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191.
We consider a MAP-modulated fluid flow queueing model with multiple vacations. As soon as the fluid level reaches zero, the server leaves for repeated vacations of random length V until the server finds any fluid in the system. During the vacation period, fluid arrives from outside according to the MAP (Markovian Arrival Process) and the fluid level increases vertically at the arrival instance. We first derive the vector Laplace–Stieltjes transform (LST) of the fluid level at an arbitrary point of time in steady-state and show that the vector LST is decomposed into two parts, one of which the vector LST of the fluid level at an arbitrary point of time during the idle period. Then we present a recursive moments formula and numerical examples. 相似文献
192.
Sang Sub Kim Sun-Woo Choi Han Gil Na Dong Sub Kwak Yong Jung Kwon Hyoun Woo Kim 《Current Applied Physics》2013,13(3):526-532
ZnO–SnO2 branch–stem nanostructures were realized on a basis of a two-step process. In step 1, SnO2-stem nanowires were synthesized. In step 2, ZnO-branch nanowires were successfully grown on the SnO2-stem nanowires through a simple evaporation technique. We have pre-deposited thin Au layers on the surface of SnO2 nanowire stems and subsequently evaporated Zn powders on the nanowires. The ZnO branches, which sprouted from the SnO2 stems, had diameters in a range of 30–35 nm. As-synthesized branches were of single crystalline hexagonal ZnO structures. Since the branch tips were comprised of Au-containing nanoparticles, the Au-catalyzed vapor–liquid–solid growth mechanism was more likely to control the growth process of the ZnO branches. To test a potential use of ZnO–SnO2 branch–stem nanostructures in chemical gas sensors, their sensing performances with respect to NO2 gas were investigated, showing the promising potential in chemical gas sensors. 相似文献
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195.
Readily Accessible and Predictable Naphthalene‐Based Two‐Photon Fluorophore with Full Visible‐Color Coverage
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Ja Young Koo Cheol Ho Heo Dr. Young‐Hee Shin Dahahm Kim Dr. Chang Su Lim Prof. Dr. Bong Rae Cho Prof. Dr. Hwan Myung Kim Prof. Dr. Seung Bum Park 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(40):14166-14170
Herein we report 22 acedan‐derived, two‐photon fluorophores with synthetic feasibility and full coverage of visible wavelength emission. The emission wavelengths were predicted by computational analysis, which enabled us to visualize multicolor images by two‐photon excitation with single wavelength, and to design a turn‐on, two‐photon fluorescence sensor for endogenous H2O2 in Raw 264.7 macrophage and rat brain hippocampus ex vivo. 相似文献
196.
We present a characterization of the open unit ball in a separable infinite dimensional Hilbert space by the property of automorphism
orbits among the domains that are not necessarily bounded. This generalizes the recent work of Kim and Krantz [6]. Key new
features of this article include: a lower bound estimate of the Kobayashi metric and distance near a pluri-subharmonic peak
boundary point of the domains in Banach spaces, an effective localization argument, and an improvement of weak-type convergence
of sequences of biholomorphic mappings of domains in Banach spaces. 相似文献
197.
Choi EY Kim D Hong BK Kwon HM Song YG Byun KH Park HY Whang KC Kim HS 《Experimental & molecular medicine》2002,34(6):391-400
Chlamydia pneumoniae infection implicated as an important etiologic factor of atherosclerosis, especially in coronary artery disease (CAD), was found in vitro to be associated with the induction of matrix metalloproteinases (MMPs). An extracellular matrix metalloproteinase inducer (EMMPRIN)/ membrane-type 1 matrix metalloproteinase (MT1-MMP) system which induces and activates MMPs, is suggested to be functional and were upregulated in the failing myocardium. However, the upstream regulation of MMPs by C. pneumoniae within atheroma itself remains unclear. We evaluated the seroepidemiologic study of C. pneumoniae infection in CAD patients (n= 391) and controls (n=97) and performed histopathological and in vitro analysis in atherosclerotic vascular tissues obtained from patients with seropositive to C. pneumoniae (n=20), by using immunochemistry for C. pneumoniae, EMMPRIN/MT1-MMP, MMP-2, and MMP-9. The seropositive rates of both anti-C. pneumoniae IgG and IgA were 56.7% in CAD group and 43.3% in control group (P=0.033). Seropositive rate was increased in subgroups of CAD patients without conventional coronary risk factors compared to those with conventional risk factors. Immunoreactivities of EMMPRIN, MT1-MMP, MMP-2, and MMP-9 were increased in the atheromatous plaque itself, predominantly in immunoreactive macrophages/mononuclear cells to C. pneumoniae. Furthermore, Western blot analysis showed that EMMPRIN and MMP-2 were detected more prominently in atherosclerotic tissues infected with C. pneumoniae compared to control tissues. Zymographic analysis revealed that activities of MMP-2 and MMP-9 were more increased in atherosclerotic tissues infected with C. pneumoniae compared to control tissues. The present study demonstrated upstream regulation of MMPs can be induced by C. pneumoniae within atheromatous plaque itself. These findings help to understand the potential role of C. pneumoniae in the progression of atherosclerosis. 相似文献
198.
[reaction: see text] 2'-Deoxy-2'-C-difluoromethylene-4'-thiocytidine (4) as a potential antitumor agent was synthesized starting from L-xylose via 2-deoxy-2-C-difluoromethylene-4-thiosugar as a key intermediate. An elimination product, 8, was always formed as the major product during removal of the protecting groups under acidic or basic conditions. However, utilizing neutral reaction conditions to remove the protecting groups afforded the desired product 4 exclusively. 相似文献
199.
Surface-enhanced emission from single semiconductor nanocrystals 总被引:1,自引:0,他引:1
The fluorescence behavior of single CdSe(ZnS) core-shell nanocrystal (NC) quantum dots is dramatically affected by electromagnetic interactions with a rough metal film. Observed changes include a fivefold increase in the observed fluorescence intensity of single NCs, a striking reduction in their fluorescence blinking behavior, complete conversion of the emission polarization to linear, and single NC exciton lifetimes that are >10(3) times faster. The enhanced excited state decay process for NCs coupled to rough metal substrates effectively competes with the Auger relaxation process, allowing us to observe both charged and neutral exciton emission from these NC quantum dots. 相似文献
200.
There is a homotopy equivalence :MM' between closed smooth manifoldsof an odd dimension such that *TM', TM are stably isomorphicbut not isomorphic to each other. 相似文献