基于模糊控制的快速循迹智能车的设计与实现

提出基于模糊控制的快速循迹智能车的实现方法.利用转速传感器、线阵CCD、舵机等构成一个闭环控制系统,并采用PI算法控制智能车后轮速度.采用模糊控制算法将线阵CCD返回的误差模糊化,然后按照MAX-MIN规则进行逻辑推理,最后将推理结果反模糊化后以控制舵机转向.实验结果证明了该方法的有效性.     

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莘县国土资源局创建文明机关的几点做法

近年来,莘县国土资源局认真贯彻中央提出的关于加强党的先进性建设,树立和落实科学发展观,加强文明机关和新型机关建设,促进文明机关和新型机关建设相互促进和谐发展。自2004年以来连续3年被评为市级文明机关,被山东省国土资源厅授予模范先进集体,为构建和谐莘县,实现莘县经济的又好又快发展发挥着积极的作用。     

Dynamic stress concentration of an elliptical cavity in a semi-elliptical hill under SH-waves

The method of wave-function expansion in elliptical coordinates,elliptical cosine half-range expansion and Mathieu function were applied to obtain an exact analytical solution of the dynamic stress concentration factor(DSCF)around an elliptical cavity in a shallow,semi-elliptical hill.An infinite system of simultaneous linear equations for solving this problem was established by substituting the wave expression obtained by the Mathieu function including the standing wave expression of elliptical lining given herein into the boundary condition obtained by the region-matching method.The finite equations system with unknown coefficients obtained by truncation were solved numerically,and the results in the case of an ellipse degenerating into a circle were compared with previous results to verify the accuracy of the method.The effects of different aspect ratios,incident wave angles and aperture ratios on the dynamic stress concentration around the elliptical cavity were described.Some numerical results,when the elliptical hill was changed into a circular one,were analyzed and compared in detail.In engineering,this model can be regarded as a semi-cylindrical hill with an elliptical cylindrical unlined tunnel under the action of SH waves,and the results are significant in aseismic design.     

Authigenic iron oxide formation in the estuarine mixing zone of the Yangtze River

Estuaries are elementary geochemical fronts where river water and seawater mix. Within this mixing zone, iron and other non-conservative elements can undergo complex reactions to form new solid phases. In order to understand authigenic iron oxide formation in the Yangtze River Estuary, two onsite water-mixing sets of experiments were conducted, one by mixing variable amounts of unfiltered Yangtze River water with filtered East China Sea water of different salinity (set 1), the other by mixing variable amounts of filtered Yangtze River water with filtered East China Sea water of different salinity (set 2). In set 2, the minerals newly formed in the course of mixing were investigated by means of a scanning electron microscope fitted with an energy-dispersive X-ray analytical system. It was found that ferrihydrite and lepidocrocite were formed in these mixing experiments, coexisting in nearly equal amounts. These iron oxides appear as aggregated particles with a large grain-size range of several microns to more than 100 μm. The electrolytic properties of seawater played an important role in the formation of these authigenic iron oxides. Kaolinite and organic aggregates were also found in the experimentally mixed pre-filtered waters. Amounts of newly formed suspended matter (set 2) were one to three orders of magnitude lower than those of total suspended matter (TSM) (set 1). This implies that newly formed minerals represent only a very small proportion of TSM in the estuarine mixing zone of the Yangtze River.     

沟槽内海底管道的水动力特性研究

基于水力模型实验，引入相对沟形系数αｒ，获得了以αｒ为表征的相对水动力系数与ＫＣ数的关系；对于浅沟而言，这种关系较有规律性。根据所设计沟形的αｒ值和所选定的ＫＣ值，应用本文结果，可以方便地判断其力折减程度和掩护效果     

夏季对马暖流区黑潮水与陆架水的相互作用──兼论对马暖流的起源

根据1994年8月28日至9月7日韩国“Onnuri”号海洋调查船获得的CTD资料及在调查期间投放的11个卫星跟踪漂流浮标资料,分析研究了东海东北部黑潮水的分离及其与陆架水的相互作用,进而探讨了夏季的对马暖流的形成过程。     

Trace metal composition of colloidal organic material in marine environments

Marine colloidal material (1 kDa–0.2 μm) was isolated by cross-flow ultrafiltration followed by diafiltration and freeze-drying from surface waters of the Gulf of Mexico and the Middle Atlantic Bight (MAB), as well as from estuarine waters of Galveston Bay. Elemental characterization of isolated colloidal material included organic carbon (OC) and selected trace metal (Cu, Pb, Zn, Cd, Co, Ni, Cr, Be, Fe, Al, Mn, V, Ba, and Ti) determinations. It was found that levels of these metals in marine colloids ranged from <0.1 to 50 μg/g colloidal matter, except for Fe which generally had a concentration >120 μg/g. Most metals (Cu, Pb, Zn, Ni, Al, Mn, V, and Ti) had an average concentration >1 μg/g while concentrations of Cd, Co and Be were usually <1 μg/g. Metal concentrations (μg/g) in isolated colloids were, in general, higher in Galveston Bay than in the Gulf of Mexico, suggesting either high abundance of trace metals in estuarine waters or differences in organic matter composition. Higher colloidal metal concentrations in the MAB than in the Gulf of Mexico might be due to higher terrestrial inputs in the MAB. Colloidal metal concentrations (μg/g) were generally lower than those in average soils, continental crust and suspended particles. However, metal/aluminum ratios (Me/Al) in isolated marine colloids were significantly higher than those for average soils and continental crust. Most importantly, colloids had a metal composition and metal/OC ratio (Me/C) similar to humic substances and marine plankton, suggesting that marine colloids largely originate from planktonic sources and are composed of predominately organic components. The Me/C ratios of Galveston Bay colloids followed the sequence of Cu>Ni, Cr, Zn>Mn>Co>Pb, Cd, which is similar to the Irving–Williams order except for Mn, suggesting that the interaction of metals with marine colloids is determined by the affinity of metals for specific organic ligands.