Edge optical scattering of two-dimensional materials

Rayleigh scattering has shown powerful abilities to study electron resonances of nanomaterials regardless of the specific shapes. In analogy to Rayleigh scattering, here we demonstrate that edge optical scattering from two-dimensional (2D) materials also has the similar advantage. Our result shows that, in visible spectral range, as long as the lateral size of a 2D sample is larger than 2 {\mu}m, its edge scattering is essentially a knife-edge diffraction, and the intensity distribution of the high-angle scattering in $\mathbf{k}$ space is nearly independent of the lateral size and the shape of the 2D samples. The high-angle edge scattering spectra are purely determined by the intrinsic dielectric properties of the 2D materials. As an example, we experimentally verify this feature in single-layer $MoS_{2}$, in which A and B excitons are clearly detected in the edge scattering spectra, and the scattering images in $\mathbf{k}$ space and real space are consistent with our theoretical model. This study shows that the edge scattering is a highly practical and efficient method for optical studies of various 2D materials as well as thin films with clear edges.Comment: 21 pages, 9 figure

LiDAR point cloud denoising for individual tree extraction based on the Noise4Denoise

The processing of LiDAR point cloud data is of critical importance in the context of forest resource surveys, as well as representing a pivotal element in the realm of forest physiological and ecological studies.Nonetheless, conventional denoising algorithms frequently exhibit deficiencies with regard to adaptability and denoising efficacy, particularly when employed in relation to disparate datasets.To address these issues, this study introduces DEN4, an unsupervised, deep learning-based point cloud denoising algorithm designed to improve the accuracy of single tree segmentation in LiDAR point clouds.DEN4 introduces a multilevel noise separation module that effectively distinguishes between signal and noise, thereby improving the signal-to-noise ratio (SNR) and reducing the error.The experimental results demonstrate that DEN4 significantly outperforms traditional denoising methods in several key metrics, including mean square error (MSE), SNR, Hausdorff distance, and structural similarity index (SSIM).In the 60 sample dataset, DEN4 achieved the best mean and standard deviation on all metrics: Specifically, the MSE mean was found to be 0.0094, with a standard deviation of 0.0008, the SNR mean was 149.1570, with a standard deviation of 0.5628, the Hausdorff mean was 0.8503, with a standard deviation of 0.0947, and the SSIM mean was 0.8399, with a standard deviation of 0.0054. For instance, in the S10 dataset, DEN4 attained a 70.2% diminution in MSE and a 37.8% augmentation in SNR in comparison with PTD.The findings demonstrate the efficacy of DEN4 in multiple forest datasets, its ability to maintain geometric integrity, and its enhanced stability without the necessity for pre-labelled data. The algorithm's superior performance and robustness in diverse forest environments underscores its potential application in single tree segmentation and forest resource management

Evolution and Hotspot Analysis of Ecological Compensation Research in Watersheds

[Objective] The research status of watershed ecological compensation was analyzed and mastered in order to provide a basis for improving the compensation system and promoting watershed ecological protection and high-quality development of river basins in China. [Methods] CiteSpace visualization software, Price's law, and the X index were used to analyze 876 studies collected by CNKI for author co-occurrence, high-frequency keywords, and research topic clustering. [Results] Domestic research on watershed ecological compensation mainly began in 2000, and the annual number of publications showed an upward trend. Research hotspots were highly coupled with national policies and watershed development, mainly including quantitative research on watershed ecological compensation standards, research on the behavior of watershed ecological compensation subjects from the perspective of game theory, and research on watershed ecological compensation mechanisms under the background of ecological protection. According to the evolution characteristics of research topics, three stages could be identified: preliminary exploration (before 2007), rapid development (2007—2017), and consolidation and improvement (from 2018 to 2021). During these time periods, research emphasis changed from theoretical analysis to quantitative analysis of compensation standards under the background of water resource governance. The objective of this research focused on the two major water systems of the Yangtze River basin and the Yellow River basin. Researches on the main stream and important tributaries were carried out alternately and gradually deepened. The researches formed multiple basic scientific research platforms, but there were few high-yield authors and little cross sectoral cooperation. [Conclusion] Over the past 20 years, research in the field of watershed ecological compensation in China has formed a certain theoretical system and research framework. The research topics and hot spots have distinctive characteristics, and the research methods have tended to be systematic and diversified. In the future, theory and application should be combined to explore the dynamic and market-oriented compensation mechanisms suitable for regional characteristics

The Design of Web-Oriented Distributed Post-Flight Data Processing Network System

ITC/USA 2009 Conference Proceedings / The Forty-Fifth Annual International Telemetering Conference and Technical Exhibition / October 26-29, 2009 / Riviera Hotel & Convention Center, Las Vegas, NevadaIt talks about a distributed net-based flight test raw data processing system, web-oriented and application oriented. The system likes a normal one, consists of database servers, web servers and NAS storage server, but with the particular distributed task scheduler servers and the calculation servers. Each type server can be a team. The user can use WEB browser with the help of OCX control to setup his own processing task according to his need, choose which plane, which flight no., and defining the parameters, flight time segments, extracting rate etc to be processed. The system can accomplish the processing using the embedded application middleware, various data processing modules in database, with the scheduler servers and processing servers. The system can meet many users' demand of huge quantity non-structural flight raw data quickly and efficient processing at the short time, ensure the flight data enhanced management, to keep from copying and distributing the great quantity raw data inefficiently and out-of-management.International Foundation for TelemeteringProceedings from the International Telemetering Conference are made available by the International Foundation for Telemetering and the University of Arizona Libraries. Visit http://www.telemetry.org/index.php/contact-us if you have questions about items in this collection

Chirality in metal-based anticancer agents

Chiral metal-based drugs are currently an interesting and rapidly growing field in anticancer research. Here the different chiral metal-based anticancer agents and the extent to which the chiral resolution affects their biological properties are discussed. This review will aid the design of new potent and efficient chiral metal-based anticancer drugs that exploit the unique properties combined with their potential selectivity toward targeted chiral biomolecules.</p