We here report naphtho[2,1-b:6,5-b']difuran derivatives as new p-type semiconductors that achieve hole mobilities of up to 3.6 cm(2) V(-1) s(-1) along with high I(on)/I(off) ratios in solution-processed single-crystal organic field-effect transistors. These features originate from the dense crystal packing and the resulting large intermolecular π-orbital overlap as well as from the small reorganization energy, all of which originate from the small radius of an oxygen atom. 相似文献
The gravitational settling of inhomogeneously suspended particles in a fluid has been investigated. Of particular interest
is whether collective or individual motion of particles is dominant during their settlings, i.e., whether the particles settle as a continuous suspension or they settle individually relative to the surrounding fluid. We
observed the settling of a stratified suspension which has the lower and upper concentration interfaces in a quasi-two-dimensional
vessel. In some cases, the suspension behaves perfectly as a continuous fluid and the motion of the constituent particle is
subject to bulk flow caused by the interfacial instability. In other cases, the particle behaves individually relative to
the surrounding fluid. The existence of a concentration interface plays a significant role in these extreme behaviors of suspension.
The transition from the collective to individual behaviors can be predicted quantitatively by a parameter which expresses
the border resolution of the concentration interface. 相似文献
An energy‐domain 57Fe‐Mössbauer spectrometer using synchrotron radiation (SR) with a diamond anvil cell (DAC) has been developed for ultrahigh‐pressure measurements. The main optical system consists of a single‐line pure nuclear Bragg reflection from an oscillating 57FeBO3 single crystal near the Néel temperature and an X‐ray focusing device. The developed spectrometer can filter the Doppler‐shifted single‐line 57Fe‐Mössbauer radiation with a narrow bandwidth of neV order from a broadband SR source. The focused incident X‐rays make it easy to measure a small specimen in the DAC. The present paper introduces the design and performance of the SR 57Fe‐Mössbauer spectrometer and its demonstrative applications including the newly discovered result of a pressure‐induced magnetic phase transition of polycrystalline 57Fe3BO6 and an unknown high‐pressure phase of Gd57Fe2 alloy placed in a DAC under high pressures up to 302 GPa. The achievement of Mössbauer spectroscopy in the multimegabar range is of particular interest to researchers studying the nature of the Earth's core. 相似文献
Yes, HIMs can! A series of 2,3,6,7‐tetraarylbenzo[1,2‐b:4,5‐b′]dipyrroles (BDPs) were synthesized using zinc‐mediated double cyclization. Organic light‐emitting diodes consisting of BDP:PPB as a hole‐injection layer could be driven at a lower voltage than a PEDOT:PSS‐based device. Correlation of the IP values with the driving voltage shed some light on the mechanism of hole‐injection processes.
Rhodium complexes with an indium metalloligand were successfully synthesized by utilizing a pyridine‐tethered cyclopentadienyl ligand as a support for an In?Rh bond. The indium metalloligand dramatically changes the electronic and redox properties of the rhodium metal, thereby enabling catalysis of sp2C?H bond activation. 相似文献
We study the dynamic behavior of temperature field in a buoyancy-driven turbulent fire from the viewpoints of symbolic dynamics, complex networks, and statistical complexity. The permutation entropy and the horizontal visibility network entropy allow us to capture the subtle changes in temperature fluctuations. The possible existence of deterministic chaos in temperature fluctuations, as well as in streamwise flow velocity fluctuations [Takagi et al., Phys. Rev. E 96 (2017) 052223], is clearly verified using the multiscale complexity-entropy causality plane. 相似文献
A hexadecyl monolayer covalently attached to Si(111) surfaces (C16–Si(111)) was prepared at 200 ○C from 1-hexadecene. Formation of the monolayer was characterized by water contact angle measurement, attenuated total reflection infrared (ATR-IR) spectroscopy, and X-ray photoelectron spectroscopy (XPS). Gas phase synthesized vanadium (V)-benzene (Bz) 1:2 (VBz2) sandwich clusters were size-selectively deposited onto the C16–Si(111) substrate thus prepared and an oxidized Si substrate. Investigation of the resultant clusters was implemented by thermal desorption spectroscopy (TDS). About 30 K increase in threshold desorption temperature of the landed clusters was observed on going from the oxidized Si to the C16–Si(111) substrate, a result indicating that the clusters are more strongly bound to the C16–Si(111) than to the oxidized Si. This result was explained by the penetration of the landed clusters into the hexadecyl monolayer. 相似文献
Dynamic secondary ion mass spectroscopy (SIMS) analysis of soft materials such as polymer or biomaterial is one of challenging subjects due to the charge up effect brought from the irradiation of a primary ion beam, hampering the collection of secondary ions. Conventional methods against the charging up are the electron beam irradiation for charge compensation and surface coating with metal, normally gold. Those methods require a compromise analytical condition, reducing the primary ion beam current to suppress the range of the charging, which degrading the performances of the SIMS analyses. We have proposed that a thicker conductive layer, capable of delocalizing the charge onto the surface, should be put on a soft insulator sample to avoid charging up. The depth profile of the hair sample coated wholly with a polythiophen-based conducting polymer was successfully measured in longer time without any charging up even in the maximum current of the oxygen primary ion beam (O2+: 7.5 keV, 400 nA) or using an electron beam compensation system. Thus, the proposed method coating with a conductive organic polymer against the charging issue would be expected as a breakthrough on SIMS analysis. 相似文献
The Mössbauer spectra of the 35.49 keV excited state of 125Te were observed in the energy domain using synchrotron radiation for the first time. The obtained isomer shifts and Debye temperature agree with previous experiments. These results show that this method will be applicable to various compounds. 相似文献