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1.
宇宙线对地球气候的影响   总被引:4,自引:2,他引:2  
对宇宙线影响地球气候的一些观测结果和物理机制的研究进行了总结和概述,主要讨论了宇宙线对大气中化学反应、云形成过程等的影响,并给出了羊八井宇宙线观测站对宇宙线流强和大气参量日变化的初步观测结果.  相似文献   

2.
王欢  李彪 《中国物理 B》2011,20(4):40203-040203
In this paper,we investigate some exact soliton solutions for a generalized variable-coefficients nonlinear Schrdinger equation (NLS) with an arbitrary time-dependent linear potential which describes the dynamics of soliton solutions in quasi-one-dimensional Bose-Einstein condensations. Under some reasonable assumptions,one-soliton and two-soliton solutions are constructed analytically by the Hirota method. From our results,some previous one-and two-soliton solutions for some NLS-type equations can be recovered by some appropriate selection of the various parameters. Some figures are given to demonstrate some properties of the one-and the two-soliton and the discussion about the integrability property and the Hirota method is given finally.  相似文献   

3.
In the present paper, we review some recent results about commutative positive operator valued measures (POVMs) and single out some open problems. We introduce a conjecture about the extension of some recent results and prove some important consequences of such conjecture. In particular, we prove that it implies the universal character of some of the mathematical objects we introduce, i.e., the fact that they do not depend on the POV measure we are considering. We analyze the relevance of this result. Finally, we point out that some of the results we present admit a constructive proof and we show the relevance of this fact to the theory of commutative POV measures.  相似文献   

4.
The real physics models are usually quite complex with some arbitrary parameters which will lead to the nonintegrability of the model.To find some exact solutions of a nonintegrable model with some arbitrary parameters is much more difficult than to find the solutions of a model with some special parameters.In this paper,we make a modification for the usual direct method to find some conditional similarity solutions of a (2 1)-dimensional general nonintegrable KdV equation.  相似文献   

5.
非线性热声理论的研究进展   总被引:4,自引:0,他引:4  
主要总结了热声系统中的非线性热声现象,指出了线性热声理论的不足,回顾了近十年来国内外热声工作者为解释这些非线性现象所做的理论探索,对其发展方向进行了展望.  相似文献   

6.
光学系统偏心测量原理及应用   总被引:6,自引:1,他引:5  
综述了光学系统偏心测试研究方面的发展概况及目前所达到的水平。简要介绍了光学系统偏心测量及基准轴变换原理,并讨论了一些必要的问题。最后介绍了测量方法的一些具体应用,指出了一些测量中应注意的问题和技巧,并介绍了几个具有代表性的,经过多年实践创造出来的应用方法实例。  相似文献   

7.
考虑激光辐照下结构变形对双层板接触传热影响可以更真实地反映两板间的传热情况,通过实验和数值模拟分析了大气压力对接触传热的影响。结果表明:大气压力对接触热阻影响非常明显,当大气压力超过一定值后,双层板界面始终接触,后板中心的温升阶段成类抛物形状;当大气压力在某一范围内,大气压力与温度矩产生的靶板挠度相当,接触面时分时合,后板的温升阶段成振荡式类线性增加;当大气压力小于某一特定值时,后板温度有一突跃过程,通过适当的设计有可能观测到该现象。  相似文献   

8.
杜勇  方炎 《光散射学报》2003,15(3):131-138
比较了染料分子结晶紫(CV)在酸性与中性条件下的金胶体系中的近红外表面增强拉曼光谱(NIR-SERS)。结果表明,结晶紫分子-金胶体系中结晶紫分子在1064nm近红外光激发条件下,其荧光得以大大淬灭,同时拉曼得到了至少不低于105倍的增强;当进一步加入硝酸使得其处于酸性气氛下时,由于部分结晶紫分子与硝酸发生了化学作用形成了结晶紫分子的单替代衍生物(HCV),而HCV与结晶紫分子相比,更容易吸附在金属表面,因此结晶紫分子NIR-SERS还将有很大的增强。这可以给我们很大的启示:改变体系的酸碱度也可以达到改变其SERS的增强效果的目的。  相似文献   

9.
In the present work we analyze the possibility of detecting some deformed dispersion relations, emerging in some quantum-gravity models, resorting to the so-called Hanbury–Brown–Twiss effect. It will be proved that in some scenarios the possibilities are not pessimistic. Forsooth, for some values of the corresponding parameters the aforementioned effect could render interesting outcomes.  相似文献   

10.
功率超声对溶液性质的影响   总被引:11,自引:1,他引:10       下载免费PDF全文
本文研究了在功率超声作用下,电解质溶液,小分子溶液和大分子溶液的粘度,表面张力和电导率等物理化学性质的变化规律。实验结果表明,在超声波作用下,溶液的粘度和表面张力暂时下降,而电导率长期升高。  相似文献   

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