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

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

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

This paper reviews recent experimental and theoretical progress concerning many-body phenomena in dilute, ultracold gases. It focuses on effects beyond standard weak-coupling descriptions, such as the Mott-Hubbard transition in optical lattices, strongly interacting gases in one and two dimensions, or lowest-Landau-level physics in quasi-two-dimensional gases in fast rotation. Strong correlations in fermionic gases are discussed in optical lattices or near-Feshbach resonances in the BCS-BEC crossover.

/pdf/many-body-physics-with-ultracold-gases-552s10zfdn.pdf

Many-Body Physics with Ultracold Gases

Topological quantum computation has emerged as one of the most exciting approaches to constructing a fault-tolerant quantum computer. The proposal relies on the existence of topological states of matter whose quasiparticle excitations are neither bosons nor fermions, but are particles known as non-Abelian anyons, meaning that they obey non-Abelian braiding statistics. Quantum information is stored in states with multiple quasiparticles, which have a topological degeneracy. The unitary gate operations that are necessary for quantum computation are carried out by braiding quasiparticles and then measuring the multiquasiparticle states. The fault tolerance of a topological quantum computer arises from the nonlocal encoding of the quasiparticle states, which makes them immune to errors caused by local perturbations. To date, the only such topological states thought to have been found in nature are fractional quantum Hall states, most prominently the $\ensuremath{\nu}=5∕2$ state, although several other prospective candidates have been proposed in systems as disparate as ultracold atoms in optical lattices and thin-film superconductors. In this review article, current research in this field is described, focusing on the general theoretical concepts of non-Abelian statistics as it relates to topological quantum computation, on understanding non-Abelian quantum Hall states, on proposed experiments to detect non-Abelian anyons, and on proposed architectures for a topological quantum computer. Both the mathematical underpinnings of topological quantum computation and the physics of the subject are addressed, using the $\ensuremath{\nu}=5∕2$ fractional quantum Hall state as the archetype of a non-Abelian topological state enabling fault-tolerant quantum computation.

Non-Abelian Anyons and Topological Quantum Computation

We construct models of interacting itinerant non-Abelian anyons moving along one-dimensional chains, focusing in particular on itinerant Ising anyon chains, and derive effective anyonic t-J models for the low energy sectors. Solving these models by exact diagonalization, we find a fractionalization of the anyons into charge and (non-Abelian) anyonic degrees of freedom -- a generalization of spin-charge separation of electrons which occurs in Luttinger liquids. A detailed description of the excitation spectrum by combining spectra for charge and anyonic sectors requires a subtle coupling between charge and anyonic excitations at the microscopic level (which we also find to be present in Luttinger liquids), despite the macroscopic fractionalization.

Fractionalization of itinerant anyons in one dimensional chains

–   The   evolution   of   underwater photogrammetry   allows   to   realize   3D   models   of submerged  object  and  structures  throughout  the  use  of rapid  and  efficient  procedures  either  in  terms  of  data acquisition  and  data  processing.  These  procedures  are based   on   solutions   that   are   applied   using   natural control  points,   signalized  markers  and   tie  points;;   the most  common  algorithms  are  based  on  Structure  from Motion  (SfM)  approach.  The  limit  of  these  applications is  sometimes  due  to  the  final  accuracy,  especially  when the  goal  is  a  centimeter  level  of  accuracy.  This  accuracy should   be   necessary   when   dealing   with   a   survey devoted  to  deformation  control  purposes.  An  example is   the   underwater   photogrammetry   for   the determination   of   coral   growth;;   it   is   effectively   a movement  or  a  deformation  detection  issue  where  the geometric   change   is   almost   at   centimeter   or   few centimeters  accuracy  level. When  dealing  with  deformation  control  applications,  a geodetic   network   is   essential   to   realize   a   stable   and unambiguous   reference   frame   through   the   accurate and  permanent  installation  of  Ground  Control  Points (GCPs).   Such   a   network,   indeed,   permits   a   robust reference  frame  for  the  georeferencing  of  images  blocks in  the  different  époques  of  data  acquisition.  Therefore, the   comparison   among   subsequent   photogrammetric restitutions   is  based  on  homogeneous  3D  models   that have   been   oriented   in   the   same   absolute   reference

High accuracy underwater photogrammetric surveying

http://absimage.aps.org/image/MAR07/MWS_MAR07-2006-003852.pdf

Engineering exotic phases for topologically protected quantum computation: Emulating quantum dimer models

We introduce a novel simulated quantum annealing (SQA) algorithm which employs a multispin quantum fluctuation operator. At variance with the usual transverse field, short-range two-spin flip interactions are included in the driver Hamiltonian. A Quantum Monte Carlo algorithm, capable of efficiently simulating large disordered systems, is described and tested. A first application to SQA, on a random square lattice Ising spin glass, reveals that the multi-spin driver Hamiltonian improves upon the usual transverse field. This work paves the way for more systematic investigations using multi-spin quantum fluctuations on a broader range of problems.

http://iopscience.iop.org/article/10.1088/1742-5468/aa6de1/pdf

Quantum Monte Carlo annealing with multi-spin dynamics

By employing quantum mechanical phenomena such as superposition, entanglement, and interference, quantum computers promise to perform certain computations exponentially faster than any classical device. Precise control over these physical systems and proper shielding from unwanted interactions with the environment become more difficult as the space/time volume of the computation grows. Code optimization is thus crucial in order to reduce resource requirements to the greatest extent possible. Besides manual optimization, previous work has successfully adapted classical methods such as constant-folding and common subexpression elimination to the quantum domain. However, such classically-inspired methods fail to exploit certain optimization opportunities that arise due to entanglement. To address this insufficiency, we introduce an optimization methodology which employs Hoare triples in order to identify and exploit these optimization opportunities. We implement the optimizer using the Z3 Theorem Prover and the ProjectQ software framework for quantum computing and show that it is able to reduce the circuit area of our benchmarks by up to 5x.

Matthias Troyer

Papers

Fractionalization of itinerant anyons in one dimensional chains

High accuracy underwater photogrammetric surveying

Engineering exotic phases for topologically protected quantum computation: Emulating quantum dimer models

Quantum Monte Carlo annealing with multi-spin dynamics

Using Hoare logic for quantum circuit optimization.