《中国沿海航行里程表》编制的新方法     

韩范畴  孙国勇  吴俊彦  成俊 《海洋测绘》2007,27(3):55-58

重点介绍《中国沿海航行里程表》的编制思路、编制过程,通过引入关键点,探讨了港间里程优化统计的新途径,提出了一套编制《中国沿海航行里程表》新的方法。  相似文献   

Analysis of Near Infrared Observations of the Symbiotic Mira RR Tel     

Dubravka Kotnik-Karuza  Michael Friedjung  Patricia Whitelock 《Astrophysics and Space Science》2006,304(1-4):311-313

JHKL photometry of the symbiotic Mira RR Tel over 25 years shows variable fading in all bands, which can be explained by variable obscuration due to dust. The evolutionary track of the star is presented in a two-colour diagram together with the corresponding mean values for normal Miras with thick and thin dust shells and pulsation periods between 350 and 600 days. The observed colours for RR Tel are significantly shifted from the range shown by normal unreddened Miras. The distance of RR Tel is estimated from its K magnitude and the Mira period luminosity relation after correcting for reddening. The dust envelope is discussed with respect to a simple model involving two blackbodies. There appears to be rather little dust emission even at 3 μm, but considerable extinction.  相似文献   

农业气候相似分析在观叶植物引种中的应用     

钱妙芬  包春娟 《成都信息工程学院学报》1997,(2)

采用计算欧氏距离的方法，分析观叶植物从广州引种到成都的农业气候相似性。统计气温、相对湿度、农业气候指标及不同管理条件下的两地欧氏距离。得出：在成都保护地生长有较好的气候适应性，引种易于成功。从理论上为观叶植物的引种提供了科学依据。  相似文献   

How do host–migrant proximities shape attitudes toward internal climate migrants?     

《Global Environmental Change》2020

Climate change is predicted to cause voluntary and forced internal migration on an unprecedented scale in the coming decades. Yet, research on host communities that will be on the front lines in receiving the climate migrants has thus far been a neglected area within climate change research. Inspired by previous research on psychological distance’s impact on people’s behavior and attitudes, this article develops a conceptual framework proposing that spatial, attitudinal, experiential, and social proximities between migrants and host community members are central to understanding how attitudes toward internal climate migrants form and develop. Using multivariate regression analysis, the article applies the framework to a survey conducted among over 630 long-term residents in Satkhira District of Bangladesh, one of the most climate-exposed districts in the country. Supporting our hypotheses, we find evidence that host–migrant proximities shape attitudes toward internal climate migrants. Although the host community’s capacity to receive migrants matters for attitudes toward them, the results for the proximity variables underscore that these attitudes are profoundly relational, positional, and complex. In particular, we provide evidence that shorter spatial distance to highly exposed areas and attitudinal distance to fellow citizens in terms of values and worldviews improve host community members’ attitudes toward migrants. Further, the results for social proximity bring out the positional nature of attitudes, as they become more negative when socio-economic differences to migrants increase.  相似文献   

Benzo[b]naphthothiophenes and alkyl dibenzothiophenes: Molecular tracers for oil migration distances     

《Marine and Petroleum Geology》2014

The secondary migration of petroleum is one of the most critical geological processes responsible for the accumulation of hydrocarbons in a sedimentary basin. Pyrrolic nitrogen compounds such as carbazoles and benzocarbazoles are thought to be practical molecular indicators for estimating relative migration distances of oil. In light oils or condensates, however, considerable analytical errors are usually caused by low concentrations of NSO-compounds. Here we show that polycyclic sulfur aromatic hydrocarbons such as dibenzothiophene, C₁∼C₃ alkylated dibenzothiophenes and benzo[b]naphthothiophenes, which are present in relatively higher concentrations than the pyrrolic nitrogen compounds, exhibit changes in both absolute and relative concentrations that correlate with migration distances. The polycyclic sulfur aromatic hydrocarbons related parameters — benzo[b]naphtho[2,1-d]thiophene/{benzo[b]naphtho[2,1-d]thiophene + benzo[b]naphtho[1,2-d]thiophene} (abbreviated as [2,1]BNT/([2,1]BNT+[1,2]BNT) and the concentration of total dibenzothiophenes plus benzo[b]naphthothiophenes — are proposed by this paper to trace the oil migration distances.  相似文献   

Anisotropic compression of edingtonite and thomsonite to 6 GPa at room temperature     

Y. Lee  J. A. Hriljac  A. Studer  T. Vogt 《Physics and Chemistry of Minerals》2004,31(1):22-27

Polycrystalline samples of natural edingtonite (New Brunswick, Canada) and thomsonite (Oregon, USA) were studied up to 6 GPa using monochromatic synchrotron X-ray powder diffraction and a diamond-anvil cell with a methanol:ethanol:water mixture as a penetrating pressure-transmitting fluid. Unlike natrolite, previously studied under the same conditions, edingtonite and thomsonite do not show any apparent pressure-induced hydration (PIH) or phase transitions. All these fibrous zeolites are characterized by their anisotropic compressibilities, with the linear compressibilities of the fibrous chains (c-axis) being as small as one third of those perpendicular to the chains (a-, b-axes); for edingtonite, ₀ ^a =0.0050(3) GPa^–1, ₀ ^b =0.0054(2) GPa^–1, ₀ ^c =0.0034(1) GPa^–1; for thomsonite, ₀ ^a = 0.0080(2) GPa^–1, ₀ ^b =0.0084(2) GPa^–1, ₀ ^c =0.0032(1) GPa^–1. The pressure–volume data were fitted to a second-order Birch–Murnaghan equation of state using a fixed pressure derivative of 4. As a result of the 0000-type connectivity of the chains, the bulk modulus of edingtonite is found to be about 40% larger than that of thomsonite; K^EDI ₀=73(3) GPa, K^THO ₀=52(1) GPa. Distance least-squares refinements were used to model the expected framework, following the observed linear compression behaviors. The chain-bridging T–O–T angle is proposed to be correlated with the different compressibilities across the chains in each framework type.  相似文献   

断层两盘岩层错动、错距和相对运动关系     

周瑞 《云南地质》2005,24(1):11-21

岩层迹线是岩层在断层面上的交迹线。它和两盘相对运动力的相交关系及相对运动力在断层面上的特殊位置,可以得出岩层错动和相对运动之间三条普遍规律和三条特殊规律。六条规律普遍存在于除了具有复杂地质现象的深、大断裂等以外的一切较常见的断层中。它们之间有简易规律可循。大量立体图形显示:一般的断层都可有多种不同的力学成因;两种不同的岩错现象,也可有相同的力学成因。总错距是上下盘相当层迹线之间的最短距离,尚未被研究过。它影响到其他各种岩(地)层错距的大小及层位错动的比例。  相似文献   

角度分类器与距离分类器比较研究——以盐渍土分类为例   总被引：3，自引：1，他引：3  

骆玉霞  陈焕伟 《国土资源遥感》2002,(2):46-48

选择理想的分类器是进行遥感图像自动分类的关键。距离分类器是以已知地物类别的亮度值作为分类基准，通过比较未知类别像元与已知类别像元亮度值间的距离进行分类。角度分类器是以光谱谱线角为分类基准，通过比较n维波段空间中未知类别像元与已知类别像元光谱角度进行分类。本通过上述两种分类器对同一遥感图像进行分类，对两种分类器的分类效果进行了比较。  相似文献   

地幔波震级的规范化标定与观测          下载免费PDF全文

左兆荣  吴建平 《地球物理学报》1993,36(5):621-632

本文基于瑞利面波的激发和传播理论,导出了零级地震的理论面波谱表达式;并以零级地震为参考地震,以零级地震所相应的面波谱和地震矩作为地幔波震级规范化标定的参照依据,进而提出了测定地幔波震级的新方案。利用CDSN-LPZ信道中的面波资料测定了1987-1990年间全球54次浅源大地震的地幔波震级M_m,并对Okal和Talandier（1989）用GEO-SCOPE-VLPZ及PAS-VLPZ信道中的基阶瑞利波所测1970-1987年间88次地震的结果作了校正。综合这两部分观测结果,得到M_m=1.00 1gM₀-12.13,由此测定的地幔波震级与中小地震的面波震级M_s趋势相一致,为解决面波震级饱和问题提供了一种可行的途径。  相似文献   

地幔波震级的规范化标定与观测   总被引：1，自引：0，他引：1  

左兆荣  吴建平  巫志玲 《地球物理学报》1993,(5)

本文基于瑞利面波的激发和传播理论,导出了零级地震的理论面波谱表达式;并以零级地震为参考地震,以零级地震所相应的面波谱和地震矩作为地幔波震级规范化标定的参照依据,进而提出了测定地幔波震级的新方案。利用CDSN-LPZ信道中的面波资料测定了1987—1990年间全球54次浅源大地震的地幔波震级M_m,并对Okal和Talandier(1989)用GEO-SCOPE-VLPZ及PAS-VLPZ信道中的基阶瑞利波所测1970—1987年间88次地震的结果作了校正。综合这两部分观测结果,得到M_m=1.00 1gM_0—12.13,由此测定的地幔波震级与中小地震的面波震级M_s趋势相一致,为解决面波震级饱和问题提供了一种可行的途径。  相似文献