Observations of PKS 1510-089 indicate the existence of a deep flux minimum with a timescale of -35 min and an interval of about 336 ± 14 d. A binary black hole system is proposed to be at the nucleus of this obje...Observations of PKS 1510-089 indicate the existence of a deep flux minimum with a timescale of -35 min and an interval of about 336 ± 14 d. A binary black hole system is proposed to be at the nucleus of this object. The secondary black hole orbits around the primary black hole. The minimum is caused by the periodic eclipse of the primary black hole by the secondary black hole. Based on the observations of PKS 1510-089, we estimate the parameters of the binary black hole system. The masses for the primary and secondary black holes are 1.37 × 10^9M⊙（M⊙ is the solar mass） and 1.37 × 10^7M⊙, and the major axis for this pair being about 0.1 parsec（pc）.展开更多
The origin of the IceCube extragalactic neutrinos remains a puzzle,and it has been argued that sources at large redshifts could be responsible for producing these neutrinos.Recently,a distant blazar at z=2.7 was propo...The origin of the IceCube extragalactic neutrinos remains a puzzle,and it has been argued that sources at large redshifts could be responsible for producing these neutrinos.Recently,a distant blazar at z=2.7 was proposed as a promising neutrino emitter.In this study,we perform a comprehensive multi-wavelength analysis of the highredshift(z=2.153)blazar PKS 0446+11,aiming to investigate its potential physical association with the cospatial IceCube neutrino event IC-240105A.At the time of the neutrino's arrival,PKS 0446+11 was undergoing an unprecedentedγ-ray flare-the most intense recorded over the entire Fermi-LAT operational history.In addition,enhanced fluxes were simultaneously observed across other electromagnetic bands.Taking advantage of the temporal coincidence,Monte Carlo simulations yield a low chance probability(~0.03),suggesting that PKS0446+11 is a plausible neutrino emitter.This provides further observational support for the hypothesis that relativistic jets from active galactic nuclei in the early Universe are efficient accelerators of ultra-high-energy cosmic rays.展开更多
目的:挖掘新疆罗布泊盐湖可培养放线菌的资源和探索该环境放线菌产生Ⅱ型聚酮合成酶(PKS)基因的潜能。方法:从新疆罗布泊盐湖采集到10份样品,采用不同盐浓度的9种选择性培养基分离放线菌,并通过PCR技术扩增其16S r DNA序列、聚酮合成酶(...目的:挖掘新疆罗布泊盐湖可培养放线菌的资源和探索该环境放线菌产生Ⅱ型聚酮合成酶(PKS)基因的潜能。方法:从新疆罗布泊盐湖采集到10份样品,采用不同盐浓度的9种选择性培养基分离放线菌,并通过PCR技术扩增其16S r DNA序列、聚酮合成酶(PKS)基因分子筛选,测序后进行系统发育分析和BLAST比较研究。结果:试验结果共得42株放线菌,包括6个属,链霉菌属(Streptomyces)和拟诺卡氏菌属(Nocardiopsis)的类群最多,糖霉菌属(Glycomyces)、放线多孢菌属(Actinopolyspora)、微球菌(Micrococcus)和栖白蚁菌属(Isoptericola)的菌株相对较少。研究获得新的放线菌分类单元,其16S r DNA基因序列与已知菌株的序列相似性低于97%。42株放线菌中共有29株产生PKSⅡ基因,主要是链霉菌属和拟诺卡氏菌属。结论:研究结果表明罗布泊盐湖放线菌具有丰富的资源多样性和较强合成抗生素的潜在能力。展开更多
植物激素脱落酸（abscisic acid,ABA）在植物生长、发育及环境胁迫中起着重要的作用。本研究发现拟南芥PKSes（SOS2-like protein kinases）蛋白激酶家族成员PKS5（SOS2-like protein kinase 5）参与植物ABA响应。PKS5功能获得性点突变...植物激素脱落酸（abscisic acid,ABA）在植物生长、发育及环境胁迫中起着重要的作用。本研究发现拟南芥PKSes（SOS2-like protein kinases）蛋白激酶家族成员PKS5（SOS2-like protein kinase 5）参与植物ABA响应。PKS5功能获得性点突变体pks5-3与pks5-4表现出对ABA的敏感表型。在外源ABA处理下,pks5-3与pks5-4种子萌发率降低,幼苗生长矮小、黄化。体外磷酸化测试显示,PKS5特异磷酸化ABA响应元件ABI5（ABA-insensitive 5）N末端多肽（1~211 aa）。q RT-PCR分析表明pks5-3与pks5-4突变体中ABI5下游ABA响应基因RAB18（RESPONSIVE TO ABA18）与EM6（LATE EMBRYOGENESIS ABUNDANT 6）表达均发生改变。这些研究结果表明,拟南芥PKS5通过磷酸化ABI5的N末端参与植物ABA响应过程。展开更多
基金Project supported by State Key Development Program for Basic Research of China （Grant No 19990754）, the National Science Foundation for 0utstanding Young Scientists of China （Grant No 10125313）, the National Natural Science Foundation of China （Grant No 10573005）, and the Fund for Top Scholars of Guangdong Province, China （Grant No 02114）. Acknowledgments The authors wish to thank the referee for the comments and suggestions, and are also grateful for useful discussion to Dr Wang Hong-Guang, Liu Yi, Zhou Ji- Liang, Chen Jian-Ling and Xu Shou-Xi.
文摘Observations of PKS 1510-089 indicate the existence of a deep flux minimum with a timescale of -35 min and an interval of about 336 ± 14 d. A binary black hole system is proposed to be at the nucleus of this object. The secondary black hole orbits around the primary black hole. The minimum is caused by the periodic eclipse of the primary black hole by the secondary black hole. Based on the observations of PKS 1510-089, we estimate the parameters of the binary black hole system. The masses for the primary and secondary black holes are 1.37 × 10^9M⊙（M⊙ is the solar mass） and 1.37 × 10^7M⊙, and the major axis for this pair being about 0.1 parsec（pc）.
基金supported in part by the NSFC under grant U2031120supported in part by the Special Natural Science Fund of Guizhou University(grant No.201911 A)the First-class Physics Promotion Programme(2019)of Guizhou University。
文摘The origin of the IceCube extragalactic neutrinos remains a puzzle,and it has been argued that sources at large redshifts could be responsible for producing these neutrinos.Recently,a distant blazar at z=2.7 was proposed as a promising neutrino emitter.In this study,we perform a comprehensive multi-wavelength analysis of the highredshift(z=2.153)blazar PKS 0446+11,aiming to investigate its potential physical association with the cospatial IceCube neutrino event IC-240105A.At the time of the neutrino's arrival,PKS 0446+11 was undergoing an unprecedentedγ-ray flare-the most intense recorded over the entire Fermi-LAT operational history.In addition,enhanced fluxes were simultaneously observed across other electromagnetic bands.Taking advantage of the temporal coincidence,Monte Carlo simulations yield a low chance probability(~0.03),suggesting that PKS0446+11 is a plausible neutrino emitter.This provides further observational support for the hypothesis that relativistic jets from active galactic nuclei in the early Universe are efficient accelerators of ultra-high-energy cosmic rays.
文摘目的:挖掘新疆罗布泊盐湖可培养放线菌的资源和探索该环境放线菌产生Ⅱ型聚酮合成酶(PKS)基因的潜能。方法:从新疆罗布泊盐湖采集到10份样品,采用不同盐浓度的9种选择性培养基分离放线菌,并通过PCR技术扩增其16S r DNA序列、聚酮合成酶(PKS)基因分子筛选,测序后进行系统发育分析和BLAST比较研究。结果:试验结果共得42株放线菌,包括6个属,链霉菌属(Streptomyces)和拟诺卡氏菌属(Nocardiopsis)的类群最多,糖霉菌属(Glycomyces)、放线多孢菌属(Actinopolyspora)、微球菌(Micrococcus)和栖白蚁菌属(Isoptericola)的菌株相对较少。研究获得新的放线菌分类单元,其16S r DNA基因序列与已知菌株的序列相似性低于97%。42株放线菌中共有29株产生PKSⅡ基因,主要是链霉菌属和拟诺卡氏菌属。结论:研究结果表明罗布泊盐湖放线菌具有丰富的资源多样性和较强合成抗生素的潜在能力。
文摘植物激素脱落酸（abscisic acid,ABA）在植物生长、发育及环境胁迫中起着重要的作用。本研究发现拟南芥PKSes（SOS2-like protein kinases）蛋白激酶家族成员PKS5（SOS2-like protein kinase 5）参与植物ABA响应。PKS5功能获得性点突变体pks5-3与pks5-4表现出对ABA的敏感表型。在外源ABA处理下,pks5-3与pks5-4种子萌发率降低,幼苗生长矮小、黄化。体外磷酸化测试显示,PKS5特异磷酸化ABA响应元件ABI5（ABA-insensitive 5）N末端多肽（1~211 aa）。q RT-PCR分析表明pks5-3与pks5-4突变体中ABI5下游ABA响应基因RAB18（RESPONSIVE TO ABA18）与EM6（LATE EMBRYOGENESIS ABUNDANT 6）表达均发生改变。这些研究结果表明,拟南芥PKS5通过磷酸化ABI5的N末端参与植物ABA响应过程。
