含铁地下水对琼胶质量的影响及其处理     

韩容畴 《广东海洋大学学报》1993,(2)

湛江某琼胶厂在生产初期出现产品颜色发黄,其原因是由于该厂使用了含铁地下水作为生产用水所致。湛江市区的地下水是属于第二类型含铁地下水,可对该类型的地下水进行深度处理,来达到除铁、提高产品质量的目的。  相似文献   

Results from the Wide Angle Search for Planets Prototype (WASP0) – III. Planet hunting in the Draco field     

Stephen R. Kane †  rew Collier Cameron  Keith Horne  David James  T. A. Lister  Don L. Pollacco  Rachel A. Street  Yiannis Tsapras 《Monthly notices of the Royal Astronomical Society》2005,364(3):1091-1103

  相似文献   

Pushing the ground-based limit: 14-μmag photometric precision with the definitive Whole Earth Telescope asteroseismic data set for the rapidly oscillating Ap star HR 1217     

《Monthly notices of the Royal Astronomical Society》2005,358(2):651-664

  相似文献   

HE 0230–4323: an unusual pulsating hot subdwarf star     

C. Koen 《Monthly notices of the Royal Astronomical Society》2007,377(3):1275-1280

  相似文献   

ȷ��1���1�����׼�ȫ����ˮ׼���ģ��ʵ��   总被引：2，自引：0，他引：2  

韩建成  申文斌 《大地测量与地球动力学》2007,27(5):38-43

???????????????1???1??(10 ^-5 ms ^-2 ??)??????????????????????????????????????????????,????????????????????????1???1??????????????????????????????÷??????????衣 ????????????????????????????????????÷??????1???1???????????????????????????  相似文献   

Colliding Blast Waves Driven by the Interaction of a Short-Pulse Laser with a Gas of Atomic Clusters     

Roland A. Smith  James Lazarus  Matthias Hohenberger  Alastair S. Moore  Joseph S. Robinson  Edward T. Gumbrell  Mike Dunne 《Astrophysics and Space Science》2007,307(1-3):131-137

Collisions between shocks are commonly found in many astrophysical objects, however robust numerical models or laboratory analogues of these complex systems remain challenging to implement. We report on the development of scaled laboratory experiments which employ new techniques for launching and diagnosing colliding shocks and high Mach number blast waves, scalable to a limited subset of astrophysically-relevant regimes. Use of an extended medium of atomic clusters enables efficient (>80%) coupling of 700 fs, 1 J, 1054 nm laser pulses to a “cluster” gas with an average density of ≈10¹⁹ particles cm⁻³, producing an initial energy density >10⁵ J cm⁻³, equivalent to ≈5×10⁹ J/g. Multiple laser foci are used to tailor the spatial profile of energy deposition, or to launch pairs of counter-propagating cylindrical shocks which then collide. By probing the collision interferometrically at multiple view angles in 5^{^} increments and applying an inverse Radon transform to the resulting phase projections we have been able to tomographicall reconstruct the full three-dimensional, time-framed electron density profile of the system.  相似文献   

Pulsation–decline relationships in R Coronae Borealis stars     

Lisa A. Crause  Warrick A. Lawson  Arne A. Henden 《Monthly notices of the Royal Astronomical Society》2007,375(1):301-306

Decline onset times were measured in long-term visual light curves for five R Coronae Borealis (RCB) variable stars. These included RY Sgr and V854 Cen, the two RCB stars previously reported to have a relationship between dust formation events and pulsational variations. Analysis of the decline epochs showed that all decline onsets for a given star obey a linear ephemeris tied to the object's dominant radial pulsation period. Thus, in addition to confirming the pulsation–decline correlation for RY Sgr and V854 Cen, this same behaviour was demonstrated in UW Cen, R CrB and S Aps for the first time. This general result firmly establishes the connection between radial pulsation and mass loss in the RCB stars. The dominant pulsation period of ≈40 d for all of these objects therefore represents the characteristic time-scale on which these stars produce dust.  相似文献   

卫星遥感制图最佳影像空间分辨率与地图比例尺关系探讨   总被引：7，自引：1，他引：6  

龚明劼  张鹰  张芸 《测绘科学》2009,34(4)

选择适宜空间分辨率的遥感影像来达到地图成图的精确度并且最大程度反映地物的信息是卫星遥感制图需要解决的一个重要问题。本文重点分析了地图比例尺与遥感影像空间分辨率的关系,指出在选择制图影像空间分辨率时需要考虑两个因素,一是地图的成图比例尺,二是最小地物的尺度,提出了估算最佳影像空间分辨率的公式R={(L×M)/2~Rmin},并通过实例验证了该公式的可行性。  相似文献   

Comparison of non-local and polar modelling of softening in hypoplasticity     

Th. Maier 《国际地质力学数值与分析法杂志》2004,28(3):251-268

  相似文献   

100-yr mass-loss modulations on the asymptotic giant branch     

Massimo Marengo  &#;eljko Ivezi&#;  Gillian R. Knapp 《Monthly notices of the Royal Astronomical Society》2001,324(4):1117-1130

We analyse the differences in infrared circumstellar dust emission between oxygen-rich Mira and non-Mira stars, and find that they are statistically significant. In particular, we find that these stars segregate in the K–[12] versus [12]–[25] colour–colour diagram, and have distinct properties of the IRAS LRS spectra, including the peak position of the silicate emission feature. We show that the infrared emission from the majority of non-Mira stars cannot be explained within the context of standard steady-state outflow models.
The models can be altered to fit the data for non-Mira stars by postulating non-standard optical properties for silicate grains, or by assuming that the dust temperature at the inner envelope radius is significantly lower (300–400 K) than typical silicate grain condensation temperatures (800–1000 K) . We argue that the latter is more probable and provide detailed model fits to the IRAS LRS spectra for 342 stars. These fits imply that two-thirds of non-Mira stars and one-third of Mira stars do not have hot dust (>500 K) in their envelopes.
The absence of hot dust can be interpreted as a recent (∼100 yr) decrease in the mass-loss rate. The distribution of best-fitting model parameters agrees with this interpretation and strongly suggests that the mass loss resumes on similar time-scales. Such a possibility appears to be supported by a number of spatially resolved observations (e.g. recent Hubble Space Telescope images of the multiple shells in the Egg Nebula) and is consistent with new dynamical models for mass loss on the asymptotic giant branch.  相似文献