摘要：Objective Cyclic nucleotide phosphodiesterase（PDE）is a critical component of the nitric oxide（NO）signaling pathway and plays critical roles in cognition and learning,Parkinson’s disease,attention deficit hyperactivity disorder, psychosis and *** PDEs in the brain of guinea pig have not yet been *** present study aimed to detect the unknown Pde cDNAs in the brain of guinea *** Reverse transcription polymerase chain reaction（RT-PCR）and sequence comparison analysis were performed to detect the expression of Pde cDNAs and to assess the identity rates of cDNA and amino acid sequences between guinea pig and human or mouse,*** RT-PCR primers were located on the conserved region of human PDE and mouse Pde *** Eleven novel Pde cDNAs were detected in the brain of guinea pig（Cavia porcellus）,including CpPde1a,CpPde1b,CpPde2a,CpPde4a,CpPde4d,CpPde5a,CpPde6c,CpPde7b, CpPde8a,CpPde9a,and *** identity rates of the Pde cDNA sequences between guinea pig and human ranged from 83.8%to 94.3%,and those of the amino acid sequences ranged from 91.9%to 100%.The identity rates of Pde cDNA sequences between guinea pig and mouse ranged from 84.6%to 92.1%,and those of amino acid sequences ranged from 91.2% to 99.2%.The average identity rate of the 11 Pde cDNA sequences between guinea pig and human was significantly higher（P 0.01）than that between guinea pig and *** putative partial amino acid sequences of guinea pig contained at least one of the conserved domains of human and mouse PDE *** These results indicate that the brainexpressed Pde genes are identified in guinea pig,which lays the foundation for further investigating the physiological roles of PDE proteins in the brain.

摘要：高等教育在创新型人才培养的过程中,教师是关键因素。因此,要求教师在教学观念、组织、内容、模式、技术、评价、环境等一系列教学相关因素上设计与创新,适应时代的需求,促进教师的专业发展。以器官系统为中心的教学团队,可以使教师更好地进行课程内容整合和课程结构体系的规划,促进教师的创新发展,实现教师创新能力的提升,从而改善教学质量。

摘要：电荷泵锁相环(charge pump phase-locked loop,CPPLL)作为频率合成器(frequency synthesizer,FS),广泛应用于接收机中来提供低杂散、低噪声、高频谱纯度的本振(local oscillator,LO)信号。电荷泵(charge pump,CP)作为关键模块之一,其存在的非理想效应以及失配会带来更高相位噪声影响锁相环(phase-locked loop,PLL)频率综合器输出本振的频谱纯度。基于台积电(Taiwan semiconductor manufacturing company,TSMC ) 0.18μm CMOS工艺,采用电流舵电荷泵结构并加入泄漏电流模块设计了一款低电流失配率、低相位噪声的电荷泵电路,较好地克服了传统电荷泵所存在的非理想效应,使整个电荷泵电路的相位噪声保持在较低的水平。利用Cadence Spectre对电荷泵的整体性能进行仿真。仿真结果表明,供电电压为1.8V时,电荷泵电流为31.71μA,最大相位噪声为-230dBc/Hz,在0.4~1.4V输出电压范围内最大电流失配率仅有0.22%。

摘要：生态美学作为一门探讨美学和生态学关系的学科正在兴起,在环境危机的大背景下出现,对人与自然的关系进行反思。但生态美学不试图改变世界或者采取直接的行动反对资本主义生产方式,其目标是理解现实的美丽程度,提供批判性的理论认知。在概念上,生态美学和自然生态美学非常接近,他们有着相似但并不完全相同的研究对象。在普遍观念中,生态美学是关于未经人类改造或者只在很小的程度上被改造的自然部分的原则,提倡顺应自然而不是控制自然,反对将自然进行人为的扭曲和变形,改变原本存在的自然之美。因此,生态美学被认为属于(或者近似属于)自然至上主义的一部分,对破坏环境的人类活动和行为持反对态度,批判资本主义生产方式。与之不同的是,由吉尔诺特·伯梅(Gernot Bohme)构想的自然生态美学,更适用于现实视角,关注人类活动的改造作用,强调经验和感官知觉,主张从生理学的角度体验自然。伯梅分析了世界范围内多种不同的花园模式,以此来肯定经验作用。法国花园的特点是垂直投影,几何布局,正式严谨;而英国花园是通过角度和场景转化来呈现,打破自然与艺术、自然与文化、自然与文明的二分法。这种关注自然、尊重自然,将自然视为艺术的产物和情感表达方式的绿化实践也可以被借鉴。概括来说,生态美学关注自然原始的存在形式,自然生态美学在强调自然价值的同时更多地关注人造环境。

摘要：针对GPS接收机易受不同传输距离和多路径衰减效应的影响使得接收的信号强度不固定的问题,基于TSMC0.18μm互补金属氧化物半导体(CMOS)工艺设计一款可变增益放大器:它与脉冲宽度调制式自动增益控制和脉冲宽度译码器组成的自动增益控制电路保证接收信号强度输出的稳定;该电路的核心结构由五位二进制码控制五级级联放大电路来产生不同的增益。仿真结果表明:当电源电压为1.8V时,总的增益最小为14dB,最大可以达到73dB;并且在各个工艺角下增益误差都小于5%,噪声系数为19.68dB;输入1dB压缩点为—22.14dBm。