Part of the challenge for quantum many-body problems comes from the difficulty of representing large-scale quantum states, which in general requires an exponentially large number of parameters. ...Neural networks provide a powerful tool to represent quantum many-body states. An important open question is what characterizes the representational power of deep and shallow neural networks, which is of fundamental interest due to the popularity of deep learning methods. Here, we give a proof that, assuming a widely believed computational complexity conjecture, a deep neural network can efficiently represent most physical states, including the ground states of many-body Hamiltonians and states generated by quantum dynamics, while a shallow network representation with a restricted Boltzmann machine cannot efficiently represent some of those states.One of the challenges in studies of quantum many-body physics is finding an efficient way to record the large system wavefunctions. Here the authors present an analysis of the capabilities of recently-proposed neural network representations for storing physically accessible quantum states.
Rayleigh’s criterion for resolving two incoherent point sources has been the most influential measure of optical imaging resolution for over a century. In the context of statistical image processing, ...violation of the criterion is especially detrimental to the estimation of the separation between the sources, and modern far-field superresolution techniques rely on suppressing the emission of close sources to enhance the localization precision. Using quantum optics, quantum metrology, and statistical analysis, here we show that, even if two close incoherent sources emit simultaneously, measurements with linear optics and photon counting can estimate their separation from the far field almost as precisely as conventional methods do for isolated sources, rendering Rayleigh’s criterion irrelevant to the problem. Our results demonstrate that superresolution can be achieved not only for fluorophores but also for stars.
Summary
Seed development largely depends on the long‐distance transport of sucrose from photosynthetically active source leaves to seed sinks. This source‐to‐sink carbon allocation occurs in the ...phloem and requires the loading of sucrose into the leaf phloem and, at the sink end, its import into the growing embryo. Both tasks are achieved through the function of SUT sucrose transporters. In this study, we used vegetable peas (Pisum sativum L.), harvested for human consumption as immature seeds, as our model crop and simultaneously overexpressed the endogenous SUT1 transporter in the leaf phloem and in cotyledon epidermal cells where import into the embryo occurs. Using this ‘Push‐and‐Pull’ approach, the transgenic SUT1 plants displayed increased sucrose phloem loading and carbon movement from source to sink causing higher sucrose levels in developing pea seeds. The enhanced sucrose partitioning further led to improved photosynthesis rates, increased leaf nitrogen assimilation, and enhanced source‐to‐sink transport of amino acids. Embryo loading with amino acids was also increased in SUT1‐overexpressors resulting in higher protein levels in immature seeds. Further, transgenic plants grown until desiccation produced more seed protein and starch, as well as higher seed yields than the wild‐type plants. Together, the results demonstrate that the SUT1‐overexpressing plants with enhanced sucrose allocation to sinks adjust leaf carbon and nitrogen metabolism, and amino acid partitioning in order to accommodate the increased assimilate demand of growing seeds. We further provide evidence that the combined Push‐and‐Pull approach for enhancing carbon transport is a successful strategy for improving seed yields and nutritional quality in legumes.
Significance Statement
We demonstrate that carbon allocation from source to sink and seed carbon pools can be improved in legumes through synergistically enhancing leaf export and seed uptake of sucrose. In addition, changes in source‐to‐sink carbon transport affect seed protein levels though improved leaf metabolism and amino acid partitioning to, and uptake into, the embryo.
Since its emergence in December 2019, corona virus disease 2019 (COVID-19) has impacted several countries, affecting more than 90 thousand patients and making it a global public threat. The routes of ...transmission are direct contact, and droplet and possible aerosol transmissions. Due to the unique nature of dentistry, most dental procedures generate significant amounts of droplets and aerosols, posing potential risks of infection transmission. Understanding the significance of aerosol transmission and its implications in dentistry can facilitate the identification and correction of negligence in daily dental practice. In addition to the standard precautions, some special precautions that should be implemented during an outbreak have been raised in this review.
The emergence of blockchain technology has created a number of potential innovations in handling business activities across various industries. However, few studies discuss the potential influence of ...blockchain technology from a business process re-engineering perspective. This study focuses on the feasibility and inceptive application of supply chain processes. We proposed a blockchain-based framework along with the use of an affiliated technology, i.e., smart contracts, to derive the feasible benefits of the supply chain process design. Through the illustrative design of an integrated process, we provide an achievable use case of the disintermediation of business processes via a conceptual, shared information ledger. This ledger not only facilitates the sharing of tracking information but also promotes a network for multilateral collaboration among supply chain members. The pursuit of transparency and accountability across supply chain processes can potentially influence decentralization and automation. A comparative analysis of the current and proposed frameworks is conducted to support the core reasoning of this study. Additionally, future implications on managerial practice and academic research are explored to provide pervasive suggestions for similar attempts in different sectors. We conclude with an evaluation of the potential influence of blockchain technology on supply chain management.
•Blockchain and smart contract technology can help conduct business process re-engineering (BPR) across enterprise borders.•A blockchain-based BPR framework is proposed and explored to automate business flows in tracking supply chain processes.•Blockchain-based business apps can be designed and implemented using the proposed framework to harvest blockchain benefits.•Blockchain and smart contract based business applications may significantly affect our digital life in the near future.
Quantum Fisher information matrix (QFIM) is a core concept in theoretical quantum metrology due to the significant importance of quantum Cramér-Rao bound in quantum parameter estimation. However, ...studies in recent years have revealed wide connections between QFIM and other aspects of quantum mechanics, including quantum thermodynamics, quantum phase transition, entanglement witness, quantum speed limit and non-Markovianity. These connections indicate that QFIM is more than a concept in quantum metrology, but rather a fundamental quantity in quantum mechanics. In this paper, we summarize the properties and existing calculation techniques of QFIM for various cases, and review the development of QFIM in some aspects of quantum mechanics apart from quantum metrology. On the other hand, as the main application of QFIM, the second part of this paper reviews the quantum multiparameter Cramér-Rao bound, its attainability condition and the associated optimal measurements. Moreover, recent developments in a few typical scenarios of quantum multiparameter estimation and the quantum advantages are also thoroughly discussed in this part.
Although efficient H2 evolution through water splitting under irradiation with light would solve severe global environmental and energy issues, finding efficient and eco-friendly photocatalysts from ...earth-abundant elements remains challenging. In this paper, we report WS2–MoS2 in-plane few-layer heterostructures that function as efficient photocatalysts. Because of the built-in potential at the epitaxially–grown WS2–MoS2 interface, the electron-hole carriers underwent rapid separation upon irradiation with light, such that the H2 generation yield rate reached as high as 9.83 mmol g–1 h–1. This improved photocatalytic H2 evolution from purely two-dimensional in-plane heterostructures has the potential to deliver outstanding catalysts for solar energy conversion as well as the production of chemical fuels.
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•Few-layer WS2–MoS2 in-plane heterostructures were synthesized using a hydrothermal method from WS2 bulk materials.•WS2–MoS2 in-plane heterostructures exhibit the atomically sharp interface.•The photocatalytic H2 evolution over the few-layer heterostructure was more than 6.5 times greater than that over the pure WS2.
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