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1.
It is proved that the quasi-proximity space induced by the bicompletion of a quasi-uniform T
0-space X is a subspace of the quasi-proximity space induced by the Samuel bicompactification of X. The result is then used to establish that the locally finite covering quasi-uniformity defined on the category Top
0 of topological T
0-spaces and continuous maps is not lower K-true (in the sense of Brümmer). It is also shown that a functorial quasi-uniformity F on Top
0 is upper K-true if and only if FX is bicomplete whenever X is sober. 相似文献
2.
In this paper I deal with an early phase of the history of research on black-body radiation. In this phase,
from 1880-1900, the American astrophysicist Samuel Pierpont Langley (1834-1906) invented and used
a key instrument, the bolometer, to measure for the first time radiation curves that displayed the
characteristic features of asymmetry and of a shifting of their maxima to shorter wavelengths with
increasing temperature. I emphasize the complex development of the construction of the bolometer and
the early experiments performed with it. I also discuss how these developments became important for
theoretical research on the black-body radiation formula. My aim is to show that the often-neglected
experimental part of the history of research on black-body radiation represents an important precondition
for the theoretical developments that followed. 相似文献
3.
Robert P. Crease 《Physics in Perspective (PIP)》2009,11(1):15-45
This is the second part of a two-part article about the National Synchrotron Light Source (NSLS), the first facility designed
and built specifically for producing and exploiting synchrotron radiation. The NSLS,a $24-million project conceived about
1970 and officially proposed in 1976, had its groundbreaking in 1978. Its construction was a key episode in Brookhaven’s history,
in the transition of synchrotron radiation from a novelty to a commodity, and in the transition of synchrotron-radiation scientists
from parasitic to autonomous researchers. In this part I cover the construction of the NSLS.The story of its construction
illustrates many of the tensions and risks involved in building a large scientific facility in a highly politicized environment:
risking a facility’s quality by underfunding it versus asking for more funding and risking not getting it; focusing on meeting time and budget promises that risk compromising machine
performance versus focusing on performance and risking cancellation; and the pros and cons of a pragmatic versus an analytic approach to commissioning.
Robert P. Crease is a Professor in the Department of Philosophy of Stony Brook University in Stony Brook, New York, and historian
at Brookhaven National Laboratory. 相似文献
4.
Robert P. Crease 《Physics in Perspective (PIP)》2008,10(4):438-467
The National Synchrotron Light Source (NSLS) was the first facility designed and built specifically for producing and exploiting
synchrotron radiation. It was also the first facility to incorporate the Chasman-Green lattice for maximizing brightness.
The NSLS was a $24-million project conceived about 1970. It was officially proposed in 1976, and its groundbreaking took place
in 1978. Its construction was a key episode in Brookhaven’s history, in the transition of synchrotron radiation from a novelty
to a commodity, and in the transition of synchrotron-radiation scientists from parasitic to autonomous researchers. The way
the machine was conceived, designed, promoted, and constructed illustrates much both about the tensions and tradeoffs faced
by large scientific projects in the age of big science. In this article, the first of two parts, I cover the conception, design,
and planning of the NSLS up to its groundbreaking. Part II, covering its construction, will appear in the next issue.
Robert P. Crease is a Professor in the Department of Philosophy of Stony Brook University in Stony Brook, New York, and historian
at Brookhaven National Laboratory. 相似文献
5.
Wang Fuzheng 《东北数学》1995,(2)
Approximately Cohen-Macaulay Rings and Samuel FunctionsWangFuzheng(王福正)(DepartmentofMathematics,PeikingUniversityBeijing,1008... 相似文献
6.
7.
We establish a short exact sequence to relate the germ model of invariant subspaces of a Hilbert space of vector-valued analytic functions and the sheaf model of the corresponding coinvariant subspaces. As a consequence we obtain an additive formula for Samuel multiplicities. As an application, we give a different proof for a formula relating the fibre dimension and the Samuel multiplicity which is first proved in Fang (2005) [11]. The feature of the new proof is that the analytic arguments in Fang (2005) [11] are now subsumed by algebraic machinery. 相似文献
8.
AbstractIn a formally unmixed Noetherian local ring, if the colength and multiplicity of an integrally closed ideal agree, then R is regular. We deduce this using the relationship between multiplicity and various ideal closure operations. 相似文献
9.
Tommaso de Fernex 《Transactions of the American Mathematical Society》2006,358(8):3717-3731
Let be an -dimensional regular local ring, essentially of finite type over a field of characteristic zero. Given an -primary ideal of , the relationship between the singularities of the scheme defined by and those defined by the multiplier ideals , with varying in , are quantified in this paper by showing that the Samuel multiplicity of satisfies whenever . This formula generalizes an inequality on log canonical thresholds previously obtained by Ein, Mustata and the author of this paper. A refined inequality is also shown to hold for small dimensions, and similar results valid for a generalization of test ideals in positive characteristics are presented.
10.
Futoshi Hayasaka 《代数通讯》2019,47(8):3250-3263
The associated Buchsbaum–Rim multiplicities of a module are a descending sequence of non-negative integers. These invariants of a module are a generalization of the classical Hilbert–Samuel multiplicity of an ideal. In this article, we compute the associated Buchsbaum–Rim multiplicity of a direct sum of cyclic modules and give a formula for the second to last positive associated Buchsbaum–Rim multiplicity in terms of the ordinary Buchsbaum–Rim and Hilbert–Samuel multiplicities. This is a natural generalization of a formula given by Kirby and Rees. 相似文献