A wide area quantum key distribution (QKD) network deployed on communication infrastructures provided by China Mobile Ltd. is demonstrated. Three cities and two metropolitan area QKD networks were ...linked up to form the Hefei-Chaohu-Wuhu wide area QKD network with over 150 kilometers coverage area, in which Hefei metropolitan area QKD network was a typical full-mesh core network to offer all-to-all interconnections, and Wuhu metropolitan area QKD network was a representative quantum access network with point-to-multipoint configuration. The whole wide area QKD network ran for more than 5000 hours, from 21 December 2011 to 19 July 2012, and part of the network stopped until last December. To adapt to the complex and volatile field environment, the Faraday-Michelson QKD system with several stability measures was adopted when we designed QKD devices. Through standardized design of QKD devices, resolution of symmetry problem of QKD devices, and seamless switching in dynamic QKD network, we realized the effective integration between point-to-point QKD techniques and networking schemes.
Multi-omics data are good resources for prognosis and survival prediction; however, these are difficult to integrate computationally. We introduce DeepProg, a novel ensemble framework of ...deep-learning and machine-learning approaches that robustly predicts patient survival subtypes using multi-omics data. It identifies two optimal survival subtypes in most cancers and yields significantly better risk-stratification than other multi-omics integration methods. DeepProg is highly predictive, exemplified by two liver cancer (C-index 0.73-0.80) and five breast cancer datasets (C-index 0.68-0.73). Pan-cancer analysis associates common genomic signatures in poor survival subtypes with extracellular matrix modeling, immune deregulation, and mitosis processes. DeepProg is freely available at https://github.com/lanagarmire/DeepProg.
Twinning and shear bands are two main deformation structures in magnesium alloys at low temperatures, however, the relationship between these two deformation structures is still under debate. To ...clarify their relationship and behaviours at low temperatures, rolling tests to various thickness reductions at room temperature (RT) and liquid nitrogen temperature (LNT) were conducted for AZ31 magnesium alloys. The evolutions of shear bands and twinning, and their interactions with geometrically necessary dislocation (GND), were observed during the RT- and LNT-rolling process. Abundant shear bands, evolving from {101¯1}-{101¯2} double twins (DTWs), were observed in the RT-rolled samples, while a high quantity of twins, including {101¯2} tension twins (TTWs), twin-twin interactions and twinning sequence, were observed in the LNT-rolled samples. More importantly, a rarely observed twinning sequence behaviour, namely primary TTW-TTW interactions→ secondary TTW-TTW interactions, creating a 45° <202¯1¯> misorientation peak, was studied. Abundant GNDs accumulated around these twin-twin interactions, twinning sequence, DTWs and shear bands, while the GND density was low around TTWs. This research delivers a systematic investigation into the deformation structures in Mg alloys during the rolling process from RT to cryogenic temperature and provides insights into the newly discovered twinning sequence and twin-twin interactions.
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•A new twinning sequence, namely primary twin-twin interactions → secondary twin-twin interactions, was discovered.•The rolling at cryogenic temperature was accommodated by tension twins → twin-twin interactions → twinning sequence.•Regarding rolling at room temperature, the deformation was governed by double twins → shear bands.•The geometrically necessary dislocation density was high in twin-twin interactions, twinning sequence and shear bands.
Red blood cells (RBCs) during microcirculation, aging and storage, lose N‐acetylneuraminic acid (NANA) and other biomaterials thereby altering cell structures, some properties and functions. Such ...cell damage very likely underlies the serious adverse effects of blood transfusion. However, a controversy has remained since 1961–1977 as to whether with aging, the RBCs, suffering loss of NANA, do have a decreased charge density. Any correlation between the changes in the cell properties with cell aging is also not clear. Therefore, to remove the ambiguity and uncertainty, we carried out multiparameteric studies on Percoll fractions of blood of 38 volunteers (lightest‐young‐Y‐RBCs, densest‐old‐O‐RBCs, two middle fractions).We found that there were striking differences between the properties of Y‐RBCs and O‐RBCs. The ζ‐potential of Y‐RBCs decreased gradually with aging. Studies in parallel on RBC fractions incubated with both positively charged quantum dots and Sambucus Nigra‐fluorescein isothiocyanate (FITC) along with their ζ‐potentials provide for the first time direct visual evidence about the lesser amount of charge density and NANA on O‐RBCs, and a collinear decrease in their respective ζ‐potentials. Close correlation was found between the surface charge on an aging RBC and its structure and functions, from the cell morphology, the membrane deformability to the intracellular Hb structure and oxidation ability. This quantitative approach not only clarifies the picture but also has implications in biology and medicine.
Paleoanthropologists and vertebrate paleontologists have for decades debated the etiology of tooth wear and its implications for understanding the diets of human ancestors and other extinct mammals. ...The debate has recently taken a twist, calling into question the efficacy of dental microwear to reveal diet. Some argue that endogenous abrasives in plants (opal phytoliths) are too soft to abrade enamel, and that tooth wear is caused principally by exogenous quartz grit on food. If so, variation in microwear among fossil species may relate more to habitat than diet. This has important implications for paleobiologists because microwear is a common proxy for diets of fossil species. Here we reexamine the notion that particles softer than enamel (e.g., silica phytoliths) do not wear teeth. We scored human enamel using a microfabrication instrument fitted with soft particles (aluminum and brass spheres) and an atomic force microscope (AFM) fitted with silica particles under fixed normal loads, sliding speeds, and spans. Resulting damage was measured by AFM, and morphology and composition of debris were determined by scanning electron microscopy with energy-dispersive X-ray spectroscopy. Enamel chips removed from the surface demonstrate that softer particles produce wear under conditions mimicking chewing. Previous models posited that such particles rub enamel and create ridges alongside indentations without tissue removal. We propose that although these models hold for deformable metal surfaces, enamel works differently. Hydroxyapatite crystallites are “glued” together by proteins, and tissue removal requires only that contact pressure be sufficient to break the bonds holding enamel together.
Multicomponent spinel metal-oxide assembled mesoporous microspheres, promising anode materials for Li-ion batteries with superior electrochemical performance, are usually obtained using different ...kinds of precursors followed by high-temperature post-treatments. Nevertheless, high-temperature calcinations often cause primary particles to aggregate and coarsen, which may damage the assembled microsphere architectures, leading to deterioration of electrochemical performance. In this work, binary spinel metal-oxide assembled mesoporous microspheres MnCo2O4 were fabricated by one-step low-temperature solvothermal method through handily utilizing the redox reaction of nitrate and ethanol. This preparation method is calcination-free, and the resulting MnCo2O4 microspheres were surprisingly assembled by nanoparticles and nanosheets. Two kinds of MnCo2O4 crystal nucleus with different exposed facet of (1̅10) and (11̅2̅) could be responsible for the formation of particle-assembled and sheet-assembled microspheres, respectively. Profiting from the self-assembly structure with mesoporous features, MnCo2O4 microspheres delivered a high reversible capacity up to 722 mAh/g after 25 cycles at a current density of 200 mA/g and capacities up to 553 and 320 mAh/g after 200 cycles at a higher current density of 400 and 900 mA/g, respectively. Even at an extremely high current density of 2700 mA/g, the electrode still delivered a capacity of 403 mAh/g after cycling with the stepwise increase of current densities. The preparation method reported herein may provide hints for obtaining various advanced multicomponent spinel metal-oxide assembled microspheres such as CoMn2O4, ZnMn2O4, ZnCo2O4, and so on, for high-performance energy storage and conversion devices.
The non-reciprocity of a Sagnac interferometer provides ultra-high sensitivity for parameter estimation and offers a wide range of applications, especially for optical fiber sensing. In this work, we ...study a new type of non-reciprocity existing in an optical fiber Sagnac interferometer where the polarization dependent loss is taken into consideration. In particular, this non-reciprocity is irrelevant to the physical effects that have been considered in previous studies, which originates from the geometric phases induced by a continuous-weak-measurement. Thus, it has a unique phenomenon of sudden phase transition, which may open a new way for the future design of high precision optical fiber sensors.
Sulfate aerosols exert profound impacts on human and ecosystem health, weather, and climate, but their formation mechanism remains uncertain. Atmospheric models consistently underpredict sulfate ...levels under diverse environmental conditions. From atmospheric measurements in two Chinese megacities and complementary laboratory experiments, we show that the aqueous oxidation of SO₂ by NO₂ is key to efficient sulfate formation but is only feasible under two atmospheric conditions: on fine aerosols with high relative humidity and NH₃ neutralization or under cloud conditions. Under polluted environments, this SO₂ oxidation process leads to large sulfate production rates and promotes formation of nitrate and organic matter on aqueous particles, exacerbating severe haze development. Effective haze mitigation is achievable by intervening in the sulfate formation process with enforced NH₃ and NO₂ control measures. In addition to explaining the polluted episodes currently occurring in China and during the 1952 London Fog, this sulfate production mechanism is widespread, and our results suggest a way to tackle this growing problem in China and much of the developing world.
In the present work, we report for the first time the use of surface functionalized graphene oxide (SGO) with bis(triethoxysilylpropyl)tetrasulfide (BTESPT) as a multi-functional nanofiller for ...natural rubber (NR). Through a facile approach BTESPT molecules are successfully grafted onto the surface of graphene oxide. The resulting SGO can be finely dispersed in NR via solution mixing. It is found that SGO is prominent in improving the mechanical and gas barrier properties of NR at significantly low filler loading. The percolation point of SGO in the nanocomposites takes place at a content of less than 0.1 wt%. With incorporation of as low as 0.3 wt% of SGO, a 100% increase in the tensile strength, a 66% improvement in the tensile modulus and a 48% reduction in the air permeability are achieved without sacrificing the ultimate strain. This remarkable improvement in the mechanical and gas barrier properties of NR nanocomposites at such low filler loading is attributed to the strong interfacial interaction and the molecular-level dispersion of SGO in the NR matrix.
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