High-resolution H i and radio continuum observations of the SNR G290.1−0.8     

Estela M. Reynoso †  Simon Johnston  Anne J. Green  Bärbel S. Koribalski 《Monthly notices of the Royal Astronomical Society》2006,369(1):416-424

We have observed the supernova remnant (SNR) G290.1−0.8 in the 21-cm H  i line and the 20-cm radio continuum using the Australia Telescope Compact Array (ATCA). The H  i data were combined with data from the Southern Galactic Plane Survey to recover the shortest spatial frequencies. In contrast, H  i absorption was analysed by filtering extended H  i emission, with spatial frequencies shorter than 1.1 kλ. The low-resolution ATCA radio continuum image of the remnant shows considerable internal structure, resembling a network of filaments across its 13-arcmin diameter. A high-resolution ATCA radio continuum image was also constructed to study the small-scale structure in the SNR. It shows that there are no structures smaller than ∼17 arcsec, except perhaps for a bright knot to the south, which is probably an unrelated object. The H  i absorption study shows that the gas distribution and kinematics in front of SNR G290.1−0.8 are complex. We estimate that the SNR probably lies in the Carina arm, at a distance 7 (±1) kpc. In addition, we have studied nearby sources in the observed field using archival multiwavelength data to determine their characteristics.  相似文献   

The Eye of the Tornado – an isolated, high-mass young stellar object near the Galactic Centre     

M. G. Burton  J. S. Lazendic †  F. Yusef-Zadeh  M. Wardle 《Monthly notices of the Royal Astronomical Society》2004,348(2):638-646

  相似文献   

龙须菜和扁江篱多糖的组成及其抗肿瘤效果   总被引：22，自引：0，他引：22  

邓志峰  纪明侯 《海洋与湖沼》1995,26(6):575-581

于１９８５－１９８７年期间用冷水和热水对采集于青岛的龙须菜和扁江篱的琼胶型多糖进行提取。两海藻的热水提取多糖都通过ＤＥＡＥ－ＳｅｐｈａｄｅｘＡ５０色谱桩用热水和不同浓度ＮａＣｌ深液前后进行洗脱分级。龙须菜和扁江篱多糖的主要级分分别为０．５ｍｏｌ／Ｌ和１．０ｍｏｌ／ＬＮａＣｌ洗脱级分。对各级分做化学分析及ＩＲ和＾１３ＣＮＭＲ光谱分析。结果表明，龙须菜多糖由琼二糖、琼胶糖前体和６－ＯＣＨ３－琼二糖组成  相似文献   

Subarcsec 10μm imaging of bipolar flow sources     

S. Cabrit  P. O. Lagage  E. Pantin 《Experimental Astronomy》1994,3(1-4):151-152

We have started a program of high-resolution (0.4/pixel) 10m imaging of bipolar outflow sources using the 10m camera CAMIRAS. We present recent results obtained at the Canada France Hawaii Telescope which reveal extended emission or IR companions in several luminous objects. The extended emission we detected probably arises from transiently heated very small grains, while the newly discovered companions could contribute significantly to the outflow activity and extended far-IR emission usually attributed to the main optical source.  相似文献   

Energy efficiency evaluation,technology gap ratio,and determinants of energy productivity change in developed and developing G20 economies: DEA super-SBM and MLI approaches     

《Gondwana Research》2024

This study employed Slack-based measure (SBM), Meta-frontier analysis, and Malmquist–Luenberger index (MLI) approaches to measure energy efficiency (EE), production technology heterogeneity, and energy productivity variation and its main determinants in developed and developing G20 countries for the period 1995–2020. The study's findings are: (i) Average EE for G20 countries is 0.8577, but still has an improvement potential of 14.23 percent. (ii) Developed countries have a higher average EE than developing (0.8927 > 0.8290). Results further revealed that energy efficiency scores in Argentina, Australia, Brazil, France, Saudi Arabia, South Africa, the US, the UK, and Korea are>1. (iii) Technology gap ratio (TGR) value in developed countries is higher than in developing (0.9869 > 0.6801), indicating that developed countries have advanced energy technologies superiority. The average MLI is less than one, showing a decline in energy productivity mainly due to a decline in technical efficiency, as EC < TC. (iv) Developed G20 countries get 0.64 percent aggregate growth in energy productivity as their MLI score is 1.0064, mainly due to technological growth (TC = 1.0161). Developing G20 countries, on the other hand, witnessed a decline in their energy productivity during 1995–2020, as MLI = 0.9925 > 1, designating that, on average, there is a 0.75 % decline in MLI.  相似文献   

G856磁力仪在地磁台站建设中的应用与实践方法     

赖加成  游永平  倪晓寅 《福建地震》2006,(Z1)

本文通过泉州地磁台重建工程中的工作实践,阐述了应用G856磁力仪在建筑材料磁性检测、施工过程中磁性跟踪监测的实践方法。  相似文献   

3G技术与现代物流管理技术的集成模式研究   总被引：3，自引：1，他引：3  

霍亮  李欣 《测绘科学》2003,28(3):59-61

3G技术能够对现代物流作业与管理进行有效地监督和控制,3G技术与现代物流管理技术的集成是物流业发展的客观需要。探讨了3G技术与现代物流管理技术的集成模式,对于以GIS技术为平台支撑、以定位技术和无线通信技术为辅助手段的分布式空间物流信息系统的建设具有一定的意义。  相似文献   

黄汲清院士与第四纪冰川研究     

施雅风 《冰川冻土》1996,18(4):289-295

黄汲清院士是在多方面作出重大贡献的地质学大师，也是第四纪冰川研究的先驱者。他于１９３２￣１９３５年在瑞士完成博士论文期间，受到良好的冰川地质学训练。于１９４３￣１９４４年与合作者对天山南麓台兰河谷中游地质调查中，对冰碛与非冰碛沉积物进行仔细的正确的调查和精美的地质制图，撰写出高水平的论文，由此对中国第四纪冰川研究作出了重要贡献。他关注中国东部第四纪冰川研究的进展，指出忽视古气候研究是工作中的重要缺  相似文献   

Respiratory adaptations to oxygen lack in three species of Glossiphoniidae (Hirudinea) in Lake Esrom, Denmark     

Bettina Pohle  Kirsten Hamburger   《Limnologica》2005,35(1-2):78-89

The weight-specific respiration rate (μl O₂ mg⁻¹ AFDW h⁻¹) of three species of leech from Lake Esrom, Denmark, Glossiphonia concolor, G. complanata and Helobdella stagnalis was measured in a closed stirred chamber with a micro electrode. At declining oxygen concentration (mg O₂ l⁻¹) all three species expressed moderate ability to regulate respiration, in G. concolor and G. complanata down to 2 mg O₂ l⁻¹, in H. stagnalis down to 0.75 mg O₂ l⁻¹. Survival in anoxia was measured in closed bottles. The time to 50% survival (LD₅₀) was 30 days in G. concolor at 20 °C and 30 and 4 days in H. stagnalis at 10 and 20 °C, respectively. The results were discussed in relation to habitat and spatial distribution of the three species in the lake.  相似文献   

Preliminary Characterisation of New Glass Reference Materials (GSA-1G, GSC-1G, GSD-1G and GSE-1G) by Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry Using 193 nm, 213 nm and 266 nm Wavelengths   总被引：5，自引：1，他引：5  

Marcel Guillong  Kathrin Hametner  Eric Reusser  Stephen A. Wilson  Detlef Günther 《Geostandards and Geoanalytical Research》2005,29(3):315-331

New glass reference materials GSA-1G, GSC-1G, GSD-1G and GSE-1G have been characterised using a prototype solid state laser ablation system capable of producing wavelengths of 193 nm, 213 nm and 266 nm. This system allowed comparison of the effects of different laser wavelengths under nearly identical ablation and ICP operating conditions. The wavelengths 213 nm and 266 nm were also used at higher energy densities to evaluate the influence of energy density on quantitative analysis. In addition, the glass reference materials were analysed using commercially available 266 nm Nd:YAG and 193 nm ArF excimer lasers. Laser ablation analysis was carried out using both single spot and scanning mode ablation. Using laser ablation ICP-MS, concentrations of fifty-eight elements were determined with external calibration to the NIST SRM 610 glass reference material. Instead of applying the more common internal standardisation procedure, the total concentration of all element oxide concentrations was normalised to 100%. Major element concentrations were compared with those determined by electron microprobe. In addition to NIST SRM 610 for external calibration, USGS BCR-2G was used as a more closely matrix-matched reference material in order to compare the effect of matrix-matched and non matrix-matched calibration on quantitative analysis. The results show that the various laser wavelengths and energy densities applied produced similar results, with the exception of scanning mode ablation at 266 nm without matrix-matched calibration where deviations up to 60% from the average were found. However, results acquired using a scanning mode with a matrix-matched calibration agreed with results obtained by spot analysis. The increased abundance of large particles produced when using a scanning ablation mode with NIST SRM 610, is responsible for elemental fractionation effects caused by incomplete vaporisation of large particles in the ICP.  相似文献