We demonstrate a diode pumped Yb：LuVO4 laser that can be passively Q-switched by a Cr^（4＋）：YAG saturable absorber having an initial transmission as high as 99.3%.A maximum pulsed output power of 2.35 W is generat...We demonstrate a diode pumped Yb：LuVO4 laser that can be passively Q-switched by a Cr^（4＋）：YAG saturable absorber having an initial transmission as high as 99.3%.A maximum pulsed output power of 2.35 W is generated at a repetition rate of 285.7 kHz,approaching or very near the intrinsic upper limit imposed by the recovery time of the Cr^（4＋）：YAG saturable absorber,and the resulting pulse energy,duration and peak power are,respectively,8.2μJ,39.2ns and 0.209kW.展开更多
A comprehensive investigation is carried out to compare the spectroscopic properties, absorption saturation behaviors and lasing properties of a Yb ion in tetragonal LuPO4 and LuVO4 isomorphic crystals. Significant di...A comprehensive investigation is carried out to compare the spectroscopic properties, absorption saturation behaviors and lasing properties of a Yb ion in tetragonal LuPO4 and LuVO4 isomorphic crystals. Significant distinctions are revealed in many aspects of the lasing behavior for the Yb ion doped in the two crystal hosts, and Yb：LuPO_4 proves to be superior to Yb：LuVO4 since it enables efficient laser action to be much more easily achieved. With a 0.6 mm thick crystal plate of Yb：LuPO4, an output power of 3.30 W can be generated with an optical–optical conversion efficiency of 50.8%; whereas with a 2 mm long miniature crystal rod, the output power produced can reach 8.35 W with an optical–optical conversion efficiency of 46.7%.展开更多
Tweety-homolog 1(Ttyh1)is expressed in neural tissue and has been implicated in the generation of several brain diseases.However,its functional significance in pain processing is not understood.By disrupting the gene ...Tweety-homolog 1(Ttyh1)is expressed in neural tissue and has been implicated in the generation of several brain diseases.However,its functional significance in pain processing is not understood.By disrupting the gene encoding Ttyh1,we found a loss of Ttyh1 in nociceptors and their central terminals in Ttyh1-deficient mice,along with a reduction in nociceptor excitability and synaptic transmission at identified synapses between nociceptors and spinal neurons projecting to the periaqueductal grey(PAG)in the basal state.More importantly,the peripheral inflammationevoked nociceptor hyperexcitability and spinal synaptic potentiation recorded in spinal-PAG projection neurons were compromised in Ttyh1-deficient mice.Analysis of the paired-pulse ratio and miniature excitatory postsynaptic currents indicated a role of presynaptic Ttyh1 from spinal nociceptor terminals in the regulation of neurotransmitter release.Interfering with Ttyh1 specifically in nociceptors produces a comparable pain relief.Thus,in this study we demonstrated that Ttyh1 is a critical determinant of acute nociception and pain sensitization caused by peripheral inflammation.展开更多
Aims With the global atmospheric nitrogen(N)deposition increasing,the effect of N deposition on terrestrial plant diversity has been widely studied.Some studies have reviewed the effects of N deposition on plant speci...Aims With the global atmospheric nitrogen(N)deposition increasing,the effect of N deposition on terrestrial plant diversity has been widely studied.Some studies have reviewed the effects of N deposition on plant species diversity;however,all studies addressed the effects of N deposition on plant community focused on species richness in specific ecosystem.There is a need for a systematic meta-analysis covering multiple dimensions of plant diversity in multiple climate zones and ecosystems types.Our goal was to quantify changes in species richness,evenness and uncertainty in plant communities in response to N addition across different environmental and experimental contexts.Methods We performed a meta-analysis of 623 experimental records published in English and Chinese journals to evaluate the response of terrestrial plant diversity to the experimental N addition in China.Three metrics were used to quantify the change in plant diversity:species richness(SR),evenness(Pielou index)uncertainty(Shannon index).Important Findings Results showed that(i)N addition negatively affected SR in temperate,Plateau zones and subtropical zone,but had no significant effect on Shannon index in subtropical zones;(ii)N addition decreased SR,Shannon index and Pielou index in grassland,and the negative effect of N addition on SR was stronger in forest than in grassland;(iii)N addition negatively affected plant diversity(SR,Shannon index and Pielou index)in the long term,whereas it did not affect plant diversity in the short term.Furthermore,the increase in N addition levels strengthened the negative effect of N deposition on plant diversity with long experiment duration;and(iv)the negative effect of ammonium nitrate(NH_(4)NO_(3))addition on SR was stronger than that of urea(CO(NH_(2))_(2))addition,but the negative effect of NH_(4)NO_(3) addition on Pielou index was weaker than that of CO(NH2)2 addition.Our results indicated that the effects of N addition on plant diversity varied depending on climate zones,ecosystem types,N addition levels,N type and experiment duration.This underlines the importance of integrating multiple dimensions of plant diversity and multiple factors into assessments of plant diversity to global environmental change.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No 11574170
文摘We demonstrate a diode pumped Yb：LuVO4 laser that can be passively Q-switched by a Cr^（4＋）：YAG saturable absorber having an initial transmission as high as 99.3%.A maximum pulsed output power of 2.35 W is generated at a repetition rate of 285.7 kHz,approaching or very near the intrinsic upper limit imposed by the recovery time of the Cr^（4＋）：YAG saturable absorber,and the resulting pulse energy,duration and peak power are,respectively,8.2μJ,39.2ns and 0.209kW.
基金Project supported by the National Natural Science Foundation of China(Grant No.11574170)
文摘A comprehensive investigation is carried out to compare the spectroscopic properties, absorption saturation behaviors and lasing properties of a Yb ion in tetragonal LuPO4 and LuVO4 isomorphic crystals. Significant distinctions are revealed in many aspects of the lasing behavior for the Yb ion doped in the two crystal hosts, and Yb：LuPO_4 proves to be superior to Yb：LuVO4 since it enables efficient laser action to be much more easily achieved. With a 0.6 mm thick crystal plate of Yb：LuPO4, an output power of 3.30 W can be generated with an optical–optical conversion efficiency of 50.8%; whereas with a 2 mm long miniature crystal rod, the output power produced can reach 8.35 W with an optical–optical conversion efficiency of 46.7%.
基金the National Natural Science Foundation of China(31671088 and 31730041)the Natural Science Foundation of Shaanxi Province,China(2017ZDJC-01)。
文摘Tweety-homolog 1(Ttyh1)is expressed in neural tissue and has been implicated in the generation of several brain diseases.However,its functional significance in pain processing is not understood.By disrupting the gene encoding Ttyh1,we found a loss of Ttyh1 in nociceptors and their central terminals in Ttyh1-deficient mice,along with a reduction in nociceptor excitability and synaptic transmission at identified synapses between nociceptors and spinal neurons projecting to the periaqueductal grey(PAG)in the basal state.More importantly,the peripheral inflammationevoked nociceptor hyperexcitability and spinal synaptic potentiation recorded in spinal-PAG projection neurons were compromised in Ttyh1-deficient mice.Analysis of the paired-pulse ratio and miniature excitatory postsynaptic currents indicated a role of presynaptic Ttyh1 from spinal nociceptor terminals in the regulation of neurotransmitter release.Interfering with Ttyh1 specifically in nociceptors produces a comparable pain relief.Thus,in this study we demonstrated that Ttyh1 is a critical determinant of acute nociception and pain sensitization caused by peripheral inflammation.
基金This study was funded by National Key R&D Program of China(2018YFC0507203)the National Natural Science Foundation of China(41471049)the Natural Science Foundation of Zhejiang Province(LQ18C030001).
文摘Aims With the global atmospheric nitrogen(N)deposition increasing,the effect of N deposition on terrestrial plant diversity has been widely studied.Some studies have reviewed the effects of N deposition on plant species diversity;however,all studies addressed the effects of N deposition on plant community focused on species richness in specific ecosystem.There is a need for a systematic meta-analysis covering multiple dimensions of plant diversity in multiple climate zones and ecosystems types.Our goal was to quantify changes in species richness,evenness and uncertainty in plant communities in response to N addition across different environmental and experimental contexts.Methods We performed a meta-analysis of 623 experimental records published in English and Chinese journals to evaluate the response of terrestrial plant diversity to the experimental N addition in China.Three metrics were used to quantify the change in plant diversity:species richness(SR),evenness(Pielou index)uncertainty(Shannon index).Important Findings Results showed that(i)N addition negatively affected SR in temperate,Plateau zones and subtropical zone,but had no significant effect on Shannon index in subtropical zones;(ii)N addition decreased SR,Shannon index and Pielou index in grassland,and the negative effect of N addition on SR was stronger in forest than in grassland;(iii)N addition negatively affected plant diversity(SR,Shannon index and Pielou index)in the long term,whereas it did not affect plant diversity in the short term.Furthermore,the increase in N addition levels strengthened the negative effect of N deposition on plant diversity with long experiment duration;and(iv)the negative effect of ammonium nitrate(NH_(4)NO_(3))addition on SR was stronger than that of urea(CO(NH_(2))_(2))addition,but the negative effect of NH_(4)NO_(3) addition on Pielou index was weaker than that of CO(NH2)2 addition.Our results indicated that the effects of N addition on plant diversity varied depending on climate zones,ecosystem types,N addition levels,N type and experiment duration.This underlines the importance of integrating multiple dimensions of plant diversity and multiple factors into assessments of plant diversity to global environmental change.
