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排序方式: 共有114条查询结果,搜索用时 999 毫秒
61.
Bourry D Sinnaeve D Gheysen K Fritzinger B Vandenborre G Van Damme EJ Wieruszeski JM Lippens G Ampe C Martins JC 《Magnetic resonance in chemistry : MRC》2011,49(1):9-15
We present the use of 1-mm room-temperature probe technology to perform intermolecular interaction studies using chemical shift perturbation methods and saturation transfer difference (STD) spectroscopy using small sample volumes. The use of a small sample volume (5-10 μl) allows for an alternative titration protocol where individual samples are prepared for each titration point, rather than the usual protocol used for a 5-mm probe setup where the ligand is added consecutively to the solution containing the protein or host of interest. This allows for considerable economy in the consumption and cost of the protein and ligand amounts required for interaction studies. For titration experiments, the use of the 1-mm setup consumes less than 10% of the ligand amount required using a 5-mm setup. This is especially significant when complex ligands that are only available in limited quantities, typically because they are obtained from natural sources or through elaborate synthesis efforts, need to be investigated. While the use of smaller volumes does increase the measuring time, we demonstrate that the use of commercial small volume probes allows the study of interactions that would otherwise be impossible to address by NMR. 相似文献
62.
63.
Jonas Van Damme Otto van den Berg Joost Brancart Guy Van Assche Filip Du Prez 《Tetrahedron》2019,75(7):912-920
A novel functional 2,6-substituted donor-acceptor anthracene derivative, bearing a long alkyl spacer and a polymerizable end-group, is synthesized from readily available compounds. This monomer possesses conjugated electron donor and acceptor moieties to achieve UV absorption and anthracene dimerization at higher wavelengths and under milder conditions, than anthracene and other reported anthracene derivatives. The compound was shown to absorb at higher wavelengths and dimerize much faster compared to most 9-substituted anthracenes. The fast photochemical and relatively slow thermal scission of the dimers were studied and related to the chemical structure, i.e. the 2,6-substitution. 相似文献
64.
The electric field-induced director reorientation is investigated by fluorescence spectroscopy and turbidimetry. The dynamics of this reorientation are studied as a function of temperature, applied voltage, and frequency. 相似文献
65.
MACCEPA,The mechanically adjustable compliance and controllable equilibrium position actuator: A 3DOF joint with two independent compliances 总被引:1,自引:0,他引:1
R. Van Ham M. Van Damme B. Verrelst B. Vanderborght D. Lefeber 《International Applied Mechanics》2007,43(4):467-474
The MACCEPA is a straightforward and easy to construct rotational actuator in which the compliance can be controlled separately
from the equilibrium position. A 3DOF joint with adaptable compliance is presented. The generated torque is a linear function
of the compliance and of the angle between the equilibrium position and actual position. This makes this actuator perfectly
suitable for dynamic walking, human-robotic interfaces, and robotic rehabilitation devices
Published in Prikladnaya Mekhanika, Vol. 43, No. 4, pp. 130–142, April 2007. 相似文献
66.
A new computer program has been designed to build and analyze quantitative-structure activity relationship (QSAR) models through regression analysis. The user is provided with a range of regression and validation techniques. The emphasis of the program lies mainly in the validation of QSAR models in chemical applications. ARTE-QSAR produces an easy interpretable output from which the user can conclude if the obtained model is suitable for prediction and analysis. 相似文献
67.
Fernand Pla Christian Fonteix Sandrine Hoppe Cornelius Schrauwen Hanno Van der Wal Freddy Van Damme 《Macromolecular Symposia》2007,259(1):53-64
Summary: This work deals with the development of a process for the radical copolymerization of acrylonitrile and styrene in a dispersed medium. This process was carried out in a continuous stirred tank reactor, in the presence of a stabilizing agent produced in situ during the polymerization. The continuous phase is a polyol. Besides all elementary chemical mechanisms related to the copolymerization and to the synthesis and grafting of the stabilizing agent, this process involves several complex physical phenomena. A tendency model of the whole process was developed, using the corresponding mass balances and thermodynamics. Its unknown parameters were identified by use of an evolutionary algorithm and experimental data resulting from an adapted experimental strategy. This model was then validated and allowed to predict monomers and transfer agent conversions, amounts of solids and average molar masses, versus the operating conditions. 相似文献
68.
69.
Kirchwehm Y Damme A Kupfer T Braunschweig H Krueger A 《Chemical communications (Cambridge, England)》2012,48(10):1502-1504
The synthesis of sterically crowded tribenzotriquinacenes with complete and partial methylation of the ortho-positions has been achieved using the double cyclodehydration strategy. This leads to a twisted tribenzotriquinacene core and enables further functionalization for the future synthesis of curved model compounds for defective carbon networks. 相似文献
70.
Hiller W Pasch H Macko T Hofmann M Ganz J Spraul M Braumann U Streck R Mason J Van Damme F 《Journal of magnetic resonance (San Diego, Calif. : 1997)》2006,183(2):290-302
The on-line coupling of gel permeation chromatography (GPC) and 1H NMR operating at temperatures up to 130 degrees C is presented. A NMR flow probe with a cell volume of 120 microL and a stop-flow valve are developed for on-flow and stop-flow NMR measurements at high temperatures. To maintain high and constant temperatures through the whole probe, the flow probe contains two separate heating circuits. A modified stop-flow valve is developed as a control device for enabling on-flow and stop-flow experiments at high temperature conditions. Heated transfer lines connect the flow probe with the high temperature GPC system. Due to their semicrystalline nature, polyolefins can be studied by liquid chromatography only at temperatures above 100 degrees C. The novel high temperature GPC-NMR system is used for the separation of complex polyolefins regarding their molar mass and for the analysis of different chemical structures. Blends of polyethylene, poly(methyl methacrylate), and ethylene-methyl methacrylate copolymers are separated according to the molar masses of the components. The compositions of the components are directly studied by on-line NMR. Moreover, the chemical composition distribution of an ethylene-methyl methacrylate copolymer sample is analysed. Differences between results of on-flow and stop-flow measurements are discussed. 相似文献