Three parallel algorithms for classical molecular dynamics are presented. The first assigns each processor a fixed subset of atoms; the second assigns each a fixed subset of inter-atomic forces to compute; the third assigns each a fixed spatial region. The algorithms are suitable for molecular dynamics models which can be difficult to parallelize efficiently—those with short-range forces where the neighbors of each atom change rapidly. They can be implemented on any distributed-memory parallel machine which allows for message-passing of data between independently executing processors. The algorithms are tested on a standard Lennard-Jones benchmark problem for system sizes ranging from 500 to 100,000,000 atoms on several parallel supercomputers--the nCUBE 2, Intel iPSC/860 and Paragon, and Cray T3D. Comparing the results to the fastest reported vectorized Cray Y-MP and C90 algorithm shows that the current generation of parallel machines is competitive with conventional vector supercomputers even for small problems. For large problems, the spatial algorithm achieves parallel efficiencies of 90% and a 1840-node Intel Paragon performs up to 165 faster than a single Cray C9O processor. Trade-offs between the three algorithms and guidelines for adapting them to more complex molecular dynamics simulations are also discussed.

Fast parallel algorithms for short-range molecular dynamics

다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

“Unpaired Image-to-Image Translation using Cycle-Consistent Adversarial Networks”の学習報告

Since the discovery of mechanically exfoliated graphene in 2004, research on ultrathin two-dimensional (2D) nanomaterials has grown exponentially in the fields of condensed matter physics, material science, chemistry, and nanotechnology. Highlighting their compelling physical, chemical, electronic, and optical properties, as well as their various potential applications, in this Review, we summarize the state-of-art progress on the ultrathin 2D nanomaterials with a particular emphasis on their recent advances. First, we introduce the unique advances on ultrathin 2D nanomaterials, followed by the description of their composition and crystal structures. The assortments of their synthetic methods are then summarized, including insights on their advantages and limitations, alongside some recommendations on suitable characterization techniques. We also discuss in detail the utilization of these ultrathin 2D nanomaterials for wide ranges of potential applications among the electronics/optoelectronics, electrocat...

Recent Advances in Ultrathin Two-Dimensional Nanomaterials

BiFeO3 is perhaps the only material that is both magnetic and a strong ferroelectric at room temperature. As a result, it has had an impact on the field of multiferroics that is comparable to that of yttrium barium copper oxide (YBCO) on superconductors, with hundreds of publications devoted to it in the past few years. In this Review, we try to summarize both the basic physics and unresolved aspects of BiFeO3 (which are still being discovered with several new phase transitions reported in the past few months) and device applications, which center on spintronics and memory devices that can be addressed both electrically and magnetically.

Physics and Applications of Bismuth Ferrite

Organolead Halid Perovskites: Organolead Halide Perovskites for Low Operating Voltage Multilevel Resistive Switching (Adv. Mater. 31/2016)

Developing sustainable and clean energy technology is critial to address the current energy and environmental crisis. As an energy carrier, hydrogen has been getting attention due to its abundance, high energy density, and zero carbon emission. Due to the difficulty of hydrogen storage and transport, the electro-oxidation of ammonia shows great potential for renewable energy since it satisfies both energy supply and environmental protection as a carbon-free fuel with high hydrogen content. However, ammonia electro-oxidation is a sluggish reaction and shows low durability. Understanding the complicated mechanism and intermediates is conducive to developing efficient electrocatalysts with high catalytic activity and durability. This review begins with the ammonia oxidation technologies and their principles. The two typical mechanisms for ammonia electro-oxidation, Oswin-Salomon mechanism and Gerischer-Mauerer mechanism, are discussed, and attention to the poisoning species is included. Then, the electrocatalysts for ammonia reaction are classified into Pt-based catalysts and non-noble metal-based catalysts, and their performances are reviewed with various strategies. Based on the progress on the electrochemical ammonia oxidation catalysts, the challenges and future insight on ammonia oxidation reaction are discussed and proposed. 

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Catalysts for electrochemical ammonia oxidation: Trend, challenge, and promise

Despite innovative advances in stent technology, restenosis remains a crucial issue for the clinical implantation of stents. Reactive oxygen species (ROS) are known to potentially accelerate re-endothelialization and lower the risk of restenosis by selectively controlling endothelial cells and smooth muscle cells. Recently, several studies have been conducted to develop biodegradable polymeric stents. As biodegradable polymers are not electrically conductive, double metallic layers are required to constitute a galvanic couple for ROS generation. Here, we report a new biodegradable hybrid material composed of a biodegradable polymer substrate and double anodic/cathodic metallic layers for enhancing re-endothelialization and suppressing restenosis. Pure Zn and Mg films (3 μm thick) were deposited onto poly-l-lactic acid (PLLA) substrates by DC magnetron sputtering, and a long-term immersion test using biodegradable hybrid materials was performed in phosphate-buffered solution (PBS) for 2 weeks. The concentrations of superoxide anions and hydrogen peroxide generated by the corrosion of biodegradable metallic films were monitored every 1 or 2 days. Both superoxide anions and hydrogen peroxide were seamlessly generated even after the complete consumption of the anodic Mg layer. It was confirmed that the superoxide anions and hydrogen peroxide were formed not only by the galvanic corrosion between the anode and cathode layers but also by the corrosion of a single Mg or Zn layer. The corrosion products of the Mg and Zn films in PBS were phosphate, oxide, or chloride of the biodegradable metals. Thus, it is concluded that ROS generation by the corrosion of PLLA-based hybrid materials can be sustained until the exhaustion of the cathode metal layer.

Development of Organic/Inorganic Hybrid Materials for Fully Degradable Reactive Oxygen Species-Releasing Stents for Antirestenosis.

Effect of Fluoropolymer Assisted Transfer on Graphene Doping

Electrocatalytic Reactions In article number 2003990, Soo Young Kim, Ho Won Jang and co-workers review how 2D molecular organic frameworks (MOFs) and covalent organic frameworks (COFs) have been synthesized and developed for several electrocatalytic reactions, including water splitting, the O2 reduction reaction, the CO2 reduction reaction, and N2 reduction reaction. Thanks to their large porosity and highly exposed reaction area, 2D MOFs and COFs have shown distinct advances recently, compared to 3D MOFs and COFs. 

Two‐Dimensional Metal–Organic Frameworks and Covalent–Organic Frameworks for Electrocatalysis: Distinct Merits by the Reduced Dimension (Adv. Energy Mater. 4/2022)

Ho Won Jang

Papers

Organolead Halid Perovskites: Organolead Halide Perovskites for Low Operating Voltage Multilevel Resistive Switching (Adv. Mater. 31/2016)

Catalysts for electrochemical ammonia oxidation: Trend, challenge, and promise

Development of Organic/Inorganic Hybrid Materials for Fully Degradable Reactive Oxygen Species-Releasing Stents for Antirestenosis.

Effect of Fluoropolymer Assisted Transfer on Graphene Doping

Two‐Dimensional Metal–Organic Frameworks and Covalent–Organic Frameworks for Electrocatalysis: Distinct Merits by the Reduced Dimension (Adv. Energy Mater. 4/2022)