In the quest to enhance Zn-air batteries (ZABs) for operating across a wide spectrum of temperatures, synthesizing robust oxygen electrocatalysts is paramount. conventional strategies focusing on orbital hybridization...
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In the quest to enhance Zn-air batteries (ZABs) for operating across a wide spectrum of temperatures, synthesizing robust oxygen electrocatalysts is paramount. conventional strategies focusing on orbital hybridization of d-d and p-d aim to moderate the excessive interaction between the d-band of the transition metal active site and oxygen intermediate, yet often yield suboptimal performance. Herein, an innovative s-block metal modulation is reported to refine the electronic structure and catalytic behavior of co & horbar;Nccatalysts. Employing density functional theory (DFT) calculations, it is revealed that incorporating Mg markedly depresses the d-band center of co sites, thereby fine-tuning the adsorption energy of the oxygen reduction reaction (ORR) intermediate. consequently, the Mg-modified co & horbar;Nccatalyst (Mgco & horbar;Nc) unveils remarkable intrinsic ORR activity with a significantly reduced activation energy (Ea) of 10.0 kJ mol(-1), outstripping the performance of both co & horbar;Nc (17.6 kJ mol(-1)), benchmark Pt/c (15.9 kJ mol(-1)), and many recent reports. Moreover, ZABs outfitted with the finely tuned Mg0.1co0.9 & horbar;Nc realize a formidable power density of 157.0 mW cm(-2), paired with an extremely long cycle life of 1700 h, and an exceptionally minimal voltage gap decay rate of 0.006 mV h(-1). Further, the Mg0.1co0.9 & horbar;Nc-based flexible ZAB presents a mere 2% specificcapacity degradation when the temperature fluctuates from 25 to -20 degrees c, underscoring its robustness and suitability for practical deployment in diverse environmental conditions.
A significant correlation between the in-plane (IP) and out-of-plane (OOP) damage propagation of masonry infills (MIs) is frequently observed after strong earthquakes, posing a serious problem as regards vulnerability...
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A significant correlation between the in-plane (IP) and out-of-plane (OOP) damage propagation of masonry infills (MIs) is frequently observed after strong earthquakes, posing a serious problem as regards vulnerability of public buildings such as schools. The present work is aimed at identifying the effects of different IP and OOP modelling assumptions of MIs on their seismic damage. To this end, the state secondary school De Gasperi-Battaglia in Norcia (Italy), object of monitoring by the Department of civil Protection since 2000, is investigated for the heterogeneity of infill typologies. The school is composed of a basement and three storeys above ground level, with a reinforced concrete (r.c.) framed structure having a long-shaped rectangular plan. Two typologies can be identified in terms of transverse layout of MIs: (i) double-leaf interior partitions, made of hollow clay bricks;(ii) double-leaf exterior infill walls, constituted by facade solid bricks paired with hollow clay bricks. In addition, partial height infills in the longitudinal direction, due to classroom windows, make the columns susceptible to short column effects. MIs are represented by a five-element macro-model predicting both in-plane (IP) and out-of-plane (OOP) behaviour through a horizontal nonlinear truss and four diagonal nonlinear beam elements, respectively. Stiffness and strength values in the OOP direction are also reduced considering the evolution of the IP damage. Three assumptions are investigated for the behaviour of structural MIs: i.e. elastic both IP and OOP;inelastic IP and elastic OOP;inelastic both IP and OOP. Bare and infilled test structures are subjected to biaxial spectrum-compatible accelerograms, to evaluate the IP and OOP damage levels and effectiveness of the OOP simplified verification proposed by seismiccodes.
The c and c++ languages define hundreds of cases as having undefined behavior (UB). These include, for example, corner cases where different cPU architectures disagree on the semantics of an instruction and the langua...
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The c and c++ languages define hundreds of cases as having undefined behavior (UB). These include, for example, corner cases where different cPU architectures disagree on the semantics of an instruction and the language does not want to force a specific implementation (e.g., shift by a value larger than the bitwidth). Another class of UB involves errors that the language chooses not to detect because it would be too expensive or impractical, such as dereferencing out-of-bounds *** there is a common belief within the compiler community that UB enables certain optimizations that would not be possible otherwise, no rigorous large-scale studies have been conducted on this subject. At the same time, there is growing interest in eliminating UB from programming languages to improve *** this paper, we present the first comprehensive study that examines the performance impact of exploiting UB in c and c++ applications across multiple cPU architectures. Using LLVM, a compiler known for its extensive use of UB for optimizations, we demonstrate that, for the benchmarks and UB categories that we evaluated, the end-to-end performance gains are minimal. Moreover, when performance regresses, it can often be recovered through small improvements to optimization algorithms or by using link-time optimizations.
c. Wright Mills's critical work on international relations is well known, but is often dismissed as being unscholarly, reductionist, and overly polemical. However, seeing the work in the context of his earlier car...
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c. Wright Mills's critical work on international relations is well known, but is often dismissed as being unscholarly, reductionist, and overly polemical. However, seeing the work in the context of his earlier career can allow for a new perspective, with Mills's activist views on war and militarism shaped very clearly by his earlier theoretical and political commitments. Mills developed a distinctive political sociological understanding of international politics, theorising the state as a historically-situated structural determinant of international power: a network of elite power that was contextualised by the influence of the socially constructed realities of the international created by elites. Mills's crucial critical contribution was to see the role of the intellectual as criticising these realities through the imaginative reconceptualisation of the world, which he called the 'politics of truth'. The article argues the international politics of truth was not only Mills's distinctive theory of the international, but that it was clearly supported by his early theorisation of the international. A revised view of the importance of Mills's international relations work can help to situate Mills as part of a broader tradition of IR scholarship, a lost lineage of the critical historical and political sociology of the international.
MXenes are a large class of materials that are chemically exfoliated from metal-aluminum-carbon (MAX) bulk crystals into low-dimensional sheets. While many MXenes have been theoretically predicted, the careful balance...
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MXenes are a large class of materials that are chemically exfoliated from metal-aluminum-carbon (MAX) bulk crystals into low-dimensional sheets. While many MXenes have been theoretically predicted, the careful balance required in the exfoliation between breaking the inter-layer bonds without damaging the intra-layer bonds of the sheets has limited synthesis and experimental study. Here, we developed the synthesis of cr2c from its parent cr2Alc MAX phase and showed the etching is optimized using sodium fluoride and hydrogen chloride with a modified minimally intensive layer delamination (mMILD) method in a cold environment of 9 celcius. We further optimized the intercalation and delamination using sonication and washing methods. The resulting cr2ccrystal structure was characterized. These results open up cr2c to experimental study, including of its predicted emergent magnetic properties, and develop guidelines for synthesizing new MXene materials.
An improved high-solid-loading slurry impregnation process was developed to introduce HfB2 particles into a low-density c/c preform efficiently, and precursor infiltration and pyrolysis process was used for densificat...
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An improved high-solid-loading slurry impregnation process was developed to introduce HfB2 particles into a low-density c/c preform efficiently, and precursor infiltration and pyrolysis process was used for densification to obtain a c/c-HfB2-Siccomposite. The microstructure characterization revealed that HfB2 particles uniformly filled the pores in the c/c preform, and Sic well densified the interstices between HfB2 particles and the small pores in the carbon fiber bundles. After being tested, the c/c-HfB2-Siccomposite had a density of 4.07 g/cm3 and a bending strength of 344.8 MPa, and exhibited a non-brittle fracture behavior. After ablation with oxyacetylene flame at 2500 for 120 s, the mass ablation rate and linear ablation rate of the c/c-HfB2-Siccomposite were 0.5 mg/s and 0.415 mu m/s, respectively. The good ablation performance is attributed to the hindering effect of the HfO2 scale on oxygen diffusion at high temperature.
The c-arm is a frequently used imaging technique in trauma surgery and orthopedics for intraoperative imaging both in diagnostics and in the treatment of open and closed reduction and osteosynthesis of fractures. The ...
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The c-arm is a frequently used imaging technique in trauma surgery and orthopedics for intraoperative imaging both in diagnostics and in the treatment of open and closed reduction and osteosynthesis of fractures. The c-arm is operated by radiology technologists/medical technologists for radiology who are experts in the field of radiological imaging and radiation protection.
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