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排序方式: 共有119条查询结果,搜索用时 15 毫秒
1.
Gianpiero Cattaneo Alberto Leporati Roberto Leporini 《International Journal of Theoretical Physics》2004,43(7-8):1769-1791
We introduce some conservative gates for finite-valued logics which are able to realize all the main connectives of the many-valued logics of ?ukasiewicz, the MV-algebras of Chang and Brower–Zadeh algebras. After a brief exposition of the motivations for this work, the gates are defined and their properties are explored. Finally, a possible quantum realization of them is proposed, using three techniques: a “brute force” method--an extension of the Conditional Quantum Control argument, and a new technique which we call the Constants Method. For all these techniques, the unitary operator which describes the gate is a sum of local operators. 相似文献
2.
Gianpiero Cattaneo 《International Journal of Theoretical Physics》1992,31(9):1573-1597
The partial ordered structure which plays for unsharp quantum mechanics the same role of orthomodular lattices for ordinary quantum mechanics is introduced. Differently from the unsharp case, in which one can identify quantum propositions (i.e., Hilbert space subspaces) with yes-no devices (i.e., orthogonal projections) they are tested by, in the unsharp case this identification is broken down: every quantum generalized proposition (i.e., pair of mutually orthogonal subspaces) is tested by many different yes-no devices (i.e., Hilbert space effects). The set of all quantum effects has a structure of Brouwer-Zadeh poset, canonically embeddable in a (minimal) Brouwer-Zadeh lattice, whereas the set of all quantum generalized propositions has a structure of Brouwer-Zadeh complete lattice.A Brouwer-Zadeh poset is defined as a partially ordered structure equipped with two nonusual orthocomplementations: a regular degenerate (Zadeh or fuzzy-like) one and a weak (Brouwer or intuitionistic-like) one linked by an interconnection rule. Using these two orthocomplementations it is possible to introduce the two modal-like operators of necessity and possibility. 相似文献
3.
Gianpiero Cattaneo Giuseppe Nisticó 《International Journal of Theoretical Physics》1992,31(10):1873-1898
We give a criterion to compare the physical content of different mathematical structures derived from a preparation-question structure. Then this criterion is used in order to compare the physical content of the (Jauch-Piron's) property lattice with the physical content of the poset of testable properties. We prove that for complete preparation-question structures these two structures carry the same physical content; moreover the set of testable properties has the algebraic structure of the Brouwer-Zadeh lattice. For more general preparation-question structures the physical content of the poset of testable property can be larger than that of the property lattice. Physically relevant examples of the possible cases are given. 相似文献
4.
Cobalt and chromium release in patients undergone a metal-on-metal total hip replacement (THR) is a matter recently discussed and whose we do not have enough information about it yet. In literature there is little data and not completely indicative, in the biological fluids and organs the amounts of released metals are different. This is also due to the fact that cobalt and chromium blood levels can change depending on physical and working activity, individual feeding and metabolism. The results obtained confirm the presence of an increase of cobalt inthe blood of patients after total hip replacement, while the chromium levels are almost alike: average values in patients operated are 4.1 +/- 1.5 microg/L for cobalt (0.3 +/- 0.1 microg/L in the control group) and 4.5 +/- 2.9 microg/L for chromium (4.7 +/- 2.4 microg/L in the control group). In spite of the cobalt values stand below the concentration generally considered dangerous, the difference between the two examined groups points out that a risk exists for the health of these patients. These results must be confirmed by further studies, providing better information and more reliable and biocompatible materials. 相似文献
5.
Some algebraic structures determined by the class (þ) of all effects of a Hilbert space þ and by some subclasses of (þ) are investigated, in particular de Morgan-Brouwer-Zadeh posets [it is proved that (þ
n
)(n<) has such a structure], Brouwer-Zadeh
*
posets (a quite trivial example consisting of suitable effects is given), and Brouwer-Zadeh
3
posets which are both de Morgan and
*.It is shown that a nontrivial class of effects of a Hilbert space exists which is a BZ
3
poset. An -preclusivity relation on the set of all vectors of þ is introduced, and it is shown that it satisfies the regularity condition also for [1/2, 1]. 相似文献
6.
Gianpiero Cattaneo 《International Journal of Theoretical Physics》1993,32(10):1709-1734
A survey of the main results of the Italian group about the logics of unsharp quantum mechanics is presented. In particular partial ordered structures playing with respect to effect operators (linear bounded operatorsF on a Hilbert space such that, 0¦F2) the role played by orthomodular posets with respect to orthogonal projections (corresponding to sharp effects) are analyzed. These structures are generally characterized by the splitting of standard orthocomplementation on projectors into two nonusual orthocomplementations (afuzzy-like and anintuitionistic-like) giving rise to different kinds of Brouwer-Zadeh (BZ) posets: de Morgan BZ posets, BZ* posets, and BZ3 posets. Physically relevant generalizations of ortho-pair semantics (paraconsistent, regular paraconsistent, and minimal quantum logics) are introduced and their relevance with respect to the logic of unsharp quantum mechanics are discussed. 相似文献
7.
Saturnino C Buonerba M Boatto G Pascale M Moltedo O de Napoli L Montesarchio D Lancelot JC de Caprariis P 《Chemical & pharmaceutical bulletin》2003,51(8):971-974
The therapy of human cancer is one of the more pursued goals by medicinal chemistry research. Most of the compounds clinically used as a treatment owe their efficacy to their cytotoxic interaction (direct or indirect) with nuclear DNA. This interaction results in the inhibition of DNA synthesis and the degradation of nucleic strands. Ellipticine is a naturally occurring 6H-pyrido[4,3-b]carbazole alkaloid endowed with antitumor activity, and several ellipticine derivatives have been used in clinical trials. We previously reported some 1,4-dimethyl-9H-carbazole derivatives structurally related to ellipticine. The purpose of our research was to transform the pyridocarbazole in a prodrug so that it would have more penetration in the tumor cells and block their replication. Our prodrug is slowly hydrolyzed in human plasma in the corresponding acid. From these preliminary results, we deduce that our compound can block cellular replication. Our hypothesis is that the antitumoral activity is probably related to the induction of damage to DNA, without cellular lysis in the short term. 相似文献
8.
Gianpiero Cattaneo Giuseppe Nisticó 《International Journal of Theoretical Physics》1991,30(10):1293-1336
Some of the most frequent misconceptions about axiomatic quantum physics are discussed with the aim of clarifying their true significance, taking Piron's approach as conceptual framework. In particular, we deal with the following topics: the wrong identification of Piron's questions and Mackey's questions, and some curious alleged empirical consequences; the role of propositions as suitable equivalence classes of questions, their partial order structure, and the paradoxical consequences of the erroneous assignment to questions of some lattice properties involving propositions; the logical and the empirical purport of some negative theorems; the standard Hilbert space model of the theory and the consequent metaphysical disasters related to some identifications, which are peculiar of this model. A controversy between Foulis-Piron-Randall and Hadjisavvas-Thieffine-Mugur-Schächter is analyzed on the basis of the proposed Hilbert space model (in which Piron's questions are realized by Hilbertian effects, i.e., linear bounded operatorsF such that which clarify the different point of views. As an example, we treat the unsharp localization operators inL
2(). 相似文献
9.
Dr. Minqiang Jia Dr. Gianpiero Cera Daniele Perrotta Prof. Magda Monari Prof. Marco Bandini 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(32):9875-9878
A careful interplay between the π electrophilicity of a cationic AuI center and the basicity of the corresponding counterion allowed for the chemo‐ and regioselective inter‐ as well as intramolecular de‐aromatization of 2,3‐disubstituted indoles with allenamides. The silver‐free bifunctional Lewis acid/Brønsted base complex [{2,4‐(tBu)2C6H3O}3PAuTFA] assisted the formation of a range of densely functionalized indolenines under mild conditions. 相似文献