Production of Two‐Dimensional Nanomaterials via Liquid‐Based Direct Exfoliation

Tremendous efforts have been devoted to the synthesis and application of two‐dimensional (2D) nanomaterials due to their extraordinary and unique properties in electronics, photonics, catalysis, etc., upon exfoliation from their bulk counterparts. One of the greatest challenges that scientists are confronted with is how to produce large quantities of 2D nanomaterials of high quality in a commercially viable way. This review summarizes the state‐of‐the‐art of the production of 2D nanomaterials using liquid‐based direct exfoliation (LBE), a very promising and highly scalable wet approach for synthesizing high quality 2D nanomaterials in mild conditions. LBE is a collection of methods that directly exfoliates bulk layered materials into thin flakes of 2D nanomaterials in liquid media without any, or with a minimum degree of, chemical reactions, so as to maintain the high crystallinity of 2D nanomaterials. Different synthetic methods are categorized in the following, in which material characteristics including dispersion concentration, flake thickness, flake size and some applications are discussed in detail. At the end, we provide an overview of the advantages and disadvantages of such synthetic methods of LBE and propose future perspectives.     

皮卫星发展展望

随着微纳技术(MNT)及微电子机械系统(MEMS)技术的迅猛发展，卫星朝着集成度高、体积小、质量轻、费用低等方向发展。纳型／皮型卫星技术处于微纳技术及卫星技术发展趋势的最前沿，其应用前景广阔。大力开展纳型／皮型卫星及其关键技术的研究，加快其产业化进程，具有十分重要的意义。     

Nanotechnologies and nanomaterials in welding production (review)

The application of nanotechnologies and nanomaterials in welding production is reviewed. The methods of joining the materials with special properties are investigated; the application of nanopowders in fusion welding and surfacing is discussed. The aim of this procedure is to reduce the effect of stress concentrators (defects) and also of nanolayer films and foils in pressure welding.     

Memory Defect Tolerance Architectures for Nanotechnologies

Memory Built In Self Repair (BISR) is gaining importance since several years. Because defect densities are increasing in future submicron technologies, more advanced solutions may be required for memories to be produced in the upcoming nanometric CMOS process generations. Moreover, this problem will be exacerbated with nanotechnologies, where defect densities are predicted to reach levels of several orders of magnitude higher than in current CMOS technologies. For such defect densities, traditional memory repair is not adequate. This work presents several Built-In Self Repair techniques addressing memories affected by high defect densities as well as an evaluation of the area cost and yield. Statistical fault injection simulations were conducted and the obtained results show that BISR architectures can be used for future high defect technologies, providing close to 100% memory yield, by means of reasonable hardware cost. Thus, the extreme defect densities that many authors predict for nanotechnologies do not represent a show-stopper, at least as concerning memories.     

Temporal Sampling of Enzymes from Live Cells by Localized Electroporation and Quantification of Activity by SAMDI Mass Spectrometry

Measuring changes in enzymatic activity over time from small numbers of cells remains a significant technical challenge. In this work, a method for sampling the cytoplasm of cells is introduced to extract enzymes and measure their activity at multiple time points. A microfluidic device, termed the live cell analysis device (LCAD), is designed, where cells are cultured in microwell arrays fabricated on polymer membranes containing nanochannels. Localized electroporation of the cells opens transient pores in the cell membrane at the interface with the nanochannels, enabling extraction of enzymes into nanoliter‐volume chambers. In the extraction chambers, the enzymes modify immobilized substrates, and their activity is quantified by self‐assembled monolayers for matrix‐assisted laser desorption/ionization (SAMDI) mass spectrometry. By employing the LCAD‐SAMDI platform, protein delivery into cells is demonstrated. Next, it is shown that enzymes can be extracted, and their activity measured without a loss in viability. Lastly, cells are sampled at multiple time points to study changes in phosphatase activity in response to oxidation by hydrogen peroxide. With this unique sampling device and label‐free assay format, the LCAD with SAMDI enables a powerful new method for monitoring the dynamics of cellular activity from small populations of cells.     

Material challenges for solar cells in the twenty-first century: directions in emerging technologies

Photovoltaic generation has stepped up within the last decade from outsider status to one of the important contributors of the ongoing energy transition, with about 1.7% of world electricity provided by solar cells. Progress in materials and production processes has played an important part in this development. Yet, there are many challenges before photovoltaics could provide clean, abundant, and cheap energy. Here, we review this research direction, with a focus on the results obtained within a Japan–French cooperation program, NextPV, working on promising solar cell technologies. The cooperation was focused on efficient photovoltaic devices, such as multijunction, ultrathin, intermediate band, and hot-carrier solar cells, and on printable solar cell materials such as colloidal quantum dots.     

Hacking Science: The ALivE Group's Material Design Methods for Interdisciplinary Environments

Advances in the understanding and processing of materials have historically been one of the foremost drivers of architectural innovation. Today, groundbreaking material developments mainly occur on the nano-scale, and thus lie outside most designers' working knowledge and expertise. Martin Bechthold , Professor of Architectural Technology at the Harvard Graduate School of Design (GSD), and Allen Sayegh , Associate Professor in Practice of Architectural Technology at the GSD, introduce the work of the Adaptive Living Environments (ALivE) group at Harvard University, which seeks to reconcile fundamental material science with architectural design through new modes of interdisciplinary collaboration drawing from contemporary cultures of computation and hacking.     

Modeling and Evaluating Errors Due to Random Clock Shifts in Quantum-Dot Cellular Automata Circuits

This paper analyzes the effect of random phase shifts in the underlying clock signals on the operation of several basic Quantum-dot Cellular Automata (QCA) building blocks. Such phase shifts can result from manufacturing variations or from uneven path lengths in the clocking network. We perform numerical simulations of basic building blocks using two different simulation engines available in the QCADesigner tool. We assume that the phase shifts are characterized by a Gaussian distribution with a mean value of , where i is the clock number and a standard deviation, σ, which is varied in each simulation. Our results indicate that the sensitivity of building blocks to phase shifts depends primarily on the layout while the reliability of all building blocks starts to drop once the standard deviation, σ exceeds 4°. A full adder was simulated to analyze the operation of a circuit featuring a combination of the building blocks considered here. Results are consistent with expectations and demonstrate that the carry output of the full adder is better able to withstand the phase shifts in the clocking network than the Sum output which features a larger combination of the simulated building blocks.

The standard base of Russia for measuring small direct-current in the 10<Superscript>−16</Superscript>–10<Superscript>−9</Superscript> a range

The present state of the standard base of Russia for measuring small direct-current in the 10⁻¹⁶–10⁻⁹ A range is considered, and the metrological characteristics of the state primary and transferable standards are given. __________ Translated from Izmeritel’naya Tekhnika, No. 11, pp. 40–42, November, 2007.