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1.
Maria Marques Zhengtian Yu Marvin D. Rausch James C. W. Chien 《Journal of polymer science. Part A, Polymer chemistry》1995,33(16):2787-2793
4-Vinylcyclohexene (VCH) and cyclooctadiene (COD) were investigated as termonomers in EPDM (ethylene/propylene/diene) synthesis by using rac-ethylenebis (1-η5-indenyl) zir-conium dichloride ( 1 ) as a catalyst precursor. Homopolymerizations of VCH, vinylcycloh-exane and cyclohexene were compared. The parameter Kπκp, which is the apparent rate constant for Ziegler-Natta polymerization, is about the same for VCH and vinylcyclohexanebut is 10 times smaller for cyclohexene. Therefore, the linear olefinic double bond is more active than the cyclic internal double bond. VCH reduces ethylene polymerization rate but not propylene polymerization rate in copolymerizations. In terpolymerizations, VCH tends to suppress ethylene incorporation especially at elevated polymerization temperature and Lowers the polymer MW by about two-fold. COD has very low activity as a termonomer. © 1995 John Wiley & Sons, Inc. 相似文献
2.
We have characterized multidielectric scaled SONOS nonvolatile memory structures with the quasi-static linear voltage ramp (LVR) technique and dynamic pulse measurements. We have formulated physically-based ERASE/WRITE and retention methods with deep level amphoteric traps which capture and emit carriers to the bands in the silicon nitride film. Amphoteric trap parameters are extracted by the LVR technique. ERASE/WRITE and retention amphoteric trap model simulations agree well with the experimental dynamic pulse measurements. Experimental scaled SONOS structures have been fabricated with tunnel oxide XOT=20 Å, nitride XN=30 Å and blocking oxide XOB=55 Å and demonstrated a static flatband shift of 3.6 V with ±5 V programming voltages. These structures may be used as the nonvolatile memory element in high density VLSI circuits. 相似文献
3.
Marvin D. Troutt M. Diane Pettypool 《The Journal of the Operational Research Society》1989,40(6):571-579
We first demonstrate that mixed strategies are relevant in decision analysis for a maximin decision-maker quite apart from any game-theory considerations. This rectifies the apparent misconception that results from MS/OR textbooks which discuss mixed strategies only in the game-theory setting. Next we show an example of an implementable mixed strategy, by which we mean a mixed decision strategy which does not require randomization for its implementation. This application is to portfolio construction. 相似文献
4.
5.
Ricardo Fierro James C. W. Chien Marvin D. Rausch 《Journal of polymer science. Part A, Polymer chemistry》1994,32(15):2817-2824
Racemic isopropylidene (1-η5-cyclopentadienyl)(1-η5-indenyl) dichlorozirconium and the 3-methylindenyl derivative have been synthesized and characterized. These precursors activated with methylaluminoxane produce poly(propylene) with hemiisotactic microstructures. © 1994 John Wiley & Sons, Inc. 相似文献
6.
John P. Priestle Jr Richard H. Rhyne Jr Jessie B. Salmon Marvin L. Hackerit 《Photochemistry and photobiology》1982,35(6):827-834
Abstract— Trimeric and hexameric solution forms of C-phycocyanin (CPC) from the cyanophyte Agme-nellum quadruplicatum have been isolated and their spectral properties compared to those obtained from single crystals. Although the absorbance peak of a suspension of small C-phycocyanin crystals is red-shifted only 7 nm relative to the solution forms, the single crystal fluorescence is red-shifted 60 nm relative to the solution forms. The crystal fluorescence spectrum exhibits a single peak at LDmax= 708 nm when excited at 514.5 or 530.9 nm and two peaks (LDmax= 661 and 708 nm) when excitation occurs at 568.2 nm. Fluorescence depolarization measurements indicate that extensive energy transfer could occur for both solution and crystal forms with the latter being dependent upon the relative orientation of the crystal with respect to the excitation dipole. Similar results were obtained with B-phycoerythrin (BPE) from the red alga Porphyridium cruentum where the single crystal fluorescence is red-shifted =50nm relative to the solution spectra with two peaks (LDmax= 583 and 617 nm) observed whose relative intensities are dependent on the excitation wavelength (LDmax– 514.5 and 530.9 nm). Single crystal fluorescent lifetimes exhibited considerable shortening relative to that observed for the solution forms. The implications of these results are discussed with respect to the possible relationships of the crystalline structures to the assembly forms present within phycobilisomes. 相似文献
7.
Prem C. Srivastava Marvin L. Tedjamulia Furn F. Knapp 《Journal of heterocyclic chemistry》1986,23(4):1167-1169
The synthesis and tissue distribution studies in rats of tetra[3H]-hydroberberine ([3H] 2 ) and 8-(p-[125I]iodobenzyl)tetrahydroberberine ([125I] 6 ) are described. Compound 2 was synthesized by sodium borohydride reduction of berberine hydrochloride ( 1 ). Treatment of berberine hydrochloride with p-bromo-benzylmagnesium bromide gave 8-(p-bromobenzyl)dihydroberberine ( 4 ) which after sodium borohydride reduction and iodine-125 bromine exchange gave [125I] 6 . The unsubstituted tetrahydro compound [3H] 2 showed significantly higher brain uptake (2.2% dose/gm after 5 minutes) as compared to the corresponding 8-substituted derivative [125I] 6 . Both radiolabeled compounds washed out from the brain relatively quickly. 相似文献
8.
Ananya Banik Theodosios Famprikis Michael Ghidiu Saneyuki Ohno Marvin A. Kraft Wolfgang G. Zeier 《Chemical science》2021,12(18):6238
The development of high-performance inorganic solid electrolytes is central to achieving high-energy- density solid-state batteries. Whereas these solid-state materials are often prepared via classic solid-state syntheses, recent efforts in the community have shown that mechanochemical reactions, solution syntheses, microwave syntheses, and various post-synthetic heat treatment routines can drastically affect the structure and microstructure, and with it, the transport properties of the materials. On the one hand, these are important considerations for the upscaling of a materials processing route for industrial applications and industrial production. On the other hand, it shows that the influence of the different syntheses on the materials'' properties is neither well understood fundamentally nor broadly internalized well. Here we aim to review the recent efforts on understanding the influence of the synthetic procedure on the synthesis – (micro)structure – transport correlations in superionic conductors. Our aim is to provide the field of solid-state research a direction for future efforts to better understand current materials properties based on synthetic routes, rather than having an overly simplistic idea of any given composition having an intrinsic conductivity. We hope this review will shed light on the underestimated influence of synthesis on the transport properties of solid electrolytes toward the design of syntheses of future solid electrolytes and help guide industrial efforts of known materials.Influence of synthesis and processing on the nature of ultimate product and the ionic transport properties of superionic conductors. 相似文献
9.
A synthesis of a-acyloxyamides is described which utilizes the reaction of 7-picoline N-oxide and various organic acids with diphenylketene N-p-tolylimine. 相似文献
10.
Hirotaka Kudo Marvin L. Tedjamulia Raymond N. Castle Milton L. Lee 《Journal of heterocyclic chemistry》1984,21(6):1833-1839
The synthesis of phenanthro[1,2-c]dibenzothiophene (6) , phenanthro[4,3-c]dibenzothiophene (10) , phenanthro[2,1-a]dibenzothiophene (14) , phenanthro[3,4-a]dibenzothiophene (16) , phenanthro[1,2-a]dibenzothiophene (19) , phenanthro[2,1-b]dibenzothiophene (20) , 8-methylphenanthro[3,2-a]dibenzothiophene (24) , 7-methylphenanthro[1,2-a]dibenzothiophene (25) , phenanthro[3,4-a]dibenzothiophene (27) , phenanthro[4,3-a]-dibenzothiophene (28) , 6-methylphenanthro[2,3-a]dibenzothiophene (31) , and 5-methylphenanthro[4,3-a]dibenzothiophene (32) is described. 相似文献