The molecular replacement method has been succesfully used to provide a structure for the photosynthetic reaction center of Rhodopseudomonas sphaeroides at 3.7 Å resolution. Atomic coordinates derived from R. viridis were in search structure. crystallographic R ‐factor is 0.39 reflections between 8 and Å. Validity resulting model further suggested by visualization amino acid side chains not included . structure, arrangements centers unit cell. In initial calculations quinones or pigments...

Carbon dots are cost-effective, environmental friendly, and biocompatible nanoparticles with many potential applications in optoelectronics biophotonics. Their dual fluorescence bands were observed could be attributed to core surface state emission. We also conduct temperature-dependent measurements from cryogenic room temperatures. The emission exhibit similar temperature dependence. strong electron–electron interactions weak electron–phonon account for the very broad photoluminescence (PL)...

Journal Article Resistance of Diamondback Moth (Lepidoptera: Plutellidae) to Bacillus thuringiensis Subspecies in the Field Get access A. M. Shelton, Shelton Search for other works by this author on: Oxford Academic PubMed Google Scholar J. L. Robertson, Robertson D. Tang, Tang C. Perez, Perez S. Eigenbrode, Eigenbrode 3 3Current address: Department Entomology, University California, Riverside, CA 92527. H. K. Preisler, Preisler W. T. Wilsey, Wilsey R. Cooley Economic Volume 86, Issue 3, 1...

Pulsed, Fourier-transform, and continuous-wave electron paramagnetic resonance methods are used to study the g=2.0319 EPR signal in synthetic diamond crystals. This is from Ni which found be located at a substitutional site lattice without detectable nearby charge compensation. The effective spin state of S=(3/2 determined Fourier-transform nutational spectroscopy. It proposed that center ${\mathrm{Ni}}^{\mathrm{\ensuremath{-}}}$ ion with electronic configuration 3${\mathit{d}}^{7}$.

The light-induced spectral diffusion and fluorescence intermittency (blinking) of semiconductor nanocrystal quantum dots are investigated theoretically using a diffusion-controlled electron-transfer (DCET) model, where one-dimensional process in energy space is considered. Unlike the conventional reactions with simple exponential kinetics, model naturally leads to power-law statistics for intermittency. We formulate possible explanation broadening its proportionality light density, -32 power...

A mechanism involving diffusion-controlled electron transfer processes in Debye and non-Debye dielectric media is proposed to elucidate the power-law distribution for lifetime of a blinking quantum dot. This model leads two complementary regimes power law with sum exponents equal 2, specific value exponent terms diffusion correlation times. It also links exponential bending tail energetic kinetic parameters.

Using a femtosecond resolved up‐conversion technique, the ultrafast carrier dynamics in fluorescent carbon nanodots are investigated order to shed light on mysterious origins of their fluorescence. These experiments reveal that fluorescence consists two spectral overlapped bands can be ascribed intrinsic and extrinsic The band exhibits small bandwidth 175 meV at 459 nm, it is attributed sp 2 nano domains. originates from surface states with much broader 450 meV. relaxation time constants few...

So-called upconversion fluorescence in CNDs and GQDs is confirmed originating from a measurement mistake; therefore cross-check very necessary.

Fluorescent Au25 nanoclusters recently have drawn considerable research interest due to their unique properties and potential applications. Despite significant advances in synthesis methods application development, the origin of fluorescence underlying mechanism still remain unclear. In this work we investigate dynamics BSA-protected by time-resolved photoluminescence transient absorption techniques covering picosecond microsecond time scales. We demonstrate here that red consists both...

Traveling a long way past the junction Diodes are central components of modern electronic circuits. They essentially consist two semiconductors sandwiched together, with one deficient in electrons (p), other enriched (n). Najafi et al. used ultrafast electron microscopy to study dynamics silicon diode on time scale trillionths second. discovered that when light excites diode's charge carriers, those carriers migrate much farther p-n than standard models would imply. The authors explain...

In real time and space, four-dimensional electron microscopy (4D EM) has enabled observation of transient structures morphologies inorganic organic materials. We have extended 4D EM to include liquid cells without the resolution being limited by response detector. Our approach permits imaging motion morphological dynamics a single, same particle on nanometer ultrashort scales. As first application, we studied rotational gold nanoparticles in aqueous solution. A full transition from...

We present a general description of electron spin polarization observed for interacting radical pairs. Unlike previous treatments, both chemically induced dynamic and correlated pair are included ST0 mixing. A key feature this model is that the members can remain throughout time sequence polarization. Explanations time-dependent evolution presented using density matrix its associated vector diagram. new method formulated calculating visualizing The approach based on vector, Δρ(t) which...

A colony of Plutella xylostella from crucifer fields in Florida was used mortality bioassays with HD-1 spore, CryIA(a), CryIA(b), CryIA(c), CryIB, CryIC, CryID, CryIE, or CryIIA. The data revealed high levels field-evolved resistance to spore and all CryIA protoxins no CryID. CryIE CryIIA were essentially not toxic. When combined 1:1 protoxin fed susceptible larvae, synergized the activity CryIC 5- 8-fold 1.7-fold, respectively, did synergize failed three protoxins, 5.3-fold, for Binding...

In this work, we investigated the temperature-dependent luminescence of bovine serum albumin-protected Au25 nanoclusters and correlation with their structure. Our experiments reveal that red consists two bands, namely, band I at 710 nm II 640 nm. The temperature dependence exhibits similarity to semiconductors, such as a shift emission bandwidth broadening upon increasing temperatures due electron–phonon electron–defect/surface scattering. contrast, different dependence. It is concluded...

Carbon nanodots (CNDs) have emerged as fascinating materials with exceptional electronic and optical properties, thus they offer many promising applications in photovoltaics photocatalysis. In this paper we investigate electron transfer nanocomposites of CNDs–graphene oxide (GO), –multi-walled carbon nanotubes (MWNTs) –TiO2 nanoparticles without linker molecules, using steady state time-resolved spectroscopy. Significant fluorescence quenching was observed the CND–GO system, it is attributed...

Combining metal and semiconducting nanomaterials into one single nanocrystal, metal–semiconducting nanocomposites have been attracting considerable research interest due to the integrated unprecedented properties that arise at heterostructure interface. Herein, dynamics of photoexcited charge carriers in CdSe/Au CdSe/Pt nanorods is probed via ultrafast spectroscopy. Upon 400 nm photoexcitation, results show both hot cold electrons transfer from CdSe counterpart. The injection photoinduced Au...

Novel electron transfer results in PL quenching both graphene oxide–Au₂₅ and oxide–Au₁₀ nanocomposites.

Atomically precise Au nanoclusters (NCs) have emerged as fascinating fluorescent nanomaterials and attracted considerable research interest in both fundamental practical applications. Due to enhanced quantum confinement, they possess extraordinary optical, electronic, magnetic properties therefore are very promising for a wide range of applications, including biosensing, bioimaging, catalysis, photonics, molecular electronics. Remarkable progress has been reported the understanding,...

We demonstrated that graphene oxide material could be used as a highly efficient saturable absorber for the Q-switched Nd:GdVO4 laser. A novel and low-cost (GO) was fabricated by vertical evaporation technique high viscosity of polyvinyl alcohol (PVA) aqueous solution. piece GO/PVA absorber, round quartz, an output coupler mirror were combined to sandwich structure passive component. Using such structure, 104 ns pulses 1.22 W average power obtained with maximum pulse energy at 2 µJ slope...

We report here the temperature dependence studies of fluorescence histidine-protected Au10 nanoclusters. conclude from experiments that process involves thermally activated nonradiative trapping with an activation energy 103 meV. At increased temperatures, peak was found to exhibit a small blue shift, largely due lattice torsional fluctuation, whereas electron–phonon scattering plays minor role. Moreover, bandwidth also slightly as result enhanced surface/defect/impurity scattering. suggest...

Experimental evaluation of the effectiveness resistance management tactics is vital to help provide guidelines for deployment transgenic insecticidal crops. Transgenic broccoli expressing a Cry1Ac gene Bacillus thuringiensis (Bt) and diamondback moth, Plutella xylostella (L.), were used in greenhouse tests evaluate influence size placement nontransgenic refuge plants on changes allele frequency pest population growth. In first test with an initial Cry1Ac-resistance (R) 0.007, P. introduced...

The results of reaction yield-detected magnetic resonance (RYDMR) experiments carried out on modified bacterial photosynthetic centers (RCs) are interpreted in terms a model that assigns the initial charge-separated radical ion-pair state, P F , as carrier spectrum. pair theory, which has been invoked to explain field effects RCs, was significantly expanded take into consideration electron dipole-dipole interaction. It is shown this largest interaction between components ion pair. Quantum...

We demonstrated that by properly coupling to silver nanoprisms, single CdSe/ZnS semiconductor quantum dots (QDs) exhibited suppressed blinking behavior, an enhanced fluorescence intensity ( approximately 2.5 fold), increased radiative decay rates 12.5 and antibunching single-photon emission. All these modifications significantly promote the overall performance of proposed sources based on colloidal QDs.

We utilize 100 fs optical pulses to induce ultrafast disorder of 35- 150-nm thick single Au(111) crystals and observe the subsequent structural evolution using 0.6-ps, 8.04-keV X-ray pulses. Monitoring picosecond time-dependent modulation diffraction intensity, width, shift, we have measured directly electron/phonon coupling, phonon/lattice interaction, a histogram lattice evolution, such as breath due pressure wave propagating at sonic velocity, melting, recrystallization, including mosaic...