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1.
在量子光学中,用电磁感应透明的方法使光速变慢,甚至减慢到0,是现在光学研究的一个重点,本文从另一个角度,用经典电动力学这样的宏观物理方法,近似求解了上述的量子光学中非常重要的问题,并且与实验结果能很好地相符,开始从经典电动力学中的折射率入手,由此导出原子极化率与波速的关系,从而最后求出折射率与波速的关系,理论结果与实验中所测出的数据完全一致。  相似文献   

2.
波动是物质运动的特殊形式,波动力学具有独特的内容、方法和意义,其概念和内涵都和经典力学有重大区别。例如,波速度(无论相速或群速)都是标量,“负波速”并不表示运动方向反了过来,而是一种从表面上看与因果性不相符的特殊现象。无论如何,最近几十年的研究已证明,负波速不仅在理论上可行,在实验中也多次证明其存在。而且,负波速是超光速的一种特殊形态。……本文指出,具有负波速的波动是超前波。它对应电磁场与电磁波基本方程的超前解;过去的做法是抛弃超前解,这是不合适的!关于超前波,虽然早就有这一概念,但从未有人明确指出这个波是真实存在的。本文认为已有的许多负群速实验正是超前波存在的证明。有人用“违反因果律”作为理由,说超前波不可能存在。但是,中国科学家已经对因果性作了更深刻、更全面的解释,这对波动力学和量子光学都是重要的贡献。众所周知,在量子力学中经典的因果律已丧失其合理性和至高无上的地位。2022年的Nobel物理学奖被授予Alain Aspect等3人是很不平常的,因为Aspect的关于Bell不等式的实验完成于1982年,今天来看它仍然是一个证明Einstein的EPR论文错了、而量子力学正确的关键...  相似文献   

3.
波动是物质运动的特殊形式,波动力学具有独特的内容、方法和意义,其概念和内涵都和经典力学有重大区别。例如,波速度(无论相速或群速)都是标量,“负波速”并不表示运动方向反了过来,而是一种从表面上看与因果性不相符的特殊现象。无论如何,最近几十年的研究已证明,负波速不仅在理论上可行,在实验中也多次证明其存在。而且,负波速是超光速的一种特殊形态。……本文指出,具有负波速的波动是超前波。它对应电磁场与电磁波基本方程的超前解;过去的做法是抛弃超前解,这是不合适的!关于超前波,虽然早就有这一概念,但从未有人明确指出这个波是真实存在的。本文认为已有的许多负群速实验正是超前波存在的证明。有人用“违反因果律”作为理由,说超前波不可能存在。但是,中国科学家已经对因果性作了更深刻、更全面的解释,这对波动力学和量子光学都是重要的贡献。众所周知,在量子力学中经典的因果律已丧失其合理性和至高无上的地位。2022年的Nobel物理学奖被授予Alain Aspect等3人是很不平常的,因为Aspect的关于Bell不等式的实验完成于1982年,今天来看它仍然是一个证明Einstein的EPR论文错了、而量子力学正确的关键...  相似文献   

4.
在大学物理实验中,旋光仪用来检测物质的旋光性,计算出该溶液浓度.阿贝折射仪经常用来测溶液折射率,对溶液浓度的测量比较少.本文根据同一种溶液浓度不变,建立了旋光度和折射率关系的理论模型.实验测定了蔗糖溶液,基于最小二乘法原理,得到了旋光性和折射率的实验模型.结果表明,实验与理论相符合.这种研究结果,对具有旋光性物质研究具...  相似文献   

5.
用和一般电动力学教材不同的方法即在介质经典微观物理模型的基础上推导出了极化强度Pω和磁化强度Mω的边值关系,使得更有利于从微观的角度理解这两个边值关系,并得出了极化电荷分布深度和磁化电流的分布深度都在分子线度的数量级这一结论.  相似文献   

6.
量子点与微腔之间的耦合强度大小对于实现各种腔量子电动力学现象,起着至关重要的作用.然而,由于量子点的选择有限性以及其在传统微腔中的位置不确定性,难以实现耦合强度的增强.在本文中,我们构造了一个填充零折射率材料的不寻常腔,其中场强的分布是均匀的.由于这种特殊的场分布,当将谐振强度为G=G0的N个谐振子随机分布在腔中时,每个谐振子均处在场强最大值处,即耦合强度相同,这样N个谐振子相当于一个具有谐振强度为NG0的谐振子,从而达到了谐振强度可调的目的.最后,我们利用类人造原子(金属开口谐振环)与零折射率材料微腔(一维复合左右手传输线)之间的耦合,从微波实验的角度验证了上述结论是正确的.这种可调节的耦合强度可能会对解决腔量子电动力学中量子点和腔模耦合强度不高的问题有一定的指导作用.  相似文献   

7.
基于阶梯形三能级原子与经典和量子腔场之间的共振相互作用,提出了一个在腔量子电动力学系统中实现Bernstein-Vazirani算法的方案.  相似文献   

8.
为进一步了解岩石弹性参数(如杨氏模量、泊松比)与超声波波速的关系,将岩石加卸载循环实验和超声波测量实验同时进行,得到同一组样品的测量数据并作对比分析。实验结果表明,应力的变化会导致岩石样品的孔隙度、裂隙、岩石结构和构造的改变。受这些因素的影响砂岩的杨氏模量、泊松比、波速,也都会有规律地变化。较低应力水平时用小循环加卸载测得的动态弹性模量是不准确的,计算的波速也不准确,只有通过波速实验才能准确测出;饱水情况的加卸载纵波波速之差比干燥情况小,饱水波速大于干燥波速;动态泊松比比较稳定,但静态泊松比随着应力的增加而增加,从0.07增加到0.12,有趋近于动态泊松比的趋势;用P-M模型从微观概率分布入手,能够很好地解释静态和动态弹性参数的差别。通过本实验,采用回归分析的方法,成功建立起了岩石介质中弹性参数与波速的关系,为类似实验提供参考依据。  相似文献   

9.
讨论了一些早期的有关光的本性的科学实验(如Michelson-Morley实验,Lebedev实验,Compton实验,Maiman实验等).然后指出:由于超光速、超慢光速、负折射率的研究的进展,人们对光波性质的兴趣大大增长了.介绍了量子光学方面的一些最新实验,如激光冷却、Bose-Einstein凝聚态、原子激光器.  相似文献   

10.
讨论了一些早期的有关光的本性的科学实验(如Michelson-Morley实验,Lebedev实验,Compton实验,Maiman实验等).然后指出:由于超光速、超慢光速、负折射率的研究的进展,人们对光波性质的兴趣大大增长了.介绍了量子光学方面的一些最新实验,如激光冷却、Bose-Einstein凝聚态、原子激光器.  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

15.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

16.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

17.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

18.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

19.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

20.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

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