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The amino-functionalization alters the microenvironment over three-dimensional nanosized mesoporous silica spheres, which is beneficial to stabilize and disperse Cu clusters. The catalyst delivers a high performance for the hydrogenation of levulinic acid into γ-valerolactone, achieving a maximum yield of 98% at relatively mild conditions. [Display omitted] • Ultrafine Cu clusters confined into amino-functionalized NMSSs were developed. • The surface amino functionalization is critical to immobilizing Cu clusters. • A prominent LA hydrogenation activity with GVL yield of 98% was achieved. • This work unlocks the potential of Cu cluster catalyst in biomass valorization. The development of noble-metal-free catalysts for upgrading biomass feedstocks to chemicals and fuels remains a crucial and challenging target. Catalytic hydrogenation of biomass-derived levulinic acid (LA) to γ-valerolactone (GVL) is one of the essential reactions for biomass valorization. Herein, we report a confined Cu cluster catalyst, Cu/NMSSs-NH 2 , in which ultrafine Cu nanoclusters are uniformly encapsulated in the channels of amino-functionalized nanosized mesoporous silica spheres (NMSSs-NH 2). The surface amino functionalization of NMSSs plays a critical role in dispersing and stabilizing Cu species. The obtained Cu/NMSSs-NH 2 affords an excellent LA hydrogenation performance, with a GVL yield as high as 98% achieved, much higher than that of unconfined Cu particles in pristine NMSSs (Cu/NMSSs, 42%). Comprehensive characterization studies including X-ray diffraction, transmission electron microscopy, and X-ray photoelectron spectroscopy reveal that the modified microenvironment of NMSSs could not only offer a confined space but also induce an electronic interaction between metal species and the support, which effectively restrains the Cu nanoclusters from aggregation. This study unlocks the potential of inexpensive Cu cluster-based catalysts for the hydrogenation of renewable biomass to high-value chemicals. [ABSTRACT FROM AUTHOR]

In this paper, we propose a scenario-based robust optimization model for the design of a water supply system considering the risk of facility failure, which is represented as an uncertainty set generated by a finite set of scenarios. New facilities are planned to be built to hedge against the possible failure of existing system facilities that would potentially damage the capacity of the system to meet given user demands. The goal is to build facilities that are both cost-effective and make the system robust. The system robustness is defined as the ability to satisfy user demands for every data realization in the uncertainty set. The proposed model is shown to be equivalent to a large-scale mixed-integer linear program that is solved by a Benders decomposition algorithm. Computational results demonstrate the efficiency of the proposed algorithm, and show that substantial improvement in system robustness can be achieved with minimal increase in system cost. [ABSTRACT FROM AUTHOR]

Structural heterogeneity has been proposed as a key intrinsic feature and mechanism underline unique properties and dynamic behavior of metallic glasses; however, it is still challenging in precisely describing and effectively characterizing the atomic-scale heterogeneity in metallic glasses. In this work, we employed the Meissner effect of superconductivity in magnetic susceptibility measurements as a sensitive bulk probe and successfully revealed the three-dimensional structural heterogeneity and its two-way evolution tuned by structural aging or rejuvenation in a La-based metallic glass. Compared with the resistivity measurements which only signal the most superconductive loop in inhomogeneous materials, the diamagnetic susceptibility signal of the Meissner effect maps the volumetric distribution of all superconductive regions and the corresponding structural heterogeneity in metallic glasses with high sensitivity. The experimental results reported in this article can be well interpreted based on a structural model of tunable "soft liquid-like" regions with soft vibration modes mixed with "hard solid-like" regions, validating the heterogeneity models of metallic glasses with new experimental data and approach. • The Meissner effect can be used to uncover the intrinsic structural heterogeneity in superconductive metallic glasses. • The heterogeneity degree and volumetric distribution of metallic glasses can be estimated by the diamagnetic susceptibility. • The diamagnetic susceptibility is susceptible to structural changes caused by aging or rejuvenation of metallic glasses. [ABSTRACT FROM AUTHOR]

Overlapping stents represent a new paradigm in endovascular interventions, especially for complex and wide-necked aneurysms. The low-profile visualized intraluminal support (LVIS) device is a new generation of self-expanding braided stents recently introduced in China for stent-assisted coiling of intracranial aneurysms. We report several cases of intracranial aneurysms coiled using overlapping LVIS stents to evaluate its efficacy and safety. Patients with ruptured intracranial aneurysms treated with double LVIS stents at our center between November 2014 and May 2016 were reviewed. The clinical data and technical results are presented. Ten patients with 15 aneurysms were treated with double LVIS stents, with a 100% technical success rate. No mortality was observed. Immediate angiographic outcome evaluation showed complete occlusion in 13 aneurysms (86.7%) and neck remnants in 2 aneurysms (13.3%). Double LVIS stents are safe and effective in the treatment of intracranial aneurysms, especially complex aneurysms. [ABSTRACT FROM AUTHOR]

Developing efficient catalysts capable of degrading organic dye free of light irradiation is highly interesting from the energy-saving point of view. In this work, we prepared a new Ce(IO 3 ) 4 catalyst by a facile precipitation method. The obtained Ce(IO 3 ) 4 sample showed remarkably superior performance to the reported CeGeO 4 analog in degradation of rhodamine B (RhB), methyl orange (MO) or methylene blue (MB) dyes in the dark at room temperature. The ultraviolet-visible (UV–vis) absorption spectra of dye solution during degradation, the XPS results of Ce(IO 3 ) 4 and the control experiments confirmed that the dye degradation is a catalytic process. The reusability of it was also investigated in the degradation experiments. [ABSTRACT FROM AUTHOR]

Hexagonal silicon (Si-IV) has recently attracted considerable research interest due to its extraordinary optical properties and possibility to convert into a direct semiconductor under strain with great potential for applications. However, the mechanical properties of Si-IV, which are critical for its applications, have not been experimentally studied yet. In this study, combining nanoindentation and in situ high-pressure synchrotron X-ray diffraction, we thoroughly investigated the mechanical properties of Si-IV. The results suggest that the elastic moduli and hardness of Si-IV are close to those of the common diamond cubic silicon. The similar mechanical properties of Si-IV and diamond cubic silicon are beneficial for integrating Si-IV into conventional Si-based devices using similar industrial processing and for its photovoltaic and optoelectronic applications. [Display omitted] [ABSTRACT FROM AUTHOR]