MXenes, a bourgeoning class of 2D transition metal carbides, are of considerable interest in catalysis due to their rich surface chemistry, tunable electronic structures, and thermal stability. Here, ...recent conceptual advances in applying MXenes and their nanocomposites in (photo)electrocatalysis and conventional heterogeneous catalysis are highlighted. In addition, the nature of active sites in the MXene‐based catalysts are discussed and the significance and challenges in the future development of catalysts using MXenes as the platforms are summarized.
MXenes, a bourgeoning class of 2D transition metal carbides, are of considerable interest in catalysis due to their outstanding properties such as rich surface chemistry, tunable bandgap structures, and thermal stability. Here, the catalytic applications of MXenes and MXene‐based catalysts in electrocatalysis, photocatalysis, and conventional heterogeneous catalysis are summarized.
The locations of the fiducial facial landmark points around facial components and facial contour capture the rigid and non-rigid facial deformations due to head movements and facial expressions. They ...are hence important for various facial analysis tasks. Many facial landmark detection algorithms have been developed to automatically detect those key points over the years, and in this paper, we perform an extensive review of them. We classify the facial landmark detection algorithms into three major categories: holistic methods, Constrained Local Model (CLM) methods, and the regression-based methods. They differ in the ways to utilize the facial appearance and shape information. The holistic methods explicitly build models to represent the global facial appearance and shape information. The CLMs explicitly leverage the global shape model but build the local appearance models. The regression based methods implicitly capture facial shape and appearance information. For algorithms within each category, we discuss their underlying theories as well as their differences. We also compare their performances on both controlled and in the wild benchmark datasets, under varying facial expressions, head poses, and occlusion. Based on the evaluations, we point out their respective strengths and weaknesses. There is also a separate section to review the latest deep learning based algorithms. The survey also includes a listing of the benchmark databases and existing software. Finally, we identify future research directions, including combining methods in different categories to leverage their respective strengths to solve landmark detection “in-the-wild”.
<正>The discovery of gravitational waves(GWs)by the LIGO collaboration 1 in 2016 has provided a direct test on the prediction made by Albert Einstein a century ago based on his general theory of ...relativity 2.It has caused a significant influence worldwide on the basic research in science.
We investigate the particle production from thermal gravitational annihilation in the very early universe, which is an important contribution for particles that might not be in thermal equilibrium ...or/and might only have gravitational interaction, such as dark matter (DM). For particles with spin 0,1/2 and 1 we calculate the relevant cross sections through gravitational annihilation and give the analytic formulas with full mass-dependent terms. We find that DM with mass between TeV and 1016 GeV could have the relic abundance that fits the observation, with small dependence on its spin. We also discuss the effects of gravitational annihilation from inflatons. Interestingly, contributions from inflatons could be dominant and have the same power dependence on Hubble parameter of inflation as that from vacuum fluctuation. Also, fermion production from inflaton, in comparison to boson, is suppressed by its mass due to helicity selection.
Nucleic acid (NA) computation has been widely developed in the past years to solve kinds of logic and mathematic issues in both information technologies and biomedical analysis. However, the ...difficulty to integrate non‐NA molecules limits its power as a universal platform for molecular computation. Here, we report a versatile prototype of hybridized computation integrated with both nucleic acids and non‐NA molecules. Employing the conformationally controlled ligand converters, we demonstrate that non‐NA molecules, including both small molecules and proteins, can be computed as nucleic acid strands to construct the circuitry with increased complexity and scalability, and can be even programmed to solve arithmetical calculations within the computational nucleic acid system. This study opens a new door for molecular computation in which all‐NA circuits can be expanded with integration of various ligands, and meanwhile, ligands can be precisely programmed by the nuclei acid computation.
With utilization of conformationally controlled ligand converters, different kinds of non‐nucleic acid molecules, including both small molecules and proteins, can be integrated into nucleic acid computation to construct circuitries with increased complexity and scalability and to even perform algorithmic calculations. This hybridized system establishes a universal platform for molecular computation.
•A skeleton mechanism of ammonia-diesel was innovatively developed.•Ammonia can be applied on Marine engines by using premixed dual-fuel mode.•Combustion and emissions performance are better in ...liquid ammonia supply.•The NOx emissions level with SCR after- treatment can meet Tier III limits.
Aiming to investigate the application feasibility of ammonia in the low-speed two-stroke marine engine theoretically, an ammonia engine model was constructed to evaluate the performance and emissions characteristics of ammonia engine. The model is based on a premixed dual-fuel engine ignited by the pilot fuel (diesel) injected into the prechamber. A skeletal mechanism with reasonable accuracy containing 104 species and 573 reactions was innovatively developed to simulate the combustion process. Meanwhile, the viability and comparison of various ammonia supply methods including liquid and gaseous forms were explored in terms of engine power, escaped and unburned ammonia, NOx and carbon emissions. The result revealed that the ammonia engine, whether supplied in liquid or gaseous form, can achieve typical ship engine load range and thermal efficiency. Whereas, the supply method of liquid ammonia is superior to gaseous ammonia in terms of power, unburned and escaped ammonia, and thermal efficiency.Furthermore, the NOx and CO2 emissions level of ammonia engine was assessed. The NOx emissions of this operation mode can fulfill the Tier Ⅱ emission limit.
Synergistic Pd/Cu catalysis has been utilized in the Sonogashira reaction since 1975. However, this strategy has not received much attention from the organic chemist community until recently. ...Synergistic Pd/Cu catalysis is becoming a proficient method for the development of catalytic reactions, including several new and efficient cross‐coupling reactions. Additionally, several challenging asymmetric reactions, including stereodivergent synthesis, have been discovered by the combined use of a chiral metal catalyst and a second achiral metal catalyst or two chiral metal catalysts. This review provides an overview of this field, with the aims of highlighting both the development of synergistic Pd/Cu catalysis in organic synthesis and the reaction mechanisms involved in this research area.
Synergistic Pd/Cu catalysis is becoming a proficient method for the development of catalytic reactions, including several new and efficient cross‐coupling reactions. Additionally, several challenging asymmetric reactions, including stereodivergent synthesis, have been discovered by the combined use of a chiral metal catalyst and a second achiral metal catalyst or two chiral metal catalysts.
Of the transition metals, Mn has the greatest number of different oxides, most of which have a special tunnel structure that enables bulk redox reactions. The high theoretical capacitance and ...capacity results from a greater number of accessible oxidation states than other transition metals, wide potential window, and the high natural abundance make MnOx species promising electrode materials for energy storage applications. Although MnOx electrode materials have been intensely studied over the past decade, their electrochemical performance is still insufficient for practical applications. Currently, there is a trade‐off between specific capacitance and loading mass. MnOx species have intrinsically poor electrical conductivity, and current structural designs are not sophisticated enough to accommodate enough redox‐active sites. Recent studies have certainly made progress in increasing capacitance through making use of electrically conductive components and controlling the morphology of the MnOx species to expose more surface area. To increase the capacitance of MnOx electrodes to the largest extent without limiting loading mass, further structural design at the nanoscale and manipulation of the electrically conductive component are required. An ideal nanostructure is proposed to guide future research toward closing the gap between achieved and theoretical capacitance, without limiting the loading mass.
The latest development and key issues on MnOx‐based electrodes for energy storage are reviewed. Considerable progress has been made toward the theoretical capacitance/capacity over the past decade. However, there is still a significant gap. Strategies in both structure designs and fabrication controls are elaborated. The future perspectives are discussed, toward fully utilizing the potential of MnOx in high‐performance energy storage.
Autophagy is a conserved bulk degradation and recycling process that plays important roles in multiple biological functions, including inflammatory responses. As an important component of the innate ...immune system, macrophages are involved in defending cells from invading pathogens, clearing cellular debris, and regulating inflammatory responses. During the past two decades, accumulated evidence has revealed the intrinsic connection between autophagy and macrophage function. This review focuses on the role of autophagy, both as nonselective and selective forms, in the regulation of the inflammatory and phagocytotic functions of macrophages. Specifically, the roles of autophagy in pattern recognition, cytokine release, inflammasome activation, macrophage polarization, LC3-associated phagocytosis, and xenophagy are comprehensively reviewed. The roles of autophagy receptors in the macrophage function regulation are also summarized. Finally, the obstacles and remaining questions regarding the molecular regulation mechanisms, disease association, and therapeutic applications are discussed.
The development of a supply chain is of great significance to enterprises. This paper explores the business model of Pagoda from the supply chain system of Pagoda. Based on the supply chain analysis, ...the existence of the supply chain concept is underdeveloped. Supply chain management systems are not sufficient to analyze and make recommendations. The establishment of a fresh supply chain in Pagoda consists of three main aspects: First, the establishment of the supply chain focuses on fresh planting links, from the location of more than 200 fruit planting bases, the establishment of 17 fresh distribution centers, and the source of quality control of fresh produce. Second, establish multifaceted fresh fruit grading criteria to improve fruit quality, strengthen quality consistency, and build brands. Widen the brand premium and gross profit space, laying the foundation; Third, on the one hand, it strengthens the scale of the direct fresh-picking base, and, on the other hand, the single-product brand thinking operation further expands the company’s differentiated pricing space. Through its internal development and external capabilities, Pagoda influences and manages the entire industry chain, from fruit cultivation to retail. Pagoda is also directly involved in the plantation to ensure the production of high-quality fruit, implementing professional or standardized quality management throughout the industry chain.
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