Bi2O2Se-Based Bimode Noise Generator for the Application of Generative Adversarial Networks.

In the emerging technology, the generative aversive networks (GANs), randomness, and unpredictability of inputting noises are the keys to the uniqueness, diversity, robustness, and security of the generated images. Compared with deterministic software-based noise generation, hardware-based noise generation introduces physical entropy sources, such as electronic and photonic noises, to add unpredictability. In this study, bimode Bi2O2Se-based noise generators have been demonstrated for the application of GANs. Harnessing its ultrahigh carrier mobility, excellent air stability, marvelous optoelectronic performance, as well as the unique surface resistive switching effect and defect locations in the energy diagram, Bi2O2Se provides a good material platform to easily integrate with multiple device architectures for generating noises in different physical sources. The noise of the black current mode in a photodetector architecture and the random telegraph noise in a memristor mode were measured, characterized, compared, and analyzed. A method of Markov chain equipped with K-means clustering was carried out to calculate the discrete noise states and the transition probability matrix between them. To evaluate the generated properties of the GANs based on the hardware noise source, the inception score and Fréchet inception distance were evaluated.

Bi2O2Se-Based True Random Number Generator for Security Applications.

The fast development of the Internet of things (IoT) promises to deliver convenience to human life. However, a huge amount of the data is constantly generated, transmitted, processed, and stored, posing significant security challenges. The currently available security protocols and encryption techniques are mostly based on software algorithms and pseudorandom number generators that are vulnerable to attacks. A true random number generator (TRNG) based on devices using stochastically physical phenomena has been proposed for auditory data encryption and trusted communication. In the current study, a Bi2O2Se-based memristive TRNG is demonstrated for security applications. Compared with traditional metal-insulator-metal based memristors, or other two-dimensional material-based memristors, the Bi2O2Se layer as electrode with non-van der Waals interface, high carrier mobility, air stability, extreme low thermal conductivity, as well as vertical surface resistive switching shows intrinsic stochasticity and complexity in a memristive true analogue/digital random number generation. Moreover, those analogue/digital random number generation processes are proved to be resilient for machine learning prediction.

Visualizing a Field of Research for the Coronavirus Replication in Humans with Knowledge Mapping: Evidence from Web of Science.

BACKGROUND: The outbreak of COVID-19 sweeping the globe in 2020 has caused widespread fear and threatened global health security. Compared to SARS and MERS, COVID-19 also causes severe respiratory diseases and even fatal diseases but have many differences, such as the unidentified gene sequence and replication mechanism. From SARS to MERS, and then to COVID-19, coronaviruses have significant variations in host adaptation, virus evolution, infectivity, spread, and pathogenicity due to its unique replication mechanism. METHODS: A field of research for the coronavirus replication in humans was visualized with a database covering 9177 kinds of literature in Web of Science from 2002 through October 2021 to provide cognitive direction for the epidemic situation of virus infection. Knowledge Mapping by CiteSpace and Bibliometrix Package in R Software was drawn to depict the underlying features of viral replication and changing trends of studies, with these analyses including co-citation, density visualization, keyword clustering, and time zone. RESULTS: The keyword frequencies of "replication," ''infection," and ''spike protein" repeatedly appeared in published papers. Coronavirus can promote or inhibit apoptosis, depending on the balance between viral protein and apoptotic factors. When the living environment of cells is irreversibly damaged by the virus, cells have to start the apoptosis mechanism to prevent the replication, transmission, and spread of the virus. The replication, assembly and transmission of coronavirus can inhibit cells from entering the apoptosis prematurely with the fusion of spike protein and cell receptor in human. CONCLUSION: Our results indicated that "viral infection," spike protein," and "mutation" might be future research hotspots on coronavirus replication in humans. The attention should be paid to the mutations of S protein and these mutants carrying mutations.

Bi2O2Se-Based Memristor-Aided Logic.

The implementation of two-dimensional materials into memristor architectures has recently been a new research focus by taking advantage of their atomic thickness, unique lattice, and physical and electronic properties. Among the van der Waals family, Bi2O2Se is an emerging ternary two-dimensional layered material with ambient stability, suitable band structure, and high conductivity that exhibits high potential for use in electronic applications. In this work, we propose and experimentally demonstrate a Bi2O2Se-based memristor-aided logic. By carefully tuning the electric field polarity of Bi2O2Se through a Pd contact, a reconfigurable NAND gate with zero static power consumption is realized. To provide more knowledge on NAND operation, a kinetic Monte Carlo simulation is carried out. Because the NAND gate is a universal logic gate, cascading additional NAND gates can exhibit versatile logic functions. Therefore, the proposed Bi2O2Se-based MAGIC can be a promising building block for developing next-generation in-memory logic computers with multiple functions.