Detection of the water-soluble fraction of crude oil by the blue crab, Callinectes sapidus     

Walter H Pearson  Stephen E Miller  J.W Blaylock  Bori L Olla 《Marine environmental research》1981,5(1):3-11

The ability of the blue crab, Callinectes sapidus, to detect petroleum hydrocarbons was measured with behavioural techniques. When presented with a water-soluble fraction of Prudhoe Bay crude oil, blue crabs abruptly changed antennular orientation, began rhythmic beating of the maxillipedal flagellae, and increased antennular flicking rate. The threshold concentration at which 50% of the crabs detected the water-soluble fraction was 2 × 10^?6 mg/litre. The blue crab apparently can readily detect petroleum hydrocarbons at concentrations found in chronically polluted areas as well as oil spill situations.  相似文献   

Neighborhood and socioeconomic change in emerging megapolitan nodes: tracking shifting social geographies in three rapidly growing United States metropolitan areas, 1980–2010     

Nathan Foote  Rebecca Walter 《Urban geography》2017,38(8):1203-1230

This paper investigates the complex demographic and social changes that have occurred in the neighborhoods of fast-growing United States metropolitan areas emerging as nodes in megapolitan regions between 1980 and 2010. A neighborhood typology is created using k-means cluster analysis to examine the demographic and housing characteristics, and geographic distribution, of neighborhoods that have existed in rapidly growing metropolitan areas. A socioeconomic index is created using principal component analysis (PCA) to analyze socioeconomic conditions within neighborhoods. Using data from the metropolitan areas of Las Vegas, Nevada; Austin, Texas; and Raleigh, North Carolina, this study identifies five neighborhood types, each of which has distinctive geographic and socioeconomic trends. The geographic orientation of each metropolitan area within their larger megapolitan region appears to have a role in the geography of neighborhood change. The results are also discussed in relation to human ecology, immigration, and economic restructuring.  相似文献   

An overview of the opportunities and challenges of promoting climate change adaptation at the local level: a case study from a community adaptation planning in Nepal     

Bimal Raj Regmi  Cassandra Star  Walter Leal Filho 《Climatic change》2016,138(3-4):537-550

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On the consequences of the interaction between the auroral plasma and the geomagnetic field     

Walter Lennartsson 《Planetary and Space Science》1980,28(2):135-147

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Non-divergent oscillations in the solar atmosphere     

Walter L. Jones 《Solar physics》1969,7(2):204-209

Non-divergent oscillations having the form of deep water waves are shown to form normal modes or free oscillations of the solar atmosphere under two approximations: the chromosphere-coronal interface behaves like a free surface, and the density scale height is sufficiently large in the convective zone. These modes show the temporal and spatial characteristics of the 300 second chromospheric oscillations.  相似文献   

Note on the Paper of A. H. Cook, "The External Gravity Field of a Rotating Spheroid to the order of e³"     

Walter D. Lambert 《Geophysical Journal International》1960,3(3):360-366

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Lamé functions of the first kind generated by computer     

H. G. Walter 《Celestial Mechanics and Dynamical Astronomy》1971,4(1):15-30

The definitions of the Lamé functions and the ellipsoidal coordinates inherent to them are introduced. Proceeding from Lamé's differential equation the four classes of Lamé functions of the first kind are generated by computer with the aid of formula manipulation techniques. For this purpose algebraic expressions for the coefficients in the Lamé polynomials are constructed by virtue of recurrence formulae and presented in tabular as well as machine readable form for further processing. The determination of a parameter appearing in the polynomial coefficients leads to an algebraic eigenvalue problem. It is shown how this eigenvalue problem is amenable to numerical treatment. The polynomial coefficients together with the eigenvalues are characteristic for the Lamé functions and define them completely.  相似文献   

Association of spherical and ellipsoidal gravity coefficients of the Earth's potential     

Hans G. Walter 《Celestial Mechanics and Dynamical Astronomy》1970,2(3):389-397

A comparison is drawn between the expansion of the potential in spherical harmonics on the one hand and in ellipsoidal harmonics on the other, with the objective of associating the spherical and ellipsoidal gravity coefficients of the Earth's potential.For this purpose the properties of orthogonality of the Lamé functions of the first kind have been tailored to this subject of investigation and become instrumental in establishing the mathematical expressions which relate the two classes of gravity coefficients to each other. In deriving the elements of the transition matrices elliptic integrals have been encountered whose reduction to the three kinds of canonical elliptic integrals is discussed.Presented at the Conference on Celestial Mechanics, Oberwolfach, Germany, August 17–23, 1969.  相似文献   

Compression of ephemerides     

Deprit  André  Poplarchek  Walter  Deprit-Bartholomé  Andrée 《Celestial Mechanics and Dynamical Astronomy》1975,11(1):53-58

Approximations in the normL ₁ by Chebyshev polynomials are generated to represent astronomical ephemerides over large intervals of time.  相似文献   

Long-Term Behaviour of an Aftershock Sequence: The Inangahua, New Zealand, Earthquake of 1968     

Russell Robinson  Walter J. Arabasz  F. F. Evison 《Geophysical Journal International》1975,41(1):37-49

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