基于分布式控制力矩陀螺的水下航行器轨迹跟踪控制   总被引：2，自引：0，他引：2  

黄道敏  徐瑞昆  唐国元  冯雷  刘智  徐国华 《海洋工程》2018,36(6):69-76

基于控制力矩陀螺群(CMGs)的水下航行器具有低速或零速机动的能力。采用基于分布式CMGs的水下航行器方案,并研究其水平面的轨迹跟踪控制问题。通过全局微分同胚变换将非完全对称的动力学模型解耦成标准欠驱动控制模型,并根据简化的模型构建其轨迹跟踪的误差动力学模型,将轨迹跟踪控制问题转化为误差模型镇定问题。基于一种分流神经元模型和反步法设计了系统的轨迹跟踪控制律,该控制器不需要对任何虚拟控制输入进行求导计算,且能确保跟踪误差的最终一致有界性。仿真结果表明该控制器能够实现在不依赖动力学参数先验知识的情况下对光滑轨迹的有效跟踪。  相似文献   

手掘式顶管在市政排水工程中的应用          下载免费PDF全文

刘会 《探矿工程》2008,35(10):52-54

从混凝土管材的选定、工作坑的设计及施工、顶管顶进中若干关键问题入手,介绍了手掘式顶管施工技术在成都市中心城水环境综合整治工程G标段管道排水工程中的应用。  相似文献   

Characteristic analysis on oxygen isotopic tracer in the East China Sea and waters to east of the Ryūkyū-guntō     

Hong Ashi  Yuan Yaochu 《海洋学报(英文版)》1995,14(3):371-381

Samples of O isotopic tracer were mlleMed at Sections P₃,P₂₅,P_cM-t/2-E and P_CM-1/2.w in both the Fast China Sea and the area to the east of the Ryūkyū-gunto during October-November,1991.Analytical results of the δ¹⁸O are as follows: (1) In the Kuroshio area,the δ¹⁸O isolines are almost parallel to the 200 m isobath.The value of δ¹⁸O is negative and reaches minimum mt the main axis of the Kuroshio,and increases on both sides.(2) In the Taiwan Warm Current (TWC) area there is a high δ¹⁸O tongue extending to the northeast.(3) In the area near the coast,the distribution of δ¹⁸O isoline shows that the Changjiang River runoff diffuses seaward and the land-ocean isotopic effect from the nearshore to the offshore.(4) The values of δ¹⁸O are from -1.0×10^-3 to -0.5×10^-3 in the shelf.(5) There is a low mre of δ¹⁸O value(<-1.6×10^-3) at the 600 m layer in the Kuroshio area,which is quite in accord with the existence of a low salinity mre (S G 34.30) between the 600 and 800 m layers in the same area.Finally,the mrrelations of the δ¹⁸O with the salinity and temperature,the upwelling and so on are discussed.  相似文献   

大亚湾海域锥状斯氏藻赤潮及其与孢囊的关系   总被引：22，自引：0，他引：22  

肖咏之  齐雨藻  王朝晖  吕颂辉 《海洋科学》2001,25(9):50-54

用沉积物捕捉器取样，研究了大亚湾海域２０００年６～９月孢囊（Ｃｙｓｔ）种群动态，同时 分析了浮游植物种群动态。研究期间（８～９月）该海域发生了一起大规模的锥状斯氏藻赤潮。 赤潮前一个月，锥状斯氏藻孢囊的平均日形成率为２．０５× １０５ｃｙｓｔｓ／（ｍ２·ｄ），丰度为５０．２２％， 该时期以有性生殖产生的静止期孢囊为主；在赤潮盛期的８，９月初，孢囊的平均日形成率达到 ２．０１ ×１０６ｃｙｓｔｓ／（ｍ２·ｄ），丰度为９６．９７％，此时期的孢囊多为营养细胞所形成的暂时性孢囊； 赤潮结束后，由于环境条件的恶化，暂时性孢囊的形成达到高峰，平均日形成率为１．２４×ｌ０７ ｃｙｓｔｓ／（ ｍ２·ｄ），丰度为９９.５３％。结果表明大亚湾丰富的孢囊是潜在的种源（Ｓｅｅｄ　ｂｅｄ），２０００年 的夏季、秋李持续高温（＞２５℃），台风减少及风力减弱等有利锥状斯氏藻的环境条件诱发孢 囊萌发，开始了该种类的赤潮。  相似文献   

南海中建南盆地构造样式分析   总被引：2，自引：0，他引：2  

陈玲 《海洋地质与第四纪地质》2006,26(1):53-58

中建南盆地是发育于南海西部陆缘我国传统疆界线附近的新生代沉积盆地,大部分区域位于我国传统疆界线内。在对盆地近万千米多道地震资料综合分析解释的基础上,对盆地的主要构造样式以及它们与油气的关系进行了分析,结果表明,盆地分布面积广,沉积厚度大,油气前景良好。盆地是属于早期断陷、后期经走滑改造而成的复合型盆地,其构造演化经历了3个阶段,不同的阶段发育不同的构造样式:早期为断陷阶段,伸展型构造样式发育;中期为断坳—压扭或走滑反转阶段,产生走滑或压扭性构造样式;晚期为区域沉降阶段,以垂向沉积为主,无明显的构造样式发育。  相似文献   

吹扫-捕集气相色谱法测定海水中挥发性卤代烃   总被引：6，自引：0，他引：6  

杨桂朋  尹士序  陆小兰  宋贵生 《中国海洋大学学报(自然科学版)》2007,37(2):299-304

挥发性卤代烃(VHC)是大气中的痕量气体,对臭氧层损耗和温室效应有重要作用。海洋是大气中VHC的主要自然排放源,开展海洋VHC的研究有助于了解海洋对大气VHC和全球变暖的贡献。本文建立了吹扫-捕集与气相色谱-微池电子捕获检测器联用技术(P-T-GC-(ECD)分析海水中6种VHC的方法,确定了吹扫-捕集条件和气相色谱分离条件。该方法的检测限在0.003~0.369 ng.L-1之间;相对标准偏差是1.83~3.97;加标回收率为98.1%~110.2%;相关系数在0.997 3~0.999 8之间。可准确地测定海水中6种VHC。  相似文献   

The feasibility of escape mechanisms in conical snow crab traps     

Winger  Paul D.; Walsh  Philip J. 《ICES Journal of Marine Science》2007,64(8):1587-1591

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镇泾地区延长组河流相砂体分布与圈闭形成的关系研究   总被引：3，自引：1，他引：2  

张宗林  周文  苏付义 《矿物岩石》2008,28(4)

鄂尔多斯盆地镇泾地区侏罗系地层以三角洲-湖泊沉积体系为主,研究区范围内主要发育主河道和部分分流河道砂体。研究区构造平缓,主要为单斜地层、在东南部存在大型鼻状构造。通过对主要储层段(长6、8油层组)砂体分布及与构造之间关系进行研究,分析砂体走向与构造线方向的关系认为在构造单斜地区,当两者相交时(交角β≠0)是形成圈闭的关键因素之一,在大型鼻状构造地区因构造线的弯曲与河道砂体组合可以形成圈闭。根据研究区砂体分布和构造线组合出4种地层-岩性及岩性圈闭。利用构造图与砂体分布图对主要储层段存在的圈闭确定出长6、8油层组10个层圈闭。  相似文献   

Geologic Characteristics of Gas Reservoirs in West Sichuan Foreland Basin     

YANG Keming 《《地质学报》英文版》2008,82(6)

The foreland basin in West Sichuan is a tectonic unit that has undergone multi-periods tectonic movements of Indosinian-Yanshanian-Himalayan. Since late Triassic, it has been in a passive subsidence environment controlled by basin margin mountain systems and by the compression with abundant sediment sources. With the complex geologic setting, the main geologic characteristics of natural gas reservoir are listed as following:(1)Source rocks are coal-bearing mud and shale series with high to over maturity, and long and progressive hydrocarbon generation-displacement period. The key accumulation period is middle-late Yanshanian epoch.(2)There are three gas-bearing systems vertically, each of which has different reservoir mechanism, main-controlled factors and distribution law, so the exploration thoughts and techniques are also different.(3)Undergoing multi-period generation-migration-accumulation, oil and gas have encountered multi-period modification or destruction, and gas accumulation overpass multiple tectonic periods. So the trap type is complicated and dominated by combination traps. Because the main accumulation period of natural gas is early and the reservoir encountered the modification of strong Himalayan movement, there is great difference in the fullness degree of gas reservoirs and complicated gas-water relation. (4) Reservoir is tight to very tight, but reservoirs of relatively high quality developed under the super tight setting. (5) The key techniques for oil and gas exploration in west Sichuan foreland basin are the prediction of relatively favorable reservoirs, fractures and gas bearing; and the key techniques for oil and gas development are how to improve the penetration rate, reservoir protection and modification.  相似文献   

Actinic flux and photolysis frequency comparison computations using the model PHOTOGT     

Carsten Blindauer  Vladimir Rozanov  John Philip Burrows 《Journal of Atmospheric Chemistry》1996,24(1):1-21

The accurate radiative transfer model GOMETRAN, initially designed to yield radiances at TOA in the wavelength range 240–790 nm, has been extended to allow for the computation of actinic fluxes down to 175 nm and for the calculation of photolysis frequencies in the atmosphere. The capability of the extended model PHOTOGT (PHOTOGOMETRAN) is demonstrated in a number of successful comparison studies both with recent experiments (ground-based, balloonborne, airborne) and model calculations of radiances, actinic fluxes and photolysis frequencies in the stratosphere and troposphere. In an atmospheric case study, the impact of new quantum yield data for the O₃ » O₂+O(¹ d) photodissociation channel on the photolytic production of O(¹ d) atoms in the lower atmosphere has been quantified.  相似文献