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

A garment includes a supercapacitor and/or heated fabrics including a first conductive yarn knitted to as to form a current collector and a second conductive yarn knitted to as to form an electrode that is in electrical contact with the current collector. The conductive yarns are knitted into a predetermined supercapacitor design having respective electrodes that are not in electrical contact with each other. An electrolyte saturates at least the electrode material either before or after knitting, and an ionically permeable electronic separator allows the electrodes to be in close proximity to each other without being in electrical contact with each other. A heating element may also be formed by knitting at least one of the first and second conductive yarns into a linear resistor or by knitting an insulated conductive yarn into a sheet of fabric. Such a heating element is connected to the supercapacitor via a switch.

Knitted electrochemical capacitors and heated fabrics

Disclosed are nanoporous carbonaceous membranes and related devices, along with associated methods.

Nanoporous carbonaceous membranes and related methods

A new class of low-angle conical carbon crystals has been described and their characteristics are reported here. These carbon nanocones were found in pores of a glassy carbon (GC) along with cylindrical multiwall nanotubes and graphite polyhedral crystals. The largest cones reach 2 to 3 microns in length, although most are in the submicron range. Scanning Electron Microscopy (SEM) reveals cones protruding from the inner pore surfaces with the tips oriented toward the inside of the pores. Transmission Electron Microscopy (TEM) and Selected Area Electron Diffraction (SAED) show that cones are made of thick (up to several hundred layers), highly-ordered graphitic walls. Their tips are graphitic as well, and exhibit a dome-like morphology. These cones also differ from any carbon cones observed earlier in that they have a much smaller apex angle, sometimes less than 3°. Small angle carbon nanocones can potentially be used for probes and field emission elements.

A Novel Class of Carbon Nanocones

It is well-known that room temperature ionic liquids (RTILs) often adopt a charge-separated layered structure, i.e., with alternating cation- and anion-rich layers, at electrified interfaces. However, the dynamic response of the layered structure to temporal variations in applied potential is not well understood. We used in situ, real-time X-ray reflectivity (XR) to study the potential-dependent electric double layer (EDL) structure of an imidazolium-based RTIL on charged epitaxial graphene during potential cycling as a function of temperature. The results suggest that the graphene-RTIL interfacial structure is bistable in which the EDL structure at any intermediate potential can be described by the combination of two extreme-potential structures whose proportions vary depending on the polarity and magnitude of the applied potential. This picture is supported by the EDL structures obtained by fully atomistic molecular dynamics (MD) simulations at various static potentials. The potential-driven transition between the two structures is characterized by an increasing width but with an approximately fixed hysteresis magnitude as a function of temperature. The results are consistent with the coexistence of distinct anion and cation adsorbed structures separated by an energy barrier (~0.15 eV).

Yury Gogotsi

Papers

Knitted electrochemical capacitors and heated fabrics

Nanoporous carbonaceous membranes and related methods

A Novel Class of Carbon Nanocones

Interfacial Ionic Liquids: Connecting Static and Dynamic Structures

Electrochemical Flow Cells: The Electrochemical Flow Capacitor: A New Concept for Rapid Energy Storage and Recovery (Adv. Energy Mater. 7/2012)