Phonon effects in tunnelling through a double quantum dot molecule

Phonon effects in tunnelling through a double quantum dot molecule are investigated by use of a recently developed technique, which is based on an exact mapping of a many-body electron-phonon interaction problem onto a multichannel one-body problem. The molecule is sandwiched between two ideal electrodes and the electron at each dot of the molecule interacts independently with Einstein phonons. Single-electron transmission rates through the molecule are computed and the nonlinear spectrum obtained shows a structure with many more satellite peaks due to the excitations of phonons. The strength of resonant peaks is found to be strongly dependent on the number of excited phonons. The effects of electron-phonon interaction on the current and shot noise, depending on the voltage bias applied at the two electrodes as well as the potential energy of the molecule, are discussed.     

转基因棉花残体土壤降解特征的红外光谱研究

采用重铬酸钾容量法和红外光谱(FTIR)法分析了转基因抗虫棉花残体降解后的土壤腐殖质组分富里酸(FA)、胡敏酸(HA)和胡敏素(HM)的含量和结构特征.结果表明,棉花残体的降解使土壤各腐殖质组分含量增加,胡敏素的相对含量增加最大,胡敏酸次之,富里酸最小.与相应非转基因对照相比,转Bt基因棉花残体处理土壤各腐殖质组分含量...     

Dysregulation of chemo-cytokine production in schizophrenic patients versus healthy controls

Background  

The exact cause of schizophrenia is not known, although several aetiological theories have been proposed for the disease, including developmental or neurodegenerative processes, neurotransmitter abnormalities, viral infection and immune dysfunction or autoimmune mechanisms. Growing evidence suggests that specific cytokines and chemokines play a role in signalling the brain to produce neurochemical, neuroendocrine, neuroimmune and behavioural changes. A relationship between inflammation and schizophrenia was supported by abnormal cytokines production, abnormal concentrations of cytokines and cytokine receptors in the blood and cerebrospinal fluid in schizophrenia. Since the neuropathology of schizophrenia has recently been reported to be closely associated with microglial activation we aimed to determined whether spontaneous or LPS-induced peripheral blood mononuclear cell chemokines and cytokines production is dysregulated in schizophrenic patients compared to healthy subjects. We enrolled 51 untreated first-episode schizophrenics (SC) and 40 healthy subjects (HC) and the levels of MCP-1, MIP-1α, IL-8, IL-18, IFN-γ and RANTES were determined by Elisa method in cell-free supernatants of PBMC cultures.     

Ultrahigh sensitivity electric field detection with a liquid electro-optical film

In this Letter, an electro-optical probe configuration with polar molecule liquids as the sensing film is proposed to improve the voltage sensitivity. This method exhibited increases in intrinsic sensitivities better than 0.1 mV/√Hz, 2 orders of magnitude larger than the normal method using a GaAs probe in the same measurement system. Based on the mechanism of orientation polarization, the electro-optic coefficient was measured to be 250 pm/V by the Teng-Man method at a modulation field of 100 Hz. This technology will be promising in applications of low-frequency field detection.     

Enhancement of chloroform degradation by the combination of hydrodynamic and acoustic cavitation

The decomposition of chloroform by the combination of hydrodynamic and acoustic cavitation (Hydrodynamic-Acoustic-Cavitation/HAC) has been investigated. The flow rate and the hole diameter of the orifice plate remarkably affect the conversion of chloroform in the combined system. The conversion increases with increasing fluid velocity without any restriction. With a 2.8mm orifice plate the conversion reaches an optimal value. A synergistic effect has been obtained by the hybrid method of acoustic and hydrodynamic cavitation. The total synergistic effect achieves 17% and 73% per pass, respectively. The analysis of the energy efficiencies shows different results. Due to high optimization potential, this hybrid method can be visualized as a new step for wastewater treatment.     

Levels in182W populated in the decay of182Ta

Theγ-rays emitted in theβ-decay of¹⁸²Ta have been reinvestigated with improved statistics in attempting to clarify the reported new levels at 1460.41, 1592.98, 1620.36, 1712.29 and 1762.91 keV in¹⁸²W observed in theβ-decay of¹⁸²Ta. The present study demonstrated that the fifteen newγ-rays, which were used to support the existence of the five new levels, are not relevant to theγ-decay of¹⁸²Ta. Therefore the five new levels are not populated in this decay. Additionally, theγ-ray with an energy of 1035.6 keV (0 ₂ ⁺ →2 ₁ ⁺ ) deexciting theβ-band head in¹⁸²W is observed for the first time in the present decay study and the previous tentative placement of the 351.0 keVγ-ray in the level scheme is confirmed by the present coincidence measurements.     

一种电流型超导储能脉冲变压器的放电模式

本文针对高温超导电感储能脉冲变压器(HTSPPT)提出了一种振荡放电模式.该模式中HTSPPT的原边绕组电感与电容器组成振荡回路,放电时原边电流通过该振荡回路使电流变化量增加,使得副边绕组感应出更大的电流脉冲.在放电过程中,电容器作为能量转换器件可实现开关的零电压关断,避免了断路开关出现过电压的问题.本文对振荡放电模式的工作原理进行了理论分析,利用一个小型HTSPPT搭建了小型实验系统,成功实现了从电流100A到3.78kA的放大,证明了的该放电模式的可行性.