Ultracompact polarization multiplexing meta-combiner for augmented reality display.

Augmented reality (AR) display, as a next-generation innovative technology, is revolutionizing the ways of perceiving and communicating by overlaying virtual images onto real-world scenes. However, the current AR devices are often bulky and cumbersome, posing challenges for long-term wearability. Metasurfaces have flexible capabilities of manipulating light waves at subwavelength scales, making them as ideal candidates for replacing traditional optical elements in AR display devices.

Self-focusing and self-splitting properties of partially coherent temporal pulses propagating in dispersive media.

Based on the coherence theory for non-stationary optical fields, we introduce a new class of partially coherent pulse sources with multi-cosine-Gaussian correlated Schell-model (MCGCSM) and derive the analytic expression for the temporally mutual coherence function (TMCF) of an MCGCSM pulse beam when it propagates through dispersive media. The temporally average intensity (TAI) and the temporal degree of coherence (TDOC) of the MCGCSM pulse beams spreading in dispersive media are investigated numerically, respectively. Our results show that over propagation distance, the evolution of pulse beams is from the primary single beam into multiple subpulses or form flat-topped TAI distributions by controlling source parameters.

Fluorescent property of carbon dots extracted from cigarette smoke and the application in bio-imaging.

Cigarette smoke is one of the six major pollution sources in the room air. It contains large number of particles with size less than 10 nm. There exist carbon dots (CDs) in cigarette smoke which have strong fluorescence and with good bio-compatibility and low toxicity.

Preparation and Fluorescent Wavelength Control of Multi-Color Nitrogen-Doped Carbon Nano-Dots.

It is known that, by taking advantage of heteroatom doping, the electronic states and transition channels in carbon nano-dots (CNDs) can be effectively modulated. Thus, the photoluminescence (PL) properties of CNDs can be changed. For potential applications of CNDs as advanced materials for optoelectronic devices, it is important and significant to develop the practical techniques for doping heteroatoms into CNDs.

Controlled direct synthesis of single- to multiple-layer MWW zeolite.

The minimized diffusion limitation and completely exposed strong acid sites of the ultrathin zeolites make it an industrially important catalyst especially for converting bulky molecules. However, the structure-controlled and large-scale synthesis of the material is still a challenge. In this work, the direct synthesis of the single-layer MWW zeolite was demonstrated by using hexamethyleneimine and amphiphilic organosilane as structure-directing agents.

Three new cadinane-type sesquiterpenes from spreng.

Three new cadinane-type sesquiterpenes, eupatorinones (-), along with seven known compounds (), were obtained from the petroleum ether fraction of 95% ethanol extract of Spreng. The structures of these new compounds were determined by NMR, MS, and ECD spectra analysis. The configuration of compound was established by quantum chemical calculations of NMR chemical shifts and ECD spectra, that matched the experimental data.

Propagation of orbital angular momentum modes carried by hollow vortex Gaussian beams in anisotropic atmospheric turbulence.

We establish the propagation model of orbital angular momentum (OAM) modes carried by hollow vortex Gaussian (hvG) beams propagating in anisotropic atmospheric turbulence. Effects of light source parameters and atmospheric conditions on the OAM mode propagation performance are investigated in detail. The findings indicate the hvG beam with a smaller OAM quantum number, a larger beam order, or a longer source wavelength has more robust resistance to atmospheric turbulence interference.

Aerobic and nitrite-dependent methane-oxidizing microorganisms in sediments of freshwater lakes on the Yunnan Plateau.

Both aerobic methane-oxidizing bacteria (MOB) and nitrite-dependent anaerobic methane oxidation (n-damo) bacteria can play an important role in mitigating the methane emission produced in anoxic sediment layers to the atmosphere. However, the environmental factors regulating the distribution of these methane-oxidizing microorganisms in lacustrine ecosystems remain essentially unclear. The present study investigated the distribution of aerobic MOB and n-damo bacteria in sediments of various freshwater lakes on the Yunnan Plateau (China).

Distribution of sediment ammonia-oxidizing microorganisms in plateau freshwater lakes.

Both ammonia-oxidizing bacteria (AOB) and archaea (AOA) can play important roles in ammonia biotransformation in ecosystems. However, the factors regulating the distribution of these microorganisms in lacustrine ecosystems remain essentially unclear. The present study investigated the effects of geographic location on the distribution of sediment AOA and AOB in 13 freshwater lakes on the Yunnan Plateau (China).

Distribution of sediment bacterial and archaeal communities in plateau freshwater lakes.

Both Bacteria and Archaea might be involved in various biogeochemical processes in lacustrine sediment ecosystems. However, the factors governing the intra-lake distribution of sediment bacterial and archaeal communities in various freshwater lakes remain unclear. The present study investigated the sediment bacterial and archaeal communities in 13 freshwater lakes on the Yunnan Plateau.

A three-dimensional water quality modeling approach for exploring the eutrophication responses to load reduction scenarios in Lake Yilong (China).

Lake Yilong in Southwestern China has been under serious eutrophication threat during the past decades; however, the lake water remained clear until sudden sharp increase in Chlorophyll a (Chl a) and turbidity in 2009 without apparent change in external loading levels. To investigate the causes as well as examining the underlying mechanism, a three-dimensional hydrodynamic and water quality model was developed, simulating the flow circulation, pollutant fate and transport, and the interactions between nutrients, phytoplankton and macrophytes. The calibrated and validated model was used to conduct three sets of scenarios for understanding the water quality responses to various load reduction intensities and ecological restoration measures.