The dual-mode stabilization scheme has been demonstrated as an efficient way to stabilize laser frequency.In this study,we propose a novel dual-mode stabilization scheme that employs a sizable Fabry-Pérot cavity ...The dual-mode stabilization scheme has been demonstrated as an efficient way to stabilize laser frequency.In this study,we propose a novel dual-mode stabilization scheme that employs a sizable Fabry-Pérot cavity instead of the microcavity used in previous studies and has enabled higher bandwidth for locking.The results demonstrate a 30-fold reduction in laser frequency drift,with frequency instability below 169 kHz for integration time exceeding 1 h and a minimum value of 33.8 kHz at 54 min.Further improvement could be achieved by optimizing the phase locking.This scheme has potential for use in precision spectroscopic measurement.展开更多
The ^(12)C+^(12)C reaction rate plays an essential role in stellar evolution and nucleosynthesis.Nevertheless,the uncertainties of this reaction rate are still large.We calculate a series of stellar evolution models w...The ^(12)C+^(12)C reaction rate plays an essential role in stellar evolution and nucleosynthesis.Nevertheless,the uncertainties of this reaction rate are still large.We calculate a series of stellar evolution models with the near solar abundance from the zero-age main-sequence through presupernova stages for initial masses of 20 M_(⊙) to 40 M_(⊙).The ^(12)C+^(12)C reaction rates from two different studies are used in our investigation.One is the rate obtained using the Trojan Horse Method(THM)by Tumino et al.[Nature 557(7707),687(2018)],and the other was obtained by Mukhamedzhanov et al.[Physical Review C 99(6),064618(2019)](Muk19).Then,comparisons of the nucleosynthesis and presupernova isotopic abundances are conducted.In particular,we find that in the C burning shell,models with the THM produce a smaller amount of ^(23)Na and some neutron-rich isotopes than Muk19.The difference in the abundance ratios of Na/Mg,S/Mg,Ar/Mg,and K/Mg between the two models are apparent.We compare Na/Mg obtained from our theoretical presupernovae models with Na/Mg in stellar atmospheres observed with high-resolution spectra as well as from the latest galactic chemical evolution model.Although Na/Mg obtained using the THM is within 2σ of the observed stellar ratio,the theoretical uncertainty on Na/Mg introduced by the uncertainty of the ^(12)C+^(12)C reaction rate is almost equivalent to the standard deviation of astronomical observations.Therefore,a more accurate ^(12)C+^(12)C reaction rate is crucial.展开更多
It is challenging to make an ultrafast diagnosis of the temporal evolution of small and short-lived plasma in two dimensions. To overcome this difficulty, we have developed a well-timed diagnostic utilizing an x-ray s...It is challenging to make an ultrafast diagnosis of the temporal evolution of small and short-lived plasma in two dimensions. To overcome this difficulty, we have developed a well-timed diagnostic utilizing an x-ray streak camera equipped with a row of multi-pinhole arrays. By processing multiple sets of one-dimensional streaked image data acquired from various pinholes, we are capable of reconstructing high-resolution two-dimensional images with a temporal resolution of 38 ps and a spatial resolution of 18 μm. The temporal fiducial pulses accessed from external sources can advance the precise timing and accurately determine the arrival time of the laser. Moreover, it can correct the nonlinear sweeping speed of the streak camera. The effectiveness of this diagnostic has been successfully verified at the Shenguang-II laser facility,providing an indispensable tool for observing complex physical phenomena, such as the implosion process of laser-fusion experiments.展开更多
Based on hourly observation data from 2016 to 2019 and hourly automatic meteorological observation data from 2018 to 2019, we analyzed the annual, monthly and daily variation characteristics of fog days in Ninglang Ai...Based on hourly observation data from 2016 to 2019 and hourly automatic meteorological observation data from 2018 to 2019, we analyzed the annual, monthly and daily variation characteristics of fog days in Ninglang Airport, and diagnosed a case of summer fog. The results show that the average annual fog days in Ninglang Airport are 128 days and the annual characteristic of fog days is bimodal. Analyzed on fog cases in 2019, it was a summer fog process lasting more than 20 hours and visibility less than 500 m. The data from the automatic observational stations around Ninglang airport can describe the near-surface layer features of fog and illustrate the progress of fog. The meteorological elements of automatic observational stations changed suddenly 2 hours before fog, so the data of the automatic observational stations can be used to forscast fog.展开更多
基金supported by the National Key R&D Program of China(No.2022YFC3700329)the National Natural Science Foundation of China(Nos.61905134,61905136,and62175139)+1 种基金the Shanxi Province Science and Technology Activities for Returned Overseas Researcher(No.20220001)the Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi(No.2019L0062)。
文摘The dual-mode stabilization scheme has been demonstrated as an efficient way to stabilize laser frequency.In this study,we propose a novel dual-mode stabilization scheme that employs a sizable Fabry-Pérot cavity instead of the microcavity used in previous studies and has enabled higher bandwidth for locking.The results demonstrate a 30-fold reduction in laser frequency drift,with frequency instability below 169 kHz for integration time exceeding 1 h and a minimum value of 33.8 kHz at 54 min.Further improvement could be achieved by optimizing the phase locking.This scheme has potential for use in precision spectroscopic measurement.
基金financially supported by the National Natural Science Foundation of China(No.22273093)the CAS Project for Young Scientists in Basic Re-search(YSBR-005)the start-up funding of University of Science and Technology of China。
基金supported by the National Key Research and Development Program of China(2022YFA1603200,2022YFA1603201,and 2022SKA0130100)the Science Challenging Project(TZ2018005)+4 种基金the National Natural Science Foundation of China(12135001,11825502,11921006,11725314,12273113,11903019,11833003,and 12041306)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA25050900)the CAS Project for Young Scientists in Basic Research(YSBR-063)the Youth Innovation Promotion Association(2023331)support from the National Natural Science Funds for Distinguished Young Scholars(11825502)。
基金Supported by the National Natural Science Foundation of China(11988101,11890694)the National Key R&D Program of China(2019YFA0405502)K.Nomoto is supported by the World Premier International Research Center Initiative(WPI),MEXT,Japan,and the Japan Society for the Promotion of Science(JSPS)KAKENHIgrant(JP17K05382,JP20K04024,JP21H04499)。
文摘The ^(12)C+^(12)C reaction rate plays an essential role in stellar evolution and nucleosynthesis.Nevertheless,the uncertainties of this reaction rate are still large.We calculate a series of stellar evolution models with the near solar abundance from the zero-age main-sequence through presupernova stages for initial masses of 20 M_(⊙) to 40 M_(⊙).The ^(12)C+^(12)C reaction rates from two different studies are used in our investigation.One is the rate obtained using the Trojan Horse Method(THM)by Tumino et al.[Nature 557(7707),687(2018)],and the other was obtained by Mukhamedzhanov et al.[Physical Review C 99(6),064618(2019)](Muk19).Then,comparisons of the nucleosynthesis and presupernova isotopic abundances are conducted.In particular,we find that in the C burning shell,models with the THM produce a smaller amount of ^(23)Na and some neutron-rich isotopes than Muk19.The difference in the abundance ratios of Na/Mg,S/Mg,Ar/Mg,and K/Mg between the two models are apparent.We compare Na/Mg obtained from our theoretical presupernovae models with Na/Mg in stellar atmospheres observed with high-resolution spectra as well as from the latest galactic chemical evolution model.Although Na/Mg obtained using the THM is within 2σ of the observed stellar ratio,the theoretical uncertainty on Na/Mg introduced by the uncertainty of the ^(12)C+^(12)C reaction rate is almost equivalent to the standard deviation of astronomical observations.Therefore,a more accurate ^(12)C+^(12)C reaction rate is crucial.
文摘目的比较腹腔镜保留幽门及迷走神经的胃切除术(laparoscopy-assisted pylorus-vagus nerve preserving gastrectomy,LAPPG)与腹腔镜远端胃切除术(laparoscopy-assisted distal gastrectomy,LADG)治疗早期胃中部癌的术式安全性、术后短期并发症及住院费用,评价LAPPG治疗早期胃中部癌的可行性.方法回顾性分析2016-06/2017-08间在上海交通大学医学院附属仁济医院胃肠外科行腹腔镜手术治疗的112例早期胃中部癌的临床病理资料、手术方式、围手术期恢复、术后并发症及住院总费用,其中46例为LAPPG组,66例为LADG组.结果两组患者的临床基线资料比较:年龄、性别、BMI、分化类型差异无统计学意义(P>0.05).两组患者的手术时间、术中失血量、肿瘤最大直径、清扫淋巴结个数差异均无统计学意义(P>0.05).LAPPG组患者近端肿瘤切缘(2.3 cm±1.49 cm vs 3.5cm±1.29 cm,P=0.001)及远端肿瘤切缘(3.1 cm±2.06 cm vs 4.0 cm±2.11 cm,P=0.038)均短于LADG组.两组患者的术后住院时间、术后首次排气时间、术后拔除胃管时间、术后首次下床活动时间、术后恢复流质时间、术后拔除引流管时间、及术后并发症发生率(≥D indoⅡ级)差异均无统计学意义(P>0.05).住院总费用方面LAPPG组低于LADG组(4.6万±0.5万vs 5.3万±0.4万,P=0.004).结论在确保肿瘤根治性的前提下开展LAPPG治疗早期胃中部癌是安全有效的,且降低了患者的住院总费用.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant Nos. XDA25030700 and XDA25030500)the National Key R&D Program of China (Grant Nos. 2022YFA1603200 and 2022YFA1603203)the National Natural Science Foundation of China (Grant Nos. 12175018, 12135001, 12075030, and 11903006)。
文摘It is challenging to make an ultrafast diagnosis of the temporal evolution of small and short-lived plasma in two dimensions. To overcome this difficulty, we have developed a well-timed diagnostic utilizing an x-ray streak camera equipped with a row of multi-pinhole arrays. By processing multiple sets of one-dimensional streaked image data acquired from various pinholes, we are capable of reconstructing high-resolution two-dimensional images with a temporal resolution of 38 ps and a spatial resolution of 18 μm. The temporal fiducial pulses accessed from external sources can advance the precise timing and accurately determine the arrival time of the laser. Moreover, it can correct the nonlinear sweeping speed of the streak camera. The effectiveness of this diagnostic has been successfully verified at the Shenguang-II laser facility,providing an indispensable tool for observing complex physical phenomena, such as the implosion process of laser-fusion experiments.
文摘Based on hourly observation data from 2016 to 2019 and hourly automatic meteorological observation data from 2018 to 2019, we analyzed the annual, monthly and daily variation characteristics of fog days in Ninglang Airport, and diagnosed a case of summer fog. The results show that the average annual fog days in Ninglang Airport are 128 days and the annual characteristic of fog days is bimodal. Analyzed on fog cases in 2019, it was a summer fog process lasting more than 20 hours and visibility less than 500 m. The data from the automatic observational stations around Ninglang airport can describe the near-surface layer features of fog and illustrate the progress of fog. The meteorological elements of automatic observational stations changed suddenly 2 hours before fog, so the data of the automatic observational stations can be used to forscast fog.
