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31.
R. Sridharan S.M. Ahmed Tirtha Pratim Das P. Sreelatha P. Pradeepkumar Neha Naik Gogulapati Supriya 《Planetary and Space Science》2010,58(12):1567-1934
The altitudinal/latitudinal profile of the lunar atmospheric composition on the sunlit side was unraveled for the first time by the Chandra’s Altitudinal Composition Explorer (CHACE) on the Moon Impact Probe, a standalone micro-satellite that impacted at the lunar south pole, as a part of the first Indian mission to Moon, Chandrayaan-1. Systematic measurements were carried out during the descent phase of the impactor with an altitude resolution of ∼250 m and a latitudinal resolution of ∼0.1°. The overall pressure on the dayside and the neutral composition in the mass range 1-100 amu have been measured by identifying 44 and 18 amu as the dominant constituents. Significant amounts of heavier (>50 amu) species also have been detected, the details of which are presented and discussed. 相似文献
32.
R. Sridharan S.M. Ahmed Tirtha Pratim Das P. Pradeepkumar Gogulapati Supriya 《Planetary and Space Science》2010,58(6):947-1934
Direct detection of water in its vapour phase in the tenuous lunar environment through in situ measurements carried out by the Chandra’s Altitudinal Composition Explorer (CHACE) payload, onboard the Moon Impact Probe (MIP) of Chandrayaan I mission vindicates the presence of water on the surface of the moon in form of ice at higher lunar latitudes inferred from IR absorption spectroscopy, (especially that of OH), by the Moon Mineralogy Mapper (M3) of Chandrayaan I. The quadrupole mass spectrometer based payload, CHACE, sampled the lunar neutral atmosphere every 4 s with a broad latitudinal (∼40°N to 90°S, with a resolution of ∼0.1°) and altitudinal (from 98 km up to impact on the lunar surface with a resolution of ∼0.25 km) coverage in the sunlit side of the moon for the first time. These two (CHACE and M3) complementary experiments are shown to collectively provide unambiguous signatures for the distribution of water in solid and gaseous phases in Earth’s moon. 相似文献
33.
Galactic cosmic rays (GCRs) encounter an outward-moving solar wind with cyclic magnetic-field fluctuation and turbulence. This causes convection and diffusion in the heliosphere. The GCR counts from the ground-based neutron monitor stations show intensity changes that are anti-correlated with the sunspot numbers with a lag of a few months. GCRs experience various types of modulation from different solar activity features and influence space weather and the terrestrial climate. In this work, we investigate certain aspects of the GCR modulation at low cut-off rigidity (R c≈1 GV) in relation to some solar and geomagnetic indices for the entire solar cycle 23 (1996?–?2008). We separately study the GCR modulation during the ascending phase of cycle 23 including its maximum (1996?–?2002) and the descending phase including its minimum (2003?–?2008). We find that during the descending phase, the GCR recoveries are much faster than those of the solar parameters with negative time-lag. The results are discussed in light of modulation models, including drift effects and previous results. 相似文献
34.
Partha Pratim Chakraborty 《Journal of Earth System Science》2006,115(1):23-36
The Rewa Group of the Vindhyan Supergroup in the Son valley begins with a thick (∼200m) dominantly shaly, shelfal succession,
occurring between the Dhandraul Formation of the Kaimur Group (fluvial sandstone) below and Drammondganj Formation of the
Rewa Group (marginal marine sandstone) above. Such a stratigraphic disposition indicates a sharp rise in relative sea level
at the onset of Rewa sedimentation, inducing a shelfal depth to the Vindhyan basin. However, a number of wedge-shaped, sandstone/conglomerate
bodies (maximum thickness 23.5 m) occur at multiple stratigraphic levels within the aforesaid deeper water shale succession,
which appear to be of much shallow water origin representing regressive deposits. Though these bodies do not define a single
physically continuous unit, either vertically or laterally, they are still designated by a single term ‘Asan Sandstone’ in
the literature. On the other hand, the encasing shelfal shales are termed as Panna and Jhiri Shales, in accordance with their
occurrence below or above the so-called ‘Asan Sandstone’. The present study reveals that in different sections spread over
the Son valley, there are several discrete regressive wedges occurring vertically, and their depositional environment is also
variable, ranging between braided fluvial, shoreface fan and braid delta. The features common to most of the regressive coarser
clastic bodies are:
相似文献
– | •invariable presence of deeper water, shelfal shale below (Panna or Jhiri); |
– | •the underlying shale at places shows signatures of emergence at the top; |
– | •laterally impersistent, wedge-like geometry; and |
– | •presence of granular transgressive lags at the top. These coarser clastic wedges record several episodes of regressive deposition during short-term falling stage or lowstand of relative sea level at the early phase of Rewa sedimentation. Each individual phase of regressive deposition was, however, followed by flooding and resumption of shelf mud deposition. |
35.
Partha Pratim Ghosh Utpal Mukhopadhyay Saibal Ray 《Astrophysics and Space Science》2012,337(2):509-510
We investigate the possible variation of c in the context of the present accelerating Universe as discovered through SN Ia observations and show that variability of
c is not permitted under the variable Λ models. 相似文献
36.
37.
Fresnel volume georadar attenuation-difference tomography 总被引:1,自引:1,他引:1
38.
39.
Wolfgang Lutz Mahendra Shah Richard E. Bilsborrow John Bon-gaarts Partha DasGupta Barbara Entwisle Günther Fischer Brigida Garcia Daniel J. Hogan Arne Jernelöv Zhenghua Jiang Robert W. Kates Sanjaya Lall F. Landis MacKellar P.K. Makinwa-Adebusoye Anthony J. McMichael Vinod Mishra Norman Myers Nebojsa Nakicenovic Sten Nilsson Brian C. O'Neill Xizhe Peng Harriet B. Presser Nafis Sadik Warren C. Sanderson Gita Sen Barbara Torrey Dirk van de Kaa Hans J.A. van Ginkel Brenda Yeoh Huda Zurayk 《Global Change & Human Health》2002,3(1):33-35
The forthcoming World Summit on Sustainable Development (WSSD) in Johannesburg (August 26-September 4, 2002) has been set
by the United Nations to consider strategies toward sustainable development in all its dimensions. Hence, its mandate is broader
than that of the Rio 1992 United Nations Conference on Environment and Development (UNCED). Population issues have so far
been discussed in a separate series of World Population Conferences (Bucharest 1974, Mexico City 1984, Cairo 1994). With no
new World Population Conference scheduled for 2004 and Johannesburg having a mandate that is stated to explicitly include
social and economic aspects, population as a key component of sustainable development should figure prominently on the Johannesburg
agenda. Yet, after the third of four preparatory meetings for Johannesburg (which ended in New York on April 5th), consideration
of population is completely absent. The reasons for this are not entirely clear. We assume that they have to do with the fear
of entering into political controversies over abortion. We are concerned that, despite its broader mandate, in most countries
inputs to Johannesburg are being prepared mainly by environment ministries who have little experience in dealing with population
questions.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
40.
N. V. Madhavan Unni Partha Sarathi Roy V. Parthasarathy 《Journal of the Indian Society of Remote Sensing》1983,11(1):37-42
The potentialities of satellite remote sensing for acquiring informations useful for forest management have already been recognised. The analysis of satellite data can provide reconnaissance survey maps showing the spatial distribution of forest type and other useful information of the existing forest resources in the area in very short time. The present study has been carried out in Godavari river Basin, Nallamalai and Seshachalam hiil ranges, which are potential areas for Teak, bamboo and red-sanders respectively. The three Landsat scenes have been analysed using Multispectral Data Analysis System (M-Das) to make maps on 1:250,000 scale. The Computer classified colour coded maps show the spatial distribution of the industrially important species and association with other forest types existing in the area. The results have been discussed in the context of using Landsat data for reconnaissance survey of forest resources at a national level. 相似文献