نتایج جستجو برای: especially environment temperature (degree
تعداد نتایج: 1551473 فیلتر نتایج به سال:
in this thesis, a better reaction conditions for the synthesis of spirobarbiturates catalyzed by task-specific ionic liquid (2-hydroxy-n-(2-hydroxyethyl)-n,n-dimethylethanaminium formate), calcium hypochlorite ca(ocl)2 or n-bromosuccinimide (nbs) in the presence of water at room temperature by ultrasonic technique is provided. the design and synthesis of spirocycles is a challenging task becaus...
drought is transient phenomenon , slow , repetitive and integral part of the climate of each region. drought begins with a substantial reduction in precipitation over the long-term average rainfall and over time, reduced soil moisture and surface and ground water resources will continue to decrease. this phenomenon is the most important in bakhtegan basin because of its importance in strategic ...
in this research, the statistics of daily temperature of meteorology stations for estimating the probable occurrence of the first and last frost temperature, the phonological thresholds of saffron and its flowering and irrigation dates were explored. furthermore, by applying different methods, the probabilities of the attained dates in different probability levels were fit in smada software. th...
Trees can record long-term effects of climate variables. Using dendroclimatology knowledge, we can reconstruct such variables especially for areas which have short-term climatic data. For this purpose, we reconstructed the temperature degree of the warm months (May-September) through annual rings width of Quercus persica and regression analysis of data obtained from stations on Dena region. Wit...
Understanding how communities respond to changes in temperature is a major challenge for community ecology. Temperature influences the relative degree to which top-down and bottom-up forces structure ecological communities. In greenhouse experiments using the aquatic community found in pitcher plants (Sarracenia purpurea), I tested how temperature affected the relative importance of top-down (m...
In a changing environment the ability to adjust physiological functions to new conditions might be especially valuable for long-living ectothermic animals such as ants. With a simple method for estimating critical thermal minima of Myrmica ants we assessed variation of the minima and their response to lowered temperature. At a cooling rate of about 1 degree C per minute the ants first displayed...
abstract in first part of this project, the use of a new and biguanid-like catalyst supported on silica as a recyclable catalyst provides a new route for the synthesis of a variety of arylalkylidene rhodanine derivatives through knoevenagle reaction in at present of solvent at room temperature. rhodanine derivatives and especially arylalkylidene rhodanines have proven to be attractive compound...
Ceramic borides, carbides and nitrides with high melting point, relatively good resistance to oxidation and corrosive environments are considered by many researchers in various high temperature industries, which is known from the family of materials as high temperature ceramic (UHTC). To be. All UHTCs have very strong bonds that give them structural stability at high temperatures, and among the...
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