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51.
This paper reports on the instrumental and experimental prerequisites of the combination of high temperature gas chromatography (HTGC) with electron impact- (El) and chemical ionization (Cl) mass spectrometry (HTGC/EI/CIMS). It describes a newly developed high temperature GC/MS interface in detail and discusses the particular problems arising in HTGC/MS. The capabilities of the system are demonstrated by direct analyses of nickel- and vanadyl porphyrins, extracted from Julia Creek oil shale. The use of CI/NH3 in the GC/MS analysis of metalloporphyrins is demonstrated for the first time. 相似文献
52.
DynamicsofPolynomialAutomorphismsofC~N¥ZhangWenjun(HenanUniversity,Kaifeng,P.R.Chian,475001)Abstract:Thispaperisassignedtodis?.. 相似文献
53.
We shall discuss the topological properties of the Fatou sets for holomorphic maps. Let f
1,f
2,....,f
N
be non-constant holomorphic maps in the plane, each having order less than 1/2. It is shown that if the lower order of f
j
, is greater than 0 for some j{1,2,...,N}, then the Fatou set of the map h=f
N
f
N-1 ... f
1 has no unbounded components 相似文献
54.
A novel Ti(Oi‐Pr)4 mediated olifination between Julia reagent and aldehydes has been developed. By this method, a series of substituted vinyl sulfones are prepared under mild conditions, all products are exclusively E isomers. All the structures of these compounds were confirmed by 1H NMR, 13C NMR HRMS and IR. 相似文献
55.
We introduce a Fourier-based harmonic analysis for a class of discrete dynamical systems which arise from Iterated Function Systems. Our starting point is the following pair of special features of these systems. (1) We assume that a measurable space comes with a finite-to-one endomorphism which is onto but not one-to-one. (2) In the case of affine Iterated Function Systems (IFSs) in , this harmonic analysis arises naturally as a spectral duality defined from a given pair of finite subsets in of the same cardinality which generate complex Hadamard matrices.
Our harmonic analysis for these iterated function systems (IFS) is based on a Markov process on certain paths. The probabilities are determined by a weight function on . From we define a transition operator acting on functions on , and a corresponding class of continuous -harmonic functions. The properties of the functions in are analyzed, and they determine the spectral theory of . For affine IFSs we establish orthogonal bases in . These bases are generated by paths with infinite repetition of finite words. We use this in the last section to analyze tiles in .
56.
Lian Rong Ding 《数学学报(英文版)》2010,26(2):265-276
In this paper, we study the dynamics of the family of rational maps fλ,(z) = zn - λ/zm, n ≥2, m ≥ 1,λ ∈ C. We construct an example of buried Sierpinski curve Julia set in this family. We also give an estimate of the location of bifurcation locus of fλ. 相似文献
57.
Stephen M BerberichRobert J Cherney John ColucciChristine Courillon Leo S GeraciThomas A Kirkland Matthew A MarxMatthias F Schneider Stephen F Martin 《Tetrahedron》2003,59(35):6819-6832
A convergent total synthesis of the novel antifungal agent ambruticin S (1) has been completed from the assembly of intermediates 18, 33 and 52 that served as the respective A-, B-, and C-ring precursors. The first generation approach to a potential A-ring intermediate eventuated in the synthesis of 9a via a route that featured oxidation of the dihydroxy furan 2 and elaboration of the dihydropyranone 3 derived therefrom. Although 9a served as a precursor of 31E to complete a formal synthesis of 1, there were several inefficiencies associated with the preparation of 9a. A more expedient and efficient route to an A-ring subunit was devised that commenced with the carbohydrate-derived bisacetonide aldehyde 10 and produced 18 in five steps and 46% overall yield. The synthesis of the cyclopropyl sulfone 33 was initiated with the enantioselective cyclopropanation of 19 catalyzed by Rh2[5(S)-MEPY]4. Ring opening of the resultant lactone 20 followed by a series of refunctionalizations gave 33 in a total of seven steps and 46% yield from 19. Coupling of the A- and B-ring precursors 18 and 33 was then achieved via a modified Julia coupling followed by deprotection and oxidation to furnish the key intermediate 35. The dihydropyran core of the C-ring subunit precursor 49 was formed from the ring closing metathesis of the diene 48, which was prepared in three steps from the known epoxide 45, followed by oxidation. A chelation-controlled addition to the methyl ketone 49 set the stage for a stereoselective [2,3]-Wittig rearrangement that delivered the alcohol 51 that was then transformed in two steps to the sulfone 52. A traditional Julia coupling of 52 and 35 proceeded with excellent stereoselectivity, and subsequent removal of the various protecting groups gave ambruticin S (1). The longest linear sequence was 13 steps and proceeded in 4.3% overall yield. 相似文献
58.
Considering the Julia set J(Tλ) of the Yang-Lee zeros of the Potts model on the diamond hierarchical Lattice on the complex plane, the authors proved that HDJ(Tλ) 〉 1 and discussed the continuity of J(Tλ) in Hausdorff topology for λ∈R. 相似文献
59.
Fang Liping 《数学学报(英文版)》1998,14(1):139-144
Letf be a holomorphic self-map of the punctured plane ℂ*=ℂ\{0} with essentially singular points 0 and ∞. In this note, we discuss the setsI
0(f)={z ∈ ℂ*:f
n
(z) → 0,n → ∞} andI
∞(f)={z ∈ ℂ*:f
n
(z) → 0,n → ∞}. We try to find the relation betweenI
0(f),I
∞(t) andJ(f). It is proved that both the boundary ofI
0(f) and the boundary ofI
∞)f) equal toJ(f),I
0(f) ∩J(f) ≠ θ andI
∞(f) ∩J(f) ≠ θ. As a consequence of these results, we find bothI
0(f) andI
∞(f) are not doubly-bounded.
Supported by the National Natural Science Foundation of China 相似文献
60.
一个稳态轴对称非Kerr Newman黑洞时空中的粒子能级分布与电磁四维势有关,黑洞电荷和磁偶极矩的存在以及裸奇点的出现都对粒子能级分布有影响,粒子能级分布与方向有关。此黑洞的量子非热辐射及其粒子的平均射程与辐射粒子的能量范围有关。 相似文献