1,916 research outputs found

    A STOCHASTIC SIMULATION-BASED HYBRID INTERVAL FUZZY PROGRAMMING APPROACH FOR OPTIMIZING THE TREATMENT OF RECOVERED OILY WATER

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    In this paper, a stochastic simulation-based hybrid interval fuzzy programming (SHIFP) approach is developed to aid the decision-making process by solving fuzzy linear optimization problems. Fuzzy set theory, probability theory, and interval analysis are integrated to take into account the effect of imprecise information, subjective judgment, and variable environmental conditions. A case study related to oily water treatment during offshore oil spill clean-up operations is conducted to demonstrate the applicability of the proposed approach. The results suggest that producing a random sequence of triangular fuzzy numbers in a given interval is equivalent to a normal distribution when using the centroid defuzzification method. It also shows that the defuzzified optimal solutions follow the normal distribution and range from 3,000-3,700 tons, given the budget constraint (CAD 110,000-150,000). The normality seems to be able to propagate throughout the optimization process, yet this interesting finding deserves more in-depth study and needs more rigorous mathematical proof to validate its applicability and feasibility. In addition, the optimal decision variables can be categorized into several groups with different probability such that decision makers can wisely allocate limited resources with higher confidence in a short period of time. This study is expected to advise the industries and authorities on how to distribute resources and maximize the treatment efficiency of oily water in a short period of time, particularly in the context of harsh environments

    Radio-frequency spectroscopy of weakly bound molecules in spin-orbit coupled atomic Fermi gases

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    We investigate theoretically radio-frequency spectroscopy of weakly bound molecules in an ultracold spin-orbit-coupled atomic Fermi gas. We consider two cases with either equal Rashba and Dresselhaus coupling or pure Rashba coupling. The former system has been realized very recently at Shanxi University [Wang et al., arXiv:1204.1887] and MIT [Cheuk et al., arXiv:1205.3483]. We predict realistic radio-frequency signals for revealing the unique properties of anisotropic molecules formed by spin-orbit coupling.Comment: 11 pages, 7 figure

    医学生创新思维和临床实践能力培养的医学遗传学教学改革与实践研究

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    To improve medical students' autonomous learning, clinical thinking and problem analysis and problem solving, and clinical practice skills, TBL teaching and clinical practice and case analysis are introduced in medical genetics teaching. The students could promote autonomous learning and independent study through consulting data, group discussion, and social practice. The whole process of heuristic, participatory teaching, could fully mobilize the enthusiasm and initiative of students, making students become the subject of learning, and interaction between teachers and students, students interaction and group discussion, as one of the social practice teaching mode. In this teaching model, students get horizontal contact of knowledge, vertical infiltration, which make the basic medical knowledge and clinical medical knowledge effectively integrate, achieving good teaching effect.为提高医学生自主学习、临床思维、分析问题和解决问题及临床实践技能,将TBL教学法及临床实践和病例分析引入医学遗传学教学中,学生通过查阅资料、团队讨论、社会实践等途径自主学习、自主研究,整个教学过程中贯穿着启发式、参与式教学,充分调动了学生学习的积极性和主观能动性,让学生成为学习的主体,集师生互动、同学互动和团队讨论、社会实践为一体的教学模式。在该教学模式中,学生对所学知识进行横向联系,纵向渗透,使基础医学知识和临床医学知识有效整合,取得了良好的教学效果

    Fermi Gases with Synthetic Spin-Orbit Coupling

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    We briefly review recent progress on ultracold atomic Fermi gases with different types of synthetic spin-orbit coupling, including the one-dimensional (1D) equal weight Rashba-Dresselhaus and two-dimensional (2D) Rasbha spin-orbit couplings. Theoretically, we show how the single-body, two-body and many-body properties of Fermi gases are dramatically changed by spin-orbit coupling. In particular, the interplay between spin-orbit coupling and interatomic interaction may lead to several long-sought exotic superfluid phases at low temperatures, such as anisotropic superfluid, topological superfluid and inhomogeneous superfluid. Experimentally, only the first type - equal weight combination of Rasbha and Dresselhaus spin-orbit couplings - has been realized very recently using a two-photon Raman process. We show how to characterize a normal spin-orbit coupled atomic Fermi gas in both non-interacting and strongly-interacting limits, using particularly momentum-resolved radio-frequency spectroscopy. The experimental demonstration of a strongly-interacting spin-orbit coupled Fermi gas opens a promising way to observe various exotic superfluid phases in the near future.Comment: 35 pages, 29 fiugres. Invited review paper for Annual Review of Cold Atoms and Molecules (Volume 2) (2014

    Phase Separation in two-Species Atomic Bose-Einstein Condensate with Interspecies Feshbach Resonance

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    We consider a mixture of two-species atomic Bose-Einstein codensates coupled to a bound molecular state at zero temperature via interspecies Feshbach resonance. The interspecies Feshbach coupling precludes the possibility of doubly mixed phases while enables not only the pure molecular superfluid but also the pure atomic superfluids to exist as distinct phases. We show that this system is able to support a rich set of phase separations, including that between two distinct mixed atom-molecule phases. We pay particular attention to the effects of the Feschbach coupling and the particle collisions on the miscibility of this multi-component condensate system.Comment: 9 pages, 3 figure

    Understanding the quantum Rabi ring using analogies to quantum magnetism

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    We map a quantum Rabi ring, consisting of NN cavities arranged in a ring geometry, into an effective magnetic model containing the XY exchange and the Dzyaloshinskii Moriya (DM) interactions. The analogue of the latter is induced by an artificial magnetic field, which modulates photon hopping between nearest-neighbor cavities with a phase. The mean-field behavior of both systems is almost identical, facilitating the description of the different phases in the quantum optical model through simple arguments of competing magnetic interactions. For the square geometry (N=4N=4) the rich phase diagram exhibits three superradiant phases denoted as ferro-superradiant, antiferro-superradiant and chiral superradiant. In particular, the DM interaction is responsible for the chiral phase in which the energetically degenerate configurations of the order parameters are similar to the in-plane magnetizations of skyrmions with different helicities. The antiferro-superradiant phase is suppressed in the triangle geometry (N=3N=3) as geometric frustration contributes to stabilize the chiral phase even for small values of the DM interaction. The chiral phases for odd and even NN show a different scaling behavior close to the phase transition. The equivalent behavior on both systems opens the possibility of simulating chiral magnetism in a few-body quantum optical platform, as well as understanding one system using the insights gained from the other.Comment: 14 pages, 6 figure

    Syntaxin 1B Mediates Berberine’s Roles in Epilepsy-Like Behavior in a Pentylenetetrazole-Induced Seizure Zebrafish Model

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    Epilepsy is a neuronal dysfunction syndrome characterized by transient and diffusely abnormal discharges of neurons in the brain. Previous studies have shown that mutations in the syntaxin 1b (stx1b) gene cause a familial, fever-associated epilepsy syndrome. It is unclear as to whether the stx1b gene also correlates with other stimulations such as flashing and/or mediates the effects of antiepileptic drugs. In this study, we found that the expression of stx1b was present mainly in the brain and was negatively correlated with seizures in a pentylenetetrazole (PTZ)-induced seizure zebrafish model. The transcription of stx1b was inhibited by PTZ but rescued by valproate, a broad-spectrum epilepsy treatment drug. In the PTZ–seizure zebrafish model, stx1b knockdown aggravated larvae hyperexcitatory swimming and prompted abnormal trajectory movements, particularly under lighting stimulation; at the same time, the expression levels of the neuronal activity marker gene c-fos increased significantly in the brain. In contrast, stx1b overexpression attenuated seizures and decreased c-fos expression levels following PTZ-induced seizures in larvae. Thus, we speculated that a deficiency of stx1b gene expression may be related with the onset occurrence of clinical seizures, particularly photosensitive seizures. In addition, we found that berberine (BBR) reduced larvae hyperexcitatory locomotion and abnormal movement trajectory in a concentration-dependent manner, slowed down excessive photosensitive seizure-like swimming, and assisted in the recovery of the expression levels of STX1B. Under the downregulation of STX1B, BBR’s roles were limited: specifically, it only slightly regulated the levels of the two genes stx1b and c-fos and the hyperexcitatory motion of zebrafish in dark conditions and had no effect on the overexcited swimming behavior seen in conjunction with lighting stimulation. These findings further demonstrate that STX1B protein levels are negatively correlated with a seizure and can decrease the sensitivity of the photosensitive response in a PTZ-induced seizure zebrafish larvae; furthermore, STX1B may partially mediate the anticonvulsant effect of BBR. Additional investigation regarding the relationship between STX1B, BBR, and seizures could provide new cues for the development of novel anticonvulsant drugs

    Blast-Induced Damage on Millisecond Blasting Model Test with Multicircle Vertical Blastholes

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    To investigate the blast-induced damage effect on surrounding rock in vertical shaft excavation, 4 kinds of millisecond blasting model tests with three-circle blastholes were designed and carried out with excavation blasting in vertical shaft as the background. The longitudinal wave velocity on the side of concrete model was also measured before and after blasting. Then blast damage factor was then calculated by measuring longitudinal wave velocity before and after blasting. The test results show that the blast-induced damage factor attenuated gradually with the centre of three-circle blastholes as centre. With the threshold value of 0.19 for blast-induced damage factor, blast-induced damage zones for 4 kinds of model tests are described and there is an inverted cone blast-induced damage zone in concrete model. And analyses of cutting effect and blast-induced damage zone indicate that in order to minimize the blast-induced damage effect and ensure the cutting effect the reasonable blasting scheme for three-circle blastholes is the inner two-circle blastholes initiated simultaneously and the outer third circle blastholes initiated in a 25 ms delay

    Research on the Influence of Moisture State, Microscopic Morphology and Physical Properties of the Resting Dough

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    To study the effect of resting on the quality of frozen dough, the changes in the moisture state of the dough during the resting process (0, 30, 60, 90, 120 min), the moisture distribution of dough and their effects on ice crystal distribution, microstructure, and creep recovery characteristics after dough freezing were investigated. The results showed that the freezable water content in the dough was decreased by 0.96% with the extension of the resting time. The pores and number of ice crystals formed in the dough during the freezing process gradually decreased and the distribution of ice crystals became more and more uniform. The average pore area decreased from 22.65 to 11.80 with the extension of the resting time from 0 min to 120 min, and the number of pores decreased from 22.65 to 11.80 with the extension of the resting time. The maximum creep flexibility Jmax increased significantly (P<0.05) and the zero shear viscosity η0 decreased significantly (P<0.05) during the creep phase as the resting time was extended. After resting for 120 mins, the maximum creep flexibility Jmax of frozen dough decreased by 0.50×10−4 Pa−1, and the zero shear viscosity η0 decreased by 0.43×105 Pa−1. This indicated that the hardness of frozen dough decreases and the shape of the dough was easier to maintain. During the recovery process, the instantaneous flexibility J0 and viscoelastic flexibility Jm increased by 1.26×10−4 and 2.88×10−4 Pa−1, respectively, and the recovery force of the frozen dough increased. In summary, resting process of dough would reduce the content of freezeable water, improve the water holding capacity, and reduce the damage of ice crystals to the dough network structure in the freezing process to improve the quality of the frozen dough
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