Heterotrophic bacterial floras in industrial area and unpolluted marine environments around Qingdao     

Du Zongjun  Li Yun  Yu Dehua  Wang Xianghong  Chen Jixiang  P. A. W. Robertson  B. Austin  Xu Huaishu 《中国海洋大学学报(英文版)》2002,1(1):59-62

From Oct. 1999 to Oct. 2000, the heterotrophic bacterial floras in the industrial marine environment around the Qingdao Power Plant (QPP) and in the unpolluted marine environments were investigated. The results showed that the numbers of the heterotrophic bacteria around QPP were much higher than those in unpolluted environments, and the average numbers in QPP Seawater, QPP Sediment, Unpolluted Seawater and Unpolluted Sediment were 5.4×10⁴cfu(mL)⁻¹, 5.0×10⁵cfug⁻¹, 3.0×10²cfu(mL)⁻¹ and 1.3×10⁵cfug⁻¹ respectively. Totally, 118 strains were isolated from QPP and 99 of them were Gram-negative. One hundred and twenty one strains were isolated from the unpolluted environments and 104 of them were Gram-negative. All the Gram-negative bacteria belonged to 13 genera. The distribution of the bacteria was varied in different marine environments. The results showed that the unpolluted marine environments contained much more Vibrio than seawater and sediment around QPP.  相似文献   

Description of the University of Auckland global Mars mesoscale meteorological model     

David R. Wing  Geoff L. Austin 《Icarus》2006,185(2):370-382

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On the magnitude of the 11-year radiocarbon cycle     

P.E. Damon  Austin Long  E.I. Wallick 《Earth and Planetary Science Letters》1973,20(3):300-306

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Comparing dispersivities and soil chloride concentrations of turfgrass-covered undisturbed and disturbed soil columns     

S. K. Starrett  N. E. Christians  T. Al Austin 《Journal of Hydrology》1996,180(1-4):21-29

Research relating to soil leaching properties under turfgrass conditions has often been conducted on disturbed soils where macropore structure has been destroyed. The objective of this study was to compare the solute movement characteristics of undisturbed and disturbed soil columns covered with turfgrass. Dispersivities and chloride (Cl) breakthrough curves of undisturbed and disturbed soils were investigated. Soil columns were excavated into three sections after testing, for which the mean bulk density was 1.33 Mg M⁻³ for the undisturbed columns and 1.16 Mg m⁻³ for the disturbed columns. The dispersivity for the undisturbed columns was over three times greater than for the disturbed columns. Chloride concentration found in Layer 1 (0–6.7 cm), Layer 2 (6.7–13.4 cm), and Layer 3 (13.4–20.0 cm) were 2.8, 5.3, and 4.8 times higher, respectively, for the disturbed soils than for the undisturbed. Applying conclusions from solute movement studies using repacked columns covered with turfgrass to actual undisturbed field conditions could lead to errors in interpretation because of the effect of macropores.  相似文献   

A SPECIFICATION AND CONDITIONS OF CONTRACT FOR TOPOGRAPHIC SURVEYS     

W. T. F. Austin  W. A. Parkes 《The Photogrammetric Record》1971,7(38):201-212

A second joint meeting between members of the Society, the Royal Institution of Chartered Surveyors and the Institution of Highway Engineers was held on 20th May, 1971. Since the first meeting (Record, 6(36): 521 -536) in December 1969, the Directorate of Highways, Department of the Environment (formerly the Ministry of Transport) has published a Specification and Conditions of Contract for Topographic Surveys. The purpose of this second meeting was to hear the comments of an engineer and a photogrammetrist on the new document and to discuss and criticise the document from the engineering and surveying points of view.  相似文献   

Migration of recharge waters downgradient from the Santa Catalina Mountains into the Tucson basin aquifer, Arizona, USA     

Erin E. B. Cunningham  Austin Long  Chris Eastoe  R. L. Bassett 《Hydrogeology Journal》1998,6(1):94-103

 Aquifers in the arid alluvial basins of the southwestern U.S. are recharged predominantly by infiltration from streams and playas within the basins and by water entering along the margins of the basins. The Tucson basin of southeastern Arizona is such a basin. The Santa Catalina Mountains form the northern boundary of this basin and receive more than twice as much precipitation (ca. 700 mm/year) as does the basin itself (ca. 300 mm/year). In this study environmental isotopes were employed to investigate the migration of precipitation basinward through shallow joints and fractures. Water samples were obtained from springs and runoff in the Santa Catalina Mountains and from wells in the foothills of the Santa Catalina Mountains. Stable isotopes (δD and δ¹⁸O) and thermonuclear-bomb-produced tritium enabled qualitative characterization of flow paths and flow velocities. Stable-isotope measurements show no direct altitude effect. Tritium values indicate that although a few springs and wells discharge pre-bomb water, most springs discharge waters from the 1960s or later. Received, February 1997 · Revised, September 1997 · Accepted, September 1997  相似文献   

A preliminary analysis of smooth roll crushers     

L.G. Austin  D.R. Van Orden  J.W. Pérez 《International Journal of Mineral Processing》1980,6(4):321-336

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Numerical modeling of wave equation by a truncated high-order finite-difference method   总被引：1，自引：0，他引：1  

Mrinal K.Sen 《地震学报(英文版)》2009,(2):205-213

Finite-difference methods with high-order accuracy have been utilized to improve the precision of numerical solution for partial differential equations.However, the computation cost generally increases linearly with increased order of accuracy.Upon examination of the finite-difference formulas for the first-order and second-order derivatives, and the staggered finite-difference formulas for the first-order derivative, we examine the variation of finite-difference coefficients with accuracy order and note th...  相似文献   

Underwater video reveals decreased activity of rocky intertidal snails during high tides and cooler days          下载免费PDF全文

Austin W. Taylor  Steven G. Morgan  Sarah A. Gravem 《Marine Ecology》2017,38(2)

Nearly all of our understanding of rocky inter‐tidal ecology comes from studies conducted at low tide. To study inter‐tidal organisms at high tide, we anchored waterproof digital GoPro^® video cameras in wave‐exposed tidepools and recorded the daytime movements of the black turban snail, Tegula funebralis, over the tidal cycle between May and August 2012 near Bodega Bay, California. Overall, snails moved more quickly and presumably foraged more during low tides and on days with warmer air and perhaps water temperatures. This is similar to other ectotherms that exhibit increased metabolic rates, movement and foraging in warmer conditions. Snails also moved less during flood and high tides, may have moved downward in tidepools at flood tides, and showed evidence of reduced activity on days with larger waves. This inactivity and refuge seeking may have been a strategy to avoid dislodgment by waves. Analysis of snail trajectories showed foraging bouts indicated by alternating zig‐zagging and straight movement. There was no effect of temperature, wave height, or tidal phase on distribution of snail turning angles, suggesting that they may have foraged consistently but moved faster during warm conditions and low tides, thereby grazing a larger area. This is one of few direct recordings of inter‐tidal organisms on wave‐exposed rocky shores during high tide. The methods used here are easily transferable to other studies, which are needed to increase our understanding of behaviors that structure rocky shore communities during high tide.  相似文献   

A subregional-scale method to assess aquifer vulnerability to pesticides   总被引：4，自引：0，他引：4  

Schlosser SA  McCray JE  Murray KE  Austin B 《Ground water》2002,40(4):361-367

A method to predict aquifer vulnerability to pesticide contamination at the subregional scale was developed. The assessment method was designed to incorporate relevant hydrologic and pesticide-transport information and to use generally available data. The method assumes steady-state advection of pesticides in the vadose zone, including sorption and biological decay. The solution is presented as a vulnerability index (VI) that increases as the aquifer vulnerability increases. The hydrologic input data for the VI model are obtained from the soil survey geographic database. Pesticides were grouped into three leachability classes using a leachability ratio (half-life divided by organic carbon partition coefficient). Pesticide transformation is assumed to occur in the surface layer. The influence of vertical transport in the remainder of the vadose zone has been incorporated by applying a multiplying factor to the VI that varies with depth to ground water. Hydraulic conductivity is used as a surrogate for soil-water velocity for practical purposes. The performance of the VI model is evaluated using ground water data from Weld County, Colorado. The model is demonstrated to be successful at predicting relative vulnerability, defined as the magnitude of pesticide concentration and percent of wells in a unit that exhibit a pesticide detection. Areas of low, medium, and high vulnerability are assigned. Results indicate that the vulnerability classifications are most dependent on the leachability ratio, hydraulic conductivity, and organic carbon content.  相似文献