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71.
72.
Md. Nur Alam Miro Antal Alvaro Tejado Theo G. M. van de Ven 《Cellulose (London, England)》2012,19(2):517-522
Chemical reactions in charged nanopores, such as present in cellulose fibers, can be accelerated by adding an inert salt,
that does not participate in the reaction. Due to a Donnan-like equilibrium between ions inside and outside the pores, the
concentration of co-ions in the nanopores (having a charge of the same sign as that of the pore wall), is lower than the concentration
in the bulk. The co-ion concentration in pores can be increased by adding an inert salt, which shifts the Donnan equilibrium.
The increased concentration of reactants in pores results in faster reaction kinetics. Reactions of cellulose with periodate
confirm these predictions. 相似文献
73.
This study has presented a performance investigation of an advanced tracked prime mover for the operation of agricultural goods and other operations on peat terrain. The maximum and continuous traction torque of the prime mover has been developed by designing an advanced controller for controlling the intelligent system. The prime mover’s mobility is studied with ultrasonic displacement sensor, torque transducer, National Instrument cRIO-9004 Compact-RIO Real-time Controller Unit (RCU), a National Instrument TPC 2106T Touch Panel Control (TPC), a Trimble AG132 GPS antenna and receiver unit, and a Dlink DIR-655 router. The fuzzy logic controller (FLC) has been equipped with the prime mover hydraulic system to increase the traction torque of the hydraulic motor when the prime mover’s sinkage is more than or equal to 70 mm. The prime mover’s design demonstrates good potential in traversing peat terrain as the measured tractive effort was found to be 48% of the vehicle’s gross weight while the recommended tractive effort is in the range of 30–36% of the vehicle’s gross weight. 相似文献
74.
Rehan Zahid Masjuki Bin Haji Hassan Mahendra Varman Riaz Ahmad Mufti Md. Abul Kalam Nurin Wahidah Binti Mohd Zulkifli 《固体与材料科学评论》2017,42(4):267-294
Tribological efficiency of industrial applications involving boundary lubrication regime can be improved to an appreciable extent by the deposition of hard coatings on interacting surfaces. Among such coatings, diamond-like carbon (DLC) coatings are considered to be one of the most suitable ones for the said role. DLC coatings possess a unique combination of physical, chemical, and material properties due to which they can help in minimizing friction-induced energy and material losses even under starved lubrication conditions. Since commercial lubricants are optimized for steel surfaces, therefore, a lot of experimental investigations were carried out to analyze the tribological compatibility of these lubricants with various DLC coatings. However, there is still a lack of understanding about how DLC coatings interact with conventional lubricant additives. Some researchers reported tribologically beneficial interactions between DLC coatings and formulated lubricants while others observed no such behavior. To address these inconsistencies, there is a need to rearrange the published data in a more apprehensible and organized manner with a special emphasis on the mechanisms responsible for a particular tribological behavior. In this way, it can be determined whether synergistic or antagonistic correlation exists between a particular DLC-lubricant combination and research on DLC coatings can be continued in a logical way. In this article, most widely investigated non-doped DLC coatings (ta-C, a-C:H, a-C, and ta-C:H) are tribologically analyzed. Average values of friction and wear coefficients are calculated for various DLC-lubricant combinations using already published data and compared to quantify the effectiveness of a particular lubricant additive in enhancing tribological characteristics of symmetrical non-doped DLC contacts. Moreover, tribological performance parameters of non-doped DLC coatings are compared with those of doped-DLC coatings to understand differences in their tribological behavior in combination with additives. 相似文献
75.
S. Fuller J. Hopwood A. Rahman N. Shinde G. J. Tiddy G. S. Attard 《Liquid crystals》2013,40(3):521-529
Abstract We have studied the lyotropic liquid-crystalline behaviour of cationic surfactants containing a potentially thermotropic moiety, a terminal cyanobiphenyloxy group. Both mono-alkyl and mid-chain substituted dialkyl surfactants have been examined using optical microscopy and NMR spectroscopy. Incorporation of the cyanobiphenyloxy group destabilizes the hexagonal and bicontinuous cubic phases, with only an extensive lamellar region being observed. For the dialkyl surfactant there is a range of compositions where two lamellar phases co-exist, one water-rich and the second surfactant-rich. 相似文献
76.
Dr. Matthieu Autillo Md. Ashraful Islam Julie Héron Laetitia Guérin Dr. Eleonor Acher Dr. Christelle Tamain Dr. Marie-Claire Illy Dr. Philippe Moisy Dr. Eric Colineau Dr. Jean-Christophe Griveau Dr. Claude Berthon Dr. Hélène Bolvin 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(24):7138-7153
Actinide +VI complexes ( = , and ) with dipicolinic acid derivatives were synthesized and characterized by powder XRD, SQUID magnetometry and NMR spectroscopy. In addition, and complexes were described by first principles CAS based and two-component spin-restricted DFT methods. The analysis of the 1H paramagnetic NMR chemical shifts for all protons of the ligands according to the X-rays structures shows that the Fermi contact contribution is negligible in agreement with spin density determined by unrestricted DFT. The magnetic susceptibility tensor is determined by combining SQUID, pNMR shifts and Evans’ method. The SO-RASPT2 results fit well the experimental magnetic susceptibility and pNMR chemical shifts. The role of the counterions in the solid phase is pointed out; their presence impacts the magnetic properties of the complex. The temperature dependence of the pNMR chemical shifts has a strong contribution, contrarily to Bleaney's theory for lanthanide complexes. The fitting of the temperature dependence of the pNMR chemical shifts and SQUID magnetic susceptibility by a two-Kramers-doublet model for the complex and a non-Kramers-doublet model for the complex allows for the experimental evaluation of energy gaps and magnetic moments of the paramagnetic center. 相似文献
77.
78.
Benzoyl peroxide has been used as a mild and efficient reagent for the preparation of benzoyl ester of oxime in moderate to good yields. 相似文献
79.
The reaction of different mercapto substituted heterocycles with o,o-dialkyl chlorphosphate or thiophosphates, gave the corresponding S- and N- alkylated derivatives instead of the expected phosphorylated products. 相似文献
80.
Dr. Teng Zhang Dr. Yuichi Kitagawa Ryoma Moriake Pedro Paulo Ferreira da Rosa Dr. Md. Jahidul Islam Dr. Tomoki Yoneda Prof. Yasuhide Inokuma Dr. Koji Fushimi Prof. Yasuchika Hasegawa 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(58):14438-14443
In this study, we have demonstrated a two-legged, upright molecular design method for monochromatic and bright red luminescent LnIII-silica nanomaterials. A novel EuIII-silica hybrid nanoparticle was developed by using a doubly binding TPPO−Si(OEt)3 (TPPO: triphenyl phosphine oxide) linker. The TPPO−Si(OEt)3 was confirmed by 1H, 31P, 29Si NMR spectroscopy and single-crystal X-ray analysis. Luminescent Eu(hfa)3 and Eu(tfc)3 moieties (hfa: hexafluoroacetylacetonate, tfc: 3-(trifluoromethylhydroxymethylene)camphorate) were fixed onto TPPO−Si(OEt)3-modified silica nanoparticles, producing Eu(hfa)3(TPPO−Si)2-SiO2 and Eu(tfc)3(TPPO−Si)2-SiO2, respectively. Eu(hfa)3(TPPO−Si)2−SiO2 exhibited the higher intrinsic luminescence quantum yield (93 %) and longer emission lifetime (0.98 ms), which is much larger than those of previously reported EuIII-based hybrid materials. Eu(tfc)3(TPPO−Si)2−SiO2 showed an extra-large intrinsic emission quantum yield (54 %), although the emission quantum yield for the precursor Eu(tfc)3(TPPO−Si(OEt)3)2 was found to be 39 %. These results confirmed that the TPPO−Si(OEt)3 linker is a promising candidate for development of EuIII-based luminescent materials. 相似文献