1,336 research outputs found

    The genus Plectrocnemia Stephens in China (Trichoptera, Polycentropodidae)

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    Currently, 21 species of the genus Plectrocnemia are known from China. Examination of material collected from 13 provinces of China from 1990–2005 has revealed 9 new species and 3 new records of this genus, bringing the number of Chinese Plectrocnemia species to 33. Newly described species include: P. monacanthus sp. nov., P. huangi sp. nov., P. maoerensis sp. nov., P. pectinata sp. nov., P. fanjingensis sp. nov., P. platilobus sp. nov., P. paragryphalis sp. nov., P. bifoliolata sp. nov., and P. wuyiensis sp. nov. Two species, Plectrocnemia sinualis Wang & Yang and P. uncata Wang & Yang are synonymized with P. tsukuiensis (Kobayashi) and P. tortosa Banks, respectively. Plectrocnemia jonam (Malicky), P. ondakeana Tsuda and P. salah Malicky are newly recorded for the Chinese fauna. All species are organized by monophyletic species groups; the diagnostic characters for the species groups are discussed

    Four New Species and Two New Records of Polyplectropus from China (Trichoptera: Polycentropodidae)

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    Four new species and 2 new records of the genus Polyplectropus Ulmer from China are described and illustrated. The new species include Polyplectropus cubitalis Zhong and Yang sp. nov., from Guizhou, Polyplectropus subteres Zhong and Yang sp. nov., from Jiangxi and Zhejiang, Polyplectropus tridentatus Zhong and Morse sp. nov., from Guangxi, and Polyplectropus tianmushanensis Zhong and Yang, sp. nov., from Zhejiang. Two species, Polyplectropus ahas Malicky and Chantaramongkol, 1993, and Polyplectropus anakgugur Malicky, 1995, are newly recorded from China, bringing the number of Chinese Polyplectropus species to 28. The newly recognized Polyplectropus anakgugur Group is probably monophyletic, as evidenced by ventromesal lobes of the inferior appendages short, positioned only at the bases of the inferior appendages

    Safety and efficacy of etomidate and propofol anesthesia in elderly patients undergoing gastroscopy: A double-blind randomized clinical study

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    The aim of the present study is to compare the safety, efficacy and cost effectiveness of anesthetic regimens by compound, using etomidate and propofol in elderly patients undergoing gastroscopy. A total of 200 volunteers (65–79 years of age) scheduled for gastroscopy under anesthesia were randomly divided into the following groups: P, propofol (1.5–2.0 mg/kg); E, etomidate (0.15-0.2 mg/kg); P+E, propofol (0.75–1 mg/kg) followed by etomidate (0.075-0.1 mg/kg); and E+P, etomidate (0.075-0.01 mg/kg) followed by propofol (0.75–1 mg/kg). Vital signs and bispectral index were monitored at different time points. Complications, induction and examination time, anesthesia duration, and recovery and discharge time were recorded. At the end of the procedure, the satisfaction of patients, endoscopists and the anesthetist were evaluated. The recovery (6.1±1.2 h) and discharge times (24.8±2.8 h) in group E were significantly longer compared with groups P, P+E and E+P (P<0.05). The occurrence of injection pain in group P+E was significantly higher compared with the other three groups (P<0.05). In addition, the incidence of myoclonus and post-operative nausea and vomiting were significantly higher in group P+E compared with the other three groups (P<0.05). There was no statistical difference among the four groups with regards to the patients' immediate, post-procedure satisfaction (P>0.05). Furthermore, there was no difference in the satisfaction of anesthesia, as evaluated by the anesthetist and endoscopist, among the four groups (P>0.05). The present study demonstrates that anesthesia for gastroscopy in elderly patients can be safely and effectively accomplished using a drug regimen that combines propofol with etomidate. The combined use of propofol and etomidate has unique characteristics which improve hemodynamic stability, cause minimal respiratory depression and less side effects, provide rapid return to full activity and result in high levels of satisfaction

    From chemical Langevin equations to Fokker-Planck equation: application of Hodge decomposition and Klein-Kramers equation

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    The stochastic systems without detailed balance are common in various chemical reaction systems, such as metabolic network systems. In studies of these systems, the concept of potential landscape is useful. However, what are the sufficient and necessary conditions of the existence of the potential function is still an open problem. Use Hodge decomposition theorem in differential form theory, we focus on the general chemical Langevin equations, which reflect complex chemical reaction systems. We analysis the conditions for the existence of potential landscape of the systems. By mapping the stochastic differential equations to a Hamiltonian mechanical system, we obtain the Fokker-Planck equation of the chemical reaction systems. The obtained Fokker-Planck equation can be used in further studies of other steady properties of complex chemical reaction systems, such as their steady state entropies.Comment: 6 pages, 0 figure, submitted to J. Phys. A: Math. Theo

    Hydrangea-Like CuS with Irreversible Amorphization Transition for High-Performance Sodium-Ion Storage

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    Metal sulfides have been intensively investigated for efficient sodium‐ion storage due to their high capacity. However, the mechanisms behind the reaction pathways and phase transformation are still unclear. Moreover, the effects of designed nanostructure on the electrochemical behaviors are rarely reported. Herein, a hydrangea‐like CuS microsphere is prepared via a facile synthetic method and displays significantly enhanced rate and cycle performance. Unlike the traditional intercalation and conversion reactions, an irreversible amorphization process is evidenced and elucidated with the help of in situ high‐resolution synchrotron radiation diffraction analyses, and transmission electron microscopy. The oriented (006) crystal plane growth of the primary CuS nanosheets provide more channels and adsorption sites for Na ions intercalation and the resultant low overpotential is beneficial for the amorphous Cu‐S cluster, which is consistent with the density functional theory calculation. This study can offer new insights into the correlation between the atomic‐scale phase transformation and macro‐scale nanostructure design and open a new principle for the electrode materials\u27 design

    Effective DBHF Method for Asymmetric Nuclear Matter and Finite Nuclei

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    A new decomposition of the Dirac structure of nucleon self-energies in the Dirac Brueckner-Hartree-Fock (DBHF) approach is adopted to investigate the equation of state for asymmetric nuclear matter. The effective coupling constants of σ\sigma , ω\omega , ÎŽ\delta and ρ\rho mesons with a density dependence in the relativistic mean field approach are deduced by reproducing the nucleon self-energy resulting from the DBHF at each density for symmetric and asymmetric nuclear matter. With these couplings the properties of finite nuclei are investigated. The agreement of charge radii and binding energies of finite nuclei with the experimental data are improved simultaneously in comparison with the projection method. It seems that the properties of finite nuclei are sensitive to the scheme used for the DBHF self-energy extraction. We may conclude that the properties of the asymmetric nuclear matter and finite nuclei could be well described by the new decomposition approach of the G matrix.Comment: 16 pages, 5 figure

    A Fully Tunable Single-Walled Carbon Nanotube Diode

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    We demonstrate a fully tunable diode structure utilizing a fully suspended single-walled carbon nanotube (SWNT). The diode's turn-on voltage under forward bias can be continuously tuned up to 4.3 V by controlling gate voltages, which is ~6 times the nanotube bandgap energy. Furthermore, the same device design can be configured into a backward diode by tuning the band-to-band tunneling current with gate voltages. A nanotube backward diode is demonstrated for the first time with nonlinearity exceeding the ideal diode. These results suggest that a tunable nanotube diode can be a unique building block for developing next generation programmable nanoelectronic logic and integrated circuits.Comment: 14 pages, 4 figure

    Quantum Theory Approach for Neutron Single and Double-Slit Diffraction

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    We provide a quantum approach description of neutron single and double-slit diffraction, with specific attention to the cold neutron diffraction (λ≈20\lambda \approx 20\AA) carried out by Zeilinger et al. in 1988. We find the theoretical results are good agreement with experimental data.Comment: 10 page

    Effects of Multi-Surface Modification on Curie temperature of ferroelectric films

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    Within the framework of mean field theory, we study the effects of multi-surface modification on Curie temperature of ferroelectric films using the transverse Ising model. The general nonlinear equations for Curie temperature of multi-surface ferroelectric films with arbitrary exchange constants and transverse fields are derived by the transfer matrix method. As an example, we consider a film consisting of top surface layers, bulk layers and bottom surface layers. Two types of surface modifications, modifications of a surface exchange constant and a surface transverse field are taken into account. The dependence of Curie temperature on the surface layer numbers, bulk layer numbers, surface exchange constants, surface transverse fields and bulk transverse fields is discussed.Comment: 11 pages, 5 figure
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