Tracer kinetic modeling of ¹¹C-acetate applied in the liver with positron emission tomography

Author name used in this publication: Dagan FengAuthor name used in this publication: Zheru ChiCentre for Multimedia Signal Processing, Department of Electronic and Information Engineering2003-2004 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

A spin injector

We theoretically put forward a spin injector, which consists of a three-terminal ferromagnetic-metal (FM) nonmagnetic-semiconductor (NS)-superconductor (SC) mesoscopic hybrid system. This device can inject not only the spin-up current but also the pure spin current into the NS lead. The crossed Andreev reflection plays a key role in this device. Such a spin injector may be realized within the reach of the present-day technology. © 2004 American Institute of Physics.published_or_final_versio

Modeling electrically small structures in layered medium with augmented EFIE method

Electrically small structures embedded in a planarly layered medium are modeled by the augmented electric field integral equation (EFIE) method in this paper. By separating charge as extra unknown list, and enforcing the current continuity equation, an augmented EFIE (A-EFIE) can be setup. The matrix-friendly formulation of layered medium Green's function is applied and the frequency scaling of the impedance matrix in the moment method is analyzed when the frequency tends to zero. Rank deficiency and the charge neutrality enforcement is also discussed in detail. Numerical results show that the low frequency breakdown of electrically small structures embedded in a layered medium can be effectively remedied by this A-EFIE method. © 2011 IEEE.published_or_final_versionThe 2011 IEEE International Symposium on Antennas and Propagation (APSURSI), Spokane, WA., 3-8 July 2011. In IEEE APSURSI Digest, 2011, p. 3218-322

An augmented electric field integral equation for layered medium Green's function

This paper proposes an augmented electric field integral equation (A-EFIE) for layered medium Green's function. The newly developed matrix-friendly formulation of layered medium Green's function is applied in this method. By separating charge as extra unknown list, and enforcing the current continuity equation, the traditional EFIE can be cast into a generalized saddle-point system. Frequency scaling for the matrix-friendly formulation is analyzed when frequency tends to zero. Rank deficiency and the charge neutrality enforcement of the A-EFIE for layered medium Green's function is discussed in detail. The electrostatic limit of the A-EFIE is also analyzed. Without any topological loop-searching algorithm, electrically small conducting structures embedded in a general layered medium can be simulated by using this new A-EFIE formulation. Several numerical results are presented to validate this method at the end of this paper. © 2010 IEEE.published_or_final_versio

Relationship between climatic conditions and the relative abundance of modern C<inf>3</inf> and C<inf>4</inf> plants in three regions around the North Pacific

Using -24‰ and -14‰ as the endpoints of stable carbon isotopic composition of total organic carbon (δ13CTOC) of surface soil under pure C3 and C4 vegetation, and surface soil δ13CTOC data from eastern China, Australia and the Great Plains of North America, we estimate the relative abundance of C3/C4 plants (i. e., the ratio of C3 or C4 biomass to local primary production) in modern vegetation for each region. The relative abundance of modern C3/C4 vegetation from each region is compared to the corresponding climatic parameters (mean annual temperature and precipitation) to explore the relationship between relative C4 abundance and climate. The results indicate that temperature controls the growth of C4 plants. However, even where temperature is high enough for the growth of C4 plants, they will only dominate the landscape when precipitation declines as temperatures increase. Our results are consistent with those of other investigations of the geographic distribution of modern C4 plant species. Therefore, our results provide an important reference for interpretation of past C3/C4 relative abundance records in these three regions. © 2010 Science China Press and Springer-Verlag Berlin Heidelberg