Yang Yang

Bio: Yang Yang is an academic researcher from Chinese Academy of Sciences. The author has contributed to research in topics: Medicine & Computer science. The author has an hindex of 171, co-authored 2644 publications receiving 153049 citations. Previous affiliations of Yang Yang include Zhejiang University & Northwest Normal University.

Creating a Nanospace under an h-BN Cover for Adlayer Growth on Nickel(111).

Abstract: Heterostructures of two-dimensional (2D) atomic crystals have attracted increasing attention, while fabrication of the 2D stacking structures remains a challenge. In this work, we present a route toward formation of 2D heterostructures via confined growth of a 2D adlayer underneath the other 2D overlayer. Taking a hexagonal boron nitride (h-BN) monolayer on Ni(111) as a model system, both epitaxial and nonepitaxial h-BN islands have been identified on the Ni surface. Surface science studies combined with density functional theory calculations reveal that the nonepitaxial h-BN islands interact weakly with the Ni(111) surface, which creates a 2D nanospace underneath the h-BN islands. An additional h-BN or graphene layer can be grown in the space between the nonepitaxial h-BN islands and Ni(111) surface, forming h-BN/h-BN bilayer structures and h-BN/graphene heterostructures. These results suggest that confined growth under 2D covers may provide an effective route to obtain stacks of 2D atomic crystals.

High efficiency microbial electrosynthesis of acetate from carbon dioxide using a novel graphene–nickel foam as cathode

Abstract: BACKGROUND Microbial electrosynthesis (MES) is a biocathode-driven process, producing high-value chemicals, from CO2. However, the low efficiency of the biocathode hinders the MES process efficiency significantly. RESULTS A novel 3D graphene–nickel foam (G-NF) cathode has been fabricated, by hydrothermal approach for the improvement of microbially-catalyzed reduction at the MES cathode. An increase of 1.8 times in the volumetric acetate production rate was obtained, compared with the untreated nickel foam. In MES with G-NF, a volumetric acetate production rate of 3.11 mmol L-1 day-1 has been achieved; 70% of the electrons consumed were recovered and the final acetate concentration reached 5.46 g L-1 within 28 days. CONCLUSION The hierarchical porous G-NF cathode improved bacterial colonization and the efficiency of mass, nutrients and protons transfer due to its 3D composition; the graphene coating considerably increased the effective surface area for microbial adhesion, as well as the electron transfer rate of biofilm in the MES. This study attempted to improve the efficiency of the biocathode, and provides a promising large electrode for large-scale MES devices. © 2017 Society of Chemical Industry

Polymer solution light-emitting devices

Abstract: Traditional conjugated polymer electroluminescent devices are thin-film solid-state devices consisting of a thin polymer film sandwiched between two electrodes. In this letter, we demonstrate the generation of luminescence from polymer solutions in a compact polymer solution configuration. This unique polymer solution light-emitting device (SLED) consists of a thin layer of a polymer solution sandwiched between two transparent indium–tin–oxide/glass substrates. When biased, the device turns on at slightly above the band-gap energy and emits bright luminescence. The emission spectrum is consistent with the photoluminescence spectrum obtained from the polymer solution. We suggest that the mechanism of the SLED is due to the electrogenerated chemiluminescence effect. The SLED combines the advantages of low operating voltage, and easy and low-cost fabrication. The SLED is also a highly transparent emissive device when transparent materials are used for the electrodes and the substrates.

ELUCID. IV. Galaxy Quenching and its Relation to Halo Mass, Environment, and Assembly Bias

Abstract: We examine the quenched fraction of central and satellite galaxies as a function of galaxy stellar mass, halo mass, and the matter density of their large scale environment. Matter densities are inferred from our ELUCID simulation, a constrained simulation of local Universe sampled by SDSS, while halo masses and central/satellite classification are taken from the galaxy group catalog of Yang et al. The quenched fraction for the total population increases systematically with the three quantities. We find that the `environmental quenching efficiency', which quantifies the quenched fraction as function of halo mass, is independent of stellar mass. And this independence is the origin of the stellar mass-independence of density-based quenching efficiency, found in previous studies. Considering centrals and satellites separately, we find that the two populations follow similar correlations of quenching efficiency with halo mass and stellar mass, suggesting that they have experienced similar quenching processes in their host halo. We demonstrate that satellite quenching alone cannot account for the environmental quenching efficiency of the total galaxy population and the difference between the two populations found previously mainly arises from the fact that centrals and satellites of the same stellar mass reside, on average, in halos of different mass. After removing these halo-mass and stellar-mass effects, there remains a weak, but significant, residual dependence on environmental density, which is eliminated when halo assembly bias is taken into account. Our results therefore indicate that halo mass is the prime environmental parameter that regulates the quenching of both centrals and satellites.

Quantifying the relation between the morphology and performance of polymer solar cells using Monte Carlo simulations

Abstract: Morphology is a crucially important factor determining the efficiency of photocurrent generation in bulk heterojunction polymer solar cells. Morphology, which depends on the characteristics of the polymers as well as on the conditions of phase separation, affects the performance of solar cells by influencing the rate of exciton dissociation and the efficiency of charge carrier transport. Using Monte Carlo simulations, we investigate the effects of annealing time on the morphology of phase separation and charge transfer behavior inside the active layers of polymer solar cells. We find that a suitably defined correlation distance is an effective parameter that quantitatively characterizes different morphologies and can be used to establish a direct link with transmission electron microscopy images of real polymer solar cells. Optimal morphologies have been investigated, showing results that are consistent with experimental data.

I and i

Abstract: 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 …

Fast parallel algorithms for short-range molecular dynamics

Abstract: 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.

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

Abstract: 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。

Electronics and optoelectronics of two-dimensional transition metal dichalcogenides.

Abstract: Single-layer metal dichalcogenides are two-dimensional semiconductors that present strong potential for electronic and sensing applications complementary to that of graphene.