全球定常波对大尺度地形的线性响应     

田永祥  Duncan  C.N.  雷兆崇 《高原气象》1991,(3)

本文应用一个定常态线性原始方程三维谱模式模拟出全球200 hPa定常波的结构特征。同时还考察了模式大气对大尺度地形的线性响应。  相似文献   

黄陵背斜东南边缘北东向线性构造特征及其与地震活动的关系   总被引：1，自引：0，他引：1  

韩晓光  徐卓民 《华南地震》1992,12(4):42-45

黄陵背斜东北,西北及西南三边为大断裂所切割,唯其东南边缘仅在卫星影象上有一线性构造。经实地考察研究,该线性构造地表以张性裂隙带的形式出现,其深部部分地段以主断面形式出现,从而在几何形态上组成一个完整的黄陵菱形断块构造。在断块的顶角处,是该地区中强地震的主要发生地带。  相似文献   

Changing Trends of Winter Temperature in Recent 53 Years in Ningxia and Impact for Agriculture     

Dong Guoqing  Li Liping  Zheng Guangfen 《地球科学进展》2016,31(11):1172-1181

Based on winter (December to February) daily temperature data of 20 meteorological stations in Ningxia Hui Autonomous Region since 1961, the interannual and interdecadal change trend and the mutation characteristics of the winter average, the maximum, and the minimum temperature of the whole Ningxia region, the Yellow River irrigation area, the central arid zone and the southern mountainous area were analyzed using linear trend, Mann-Kendall test and other methods; Meanwhile,the new characteristics of average temperature of the coldest month, <0 ℃ negative accumulated temperature in winter of the 21^st century and impact on agriculture were comparatively analyzed. The results showed that: Firstly, in the whole region and different areas of Ningxia, winter average temperature rose significantly before 2000, the Yellow River irrigation area was the most obvious in winter warming than that in the central arid zone and the southern mountainous area. 1985 was the abrupt change point of winter average temperatures in most areas of Ningxia. In the early 21^st century the winter average temperature rose slowly in most areas of Ningxia, even falling in the central arid zone. Secondly, the rise of average minimum temperature was significantly higher than average temperature and average maximum temperature in the winter, indicating that the rise of winter temperature in Ningxia was mainly due to winter minimum temperature. Since the 21^st century, the average maximum temperature had changed more dramatically than the average temperature in the winter, dropping in most areas. Winter average minimum temperature in addition to the central arid zone declined slightly after 2002, and continued to rise in most areas of Ningxia.Thirdly, both rise of the average temperature of the coldest month and dramatic reduction of the absolute value of negative accumulated temperature is not only beneficial to the northern planting boundary of winter crops spreading further to north and planting areas expanding with a lower risk of freezing injury, but also beneficial to crop pests increase.  相似文献   

层次分析法创建地热水前景评价模型的研究     

王永波  丁文萍  马奎羽  温延星  丁蕊 《城市地质》2016,(2):10-13

在地热能源不断得到关注和利用的当今社会,对其科学合理地开发利用显得尤为重要。文章采用层次分析法和多目标决策的线性加权相结合的方法建立了地热水开发利用前景评价模型,避免了以往单纯从定性角度分析地热水开发利用前景的人为主观性及片面性,保证了评价结果的客观准确,经实例验证,是一种行之有效的评价方法。作者选取地热地质条件、经济发展水平、开发利用现状作为层次分析法的中间层要素,进而将其进一步分解为不同的组成因素,运用层次分析法计算出各项指标的权重,结合多目标决策的线性加权方法建立综合评价评分的数学模型,最后根据地热田的实际情况,综合评价,确定评价结果。  相似文献   

Estimation of the responses of axisymmetric bodies in spread irregular waves     

A.P. McCabe  T.J. Stallard  N.J. Baker  H. Yavuz   《Ocean Engineering》2007,34(10):1371-1382

A method is presented of estimating the responses of axisymmetric bodies floating in spread irregular seas, using a Laplace transfer-function formulation of a floating body time-domain model. A general-case spread-wave model is formulated, using separate wave excitation transfer functions, and a simplification of this approach is proposed, reducing both model complexity and computation time. Responses are computed using both approaches and a comparison made to assess the circumstances in which the simplified approach may be used effectively. The results are also interpreted to highlight the implications of using an equivalent unidirectional wave as an approximation to a spread wave.  相似文献   

Analysis of single and tandem cylinder data using an orthogonal Volterra model approach     

I.A. Sibetheros  J.M. Niedzwecki   《Ocean Engineering》2005,32(2):881-156

The development of a definitive predictive model that accurately accounts for the nonlinear hydrodynamics and structural response behavior observed in arrays of closely spaced risers on deep water structures will require a more detailed understanding of this fluid–structure interaction. Through the analysis and interpretation of data from model basin tests on single and paired tandem cylinder configurations this study is directed at uncovering the nature of some aspects of this nonlinear response behavior using an orthogonal third-order Volterra technique that can delineate between linear, quadratic and cubic nonlinear frequency dependent behavior. As part of the analysis procedure the data was organized in input–output pairs that would provide logical groupings of the measured quantities. The data pairs presented in this study include wave excitation and inline cylinder displacement, wave excitation and transverse cylinder displacement, wave excitation and inline reaction force, and, upstream cylinder and downstream cylinder response. This information is presented in terms of spectral and coherence plots. The single cylinder data is presented as a means to contrast the behavior of the tandem cylinders. Both configurations were analyzed at two different pretensions adding another dimension to this investigation. It is shown that although a primary variable such as displacement may be more easily measured, pretension and force measurements provide an important key to our understanding of this difficult problem.  相似文献   

海洋中液-固界面作用的分形研究 Ⅱ.混合交换剂表面分维的加和性规律和非加和性规律研究     

刘莲生  张正斌  杨长春  管清录  王超英  郭国霖 《海洋与湖沼》1992,23(6):581-590

用SAXS方法验证了海洋化学液-固界面研究中一些混合交换剂体系的分维分别具有加和性和非加性规律。实验测得:针铁矿/蒙脱石、水锰矿/无定形氧化铁、δ-MnO_2/针铁矿、δ-MnO_2/无定形氧化铁等混合交换剂体系的表面分维对混合百分率具有线性加和性;而高岭石/无定形氧化铁、无定形氧化铁/蒙脱石、δ-MnO_2/蒙脱石、δ-MnO_2/氧化铁凝胶等混和交换剂具有非线性加和性。上述诸体系在海水介质中平衡一年后,SAXS测定的表面分维皆具有非线性加和性,或非线的程度有所增加。  相似文献   

A nonlinear wave profile correction of the diffraction of a wave by a long breakwater: Fixed point approach     

T.S. Jang  S.H. Kwon  Takeshi Kinoshita  B.J. Kim 《Ocean Engineering》2007,34(3-4):500-509

The authors of the present paper have suggested an iterative scheme to calculate the nonlinear wave profiles [Jang and Kwon, 2005. Application of nonlinear iteration scheme to the nonlinear water wave problem: Stokes wave. Ocean Engineering 32, 1862–1872]. The scheme was shown to be good for estimating nonlinear wave profiles. In the study, the iterative scheme is applied to the wave-diffraction problem by a long breakwater to calculate a diffracted wave by the breakwater. The iterative solution of diffraction was compared with the linear solution of Sommerfeld, 1896. [Mathematische Theoried der Diffraction. Mathematical Annals 47, 317–374]. For a small wave slope, the two solutions were in good agreement. However, the scheme enabled us to observe the nonlinear behaviors of a beating phenomenon and of wave profile such as Stokes’ wave for a relatively large wave slope: as the wave slope becomes larger, we can examine the nonlinear wave characteristics of the actual shapes of waves, i.e., the crests are steeper and the troughs are flatter.  相似文献   

一种综合修正线阵声呐基阵误差的方法     

陈非凡  吴英姿 《海洋技术学报》1997,16(4):23-28

线阵声呐的基阵误差包括基元物理相位误差和相邻基元之间的间隔误差，本文提出了一种综合修正以上两种误差实用方法，利用该方法可以有效地提高线阵声呐系统的波束定位精度，并通过一个具体的实例进行了验证。  相似文献   

应用卫星遥感影像分析青岛市地下水资源     

冯文珍 《海洋科学》1989,13(3):1-6

本文应用卫星遥感影像解译、研究青岛市线性构造在空间上的分布特征。分析了地下水类型和富水性,圈定了隐状含水层的分布范围,指出了地下水局部富集带的构造部位。  相似文献