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.

Highly Reversible and Recyclable Absorption under Both Hydrophobic and Hydrophilic Conditions using a Reduced Bulk Graphene Oxide Material

Abstract: A 3D crosslinked reduced bulk graphene oxide material with switchable absorption capability between hydrophobicity and hydrophilicity is achieved by a simple O3 and annealing treatment.

Reaction pathways for the formation of Cu2ZnSn(Se,S)4 absorber materials from liquid-phase hydrazine-based precursor inks

Abstract: Kesterite Cu2ZnSn(Se,S)4 (CZTSSe) is rapidly becoming an important photovoltaic material due to the abundance and industrial compatibility of its constituent elements. Hydrazine-based slurry deposition has taken a leading role in producing high efficiency devices from this material system, outperforming even high vacuum deposition methods. In this paper, we study the reaction mechanisms involved in the overall transformation from the precursor ink to the solid-state framework and finally to the CZTSSe phase during deposition and subsequent thermal treatment. X-ray diffraction and Raman spectroscopy have been employed to track the various stages of the reaction pathway, and to mark the formation and consumption of precursor phases as they interact to form the final material. It was found that drying the precursor ink at room temperature results in the integration of copper and tin chalcogenide complexes to form a bimetallic framework, with hydrazine and hydrazinium molecules as spacers. After mild thermal annealing, the spacers are removed and the Cu2Sn(Se,S)3 + Zn(Se,S) → Cu2ZnSn(Se,S)4 reaction is triggered. This reaction pathway contains far fewer steps than most deposition processes, which typically start with elemental or binary chalcogenides. As the formation of secondary phases such as Cu2−xS, SnSe, and SnSe2 is no longer necessary to produce the final Cu2ZnSn(Se,S)4 phase, the relative simplicity of this formation mechanism is likely beneficial for the performance of the resulting solar cells.

Control of the magnon-photon level attraction in a planar cavity

Abstract: Hybrid circuits uniting charges, spins, and photons in integrated solid-state devices are seen as crucial to the development of information processing. This work reports an on-chip hybrid device based on the strong coupling between a yttrium iron garnet sphere and microwaves in an interferometric setup, which enables the control of both level repulsion and level attraction. In modeling the system, hybrid circuits are generalized by introducing both mutual capacitance/inductance and mutual resistance. The realization of both coherent and dissipative couplings in a planar cavity may open avenues for the design of dissipatively coupled systems for information processing.

On the origin of efficiency roll-off in InGaN-based light-emitting diodes

Abstract: The external quantum efficiency (EQE) of AlInGaN-based light-emitting diodes (LEDs) on sapphire and bulk GaN substrates was measured over a wide range of pulsed currents with small duty cycles. The current dependence of the EQE appeared to be a strong function of the In content but nearly independent of the dislocation density in the active region. The EQE of the InGaN LEDs peaked at very low currents and decreased dramatically at high currents, whereas the AlGaN UV LED attained a saturated EQE as current increases. In contrast to minimal peak shift in the UV LED, a monotonic current-induced blueshift of the peak energy was seen up to 1 kA/cm2 for the InGaN blue and green LEDs. These results suggest that the capture of delocalized carriers by nonradiative recombination centers such as misfit defects is the major nonthermal mechanism of efficiency roll-off in InGaN LEDs.

Phosphorescent light-emitting electrochemical cell

Abstract: Due to the harvest of singlet and triplet excitons, highly-efficient phosphorescent polymer light-emitting diodes have been demonstrated. However, the driving voltage of these devices remains high because of the carrier trapping at the dopant sites. To achieve high power efficiency, a phosphorescent light-emitting electrochemical cell, which consists of bis[2-(2′-benzothienyl)-pyridinato-N,C3′]iridium(acetylacetonate) as the dopant, poly[9,9-bis(3,6-dioxaheptyl)-fluorene-2,7-diyl] as the host polymer, and lithium trifluoromethane sulfonate has been demonstrated in this letter. The turn-on voltage for light emission was as low as the band gap of the host material (2.8 eV). Compared with the light-emitting diode with a similar device structure, a sixfold enhancement in power efficiency has been achieved.

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.