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排序方式: 共有250条查询结果,搜索用时 31 毫秒
101.
102.
Schuster ME Hävecker M Arrigo R Blume R Knauer M Ivleva NP Su DS Niessner R Schlögl R 《The journal of physical chemistry. A》2011,115(12):2568-2580
Diesel soot (Euro IV and Euro VI) was investigated with spectroscopic methods such as near-edge X-ray absorption fine structure (NEXAFS) spectroscopy and X-ray photoemission spectroscopy (XPS). C and O K-edge NEXAFS show that structural disorder on the surface is accompanied by a higher amount of oxygen functional groups. O K-edge NEXAFS and O1s XPS results are discussed with the aim to elucidate the nature of the oxygen surface species. The analysis of the data presented here allows the postulation of a hypothetical structure for soot samples emitted by diesel engines. 相似文献
103.
den Hollander MJ Magis JG Fuchsenberger P Aartsma TJ Jones MR Frese RN 《Langmuir : the ACS journal of surfaces and colloids》2011,27(16):10282-10294
The utilization of proteins as nanodevices for solar cells, bioelectronics, and sensors generally necessitates the transfer of electrons to or from a conducting material. Here we report on efforts to maximize photocurrent generation by bacterial photosynthetic reaction center pigment-protein complexes (RCs) interfaced with a metal electrode. The possibility of adhering RCs to a bare gold electrode was investigated with a view to minimizing the distance for electron tunneling between the protein-embedded electron-transfer cofactors and the metal surface. Substantial photocurrents were achieved despite the absence of coating layers on the electrode or engineered linkers to achieve the oriented deposition of RCs on the surface. Comparison with SAM-covered gold electrodes indicating enhanced photocurrent densities was achieved because of the absence of an insulating layer between the photoactive pigments and the metal. Utilizing RCs surrounded by light-harvesting 1 complex resulted in higher photocurrents, surprisingly not due to enhanced photoabsorption but likely due to better surface coverage of uniformly oriented RC-LH1 complexes and the presence of a tetraheme cytochrome that could act as a connecting wire. The introduction of cytochrome-c (cyt-c) as a molecular relay also produced increases in current, probably by intercalating between the adhered RCs or RC-LH1 complexes and the electrode to mediate electron transfer. Varying the order in which components were introduced to the electrode indicated that dynamic rearrangements of RCs and cyt-c occurred at the bare metal surface. An upper limit for current generation could not be detected within the range of the illumination power available, with the maximum current density achieved by RC-LH1 complexes being on the order of 25 μA/cm(2). High currents could be generated consecutively for several hours or days under ambient conditions. 相似文献
104.
Mens R Chambon S Bertho S Reggers G Ruttens B D'Haen J Manca J Carleer R Vanderzande D Adriaensens P 《Magnetic resonance in chemistry : MRC》2011,49(5):242-247
PCBM or [6,6]-phenyl-C(61)-butyric acid methyl ester is nowadays still one of the most successful electron acceptors for plastic bulk heterojunction (BHJ) photovoltaic devices. In this study, a set of complementary techniques, i.e. solid-state NMR, XRD and DSC, is proposed as a fast and sensitive tool to screen the morphology of PCBM specimens with different preparation histories. Based on proton NMR relaxation decay time values, an interval can be derived that situates the average crystal dimensions and which can further be refined on the basis of XRD patterns and DSC thermograms. 相似文献
105.
Raoul Bourquin Vasile Gradinaru George A. Hagedorn 《Journal of mathematical chemistry》2012,50(3):602-619
We present a review of rigorous mathematical results about non-adiabatic transitions in molecular systems that are associated
with avoided crossings of electron energy level surfaces. We then present a novel numerical technique for studying these transitions
that is based on expansions in semiclassical wavepackets. 相似文献
106.
A minimal solution to the flavor problem of warped extra-dimension models, i.e., the excessive mixed-chirality contribution to CP violation in K-K ˉ mixing arising from Kaluza-Klein (KK) gluon exchange, is proposed. Extending the strong-interaction gauge group in the bulk by an additional SU(3), and breaking this symmetry to QCD via boundary conditions, the constraints arising from the ε(K) parameter are significantly relaxed. As a result, KK scales M(KK)~2 TeV are consistent with all flavor observables without significant fine-tuning. The model predicts an extended Higgs sector featuring massive color-octet scalars and a tower of KK pseudoaxial gluon resonances, whose existence is not in conflict with recent LHC dijet bounds. 相似文献
107.
Pejman Hojati-Talemi Raoul Cervini George P. Simon 《Journal of nanoparticle research》2010,12(2):393-403
Three new methods for the functionalization of multi-walled carbon nanotubes (MWCNTs) are reported using microwave (MW) energy
and water as a mild chemical agent. In the first method we reported the effect of MW irradiation on a dispersion of MWCNTs
in deionized water, in the second method we studied the exposing of MWCNT to microwave irradiation in the presence of steam,
and in the third method we used microwave oven-generated plasma for the functionalization of MWCNTs. We also performed thermal
oxidation and acid treatment as two conventional methods for oxidative functionalization of carbon nanotubes, to compare their
effect with our results. Transmission electron microscopy (TEM) and Raman spectroscopy results showed that although these
microwave methods introduced some defects to the carbon nanotubes, the damage was less severe than conventional treatments.
X-ray photoelectron spectroscopy (XPS) measurements confirmed that the functionalization of carbon nanotubes by these methods
favored hydroxyl groups, which are useful when further functionalization is required. 相似文献
108.
Dumitru Baleanu Alireza K. Golmankhaneh Raoul Nigmatullin Ali K. Golmankhaneh 《Central European Journal of Physics》2010,8(1):120-125
In the present paper, we have introduced the generalized Newtonian law and fractional Langevin equation. We have derived potentials
corresponding to different kinds of forces involving both the right and the left fractional derivatives. Illustrative examples
have worked out to explain the formalism. 相似文献
109.
Lucas Andreo Carla A. Soldera Beatriz Guimares Ribeiro Patrick Raoul Vicente de Matos Paola Bindes Sousa Weslley Wallace de Alcntara Araújo Amorim Anna Carolina Ratto Tempestini Horliana Sandra Kalil Bussadori Kristianne Porta Santos Fernandes Raquel Agnelli Mesquita‐Ferrari 《Photochemistry and photobiology》2019,95(3):879-885
A peripheral nerve injury (PNI) can result in motor or sensory disorders. Low‐level laser therapy (LLLT) has demonstrated positive results as a treatment option for PNI. Wistar rats were divided into five groups: Control, Injury, Injury + LLLTn (nerve), Injury + LLLTm (muscle) and Injury + LLLTn + m (nerve and muscle irradiation). The groups were analyzed after one, two, three and four weeks. PNI was achieved by crushing the sciatic nerve. Laser treatment (780 nm, 3.2 J) was realized over the nerve and/or tibialis anterior muscle. In gait analyses, the groups irradiated over the nerve demonstrated an improvement after two weeks. In the analysis of mechanical sensitivity, the Injury + LLLTn demonstrated a reduction after one week in comparison with Injury group; the Injury + LLLTn + m and Injury + LLLTm demonstrated an increase after two weeks in comparison with Injury group; and the irradiated groups demonstrated a reduction in nociception after four weeks in comparison with Injury group. In the analysis of muscle atrophy, the Injury + LLLTn demonstrated more muscle mass after two weeks. LLLT improves functional aspects related to gait, mechanical sensitivity and muscle mass, with better results regarding motor aspects and muscle mass when administered over the injured nerve and better results regarding sensory aspects when administered over the muscle. 相似文献
110.