207 research outputs found

    Electronic mechanism of critical temperature variation in RBa_2Cu_3O_(7− δ)

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    We have performed systematic studies of the trend of the critical temperature T_c due to both Madelung site potential difference between in-plane oxygen and copper sites ΔV_M and interlayer effect in the optimally doped 123 superconductors RBa_2Cu_3O_(7−δ). ΔV_M is found to decrease with the increase of the trivalent rare-earth ionic radius r_(R^(3^+)). This change enhances the next-nearest-neighbor hopping integral t′, which results in the experimentally observed increase of T_c with r_(R^(3^+)). The coherent interlayer single-particle hopping t_⊥ has a more profound effect than t′ on the nearly linear trend of T_c as a function of r_(R^(3^+)). These results reveal the importance of the electronic origin of the rare-earth ionic size effect on T_c in this family

    Effects of tea garden soil on aroma components and related gene expression in tea leaves

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    In order to explore the effect of soil on the synthesis of aroma components in tea leaves, tea seedlings replanted in tea rhizosphere soil of different ages were used as research materials. Tea seedlings were replanted in soils aged 0, 4, 9, and 30 years, and after one year of growth, 34, 37, 29, and 26 substances were detected in the tea leaves, respectively, using gas chromatography-mass spectrometry (GC-MS). The relative contents of terpenoids and alcohols in the tea leaves dropped from 66.40% to 44.52% and 5.21% to 2.61%, respectively, as the age of the rhizosphere soil increased. Aldehydes, esters, and nitrogen compounds increased from 3.80% to 22.36%, 1.33% to 12.02%, and 3.13% to 19.96%, respectively, as the age of the rhizosphere soil increased. Gene differential expression measured by fluorescence quantitative PCR (qRT-PCR) showed that the number of nerolidol synthetase and linalool synthase genes in tea leaves increased significantly, and the terpineol synthetase, phellandrene synthase, myrcene synthetase, ocimene synthase, limonene synthetase, germacrene synthase, and farnesene synthase genes declined significantly with the increase in soil age. In summary, as the number of years tea had been planted in the soil increased, the soil significantly affected the expression of terpene synthase genes in tea leaves, and then the composition and content of aroma substances in tea leaves changed. The results provide a theoretical basis for the improvement of tea quality

    Comparison between anterolateral thigh perforator free flaps and pectoralis major pedicled flap for reconstruction in oral cancer patients-A quality of life analysis

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    The aim of this study was to compare the differences between anterolateral thigh perforator free flaps (ALTFF) and pectoralis major myocutaneous flap (PMMF) for reconstruction in oral cancer patients. Method and Patients: who received free flap or PMMF reconstruction after ablation surgeries were eligible for the current study. The patients' demographic data, medical history, and quality of life scores(Medical Outcomes Study-Short Form-36 (MOS SF-36) and the University of Washington Quality of Life (UW-QOL) questionnaires were collected. Results: 81 of 118 questionnaires were returned (68.64%). There was signi.cant differences between two groups in the gender (P<0.005). Patients reconstructed with ALTFF had better appearance domains and better shoulders domains, in addition to better role emotion domains. Conclusions: Using either PMMF or ALTFF for reconstruction of oral defects after cancer resection signi.cantly in.uences a patient's quality of life. Data from this study provide useful information for physicians and patients during their discussion of reconstruction modalities for oral cancers

    BG: A Modular Treatment of BFT Consensus

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    We provide an expressive framework that allows analyzing and generating provably secure, state-of-the-art Byzantine fault-tolerant (BFT) protocols. Our framework is hierarchical, including three layers. The top layer is used to model the message pattern and abstract key functions on which BFT algorithms can be built. The intermediate layer provides the core functions with high-level properties sufficient to prove the security of the top-layer algorithms. The bottom layer carefully defines predicates according to which we offer operational realizations for the core functions. All three layers in our framework are extensible and enable innovation. One may modify or extend any layer to theoretically cover all BFT protocols, known and unknown. Indeed, unlike prior BFT frameworks, our framework can analyze and recast BFT protocols in an exceedingly fine-grained manner. More importantly, our framework can readily generate new BFT protocols by simply enumerating the parameters in the framework. In this paper, we show that the framework allows us to fully specify and formally prove the security for 23 BFT protocols, including protocols matching HotStuff, Fast-HotStuff, Jolteon, and Marlin, and among these protocols, seven new protocols outperforming existing ones or achieving meaningful trade-offs among various performance metrics
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