首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 62 毫秒
1.
采用喷射沉积坯轧制和RS/PM粉末挤压坯轧制的2种工艺制各了Al-8.5Fe-1.3V-1.7Si和Al-8.5Fe-1.3W-1.7Si合金的板材,并通过透射电镜,扫描电镜和力学拉伸实验研究了板材的组织性能.结果表明,综合性能AlFeWSi合金优于AlFeVSi合金的喷射沉积坯轧制板材.  相似文献   

2.
LaH分子基态X^1∑^+的量子力学计算   总被引:2,自引:1,他引:1  
有考虑相对论有效原子实势近似下,用G94W程序的QCISD方法计算了LaH分子基态X^1∑^+的Murrell-Sorbie解析势能函数及其对应的平衡几何与光谱参数,计算得到的Re,De,Be,ce,ωe和ωexe的理论计算值分别为:0.2125nm,2.623eV,3.7333,0.0723,1461.72和21.383(cm^-1),该结果与实验数据及理论数据符合得比较好。  相似文献   

3.
本文报导了关于高阻N型区熔NTD-Si-P^+N结二极管经电子辐照后的等温退火特性,获得5个缺陷能级:E1=0.16eV,E2=0。.27eV,E3=0.31eV,E4=0.37eV6和E5=0.42eV,结果表明E3和R4有比其它3个能极更好的热稳定性。  相似文献   

4.
本文利用光学势方法计算了能量在10-1000eV范围内电子被氢原子和氮原子散射的总截面,并利用可加性规则得到了电子被氨分子散射的总截面.计算结果与实验进行了比较,在200—1000eV能量范围内计算结果和实验结果符合得比较好.  相似文献   

5.
利用Competl的观测处理结果,对SNR及W-R星与1.8MeVγ射线沿银经的分布做了拟合优度的检验和相关分析。K-S统计检验的结果认为,在α-0.10水平上W-R星与1.8MeV来自同样的分布,相关分析的结果也表明W-R星与1.8MeV的分布有较好的相关性。  相似文献   

6.
铁基非晶软磁合金及其晶化   总被引:22,自引:0,他引:22  
用差热分析,X射线衍射,冲击法等方法研究了铁基非晶Fe72.5,Cu1Nb2V2SI13.5B9合金及其经不同温度退火处理后材料的结构和磁性。结果表明,合金经350℃退火,结构短程有序范围扩大,材料磁化比非晶合金容易;经520-560℃退火,α-Fe(Si)晶粒析出,得到微晶结构并具有优良的软磁性能,例如相对初始磁导率μi≥4.7×10^4,矫顽力Hc≤1.4A/m;在620℃以上退火,第二相Fe  相似文献   

7.
利用组合规则计算了Li-He与Li-Xe原子体系的Born-Mayer短程排斥势参数,采用Tang-Toennies势模型构成了Li原子与He及Xe原子间的全程势曲线,计算所得的势阱参数与实验值符合较好。  相似文献   

8.
在(Xn)独立,且满足E/Xn-EXn/^4≤∞条件下:(c为一正数V为方差)用对称化方法和了随机狄里克莱级数∑XnE^λn^s在L2中收敛与a.s.收敛等价性,并将∑Xne^-λn^sa.s.收敛性转化为级数∑V(Xn)e^-λn^s与∑EXne^-λn^s收敛性予以解决得到了新形式的瓦里隆公式,克诺普-柯基马公式及附带的有趣结果。  相似文献   

9.
图的第二个最小特征值的界   总被引:2,自引:0,他引:2  
设G是n个顶点的简单图,λn-1(G)为G的第二个最小特征值。G的非孤立点形成的图记为G1,V(G1)=s,(3≤s≤n)。本文主要证明了:a.若G1不是完全偶图,则λn-1(G)≤λs-1(K2,s-2^-e),等式成立=G1≌K2,s-2^-^e。其中图K2,s-2^-^e为完全偶图K2,s-2去掉一边e而得到的图b.若G1既不是完全偶图,又不是K2,s-2^-e,则λn-1(G)<-√2/2  相似文献   

10.
提出用高频C-V法测量半导体异质结中集中分布的界面态的能位位置的方法,并分析了测试温度以及由异质结的能带偏移所引起的载流子积累对测试结果的影响,有这一方法对GaS/GaAs和ZnSe/GaAs两种异质结进行了测试,发现在这两种异质界面上均存在集中分布的界面态,其能级位置分别为Ec-0.41eV,Ec-0.51eV。  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   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号