Resonance-enhanced multiphoton ionization of the titanium atoms has been investigated in the 293 321 nm wavelength. We couple a laser-ablated metal target into a molecular beam to produce free atoms. Ions produced fro...Resonance-enhanced multiphoton ionization of the titanium atoms has been investigated in the 293 321 nm wavelength. We couple a laser-ablated metal target into a molecular beam to produce free atoms. Ions produced from photoionization of the neutral atoms are monitored by a home-built time-of-flight mass spectrometer. Photoionization cross sections of the excited states of Ti I were deduced from the dependence of the ion signal intensity on the laser intensity for photon energies close to the ionization threshold. The values obtained range from 0.2 Mb to 6.0 Mb. No significant isotope-dependence was found from measurements of the photoionization cross sections of ^46Ti, ^47Ti, and ^48Ti.展开更多
This paper describes the development of a timer based voltage to frequency converter(V FC).Timer LM555is used in astable multivibrator mode with two OPTO-LDRs(light dependent resistors)in the circuitry.The frequency o...This paper describes the development of a timer based voltage to frequency converter(V FC).Timer LM555is used in astable multivibrator mode with two OPTO-LDRs(light dependent resistors)in the circuitry.The frequency of timer output waveform which is measured using a digital storage oscillator(DSO)is almost linearly proportional to the applied input voltage.Hence we obtain a linear relationship between the frequency of timer output waveform and the input voltage.Because of its quasi-digital output,the main advantages of this developed converter are linear input-output relationship,small size,easy portabilityand high cost performance.In addition,the timer output waveform can be directly interfaced with personal computer or microprocessor/microcontroller for further processing of the input voltage signal without intervening any analog-to-digital converter(ADC).展开更多
This study investigated the genetic association of three single nucleotide polymorphisms （SNPs; rs 10483727, rs33912345, and rs146737847） at the SIX1-SIX6 locus with primar-y open angle glaucoma （POAG） in the Chin...This study investigated the genetic association of three single nucleotide polymorphisms （SNPs; rs 10483727, rs33912345, and rs146737847） at the SIX1-SIX6 locus with primar-y open angle glaucoma （POAG） in the Chinese population. A total of 866 subjects with POAG （685 high-tension glaucoma （HTG） and 181 normal-tension glaucoma （NTG）） and 266 control individu- als were included. Significant genetic association was identified for rs 10483727 in HTG （P=0.02; odds ratio （OR）=l.31）, NTG （P=7.41x10-6; OR=2.71）, and POAG （i.e., HTG and NTG combined; P=0.001; OR=1.44）. rs33912345 was also significantly associated with HTG （P=0.008; OR=1.36）, NTG （P=2.72x10-6; OR=2.27）, and POAG （P=3.84x10-4; OR=1.49）. The rare SIX6 mutation, rs146737847, was not found in the subjects enrolled in this study. Stratification by patient age identified that both rs10483727 and rs33912345 were significantly associated with NTG in patients aged above 40 years （P=2.08x10-5; OR=2.28）, whereas in patients aged between 20-40 years, rs33912345 was significantly associated with NTG （P=0.017; OR=2.06）. In HTG, the genetic associations for both rs10483727 and rs33912345 were significant in patients aged between 20-40 years （P=0.006; OR= 1.56） but not in those aged above 40 years （P=0.118, 0R=1.21 and P=0.042, OR= 1.29, respec- tively）. This study replicated the association of POAG with two SNPs at the SIX1-SIX6 locus and demonstrated that SNPs, rs10483727 and rs33912345, are significantly associated with POAG, especially with NTG in patients aged above 40 years.展开更多
基金V. ACKNOWLEDGMENTS This work is supported by the National Natural Science Foundation of China （No.10674002 and No.20973001） and the Science Foundation of Anhui Education Committee （No.ZD2007001-1）.
文摘Resonance-enhanced multiphoton ionization of the titanium atoms has been investigated in the 293 321 nm wavelength. We couple a laser-ablated metal target into a molecular beam to produce free atoms. Ions produced from photoionization of the neutral atoms are monitored by a home-built time-of-flight mass spectrometer. Photoionization cross sections of the excited states of Ti I were deduced from the dependence of the ion signal intensity on the laser intensity for photon energies close to the ionization threshold. The values obtained range from 0.2 Mb to 6.0 Mb. No significant isotope-dependence was found from measurements of the photoionization cross sections of ^46Ti, ^47Ti, and ^48Ti.
文摘This paper describes the development of a timer based voltage to frequency converter(V FC).Timer LM555is used in astable multivibrator mode with two OPTO-LDRs(light dependent resistors)in the circuitry.The frequency of timer output waveform which is measured using a digital storage oscillator(DSO)is almost linearly proportional to the applied input voltage.Hence we obtain a linear relationship between the frequency of timer output waveform and the input voltage.Because of its quasi-digital output,the main advantages of this developed converter are linear input-output relationship,small size,easy portabilityand high cost performance.In addition,the timer output waveform can be directly interfaced with personal computer or microprocessor/microcontroller for further processing of the input voltage signal without intervening any analog-to-digital converter(ADC).
基金supported by National Natural Science Foundation of China (81271005, 81300767)the Beijing Scholar Program
文摘This study investigated the genetic association of three single nucleotide polymorphisms （SNPs; rs 10483727, rs33912345, and rs146737847） at the SIX1-SIX6 locus with primar-y open angle glaucoma （POAG） in the Chinese population. A total of 866 subjects with POAG （685 high-tension glaucoma （HTG） and 181 normal-tension glaucoma （NTG）） and 266 control individu- als were included. Significant genetic association was identified for rs 10483727 in HTG （P=0.02; odds ratio （OR）=l.31）, NTG （P=7.41x10-6; OR=2.71）, and POAG （i.e., HTG and NTG combined; P=0.001; OR=1.44）. rs33912345 was also significantly associated with HTG （P=0.008; OR=1.36）, NTG （P=2.72x10-6; OR=2.27）, and POAG （P=3.84x10-4; OR=1.49）. The rare SIX6 mutation, rs146737847, was not found in the subjects enrolled in this study. Stratification by patient age identified that both rs10483727 and rs33912345 were significantly associated with NTG in patients aged above 40 years （P=2.08x10-5; OR=2.28）, whereas in patients aged between 20-40 years, rs33912345 was significantly associated with NTG （P=0.017; OR=2.06）. In HTG, the genetic associations for both rs10483727 and rs33912345 were significant in patients aged between 20-40 years （P=0.006; OR= 1.56） but not in those aged above 40 years （P=0.118, 0R=1.21 and P=0.042, OR= 1.29, respec- tively）. This study replicated the association of POAG with two SNPs at the SIX1-SIX6 locus and demonstrated that SNPs, rs10483727 and rs33912345, are significantly associated with POAG, especially with NTG in patients aged above 40 years.
