Dy3+激活的几种硼酸盐在VUV-VIS范围的光谱性质

本文报道了SrAl2B2o7:Dy^3 、BaAl2B2O7:Dy^3 、SrAl3BO7:Dy^3 、La2CaB10O19:Dy^3 的紫外－真空紫外（UV－VUV）激发光谱和UV激发下的发射光谱。根据发射光谱讨论了Dy^3 离子在这几种基质中发光的黄蓝比（Y／B）。在VUV激发光谱中推测了Dy^3 的f-d跃迁及电荷迁移态（CTS）和基质吸收的位置。     

基于电子现金的新型支付协议

本文提出了一种基于电子现金的新型支付协议,该协议通过第三方实时核算客户拥有的电子现金,但不进行实时转账。协议模型较好地克服了现有在线支付的交易瓶颈问题以及离线支付中电子现金容易被重用、伪造或篡改的问题,在交易过程中有效地保证了安全性,并且实现了电子现金的原子性、匿名性、可分割性和可验证性。     

An experimental study of carrier heating on channel noise in deep-submicrometer NMOSFETs via body bias

In this paper, RF noise in 0.18-mum NMOSFETs concerning the contribution of carrier heating and hot carrier effect is characterized and analyzed in detail via a novel approach that modulates the channel carrier heating and number of hot carriers using body bias. We confirm qualitatively a negligible role of hot carrier effect on the channel noise in deep-submicrometer MOSFETs. For a device under reverse body bias (V_b), even though the increase in hot carrier population is clearly characterized by dc measurements, the device high-frequency noise is found to be irrelevant to the increase in the channel hot carriers. Experimental results show that the high-frequency noise is slightly reduced with the increase in |V_b|, and can be qualitatively explained by secondary effects such as the suppression of nonequilibrium channel noise and substrate induced noise. The reduction of NF_min and R_n with the increase in |V_b| may provide a possible methodology to finely adjust the device high-frequency noise performance for circuit design     

金华历史文化名城保护

本文较为详细地叙述了浙江金华历史文化名城的资源存在状况、保护价值、保护内容和主要文物单位及保护范围等。     

Influence of CYP3A5 polymorphism on tacrolimus blood concentrations in renal transplant patients

Objective Tacrolimus is an immunosuppressive drug with narrow therapeutic range and wide interindividual variation in its pharmacokinetics. Tacrolimus is a substrate of cytochrome P450(CYP)3A5. The aim of this study was to evaluate whether the A6986G polymorphism is associated with tacrolimus concentration /dose ratio. Methods Fifty-two Chinese renal transplant patients were enrolled in this study. Their body weight, dosage and concentration of tacrolimus were observed. CYP3A5 genotype was determined by polymerase chain reaction followed by restriction fragment length polymorphism analysis. Results A significant association was found between tacrolimus levels per dose/kg/d and CYP3A5 gene A6986G polymorphism (P<0.001). The CYP3A5 * 3 * 3 patients have a significantly higher tacrolimus level/dose than CYP3A5 * 1 * 1 and CYP3A5 * 1 * 3. Conclusions CYP3A5 gene A6986G polymorphism is associated with tacrolimus pharmacokinetics and dose requirements. Pharmacogenetic methods could be employed prospectively to help the dose selection and to individualize immunosuppressive therapy according to the result. Foundation item: Project (03GZ3072) supported by the Science and Technology Department of Hunan Province; project (2004035206) supported by the China Postdoctoral Foundation and project (30300383) supported by the National Natural Sciences Foundation of China     

Direct adaptive control of nonminimum phase systems using integralaction

A direct adaptive control scheme is proposed for nonminimum-phase systems in which controller parameters are estimated from the recursive least-squares algorithm and additional auxiliary parameters are obtained from the proposed polynomial identity. A local convergence is guaranteed without any extra condition. Integral action is incorporated into the adaptive controller to eliminate the steady-state error and to satisfy a condition of the unique solution for the polynomial identity. The control law used in this scheme is based on the set-point-on-I-only proportional-integral-derivative (PID) structure     

Re-examination of analytical models for microwave scattering from deciduous leaves

This paper presents an examination of classical scattering models for radar cross sections of deciduous leaves, such as the generalised Rayleigh-Gans (GRG) model and the physical optics (PO) model. The PO model employs the resistive sheet approximation in this study. The validity regions of the analytical models for microwave scattering from deciduous leaves are investigated by comparison with the precise numerical results of the method of moment. It was found that the GRG and PO models extend their validity regions for estimating the scattering amplitudes as the thickness of a lossy dielectric disk decreases. The GRG and PO models can be used alternatively for computing the scattering matrices of natural deciduous leaves at microwave frequencies regardless of the size of the leaves, because of the very small thickness of the leaves (0.2-0.4 mm)     

跳时超宽带无线电的性能分析

超宽带脉冲无线电是无线通信领域的一种全新技术,有着广阔的应用前景.它是一种基带无载波短脉冲,不同于使用正弦载波的传统通信系统.本文用满足FCC频谱规划的脉冲--高斯脉冲的五阶导数推导了TH-BPSK方式下的跳时超宽带扩频系统的误码与多址性能,并研究了多径对其性能的影响,比较了TH-BPSK 与TH-PPM系统性能,分析结果表明TH-BPSK的性能(未考虑多径)明显优于TH-PPM,但是TH-PPM抗多径性能优于TH-BPSK.