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71.
We prove the existence of a simultaneous projectional skeleton for certain subspaces of C(K) spaces. This generalizes a result on simultaneous projectional resolutions of identity proved by M. Valdivia. We collect some consequences of this result. In particular we give a new characterization of Asplund spaces using the notion of projectional skeleton. 相似文献
72.
73.
对于GI^(1) GI^(2)/G/I排队模型,本借助献[1]中引入的Markov骨架过程方法求出了此模型到达过程,等待时间及队长的概率分布。 相似文献
74.
Joseph Feit 《International Journal of Mathematical Education in Science & Technology》2013,44(4):463-471
It is advocated that introductory calculus texts should present topics in a manner that is understandable to students without necessarily sacrificing rigour. Illustrative examples are given of a conversational approach to problem solving. 相似文献
75.
Recently, observation and tracking of single fluorophores, which we term single fluorophore dynamic imaging (SFDI) in this review, in living cells have been achieved. In particular, the recent success of SFDI of individual proteins tagged with green fluorescent protein (GFP) in live cells has opened new important possibilities for studying events occurring in living cells at the level of single molecules. Specifically, SFDI of GFP allows the tracking of movement and oligomerization levels of individual oligomers (monomers) in living cells and, thus, provides powerful means to investigate the movement, assembly, localization, and activation that signaling molecules undergo following an external stimulus. In this short account, we first review technologically important points for SFDI of GFP molecules in living cells, then give examples of its application, and, finally, propose a synergistic use of SFDI and single-particle tracking, a technique used for investigating single or small groups of molecules in live cells over the past 15 years. 相似文献
76.
77.
The title compound,spiro[1-bromo-4-l-menthyloxy-5-oxo-6-oxa-bicyclo[3.1.0]-hexane-2,2'-3'-(16'-methoxyacetatyl-4'-l-menthyloxybutyrolactone)] 1,was obtained via tandem asymmetric double Michael addition/internal nucleophilic substitution of the chiral synthon,5-l-menthyloxy-3-bromo-2-(5H)-furanone 2 with methoxy α-chloroacetate as a nucleophile under mild conditions,and structurally determined by single-crystal X-ray diffraction.Crystal data:C31H47BrO9,Mr = 643.60,orthorhombic,space group P212121,a = 9.6564(7),b = 14.8994(11),c =23.6771(17) (A),V= 3406.5(4) (A)3,Z= 4,Dc= 1.255 g/cm3,λ(MoKα) = 0.71073(A),μ= 1.254 mm-1and F(000) = 1360.The structure was refined to R =0.0324 and wR = 0.0737 for 5123 observed reflections (I > 2σ(I)).The crystallographic results of molecule 1 show that the interesting reaction of 2 with methoxy α-chloroacetate,in the usual manner,gave the spiro-cyclopropane skeleton with O-linked derivative containing multiple stereogenic centers 1 rather than the expected C-linked derivative. 相似文献
78.
We present primary and secondary generators for the algebra of polynomial invariants of the direct product of two copies of the special linear group Sl3 acting naturally on triples of 3 × 3 matrices over a field of characteristic zero. We handle also the analogous problem for triples and quadruples of 2 × 2 matrices. 相似文献
79.
Giampiero Chiaselotti 《Annali di Matematica Pura ed Applicata》2001,180(3):359-372
We simplify the Steinberg presentation of SL
n
(F
d
), where n≥1 and F
d
is any finite field with d elements. That presentation has the elementary matrices e
ij
(r), with i,j∈{1,...,n}, i≠=j and r∈F
d
, as generators, and (E1)–(E3), described at the opening of this work, as relations. The presentation that we shall obtain
reduces the number of generators e
ij
(r) and relations (E1)–(E3). In particular, relations (E3) are considerably reduced.
Received: March 16, 1998; in final form: November 3, 2000?Published online: October 2, 2001 相似文献
80.
Surasak Seesukphronrarak Shinichi Kawasaki Kana Kobori Toshikazu Takata 《Journal of polymer science. Part A, Polymer chemistry》2007,45(14):3073-3082
Several poly(arylene thioether)s ( PTEs ) containing a fluorene moiety were synthesized by the polycondensation of masked dithiols such as 9,9‐bis(4‐(N,N‐dimethyl‐S‐carbamoyl)phenyl)fluorene and various difluoroarenes. All PTEs were obtained in quantitative yields. The PTEs showed good thermal stability: the 10% weight loss temperature was over 480 °C under both nitrogen and air atmosphere by TGA, and glass temperature was within a range of 204–275 °C by DSC. Most PTEs exhibited remarkably high refractive index values in a range of 1.66–1.72 at 589 nm, whereas they had a very low degree of birefringence properties. Furthermore, the PTEs showed high solubility in ordinary organic solvents such as chloroform, N‐methylpyrrolidone, and tetrahydrofuran. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 3073–3082, 2007 相似文献