应用迭代学习控制的减震系统主动控制

在大多数工程系统中,要求减少或者消除振动的影响。过去被动的解决方法是利用弹性体装置,这样会人为地降低机械性能。所以针对这一控制问题,提出了振动主动控制的方法,从而大大地提高了在低频时的减震效果。针对周期性震动源的问题,提出应用迭代学习控制的参数最优算法,采用主动/被动混合控制的"质量弹簧阻尼"装置,其仿真结果表明该控制方案具有良好的性能,特别在10Hz及20Hz频率下,能在较短的时间内使得系统位移为零,从而达到减震的效果。     

兰州皋兰山北坡稳定性问题探讨

通过对兰州皋兰山北坡滑坡,泥石流灾害的成生自然环境研究,认为活动构造,岩土体特性,地形地貌及应力场特征为影响皋兰山北坡稳定性的主导因素,地下水,地震和人文活动是诱发因素。     

从北方神鹿到北方龟蛇观念的演变——关于图腾崇拜与四象观念形成的补充研究

作者曾论述过四象观念起源于华夏族的图腾崇拜,即东方苍龙源于东方东夷民族的龙图腾,北方龟蛇源于北方夏民族的龟蛇图腾等。近发现战国以前四象文物图案北方是鹿而不是龟蛇。该文因此作出补充研究,论证了北方神鹿也是北方民族的图腾,并且论述了从神鹿到龟蛇的演变过程和思想基础     

鄂尔多斯盆地西缘冲断带深井井壁稳定性研究

鄂尔多斯盆地西缘冲断带深层页岩气井钻井工程中垮塌、漏失、卡钻等复杂情况频发。为保障安全高效钻井,降低勘探开发成本,早日实现该区深层海相页岩气资源的经济高效开发,基于地应力、岩石力学等室内物理实验,结合现场工程参数及塌漏信息,考虑力学弱面影响,建立了西缘冲断带深井全井段地层力学参数、全井段四压力剖面模型,评价了不同岩性地层力学参数分布规律,揭示了西缘冲断带深井井壁坍塌、漏失等失稳机理。研究结果表明,羊虎沟组以上砂泥岩地层强度较低,约为20~100 MPa,拉什仲组至桌子山组灰岩强度较高,超过100 MPa。较大的水平主应力差,发育的裂缝带、煤层是诱发井壁失稳的主要原因。建立的西缘冲断带深井岩石力学性能及四压力剖面预测,可为该地区井身结构优化设计,关键工程参数选取提供科学依据。     

南海北部深水油气新认识

南海北部陆缘深水区由于陆缘地壳的强烈伸展减薄,形成了多个宽深断陷所构成的盆地群,发育多种类型烃源岩和大型储集砂体。大型盆地、广泛分布的多类型烃源岩、高-变地温场的耦合共控,奠定了深水油气资源的物质基础。大型供给水系、构造地貌、相对海平面升降的相互作用,形成3种类型的沉积体系,控制了深水区大型储集体的发育和展布,但高热流加速了深水沉积物压实和成岩作用。南海北部陆缘深水油气勘探前景广阔,烃源岩、有效储层以及热流3因素的复杂多变,决定了油气勘探中机遇与挑战并存。     

基于现场总线的子午胎帘布裁断机的研究

子午胎纤维帘布全自动断机控制系统采用矢量式变频控制器、全数字交流服驱动系统、帘布光纤自动测边系统、变角度设备移动定位锁紧系统及基于现场总线的PLC系统，实现了恒速张力送布、自动定长拉缝，精确对接，及全自动贴胶和卷取。软件系统实现了裁断效率对断精度的自适应、速度对定长的自整定、误差自调整及故障自诊断的功能。     

浅析杜邦财务分析的应用

简要介绍了杜邦财务分析的基本原理及杜邦财务分析的应用。     

Evidence of crustal ＇channel flow＇ in the eastern margin of Tibetan Plateau from MT measurements

Magnetotelluric （MT） survey has been carried out in the eastern margin of the Tibetan Plateau and its neighboring Shimian-Leshan area, Sichuan Province. Analysis of this MT data reveals that the electric structure of the Tibetan Plateau differ much from that of the Sichuan block. In general, the electric resistivity of crust beneath the Sichuan block in the east is larger than that of the eastern margin of the Tibetan Plateau in the west. The crust of the plateau is divided into upper, middle, and lower layers. The middle crust is a low resistivity layer with minimum down to 3-10Ωm about 10-15 km thick. It presumably contains partial melt and/or salt-bearing fluids with low viscosity, prone to deform and flow, producing a ＂channel flow＂ under the southeastward squeeze of the eastern Tibetan Plateau. This low-resistivity layer makes the upper crust decoupled mechanically from the lower crust. In the brittle upper crust, faults are dominated by left-lateral strike-slip and thrust motions, leading to surface rising and shallow earthquakes. The low-resistivity layer also cut the Xianshuihe-Anninghe fault zone into two sections vertically. In this region, the thicknesses of upper, middle, and lower crust vary laterally, producing a transitional zone in the eastern margin of the Tibetan Plateau characterized by thicker crust and higher elevation in the west and thinner crust and lower elevation in the east.     

Timing of the Wudangshan, Yaolinghe volcanic sequences and mafic sills in South Qinling: U-Pb zircon geochronology and tectonic implication

The Wudangshan, Yaolinghe volcanic-sedimentary sequences and doleritic-gabbroic sills comprise the largest exposed Precambrian basement in South Qinling. Zircons separated from 5 volcanic-pyroclastic samples of the Wudangshan Group, 2 volcanic samples of the Yaolinghe Group and one sample for the mafic sills were used for U-Pb dating by laser ablation-inductively coupled plasma mass spectrometry （LA-ICPMS）. The results reveal that the Wudangshan volcanic sequence was formed at （755±3） Ma （a weighted mean from the 5 samples, MSWD=0.47）, whereas the Yaolinghe volcanic suite and the mafic sill were crystallized at （685±5） （2 samples, MSWD=0.36） and （679±3） Ma （MSWD=1.6）, respectively, which are equal to each other within analysis errors. These ages are markedly younger than those previously documented for the rocks. The newly obtained ages for the Wudangshan and Yaolinghe Groups are Identical to those of the bottom Liantuo and slightly older than those of the Nantuo Formations, respectively, lower strata of the Nanhua （middle to late Neoproterozoic） stratotype section in eastern Three Gorges, Yangtze creton. A range of inherited magmatic zircons was recognized with ages of 830 to 780 Ma, which are typical of Neoprotzrozoic magmatisms recorded along the margins and interior of the Yangtze craton. Thus, there is Neoproterozoic basement comprising 830-780 Ma igneous suites in South Qinling; the inherited zircons were detrital sediments derived from the northern margin of the Yangtze craton. Accordingly, it is suggested that the South Qinling is a segment of the Yangtze creton before the Qinling Orogeny.     

浙江中北部沿海人工渔礁拟投放区夏季近底层水生游泳动物组成分析

通过对浙江中北部海区13个人工渔礁拟投放点的拖网调查,从而获得了各拟投放点的水生游泳动物组成数据并进行分析,研究结果表明:在浙江中北部人工渔礁拟投放区海域共捕获水生游泳动物50种,分别隶属于3门,3纲,14目,34科。其中,鱼类26种,虾蟹类20种,头足类3种,其他甲壳类1种。各类群的资源重量密度指数和资源尾数密度指数的最大值分别出现在P1号站和P7号站。水生游泳动物的优势种为中国毛虾Acetes chinensis、中华管鞭虾Solenocera crassicor-nis、矛尾鰕虎鱼Chaeturichthys stigmatias、口虾蛄Oratosquilla oratoria、须赤虾Metapenaeopsis barbata、葛氏长臂虾Palaemon gravieri,常见种为双斑蟳Charybdis bimaculata、鹰爪虾Trachypenaeus curvirostris、狼牙鳗鰕虎鱼Taenioides rubicundus、哈氏仿对虾Parapenaeopsis hardwickii、长蛸Octopus variabilis、日本蟳Charybdis japonica、皮氏叫姑鱼Johnius belengerii、带鱼Trichiurus japonicus、前肛鳗Dysomma anguillare、剑尖枪乌贼Loligo edulis、刺鲳Psenopsis anomala、小黄鱼Larimichthys poly-actis、细巧仿对虾Parapenaeopsis tenella等。