ALBERT — All Library Books, journals and Electronic Records Telegrafenberg

Hits per page

hits 1 - 2 | 2 hits

Sorting

Electronic Resource

The effect of radiative cascade on electron excitation temperature measurements (1991)

Marcum, S. D. ; Myers, J. L. ; Gieske, M. A. ; [et al.]

[S.l.] : American Institute of Physics (AIP)

Journal of Applied Physics 69 (1991), S. 27-33

add to mindlist on the mindlist

Details

ISSN: 1089-7550

Source: AIP Digital Archive

Topics: Physics

Notes: Electron excitation temperatures have been measured in a low-pressure (0.05-Torr Cs, 2-Torr total pressure) argon-cesium discharge that uses a heated cathode (900–1100 K). The excitation temperature determinations are based upon a model that allows calculation of cesium excited state densities for low electron density (〈1011 cm−3). The model assumes that the dominant creation processes for excited states are electron impact excitation from the ground state and radiative cascade from higher levels, while destruction is by spontaneous emission. Maxwellian electron energy distributions were used and the plasmas were considered to be optically thin. The model indicates that cascade contributions to the production of excited states can be as high as 50% for some cesium levels. Predicted emission spectra with cascade contributions to spontaneous emission intensities agree well with measured spectra except for radiation trapped transitions from low nP states to the ground state. Excitation temperatures are determined by fitting measured and calculated spectra.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1063/1.347709

Permalink

	Location	Call Number	Expected	Availability

Others were also interested in ...

Paper (German National Licenses)

Fulltext

Electronic Resource

Improving efficiency of breeding for higher crop yield (1993)

Wallace, D. H. ; Baudoin, J. P. ; Beaver, J. ; [et al.]

Springer

Theoretical and applied genetics 86 (1993), S. 27-40

add to mindlist on the mindlist

Details

ISSN: 1432-2242

Keywords: Yield physiology ; Photoperiod/temperature ; Partitioning ; Harvest index ; Maturity ; Culivar adaptation

Source: Springer Online Journal Archives 1860-2000

Topics: Biology

Notes: Summary Exclusive selection for yield raises, the harvest index of self-pollinated crops with little or no gain in total bipmass. In addition to selection for yield, it is suggested that efficient breeding for higher yield requires simultaneous selection for yield's three major, genetically controlled physiological components. The following are needed: (1) a superior rate of biomass accumulation. (2) a superior rate of actual yield accumulation in order to acquire a high harvest index, and (3) a time to harvest maturity that is neither shorter nor longer than the duration of the growing season. That duration is provided by the environment, which is the fourth major determinant of yield. Simultaneous selection is required because genetically established interconnections among the three major physiological components cause: (a) a correlation between the harvest index and days to maturity that is usually negative; (b) a correlation between the harvest index and total biomass that is often negative, and (c) a correlation between biomass and days to maturity that is usually positive. All three physiological components and the correlations among them can be quantified by yield system analysis (YSA) of yield trials. An additive main effects and multiplicative interaction (AMMI) statistical analysis can separate and quantify the genotype × environment interaction (G × E) effect on yield and on each physiological component that is caused by each genotype and by the different environment of each yield trial. The use of yield trials to select parents which have the highest rates of accumulation of both biomass and yield, in addition to selecting for the G × E that is specifically adapted to the site can accelerate advance toward the highest potential yield at each geographical site. Higher yield for many sites will raise average regional yield. Higher yield for multiple regions and continents will raise average yield on a world-wide basis. Genetic and physiological bases for lack of indirect selection for biomass from exclusive selection for yield are explained.