Room temperature deformable shape memory composite with fine‐tuned crystallization induced via nanoclay particles

It is known that particular types of semi‐crystalline/elastomer polymer blends exhibit shape memory effects (SME) due to the dispersion of two immiscible phases. In this study, the crystal structure of polylactic acid (PLA)/ thermoplastic polyurethane (TPU) based shape memory polymer (SMP) is altered by incorporating small amounts of montmorillonite (MMT) nanoclay. The results indicate the incorporation of MMT can improve the compatibility of the two different polymers. Moreover, the presence of MMT affects the total crystallinity of the SMP and improves mechanical properties. Lastly, uniaxial stretching deformation can be applied to the SMP at room temperature conditions while maintaining its shape memory properties. With 1 wt % MMT particles, the recovery ratio (Rr) was nearly 95%, which indicated a strong recovery effect. The shape‐fixing ratio (Rf) remained above 95% for all composites due to plastic deformation applied at room temperature. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2017 , 55, 1197–1206     

用硝基磺酚S分光光度法测定蛋白质

1引言用光度法测定蛋白质以其重视性好、灵敏度高而在临床检验和生化实验中得到应用。实验表明,硝基磺酚S在酸性条件下可与蛋白质作用生成蓝色复合物。此方法用于实际人血清样品中蛋白质的测定,结果准确,回收率高,方法简便。2实验方法向钻niL比色管中依次加入2．SInL硝基磺酚s简写回二jlnLEritto。hb＿（R刚缓冲液、6InL无水乙醇及一定体积的牛血清白蛋白（BSA）标准溶液,用去离子水稀释至刻度,摇匀。以相应试剂空白为参比,用Icrn比色M于685run波长处测定溶液的吸光度。3结果与讨论3．互吸收光谱pH3．l时硝基磺酚S的最大吸收…     

7A04铝合金产品黑斑原因分析

利用金相显微镜、扫描电镜和能谱仪,分析了7A04铝合金产品产生黑斑的原因.结果表明,化合物偏析和局部腐蚀是引起7A04铝合金产品产生黑斑的原因.     

带喷头混合型毛细管色谱柱的制备及其在蛋白质组分离分析中的应用

本研究制备了一种应用于液-质联用（LC-MS）系统中的带喷头混合型毛细管色谱柱．用标准蛋白和酵母蛋白胰蛋白酶酶切溶液考察了其在LC—MS中的离子化效率、毛细管色谱柱分离性能和寿命,并与直接填充型毛细管色谱柱的色谱性能进行比较,未见显著性差异．将制备的带喷头混合型毛细管色谱柱应用于鼠肝蛋白组的分析,在假阳性率为1％的条件下鉴定到1262个肽段,归属于513个蛋白簇．通过对鉴定蛋白质理化性能的统计分析,其等电点和分子量分布高于一般两维凝胶电泳的范围．实验结果还表明该混合型毛细管色谱柱在肽段的理化性能上没有偏性,可以广泛应用于蛋白质组学的研究中．     

Structural Revision of Isovalertatins D03 and D23 Isolated from the Culture Filtrate of Streptomyces luteogriseus

In a program of sequentially investigating the chemical constituents of the complex, WC670, extracted from the culture filtrate of Streptomyces luteogriseus, we found it contains the reported aminooligosaccharides, yiwutadings B-F. But, when verifying their structures, there were several inconsistencies against the corresponding ESI ion trap multistage mass spectra. Our previous paper1 reported the structural revision of yiwutadings F, D and C, and these monomers were re-designated as isov…     

Modular synthesis of a block copolymer with a cleavable linkage via click chemistry

A diblock copolymer poly(ethylene glycol)-block-polystyrene or PEG-b-PS with an olefinic double bond at the PEG and PS junction has been prepared by modular synthesis viaclickchemistry.This involved the synthesis of PS by atom transfer radical polymerization and the nucleophilic substitution of the terminal bromide group with azide to yield azide-terminated PS. PEG with an alkynyl terminal group was prepared from reacting carboxyl-end-functionalized PEG with 4-hydroxybut-2-enyl prop-2-ynyl succinate,which c...     

A new dammarane-type triterpene saponin from Gynostemma pentaphyllum

<正>One new dammarane-type triterpene saponin,named(20S)-3β,20,21-trihydroxydammar-24-ene 3-O-[α-L-rhamnopyranosyl- (1→2)][β-D-xylopyranosyl(1→3)]-β-D-glucopyranoside(1),was isolated from the aerial parts of Gynostemma pentaphyllum (Thunb.) Makino.Its structural elucidation was accomplished mainly on the basis of the interrelation of spectroscopic methods, such as IR,HR-TOF-MS,NMR.     

Iridoid glucosides from Allamanda neriifolia

<正>A new iridoid glucoside,allamanoid(1),was isolated from the aerial parts of Allamanda neriifolia,together with three known glucosides,plumieride,protoplumericin,and nicotiflorin.Their structures were elucidated by 1D and 2D spectroscopic analyses, hydrolysis,and comparison with literature data.     

Three new compounds from the leaves of Acanthopanax senticosus Harms

<正>Three new compounds named(2E)-prenyl benzoate-4-O-α-L-arabinopyranosyl(1→6)β-D-glucopyranoside(1),7-methoxy-8- O-β-D-glucopyranosyl coumarin(2),and 3,4'-dihydroxy-3'-methoxy benzenepentanoic acid(3) were isolated from the leaves of Acanthopanax senticosus Harms.The structures of new compounds were determined by means of 2D NMR experiments and chemical methods.