In order to study the complex effects of photoperiod,temperature,and light intensity on the spore maturation and release number of Ulva prolifera,we cultured thalli segment(2–3 mm)under three different photoperiods(L...In order to study the complex effects of photoperiod,temperature,and light intensity on the spore maturation and release number of Ulva prolifera,we cultured thalli segment(2–3 mm)under three different photoperiods(L:D=12:12,14:10 and 10:14),temperature(15℃(LT),25℃(MT)and 30℃(HT))and light intensity(100,200 and 400μmol m^(−2)s^(−1),noted as LL,ML and HL,respectively)conditions.Then the maturation time,spore release number and chlorophyll fluorescence were analyzed.The results suggested that:1)The spore maturation time was accelerated by higher temperature or higher light intensity from 62 h to 36 h,and changes in day length accelerated the spore maturation to a certain extent as compared with 12:12 light/dark cycle;2)Higher light intensity significantly decreased the chlorophyll fluorescence(Fv′/Fm′,NPQ,rETRmax andα)of the mature reproductive segment under 30℃with 12:12 light/dark cycle.But when in the other photoperiods(10:14 and 14:10 conditions),the inhibitory effects of high light intensity were alleviated significantly;3)The optimum condition for the spore maturation and release was 12:12 light/dark cycle,25℃,400μmol m^(−2)s^(−1),with both shorter and longer photoperiod reducing the spore release number;4)Higher light intensity significantly increased the spore release number under 25℃,but these effects were alleviated by 30℃treatment.This study is the first attempt to elucidate the coincidence effects of photoperiod,temperature and light intensity on the reproduction of Ulva,which would help to reveal the mechanism of the rapid proliferation of green tide.展开更多
目的探讨连续硬膜外分娩镇痛在瘢痕子宫阴道试产产妇中应用的安全性和有效性。方法选择2021年6—12月在本院分娩的瘢痕子宫再次妊娠行阴道试产的产妇200例作为研究对象,按连续硬膜外分娩镇痛和拒绝药物分娩镇痛分为实验组和对照组两组,...目的探讨连续硬膜外分娩镇痛在瘢痕子宫阴道试产产妇中应用的安全性和有效性。方法选择2021年6—12月在本院分娩的瘢痕子宫再次妊娠行阴道试产的产妇200例作为研究对象,按连续硬膜外分娩镇痛和拒绝药物分娩镇痛分为实验组和对照组两组,每组各100例。实验组产妇行连续硬膜外分娩镇痛,对照组产妇拒绝药物分娩镇痛。记录比较两组产妇顺利完成实验人数、分娩结局、分娩过程中视觉模拟(VAS)评分、各产程时间、运动神经阻滞(Bromage)评分、出血量、缩宫素使用率、产妇不良反应、新生儿体重、Apgar评分、脐动脉血气pH值和Lac值等。结果对照组中有23例产妇因无法忍受疼痛而接受硬膜外分娩镇痛,退出实验,对照组产妇77例完成研究;实验组产妇100例全部完成研究。两组产妇阴道分娩率、剖宫产率、产钳助产率、阴道侧切率比较,差异均无统计学意义(P>0.05);在各产程接受连续硬膜外分娩镇痛后,实验组产妇的VAS评分均明显低于对照组,差异有统计学意义(P<0.05);两组产妇分娩过程中各产程时间、Bromage评分、出血量和缩宫素使用率比较,差异均无统计学意义(P>0.05);两组成功生理产产妇新生儿体重、1 min和10 min Apgar评分、新生儿脐动脉血气pH值和Lac值比较,差异均无统计学意义(P>0.05);两组产妇不良反应发生率比较,差异无统计学意义(P>0.05)。结论连续硬膜外分娩镇痛可明显减轻瘢痕子宫阴道试产产妇的分娩过程中的VAS评分,对产妇及新生儿无不良影响,是一种安全且有效的镇痛方式,值得在临床中推广。展开更多
为了设计具有小步进和低相噪的频率合成器,分析了直接式、锁相式和直接数字式频率合成器的优缺点,以及结合锁相环与直接数字式频率合成器的多种设计方案。在此基础上,使用DDS激励PLL的频率合成技术,设计了满足多种指标的频率合成器。该...为了设计具有小步进和低相噪的频率合成器,分析了直接式、锁相式和直接数字式频率合成器的优缺点,以及结合锁相环与直接数字式频率合成器的多种设计方案。在此基础上,使用DDS激励PLL的频率合成技术,设计了满足多种指标的频率合成器。该合成器的步进是1 Hz,当频率是10 k Hz时,合成器的相位噪声低于-90 d Bc/Hz,同时其输出带宽较大。展开更多
基金supported by the Natural Science Foundation of Zhejiang Province(No.LY23D060003)the Key Program of Science and Technology Innovation in Ningbo(2021Z114,2023Z118)sponsored by K.C.Wong Magna Fund in Ningbo University.
文摘In order to study the complex effects of photoperiod,temperature,and light intensity on the spore maturation and release number of Ulva prolifera,we cultured thalli segment(2–3 mm)under three different photoperiods(L:D=12:12,14:10 and 10:14),temperature(15℃(LT),25℃(MT)and 30℃(HT))and light intensity(100,200 and 400μmol m^(−2)s^(−1),noted as LL,ML and HL,respectively)conditions.Then the maturation time,spore release number and chlorophyll fluorescence were analyzed.The results suggested that:1)The spore maturation time was accelerated by higher temperature or higher light intensity from 62 h to 36 h,and changes in day length accelerated the spore maturation to a certain extent as compared with 12:12 light/dark cycle;2)Higher light intensity significantly decreased the chlorophyll fluorescence(Fv′/Fm′,NPQ,rETRmax andα)of the mature reproductive segment under 30℃with 12:12 light/dark cycle.But when in the other photoperiods(10:14 and 14:10 conditions),the inhibitory effects of high light intensity were alleviated significantly;3)The optimum condition for the spore maturation and release was 12:12 light/dark cycle,25℃,400μmol m^(−2)s^(−1),with both shorter and longer photoperiod reducing the spore release number;4)Higher light intensity significantly increased the spore release number under 25℃,but these effects were alleviated by 30℃treatment.This study is the first attempt to elucidate the coincidence effects of photoperiod,temperature and light intensity on the reproduction of Ulva,which would help to reveal the mechanism of the rapid proliferation of green tide.
文摘目的探讨连续硬膜外分娩镇痛在瘢痕子宫阴道试产产妇中应用的安全性和有效性。方法选择2021年6—12月在本院分娩的瘢痕子宫再次妊娠行阴道试产的产妇200例作为研究对象,按连续硬膜外分娩镇痛和拒绝药物分娩镇痛分为实验组和对照组两组,每组各100例。实验组产妇行连续硬膜外分娩镇痛,对照组产妇拒绝药物分娩镇痛。记录比较两组产妇顺利完成实验人数、分娩结局、分娩过程中视觉模拟(VAS)评分、各产程时间、运动神经阻滞(Bromage)评分、出血量、缩宫素使用率、产妇不良反应、新生儿体重、Apgar评分、脐动脉血气pH值和Lac值等。结果对照组中有23例产妇因无法忍受疼痛而接受硬膜外分娩镇痛,退出实验,对照组产妇77例完成研究;实验组产妇100例全部完成研究。两组产妇阴道分娩率、剖宫产率、产钳助产率、阴道侧切率比较,差异均无统计学意义(P>0.05);在各产程接受连续硬膜外分娩镇痛后,实验组产妇的VAS评分均明显低于对照组,差异有统计学意义(P<0.05);两组产妇分娩过程中各产程时间、Bromage评分、出血量和缩宫素使用率比较,差异均无统计学意义(P>0.05);两组成功生理产产妇新生儿体重、1 min和10 min Apgar评分、新生儿脐动脉血气pH值和Lac值比较,差异均无统计学意义(P>0.05);两组产妇不良反应发生率比较,差异无统计学意义(P>0.05)。结论连续硬膜外分娩镇痛可明显减轻瘢痕子宫阴道试产产妇的分娩过程中的VAS评分,对产妇及新生儿无不良影响,是一种安全且有效的镇痛方式,值得在临床中推广。
文摘为了设计具有小步进和低相噪的频率合成器,分析了直接式、锁相式和直接数字式频率合成器的优缺点,以及结合锁相环与直接数字式频率合成器的多种设计方案。在此基础上,使用DDS激励PLL的频率合成技术,设计了满足多种指标的频率合成器。该合成器的步进是1 Hz,当频率是10 k Hz时,合成器的相位噪声低于-90 d Bc/Hz,同时其输出带宽较大。
