Competitive removal of Pb2+, Cd2+, and Zn2+ by poly(acrylamide‐co‐maleic acid) hydrogels/differential pulse polarographic determination

Poly(acrylamide‐co‐maleic acid) [P(AAm/MA)] hydrogels, with various compositions, were prepared from ternary mixtures of acrylamide (AAm)/maleic acid (MA)/water by using ⁶⁰Co γ‐rays. The effect of composition of these hydrogels, on the competitive removal of Pb²⁺, Cd²⁺, and Zn²⁺ ions from aqueous solution, was investigated. The hydrogel compositions and their adsorption behaviors were determined by use of differential pulse polarography, a very sensitive electroanalytical technique. It was observed that the external stimuli of pH, temperature, and ionic strength have an important role on the adsorption. The increments of MA content in P(AAm/MA) hydrogels caused a significant increase in the adsorption these ions. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 2401–2406, 2004     

南京地区固定式安装太阳能电池板最佳倾角设计

对于固定安装的光伏电池板,其倾角的选择直接影响到所接收到的太阳辐射量,从而决定着太阳能利用系统的性能。本文在获得南京地区辐射资料的基础上,采用太阳辐射量气象学模型,针对任意方位角固定式安装的光伏电池板给出了最佳倾角的计算结果。该结果可为南京地区太阳能系统的设计与安装提供理论依据,并为相近地区太阳辐射量计算提供参考。     

Raman spectra of virgin and damaged graphite edge planes

First-order Raman spectra of virgin and ion irradiated highly oriented pyrolytic graphite were performed along the basal and edge planes. Ion irradiation was performed in the low fluence regime (≈ 10¹²–10¹³ ions cm⁻²) using a 400 keV Ar⁺ beam in order to a introduce controlled amount of defects in the structure. Virgin edge Raman spectra reveal the presence of a 1351 cm⁻¹ structure (D^*) shifted 10 cm⁻¹ away from the disorder induced D-line found upon irradiating or grinding the graphite surface.The 1351 cm⁻¹ D^* structure is then considered as the feature coming from the rupture of the D_6h⁴ space group symmetry. A comparison between D^* and the classical 1360 cm⁻¹ D-line is discussed in terms of induced disorder.     

基于RecurDyn的旋转弹发射出筒过程动力学仿真

针对某旋转弹筒弹分离试验时出现尾翼座与筒壁刮擦的问题,用Recur Dyn对弹体出筒过程进行动力学仿真.对筒弹分离试验进行故障复现,分析故障原因;根据故障分析结论对筒弹设计方案提出更改建议并再次仿真;第二次试验结果表明该分析结论和仿真结果正确.此外,还给出设计方案更改后正常发动机推力状况下的弹体出筒过程的重要总体仿真结果.该研究缩短产品设计周期、降低研制成本.     

Effect of alkali and ultraviolet (UV) radiation pretreatment on physical and mechanical properties of 1,6‐hexanediol diacrylate–grafted jute yarn by UV radiation

To improve the physicomechanical properties of jute yarn, grafting with 1,6‐hexanediol diacrylate (HDDA) monomer was performed by a UV radiation technique. A series of HDDA solutions of various concentrations in methanol were prepared. A small quantity of photoinitiator (Darocur‐1664) was also added to HDDA solutions. To optimize the conditions for grafting, the effects of monomer concentration, soaking time, and radiation doses were studied by varying the number of soaking times along with variation of monomer concentrations and UV radiation intensities. The extent of polymer loading and the mechanical properties like tensile strength (TS), elongation at break (Eb), and tensile modulus of both treated and untreated jute were investigated. The highest tensile strength, polymer loading, and modulus were achieved with 5% HDDA concentration, 5 min soaking time, and the 4th pass of UV radiation. This set of conditions was selected as optimum and produced enhanced tensile strength (67%), modulus (108%), and polymer loading (11%) over those of virgin fiber. To further improve the mechanical properties the jute yarns were pretreated with alkali (5% NaOH) solution and after that the alkali‐treated yarn were treated under UV radiation of various intensities. The pretreated samples were grafted with optimized monomer concentration (5% HDDA). Increased properties of alkali + UV‐pretreated and grafted samples such as polymer loading (12%), tensile strength (103%), elongation at break (46%), and modulus (114%) were achieved over those of virgin jute yarn. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 18–24, 2004     

吸收剂量对二甲基硅橡胶与甲基乙烯基硅橡胶分子量和凝胶含量的影响

将ＧＰＣ和特性粘数［η］测定相结合，在室温和－７８℃下，用Ｃｏ~（６０）辐射源辐照，研究了二甲基硅橡胶（ＭＱ，吸收剂量２．０５×１０~３～３．９７×１０~４Ｇｙ）和甲基乙烯基硅橡胶（ＭＶＱ，吸收剂量１０~２～１０~４）分子量和凝胶含量的变化。结果表明，辐照ＭＶＱ较辐照ＭＱ易生成凝胶，在凝胶点前的较低吸收剂量时，溶胶的分子量出现极大值，分子量分布曲线呈单峰；随吸收剂量的增加，分子量分布变窄，分子量降低；出现凝胶的吸收剂量，ＭＱ大约是ＭＶＱ的１０倍。辐照ＭＱ时，凝胶点前的溶胶的分子量分布曲线为双峰，并随吸收剂量的增加，双峰消失，分子量下降；在凝胶点时，分子量出现极大值。     

柔软热收缩材料的研制

总结了经共混和辐射交联制备柔软耐老化的热收缩材料的研制过程。测得了不同乙丙橡胶含量和不同辐照剂量下的共混物的力学性能和凝胶含量，确定了共混物辐射交联的合适剂量。此外，还测试了ＥＰＤＭ和ＰＥ共混物经辐照后的耐油性能。在此基础上，制得了手感柔软的热收缩管材。     

无机纳米材料的改性及其在纺织工业中的应用

选用硬脂酸和钛酸丁酯对纳米级ZnO，TiO2和无机抗菌粉体进行表面处理，使硬脂酸和钛酸丁酯包覆于粉体表面，不但解决了粉体的团聚问题，而且将粉体的表面由极性变为非极性，能很好地与纤维表面相结合。加入这类粉体生产的织物，经测试达到了较好的抗菌和抗紫外线的要求。     

核工业专用橡胶型可剥掩蔽涂料的研制和应用

介绍了核电、核能工业专用橡胶型可剥掩蔽涂料的研制和应用,选用新型含有苯基的聚丁二烯弹性体为基料,加入耐酸、耐辐照的颜填料和防黏剂、偶联剂及N-13a固化剂配成JF系列常温固化的核电、核能工业专用橡胶型可剥掩蔽涂料,该涂料耐酸碱、耐辐照,防污性能优良。     

Radiation-induced copolymerization of trioxane with tetrahydrofuran

Radiation-initiated copolymerization of solid trioxane (TOX) with tetrahydrofuran (THF) was investigated. The effects of radiation dose, THF concentration, and post-polymerization temperature and duration on copolymer yield and THF incorporation were studied. These results are compared with the results of TOX homopolymerization under identical conditions. Copolymer yield was lower than that of homopolymer. Only a fraction of charged THF entered into the polymer chain. THF content and radiation dose also altered the MW of the copolymer but it showed better thermal stability. The initial reaction rates of the copolymerization were determined and from these the activation energy was found to be 36.2 kcal mol^?1.