HDPE膜电子束引发预辐照接枝甲基丙烯酸缩水甘油酯的研究

用电子束引发预辐照接枝的方法，在高密度聚乙烯（High density polyethylene，HDPE）薄膜上接枝甲基丙烯酸缩水甘油酯（Glycidyl methacrylate，GMA），制备了含有高活性环氧基团的聚合物膜。详细研究了单体浓度、反应温度和时间以及吸收剂量等因素对接枝率的影响规律。应用傅立叶变换红外光谱（FT-IR）、差示扫描量热仪（DSC）、原子力显微镜（AFM）研究了接枝物的组成、热性能和表面形貌。FT-IR测试表明接枝物为HDPE-g-GMA共聚物；接枝膜的熔融温度Tm以及修正后HDPE组分△Hf（HDPE）均随着接枝率的增大而降低，原因归结于HDPE接枝后结晶度降低。HDPE-g-GMA膜的AFM图像显示其表面粗糙度增加，进一步证明膜表面发生了接枝反应。     

预辐射接枝法制备FEP-g-PSSA/AA膜

采用γ射线预辐射接枝方法制备了FEP—g—PSSA／AA膜，反应制得的接枝膜是一种含氟磺酸型质子交换膜。系统研究了影响接枝反应的阻聚剂用量、膜的厚度、单体摩尔比及总摩尔浓度变化等因素。结果表明，丙烯酸（Acrylic acid，AA）与苯乙烯磺酸钠（Sodium styrene sulfonate，SSS）对全氟乙丙烯（Polytetranuoroethyleneco-hexanuoropropylene，FEP）的接枝率几乎不受膜厚度变化的影响，而且全氟乙丙烯（FEP）辐照后放置三个月再进行接枝反应，接枝率也几乎没有变化。     

预辐射聚丙烯膜接枝甲基丙烯酸聚乙二醇酯及其性能研究

采用预辐射接枝法对预辐射的聚丙烯（ＰＰ）膜接枝不同分子量的甲基丙烯酸聚乙二醇酯（ＰＥＧＭＡ）。分别研究了不同接枝溶液体系对接枝率的影响;通过全反射傅里叶红外光谱（ＦＴＩＲ－ＡＲＴ）和水接触角等的测定,观察了接枝前后ＰＰ膜表面性能的变化;还接枝前后ＰＰ膜绎血液蛋白吸附、血小弧的吸附以及样品表面血栓量等,以比较接枝前后样品的血液相容性。     

聚乙烯辐照接枝体系改变pH对接枝率的影响

采用γ射线辐照引发接枝的方法，在高密度聚乙烯（HDPE）上接枝丙烯酸（AA）和对接枝苯乙烯磺酸钠（SSS），制备了一种含羧酸基团和磺酸基团的阳离子交换膜，详细研究了反应体系在不同pH值下的接枝率变化规律。实验表明，在共辐照接枝方法中，当AA与SSS一步法接枝HDPE或接枝上AA的HDPE膜再共辐照接枝SSS时，总接枝率（Gt）及对苯乙烯磺酸钠的接枝率（Gs）随体系的pH的降低而升高，在预辐照一步法接枝中，Gt与Gs随体系pH的降低先升高后又有所降低，综合分析认为，改变pH值使体系粘度发生变化，从而影响了单体向基体的扩散速率。     

聚醚砜微孔膜电子辐照接枝改性及过滤性能研究

利用电子束辐照技术对聚醚砜（PES）微孔膜进行接枝丙烯酸（AA）改性。用称重法测量接枝率,分析辐照剂量及气氛对膜接枝率的影响规律,用红外光谱分析膜接枝后官能团的变化,用扫描电镜观察样品的表面形貌;并分析了接枝率对水通量及牛血清白蛋白（BSA）溶液通量的影响。研究结果表明,对浓度为1mol/L的单体丙烯酸,在氮气或空气的氛围下辐照,接枝率随辐照剂量的增加先增大而后降低,并在整个辐照剂量范围内,氮气氛围下辐照的接枝率均高于空气氛围的接枝率。当接枝率较小时,水通量及BSA溶液通量均随接枝率的增大而增大,并当接枝率为11%时,二者同时达到最大值,随着接枝率的进一步增大,其值反而降低。     

PVA膜共辐射接枝改性的初步研究

研究了温度敏感性聚合物聚Ｎ－异丙基丙烯酰胺在ＰＶＡ膜上的共辐射接枝反应，及吸收剂量，剂量率，单体浓度，无机酸及Ｃｕ＾２＋浓度妆枝率的影响，同时测定了接枝膜的溶胀性能。结果表明ＰＶＡ膜接枝后溶胀比增加且具有温度敏感性。     

热敏智能径迹膜的研制

以N－异丙基丙烯酰胺热酶材料为单体，核径迹微孔膜为基材，用过氧化预辐照接枝技术研制出能控制开关的热敏智能径迹膜，考察了预辐照剂量，接枝温度，单体浓度和反应时间时间等因素对接枝的影响，以及膜孔开闭动态变化。亚微米级孔径上极薄的热敏接枝层，溶胀与收缩迅速，对温度开关响应更为灵魂。     

聚四氟乙烯膜辐射接枝反应条件的研究

采用了共辐射接枝技术，在室温下将苯乙烯接枝到聚四氟乙烯薄膜上，合成了辐射接枝膜。研究了溶剂种类、单体浓度、辐射剂量以及剂量率等因素对接枝反应的影响。结果表明，单体浓度和辐射剂量率是反应的主要影响因素，两者对接枝反应速率的影响指数分别为1．2和0．4。     

聚醚砜接枝聚乙烯基吡咯烷酮超滤膜的制备及其抗污染性能

采用均相共辐照方法,将聚乙烯基吡咯烷酮(PVP)接枝到聚醚砜(PES)的分子链上,制备改性的制膜材料(PES-g-PVP),并采用非溶剂致相转换法制备PES滤膜以及PES-g-PVP改性滤膜。研究了单体浓度和吸收剂量等因素对改性膜材料接枝率的影响。结果表明,当单体浓度低于12%、吸收剂量低于35 kGy时,提高单体浓度和吸收剂量,均能有效提升产物的接枝率。傅里叶红外光谱图证实了接枝反应的有效进行。扫描电子显微镜照片发现,不同于PES超滤膜的"指状孔",PES-g-PVP膜呈现一种"海绵状孔"型的断面结构。相比PES超滤膜,接枝率为8.42%的PES-g-PVP超滤膜的接触角下降12.1%,说明改性后膜材料的亲水性得到有效提高;同时,其对牛血清白蛋白的截留率保持在90%以上,且膜的纯水通量提高了4.9倍,说明接枝后膜材料的抗污染性能得到有效提升。     

磺酸型阳离子交换膜的性能研究

通过辐照接枝法在高密度聚乙烯(HDPE)上引入磺酸基团,从而制备了一种强酸性阳离子交换膜。就所制备离子交换膜的热稳定及化学稳定性能进行了详细考察。结果表明,接枝膜上引入磺酸基团后抗氧化性能较仅含羧酸基团的离子交换膜有所提高,接枝膜的热稳定性较之接枝前稍差,热重分析表明,接枝后样品的成碳量较接枝前有相当大的提高,原因归结于表面接枝层对成碳过程有促进作用。由于接枝膜中HDPE组份的“结晶破坏”及接枝链对晶区的“稀释作用”综合影响,结晶度随着接枝率的升高而降低。     

利用辐射接枝化学共价法固定酶的研究

文章叙述了利用辐射接枝技术,缩合共价法,使葡萄糖氧化酶固定在聚乙烯、氟46膜上。并用红外光谱法证明葡萄糖氧化酶固定在聚乙烯膜上是有效的。实验结果发现,对于氟46膜,共价率、接枝率、膜蛋白含量和膜酶活力间的相互关系,剂量率低,共价率低时,显示出单位膜酶活力较大。当共价率在4.3%时,单位膜酶活力达到最大值,实验也说明了丙烯酸会影响酶的保留活力。对于聚乙烯酶膜,证明红外光谱法表征是一种简便、有效的方法。     

铀铌合金真空热氧化膜的俄歇电子能谱研究

用俄歇电子能谱(AES)研究了高真空下，环境温度对铀铌合金真空氧化膜的影响。当温度高于603K时，氧化膜表面结构发生明显改变，表面主要由铀碳化合物、金属态的U和Nb组成。利用Ar^ 溅射铀铌合金真空热氧化膜进行深度分布分析，发现在热氧化膜的表面氧含量很小，而在热氧化膜的内部有氧增多的现象。     

对接焊缝检验中60Co源替代192Ir源的可行性试验

本文描述了大亚湾核电站稳压器上封头与筒全对接环焊缝线检验中存在的问题及产生的原因，对可能的解决方法进行了分析和评价，认为使用６０Ｃｏ源替代１９２Ｉｒ源是合理的解决透照时间和底片黑度问题的办法。通过实验室和稳压器实体上的对比试验，证明了方法的可行性。同时对增感屏，冲片条件等因素对底片质量和照相灵敏度的影响做出了定量的评价。     

The effect of crystal textures on the anodic oxidization of zirconium in a boiling nitric acid solution

The effects of crystal textures and the potentials in the anodic oxidation of zirconium in a boiling nitric acid solution were investigated to study the stress corrosion cracking of zirconium in nitric acid solutions. The test specimen was machined such that the specimen surface was parallel to the rolling surface, arranged with a (0002) crystal texture. The potentials applied for the anodic oxidation of zirconium were set at 1.2, 1.4, and 1.5 V against a saturated KCl–Ag/AgCl electrode (SSE) in boiling 6 M HNO₃. The growth of the zirconium oxide film dramatically changed depending on the applied potential at a closed depassivation potential (1.47 V vs. SSE in this study). At 1.5 V, the zirconium oxide film rapidly grows, and its growth exhibits cyclic oxidation kinetics in accordance with a nearly cubic rate law. The zirconium oxide film grows according to the quantity of electric charge and the growth rate does not depend on the crystal texture in the pretransition region before the cyclic oxidation kinetics. However, the growth and cracking under the thick oxide film depend on the crystal texture in the transition region. On the normal direction side, the oxide film thickness decreases on average since some areas of the thick oxide film are separated from the specimen surface owing to the cracks in the thick oxide. On the rolling direction (RD) side, no cracks in the thick oxide film are observed, but cracks are found under the thick oxide film, which deeply propagate in metal matrix along the RD without an external stress. The cracks under the thick oxide film propagate to the center of the oxide layer. The crystal orientation relationship between the oxide layer and the zirconium matrix is (0002)_Zr//(111)_ZrO2, and the cracks in the oxide layer propagate in the (0002)_Zr plane in the zirconium matrix. The oxide layer consists of string-like zirconium oxide and zirconium hydride. The string-like zirconium oxide contains orthorhombic ZrO₂ in addition to monoclinic ZrO₂. It is not well known why the cracks propagate along the (0002)_Zr plane under the thick oxide film. As one assumption for the mechanism of crack initiation and propagation without an external stress, it is considered that the oxidizing zirconium hydrides precipitated in the (0002)_Zr plane near the interface of the thick oxide film and the matrix. Then, the phase transformation from orthorhombic ZrO₂ to monoclinic ZrO₂ in the oxide layer causes the crack propagation in the (0002) plane.     

Annealing behavior of ultrathin Mo layer located at interface or on surface of Ti－Si system

Annealing behavior,at different annealing temperatures,of an ultrathin Mo layer located between a Ti film and Si substrate or deposited on the top of surface of a Ti film was investigated by Rutherford backscattering spectrometry(RBS), cross-sectional transmission electron microscopy(TEM) and energy dispersive X-ray spectrometry(EDS),In a Ti/Mo/Si structure,partially reacted film with layer structure of Ti-rich silicide/TiSi2/(Mo,Ti) Si2 on a Si substrate was formed after 550℃ annealing for 30min.The ratio of Mo to Ti in(Mo,Ti)Si2 layer decreases from near Si substrate upwards and becomes zero at about 20nm away.In a Mo/Ti/Si structure, The surface Mo layer enhances the Si diffusion from the substrate during annealing.Mo bearing Ti rich silicide exists on the surface until 600℃ and then converts to (Mo,Ti )Si2 after 650℃ annealing,and the atomic ratio of Mo to Ti decreases from the top surface into Ti silicide film,and becomes zero at about 30nm away from the surface.In both cases of interface Mo and surface Mo layer,thd atomic ratio of Mo to Ti in the region of (Mo,Ti)Si2 was found to be very low,with an average value of less than 0.2.Low content of Mo in Mo containing ternary silicide leads easily to the formation of the stable phase of C54(Mo,Ti)Si2,which acts as a template for the formation of C54 TiSi2 beneath when Mo is deposited on the surface.     

Research on corona discharge suppression of high-voltage direct-current transmission lines based on dielectric-film-covered conductor

Corona discharge suppression for high-voltage direct-current(HVDC) transmission lines at line terminals such as converter stations is a subject that requires attention. In this paper, a method based on a conductor covered with dielectric film is proposed and implemented through a bench-scale setup. Compared with the bare conductor, the corona discharge suppression effect of the dielectricfilm-covered conductor under positive polarity is studied from the composite field strength and ion current density using a line-plate experimental device. The influences of film thickness and film material on the corona discharge suppression effect are investigated. The charge accumulation and dissipation characteristics of different film materials are also studied. The results show that the conductor covered with dielectric film has excellent ability to inhibit corona discharge. The groundlevel composite field strength of the conductor covered with dielectric film is lower than its nominal field strength, and its ion current density is at the n A m~(-2) level. The corona threshold voltage can be promoted by increasing the film thickness, but the ability to inhibit corona discharge becomes weak.The larger the surface electric field strength, the more charge accumulated, but the faster the charge dissipation rate. Compared with polyvinyl chloride film, cross-linked polyethylene film has stronger charge accumulation ability and slower charge dissipation rate, which can better restrain the corona discharge of HVDC transmission lines.     

ZnO(In)闪烁体在α粒子辐照下的发光特性

采用241Am-α源研究了ZnO(In)样品(购自美国Cermet Inc.公司)的发光和表面光输出特性、α粒子能谱响应和单脉冲时间响应,同时对EJ212、BC418、ST401、CeF3等闪烁体进行了比较测量。实验发现,ZnO(In)样品在α粒子轰击下,两表面的光输出相差3～5倍,显示出表面不同的光学性质。测试结果表明,ZnO(In)晶体对α粒子的能谱响应波形光滑,发光效率仅次于有机闪烁体,对单粒子脉冲时间响应快,是超快脉冲射线束探测较理想的闪烁元件。     

金属铀在氢氧化钠溶液中阳极氧化膜的XPS特性研究

采用X射线光电子能谱法（XPS）研究了金属铀在0．8mol/L NaOH溶液中阳极氧化膜的组成。结果表明，在本实验条件下，金属铀表面的阳极氧化膜主要由UO3和少量UO2 x组成；在超真空条件下，氧化膜中的部分 UO3逐渐还原成UO2 x。     

NF-86、NF-87与FWT-60三种辐射变色染料尼龙薄膜剂量计性能的比较研究

NF-86和NF-87两种剂量计均是以尼龙为基质材料,分别以六羟乙基付品红氰化物和付品红氰化物为辐射变色染料的薄膜剂量计。本文给出这两种剂量计与国外同类产品——美国远西公司的FWT-60辐射变色尼龙薄膜剂量计主要剂量学性能比较研究的结果。结果表明NF-86、NF-87剂量计的性能已接近和达到美国FWT-60剂量计的水平,能够为国内辐射加工中γ剂量测量(10~3—10~5Gy)提供一种简便快速而又可靠的监测手段。     

用弹性反冲分析法测定吸附剂中氢的含量

本文介绍用弹性反冲分析技术分析了对二甲苯吸附剂中的氢含量。首先测定已知氢含量的Mylar膜的原子比,实验结果与预期值一致。实验中用Kapton膜作为标样,测定了各种工艺条件的吸附剂中的氢含量,为实际使用提供了依据。 本方法在E_0=2MeV下,可探测深度范围为0.5μm左右,深度分辨率约为700A,灵敏度为0.1％原子数。