This paper investigated the impact of phosphorus on periphyton communities in a subtropical eutrophic lake.The results showed that increase in phosphorus supply significantly increased the abundance and biomass of periphyton.Dominant groups of periphyton were Bacillariophyta and Chlorophyta.Dominant species included Melosira sp.,Synedra sp.,Fragilaria sp.,Scenedesumus quadricauda,Pediastrum duplex and Cosmarium sp.The increase in phosphorus had no effect on species number of Bacillariophyta,but increased the species number of Chlorophyta.The study suggests that phosphorus is the key factor controlling the development of periphyton,and reduction in phosphorus input is needed in order to protect submerged macrophytes.

The mechanism of absorption,transferring and release of submerged macrophytes to nutrient salt phosphorous was summarized.It was pointed out that the mechanisms of different submerged plants to nutrient salt phosphorous were different and their influence mechanisms on the circulation of nutrient salt phosphorous also had difference.Finally,it induce the structure and function of whole aquatic ecosystem to change.

In shallow and eutrophicated lakes,submerged macrophyte is the crucial factor for clear water state or turbid state.While strong competition of periphyton for illumination,carbon sources,and nutrition has become the determinant on growth and development of submerged macrophytes communities.Tilapia,as the dominant species in south freshwater ecosystem,its top-down effect could alleviate the negative influences of periphyton on submerged macrophytes growth because of its probability of gazing and consumption on periphyton.So,as the dominant species of waterbody in South China,author think that tilapia can be used to control growth of periphyton and prompt submerged macrophyte development in shallow and eutrophic lake.Besides,tilapia can also accelerate nutrition regeneration by excretion and herbivory on submerged macrophytes.Therefore,this paper summarizes predecessor's conclusions,and proposes some intensive studies should be down to the relationship among tilapia,periphyton and submerged macrophytes with consideration of all the factors.It is very important for management and ecological restoration of shallow and eutrophicated lakes in south of China.

The infrared baits which the airplane uses in view of the current air fight are getting more and more,and the current infrared air-to-air missile's detection wave band is relatively narrow.To improve air-to-air missile's detectivity and recognition capability,the viewpoint of multi-wave band dual-color detection and recognition is proposed.In the paper the energy distribution of aircraft engines caudal flame,aircraft skin and infrared decoy in different bands are analyzed,by using Planck's Law and Wien's Displacement Law.The stimulation of dual color integral ratio in the midwave/long wave,the shortwave/midwave,the shortwave/long wave bands are carried out.The method of multi-wave band dual-color detection is put forward based on the analysis and simulation results.

为研究和实现珍珠的自动分选,提出了一种对珍珠的色调及饱和度进行分选的方法.将珍珠图像由RGB颜色模型转换到HIS模型中进行处理,根据,(亮度)分量直方图,通过全局分割提取珍珠光亮区,掩模后得到光亮区H(色调信息)、S(饱和度信息)均值.其中针对色调分选要求,运用了基于RPROP算法的人工神经网络学习方法;针对各色系内色彩的深浅差异,运用了K-均值聚类方法对S均值进行分类.从而实现了先按照珍珠表面色彩进行分类,再将同一色系内的珍珠按照饱和度进行再度分选,最终达到颜色分选要求.

Submerged macrophyte coverage,percentage of Vallisneria natans and nyaritta verticillata,and concentrations of total nitrogen(TN)、total phosphorris(TP)and Chl α,were studied in a shallow eutrophic lake.The results showed that:1)Percentage of Vallisneria natans increased from 30%to 95%,while Hydrilla verticillata decreased from 60%to 5%before May,respectively;2)Content of nutrients and chl a reduced quickly with the stabilization of ecosystem after rapid increasing period in the process of transition,concentrations of TN、TP and Chl α reduced to about 0.840 mg·L-1、0.028 mg/L and 2.562μg·L-1,respectively,Secchi depth (SD)increased to 120cm,water quality improved obviously;3)Our results indicated that ecosystem ofNan Lake was at a clear water state dominated by Vallisneria natans which shifted from turbid state dominated by phytoplankton,after a short interim state dominated by Hydrilla verticillata,gradually.

An approach for pearl shape fuzzy pattern recognition based on the Zernike moments was proposed.After a series of preprocessing on the pearl image obtained,transformed it to the polar coordinates,then computed eight-Derivative Zernike moment means as each kind of typical shape 's characteristic parameter.The utilization of fuzzy pattern recognition method real-ized the shape effective distinction of each pearl image,finally,by seeking and comparison of characteristics image through multi-angles of view,realized the pearl shape distinction classification.