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1.
本文设计了波导测量系统,在稳频、稳幅及电路匹配条件下,对介质参量进行测量。从理论和实验上得出了“短路”“开路”情况下的反射系数的振幅|Γ|与试样厚度d/λ_cg的关系曲线。通过误差分析,找出了准确测量介质材料时试样的厚度。图7,参5。  相似文献   

2.
通过对涂型吸波材料内电磁波传输损耗机理的研究,提出了单涂层吸波材料优化设计的两项原则.此外,研究了一系列相关参数间的作用规律,讨论了涂层介质参量在偏离匹配条件的前提下对涂层吸收性能的影响,这对研究吸波材料的性质具有一定的意义.  相似文献   

3.
对不同浓度的旋波介质进行了测量,给出一种在自由空间测量旋波介质手性参量的方法.通过测量介质板的两次复反射系数、透射波偏转角和椭偏率,计算得到介质的手性参量和电磁参量.对手性参量及偏转角、椭偏率测量结果进行了分析.以波导测量线为主要测量装置,测量方法简便,与国外网络分析仪测量结果比较,符合较好.  相似文献   

4.
利用波导测量系统,在稳频、稳幅及电路匹配的条件下,对介电参数进行测量。在短路、开路的情况下,得到了反映系数的振幅Γ与试样厚度d/λω的关系。通过误差分析,找出了准确测量介质材料时试样的厚度。  相似文献   

5.
通过对涂型吸波材料内电磁波传输损耗机理的细致研究,提出了单涂层吸波材料优化设计的两项原则- 研究了一系列相关参数间的作用规律- 通过分析说明这两项设计原则可具体指导单涂层结构设计- 最后得出了涂层介质参量在偏离匹配条件的前提下对涂层吸收性能影响的偏差研究结果- 图2,参5-  相似文献   

6.
提出了可以宽频带扫频同时测量电磁介质的复介电常数εr和复磁导率μr的带线法,推导出了由带线网络的S11及S21表示εr及μr的理论公式.对带线夹具进行了设计,给出了铁氧体及吸波材料样品的测试数据.测试表明,带线法具有准确性高、特别适宜大损耗材料的测量和容易操作等优点.  相似文献   

7.
本文通过对单涂层吸波材料内电磁波传输损耗机理的细致研究,提出了单涂层吸波材料优化设计的两项原则。结合具体实例详细说明这两项原则的具体应用,最后讨论涂层电磁参量在偏离匹配条件的情况下,对涂层吸波性能影响的具体结果分析。图3.表1,参3。  相似文献   

8.
不同浓度螺旋体旋波介质手性参量的研究   总被引:6,自引:2,他引:4  
对不同浓度的旋波介质进行了测量,给出一种在自由宽间测量旋波介质手性参量的方法。通过测量介质板的两次反射系数,透射波偏转角和椭偏率,计算得到介质的手性参量和电磁参量。  相似文献   

9.
超介质吸波体具有传统吸波材料所不具备的电磁特性,为设计新型电磁防护材料和目标隐身材料提供了一种新的途径.本文介绍了分析超介质吸波体吸波机理的理论方法:等效介质理论,阻抗匹配理论以及分层介质的多次干涉理论.同时,利用单元组合法设计了多频点的螺旋吸波体、单层、多层和加载集总电阻的宽频吸波体,并对其吸波机理进行了研究.  相似文献   

10.
介绍了一种双层介质高阻抗频率选择性表面的吸波结构,这种结构在7GHz-16.5GHz具有很好的吸波特性,满足S11小于-10dB,厚度仅3.9mm。探究了高阻抗FSS的大小以及在介质中放置角度、位置对吸波性能的影响,提出了提高吸波性能,特别是提高低频吸波效果的方法。然后,针对这种吸波材料提出一种新的等效电路结构并用这种结构对该吸波材料建模和分析,最后与仿真结果进行了对比,证明了仿真结果的正确性以及等效电路方法的有效性。  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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