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金矿勘查中用于解释IP数据的某些准定时方法

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物探化探译丛 1997年第A2期 49-54页

作者： Eaton,pa 高平

臭氧与二乙胺和三乙胺气相反应的速率常数(英文)

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物理化学学报 2010年第7期26卷 1768-1772页

作者：盖艳波葛茂发王炜罡中国科学院化学研究所、分子动态与稳态结构国家重点实验室、北京分子科学国家实验室北京100190

利用自制的烟雾箱系统研究了臭氧与二乙胺和三乙胺的气相反应动力学.实验过程中保证二乙胺和三乙胺浓度远远大于臭氧浓度,使得实验在准一级条件下进行.加入环己烷以消除实验过程中可能产生的OH自由基对反应的影响.在(298±1)K和1.01×10... 详细信息

利用自制的烟雾箱系统研究了臭氧与二乙胺和三乙胺的气相反应动力学.实验过程中保证二乙胺和三乙胺浓度远远大于臭氧浓度,使得实验在准一级条件下进行.加入环己烷以消除实验过程中可能产生的OH自由基对反应的影响.在(298±1)K和1.01×105pa条件下,测得臭氧与二乙胺和三乙胺反应的绝对速率常数值分别为(1.33±0.15)×10-17和(8.20±1.01)×10-17cm3·molecule-1·s-1.与文献中已有的其它胺类的臭氧反应数据比较后发现,臭氧与胺的反应可以用亲电反应机制来解释.另外,通过对比发现,臭氧与三取代的烷基胺类的反应速率要远远大于其与二取代的烷基胺类的反应速率.这在一定程度上可有助于解释外场观测到的气溶胶相中二烷基胺盐较多的事实.利用测得的速率常数和大气中臭氧浓度,还估算了二乙胺和三乙胺与臭氧反应的大气寿命.结果显示,与臭氧的反应是二乙胺和三乙胺在大气中的一种重要的消除途径,尤其是在污染严重地区.

关键词：动力学臭氧二乙胺三乙胺速率常数

SYNTHESIS OF HYBRID MESOPOROUS POLYSTYRENE-SILICA MATERIALS WITH NON-SURfaCTANT CITRIC ACID AS TEMPLATE VIA SOL-GEL PROCESS

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Chinese Journal of Polymer Science 2002年第6期20卷 565-572页

作者： Jie Bai Jin-yu Zheng Kun-yuan Qiu Yen Wei Department of Polymer Science & Engineering College of Chemistry & Molecular Engineering, Peking University Beijing 100871, China Department of Chemistry, Drexel University, Philadelphia, pa 19104, USA Peking Univ Coll Chem & Mol Engn Dept Polymer Sci & Engn Beijing 100871 Peoples R China Drexel Univ Dept Chem Philadelphia PA 19104 USA

Hybrid mesoporous polystyrene-silica materials were successfully prepared through HCl-catalyzed sol-gel reactions of tetraethyl orthosilicate (TEOS) and triethoxysilyl-functionalized polystyrene obtained via atom transfer radical polymerization (ATRP) of styrene, in the presence of citric acid (CA) as non-surfactant template or pore-forming agent and followed by ethanol extraction to remove template molecules. The materials were characterized by infrared spectroscopy OR), N-2 adsorption-desorption measurements, powder X-ray diffraction (XRD), thermogravimetric analysis (TGA) and transmission electron microscopy (TEM). The results indicate that the materials prepared with 50 wt%-60 wt% template contents have average pore sizes of 2-3 nm and large surface areas (ca. 886 m(2)/g) as well as high pore volumes (ca. 0.53 cm(3)/g). The mesoporosity arises from interconnected channels and pores with disordered arrangements. The pore diameters and pore volumes increase as the template content is increased. The pore diameters show a little change upon heating at 200degreesC overnight. However, the materials do not have good hydrothermal stability.

关键词： atom transfer radical polymerization hybrid material mesoporous polystyrene silica

Studies on the role of microtubules in myofibrillogenesis

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Cell Research 1990年第2期1卷 119-129页

作者： LIN ZHONGXIANG AND HOWARD HOLTZERDepartment of Cell Biology, Beijing Institute for Cancer Research,Beijing, China.Department of Anatomy,School of Medicine,University ofPennsylvania, Philadelphia, pa, USA. Depactment of Anatomy School of Medicine University of Pennsylvania Philadelphia PA USA.

Co-localization of microtubule (MT) and muscle myosin (MHC) myofibril immunofluorescence in developing myotubes of chieken skeletal muscle eultures was observed by using double staining of tubulin and MHC indirect immunofluorescence. 12-o-tetradecanoyl-phorbol-13-acetate (Tpa) selectively and reversibly blocks myofibrillogenesis and alters the morphology of myotubes into myosacs where MTs are present in radiating pattern. when the arrested myogenic cells recover and start myofibrillogenesis after released from Tpa, prior to the emergence of myofibrils, the pre-existing MTs become bipolarly aligned coincidently with the tubular restoration of cell shape. Single nascent myofibrils overlapping with MTs extend into the base of growth tips where MTs go farther to the end of the tips. That MT might act as scaffold in guiding the bipolar elongation of the growing myofibrils was suggested. Taxol and colcemid disturbed MT polymerization and disposition, and interfered with the normal spatial assembly of myofibrils in developing myotubes.

关键词： Microtubules mycsin heavy chain (MHO) doubled indirect immunofluorescence myofibrillogenesis.

SYNTHESIS AND CHARACTERIZATION OF STRUCTURALLY WELL-DEFINED POLYMER-INORGANIC HYBRID NANOpaRTICLES VIA ATRP

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Chinese Journal of Polymer Science 2002年第3期20卷 261-267页

作者： Jie Bai Jie-bin pang Kun-yuan Qiu Yen Wei Department of Polymer Science & Engineering College of Chemistry & Molecular Engineering Peking University Beijing 100871, China Department of Chemistry Drexel University Philadelphia, pa 19104 USA Peking Univ Coll Chem & Mol Engn Dept Polymer Sci & Engn Beijing 100871 Peoples R China Drexel Univ Dept Chem Philadelphia PA 19104 USA

Atom transfer radical polymerization (ATRP) using cuprous chloride/2,2'-bipyridine (bipy) was applied to graft polymerization of styrene on the surface of silica nanoparticles to synthesize polymer-inorganic hybrid nanoparticles, 2-(4Chloromethylphenyl) ethyltriethoxysilane (CTES) was immobilized on the surface of silica nanoparticles through condensation reaction of the silanol groups on silica with triethoxysilane group of CTES. Then ATRP of St was initiated by this surface-modified silica nanoparticles bearing benzyl chloride groups, and formed PSt graft chains on the surface of silica nanoparticles. The thickness of the graft chains increased with reaction time. End group analysis confirmed the occurrence of ATRP. Thermal analysis indicated that thermal stabilization of these resulting hybrid nanoparticles also increases with polymerization conversion. The results above show that this 'grafting from' reaction could be used for the preparation of polymer-inorganic hybrid nanoparticles with controlled structure of the polymer's end groups.

关键词： atom transfer radical polymerization polymer-inorganic hybrid nanoparticles 2-(4-chloromethylphenyl)ethyltriethoxysilane surface-modification

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儿科癌症患者的真菌感染

国外医学（儿科学分册） 1991年第3期18卷 140-142页

作者： Pizzo pa Walsh TJ 沈志祥张慧英

目前,约50%以上癌症儿童可能存活,但细胞毒药物对机体防御功能影响,尤其是嗜中性粒细胞减少使癌症患者极易并发严重感染。随着有效的抗生素大量应用,细菌感染一般可以治愈。与之相反,真菌感染既难诊断又不易治疗,特别是深部真菌感染。... 详细信息

目前,约50%以上癌症儿童可能存活,但细胞毒药物对机体防御功能影响,尤其是嗜中性粒细胞减少使癌症患者极易并发严重感染。随着有效的抗生素大量应用,细菌感染一般可以治愈。与之相反,真菌感染既难诊断又不易治疗,特别是深部真菌感染。促发因素和成人患者一样,细胞毒药物引起的粒细胞缺乏症(<500/μl)是癌症儿童并发真菌感染的主要诱因,尤其是长期粒细胞缺乏。

关键词：肿瘤并发症真菌感染儿童

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拉丁美洲医学教育的变化、趋势与挑战

复旦教育论坛 2007年第4期5卷 89-92页

作者： pa Pulido 曾勇复旦大学上海医学院上海200032

泛美医学院校协会(pafaMS)董事pa Pulido等人撰文[Medical Teacher,2006,28(1):24-29]分析了拉丁美洲医学教育的多种影响因素,认为该地区的医学院校无计划地高速增长,质量得不到有效保障,卫生人力分布不合理。他们认为开展医学院校认证... 详细信息

泛美医学院校协会(pafaMS)董事pa Pulido等人撰文[Medical Teacher,2006,28(1):24-29]分析了拉丁美洲医学教育的多种影响因素,认为该地区的医学院校无计划地高速增长,质量得不到有效保障,卫生人力分布不合理。他们认为开展医学院校认证是解决上述问题的一条途径,并介绍了该地区医学院校认证的进展情况和趋势。

关键词：拉丁美洲医学教育挑战趋势认证

Roles of Cell Cycle Inhibitors in Stem Cell Regulation

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Roles of Cell Cycle Inhibitors in Stem Cell Regulation

ON THE INTEGRAL CURVATURE OF A CURVILINEAR POLYGON

第九届全国实验血液学会议

作者： Tao Cheng University of Pittsburgh Cancer Institute, Pittsburgh, pa 15213, USA

＜正＞ Therapeutic promises of adult stem cells from a variety of tissue types have gained strong experimentalsuppoft in the last few ***,hurdles remain for stem cell manipulation in vitro and tissueregeneration in vivo due to a limited understanding of their molecular *** regarding specificcell cycle control in stem and progenitor cell populations may provide one basis for designing rational stemcell manipulation *** my talk,I will describe the unique cell cycle kinetics of stem cells In vivo andex vivo,briefly introduce the current understanding of general cell cycle regulation in mammalian cells,and

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Science in China,Ser.A 1958年第1期 11-18页

作者：白正国 Fu-Tan University

*** a recent papert on the theory of a closed space curve,theauthor has obtained among others the following result:If a closedspace curve C has an angular point of an interior angle θ,then theintegral curvature of C is not less than π+θ,or in other words:ifdenotes the curvature of C,then∮（c）kds≥π+θ.At the end ofthe same paper we have proposed a more general problem:Whatwill be the lower bound of the integral curvature∮（v）kds if the closedspace curve C has n（n>1）angular points?In the present paper,itis shown that the answer there conjectured is *** a cur-vilinear polygon we mean,in what follows,a closed space curve witha finite nuraber of angular points.A theorem for a curvilinearpolygon in aa ordinary space is proved with its generalization in aEuclidean space of higher dimensions.

关键词： ON THE INTEGRAL CURVATURE OF A CURVILINEAR POLYGON 留人 length