The selection and design of modern high-performance structural engineering materials is driven by optimizing combinations of mechanical properties such as strength, ductility, toughness, elasticity and requirements for predictable and graceful (non-catastrophic) failure in service. Highly processable bulk metallic glasses (BMGs) are a new class of engineering materials and have attracted significant technological interest. Although many BMGs exhibit high strength and show substantial fracture toughness, they lack ductility and fail in an apparently brittle manner in unconstrained loading geometries. For instance, some BMGs exhibit significant plastic deformation in compression or bending tests, but all exhibit negligible plasticity (<0.5% strain) in uniaxial tension. To overcome brittle failure in tension, BMG-matrix composites have been introduced. The inhomogeneous microstructure with isolated dendrites in a BMG matrix stabilizes the glass against the catastrophic failure associated with unlimited extension of a shear band and results in enhanced global plasticity and more graceful failure. Tensile strengths of approximately 1 GPa, tensile ductility of approximately 2-3 per cent, and an enhanced mode I fracture toughness of K(1C) approximately 40 MPa m(1/2) were reported. Building on this approach, we have developed 'designed composites' by matching fundamental mechanical and microstructural length scales. Here, we report titanium-zirconium-based BMG composites with room-temperature tensile ductility exceeding 10 per cent, yield strengths of 1.2-1.5 GPa, K(1C) up to approximately 170 MPa m(1/2), and fracture energies for crack propagation as high as G(1C) approximately 340 kJ m(-2). The K(1C) and G(1C) values equal or surpass those achievable in the toughest titanium or steel alloys, placing BMG composites among the toughest known materials.

The FLUXNET2015 dataset provides ecosystem-scale data on CO 2 , water, and energy exchange between the biosphere and the atmosphere, and other meteorological and biological measurements, from 212 sites around the globe (over 1500 site-years, up to and including year 2014). These sites, independently managed and operated, voluntarily contributed their data to create global datasets. Data were quality controlled and processed using uniform methods, to improve consistency and intercomparability across sites. The dataset is already being used in a number of applications, including ecophysiology studies, remote sensing studies, and development of ecosystem and Earth system models. FLUXNET2015 includes derived-data products, such as gap-filled time series, ecosystem respiration and photosynthetic uptake estimates, estimation of uncertainties, and metadata about the measurements, presented for the first time in this paper. In addition, 206 of these sites are for the first time distributed under a Creative Commons (CC-BY 4.0) license. This paper details this enhanced dataset and the processing methods, now made available as open-source codes, making the dataset more accessible, transparent, and reproducible.

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We report the unusual glass-forming ability (GFA) of a family of Cu-based alloys, Cu 46 Zr 47ÿx Al 7 Y x (0 < x 10, in at. %), and investigate the origin of this unique property. By an injection mold casting method, these alloys can be readily solidified into amorphous structures with the smallest dimension ranging from 4 mm up to 1 cm without detectable crystallinity. Such superior GFA is found primarily due to the alloying effect of Y, which lowers the alloy liquidus temperature and brings the composition closer to a quaternary eutectic. Other beneficial factors including appropriate atomic-size mismatch and large negative heat of mixing among constituent elements are also discussed. DOI: 10.1103/PhysRevLett.92.245504 PACS numbers: 61.43.Dq, 61.10.Nz, 65.60.+a, 81.05.Kf Bulk amorphous alloys (also known as BMGs: bulk metallic glasses) have been drawing increasing attention in recent years due to their scientific and engineering significance [1,2]. A great deal of effort in this area has been devoted to developing BMGs in different alloy systems. BMGs based on certain late transition metals (e.g., Fe, Co, Ni, Cu) have many potential advantages over those based on early transition metals. These include even higher strength and elastic moduli, and lower materials cost, to name a few, which are highly preferable for a broad application of BMGs as engineering materials. Nevertheless, these ordinary-late-transition-metal-based BMGs generally have quite limited glass-forming ability (GFA). Their favored single-amorphous-phase structures get compromised and undesired first-order phase transitions start to intervene once their casting thickness (or diameter) exceeds a critical value 5 mm (or lower) [3][4][5][6][7][8][9][10][11]. In contrast, this critical value of thickness for many early-transition-metal-based BMGs to sustain their fully glassy structures can reach as high as several centimeters [12 -15].Very recently, BMGs have surprisingly been found in the binary Cu-Zr system by several groups [10,11,16,17], among which Cu 46 Zr 54 has a critical casting thickness up to 2 mm, highest within its local compositional vicinity [16]. The discovery of these binary BMGs strongly suggests that even higher GFA may be achievable in Cubased alloys by appropriately introducing additional alloying elements. As a matter of fact, Inoue et al. reported earlier [18] that the critical casting thickness of certain ternary Cu-based alloys in a Cu-Zr-Al system is 3 mm. Following the ''confusion principle'' proposed by Greer [19], we further examined the effects of other alloying elements on the GFA of a preselected ternary alloy Cu 46 Zr 47 Al 7 (''matrix alloy'' in the following context). In this Letter, we report a series of quaternary Cubased alloys, Cu 46 Zr 47ÿx Al 7 Y x (0 < x 10, in at. %), which possess unusually high GFA. The amorphous structure of a representative alloy Cu 46 Zr 42 Al 7 Y 5 can be readily obtained even when the casting diameter exceeds 1 cm.The possible mechanisms involved in the achievement of this unusu...

The COVID-19 pandemic has accounted for millions of infections and hundreds of thousand deaths worldwide in a short-time period. The patients demonstrate a great diversity in clinical and laboratory manifestations and disease severity. Nonetheless, little is known about the host genetic contribution to the observed interindividual phenotypic variability. Here, we report the first host genetic study in the Chinese population by deeply sequencing and analyzing 332 COVID-19 patients categorized by varying levels of severity from the Shenzhen Third People’s Hospital. Upon a total of 22.2 million genetic variants, we conducted both single-variant and gene-based association tests among five severity groups including asymptomatic, mild, moderate, severe, and critical ill patients after the correction of potential confounding factors. Pedigree analysis suggested a potential monogenic effect of loss of function variants in GOLGA3 and DPP7 for critically ill and asymptomatic disease demonstration. Genome-wide association study suggests the most significant gene locus associated with severity were located in TMEM189–UBE2V1 that involved in the IL-1 signaling pathway. The p.Val197Met missense variant that affects the stability of the TMPRSS2 protein displays a decreasing allele frequency among the severe patients compared to the mild and the general population. We identified that the HLA-A*11:01, B*51:01, and C*14:02 alleles significantly predispose the worst outcome of the patients. This initial genomic study of Chinese patients provides genetic insights into the phenotypic difference among the COVID-19 patient groups and highlighted genes and variants that may help guide targeted efforts in containing the outbreak. Limitations and advantages of the study were also reviewed to guide future international efforts on elucidating the genetic architecture of host–pathogen interaction for COVID-19 and other infectious and complex diseases.