جستجوی مقالات مرتبط با کلیدواژه « اقیانوس هند » در نشریات گروه « زیست شناسی »

Due to the good propagation of sound waves in the ocean, sound energy is used to reveal the subsurface of the sea. In order to take advantage of the different characteristics of the environment in which sound is emitted, modeling and simulation of sound waves should be used. For this purpose, the environmental factors should be investigated and the way of sound rays propagation and the efficiency of sonar should be simulated in different conditions and in different times and places. This research is designed with the aim of investigating the effects of topographical shape on the propagation of ultrasound rays. In this research, firstly, the environmental data of the study area, which includes salinity, temperature and depth data in the northern Indian Ocean, has been extracted from international databases (such as HYCOM, GEBCO, WOA, etc.). Then, using the beam method, the propagation of ultrasonic waves in the presence of roughness of the seabed has been simulated. First, changes in hydrophysical parameters were analyzed using temperature and salinity data in the Indian Ocean and with the help of graphic models. Then, using Mackenzie's formula, the speed of sound in these sections was calculated and analyzed. With the help of the existing acoustic model, pressure changes were first checked and then this output was used to calculate the amount of return signal from a hypothetical underwater target. The results of different simulation scenarios of ultrasonic beam propagation show that when the source is placed under the thermocline layer, the acoustic beams are deflected downwards. As the frequency increases, the transmission loss increases and the intensity of the acoustic pressure decreases. Because the amount of absorption of sound waves increases with increasing frequency.

 The Indian Ocean has come to the attention of major global and regional powers in recent years due to its geopolitical position, strategic straits and waterways, its transport role, and its strategic and economic importance. On the other hand, in order to become a world power, China seeks an active presence in the open waters and strategic ports of the world. The country is implementing a plan to revitalize the Silk Road as a one-way belt initiative, which has various strategic, geopolitical, political, economic and security dimensions. This project has two routes, sea and sea. The project's sea route, called the 21st Century Sea Silk Road, connects to the port of Venice in Europe after crossing the Indian Ocean. Another emerging regional power is India, which is seeking to increase its geopolitical influence in the subcontinent. This descriptive-analytical study examines the strategic and geopolitical rivalry of the "One Belt One Way Belt Project" in the Indian Ocean.

The research method of this research is descriptive-analytical. It is descriptive because it examines the current situation and systematically and systematically describes the current situation of the research subject. It is based on this analysis that in addition to stating the current situation, the reasons for how and why the situation and its dimensions are explained and the strategic and geopolitical competition of the China Ring Road project in the Indian Ocean has been analyzed. The method of collecting information is library and using articles, books, documents and Internet resources is valids.

China and India are both emerging powers in the international system. Although there are different and sometimes contradictory views on the degree of stability and strength of each of them, there can be no doubt that both countries are economically world-class and their continuous economic growth is itself a new condition of behavior. Brings political and strategic. India, on the other hand, will become the world's fourth largest economy in the next few years and will be forced to import energy, 90 percent of which will pass through the Strait of Hormuz. Economic conditions and reliance on the Indian Ocean have led both countries to strengthen their military and naval forces in the Indian Ocean. India has paid close attention to the navy over the past decade and is currently one of the world's largest navies with 155 warships. China is also present in eastern and western India, building a network of naval bases and centers in neighboring countries, from Pakistan to Myanmar. China and India are monitoring each other alongside maritime protection of their economic interests, which are heavily dependent on the Indian Ocean, and there is a slow rivalry between the two, including the Sino-Pakistani alliance against India. In this regard, it is clear that the Sino-Pakistani alliance is a strategic concern for India. In recent years, within the framework of this coalition, China has found an increasing presence in the port of Gwadar. In fact, this port is one of the important areas of the country's presence in the Indian Ocean, and many, especially in India, have talked about the possibility of establishing a Chen military base in this port. However, in the current context, as it is very provocative for India and the United States, it is unlikely that this action will be taken openly by China. In any case, Gwadar is a strategic lever at China's disposal that it can use against India in critical situations. India is also quite concerned about the cooperation between China and Pakistan and is trying to use the Iranian port of Chabahar as a trump card against China.

China is achieving its long-held dream of becoming a world power, and China's success will push the development model out of the monopoly of the West, and another power emerging in the Indian Ocean in the 21st century is India. There are differing views on Sino-Indian relations. Some believe that the deep and long-lasting geopolitical rivalry has shaped relations between the two countries for many years, and that the source of these rivalries is the lands and people that are around or between the two countries. Some have gone so far as to believe that India and China will become dangerous rivals in the near future. Some also believe that any drastic progress in India-China relations is unlikely and that relations between the two will remain competitive, and that despite the deep differences between India and China, the two sides must avoid the escalation of tensions into a public rivalry. To take. But in the meantime, trans-regional actors such as the United States are influencing China-India relations and trying to somehow manage the current developments in the Indian Ocean. The Islamic Republic of Iran, as an Asian country, due to its geopolitical position, is bound to have good relations with Asian countries and powers, and with a brief look at the history of Iran's relations with Asian countries, it can be seen that relations with these countries are always in different dimensions. It has been established at an appropriate level, although at times, due to the political conditions and developments in the region, these relations have had ups and downs. In this regard, the geopolitical position and capabilities of Iran (Chabahar) will have a good ground in various dimensions to influence the relations between India and China and, consequently, the developments in the Indian Ocean. Thus, Iran's role in the power relations between India and China can enhance the understanding of the future international system and facilitate knowledge of future developments in the Indian Ocean for decision-making. Gwadar Port not only as a port Important for Pakistan, but also a port where merchant ships, warships and even Chinese submarines can be stationed. And given that the port is located east of the Strait of Hormuz, Western countries have become very sensitive to this issue, and this is one of the main reasons for Western pressure on Pakistan. The Chinese have signed a $ 5 billion contract in the port of Salameh and Qawin to support the port in eastern Oman. In 2018, the United States of America also signed a contract with Oman in these ports under the pressure of Oman. The Omani, who initially resisted the negotiations, eventually agreed to the deal. China then invested $ 1,900 in the port of Hambantota, which could effectively control both the center and south of the Indian Ocean. Chabahar port, the development contract of which has been signed between Iran and India and is to be developed by this country, and this country is the main axis of its development, is 70 km away from Gwadar port, and these two ports have a common geography and common culture. have. One of these ports, Chabahar, wants to be developed by India, which is an ally of the West, and the port of Gwadar, which is opposed by China, which is opposed by the West, has to some extent followed this path. Under these circumstances, a geopolitical competition will be created in the future, and due to lack of maturity and without examining Iran's geopolitical analysis of issues and concluding a contract with India for the development of Chabahar, not much work has been done by India in this regard. In particular, it is propagandizing that this propaganda has made Pakistan very sensitive because Pakistan opposes the development of the port of Chabahar by its rival, India. On the other hand, it has infiltrated Afghanistan from the north and its government agencies, which is Pakistan's strategic depth. On the other hand, India is located in the east of Lahore, India, and finally in the west of Pakistan, the Indians are active. The Islamic Republic of Iran must act in such a way that the port of Chabahar, as an axis in the bed of the "One Belt - One Way" project, moves in the same way and like the port of Gwadar, and has no other way. And in fact, allow China to be active in this field, and in fact, these two should be considered as a project, and if there are two projects, one is India and the other is China, we will not succeed. On the other hand, due to India's internal problems, the country does not have the capacity to invest in the port of Chabahar because India is not ready to invest abroad. Therefore, the Islamic Republic of Iran must develop Chabahar in the southeast of the country with the help of the Chinese, and this does not mean that India or other countries are not allowed to cooperate. On the other hand, China is ready to create the bed and infrastructure for development in the port. It has Chabahar.