This paper introduces a novel digital transceiver for the cordless telephone zero （CT0） standard,which uses a digital modulation and demodulation technique to handle the signal instead of the traditional analog meth...This paper introduces a novel digital transceiver for the cordless telephone zero （CT0） standard,which uses a digital modulation and demodulation technique to handle the signal instead of the traditional analog meth-od. In the transmitter,a fractional-N phase locked loop （PLL） is utilized to realize the continuous phase frequency shift key （CPFSK） modulation,and a 2 Ts raised cosine （2RC） shaping technique is used to reduce the occupied bandwidth. In the receiver,a novel digital method is proposed to demodulate the 2RC CPFSK signal. This chip is fabricated using an SMIC 0.35μm mixed signal CMOS process with a die size of 2mm × 2mm. With an external low noise amplifier （LNA）,the sensitivity of the chip is better than -103dBm.展开更多
The quest for the origin of species has entered the genomics era. Despite decades of evidence confirming the role of the environment in ecological speciation, an understanding of the genomics of ecological speciation ...The quest for the origin of species has entered the genomics era. Despite decades of evidence confirming the role of the environment in ecological speciation, an understanding of the genomics of ecological speciation is still in its infancy. In this review, we explore the role of genomic architecture in ecological speciation in postglacial fishes. Growing evidence for the num- ber, location, effect size, and interactions among the genes underlying population persistence, adaptive trait divergence, and re- productive isolation in these fishes reinforces the importance of considering genomic architecture in studies of ecological speci- ation. Additionally, these populations likely adapt to new freshwater environments by selection on standing genetic variation, as de novo mutations are unlikely under such recent divergence times. We hypothesize that modular genomic architectures in post- glacial fish taxa may be associated with the probability of population persistence. Empirical studies have confirmed the genic na- ture of ecological speciation, implicating surprisingly extensive linkage disequilibrium across the genome. An understanding of these genomic mosaics and how they contribute to reproductive barriers remains unclear, but migration rates and the strength of selection at these loci is predicted to influence the likelihood of population divergence. Altogether, understanding the role of ge- nomic architecture is an important component of speciation research and postglacial fishes continue to provide excellent organ- isms to test these questions, both from the perspective of variation in architectures among taxa, and with respect to the distinct environments they have colonized. However, more empirical tests of ecological speciation predictions are needed [Current Zoo- logy 59 （1）： 53-71, 2013].展开更多
文摘This paper introduces a novel digital transceiver for the cordless telephone zero （CT0） standard,which uses a digital modulation and demodulation technique to handle the signal instead of the traditional analog meth-od. In the transmitter,a fractional-N phase locked loop （PLL） is utilized to realize the continuous phase frequency shift key （CPFSK） modulation,and a 2 Ts raised cosine （2RC） shaping technique is used to reduce the occupied bandwidth. In the receiver,a novel digital method is proposed to demodulate the 2RC CPFSK signal. This chip is fabricated using an SMIC 0.35μm mixed signal CMOS process with a die size of 2mm × 2mm. With an external low noise amplifier （LNA）,the sensitivity of the chip is better than -103dBm.
文摘The quest for the origin of species has entered the genomics era. Despite decades of evidence confirming the role of the environment in ecological speciation, an understanding of the genomics of ecological speciation is still in its infancy. In this review, we explore the role of genomic architecture in ecological speciation in postglacial fishes. Growing evidence for the num- ber, location, effect size, and interactions among the genes underlying population persistence, adaptive trait divergence, and re- productive isolation in these fishes reinforces the importance of considering genomic architecture in studies of ecological speci- ation. Additionally, these populations likely adapt to new freshwater environments by selection on standing genetic variation, as de novo mutations are unlikely under such recent divergence times. We hypothesize that modular genomic architectures in post- glacial fish taxa may be associated with the probability of population persistence. Empirical studies have confirmed the genic na- ture of ecological speciation, implicating surprisingly extensive linkage disequilibrium across the genome. An understanding of these genomic mosaics and how they contribute to reproductive barriers remains unclear, but migration rates and the strength of selection at these loci is predicted to influence the likelihood of population divergence. Altogether, understanding the role of ge- nomic architecture is an important component of speciation research and postglacial fishes continue to provide excellent organ- isms to test these questions, both from the perspective of variation in architectures among taxa, and with respect to the distinct environments they have colonized. However, more empirical tests of ecological speciation predictions are needed [Current Zoo- logy 59 （1）： 53-71, 2013].
