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Two cases of lamellar macular hole secondary to the rupture of the cystoid inner wall in patients with diabetic macular edema
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作者 Zhi-Hui Dong Jia-Yu Zhang +2 位作者 Chao-Yang Zhang Zhen-Guo Chen Jing-Fa Zhang 《International Journal of Ophthalmology(English edition)》 2025年第8期1610-1612,共3页
Dear Editor,Diabetic macular edema(DME)is a major cause of visual loss in diabetic patients,which is mainly caused by disruption of the blood-retinal barrier and loss of pericytes and endothelial cells,resulting in th... Dear Editor,Diabetic macular edema(DME)is a major cause of visual loss in diabetic patients,which is mainly caused by disruption of the blood-retinal barrier and loss of pericytes and endothelial cells,resulting in the leakage of plasma and lipids[1].Nowadays,laser photocoagulation,intravitreal injections of anti-vascular endothelial growth factor(anti-VEGF)drugs and dexamethasone implant. 展开更多
关键词 diabetic macular edema macular edema dme lamellar macular hole endothelial cellsresulting cystoid inner wall dexamethasone implant blood retinal barrier visual loss
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A search for double-peaked narrow emission line galaxies and AGNs in the LAMOST DR1
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作者 Zhi-Xin Shi A-Li Luo +15 位作者 Georges Comte Xiao-Yan Chen Peng Wei Yong-Heng Zhao Fu-Chao Wu Yan-Xia Zhang Shi-Yin Shen Ming Yang Hong Wu Xue-Bing Wu Hao-Tong Zhang Ya-Juan Lei Jian-Nan Zhang Ting-Gui Wang Ge Jin Yong Zhang 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2014年第10期1234-1250,共17页
The Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) has released more than two million spectra, which provide the opportunity to search for double-peaked narrow emission line (NEL) galaxies and ... The Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) has released more than two million spectra, which provide the opportunity to search for double-peaked narrow emission line (NEL) galaxies and active galactic nuclei (AGNs). The double-peaked narrow-line profiles can be well modeled by two velocity components, respectively blueshifted and redshifted with respect to the sys- temic recession velocity. This paper presents 20 double-peaked NEL galaxies and AGNs found from LAMOST DR1 using a search method based on a multi-Gaussian fit of the narrow emission lines. Among them, ten have already been published by other authors, either listed as genuine double-peaked NEL objects or as asymmetric NEL objects, and the remaining ten are original discoveries. We discuss some pos- sible origins for the double-peaked narrow-line features, such as interaction between jet and narrow line regions, interaction with companion galaxies, and black hole bina- ries. Spatially resolved optical imaging and/or follow-up observations in other spectral bands are needed to further discuss the physical mechanisms at work. 展开更多
关键词 GALAXIES emission lines -- quasars emission lines -- methods dataanalysis
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施图伦联合视功能训练治疗屈光术后视功能异常的临床效果探究
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作者 贾丽华 《中国实用医药》 2025年第16期169-172,共4页
目的探究七叶洋地黄双苷滴眼液(商品名:施图伦)联合视功能训练治疗屈光术后视功能异常的临床效果。方法选取88例屈光术后视功能异常患者为研究对象,使用数字随机分组法将患者分为对照组和实验组,各44例。两组均采用常规调理,对照组在此... 目的探究七叶洋地黄双苷滴眼液(商品名:施图伦)联合视功能训练治疗屈光术后视功能异常的临床效果。方法选取88例屈光术后视功能异常患者为研究对象,使用数字随机分组法将患者分为对照组和实验组,各44例。两组均采用常规调理,对照组在此基础上进行视功能训练干预,实验组在对照组基础上进行施图伦治疗。比较两组治疗效果、视功能及视觉不良异常发生情况。结果实验组治疗总有效率88.64%高于对照组的65.91%(P<0.05)。治疗后,实验组单眼视功能、双眼视功能及立体视功能评分分别为(12.47±1.88)、(12.14±1.59)、(8.31±0.39)分,均高于对照组的(10.21±1.63)、(9.67±1.64)、(6.14±0.57)分(P<0.05)。实验组视觉不良发生率13.64%低于对照组的36.36%(P<0.05)。结论施图伦联合视功能训练治疗屈光术后视功能异常能够改善视功能,提升屈光术后患者的视觉效果,是视力保健和康复的有效方法。 展开更多
关键词 七叶洋地黄双苷滴眼液 视功能训练 屈光术 视功能异常
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Maximizing extend visual outcomes with extend focus intraocular lens in eyes with axial length shorter than 24 mm
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作者 Yuan-Fei Zhu Li-Zhen Chen +1 位作者 Tie-Ying Zhao Shao-Chong Zhang 《International Journal of Ophthalmology(English edition)》 2025年第11期2073-2078,共6页
AIM:To evaluate the efficacy of the Tecnis Symfony ZXR00 lens in achieving optimal visual outcomes for cataract surgery patients with axial length(AL)shorter than 24 mm.METHODS:A total of 21 subjects(37 eyes)were subm... AIM:To evaluate the efficacy of the Tecnis Symfony ZXR00 lens in achieving optimal visual outcomes for cataract surgery patients with axial length(AL)shorter than 24 mm.METHODS:A total of 21 subjects(37 eyes)were submitted to cataract surgery and implantation of Tecnis Symfony ZXR00 lens(Johnson&Johnson Vision)was assessed.Patients were examined at 5 m,80 cm,and 40 cm for uncorrected distance visual acuity(UCDVA)and corrected distance visual acuity(CDVA),uncorrected intermediate(UCIVA),and uncorrected near visual acuity(UCNVA).Further,based on the optimal distance correction,the monocular defocusing curve in the range of+0.5 to-3.5 D was investigated.A simple patient-reported spectacle independence questionnaire(PRSIQ)was used to evaluate subjects’subjective feelings about their dependence on glasses at various distances.Multiple linear regression was employed to examine the association amony intraocular lenses(IOLs)diopter,AL,corneal curvature,anterior chamber depth,mean manifest refractive spherical equivalent,pupil,pupil/scan,target refraction,and near vision(logMAR).RESULTS:The study demonstrated enhanced UCNVA alongside comparable distant vision and UCIVA outcomes in eyes with AL shorter than 24 mm.Mean post-operative UCDVA significantly improved from preoperative levels 0.530±0.406(P=0.000).Notably,83.3%of eyes achieved 0.01 logMAR in UCNVA.Five unilateral cases with blended IOL implantation also showed satisfactory visual acuity and satisfaction.The 90.5%(19/21)achieved spectacle independence.The average score for self-reported spectacle-independence on the PRSIQ was 3.52 with a standard deviation of 0.98.The results of the regression analysis revealed that one predictor,the pupil/scan accounted for 27.6%of the variation in near vision[logMAR;F(1,35)=13.33,P<0.01].CONCLUSION:The results affirm the effectiveness of the Tecnis Symfony ZXR00 lens in enhancing visual outcomes for cataract surgery patients with AL shorter than 24 mm.Additionally,the pupil/scan emerges as a critical factor influencing postoperative near vision. 展开更多
关键词 extended depth-of-focus near vision axial length PUPIL cataract surgery
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Development of Interpenetrating Phase Structure AZ91/Al_(2)O_(3)Composites with High Stiffness,Superior Strength and Low Thermal Expansion Coefficient
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作者 Zhiqing Chen Zhixian Zhao +6 位作者 Yiqiang Hao Xiaoling Chen Liping Zhou Jingya Wang Tao Ying Bin Chen Xiaoqin Zeng 《Acta Metallurgica Sinica(English Letters)》 2025年第2期245-258,共14页
Mg alloys have the defects of low stiffness,low strength,and high coefficient of thermal expansion(CTE).The composites strategy and its architecture design are effective approaches to improve the comprehensive perform... Mg alloys have the defects of low stiffness,low strength,and high coefficient of thermal expansion(CTE).The composites strategy and its architecture design are effective approaches to improve the comprehensive performance of materials,but the processing difficulty,especially in ceramics forming,limits the control and innovation of material architecture.Here,combined with 3D printing and squeeze infiltration technology,two precisely controllable architectures of AZ91/Al_(2)O_(3)interpenetrating phase composites(IPC)with ceramic scaffold were prepared.The interface,properties and impact of different architecture on IPC performance were studied by experiments and finite element simulation.The metallurgical bonding of the interface was realized with the formation of MgAl_(2)O_(4)reaction layer.The IPC with 1 mm circular hole scaffold(1C-IPC)exhibited significantly improved elastic modulus of 164 GPa,high compressive strength of 680 MPa,and good CTE of 12.91×10^(-6)K^(−1),which were 3.64 times,1.98 times and 55%of the Mg matrix,respectively.Their elastic modulus,compressive strength,and CTE were superior to the vast majority of Mg alloys and Mg based composites.The reinforcement and matrix were bicontinuous and interpenetrating each other,which played a critical role in ensuring the potent strengthening effect of the Al_(2)O_(3)reinforcement by efficient load transfer.Under the same volume fraction of reinforcements,compared to IPC with 1 mm hexagonal hole scaffold(1H-IPC),the elastic modulus and compressive strength of 1C-IPC increased by 15%and 28%,respectively,which was due to the reduced stress concentration and more uniform stress distribution of 1C-IPC.It shows great potential of architecture design in improving the performance of composites.This study provides architectural design strategy and feasible preparation method for the development of high performance materials. 展开更多
关键词 Interpenetrating phase composites Al_(2)O_(3)/Mg composites Interface Elastic modulus Compressive strength Coefficient of thermal expansion(CTE)
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A Comparison among Different Machine Learning Algorithms in Land Cover Classification Based on the Google Earth Engine Platform: The Case Study of Hung Yen Province, Vietnam
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作者 Le Thi Lan Tran Quoc Vinh Phạm Quy Giang 《Journal of Environmental & Earth Sciences》 2025年第1期132-139,共8页
Based on the Google Earth Engine cloud computing data platform,this study employed three algorithms including Support Vector Machine,Random Forest,and Classification and Regression Tree to classify the current status ... Based on the Google Earth Engine cloud computing data platform,this study employed three algorithms including Support Vector Machine,Random Forest,and Classification and Regression Tree to classify the current status of land covers in Hung Yen province of Vietnam using Landsat 8 OLI satellite images,a free data source with reasonable spatial and temporal resolution.The results of the study show that all three algorithms presented good classification for five basic types of land cover including Rice land,Water bodies,Perennial vegetation,Annual vegetation,Built-up areas as their overall accuracy and Kappa coefficient were greater than 80%and 0.8,respectively.Among the three algorithms,SVM achieved the highest accuracy as its overall accuracy was 86%and the Kappa coefficient was 0.88.Land cover classification based on the SVM algorithm shows that Built-up areas cover the largest area with nearly 31,495 ha,accounting for more than 33.8%of the total natural area,followed by Rice land and Perennial vegetation which cover an area of over 30,767 ha(33%)and 15,637 ha(16.8%),respectively.Water bodies and Annual vegetation cover the smallest areas with 8,820(9.5%)ha and 6,302 ha(6.8%),respectively.The results of this study can be used for land use management and planning as well as other natural resource and environmental management purposes in the province. 展开更多
关键词 Google Earth Engine Land Cover LANDSAT Machine Learning Algorithm
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Large language models in ophthalmology: a bibliometric analysis
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作者 Ruyue Shen Eunice See Heng Lee +2 位作者 Xiaoyan Hu Clement C.Tham Carol Y.Cheung 《Eye Science》 2025年第3期222-237,共16页
Background:With the rapid development of artificial intelligence(AI),large language models(LLMs)have emerged as a potent tool for invigorating ophthalmology across clinical,educational,and research fields.Their accura... Background:With the rapid development of artificial intelligence(AI),large language models(LLMs)have emerged as a potent tool for invigorating ophthalmology across clinical,educational,and research fields.Their accuracy and reliability have undergone tested.This bibliometric analysis aims to provide an overview of research on LLMs in ophthalmology from both thematic and geographical perspectives.Methods:All existing and highly cited LLM-related ophthalmology research papers published in English up to 24th April 2025 were sourced from Scopus,PubMed,and Web of Science.The characteristics of these publications,including publication output,authors,journals,countries,institutions,citations,and research domains,were analyzed using Biblioshiny and VOSviewer software.Results:A total of 277 articles from 1,459 authors and 89 journals were included in this study.Although relevant publications began to appear in 2019,there was a significant increase starting from 2023.He M and Shi D are the most prolific authors,while Investigative Ophthalmology&Visual Science stands out as the most prominent journal.Most of the top-publishing countries are high-income economies,with the USA taking the lead,and the University of California is the leading institution.VOSviewer identified 5 clusters in the keyword co-occurrence analysis,indicating that current research focuses on the clinical applications of LLMs,particularly in diagnosis and patient education.Conclusions:While LLMs have demonstrated effectiveness in retaining knowledge,their accuracy in image-based diagnosis remains limited.Therefore,future research should investigate fine-tuning strategies and domain-specific adaptations to close this gap.Although research on the applications of LLMs in ophthalmology is still in its early stages,it holds significant potential for advancing the field. 展开更多
关键词 artificial intelligence large language models OPHTHALMOLOGY bibliometric analysis
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Metal leaching accompanied with natural photo-aging behavior of e-waste plastic derived microplastics in aquatic environment
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作者 Jianshuai Zhang Shuyuan Yu +5 位作者 Zhe Xu Ruimin Qi Yihan Chi Lijuan Wang Lili Liu Yuanyuan Tang 《Journal of Environmental Sciences》 2025年第8期703-712,共10页
As the main component of electronic products,plastics contain complex and diverse metal additives.Recycling process is not conducive to stable existence of metal additives in electronic plastics.Once the e-waste plast... As the main component of electronic products,plastics contain complex and diverse metal additives.Recycling process is not conducive to stable existence of metal additives in electronic plastics.Once the e-waste plastics enter the environment,they will continue to release harmful metals into environment after aging,causing serious hazards.This study delved into the analysis and comparison of metal content of e-waste plastics,elucidating aging process and metal leaching behavior over a 112-day natural light exposure period.The findings underscored that metal content in recycled plastics surpassed that in their new counterparts.Specifically,Ti content in new plastics remained below 100 mg/kg,while recycled plastics exhibited Ti content surpassing 100 mg/kg threshold.Throughout prolonged natural light exposure,metals such as Zn,Ba and Sb demonstrated a heightened likelihood of release from electronic plastics in comparison to other metals.The aging process during light exposure led to fragmentation of electronic plastics,accompanied by a reduction in particle size.Notably,the particle size reduction was more pronounced in poly acrylonitrile butadiene styrene(ABS)and recycled ABS,experiencing reductions of 40µm and 85µm,respectively.This phenomenon was attributed to the presence of polybutadiene structural units,which proved more susceptible to aging.Along with the breaking of plastics,the ABS plastics released metal species such as Pb,Cd,Ni,Al that had not been detected in other plastics solutions.The collective evidence from this study suggested that ABS and recycled ABS electronic plastics might pose a heightened potential environmental risk compared to other electronic plastics. 展开更多
关键词 Electronic E-waste plastics Microplastics AGING LEACHING Metal
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Bioaccumulation of Selected Heavy Metals in Bivalve Molluscs from Northeastern Vietnam:Implications for Safe Seafood Utilization
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作者 Sinh Xuan Le Bach Van Nguyen +5 位作者 Hien Thi Minh Bui Nam Van Le Huy Van Dinh Khuong Duy Le Son Truong Cao Kien Nguyen 《Research in Ecology》 2025年第3期115-134,共20页
Rapid industrial growth,urbanization,and agricultural activities have led to the discharge of large volumes of pollutants into coastal environments,raising levels of metals such as arsenic(As),cadmium(Cd),and mercury(... Rapid industrial growth,urbanization,and agricultural activities have led to the discharge of large volumes of pollutants into coastal environments,raising levels of metals such as arsenic(As),cadmium(Cd),and mercury(Hg)in water and sediments.Bivalve molluscs,such as Meretrix lyrata and Saccostrea glomerata can accumulate high amounts of toxic heavy metals in their tissues that pose potential risks to human health.They are frequently used as bioindicators due to their filter-feeding behavior and high accumulation potential.This study evaluates heavy metal accumulation in bivalve molluscs from Northeastern Vietnam,including Quang Ninh Province and Hai Phong City.In this study,a systematic literature review was conducted,combined with a bibliometric analysis,to synthesize and evaluate data on heavy metal accumulation in bivalve molluscs from Northeastern Vietnam.The analysis results showed bio-concentration factors exceeding 1,000 for As,Cd,and Hg in certain species,particularly in samples from Quang Ninh Province.Meanwhile,sediment accumulation factors(BSAF)were lower,suggesting that waterborne pathways predominantly contribute to heavy metal uptake.These findings highlight significant food safety risks due to toxic metal accumulation in seafood resources,emphasizing the urgent need for continuous monitoring and the establishment of local safety standards.The study provides important scientific evidence to support marine environmental management and public health protection. 展开更多
关键词 Heavy Metal Accumulation Bivalve Molluscs Coastal Pollution Environmental Monitoring Viet Nam
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Enhancement of retinal Müller glia’s phagocytic activity against hard exudates by conbercept via activation of PPARγ-CD36 axis in diabetic retinopathy
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作者 Ying-Ying Zhu Shi-Yue Qin +5 位作者 Hai Xie Yin-Ping Liu Xiao-Sa Li Chao-Yang Zhang Yan-Chun Zhang Jing-Fa Zhang 《International Journal of Ophthalmology(English edition)》 2025年第7期1252-1261,共10页
AIM:To investigate the effects and the underlying mechanism(s)of conbercept on the phagocytosis of hard exudates(HEs)by Müller glia in diabetic retinopathy(DR).METHODS:Twenty-one eyes from 17 patients with diabet... AIM:To investigate the effects and the underlying mechanism(s)of conbercept on the phagocytosis of hard exudates(HEs)by Müller glia in diabetic retinopathy(DR).METHODS:Twenty-one eyes from 17 patients with diabetic macular edema(DME)underwent optical coherence tomography(OCT)imaging to examine the changes of HEs before and after intravitreal conbercept injection(IVC).In vitro,rat retinal Müller cell line(rMC-1)was cultured under high glucose and treated with oxidized low-density lipoprotein(Ox-LDL)with or without conbercept.Phagocytosis was analysed with immunofluorescence,flow cytometry,and Western blot.Expressions of scavenger receptors(LOX-1,CD36)were analyzed by quantitative real-time polymerase chain reaction(qRT-PCR).Conbercept’s effects on vascular endothelial growth factor A(VEGF-A),VEGFR2,inflammation(NF-κB,IL-6,iNOS),and oxidative stress(ROS)were evaluated with Western blot and immunofluorescence.RESULTS:The area of HEs showed minimal change after the first IVC(1.39±1.41 to 1.38±1.3 mm2,P=0.938),but significantly decreased after the third IVC(0.45±0.66 mm2,P=0.002).In vitro,conbercept enhanced the phagocytosis of Ox-LDL by rMC-1 cells under high glucose condition.Conbercept reduced ROS and inflammation(NF-κB,IL-6,iNOS)in high glucose-treated rMC-1 cells by suppression of VEGF/VEGFR2 pathway.The inhibition of NF-κB by conbercept further activated PPARγ-CD36 axis,increasing CD36 expression and promoting Ox-LDL uptake,thereby facilitating the clearance of HEs.CONCLUSION:Conbercept reduces HEs in DR by enhancing Müller glia phagocytosis possibly through activating PPARγ-CD36 axis,which is mediated by inhibition of VEGF signaling.Modulation of Müller glia phagocytic capacity might provide a novel therapeutic strategy to treat DR and DME. 展开更多
关键词 conbercept Müller glia oxidized low-density lipoprotein PHAGOCYTOSIS vascular endothelial growth factor
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大都市边缘区农村居民对宅基地退出和定居的思考--以南京市江宁区为例 被引量:17
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作者 汤爽爽 郝璞 黄贤金 《人文地理》 CSSCI 北大核心 2017年第2期72-79,共8页
中国的快速城镇化推动了乡村发展转型与空间重构,农村居民对于土地退出、定居的想法正发生着变化。基于2014年在南京市江宁区的问卷及访谈调查,本文探索了发达地区大都市边缘区中农村居民针对宅基地退出和未来定居的意愿。通过运用访谈... 中国的快速城镇化推动了乡村发展转型与空间重构,农村居民对于土地退出、定居的想法正发生着变化。基于2014年在南京市江宁区的问卷及访谈调查,本文探索了发达地区大都市边缘区中农村居民针对宅基地退出和未来定居的意愿。通过运用访谈资料和回归模型,本文发现村庄属性、一些个人主客观因子都影响着农村居民对于土地退出和未来定居的决策。本文还发现,相当多的农村居民倾向于在邻近小城镇定居,对宅基地退出普遍持负面态度。随着宅基地财产功能的提升、城乡一体化进程推进等方面的变化,关于宅基地流转制度的改革势在必行。 展开更多
关键词 宅基地退出 农村居民 定居 回归模型 南京
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非接触式视频引伸计在力学性能试验中的应用 被引量:7
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作者 胡世军 张红香 +1 位作者 张代录 杨笠 《科技导报》 CAS CSCD 北大核心 2012年第19期60-62,共3页
为了在材料力学性能试验中推广和应用非接触式视频引伸计,在20kN电子万能试验机上对2A12T4铝合金型材试样进行拉伸试验,用非接触式视频引伸计对该合金的伸长率和宽度变形进行自动测量;同时,在长度方向安装电子应变引伸计跟踪测量,宽度... 为了在材料力学性能试验中推广和应用非接触式视频引伸计,在20kN电子万能试验机上对2A12T4铝合金型材试样进行拉伸试验,用非接触式视频引伸计对该合金的伸长率和宽度变形进行自动测量;同时,在长度方向安装电子应变引伸计跟踪测量,宽度方向缩减变形量在保持相应力值的情况下采用千分尺测量,试样断裂后用工具显微镜测量长度和宽度方向变形;比较用两组测量工具测量出的变形情况,并做出纵、横向变形绝对偏差的平均值曲线,对其进行分析。结果表明,使用非接触式视频引伸计对材料力学性能指标的测量完全能够满足生产和试验研究的需要。 展开更多
关键词 非接触式视频引伸计 亚像素法 力学性能试验
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GRB 240825A:Early Reverse Shock and Its Physical Implications
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作者 Chao Wu Yun Wang +84 位作者 Hua-Li Li Li-Ping Xin Dong Xu Benjamin Schneider Antonio de Ugarte Postigo Gavin Lamb Andrea Reguitti Andrea Saccardi Xing Gao Xing-Ling Li Qiu-Li Wang Bing Zhang Jian-Yan Wei Shuang-Nan Zhang Frédéric Daigne Jean-Luc Atteia Maria-Grazia Bernardini Hong-Bo Cai Arnaud Claret Bertrand Cordier Jin-Song Deng Olivier Godet Diego Götz Xu-Hui Han Zhe Kang Guang-Wei Li Zhen-Wei Li Cheng-Zhi Liu Xiao-Meng Lu You Lv Julian P Osborne Jesse T.Palmerio Yu-Lei Qiu Stéphane Schanne Damien Turpin Susanna Diana Vergani Jing Wang Yu-Jie Xiao Wen-Jin Xie Yang Xu Zhu-Heng Yao Pin-Pin Zhang Ruo-Song Zhang Cheng-Wei Zhu Riccardo Brivio Stefano Covino Paolo D’Avanzo Matteo Ferro Andrea Melandri Andrea Rossi JoséFeliciano AgüíFernández Christina C.Thöe Chun-Hai Bai Ali Esamdin Abdusamatjan Iskandar Shahidin Yaqup Yu Zhang Tu-Hong Zhong Shao-Yu Fu Shuai-Qing Jiang Xing Liu Jie An Zi-Pei Zhu Jia-Xin Cao En-Wei Liang Da-Bin Lin Xiang-Gao Wang Guo-Wang Du Xin-Zhong Er Yuan Fang Xiao-Wei Liu Christophe Adami Michel Dennefeld Emeric Le Floc’h Johan Peter Uldall Fynbo Páll Jakobsson Daniele Bjøn Malesani Zhi-Ping Jin Jia Ren Hao Wang Da-Ming Wei Hao Zhou Sergio Campana Shiho Kobayashi Massimiliano De Pasquale 《Research in Astronomy and Astrophysics》 2025年第10期129-143,共15页
Early multiwavelength observations offer crucial insights into the nature of the relativistic jets responsible for gamma-ray bursts and their interaction with the surrounding medium.We present data of GRB 240825A from... Early multiwavelength observations offer crucial insights into the nature of the relativistic jets responsible for gamma-ray bursts and their interaction with the surrounding medium.We present data of GRB 240825A from 17 space-and ground-based telescopes/instruments,covering wavelengths from NIR/optical to X-ray and GeV,and spanning from the prompt emission to the afterglow phase triggered by Swift and Fermi.The early afterglow observations were carried out by SVOM/C-GFT,and spectroscopic observations of the afterglow by GTC,VLT,and TNG determined the redshift of the burst(z=0.659)later.A comprehensive analysis of the prompt emission spectrum observed by Swift-BAT and Fermi-GBM/LAT reveals a rare and significant high-energy cutoff at 76 MeV.Assuming this cutoff is due toγγabsorption allows us to place an upper limit on the initial Lorentz factor,Γ_(0)<245.The optical/NIR and GeV afterglow light curves can be described by the standard external shock model,with early-time emission dominated by a reverse shock(RS)and a subsequent transition to forward shock(FS)emission.Our afterglow modeling yields a consistent estimate of the initial Lorentz factor(Γ_(0)∼234).Furthermore,the RS-to-FS magnetic field ratio(R 302B)indicates that the RS region is significantly more magnetized than the FS region.An isotropic-equivalent kinetic energy of E_(k,iso)=5.25×10^(54) erg is derived,and the correspondingγ-ray radiation efficiency is estimated to beη_(γ)=3.1%.On the other hand,the standard afterglow model cannot reproduce the X-ray light curve of GRB 240825A,calling for improved models to characterize all multiwavelength data. 展开更多
关键词 (stars )gamma-ray burst INDIVIDUAL (GRB 240825A)-(stars )gamma-ray burst general-(transient )gamma-ray bursts
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长白山天池火山千年大喷发期后火山泥石流沉积特征及其源-汇响应关系 被引量:3
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作者 王璞珺 许伟东 +5 位作者 陈海潮 衣键 王寒非 唐华风 王文华 武成智 《岩石学报》 SCIE EI CAS CSCD 北大核心 2020年第9期2893-2911,共19页
源于长白山天池地区的火山泥石流沉积可分为粗碎屑岩块(岩屑)泥石流和细碎屑浮岩泥石流,它们沿二道白河和松花江水系搬运的路径为从距天池火山口40km的三合水电站经过丰满大坝(360km)和吉林市(380km)到小白旗屯(450km),形成广泛的沉积... 源于长白山天池地区的火山泥石流沉积可分为粗碎屑岩块(岩屑)泥石流和细碎屑浮岩泥石流,它们沿二道白河和松花江水系搬运的路径为从距天池火山口40km的三合水电站经过丰满大坝(360km)和吉林市(380km)到小白旗屯(450km),形成广泛的沉积区域。这两类火山泥石流的沉积成因有两种解释:一是形成于千年大喷发同期,是由一次性洪水事件搬运和沉积形成的;二是形成于千年大喷发期后经过多次搬运和沉积的产物。两个模式的共同问题是都没有考虑天池当时是否有水及其蓄水过程。后一模式在某种程度上,还回避了导致岩屑与浮岩两类泥石流频繁互层的沉积物源和水动力条件以及二者的转换机制,而这恰恰是关于泥石流沉积成因的基本要素。通过重新研究火山泥石流经典剖面(位于天池西北57.73km的水田村),作者发现本区火山泥石流沉积存在明显的物源剥蚀区与沉积堆积区的反剖面关系。即无论是粒径32~500mm的粗碎屑还是0.0625~16mm的细碎屑,成分自下而上(或沉积早期到晚期)呈现规律性变化:剖面下部的碎屑成分以浮岩为主(浮岩在物源区位于顶部),向上粗面岩和玄武岩明显增多(在源区它们位于浮岩之下),而沉积序列上部的碎屑成分是在物源区处于较深层位的岩脉辉绿岩和基底流纹岩。整个序列碎屑成分的沉积分异特征明显。沉积构造和岩相组合特征显示,该火山泥石流剖面的下部和上部碎屑粒度细、分选较好、成层性好、水平状层理发育,主要表现为环境较为稳定的以地面径流为主的河流相和末端扇相背景沉积;中部粒度粗、成层性差、主要表现为突发性洪水作用导致的洪积相事件沉积。沉积序列中频繁出现的冲刷面构造指示水流强度曾出现周期性的快速增加。自下而上冲刷面规模由小变大再变小,指示水流强度由弱变强再变弱。为了探讨天池的积水条件和蓄水过程,作者基于达西定律和质量守恒原理,模拟计算降水量、蒸发量、地表径流量、火山机构整体的平均渗透率和天池积水速率之间的关系。结果显示,当天池火山机构平均渗透率高于6m D(毫达西)时,天池地区降水量减蒸发量即使高达2000mm/y,水亦会全部渗流而出,因此天池不存在积水环境。当降水量减蒸发量小于1500mm/y时,则天池火山体平均渗透率需要小于4m D,天池才可能在200年之内集满现今的水量。当天池降水量减蒸发量小于1000mm/y时,天池火山体平均渗透率需要小于2.5m D,天池才可能在200年之内集满现今的水量。将水田村火山泥石流沉积序列与天池蓄水过程计算结果加以对比,我们提出本区火山泥石流沉积序列的另一种成因解释:(1)这是形成于千年大喷发之后的以地面径流或河流为主的背景沉积与洪水导致的突发性事件沉积互层的序列;上部和下部的细碎屑层主要表现为背景沉积,中部的粗碎屑岩块泥石流主要表现为洪流事件沉积。(2)下部的背景沉积可能对应于天池千年大喷发之后的持续积水过程,时间可能不少于200年;而上部的背景沉积则对应于本区的水系和地貌逐渐稳定并接近于现今条件的稳定型河流沉积。结合天池北坡和西坡古老树木年轮指示的沙松冷杉生长年代(公元1749-1768)同时考虑松柏类植物对水系和地貌稳定性较为敏感等因素,推测上部沉积环境趋于稳定的时间应该不晚于公元十八世纪初。 展开更多
关键词 长白山火山千年大喷发 火山岩渗透率 天池积水数学模拟 岩屑和浮岩泥石流 源-汇响应
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陕西红花椒树冠结构对产量的影响 被引量:10
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作者 李孟楼 惠文斌 张正清 《西部林业科学》 CAS 北大核心 2021年第1期1-11,共11页
根据花椒树冠结构与产量的关系,确定影响花椒产量的主要结构因素,为丰产管理提供依据。对4个品种(‘大红袍’‘豆椒’‘黄盖狮子头’‘小红袍’)的树龄、地径、树高、冠幅、标准枝(结果枝)数和产量进行调查,分析产量与树冠结构因子的关... 根据花椒树冠结构与产量的关系,确定影响花椒产量的主要结构因素,为丰产管理提供依据。对4个品种(‘大红袍’‘豆椒’‘黄盖狮子头’‘小红袍’)的树龄、地径、树高、冠幅、标准枝(结果枝)数和产量进行调查,分析产量与树冠结构因子的关系。结果表明:(1)花椒适宜栽植密度约50株/666.7m 2,栽植后树高应控制在2.50 m左右;伴随树龄增大各品种冠幅扩张速度虽有差异,但地径年平均约递增0.68 cm/a,各年龄段(3~6 a、7~12 a、13~18 a及19 a以上)冠幅最适扩放幅度为25、20、7及6 cm/a。(2)4个品种的株标准枝数、标准枝果穗数和鲜花椒产量有差异,平均株标准枝数105个、标准枝果穗数16枝、标准枝鲜花椒产量58 g,但株标准枝数与树龄相关性强,标准枝果穗数与树龄、标准枝果穗数与标准枝产量相关性弱。(3)与树龄的相关性地径>株标准枝数>冠幅,树高与株产量无相关性,与株产量的相关性株标准枝数>冠幅>树龄及地径。(4)株标准枝数是制约株产量的重要因素,若x为树龄,则丰产花椒园株标准枝留置模式可选用S-1=2.6817x 1.3160、精细管理高产花椒园可用S-2=12.6700e 0.1304 x。(5)按照666.7 m 2栽植50株进行产量预测结果说明,果穗及花椒颗粒大的‘黄盖大红袍’和‘豆椒’产量高,其次是抽生结果枝数量多的‘大红袍’,而株标准枝上的果穗数对产量影响不大。以上调查研究结果说明,花椒树龄、株标准枝数和冠幅与株产量关联密切,株标准枝数是形成产量的关键因素,果穗和花椒颗粒大、抽生结果枝数量多的品种产量高。 展开更多
关键词 花椒 树冠结构 品种 产量
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2种单体皂苷及三七总皂苷对白菜幼苗生长生理的影响 被引量:1
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作者 张红瑞 张云霞 +3 位作者 李纪红 沈玉聪 高致明 张子龙 《河南农业科学》 北大核心 2019年第1期94-98,104,共6页
研究了三七皂苷R_1、人参皂苷Rg1和三七总皂苷对白菜幼苗苗高、主根长等生长性状以及过氧化物酶(POD)、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)活性,可溶性糖、可溶性蛋白质含量等生理特性的影响。结果表明,与对照(蒸馏水)相比,0. 01~10... 研究了三七皂苷R_1、人参皂苷Rg1和三七总皂苷对白菜幼苗苗高、主根长等生长性状以及过氧化物酶(POD)、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)活性,可溶性糖、可溶性蛋白质含量等生理特性的影响。结果表明,与对照(蒸馏水)相比,0. 01~100. 00 mg/L三七皂苷R_1和人参皂苷Rg1处理均不同程度地降低了白菜幼苗的苗高、主根长和POD、SOD活性,其中,10. 00、100. 00mg/L三七皂苷R_1处理组和0. 01、50. 00 mg/L人参皂苷Rg1处理组白菜幼苗的主根长降低达显著水平,白菜幼苗CAT活性升高,可溶性糖含量和可溶性蛋白质含量增加;三七总皂苷处理能增加白菜幼苗的SOD、CAT活性和可溶性蛋白质含量,降低其主根长、POD活性,而苗高、可溶性糖含量呈现低促高抑的趋势,其中,0. 01、10. 00、50. 00、100. 00 mg/L处理组白菜幼苗POD活性分别比对照显著下降35. 57%、37. 90%、45. 35%、35. 42%。三七皂苷R_1、人参皂苷Rg1及三七总皂苷对白菜幼苗均具有一定的化感抑制作用,但在质量浓度0. 01~100. 00 mg/L的范围内,白菜可以作为三七的轮作作物。 展开更多
关键词 三七 三七皂苷R1 人参皂苷RG1 三七总皂苷 白菜幼苗
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关中地区竹叶花椒优良品系引进试验 被引量:1
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作者 李孟楼 史易娟 《陕西林业科技》 2023年第3期41-44,共4页
为明确竹叶花椒能否在秦岭以北的关中种植和安全越冬,分别从云南、四川和重庆收集13份地理品系试种于杨凌。试种结果表明,仅来自云南永胜县的株系Y_(2)可在杨凌过冬,Y_(2)萌生新梢能力强,芽和新梢无休眠现象,但新梢木质化程度弱、常难... 为明确竹叶花椒能否在秦岭以北的关中种植和安全越冬,分别从云南、四川和重庆收集13份地理品系试种于杨凌。试种结果表明,仅来自云南永胜县的株系Y_(2)可在杨凌过冬,Y_(2)萌生新梢能力强,芽和新梢无休眠现象,但新梢木质化程度弱、常难以越冬;修剪措施可控制其旺长,促进新枝木质化、安全过冬;该株系枝条较细弱并下垂,皮刺较直,花椒果粒直径为4~5 mm,生物学特征似于竹叶椒中的藤椒品系。以上说明,在与杨凌气候条件相同的地区,Y_(2)株系有繁育和扩大试种前景。 展开更多
关键词 竹叶花椒 陕西杨凌 试种
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中国香港新记录的十个分类单元(英文) 被引量:3
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作者 朱慧玲 刘金刚 +3 位作者 张金龙 幸敬阳 杨永佳 Gunter A.FISCHER 《广西植物》 CAS CSCD 北大核心 2018年第9期1221-1228,共8页
中国香港位于热带北缘,其植被在历史上曾遭到大规模破坏,近几十年来逐渐恢复。香港植物标本采集有很长的历史,迄今为止已记录的维管植物超过2 170种,然而新种和新分布仍在不断增加。在最近的野外工作中,作者发现10种在香港新记录到的维... 中国香港位于热带北缘,其植被在历史上曾遭到大规模破坏,近几十年来逐渐恢复。香港植物标本采集有很长的历史,迄今为止已记录的维管植物超过2 170种,然而新种和新分布仍在不断增加。在最近的野外工作中,作者发现10种在香港新记录到的维管植物,分别是唇边书带蕨[Haplopteris elongata (Swartz) E. H.Crane]、雷公连[Amydrium sinense (Engl.) H. Li]、百足藤[Pothos repens (Lour.) Druce]、四川轮环藤(Cycleasutchuenensis Gagnep.)、山黑豆(Dumasia truncata Siebold&Zucc.)、倒心叶珊瑚[Aucuba obcordata (Rehder) Fu ex W. K. Hu et Soong]、竹叶榕(Ficus stenophylla Hemsl.)、长叶冠毛榕[F. gasparriniana var. esquirolii (H. Lév.&Vaniot) Corner]、硬叶冬青(Ilex ficifolia C. J. Tseng ex S. K. Chen et Y. X. Feng)、假福王草[Paraprenanthes sororia(Miq.) C. Shih.]。雷公连属(Amydrium Schott)、山黑豆属(Dumasia DC.)和假福王草属(Paraprenanthes C. C.Chang ex C. Shih)为香港的新记录属。以上的发现不仅丰富了香港的植物区系,而且表明保护残存植被非常重要,且极小种群的保护也值得特别关注。 展开更多
关键词 新记录 维管植物 植物区系 保护 生物多样性
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油桐NPR1家族全基因组鉴定及表达模式分析 被引量:9
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作者 江慎秀 尚海 +5 位作者 李涛 王静雅 庄婧怡 刘文娟 张琳 刘美兰 《植物遗传资源学报》 CAS CSCD 北大核心 2021年第2期521-531,共11页
本研究利用油桐(Vernicia fordii)基因组数据鉴定出3个NPR1家族成员,并将其命名为VfNPR1、VfNPR3、VfNPR5。通过生物信息学分析方法,分析了其理化性质、亚细胞定位、染色体分布、保守结构域、基因结构及启动子顺势作用元件等,研究了大戟... 本研究利用油桐(Vernicia fordii)基因组数据鉴定出3个NPR1家族成员,并将其命名为VfNPR1、VfNPR3、VfNPR5。通过生物信息学分析方法,分析了其理化性质、亚细胞定位、染色体分布、保守结构域、基因结构及启动子顺势作用元件等,研究了大戟科5个物种及拟南芥NPR1家族成员的进化关系,并利用转录组测序技术探究了油桐NPR1家族成员在不同类型花、不同发育时期种子和根系尖孢镰孢菌胁迫响应过程中的表达模式。结果表明:油桐NPR1家族3个成员属于疏水性蛋白,VfNPR1/3/5分别在chr 8、chr 10、chr 4染色体上,VfNPR1定位在细胞核中,而VfNPR3/5定位在叶绿体中;大戟科5个物种中的NPR1家族成员可明显划分成亚类Ⅰ、亚类Ⅱ、亚类Ⅲ3个亚类,其中蓖麻、麻疯树、油桐出现明显的收缩;npr1-1(His334Tyr)、npr1-2(Cys150tyr)和nim1-2(His300tyr)等重要功能位点在大戟科5个物种中有较高的保守性;油桐NPR1家族3个成员在雌花、雄花、两性花中都显著差异表达,且都在雄花中表达量最高,在油桐种子不同发育时期,VfNPR1/5在早期(花后10周、15周)表达量较高,VfNPR3则在后期(花后30周)表达量较高,在尖孢镰孢菌不同侵染时间的油桐幼苗根系中,NPR1家族3个成员表达被显著抑制,其中VfNRP3在侵染后期被完全抑制表达。由此表明,油桐NPR1家族3个成员可能参与了花果发育和根系系统获得性抗性信号途径,该研究为油桐丰产栽培提供了重要的科学依据,同时也为林木抗病改良提供重要的基因资源。 展开更多
关键词 油桐 NPR1 生物信息学分析 油桐枯萎病 表达分析
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基于居民感知的跨界意义研究——以深港跨界居民为例 被引量:7
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作者 封丹 朱竑 Werner Breitung 《人文地理》 CSSCI 北大核心 2019年第3期53-60,共8页
对于在边界两侧居住的居民,跨界流动、居民对边界另一侧的地方感、跨界的个人意义以及跨界的区域意义这四者之间的互动关系是值得关注的话题。本文基于深港跨界居民的调查数据,构建了路径模型来分析上述四者之间的关系。发现:跨界频率... 对于在边界两侧居住的居民,跨界流动、居民对边界另一侧的地方感、跨界的个人意义以及跨界的区域意义这四者之间的互动关系是值得关注的话题。本文基于深港跨界居民的调查数据,构建了路径模型来分析上述四者之间的关系。发现:跨界频率对深港居民的地方感具有显著的正向作用;跨界频率对个人和区域意义的感知均具有显著影响,对个人意义的感知影响是正向的,但对区域意义的感知影响却是负向的;地方感对边界的个人和区域意义感知均具有显著的正向影响。本文通过对深港边界居民的实证研究,深化了对跨界流动意义的理解,以期为深港一体化相关政策制定和实施提供依据和借鉴。 展开更多
关键词 深港居民 跨界流动 一体化 地方感 路径分析
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