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11.
我们用爱氏光源(低电流交流电弧)作高速钢的光谱分析时,发现样品的组织结构对于分析结果有影响。为了对这个现象得到进一步的了解,我们选择了10种含碳量不同的铬钢进行热处理试验和光谱分析。一系列实验的结果指出,用小电流(5安)电弧光源时,铬的光谱分析结果由于试样是退火组织或淬火组织而有差别,这个差别又随着钢中含碳量的增加而增加。我们认为,这种影响是由于碳在试样中存在状态的不同所引起的。在低功率光源中,这种不同使合金元素被蒸发和被激发的情况有所差别,因而就影响了光谱分析的结果。这种影响由于合金元素之不同而有程度上的不同,对铬的影响很显著,对锰和矽的影响则很小。此外,所选择的分析线对是弧线还是火花线,对于这种组织结构的效应也有显著的影响。曾经进行了一些消除组织结构影响的实验。发现在应用低功率光源时,增加预燃时间并不能消除这个效应。用火花光源或大电流(8安)电弧光源时,这种影响大为减小。 相似文献
12.
本文推导出描述三能级Laser工作过程的准经典方程组,并分析了输出振动的稳定性。在阈值以上,当T1?T2,q-1时,只在1/(qT2)>1时,输出振幅是稳定的(其中T1,T2,q-1分别是分子纵向、横向及谐振腔的弛豫时间)。在稳定区域,趋向平衡的时间与T1成正比。当分子线宽小于谐振腔宽度时,输出是不稳定的,而在1/(qT2)减小时,平衡点由稳定变到不稳定时产生一个稳定的极限环,即输出振幅逐渐开始振动。关于稳定性的结论在气体Laser中是可以检验的。本文指出,在红宝石Laser中看到的输出不稳定,可能就是谐振腔的q很大的结果。 相似文献
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14.
We present an ultra compact and high resolution free space optical spectrometer and demonstrate it by using FDTD simulations. The miniature interferometer-based speetrometer is a series of submicron phase objects on a polymethyl methacrylate(PMMA) film with a CCD as the detector. The speetrum is obtained by solving a system of simultaneous linear equations. The Tikhonov regularization method is used to achieve a resolution at the picometer level. Compared with conventional speetrometers, the proposed device is low-cost and easy to fabricate due to its simple structure. Furthermore, its compact feature renders the device ideal for miniaturization and integration as the systems in microfluidics architectures and lab-on-chip designs. 相似文献
15.
We propose an iterated local search based on several classes of local and large neighborhoods for the bin packing problem with conflicts. This problem, which combines the characteristics of both bin packing and vertex coloring, arises in various application contexts such as logistics and transportation, timetabling, and resource allocation for cloud computing. We introduce \({\mathcal O}(1)\) evaluation procedures for classical local-search moves, polynomial variants of ejection chains and assignment neighborhoods, an adaptive set covering-based neighborhood, and finally a controlled use of 0-cost moves to further diversify the search. The overall method produces solutions of good quality on the classical benchmark instances and scales very well with an increase of problem size. Extensive computational experiments are conducted to measure the respective contribution of each proposed neighborhood. In particular, the 0-cost moves and the large neighborhood based on set covering contribute very significantly to the search. Several research perspectives are open in relation to possible hybridizations with other state-of-the-art mathematical programming heuristics for this problem. 相似文献
16.
以三苯胺、咔唑、4,4′-二羧基联吡啶为原料,设计并合成了两个联吡啶铱(III)配合物Ir1和Ir2,其结构经1H NMR, 13C NMR和HR-MS(MALDI-TOF)表征。并利用紫外可见光谱(UV-Vis)、荧光发射光谱(Photoluminescence)和循环伏安法研究了化合物的光学和电学性质。结果表明:Ir1和Ir2的紫外可见光吸收波长分别位于456 nm 和448 nm,相应的发射波长分别为645 nm和678 nm,说明其均能利用可见光; Ir1和Ir2的HOMO电位为-5.125~-5.510 eV, LOMO电位为-2.880~-0.310 eV,满足作为光敏剂的基本条件。研究了化合物在可见光照射下光催化水分解产生氢气的效果。结果表明:Ir1和Ir2的氢气值TONs(turnover numbers)达到2 827和1 908。 相似文献
17.
In this paper, three hotly discussed problems, namely the neutrino bursts, the blue progenitor, and the mixing phenomenon, observed in SN1987A are summarized. But it is pointed that while all the observations on SN1987A do not favour a twice-banged scenario, we have found three historical cases from ancient Chinese documents that might be interpreted as twice- or even multi-explosions of a supernova. Finally in a one-dimensional simulation we demonstrate that an induced gravitational collapse b possible. 相似文献
18.
It is found that owing to the large energy difference in K-and L-shells of the daughter atom, 158Tb is not the best candidate for neutrino "balance". Instead, l57Tb can offer a better chance for. neutrino mass determination if the Q-value 55 far obtained is verified. If it is so,then the relevant atomic calculation with high precision is very necessary. It is shown that to include the radiative correction in the Hartree-Fock calculation is very important for such atoms as 157Gd and 157Tb. 相似文献
19.
APPROXIMATE B.S. WAVE FUNCTIONS FOR AN ELECTROMAGNETIC BOUND SYSTEM OF SPINS (1/2, 1/2) OR (1/2, 1/2) WITH UNEQUAL MASSES 下载免费PDF全文
The Bethe-Salpeter equation for an electromagnetic bound system of spins (1/2—1/2) or (1/2—1/2) with unequal masses are solved in this paper. The approximate B.S. wave functions for these systems are given. Utilising these wave functions, the decay rate and branching ratio for Ξ0→(Σ+μ-)+vμ are calculated with accuracy up to order O(α). The results are wΞ0→(Σ+μ-)+vμ1.12(1/sec) and R=[wΞ0→(Σ+μ-)+vμ]/[wΞ0→(Σ+μ-)+vμ]4.7×10-7. Similarly, the process Λ→(pμ-)+vμ is also discussed. 相似文献
20.
The rapid increase of both and T> as S increases in superhigh energy cosmic ray experiments manifests some inconsistencies with the 1> ≤ π/4 S1/2 rule. It is shown that these inconsistencies can be weakened with the assumption that only the secondary particles of the small fireballs are measured in the Ashtonsr experiment [3], but still not removed. 相似文献