连续服用褪黑激素51天小鼠血液及肝部分生化指标的变化

以雄性昆明种小鼠为实验对象,连续服用褪黑激素(MT)51d建立动物模型。分别测试血红蛋白(Hb)含量、血清谷丙转氨酶(SGPT)活性、血清谷草转氨酶(SGOT)活性、超氧化物歧化酶(SOD)活性、丙二醛(MDA)含量与总抗氧化能力(T-AOC)。结果表明,连续服用MT后,对小鼠Hb含量、肝SOD活性及SGOT活性无显著性影响(P>0.05),可使SGPT活性、血清及肝MDA含量显著下降(P<0.01)。肝T-AOC明显升高(P<0.05)。实验结果提示,MT具有很强的抗氧化能力,对机体的抗氧化系统有明显的辅助作用。     

Comparison Between Anode‐Supported and Electrolyte‐Supported Ni‐CGO‐LSCF Micro‐tubular Solid Oxide Fuel Cells

Two types of micro‐tubular hollow fiber SOFCs (MT‐HF‐SOFCs) were prepared using phase inversion and sintering; electrolyte‐supported, based on highly asymmetric Ce_0.9Gd_0.1O_1.95(CGO) HFs and anode‐supported based on co‐extruded NiO‐CGO(CGO)/CGO HFs. Electroless plating was used to deposit Ni onto the inner surfaces of the electrolyte‐supported MT‐HF‐SOFCs to form Ni‐CGO anodes. LSCF‐CGO cathodes were deposited on the outer surface of both these MT‐HF‐SOFCs before their electrochemical performances were compared at similar operating conditions. The performance of the anode‐supported MT‐HF‐SOFCs which delivered ca. 480 mW cm^–2 at 600 °C was superior to the electrolyte‐supported MT‐HF‐SOFCs which delivered ca. six times lower power. The contribution of ohmic and electrode polarization losses of both FCs was investigated using electrochemical impedance spectroscopy. The electrolyte‐supported MT‐HF‐SOFCs had significantly higher ohmic and electrode polarization ASR values; this has been attributed to the thicker electrolyte and the difficulties associated with forming quality anodes inside the small (<1 mm) lumen of the electrolyte tubes. Further development on co‐extruded anode‐supported MT‐HF‐SOFCs led to the fabrication of a thinner electrolyte layer and improved electrode microstructures which delivered a world leading 2,400 mW cm^–2. The newly made cell was investigated at different H₂ flow rates and the effect of fuel utilization on current densities was analyzed.     

Effect of pharmaceutical agent degradation on axonal transport drug delivery: An analytical solution for a transient situation

This paper is motivated by recent experimental research that demonstrated pharmacological efficiency of axonal transport drug delivery. The purpose is to develop a model of this process and to study how the rate of destruction of pharmaceutical agent complexes (PACs) affects their transport in the axon. The model includes two populations of PACs: PACs in the state when they are driven retrogradely (from the axon terminal toward the neuron soma) by dynein motors and PACs residing in the accumulated state (but can still be re-released to the dynein-driven state). The coupling between the kinetic states is accounted for by first-order reactions. Utilizing Laplace transform, analytical solutions for concentrations of these two populations of PACs are obtained. The effect of PAC destruction is investigated for different values of other parameters. It is shown that the shapes of the waves describing the PAC concentrations can be significantly affected by transport parameters.     

A preliminary coupled MT-GA model for the prediction of highway runoff quality

Pollutants accumulated on road pavement during dry periods are washed off the surface with runoff water during rainfall events, presenting a potentially hazardous non-point source of pollution. Estimation of pollutant loads in these runoff waters is required for developing mitigation and management strategies, yet the numerous factors involved and their complex interconnected influences make straightforward assessment impossible. Data-driven models (DDMs) have lately been used in water and environmental research and have shown very good prediction ability. The proposed methodology of a coupled MT-GA (model tree-genetic algorithm) model provides an effective, accurate and easily calibrated predictive model for EMC (event mean concentration) of highway runoff pollutants. The models were trained and verified using a comprehensive data set of runoff events monitored in various highways in California, USA. EMCs of Cr, Pb, Zn, TOC and TSS were modeled, using different combinations of explanatory variables. The models' prediction ability in terms of correlation between predicted and actual values of both training and verification data was mostly higher than previously reported values. Sensitivity analysis was performed to examine the relative significance of each explanatory variable and the models' response to changes in input values.     

DTMF信号收、发芯片 MT8888原理及应用

MT8888芯片是MITEL公司采用CMOS工艺生产的一种低功耗、高集成度的DTMF信号收、发芯片，它可方便地与微机接口。文中介绍了MT8888的主要功能结构及控制指令，给出了它的具体应用电路。     

MT model space: statistical versus compositional versus example-based machine translation

We offer a perspective on EBMT from a statistical MT standpoint, by developing a three-dimensional MT model space based on three pairs of definitions: (1) logical versus statistical MT, (2) schema-based versus example-based MT, and (3) lexical versus compositional MT. Within this space we consider the interplay of three key ideas in the evolution of transfer, example-based, and statistical approaches to MT. We depict how all translation models face these issues in one way or another, regardless of the school of thought, and suggest where the real questions for the future may lie.     

基于DTMF技术的电力线载波通信系统的设计

本文介绍一种基于电力线载波的住宅智能化控制系统的实现方法。其以MT8880实现对双音多频信号的接收与发送，并由其侦听电力线上是否有双音多频信号在传输。     

平面聚类静态校正法

大地电磁测深法中的静态效应校正一直是国内外电法勘探界人士广泛关注的问题，并提出了多种解决方法，其中的曲线平移校正法仍是目前的主要手段。然而当曲线平移校正法用于面积性勘探时，剖面间的视电阻率经过校正后会产生系统偏差，而且两条测线相交处各测线视电阻率可能不一致；另一方面，此法可能将由实际地质构造变化引起的曲线幅值突变也视为静位移被消除，造成有用信息丢失。因此本文提出平面聚娄静态校正法，该法可在平面先进行汉宁滤波，再将测区各测点的视电阻率曲线进行聚类分析，自动实现以构造单元分区校正的目的。此法的应用实例与同一地段的地震剖面对比，两者有很好的可比性，说明此法的有效性。     

基于坐标变换的异步电机控制

介绍了坐标变换在异步电机中的应用条件和原则,以便能够快速地在异步电机中选择合适的坐标,提高工作效率.并结合异步电机矢量控制在MT坐标系中变换后,可类似于直流电机的转矩电流分量和磁场电流分量,以便简化矢量控制原理,能够加深对矢量控制理解和学习,并对实际应用和系统的设计具有很好地指导作用.     

基于块状有理Krylov方法的大地电磁三维模型降阶正演

三维大地电磁正演需要求解两个极化源在不同频率下的电磁场分布,计算量巨大。基于块状有理Krylov方法,文中实现了大地电磁三维模型降阶快速正演计算。所用算法的创新点包括：①将大地电磁的源项显式表示为平面电流源,将随频率变化的电场响应表示为一个传递函数与电流源常矢量的乘积,从而可通过构建有理Krylov子空间实现所有频率电场响应的快速求解,避免多次求解不同频率的大型稀疏线性方程组;②采用块状Krylov技术,将TE和TM极化源表示为块状源矢量,将求解两个极化源的正演响应简化为构建一个块状有理Krylov子空间。引入渐近收敛公式得到了块状有理Krylov方法的最优化单个重复极点,结合直接求解器,将大地电磁三维正演的计算量降为一次系数矩阵分解和几十次矩阵回代。该算法在保证正演精度的同时,极大地提高了正演速度。半空间模型和三维DTM1模型的正演数值结果表明,相比常规的逐个频率的正演求解方法,块状有理Krylov方法可显著提高正演速度。