<div style="text-align:justify;"> A generalized optical filterless approach to achieve photonic generation of frequency 16-tupling millimeter-wave (mm-wave) signal based on two cascaded dual-parallel M...<div style="text-align:justify;"> A generalized optical filterless approach to achieve photonic generation of frequency 16-tupling millimeter-wave (mm-wave) signal based on two cascaded dual-parallel Mach-Zehnder modulators (DPMZMs) is presented. A theoretical analysis leading to the operating conditions to achieve frequency 16-tupling is developed. Different modulation indices (MIs) can be implemented to achieve the frequency multiplication by adjusting the delay of tunable optical delay line (TODL). It is confirmed by simulation that the proposed scheme is effective, and the radio frequency spurious suppression ratio (RFSSR) of the generated frequency 16-tupling signal can be as high as 40 dB when the sub-MZMs have extinction ratios of 30 dB. Influencing factors such as extinction ratio, DC bias drift, phase shift deviation and RF voltage deviation on the performance of optical sideband suppression ratio (OSSR) and RFSSR are also investigated. </div>展开更多
The study was carried out to find the prevalence of ectoparasites in carp species specifically Indian Major Carps(IMC)during the post monsoon season(November’16 to March’17).Four groups of ectoparasites viz.myxozoan...The study was carried out to find the prevalence of ectoparasites in carp species specifically Indian Major Carps(IMC)during the post monsoon season(November’16 to March’17).Four groups of ectoparasites viz.myxozoan,ciliophoran,monogenean and crustacean were recorded from a total 500 number of carp species like,Labeo rohita,Catla catla,Cirrhinus mrigala and Labeo calbasu collected from different ponds of selected blocks of South 24-Parganas district of West Bengal.The highest prevalence(64.8%)of infestation had been recorded by Myxozoans and the lowest was by Monogeneans(4.8%).The highest and lowest ectoparasitic prevalence in carp was observed in L.rohita(32.9%)and C.catla(27.3%).Beside these,lower temperature(Average 19.3℃),low pH(Average 6.9)and marginal level of dissolved oxygen(Average 6.0ppm)were also created an unfavorable condition for parasitic infestation during this season.At the end of this experiment it was concluded that disease occurrences due to ectoparasites was high in winter with some key factors like temperature,pH and dissolved oxygen(DO).展开更多
目的评估和分析一份男性食物频率问卷(food frequency questionnaire,FFQ)中食物组摄入量的重现性和有效性的影响因素。方法从一项大规模人群队列研究"上海市男性健康队列"中随机选取了214名对象,在进入队列时均完成了第1次FF...目的评估和分析一份男性食物频率问卷(food frequency questionnaire,FFQ)中食物组摄入量的重现性和有效性的影响因素。方法从一项大规模人群队列研究"上海市男性健康队列"中随机选取了214名对象,在进入队列时均完成了第1次FFQ调查,其后开始进行每月1次、为期1年的24 h膳食回顾调查(24-hour dietary recall,24-HDR),在12次24-HDR调查完成后再重新进行与第1次FFQ相同的第2次FFQ调查,2次FFQ的平均间隔时间为1.2年。将FFQ及24-HDR调查所得的食物项归类为11个食物组,通过2次FFQ的食物组摄入量的Pearson相关系数,来评估和分析FFQ测量食物组摄入量的重现性的影响因素。有效性的影响因素则通过比较第2次FFQ与24-HDR的食物组摄入量的Pearson相关系数来评估。结果共有195名研究对象完成了全部的2次FFQ与12次24-HDR调查。2次FFQ之间各食物组摄入量的Pearson相关系数的中位数在高、低年龄组分别为0.62、0.50;高、低教育水平组分别为0.58、0.50;高、低收入组分别为0.51、0.50;高、低BMI组分别为0.50、0.49。第2次FFQ与24-HDR的各食物组摄入量的Pearson相关系数的中位数在高、低年龄组分别为0.61、0.45;高、低教育水平组分别为0.49、0.47;高、低收入组分别为0.43、0.57;高、低BMI组分别为0.48、0.51。结论上海市男性健康队列所采用的食物频率问卷中食物组摄入量的重现性的影响因素主要是研究对象的年龄,有效性的影响因素主要是年龄和收入水平。展开更多
文摘<div style="text-align:justify;"> A generalized optical filterless approach to achieve photonic generation of frequency 16-tupling millimeter-wave (mm-wave) signal based on two cascaded dual-parallel Mach-Zehnder modulators (DPMZMs) is presented. A theoretical analysis leading to the operating conditions to achieve frequency 16-tupling is developed. Different modulation indices (MIs) can be implemented to achieve the frequency multiplication by adjusting the delay of tunable optical delay line (TODL). It is confirmed by simulation that the proposed scheme is effective, and the radio frequency spurious suppression ratio (RFSSR) of the generated frequency 16-tupling signal can be as high as 40 dB when the sub-MZMs have extinction ratios of 30 dB. Influencing factors such as extinction ratio, DC bias drift, phase shift deviation and RF voltage deviation on the performance of optical sideband suppression ratio (OSSR) and RFSSR are also investigated. </div>
文摘The study was carried out to find the prevalence of ectoparasites in carp species specifically Indian Major Carps(IMC)during the post monsoon season(November’16 to March’17).Four groups of ectoparasites viz.myxozoan,ciliophoran,monogenean and crustacean were recorded from a total 500 number of carp species like,Labeo rohita,Catla catla,Cirrhinus mrigala and Labeo calbasu collected from different ponds of selected blocks of South 24-Parganas district of West Bengal.The highest prevalence(64.8%)of infestation had been recorded by Myxozoans and the lowest was by Monogeneans(4.8%).The highest and lowest ectoparasitic prevalence in carp was observed in L.rohita(32.9%)and C.catla(27.3%).Beside these,lower temperature(Average 19.3℃),low pH(Average 6.9)and marginal level of dissolved oxygen(Average 6.0ppm)were also created an unfavorable condition for parasitic infestation during this season.At the end of this experiment it was concluded that disease occurrences due to ectoparasites was high in winter with some key factors like temperature,pH and dissolved oxygen(DO).
