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41.
m‐Xylylene bismaleimide, Compimide ? ? Compimide® is a registered trademark.
MXBI (hereafter MXBI), was developed as a building block for formulating bismaleimide resins with improved processability. MXBI on its own, or in combination with 4,4′‐bismaleimidodiphenylmethane (Compimide MDAB, hereafter MDAB) and with 2,2′‐diallylbisphenol‐A as a co‐monomer, provides very low‐melting resin blends, which can be processed at temperatures around 60–80°C via RTM (Resin Transfer Moulding), VARIM (Vacuum Assisted Resin Infusion Moulding), prepregging, and wet filament winding (FW). Uncured and cured resin properties were evaluated. The mechanical property spectrum of the MXBI/MDAB/diallylbisphenol‐A system with varying MXBI/MDAB ratio shows almost equivalent contributions of MXBI and MDAB to the mechanical properties of a system. Higher MXBI proportions are responsible for lower resin viscosities and hence superior processability. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
MXBI (hereafter MXBI), was developed as a building block for formulating bismaleimide resins with improved processability. MXBI on its own, or in combination with 4,4′‐bismaleimidodiphenylmethane (Compimide MDAB, hereafter MDAB) and with 2,2′‐diallylbisphenol‐A as a co‐monomer, provides very low‐melting resin blends, which can be processed at temperatures around 60–80°C via RTM (Resin Transfer Moulding), VARIM (Vacuum Assisted Resin Infusion Moulding), prepregging, and wet filament winding (FW). Uncured and cured resin properties were evaluated. The mechanical property spectrum of the MXBI/MDAB/diallylbisphenol‐A system with varying MXBI/MDAB ratio shows almost equivalent contributions of MXBI and MDAB to the mechanical properties of a system. Higher MXBI proportions are responsible for lower resin viscosities and hence superior processability. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
42.
Tauseef Ahmad Rangreez Mu Naushad Hamid Ali 《International journal of environmental analytical chemistry》2015,95(6):556-568
In this study, poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) zirconium(IV) monothiophosphate composite cation exchanger was prepared by sol–gel precipitation method. The presence of sulphur in the cation exchanger enhances affinity towards the heavy metal ions which can improve the selectivity of the material. The selectivity studies showed that the material is selective towards Pb(II) ions. To characterise the material, several physicochemical properties were also studied which includes X-ray, scanning electron microscopy and transmission electron microscopy studies. The ion-exchange behaviour of this cation exchanger was studied by using some of the selected properties like ion-exhange capacity for various metal ions, elution, effect of eluent concentration, thermal effect on ion-exchange capacity (IEC). The results of IEC and physicochemical properties revealed that the material is nanocomposite, crystalline, chemically, mechanically and thermally stable. The analytical ability of this cation exchanger was demonstrated in binary separation of Pb(II) ions from a mixture of other metal ions. The recovery is qualitative and the separations are reproducible. 相似文献
43.
文章合成了Lu(NO3)3(C2H5O2N)4.H2O,用红外和元素分析对其进行了表征。用高精度全自动绝热量热仪,测定了该配合物80-382 K温区的热容, 利用实验热容数据, 根据热容与焓、熵的热力学关系, 求出了配合物85-350 K温区内每隔5 K相对于298.15K的标准热力学函数(HT - H298.15)m和(ST - S298.15)m.在80-350 K温度区间内,配合物的热容随温度升高而增大,没有相转移点和热力学吸收峰的出现,该配合物在此温度区间内是稳定存在的。 相似文献
44.
Locked by Design: A Conformationally Constrained Transglutaminase Tag Enables Efficient Site‐Specific Conjugation 下载免费PDF全文
Dr. Vanessa Siegmund Dr. Stefan Schmelz Stephan Dickgiesser Jan Beck Aileen Ebenig Heiko Fittler Dr. Holm Frauendorf Dr. Birgit Piater Dr. Ulrich A. K. Betz Dr. Olga Avrutina Dr. Andrea Scrima Prof. Dr. Hans‐Lothar Fuchsbauer Prof. Dr. Harald Kolmar 《Angewandte Chemie (International ed. in English)》2015,54(45):13420-13424
Based on the crystal structure of a natural protein substrate for microbial transglutaminase, an enzyme that catalyzes protein crosslinking, a recognition motif for site‐specific conjugation was rationally designed. Conformationally locked by an intramolecular disulfide bond, this structural mimic of a native conjugation site ensured efficient conjugation of a reporter cargo to the therapeutic monoclonal antibody cetuximab without erosion of its binding properties. 相似文献
45.
The heat capacity of levoglucosan was measured over the temperature range (5 to 370) K by adiabatic calorimetry. The temperatures and enthalpies of a solid-phase transition and fusion for the compound were found by DSC. The obtained results allowed us to calculate thermodynamic properties of crystalline levoglucosan in the temperature range (0 to 384) K. The enthalpy of sublimation for the low-temperature crystal phase was found from the temperature-dependent saturated vapor pressures determined by the Knudsen effusion method. The thermodynamic properties of gaseous levoglucosan were calculated by methods of statistical thermodynamics using the molecular parameters from quantum chemical calculations. The enthalpy of formation of the crystalline compound was found from the experiments in a combustion calorimeter. The gas-phase enthalpy of formation was also obtained at the G4 level of theory. The thermodynamic analysis of equilibria of levoglucosan formation from cellulose, starch, and glucose was conducted. 相似文献
46.
47.
Several conflicting reports have suggested that the thermodynamic properties of materials change with respect to particle size. To investigate this, we have measured the constant pressure heat capacities of three 7 nm TiO2 rutile samples containing varying amounts of surface-adsorbed water using a combination of adiabatic and semi-adiabatic calorimetric methods. These samples have a high degree of chemical, phase, and size purity determined by rigorous characterization. Molar heat capacities were measured from T = (0.5 to 320) K, and data were fitted to a sum of theoretical functions in the low temperature (T < 15 K) range, orthogonal polynomials in the mid temperature range (10 > T/K > 75), and a combination of Debye and Einstein functions in the high temperature range (T > 35 K). These fits were used to generate , , , and values at selected temperatures between (0.5 and 300) K for all samples. Standard molar entropies at T = 298.15 K were calculated to be (62.066, 59.422, and 58.035) J · K−1 · mol−1 all with a standard uncertainty of 0.002· for samples TiO2·0.361H2O, TiO2·0.296H2O, and TiO2·0.244H2O, respectively. These and other thermodynamic values were then corrected for water content to yield bare nano-TiO2 thermodynamic properties at T = 298.15 K, and we show that the resultant thermodynamic properties of anhydrous TiO2 rutile nanoparticles equal those of bulk TiO2 rutile within experimental uncertainty. Thus we show quantitatively that the difference in thermodynamic properties between bulk and nano-TiO2 must be attributed to surface adsorbed water. 相似文献
48.
Heat capacities and phase-transition properties for xanthone (IUPAC name 9H-xanthen-9-one and Chemical Abstracts registry number [90-47-1]) are reported for the temperature range 5 < T/K < 524. Statistical calculations were performed and thermodynamic properties for the ideal gas were derived based on molecular geometry optimization and vibrational frequencies calculated at the B3LYP/6-31+G(d,p) level of theory. These results are combined with sublimation pressures from the literature to allow critical evaluation of inconsistent enthalpies of sublimation for xanthone, also reported in the literature. Literature values for the enthalpy of combustion of xanthone are re-assessed, a revision is recommended for one result, and a new value for the enthalpy of formation of the ideal gas is derived. Comparisons with thermophysical properties reported in the literature are made for all other reported and derived properties, where possible. 相似文献
49.
A thorough understanding of amino acid adsorption by mineral and oxide surfaces has a major impact on a variety of industrial and biomedical applications. Little information currently exists regarding temperature effects on most of these adsorption processes. Deeper thermodynamic analyses of their multiple temperature adsorption isotherms would aid the interpretation of the interfacial interactions. Low solution concentration adsorption isotherms for glycine, lysine and glutamic acid on a silica adsorbent were generated for T = (291, 298 and 310) K. Data analysis via the Clausius–Clapeyron method yielded the isosteric heat of adsorption as a function of fractional monolayer coverage for each adsorptive. Each amino acid showed an exothermic adsorption response. Glycine and lysine experienced a greater negative effect of increased temperature compared with glutamic acid, indicating a greater number of adsorbed molecules than glutamic acid, with the former undergoing intermolecular clustering within the adsorbed phase. Isosteric heat analyses suggest ionic interactions for lysine and hydrogen bonding for glutamic acid, both weakening with increased coverage. In contrast, initial hydrogen bonding led to ionic bonding for glycine with increasing coverage. 相似文献
50.
Genetic diversity and haplotype structure of 21 Y‐STRs,including nine noncore loci,in South Tunisian Population: Forensic relevance 下载免费PDF全文
Faten Makki‐Rmida Arwa Kammoun Nadia Mahfoudh Adnene Ayadi Abdullah Ahmed Gibriel Bakhta Mallek Leila Maalej Zouheir Hammami Samir Maatoug Hafedh Makni Saber Masmoudi 《Electrophoresis》2015,36(23):2908-2913
Y chromosome STRs (Y‐STRs) are being used frequently in forensic laboratories. Previous studies of Y‐STR polymorphisms in different groups of the Tunisian population identified low levels of diversity and discrimination capacity (DC) using various commercial marker sets. This definitely limits the use of such systems for Y‐STRs genotyping in Tunisia. In our investigation on South Tunisia, 200 unrelated males were typed for the 12 conventional Y‐STRs included in the PowerPlex® Y System. Additional set of nine noncore Y‐STRs including DYS446, DYS456, DYS458, DYS388, DYS444, DYS445, DYS449, DYS710, and DYS464 markers were genotyped and evaluated for their potential in improving DC. Allele frequency, gene diversity, haplotype diversity (HD), and DC calculation revealed that DYS464 was the most diverse marker followed by DYS710 and DYS449 markers. The standard panel of 12 Y‐STRs (DC = 80.5%) and the nine markers were combined to obtain DC of 99%. Among the 198 different haplotypes observed, 196 haplotypes were unique (HD = 99.999). Out of the nine noncore set, six Y‐STRs (DYS458, DYS456, DYS449, DYS710, DYS444, and DYS464) had the greatest impact on enhancing DC. Our data provided putative Y‐STRs combination to be used for genetic and forensic applications. 相似文献