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81.
82.
Louhivuori M Otten R Lindorff-Larsen K Annila A 《Journal of the American Chemical Society》2006,128(13):4371-4376
The discovery of dilute liquid crystalline media to align biological macromolecules has opened many new possibilities to study protein and nucleic acid structures by NMR spectroscopy. We inspect the basic alignment phenomenon for an ensemble of protein conformations to deduce relative contributions of each member to the residual dipolar coupling signals. We find that molecular fluctuations can affect the alignment and discover a resulting emphasis of certain conformations. However, the internal fluctuations are largely uncorrelated with those of the alignment, implying that proteins have liquidlike molecular surfaces. Furthermore, we consider the implications of a dynamic bias to structure determination using data from the weak alignment method. 相似文献
83.
J Harra J M?kitalo R Siikanen M Virkki G Genty T Kobayashi M Kauranen JM M?kel? 《Journal of nanoparticle research》2012,14(6):870
Aerosol techniques were used to synthesize spherical and monodisperse silver nanoparticles for plasmonic materials. The particles were generated with an evaporation-condensation technique followed by size selection and sintering with a differential mobility analyzer and a tube furnace, respectively. Finally, the nanoparticles were collected on a glass substrate with an electrostatic precipitator. The particle size distributions were measured with a scanning mobility particle sizer and verified with a transmission electron microscope. A spectrophotometer was used to measure the optical extinction spectra of the prepared samples, which contained particles with diameters of approximately 50, 90 and 130?nm. By controlling the particle size, the dipolar peak of the localized surface plasmon resonance was tuned between wavelengths of 398 and 448?nm. In addition, quadrupolar resonances were observed at shorter wavelengths as predicted by the simplified theoretical model used to characterize the measured spectra. 相似文献
84.
We demonstrate a simple method for monitoring all-optical poling in real time. The poling pattern created by the writing beam at the fundamental frequency and the seed beam at the second-harmonic frequency is reconstructed by two-beam second-harmonic generation because of the writing beam and an additional probe beam at the fundamental frequency. When the probe beam is sufficiently weak, it does not distort the poling process. The method provides a significantly stronger signal than monitoring based on a probe beam alone. 相似文献
85.
Hannu Teisala Mikko Tuominen Mikko Aromaa Milena Stepien Jyrki M. Mäkelä Jarkko J. Saarinen Martti Toivakka Jurkka Kuusipalo 《Colloid and polymer science》2013,291(2):447-455
Surface wetting is an important and relevant phenomenon in several different fields. Scientists have introduced a large number of applications where special surface wetting could be exploited. Here, we study wetting phenomena on high- and low-adhesive superhydrophobic liquid flame spray (LFS)-generated TiO2 coatings on paper and pigment-coated board substrates using water–ethanol solution as a probe liquid. Submicrometer-scale air gaps, which exist on superhydrophobic surfaces below the liquid droplets, were more stable with the ethanol increment than the larger-scale micrometric air gaps. With the droplet ethanol concentration of 15 wt%, static contact angle as high as 155?±?2° was measured on the LFS–TiO2-coated board. Transition from the low-adhesive wetting state to the high-adhesive state was demonstrated on the LFS–TiO2-coated paper. The LFS method enables efficient roll-to-roll production of surfaces with special wetting properties on economically viable board and paper substrate materials. 相似文献
86.
87.
The effect of word order and prosodic focus on the tonal shape and intensity in the production of prosody was studied. The results show that the production of focus in Finnish follows a global pattern with regard to tonal features. The relative pitch height difference between contrasted words is the most important pitch-related factor in signaling narrow prosodic focus. Narrow focus is not localized to prosodically emphasized words only but relates to the utterance as a whole. It was also found that syntactic structure with respect to both intensity and tonal structure modulated relative prosodic prominence of individual words. 相似文献
88.
We provide experimental evidence of higher multipole (magnetic dipole and electric quadrupole) radiation in second-harmonic (SH) generation from arrays of metal nanoparticles. Fundamental differences in the radiative properties of electric dipoles and higher multipoles yield opposite interference effects observed in the SH intensities measured in the reflected and transmitted directions. These interference effects clearly depend on the polarization of the fundamental field, directly indicating the importance of multipole effects in the nonlinear response. We estimate that higher multipoles contribute up to 20% of the total emitted SH field amplitude for certain polarization configurations. 相似文献
89.
K. I. Popov H. Ronkkomaki M. Hannu-Kuure T. Kuokkanen M. Lajunen A. G. Vendilo I. V. Glazkova L. H. J. Lajunen 《Russian Journal of Coordination Chemistry》2007,33(6):393-395
The stability constant of the Na+ complex with dibenzo-18-crown-6, [Na(DB18C6)]+, was measured by the 23Na NMR method in the mixed water-ionic liquid solvent at 23°C. N-Butyl-4-methylpyridinium tetrafluoroborate (BMPTB) was used as room temperature ionic liquid. It was found that for the solvent containing 0.8 mol fraction of water and 0.2 mol fraction of BMPTB, the value log K = 0.77 ± 0.05. The addition of BMPTB to water was found to increase the solubility of the crown ether but to decrease the sodium nitrate solubility. 相似文献
90.
Vinay Kumar Roger Bollström Arthas Yang Qingxia Chen Gang Chen Pekka Salminen Douglas Bousfield Martti Toivakka 《Cellulose (London, England)》2014,21(5):3443-3456
Nanocellulose is an interesting building block for functional materials and has gained considerable interest due to its mechanical robustness, large surface area and biodegradability. It can be formed into various structures such as solids, films and gels such as hydrogels and aerogels and combined with polymers or other materials to form composites. Mechanical, optical and barrier properties of nanofibrillated cellulose (NFC) and microfibrillated cellulose (MFC) films were studied in order to understand their potential for packaging and functional printing applications. Impact of raw material choice and nanocellulose production process on these properties was evaluated. MFC and NFC were produced following two different routes. NFC was produced using a chemical pretreatment followed by a high pressure homogenization, whereas MFC was produced using a mechanical treatment only. TEMPO-mediated oxidation followed by one step of high pressure (2,000 bar) homogenization seems to produce a similar type of NFC from both hardwood and softwood. NFC films showed superior mechanical and optical properties compared with MFC films; however, MFC films demonstrated better barrier properties against oxygen and water vapor. Both the MFC and NFC films were excellent barriers against mineral oil used in ordinary printing inks and dichlorobenzene, a common solvent used in functional printing inks. Barrier properties against vegetable oil were also found to be exceptionally good for both the NFC and MFC films. 相似文献