用子波控制实现二维与三维之间的求差

时延地震的基本前提包括对相继的三维勘查进行比较,根据由于流体的开采所引起的声学变化来监测衰减和因绕流而形成的死油层。 但是,如果在开采前没有取得基准的三维勘查数据怎么办?这几乎是常见的情况。现今许多油田通常在采用三维地震前就开采起来了。然而,老的二维地震差不多总是可利用的。

Generation of Broadband Attosecond Pulse via Controlling Quantum Path by Two Color Field in Long Wavelength Driving Regime

In this paper, we have investigated theoretically the high harmonic generation form helium atom in long wavelength driving regime at 2000 nm through solving time-dependent Schr6dinger equation. By adding a second harmonic pulse （1000 nm） and a UV attosecond pulse （200 nm） to the driving field, an efficient method for picking out and enhancing ionization path to generate high-yield supercontinuum harmonics is realized, and then an isolated sub-100 as pulse with a bandwidth of 190 eV is significantly obtained.

DCS devices based non-linear process control system design for plants with distributed time-delay using particle filter

Remote control process system with distributed time-delay has attracted much attention in different fields.In this paper,non-linear remote control of a single tank process system with wireless network is considered.To deal with the distributed time-delay in a large-scale plant,the time-delay compensation controller based on DCS devices is designed by using operator theory and particle filter.Distributed control system(DCS)device is developed to monitor and control from the central monitoring room to each process.The particle filter is a probabilistic method to estimate unobservable information from observable information.First,remote control system and experimental equipment are introduced.Second,control system based on an operator theory is designed.Then,process system with distributed time-delay using particle filter is carried out.Finally,the actual experiment is conducted by using the proposed time-delay compensation controller.When estimating with the proposed method,the result is close to the case in which the distributed time-delay does not exist.The effectiveness of the proposed control system is confirmed by experiment results.

Microwave-Controlled Light-Pulse Propagation in a Driven A-Type Atomic System with Two-Folded Levels

The temporal and spatial dynamics of one weak probe laser pulse, propagating through a A-type atomic medium with two-folded levels under the resonant excitation of one microwave driving field and one strong control field, is investigated in this paper. By numerically solving coupled Bloch-Maxwell equations, it is found that, in the absence of the microwave driving field, the atomic medium is transparent to the probe pulse at line center, which propagates over sufficiently long distances. By contrast, when the microwave driving field is applied, the probe pulse at line center can be rapidly absorbed on propagation. This substantial reduction of probe transmittance caused by the microwave driving field may lead to potential applications in designing a new kind of optical switching.

Effects of Spin Quantum Force in Magnetized Quantum Plasma

Starting from the governing equations for a quantum magnetoplasma including the electron spin -1/2 effects and quantum Bohm potential, we derive Korteweg-de Vries （KdV） equation of the system of quantum magneto- hydrodynamics （QMHD）. The amplitude and width of magnetosonic soliton with different parameters in the system are studied. It is found that the normalized Zeeman energy E plays a crucial role, for E ≥ 1 the amplitude τmξ and the width we of solitary wave all decrease as E increases. That is, the introduction of spin quantum force modifies the shape of solitary magnetosonic waves and makes them more narrower and shallower.

Transferring and Bounding Single Photon in Waveguide Controlled by Quantum Node Based on Atomic Ensemble

We study the scattering process of photons confined in a one-dimensional optical waveguide by a laser controlled atomic ensemble. The investigation leads to an alternative setup of quantum node controlling the coherent transfer of single photon in such one dimensional continuum. To exactly solve the effective scattering equations by using the discrete coordinate approach, we simulate the linear waveguide as a coupled resonator array at the high energy limit. We generally calculate the transmission eoet^cients and its vanishing at resonance reflects the good controllability of our scheme. We also show that there exist two bound states to describe the localize photons around the cavity.

Retainability of canonical distributions for a Brownian particle controlled by a time-dependent harmonic potential

The retainability of canonical distributions for a Brownian particle controlled by a time-dependent harmonic potential is investigated in the overdamped and underdamped situations, respectively. Because of different time scales, the overdamped and underdamped Langevin equations(as well as the corresponding Fokker-Planck equations) lead to distinctive restrictions on protocols maintaining canonical distributions. Two special cases are analyzed in details: First, a Brownian particle is controlled by a time-dependent harmonic potential and embedded in medium with constant temperature; Second, a Brownian particle is controlled by a timedependent harmonic potential and embedded in a medium whose temperature is tuned together with the potential stiffness to keep a constant effective temperature of the Brownian particle. We find that the canonical distributions are usually retainable for both the overdamped and underdamped situations in the former case. However, the canonical distributions are retainable merely for the overdamped situation in the latter case. We also investigate general time-dependent potentials beyond the harmonic form and find that the retainability of canonical distributions depends sensitively on the specific form of potentials.

High Efficiency Four-Wave Mixing with Relaxation Coupling of Longitude-Optical Phonons in Semiconductor Quantum Wells

The time-dependent analysis of four-wave mixing(FWM) has been performed in four-level double semiconductor quantum wells(SQWs) considering the cross-coupling of the longitude-optical phonons(LOP) relaxation. It is shown that both the amplitude and the conversion efficiency of the FWM field enhance greatly with the increasing strength of cross-coupling of LOP relaxation. Interestingly, a double peak value of the conversion efficiency is obtained under a relatively weak single-photon detuning considering the LOP coupling. When the detuning becomes stronger,the double peaks turn into one peak appearing at the line respect to the about equality two control fields. The results can be interpreted by the effect of electromagnetically induced transparency and the indirect transition. Such controlled high efficiency FWM based on the cross-coupling LOP may have potential applications in quantum control and communications.

Nonlinear Structures of Lower Hybrid Wave in Collision Plasmas

Nonlinear structures of lower hybrid wave in collision plasmas are studied using the two-fluid theory.The oscillatory shock wave is observed due to the effects of the electron-neutral collision and the density inhomogeneity.In the cold electron limit,the oscillatory shock wave becomes the ordinary shock wave.In the collisionless limit,the dominated equation becomes Kd V equation and the lower hybrid solitons arise.The amplitude of the nonlinear structure is depressed by the plasma inhomogeneity,but is hardly affected by the electron-neutral collision.

A widely tunable microwave photonic notch filter with adjustable bandwidth based on multi-wavelength fiber laser

A widely tunable microwave photonic notch filter with adjustable bandwidth based on multi-wavelength fiber laser is proposed and demonstrated. The multi-wavelength fiber laser generates the multi-taps of the microwave photonic filter （MPF）. In order to obtain notch frequency response, a Fourier-domain optical processor （FD-OP） is introduced to con- trol the amplitude and phase of the optical carrier and phase modulation sidebands. By adjusting the polarization con- troller （PC）, different numbers of taps are got, such as 6, 8, 10 and 121 And the wavelength-spacing of the multi-wavelength laser is 0.4 nm. The bandwidth of the notch filter is changed by adjusting the number of taps and the corresponding bandwidths are 4.41 GHz, 3.30 GHz, 2.64 GHz and 2.19 GHz, respectively. With the additional phase shift introduced by FD-OP, the notch position is continuously ttmed in the whole free spectral range （FSR） of 27.94 GHz. The center frequency of the notch filter can be continuously tuned from 13.97 GHz to 41.91 GHz.