, surface area, and mean width. In this paper, the geometric optimization problems associated with minimizing mixed volumes are examined from two perspectives: enumerative search and symbolic computation. The problem of minimizing the polar area through an enumerative search is first considered. The dual polygon (Pm*;Q) is constructed for an arbitrary point of duality QPm° by using an algebraic correspondence between the edges of Pm and the vertices of (Pm*;Q), and the area of (Pm*;Q), A(P*m;Q), is calculated and minimized using naive search techniques. A result due to Santaló is applied to verify the minimizing solution, and computational tests are described for various classes of randomly generated polygons. Statistical evidence indicates that a “good” approximation to the minimum area polar polygon occurs when the duality point is located at the center-of-gravity of Pm. The polar area problem is then investigated using symbolic procedures. Explicit symbolic expressions for the polar area and length functionals are computed and solved directly using the differential optimality conditions and Newton's iterative method of solution. The mixed volume and surface area functionals are formulated and solved using numerical products, and the mean width functional is described. Examples are used throughout to illustratethe methodology. 相似文献
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李萨如图在捷联惯导系统圆锥误差估计中的应用 总被引:2,自引:0,他引:2
分析了激光陀螺捷联惯导系统产生圆锥运动的原因,给出了估计圆锥误差的一般方法,并在此基础上给出了一种简单、实用的方法-李萨如图法,后比前更加接近工程应用。最后给出了验证试验结果。 相似文献
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A new phase-stepping algorithm is proposed, the algorithm can be implemented without knowing or calculating the phase steps. New phase extraction expressions based on using Lissajous figures and ellipse fitting are derived by introducing a simple difference transform for the intensity of the interferograms. The simulating results indicate that the new algorithm is insensitive to phase-stepping errors and the accuracy of the new algorithm is only limited by the computation truncation errors. 相似文献
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浅谈环境水质分析结果的审核工作 总被引:3,自引:0,他引:3
王俊荣 《理化检验(化学分册)》2005,41(7):500-501
对分析结果的有效数字和数据之间的合理性关系问题从理论上进行了研究,为数据审核工作提供科学参考。 相似文献
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Temperature modulated DSC (TMDSC) at low temperatures requires attention to the selection of experimental parameters that
are within the capability of the instrumentation as well as special care in calibration of heat capacity measurement when
high precision is required. Data are presented to facilitate selection of appropriate modulation periods and amplitudes at
low temperature when using a mechanical cooling accessory. The standard error of the mean heat capacity measurement for a
sapphire standard increased with decreasing temperature, decreasing period, and increasing pan mass. For ice in hermetically
sealed pans, the standard error of the mean heat capacity measurement was larger than for sapphire and did not follow a predictable
trend with changes in temperature and period of modulation. This was attributed to changes in sample geometry between successive
measurements due to melting and resolidification. A simple one-point temperature calibration by TMDSC may be unsuitable for
precise measurement of heat capacity because of the random error caused by sample placement and the systematic error caused
by cell asymmetry, temperature dependence of the calibration constant, and different sample thermal conductivities. An alternative
calibration procedure using standard DSC and either a linear or second order fit of the calibration constant over the temperature
range of interest is proposed.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
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EBSD measurements were carried out on four different martensitic steels (T91, P92, EM10 and Eurofer) in various metallurgical conditions (nine different microstructural states). The usual orientation relationships (ORs) between the parent austenitic phase and the resulting martensite in martensitic steels are those of Nishiyama–Wassermann (NW) and Kurjumov–Sachs (KS). The present study first proposes a methodology based on the combined analysis of the misorientation distribution, the pole figures (PFs) and the angle/axis pairs. This methodology leads to the conclusion that neither NW nor KS relationships are able to account for all the features observed whatever the material under study. A third OR proposed by Greninger and Troiano (GT) proves to describe the relationship between austenite and ferrite in all four different martensitic steels much more accurately. 相似文献
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