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101.
Thin films of two laterally patterned functional oxides of uniform thickness were obtained in a two-step soft-lithographic micromolding process. CoFe(2)O(4)/ZnO and CoFe(2)O(4)/BaTiO(3) dual-phase patterns were fabricated. The films showed good replication of the pattern that was defined in the first patterning step. X-ray diffraction showed that the films consisted of two distinct phases, and magnetic force microscopy showed that the compounds were laterally separated, the separation pattern being the same as that of the initial soft-lithographic process. The films exhibited slight height variations near the edges of the phases, which were introduced in the first deposition step and were not fully compensated in the second deposition step. The films are sufficiently smooth to allow fabrication of multilayer structures. 相似文献
102.
Gurevich L Poulsen TW Andersen OZ Kildeby NL Fojan P 《Journal of nanoscience and nanotechnology》2010,10(12):7946-7950
Self-assembly of amphiphilic peptides designed during the last ten years by different research groups lead to a large variety of 3D-structures that already found applications in e.g., for stabilization of large protein complexes, cell culturing systems etc. We present synthesis and characterization of a novel amphiphilic peptide KA6 that exhibits clear charge separation controllable by the pH of the environment. The self-assembly in this system is largely governed by electrostatic interaction, thus a change in pH will not only lead to a change in critical micellar concentration (CMC) of the peptide but also to the changes in micellar structure as revealed by atomic force microscopy (AFM) and circular dichroism (CD) study. At basic pH the micellar structure inverts exposing the opposite end of the peptide chain to the solution. This interesting phenomenon could provide basis for novel pH sensitive materials including drug delivery and controlled release systems. 相似文献
103.
Göbel OF Branfield TE Stawski TM Veldhuis SA Blank DH ten Elshof JE 《ACS applied materials & interfaces》2010,2(11):2992-2994
Stacks of up to five relief patterned functional oxide thin films were obtained by a low-cost and low-tech soft-lithographic patterning technique. Micromolding was used to pattern a film of a metal-organic precursor solution for Y-stabilized ZrO(2) (YSZO). Subsequent drying and pyrolysis yielded a line-patterned YSZO film. The process was repeated up to four times with a precursor solution for BaTiO(3) on top of the YSZO film, resulting in stacks of YSZO and BaTiO(3) lines with well-defined edges. This approach presents a step forward on the way to a versatile additive micropatterning technique with which simple multi-material device structures can be fabricated in a reliable, fast, and cost-effective manner. 相似文献
104.
Zhigang Zhu Lise Kristensen Gareth F. Difford Morten Poulsen Samantha J. Noel Waleed Abu Al-Soud Søren J. Sørensen Jan Lassen Peter Løvendahl Ole Højberg 《Journal of dairy science》2018,101(11):9847-9862
In the present study, we hypothesized that the rumen bacterial and archaeal communities would change significantly over the transition period of dairy cows, mainly as an adaptation to the classical use of low-grain prepartum and high-grain postpartum diets. Bacterial 16S rRNA gene amplicon sequencing of rumen samples from 10 primiparous Holstein dairy cows revealed no changes over the transition period in relative abundance of genera such as Ruminococcus, Butyrivibrio, Clostridium, Coprococcus, and Pseudobutyrivibrio. However, other dominant genus-level taxa, such as Prevotella, unclassified Ruminococcaceae, and unclassified Succinivibrionaceae, showed distinct changes in relative abundance from the prepartum to the postpartum period. Overall, we observed individual fluctuation patterns over the transition period for a range of bacterial taxa that, in some cases, were correlated with observed changes in the rumen short-chain fatty acids profile. Combined results from clone library and terminal-restriction fragment length polymorphism (T-RFLP) analyses, targeting the methyl-coenzyme M reductase α-subunit (mcrA) gene, revealed a methanogenic archaeal community dominated by the Methanobacteriales and Methanomassiliicoccales orders, particularly the genera Methanobrevibacter, Methanosphaera, and Methanomassiliicoccus. As observed for the bacterial community, the T-RFLP patterns showed significant shifts in methanogenic community composition over the transition period. Together, the composition of the rumen bacterial and archaeal communities exhibited changes in response to particularly the dietary changes of dairy cows over the transition period. 相似文献
105.
A mathematical model has been developed to describe solute mixing in surcharged manholes using the submerged jet theory. The model has been applied for straight-through flow manholes and for manholes with a difference in the level of the inlet and outlet pipes. The model is applicable to dissolved substances, i.e. the model has not been validated for high sediment concentrations (above 1 g/l) and care should be taken in such cases. Simulation results from the new model are compared with laboratory measurements and are further compared to conventional modelling techniques currently available in commercial software specially developed for modelling the water quality in sewers. The results prove that the new model produces considerably better results compared to the traditional assumption of full mixing in a manhole. The new model compares well to the laboratory measurements and hence improves the accuracy of modelling soluble pollutant transport in sewers. The applicability of the new modelling approach is discussed and further studies are recommended. 相似文献
106.
In this work, the thermodynamic stability of gas hydrates is investigated in the presence of electrolyte solutions. The proposed model is based on the Van der Waals–Platteeuw model for gas hydrate equilibrium, and the Pitzer and Mayorga model is employed to calculate the water activity in the electrolyte solutions. Available values for the Pitzer model parameters are usually adjusted using experimental data at 25°C, which is usually higher than the gas hydrate formation temperature. In order to eliminate this problem, those adjustable parameters are re-optimized using experimental data from the literature at the lowest temperature. In the case of mixed electrolyte solutions and without using any adjustable parameters, a mixing rule is proposed to estimate the water activity. The new mixing rule is based on the ionic strength of the mixture and estimates the mixture water activity by using properties of the single electrolytes that constitute the mixture. The results show the proposed model can calculate hydrate equilibrium conditions with good accuracy, especially at low concentrations, which is the case for most industrial applications. 相似文献
107.
Vaskinn Anja; Sundet Kjetil; Simonsen Carmen; Hellvin Tone; Melle Ingrid; Andreassen Ole A. 《Canadian Metallurgical Quarterly》2011,25(4):499
Objective: To investigate sex differences in neurocognition and social functioning in schizophrenia and bipolar disorder and the possible role of sex as a moderator of this relationship. Method: Participants with schizophrenia (60 women/94 men), bipolar I disorder (55 women/51 men), and healthy controls (158 women/182 men) were assessed with an extensive neuropsychological test battery and a social functioning questionnaire. Results: We found significant main effects of sex for neuropsychological tests (p 相似文献
108.
Peters O 《Philosophical transactions. Series A, Mathematical, physical, and engineering sciences》2011,369(1956):4913-4931
A resolution of the St Petersburg paradox is presented. In contrast to the standard resolution, utility is not required. Instead, the time-average performance of the lottery is computed. The final result can be phrased mathematically identically to Daniel Bernoulli's resolution, which uses logarithmic utility, but is derived using a conceptually different argument. The advantage of the time resolution is the elimination of arbitrary utility functions. 相似文献
109.
Anne-Marie Hermansson Ole Harbitz Maud Langton 《Journal of the science of food and agriculture》1986,37(1):69-84
Myosin was isolated from bovine m. semimembranosus and gels were formed by heat treatment at different pH values and ionic strengths. The gels were subjected to rigidity measurements and their microstructure was studied by scanning electron microscopy. This article provides evidence that myosin can form two completely different gel structures in the pH range 5.5–6.0, depending on ionic strength. Fine stranded gel structures were formed at low ionic strength (0.25M KCl), whereas coarsely aggregated gel structures were formed at high ionic strength (0.6M KCl). The fine stranded structure had a higher rigidity than the coarsely aggregated structure. It was found that all fine strand myosin gels were formed from turbid solutions and the aggregate gels from clear solutions. When the pH was lowered to 4 in 0.6M KCl a strand-type gel structure formed spontaneously on dialysis, even without heat treatment. This structure did not change in character on heating. It was concluded that the conditions required for the formation of strand-type myosin gels were already present before the heat treatment and that the strands were made up of myosin filaments at certain pH and ionic strength combinations, which produced a turbid solution. The strand-type structures were considered specific with regard to myosin interactions which was not the case for the aggregated structures. Variation of the heating temperature in the range 55 to 65°C had no major effect on the type of structure formed. 相似文献
110.
We extend the infinite wind‐farm boundary‐layer (IWFBL) model of Frandsen to take into account atmospheric static stability effects. This extended model is compared with the IWFBL model of Emeis and to the Park wake model used in Wind Atlas Analysis and Application Program (WAsP), which is computed for an infinite wind farm. The models show similar behavior for the wind‐speed reduction when accounting for a number of surface roughness lengths, turbine to turbine separations and wind speeds under neutral conditions. For a wide range of atmospheric stability and surface roughness length values, the extended IWFBL model of Frandsen shows a much higher wind‐speed reduction dependency on atmospheric stability than on roughness length (roughness has been generally thought to have a major effect on the wind‐speed reduction). We further adjust the wake‐decay coefficient of the Park wake model for an infinite wind farm to match the wind‐speed reduction estimated by the extended IWFBL model of Frandsen for different roughness lengths, turbine to turbine separations and atmospheric stability conditions. It is found that the WAsP‐recommended values for the wake‐decay coefficient of the Park wake model are (i) larger than the adjusted values for a wide range of neutral to stable atmospheric stability conditions, a number of roughness lengths and turbine separations lower than ~ 10 rotor diameters and (ii) too large compared with those obtained by a semiempirical formulation (relating the ratio of the friction to the hub‐height free velocity) for all types of roughness and atmospheric stability conditions. © 2013 The Authors. Wind Energy published by John Wiley & Sons, Ltd. 相似文献