雉科基部类群分子钟的标定

使用 10个细胞色素b蛋白质全序列对雉科基部类群的分子钟进行了顺序标定 .以鸡形目 /雁形目的分歧时间作为锚定点 ,估计雉科 /珠鸡科 林鹑科的分歧时间为 (46 .94± 7.2 7)× 10 6aBP ,Francolinus/Bambusicola Gallus,Bambusicola/Gallus和Gallusgallus/G .sonneratii的分歧时间为 (40 .36± 8.4 0 )× 10 6 ,(35 .5 3± 8.15 )× 10 6 和 (8.5 2± 3.89)× 10 6 aBP .基于生物地理格局 ,我们推测 :①雉科起源于同南美洲分离之后的非洲 ;②在Francolinus的分化过程中 ,该属的某些成员通过印度的漂移从非洲进入欧亚大陆 ;③侵入新的生境后 ,Bambusicola和Gallus的共同祖先迅速从地Francolinus分歧出来 ;④原始的Bambusicola被Gallus排挤到南中国地区 ;⑤Gallus的祖先种分裂为大陆型和岛屿型 2类 ,前者分化为Gallusgallus和G .sonneratii,后者则分化为G .lafayettei和G .varius.估计结果同前两点假设是一致的 .     

一种使Charge-pump的输出电压稳定的时钟电路

随着工艺的提高和电源电压的降低,需要能够在低电压下工作的电路。该文介绍了一种能在1.8V电压下工作的时钟产生器。它的频率随着电源电压的增大而减小,随着温度的升高而增大,并能抑制制程的偏差对频率产生的影响。从而使Charge-pump的输出电压稳定。     

Molecular phylogeny of the specialized schizothoracine fishes （Teleostei： Cyprinidae）,with their implications for the uplift of the Qinghai-Tibetan Plateau

Molecular phylogeny of three genera containing nine species and subspecies of the specialized schizothoracine fishes are investigated based on the complete nucleotide sequence of mitochondrial cytochrome b gene. Meantime relationships between the main cladogenetic events of the specialized schizothoracine fishes and the stepwise uplift of the Qinghai-Tibetan Plateau are also conducted using the molecular clock, which is calibrated by geological isolated events between the upper reaches of the Yellow River and the Qinghai Lake. Results indicated that the specialized schizothoracine fishes are not a monophyly. Five species and subspecies of Ptychobarbus form a monophyly. But three species of Gymnodiptychus do not form a monophyly. Gd.integrigymnatus is a sister taxon of the highly specialized schizothoracine fishes while Gdo pachycheilus has a close relation with Gd. dybowskii, and both of them are as a sister group of Diptychus maculatus. The specialized schizothoracines fishes might have originated during the Miocene(about 10 MaBP), and then the divergence of three genera happened during late Miocene (about 8 MaBP). Their main specialization occurred during the late Pliocene and Pleistocene (3.54-0.42 MaBP). The main cladogenetic events of the specialized schizothoracine fishes are mostly correlated with the geological tectonic events and intensive climate shift happened at 8, 3.6, 2.5 and 1.7 MaBP of the late Cenozoic.Molecular clock data do not support the hypothesis that the Qinghai-Tibetan Plateau uplifted to near present or even higher elevations during the Oligocene or Miocene, and neither in agreement with the view that the plateau uplifting reached only to an altitude of 2000 m during the late Pliocene(about 2.6 MaBP).     

大型数字石英钟的整机设计

应用数字集成电路和石英振荡晶体、发光二极管等制成性能优良,具有装饰作用的高精度数字石英钟．     

论西汉千章铜漏的使用方法

西汉千章铜漏是一件有明确纪年、保存完好、容量很大的泄水型沉箭式漏壶。作者通过试验和文献考察，证明这种单漏是记述某段时刻的记时器，不能用于天文观测。     

利用卡诺图寻找内时钟复盖区的规范方法──复杂时钟下异步时序罗辑电路分析

讨论了内时钟方程复杂情况下，如何利用卡诺图寻找时钟复盖区的规范方法。以便规范并简化异步时序逻辑电路分析中的难点问题。     

微型机定时管理系统

在认真分析微型机内部时钟与实时时钟报警功能的基础上，用软件方法实现了微型机定时管理功能，使之到时发声报警，提示用户关机，并在指定时间自动停止计算机的运行。     

系统实时打印功能的实现

本文详细介绍了在以单片机为核心的测控系统中，使用专用时钟芯片与ＴＰμＰ系列微型打印机实现系统实时打印功能的硬件设计与软件流程．     

利用沃尔什函数综合低频扫频系统的方法

本文讨论用沃尔什函数合成正弦波的理论与技术，及基于该技术采用数字电路构成低频扫频系统的问题，给出了实用电路和系统框图．