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321.
The main reasons for the high content of inorganic N and its increase by several times in the Changjiang River and its mouth during the last 40 years were analysed in this work. The inorganic N in precipitation in the Changjiang River catchment mainly comes from gaseous loss of fertilizer N, N resulting from the increases of population and livestock, and from high temperature combustions of fossil fuels. N from precipitation is the first N source in the Changjiang River water and the only direct cause of high content of inorganic N in the Changjiang River and its mouth. The lost N in gaseous form and from agriculture non-point sources fertilizer comprised about 60% of annual consumption of fertilizer N in the Changjiang River catchment and were key factors controlling the high content of inorganic N in the Changjiang River mouth. The fate of the N in precipitation and other N sources in the Changjiang River catchment are also discussed in this paper.  相似文献   
322.
Rodin  A. V. 《Solar System Research》2003,37(2):101-111
The previously proposed (Rodin, 2002) method for calculating the microphysical properties of spatially inhomogeneous rarefied aerosol media with mixing using the lowest-order moments of the size distribution is generalized to particle coagulation. We show that when the problem is formulated in terms of moments, all of the solutions admitted by the stochastic coagulation equation lie within a narrow range whose boundaries can be determined by means of quadratic programming. We discuss the choice of an optimal solution within this range and compare the moment method with the results of our computations by the classical finite-difference method using a model of photochemical aerosols in Titan's atmosphere as an example. The moment method allows the efficiency of microphysical computations to be significantly increased by using precomputed low-dimension interpolation tables. It can be used to construct self-consistent models for the globular circulation of planetary atmospheres.  相似文献   
323.
We found the equilibrium conditions for a self-gravitating toroidal vortex by taking thermal pressure into account. These conditions are shown to significantly differ from those for a disk or a sphere. The evolution of a thin vortex turns it into a compact vortex that loses mechanical stability for low masses at a polytropic index γ<4/3 but retains stability for sufficiently high masses and densities determined by the velocity circulation in the vortex.  相似文献   
324.
Mel'nik  V.N. 《Solar physics》2003,212(1):111-119
It was found recently that fast electrons travel through the plasma of the solar corona in the form of beam-plasma structure (BPS), which consists of electrons and Langmuir waves. In this paper the influence of scattering BPS Langmuir waves off plasma ions (l+i=l+i) on BPS velocity is studied. We show that the maximum BPS velocity equals 0.35c, which is close to the velocity of Type III bursts sources.  相似文献   
325.
The Nilgiri Mountains of south India is considered unique by anthropologists, geologists, climatologists, botanists as well as tourists. It has remained a subject of constant study and research over the last two centuries. Man-nature balance had continued undisturbed in the Nilgiris for thousands of years until the early 19th century when it became a British colony attracting, in due course, various developmental activities. Subsequently, the Nilgiris and its popular hill stations emerged as favourite places for the British population in India for rest and recuperation, game and for raising commercial plantations. In the process, the traditional indigenous crops were replaced by “English“ vegetables and the natural forests gave way to commercial plantations of coffee, tea and other exotic species of trees.  相似文献   
326.
Abstract— Clasts of alkaline (the second find in meteorites) and subalkaline rocks were found in the Kaidun meteorite. One of them (#d4A) is a large crystal of albite with inclusions of fluorapatite, arfvedsonite, aenigmatite, and wilkinsonite. The two latter minerals were previously unknown in meteorites. Another clast (#d[3–5]D) has a melt crystallization texture of mainly feldspar (oligoclase) composition and contains relict grains of both high‐Ca and low‐Ca pyroxene and fluorapatite. The mineralogical characteristics of these clasts suggest a genetic relationship and an origin from the same parent body. The textural and mineralogical characteristics of the clasts indicate origin by extensive igneous differentiation. Such processes most likely took place in a rather large differentiated body. The material of clast #d(3–5)D is similar in some mineralogical respects to basaltic shergottites.  相似文献   
327.
We have obtained optical and near-infrared images of the field of the accreting millisecond X-ray pulsar XTE J1751−305. There are no stars in the 0.7-arcsec error circle (0.7 arcsec is the overall uncertainty arising from tying the optical and X-ray images and from the intrinsic uncertainty in the Chandra X-ray astrometric solution). We derive limiting magnitudes for the counterpart of   R > 23.1, I > 21.6, Z > 20.6, J > 19.6  and   K > 19.2  . We compare these upper limits with the magnitudes one would expect for simple models for the possible donor stars and the accretion disc subject to the reddening observed in X-rays for XTE J1751−305 and when put at the distance of the Galactic Centre (8.5 kpc). We conclude that our non-detection does not constrain any of the models for the accretion disc or possible donor stars. Deep, near-infrared images obtained during quiescence will, however, constrain possible models for the donor stars in this ultracompact system.  相似文献   
328.
Development and Extension of Seawater Desalination by Reverse Osmosis   总被引:2,自引:0,他引:2  
Seawater desalination has been people‘s fond dream since ancient times,the dream is now becoming a reality.This paper presents a brief development history of reverse osmosis.Much attention was paid to innovative development in mebranes,modules.equipments and applied technology,including asymmetric and composite membranes,spiral-wound element and hollow fiber module,energy recovery equipments and different technological processes.The extension of reverse osmosis,such as desalination,pre-concentration,integrated processes and nanofiltration,is also briefly mentioned.  相似文献   
329.
Subramanian  Prasad  Ananthakrishnan  S.  Janardhan  P.  Kundu  M.R.  White  S.M.  Garaimov  V.I. 《Solar physics》2003,218(1-2):247-259
We present the first observations of a solar flare with the GMRT. An M2.8 flare observed at 1060 MHz with the GMRT on 17 November 2001 was associated with a prominence eruption observed at 17 GHz by the Nobeyama radioheliograph and the initiation of a fast partial halo CME observed with the LASCO C2 coronagraph. Towards the start of the eruption, we find evidence for reconnection above the prominence. Subsequently, we find evidence for rapid growth of a vertical current sheet below the erupting arcade, which is accompanied by the flare and prominence eruption.  相似文献   
330.
Deep imaging and long-slit spectroscopy was obtained for a sample of dwarf ellipticals in the Fornax cluster, NGC 5044 and NGC 5898 groups using the ESO VLT. The observational data extend out to typically 1.5–2 effective radii and indicate a kinematic dichotomy in the family of ellipticals. The observed stellar kinematics indicate a luminosity–velocity dispersion relation largely supporting Supernova-driven stellar mass loss scenarios for the formation of dwarf ellipticals. Stellar dynamical models favour dark matter halos with typical mass-to-light ratios in the range of 3 to 9 solar units. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   
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