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

We report on a new method to produce quasi-oriented α-MoO3 nanobelts on TiO2 coated glass substrates. Using a simple yet efficient wet-chemical method with subsequent calcination, various morphologies of α-MoO3 including oriented nanobelts, rods and platelets were produced. The crystal morphology can be controlled by changing the substrate and/or the process parameters. Some applications of the resulting structures were demonstrated by coating them with TiO2 and carbon. The photocatalytic activity of the TiO2 coated α-MoO3 nanobelts was several times higher than that of the smooth TiO2 coatings prepared on soda-lime glass. A very thin layer (20–30 nm) of carbon coated on nanobelts by sputtering resulted in a highly light absorbing film with an average reflectivity of 4%, while fluorosilane coated nanobelts showed superhydrophobic properties.

Synthesis of quasi-oriented α-MoO3 nanobelts and nanoplatelets on TiO2 coated glass

We report the vertical alignment of propylene carbonate (PC) molecules interacting with Et4N+ and BF4– which are confined in extremely narrow slit pores (w ∼ 0.7 nm) of carbide-derived carbon and pitch-based activated carbon fiber. On the basis of X-ray diffraction (XRD), electron radial distribution function analysis reveals that the nearest PC–PC distance is 0.05–0.06 nm shorter than that in the bulk solution, indicating dense packing of PC molecules in the pores. This confinement effect results from the vertically aligned PC molecules, which are indicated by the reverse Monte Carlo analysis. The ensemble structure of PC molecules in the subnanometer carbon pores will provide better understanding the supercapacitor function.

/pdf/vertically-oriented-propylene-carbonate-molecules-and-38jmr1c20l.pdf

Vertically Oriented Propylene Carbonate Molecules and Tetraethyl Ammonium Ions in Carbon Slit Pores

Material made with atom-thin tubular crystals portends the creation of inventive nanodevices From the Stone Age to the Silicon Age, humans have crafted tools by carving them out of large pieces of material, such as bones or silicon crystals. In the nanotechnology era, scientists began creating—atomic layer by atomic layer—materials, building blocks, structures, or even entire devices that do not exist in nature but offer new combinations of properties. On page 537 of this issue, Xiang et al. (1) report on the synthesis of one-dimensional (1D) van der Waals heterostructures that stack in ways reminiscent of traditional Russian dolls.

Nested hybrid nanotubes

Surface Redox Pseudocapacitance of Partially Oxidized Titanium Carbide MXene in Water-in-Salt Electrolyte

Nanocellular high surface area materials of a carbon material with high surface area that is controllable and which exhibits high conductivity, controllable structure and a precisely controllable pore size and methods for production and use of these materials are provided.

Yury Gogotsi

Papers

Synthesis of quasi-oriented α-MoO3 nanobelts and nanoplatelets on TiO2 coated glass

Vertically Oriented Propylene Carbonate Molecules and Tetraethyl Ammonium Ions in Carbon Slit Pores

Nested hybrid nanotubes

Surface Redox Pseudocapacitance of Partially Oxidized Titanium Carbide MXene in Water-in-Salt Electrolyte

Nanocellular high surface area material and methods for use and production thereof