A frequency servo system-on-chip(FS-SoC)featuring output power stabilization technology is introduced in this study for high-precision and miniaturized cesium(Cs)atomic clocks.The proposed power stabilization loop(PSL...A frequency servo system-on-chip(FS-SoC)featuring output power stabilization technology is introduced in this study for high-precision and miniaturized cesium(Cs)atomic clocks.The proposed power stabilization loop(PSL)technique,incorporating an off-chip power detector(PD),ensures that the output power of the FS-SoC remains stable,mitigating the impact of power fluctuations on the atomic clock's stability.Additionally,a one-pulse-per-second(1PPS)is employed to syn-chronize the clock with GPS.Fabricated using 65 nm CMOS technology,the measured phase noise of the FS-SoC stands at-69.5 dBc/Hz@100 Hz offset and-83.9 dBc/Hz@1 kHz offset,accompanied by a power dissipation of 19.7 mW.The Cs atomic clock employing the proposed FS-SoC and PSL obtains an Allan deviation of 1.7×10^(-11) with 1-s averaging time.展开更多
This paper experimentally demonstrates a low-cost energy efficient alternative technique for long reach transfer of accurate reference frequency(RF) clock signals for extended reach RF distribution systems.This is ach...This paper experimentally demonstrates a low-cost energy efficient alternative technique for long reach transfer of accurate reference frequency(RF) clock signals for extended reach RF distribution systems.This is achieved by adopting distributed forward Raman amplification and vertical cavity surface emitting laser(VCSEL) technology.A class 10 G VCSEL is directly modulated with a 2 GHz RF clock signal.By exploiting a forward Raman pump with the flat gain of 8.6 dB, a 100.8-km-long standard single mode fiber(SMF) RF clock distribution is experimentally achieved.A maximum phase noise of-117.66 dBc/Hz at offset frequency of 100 kHz and an RF clock jitter(RMS) of 5.36 ps is experimentally measured for 100.8-km-long fiber transmission without forward Raman amplification.However, with the adoption of forward Raman amplification, the measured phase noise and RMS improves to-86.59 dBc/Hz and 1.7 ps, respectively.Forward Raman pumping offers distributed high flat gain over a wide spectra range(over 35.5 nm), while VCSELs offer cost effective broadband signal distribution, therefore keeping the network optics investment low.展开更多
In recent years,with the rapid development of molecular biology diagnostic technology,many new polymerase chain reaction(PCR)technologies with high specificity and good sensitivity have gradually been developed.While ...In recent years,with the rapid development of molecular biology diagnostic technology,many new polymerase chain reaction(PCR)technologies with high specificity and good sensitivity have gradually been developed.While expanding the range of detection methods,these technologies inevitably have some disadvantages.Therefore,in clinical pathogen diagnosis,medical personnel should choose the detection method according to the detection purpose and pathogen characteristics.In this paper,the basic principle,application scope,advantages and disadvantages and development of various emerging PCR diagnostic techniques are respectively described in order to provide a theoretical reference for the selection of pathogenic biological diagnostic techniques in the clinical practice.展开更多
A design of a ll. 6-GHz phase-locked loop （PLL） fabricated in 49-GHz 0. 18-μm CMOS （complementary metal-oxide-semiconductor transistor） technology is described. An analog multiplier phase detector （PD）, a one-p...A design of a ll. 6-GHz phase-locked loop （PLL） fabricated in 49-GHz 0. 18-μm CMOS （complementary metal-oxide-semiconductor transistor） technology is described. An analog multiplier phase detector （PD）, a one-pole passive low pass filter and a three-stage ring oscillator with variable negativeresistance loads build up the monolithic phase-locked loop. The measured rms jitter of output signal via onwafer testing is 2. 2 ps under the stimulation of 2^31 - 1 bit-long pseudo random bit sequence （PRBS） at the bit rate of 11.6 GHz. And the tracking range is 250 MHz. The phase noise in the locked condition is measured to be - 107 dBc/Hz at 10 MHz offset, and that of the ring VCO at the central frequency is -99 dBc/Hz at 10 MHz offset. The circuit area of the proposed PLL is only 0. 47mm×0.72mm and the direct current （DC） power dissipation is 164 mW under a 1.8-V supply.展开更多
Sensitive and accurate detection of biological analytes,such as proteins,genes,small molecules,ions,cells,etc.,has been a significant project in life science.Signal amplification is one of the most effective approache...Sensitive and accurate detection of biological analytes,such as proteins,genes,small molecules,ions,cells,etc.,has been a significant project in life science.Signal amplification is one of the most effective approaches to improve the sensitivity of bioanalysis.Taking advantage of specific base pairing,programmable operation,and predictable assembly,DNA is flexible and suitable to perform the signal amplification procedure.In recent years,signal amplification strategies by means of DNA technology have been widely integrated into the construction of electrochemiluminescence(ECL)biosensors,achieving desirable analytical performance in clinical diagnosis,biomedical research,and drug development.To the best of our knowledge,these DNA signal amplification technologies mainly include classical polymerase chain reaction,and various amplification approaches conducted under mild conditions,such as rolling circle amplification(RCA)or hyperbranched RCA,cleaving enzyme-assisted amplification,DNAzyme-involved amplification,toehold-mediated DNA strand displacement amplification without enzyme participation,and so on.This review overviews the recent advancements of DNA signal amplification strategies for bioanalysis in the ECL realm,sketching the creative trajectory from strategies design to ultrasensitive ECL platform construction and resulting applications.展开更多
Gene amplification is a common mechanism of oncogene activation and contributes to tumor progression. Analysis of such genetic alterations are relevant to the understanding of tumor genetics and could provide prognost...Gene amplification is a common mechanism of oncogene activation and contributes to tumor progression. Analysis of such genetic alterations are relevant to the understanding of tumor genetics and could provide prognostic information for the individual patient. Standard analytical approaches using Southern blot and slot blot require a large amount of good展开更多
可视化检测技术具有直观性和便捷性的优势,但在灵敏度和痕量分析方面存在局限性。滚环扩增技术(rolling circle amplification, RCA)作为一种新兴的核酸等温扩增技术,具有高灵敏、高特异性等优点,在体外诊断及食品安全检测等领域极具应...可视化检测技术具有直观性和便捷性的优势,但在灵敏度和痕量分析方面存在局限性。滚环扩增技术(rolling circle amplification, RCA)作为一种新兴的核酸等温扩增技术,具有高灵敏、高特异性等优点,在体外诊断及食品安全检测等领域极具应用前景。将可视化检测与RCA技术相结合,可极大提高检测灵敏度,具有即时检测(point-of-care testing, POCT)的潜力。综述RCA技术的原理、类型、信号放大机制以及基于RCA的各类可视化生物传感器(包括荧光、比色等生物传感器),旨在为RCA技术在快速可视化检测领域中的开发与应用提供新的思路。展开更多
We develop a splicing technology of Ti:sapphire crystals for a high-energy chirped pulse amplifier laser system that can suppress the parasitic lasing to improve the amplification efficiency compared to a large-size s...We develop a splicing technology of Ti:sapphire crystals for a high-energy chirped pulse amplifier laser system that can suppress the parasitic lasing to improve the amplification efficiency compared to a large-size single Ti:sapphire crystal amplifier. Theoretical investigations on the characteristics of the amplifier with four splicing Ti:sapphire crystals,such as parasitic-lasing suppression and amplification efficiencies, are carried out. Some possible issues resulting from this splicing technology, including spectral modulation, stretching or splitting of the temporal profile, and the sidelobe generation in the spatial domain(near field and far field), are also investigated. Moreover, the feasibility of the splicing technology is preliminarily demonstrated in an experiment with a small splicing Ti:sapphire crystals amplifier. The temporal profile and spatial distribution of the output pulse from the splicing Ti:sapphire crystal amplifier are discussed in relation to the output pulse from a single Ti:sapphire crystal amplifier.展开更多
基金supported by the National Natural Science Foundation of China under Grant 62034002 and 62374026.
文摘A frequency servo system-on-chip(FS-SoC)featuring output power stabilization technology is introduced in this study for high-precision and miniaturized cesium(Cs)atomic clocks.The proposed power stabilization loop(PSL)technique,incorporating an off-chip power detector(PD),ensures that the output power of the FS-SoC remains stable,mitigating the impact of power fluctuations on the atomic clock's stability.Additionally,a one-pulse-per-second(1PPS)is employed to syn-chronize the clock with GPS.Fabricated using 65 nm CMOS technology,the measured phase noise of the FS-SoC stands at-69.5 dBc/Hz@100 Hz offset and-83.9 dBc/Hz@1 kHz offset,accompanied by a power dissipation of 19.7 mW.The Cs atomic clock employing the proposed FS-SoC and PSL obtains an Allan deviation of 1.7×10^(-11) with 1-s averaging time.
文摘This paper experimentally demonstrates a low-cost energy efficient alternative technique for long reach transfer of accurate reference frequency(RF) clock signals for extended reach RF distribution systems.This is achieved by adopting distributed forward Raman amplification and vertical cavity surface emitting laser(VCSEL) technology.A class 10 G VCSEL is directly modulated with a 2 GHz RF clock signal.By exploiting a forward Raman pump with the flat gain of 8.6 dB, a 100.8-km-long standard single mode fiber(SMF) RF clock distribution is experimentally achieved.A maximum phase noise of-117.66 dBc/Hz at offset frequency of 100 kHz and an RF clock jitter(RMS) of 5.36 ps is experimentally measured for 100.8-km-long fiber transmission without forward Raman amplification.However, with the adoption of forward Raman amplification, the measured phase noise and RMS improves to-86.59 dBc/Hz and 1.7 ps, respectively.Forward Raman pumping offers distributed high flat gain over a wide spectra range(over 35.5 nm), while VCSELs offer cost effective broadband signal distribution, therefore keeping the network optics investment low.
文摘In recent years,with the rapid development of molecular biology diagnostic technology,many new polymerase chain reaction(PCR)technologies with high specificity and good sensitivity have gradually been developed.While expanding the range of detection methods,these technologies inevitably have some disadvantages.Therefore,in clinical pathogen diagnosis,medical personnel should choose the detection method according to the detection purpose and pathogen characteristics.In this paper,the basic principle,application scope,advantages and disadvantages and development of various emerging PCR diagnostic techniques are respectively described in order to provide a theoretical reference for the selection of pathogenic biological diagnostic techniques in the clinical practice.
基金The National High Technology Research and Devel-opment Program of China (863Program) (No2001AA312010)
文摘A design of a ll. 6-GHz phase-locked loop （PLL） fabricated in 49-GHz 0. 18-μm CMOS （complementary metal-oxide-semiconductor transistor） technology is described. An analog multiplier phase detector （PD）, a one-pole passive low pass filter and a three-stage ring oscillator with variable negativeresistance loads build up the monolithic phase-locked loop. The measured rms jitter of output signal via onwafer testing is 2. 2 ps under the stimulation of 2^31 - 1 bit-long pseudo random bit sequence （PRBS） at the bit rate of 11.6 GHz. And the tracking range is 250 MHz. The phase noise in the locked condition is measured to be - 107 dBc/Hz at 10 MHz offset, and that of the ring VCO at the central frequency is -99 dBc/Hz at 10 MHz offset. The circuit area of the proposed PLL is only 0. 47mm×0.72mm and the direct current （DC） power dissipation is 164 mW under a 1.8-V supply.
基金financially supported by the National Natural Science Foundation of China(21834004 and 21904063)the Natural Science Foundation of Jiangsu Province(BK20190279)the Fundamental Research Funds for the Central Universities(021314380151)
文摘Sensitive and accurate detection of biological analytes,such as proteins,genes,small molecules,ions,cells,etc.,has been a significant project in life science.Signal amplification is one of the most effective approaches to improve the sensitivity of bioanalysis.Taking advantage of specific base pairing,programmable operation,and predictable assembly,DNA is flexible and suitable to perform the signal amplification procedure.In recent years,signal amplification strategies by means of DNA technology have been widely integrated into the construction of electrochemiluminescence(ECL)biosensors,achieving desirable analytical performance in clinical diagnosis,biomedical research,and drug development.To the best of our knowledge,these DNA signal amplification technologies mainly include classical polymerase chain reaction,and various amplification approaches conducted under mild conditions,such as rolling circle amplification(RCA)or hyperbranched RCA,cleaving enzyme-assisted amplification,DNAzyme-involved amplification,toehold-mediated DNA strand displacement amplification without enzyme participation,and so on.This review overviews the recent advancements of DNA signal amplification strategies for bioanalysis in the ECL realm,sketching the creative trajectory from strategies design to ultrasensitive ECL platform construction and resulting applications.
文摘Gene amplification is a common mechanism of oncogene activation and contributes to tumor progression. Analysis of such genetic alterations are relevant to the understanding of tumor genetics and could provide prognostic information for the individual patient. Standard analytical approaches using Southern blot and slot blot require a large amount of good
基金partially supported by the National Basic Research Program of China (Grant No. 2011CB808101)the National Natural Science Foundation of China (NSFC) (Grant Nos. 61221064, 61078037, 11127901, 11134010)the International S&T Cooperation Program of China (Grant No. 2011DFA11300)
文摘We develop a splicing technology of Ti:sapphire crystals for a high-energy chirped pulse amplifier laser system that can suppress the parasitic lasing to improve the amplification efficiency compared to a large-size single Ti:sapphire crystal amplifier. Theoretical investigations on the characteristics of the amplifier with four splicing Ti:sapphire crystals,such as parasitic-lasing suppression and amplification efficiencies, are carried out. Some possible issues resulting from this splicing technology, including spectral modulation, stretching or splitting of the temporal profile, and the sidelobe generation in the spatial domain(near field and far field), are also investigated. Moreover, the feasibility of the splicing technology is preliminarily demonstrated in an experiment with a small splicing Ti:sapphire crystals amplifier. The temporal profile and spatial distribution of the output pulse from the splicing Ti:sapphire crystal amplifier are discussed in relation to the output pulse from a single Ti:sapphire crystal amplifier.
