Preface     

J. Ireland  C. A. Young  J. Leibacher 《Solar physics》2010,262(2):233-233

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New Horizons Alice ultraviolet observations of a stellar occultation by Jupiter’s atmosphere     

Thomas K. Greathouse  G.R. Gladstone  S.A. Stern  R.J. Vervack Jr.  M.H. Versteeg  L.A. Young  H. Throop 《Icarus》2010,208(1):293-305

The Alice ultraviolet spectrograph onboard the New Horizons spacecraft observed two occultations of the bright star χ Ophiucus by Jupiter’s atmosphere on February 22 and 23, 2007 during the approach phase of the Jupiter flyby. The ingress occultation probed the atmosphere at 32°N latitude near the dawn terminator, while egress probed 18°N latitude near the dusk terminator. A detailed analysis of both the ingress and egress occultations, including the effects of molecular hydrogen, methane, acetylene, ethylene, and ethane absorptions in the far ultraviolet (FUV), constrains the eddy diffusion coefficient at the homopause level to be  cm² s⁻¹, consistent with Voyager measurements and other analyses (Festou, M.C., Atreya, S.K., Donahue, T.M., Sandel, B.R., Shemansky, D.E., Broadfoot, A.L. [1981]. J. Geophys. Res. 86, 5717-5725; Vervack Jr., R.J., Sandel, B.R., Gladstone, G.R., McConnell, J.C., Parkinson, C.D. [1995]. Icarus 114, 163-173; Yelle, R.V., Young, L.A., Vervack Jr., R.J., Young, R., Pfister, L., Sandel, B.R. [1996]. J. Geophys. Res. 101 (E1), 2149-2162). However, the actual derived pressure level of the methane homopause for both occultations differs from that derived by [Festou et al., 1981] and [Yelle et al., 1996] from the Voyager ultraviolet occultations, suggesting possible changes in the strength of atmospheric mixing with time. We find that at 32°N latitude, the methane concentration is  cm⁻³ at 70,397 km, the methane concentration is  cm⁻³ at 70,383 km, the acetylene concentration is  cm⁻³ at 70,364 km, and the ethane concentration is  cm⁻³ at 70,360 km. At 18°N latitude, the methane concentration is  cm⁻³ at 71,345 km, the methane concentration is  cm⁻³ at 71,332 km, the acetylene concentration is cm⁻³ at 71,318 km, and the ethane concentration is  cm⁻³ at 71,315 km. We also find that the H₂ occultation light curve is best reproduced if the atmosphere remains cold in the microbar region such that the base of the thermosphere is located at a lower pressure level than that determined by in situ instruments aboard the Galileo probe (Seiff, A., Kirk, D.B., Knight, T.C.D., Young, R.E., Mihalov, J.D., Young, L.A., Milos, F.S., Schubert, G., Blanchard, R.C., Atkinson, D. [1998]. J. Geophys. Res. 103 (E10), 22857-22889) - the Sieff et al. temperature profile leads to too much absorption from H₂ at high altitudes. However, this result is highly model dependent and non-unique. The observations and analysis help constrain photochemical models of Jupiter’s atmosphere.  相似文献   

Depth of settlement of two mussel species on suspended collectors in Marlborough Sounds,New Zealand (Note)     

J. L. Meredyth‐Young  R. J. Jenkins 《新西兰海洋与淡水研究杂志》2013,47(1):83-86

The preferred depth of settlement and settlement period of two species of mussel spat were monitored at Yncyca Bay (NZMS1 S15 220460) and Wet Inlet (NZMS1 S16 265432) in the Marlborough Sounds on collectors suspended in 0–4 m of water between 20 October 1975 and 4 April 1976. Peak settlement of Mytilus edulis aoteanus was between 20 October 1975 and 4 January 1976, and decreased with increasing depth. Peak settlement of Perna canaliculus was between 16 February 1976 and 12 April 1976, and showed no preferred depth of settlement.

Capture of wild stocks of Mytilus edulis aoteanus and Perna canaliculus spat for use in aquaculture has become more reliable through accurate forecasting of peak settlement periods, and knowledge of preferred depth of settlement of the two species.

Preferred depth of settlement of spat may affect the shore zonation of mussels.  相似文献   

Development of a skill assessment tool for the Korea operational oceanographic system   总被引：1，自引：1，他引：0  

CHO Kyoung-Ho  CHOI Jin-Yong  JEONG Sang-Hun  CHOI Jung-Woon  KWON Jae-Il  PARK Kwang-Soon 《海洋学报(英文版)》2013,32(9):74-81

A standard skill assessment(SA) tool was developed and implemented to evaluate the performance of operational forecast models in the Korea operational oceanographic system.The SA tool provided a robust way to assess model skill in the system by comparing predictions and observations,and involved the computation of multiple skill metrics including correlation and error skills.User-and system-based acceptance criteria of skill metrics were applied to determine whether predictions were acceptable for the system.To achieve this,the tool produced a time series comparison plot,a skill score table,and an advanced summarized diagram to effectively demonstrate the multiple skill scores.Moreover,the SA was conducted to evaluate both atmospheric and hydrodynamic forecast variables.For the atmospheric variables,acceptable error criteria were preferable to acceptable correlation criteria over short timescales,since the mean square error overwhelmed the observation variance.Conversely,for the hydrodynamic variables,acceptable root mean square percentage error(e.g.,p erms) criteria were preferable to acceptable error(e.g.,erms) criteria owing to the spatially variable tidal intensity around the Korean Peninsula.Furthermore,the SA indicated that predetermined acceptance error criteria were appropriate to satisfy a target central frequency(fc) for which errors fell within the specified limits(i.e.,the fc equals 70%).  相似文献   

Estimating gambling venue catchments for impact assessment using a calibrated gravity model     

Francis Markham  Bruce Doran  Martin Young 《International journal of geographical information science》2014,28(2):326-342

Gambling using electronic gaming machines (EGMs) has emerged as a significant public health issue. While social impact assessments are required prior to the granting of new gaming machine licenses in Australia, there are a few established techniques for estimating the spatial distribution of a venue’s clientele. To this end, we calibrated a Huff model of gambling venue catchments based on a geocoded postal survey (n = 7040). We investigated the impact of different venue attractiveness measures, distance measures, distance decay functions, levels of spatial aggregation and venue types on model fit and results. We then compared model estimates for different behavioural subgroups. Our calibrated spatial model is a significant improvement on previously published models, increasing R² from 0.23 to 0.64. Venue catchments differ radically in size and intensity. As different population subgroups are attracted to different venues, there is no single best index of venue attractiveness applicable to all subpopulations. The calibrated Huff model represents a useful regulatory tool for predicting the extent and composition of gambling venue catchments. It may assist in decision-making with regard to new license applications and evaluating the impact of health interventions such as mandated reductions in EGM numbers. Our calibrated parameters may be used to improve model accuracy in other jurisdictions.  相似文献   

Effects of the oophagous bivalve Acesta oophaga on the morphology and fecundity of its deep‐sea tubeworm host,Lamellibrachia luymesi     

Zair P. Burris  Joshua P. Lord  Craig M. Young 《Marine Ecology》2014,35(1):106-111

The deep‐sea bivalve Acesta oophaga lives attached to the anterior end of the vestimentiferan tubeworm, Lamellibrachia luymesi, at cold methane seeps. The bivalve is found almost exclusively on female tubeworms, where it consumes the lipid‐rich eggs of L. luymesi that are spawned year round (Biological Bulletin, 209, 2005, 87). It is apparent that A. oophaga benefits directly from this close association, but the consequences for the tubeworm host may be more complicated than just a simple predator–prey interaction. Since A. oophaga completely surrounds the tube opening and plume of the worm, it is likely that its presence would limit oxygen uptake by L. luymesi, thereby inhibiting worm growth and reproduction. We hypothesized that occupied tubeworms would compensate for this by growing larger plumes for oxygen uptake. To explore the effects of bivalve presence/absence on female tubeworms, several morphological features, including body size, plume length, tube diameter, and tube segment length, as well as instantaneous fecundity, were compared. Results suggest that the mere presence of A. oophaga has a significant impact on the morphology of its host worm, as all measures of worm size, except for tube segment length, were significantly greater with clams present. Additionally, instantaneous fecundity was 3.5 times higher in occupied worms, implying that tubeworms are not oxygen‐deprived or energy limited as a result of bivalve presence. Our findings suggest that the association between these two deep‐sea organisms may be a more complex form of symbiosis than the simple predator–prey relationship, as previously thought.  相似文献   

Effects of biochar, cow bone, and eggshell on Pb availability to maize in contaminated soil irrigated with saline water   总被引：2，自引：0，他引：2  

Yaser A. Almaroai  Adel R. A. Usman  Mahtab Ahmad  Deok Hyun Moon  Ju-Sik Cho  Young Kyoo Joo  Choong Jeon  Sang Soo Lee  Yong Sik Ok 《Environmental Earth Sciences》2014,71(3):1289-1296

Toxicity of heavy metals adversely affects environment and human health. Organic materials derived from natural matters or wastes have been applied to soils to reduce the mobility of contaminants such as heavy metals. However, the application of cow bone powder (CB), biochar (BC), and eggshell powder (ES) is rarely investigated for the reduction of Pb bioavailability in soils irrigated with saline water. The objective of this study was to assess the effectiveness of CB, BC, and ES additions as immobilizing substances on Pb bioavailability in shooting range soil irrigated with deionized and saline water. Each additive of CB, BC, and ES at 5 % (w/w) was mixed with soils and then the deionized and saline water were irrigated for 21 days. With deionized water irrigation, the soils treated with CB, BC, and ES exhibited higher pH when compared with saline water irrigation. With saline water irrigation, the electrical conductivity, water-soluble anions, and cations were significantly increased in soils treated with CB, BC, and ES. The water-soluble Pb in soils treated with CB, BC, and ES was significantly decreased with saline water irrigation. On the other hand, the water-soluble Pb in soil treated with CB was increased with deionized water irrigation. Only BC with saline water irrigation decreased the Pb concentration in maize shoots.  相似文献   

Double injection events of mafic magma into supersolidus Yucheon granites to produce two types of mafic enclaves in the Cretaceous Gyeongsang Basin,SE Korea     

Jong-Sun Kim  Moon Son  Byoung-Hoon Hwang  Ki-Cheol Shin  Hyeongseong Cho  Young Kwan Sohn 《Mineralogy and Petrology》2014,108(2):207-229

Petrographic and geochemical features of the Cretaceous Yucheon granites and their mafic microgranular/magmatic enclaves (MMEs), SE Korea, reveal that the MMEs originated from magma mixing. Mesoscopic and microscopic features indicate that mechanical mixing operated heterogeneously to produce the MMEs with a wide range of sizes and textures. Chemical compositions of amphibole, biotite, and plagioclase rims of both the MMEs and host granites are almost identical, indicating that chemical homogenization took place to some extent after the mechanical mixing. Plagioclase cores, however, have various compositions depending on the host rocks and/or sampling locations, suggesting their sluggish re-equilibration. The MMEs are divided into Type A (low TiO₂, very fine-grained, chilled margins) and Type B (high TiO₂, fine- to medium-grained, no chilled margins). The lower TiO₂ MMEs cooled more rapidly and interacted with granitic magma for a shorter period of time than the higher TiO₂ MMEs. Additionally, the former are less enriched in HREEs than the latter. Zoned plagioclase has two zones of increased An content. These features are indicative of double injection events of mafic magma. A previous model explains the magma mixing as resulting from the generation of a slab window due to Kula-Pacific ridge subduction. The model cannot, however, explain the eastward younging of the granites in Korea, necessitating a new, more elaborate model of Cretaceous geodynamics and magmatism in East Asia.  相似文献   

A GNSS interference identification using an adaptive cascading IIR notch filter     

Chang Ho Kang  Sun Young Kim  Chan Gook Park 《GPS Solutions》2014,18(4):605-613

A low-complexity time-domain approach for global navigation satellite systems is proposed to detect and identify single-tone, multi-tone, swept continuous wave interference (CWI) and band-limited white Gaussian noise (BLWN). An adaptive notch filter and adaptive cascading filter structure are employed to identify the type of interference signals. The number of the cascading stages is selected by comparing the total power in receiver bandpass, and after, passing the adaptive notch filter. For this reason, the proposed filter structure is more efficient in identifying and mitigating interference signals than the conventional filter structure. In addition, the automatic gain control gain is used to detect the existence of continuous wave interference. The performance of the interference detection and identification method is evaluated for the cases of GPS signal in the presence of single-tone, multi-tone, swept CWI and BLWN.  相似文献   

Time‐scale analysis in unsaturated porous media under external wave loads     

Heng Xiao  Yin Lu Young  Jean H. Prévost 《国际地质力学数值与分析法杂志》2010,34(18):1935-1959

Extreme waves caused by tsunamis and storm surges can lead to soil failures in the near‐shore region, which may have severe impact on coastal environments and communities. Multiphase flows in deformable porous media involve several coupled processes and multiple time scales, which are challenging for numerical simulations. The objective of this study is to investigate the roles of the various processes and their interactions in multiphase flows in unsaturated soils under external wave loading, via theoretical time‐scale analysis and numerical simulations. A coupled geomechanics–multiphase flow model based on conservation laws is used. Theoretical analysis based on coupled and decoupled models demonstrates that transient and steady‐state responses are governed by pore pressure diffusion and saturation front propagation, respectively, and that the two processes are essentially decoupled. Numerical simulations suggest that the compressibility of the pore fluids and the deformation of the soil skeleton are important when the transient responses of the media are of concern, while the steady‐state responses are not sensitive to these factors. The responses obtained from the fully coupled numerical simulations are explained by a simplified time‐scale analysis based on coupled and decoupled models. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献