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61.
分层序列法是一种多目标决策方法,本文将其用于山西省管涔山森林经营局千秋沟林场落叶松经营类型的森林收获调整.结果表明:使用该法,决策者可将对不同目标的要求落实到合理的水平上;该法求解简单,是进行森林收获调整有力的数学工具 相似文献
62.
Ur?a?VilharEmail author Michael?Starr Mihej?Urban?i? Igor?Smolej Primo??Simon?i? 《European Journal of Forest Research》2005,124(3):165-175
The monthly water balance in gaps in a managed Dinaric silver fir–beech forest and a virgin forest remnant located in SE Slovenia
was modelled using a capacity water balance model for two growing seasons. Two gaps of different size (ca. 0.07 and 0.15 ha)
were selected in each forest and plots for soil moisture monitoring were established in each gap (2–4) and in the surrounding
forest (2–3). We report on the modelled actual evapotranspiration (AET) and potential evapotranspiration (PET) and drainage
fluxes (DF) from the rooting zone at the plots. Precipitation over the 2001 growing season (May–October) was considerably
drier than average and that for 2002 growing season was wetter than average. Modelled AET for the 2001 growing season varied
between 88% and 96% of PET for the managed forest plots and between 90% and 100% for the virgin forest plots. The values for
the gap plots varied between 87% and 100% at the managed forest site and between 92% and 96% for the gaps in the virgin forest
site. Monthly AET values declined to 57–59% of PET at plots in the centre of the gaps in the managed forest site and to 63–74%
in the gaps in the virgin forest site (July), indicating that the highest drought stress occurs in gap centres. For 2002 growing
season, AET for all plots was 100% of PET. Modelled DF values in 2001 were 13–35% of rainfall for plots in the gap centres
and 12–16% for plots in the forest at the managed forest site. On an average, gap DF values were 20% (154 mm) higher than
the forest plot values. DF values in 2002 were similar for all plots at the managed forest site, 31–33% of rainfall. At the
virgin forest site, 2001 growing season, DF values varied between 12% and 30% of rainfall at the forest plots and between
12% and 32% at the gap plots. In 2002, DF values for all plots in the virgin forest site varied between 24% and 38% of growing
season rainfall. The varying development of vegetation and forest in the gaps of the virgin forest remnant resulted in more
variable evapotranspiration and DF during the drought year 2001, with values not as clearly related to distance from the gap
centre as in the managed forest site. 相似文献
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66.
SUALEHA RIFFAT MUHAMMAD NAWAZ ZIA-UR- REHMAN 《Journal of veterinary pharmacology and therapeutics》1982,5(2):131-135
Pharmacokinetic parameters which describe the distribution and elimination of sulphadimidine were determined in normal dogs and dogs in which fever was produced by an intravenous injection of escherichia and staphylococcal species of bacteria. Sulphadimidine was injected as a single intravenous bolus at the dose of 100 mg/kg and the kinetics of the drug were described in terms of the bi-exponential expression: Cp = Ae -α t + Be -β t . The distribution half-times of the drug were 1.52 h in the normal and 0.81 h in the febrile dogs. The drug distribution was significantly more rapid ( P < 0.05) in febrile than in normal dogs. Average ± SD values for the half-lives of the drug were 16.2 ± 5.7 h in normal and 16.7 ± 4.7 h in the febrile dogs. The apparent volume of distribution ( V ' d (area)) was 628 ± 251 ml/kg in the normal dogs, and was not statistically different from 495 ± 144 ml/kg in the febrile dogs. The volume of the central compartment ( V ' c ) was 445 ± 55 ml/kg in normal dogs and this was significantly higher ( P < 0.01) than the V ' c of 246 ± 72 ml/kg in the febrile dogs. The body clearance was 22.4 ± 4.8 and 20.2 ± 3.6 ml/hour. kg in the normal and febrile dogs, respectively. The investigation revealed that the dosage regimen of sulphadimidine did not differ significantly between normal and febrile dogs. 相似文献
67.
A Ur 《Research in veterinary science》1974,16(2):204-207
68.
It has been thought that the first cities in the Near East were spatially extensive and grew outward from a core nucleated village while maintaining a more or less constant density in terms of persons or households per unit of area. The general applicability outside of the Near East of this southern Mesopotamian.derived model has been questioned recently, and variations from it are increasingly recognized. We can now demonstrate that such variation was present at the beginnings of urbanism in the Near East as well. 相似文献
69.
Saif Ur Rehman Kashif Muhammad Yaseen Hamaad Raza Asma Kirn 《Journal of plant nutrition》2013,36(13):2024-2036
The ability to sense and respond to physical stimuli is of key importance to all living things. Among the common environmental stimuli detected by living organisms are light, temperature, and a variety of chemical signals. A number of these stimuli appear to be closely related and can be considered as physico-mechanical stimuli. Plant hormones like ethylene have a definite role in plant growth stages from seed germination to senescence and death of plants. Calcium carbide, a solid material, has been proven in recent years to be a new source of this hormone. Calcium carbide absorbs moisture from soil and releases acetylene gas which by the microbial activities are converted to plant hormone ethylene. The role of calcium carbide was studied, especially the effects of this material during the seed germination stage. Under closed conditions this material was applied to okra seeds and its physico-chemical changes in seed during germination were observed. It was concluded from the experiment that calcium carbide has a definite role in okra seed germination as there was early germination and root formation observed in treated seeds with a callus formation on the roots of germinating seeds which developed in to secondary roots in very short time as compare to control in the same period. It was also observed that in treated okra plants, early flowering and fruit formation was initiated which contributed about 27% green pod yield increase in okra. 相似文献
70.
Mustafa Roma Iqbal Muhammad Javed Hamza Muhammad Rehman Atiq Ur Buzdar Ismail Kamal Hira Mansoor Shahid Amin Imran 《European journal of plant pathology / European Foundation for Plant Pathology》2021,161(4):917-931
European Journal of Plant Pathology - Virus-induced gene silencing (VIGS) is a reverse genetic tool used to identify the function of individual genes by reducing their expression. Here VIGS was... 相似文献