Corner Foam Versus Flat Foam: An Experimental Comparison on Cushion Performance

Most cushion structures used in the industry are end caps, edge or corner foam. The bearing area and thickness of the cushioning obtained from cushion curves apply, in principle only, to flat foam because the specimens used to develop the cushion curves are flat foam samples. This study is aimed at finding the difference between the two foams in stress–strain relationship and dynamic impact. A hysteresis cycle compression test, in conjunction with digital image correlation techniques, and a shock cushion test were performed to assess the static stress and strain, energy dissipated and maximum acceleration of flat and corner foams. The study found that the static stress of the corner foam that occurred during the compression testing is 23% higher in average than the flat foam, depending on the compression speed. The shock cushion curve of the corner foam showed a similar pattern as the flat cushion curve but was shifted horizontally to the right as a result of the increased static stress. This study recommends that the conventional cushion curve should be shifted to the right horizontally by about 23–35% in order for a packaging designer to apply it for corner foam. Copyright © 2014 John Wiley & Sons, Ltd.     

扇贝异源四倍体诱导后代的细胞遗传学研究

采用50mg/L 6-二甲氨基嘌呤(6-DMAP)处理15min抑制栉孔扇贝(Chlamys farreri♀)×虾夷扇贝(Patinopecten yessoensis♂)异源受精卵第一极体的释放诱导扇贝异源四倍体.采用基因组荧光原位杂交技术(GISH)结合染色体滴片技术对扇贝异源四倍体诱导后代的染色体遗传构成进行研究,对授精后17～66h内6个时间段各300多个分裂相进行统计分析.结果表明,诱导异源四倍体过程中产生了多种倍性的幼虫,包括5.192%的四倍体、16.577%的三倍体以及单倍体、二倍体、五倍体和大量的非整倍体.在17～66h内同一组染色体数,所占比率并未出现随着取样时间的变化而发生明显上升或下降的趋势.在染色体构成上,诱导后代都分别继承了双亲的染色体,除正常杂交产生的异源二倍体外均为非对称性继承.GISH鉴定结果表明本实验所诱导的四倍体为真正的异源四倍体,同时也说明两套异源染色体具有较强的亲和性.在诱导后代中还出现了较小比例的染色体不完全继承个体.对产生这些现象的可能原因进行了探讨.     

双酚A分子印迹微球的制备及其识别性能

以乙酸为溶剂,预组织沉淀聚合制备了双酚A分子印迹聚合物(BPA-MIPs)微球。所制备MIPs微球的比表面积为552m2/g,采用双位点结合模型拟合,特异性位点的结合位点数为0.45mmol/g;结合常数为364L/mmol,相对于双酚F(BPF)、对叔丁基苯酚(TBP)、对苯二酚(HQ)、间苯二酚(RSO)和苯酚,MIPs微球对双酚A(BPA)的选择性因子分别为3.22、14.70、500、333和62.50,在低浓度下MIPs微球对BPA的结合速度快,可用双位点Lagergren一级动力学方程描述。     

加强项目资金监管 统筹城乡经济发展——对完善城乡建设用地增减挂钩工作的思考

虽然城乡建设用地增减挂钩工作为＂双保＂工作开辟了新思路,但是也暴露出一些问题,其矛盾的焦点主要集中在资金上。本文在深入分析挂钩工作中涉及资金事项存在系列问题的基础上,提出了解决的具体对策,为完善挂钩试点工作提供参考。     

四种热带水果中膳食纤维的结构表征及单糖组成和理化性质分析

以菠萝蜜、洋蒲桃、莽吉柿、番荔枝为原料,采用化学结合酶法对其膳食纤维进行制备,并利用扫描电镜、红外光谱和化学分析等方法对制备的上述膳食纤维的结构表征、单糖组成和理化性质进行研究.结果表明:番荔枝中膳食纤维的含量较高,达(74.31±0.07)g/100 g;纤维素、半纤维素、木质素在四种热带水果的膳食纤维中含量存在明显...     

Site Selective Spectroscopy of Surfactant-Assembled Y_2O_3∶Eu Nanotubes

Nanometermaterialshaveattractedagreatdealofattentioninthelastdecadebecauseoftheirgreatpo tentialfornanotechnologicalapplicationsandforun derstandingsomefundamentalconceptsabouttherolesofdimensionalityandsizein ,forexample ,optical ,electrical ,andmechanicalproperties[1,2 ] .Differentshapes ,suchasparticles ,films ,wires ,andtubes ,havebeenfabricatedwithvarioustechniques[3～ 6 ] .Inparticular ,thenanotubesusuallypresentnovelproper tiesassociatingwiththeirsmalldimensions ,highanisotropy ,andintr…     

Infrared-to-Visible Frequency up-Conversion in Trivalent Erbium Ions Doped Fluoride Glasses （ZnF2-AlF3-PbF2-LiF）

High-efficiency frequency up-conversion in trivalent erbium ion doped new fluoride glass matrix (ZnF2-A1F3-PbF2-LiF) was investigated. Under 950 nm laser-diode excitation, the glasses gave very intense green, weak red and violet emissions. The up-conversion mechanism is discussed. In addition, the infrared transmittance spectrum, the Raman spectrum and the lifetime of the trivalent erbium states in the samples were measured. The results illustrate the large potential of these new glasses for photonic applications.     

空间限制法制备纳米沸石的研究进展

综述了空间限制法在制备纳米沸石方面的应用,主要介绍了微乳法与反胶束法的机理及其在合成纳米沸石方面的应用,以及惰性介质空间限制法与水凝胶制约法在小晶粒沸石合成方面的研究现状。采用这些方法合成的纳米沸石粒径较小,且分布均匀,大小可调。另外还归纳了这3类空间限制法在纳米沸石合成中的共同特点,比较了其优缺点,并对其应用前景进行了展望。     

三唑-香兰素Schiff碱配合物合成及活化CO_2性能的研究

合成两种新型三唑－香兰素Ｓｃｈｉｆ碱和四种金属配合物。通过元素分析、红外光谱、电导率、电子光谱等手段对所合成的化合物进行结构表征，认为该配合物为２１（ＬＭ）型的单核配合物，配位环境为金属离子四配位，分别与两个配体酚羟基中的氧和两个氯配位。将其六种化合物作催化剂，催化ＣＯ２与环氧乙烷生成碳酸乙烯酯的反应。结果表明，六种催化剂均对该反应有较高的催化活性，选择性单一，配合物催化活性高于配体。初步探讨了该类反应的机理。