The Spectroscopic Orbit of the Planetary Companion Transiting HD 209458     

Mazeh T  Naef D  Torres G  Latham DW  Mayor M  Beuzit JL  Brown TM  Buchhave L  Burnet M  Carney BW  Charbonneau D  Drukier GA  Laird JB  Pepe F  Perrier C  Queloz D  Santos NC  Sivan JP  Udry S  Zucker S 《The Astrophysical journal》2000,536(1):L55-L58

Three new silicon-bearing radicals of astrophysical interest, SiCCH and the two nearly isoenergetic isomers SiCN and SiNC, were detected in a laboratory discharge in their X2Pi ground states by Fourier transform microwave and millimeter-wave absorption spectroscopy. Hyperfine structure was observed in the low rotational transitions of the (2)Pi(1/2) ladder, and well-resolved Lambda-doubling was observed in both fine-structure ladders. With the spectroscopic constants derived from the laboratory measurements, the spectra of all three can be calculated to an uncertainty of less than 0.1 km s(-1) in equivalent radial velocity over the entire range of interest to radio astronomers. SiCN, with a dipole moment of 2.9 D, is probably the most promising of the three for astronomical discovery.  相似文献   

Thermal treatment as a method to control transfers of invasive biofouling species via vessel sea chests     

Piola RF  Hopkins GA 《Marine pollution bulletin》2012,64(8):1620-1630

This study examined the efficacy of heated seawater for the treatment and remediation of fouled vessel sea chest habitats. In laboratory trials, three temperature regimes (37.5°C for 60 min, 40°C for 30min and 42.5°C for 20 min) were tested on a range of temperate taxa commonly found in sea chests. Field validation trials further assessed the efficacy of heat treatment within a replica sea chest environment. During laboratory trials, 100% mortality was achieved across all three treatments for the majority of taxa; the exceptions being the barnacle Elminius modestus and the oyster Crassostrea gigas. Temperature tolerance limits observed in the laboratory were successfully replicated under simulated sea chest conditions; however, a failure to achieve even heat distribution was an obstacle to achieving uniform mortality. This study provides guidance on the temperature/exposure parameters required for vessels plying temperate latitudes, and demonstrates that heated seawater has potential for controlling biofouling in vessel sea chests.  相似文献   

评《大陆下地壳》     

豪.  GA 梁慧云 《地震科技情报》1994,(8):36-38

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科威特沙漠风成沉积物与气侯,土壤和植被的关系     

AL－N.  GA  周纪侠 《世界沙漠研究》1989,(2):8-13

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New approaches to the study of population dynamics in cities of Moscow Oblast     

Gornostayeva GA  Petrov PV 《Soviet geography》1990,29(1):66-77

New approaches to the study of population growth, spatial distribution, and urbanization in the USSR are presented. "Quantitative analysis of historical trends in city growth rates within Moscow Oblast (1926-1984) reveals two major components or city types: a group of cities with below-(oblast) average rates for each of five periods of analysis (1926-39, 1939-59, 1959-70, 1970-79, 1979-84) and a second category experiencing above-average growth until 1970, with subsequent reduction of rates below the oblast average."  相似文献   

The cities of the RSFSR: trends and prospects of development     

Gornostayeva GA  Khanin SY 《Soviet geography》1985,26(6):436-444

The relationship between function and city size in cities of the Russian part of the USSR with a population of over 100,000 is examined for the period 1939 to 1980. The results suggest that "the relationship between city growth and functional change is wavelike in nature. In the initial stages of development of a city, it is the construction and transport functions that predominate, and they are associated with high rates of population growth. Increasing functional complexity leads to slower rates of population growth. When the given city reaches a higher stage of development...it again begins to attract population, with relatively low rates of growth."  相似文献   

Noise in pressure transducer readings produced by variations in solar radiation     

Cain SF  Davis GA  Loheide SP  Butler JJ 《Ground water》2004,42(6-7):939-944

Variations in solar radiation can produce noise in readings from gauge pressure transducers when the transducer cable is exposed to direct sunlight. This noise is a result of insolation-induced heating and cooling of the air column in the vent tube of the transducer cable. A controlled experiment was performed to assess the impact of variations in solar radiation on transducer readings. This experiment demonstrated that insolation-induced fluctuations in apparent pressure head can be as large as 0.03 m. The magnitude of these fluctuations is dependent on cable color, the diameter of the vent tube, and the length of the transducer cable. The most effective means of minimizing insolation-induced noise is to use integrated transducer-data logger units that fit within a well. Failure to address this source of noise can introduce considerable uncertainty into analyses of hydraulic tests when the head change is relatively small, as is often the case for tests in highly permeable aquifers or for tests using distant observation wells.  相似文献   

黑潮海域海洋异常加热时后期北半球大气环流影响的分析   总被引：6，自引：0，他引：6  

赵永平 McBe.  GA 《海洋与湖沼》1996,27(3):246-250

计算了黑潮海域海洋异常加热与后期１－１２个月北半球大气环流的时滞相关，分析了二者的相关关系。结果表明，海洋异常加热对后期半年到一年北半球大气环流场有重要影响，当黑潮海域海洋异常多加热时，后期半球范围内大气环流的经向度将趋减小，反之则趋加强，在分析相关演变的基础上，讨论了上述时滞关系的可能物理过程，指出黑潮海域海洋异常加热对后期下游大气环流型的影响，是通过改变中纬大气与高纬极地大气之间温度和位势高度  相似文献   

An isotopic biogeochemical study of Neoproterozoic and Early Cambrian sediments from the Centralian Superbasin, Australia   总被引：4，自引：0，他引：4  

Logan GA  Summons RE  Hayes JM 《Geochimica et cosmochimica acta》1997,61(24):5391-5409

Organic matter from Neoproterozoic and Early Cambrian sediments of the Amadeus and Officer basins of the Centralian Superbasin, Australia, has been studied for biomarker distributions and the carbon isotopic compositions of kerogen and individual hydrocarbons. These sediments represent both shallow and deep water marine facies in the older sections and marine and saline lacustrine carbonate deposits in the Cambrian. Hydrocarbon biomarker patterns were found to be quite consistent with the known sedimentary environments and provide valuable insights into the biogeochemical changes which accompanied the transition from a microbially-dominated ocean to the early stages of metazoan radiation. In particular, carbon isotopic data for n-alkyl and isoprenoid lipids presented here, and in earlier studies, showed a reversal in carbon isotopic ordering between the Proterozoic and Phanerozoic. By comparison with the delta 13C of kerogen, n-alkyl lipids from deep-water Proterozoic sediments were enriched in 13C and appear to be derived mainly from heterotrophs whilst open marine Phanerozoic counterparts are 13C depleted and evidently derived mainly from autotrophs. Data from the samples studied here are consistent with a model invoking a change in the redox structure of the ocean, possibly aided by the innovation of faecal pellets.  相似文献   

A line survey of Orion KL from 325 to 360 GHz     

Schilke P  Groesbeck TD  Blake GA  Phillips TG 《The Astrophysical journal. Supplement series》1997,108(1):301-337

We present a high-sensitivity spectral line survey of the high-mass star-forming region Orion KL in the 325-360 GHz frequency band. The survey was conducted at the Caltech Submillimeter Observatory on Mauna Kea, Hawaii. The sensitivity achieved is typically 0.1-0.5 K and is limited mostly by the sideband separation method utilized. We find 717 resolvable features consisting of 1004 lines, among which 60 are unidentified. The identified lines are due to 34 species and various isotopomers. Most of the unidentified lines are weak, and many of them most likely due to isotopomers or vibrationally or torsionally excited states of known species with unknown line frequencies, but a few reach the 2-5 K level. No new species have been identified, but we were able to strengthen evidence for the identification of ethanol in Orion and found the first nitrogen sulfide line in this source. The molecule dominating the integrated line emission is S02, which emits twice the intensity of CO, followed by SO, which is only slightly stronger than CO. In contrast, the largest number of lines is emitted from heavy organic rotors like HCOOCH3, CH3CH2CN, and CH3OCH3, but their contribution to the total flux is unimportant. CH3OH is also very prominent, both in the number of lines and in integrated flux. An interesting detail of this survey is the first detection of vibrationally excited HCN in the v2 = 2 state, 2000 K above ground. Clearly this is a glimpse into the very inner part of the Orion hot core.  相似文献