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

[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

Hydrogen evolution reaction (HER) is a key reaction in hydrogen production through water electrolysis. Platinum (Pt) is the best-known element for HER catalysis. Due to the scarcity of Pt, the development of non-Pt nanocatalysts is desired to achieve broad scale implementations. Here we demonstrate that the PdCu nanostructure containing an intermetallic B2 phase (PdCu-B2) shows a smaller Tafel slope, higher exchange current density, and lower overpotential for HER compared to commercial Pt/C in acidic conditions. Density functional theory (DFT) calculations demonstrate that the improved HER performance in acidic conditions can be attributed to the decrease in the hydrogen binding energy (HBE) on the compressed intermetallic PdCu-B2, shifting the HBE to a more optimal position even compared to Pt/C. In addition, PdCu-B2 exhibits the highest mass activity toward the formic acid oxidation reaction, making it a good anode catalyst candidate for formic-acid-based fuel cells.

Compressed Intermetallic PdCu for Enhanced Electrocatalysis

Chiral molecular intercalation superlattices

Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, USA(Received 29 April 2015; published 10 July 2015)Nanoscale near-infrared optical amplification is important but remains a challenge to achieve. Here wereport a unique design of silicon and erbium silicate core-shell nanowires for high gain submicrometeroptical amplification in the near-infrared communication band. The high refraction index silicon core isused to tightly confine the optical field within the submicron structures, and the single crystalline erbium-ytterbium silicates shell is used as the highly efficient gain medium. Both theoretical and experimentalresults show that, by systematically tuning the core diameter and shell thickness, a large portion of theoptical power can be selectively confined to the erbium silicate shell gain medium to enable a low losswaveguide and high gain optical amplifier. Experimental results further demonstrate that an optimizedcore-shellnanowirecanexhibitanexcellentnetgainupto31 dBmm

High Gain Submicrometer Optical Amplifier at Near-Infrared Communication Band.

A graphene nanomesh includes a sheet of graphene having a plurality of periodically arranged apertures, wherein the plurality of apertures have a substantially uniform periodicity and substantially uniform neck width. The graphene nanomesh can open up a large band gap in a sheet of graphene to create a semiconducting thin film. The periodicity and neck width of the apertures formed in the graphene nanomesh may be tuned to alter the electrical properties of the graphene nanomesh. The graphene nanomesh is prepared with block copolymer lithography. Graphene nanomesh field-effect transistors (FETs) can support currents nearly 100 times greater than individual graphene nanoribbon devices and the on-off ratio, which is comparable with values achieved in nanoribbon devices, can be tuned by varying the neck width. The graphene nanomesh may also be incorporated into FET-type sensor devices.

Graphene nanomesh and method of making the same

Methods and systems for transcoding in a cloud computing platform are disclosed. According to an embodiment, a receiver receives an uploading file by one data block at a time, and stores the received data blocks in various storage modules. Small segment files are then generated when the size of the received data blocks is larger than a threshold. A transcoder transcodes the small segment files from one format such as a bit rate or a frame size to another while the receiver is still receiving a new data block. The transcoded small segment files may be stitched together to form a stitched file, which may be stored in a storage module to be downloaded through a content distribution network (CDN). The transcoded small segment files may be passed to streaming servers for streaming over a network while the receiver is still receiving a new data block of the uploading file.

Yu Huang

Papers

Compressed Intermetallic PdCu for Enhanced Electrocatalysis

Chiral molecular intercalation superlattices

High Gain Submicrometer Optical Amplifier at Near-Infrared Communication Band.

Graphene nanomesh and method of making the same

Cloud-Based Transcoding Platform Systems and Methods