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高功率光纤激光器反常模式不稳定效应实验研究

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中国激光 2024年第6期51卷 1-8页

作者：曾令筏文榆钧王小林王鹏奚小明杨保来张汉伟习锋杰韩凯王泽锋许晓军国防科技大学前沿交叉学科学院湖南长沙410073 国防科技大学南湖之光实验室湖南长沙410073 国防科技大学高能激光技术湖南省重点实验室湖南长沙410073

模式不稳定是限制当前高功率光纤激光器功率提升的主要因素。在近单模光纤激光器中,一般采用减小光纤弯曲直径的方法增加高阶模损耗、提升模式不稳定阈值;然而,少模光纤激光器中存在多个高阶模式,会导致动态模式不稳定(TMI)阈值随着弯... 详细信息

模式不稳定是限制当前高功率光纤激光器功率提升的主要因素。在近单模光纤激光器中,一般采用减小光纤弯曲直径的方法增加高阶模损耗、提升模式不稳定阈值;然而,少模光纤激光器中存在多个高阶模式,会导致动态模式不稳定(TMI)阈值随着弯曲直径减小而降低的反常模式不稳定现象。基于纤芯/包层直径为30/600μm的双包层掺镱光纤以及具有不同直径的光纤水冷柱,设计了一台后向泵浦的高功率光纤放大器,研究了该激光器中的反常模式不稳定现象。结果表明:当采用中心波长为976 nm的稳波长激光二极管(LD)作为泵浦源时,随着增益光纤弯曲直径由13 cm增加至16 cm,激光器的TMI阈值由1650 W提升至3740 W,提升幅度约为1.27倍,输出激光的相对亮度提升了87%。光纤弯曲直径的增加虽然会带来输出激光光束质量的轻微退化,但输出激光的相对亮度能够大幅提升。最终,结合光纤弯曲以及泵浦波长优化,实现了7.1 kW高亮度光纤激光输出,相对亮度为1293。

关键词：光纤光学光纤放大器反常模式不稳定光纤弯曲泵浦波长优化

Theoretical study of the ionospheric dynamo region inside the South Atlantic Anomaly

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Earth and Planetary Physics 2023年第1期7卷 84-92页

作者： SiQi Yi xiaojun xu ZiLu Zhou Qing Chang Xing Wang Lei Luo PeiShan He Hui Li State Key Laboratory of Lunar and Planetary Sciences Macao University of Science and TechnologyTaipa Macao 999078China CNSA Macao Center for Space Exploration and Science Taipa Macao 999078China State Key Laboratory of Space Weather National Space Science CenterChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China

The South Atlantic Anomaly(SAA)is a region where the geomagnetic field is significantly lower than that of the surrounding *** the basis of the models of CHAOS-7.8,Mass Spectrometer Incoherent Scatter Model(NRLMSISE-00),and International Reference Ionosphere 2016(IRI-2016),we theoretically investigated the lower and upper boundaries of the ionospheric dynamo region inside the *** the ionospheric dynamo region,electrons are coupled with magnetic field lines,whereas ions are decoupled from magnetic field *** results showed that the ionospheric dynamo region inside the SAA is higher and larger than that outside the *** also studied the boundary variations of the dynamo region inside the SAA depending on the seasons and solar *** found that the dynamo region inside the SAA is the highest and largest in the summer of the southern hemisphere at solar *** larger and higher altitude range of the ionospheric dynamo region in the SAA can contribute to the stronger ionospheric currents in this region.

关键词： South Atlantic Anomaly ionospheric dynamo region ionosphere

Longitudinal Alterations of Local Spontaneous Brain Activity in Parkinson's Disease

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Neuroscience Bulletin 2017年第5期33卷 501-509页

作者： Qiaoling Zeng xiaojun Guan Jason C.F.Law Yan Lun Zhujing Shen Tao Guo Min xuan Quanquan Gu xiaojun xu Min Chen Minming Zhang Department of Radiology The Second Affiliated HospitalZhejiang University School of Medicine Department of Radiology Beijing Hospital

We used resting-state fMRI to evaluate longitu- dinal alterations in local spontaneous brain activity in Parkinson＇s disease （PD） over a 2-year period. Data were acquired from 23 PD patients at baseline and follow-up, and 27 age- and sex-matched normal controls. Regional homogeneity （ReHo） and voxel-based-morphometry （VBM） were used to identify differences in local sponta- neous brain activity and grey matter volume. With disease progression, we observed a progressive decrease in ReHo in the sensorimotor cortex, default-mode network, and left cerebellum, but increased ReHo in the supplementary motor area, bilateral temporal gyrus, and hippocampus. Moreover, there was a significant positive correlation between the rates of ReHo change in the left cerebellum and the rates of change in the Unified Parkinson＇s Disease Rating Scale-III scores. VBM revealed no significant differences in the grey matter volume among the three sets of acquisitions. We conclude that ReHo may be a suitable non-invasive marker of progression in PD.

关键词： Longitudinal Parkinson's disease Regionalhomogeneity ·Functional magnetic resonance imaging

A Prediction Method for △f_0F_(2min) of a Single Station From Interplanetary Parameters Based on Statistical Study

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空间科学学报 2012年第3期32卷 312-320页

作者： LI Zheng WEI Fengsi FENG xueshang GUO Jianpeng xu xiaojun State Key Laboratory of Space Weather Center for Space Science and Applied ResearchChinese Academy of SciencesBeijing 100190 Graduate University of the Chinese Academy of Sciences Beijing 100049

Using 86 CME-interplanetary shock events,the correlation between the peak values of (a) the solar wind parameters(B_z,E_y,P_(dyn)) and the geomagnetic indices(SYM-H,ASY-H,Kp), (b) the coupling functions(Borovsky,Akasofu,Newell) and the geomagnetic indices,(c) the solar wind parameters/coupling functions/geomagnetic indices and the ionospheric parameter(Δf_0F_(2min)), are *** statistical results show that in group(a),B_(z min) and SYM-H_(min) have the best correlation,that in group(b),the best correlation is between the peak values of Akasofu function (A_(min)) and SYM-H_(min),and that in group(c),the best correlation is between K_(pmax) andΔf_0F_(2min). Based on the statistical results,a method for predicting f_0F_2 of a single station is attempted to be set *** input is modified B_(z min) and the outputs are SYM-H_(min) andΔf_0F_(2min).Then 25 CME-IPS events that caused geomagnetic storms in 1998 and 2009 are used to check the prediction method. The results show that our method can be used to predict SYM-H_(min) andΔf_0F_(2min).

关键词：行星际激波统计预报方法单站最小距离基础地磁指数电离层参数

数字孪生在水利应用中的探索——以数字孪生分水江为例

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浙江水利科技 2024年第3期52卷 1-7页

作者：沈鹏飞江岚童览唐治徐晓军杭州市水利发展规划研究中心浙江杭州330105 临安区水利水电局浙江临安330112 桐庐县林业水利局浙江桐庐330122

以分水江流域数字孪生系统建设为核心,针对分水江流域当前流域防洪和水资源管理2个突出问题,从预报调度和水资源管理核心模型设计、总体框架设计、业务框架设计、建设成效4方面,简述数字孪生分水江流域项目按“预报”“预警”“预演”... 详细信息

以分水江流域数字孪生系统建设为核心,针对分水江流域当前流域防洪和水资源管理2个突出问题,从预报调度和水资源管理核心模型设计、总体框架设计、业务框架设计、建设成效4方面,简述数字孪生分水江流域项目按“预报”“预警”“预演”“预案”要求,以“2+N”智能业务体系开展业务建设的流域防洪和水资源监管的场景建设初步成果,对于数字孪生流域建设具有很大的实践参考意义。

关键词：数字孪生流域建设分水江流域智慧水利建设

Diurnal and seasonal variations in carbon fluxes in bamboo forests during the growing season in Zhejiang province, China

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Journal of Forestry Research 2019年第2期30卷 657-668页

作者： Liang Chen Yuli Liu Guomo Zhou Fangjie Mao Huaqiang Du xiaojun xu Pingheng Li xuejian Li State Key Laboratory of Subtropical Silviculture Zhejiang A & F University Key Laboratory of Carbon Cycling in Forest Ecosystems and Carbon Sequestration of Zhejiang Province Zhejiang A & F University School of Environmental and Resources Science Zhejiang A & F University

Bamboo forest is an important forest type in subtropical China and is characterized by fast growth and high carbon sequestration capacity. However, the dynamics of carbon fluxes during the fast growing period of bamboo shoots and their correlation with environment factors are poorly understood. We measured carbon dioxide exchange and climate variables using open-path eddy covariance methods during the 2011 growing season in a Moso bamboo forest(MB, Phyllostchys edulis) and a Lei bamboo forest(LB, Phyllostachys violascens) in Zhejiang province,China. The bamboo forests were carbon sinks during the growing season. The minimum diurnal net ecosystem exchange(NEE) at MB and LB sites were-0.64 and-0.66 mg C m^(-2) s^(-1), respectively. The minimum monthly NEE, ecosystem respiration(RE), and gross ecosystem exchange(GEE) were-99.3 ± 4.03, 76.2 ±2.46, and^(-1)91.5 ± 4.98 g C m^(-2) month^(-1), respectively,at MB site, compared with-31.8 ± 3.44, 70.4 ± 1.41,and^(-1)57.9 ± 4.86 g C m^(-2) month^(-1), respectively, at LB site. Maximum RE was 92.1 ± 1.32 g C m^(-2) month^(-1) at MB site and 151.0 ± 2.38 g C m^(-2) month^(-1) at LB *** control factors varied by month during the growing season, but across the whole growing season, NEE and GEE at both sites showed similar trends in sensitivities to photosynthetic active radiation and vapor pressure deficit,and air temperature had the strongest correlation with RE at both sites. Carbon fluxes at LB site were more sensitive to soil water content compared to those at MB site. Both onyear(years when many new shoots are produced) and offyear(years when none or few new shoots are produced)should be studied in bamboo forests to better understand their role in global carbon cycling.

关键词： Bamboo forest Eddy covariance Carbon fluxes Carbon sequestration

Sodium cantharidinate,a novel anti-pancreatic cancer agent that activates functional p53

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Science China(Life Sciences) 2021年第8期64卷 1295-1310页

作者： Xiaoxiao Liu Li Zhang Pyone Myat Thu Wenjian Min Peng Yang Ji Li Ping Li xiaojun xu State Key Laboratory of Natural Medicines China Pharmaceutical UniversityNanjing 210009China Jiangsu Key Laboratory of Drug Discovery for Metabolic Diseases China Pharmaceutical UniversityNanjing 210009China Department of Pancreatic Surgery Huashan HospitalFudan UniversityShanghai 200040China

Despite the use of many types of chemotherapies for pancreatic cancer, optimal efficacy has not been obtained so far. Pancreatic cancer shows a high incidence of TP53 mutations, inactivating its tumor suppressor activity. In this study, we identified sodium cantharidinate as a novel, potential anti-pancreatic cancer agent that activates p53 function. Sodium cantharidinate reduced the viability of pancreatic cancer cells, including the human primary pancreatic cancer cells, PANC-1, As PC-1, SW1990 and BXPC-3, in a dose-dependent manner. Sodium cantharidinate induced apoptosis and DNA damage of pancreatic cancer cells. Furthermore, proteome-wide sequencing analysis detected a marked perturbation in p53 signaling pathway on PANC-1 cells upon sodium cantharidinate. Consistent with the previous results, sodium cantharidinate treatment decreased Bcl-2 and mitochondrial cytochrome-c protein expression, as well as phosphorylation of MDM2;meanwhile, it increased the levels of cleaved-caspase-3,cleaved-caspase-9, cleaved-PARP, Bax, and phosphorylated p53, thus inducing the apoptosis of pancreatic cancer cells. The p53-activating effect of sodium cantharidinate was strongly abrogated by treatment with TP53-targeting sh RNA. Moreover, sodium cantharidinate inhibited neoplasm growth via the JAK2-STAT3 pathway, which was inhibited by sh RNA-TP53 and triggered by combination with gemcitabine. Combination therapy indicated that sodium cantharidinate and gemcitabine synergistically reduced ex vivo and in vivo growth of pancreatic neoplasm. Further docking studies revealed the different binding fates of sodium cantharidinate to activate wild-type p53 function. Thus, sodium cantharidinate could be a potential agent with promising anti-pancreatic cancer efficacy.

关键词： inhibited agent MDM2

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古诗词艺术歌曲的传承与发展探讨

文化创新比较研究 2024年第6期8卷 5-9页

作者：徐小军良邑学区甘肃庄浪744600

古诗词作为中华文化的瑰宝,历久弥新。而当古老的诗词遇上现代的音乐,便诞生了一种独特的艺术形式——古诗词艺术歌曲,这种融合了传统与现代的艺术形式,既承载了深厚的历史底蕴,又富有鲜明的时代特征。古诗词作为历史发展的积淀,作为文... 详细信息

古诗词作为中华文化的瑰宝,历久弥新。而当古老的诗词遇上现代的音乐,便诞生了一种独特的艺术形式——古诗词艺术歌曲,这种融合了传统与现代的艺术形式,既承载了深厚的历史底蕴,又富有鲜明的时代特征。古诗词作为历史发展的积淀,作为文学艺术的璀璨明珠,自然也能为优秀传统文化的传承出一份力。在当今社会,如何更好地传承与发展古诗词艺术歌曲,成为音乐界和学术界共同关注的焦点。对此,该文将立足于古诗词艺术歌曲,探究在诗乐文化下,诗和乐的演变,解析中国古诗词艺术歌曲的艺术特征。

关键词：古诗词艺术歌曲融合发展艺术价值作品类型歌词意境传承发展

hTAC internalizes via both clathrin-dependent and clathrin-independent endocytosis in mammalian cells

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Protein & Cell 2018年第10期9卷 896-901页

作者： Xinyu Zhu Min Li xiaojun xu Rui Zhang Xiaofei Zhang Zhuo Ma Jingze Lu Tao xu Junjie Hou Eli Song Key Laboratory of Molecular Biophysics of the Ministry of Educa-tion College of Life Science and Technology Huazhong Universityof Science and Technology Wuhan 430074 China National Laboratory of Biomacromolecules CAS Center forExcellence in Biomacromolecules Institute of Biophysics ChineseAcademy of Sciences Beijing 100101 China College of Life Sciences University of Chinese Academy ofSciences Beijing 100049 China

Dear Editor, Endocytosis is a crucial process employed by cells to internal- ize nutrients and turnover membrane components and is essential for many functions, including nutrient uptake, signal transduction, cytokinesis, morphogenesis, cell adhesion and migration. Endocytosis is classified as clathrin-dependent endocytosis （CDE） or clathrin-independent endocytosis （CIE） according to its dependence on clathrin. Several different CIE pathways have been proposed, including caveolin-dependent endocytosis, flotillin-dependent endocytosis, the clathrin-inde- pendent carrier pathway, ARF6-dependent endocytosis, phagocytosis, macropinocytosis, the IL2RI3 pathway （Doherty and McMahon, 2009）, the newly identified fast endophilin-me- diated endocytosis pathway （Boucrot et al., 2015） and the EGFR-NCE pathway （Caldieri et al., 2017）.

关键词： PLASMA-MEMBRANE PROTEINS PATHWAY CARGO