紫外光辐照引发接枝制备卤胺抗菌棉织物

以安息香双甲醚（DMPA）为光引发剂,通过紫外光辐照引发卤胺前驱体3-(4’-乙烯基苄基)-5,5-二甲基海因（VBDMH）在棉织物表面接枝,氯化后得到卤胺抗菌棉织物。探讨了VBDMH浓度、辐照时间、辐照距离对织物氯含量的影响,得到最佳整理工艺：VBDMH质量浓度为30 g/L,辐照距离为20 cm,辐照时间为30 min。红外光谱分析和扫描电镜形貌分析表明：VBDMH已经成功接枝到织物上。制备的抗菌棉织物在10 min内灭活对数值为6.62的金黄色葡萄球菌和6.55的大肠杆菌,且抗菌性能可再生。     

酸性鞘磷脂酶活化在微波辐照致神经细胞凋亡中的作用研究

为阐明微波辐照致神经细胞酸性鞘磷脂酶（Acid Sphingomyelinase，ASM）活化的规律，揭示ASM活化在微波辐照致神经细胞凋亡中的作用，以原代培养神经元细胞，采用30W／era2微波辐照10min，采用Hoechst33342荧光染色观察细胞凋亡，以ASM活性测定试剂盒测定ASM活性，RT-PCR、western blot分别检测ASM基因和蛋白表达的变化。用ASM活性抑制剂米帕明预处理，观察微波辐照后神经细胞凋亡情况。研究发现，微波辐照引起海马神经元细胞发生凋亡，神经元ASMmRNA和蛋白表达上调，ASM酶活性增高，给予ASM活性抑制剂米帕明预处理后，可部分拮抗微波辐照引起的神经细胞凋亡率增加。结果提示，微波辐照引起神经细胞ASM活化及表达上升，ASM活化在微波辐照所致的神经细胞凋亡中起重要作用。     

苎麻纤维预辐照二步接枝胺化提高染色性研究

通过电子束预辐照将丙烯酸（AA）接枝到苎麻纤维上形成苎麻-g（接枝）-AA,再用乙二胺（EDA）对苎麻-g-AA进行预辐照接枝胺化形成苎麻-g-AA-EDA,讨论了预辐照接枝率和胺化率与单体浓度的关系。在此基础上对改性苎麻纤维进行无盐染色实验,分析了AA接枝率和EDA胺化率对其上染率的影响。结果表明：苎麻纤维通过预辐照成功接上AA,并进一步接枝EDA实现了胺化,且AA的接枝率和EDA的胺化率随单体浓度的增加而增大,当吸收剂量为40 kGy、EDA浓度为35%时,AA接枝率为25%的苎麻-g-AA样品的EDA胺化率可达20.1%;接枝AA后的苎麻纤维上染率降低,且随AA接枝率的增大而减小,当AA接枝率为25.1%时,上染率低至4.2%;胺化后的苎麻-g-AA-EDA纤维上染率较未胺化的苎麻-g-AA纤维的上染率明显提高,上染率随胺化率的增加而增大,AA接枝率约为25%、胺化率为25%的改性苎麻纤维的上染率达49%。     

聚丙烯胺肟螯合纤维的辐射合成及其对Pb(Ⅱ)离子的吸附性能

采用预辐照接枝法,在空气或氮气气氛下利用电子束对聚丙烯纤维进行辐照。然后,将样品置于4种不同溶剂(水、甲醇、正丁醇、10％甲醇水溶液)的丙烯腈溶液体系中进行接枝反应,并通过与盐酸羟胺溶液反应,引入胺肟基团,获得一种机械性能较好的偕胺肟螯合纤维(PPAO)。最后浸于硝酸铅标准溶液中,测定其对铅的吸附量。结果表明,接枝率与预辐照气氛、反应温度、反应液体积、单体浓度都有密切关系。聚丙烯纤维在水溶液和10％甲醇水溶液中接枝率较高。当纤维在空气中预辐照,丙烯腈单体体积浓度为30％,温度为70℃时,聚丙烯纤维的接枝率最高;对Pb(Ⅱ)的吸附容量为0．362mg／g(纤维)。     

预辐照接枝丙烯酸与丙烯酰胺改性苎麻纤维及其吸附铜离子性能研究

将丙烯酸(AA)与丙烯酰胺(AM)通过预辐照接枝在苎麻纤维上,通过协同作用提高其接枝率,并研究了其对Cu2+的吸附性能。傅里叶红外光谱(FT-IR)对苎麻纤维表面分析结果显示,AA及AM成功接枝在苎麻纤维上,吸收剂量为35kGy时,接枝率可达151%(AA与AM浓度比为1∶1)。对Cu2+的吸附实验结果表明,接枝后的苎麻纤维在吸附反应初期,Cu2+吸附量迅速增加,20~30min增加速度变缓,30min后趋于饱和;随着温度升高,吸附量迅速增加,但温度高于40℃后,吸附量不再增加;吸附量随初始Cu2+浓度的增加而增大,在初始浓度为1 000mg/L的Cu2+溶液中,苎麻纤维的Cu2+吸附量可达14.40mg/g。     

加热去氩处理工艺对离子束混合沉积的C-SiC涂层阻氢性能的影响

利用Ar＋离子束混合技术在不锈钢基体上沉积C-SiC涂层，然后对部分样品进行加热去氩处理（400℃，30min），再用5keV氢离子源辐照样品。通过扫描电镜（SEM）的表面形貌观察、二次离子质谱仪（SIMS）的H与Ar元素深度分布和正离子质谱分析，研究去氩处理对氢离子辐照的C-SiC涂层的形貌和阻氢性能的影响。结果表明，经去氩处理，样品中不锈钢基体内的氢浓度降低了80%，显示出去氩处理的C-SiC涂层具有更高的阻氢性能。研究结果将为该技术应用于不锈钢基体上C-SiC涂层制备工艺的进一步改善提供依据。     

60Coγ射线预辐照制备淀粉-丙烯酰胺接枝物

采用预辐照的方法研究了淀粉与丙烯酰胺的接枝反应,制备出了淀粉与丙烯酰胺的接枝物;采用元素分析法测量了接枝率.对预辐照接枝反应的一些影响因素,如吸收剂量、反应温度、反应时间、阻聚剂及辐照后效应也进行了研究,并获得了相关结果.淀粉预辐照的吸收剂量约10kGy,辐照后10min内在2530C下进行接枝可以获得80%以上的接枝率.     

电子束辐照灭菌对南美白对虾性能的影响

电子束（Electron beam,EB）辐照灭菌是避免微生物污染影响食物品质的有效方法。为探究南美白对虾使用电子束灭菌后的性能变化，采用10 MeV电子加速器辐照加工系统对样品进行辐照（吸收剂量范围0～12 kGy），并对虾的蛋白质、脂肪和氨基酸含量，pH，挥发性盐基氮，质构特征，微生物学及感官满意度进行测试。结果表明：蛋白质、脂肪含量均在正常范围内。在最佳吸收剂量（6～8 kGy）时，表征虾新鲜度的挥发性盐基氮含量较低，大部分氨基酸含量达峰值，咀嚼性、内聚性等质构特征明显提升，未检出微生物菌落，颜色和口感更好。这表明EB辐照灭菌是一种有效的食品微生物控制手段，在不降低冷冻南美白对虾营养成分等性能的情况下，使其口感更为新鲜。     

超高分子量聚乙烯纤维预辐照接枝丙烯酸甲酯

采用预辐照接枝的方法研究了丙烯酸甲酯（MA）单体在超高分子量聚乙烯（UHMWPE）纤维表面的接枝聚合反应。考察了吸收剂量、单体浓度、接枝聚合反应温度对接枝率的影响。结果表明：UHMWPE纤维接枝MA的接枝率较高,最高可达约151％,接枝率随吸收剂量、单体浓度、反应温度升’高而增加。用红外光谱法分析了接枝前后纤维官能团的变化,通过扫描电镜观察了接枝前后纤维表面的形貌。     

辐射接枝制备聚丙烯纤维基海水提铀吸附剂

采用电子束预辐射接枝法将丙烯腈和丙烯酸接枝于聚丙烯(Polypropylene,PP)纤维上,并探讨了吸收剂量和反应温度对接枝率的影响。随后通过偕胺肟化反应制备出含偕胺肟基和羧基的PP纤维吸附剂。红外光谱数据表明,丙烯腈和丙烯酸成功接枝到PP纤维上,偕胺肟化反应将腈基转化为偕胺肟基,同时对改性前后PP纤维的表面形貌和热性能进行了表征。厦门海域真实海水吸附性能测试结果表明,所制备的PP纤维吸附剂铀吸附容量最高可达到0.81 mg·g~(-1)(吸附时间为68 d),PP纤维吸附剂的铀吸附容量与其接枝率和偕胺肟基密度不呈正相关。     

Cleaning of nitrogen-containing carbon contamination by atmospheric pressure plasma jet

Atmospheric pressure plasma jet (APPJ) was used to clean nitrogen-containing carbon films (C–N) fabricated by plasma-assisted chemical vapor deposition method employing the plasma surface interaction linear device at Sichuan University (SCU-PSI). The properties of the contaminated films on the surface of pristine and He-plasma pre-irradiated tungsten matrix, such as morphology, crystalline structure, element composition and chemical structure were characterized by scanning electron microscopy, grazing incidence x-ray diffraction and x-ray photoelectron spectroscopy. The experimental results revealed that the removal of C–N film with a thickness of tens of microns can be realized through APPJ cleaning regardless of the morphology of the substrates. Similar removal rates of 16.82 and 13.78 μm min−1 were obtained for C–N films deposited on a smooth pristine W surface and rough fuzz-covered W surface, respectively. This is a remarkable improvement in comparison to the traditional cleaning method. However, slight surface oxidation was found after APPJ cleaning, but the degree of oxidation was acceptable with an oxidation depth increase of only 3.15 nm. Optical emission spectroscopy analysis and mass spectrometry analysis showed that C–N contamination was mainly removed through chemical reaction with reactive oxygen species during APPJ treatment using air as the working gas. These results make APPJ cleaning a potentially effective method for the rapid removal of C–N films from the wall surfaces of fusion devices.     

高能电子束辐射对碳纤维表面结构的影响

利用激光拉曼光谱（Raman Spectroscopy）、X射线光电子能谱（XPS）、原子力显微镜（AFM）和X射线衍射（XRD）对高能电子束辐射前后的表面结构进行分析，结果表明，随着剂量的增加，碳纤维表面石墨微晶尺寸增大。碳原子在高能电子束的作用下离位，使表面棱角超于圆滑，当剂量较大时，处于石墨片层边缘的活性碳原子重新增多。碳纤维表面极性官能团受辐射介质产生的活性种的影响，同时在高能电子束辐射下激活，发生自淬灭反应和解离反应，前者占优势时，高价态的C＝O增多，反之，C－O基团增多。在试验范围内，高能电子束对碳纤维的晶型结构无影响。     

Syntheses of amine-type adsorbents with emulsion graft polymerization of glycidyl methacrylate

Glycidyl methacrylate (GMA) which was precursor monomer for the synthesis of metal ion adsorbent was emulsified by surfactant of Tween 20 (Tw-20). The emulsion of 5% GMA in the water was stable for 48 h at Tw-20 concentration of 0.5%. Graft polymerization of GMA on polyethylene fiber was carried out in the emulsion state at various pre-irradiation doses. Degree of grafting (Dg) reached 103%, 301% and 348% for 1 h grafting at 40 °C with pre-irradiation of 10, 30 and 40 kGy, respectively. But the Dg was depressed when the pre-irradiation dose was over 50 kGy since cross-linking occurred simultaneously in the trunk polymer. Dg decreased with increment of Tw-20 concentration in emulsion of 5% GMA at pre-irradiation of 40 kGy. The three kinds of amine-type adsorbents were synthesized by reacting diethylenetriamine (DETA), triethylenetetramine (TETA) and ethylenediamine (EDA) with GMA-grafted polyethylene fiber. The synthesized EDA-type adsorbent had the highest selectivity against U ion and the distribution coefficient was 2.0 × 10⁶.     

Radiation-induced grafting of N-isopropylacrylamide and acrylic acid onto polypropylene films by two step method

Binary graft copolymerization of pH sensitive acrylic acid (AAc) and thermosensitive N-isopropylacrylamide (NIPAAm) monomers onto pre-irradiated polypropylene films (PP) was carried out by two individual steps using a Co⁶⁰ gamma radiation source. The influence of preparation conditions, such as pre-irradiation dose and reaction time on grafting yield was studied. The swelling behavior and FTIR-ATR study for PP films grafted films were investigated.     

辐照接枝改性涤纶织物的亲水性能

利用电子束辐照接枝的方法将丙烯酸(Acrylic acid,AA)单体接枝到涤纶织物上来改善其亲水性。通过改变吸收剂量、接枝单体浓度、阻聚剂浓度、预辐照的吸收剂量以及前处理氢氧化钠浓度等影响因素来获得具有不同接枝率的改性涤纶织物。优化的反应条件:吸收剂量为195 k Gy、AA浓度为50%、阻聚剂(Fe SO4?7H2O)浓度为0.8%、预辐照的吸收剂量为43 k Gy、前处理Na OH浓度为15 g/L。傅里叶红外光谱证明AA已接枝成功;扫描电子显微镜分析表明改性涤纶织物的表面具有覆盖物,且随着接枝率的增大,其覆盖物明显增多;回潮率测试结果表明,改性涤纶的回潮率随接枝率的增加而逐渐增大,当接枝率达到最大值27.84%时,改性涤纶的回潮率可达3.51%。涤纶织物经30次洗涤后减重率仅1%左右,说明接枝牢度优异。     

圆环形截面碳化硅纤维管的辐射化学法合成

为制备碳化硅(Silicon carbide,SiC)纤维管,本研究利用10MeV电子直线加速器产生的高能电子束在空气中辐照聚碳硅烷(Polycarbosilane,PCS)先驱丝。研究了辐照工艺、热处理温度、吸收剂量对制备SiC纤维管的影响,并运用红外光谱分析对SiC纤维管的辐射制备机理作了初步探讨。结果表明,合适的辐照工艺为每次定点辐照20s,停车冷却5min;最佳热处理温度为350℃;红外光谱分析表明,空气中的氧通过与PCS中的Si-H、Si-CH3反应而被引入到辐照产物中,形成了Si-OH和C=O结构;在经热处理的先驱丝中有Si-O-Si,Si-C-Si等桥联结构生成;吸收剂量介于2.0-3.5MGy之间的PCS先驱丝均能制得SiC纤维管,且管壁厚度随着吸收剂量的增加而逐渐增加。     

Improvement of carbon fiber surface properties using electron beam irradiation

Carbon fiber-reinforced advance composites have been used for structural applications,mainly on account of their mechanical properties.The main factor for a good mechanical performance of carbon fiber-reinforced com- posite is the interfacial interaction between its components,which are carbon fiber and polymeric matrix.The aim of this study is to improve the surface properties of the carbon fiber using ionizing radiation from an electron beam to obtain better adhesion properties in the resultant composite.EB radiation was applied on the carbon fiber itself before preparing test specimens for the mechanical tests.Experimental results showed that EB irradiation improved the ten- sile strength of carbon fiber samples.The maximum value in tensile strength was reached using doses of about 250 kGy.After breakage,the morphology aspect of the tensile specimens prepared with irradiated and non-irradiated car- bon fibers were evaluated.SEM micrographs showed modifications on the carbon fiber surface.     

预辐照对铍在EDM-1中冲刷腐蚀的影响

本文通过构建旋转式冲刷腐蚀实验装置来研究中子和γ预辐照对铍在EDM-1(1号电火花加工油)中冲刷腐蚀的影响。用天平测量铍试样质量变化,用扫描电子显微镜观察其微观形貌,用X射线光电子能谱仪分析表面成分。实验结果表明,在腐蚀前期以腐蚀介质与铍表面发生化学反应生成腐蚀产物为主,在腐蚀后期以腐蚀介质对铍的机械冲刷腐蚀为主;EDM-1中的硫元素在腐蚀过程中转变成氧化物SOx和SO2,分别以化学和物理吸附分布在腐蚀产物表面和内部;对比相同腐蚀条件下受不同预辐照铍试样的腐蚀程度,受单独γ预辐照的铍试样的腐蚀程度最大,受中子和γ共同预辐照的铍试样的次之,未经预辐照的铍试样的腐蚀程度最轻,表明预辐照促进了铍在EDM-1中的腐蚀。     

Localised modifications of anatase TiO2 thin films by a Focused Ion Beam

A Focused Ion Beam (FIB) has been used to implant micrometer-sized areas of polycrystalline anatase TiO₂ thin films with Ga⁺ ions using fluencies from 10¹⁵ to 10¹⁷ ions/cm². The evolution of the surface morphology was studied by scanning electron microscopy (SEM) and atomic force microscopy (AFM). In addition, the chemical modifications of the surface were followed by X-ray photoelectron spectroscopy (XPS). The implanted areas show a noticeable change in surface morphology as compared to the as-deposited surface. The surface loses its grainy morphology to gradually become a smooth surface with a RMS roughness of less than 1 nm for the highest ion fluence used. The surface recession or depth of the irradiated area increases with ion fluence, but the rate with which the depth increases changes at around 5 × 10¹⁶ ions/cm². Comparison with implantation of a pre-irradiated surface indicates that the initial surface morphology may have a large effect on the surface recession rate. Detailed analysis of the XPS spectra shows that the oxidation state of Ti and O apparently does not change, whereas the implanted gallium exists in an oxidation state related to Ga₂O₃.     

Recovery of fused silica surface damage resistance by ion beam etching

An increase of photoluminescence induced by laser irradiation in vacuum was observed for the fused silica. The degradation of transmittance and damage resistance performance of fused silica surfaces may be due to substoichiometric silica and a sufficient defect population introduced in the near surface. When the laser-irradiated surface layers were removed by ion beam etching, the laser-induced damage threshold recovered to that of un-irradiated samples. The photoluminescence also decreased after ion beam etching. According to the calculated etching depth, the laser-induced defects formed in the surface layer of 10-20 nm when different parameters used during vacuum exposure. In addition, the evolution of surface root-mean-square microroughness as a function of ion beam etching time was studied by the optical interferometric technique and atomic force microscopy.