A monolithic integrated medium wave Mercury Cadmium Telluride polarimetric focal plane array

A medium wave(MW)640×512(25μm)Mercury Cadmium Telluride(HgCdTe)polarimetric focal plane array(FPA)was demonstrated.The micro-polarizer array(MPA)has been carefully designed in terms of line grating structure optimization and crosstalk suppression.A monolithic fabrication process with low damage was explored,which was verified to be compatible well with HgCdTe devices.After monolithic integration of MPA,NETD<9.5 mK was still maintained.Furthermore,to figure out the underlying mechanism that dominat⁃ed the extinction ratio(ER),specialized MPA layouts were designed,and the crosstalk was experimentally vali⁃dated as the major source that impacted ER.By expanding opaque regions at pixel edges to 4μm,crosstalk rates from adjacent pixels could be effectively reduced to approximately 2%,and promising ERs ranging from 17.32 to 27.41 were implemented.

用猛振原理设计振动机的研究

作者提出用猛振原理指导振动机的设计，文中详细阐述了猛振原理及其应用成果。生产实践证明，按猛振原理设计的平振式振动机，是典型的优化振动机，可供推广使用。

Solidification of horizontally continuous casting of super-thin slab in stable magnetic field and alternating current

The solidified structures of horizontally continuous casting（HCC） of super-thin slab and its relations with the current were studied under the electromagnetic vibration（EMV）.The results show that,under the action of the periodical forces from EMV,the solidified structures of the super-thin slab of pure tin is greatly refined,and the extent of grain refinement is increased with the magnitude of alternating current.For the Sn-10%Pb alloy,it is shown that the EMV promotes the growth of equiaxed grains in the center of super-thin slab,and the grains are refined with the alternating current increasing.This is useful to prevent some solidification defects in the horizontally continuous casting of super-thin slab,such as columnar grains butting,porosity,inclusions and gases gathering,and composition segregation in the centre of slab.

NONLINEAR DYNAMIC ANALYSIS OF THE PLATFORM STRUCTURES SUBJECTED TO ICE EXCITATION(PART Ⅰ): EQUATION OF MOTION

In this paper,we established the equation of motion of a platform structure with four legs by way of Hamilton' s Principle and obtained the nonlinear dynamical model of platform structures. By using Laplace transformation we obtain the mode shapes of the system. The nonlinear model of the platform structure in this paper provded an accurate way of analysis for the engineering prediction of the dynamical characteristics of the platform and the understanding of its vibrational mechanism.

Microstructural characteristics of Al-20Si-2Cu-0.4Mg-1Ni alloy formed by rheo-squeeze casting after ultrasonic vibration treatment

A swash plate for air conditioning compressor of cars was formed by rheo-squeeze casting with semi-solid Al-Si alloy slurry prepared by ultrasonic vibration process, and the microstructure of this alloy was investigated. Besides the microstructures of primary Si particles and α(Al)+β-Si eutectic phases, non-equilibrium α(Al) particles or dendrites are discovered in the microstructure of the Al-20Si-2Cu-0.4Mg-1Ni alloy. Rapid cooling generated by squeeze casting process rather than the pressure is considered as the main reason for the formation of non-equilibrium α(Al) phase. The sound pressurizing effect of ultrasonic vibration also enables the non-equilibrium α(Al) phases to form above eutectic temperature and grow into non-dendritic spheroids in the process of semi-solid slurry preparation. Non-equilibrium α(Al) phases formed in the hypereutectic Al-Si alloy with ultrasonic vibration treatment, consist of round α(Al) grains formed above the eutectic temperature and a small amount of fine α(Al) dendrites formed under the eutectic temperature. The volume fraction of primary Si particles is decreased significantly by the effect of ultrasonic vibration through increasing the solid solubility of Si atoms in α(Al) matrix and decreasing the forming temperature range of primary Si particles. The average particle diameter and the volume fraction of primary Si particles in microstructure of the swash-plate by rheo-squeeze casting are 24.3 μm and 11.1%, respectively.

用旋转偏重平衡斜振振动体惯性力

用旋转偏重平衡平振振动体惯性力的理论,历来已有很多文献介绍,这个方法也已经被广泛地用于曲柄连杆机构传动的振动筛、振动输送机等往复振动机械。用旋转偏重平衡斜振振动体惯性力的理论和方法,还没有见到文献介绍,也未见到生产中应用。

Amplitude.preserving plane-wave prestack time migration for AVO analysis

To support amplitude variation with offset （AVO） analysis in complex structure areas, we introduce an amplitude-preserving plane-wave prestack time migration approach based on the double-square-root wave equation in media with little lateral velocity variation. In its implementation, a data mapping algorithm is used to obtain offset-plane-wave data sets from the common-midpoint gathers followed by a non-recursive phase-shift solution with amplitude correction to generate common-image gathers in offset-ray-parameter domain and a structural image. Theoretical model tests and a real data example show that our prestack time migration approach is helpful for AVO analysis in complex geological environments.

Ghost artifact removal in EPI using projection in hybrid-space

Ghost artifacts occur in magnetic resonance imaging （MRI） reconstruction because odd and even echoes have different phase offsets. A method based on the projection in hybrid-space is described to remove ghost artifacts. First, the projection of the even and odd lines along phase-encoding direction in hybrid-space was used to estimate the phase difference between odd and even echoes. Secondly, we fit the phase difference and used it to correct the phase of even or odd echoes. Finally, the corrected image was obtained by performing the inverse Fourier transform along phase-encoding direction in hybrid-space. The experimental results show that linear and nonlinear differences can be corrected and the intensity of ghost artifacts is significantly reduced. The effectiveness of the proposed method is demonstrated in ghost artifact removal.

Calculation of Valence Subband Structures for Strained Quantum-Wells by Plane Wave Expansion Method Within 6×6 Luttinger-Kohn Model

The valence subband energies and wave functions of a tensile strained quantum well are calculated by the plane wave expansion method within the 6×6 Luttinger Kohn model.The effect of the number and period of plane waves used for expansion on the stability of energy eigenvalues is examined.For practical calculation,it should choose the period large sufficiently to ensure the envelope functions vanish at the boundary and the number of plane waves large enough to ensure the energy eigenvalues keep unchanged within a prescribed range.

~1H and ^(13)C NMR Assignments for Amlodipine and Risperidone

Aim To investigate the NMR spectroscopy of amlodipine and risperidone.Methods 1D NMR and 2D NMR experimental techniques of gCOSY, gHSQC and gHMBC were wsed. Results Theassignments of the ~1H and ^(13) C NMR data for the two drugs were performed and confirmed by theevidence of J_(HF) and J_(CF). Conclusion The structures of amlodipine and risperidone wereconfirmed by careful analysis of regular 1D and 2D NMR spectroscopy.

Simultaneous investigation of blast induced ground vibration and airblast effects on safety level of structures and human in surface blasting

The significance of studying, monitoring and predicting blast induced vibration and noise level in mining and civil activities is justified in the capability of imposing damages, sense of uncertainty due to negative psychological impacts on involved personnel and also judicial complaints of local inhabitants in the nearby area. This paper presents achieved results during an investigation carried out at Sungun Copper Mine, lran. Besides, the research also studied the significance of blast induced ground vibration and air- blast on safety aspects of nearby structures, potential risks, frequency analysis, and human response. According to the United States Bureau of Mines （USBM） standard, the attenuation equations were devel- oped using field records. A general frequency analysis and risk evaluation revealed that： 94% of generated frequencies are less than 14 Hz which is within the natural frequency of structures that increases risk of damage. At the end, studies of human response showed destructive effects of the phenomena by ranging between 2.54 and 25.40 mm/s for ground vibrations and by the average value of 110 dB for noise levels which could increase sense of uncertainty among involved employees.

Study on online elimination of sudden unbalance-induced vibration using active balancing technology

An active balancing technology has been applied to solve the severe vibration caused by sudden unbalance in rotating machineries during their working process. First, based on the generation principle of sudden unbalance, a simulation test stand with a sudden unbalance generation device was set up. Then, the balancing planes were optimized by using the finite element method （FEM） to determine the position for balancing device installation. Finally, the active balancing experiments were carried out on the test stand. The experimental results indicate that the vibration response caused by sudden unbalance can be decreased from 77μm to 8μm by using the active balancing device, and the vibration amplitude reduction was up to 89.6%. From this example, it can be concluded that the active balancing device, which is installed on a proper position of the rotor, can effectively control the random transient synchronous vibration, demonstrating its high value in engineering practice.

Ride quality evaluation of the soil compactor cab supplemented by auxiliary hydraulic mounts via simulation and experiment

In order to evaluate the ride quality of the soil compactor cab supplemented by the auxiliary hydraulic mounts (AHM), a nonlinear dynamic model of the soil compactor interacting with the off-road deformable terrain is established based on Matlab/Simulink sofware. The power spectral density (PSD) and the weighted root mean square (RMS) of acceleration responses of the vertical driver s seat, the cab s pitch and roll angle are chosen as objective functions in low-frequency range. Experimental investigation is also used to verify the accuracy of the model. The influence of the damping coefficients of the AHM on the cab s ride quality is analyzed, and damping coefficients are then optimized via a genetic algorithm program. The research results show that the cab s rubber mounts added by the AHM clearly improve the ride quality under various operating conditions. Particularly, with the optimal damping coefficients of the front-end mounts c a 1,2 = 1 500 N · s/m and of the rear-end mounts c a 3,4 =2 335 N · s/m, the weighted RMS values of the driver s seat, the cab s pitch and roll angle are reduced by 22.2%, 18.8%, 58.7%, respectively. Under the condition of the vehicle travelling, with the optimal damping coefficients of c a 1,2 = 1 500 N · s/m and c a 3,4 =1 882 N · s/m, the maximum PSD values of the driver s seat, the cab s pitch and roll angle are clearly decreased by 36.7%, 54.7% and 50.6% under the condition of the vehicle working.

Characterization of Average Molecular Structure of Heavy Oil Fractions by ~1H Nuclear Magnetic Resonance and X-ray Diffraction

The chemical structure of heavy oil fractions obtained by liquid-solid adsorption chromatography was character-ized by 1 H nuclear magnetic resonance and X-ray diffraction.The molecular weight and molecular formula of asphaltene molecules were estimated by combining 1 H nuclear magnetic resonance and X-ray diffraction analyses,and were also ob-tained from vapor pressure osmometry and elemental analysis.Heteroatoms,such as S,N,and O atoms,were considered in the construction of average molecular structure of heavy oils.Two important structural parameters were proposed,including the number of alkyl chain substituents to aromatic rings and the number of total rings with heteroatoms.Ultimately,the av-erage molecular structures of polycyclic aromatics,heavy resins and asphaltene molecules were constructed.The number of α-,β-,γ-,and aromatic hydrogen atoms of the constructed average molecular structures fits well with the number of hydro-gen atoms derived from the experimental spectral data.

Potential Correlation between the Decadal East Asian Summer Monsoon Variability and the Pacific Decadal Oscillation

This study discusses the potential contribution of the Pacific decadal oscillation(PDO)to the weakening of the East Asian summer monsoon(EASM)and the evident correlation between the positive PDO and"Southern flood and Northern drought(SFND)"summer rainfall pattern over East China.The mechanism behind this contribution is also discussed.

Heat Transfer Between Immersed Horizontal Tubes and Aerated Vibrated Fluidized Beds

Heat transfer coefficients between an immersed horizontal tube and an aerated vibrated fluidized bed are measured. There is a maximum value in the h-P experimental curve. The heat transfer coefficient increases with decreases in particle diameter in the fully fluidized region. The particle density has less effect on the heat transfer coefficients. High amplitude and low frequency, or low amplitude and high frequency are favorable to heat transfer. Exceedingly high gas velocity is unfavorable to the surface-bed heat transfer. A model based on the 'pocket' theory was proposed for predicting the surface-to-bed heat transfer coefficients in fully fluidized region. The predictions from the model were compared with observed data. The reasonable fit suggests the adequacy of the model.

Fatigue Life Assessment of Top Tensioned Risers Under Vortex-Induced Vibrations

The fatigue life of top tensioned risers under vortex-induced vibrations (VIVs) with consideration of the effect of internal flowing fluid on the riser is analyzed in the time domain.The long-term stress histories of the riser under VIVs are calculated and the mean stresses,the number of stress cycles and amplitudes are determined by the rainflow counting method.The Palmgren-Miner rule for cumulative damage theory with a specified S-N curve is used to estimate the fatigue life of the riser.The corresponding numerical programs numerical simulation of vortex-induced vibrations (NSVIV) which can be used to calculate the VIV response and fatigue life of the riser are compiled.Finally the influences of the riser's parameters such as flexural rigidity,top tension and internal flow velocity on the fatigue life of the riser are analyzed in detail and some conclusions are drawn.

Vibration Control of Jacket Platforms with Magnetorheological Damper and Experimental Validation~

Magnetorheological （MR） dampers have been proposed to control the vibration of offshore platforms in this paper. The semi-active control strategy based on fuzzy control algorithm was adopted to determine the optimal output control force based on the responses of jacket platforms. A typical jacket platform in Mexico Gulf was selected as the numerical example to investigate the effectiveness of the proposed control method. Furthermore, a model experiment was performed to validate the results of the numerical simulation. The experimental model of the jacket platform was designed based on dynamical similarity criterion by the scale of 1：50. Both of the numerical and experimental results show that the semi-active control system with the MR damper can reduce vibrations of jacket platforms effectively and at the same time the control effect is stable.

Steering Vibrational Population Transfer via Double-∑-Type Laser Scheme

The vibrational state-selected population transfer from a highly vibrationally excited level to the ground level is of great importance in the preparation of ultra-cold molecules. By using the time-dependent quantum-wave-packet method, the population transfer dynamics is investigated theoretically for the HF molecule. A double-E-type laser scheme is proposed to transfer the population from the ｜v=16〉 level to the ground vibrational level ｜v=0〉 on the ground electronic state. The scheme consists of two steps： The first step is to transfer the population from ｜v=16〉 to ｜v=7〉 via an intermediate level ｜v=11〉, and the second one is to transfer the population from ｜v=7〉 to ｜v=0〉 via ｜v=3〉. In each step, three vibrational levels form a E-type population transfer path under the action of two temporally overlapped laser pulses. The maximal population-transfer efficiency is obtained by optimizing the laser inten- sities, frequencies, and relative delays. Cases for the pulses in intuitive and counterintuitive sequences are both calculated and compared. It is found that for both cases the population can be efficiently （over 90%） transferred from the ｜v=-16〉 level to the ｜v=0〉 level.

A Review of Interaction Between Neon Flying Squid(Ommastrephes bartramii) and Oceanographic Variability in the North Pacific Ocean

The neon flying squid （Ommastrephes bartramii） is a short-lived opporttmistic species widely distributed in subtropical and temperate waters in the North Pacific Ocean. The life cycle of O. bartramii from planktonic eggs to nektonic adults is closely linked to oceanographic conditions. The fluctuations in O. bartramii abundance and distribution tend to increase and widen continu- ously due to the heavy influences of ocean-climate events on various spatio-temporal scales. In this study, we reviewed the interac- tion between O. bartramii and oceanography variability in the North Pacific with respect to large-scale climatic-oceanic phenomena including E1 Nifio, La Nifia, Kuroshio, Oyashio and Pacific Decadal Oscillation （PDO）, as well as regional environmental variables such as sea surface temperature （SST）, sea surface height （SSH）, sea surface salinity （SSS）, chlorophyll-a （Chl-a） concentration, and plankton density. The population dynamics of O. bartramii is mediated mainly by meso- and large-scale climatic-oceanic events （e.g., Kuroshio and Oyashio Currents） rather than other local environmental conditions （e.g., SST and Chl-a concentration）, because all of the oceanographic influences are imposed on the context of large-scale climate changes （e.g., PDO）. An unstructured-grid finite- volume coastal ocean model coupled with an individual-based model is proposed to simulate relevant physical-biological oceano- graphic processes for identifying ocean-climate influence and predicting O. bartramii distribution and abundance in the North Pacific. Future research needs to be focused on improving the knowledge about early life history of O. bartramii and evaluating the relation- ship between marine physical environment and two separate passive drifting life stages of O. bartramii including free-floating eggs and planktonic paralarvae.