高精度局域大地水准面对布测GPS水准和重力的要求

给定局域 (似 )大地水准面所要求的精度后 ,对该局域中应该布测 GPS水准网的密度和精度进行了研究 ,并对不同地形类型的地区中 ,重力扰动对该局域 (似 )大地水准面精度的影响进行了讨论 ,并提出了相应布测密度的要求。

Characteristics of water exchange in the Luzon Strait during September 2006

The Luzon Strait is the only deep channel that connects the South China Sea(SCS) with the Pacific.The transport through the Luzon Strait is an important process influencing the circulation,heat and water budgets of the SCS.Early observations have suggested that water enters the SCS in winter but water inflow or outflow in summer is quite controversial.On the basis of hydrographic measurements from CTD along 120° E in the Luzon Strait during the period from September 18 to 20 in 2006,the characteristics of temperature,salinity and density distributions are analyzed.The velocity and volume transport through the Luzon Strait are calculated using the method of dynamic calculation.The major observed results show that water exchanges are mainly from the Pacific to the South China Sea in the upper layer,and the flow is relatively weak and eastward in the deeper layer.The net volume transport of the Luzon Strait during the observation period is westward,amounts to about 3.25 Sv.This result is consistent with historical observations.

Limnological instrumentation in the middle of the 19^(th) century:the first temperature and density profiles measured in the Dead Sea

The first modem survey of the Dead Sea was performed by the Geological Survey of Israel in 1959-1960, and the report published remains the baseline study for our understanding of the physical and chemical properties of the lake. At the time the Dead Sea was a meromictic lake with a strong salinity gradient separating the deep waters （〉40 m depth） from the less saline surface waters. A few results of analyses of deeper water samples collected in the 1930s were reported, but overall we have very little information about the structure of the lake＇s water column before the 1959-1960 survey. However, it is little known that data on the physical and the chemical structure of the Dead Sea water column were obtained already in the middle of the 19~ century, and the information collected then is highly relevant for the reconstruction of the limnological properties of the lake in earlier times. The expedition of Lieutenant William Lynch （U.S. Navy） in 1848 reported the presence of a temperature minimum at a depth of-18 m, and also retrieved a water sample collected close to the bottom for chemical analysis. In 1864, the French Dead Sea exploration by the Duc de Luynes and his crew yielded detailed density and salinity profiles for a number of sampling stations. The results of these pioneering studies are discussed here, as well as the sampling equipment and measuring instruments used by the 1848 and the 1864 expeditions.

Abnormal distribution of ionospheric electron density during November 2004 super-storm by 3D CT reconstructions from IGS and LEO/GPS observations

Using time-dependent 3D tomography method, the electron density distributions in the low-latitude ionosphere during November 2004 super-storm are reconstructed from GPS observations of joint ground-based IGS network and onboard CHAMP/GRACE satellites. The reconstructed electron densities are validated by satellite in situ measurements of CHAMP and GRACE satellites. It is indicated by computer tomography （CT） reconstructions that the long-lived positive storm phase during the first main phase of the storm （November 8） is mainly attributed to enhancement of electron density in the upper F region above the F2 peak. It is found by the CT imaging that the top-hat-like F2-3 double layers occurred in the equatorial ionization anomaly region during the main phase of the storm （at forenoon of November 8）. The structures of column-like enhanced electron density are found at the time near the minimum of Dst and in the longitudinal sector about 157°E, which extend from the topside ionosphere toward plasmasphere, reaching at least about 2000 km as high. Their footprints stand on the two peaks of the EIA.

Application of the oblique ionogram as vertical ionogram

The vertical ionogram can provide the important ionospheric parameters, such as critical frequency, virtual height and electron density, for ionospheric research. The oblique ionosonde has the ability to detect the ionosphere over sea and other terrain where it is not practical to deploy vertical sounder and provide more ionograms with less transmitting and receiving devices. Therefore, the conversion of the oblique ionogram to vertical ionogram for obtaining the important ionospheric parameters is a very useful inversion technology. The experimental comparison between oblique and vertical detections was carried out in the equatorial ionospheric anomaly (EIA) region of south China on 25 and 26 August 2010. The oblique detecting path was from Wuhan to Shenzhen and the VI ionosonde was located in the midpoint of the oblique path. The oblique ionogram reversion results showed a small deviation of the critical frequency, minimum virtual height as well as the electron density profile of the ionospheric F layer, as compared with the real vertical observations.

Fisher Information and Complexity Measure of Generalized Morse Potential Model

The spreading of the quantum-mechanical probability distribution density of the three-dimensional system is quantitatively determined by means of the local information-theoretic quantity of the Shannon information and information energy in both position and momentum spaces. The complexity measure which is equivalent to Cramer–Rao uncertainty product is determined. We have obtained the information content stored, the concentration of quantum system and complexity measure numerically for n = 0, 1, 2 and 3 respectively.

Chiral flux phase in the Kagome superconductor AV_(3)Sb_(5)

We argue that the topological charge density wave phase in the quasi-2D Kagome superconductor AV3Sb5 is a chiral flux phase.Considering the symmetry of the Kagome lattice,we show that the chiral flux phase has the lowest energy among those states which exhibit 2×2 charge orders observed experimentally.This state breaks the time-reversal symmetry and displays anomalous Hall effect.The explicit pattern of the density of state in real space is calculated.These results are supported by recent experiments and suggest that these materials are new platforms to investigate the interplay between topology,superconductivity and electron–electron correlations.