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.

17% efficiency all-small-molecule organic solar cells enabled by nanoscale phase separation with a hierarchical branched structure

Abstract: For all small-molecule-based organic solar cells (SM-OSCs), it is very challenging to obtain a nanoscale bicontinuous network structure in the active layers, so their power conversion efficiencies (PCEs) still lag behind those of the polymer-based OSCs. In this work, highly efficient SM-OSCs based on a ternary bulk heterojunction (BHJ) layer of B1:BO-2Cl:BO-4Cl were constructed. Ternary cells with the three different BO-2Cl:BO-4Cl weight ratios exhibit higher PCEs than those of B1:BO-2Cl- and B1:BO-4Cl-based binary cells. The results obtained from the transient absorption, time-resolved photoluminescence spectroscopy and device physics analysis reveal that the ternary cell with the optimal composition (B1:BO-2Cl:BO-4Cl = 1 : 0.5 : 0.5 in weight ratio) exhibits faster charge transfer processes, suppressed geminate and non-geminate charge recombination, lower energetic disorder, and higher and more symmetric carrier mobilities than the two binary cells. The transmission electron microscopy measurement results reveal that the nanoscale bicontinuous interpenetrating network with a hierarchical branched structure can be fully evolved in the BHJ layer with the optimal ternary composition. As a result, the optimal ternary cell exhibits a PCE of 17.0% (certified to be 16.9%) and a fill factor of 0.78, which are the highest values obtained for SM-OSCs.

Combining Energy Transfer and Optimized Morphology for Highly Efficient Ternary Polymer Solar Cells

Abstract: Aimed at achieving ideal morphology, illuminating morphology–performance relationship, and further improving the power conversion efficiency (PCE) of ternary polymer solar cells (TSCs), a ternary system is designed based on PTB7-Th:PffBT4T-2OD:PC71BM in this work. The PffBT4T-2OD owns large absorption cross section, proper energy levels, and good crystallinity, which enhances exciton generation, charge dissociation and transport and suppresses charge recombination, thus remarkably increasing the short-circuit current density (Jsc) and fill factor (FF). Finally, a notable PCE of 10.72% is obtained for the TSCs with 15% weight ratio of PffBT4T-2OD. As for the working mechanism, it confirmed the energy transfer from PffBT4T-2OD to PTB7-Th, which contributes to the improved exciton generation. And morphology characterization indicates that the devices with 15% PffBT4T-2OD possess both appropriate domain size (25 nm) and enhanced domain purity. Under this condition, it affords numerous D/A interface for exciton dissociation and good bicontinuous nanostructure for charge transport simultaneously. As a result, the device with 15% PffBT4T-2OD exhibits improved exciton generation, enhanced charge dissociation possibility, elevated hole mobility and inhibited charge recombination, leading to elevated Jsc (19.02 mA cm−2) and FF (72.62%) simultaneously. This work indicates that morphology optimization as well as energy transfer plays a significant role in improving TSC performance.

Polysaccharide-gold nanocluster supramolecular conjugates as a versatile platform for the targeted delivery of anticancer drugs.

Abstract: Through the high affinity of the β-cyclodextrin (β-CD) cavity for adamantane moieties, novel polysaccharide-gold nanocluster supramolecular conjugates (HACD-AuNPs) were successfully constructed from gold nanoparticles (AuNPs) bearing adamantane moieties and cyclodextrin-grafted hyaluronic acid (HACD). Due to their porous structure, the supramolecular conjugates could serve as a versatile and biocompatible platform for the loading and delivery of various anticancer drugs, such as doxorubicin hydrochloride (DOX), paclitaxel (PTX), camptothecin (CPT), irinotecan hydrochloride (CPT-11), and topotecan hydrochloride (TPT), by taking advantage of the controlled association/dissociation of drug molecules from the cavities formed by the HACD skeletons and AuNPs cores as well as by harnessing the efficient targeting of cancer cells by hyaluronic acid. Significantly, the release of anticancer drugs from the drug@HACD-AuNPs system was pH-responsive, with more efficient release occurring under a mildly acidic environment, such as that in a cancer cell. Taking the anticancer drug DOX as an example, cell viability experiments revealed that the DOX@HACD-AuNPs system exhibited similar tumor cell inhibition abilities but lower toxicity than free DOX due to the hyaluronic acid reporter-mediated endocytosis. Therefore, the HACD-AuNPs supramolecular conjugates may possess great potential for the targeted delivery of anticancer drugs.

Extremely stable graphene electrodes doped with macromolecular acid.

Abstract: Although conventional p-type doping using small molecules on graphene decreases its sheet resistance (Rsh), it increases after exposure to ambient conditions, and this problem has been considered as the biggest impediment to practical application of graphene electrodes. Here, we report an extremely stable graphene electrode doped with macromolecular acid (perfluorinated polymeric sulfonic acid (PFSA)) as a p-type dopant. The PFSA doping on graphene provides not only ultra-high ambient stability for a very long time (> 64 days) but also high chemical/thermal stability, which have been unattainable by doping with conventional small-molecules. PFSA doping also greatly increases the surface potential (~0.8 eV) of graphene, and reduces its Rsh by ~56%, which is very important for practical applications. High-efficiency phosphorescent organic light-emitting diodes are fabricated with the PFSA-doped graphene anode (~98.5 cd A-1 without out-coupling structures). This work lays a solid platform for practical application of thermally-/chemically-/air-stable graphene electrodes in various optoelectronic devices.

Field test of the wavelength-saving quantum key distribution network

Abstract: We propose a wavelength-saving topology of quantum key distribution(QKD) network based on passive optical elements, and report the field test of this network on the commercial telecom optical fiber. In this network, 5 nodes are supported with 2 wavelengths, and every two nodes can share secure keys directly at the same time. All QKD links in the network operate at the frequency of 20 MHz. We also characterized the insertion loss and crosstalk effects on the point-to-point QKD system after introducing this QKD network.

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.