Controllable Ultra Low- k by Via-Typed Air Gap with the Better Design Margin for Logic Devices below 45nm Node

By changing the air gap to a via-typed air gap, the height of the air gap is reduced up to about 50% compared to the height of the trench-typed air gap. The controllable （1 ≤h 〈 2.9） ultra low-k is also easily fabricated by adjusting the space of the via-typed air gap. The via-typed air gap makes the design margin better due to its lower height in the dense and narrow lines.     

Non-Invasive Measurements of Thickness of Superconductor Films by Using Two-Resonant-Mode Rutile Resonator

The film thickness should be known for extrazting the intrinsic surface resistance from the effective surface resistance as measured by using the dielectric resonator method. Thicknesses of 70 nm to 360 nm are measured for YBa2 Cu3 O7-δ films in a non-invasive way by using the two-resonant-mode dielectric resonator （TDR） method. A futile resonator with the respective resonant frequencies of 15.25-15.61 GHz and 15.10-15.37 GHz for the TE021 and the TE012 modes is used for this purpose. Differences between the values as measured by using the TDR technique and those measured by using a step profilometer appear to be less than 3%, which is smaller than the previous value of 5% as measured by using a 8. 6 GHz single-resonance mode futile resonator [Lee et al. J. Korean Phys. Soc. 54（2009）1619]. Merits of using the TDR method are discussed.     

A Characteristic Non-Reflecting Boundary Treatment in Lattice Boltzmann Method

In lattice Boltzmann methods, disturbances develop at the initial stages of the simulation, the decay characteristics depend mainly on boundary treatment methods; open boundary conditions such as equilibrium and bounce-back schemes potentially generate uncontrollable disturbances. Excessive disturbances originate from non-physical reflecting waves at boundaries. Characteristic boundary conditions utilizing the signs of waves at boundaries which suppress these reflecting waves, as well as their implementation in the lattice Boltzmann method, are introduced herein. The performance of our novel boundary treatment method to effectively suppress excessive disturbances is verified by three different numerical experiments.     

A STUDY ON THE VIBRATION CHARACTERISTICS OF A LARGE SIZE KOREAN BELL

Structural elements which determine the vibration and sound properties of the Korean bell are reviewed. Vibration response characteristics under an impact excitation are investigated by the analysis and experiment. Numerical and experimental methods to predict and tune the vibration and sound properties of a large Korean bell (named the New Bosingak Bell) are introduced. Beat phenomenon, which is a very important sound property of the Korean bell, is analytically examined, and an experimental technique to enhance the beat property is proposed.     

MODELLING OF VIBRATING SYSTEMS USING TIME-DOMAIN FINITE ELEMENT METHOD

In this paper, several dynamic systems are modelled using the time-domain finite element method. Galerkin's weak principle is used to model the general second order mechanical system, and is applied to the dynamics of the simple pendulum. Problems that arise during the approximation of the final momentum are also investigated. Furthermore, additional dynamic analysis methods are suggested for hybrid co-ordinate systems that have both slew and flexible modes. The proposed methods are based on both extended Hamilton's principle and Galerkin's weak principle. The matrix wave equation is propagated in a space domain, satisfying the geometric/natural boundary conditions. As a result, the flexible motion can be obtained, and this was compatible with the applied control input. A numerical example is used to demonstrate the effectiveness of the proposed modelling methods for the hybrid co-ordinate systems.     

Investigation of the Interaction Between Sodium （meta） Arsenite and Catechin via ESI Tandem Mass Spectrometry

Catechin,one of the main components of green tea,is considered to have the remedy effect of arsenic poison,although the chemical mechanism is not well known.In this study,sodium(meta)selenite,which is used as herbicide and insecticide as well as rodenticide,was simply mixed with catechin in the CH3OH/H2O(volume ratio 50∶50)solution to investigate the interaction between toxic inorganic arsenic compound and catechin via ESI tandem mass spectrometry.The interaction products of mono-methylated arsenic with catechin in the presence of methanol were identified in the negative mode.Collission induced dissociation(CID)mass spectrometric measurements indicate that monomethylated arsenic was "alkylated" strongly by conjugation at the sites of C2' and C5' in the phenyl ring B of the catechin.The interaction mechanism between sodium(meta)arsenite and catechin was proposed.The results provide useful information to understand the chemical pathway of the detoxification of the arsenic toxicity by catechin.     

A SPECTROPHOTOMETRIC METHOD FOR CHLOROPLAST ATP SYNTHETASE ASSAY

Ultraviolet-B (UV-B,280–320 nm) irradiance was calculated for more than 1200 sites in Asia to characterize the spatial and temporal variation in the present UV-B climate for rice-growing regions. The analytical model of Green et al. (Photochem. Photobiol. 31 ,59–65, 1980) was used to compute UV-B irradiance for clear skies using satellite-observed ozone column thickness and local elevation data. Ground-based observations of cloud cover were then used to approximate the average effect of cloud cover on UV-B irradiance using the approach of Johnson et al. (Photochem. Photobiol. 23 ,179–188, 1976). Over the geographic range of rice cultivation, the maximum daily effective UV-B irradiance (UV-B_BE), when weighted according to a general plant action spectrum, was found to vary approx. 2.5-fold under both clear and cloudy sky conditions. Under clear skies, the timing of maximum solar UV-B_BE changed with latitude and varied from February-March near the equator to July-August at temperate locations. Cloud cover was found to alter the season of maximum UV-B_BE in many tropical regions, due to the pronounced monsoonal climate, but had little effect on UV-B seasonality at higher latitudes. Under a climate resulting from a doubling of atmospheric carbon dioxide, estimated UV-B using predicted cloud cover was found to change by up to 17% from present conditions in Thailand. Both latitudinal and seasonal variation in solar UV-B radiation may be important aspects of the UV-B climate for rice as cultivars differ in sensitivity to UV-B and are grown under diverse conditions and locations.     

Synthesis and Optical Properties of 2,13‐Dibenzothiazol‐2′‐yldibenzo[b,k]‐18‐crown‐6

A new crown ether of 2,13‐dibenzothiazol‐2′‐yldibenzo[b,k]‐18‐crown‐6 was synthesized from 2,13‐diformyl‐ dibenzo[b,k]‐18‐crown‐6 with 2‐aminothiophenol. The binding behavior and the optical properties of the crown ether were examined through UV‐visible spectroscopy and fluorescence spectroscopy. When complexed with Na⁺, K⁺, Rb⁺ and Cs⁺ ions, it led to intramolecular charge transfer and caused the changes of the fluorescence spectra. The protonation of the crown ether was also studied.     

Analysis of piezoelectric ceramic multilayer actuators based on an electro-mechanical coupled meshless method

This paper presents an efficient meshless method for analyzing cracked piezoelectric structures subjected to mechanical and electrical loading. In this method, an element free Galerkin (EFG) formulation, an enriched basic function and some special shape functions that contain discontinuous derivatives are employed. Based on the moving least squares (MLS) interpolation approach, the EFG method is one of the promising methods for dealing with problems involving progressive crack growth. Since the method is meshless and no element connectivity data are needed, the burdensome remeshing procedure required in the conventional finite element method (FEM) is avoided. The numerical results show that the proposed method can yield an accurate near-tip stress field in an infinite piezoelectric plate containing an interior hole. In another example studying a ceramic multilayer actuator, the proposed model was found to be accurate in the simulation of stress and electric field concentrations arround the abrupt end of an internal electrode. The project supported by the National Natural Science Foundation of China (10025209, 10132010, and 90208002), and the Research Grants Council of the Hong Kong Special Administrative Region, China (HKU 7203/03E). The English text was polished by Yunming Chen.     

CONTROLLING GROUNDWATER QUALITY WITH ENDOGENOUS REGULATORY INSTRUMENTS

ABSTRACT. This research presents a competitive dynamic model that endogenously evaluates the economics of regulatory tax-policy options. This model is then applied to an irrigated corn production area west of Kearney, Nebraska, where the average groundwater contamination level from nitrates is reported to be 8.7 parts per million (ppm). Results indicate that no regulatory policies are necessary for maintaining potable groundwater quality with either a surge-flow irrigation system or a sprinkler irrigation system. In areas where conventional furrow irrigation technology is being used, higher net economic benefits result from the adoption of a variable-tax on nitrogen fertilizer use, followed by a constant-unit tax and a pollution tax.