We demonstrate that the cycling between internal states of quantum dots during fluorescence blinking can be used to tune the near-field coupling with a sharp tip. In particular, the fluorescence emission from states with high quantum yield is quenched due to energy transfer, while that from low-yield states is elevated due to field enhancement. Thus, as a quantum dot blinks, its emission fluctu...

Due to past limitations in experimental technology, canopy function has generally been inferred from leaf properties through scaling and/or indirect measurements. The development of a facility (EcoCELLs) at the Desert Research Institute has now made it possible to directly measure canopy gas exchange. In this experiment, sunflowers (Helianthus annus) were planted in the EcoCELLs and grown under...

After providing an extensive overview of the conceptual elements – such as Einstein’s ‘hole argument’ – that underpin Penrose’s proposal for gravitationally induced quantum state reduction, the proposal is constructively criticised. Penrose has suggested a mechanism for objective reduction of quantum states with postulated collapse time τ = h̄/∆E , where ∆E is an ill-definedness in the gravitati...

Solvent effects play a very important role in photochemical reactions and energy transfer processes in solution; however, these effects are rarely mentioned in the triplet-triplet annihilation (TTA) upconversion fluorescence experiments. In a typical TTA upconversion system of a photosensitizer of diiodo-Bodipy (I2-Bodipy) and a triplet acceptor of perylene, five common inert solvents, hexane, ...

Radix Isatidis (Isatis indigotica Fort.) is one of the most important traditional Chinese medicine plants. However, there is no suitable herbicide used for weed control in Radix Isatidis field during postemergence stage. To explore the safety of sulfonylurea herbicide nicosulfuron on Radix Isatidis (Isatis indigotica Fort.) seedlings and the photosynthetic physiological response of the plant to...

The term photocatalysis is one amongst several in a quagmire of labels used to describe a photon-driven catalytic process; a simple description of photocatalysis is proposed herein. Other labels such as quantum yield and/or quantum efficiency used in solid/liquid and solid/gas heterogeneous photocatalytic systems to express process efficiencies have come to refer (incorrectly) to the ratio of t...

The effect of an applied electric field has been measured for the quantum yield of formation of the P H , P+QA-, and 3P states of nonoriented Rb. sphaeroides reaction centers a t 80 K in poly(viny1 alcohol) (PVA) films and in glycerol-buffer glasses. Both the shape and magnitude of the field dependence are very similar for all three observables in both media where the data overlap. This result ...

In the last decade, developments in nanotechnology have provided a new field in medicine called “Nanomedicine”. Nanomedicine has provided new tools for photodynamic therapy. Quantum dots (QDs) are approximately spherical nanoparticles that have attracted broad attention and have been used in nanomedicine applications. QDs have high molar extinction coefficients and photoluminescence quantum yie...