5,375 research outputs found
Temporal variations in the size and composition of Formosan leaf-nosed bat (Hipposideros terasensis) colonies in central Taiwan.
Electron transfer and binding affinities in an electrochemically controlled ligand transfer system containing zinc porphyrin and a meso-phenylenediamine substituent
[[abstract]]Investigations on the transfer of the ligand, imidazole (HIm), between two covalently linked redox centres - zinc porphyrin and phenylenediamine (PD) - and the influence of the length of the linker are reported. Since the binding affinity of the ligand with zinc porphyrin is different from that of the ligand with the phenylenediamine moiety, the transfer of the ligand could be electrochemically controlled by adjusting the oxidation potentials. Changes in cyclic voltammograms and absorption spectra of the complexes revealed the site of ligand binding in the various oxidation states of the modified zinc porphyrins. Binding constants of the modified zinc porphyrins in various oxidation states were also determined by photometric titration with the ligand and digital simulations. Evidence for the delocalization of the electron from the zinc porphyrin to the phenylenediamine moiety and the influence of the delocalization on them were obtained from EPR studies.[[note]]SC
Observation of hc radiative decay hc › ??' and evidence for hc › ??
Kolcu, Onur Buğra (Arel Author) --- Makale 69 yazarlıdır.A search for radiative decays of the P-wave spin singlet charmonium resonance hc is performed based on 4.48 × 108 ? events collected with the BESIII detector operating at the BEPCII storage ring. Events of the reaction channels hc › ??' and ?? are observed with a statistical significance of 8.4? and 4.0?, respectively, for the first time. The branching fractions of hc › ??' and hc › ?? are measured to be B(hc › ??' ) = (1.52±0.27±0.29)×10-3 and B(hc › ??) = (4.7±1.5±1.4)×10-4 , respectively, where the first errors are statistical and the second are systematic uncertainties
Repair of Perforating Internal Resorption with Mineral Trioxide Aggregate: A Case Resport
Intriguing Electrochemical Behavior of Free Base Porphyrins: Effect of Porphyrin-meso-Phenyl Interaction Controlled by Position of Substituents on meso-Phenyls
[[abstract]]Electrochemical properties of substituted free base meso-tetraphenylporphyrins (H2T(o,o'-X)PP, H2T(o-X)PP, and H2T(p-X)PP, where X = OCH3, CH3, H, F, or Cl on the phenyl rings) are examined by cyclic voltammetry. When a substituent is located only at the para position of the meso-phenyl group, the difference between the first and second oxidation potentials (Delta E-ox, i.e., E-2(ox) - E-1(ox)), is generally significantly smaller than those of the H(2)TPPs with bulky o,o'-substituents on the phenyl group. This trend is elucidated with density functional theory calculations and attributed mainly to the sterically controlled pi-conjugation of the meso-phenyl groups to the central porphyrin ring, rather than the often discussed deformation of porphyrin.[[note]]SC
Glypican-3-mediated oncogenesis involves the Insulin-like growth factor-signaling pathway.
Effect of Operation Strategy on First Cycle CO, HC, and PM/PN Emissions in a GDI Engine
The impact of the operating strategy on emissions from the first combustion cycle during cranking was studied quantitatively in a production gasoline direct injection engine. A single injection early in the compression cycle after IVC gives the best tradeoff between HC, particulate mass (PM) and number (PN) emissions and net indicated effective pressure (NIMEP). Retarding the spark timing, it does not materially affect the HC emissions, but lowers the PM/PN emissions substantially. Increasing the injection pressure (at constant fuel mass) increases the NIMEP but also the PM/PN emissions.Borg-Warner CorporationChrysler CorporationFord Motor CompanyGeneral Motors Corporatio
Excited State Luminescence of Multi-(5-phenyl-1,3,4-oxadiazo-2-yl)benzenes in an Electron-Donating Matrix: Exciplex or Electroplex?
[[abstract]]Multi-(5-phenyl-1,3,4-oxadiazo-2-yl)benzenes show emission in organic solvents from ultraviolet to blue (339-447 nm). The reduction potentials E(1/2)(red) cover a large range of -2.11 V for 2,5-diphenyl-1,3,4-oxadiazole to -0.76 V for l,2,3,4,5,6-hexa(5-phenyl-1,3,4-oxadiazo-2-yl)benzene. An unexpectedly wide spectral range of the oxadiazole (OXD) exciplex emissions in PVK is observed, ranging from 406 to 603 nm. The OXDs also exhibit similar electroluminescence (EL) when blended into polyvinylcarbazole (PVK). A linear correlation between the lambda(max) of the electroluminescence and photoluminescence is observed, implying that the emission mechanisms in both processes are similar. In addition, the linear correlation between the E(1/2)(red) versus of lambda(max) of EL (eV) reflected that the term of the charge-transfer configuration of the contact electron-hole pair plays a major role in the exciplex emission. The exciplex EL of 1,2,5-tri(5-phenyl- 1,3,4-oxadiazo-2-yl)benzene (5) could be as high as 1.0 cd/A. Since the exciplex emission usually has a large Stokes shift, this provides a window for us to generate duo emissions for near white light EL with high efficiency. Among the devices we tried, the device of PVK/2-tert-butylphenyl-5-biphenyl-1,3,4-oxadiazole/5/2,5,8,11-tetra-tert-butylperylene (100: 40:40:4) gave EL with good current efficiency of 1.63 cd/A.[[note]]SC
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