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排序方式: 共有117条查询结果,搜索用时 15 毫秒
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Miroslawa Kolowska-Gawiejnowicz 《Mathematical Logic Quarterly》1997,43(1):60-72
We prove a representation theorem for (abstract) residuated algebras: each residuated algebra is isomorphically embeddable into a powerset residuated algebra. As a consequence, we obtain a completeness theorem for the Generalized Lambek Calculus. We use a Labelled Deductive System which generalizes the one used by Buszkowski [4] and Pankrat'ev [17] in completeness theorems for the Lambek Calculus. 相似文献
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A new colorimetric and fluorogenic probe (RN3) based on rhodamine-B has been successfully designed and synthesized. It displays a selective response to Hg2+ in the aqueous buffer solution over the other competing metals. Upon addition of Hg2+, the solution of RN3 exhibits a ‘naked eye’ observable color change from colorless to red and an intensive fluorescence with about 105-fold enhancement. The changes in the color and fluorescence are ascribed to the ring-opening of spirolactam in rhodamine fluorophore, which is induced by a binding of the constructed receptor to Hg2+ with the association and dissociation constants of 0.22 × 105 M−1 and 25.2 μM, respectively. The Job's plot experiment determines a 1:1 binding stoichiometry between RN3 and Hg2+. The resultant “turn-on” fluorescence in buffer solution, allows the application of a method to determine Hg2+ levels in the range of 4.0–15.0 μM, with the limit of detection (LOD) calculated at 60.7 nM (3σ/slope). In addition, the fluorescence ‘turn-off’ and color ‘fading-out’ happen to the mixture of RN3-Hg2+ by further addition of I− or S2−. The reversible switching cycles of fluorescence intensity upon alternate additions of Hg2+ and S2− demonstrate that RN3 can perform as an INHIBIT logic gate. Furthermore, the potential of RN3 as a fluorescent probe has been demonstrated for cellular imaging. 相似文献
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采用新的数学模型研究二元颗粒混合物的取样误差,首次提出了取样的逻辑质量单元的理论,探讨了逻辑质量单元的物理意义,建立了按质量取样的标准偏差的计算公式.应用颗粒药品二元混合物的取样实验,证实了该公式的正确性. 相似文献
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T.O. Bonates 《Discrete Applied Mathematics》2008,156(6):846-861
Given a binary dataset of positive and negative observations, a positive (negative) pattern is a subcube having a nonempty intersection with the positive (negative) subset of the dataset, and an empty intersection with the negative (positive) subset of the dataset. Patterns are the key building blocks in Logical Analysis of Data (LAD), and are an essential tool in identifying the positive or negative nature of “new” observations covered by them. We develop exact and heuristic algorithms for constructing a pattern of maximum coverage which includes a given point. It is shown that the heuristically constructed patterns can achieve 81-98% of the maximum possible coverage, while requiring only a fraction of the computing time of the exact algorithm. Maximum patterns are shown to be useful for constructing highly accurate LAD classification models. In comparisons with the commonly used machine learning algorithms implemented in the publicly available Weka software package, the implementation of LAD using maximum patterns is shown to be a highly competitive classification method. 相似文献
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Bonk FA deAzevedo ER Sarthour RS Bulnes JD Freitas JC Guimarães AP Oliveira IS Bonagamba TJ 《Journal of magnetic resonance (San Diego, Calif. : 1997)》2005,175(2):226-234
This article presents the realization of many self-reversible quantum logic gates using two-qubit quadrupolar spin 3/2 systems. Such operations are theoretically described using propagation matrices for the RF pulses that include the effect of the quadrupolar evolution during the pulses. Experimental demonstrations are performed using a generalized form of the recently developed method for quantum state tomography in spin 3/2 systems. By doing so, the possibility of controlling relative phases of superimposed pseudo-pure states is demonstrated. In addition, many aspects of the effect of the quadrupolar evolution, occurring during the RF pulses, on the quantum operations performance are discussed. Most of the procedures presented can be easily adapted to describe selective pulses of higher spin systems (>3/2) and for spin 1/2 under J couplings. 相似文献
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Ivar Ugi Dieter Marquarding Hans Klusacek George Gokel Paul Gillespie 《Angewandte Chemie (International ed. in English)》1970,9(9):703-730
The utility of the basic structures of modern mathematics for chemistry is discussed; general set theory, topology, and group theory are shown to pervade almost all static and dynamic aspects of chemistry. Chemical analogy, the systematic classification of molecules and a corresponding nomenclature system, conformational transformations, polyhedral rearrangements, and the relations between starting materials, transition complexes, and final products of chemical reactions are examples of where we apply the elements of modern mathematics to the solution of chemical problems. 相似文献
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本文根据逻辑余式的基本原理,在二变量基本项与复合项组合险象的基础上,导出了三变量基本项与复合项。采用K=1状态变化过程中赋值不同的中间逻辑状态,得到了三变量复合项功能冒险之简化计算法则。这种计算方法简单而快建,使工作量大大降低.为四变量逻辑函数以及多变量函数组合险象的最终解决提供了一条效途径。 相似文献