Remarks on Normal Generation of Special Line Bundles on Algebraic Curves

Let L be a very ample line bundle with h ¹(L) ≥2 on a curve of genus g. We prove that L is normally generated if deg(L) ≥2g ? 1 ? 4h ¹(L) for large enough genus g.     

Iron speciation and mineral characterization of upper Jurassic reservoir rocks in the Minhe Basin,NW China

Six samples from a natural outcrop of reservoir rocks with oil seepage and two control samples from surrounding area in the Minhe Basin, northwestern China were selectively collected and analyzed for mineralogical composition as well as iron speciation using X-ray powder diffraction (XRD) and Mössbauer spectroscopy, respectively. Iron species revealed that: (1) the oil-bearing reservoir rocks were changed by water-rock-oil interactions; (2) even in the same site, there was a different performance between sandstone and mudstone during the oil and gas infusion to the reservoirs; and (3) this was evidence indicating the selective channels of hydrocarbon migration. In addition, these studies showed that the iron speciation by Mössbauer spectroscopy could be useful for the study of oil and gas reservoirs, especially the processes of the water-rock interactions within petroleum reservoirs.     

Steady surface modification of polydimethylsiloxane microchannel and its application in simultaneous analysis of homocysteine and glutathione in human serum

A novel polydimethylsiloxane (PDMS) surface modification method for microchip electrophoresis has been developed to make a stable and sufficient electroosmotic flow (EOF). Poly(l-glutamic acid) (PGA) which had ionizable carboxyl groups at a high pH-range was immobilized on the surface of microchannel fabricated with PDMS. The surface modification involved surface oxidation by plasma, the silanization of 3-aminopropyldimethylethoxysilane (APDMES) and immobilization of PGA via amide bond. The modified channel was extremely stable against consecutive electric power supply over 5h, and its long-term stability was demonstrated by the efficient separation of four amino acid derivatives reproducibly after a week. Additionally, homocysteine (Hcy), important risk factor of cardiovascular disease, osteoporosis and problems in pregnancy, was successfully measured in human serum in modified PDMS channel with the other thio amino acid simultaneously.     

Development of laser photoelectron spectroscopy based on resonantly enhanced multiphoton ionization

This review article is mainly concerned with laser photoelectron spectroscopy based on REMPI (resonantly enhanced multiphoton ionization), consisting of two parts. One is associated with the measurement of photoelectron kinetic-energy distribution and the other is associated with the measurement of zero-kinetic-energy (ZEKE) photoelectrons in very high resolution. These two techniques are complementary to each other. During the last three decades, the author and co-workers have carried out photoelectron spectroscopic studies of molecules in the gas phase, using the HeI 584 Å resonance line and a nanosecond tunable UV–visible laser. In this article, firstly the author’s background in the field of molecular photoelectron spectroscopy is described briefly, by mentioning three topics of HeI photoelectron spectroscopy. Secondly, the principle and characteristics of laser photoelectron kinetic-energy spectroscopy and its application to several typical topics, namely, one-photon forbidden states (O₂), autoionization from a super-excited state (NO), and small van der Waals molecules (NO–Ar and the NO₂ dimer), and some others. Thirdly, the principle and characteristics of ZEKE photoelectron spectroscopy are described, together with its application to the following several topics: (1) rotational spectra of NO⁺, (2) vibrational coupling of (naphthalene)⁺, (3) large-amplitude torsional motion of (tolane)⁺, (4) rotational isomers of (cis and trans n-propylbenzene)⁺ and structural isomers of (2-hydroxypyridine)⁺, (5) proton tunneling of (tropolone)⁺ and (9-hydroxyphenalenone)⁺, (6) intramolecular vibrational redistribution of trans stilbene, and (7) cation van der Waals molecules of aniline–Ar_n (n=1,2) and azulene–Ar. All the results mentioned as examples are those obtained in the author’s laboratory.     

Enhancement of electroluminescence intensity in poly(3-alkylthiophene) with different alkyl side-chain length by doping of fluorescent dye

Electroluminescent diodes utilizing poly(3-alkylthiophene) (PAT) containing fluorescent dyes have been fabricated and their unique enhancement of emission characteristics have been studied. Remarkable enhancement of the electroluminescence efficiency has been observed for diodes with PAT doped with oxadiazole derivative (2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole; PBD) and perylene derivative (N,N′ - Bis(2,5 - di - tert - butylphenyl) - 3,4,9,10 - perylenedi- carboximide; BPPC). The mechanism of emission enhancement by doping of PBD into PAT has been discussed with different alkyl side-chain lengths. © 1997 John Wiley & Sons, Ltd.