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81.
82.
Injection-molded β-isotactic polypropylene (β-iPP) was prepared with a commercial β-nucleating agent (NT-A). The effect of NT-A on the crystallization, mechanical properties, and heat resistance of β-iPP was investigated by differential scanning calorimetry (DSC), wide-angle X-ray diffraction (WAXD), polarized light microscopy (PLM), and mechanical and heat deflection tests. DSC and WAXD analysis showed that the content of β-crystals in the nucleated iPP was higher than that of pure iPP, and the content of β-crystals of the core was higher than that of the skin. PLM observations showed that injection-molded iPP had an obvious skin-core structure. NT-A induced abundant β-crystals and resulted in small spherulites which improved the Izod notched impact strength. When the content of NT-A was 0.075wt%, the Izod notched impact strength reached a maximum, 2.6 times more than that of pure iPP. The heat distortion temperature was also improved by NT-A. 相似文献
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Six new coordination complexes, Ln2(2,2′-oba)2(phen)2(ox)(H2O)2 (Ln = Eu 1, Tb 2), Ln4(2,2′-oba)6(phen)2 (Ln = Eu 3, Tb 4), Eu4(2,2′-oba)6(phen)2(H2O) (5), and K[Eu(2,2′-oba)2(phen)2] (6) [2,2′-H2oba = 2,2′-oxybis(benzoic acid), phen = 1,10-phenanthroline, H2ox = oxalic acid] were synthesized by hydrothermal reactions with the same compound molar ratios but different modulatory reagents (MRs). Complexes 1–5 have different 1-D chain structures and 6 shows a mononuclear structure. These complexes form diverse 3-D supramolecular networks through hydrogen bonds. The interaction between these complexes and hippuric acid (HA) or bovine serum albumin (BSA) was investigated by fluorescence spectral analysis. Interestingly, the hippuric acid could quench the luminescence of these complexes while the fluorescence of BSA could be quenched by these complexes. Results suggested that the complexes may be potential luminescent testing reagents for HA or BSA by significant fluorescence quenching of Ln3+ or BSA, respectively, through a static and dynamic quenching process. 相似文献
86.
B←N coordination bond can be used to develop polymer electron acceptors for efficient all-polymer solar cells(all-PSCs). Here, we report a new alternating conjugated polymer containing two building blocks based on B←N unit. The polymer exhibits strong light absorption in the visible range, low-lying LUMO/HOMO energy levels and moderate electron mobility. The resulting all-PSC devices exhibit power conversion efficiencies of 1.50%–2.47%. 相似文献
87.
用有限元自适网格控制结构应力分析的精度 总被引:1,自引:0,他引:1
本文涉及有限元结构应务分析精度控制的三个基本方面:1)自适应的有限元网格自动生成技术;2)有限元应力分析的误差估计:3)用单元尺寸场将误差分布用于形成新网格。 相似文献
88.
无标记DNA在氨基改性导电聚吡咯表面的固定/杂交 总被引:1,自引:0,他引:1
通过吡咯(Py)与其衍生物——6-吡咯己胺(PyHA)的共聚物聚(吡咯-co-6-吡咯己胺)[poly(Py-co-PyHA)]的合成研究,并采用电化学循环伏安法来考察体系的电化学活性.在缓冲溶液中,由于探针DNA链上的负电荷与共聚物分子链上的正电荷之间存在强烈的静电吸引力,使得DNA能够固定在导电聚合物膜上.实验结果证明,目标DNA和聚吡咯薄膜之间不存在非特异性吸附,而能和探针DNA进行顺利杂交.此结果为以后研究更为敏感的DNA固定及导电聚合物敏感膜提供了实验基础. 相似文献
89.
Guanglin Xia Dr. Xuebin Yu Prof. Yanhui Guo Zhu Wu Prof. Chuanzhen Yang Prof. Huangkun Liu Prof. Shixue Dou Prof. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(12):3763-3769
The monoammoniate of lithium amidoborane, Li(NH3)NH2BH3, was synthesized by treatment of LiNH2BH3 with ammonia at room temperature. This compound exists in the amorphous state at room temperature, but at ?20 °C crystallizes in the orthorhombic space group Pbca with lattice parameters of a=9.711(4), b=8.7027(5), c=7.1999(1) Å, and V=608.51 Å3. The thermal decomposition behavior of this compound under argon and under ammonia was investigated. Through a series of experiments we have demonstrated that Li(NH3)NH2BH3 is able to absorb/desorb ammonia reversibly at room temperature. In the temperature range of 40–70 °C, this compound showed favorable dehydrogenation characteristics. Specifically, under ammonia this material was able to release 3.0 equiv hydrogen (11.18 wt %) rapidly at 60 °C, which represents a significant advantage over LiNH2BH3. It has been found that the formation of the coordination bond between ammonia and Li+ in LiNH2BH3 plays a crucial role in promoting the combination of hydridic B? H bonds and protic N? H bonds, leading to dehydrogenation at low temperature. 相似文献
90.
Boronate affinity solid phase microextraction (BA-SPME) is a new format appeared recently with great potential for specific extraction of cis-diol-containing compounds. Unlike conventional SPME, BA-SPME relies on covalent interactions and thereby features with specific selectivity, eliminated matrix effect and manipulable capture/release. However, only on-fiber BA-SPME and its off-line combination with high performance liquid chromatography (HPLC) have been reported so far. In this study, we report on-line coupling of in-tube BA-SPME with HPLC-electrospray ionization tandem mass spectroscopy (in-tube BA-SPME-HPLC-ESI-MS/MS) for the specific and sensitive determination of cis-diol-containing biomolecules. A boronate affinity extraction phase was prepared onto the inner surface of the capillary by copolymerization of vinylphenylboronic acid (VPBA) and ethylene glycol dimethacrylate (EDMA). The extraction conditions were optimized by choosing appropriate extraction/desorption solutions and extraction time. The extraction capacity, linear range, reproducibility and life-time were investigated. The developed method was successfully applied for the determination of dopamine in urine samples. Since many cis-diol-containing compounds are of great biological importance, the in-tube BA-SPME-HPLC method can be a promising tool. 相似文献