the series of mono-metallic and bi-metallic catalysts have been prepared by impregnatingwith solutions containing compound of h2ptc15,nbc15 and lml hc1 (0.1 mol). the activityand selectivity of the catalysts have been determined under conditions at 450-500°c, 15-30atm. molar ratio h2/c7h16=5 and vvh=1.5/h for converting n-heptane. under theseexperimental conditions it has been established that ...

two n4-type schiff base ligands named n,n'-bis(2-pyridylmethylidene)-1,2-diiminoethane (l1) and n,n'-bis(2-pyridylmethylidene)-1,3-diiminopropane (l2) have been synthesized by the reaction of pyridine-2-carbaldehyde with ethylenediamine and propylenediamine, respectively. the binding abilities of l1 and l2 in dichloromethane towards cu2+, cd2+, co2+, ni2+, zn2+ and pb2+ ions were evaluated by p...

The rate of N uptake of crops is highly variable during crop development and between years and sites. However, under ample soil N availability, crop N accumulation is highly related to crop growth rate and to biomass accumulation. Critical N concentration has been defined as the minimum N concentration which allows maximum growth rate. Critical N concentration declines during crop growth. The r...

A genetic algorithm is used to optimize the modified benzene alkylation process. Based on the previous studies, the modified process increases ethylbenzene selectivity and decreases energy consumption at the same time. The inlet ethylene flow rate of each alkylation reactor is optimized in order to reduce the chance of transalkylation reactions but increase ethylbenzene selectivity. The byprodu...

In this study, Co (III) salen complex was synthesized and immobilized onto the surface of Fe3O4@SiO2 magnetic nanoparticle. The heterogeneous nanocatalyst was characterized by different techniques including X-ray diffraction (XRD), Fourier transform infrared spectra (FT-IR), thermogravimetric analysis (TGA), transmission electron microscopy (TEM), nitrogen adsorption−desorption isotherm (BET), ...

Cover crops are essential in agricultural management and especially in organic farming for protecting the soil from erosion, competing with weeds, preventing evaporative losses and improving soil quality and fertility. The choice of cover crop species is crucial in achieving the highest level of weed suppression and soil fertility enhancement. Cover crop systems with rye or mixtures of legumes ...

The organization of crop cultivation practices is still far from completion, and Web Resources are not used adequately. This paper proposed a method, based on SVM, to organize the knowledge of crop cultivation practices efficiently from Web Resources. The knowledge organization method of crop cultivation was proposed with Good Agricultural Practices (GAP) in the application of the crop cultivat...

Based on SuperMap IS.NET and the empirical models about crop potential output, the paper firstly designed the model system of crop potential output by using componentware method based on distributed computing architecture under network environment. Secondly, the paper implemented crop potential model components by using componentware technology. Finally, with the abstract mechanism of interface...

Effects of water stress on fruit fresh and dry weights were investigated in peach trees, Prunus persica (L.) Batsch., with varying crop loads: light, moderate and heavy. In well-watered controls, tree water status was independent of crop load. In trees receiving reduced irrigation, the degree of water stress increased with increasing crop load. Water stress induced fruit fresh weight reductions...

Operational remote sensing systems are currently being used to monitor crop growth and climate to map impacts on crop production. The linking of these data to traditional crop forecasting systems has the capacity to improve both the spatial and temporal resolution of crop forecasts.