Estimation of Wind Wave Frequency Spectra by Use of the Arcsine Law   总被引：1，自引：0，他引：1  

戴德君  乔方利王伟 袁业立 《中国海洋工程》2007,21(1):105-114

In the present study,the surface elevation of wind waves oberved in laboratory and in the Bohai Sea are adopted for the estimation of the wind wave frequency spectrum by use of the method of the arcsine law(MAL).The traditional method uses the surface elevation to calculate the correlation and then estimate the frequency spectrum while the MAL,presented by Yu and Lan(1979),uses the time sequence of zero-crossing points of surface elevation rather than directly the surface elevation to calculate the correlation.66 sets of wind wave data obtained in laboratory and 420 sets of data observed in the Bohai Sea are adopted for the examination of the method introduced by Yu and Lan.Results show that the MAL can give reliable estimation of wind wave spectra.Correlation and form of spectra estimated by the MAL are similar to those estimated by the traditional method.The peak frequency and the spectral density in peak frequency by the MAL are close to those obtained by the traditional method.  相似文献   

国际海洋划界技术发展与探讨   总被引：3，自引：0，他引：3  

魏合龙  林峰  何书锋  沈文周 《海洋地质前沿》2003,19(6):1-4

国际海洋划界的地理环境复杂，涉及学科多，既有法律问题也有技术方法问题。适用于海域划界的国际法原则有多种，在这些海域划界原则指手下涉及了多种因素，并形成了多种划界方法，这样必将使划界工作变得异常复杂。GIS、决策支持系统等技术的应用将在国际海洋划界的管理方面提供强有力的支持，并成为重要的决策工具。  相似文献   

深水风浪的风区指数律     

管长龙  张淑芳  孙建  孙群 《中国海洋大学学报(自然科学版)》2004,34(5):704-712

对已有根据观测提出的幂函数形式风浪成长关系进行了分析。发现这些风浪成长关系在消去无因次风区后一致地与3／2指数律相协调，尽管它们原来存在较大的不协调性。发现Jeffreys，Sverdrup和Munk以及Platit的风能输入源函数在谱积分意义下具有相似性，而Tsikunov，Hasselmann和Phillips的破波耗散源函数在谱积分意义下也具有相似性，尽管这些源函数的原始形式和物理背景显著地不同。利用有效波能量平衡方程，将3／2指数律和发现的风能输入及破波耗散源函数相似性相结合，提出了深水风浪随风区成长的分式指数律，以得到的分式指数律拟合已有基于观测提出的风浪成长关系提出了半经验的风浪成长关系，与已有观测数据符合。  相似文献   

Self-affine growth pattern of earthquake rupture zones     

Hiroyuki Nagahama 《Pure and Applied Geophysics》1994,142(2):263-271

Data from 41 moderate and large earthquakes have been used to derive a scaling law for fault parameters. Fault lengthL, widthW and areaS are empirically related byLS andWS where 0.6<<0.7, 0.3<<0.4 and +=1. These relations indicate that the growth pattern of earthquake rupture zones is statistically self-affine. It is also found that these relations are similar to the relation derived from a diffusion-limited aggregation (DLA) model with anisotropic sticking probability. This suggests that a modified DLA model could describe the evolution of earthquake rupture zones.  相似文献   

四川省乡镇矿业管理法规的特色和几个问题的探讨     

何继强 《四川地质学报》1994,(3)

１９９４年四川省八届人大常委会第九次会议通过的《四川省乡镇集体矿山企业和个体采矿管理条例》,体现了社会主义市场经济的基本原则．明确了省、市（地、州）、县三级地矿行政主管部门的法律地位和职能、职责,强化和完善了采矿权管理制度和矿产资源开发及矿产品运销的监督管理制度,这标志着四川省乡镇矿业管理的法规体系逐渐趋于完备,为乡镇矿业管理创造了良好的行政执法条件。同时给各级地矿部门提出了新的要求,在实施这一条例中,需要引起注意的若干问题,本文也作了探讨。  相似文献   

高分辨率遥感技术在地质灾害调查与成灾规律分析中的应用——以攀西米易地区为例     

唐尧  马松  王立娟  朱云波 《中国地质调查》2022,9(3):96-103

攀西地区山高谷深,地形切割强烈,历来是地质灾害的重灾区和易发区。为摸清地质灾害家底,查明地质灾害分布与发育规律,排查出可能存在的地质灾害隐患,支撑灾害现场核查与工程防治,利用高分辨率遥感技术(简称高分遥感技术)对四川攀西米易地区开展地质灾害遥感调查与现场验证,共确定有明显威胁对象的地质灾害隐患点106处,主要以崩塌、滑坡为主,其次为泥石流。结合调查结果,开展隐患点成灾规律分析,结果表明: 地质灾害主要发育于安宁河及其支流沿岸一线,沿省道S214线及米普路、麻楠路、二滩库区环湖路段呈带状分布,主要分布于断层两侧500 m范围内,达到51处,占遥感调查隐患点总数的35.8%; 2019年5—9月共发生地质灾害104处,占全年发生地质灾害总数的98.11%; 区域西北部和中北部地质灾害发育程度相对较低。应用结果表明,利用高分遥感技术能够有效查明地质灾害隐患分布与成灾规律,对服务基层防灾减灾工作,减轻灾害损失,提升地质灾害科技水平和防灾能力具有重要意义。  相似文献   

合肥断陷盆地北缘古近、新近系定远组含膏、含盐岩沉积特征,分布规律   总被引：1，自引：1，他引：0  

孙亚力  程光文  李凤强  朱琨 《安徽地质》2007,17(2):101-104

合肥断陷盆地北缘古近、新近系含膏,含岩盐系可分为三个阶段:即早期为成膏,成盐准备阶段;中期为成膏,成盐强烈阶段;晚期为成膏,成盐消亡阶段.其韵律组成:定远东兴盐矿为两个或两个以上的韵律组成的韵律,即石膏-钙芒硝-盐岩-石膏,未达到钾盐沉积阶段.外围以硫酸盐为主的韵素组成的韵律,即石膏-钙芒硝-石膏韵素组成的韵律,未达到岩盐沉积阶段.水平分带呈"类似牛眼式构造".近东西构造控制着含盐盆地的演化、发展.  相似文献   

顾及GNSS坐标时间序列中季节信号的CEEMD降噪方法     

梁沛  杨志强  杨兵  田镇  陈祥 《大地测量与地球动力学》2022,42(10):1010-1014

针对互补集合经验模态分解（complementary ensemble empirical mode decomposition,CEEMD）在GNSS坐标时间序列降噪过程中需要选取筛选准则的问题,提出一种顾及GNSS坐标时间序列中季节信号的CEEMD降噪方法。首先利用CEEMD方法对GNSS坐标时间序列进行分解,然后计算各本征模态函数（intrinsic mode function,IMF）的平均周期,将平均周期低于120 d的IMF分量作为噪声分量扣除,并重构剩余分量为信号分量。利用该方法对中国大陆227个GNSS垂向坐标时间序列进行降噪,并与以连续均方误差和相关系数为筛选准则的CEEMD降噪方法的结果进行对比。结果表明,本文方法未出现过度降噪,而其他2种方法均导致部分测站的季节信号被扣除;在未过度降噪站点,本文方法GNSS坐标时间序列的RMS、幂律噪声和速度不确定度的平均改正率分别为19.13%、88.29%和86.46%,优于其他2种方法。  相似文献   

First Principles Calibration of 40Ar Abundances in 40Ar/39Ar Mineral Neutron Fluence Monitors: Methodology and Preliminary Results     

Leah E. Morgan  Brett Davidheiser-Kroll  Klaudia F. Kuiper  Darren F. Mark  Noah M. McLean  Jan R. Wijbrans 《Geostandards and Geoanalytical Research》2023,47(1):91-104

The accuracy and traceability of geochronometers are of vital importance to questions asked by many Earth scientists. The widely applied ⁴⁰Ar/³⁹Ar geochronometer relies on the co-irradiation of samples with neutron fluence monitors (reference materials) of known ages; the ages and uncertainties of these monitors are critical to our ability to apply this chronometer. Previously, first principles, astronomical and optimisation calibrations have been made. The first principles method for determining the age of monitor minerals is the K-Ar method, which involves measurement of their ⁴⁰K and ⁴⁰Ar* abundances. The AQuA (Absolute Quantities of Argon) pipette system, which emits calibrated quantities of ⁴⁰Ar* via the ideal gas law, was used to calibrate the sensitivity of the system across a range of source pressures and estimate ⁴⁰Ar* abundances in neutron fluence monitors. These ⁴⁰Ar abundances were combined with existing ⁴⁰K abundance data for these monitors. Ages for HD-B1 and MD2 (GA1550) biotite fluence monitors were calculated and combined with intercalibration data for HD-B1 and Fish Canyon sanidine (FCs) to determine ages for FCs. Current results do not have the targeted accuracy when compared with previous calibrations; however, we show how the extensive methodology development presented here can be used towards making reliable future measurements.  相似文献   

Spatio-temporal deposition profile of an experimentally produced turbidity current with a continuous suspension supply     

Shun Nomura  Giovanni De Cesare  Mikito Furuichi  Yasushi Takeda  Hide Sakaguchi 《国际泥沙研究》2022,37(3):299-306

A turbidity current is a turbulent, particle-laden gravity current that is driven by density differences resulting from the presence of suspended sediment particles. The current travels downslope, bearing a large amount of sediment over a great distance, and forms fluvial and submarine bedforms. Knowledge of the spatio-temporal deposition profile of turbidity-deposited sediment is important for a better understanding of sediment transport by turbidity currents. In the current study, the depositi...  相似文献