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To demonstrate the effects of surface atoms on photoluminescence (PL) and photocatalytic activities of luminescent carbon dots (CDs), we design and tailor the surface groups of CDs with heteroatoms by a facile and effective approach. The coexistence of O and N radicals in CDs results in strong PL while CDs containing O and Cl radicals show high photocatalytic activity. This is attributed to the different degrees and directions of energy band bending from inner to surface induced by O, N, and Cl radicals at the surface of CDs. The coexistence of both upward and downward band bending that are caused by the O and Cl radicals, respectively, in CDs is similar to an internal electronic field that facilitates the separation of electron-hole pairs and carrier migration, leading to high photocatalytic activity. These results may also be used for designing and tailoring optical-electronic properties of carbon nanostructures.

Carbon quantum dots (CQDs) were synthesized by heating various carbon sources in HNO3 solution at reflux, and the effects of HNO3 concentration on the size of the CQDs were investigated. Furthermore, the oxygen-containing surface groups of as-prepared CQDs were selectively reduced by NaBH4 , leading to new surface states. The experimental results show that the sizes of CQDs can be tuned by HNO3 concentration and then influence their photoluminescent behaviors; the photoluminescent properties are related to both the size and surface state of the CQDs, but the photocatalytic activities are determined by surface states alone. The different oxygen-containing groups on the surface of the CQDs can induce different degrees of the band bending upward, which determine the separation and combination of the electron-hole pairs. The high upward band bending, which is induced by C=O and COOH groups, facilitates separation of the electron-hole pairs and then enhances high photocatalytic activity. In contrast, the low upward band bending induced by C-OH groups hardly prevents the electron-hole pairs from surface recombination and then exhibits strong photoluminescence. Therefore, both the photocatalytic activities and optical properties of CQDs can be tuned by their surface states.

KEYWORDS dynamic surface control (DSC), explosion of complexity, extended state observer (ESO), quadrotor unmanned aerial vehicle (UAV), unmeasurable velocity statesRecently, the control of a quadrotor unmanned aerial vehicle (UAV) has received considerable attention from the research community due to its significant characteristics in rapid maneuverability, precise hovering, and low-cost manufacturability with reduced mechanical complexity, thereby providing a well-suited mission platform for a variety of applications from military and civilian scenarios, including small-area monitoring, surveillance, detection in restricted terrains, and reconnaissance and mapping after disasters. [1][2][3] However, how to develop an effective robust flight controller that performs well in practice while ensuring asymptotic stability in theory is still a significant challenge because of the following essential reasons. 4 (i) The quadrotor UAV only 2700 Damping matrices = diag(k x ,k y ,k z ) = diag(0.01, 0.01, 0.01) Nms 2 = diag(k ,k ,k ) = diag(0.012, 0.012, 0.012) Nms 2 J Inertial matrix J = diag(J 1 ,J 2 ,J 3 ) = diag(0.016, 0.016, 0.016) kgm 2 l Distance from each rotor 0.4 m to the center of mass c Force-to-moment factor 0.05

This paper demonstrates a fabrication technology of Ag wrinkled electrodes with application in highly stretchable wireless sensors. Ag wrinkled thin films that were formed by vacuum deposition on top of pre-strained and relaxed polydimethylsiloxane (PDMS) substrates which have been treated using an O2 plasma and a surface chemical functionalization process can reach a strain limit up to 200%, while surface adhesion area can reach 95%. The electrical characteristics of components such as resistors, inductors and capacitors made from such Ag conductors have remained stable under stretching exhibiting low temperature and humidity coefficients. This technology was then demonstrated for wireless wearable electronics using compatible processing with established micro/nano fabrication technology.