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991.
992.
Carl F. Meyer Andre B. Corbeau Harold L. Mack 《Journal of the American Water Resources Association》1974,10(5):952-968
ABSTRACT: This paper describes the philosophy, algorithms, and implementation of a computer-oriented land use forecasting-water policy simulation model. The model is applicable to SMSA's organized on a census tract basis by counties. The forecasts are macro to the census tract level for industrial, residential, commercial and public land uses, and are dynamically altered by hypothesized water management policies. Modeling is based on an economic data base of the region, and is extremely flexible for the user. An example set of simulations is included for illustrative purposes. 相似文献
993.
994.
Jüttner F 《Environmental pollution (Barking, Essex : 1987)》1990,68(3-4):377-382
Volatile microbial metabolites were analysed in the soil beneath 15 H year-old Picea abies which had been fumigated for 5 consecutive years with charcoal-filtered air enriched with ozone and sulphur dioxide. Major compounds which could be attributed to the metabolism of basidiomycete fungi were oct-1-en-3-ol, oct-1-en-3-one and 1,3-octadiene. They were accompanied by other C(8)-compounds. The lower amounts of C(8)-compounds observed in the soil of the sulphur dioxide and ozone treatment chambers indicate a reduced development of basidiomycetes. The higher amounts of geosmin and 2-methylisoborneol found in the soil of the ozone treatment chamber indicate an increase in actinomycete populations. The differences of the monoterpene patterns in the particular soils were not large enough to recognize trends unequivocally. 相似文献
995.
The Science of Nature - 相似文献
996.
997.
P.C.F. Crowson 《Resources Policy》1982,8(1):3-12
The author reviews recent estimates of world resources and reserves and notes that reserves tend to grow with mineral consumption. Legal and economic constraints to the extraction of minerals are at least as important as physical availability. The author also points out that there is far more investment in minerals (government induced investment, companies diversifying into mining, etc) than some commentators suggest. However, the large mining projects of the 1960s belong to the past, and supplies of minerals may well become tight if there is a concerted economic boom. 相似文献
998.
999.
A study of reproduction and other life cycle phenomena in planktonic protists using an acridine orange fluorescence technique 总被引:3,自引:0,他引:3
The percentage of dividing individuals and temporal reproductive patterns were determined for natural populations of several planktonic protists including five species of tintinnids, a dinoflagellate, and a diatom. To obtain these data, a method was used in which the nuclei of planktonic ciliates and phytoplankters can be fluorescently stained with acridine orange at the time of collection and fixation. The technique is simple and can be used routinely in studies of reproduction or other life cycle phenomena of natural protistan populations. For the tintinnids, often more than half of the individuals were in some recognizable stage of fission; periodicity in the division process was only observed once and apparently followed a pulse of conjugation in the population. With the diatom Ditylum brightwellii the fluorescent staining technique yielded data on the extent and timing of division which were consistent with, but more complete than, previous enumerations of paired cells.The support of the National Science Foundation (OCE-7819566) is acknowledged 相似文献
1000.