Trinitite—the atomic rock     

Nelson Eby  Robert Hermes  Norman Charnley  John A. Smoliga 《Geology Today》2010,26(5):180-185

On 16 July 1945, the first atomic bomb was detonated at the Alamogordo Bombing range in New Mexico, USA. Swept up into the nuclear cloud was the surrounding desert sand, which melted to form a green glassy material called ‘trinitite’. Contained within the glass are melted bits of the first atomic bomb and the support structures and various radionuclides formed during the detonation. The glass itself is marvelously complex at the tens to hundreds of micrometre scale, and besides glasses of varying composition also contains unmelted quartz grains. Air transport of the melted material led to the formation of spheres and dumbbell shaped glass particles. Similar glasses are formed during all ground level nuclear detonations and contain forensic information that can be used to identify the atomic device.  相似文献   

Molecular signatures of MHD waves     

S. B. Charnley  H. Butner 《Astrophysics and Space Science》1995,224(1-2):443-444

The small ion-neutral drift speeds attained in MHD waves lead to a significant increase in the rates of several important ion-molecule reactions. The effect on the deuterium chemistry of dark clouds could allow MHD wave motion to be observed directly. The results of some recent observations to test this theory are outlined.  相似文献   

Chemical chronology of the Southern Coalsack     

S. D. Rodgers  S. B. Charnley  R. G. Smith  H. M. Butner 《Monthly notices of the Royal Astronomical Society》2007,379(2):807-815

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Chemical Processes in Cometary Comae     

Charnley  S. B.  Rodgers  S. D.  Butner  H. M.  Ehrenfreund  P. 《Earth, Moon, and Planets》2002,90(1-4):349-360

Recent developments in the chemical modelling of cometary comae aredescribed. We discuss the cyanide chemistry and present new HCNobservations of the recent comet C/2002 C1 (Ikeya–Zhang). Theconnection between interstellar and cometary organic molecules isdiscussed from the perspective of recent theories of interstellargas-grain chemistry.  相似文献   

Organic synthesis in the coma of Comet Hale–Bopp?     

S. D. Rodgers  S. B. Charnley 《Monthly notices of the Royal Astronomical Society》2001,320(4):L61-L64

Several organic molecules have now been detected in the coma of Hale–Bopp. These species may either emanate from the nucleus, or, as has been suggested by Bockelée–Morvan et al., could be synthesized in the coma. We have modelled the gas phase chemistry which occurred in the coma of Hale–Bopp, concentrating on the observed organic molecules HCOOH, HCOOCH₃, HC₃N and CH₃CN. We find that gas phase chemical reactions are unable to synthesize the observed abundances of these molecules, so all these species are most probably present in the nuclear ice. We briefly discuss the implications of this result for the connection between cometary and interstellar ices.  相似文献   

Hot core chemistry     

S. B. Charnley 《Astrophysics and Space Science》1995,231(1-2):251-254

The BATSE/COMPTEL/NMSU Rapid Response Network (RRN) was formed to provide rapid follow-up of-ray bursts imaged by the COMPTEL instrument on the Compton Gamma-Ray Observatory. The RRN consists of 22 professional observatories located around the world spanning both northern and southern hemispheres. Also included in the RRN is the Airforce GEODSS network. The goal of the RRN is to perform optical and radio observations of COMPTEL error boxes as soon after the burst as possible. We present results from the first two years of operation of this network.  相似文献   

The interstellar chemistry of protostellar disks     

S. B. Charnley 《Astrophysics and Space Science》1995,224(1-2):441-442

A study has been undertaken of the gas-grain chemistry of protostellar disks which are sufficiently cool that in the outer regions, where the gas density is less than 10¹³ cm^–3 and the ionization rate highest, a bimolecular chemistry resembling that of dark clouds can occur. Since the gas-grain collision rate is so high, outgassing mantle molecules effectively determine the gas phase composition at any position in the disk. In contrast to previous work, a detailed gas phase chemistry is considered along with the accretion and desorption of mantle species which is controlled locally by the dust temperature.  相似文献   

Natural Resource Access Rights and Wrongs: Nontimber Forest Products Gathering in Urban Environments     

Susan Charnley  Rebecca J. McLain  Melissa R. Poe 《社会与自然资源》2018,31(6):734-750

This article uses research about non-timber forest products (NTFP) gathering in Seattle, Washington, USA to examine how people gain access to natural resources in urban environments. Our analysis focuses on gathering in three spaces: parks, yards, and public rights of way. We present a framework for conceptualizing access, and highlight cognitive mechanisms of access associated with foragers’ internal moral judgments about harvesting. Key findings are: (1) internal moral calculations about whether it is right or wrong to harvest a particular NTFP in a particular place are an important but previously unacknowledged mechanism governing resource access; and (2) these calculations may help prevent over-harvesting of NTFPs, which are common pool resources, in urban environments where social and environmental conditions lend themselves to a de facto situation of open access. Our findings suggest that voluntary codes of conduct may be the best way to manage NTFP access in cities.  相似文献   

Suprathermal chemical reactions driven by fast hydrogen atoms in cometary comae     

S. D. Rodgers  S. B. Charnley 《Monthly notices of the Royal Astronomical Society》2005,356(4):1542-1548

We have investigated the role that energetic hydrogen atoms, produced in cometary comae by the photodissociation of water molecules, could have in driving chemical reactions that are endothermic, or possess activation energy barriers. We have developed a model of the density and energy spectrum of these atoms in the coma and have incorporated a number of reactions driven by fast H atoms into our existing coma model. We find that, in high-activity comets close to the Sun, such reactions are competitive with direct photodissociation as the principal destruction mechanism for molecules with long lifetimes in the solar radiation field. We show that measurements of the CH₂OH : CH₃O ratio may be used to assess the importance of suprathermal reactions in the coma. We also confirm that these reactions are probably unable to account for the observed HNC : HCN ratios.  相似文献   

Organic astrochemistry: observations of interstellar ketene     

R. Ruiterkamp  S. B. Charnley  H. M. Butner  H.-C. Huang  S. D. Rodgers  Y.-J. Kuan  P. Ehrenfreund 《Astrophysics and Space Science》2007,310(3-4):181-188

We have observed emission from both ortho and para spin states of ketene (CH₂CO) towards several deeply-embedded protostars. The low CH₂CO fractional abundances (∼10⁻¹⁰) and the rotation temperatures (∼20 K) are consistent with emission from the cooler envelope. We compare our results with previous studies and discuss possible production pathways to interstellar ketene. We suggest that, if low observed excitation temperatures of CH₂CO, CH₃CHO and H₂CO are indicative of their absence from the hot core region, then this may be due to the extensive hydrogenation of pre-existing grain mantles prior to evaporation into the inner envelope, leading to lower abundances of these compounds and to mantles rich in alcohols.  相似文献