K-shell ionization by protons for Cr,Cu, In and by alpha-particles for Cr,Cu

K-shell ionization cross sections have been determined for Cr, Cu and In at proton bombardment in the energy region from 0.9 to 2.5 MeV. The same cross sections were determined for Cr and Cu at alpha bombardment in the 0.9–4.0 MeV region. The experimental results are compared with five different theoretical calculations.     

In Vivo EPR For Dosimetry

As a result of terrorism, accident, or war, populations potentially can be exposed to doses of ionizing radiation that could cause direct clinical effects within days or weeks. There is a critical need to determine the magnitude of the exposure to individuals so that those with significant risk have appropriate procedures initiated immediately, while those without a significant probability of acute effects can be reassured and removed from the need for further consideration in the medical/emergency system. In many of the plausible scenarios there is an urgent need to make the determination very soon after the event and while the subject is still present. In vivo EPR measurements of radiation-induced changes in the enamel of teeth is a method, perhaps the only such method, which can differentiate among doses sufficiently for classifying individuals into categories for treatment with sufficient accuracy to facilitate decisions on medical treatment. In its current state, the in vivo EPR dosimeter can provide estimates of absorbed dose with an error approximately +/- 50 cGy over the range of interest for acute biological effects of radiation, assuming repeated measurements of the tooth in the mouth of the subject. The time required for acquisition, the lower limit, and the precision are expected to improve, with improvements in the resonator and the algorithm for acquiring and calculating the dose. The magnet system that is currently used, while potentially deployable, is somewhat large and heavy, requiring that it be mounted on a small truck or trailer. Several smaller magnets, including an intraoral magnet are under development, which would extend the ease of use of this technique.     

An algorithm for finding factorizations of complete graphs

We show how to find a decomposition of the edge set of the complete graph into regular factors where the degree and edge‐connectivity of each factor is prescribed. © 2003 Wiley Periodicals, Inc. J Graph Theory 43: 132–136, 2003     

Alternating hamiltonian cycles in two colored complete bipartite graphs

We give necessary and sufficient conditions for the existence of an alternating Hamiltonian cycle in a complete bipartite graph whose edge set is colored with two colors.     

Quantum state tomography of an itinerant squeezed microwave field

We perform state tomography of an itinerant squeezed state of the microwave field prepared by a Josephson parametric amplifier (JPA). We use a second JPA as a preamplifier to improve the quantum efficiency of the field quadrature measurement from 2% to 36%±4%. Without correcting for the detection inefficiency we observe a minimum quadrature variance which is 68(-7)(+9)% of the variance of the vacuum. We reconstruct the state's density matrix by a maximum likelihood method and infer that the squeezed state has a minimum variance less than 40% of the vacuum, with uncertainty mostly caused by calibration systematics.     

HSQC-ADEQUATE correlation: a new paradigm for establishing a molecular skeleton

Various experimental methods have been developed to unequivocally identify vicinal neighbor carbon atoms. Variants of the HMBC experiment intended for this purpose have included 2J3J-HMBC and H2BC. The 1,1-ADEQUATE experiment, in contrast, was developed to accomplish the same goal but relies on the (1) J(CC) coupling between a proton-carbon resonant pair and the adjacent neighbor carbon. Hence, 1,1-ADEQUATE can identify non-protonated adjacent neighbor carbons, whereas the 2J3J-HMBC and H2BC experiments require both neighbor carbons to be protonated to operate. Since 1,1-ADEQUATE data are normally interpreted with close reference to an HSQC spectrum of the molecule in question, we were interested in exploring the unsymmetrical indirect covariance processing of multiplicity-edited GHSQC and 1,1-ADEQUATE spectra to afford an HSQC-ADEQUATE correlation spectrum that facilitates the extraction of carbon-carbon connectivity information. The HSQC-ADEQUATE spectrum of strychnine is shown and the means by which the carbon skeleton can be conveniently traced is discussed.     

Observation of collective friction forces due to spatial self-organization of atoms: from Rayleigh to Bragg scattering

We demonstrate that emission-induced self-organization of two-level atoms can effect strong damping of the sample's center-of-mass motion. When illuminated by far-detuned light, cold cesium atoms assemble into a density grating that efficiently diffracts the incident light into an optical resonator. We observe random phase jumps of pi in the emitted light, confirming spontaneous symmetry breaking in the atomic self-organization. The Bragg diffraction results in a collective friction force with center-of-mass deceleration up to 1000 m/s(2) that is effective even for an open atomic transition.     

Optimization of microwire/glass-fibre reinforced polymer composites for wind turbine application

We here report a comprehensive study of glass-fibre reinforced polymers (GFRP) incorporating ferromagnetic microwires for microwave absorption applications. With wire addition, a remarkable dependence of microwave absorption performance appears on the local properties of wires such as wire geometry and the mesostructure such as inter-wire spacing, as well as the embedded depth of the wires layer. The impact testing further demonstrates that the metallic microwires can to some extent improve the impact performance. Based on both the absorption and impact behavior, we propose an optimized design of the microwire/GFRP composites to achieve simultaneous best possible absorption and impact performance for multifunctional applications in aeronautical structures and wind turbines.     

Terahertz time-domain magnetospectroscopy of a high-mobility two-dimensional electron gas

We have observed cyclotron resonance in a high-mobility GaAs/AlGaAs two-dimensional electron gas by using the techniques of terahertz time-domain spectroscopy combined with magnetic fields. From this, we calculate the real and imaginary parts of the diagonal elements of the magnetoconductivity tensor, which in turn allows us to extract the concentration, effective mass, and scattering time of the electrons in the sample. We demonstrate the utility of ultrafast terahertz spectroscopy, which can recover the true linewidth of cyclotron resonance in a high-mobility (>10(6) cm(2)V(-1)s(-1)) sample without being affected by the saturation effect.