In view of the current problems of low detection accuracy, poor stability and slow detection speed of intelligent vehicle violation detection systems, this article will use human–computer interaction ...and computer vision technology to solve the existing problems. First, the picture data required for the experiment is collected through the Bit Vehicle model dataset, and computer vision technology is used for preprocessing. Then, use Kalman filtering to track and study the vehicle to help better predict the trajectory of the vehicle in the area that needs to be detected; finally, use human–computer interaction technology to build the interactive interface of the system and improve the operability of the system. The violation detection system based on computer vision technology has an accuracy of more than 96.86% for the detection of the eight types of violations extracted, and the average detection is 98%. Through computer vision technology, the system can accurately detect and identify vehicle violations in real time, effectively improving the efficiency and safety of traffic management. In addition, the system also pays special attention to the design of human–computer interaction, provides an intuitive and easy-to-use user interface, and enables traffic managers to easily monitor and manage traffic conditions. This innovative intelligent vehicle violation detection system is expected to help the development of traffic management technology in the future.
The emergence of inorganic–organic hybrid perovskites, a unique class of solution-processable crystalline semiconductors, provides new opportunities for large-area, low-cost and colour-saturated ...light-emitting diodes (LEDs) ideal for display and solid-state lighting applications1. However, the performance of blue perovskite LEDs (PeLEDs)2–11 is far inferior to that of their near-infrared, red and green counterparts12–19, strongly limiting the practicality of the PeLED technology. Here, we demonstrate blue PeLEDs emitting at 483 nm with colour coordinates of (0.094, 0.184) and operating with a peak external quantum efficiency of up to 9.5% at a luminance of 54 cd m–2. The devices have a T50 lifetime of 250 s for an initial brightness of 100 cd m–2. The efficient blue electroluminescence originates from a structure of quantum-confined perovskite nanoparticles embedded within quasi-two-dimensional phases with higher bandgaps, prepared by an antisolvent processing scheme. Our work paves the way towards high-performance PeLEDs in the blue region.
This paper examines the process and internal mechanisms of rural ecommerce industry agglomeration and space reconstruction in metropolitan fringe areas, employing Lirendong village in Guangzhou, ...China, as a case study. Questionnaire surveys and in-depth interviews were utilized and interpreted through the perspective of the actor-network theory. The results show that, in Lirendong village, local government, processing enterprises, rural collectives, e-commerce entrepreneurial talent, and other key actors participate in the pursuit and realization of suburban land value according to their action logic. Actors jointly evolved and constructed the phased industrial processes and space value accumulation process of the e-commerce industry. The reconstruction process experienced three stages, including the government-led agricultural decentralization stage, the market-oriented industrialization stage, and the Internet+ stage dominated by the social network of fellow villagers. The development process has evolved from the dominance of exogenous forces to that of endogenous forces, and, as a result, the types and structures of rural land use are diversified. The spatial texture and rural environment of the traditional country gradually disappeared, forming a diversified mixed form of urban-rural land and mixed-use landscape of industrial, commercial, and residential land in vertical space. At the same time, the social network changed from a single and homogeneous social network of acquaintances to a multiple network of strangers.
Rechargeable zinc‐ion batteries (ZIBs) are emerging as a promising alternative for Li‐ion batteries. However, the developed cathodes suffer from sluggish Zn2+ diffusion kinetics, leading to poor rate ...capability and inadequate cycle life. Herein, an in situ polyaniline (PANI) intercalation strategy is developed to facilitate the Zn2+ (de)intercalation kinetics in V2O5. In this way, a remarkably enlarged interlayer distance (13.90 Å) can be constructed alternatively between the VO layers, offering expediting channels for facile Zn2+ diffusion. Importantly, the electrostatic interactions between the Zn2+ and the host O2−, which is another key factor in hindering the Zn2+ diffusion kinetics, can be effectively blocked by the unique π‐conjugated structure of PANI. As a result, the PANI‐intercalated V2O5 exhibits a stable and highly reversible electrochemical reaction during repetitive Zn2+ insertion and extraction, as demonstrated by in situ synchrotron X‐ray diffraction and Raman studies. Further first‐principles calculations clearly reveal a remarkably lowered binding energy between Zn2+ and host O2−, which explains the favorable kinetics in PANI‐intercalated V2O5. Benefitting from the above, the overall electrochemical performance of PANI‐intercalated V2O5 electrode is remarkable improved, exhibiting excellent high rate capability of 197.1 mAh g−1 at current density of 20 A g−1 with capacity retention of 97.6% over 2000 cycles.
An in situ polyaniline (PANI) intercalation strategy is developed to facilitate the Zn2+ (de)intercalation kinetics in V2O5. PANI not only expands the diffusion channels for facilitating Zn2+ diffusion, but also maintains the structural stability as interlayer pillars. Especially, its unique π‐conjugated structure, serving as electron‐reservoir, simultaneously shields the electrostatic interactions between Zn2+ and V2O5 host.
•(1) S. alterniflora invasion is a worldwide issue which needs detailed soil characterization to maintain coastal security.•(2) Patterns of soils and VNIR spectra were identified from a ...chronosequence of measurements.•(3) Results demonstrate the linkages between soils and VNIR spectra within spatial and temporal scales.•(4) VNIR spectra is an effective tool for the rapid characterization of S. alterniflora soils.
Introduction of exotic Spartina alterniflora (S. alterniflora) is important to re-establish the structure and function of salt marsh ecosystems along the coast of China. Characterization the spatial-temporal patterns of S. alterniflora soils is thus essential for the assessment of the pace of ecosystem development. However, the determination of soil properties by traditional analysis almost impossible achieve a timely detection of soil changes that is generally required by soil monitoring tasks for demonstrating impacts of S. alterniflora invasion. This work focused on the use of visible-near-infrared spectroscopy (VNIRS) for characterizing soils and predicting key physical and chemical soil properties in S. alterniflora areas. A set of soil profiles representing a chronosequence of S. alterniflora invasion was used, comprising 45 samples from 15 sites. The results showed that approximately 20-year of S. alterniflora invasion has altered soil characteristics especially in the topsoil. Changes of soil associated with sampling horizons and ages of S. alterniflora could be distinguishable using soil variables and VNIRS, and high correlations were found between soils and spectra information. The results of predictions showed that predictive accuracy for salinity, pH, clay, the ratio of carbon to nitrogen, organic carbon and calcium carbonate were acceptable, but models for total nitrogen, bulk density, sand and silt were less satisfactory. These results suggested the possibility of VNIRS for the rapid assessment of key physical and chemical soil properties in S. alterniflora areas. This work highlights that VNIRS technique could be taken as a useful tool to investigate soil changes and explore understanding of soil development in S. alterniflora marshes.
Abstract
Graphite, a robust host for reversible lithium storage, enabled the first commercially viable lithium-ion batteries. However, the thermal degradation pathway and the safety hazards of ...lithiated graphite remain elusive. Here, solid-electrolyte interphase (SEI) decomposition, lithium leaching, and gas release of the lithiated graphite anode during heating were examined by in situ synchrotron X-ray techniques and in situ mass spectroscopy. The source of flammable gas such as H
2
was identified and quantitively analyzed. Also, the existence of highly reactive residual lithium on the graphite surface was identified at high temperatures. Our results emphasized the critical role of the SEI in anode thermal stability and uncovered the potential safety hazards of the flammable gases and leached lithium. The anode thermal degradation mechanism revealed in the present work will stimulate more efforts in the rational design of anodes to enable safe energy storage.
Precipitation-hardening high-entropy alloys (PH-HEAs) with good strength-ductility balances are a promising candidate for advanced structural applications. However, current HEAs emphasize ...near-equiatomic initial compositions, which limit the increase of intermetallic precipitates that are closely related to the alloy strength. Here we present a strategy to design ultrastrong HEAs with high-content nanoprecipitates by phase separation, which can generate a near-equiatomic matrix in situ while forming strengthening phases, producing a PH-HEA regardless of the initial atomic ratio. Accordingly, we develop a non-equiatomic alloy that utilizes spinodal decomposition to create a low-misfit coherent nanostructure combining a near-equiatomic disordered face-centered-cubic (FCC) matrix with high-content ductile Ni
Al-type ordered nanoprecipitates. We find that this spinodal order-disorder nanostructure contributes to a strength increase of ~1.5 GPa (>560%) relative to the HEA without precipitation, achieving one of the highest tensile strength (1.9 GPa) among all bulk HEAs reported previously while retaining good ductility (>9%).
Refractory high‐entropy alloys (RHEAs) show promising applications at high temperatures. However, achieving high strengths at elevated temperatures above 1173K is still challenging due to heat ...softening. Using intrinsic material characteristics as the alloy‐design principles, a single‐phase body‐centered‐cubic (BCC) CrMoNbV RHEA with high‐temperature strengths (beyond 1000 MPa at 1273 K) is designed, superior to other reported RHEAs as well as conventional superalloys. The origin of the high‐temperature strength is revealed by in situ neutron scattering, transmission‐electron microscopy, and first‐principles calculations. The CrMoNbV's elevated‐temperature strength retention up to 1273 K arises from its large atomic‐size and elastic‐modulus mismatches, the insensitive temperature dependence of elastic constants, and the dominance of non‐screw character dislocations caused by the strong solute pinning, which makes the solid‐solution strengthening pronounced. The alloy‐design principles and the insights in this study pave the way to design RHEAs with outstanding high‐temperature strength.
Structural materials with exceptional high‐temperature strengths are highly desirable for high‐temperature applications. In this work, three alloy‐design principles of the large atomic‐size and elastic‐modulus mismatches, the insensitive temperature‐dependence of elastic properties, and the dominance of non‐screw dislocations are used to design a CrMoNbV refractory high‐entropy alloy, which exhibits outperforming high‐temperature strengths.
Alloying noble metals with non-noble metals enables high activity while reducing the cost of electrocatalysts in fuel cells. However, under fuel cell operating conditions, state-of-the-art oxygen ...reduction reaction alloy catalysts either feature high atomic percentages of noble metals (>70%) with limited durability or show poor durability when lower percentages of noble metals (<50%) are used. Here, we demonstrate a highly-durable alloy catalyst derived by alloying PtPd (<50%) with 3d-transition metals (Cu, Ni or Co) in ternary compositions. The origin of the high durability is probed by in-situ/operando high-energy synchrotron X-ray diffraction coupled with pair distribution function analysis of atomic phase structures and strains, revealing an important role of realloying in the compressively-strained single-phase alloy state despite the occurrence of dealloying. The implication of the finding, a striking departure from previous perceptions of phase-segregated noble metal skin or complete dealloying of non-noble metals, is the fulfilling of the promise of alloy catalysts for mass commercialization of fuel cells.
Plastic waste is an emerging environmental issue for our society. Critical action to tackle this problem is to upcycle plastic waste as valuable feedstock. Thermochemical conversion of plastic waste ...has received growing attention. Although thermochemical conversion is promising for handling mixed plastic waste, it typically occurs at high temperatures (300–800 °C). Catalysts can play a critical role in improving the energy efficiency of thermochemical conversion, promoting targeted reactions, and improving product selectivity. This Review aims to summarize the state‐of‐the‐art of catalytic thermochemical conversions of various types of plastic waste. First, general trends and recent development of catalytic thermochemical conversions including pyrolysis, gasification, hydrothermal processes, and chemolysis of plastic waste into fuels, chemicals, and value‐added materials were reviewed. Second, the status quo for the commercial implementation of thermochemical conversion of plastic waste was summarized. Finally, the current challenges and future perspectives of catalytic thermochemical conversion of plastic waste including the design of sustainable and robust catalysts were discussed.
Thermochemical conversion: Plastic waste is one of the most critical issues in recent years. Upcycle plastic waste as valuable feedstock has attracted huge attention. This Review summarizes thermochemical conversion methods that can convert plastic waste into energy, chemicals, and value‐added materials. It also highlights the recent development of catalytic thermochemical conversions and the current challenges of catalytic thermochemical conversion of plastic waste.
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