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151.
We show that in six-quark models with a hierarchy of small mixing angles, θ3 < θ2 ? 1, and a sizable CP-violating phase δ ~ 1, there is a large difference in the angular distributions, as well as in the rates, when comparing a particular nonleptonic decay mode of a meson containing one bottom quark with the same decay mode of the antiparticle. 相似文献
152.
Saul Barshay 《Physics letters. [Part B]》1978,78(4):384-388
New laboratory probes for the occurence of meson condensation in nuclei are proposed. They involve experiments which detect the simultaneous emission of two photons. Pion condensation stimulates a new mechanism for such emission which depends essentially upon the ratio of the condensate amplitude to the vacuum expectation value of the effective scalar meson field. We exhibit the special features of this mechanism for the photon energy spectrum and angular correlation, and compare with other mechanisms. 相似文献
153.
The role of coordinate systems in boundary-layer theory 总被引:1,自引:0,他引:1
Saul Kaplun 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》1954,5(2):111-135
Zusammenfassung Die Grenzschichtnäherung zu einem gegebenen Strömungsproblem ist nicht invariant, das heisst, sie hängt von dem Koordinatensystem ab, in dem der Näherungsprozess durchgeführt wird. Zwar ist die von der Flüssigkeit ausgeübte Reibungskraft von der Wahl des Koordinatensystems unabhängig, aber das Strömungsfeld selbst hängt im allgemeinen vom Koordinatensystem ab. Theorem 1 besagt, dass die Grenzschichtlösung eines Koordinatensystems durch eine einfache Substitution in die Lösung irgendeines anderen Systems übergeführt werden kann. Nur wenn die zwei Koordinatensysteme durch eine ganz spezielle Beziehung verbunden sind, bleibt das entsprechende Strömungsfeld dabei unverändert. Diese Abhängigkeit des Strömungsfeldes von der Wahl des Koordinatensystems wird benutzt, um Theorem 2 zu beweisen, das besagt, dass Koordinatensysteme gefunden werden können, die in dem folgenden Sinne optimal sind: Die entsprechende Grenzschichtlösung ist im ganzen Raum, auch ausserhalb der eigentlichen Grenzschicht, als Näherung gültig. Sie enthält die äussere Potentialströmung und auch die Strömung, die von der Verdrängungswirkung der Grenzschicht herrührt. Durch dieses Theorem wird das Problem hinfällig, wie man die äussere Potentiallösung und die innere Grenzschichtlösung an irgendeinem Rande der Grenzschicht zusammenfügt. Die vorliegende Arbeit beschränkt sich auf Strömungen ohne Ablösung, weil die Grenzschichttheorie im Ablösungsfalle mit prinzipiellen Schwierigkeiten behaftet ist. Es wird ausserdem vorausgesetzt, dass die Strömung zweidimensional, stationär und inkompressibel ist. Die letzteren Beschränkungen sind weniger wesentlich und werden in einer demnächst erscheinenden Arbeit diskutiert.
Research prepared under Office of Naval Research Contract N 6 ONR-244, Task Order VIII, Project NR 061-036. 相似文献
Research prepared under Office of Naval Research Contract N 6 ONR-244, Task Order VIII, Project NR 061-036. 相似文献
154.
155.
Manson JL Woods TJ Lapidus SH Stephens PW Southerland HI Zapf VS Singleton J Goddard PA Lancaster T Steele AJ Blundell SJ 《Inorganic chemistry》2012,51(4):1989-1991
Square-planar S = 1/2 Ag(II) ions in polymeric Ag(nic)(2) are linked by bridging nic monoanions to yield 2D corrugated sheets. Long-range magnetic order occurs below T(N) = 11.8(2) K due to interlayer couplings that are estimated to be about 30 times weaker than the intralayer exchange interaction. 相似文献
156.
157.
Saul Lubkin 《Journal of Number Theory》1979,11(3):412-464
In Section 1, if is a c.d.v.r. with quotient field of characteristic zero and residue class field k, if is an -algebra and if ?k, then for algebraic families X over A that are polynomially properly embeddable over , we define the lifted p-adic homology with compact supports2 ?zQ), which are functors with respect to proper maps. In Section 2, it is shown that, if X is an algebraic variety over k (i.e., if A = k), then the lifted p-adic homology of X with compact supports with coefficients in K is finite dimensional over K = quotient field of . In Section 3, the results of Sections 1 and 2 are used to generalize both the statement and proof of the Weil “Lefschetz Theorem” Conjecture and the statement (but not the proof) of the Weil “Riemann Hypothesis” Conjecture, to non-complete, singular varieties over finite fields. In addition, the Weil zeta function of varieties over finite fields, is generalized by a device which we call the zeta matrices, Wh(X), 0 ≤ h ≤ 2 dim X, of an algebraic variety X, to varieties over even infinite fields of non-zero characteristic. These are used to give formulas for the zeta functions of each variety in an algebraic family, by means of the zeta matrices of an alebraic family. Sketches only are given. In Section 4, some of the material is duplicated, to define a q-adic homology with compact supports, q ≠ characteristic. The definition only makes sense for algebraic varieties; finite generation is proved. And the Weil “Lefschetz Theorem” Conjecture is established, even for singular, non-complete varieties, as well as a generalization of the Weil “Riemann Hypothesis” Conjecture. (However, zeta matrices do not make sense q-adically.)In Section 5, some special results are proved about p-adic homology with compact supports on affines. And the Weil “Riemann Hypothesis” conjecture is proved p-adically, p = characteristic, for projective, non-singular liftable varieties. 相似文献
158.
Herbert Meier Klaus Saul Rudolf Mengel Hans-Peter Niedermann 《Journal of heterocyclic chemistry》1991,28(4):843-848
Benzothiete 1 generates by thermal ring opening an 8π electron system 2 which undergoes [8π + 2π] cycloaddition reactions with the oxime systems 3a-g . In accordance with the FMO theory the 1,3-thiazine derivatives 4a-g are formed in a regiospecific and 4f additionally in a stereospecific manner. The O-acylated adducts 4h-j enter the same cycloaddition; however, an elimination reaction 4 ← 5, 6 can provoke the addition of a second benzothiete, yielding the tetracyclic compounds 7j , and 8i,j . 相似文献
159.
160.
The rate of hybridization of oligonucleotide target sequences to chemically immobilized oligonucleotide probes has been studied both with and without an electrical field. The probe size was 20-24 nucleotides (nt) while the target size ranged from 157 to 864 nt. In agreement with previous studies, complete hybridization under normal conditions required 10-30 hours, depending on target size. The kinetics were characterized by a characteristic lag time followed by an asymptotic rise to the final value. In contrast, with an applied electrical field, all but the largest target hybridized in about 10 min while the longest hybridized within 1 h. Deleterious electrode reactions were avoided by close spacing of the anode and cathode and application of very small voltages. Our results suggest that probes and targets orient flat on the surface. A model is suggested to explain the kinetics observed that involves a series of surface states between initial target arrival and final hybridized state. Our results show that the electric field accelerated hybrid capture of solution-phase targets by surface-bound probes. This approach may have implications for enhancing array-based hybrid capture for mutation detection, copy number determination and/or gene expression profiling. 相似文献