There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

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

抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

Electrochemical capacitors, also called supercapacitors, store energy using either ion adsorption (electrochemical double layer capacitors) or fast surface redox reactions (pseudo-capacitors). They can complement or replace batteries in electrical energy storage and harvesting applications, when high power delivery or uptake is needed. A notable improvement in performance has been achieved through recent advances in understanding charge storage mechanisms and the development of advanced nanostructured materials. The discovery that ion desolvation occurs in pores smaller than the solvated ions has led to higher capacitance for electrochemical double layer capacitors using carbon electrodes with subnanometre pores, and opened the door to designing high-energy density devices using a variety of electrolytes. Combination of pseudo-capacitive nanomaterials, including oxides, nitrides and polymers, with the latest generation of nanostructured lithium electrodes has brought the energy density of electrochemical capacitors closer to that of batteries. The use of carbon nanotubes has further advanced micro-electrochemical capacitors, enabling flexible and adaptable devices to be made. Mathematical modelling and simulation will be the key to success in designing tomorrow's high-energy and high-power devices.

https://hal.archives-ouvertes.fr/hal-02417326/document

Materials for electrochemical capacitors

Due to their versatile properties combined with a favorable strength-to-weight ratio, polymer composites find numerous applications in industry. To further improve their performance, new matrix and reinforcing materials are required. Nanocomposites, containing fillers with particle sizes smaller than 100 nm, hold a great potential to fulfill this demand. At these small length scales, the specific surface area becomes large and polymer–filler interactions, leading to the formation of an interphase with improved properties, can dominate the properties of the composite. Tailoring the properties of the interphase allows for creating new nanocomposite materials. The small size of detonation nanodiamond particles in combination with their superior mechanical properties (diamond properties) and rich surface chemistry makes nanodiamond the superior material for reinforcing and tuning polymer matrices, where it can act through changing the properties of the interphase as well as forming a strong covalent interface with the matrix. This chapter summarizes recent developments in applications of nanodiamond in polymer composites.

Nanodiamonds in composites: polymer chemistry and tribology

1. Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, USA 2. Department of Mechanical and Nuclear Engineering, The Pennsylvania State University, University Park, PA, USA 3. Department of Materials Science and Engineering, and A. J. Drexel Nanomaterials Institute, Drexel University, Philadelphia, PA 19104, USA 4. Computer Science and Mathematics Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA

/pdf/atomic-defects-and-edge-structure-in-single-layer-ti3c2tx-2rxdog4qy5.pdf

Atomic Defects and Edge Structure in Single-layer Ti3C2Tx MXene

The present disclosure is directed to antennas for transmitting and/or receiving electrical signals comprising a MXene composition, devices comprising these antennas, and methods of transmitting and receiving signals using these antennas

Antennas comprising mx-ene films and composites

Pseudocapacitive charge storage with Ti3C2Tx in protic electrolytes has received significant attention. However, other MXene compositions have received less attention so far. Additionally, pseudocapacitance of MXenes has only been reported in acidic electrolytes. Herein, we report on the pseudocapacitance of two vanadium carbide MXenes (V2CTx and V4C3Tx) in various basic electrolytes and sulfuric acid, showing distinct redox couples in their cyclic voltammograms. Freestanding V2CTx film electrodes could deliver gravimetric capacitances above 250 F g–1 in different basic electrolytes with the highest capacitance of 386 F g–1 in 1 M LiOH at 2 mV s–1. Moreover, the cycle life performance showed an increasing capacitance over thousands of cycles (121% of initial capacitance after 60,000 cycles at 10 A g–1 in 6 M KOH). Both materials also exhibit higher capacitances than Ti3C2Tx in 3 M sulfuric acid, with 475 and 284 F g–1 for V2CTx and V4C3Tx, respectively. 

Pseudocapacitance of Vanadium Carbide MXenes in Basic and Acidic Aqueous Electrolytes

The processes that govern fluid transport in pipes are well understood for diameters in the range of micrometers and above. As the diameters diminish (e.g., in the range of a few nanometers), the roles of surface tension and capillarity seem to vary. Thus, the expected promise of carbon nanotubes (CNT, 1-50 nm inner diameter) and nanopipes (CNP, 50-300 nm inner diameter) in technological applications is in urgent need of a well-documented, basic understanding of such forces, especially since no consistent experimental data have been collected until recently. We have investigated the liquid/vapor distribution in nanotubes, the interaction of fluids with the tube walls, and the effect of surface chemistry on liquid behavior in carbon nanotubes. On this basis, we are developing a research program that will thoroughly explore the various aspects of phase interfacing in a number of different nanotube situations. Hydrothermal and CVD-grown CNP and CNT have been examined. Fluid behavior and chemical modification of the tubes have been investigated. This paper will give an overview of experimental studies of behavior of aqueous fluids in carbon nanotubes.

http://www.wseas.us/e-library/conferences/2007athensmech/papers/565-201.pdf

Yury Gogotsi

Papers

Nanodiamonds in composites: polymer chemistry and tribology

Atomic Defects and Edge Structure in Single-layer Ti3C2Tx MXene

Antennas comprising mx-ene films and composites

Pseudocapacitance of Vanadium Carbide MXenes in Basic and Acidic Aqueous Electrolytes

In situ Fluid Studies in Carbon Nanotubes with Diameters Ranging from 1 to 500 nm