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

Thermoelectric materials, which can generate electricity from waste heat or be used as solid-state Peltier coolers, could play an important role in a global sustainable energy solution. Such a development is contingent on identifying materials with higher thermoelectric efficiency than available at present, which is a challenge owing to the conflicting combination of material traits that are required. Nevertheless, because of modern synthesis and characterization techniques, particularly for nanoscale materials, a new era of complex thermoelectric materials is approaching. We review recent advances in the field, highlighting the strategies used to improve the thermopower and reduce the thermal conductivity.

/pdf/complex-thermoelectric-materials-59e25n2qme.pdf

Complex thermoelectric materials.

This study presents a thorough analysis of the electronic structures of the TaPxAs1−x series of compounds, which are of significant interest due to their potential as topological materials. Using a combination of first principles and Wannier‐based tight‐binding methods, this study investigates both the bulk and surface electronic structures of the compounds for varying compositions (x = 0, 0.25, 0.50, 0.75, 1), with a focus on their topological properties. By using chirality analysis, (111) surface electronic structure analysis, and surface Fermi arcs analysis, it is established that the TaPxAs1−x compounds exhibit topologically nontrivial behavior, characterized as Weyl semimetals (WSMs). The effect of spin–orbit coupling (SOC) on the topological properties of the compounds is further studied. In the absence of SOC, the compounds exhibit linearly dispersive fourfold degenerate points in the first Brillouin zone (FBZ) resembling Dirac semimetals. However, the introduction of SOC induces a phase transition to WSM states, with the number and position of Weyl points (WPs) varying depending on the composition of the alloy. For example, TaP has 12 WPs in the FBZ. The findings provide novel insights into the electronic properties of TaPxAs1−x compounds and their potential implications for the development of topological materials for various technological applications.

https://onlinelibrary.wiley.com/doi/pdfdirect/10.1002/qute.202300072

Emerging Weyl Semimetal States in Ternary TaPxAs1−x Alloys: Insights from Electronic and Topological Analysis

This article provides the latest advances from the NSF Advanced Self-powered Systems of Integrated sensors and Technologies (ASSIST) center. The work in the center addresses the key challenges in wearable health and environmental sys- tems by exploring technologies that enable ultra-long battery lifetime, user comfort and wearability, robust medically vali- dated sensor data with value added from multimodal sensing, and access to open architecture data streams. The vison of the ASSIST center is to use nanotechnology to build miniature, self- powered, wearable, and wireless sensing devices that can ena- ble monitoring of personal health and personal environmental exposure and enable correlation of multimodal sensors. These devices can empower patients and doctors to transition from managing illness to managing wellness and create a paradigm shift in improving healthcare outcomes. This article presents the latest advances in high-efficiency nanostructured energy harvesters and storage capacitors, new sensing modalities that consume less power, low power computation, and communi- cation strategies, and novel flexible materials that provide form, function, and comfort. These technologies span a spatial scale ranging from underlying materials at the nanoscale to body worn structures, and the challenge is to integrate them into a unified device designed to revolutionize wearable health applications.

Flexible Technologies for Self-Powered Wearable Health and Environmental Sensing This article addresses the key challenges in wearable health and environmental systems that enable ultra-long battery lifetime, user comfort and wearability.

The effects of electromagnetic fields (EMF) have been widely debated concerning their role in chemical reactions. Reactions, usually took hours or days to complete, have been shown to happen a thousand times faster using EMF radiations. This work develops a formalism and a computer program to evaluate and quantify the EMF effects in chemical reactions. The master equation employed in this program solves the internal energy of the reaction under EMFs while including collisional effects. Multiphoton absorption and emission are made possible with the transitioning energy close to the EMF and are influenced by the dielectric properties of the system. Dimethyl Sulfoxide and Benzyl Chloride are simulated under different EMF intensities. The results show that EMF absorption is closely related to the collisional redistribution of energy in molecules. The EMF effect can be interpreted as a shift of the thermodynamic equilibrium. Under such nonequilibrium energy distribution, the ‘temperature’ is not a reliable quantity for defining the state of the system. GRAPHICAL ABSTRACT

/pdf/emreact-a-tool-for-modelling-electromagnetic-field-induced-3btyj0pm.pdf

EMReact: a tool for modelling electromagnetic field induced effects in chemical reactions by solving the discrete stochastic master equation

Erratum: “ElTools: A tool for analyzing anisotropic elastic properties of the 2D and 3D materials” [Comput. Phys. Commun. 271 (2022) 108195]

Thermal fluctuation of local magnetization in magnetic metals intercoupled with charge carriers and phonons offers a path to enhance thermoelectric performance. The thermopower enhancement by spin fluctuations (SF) has been observed before. However, the crucial evidence for enhancing thermoelectric-figure-of-merit (zT) by SF has not been reported until now. Here we report evidence for such enhancement in the ferromagnetic CrTe. The SF leads to nearly 80% zT enhancement in ferromagnetic CrTe near and below TC~335 K. The ferromagnetism in CrTe is originated from the collective electronic and localized magnetic moments. The field-dependent transport properties demonstrate the profound impact of SF on the electrons and phonons. The SF simultaneously enhances the thermopower and reduces the thermal conductivity. Under an external magnetic field, the enhancement in thermopower is suppressed, and the thermal conductivity is enhanced, evidencing the existence of a strong SF near and below TC. The anomalous thermoelectric transport properties are analyzed based on theoretical models, and a good agreement with experimental data is found. Furthermore, the detailed analysis proves an insignificant impact from spin-wave contribution to the transport properties. This study contributes to the fundamental understanding of spin fluctuation for designing high-performance spin-driven thermoelectric materials.

Daryoosh Vashaee

Papers

Emerging Weyl Semimetal States in Ternary TaPxAs1−x Alloys: Insights from Electronic and Topological Analysis

Flexible Technologies for Self-Powered Wearable Health and Environmental Sensing This article addresses the key challenges in wearable health and environmental systems that enable ultra-long battery lifetime, user comfort and wearability.

EMReact: a tool for modelling electromagnetic field induced effects in chemical reactions by solving the discrete stochastic master equation

Erratum: “ElTools: A tool for analyzing anisotropic elastic properties of the 2D and 3D materials” [Comput. Phys. Commun. 271 (2022) 108195]

Spin Fluctuations Yield zT Enhancement in Ferromagnets.