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’

Deposits of clastic carbonate-dominated (calciclastic) sedimentary slope systems in the rock record have been identified mostly as linearly-consistent carbonate apron deposits, even though most ancient clastic carbonate slope deposits fit the submarine fan systems better. Calciclastic submarine fans are consequently rarely described and are poorly understood. Subsequently, very little is known especially in mud-dominated calciclastic submarine fan systems. Presented in this study are a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) that reveals a >250 m thick calciturbidite complex deposited in a calciclastic submarine fan setting. Seven facies are recognised from core and thin section characterisation and are grouped into three carbonate turbidite sequences. They include: 1) Calciturbidites, comprising mostly of highto low-density, wavy-laminated bioclast-rich facies; 2) low-density densite mudstones which are characterised by planar laminated and unlaminated muddominated facies; and 3) Calcidebrites which are muddy or hyper-concentrated debrisflow deposits occurring as poorly-sorted, chaotic, mud-supported floatstones. These

Phd by thesis

The invention relates to a system for the optical analysis of a sample (1), said system comprising a modulated laser pump-probe source (2) for analysing the sample and adapted for delivering, from the sample, a reference signal as well as an analysis signal thereof, and a means (5) for analysing said signals for delivering a piece of sample response information, characterised in that the analysis means (5) includes means defining a matrix imager (6, 7) of the reference and analysis signals for delivering corresponding images of said images to an image processing means (8) in order to extract an image of the sample.

System for the optical analysis of a sample

THz pulses with over ten microjoules of energy are generated and used to drive nonlinear material responses. Nonlinear THz coherent spectroscopy and coherent control are illustrated.

THz High Field Generation, THz Coherent Spectroscopy, and THz Coherent Control

Spatiotemporal pulse shaping is used to transform a single femtosecond excitation pulse into a spatially and temporally tailored output which may take the form of many separate beams, each of which has an independently specified time-dependent waveform. Through impulsive stimulated Raman scattering, the separate beams and pulses excite coherent phonon-polaritons and manipulate them as they propagate within the crystalline sample at light-like speeds. Variably delayed probe pulses are expanded to a large size within the sample and projected onto a CCD camera to record real-space images of the propagating responses. The images are used to guide the spatiotemporal pulse shaping and coherent control processes.

http://ieeexplore.ieee.org/iel5/7649/20884/00968978.pdf

Terahertz polaritonics: spatiotemporal imaging, spatiotemporal femtosecond pulse shaping, and spatiotemporal coherent control

We use femtosecond x-ray diffraction to measure the coherent lattice displacements associated with the excitation and propagation of THz phonon polaritons in LiTaO3.

/pdf/lattice-motions-from-thz-phonon-polaritons-measured-with-47e6bhtdhp.pdf

Keith A. Nelson

Papers

System for the optical analysis of a sample

THz High Field Generation, THz Coherent Spectroscopy, and THz Coherent Control

Terahertz polaritonics: spatiotemporal imaging, spatiotemporal femtosecond pulse shaping, and spatiotemporal coherent control

Lattice Motions from THz Phonon-polaritons measured with Femtosecond X-ray Diffraction.

Design of Novel Optical Cavities for Strong Shock Compression