The Radiation Energy Distribution over the Tibetan Plateau: A Review and Perspective

Experimental and theoretical investigations were made of the excitation and emission from a high-power HF laser pumped by a nonchain chemical reaction initiated by a radially converging electron beam. The distribution of the specific radiation energy in the output beam was determined and the distribution of the input energy over the laser chamber cross section was calculated for various gas mixtures. The space-charge field influenced the input energy distribution. The output radiation energy of a mixture of the SF6 : H2=8 : 1 composition was ∼115 J at a pressure of 0.45bar when the active volume was ∼30 litres, the efficiency relative to the input energy was ∼7%—8%, and the distribution of the radiation energy over the output beam cross section was relatively uniform. For the same input energy, because of the high density of SF6, a pressure jump in SF6— H2(D2) mixtures resulting from the combined effect of the electron beam injection and the chemical reaction was several times less than in active mixtures of exciplex lasers.

The mountains of Himalayas are the important channels for the mass exchange between surface layer of Northern Hemisphere and troposphere. The mountains relate surface layer atmosphere over the Tibetan Plateau and the above free atmosphere through many atmospheric circulation systems including mountain-valley wind and glacier wind etc. Mt. Qomolangma (Mt. Everest) is the highest peak in the world, and its nearby region is a representative case of mountains of Himalayas. Firstly the back ground of the establishment of the Qomolangma Station for Atmospheric and Environmental Observation and Research, Chinese Academy of Sciences (QOMS/ CAS) and the role of the station in the study of the atmosphere-land interaction over Himalayan area were intro-duced in this paper. Then some preliminary observational analysis results, such as the structure of the Atmo-spheric Boundary Layer (ABL) and the characteristics of the atmospheric turbulence and the radiation energy distribution were shown. The results showed that: The excess resistance to heat transfer kB-1 has obvious diurnal variations with lower values in the night and higher values in the daytime; The low frequency perturbations have a large influence on the spectra variation of all wind components, but mid frequency perturbations have only in-fluence on the spectra variation of vertical wind components and also alter the co-spectra of momentum and sen-sible heat flux under near neutral stratification; The downward shortwave radiation over this area are obviously larger than that in other areas; There is very clear constant layer of potential temperature existing in the northern slope of Mt. Qomolangma area around 12:00 (Beijing Standard Time, BST) in May, and the layer is about 2,200 m during the period over this area. In comparison with study results from other areas, some uniqueness and commonness of the Himalayan region are clearly identified.

The radiation energy distribution over the Tibetan Plateau

Nuclear power accidents have demonstrated the need for reliable passive dosemeters that can estimate the doses from effluent gamma emitters with a wide range of energies, and give information on the energy distribution of the environmental gamma radiation. For this purpose, experimentally obtained energy responses from a TL dosemeter combination consisting of five CaSO4:Dy dosemeters with different filters were used as input for the SAND II computer code (Spectrum Analysis by Neutron Detectors) that had been adapted to evaluate the energy distribution of environmental gamma radiation and related doses. The dosemeters were exposed to radiation from the natural environment as well as that produced by artificial sources, and the estimated gamma ray energy distributions and doses were tested against results from measurements made with a sodium iodide spectrometer and a high pressure ionisation chamber.

Shoemaker-Levy 9: distribution of radiant energy

A method for calculating absolute values of the spectral distribution of the radiant energy of a polychromatic source is described for the case in which the spectral distribution of the radiant energy is recorded in relative units, and the time dependence of a current pulse of a photodetector the spectral sensitivity of which is known in absolute units is measured. The expression for the time-averaged spectral density of the radiation power for the pulse-periodic operation of a radiant source is given.

This article presents the results of the analysis of energy distribution of optical radiation emitted by electrical discharges in insulating liquids, such as synthetic ester, natural ester, and mineral oil. The measurements of optical radiation were carried out on a system of needle–needle type electrodes and on a system for surface discharges, which were immersed in brand new insulating liquids. Optical radiation was recorded using optical spectrophotometry method. On the basis of the obtained results, potential possibilities of using the analysis of the energy distribution of optical radiation as an additional descriptor for the recognition of individual sources of electric discharges were indicated. The results can also be used in the design of various types of detectors, as well as high-voltage diagnostic systems and arc protection systems.

The study on radiant energy distribution in guava was carried out to optimize the planting density with respect to solar radiation interception by the plants to get higher yield of good quality fruits per unit area. The present investigations reveals that with increase in plant spacing from 6x2m to 6x4m the interception of radiation increased significantly during both rainy and winter crop seasons. However, it starts declining with further increase in plant spacing to 6x5m level. The interception of radiation remains somewhat static during the summer and rainy season months (May-September) and then starts decreasing with the advent of winter season upto April with sharp decline during the month of December to February. In the upper 1/3rd portion of plant canopy, more than 75% radiations were intercepted irrespective of plant spacing followed by 12-16% in middle and 6-9% in the lower 1/3rd parts of plant canopies. The plant spacing of 6x2m and 6x3m was found to be not encouraging owing to lower distribution of radiations particularly in middle and lower parts of plants. The plant spacing of 6x4m was found to be best due tomaximum absorption of solar radiation for higher fruiting of better quality fruits.

The penetration of radiation into snow is assumed to follow Fick's second law of diffusion with a term for simultaneous absorption. From this, the distribution of radiant energy in a deep homogeneous snow cover, a laminated snow cover, and a snow cover with an absorbing surface beneath is deduced. An equation for albedo is also derived. The penetration phenomenon is then analyzed in terms of the physical processes occurring and formulated as a random walk process. After a correction is made for a certain amount of nondiffuse radiation in the snow, more accurate equations for energy distribution and albedo are obtained. These results are applied to the theory of radiation measurement in snow. After experimental procedures were established on the Blue Glacier summer firn, field data were collected from winter snow at Alta, Utah, and used to check the theoretical equations for albedo and transmission to a black surface. The agreement of theory and experiment is very satisfactory.

Measurements of radiation energy distributions of infrared laser using an interference method

Blackbody radiation theory is one of the important origins of light quantum theory in the twentieth century. It is not only an important basis for quantum mechanics and photonics theory, but also an important conclusion of blackbody radiation, and an important foundation of modern measurement. In the early nineteenth century, the study of thermal radiation was supported by thermodynamics and spectroscopy, and the rapid development of electromagnetism and optics was used. By the end of the 19th century, it was recognized that both the thermal radiation and the optical radiation were electromagnetic waves, and began to study the distribution of radiant energy in different frequency ranges, especially the study of blackbody radiation in theory and practice. Blackbody radiation experiment is one of the contents of modern physics experiment in colleges and universities. This paper mainly studies and validates the law of blackbody radiation by the WGH-10 blackbody experimental device. There is already a calibrated bromine tungsten lamp energy curve at 2940k. At the beginning of the experiment, we should scan at 2940k color temperature to get the baseline, and then calculate the transfer function. Again, the energy curve obtained by scanning at diff erent color temperatures is divided by the transfer function to obtain the correct energy radiation curve. The experimental study of blackbody radiation by computer scanning grating spectrometer and bromine tungsten lamp was carried out. By means of scrolling grating and sine mechanism, the data were recorded by computer scanning to verify the three laws of blackbody radiation directly, and the radiation, transmission and reception of blackbody were analyzed Error correction.

Objective. For calculating shielding in x-ray rooms, it is often assumed that the beams impinge perpendicularly on the protective barriers. This is not always true, but this premise simplifies the calculations and enhances protection by being a conservative calculation. In this work, a method for calculating radiation transmission through planar shielding that considers the obliquity of the incident beam is presented.Approach. The output of the method produces energy spectra according to the direction of radiation impinging on the shielding. Four angles of incidence on the barrier are considered, along with monoenergetic pencil beams with energies ranging from 10 to 150 keV and two materials: lead and concrete. The direction of emerging photons is discretized into 49 different direction vectors. Monte Carlo calculations are performed for thicknesses of 0.1, 0.5, and 1.0 mm of lead, and 1, 5, 10, and 15 cm of concrete. Additionally, a multilayer iterative method is implemented for calculating attenuation of other thicknesses.Main results. The distribution of radiant energy according to the coordinates of its directional vector illustrates the effect of the obliquity of the incidence and the significance of the shielding material employed. In the case of concrete, the dispersion of radiation away from the original direction of incidence is much more pronounced than in the case of lead at energies below its K-edge. The multilayer iterative method provides highly accurate values of transmitted radiant energy in both monoenergetic and polyenergetic beams, for both lead and concrete, across the various studied incidence directions.Significance. Considering the direction of the photons reaching a shield and the direction of the photons passing through it allows multilayer composite shielding calculations to closely approximate the calculation made for the composite shielding.

Model approaches are developed to the description of the mechanism of the formation of different types of atomic-level DNA lesions under accelerated heavy ions. The radial distribution of radiant energy and the absorbed dose are calculated in accelerated 4He, 12C, and 40Ar ion tracks in the energy range of 3–20 MeV/nucleon. The spatial location of the atoms of an adenine-thymine nucleotide pair is compared with the calculated radial dose and radiant energy density distributions.

Variation and attribution of energy distribution for salinized sunflower farmland in arid area

Various simplifying assomptions were used in the past to overcome the difficulties arising from a strict mathematical determination of the passage of gamma rays through a medium. The energy spectrum was determined for small scattering angles under given boundary conditions by making use of the equations derived by V. I. Ogievetskii (Zhur. Eksper. i Teoret. Fiz. 29, 459 (1955)), estimating the probability of the creation of scattered gamma quanta by Compton scattering within a given wavelength region from a primary quantum. Expressions were obtained for the case when the spectrum consists of n gamma lines by approximating the original function on the basis of a graduated function. The formulas obtained may be used for determining the energy distribution of gamma radiation in a material medium. The accuracy of the calculation, which depends on the energy of the primary radiation and the depth of penetration into the medium, increases with the energy and the depth. In order to evaluate the practical applicability of the method, the energy distribution of the 320-kev gamma radiation of Cr/sup 51/ in sand was determined; the numerical values were found to agree with previously obtained experimental data. (TTT)