先进栅叠层的在线光谱分析法

量测平台的复杂性和光学原理上的局限性制约着测量系统的应用，直到真空紫外光谱反射仪的出现，这种状况才得到改变。     

Intrinsic bonding defects in transition metal elemental oxides

Gate dielectrics comprised of nanocrystalline HfO₂ in gate stacks with thin SiO₂/SiON interfacial transition regions display significant asymmetries with respect to trapping of Si substrate injected holes and electrons. Based on spectroscopic studies, and guided by ab initio theory, electron and hole traps in HfO₂ and other transition metal elemental oxides are assigned to O-atom divacancies, clustered at internal grain boundaries. Three engineering solutions for defect reduction are identified: i) deposition of ultra-thin, <2 nm, HfO₂ dielectric layers, in which grain boundary formation is suppressed by effectively eliminating inter-primitive unit cell π-bonding interactions, ii) chemically phase separated high HfO₂ silicates in which inter-primitive unit cell p-bonding interactions are suppressed by the two nanocrystalline grain size limitations resulting from SiO₂ inclusions, and iii) non-crystalline Zr/Hf Si oxynitrides without grain boundary defects.     

High flux hemofiltration

Experiments were performed using a new hollow fiber hemofilter. Ultrafiltration rates and whole blood urea clearances were measured in post-dilution hemofiltration. High ultrafiltration rates were obtained with the new hemofilter. No adverse effects were detected despite filtration fractions above 45%. These experiments suggest that it is possible in post-dilution hemofiltration to obtain small solute clearances comparable to those of hemodialysis without apparent deleterious effects.     

High resolution radially symmetric nanostructures from simultaneous electron beam induced etching and deposition

Electron beam induced etching (EBIE) and deposition (EBID) are promising fabrication techniques in which an electron beam is used to dissociate surface-adsorbed precursor molecules to achieve etching or deposition. Spatial resolution is normally limited by the electron flux distribution at the substrate surface. Here we present simultaneous EBIE and EBID (EBIED) as a method for surpassing this resolution limit by using adsorbate depletion to induce etching and deposition in adjacent regions within the electron flux profile. Our simulation results indicate the possibility of growth control of radially symmetric nanostructures at the sub-1 nm length scale on bulk substrates. The technique is well suited to the fabrication of ring-shaped nanostructures such as those employed in plasmonics, sensing devices, magneto-optics and magnetoelectronics.     

Effect of particle size on iron nanoparticle oxidation state

Selecting catalyst particles is a very important part of carbon nanotube growth, although the properties of these nanoscale particles are unclear. In this article iron nanoparticles are analyzed through the use of atomic force microscopy and x-ray photoelectron spectroscopy in order to understand how the size affects the chemical composition of nanoparticles and thus their physical structure. Initially, atomic force microscopy was used to confirm the presence of iron particles, and to determine the average size of the particles. Next an analytical model was developed to estimate particle size as a function of deposition time using inputs from atomic force microscopy measurement. X-ray photoelectron spectroscopy analysis was then performed with a focus on the spectra relating to the 2p Fe electrons to study the chemical state of the particles as a function of time. It was shown that as the size of nanoparticles decreased, the oxidation state of the particles changed due to a high proportion of atoms on the surface.     

Co-optimization of the metal gate/high-k stack to achieve high-field mobility >90% of SiO/sub 2/ universal mobility with an EOT=/spl sim/1 nm

HfO/sub 2/ and HfSiON gate dielectrics with high-field electron mobility greater than 90% of the SiO/sub 2/ universal mobility and equivalent oxide thickness (EOT) approaching 1 nm are successfully achieved by co-optimizing the metal gate/high-k/bottom interface stack. Besides the thickness of the high-/spl kappa/ dielectrics, the thickness of the ALD TiN metal gate and the formation of the bottom interface also play an important role in scaling EOT and achieving high electron mobility. A phase transformation is observed for aggressively scaled HfO/sub 2/ and HfSiON, which may be responsible for the high mobility and low charge trapping of the optimized HfO/sub 2/ gate stack.     

Future trends in renal replacement therapy

The authors report a case about relapsing corneal ulceration in a patient with rheumatoid arthritis. Treatment of such perforated and preperforated corneal ulcers is a difficult task. The poor visual outcome of an emergency penetrating keratoplasty leads to the use of other methods (conjunctival flaps, corneal graft, keratopatch, tissue adhesive). This case report stresses the importance of preserving the anatomy of the eye allowing in a record time the performance of corneal graft. The use of immunosuppressive drugs is also discussed because of the existence of a rheumatoid arthritis with eye involvement.     

Guest Editors' Introduction: Advances in Configurable Computing

At times, it appears that the many definitions of configurable computing are every bit as configurable as the technology itself. For example, Wikipedia-the free, online, user-editable encyclopedia-defines configurable computing (or, synonymously, reconfigurable computing) as ".... computer processing with highly flexible computing fabrics. The principal difference when compared to using ordinary microprocessors is the ability to make substantial changes to the data path itself in addition to the control flow' (http://en.wikipedia.org/wiki/Configurable_computing).     

Rapid method for the determination of meat in food products

A method for the determination of meat in food products is described based on the determination of protein-bound 3-methylhistidine. The method involved high pressure liquid chromatography and reduced the elution time of previous methods from 7 h to 10 min. The accuracy of the method was increased by using electronic integration. The method was used to determine the meat content of nine meat pies and three hamburger patties.     

Modeling of the carbon nanotube chemical vapor deposition process using methane and acetylene precursor gases

Chemical vapor deposition of carbon nanotubes (CNTs) in a horizontal tube-flow reactor has been investigated with a fully coupled reactor-scale computational model. The model combined conservation of mass, momentum, and energy equations with gas-phase and surface chemical reactions to describe the evolution of a hydrogen and hydrocarbon feed-stream as it underwent heating and reactions throughout the reactor. Investigation was directed toward steady state deposition onto iron nanoparticles via methane and hydrogen as well as feed-streams consisting of acetylene and hydrogen. The model determines gas-phase velocity, temperature, and concentration profiles as well as surface concentrations of adsorbed species and CNT growth rate along the entire length of the reactor. The results of this work determine deposition limiting regimes for growth via methane and acetylene, demonstrate the need to tune reactor wall temperature to specific inlet molar ratios to achieve optimal CNT growth, and demonstrate the large effect that active site specification can have on calculated growth rate.