We used spectroscopic photoemission and low-energy electron microscopy to investigate the electronic properties of epitaxial few-layer graphene grown on 6H-SiC͑0001͒. Photoelectron emission microscopy ͑PEEM͒ images using secondary electrons ͑SEs͒ and C 1s photoelectrons can discriminate areas with different numbers of graphene layers. The SE emission spectra indicate that the work function increases with the number of graphene layers and that unoccupied states in the few-layer graphene promote SE emission. The C 1s PEEM images indicate that the C 1s core level shifts to lower binding energies as the number of graphene layers increases, which is consistent with the reported thickness dependence of the Dirac point energy.

Transformations within container-molecules provide a good alternative between traditional homogeneous and heterogeneous catalysis, as the containers themselves can be regarded as single molecular nanomicelles. We report here the designed-synthesis of a water-soluble redox-active supramolecular PdL cage and its application in the encapsulation of aromatic molecules and polyoxometalates (POMs) catalysts. Compared to the previous known PdL cage, our results show that replacement of two cis-blocked palladium corners with p-xylene bridges through pyridinium bonds formation between the 2,4,6-tri-4-pyridyl-1,3,5-triazine (TPT) ligands not only provides reversible redox-activities for the new PdL cage, but also realizes the expansion and subdivision of its internal cavity. An increased number of guests, including polyaromatics and POMs, can be accommodated inside the PdL cage. Moreover, both conversion and product selectivity (sulfoxide over sulfone) have also been much enhanced in the desulfurization reactions catalyzed by the POMs@PdL host-guest complexes. We expect that further photochromic or photoredox functions are possible taking advantage of this new generation of organo-palladium cage.

The field-induced blockage of magnetization behavior was first observed in an Yb(III)-based molecule with a trigonally distorted octahedral coordination environment. Ab initio calculations and micro-SQUID measurements were performed to demonstrate the exhibition of easy-plane anisotropy, suggesting the investigated complex is the first pure lanthanide field-induced single-ion magnet (field-induced SIM) of this type. Furthermore, we found the relaxation time obeys a power law instead of an exponential law, indicating that the relaxation process should be involved a direct process rather than an Orbach process.

Nanodiamond particles produced by detonation synthesis and having ∼5 nm diameter possess unique properties, including low cell toxicity, biocompatibility, stable structure, and highly tailorable surface chemistry, which render them an attractive material for developing drug delivery systems. Although the potential for nanodiamonds in delivery and sustained release of anticancer drugs has been recently demonstrated, very little is known about the details of adsorption/desorption equilibria of these and other drugs on/from nanodiamonds with different purity, surface chemistry, and agglomeration state. Since adsorption is the basic mechanism most commonly used for the loading of drugs onto nanodiamond, the fundamental studies into the details of adsorption and desorption on nanodiamond are critically important for the rational design of the nanodiamond drug delivery systems capable of targeted delivery and triggered release, while minimizing potential leaks of dangerous drugs. In this paper we report on a physical-chemical study of the adsorption of doxorubicin and polymyxin B on nanodiamonds, analyzing the role of purification and surface chemistry of the adsorbent.

The Jefferson Lab Q weak experiment determined the weak charge of the proton by measuring the parityviolating elastic scattering asymmetry of longitudinally polarized electrons from an unpolarized liquid hydrogen target at small momentum transfer. A custom apparatus was designed for this experiment to meet the technical challenges presented by the smallest and most precise ep asymmetry ever measured. Technical milestones were achieved at Jefferson Lab in target power, beam current, beam helicity reversal rate, polarimetry, detected rates, and control of helicity-correlated beam properties. The experiment employed 180 µA of 89% longitudinally polarized electrons whose helicity was reversed 960 times per second. The electrons were accelerated to 1.16 GeV and directed to a beamline with extensive instrumentation to measure helicitycorrelated beam properties that can induce false asymmetries. Møller and Compton polarimetry were used to measure the electron beam polarization to better than 1%. The electron beam was incident on a 34.4 cm liquid hydrogen target. After passing through a triple collimator system, scattered electrons between 5.8• and 11.6• were bent in the toroidal magnetic field of a resistive copper-coil magnet. The electrons inside this acceptance were focused onto eight fused silicaČerenkov detectors arrayed symmetrically around the beam axis. A total scattered electron rate of about 7 GHz was incident on the detector array. The detectors were read out in integrating mode by custom-built low-noise pre-amplifiers and 18-bit sampling ADC modules. The momentum transfer Q 2 = 0.025 GeV 2 was determined using dedicated low-current (∼100 pA) measurements with a set of drift chambers before (and a set of drift chambers and trigger scintillation counters after) the toroidal magnet.