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991.
Vahideh Khademhosseini Daryoosh Dideban Mohammad Taghi Ahmadi Hadi Heidari 《Molecules (Basel, Switzerland)》2022,27(1)
The single electron transistor (SET) is a nanoscale switching device with a simple equivalent circuit. It can work very fast as it is based on the tunneling of single electrons. Its nanostructure contains a quantum dot island whose material impacts on the device operation. Carbon allotropes such as fullerene (C60), carbon nanotubes (CNTs) and graphene nanoscrolls (GNSs) can be utilized as the quantum dot island in SETs. In this study, multiple quantum dot islands such as GNS-CNT and GNS-C60 are utilized in SET devices. The currents of two counterpart devices are modeled and analyzed. The impacts of important parameters such as temperature and applied gate voltage on the current of two SETs are investigated using proposed mathematical models. Moreover, the impacts of CNT length, fullerene diameter, GNS length, and GNS spiral length and number of turns on the SET’s current are explored. Additionally, the Coulomb blockade ranges (CB) of the two SETs are compared. The results reveal that the GNS-CNT SET has a lower Coulomb blockade range and a higher current than the GNS-C60 SET. Their charge stability diagrams indicate that the GNS-CNT SET has smaller Coulomb diamond areas, zero-current regions, and zero-conductance regions than the GNS-C60 SET. 相似文献
992.
不同溶剂中番茄红素的荧光光谱及其特性研究 总被引:5,自引:5,他引:0
用970CRT荧光光度计测定了番茄红素在正己烷、乙酸乙酯、四氢呋喃、氯仿、丙酮和苯等6种溶剂中的荧光光谱以及番茄红素在四氢呋喃溶液中不同浓度下的荧光光谱。对所测光谱分析得出:6种溶剂中荧光光谱的最大峰值波长(λmax)分别为542.5 nm5、48.2 nm5、55.0 nm、555.7 nm、556.4 nm和565.7 nm,由于溶剂效应,随溶剂极性由小到大,荧光光谱的最大峰值波长(λmax)逐渐红移,由这些峰值波长计算得出相应的番茄红素分子在6种溶剂中的跃迁能ET分别为220.5 kJ/mol2、18.2 kJ/mol2、15.6 kJ/mol2、15.3 kJ/mol2、14.9 kJ/mol和211.5 kJ/mol,可见跃迁能ET也随溶剂极性增大而降低;当番茄红素在四氢呋喃溶液中的质量浓度低于50μg/ml时,溶液的荧光强度随溶液浓度增加而增大,当质量浓度高于50μg/ml时,由于番茄红素的激发态分子与基态分子相互作用,荧光强度反而减小;在浓度低于80μg/ml的溶液中,番茄红素的荧光光谱除最大峰值外还有三个较小峰值,据此计算得出相应的番茄红素分子的跃迁能分别为E(T1)=278.2 kJ/mol、E(T2)=260.2 kJ/mol和E(T3)=239.3 kJ/mol。 相似文献
993.
The properties of decays that take place during jet formation cannot be easily deduced from the final distribution of particles in a detector. In this work, we first simulate a system of particles with well-defined masses, decay channels, and decay probabilities. This presents the “true system” for which we want to reproduce the decay probability distributions. Assuming we only have the data that this system produces in the detector, we decided to employ an iterative method which uses a neural network as a classifier between events produced in the detector by the “true system” and some arbitrary “test system”. In the end, we compare the distributions obtained with the iterative method to the “true” distributions. 相似文献
994.
We explore a particular way of reformulating quantum theory in classical terms, starting with phase space rather than Hilbert space, and with actual probability distributions rather than quasiprobabilities. The classical picture we start with is epistemically restricted, in the spirit of a model introduced by Spekkens. We obtain quantum theory only by combining a collection of restricted classical pictures. Our main challenge in this paper is to find a simple way of characterizing the allowed sets of classical pictures. We present one promising approach to this problem and show how it works out for the case of a single qubit. 相似文献
995.
In previous research, we showed that ‘texts that tell a story’ exhibit a statistical structure that is not Maxwell–Boltzmann but Bose–Einstein. Our explanation is that this is due to the presence of ‘indistinguishability’ in human language as a result of the same words in different parts of the story being indistinguishable from one another, in much the same way that ’indistinguishability’ occurs in quantum mechanics, also there leading to the presence of Bose–Einstein rather than Maxwell–Boltzmann as a statistical structure. In the current article, we set out to provide an explanation for this Bose–Einstein statistics in human language. We show that it is the presence of ‘meaning’ in ‘texts that tell a story’ that gives rise to the lack of independence characteristic of Bose–Einstein, and provides conclusive evidence that ‘words can be considered the quanta of human language’, structurally similar to how ‘photons are the quanta of electromagnetic radiation’. Using several studies on entanglement from our Brussels research group, we also show, by introducing the von Neumann entropy for human language, that it is also the presence of ‘meaning’ in texts that makes the entropy of a total text smaller relative to the entropy of the words composing it. We explain how the new insights in this article fit in with the research domain called ‘quantum cognition’, where quantum probability models and quantum vector spaces are used in human cognition, and are also relevant to the use of quantum structures in information retrieval and natural language processing, and how they introduce ‘quantization’ and ‘Bose–Einstein statistics’ as relevant quantum effects there. Inspired by the conceptuality interpretation of quantum mechanics, and relying on the new insights, we put forward hypotheses about the nature of physical reality. In doing so, we note how this new type of decrease in entropy, and its explanation, may be important for the development of quantum thermodynamics. We likewise note how it can also give rise to an original explanatory picture of the nature of physical reality on the surface of planet Earth, in which human culture emerges as a reinforcing continuation of life. 相似文献
996.
The ability to control the flow of quantum information is deterministically useful for scaling up quantum computation. In this paper, we demonstrate a controllable quantum switchboard which directs the teleportation protocol to one of two targets, fully dependent on the sender’s choice. Importantly, the quantum switchboard also acts as a optimal quantum cloning machine, which allows the receivers to recover the unknown quantum state with a maximal fidelity of . This protects the system from the complete loss of quantum information in the event that the teleportation protocol fails. We also provide an experimentally feasible physical implementation of the proposal using a coupled-cavity array. The proposed switchboard can be utilized for the efficient routing of quantum information in a large quantum network. 相似文献
997.
LI Jun-Linga① GU Juna QIU Guang-Minb a 《结构化学》2006,25(5):589-593
1 INTRODUCTION Since the introduction of QSAR by Hansch and Fujita in 1964, Deutsch and Hansch have quickly used it in the study of nitrophenylamine sweet reagents. They found good correlation between their distribution coefficients in octanol/water system and sweetness degree. Subsequently, they detected that vibration of aroma-substituent compounds has so- mething to do with sweetness. Henceforth, statistic correlations between structure and sweetness ofseries compounds have been inv… 相似文献
998.
999.
Denise D. Deppe Robert D. Miller John M. Torkelson 《Journal of Polymer Science.Polymer Physics》1996,34(17):2987-2997
A novel experimental approach involving fluorescence nonradiative energy transfer (NRET) is employed to study the Fickian diffusion of small molecules in rubbery poly(isobutyl methacrylate) (PiBMA) films near the glass transition, using a formalism that directly relates the small molecule translational diffusion coefficient, D, to changes in the normalized nonradiative energy transfer efficiency, EN. Values of D for pyrene, 1,3-bis-(1-pyrene) propane (BPP), 1,3-bis-(1-pyrene) decane (BPD), 9,10-bis-phenyl ethynyl anthracene (BPEA), diphenyl Disperse Red 4 (DPDR4), and decacyclene in PiBMA are measured over temperatures ranging from approximately Tg to Tg + 25°C. Among these chromophores, significant differences in both the magnitude and temperature dependence of D are observed which are attributed to differences in molecule shape and flexibility, as well as molar volume. Other factors being equal, chromophore flexibility was shown both to increase the magnitude of D and to decrease its dependence on temperature, as does an increase in aspect ratio. For BPD, these effects are attributed to the ability of the flexible molecule to diffuse in a piecewise manner, requiring the cooperative mobility of fewer polymer chain segments than a rigid molecule of the same molar volume. For BPEA and DPDR4, this deviation from D being dominated by molar volume effects is attributed the to high aspect ratio of these elongated molecules. © 1996 John Wiley & Sons, Inc. 相似文献
1000.
The transport of fluids in the semicrystalline polymer, poly(aryl ether ether ketone) (PEEK), was investigated. Both solubility and rate of penetration of toluene into PEEK are markedly increased by the application of an external stress. The induction period (i.e., the time for the sorption to begin) is a function of applied stress as well as temperature and crystallinity. At 22°C in 29% crystalline PEEK the induction period was reduced from more than 2000 h to approximately 10 h whereas the solubility of toluene was increased from 9 to 44 wt % upon the application of an external tensile stress of 30 MPa. A critical stress (i.e., a stress value below which the stress-enhanced effects are not observed) was determined. The critical stress is a strong function of crystallinity and temperature. © 1996 John Wiley & Sons, Inc. 相似文献