Recent progress on the active limb sounding of the earth with GPS signals

2005 ◽  
Author(s):  
C.O. Ao ◽  
G.A. Hajj ◽  
B.A. Iijima ◽  
A.J. Mannucci ◽  
T.K. Meehan ◽  
...  
Keyword(s):  
Recent Progress ◽  
The Earth

Review Lecture: The dynamical properties and internal structures of the Earth, the Moon and the planets

1972 ◽  
Vol 328 (1574) ◽  
pp. 301-336 ◽  
Keyword(s):  
Internal Structure ◽  
Recent Progress ◽  
High Pressures ◽  
Artificial Satellites ◽  
The Moon ◽  
The Earth ◽  
Internal Structures ◽  
Theoretical Investigations ◽  
Dynamical Properties ◽  
Very High

The aim of this review is to bring together and relate recent progress in three subjects - the internal structure of the Earth, the behaviour of materials at very high pressures and the dynamical properties of the planets. Knowledge of the internal structure of the Earth has been advanced in recent years, particularly by observations of free oscillations of the whole Earth excited by the very largest earthquakes; as a consequence, it is clear that K. E. Bullen’s hypothesis that bulk modulus is a smooth function of pressure irrespective of composition is close to the truth for the Earth. Understanding of the behaviour of materials at very high pressure has increased as a result both of experiments on the propagation of shock waves and of theoretical investigations along a number of lines and it can now be seen that Bullen’s hypothesis is not true irrespective of chemical composition and crystal structure but that it happens to apply to the Earth because of particular circumstances. Studies of the orbits of artificial satellites and space probes have led to better knowledge of the dynamics of the Moon, Mars and Venus, and there have also been recent improvements in the traditional studies of Uranus and Neptune. Our knowledge of the dynamics of the planets is on the whole rather restricted, and Bullen’s hypothesis only applies directly to the Moon (for which the application is trivial) and possibly to Mars; the dynamical properties do none the less set fairly restrictive limits to the models that can be constructed for other planets. It would be possible for all planets to have cores of similar composition to the Earth ’s, surrounded by mantles of different sorts, silicates for the terrestrial planets and mostly hydrogen for Jupiter, Saturn, Uranus and Neptune.

scholarly journals Land as a Basis for Recent Progress in the Study of Urbanization Dynamics

Land ◽  
2022 ◽  
Vol 11 (1) ◽  
pp. 118
Author(s):  
Iwona Cieślak ◽  
Andrzej Biłozor ◽  
Luca Salvati
Keyword(s):  
Recent Progress ◽  
Dynamic Processes ◽  
The Earth

Urbanization is one of the most dynamic processes occurring on the Earth [...]

Chairman’s opening remarks

1968 ◽  
Vol 171 (1022) ◽  
pp. 2-2 ◽  
Keyword(s):  
Organic Chemistry ◽  
Recent Progress ◽  
Chemical Elements ◽  
Fundamental Properties ◽  
The Earth ◽  
Present Context ◽  
Boron Nitrogen ◽  
Boron Carbon

First I would like to express some doubt about the suitability of the adjective ‘anomalous’, which in the present context can only mean ‘unusual’. Nothing in Nature can be truly anomalous in the broad scheme of things. Furthermore, the programme shows that what we are looking for is indication from known terrestrial biochemistry of directions in which we may find possible extensions to other bio-logical systems of a novel type, even to some in which the role of chemical elements may be modified or more drastically changed. Recent progress in organic chemistry offers many suggestions such as the boron-nitrogen and boron-carbon and phosphorus-nitrogen combinations. Silicon has often been suggested as a basis for life chemistry under non-terrestrial conditions. All these ideas have to be entertained as possibilities, but my own belief is that the carbon-oxygen-nitrogen-hydrogen structures would always be preferred as the basis of life in a range of conditions approximating to those of the Earth. This view is based on the fundamental properties of compounds of these elements and the nature of the chemical links between their atoms. Phosphorus, sulphur and various metals have essential parts to play, mainly in the promotion of biochemical transformations.

Using Controlled Graft Copolymerization Technology to Prepare Structure-Controllable Cellulose Functional Materials

2013 ◽  
Vol 734-737 ◽  
pp. 2108-2112 ◽  
Author(s):  
De Juan Li ◽  
Ying Juan Fu ◽  
Meng Hua Qin
Keyword(s):  
Natural Resource ◽  
Recent Progress ◽  
Graft Polymerization ◽  
Graft Copolymerization ◽  
Functional Materials ◽  
Grafting Modification ◽  
The Earth ◽  
Grafting Copolymerization ◽  
Application Scope

Cellulose is the most abundant, renewable, and biodegradable natural resource on the earth. Grafting copolymerization technique is one of the key methods to widen the application scope of cellulose. This paper concerned with the recent progress and application of living/controlled radical graft polymerization techniques such as NMP, ATRP, and RAFT in the grafting modification of cellulose. The advantages and disadvantage of them were also reviewed.

The motion of a lunar orbiter

1966 ◽  
Vol 25 ◽  
pp. 373
Author(s):  
Y. Kozai
Keyword(s):  
Degrees Of Freedom ◽  
Dimensional Space ◽  
Artificial Satellite ◽  
Equations Of Motion ◽  
Triaxial Ellipsoid ◽  
The Moon ◽  
Secular Motion ◽  
The Earth ◽  
Close Satellite ◽  
The Mean

The motion of an artificial satellite around the Moon is much more complicated than that around the Earth, since the shape of the Moon is a triaxial ellipsoid and the effect of the Earth on the motion is very important even for a very close satellite.The differential equations of motion of the satellite are written in canonical form of three degrees of freedom with time depending Hamiltonian. By eliminating short-periodic terms depending on the mean longitude of the satellite and by assuming that the Earth is moving on the lunar equator, however, the equations are reduced to those of two degrees of freedom with an energy integral.Since the mean motion of the Earth around the Moon is more rapid than the secular motion of the argument of pericentre of the satellite by a factor of one order, the terms depending on the longitude of the Earth can be eliminated, and the degree of freedom is reduced to one.Then the motion can be discussed by drawing equi-energy curves in two-dimensional space. According to these figures satellites with high inclination have large possibilities of falling down to the lunar surface even if the initial eccentricities are very small.The principal properties of the motion are not changed even if plausible values ofJ3andJ4of the Moon are included.This paper has been published in Publ. astr. Soc.Japan15, 301, 1963.

Formation of Lunar Craters and Bright Rays as a Result of Meteorite Impacts

1962 ◽  
Vol 14 ◽  
pp. 415-418
Author(s):  
K. P. Stanyukovich ◽  
V. A. Bronshten
Keyword(s):  
Explosive Charge ◽  
The Moon ◽  
Meteorite Impacts ◽  
The Earth ◽  
Lunar Craters ◽  
The Impact

The phenomena accompanying the impact of large meteorites on the surface of the Moon or of the Earth can be examined on the basis of the theory of explosive phenomena if we assume that, instead of an exploding meteorite moving inside the rock, we have an explosive charge (equivalent in energy), situated at a certain distance under the surface.

The Origin of the Moon

1962 ◽  
Vol 14 ◽  
pp. 149-155 ◽  
Author(s):  
E. L. Ruskol
Keyword(s):  
Chemical Composition ◽  
Solar System ◽  
The Moon ◽  
The Earth ◽  
The Difference ◽  
Origin Of The Moon

The difference between average densities of the Moon and Earth was interpreted in the preceding report by Professor H. Urey as indicating a difference in their chemical composition. Therefore, Urey assumes the Moon's formation to have taken place far away from the Earth, under conditions differing substantially from the conditions of Earth's formation. In such a case, the Earth should have captured the Moon. As is admitted by Professor Urey himself, such a capture is a very improbable event. In addition, an assumption that the “lunar” dimensions were representative of protoplanetary bodies in the entire solar system encounters great difficulties.

The Origin of the Moon and its Relationship to the Origin of the Solar System

1962 ◽  
Vol 14 ◽  
pp. 133-148 ◽  
Author(s):  
Harold C. Urey
Keyword(s):  
Solar System ◽  
The Moon ◽  
The Past ◽  
The Earth ◽  
Short Period ◽  
Origin Of The Moon

During the last 10 years, the writer has presented evidence indicating that the Moon was captured by the Earth and that the large collisions with its surface occurred within a surprisingly short period of time. These observations have been a continuous preoccupation during the past years and some explanation that seemed physically possible and reasonably probable has been sought.

Probable Structure and Nature of the Formations on the Reverse Side of the Moon According to Photometric Measurements of Lunar Photographs

1962 ◽  
Vol 14 ◽  
pp. 39-44
Author(s):  
A. V. Markov
Keyword(s):  
The Moon ◽  
Probable Structure ◽  
The Earth ◽  
Interplanetary Station ◽  
Photometric Measurements ◽  
Automatic Interplanetary Station

Notwithstanding the fact that a number of defects and distortions, introduced in transmission of the images of the latter to the Earth, mar the negatives of the reverse side of the Moon, indirectly obtained on 7 October 1959 by the automatic interplanetary station (AIS), it was possible to use the photometric measurements of the secondary (terrestrial) positives of the reverse side of the Moon in the experiment of the first comparison of the characteristics of the surfaces of the visible and invisible hemispheres of the Moon.

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