The utilization of sunlight to drive energy conversion via photocatalysis is a promising approach to pursue a sustainable future. In the past decade, the research of photocatalysts has been shifted from inorganic to abundant organic polymeric catalysts. Polymeric carbon nitride (PCN) has emerged as a promising photocatalyst for solar energy conversion on account of its superior physicochemical properties. However, its practical applications are still hindered by several limitations, including high-charge recombination probability and weak visible-light absorption, etc. As a result of facile structure modifications at the nano-and molecular levels, the structure engineering of PCN has been proven as an efficient solution. This review highlights a panorama of the latest research advancements regarding the structure engineering of PCN at the nano-and molecular scales. A perspective about the challenges and future trends in the structure engineering and applications of PCN is provided at the end of the review.

The cross-coupling of Baylis-Hillman acetate adducts and bis(pinacolato)diboron proceeds readily in high yields in the presence of palladium catalyst to produce 3-substituted-2-alkoxycarbonyl allylboronates. These allylboronates can be transformed to stable allyl trifluoroborate salts by addition of excess aqueous KHF2. Both the allylboronate and allyltrifluoroborate derivatives react with aldehydes to afford functionalized homoallylic alcohols stereoselectively.

The single-molecule break junction technique provides a high-throughput method to explore the charge transport phenomena through a molecular junction at the ultimate scale of a single molecule. The most probable conductance of a molecular junction is normally extracted from histogram generated from repeated and massive break junction data. However, this conventional data analysis method only exhibits general charge transport properties of molecular junctions, and insightful information hidden in those recorded data remains unexplored. Among them, some of the conductance variations corresponding to different molecular junction conformations that occur during the break junction process might easily be overlooked. To accurately extract those hidden events, here we demonstrated a customized spectral clustering method with the evaluation of the Calinski–Harabasz index, which could be employed to analyze a large amount of data and to automatically extract different molecular junction conformations without subjective bias. Our approach was first validated through simulated data sets and was confirmed to be suitable for the product analysis during a chemical reaction. Moreover, using this method, an easily overlooked but unignorable junction conformation was found during the carborane molecular junction measurement, suggesting that spectral clustering with the Calinski–Harabasz index as a criterion offers a promising algorithm for junction conformation analysis in massive break junction data.

We present a system for real-time hand-tracking to drive virtual and augmented reality (VR/AR) experiences. Using four fisheye monochrome cameras, our system generates accurate and low-jitter 3D hand motion across a large working volume for a diverse set of users. We achieve this by proposing neural network architectures for detecting hands and estimating hand keypoint locations. Our hand detection network robustly handles a variety of real world environments. The keypoint estimation network leverages tracking history to produce spatially and temporally consistent poses. We design scalable, semi-automated mechanisms to collect a large and diverse set of ground truth data using a combination of manual annotation and automated tracking. Additionally, we introduce a detection-by-tracking method that increases smoothness while reducing the computational cost; the optimized system runs at 60Hz on PC and 30Hz on a mobile processor. Together, these contributions yield a practical system for capturing a user's hands and is the default feature on the Oculus Quest VR headset powering input and social presence.

This review highlights the latest research advancements regarding the electrochemical energy conversion and storage application from PCN to PCN-derived carbon materials.