فهرست مطالب ali reyhani

In this study, tungsten disulfide nanostructures are synthesized on the Si/SiO2 substrates by thermal chemical vapor deposition in a three-zone furnace. For this purpose, sulfur and tungsten oxide powders are first placed under argon gas in the first and third regions of the furnace at 220 and 1100 °C, respectively. A scanning electron microscope is then used to evaluate the morphology of the grown layers. The images confirm the growth of WS2 hexagonal flakes. The samples are then placed in a ceramic plant in the center of a single-zone furnace for re-annealing. The grown layers are reheated under different gases of Argon, Argon/Hydrogen, Oxygen, and Ammonia/Water at 450 °C for 30 minutes. To evaluate the annealing effect, X-ray diffraction, Raman spectroscopy, and Ultraviolet-Visible spectroscopy are employed. The results confirmed the effect of the Argon/Hydrogen atmosphere on the improvement in the optical and crystalline properties of the WS2 synthesized layers.

The ‘time’ plays a considerable role in understanding the existence and various philosophical issues. Thus, throughout history, the philosophers have always paid heed to it and regarded a different status for it, to the extent that some, among the philosophers, have regarded it as a necessary being and some other have regarded it as a merely mental concept.
This study is a brief report of the existence and the quiddity of ‘time’ in Avicenna’s view. In the first part, we deal with the following key question: can we consider the ‘time’ as invalid in the outer world or is it a mentally-founded concept having no reality or objectivity? Similarly, it is said that Avicenna accepts the ‘time’ as an objective and real being in his philosophical thought and, to prove that claim, gets help from the two arguments: naturalists’ argument and the metaphysicians’ argument. We will, then, investigate the functions of those arguments.
In the second part, the quiddity of the ‘time’ in Avicenna’s view has been studied and it is said, with a reference to the process of the aforementioned definitions and features in Avicenna’s works, that the quiddity of the ‘time’ in his philosophy is the amount of motion as having the irreconcilable prior and posterior parts.
In the third part, we will explain the fashion of moving in ‘time’ and antiquity of ‘time’, and will state motion is the preserver of the continuous and non-stop time, and thus, the ‘time’ lacks the beginning and the end.