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Photocatalytic Oxygen Reduction to H202 from Water and Air Using Cocatalyst-Free Porous Organic Polymers
No full textElectrochemical reconstruction of Ru-based Polyoxometalates into Si, W-codoped RuOx for Acidic Overall Water Splitting
No full textChimeric MOFs: SBU Transformation from Zn-cluster to Fe-cluster and Its Effects on Gas Adsorption and Dye Selectivity
No full textLearning-based reflection-aware virtual point removal for large-scale 3D point clouds
No full text3D point clouds are widely used for robot perception and navigation. LiDAR sensors can provide large scale 3D point clouds (LS3DPC) with a certain level of accuracy in common environment. However, they often generate virtual points as reflection artifacts associated with reflective surfaces like glass planes, which may degrade the performance of various robot applications. In this letter, we propose a novel learning-based framework to remove such virtual points from LS3DPCs. We first project 3D point clouds onto 2D image domain to investigate the distribution of the LiDAR's echo pulses, which is then used as an input to the glass probability estimation network. Moreover, the 3D feature similarity estimation network exploits the deep features to compare the symmetry and geometric similarity between real and virtual points with respect to the estimated glass plane. We provide a LS3DPC dataset with synthetically generated reflection artifacts to train the proposed network. Experimental results show that the proposed method achieves the better performance qualitatively and quantitatively compared with the existing state-of-the-art methods of 3D reflection removal
Feasibility of using high-volume pozzolanic fillers to develop sustainable engineered cementitious composites (ECC)
No full textTo decrease the environmental load caused by the cement production, high volume of supplementary cementitious materials (SCMs) are adopted to prepare the engineered cementitious composites (ECC). This work prepares an eco-friendly ECC mixed with high-volume SCM (HSECC) by incorporating silica fume, fly ash and diatomite powder (DP) to reduce the cement dosage. The mechanical properties, volume deformation, microstructure, and environmental benefit of HSECC are investigated. Experimental results present that with increasing the DP replacement ratio, the compressive strength of the HSECC gradually reduces, whereas its autogenous shrinkage deformation increases. Furthermore, with increasing the DP content, tensile strain capacity and crack number of HSECC increase, but the tensile strength reduces. The tensile strain capacity of HSECC containing 20% DP increases by 67.8% compared with the HSECC without DP. Utilizing DP to replace the cement reduces the amount of hydration production, but it optimizes the pore structure of sample because of the filling effect, pozzolanic reaction and internal curing effect of DP. Moreover, the HSECC containing DP has a lower carbon emission and cost compared to the HSECC without DP. This study gives a new strategy and theoretical support for producing the eco-friendly high-ductility ECC
Lead-carbon batteries for automotive applications: Analyzing negative plate performance under partial state-of-charge cycles
No full textThis study analyzes the cycle performance of negative plate-limited lead-carbon (LC) and lead-acid (LA) cells via a 17.5% depth-of-discharge cycle test. Both cells are above the cycling termination (voltage of 1.6667 V), but their 20-h capacities constantly decreased, revealing a progressing wear-out. The LC electrode relieves the decay shown by lower sulfation, less spatially uneven distribution of PbSO4 on the electrode cross-section, and minor loss of electrode reactivity. These result from the retarded polarization, thus the overpotential of the LC electrode varies in a smaller range and maintains the system at its effective state. This study reveals the improvement due to the carbon-coating by regulating the voltage over-change, thereby decelerating the degradation based on its large surface area and high electrochemical stability. Additionally, the study highlights that the LC electrode's high electrochemical surface can decelerate the potential increase toward the gassing level, thus, lowering the chance for the hydrogen evolution to occur. These findings suggest potential avenues for the LC electrode to maintain the cell at effective operating states based on the controlled voltage change, thereby enhancing the cell performance and lifespan
Solid-body trajectoids shaped to roll along desired pathways
No full textIn everyday life, rolling motion is typically associated with cylindrical (for example, car wheels) or spherical (for example, billiard balls) bodies tracing linear paths. However, mathematicians have, for decades, been interested in more exotically shaped solids such as the famous oloids(1), sphericons(2), polycons(3), platonicons(4) and two-circle rollers(5) that roll downhill in curvilinear paths (in contrast to cylinders or spheres) yet indefinitely (in contrast to cones, Supplementary Video 1). The trajectories traced by such bodies have been studied in detail(6-9), and can be useful in the context of efficient mixing(10,11) and robotics, for example, in magnetically actuated, millimetre-sized sphericon-shaped robots(12,13), or larger sphericon- and oloid-shaped robots translocating by shifting their centre of mass(14,15). However, the rolling paths of these shapes are all sinusoid-like and their diversity ends there. Accordingly, we were intrigued whether a more general problem is solvable: given an infinite periodic trajectory, find the shape that would trace this trajectory when rolling down a slope. Here, we develop an algorithm to design such bodies-which we call 'trajectoids'-and then validate these designs experimentally by three-dimensionally printing the computed shapes and tracking their rolling paths, including those that close onto themselves such that the body's centre of mass moves intermittently uphill (Supplementary Video 2). Our study is motivated largely by fundamental curiosity, but the existence of trajectoids for most paths has unexpected implications for quantum and classical optics, as the dynamics of qubits, spins and light polarization can be exactly mapped to trajectoids and their paths(16)
High-Power Hybrid Solid-State Lithium-Metal Batteries Enabled by Preferred Directional Lithium Growth Mechanism
Get PDFSolid electrolytes are revolutionizing the field of lithium-metal batteries; however, their practical implementa-tion has been impeded by the interfacial instability between lithium metal electrodes and solid electrolytes. While various interlayers have been suggested to address this issue in recent years, long-term stability with repeated lithium deposition/ stripping has been challenging to attain. Herein, we successfully operate a high-power lithium-metal battery by inducing the preferred directional lithium growth with a rationally designed interlayer, which employs (i) crystalline-direction-controlled carbon material providing isotropic lithium transports, with (ii) prelithium deposits that guide the lithium nucleation direction toward the current collector. This combination ensures that the morphology of the interlayer is mechanically robust while regulating the preferred lithium growth underneath the interlayer without disrupting the initial interlayer/electrolyte interface, enhancing the durability of the interface. We illustrate how these material/geometric optimizations are conducted from the thermodynamic considerations, and its applicability is demonstrated for the garnet-type Li7-xLa3-aZr2-bO12 (LLZO) solid electrolytes paired with the capacity cathode. It is shown that a lithium-metal cell with the optimized amorphous carbon interlayer with prelithium deposits exhibits outstanding room-temperature cycling performance (99. 6% capacity retention after 250 cycles), delivering 4.0 mAh cm-2 at 2.5 mA cm-2 without significant degradation of the capacity. The successful long-term operation of the hybrid solid-state cell at room temperature (approximately a cumulative deliverable capacity of over 1000 mAh cm-2) is unprecedented and records the highest performance reported for lithium-metal batteries with LLZO electrolytes until date