94 research outputs found

    New vacuum state and symmetry breaking in polariton system

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    The polariton system is studied by a concise approach using a simple model. A new ground state with negative energy is obtained and found to exhibit the symmetry breaking.Comment: Revtex, accepted by Phys. Lett. A. E-mail: [email protected] after Oct. 10, 199

    Synchronization of Chaotic Delayed Neural Networks via Impulsive Control

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    This paper is concerned with the impulsive synchronization problem of chaotic delayed neural networks. By employing Lyapunov stability theorem, impulsive control theory and linear matrix inequality (LMI) technique, several new sufficient conditions ensuring the asymptotically synchronization for coupled chaotic delayed neural networks are derived. Based on these new sufficient conditions, an impulsive controller is designed. Moreover, the stable impulsive interval of synchronized neural networks is objectively estimated by combining the MATLAB LMI toolbox and one of the two given equations. Two examples with numerical simulations are given to illustrate the effectiveness of the proposed method

    Efficacy of massage therapy for postprandial distress syndrome : a protocol for systematic review and meta-analysis

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    BACKGROUND: Postprandial distress syndrome (PDS), characterized by the presence of prevalently meal-related early satiation and fullness, is a highly prevalent condition with major socioeconomic and healthcare impact. To date, there is a lack of pharmacological treatment proven value for PDS. Therefore, an ideal strategy to relieve PDS is urgently needed. In recent years, massage therapy has been increasingly accepted by PDS patients due to its lower costs, fewer unwanted side effects and safety for clinical use. In this systematic review, we aim to evaluate the effectiveness and safety of massage therapy for patients with postprandial distress syndrome. METHODS: We will search the following electronic databases for randomized controlled trials to evaluate the effectiveness and safety of massage therapy in treating postprandial distress syndrome: Wanfang and Pubmed Database, CNKI, CENTRAL, CINAHL, and EMBASE. Each database will be searched from inception to October 2020. The entire process will include study selection, data extraction, risk of bias assessment, and meta-analyses. RESULTS: This proposed study will evaluate the effectiveness and safety of massage therapy for patients with postprandial distress syndrome. The outcomes will include changes in PDS relief and adverse effect. CONCLUSIONS: This proposed systematic review will evaluate the existing evidence on the effectiveness and safety of massage therapy for patients with postprandial distress syndrome. DISSEMINATION AND ETHICS: The results of this review will be disseminated through peer-reviewed publication. Because all of the data used in this systematic review and meta-analysis has been published, this review does not require ethical approval. Furthermore, all data will be analyzed anonymously during the review process. OSF REGISTRATION NUMBER: DOI 10.17605/OSF.IO/9WRX8

    Preparation of pseudo-pure states by line-selective pulses in Nuclear Magnetic Resonance

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    A new method of preparing the pseudo-pure state of a spin system for quantum computation in liquid nuclear magnetic resonance (NMR) was put forward and demonstrated experimentally. Applying appropriately connected line-selective pulses simultaneously and a field gradient pulse techniques we acquired straightforwardly all pseudo-pure states for two qubits in a single experiment much efficiently. The signal intensity with the pseudo-pure state prepared in this way is the same as that of temporal averaging. Our method is suitable for the system with arbitrary numbers of qubits. As an example of application, a highly structured search algorithm----Hogg's algorithm was also performed on the pseudo-pure state ∣00>\mid 00> prepared by our method.Comment: RevTEX,10 pages,5 PS figure

    Comparison of Rooting Strategies to Explore Rock Fractures for Shallow Soil-Adapted Tree Species with Contrasting Aboveground Growth Rates: A Greenhouse Microcosm Experiment

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    For tree species adapted to shallow soil environments, rooting strategies that efficiently explore rock fractures are important because soil water depletion occurs frequently. However, two questions: (a) to what extent shallow soil-adapted species rely on exploring rock fractures and (b) what outcomes result from drought stress, have rarely been tested. Therefore, based on the expectation that early development of roots into deep soil layers is at the cost of aboveground growth, seedlings of three tree species (Cyclobalanopsis glauca, Delavaya toxocarpa, and Acer cinnamomifolium) with distinct aboveground growth rates were selected from a typical shallow soil region. In a greenhouse experiment that mimics the basic features of shallow soil environments, 1-year-old seedlings were transplanted into simulated microcosms of shallow soil overlaying fractured bedrock. Root biomass allocation and leaf physiological activities, as well as leaf δ13C values were investigated and compared for two treatments: regular irrigation and repeated cycles of drought stress. Our results show that the three species differed in their rooting strategies in the context of encountering rock fractures, however, these strategies were not closely related to the aboveground growth rate. For the slowest-growing seedling, C. glauca, percentages of root mass in the fractures, as well as in the soil layer between soil and bedrock increased significantly under both treatments, indicating a specialized rooting strategy that facilitated the exploration of rock fractures. Early investment in deep root growth was likely critical to the establishment of this drought-vulnerable species. For the intermediate-growing, A. cinnamomifolium, percentages of root mass in the bedrock and interface soil layers were relatively low and exhibited no obvious change under either treatment. This limited need to explore rock fractures was compensated by a conservative water use strategy. For the fast-growing, D. toxocarpa, percentages of root mass in the bedrock and interface layers increased simultaneously under drought conditions, but not under irrigated conditions. This drought-induced rooting plasticity was associated with drought avoidance by this species. Although, root development might have been affected by the simulated microcosm, contrasting results among the three species indicated that efficient use of rock fractures is not a necessary or specialized strategy of shallow-soil adapted species. The establishment and persistence of these species relied on the mutual complementation between their species-specific rooting strategies and drought adaptations
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