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1.
在半空间中及Bron近似下,探讨了采用地表发射和地表接收配置下的弹性波方程,得到散射波总场并从中 分离出散射波的四类波型转换。  相似文献   

2.
提出了一种根据波型转换原理单面评估表面半球形细小凹坑(0.95~2.5mm)直径的新方法,用自制的电磁超声换能器测定了纵波(P波)正入射至多种不同直径的凹坑上后转型横波(SV波)的标准散射指向图,提出了以45°和60°散射方向SV波的振幅比作为凹坑直径评估的依据,凹坑评估测量值与实际值符合较好.  相似文献   

3.
在研究带电粒子与原子的非弹性散射中,原子的广义振子强度(GOS)是一个重要的角色.最近,Takayanagi等人通过非弹性散射中电子能损谱的测量得到了氪(Kr)原子在4p6→4p5(2P1/2)5s和4p6→4p5(2P3/2)5s转换过程中的GOS.我们用相对论Slater定域密度方程得到的波函数计算了该过程在动量平方转移从0.01到10(原子单位)范围内的GOS.所得结果对Takayanagi等人的实验给出了较圆满的理论解释.  相似文献   

4.
提出一种根据小型转换原理单面评估表面半球形细小凹坑直径的新方法,用自制的电磁超声换能器测定了纵波(P波)正入射至多种不同直径的凹坑上后转型横波(SV波)的标准散射指向图,提出了以45°和60°散射方向SV波的振幅比作为凹坑直径评估的依据,凹坑评估测量值与实际值符合较好。  相似文献   

5.
不同月龄Beagle犬的心电图研究   总被引:1,自引:0,他引:1  
对不同月龄的66只健康Beagle犬采用3%戊巴比妥钠麻醉,进行了9个导联的心电图描记和分析。结果表明:健康Beagle犬为窦性心律:30月龄以下育成犬心律平均为173.8次/分,种用犬(50月龄以上)心率平均为131.7次/分;二者经统计学处理,有极显著差异。P波间期平均为0.051±0.013Sec。P波振幅平均0.061mv,P波直立在导联中占92.6%,在aVR导联中P波倒置率98.75%;QRS波间期均值为:0.027±0.005Sec。在Ⅱ导联中范围为0.02-0.04S-ec。在各导联中,Ⅰ导联以r波为主(51.85%),Ⅱ导联以Rs波多见(50%),Qr波和qr波在aVR导联中出现较多(38.89%,31.48%)。T波在Ⅰ、Ⅱ、Ⅲ、avF、Ⅴ1、Ⅴ2、Ⅴ3导联中直立为主,在avL导联中倒置多见(89.2%,73.1%)。T波方向与QRS波一致。T波振幅平沟0.137mv。P-R间期范围在此0。075-0.140Sec。在9个导联中,无明显S-P段偏移。P-P间隔<0.01Sec。  相似文献   

6.
合成了Tb(DPSO)6·(ClO4)3、Tb(DPSO)7·(PF6)3及Tb(PBSO)6·(ClO4)3配合物(DPSO为二苯基亚砜PBSO为苯丁基亚砜).在室温下测定了它们的固体粉末荧光激发和发射光谱,结果表明Tb(DPSO)6·(ClO4)3配合物中Tb3+的发光强度最高,其中5D4→7F5跃迁谱带强度高达806.2cd,Tb(DPSO)7(PF6)3配合物中Tb3+发光强度次之,Tb(PBSO)6(ClO4)3配合物中Tb3+的发光强度最弱.这说明二苯亚砜做为配体受激后向Tb3+离子传递能量的效率高于苯丁基亚砜,另外ClO4-做为阴离子也可增加Tb3+的发光强度,原因是部分外界ClO4-离子可进入内界参予配位,降低了配合物的对称性,部分解除了跃迁禁律,提高了Tb3+的发光强度.  相似文献   

7.
用排列通道线性组合散射方法(LCAC-SW方法)计算了一维共线反应F+H2(0)→H+HF(v)的反应几率,在采用一较小基组(振动能级数目nvib(H2)=8,nvib(HF)=12,分布高斯函数项目gas=10)的情况下,得到了与Kuppermann的精确量子计算数值比较一致的结果,算得F+H2(0)→H+HF(v)=2)变换反应几率P^R02在E≈0.014eV附近有一尖峰出现。  相似文献   

8.
用排列通道线性组合散射波方法(LCAC-SW方法)计算了一维共线反应F+H2(0)→H+HF(υ)的反应几率。在采用一较小基组(振动能级数目nvib(H2)=8,nvib(HF)=12,分布高斯基函数数目ngas=10)的情况下,得到了与Kuppermann的精确量子计算数值比较一致的结果。算得F+H2(0)→H+HF(υ=2)交换反应几率PR02在E≈0.014eV附近有一尖峰出现  相似文献   

9.
合成了高氯酸钐二苯亚砜Sm(DPSO)7·(ClO4)3、六氟磷酸钐二苯亚砜Sm(DPSO)7(PF6)3、高氯酸钐苯丁基亚砜Sm(PBSO)7·(ClO4)3三个配合物.测定了配合物的组成、摩尔电导及粉晶荧光激发和发射光谱.荧光光谱测定结果表明:Sm(DPSO)7(ClO4)3的发光强度最高,其中4G5/2→6H7/2谱带强度高达119.3cd.这说明DPSO二苯亚砜作为配体受激发后将能量传递给Sm3+使其敏化发光的能力高于苯了基亚砜.另外在一定的条件下阴离子ClO可以增强Sm3+的发光性能.  相似文献   

10.
电位溶出分析法(P.S.A)可间接测定配合物稳定常数,本文根据这一方法原理,首次采用双通道FIA传递系统以及自制的静止电极壁喷式(wall-jet)流通池,分别用流动注射-电位溶出分析法(FIPSA)和P.S.A法测定了5种Re-EDTA配合物稳定常数,并导出了一组FIPSA法间接测定配合物稳定常数的公式。结果表明,间接P.S.A法测定配合物稳定常数的方法适宜于稀土配合物的研究,而对于FIPSA法,由于快速流体条件下,置换配合反应的不完全性及可精确控制其反应程度,使其能测定K_(MIy)与K_(MIy)相近的K_(MIy),优于P.S.A法。  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.
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   

13.
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   

14.
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   

15.
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   

16.
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   

17.
For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the  相似文献   

18.
Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of  相似文献   

19.
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with  相似文献   

20.
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