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1.
By means of an improved ligand-field theory, the "pure electronic" PS and the PS due to EPI of R line of MgO: V^2+ have been calculated, respectively. The calculated results are in very good agreement with the experimental data. The behaviors of the pure electronic PS of R line of MgO:V^2+ and the PS of its R line due to EPI are different. It is the combined effect of them that gives rise to the total PS of R line, which has satisfactorily explained the experimental results. The mixing-degree of |t2^2(^3T1)e^4T2〉 and |t2^3 ^2E〉 in the wavefunetion of R level and its variation with pressure have been calculated and analyzed. The comparison between the feature of R-line PS of MgO:V^2+ and that of MgO:Cr^3+ has been made.  相似文献   

2.
The most accurate measturements in physical sciences will be precision spectroscopic experiments which are based on the usage of most narrow lines in cooperation with interference phenomena. We present a novel experimental observation of "a sharp absorption resonance line" with much more broad laser lights. The mechanism of such a novel phenomenon will be elucidated and its implications will be discussed.  相似文献   

3.
IllltllodllCtloll Improving sonar血tectlon performance by the fe毗"res ofvessel’s rMl砒eAnoise Is animportantneld In underwater signal processing.The line spectrum ofvessel’s radiated-noisehas a broad aPplication prospect on sonar detection because the Intensities ofspectral lines Ishigher than those In continuous spectrum,even more than 20 dB,which can enlarge the rangeof sonar detection.One of important features of line spectrum Is the nonstatlonarlty.Thenon-statlonarlty ofllne spect…  相似文献   

4.
For improving passive ranging of three-sensor array, a sliding cross-correlation method is adopted to improve the performance of time delay estimation. Compared with the traditional cross-correlation, the sliding cross-correlation's ability is evidently increased. An improved formula which is in high precision for near target is employed. An algorithm of kicking out wild value is presented, which is on line, can track the target automatically. The algorithm named "round filter" can pick out the data in high quality with robustness. A "dynamic filter" is presented, which is combined with the "round filter" as the post processor. The experimental result of three-sensor array passive ranging of near field target in shallow water is introduced, which suggests that the post processor is indeed obvious in improving the ranging performance.  相似文献   

5.
Phase-change line memory cells with different line widths are fabricated using focused-ion-beam deposited C-Pt as a hard mask. The electrical performance of these memory devices was characterized. The current-voltage (I-V ) and resistance-voltage (R-V ) characteristics demonstrate that the power consumption decreases with the width of the phase-change line. A three-dimensional simulation is carried out to further study the scaling properties of the phase-change line memory. The results show that the resistive amorphous (RESET) power consumption is proportional to the cross-sectional area of the phase-change line, but increases as the line length decreases.  相似文献   

6.
冯志芳 《中国物理 B》2010,19(6):67201-067201
We investigate in detail the influence of line defects on focusing of electromagnetic waves in a two-dimensional photonic-crystal flat lens. Through simulations, we find that a focusing can always be observed when a line defect in the lens is introduced along the light transmission direction and the width of the line defect is less than \lambda /2. However, there appear two focusings when the width of the line defect is more than \lambda /2. When the line defect is introduced along the direction perpendicular to the transmission, there is always one focusing.  相似文献   

7.
Based on the multi-configuration Dirac-Fock method, this paper has made theoretical calculations for the dielectronic recombination cross-sections and the high-n dielectronic satellites to Kα resonance line in helium-like aluminium ions. It is found that high-n dielectronic satellites are seriously mixed with resonance line, which leads to a significant increase in both the apparent width and the intensity of Kα resonance line. They also induce a positional shift of Kα resonance line.  相似文献   

8.
Si16Sbs4-based line cell phase change random access memory (PCRAM), in which the Si16Sbs4 phase change line is contacted by TiN electrodes with a nanoscale gap, is fabricated by electron beam lithography. The lowest current and measured pulse width for RESET operation are 115 μA and 18 ns, respectively. The measured shortest pulse width for recrystallization is 110ns, with applied pulse amplitude of 1.5 V. SET and RESET currents for line cells with different line lengths are determined. Endurance of 106 cycles with a resistance ratio of above 800 has been achieved.  相似文献   

9.
杨帅  左群杰  高守亭 《中国物理 B》2017,26(8):89201-089201
Considering some simple topological properties of vorticity vector, the frozen-in property of vorticity herein is revisited. A vortex line, as is analogous to velocity vector along a streamline, is defined as such a coincident material(curve) line that connects many material fluid elements, on which the local vorticity vector for each fluid element is also tangent to the vortex line. The vortex line evolves in the same manner as the material line that it is initially associated with. The vortex line and the material line are both oriented to the same directions, and evolve with the proportional magnitude, just like being ‘frozen' or ‘glued' to the material elements of the fluid under the barotropic assumption. To relax the limits of incompressible and barotropic atmosphere, the frozen-in property is further derived and proved in the baroclinic case. Then two effective usages are given as examples. One is the derivation of potential vorticity conservation from the frozen-in property in both barotropic and baroclinic atmospheres, as a theory application, and the other is used to illuminate the vorticity generation and growth in ideal cases and real severe weather process, e.g., in squall line, tornado, and other severe convection weather with vortex. There is no necessity to derive vorticity equation, and this method is very intuitive to explain vorticity development qualitatively, especially for fast analysis for forecasters. Certainly, by investigating the evolution of vortex line, it is possible to locate the associated line element vector and its development on the basis of the frozen-in property of vorticity. Because it is simple and visualized, it manifests broad application prospects.  相似文献   

10.
In this paper, evaporation of sessile water droplets containing fluorescent polystyrene(PS) microparticles on polydimethylsiloxane(PDMS) surfaces with different curing ratios was studied experimentally using laser confocal microscopy. At the beginning, there were some microparticles located at the contact line and some microparticles moved towards the line. Due to contact angle hysteresis, at first both the contact line and the microparticles were pinned. With the depinning contact line, the microparticles moved together spontaneously. Using the software ImageJ, the location of contact lines at different time were acquired and the circle centers and radii of the contact lines were obtained via the least square method. Then the average distance of two neighbor contact lines at a certain time interval was obtained to characterize the motion of the contact line. Fitting the distance-time curve at the depinning contact line stage with polynomials and differentiating the polynomials with time, we obtained the velocity and acceleration of both the contact line and the microparticles located at the line. The velocity and the maximum acceleration were,respectively, of the orders of 1 μm/s and 20-200 nm/s~2, indicating that the motion of the microparticles located at the depinning contact line was quasi-static. Finally, we presented a theoretical model to describe the quasi-static process, which may help in understanding both self-pinning and depinning of microparticles.  相似文献   

11.
二维光栅是光刻机光栅尺系统的核心元件。搭建了超精密激光直写系统,基于二维超精密工件台,通过旋转基片90°进行两次曝光,制作出栅线密度为1200 line/mm的二维光栅掩模。原子力显微镜和扫描电镜结果表明,所制作的掩模轮廓清晰,空间分布均匀。实验结果证明了超精密激光直写系统能够制作出二维光栅掩模,在制作大尺寸、高精度二维计量光栅方面有着广阔的应用前景。  相似文献   

12.
Although numerical simulation tools are now very powerful,the development of analytical models is very important for the prediction of the mechanical behaviour of line contact structures for deeply understanding contact problems and engineering applications.For the line contact structures widely used in the engineering field,few analytical models are available for predicting the mechanical behaviour when the structures deform plastically,as the classic Hertz’s theory would be invalid.Thus,the present study proposed an elastic-plastic model for line contact structures based on the understanding of the yield mechanism.A mathematical expression describing the global relationship between load history and contact width evolution of line contact structures was obtained.The proposed model was verified through an actual line contact test and a corresponding numerical simulation.The results confirmed that this model can be used to accurately predict the elastic-plastic mechanical behaviour of a line contact structure.  相似文献   

13.
Simply speaking, the drip line is the margin in chart of the nuclides where the nu-clides with the lower limits of detectable lifetime survive. The N/Z ratios of the nuclides on the drip line are extreme. Synthesis of the nuclei near the drip line and study of their exotic decays deal with the physics under extreme conditions, and therefore become one of the frontiers in nuclear physics today. The rare-earth nuclei near the proton drip line have been predicted to be highly deformed[1]. They a…  相似文献   

14.
The analysis of the radiated noise of vessels given in this paper showssome strong superposed line components in low frequency speetrum below100Hz occurring at discrete frequencies which correspond with the rotationspeed of propeller shaft,or propeller blade frequency,or their harmonic fre-quencies.since the line components reflect propeller'working characteristics,the propller's features can be extracted directly from low-frequency line com-ponents in addition to demodulated line component.So there are two ways toextract the features,one is direct way,the other is demodulation way.Detec-tion performance of the line component in background-noise is discussed inthis paper.The signal level is defined as the difrerence between the PDF's(Probability Density Function)mean of the peak of the line component andPDF's mean or the background-noise.In dircet way the signal level of the linecomponent is proportional to the signal noise ratio(S/N).In demodulationway the signal level of demodulated line component  相似文献   

15.
The abundant generalized dromion structures for the (2+1)-dimensional KdV equation are obtained using the homogeneous balance method. We give not only the general curve soliton which is finite on a curved line and localized apart from the curve, find but also the dromion solutions which can be driven by two perpendicular line soliton and by two non-perpendicular line soliton and by one line soliton and one curve line soliton. Various types of multi-dromion solutions can be constituted by selecting different arbitrary functions of y. The (1+N) dromion obtained by Radha et al.[3] is only a very special case of our results.  相似文献   

16.
马欣  李克平  罗自炎  周进 《中国物理 B》2014,23(2):28904-028904
In this paper, a new model is constructed for the causation analysis of railway accident based on the complex network theory. In the model, the nodes are defined as various manifest or latent accident causal factors. By employing the complex network theory, especially its statistical indicators, the railway accident as well as its key causations can be analyzed from the overall perspective. As a case, the "7.23" China-Yongwen railway accident is illustrated based on this model. The results show that the inspection of signals and the checking of line conditions before trains run played an important role in this railway accident. In conclusion, the constructed model gives a theoretical clue for railway accident prediction and, hence, greatly reduces the occurrence of railway accidents.  相似文献   

17.
Two types of pulse forming lines for dielectric wall accelerator (DWA) were investigated preliminarily. By simulation with CST Microwave Studio, the results indicate the pulse forming process, which can help to understand the voltage wave transmission process and optimize the line parameters. Furthermore, the principle of the pulse forming process was proved by experiments and some excellent pulse waveforms were obtained. During the experiments, the Blumlein line and zero integral pulse (ZIP) forming line, constructed with aluminum foil, poly plate and air gap self-closing switch, were tested. The full width at half maximum (FWHM) of the waveform is 16 nanoseconds (BL) and 17 nanoseconds (ZIP line),and the formed pulse voltage amplitude is 5 kV (BL) and +2.2 kV/ - 1.6 kV (ZIP line). The experiments result coincides well with the simulation.  相似文献   

18.
Properties of the even-N Zr isotopes and their corresponding single-Λ and double-Λ hypernuclei are studied in the deformed Skyrme-Hartree-Fock approach. Binding energy, the two-neutron separation energies, radii are studied from beta-stable zone to the neutron drip line in this paper. The neutron drip line nuclei predicted with SLy4 and SkI4 interactions are 122Zr and 138Zr, respectively. The neutron drip line of single-Λ and double-Λ hypernuclei are Λ139Zr and 2Λ142 Zr with SkI4 interaction, respectively. The predicted hyperon drip line hypernuclei with 80Zr and 138Zr cores are 20Λ100Zr and 50Λ188Zr, respectively.  相似文献   

19.
Starting from the variable separation approach, the algebraic soliton solution and the solution describing the interaction between line soliton and algebraic soliton are obtained by selecting appropriate seed solution for (2+1)-dimensional ANNV equation. The behaviors of interactions are discussed in detail both analytically and graphically. It is shown that there are two kinds of singular interactions between line soliton and algebraic soliton: 1) the resonant interaction where the algebraic soliton propagates together with the line soliton and persists infinitely; 2) the extremely repulsive interaction where the algebraic soliton affects the motion of the line soliton infinitely apart.  相似文献   

20.
Following Chen's method [Commun. Theor. Phys. 52 (2009) 549] to use &step line tilting to realize tip tilting, to achieve finer rotation, it is discovered that a 16-step line tilting method may realize a rotation two order smaller than that achieved by &step.  相似文献   

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