163 research outputs found
The Policy Network Theory and Its Application
随着全球化、国际化、信息化的不断发展,政府的责任范围不断拓展,公共事务日趋复杂。而传统的多元主义和统合主义又无法解释和解决这一政治现象,政策网络理论从中观层面的角度弥补了宏观研究方法和微观研究方法的裂痕。政策网络理论以政策共同体为核心,通过结构、网络、组织互动以及人际互动等分析法,展现了政策过程中政策主体之间竞争与合作的互动行为,更清晰地展现了当代政策过程的真实画面。作为一个新视角的研究方法,政策网络理论具有重大的理论价值和现实意义。文章可以分为如下五部分:第一部分,导论。阐述了文章的研究背景、研究意义以及国内外研究现状、研究价值和局限性等;同时指出了本文的研究方法、论文框架和论文的创新点。第...With the globalization, internationalization, the continuous development of information, the scope of government responsibility becomes expand. Country's politics tending to disaggregation, decentralization and fragmentation, more interest groups or policy community are admitted into the policy arena, making the increasing complexity of public affairs. While the traditional pluralism and corporati...学位:管理学硕士院系专业:公共事务学院公共管理系_行政管理学号:1392006115072
海底隧道衬砌混凝土抗蚀影响因素分析与模拟
对海底隧道衬砌混凝土抗蚀影响因素进行了全面分析,建立了多因素的影响模型。指出以氯盐、硫酸盐和镁盐为代表的海洋环境介质的化学侵蚀破坏、以气候因素和盐类结晶为代表的物理因素作用、以自身结构的密实程度与收缩变形为代表的自身因素是影响隧道衬砌混凝土抗蚀性的3大主要因素。它们既相互联系又相互促进。其中,混凝土自身的密实程度和微裂缝是关键影响因素
Simultaneous determination of 7 nucleosides in Asterias rollestoni using reversed-phase high performance liquid chromatography
建立了罗氏海盘车中7种核苷化合物的反相高效液相色谱分析测定方法。采用超声波辅助提取,选用两根不同的C18色谱柱串联,以甲醇和0.2%(体积分数)乙酸/水溶液为流动相梯度洗脱分离。优化的色谱条件为:柱温为室温,检测波长为260nM,流速为0.8Ml/MIn,进样量为20μl。结果表明,7种核苷化合物在一定的浓度范围内线性关系良好,次黄嘌呤和胸苷的线性范围为0.65~40Mg/l,尿苷、黄嘌呤和肌苷的线性范围为0.80~40Mg/l,胸腺嘧啶的线性范围为1.15~40Mg/l,鸟苷的线性范围为0.50~40Mg/l。样品中7种核苷化合物的加标回收率为90.00%~105.00%,相对标准偏差为0.72%~3.23%。该方法操作简便、灵敏度高、重复性好,回收率高,适用于罗氏海盘车中7种核苷类成分的同时分析,也可用于罗氏海盘车的质量控制和综合评价。A method for the simultaneous determination of 7 nucleosides in Asterias rollestoni was devel-oped using reversed-phase high performance liquid chromatography ( RP-HPLC) .Analytes were extracted by ultrasonic-assisted extraction and separated on two different C18 columns,which were connected in se-ries,under the gradient elution with the mobile phases of methanol and 0.2% ( v/v) acetic acid/water at room temperature.The chromatographic conditions were as follows: flow rate,0.8 mL/min; detection wavelength,260 nm; injection volume,20 μL.Under the optimized conditions,good linear relationships between the values of mass concentrations and the peak areas of hypoxanthine,uridine,xanthine,thy-mine,inosine,guanosine and thymidine were observed in the ranges of 0.65-40,0.80-40,0.80-40,1.15-40,0.80-40,0.50-40,and 0.65-40 mg/L,respectively.The relative standard devia-tions were around 0.72%-3.23% and the recoveries were around 90.00%-105.00%.The results showed that the developed method is sensitive,accurate and reproducible.It is suitable for the analysis of nucleosides in Asterias rollestoni with high recoveries and it is expected to be used for the quality control and evaluation of Asterias rollestoni.国家自然科学基金项目(20905017);海洋公益性行业科研专项(200705011;200805039);海洋局青年基金项目(2010140);海洋一所基本科研业务专项(GY-022008T32;2010G25);中国科学院实验海洋生物学重点实验室开放基金课
Identification of Bohai Sea crude oil based on characteristic fingerprinting by MSPD-RP-HPLC
建立渤海原油的高效液相色谱(HPlC)特征指纹图谱,为渤海原油的鉴别提供一种新方法。以氧化铝作为基质固相分散剂进行样品处理,采用HPlC法进行分析,双反相C18色谱柱串联,以乙腈-水为流动相,二元线性梯度洗脱,流速为1.0 Ml/MIn,柱温为20℃,双波长检测226 nM、254 nM,进样量10μl;采用所发展的方法对10批渤海原油样品进行分析,建立渤海原油的HPlC特征指纹图谱,结合相似度分析用于渤海原油的鉴别。该方法具有很好的精密度、重复性和稳定性,10批渤海原油特征指纹图谱有13个共有峰,结合相似度分析可以用于渤海原油样品的鉴别,说明HPlC特征指纹图谱是渤海原油鉴别的有力工具。Based on the high performance liquid chromatography(HPLC) characteristic fingerprinting,a new method for crude oil identification of Bohai Sea was developed.The sample pretreatment was done using matrix solid-phase dispersion,and Al2O3 was used as the dispersant.The chromatographic fingerprints were determined by injecting 10 L sample solution each time on two reverse phase C18 columns in series with the gradient elution solvent system composed of water and acetonitrile.The flow rate was 1.0 mL/min,the column temperature was maintained at 20℃ and the signals were acquired at 226 nm and 254 nm.The characteristic fingerprints of crude oil were established by analysis of ten representative samples derived from Bohai Sea,and identification was carried out by the similarity analysis of the characteristic fingerprints.The method was ideally suited for the fingerprinting of Bohai Sea crude oil with good precision,repeatability and stability.13 peaks were selected as the common peaks of the characteristic fingerprint and used for the similarity analysis,which could be applied to distinguish crude oil of Bohai Sea from that of other sources.The characteristic HPLC fingerprinting technique thus was a powerful tool for the identification of crude oil originated from Bohai Sea.海洋公益性行业科研专项(200705011;201005034-3);中国海监技术支撑体系项目;2008年海洋环境保护及节能减排专
Determination of Lead Content in Standard Materials of Lake Sediment and Tea by ID-ICP-MS
采用2种微波消解体系(HNO3-H2O2和HNO3-H2O2-HF)及3种定量模式(同位素稀释法、标准工作曲线法和标准加入法),对沉积物和茶叶标准物质中的铅进行测定,结果表明:同位素稀释质谱法的各项检测指标显著优于其它两种定量模式(茶叶中铅含量测定值为4.30μg/g),标准加入法次之(3.75μg/g),标准工作曲线法较差(3.61μg/g)。二种微波消解体系中,加HF酸优于不加HF酸,不加HF,茶叶中铅的回收率仅有89%,加入HF则上升为98%。Three different quantitative modes,namely external calibration,standard addition and isotope diluˉtion were compared for the determination of lead contents in lake sediment and tea standard materials with two digestion systems.The results showed that the isotope dilution gave the highest accuracy and precision in comˉparison with the other two modes.But the results were affected by the digestion system.For example,the reˉcoveries of lead content for tea were98%and89%for HNO 3 -H 2 O 2 -HF and HNO 3 -H 2 O 2 digesting sysˉtem,respectively.福建省重大科技项目子课题(2003Y005-04);; 厦门大学现代分析科学教育部重点实验室开放课题(B40402
Experimental study on reperfusion of intraocular lens
作者简介: 祁明信, 男, 1945 年7 月
出生, 教授、主任医师、博士研究生
导师, 主要从事白内障的基础与临
床研究。联系电话: 0591-83570887;
E-mail:qihuang@netease. com
通讯作者: 黄秀榕,E-mail:[email protected][中文文摘]目的开展晶状体再灌注的离体和动物实验研究,并对再灌注人工晶状体技术进行评价。方法采用新鲜离体幼兔眼、离体猪眼、新西兰白兔眼,应用自行研制的人工晶状体材料,进行以下实验:(1)体外固化实验;(2)晶状体前囊膜微型撕囊及其稳固性实验;(3)经微型前囊膜开口超声乳化吸出晶状体内容物实验;(4)活的新西兰白兔眼内人工晶状体再灌注实验。结果(1)按硅酮聚合物与固化剂50:1的比例可获得柔软、弹性好、固化时间短(完全固化时间为60min)的注入材料;(2)晶状体前囊膜1.8~2.0mm的连续环形撕囊口具有较好的稳定性,可经该微型开口吸出晶状体内容物并灌注材料;(3)超声能量18%、流量25mL·min-1、负压120mmHg(1kPa=7.5mmHg)为晶状体内容物经微型前囊膜开口吸出的最佳条件;(4)注入灌注材料后可形成由晶状体囊膜包裹的、置换原晶状体皮质和核的、新的再灌注人工晶状体。结论采用再灌注人工晶状体的方法可进行新型人工晶状体再灌注,可为治疗白内障和老视提供参考。[英文文摘]Objective To carry out the experimental study on reperfusion of intraocular lens(IOLs) in vitro or in animal,and to assess the technique of IOLs reperfusion.Methods The following experiments were performed by using self-developed materials in fresh rabbit eyes and pig eyes in vitro,as well as in eyes of alive New-Zea-land rabbits:(1)Solidification study of self-developed material in vitro;(2)Continuous circular capsulorhexis(CCC) in anterior capsule of lens and its stability;(3)Draw of lens contents via phaco through
mini-CCC;(4)IOLs ref illing in the eyes of alive New-Zea land rabbits. Results(1) Thematerialwhich was soft, springy and short-term solidification(full solidification time was 60 minutes) were obtained in certain proportion
of geland solidified agent(50:1) in vitro; ( 2)The CCC in anterior capsule of lens with 1.8-2.0 mm diameter had very good stability. The lens contents were drawn and the
materialwere refilled through themini-CCC; (3) The best conditions of drawing out lens
contents through m ini-CCC were phaco energy 18% , flow 25 mL·min- 1, and negative
pressure 120 mmH g (1kPa=7.5 mmHg);(4) The new refilled IOLs, which were
wrapped by capsule of lens and were replaced original cortex and nucleus of lens, were
obtained after thematerial refillied. Conc lusion. New IOLs are refilled through this
method, which can prov ide reference for the treatment of cataract and presbyopia.福建省科技三项费用;教育厅重点资助项目基金资助(编号:K98041
关于建筑模板工程施工技术的应用分析
社会的发展不仅带动了经济的发展,也使得科学技术在发展浪潮中不断进行着更新和完善,同时也促进了建筑行业水平的进一步发展和提升。其中,建筑模板工程施工技术在当前科学技术与经济形势快速发展的大背景下,也在不断地更新和完善,并且逐步运用到实际的建筑工程建设过程中,但由于诸多方面的原因,在应用过程中问题也随之产生。本文对在模板工程施工过程中出现的主要问题进行了分析,并在此基础上提出了对应的优化措施。</jats:p
BIM技术在装配式建筑结构施工中的应用
装配式建筑是建筑工程中的重要组成部分,凭借独特的优势广泛应用,大量材料、技术和工艺应用,促使装配式建筑结构施工愈加复杂。通过BIM技术的应用,可以整合工程信息,构建建筑信息模型,直观了解工程各个环节施工可行性,对于不合理之处可以及时优化改进,以便于打造高质量装配式建筑工程项目。本文就装配式建筑结构施工中BIM技术应用进行分析,明确BIM技术应用价值,提出合理措施更大范围推广和应用。</jats:p
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