Wind energy is considered to be a very promising alternative for power generation because of its tremendous environmental, social, and economic benefits. Electrical power generation from wind energy ...behaves quite differently from that of conventional sources. The fundamentally different operating characteristics of those facilities, therefore, affect the power system reliability in a manner different from that of the conventional systems. This paper is focused on the development of suitable models for wind energy conversion systems, in adequacy assessments of generating systems, using wind energy. These analytical models can be used in the conventional generating system adequacy assessment utilizing analytical or Monte Carlo state-sampling techniques. This paper shows that a five-state wind energy conversion system model can be used to provide a reasonable assessment of the practical power system adequacy studies, using an analytical method, or a state-sampling simulation approach.
Highly Dispersed Co3O4/NPC were rationally prepared from ZIF-67/COF and exhibit excellent OER and LIB property.
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•Highly-dispersed Co3O4/N-doped porous carbons were ...synthesized.•Co3O4/NPC features highly active crystal plane and a large specific surface area.•Co3O4/NPC shows high oxygen evolution reaction and Li-ion battery properties.
Herein we report a facile bottom-up strategy to prepare highly dispersed supported Co3O4 on N-doped Porous Carbon (NPC). Specifically, ZIF-67 (ZIF=Zeolitic Imidazolate Frameworks) microcrystals firstly grow on benzoic acid modified covalent organic framework (BFC), resulting in ZIF-67/COF composite. Subsequently, highly dispersed Co3O4/NPC was obtained via the calcination of ZIF-67/COF. Interestingly, high dispersion of supported Co3O4 is dominated by homogeneous distribution of benzoic acid auchoring on nanoporous COF. More notably, largely triggered by the porosity and confining effect of COF, the resultant Co3O4/NPC features highly active crystal plane and a large specific surface area of 228.0m2/g. Furthermore, the oxygen evolution reaction (OER) measurement results demonstrated that highly dispersed Co3O4/NPC features good catalytic activity (330mV overpotential at 10mA.cm−2, 79mV.dec−1 Tafel slope and mass activity of 130A.g−1 at overpotential of 400mV) and durable stability, superior to currently available counterparts. Moreover, Li-ion battery (LIB) tests also showed high reversible capacity (785mA.h.g−1 at 500mA.g−1) as well as excellent cycling stability and rate performance. Furthermore, Density functional theory (DFT) calculation results demonstrated that these superior OER properties can be attributed to the geometrical and electronic effects of Co3O4/NPC on activation and adsorption/desorption of reaction species.
Besides genome editing, CRISPR-Cas12a has recently been used for DNA detection applications with attomolar sensitivity but, to our knowledge, it has not been used for the detection of small ...molecules. Bacterial allosteric transcription factors (aTFs) have evolved to sense and respond sensitively to a variety of small molecules to benefit bacterial survival. By combining the single-stranded DNA cleavage ability of CRISPR-Cas12a and the competitive binding activities of aTFs for small molecules and double-stranded DNA, here we develop a simple, supersensitive, fast and high-throughput platform for the detection of small molecules, designated CaT-SMelor (CRISPR-Cas12a- and aTF-mediated small molecule detector). CaT-SMelor is successfully evaluated by detecting nanomolar levels of various small molecules, including uric acid and p-hydroxybenzoic acid among their structurally similar analogues. We also demonstrate that our CaT-SMelor directly measured the uric acid concentration in clinical human blood samples, indicating a great potential of CaT-SMelor in the detection of small molecules.
Water waves are one of the most common phenomena in nature, the study of which helps in designing the related industries. In this paper, a generalized (
3
+
1
)-dimensional B-type ...Kadomtsev–Petviashvili equation for the water waves is investigated. Gramian solutions are constructed via the Kadomtsev–Petviashvili hierarchy reduction. Based on the Gramian solutions, we construct the breathers. We graphically analyze the breather solutions and find that the breathers can be reduced to the homoclinic orbits. For the higher-order breather solutions, we obtain the mixed solutions consisting of the breathers and homoclinic orbits. According to the long-wave limit method, rational solutions are constructed. We look at two types of the rational solutions, i.e., the lump and line rogue wave solutions, and give the condition for the lumps being reduced to the line rogue waves. Taking another set of the parameters for the Gramian solutions, we also derive the kinky breather solutions which can be reduced to the kink solitons. For the higher-order kinky breather solutions, we obtain the mixed solutions consisting of the breathers and kink solitons. Combining the breather and rational solutions, we construct two kinds of the hybrid solutions composed of the breathers, lumps, line rogue waves and kink solitons. Characteristics of those hybrid solutions are graphically analyzed and the conditions for the generation of those hybrid solutions are given.
Summary
Aims
Ferroptosis, a new form of iron‐dependent programmed cell death, has been shown to be involved in a range of diseases. However, the role of ferroptosis in traumatic brain injury (TBI) ...has yet to be elucidated. We aimed to investigate whether ferroptosis is induced after TBI and whether the inhibition of ferroptosis would protect against traumatic brain injury in a controlled cortical impact injury (CCI) mouse model.
Methods
After establishing the TBI model in mice, we determined the biochemical and morphological changes associated with ferroptosis, including iron accumulation with Perl's staining, neuronal cell death with Fluoro‐Jade B (FJB) staining, iron metabolism dysfunction with Western blotting, reactive oxygen species (ROS) accumulation with malondialdehyde (MDA) assays, and shrunken mitochondria with transmission electron microscopy. Furthermore, a specific inhibitor of ferroptosis, ferrostatin‐1(fer‐1), was administrated by cerebral ventricular injection after CCI. We used cresyl violet (CV) staining to assess lesion volume, along with the Morris water maze and beam walk test to evaluate long‐term outcomes.
Results
TBI was followed by iron accumulation, dysfunctional iron metabolism, the upregulation of ferroptosis‐related genes, reduced glutathione peroxidase (GPx) activity, and the accumulation of lipid‐reactive oxygen species (ROS). Three days (d) after TBI, transmission electron microscopy (TEM) confirmed that the mitochondria had shrunk a typical characteristic of ferroptosis. Importantly, the administration of Fer‐1 by cerebral ventricular injection significantly reduced iron deposition and neuronal degeneration while attenuating injury lesions and improving long‐term motor and cognitive function.
Conclusion
This study demonstrated an effective method with which to treat TBI by targeting ferroptosis.
•This study provides US Primary Hub airports with benchmarks that can help airports predict the recovery of air travel demand during the COVID-19 pandemic.•This study uses relevant datasets and ...modern analytical methods to address a special airport clustering problem.•This study tests the impact of political preference and geographic locations of airports in determining the recovery of air travel demands at airport levels.
The aviation industry has gone through numerous ups and downs in the past decades. Despite the devastating damage caused by the COVID-19 Pandemic, the aviation industry worldwide still manages to bounce back from the abyss of Q2, 2020, though the speed of recovery is less than satisfactory for most regions. Being aware of the existing literature on air travel demands published since March 2020, this study aims to provide US Primary Hub airports with benchmarks that can help airports predict the recovery of air travel demand during the COVID-19 Pandemic. This study uses the passenger numbers going through airport security checkpoints as the input data and the k-shape clustering algorithm to group airports by their travel demand recovery patterns. The clustering analysis results are presented in a circular dendrogram so that any of the 118 subject airports can quickly locate their benchmarking airports. In this process, the geographic location and hub category of an airport are found to play important roles in determining how local outbound traffic recovers during the Pandemic. We also test if state political preference in the 2020 Presidential Election affects local airport traffic but cannot find any convincing results. The method used by this study can be fed with up-to-date data to produce more timely and reliable results to guide airports and other stakeholders through the recovery journey.
Recently, the emergence of photoactive metal–organic frameworks (MOFs) has given great prospects for their applications as photocatalytic materials in visible‐light‐driven hydrogen evolution. Herein, ...a highly photoactive visible‐light‐driven material for H2 evolution was prepared by introducing methylthio terephthalate into a MOF lattice via solvent‐assisted ligand‐exchange method. Accordingly, a first methylthio‐functionalized porous MOF decorated with Pt co‐catalyst for efficient photocatalytic H2 evolution was achieved, which exhibited a high quantum yield (8.90 %) at 420 nm by use sacrificial triethanolamine. This hybrid material exhibited perfect H2 production rate as high as 3814.0 μmol g−1 h−1, which even is one order of magnitude higher than that of the state‐of‐the‐art Pt/MOF photocatalyst derived from aminoterephthalate.
The in visible MOF: A high performance for visible‐light‐driven H2‐evolution is obtained with a new methylthio‐functionalized metal–organic framework (MOF) photocatalyst that is rationally designed and facilely prepared. This approach opens up a new way to achieve photocatalysis based on MOF materials with high quantum efficiency value (up to 8.9 %) and excellent photoactivity.
In this paper, the hierarchical analysis method is improved based on the expert empowerment method, and the enhanced cluster AHP variable weight comprehensive evaluation model is constructed. Then, ...various elements and important features of music were evaluated perceptually. The correlation between musical elements and emotional appreciation of music art was analyzed through the indexes of harmonic concordance and sound area. The constructed model was used to make a comprehensive evaluation of the application effect of musical elements in the appreciation of music art. The results show that the proportion of people paying attention to the acoustic concordance of melody, tempo, and rhythm in music appreciation is 88.2%, 66.5%, and 75%, respectively. All VIP values for acoustic consonance and the range of tonal regions exceeded 1, which implies that harmonies with more unity and music in higher tonal regions can increase pleasantness perception. This study explores new research paths and provides new theoretical guidance for designing music appreciation teaching.
Conspectus Understanding special stability of numerous ligand-protected gold nanoclusters has always been an active area of research. In the past few decades, several theoretical models, including ...the polyhedral skeletal electron pair theory (PSEPT), superatom complex (SAC), and superatom network (SAN), among others, have been developed for better understanding the stabilities and structures of selected ligand-protected gold nanoclusters. This Account overviews the recently proposed grand unified model (GUM) to offer some new insights into the structures and growth mechanism of nearly all crystallized and predicted ligand-protected gold nanoclusters. The main conceptual advancement of the GUM is identification of the duet and octet rules on the basis of the “big data” of 70+ reported ligand-protected gold nanoclusters. According to the two empirical rules, the cores of the gold nanoclusters can be regarded as being composed of two kinds of elementary blocks (namely, triangle Au3 and tetrahedron Au4), each having 2e closed-shell valence electrons (referred as Au3(2e) and Au4(2e)), as well as the secondary block (icosahedron Au13) with 8e closed-shell valence electrons (referred as Au13(8e)). The two elementary blocks (Au3(2e) and Au4(2e)) and the secondary block (Au13(8e)), from electron counting point of view, can be regarded as an analogy of the highly stable noble-gas atoms of He and Ne, respectively. In each elementary block, the Au atoms exhibit three different valence-electron states (i.e., 1e, 0.5e, and 0e), depending on the type of ligands bonded with these Au atoms. Such three valence-electron states are coined as three “flavors” of gold (namely, bottom, middle, and top “flavor”), a term borrowed from the quark model in the particle physics. Upon application of the duet and octet rules with accounting the three valence states of gold atoms, the Au3(2e), Au4(2e), and Au13(8e) blocks can exhibit 10 (denoted as Δ1–Δ10), 15 (denoted as T1–T15), and 91 (denoted as I1–I91) variants of valence states, respectively. When packing these blocks (with distinct electronic states) together, it forms the gold core of ligand-protected gold nanocluster. As such, the special stabilities of the ligand-protected gold nanoclusters are explained based on the local stability of each block. With GUM, rich and complex structures of ligand-protected gold nanoclusters have been analyzed through structure anatomy. Moreover, the growth of these clusters can be simply viewed as sequential addition of the blocks, rather than as addition of the gold atoms. Another useful application of the GUM is to analyze the structural isomerism. The three types of isomerism for the gold nanoclusters, i.e., core, staple, and complex isomerism, can be considered as an analogy of chain, point, and functional isomerism (known in organic chemistry), respectively. GUM can be applied to predict new clusters, thereby guiding experimental synthesis. Indeed, a number of ligand-protected gold nanoclusters with high stabilities were rationally designed based on the GUM.
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