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

QUANTUM ESPRESSO is an integrated suite of computer codes for electronic-structure calculations and materials modeling, based on density-functional theory, plane waves, and pseudopotentials (norm-conserving, ultrasoft, and projector-augmented wave). The acronym ESPRESSO stands for opEn Source Package for Research in Electronic Structure, Simulation, and Optimization. It is freely available to researchers around the world under the terms of the GNU General Public License. QUANTUM ESPRESSO builds upon newly-restructured electronic-structure codes that have been developed and tested by some of the original authors of novel electronic-structure algorithms and applied in the last twenty years by some of the leading materials modeling groups worldwide. Innovation and efficiency are still its main focus, with special attention paid to massively parallel architectures, and a great effort being devoted to user friendliness. QUANTUM ESPRESSO is evolving towards a distribution of independent and interoperable codes in the spirit of an open-source project, where researchers active in the field of electronic-structure calculations are encouraged to participate in the project by contributing their own codes or by implementing their own ideas into existing codes.

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QUANTUM ESPRESSO: a modular and open-source software project for quantum simulations of materials

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

Electronic symmetry breaking in polyatomic molecules. multiconfiguration self-consistent field study of the cyclopropenyl radical c3h3

Activation of Superoxide: Application of Peroxysulfur Intermediates to Organic Synthesis

Poor crystallization and nonradiative recombination at charge transfer interfaces are the main challenges in scaling up mixed-halide perovskite solar cells. If the theoretical open-circuit voltage (VOC) limit is to be achieved, surface defects at the perovskite surface and grain boundaries must be suppressed by passivation. However, it is unavoidable that the passivation material will strongly bind to the perovskite without disrupting the three-dimensional (3D) symmetry. When primary amines are introduced into perovskite precursors, they generate a quasi-2D/3D perovskite with poor photocurrent charge transport properties. To address these constraints, we show that secondary amine (N,N′-dimethyl-1,3-propanediammonium dichloride) can stabilize the bulk phase of perovskite materials, passivating both surfaces and improving the charge carrier lifetime. In particular, a record-high VOC of 1.27 V is achieved at an optimal band gap of 1.63 eV. Our findings will help to guide future efforts to improve the performance and stability of perovskite solar cells. 

Dual Interface Passivation in Mixed-Halide Perovskite Solar Cells by Bilateral Amine

The effects of low net-doped region on the electrical performance of tunnel field-effect transistors (TFETs) are investigated using a TCAD simulation. Compared with previous studies, it is observed that the low net-doped region between the source and pocket can enhance TFET electrical characteristics such as the on-current (<inline-formula> <tex-math notation="LaTeX">$I_{\mathrm {on}}$ </tex-math></inline-formula>) and subthreshold swing (SS) with fine on-off current ratio (<inline-formula> <tex-math notation="LaTeX">$I_{\mathrm {on}}/I_{\mathrm {off}})$ </tex-math></inline-formula>. By optimizing the length of the low net-doped region, <inline-formula> <tex-math notation="LaTeX">$I_{\mathrm {on}}$ </tex-math></inline-formula> increased 14.6 times and SS is reduced by 34.6 % compared with the TFET where the low net-doped region was not considered. Furthermore, guidelines for designing counter-doped pocket are proposed considering the low net-doped region. The local minimum in the conduction band can be used to further improve the on-current and SS performance by adjusting the pocket width and doping concentration. To avoid pocket-induced SS degradation, the pocket doping concentration must also considered when determining the optimal value of the pocket width and vice versa.

Kwang S. Kim

Papers

Electronic symmetry breaking in polyatomic molecules. multiconfiguration self-consistent field study of the cyclopropenyl radical c3h3

Activation of Superoxide: Application of Peroxysulfur Intermediates to Organic Synthesis

Dual Interface Passivation in Mixed-Halide Perovskite Solar Cells by Bilateral Amine

Electrical Characterization by Counter-Doped Pocket Design in Tunnel FETs

Structure and energetics of realistic carbynes: (carbohydroxy)carbyne (hococ)