检索结果-南通市图书馆

Kerr Lens mode-locked Operation of Yb∶KYW Laser

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Lasers 2002年第3期 7-9页

作者： Falihati. mejiti 1 V.L.Kalashnikov 2 I.G.Poloyko 2 Toran. Vajidi 1 1Physics Department, Xinjiang University, Urumqi 830046, China 2International Laser Center, Belorussian State Poletechnical Academy, 65 Skoryna Ave., Bldg.17.220027 m

Using a modified ABCD matrix  approach accounting for nonlinear refraction in active medium, the ranges of cavity parameters that provide a mode locking of Yb∶KYW laser in usual z fold cavity configuration are determined. Taking the cavity parameters that provide a most efficient mode locking and based on fluctuation model, a numerical simulation of laser operation is performed. In the calculations the side band pump power of 6W at 982 nm is used in 1 cm length KYW crystal with 1 cm×0 005 cm beam cross section. Calculations show that self starting operation is possible with these parameters and dispersion compensation allows for bandwidth limited ultrashort pulse generation. The shortest pulse duration was determined to be about 200 fs with self starting buid up time of 130 μs. Such a built up time is comparable and even shorter than that one for the lasers with semiconductor saturable absorbers. The region of negative dispersion provided by prism pair for a stable ultrashort pulse generation was determined to be (-17000～-42000)fs 2.

关键词： ultra short pulse solid state laser Kerr lens mode locking

2-6 First Direct measurement of 12C(12C, n)23mg at Stellar Energies

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

ImP & HIRFL Annual Report 2015年第1期 56-58页

作者： Tang Xiaodong B. Bucher X. Fang A. Heger S. Almaraz-Calderon A. Alongi A.D. Ayangeakaa m. Beard A. Best J. Browne C. Cahillane m. Couder R.J. deBoer A. Kontos L. Lamm Y.J. Li A. Long W. Lu S. Lyons m. Notani D. Patel N. Paul m. Pignatari A. Roberts D. Robertson K. Smith E. Stech R. Talwar W.P. Tan m. Wiescher S.E. Woosley Institute of modern Physics Chinese Academy of Science Lanzhou 730000 China Institute for Structure and Nuclear Astrophysics Joint Institute for Nuclear AstrophysicsUniversity of Notre Dame Notre Dame Indiana 46556 USA Lawrence Livermore National Laboratory Livermore California 94550 USA monash Center for Astrophysics School of Physics and Astronomy Monash University Victoria 3800 Australia Department of Physics and Astronomy Shanghai Jiao-Tong University CNA Shanghai 200240 China School of Physics and Astronomy University of Minnesota Minneapolis Minnesota 55455 USA China Institute of Atomic Energy Beijing 102413 China Konkoly Observatory Research Centre for Astronomy and Earth Sciences Hungarian Academy of SciencesKonkoly Thege Mikl′os′ut 15-17 H-1121 Budapest Hungary Department of Physics University of Basel Basel CH-4056 Switzerland Department of Astronomy and Astrophysics University of California Santa Cruz California 95064 USA

The first stars in the early Universe were formed about 400 million years after the big bang. Verification of the existence of these stars is important for our understanding of the evolution of the Universe[1]. It has been predicted that for Population-III stellar production yields, the abundances of odd-z elements are remarkably deficient compared to their adjacent even-z elements[2]. Astronomers are searching for long-lived, low mass stars with the unique nucleosynthetic pattern matching the predicted yields[3].

关键词： First Direct measurement

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

离化态原子K_α射线移位的规律

物理学报 1981年第1期 105-110页

作者：李家明赵中新中国科学院物理研究所

本文从理论上对离化态原子的K_α射线所发生的移位作了初步的研究,并总结了K_α射线随离化度和原子序变化的规律。提供了有关的数据图表,这可以用来估算各种离化态原子(原子序z≤42)的K_α射线移位。最后还讨论了测量移位的K_α射线谱,... 详细信息

本文从理论上对离化态原子的K_α射线所发生的移位作了初步的研究,并总结了K_α射线随离化度和原子序变化的规律。提供了有关的数据图表,这可以用来估算各种离化态原子(原子序z≤42)的K_α射线移位。最后还讨论了测量移位的K_α射线谱,这可以应用于等离子体的杂质诊断。

关键词： α射线电离度 α辐射玻色子离化态原子原子序

类癌性心脏疾病患者行瓣膜手术的术中管理：100例连续病例的回顾

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

麻醉与镇痛 2008年第6期4卷 27-35页

作者： Toby N. Weingarten, mD martin D. Abel, mD Heidi m. Connolly, mD DarrellR. Schroeder, mS Hartzell V. Schaff, mD 张益(译) 喻田(校) Department of Anesthesiology the Division of Cardiovascular Diseasethe Division of Cardiac Surgery and the Section of Biostatistics Mayo Clinic and Mayo Foundation Rochester Minnesota 不详

背景在类癌性心脏病患者的心脏手术中，常因类癌危象、心血管功能障碍和失血导致血流动力学不稳定。在使用奥曲肽的同时，合用血管加压药物的安全性以及抑肽酶的益处尚不明确。方法我们回顾了从1985年到2003年的18年中，连续100例类癌... 详细信息

背景在类癌性心脏病患者的心脏手术中，常因类癌危象、心血管功能障碍和失血导致血流动力学不稳定。在使用奥曲肽的同时，合用血管加压药物的安全性以及抑肽酶的益处尚不明确。方法我们回顾了从1985年到2003年的18年中，连续100例类癌性心脏病患者行心脏手术的病例，对奥曲肽给药期间合用血管加压药物和抑肽酶的影响以及患者的死亡率进行了单因素分析。由于抑肽酶可以暂时性降低死亡率，因此行双因素分析以鉴别其他与死亡率相关的因素。结果分别用奥曲肽（胛=89）和（或）血管加压药（门=93）处理类癌症状和低血压。血管加压药并没有随着奥曲肽用量的增加而增加。手术中需要使用肾上腺素的患者死亡率较高，但其手术前的纽约心脏协会分级就较差，尿中5．羟哼J哚乙酸水平以及对输血的需求都较高。抑肽酶（，z=54）可降低患者对输血的需求，并增加奥曲肽的用量，但对死亡率无影响。死亡率方面，从1985年到1994年的28％，下降至1995年到2003年的6％，平均总死亡率为13％。死亡率与大量输血和长时间心肺转流有关。结论血管加压药物可以与奥曲肽合用于类癌患者。死亡率的增加可能与肾上腺素的使用有关，这主要是由选择性差异导致的，而不是药物的原发不良反应。类癌患者的存活率随着时间推移而增加是由多因素造成的，与使用抑肽酶无关，说明在应用奥曲肽的情况下，在这类患者中进一步抑制激肽释放酶——激肽系统对预后并无益处。

关键词：心脏病患者类癌性术中管理瓣膜手术心血管功能障碍病例血管加压药血流动力学不稳定

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

太赫兹连续波DCN激光器的实验研究

激光技术 2006年第1期30卷 64-66,69页

作者：高翔刘海庆揭银先 ASIFm 高丽刘瑾童兴德程永飞中国科学院等离子体物理研究所合肥230031

介绍了运行在1.54THz(195μm)和1.58THz(190μm)的波导型辉光放电激励的大功率连续波DCN激光器的开发和研制工作。该激光器的谐振腔长3.4m,放电长度3m,谐振腔由耐热玻璃制成,直径54mm。谐振腔一端为平面反射镜,一端为金属栅网。工作气体... 详细信息

介绍了运行在1.54THz(195μm)和1.58THz(190μm)的波导型辉光放电激励的大功率连续波DCN激光器的开发和研制工作。该激光器的谐振腔长3.4m,放电长度3m,谐振腔由耐热玻璃制成,直径54mm。谐振腔一端为平面反射镜,一端为金属栅网。工作气体为N2,CD4和He(或D2)的混合气体,在1.54THz的连续激光输出功率大于0.2W。实验中对放电电流、激光管温度、气压等参数进行了优化,研究了EH11模DCN激光在自由空间的传输特性。研究表明,利用新的N2,CD4和D2混合气体的太赫兹DCN激光器可以得到稳定连续的高功率放电。光束传输远场满足高斯分布(z>4m),对各种参数进行优化后,190μm和195μm窗口处输出EH11模功率分别为0.15W和0.16W,可以满足超导托卡马克连续运行的干涉测量的需要。

关键词：激光技术太赫兹激光 DCN激光器输出功率优化传输特性

Optical Detection of Distal Lung Enzyme Activity in Human Inflammatory Lung Disease

在线全文

学校读者我要写书评

暂无评论

Biomedical Engineering Frontiers 2021年第1期2卷 44-54页

作者： Alicia megia-Fernandez Adam marshall Ahsan R.Akram Bethany mills Sunay V.Chankeshwara Emma Scholefield Amy miele Bruce C.mcGorum Chesney michaels Nathan Knighton Tom Vercauteren Francois Lacombe Veronique Dentan Annya m.Bruce Joanne mair Robert Hitchcock Nik Hirani Chris Haslett mark Bradley Kevin Dhaliwal EaStCHEm The University of Edinburgh School of ChemistryJoseph Black BuildingWest Mains RoadEdinburghUK EH93FJ Translational Healthcare Technologies Group Centre for Inflammation ResearchQueen’s Medical Research InstituteUniversity of Edinburgh47 Little France CrescentEdinburgh BioQuarterEdinburghUK EH164TJ The Roslin Institute and Royal(Dick)School of Veterinary Studies University of EdinburghEaster BushMidlothianUK EH259RG Department of Biomedical Engineering University of Utah36 S Wasatch DrSalt Lake CityUT 84112USA School of Biomedical Engineering&Imaging Sciences King’s College LondonLondonUK SE17EH mauna Kea Technologies 9Rue d’EnghienParisFrance 75010

Objective and Impact *** is a need to develop platforms delineating inflammatory biology of the distal human *** describe a platform technology approach to detect in situ enzyme activity and observe drug inhibition in the distal human lung using a combination of matrix metalloproteinase(mmP)optical reporters,fibered confocal fluorescence microscopy(FCFm),and a bespoke delivery *** development of new therapeutic agents is hindered by the lack of in vivo in situ experimental methodologies that can rapidly evaluate the biological activity or drug-target engagement in *** optimised a novel highly quenched optical molecular reporter of enzyme activity(FIB One)and developed a translational pathway for in-human *** demonstrate the specificity for matrix metalloproteases(mmPs)2,9,and 13 and probe dequenching within physiological levels of mmPs and feasibility of imaging within whole lung models in preclinical ***,in a first-in-human exploratory experimental medicine study of patients with fibroproliferative lung disease,we demonstrate,through FCFm,the mmP activity in the alveolar space measured through FIB One fluorescence increase(with pharmacological inhibition).*** translational in situ approach enables a new methodology to demonstrate active drug target effects of the distal lung and consequently may inform therapeutic drug development pathways.

关键词： Lung lung specificity

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

融合细节与整体特征的三维模型检索方法

西南大学学报（自然科学版） 2015年第10期37卷 131-137页

作者：徐平安唐雁牟春倩陈强石教开张辉荣西南大学计算机与信息科学学院重庆400715

三维模型检索技术能有效提高三维模型的复用率和共享率.为了提高三维模型检索结果的准确率,提出一种融合细节与整体特征的三维模型检索方法,通过SIFT特征和傅立叶描述子特征来对三维模型进行特征描述.分别利用这2种特征来对三维模型进... 详细信息

三维模型检索技术能有效提高三维模型的复用率和共享率.为了提高三维模型检索结果的准确率,提出一种融合细节与整体特征的三维模型检索方法,通过SIFT特征和傅立叶描述子特征来对三维模型进行特征描述.分别利用这2种特征来对三维模型进行相似度度量,再通过加权求和的方式对这2种特征进行融合.通过融合这2种特征可以达到同时兼顾三维模型的整体形状特征和局部细节特征,实验证明该方法能提高三维模型检索结果的准确率.

关键词：三维模型检索傅立叶描述子特征 SIFT特征特征融合

磐石千塘稻永久基本农田生态环境保护与可持续发展案例研究

在线全文

学校读者我要写书评

暂无评论

全球变化数据学报（中英文） 2022年第2期6卷 157-168,329-340页

作者：宋献方于技群戚武王政文乔云波杨丽虎姚东绪付晶莹都兴林吴烽刘宏斌祝晓光陈存华任建行吴云明李丽李恩贵姚丽萍郑霏闫国栋张传民朴日郭传海孙志刚顾强周立国胡汉永张立军孙慧发李海胜中国科学院地理科学与资源研究所北京100010 中国科学院大学北京100049 雄安创新研究院雄安新区071899 磐石市人民政府磐石132000 磐石市农业农村局磐石132300 吉林大学植物科学学院长春130062 磐石市供销投资集团有限公司磐石132300 中国农业科学院农业资源与农业区划研究所北京100081 北京天航华创科技股份有限公司北京100085 磐石市富太镇磐石132308 磐石市牛心镇磐石132315 磐石市吉昌镇磐石132301 磐石市宝山乡磐石132327 磐石市松山镇磐石132313 磐石市呼兰镇磐石132309 磐石市烟筒山镇磐石132302 磐石市取柴河镇磐石132303 磐石市朝阳山镇磐石132323 磐石市福安街道磐石132300 磐石市明城镇磐石132301 磐石市红旗岭镇磐石132312 磐石市驿马镇磐石132305 磐石市石嘴镇磐石132321 磐石市磐石经济开发区磐石132300 磐石市黑石镇磐石132312

磐石千塘稻永久基本农田生态环境保护与可持续发展案例产品种植于吉林磐石市境内水库、塘坝下游地势低洼处,水稻田面积17,787hm^(2)。案例区地处长白山脉向松嫩平原的过渡地带,属丘陵山区,降雪融水、自然降水天然汇集,水稻田内土壤主要... 详细信息

磐石千塘稻永久基本农田生态环境保护与可持续发展案例产品种植于吉林磐石市境内水库、塘坝下游地势低洼处,水稻田面积17,787hm^(2)。案例区地处长白山脉向松嫩平原的过渡地带,属丘陵山区,降雪融水、自然降水天然汇集,水稻田内土壤主要为富含有机质的黑土,土质优于土壤环境质量标准,灌溉用水的水质优于城市生活饮用水供水标准。当前主要种植六个水稻品种,水稻品质与五常大米标准和盘锦大米标准相当或者更好。案例提出了黑土地保护与永久基本农田生态环境可持续发展新模式。该案例数据集由案例范围、自然地理数据、水稻品种特性数据、经营管理数据、自然特色与历史文化传统等5个数据文件包组成,存储格式为.shp、.docx、.jpg、.tif及.xlsx,数据量为22.4 mB。

关键词：磐石千塘稻永久基本农田黑土地面向环境保护与可持续发展的地理标志案例12

糖尿病视网膜病变进展的定位预测模型的形成和评估

在线全文

学校读者我要写书评

暂无评论

世界核心医学期刊文摘（眼科学分册） 2005年第4期1卷 44-44页

作者： Schneck m.E. Bearse Jr. m.A. 杨建刚

PURPOSE. To formulate and test a model to predict the development of local patches of nonproliferative diabetic retinopathy (NPDR), based on multifocal electroretinogram (mfERG) implicit times and candidate diabetic risk factors. mETHODS. mfERGs and fundus photographs were obtained from 28 eyes of 28 diabetic patients during an initial and 12- month followup examination. mfERG implicit times were derived at 103 locations using a template- stretching method, and a z- score was calculated in comparison with 20 age- matched normal subjects. Thirty- five nonoverlapping retinal zones were constructed by grouping two to three adjacent stimulated locations, and each zone was assigned the maximum z- score within it. zones containing initial retinopathy were excluded from further analysis. The probability that new retinopathy would develop in the remaining zones by the follow- up examination was modeled based on the mfERG implicit time z- score for the zone and other candidate diabetic risk factors determined during the initial visit. Data collected from four previously untested diabetic subjects and the other eye of eight previous subjects during their second year follow- up were used to test the predictive model. RESULTS. After 1 year, new retinopathy developed in 11 of the 12 NPDR eyes and 1 of the 16 eyes without initial retinopathy. After accounting for the correlation among zones within each eye, a predictive model was formulated with the variables mfERG implicit time, duration of diabetes, presence of retinopathy (NPDR or no retinopathy), and blood glucose level, at initial visit. The area under the receiver operating characteristic (ROC) curve of this multivariate model is 0.90 (P model has an expected sensitivity of 86% and a specificity of 84% , which was verified by the test data. CONCLUSIONS. The development of diabetic retinopathy over a 1- year period can be well predicted by a multivariate model. The inclusion of local mfERG implicit t

关键词：预测模型视网膜病变视网膜电图眼底照相局灶病变随访检查月检查相关性因素测定时间预测时间