小型光学惯性稳象跟踪系统的研究

主要论述了光学惯性稳象跟踪系统的原理,利用平行光路的相对稳象矩阵方程,设计了光学惯性稳象系统.对光惯稳跟系统的主要技术指标进行了分析和讨论。

光学稳象、广义光学稳象

本文将光学稳象方法抽象为稳象模式,建立起稳象数学模型。该数学模型不只对纯稳象系统有用,它可用于分析研究任何动态光学系统象面运动与光学元件运动之间的关系。

盘型三轴稳象棱镜组

为了减小三轴稳象棱镜组的纵向尺寸，通过对道威棱镜的结构和成象特性两个方面的分析和研究，提出了一种新的盘型三轴稳象棱镜组．这种棱镜组不仅具有大的通光口径和小的外形尺寸，而且保持了三轴稳象棱镜组的一切优点．

稳象式坦克火控系统智能射击门数学模型研究

应用随机穿越理论 ,提出了稳象式坦克火控系统智能射击门概念 ,对其数学模型进行了推导 ,并对智能射击门应用的一些技术问题进行了分析说明 。

光学稳象系统

本文从稳象模式出发推出并讨论各种典型的光学稳象系统以说明稳象数学模型的具体应用。

导弹光学寻的器及其稳象技术的进展

寻的导弹中有相当大一部分采用光学寻的器(导引头)进行制导。本文叙述从点源信号制导发展到图象信号制导的进展,论述在光学寻的器中实现稳定与跟踪的技术并阐述了笔者的一点见解。

稳像光学系统设计

重点沦述光学稳像的光学原理,并引用具体的平面反射镜作为光学补偿元件(也就是光稳元件)的稳像方式加以阐述,由此导出倒像系统和正像系统达到相对稳像和绝对隐像时补偿角与扰动角之间的关系式。论述采用会聚光路稳像时由棱镜的微量转动而达到绝对稳像时棱镜转动中心的求法。论述光稳元件兼作转像棱镜时光稳元件的有效孔径与转功中心和棱镜位置的关系。

光学稳像扫瞄头稳像条件分析计算研究

在车机载光学系统中,为克服载体角扰动对观察瞄准的影响,应该采取稳定措施。本文就平行光路光学扫描头稳像条件的设计计算方法作分析研究。

Advances in the Theory of Conjugation for Reflecting Prisms in China

The achievements made in China in the field of the theory of conjugation for reflecting prisms are outlined which mainly includes 6 theorems, 2 corollaries, over 30 formulae, 4 matric operators, 20 characteristic parameters, a new principle for dassification, and a new system of graphical tabulation for reflecting prisms. As an approach to developing the theory, an imaginary physical model called 'rigid body's kinematics model' has been creatively initiated to simulate the real physical phenomena of both image formation and image motion for reflecting prisms. Such a method of treatment has been successfully making the evolving theory more complete, more systematic, more generalized, and unique as well.

光学系统及设计

TH703 94031582盘型三轴稳象棱镜组=Discal three-axis image-stabilizing reflecting prism assembly[刊,中]/赵跃进(北京理工大学)∥北京理工大学学报.—1994,14(1).—22～26为了减小三轴稳象棱镜组的纵向尺寸,通过对道戚棱镜的结构和成象特性两个方面的分析和研究.提出了一种新的盘型三轴稳象棱镜组。

Electronic image stabilization algorithm based on fixed-lag smooth filtering

An algorithm using fixed-lag smooth filtering to improve the precision of EIS algorithm is presented in this paper. Ftrstly, gray projection algorithm （GPA） is used to calculate the interframe global motion vectors. Secondly, the fixed-lag smooth filter is used to smoothen the motion track of the original video sequence, according to different motion models. At last, the original sequence is compensated by using the compensation vectors calculated from filtering. This algorithm has been proved superior in filtering precision by experiments of video sequences in different motion scenes. This algorithm also satisfies the real-time request.

Fretting instability characteristics for gear shaft shoulder

In order to solve fretting instability problem of gear shaft shoulder due to torsional vibration in mechanical system, the mathematical model of fretting instability vibration of gear shaft shoulder was established by adopting the method of combining kinematics and tribology, and the numerical analysis was applied to the fretting instability mechanism of gear shaft shoulder by introducing the friction instability damping ratio. The numerical results show that the main factors causing the unstable and vibrating gear shaft shoulder are the large tightening torque and too large static friction coefficient. The reasonable values of the static friction coefficient, the amount of interference and tightening torque can effectively mitigate the fretting instability phenomenon of gear shaft shoulder. The experimental results verify that damping plays a significant role in eliminating the vibration of gear shaft control system.

Energy dissipation of coal and rock during damage and failure process based on EMR

The physical and mechanical change processes of coal and rock are closely related to energy transformation,and the destruction and failure of coal and rock is an instability phenomena driven by energy change.However,the energy change of large-scale coal rock in the mine site is hardly calculated accurately,making it difficult to monitor coal-rock systematic failure and collapse from the perspective of energy.By the energy dissipation EMR monitoring system,we studied the damage and failure of coal and rock with bursting liability from the energy dissipation point using the geophysical method-EMR,and explored the energy dissipation characteristics during uniaxial compression and their main influencing factors.The results show that under displacement-control loading mode,there are 2 types of energy dissipation trends for both coal and rock with bursting liability.The type Ⅰ trend is a steady increase one during the whole process,therein,the energy dissipation of rock samples is accelerated at the peak load.The type Ⅱ trend energy is a W-shaped fluctuating one containing 6 stages.Under load-control loading mode,there is one energy dissipation trend of shock downward-steady rise.Besides that,rock samples also present a trend of 4 stages.The energy dissipation characteristics of coal and rockduring loading failure process can be used as effective criteria to assess whether they are in a stable or destructive stage.The factors influencing energy dissipation in the loading failure process of coal and rock mainly include strength,homogeneity,and energy input efficiency.

Stability study on naturally filling body in gob-side entry retaining

In the construction of the filling gob-side entry retaining in a lane, we utilize the self-slide natural phenomenon of a falling gangue in an inclined coal seam goaf. First, we put the falling gangue of goal above the laneway and made it the main filling material by adopting the measurement of flexible supporting system combined with those of rigid supporting system. Then we made the filling material gunited and solidified to maintain the filling goal of the gob-side entry retaining beside the lane. Considering the law of energy conservation and law of pressure distribution for retaining the active and Static soil of the wall, we analyzed the reliability of a gangue blocking facilities and the stability of the filling mate- rial in the lane. We analyze the figures to see the stability. The result shows that the gangue block sup- porting system is reliable, and has been successfully practically applied.

The Study of a New Method for Forecasting Non-stationary Series

A new method for forecasting non stationary series is developed. Its steps are as follows: Step 1. Data delaminating. Non stationary series is delaminated into several multi scale steady data layers and one trend layer. Step 2. Modeling and forecasting each stationary data layer. Step 3. Imitating trend layer using polynomial. Step 4. Combining the forecasting layers and imitating layer into one series. The EMD (Empirical Mode Decomposition) method suitable to process non stationary series is selected to delaminate data, while ARMA (Auto Regressive Moving Average) model is employed to model and forecast stationary data layer and least square error method for trend layer regression. Aiming at forecasting length, forecasting orientation and selective method, experiments are performed for SAR (Synthetic Aperture Radar) images. Finally, an example is provided, in which the whole SAR image is restored via the method proposed by this paper.

Stopping and Remaking Approaches to Degradation of the Black Sea Coast in the Romanian Seaside Area

There is presented a degradation case study of the Romanian shoreline belonging to the seaside of the Black Sea. The Romanian coastal Black Sea is in a continuously degradation due to the destructive action exerted by waves on the shore and, respectively, to the instability phenomena that manifest itself in the area. There are presented the influences of different causes of the degradation, the characteristics of the seaside shoreline and the interventions already made. There are done evolution foresights of the ground instability phenomena as well as shoreline degradation and recommend measures for rehabilitation.

A Test for Stabilization of an Oligomeric Protein by Introduction of Aromatic Residues into the Interface

The design of variants to enhance conformational stability of proteins is an important aspect of protein engineering. Oligomeric proteins are often stabilized by aromatic clusters located within the subunit interfaces. In the present study, the authors constructed five variants of Ps3aHSD （Pseudomonas sp. B-0831 3a-hydroxysteroid dehydrogenase） in which one or two residues at the dimer interface were replaced with aromatic residues, and examined the effects of introducing aromatic residues in this region on protein thermostability. Under their experimental conditions, all variants formed dimers, similar to wild-type Ps3aHSD. Thermal denaturation experiments indicated that Tm of all variants was 0.2-16.2 °C lower than that of wild-type protein, indicating less stable thanwild-type protein. The results collectively suggest that aromatic residues of natural oligomeric proteins are strictly posted in the interface to facilitate optimal interactions and avoid conformational strain.

THE ROLE OF MERIDIONAL WIND STRESS IN THE TROPICAL UNSTABLE AIR-SEA INTERACTION

With a simple tropical coupled ocean-atmosphere model, this paper presents an analysis aiming to understand the relative role of the meridional and zonal wind stresses in the tropical unstable air-sea interaction. The roles of the zonal wind stress, the meridional wind stress and the both are considered respectively into the coupled system. It is demonstrated that the meridional component of the wind stress does not lead to any instability under the local thermal balance assumption, but it does lead to a weak instability under the sea surface temperature advection assumption. Unstable air-sea interaction is dominated by the zonal component of the wind stress, suggesting that ignoring the meridional wind stress is approximately feasible in studying the tropical unstable air-sea interaction.

Distortion Identification Technique Based on Hilbert-Huang Transform in Video Stabilization

A distortion identification technique is presented based on Hilbert-Huang transform to identify distortion model and distortion frequency of distorted real-world image sequences. The distortion model is identified simply based on Hilbert marginal spectral analysis after empirical mode decomposing. And distortion frequency is identified by analyzing the occurrence frequency of instantaneous frequency components of every intrinsic mode functions. Rational digital frequency filter with suitable cutoff frequency is designed to remove undesired fluctuations based on identification results. Experimental results show that this technique can identify distortion model and distortion frequency of displacement sequence accurately and efficiently. Based on identification results, distorted image sequence can be stabilized effectively.

Evaluations and Suggestions about Effect of Weather in Guangxi on Rice Production

[Objective] The paper aims to study the effect of weather on rice production in Guangxi. [Method] The authors evaluated the effect of weather and weather disasters in Guangxi on rice production by comparison and analysis in terms of temperature,rain and sunlight in 2009. [Result] The study summarized the main favorable and unfavorable weather conditions of rice growth,and proposed the measures and suggestions to tend to interest and avoid harm on rice production in Guangxi. [Conclusion] This study provides references to the evaluations about effect of weather in Guangxi on rice production and suggestions on how to reduce weather disasters influence and ensure rice production security.