The Experts below are selected from a list of 178359 Experts worldwide ranked by ideXlab platform
Sabre Kais - One of the best experts on this subject based on the ideXlab platform.
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quantum machine learning for electronic structure calculations
Nature Communications, 2018Co-Authors: Sabre KaisAbstract:Considering recent advancements and successes in the development of efficient quantum algorithms for electronic structure calculations—alongside impressive results using machine learning techniques for computation—hybridizing quantum computing with machine learning for the intent of performing electronic structure calculations is a natural progression. Here we report a hybrid quantum algorithm employing a restricted Boltzmann machine to obtain accurate molecular potential energy surfaces. By exploiting a quantum algorithm to help optimize the underlying objective function, we obtained an efficient procedure for the calculation of the electronic ground state energy for a small molecule system. Our approach achieves high accuracy for the ground state energy for H2, LiH, H2O at a specific location on its potential energy surface with a finite basis set. With the Future Availability of larger-scale quantum computers, quantum machine learning techniques are set to become powerful tools to obtain accurate values for electronic structures. With the rapid development of quantum computers, quantum machine learning approaches are emerging as powerful tools to perform electronic structure calculations. Here, the authors develop a quantum machine learning algorithm, which demonstrates significant improvements in solving quantum many-body problems.
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quantum machine learning for electronic structure calculations
arXiv: Quantum Physics, 2018Co-Authors: Rongxin Xia, Sabre KaisAbstract:Considering recent advancements and successes in the development of efficient quantum algorithms for electronic structure calculations --- alongside impressive results using machine learning techniques for computation --- hybridizing quantum computing with machine learning for the intent of performing electronic structure calculations is a natural progression. Here we report a hybrid quantum algorithm employing a restricted Boltzmann machine to obtain accurate molecular potential energy surfaces. By exploiting a quantum algorithm to help optimize the underlying objective function, we obtained an efficient procedure for the calculation of the electronic ground state energy for a small molecule system. Our approach achieves high accuracy for the ground state energy for H$_2$, LiH, H$_2$O at a specific location on its potential energy surface with a finite basis set. With the Future Availability of larger-scale quantum computers, quantum machine learning techniques are set to become powerful tools to obtain accurate values for electronic structures.
T E Graedel - One of the best experts on this subject based on the ideXlab platform.
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uncovering the global life cycles of the rare earth elements
Scientific Reports, 2011Co-Authors: T E GraedelAbstract:The rare earth elements (REE) are a group of fifteen elements with unique properties that make them indispensable for a wide variety of emerging, critical technologies. Knowledge of the life cycles of REE remains sparse, despite the current heightened interest in their Future Availability. Mining is heavily concentrated in China, whose monopoly position and potential restriction of exports render primary supplies vulnerable to short and long-term disruption. To provide an improved perspective we derived the first quantitative life cycles (for the year 2007) for ten REE: lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy) and yttrium (Y). Of these REE, Ce and Nd in-use stocks are highest; the in-use stocks of most REE show significant accumulation in modern society. Industrial scrap recycling occurs only from magnet manufacture. We believe there is no post-customer recycling of any of these elements.
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on the Future Availability of the energy metals
Annual Review of Materials Research, 2011Co-Authors: T E GraedelAbstract:The routine Availability of metals, long assumed by materials scientists to be unworthy of concern, is now a topic of wide interest but one with little clear guidance. This review discusses Availability issues from the perspective of the metals utilized in the energy industry. Although the Availability of metals is a dynamic characteristic, Availability of the widely used base metals appears assured in the immediate Future. The same cannot be said for by-product (daughter) metals, which are increasingly vital for many carbon-free energy technologies but are produced only if recovered as part of parent metal processing. Additionally, the direct substitution of one metal for another in short supply is often difficult because the best substitutes tend to have the same Availability constraints as did the original metal. Gallium, indium, and neodymium are singled out as elements of particular concern from a long-term-supply standpoint.
Chang Wang - One of the best experts on this subject based on the ideXlab platform.
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analyzing present and Future Availability of critical high tech minerals in waste cellphones a case study of india
Waste Management, 2021Co-Authors: Chang Wang, Kasun Hewage, Rehan Sadiq, Haibo FengAbstract:Abstract Critical high-tech minerals (CHTMs) are raw materials that are essential for a Future clean-energy transition and the manufacture of high-end products. Cellphones, one of the fastest growing electronic products, contain various CHTMs. Since 2019, India has surpassed the United States to become the second largest smartphone market in the world. An increasing and alarming number of excessive waste cellphones will be generated in India in the near Future. In this study, the dynamic material flow analysis approach and the Weibull distribution are adopted to analyze the volumes of accumulated waste cellphones and the contained CHTMs based on the differentiation between smartphones and feature phones in India. Moreover, a market supply model is adopted to predict the Future trends of CHTMs in waste cellphones. The results show a general upward tendency of waste cellphone volume in India, which indicates that various CHTMs contained in cellphone waste can be properly reused or recycled. Future implications based on the analysis results are provided for efficient cellphone management in India.
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the present and Future Availability of high tech minerals in waste mobile phones evidence from china
Journal of Cleaner Production, 2018Co-Authors: Chang Wang, Lyushui ZuoAbstract:Abstract High-tech minerals are key raw materials in national strategic emerging industries. Waste mobile phones contain a variety of high-tech minerals. With rapid economic development and improvements in living standards, mobile phones are becoming one of the most commonly used electronic devices among all electrical and electronic products. Since 2004, China has been world's largest mobile phone-producing and phone-consuming country, and correspondingly, it has generated excessive waste. In this paper, the dynamic material flow method and the Weibull distribution are used to analyze the quantity of waste mobile phones generated and the quantities of the high-tech minerals they contain based on the differentiation between feature phones and smartphones. Additionally, Future trends regarding high-tech minerals in waste mobile phones are predicted using a market supply A model. Our research results show an increasing trend of waste mobile phone generation, indicating that a considerable amount of the high-tech minerals they contain can be recycled. Finally, the following recommendations were proposed to further improve the management and development system of waste mobile phones in China: the development of a high-tech mineral data base is urgent; policies should be formulated and implemented by governments to improve the overall waste management system; the ecological design of products should be improved by manufacturers; dismantling and refining technologies should be enhanced by recycling companies to improve the recycling rate; and the public awareness of recycling should be strengthened.
Alejandra Matovelle - One of the best experts on this subject based on the ideXlab platform.
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current state and Future development of blue water Availability and blue water demand a view at seven case studies
Journal of Hydrology, 2010Co-Authors: Lucas Menzel, Alejandra MatovelleAbstract:Summary The current and Future situation of blue water Availability, blue water withdrawals and the occurrence of water stress is investigated in seven case studies distributed over Africa, Europe and Central Asia, thus representing very different physiographic, climatic and socio-economic conditions. Four scenarios from two major projects dealing with global change are applied to a large scale water model which simulates the case-specific hydrological conditions and water uses. For the assessment of water stress, the ratio between simulated blue water withdrawals and blue water Availability is determined. The results of this study clearly demonstrate that climate as well as socio-economic change will have a large impact on the Future Availability and use of water resources, and consequently on the occurrence of water stress. It is however evident that there are large regional differences of the current and Future water stress levels. The application of a number of contrasting scenarios leads to a wide range of possible water Futures in some of the investigated regions, thus introducing high uncertainties. Therefore, possible activities towards an implementation of integrated water resources management have to deal with these uncertainties.
Lyushui Zuo - One of the best experts on this subject based on the ideXlab platform.
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the present and Future Availability of high tech minerals in waste mobile phones evidence from china
Journal of Cleaner Production, 2018Co-Authors: Chang Wang, Lyushui ZuoAbstract:Abstract High-tech minerals are key raw materials in national strategic emerging industries. Waste mobile phones contain a variety of high-tech minerals. With rapid economic development and improvements in living standards, mobile phones are becoming one of the most commonly used electronic devices among all electrical and electronic products. Since 2004, China has been world's largest mobile phone-producing and phone-consuming country, and correspondingly, it has generated excessive waste. In this paper, the dynamic material flow method and the Weibull distribution are used to analyze the quantity of waste mobile phones generated and the quantities of the high-tech minerals they contain based on the differentiation between feature phones and smartphones. Additionally, Future trends regarding high-tech minerals in waste mobile phones are predicted using a market supply A model. Our research results show an increasing trend of waste mobile phone generation, indicating that a considerable amount of the high-tech minerals they contain can be recycled. Finally, the following recommendations were proposed to further improve the management and development system of waste mobile phones in China: the development of a high-tech mineral data base is urgent; policies should be formulated and implemented by governments to improve the overall waste management system; the ecological design of products should be improved by manufacturers; dismantling and refining technologies should be enhanced by recycling companies to improve the recycling rate; and the public awareness of recycling should be strengthened.
