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71.
72.
We previously introduced and analyzed the G
t
/M
t
/s
t
+GI
t
many-server fluid queue with time-varying parameters, intended as an approximation for the corresponding stochastic queueing
model when there are many servers and the system experiences periods of overload. In this paper, we establish an asymptotic
loss of memory (ALOM) property for that fluid model, i.e., we show that there is asymptotic independence from the initial
conditions as time t evolves, under regularity conditions. We show that the difference in the performance functions dissipates over time exponentially
fast, again under the regularity conditions. We apply ALOM to show that the stationary G/M/s+GI fluid queue converges to steady state and the periodic G
t
/M
t
/s
t
+GI
t
fluid queue converges to a periodic steady state as time evolves, for all finite initial conditions. 相似文献
73.
Anthony D. Appelhans John E. Olson David A. Dahl Michal B. Ward Troy A. Robinson James E. Delmore 《Journal of Radioanalytical and Nuclear Chemistry》2018,315(2):207-209
A new isotope separator has been designed, constructed, and put into routine operation for separation of 133Xe providing a major advancement and significant cost reduction in preparation of this radioactive isotope. The design features and advantages are discussed that expedite high purity separation of relatively small quantities of this isotope. These advantages could be easily used to expedite separation of other shorter-lived radioactive isotopes. 相似文献
74.
Madison J. Sowden Dr. Jas S. Ward Prof. Michael S. Sherburn 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(10):4174-4182
The first general preparative access to compounds of the 2,3-diethynyl-1,3-butadiene (DEBD) class is reported. The synthesis involves a one-pot, twofold Sonogashira-type, Pd0-catalyzed coupling of two terminal alkynes and a carbonate derivative of a 2-butyne-1,4-diol. The synthesis is broad in scope and members of this structural family are kinetically stable enough to be handled using standard laboratory techniques at ambient temperature. They decompose primarily through heat-promoted cyclodimerizations, which are impeded by alkyl substitution and accelerated by aryl or alkenyl substitution. An iterative sequence of these unprecedented Sonogashira-type couplings generates a new type of expanded dendralene. A suitably substituted DEBD carrying two terminal alkyne groups undergoes Glaser–Eglinton cyclo-oligomerization to produce a new class of expanded radialenes, which are chiral due to restricted rotation about their 1,3-butadiene units. The structural features giving rise to atropisomerism in these compounds are distinct from those reported previously. 相似文献
75.
Journal of Radioanalytical and Nuclear Chemistry - Polonium is rapidly emerging as an international environmental health concern primarily because of the recent rise in hydraulic fracturing... 相似文献
76.
Ariadna Lázaro Cristina Balcells Dr. Josefina Quirante Prof. Josefa Badia Prof. Laura Baldomà Dr. Jas S. Ward Prof. Kari Rissanen Dr. Mercè Font-Bardia Prof. Laura Rodríguez Dr. Margarita Crespo Prof. Marta Cascante 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(9):1947-1952
Platinum-based chemotherapy persists to be the only effective therapeutic option against a wide variety of tumours. Nevertheless, the acquisition of platinum resistance is utterly common, ultimately cornering conventional platinum drugs to only palliative in many patients. Thus, encountering alternatives that are both effective and non-cross-resistant is urgent. In this work, we report the synthesis, reduction studies, and luminescent properties of a series of cyclometallated (C,N,N′)PtIV compounds derived from amine–imine ligands, and their remarkable efficacy at the high nanomolar range and complete lack of cross-resistance, as an intrinsic property of the platinacycle, against multiplatinum-resistant colorectal cancer (CRC) and castration-resistant prostate cancer (CRPC) metastatic cell lines generated for this work. We have also determined that the compounds are effective and selective for a broader cancer panel, including breast and lung cancer. Additionally, selected compounds have been further evaluated, finding a shift in their antiproliferative mechanism towards more cytotoxic and less cytostatic than cisplatin against cancer cells, being also able to oxidize cysteine residues and inhibit topoisomerase II, thereby holding great promise as future improved alternatives to conventional platinum drugs. 相似文献
77.
Summary An increasingly important problem in exploratory data analysis and visualization is that of scale; more and more data sets
are much too large to analyze using traditional techniques, either in terms of the number of variables or the number of records.
One approach to addressing this problem is the development and use of multiresolution strategies, where we represent the data
at different levels of abstraction or detail through aggregation and summarization. In this paper we present an overview of
our recent and current activities in the development of a multiresolution exploratory visualization environment for large-scale
multivariate data. We have developed visualization, interaction, and data management techniques for effectively dealing with
data sets that contain millions of records and/or hundreds of dimensions, and propose methods for applying similar approaches
to extend the system to handle nominal as well as ordinal data. 相似文献
78.
L. Ward 《Optics & Laser Technology》1997,29(2):103-108
Abelès' equations (in terms of 1; 2 and optical film thickness x) for all the eight optical functions (Rs; Rp; Ts; Tp; Fs; Fp; Xs and Xp) have been expressed in the form of equations representing standard geometrical three-dimensional figures. Xs and Xp are represented by plane surfaces whilst the remainder are skew cones. Translated into the n; k notation; Xs and Xp generate hyperboloids whilst the remainder produce paraboloids whose cross-sections are parts of figures of eight. 相似文献
79.
The motion of internal layers for three singularly perturbed reaction diffusion problems, including the Allen–Cahn equation, is studied in a two-dimensional dumbbell-shaped domain. The channel region that connects the two attachments, or lobes, of the dumbbell is taken to be rectangular. The motion of straight-line internal layers in the channel region is analyzed by using an asymptotic projection method. It is shown that this motion is metastable and highly dependent on the local convexity properties of the boundary near the contact region between the ends of the channel and the two attachments. When the domain is nonconvex it is shown that the metastable internal layers dynamics in the channel tends, as t →∞, to a limiting, stable, spatially inhomogeneous equilibrium solution. 相似文献
80.
A.?N.?WilsonEmail author G.?D.?Dracoulis A.?P.?Byrne P.?M.?Davidson G.?J.?Lane R.?M.?Clark P.?Fallon A.?G?rgen A.?O.?Macchiavelli D.?Ward 《The European Physical Journal A - Hadrons and Nuclei》2005,24(2):179-183
A superdeformed band has been observed in the N = 108 isotope 190Pb. This is the most neutron-deficient Pb isotope in which superdeformed states have been observed. Several theoretical approaches have predicted that N = 108 will mark the limit of observable superdeformation in the Pb isotopes. The band, which consists of five (possibly six) transitions, is observed to feed at least one isomeric level in its decay to the ground state. This decay pattern supports a spin assignment of 10 for the lowest observed level. 相似文献