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1.
This paper presents a new spectral model for solving the fully nonlinear potential flow problem for water waves in a single horizontal dimension. At the heart of the numerical method is the solution to the Laplace equation which is solved using a variant of the ‐transform. The method discretizes the spatial part of the governing equations using the Galerkin method and the temporal part using the classical fourth‐order Runge‐Kutta method. A careful investigation of the numerical method's stability properties is carried out, and it is shown that the method is stable up to a certain threshold steepness when applied to nonlinear monochromatic waves in deep water. Above this threshold artificial damping may be employed to obtain stable solutions. The accuracy of the model is tested for: (i) highly nonlinear progressive wave trains, (ii) solitary wave reflection, and (iii) deep water wave focusing events. In all cases it is demonstrated that the model is capable of obtaining excellent results, essentially up to very near breaking. 相似文献
2.
Archiv der Mathematik - It is a classical result in matrix algebra that any square matrix over a field can be conjugated to its transpose by a symmetric matrix. For F a non-Archimedean local field,... 相似文献
3.
The Grignard addition reaction is known to be a reversible process with allylic reagents, but so far the reversibility has not been demonstrated with other alkylmagnesium halides. By using crossover experiments it has been established that the benzyl addition reaction is also a reversible transformation. The retro benzyl reaction was shown by the addition of benzylmagnesium chloride to di-tert-butyl ketone followed by exchange of both the benzyl and the ketone moiety with another substrate. Similar experiments were performed with phenylmagnesium bromide and tert-butylmagnesium chloride, but in these two cases the Grignard addition reaction did not show any sign of a reverse transformation. 相似文献
4.
Dr. Karin Mannerstedt Dr. Narendra Kumar Mishra Dr. Ebbe Engholm Dr. Morten Lundh Dr. Charlotte S. Madsen Dr. Philip J. Pedersen Dr. Priska Le-Huu Dr. Søren L. Pedersen Dr. Nina Buch-Månson Dr. Björn Borgström Dr. Thomas Brimert Dr. Lisbeth N. Fink Dr. Keld Fosgerau Prof. Niels Vrang Prof. Knud J. Jensen 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(9):3166-3176
A glucose responsive insulin (GRI) that responds to changes in blood glucose concentrations has remained an elusive goal. Here we describe the development of glucose cleavable linkers based on hydrazone and thiazolidine structures. We developed linkers with low levels of spontaneous hydrolysis but increased level of hydrolysis with rising concentrations of glucose, which demonstrated their glucose responsiveness in vitro. Lipidated hydrazones and thiazolidines were conjugated to the LysB29 side-chain of HI by pH-controlled acylations providing GRIs with glucose responsiveness confirmed in vitro for thiazolidines. Clamp studies showed increased glucose infusion at hyperglycemic conditions for one GRI indicative of a true glucose response. The glucose responsive cleavable linker in these GRIs allow changes in glucose levels to drive the release of active insulin from a circulating depot. We have demonstrated an unprecedented, chemically responsive linker concept for biopharmaceuticals. 相似文献
5.
Jon E. Carlé Martin Helgesen Natalia K. Zawacka Morten V. Madsen Eva Bundgaard Frederik C. Krebs 《Journal of Polymer Science.Polymer Physics》2014,52(13):893-899
Two low‐band gap polymer series based on benzo[1,2‐b:4,5‐b′]dithiophene (BDT) and dithienylbenzothiadiazole, with different numbers of fluorine substituents on the 2,3,1‐benzothiadiazole unit, have been synthesized and explored in a comparative study of the photochemical stability and operational lifetime in flexible large area roll‐coated bulk heterojunction solar cells. The two polymer series have different side chains on the BDT unit, namely 2‐hexyldecyloxy (BDTHDO) ( P1–P3 ) or 2‐hexyldecylthiophene (BDTTHD) ( P4–P6 ). The photochemical stability clearly shows that the stability enhances along with the number of fluorine atoms incorporated on the polymer backbone. Fabrication of the polymer solar cells based on the materials was carried out in ambient atmosphere on a roll coating/printing machine employing flexible and indium‐tin‐oxide‐free plastic substrates. Solar cells based on the P4–P6 series showed the best performance, reaching efficiencies up to 3.8% for an active area of 1 cm2, due to an enhanced current compared to P1–P3 . Lifetime measurements, carried out according to international summit on OPV stability (ISOS), of encapsulated devices reveals an initial fast decay for P1–P6 in the performance followed by a much slower decay rate, still retaining 40–55% of their initial performance after 250 h of testing under ISOS‐L‐1 conditions. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2014 , 52, 893–899 相似文献
6.
Tommy Sonne Alstrøm Mads Peter Sørensen Niels Falsig Pedersen Søren Madsen 《Acta Appl Math》2011,115(1):63-74
The time-dependent Ginzburg-Landau equation is solved numerically for type-II superconductors of complex geometry using the
finite element method. The geometry has a marked influence on the magnetic vortex distribution and the vortex dynamics. We
have observed generation of giant vortices at boundary defects, suppressing the superconducting state far into the superconductor. 相似文献
7.
Synthesis of Oxacyclic Scaffolds via Dual Ruthenium Hydride/Brønsted Acid‐Catalyzed Isomerization/Cyclization of Allylic Ethers 下载免费PDF全文
Dr. Erhad Ascic Ragnhild G. Ohm Dr. Rico Petersen Dr. Mette R. Hansen Casper L. Hansen Daniel Madsen Prof. Dr. David Tanner Prof. Dr. Thomas E. Nielsen 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(12):3297-3300
A ruthenium hydride/Brønsted acid‐catalyzed tandem sequence is reported for the synthesis of 1,3,4,9‐tetrahydropyrano[3,4‐b]indoles (THPIs) and related oxacyclic scaffolds. The process was designed on the premise that readily available allylic ethers would undergo sequential isomerization, first to enol ethers (Ru catalysis), then to oxocarbenium ions (Brønsted acid catalysis) amenable to endo cyclization with tethered nucleophiles. This methodology provides not only an attractive alternative to the traditional oxa‐Pictet–Spengler reaction for the synthesis of THPIs, but also convenient access to THPI congeners and other important oxacycles such as acetals. 相似文献
8.
J. D. Brockman J. M. Guthrie J. S. Morris J. Davis R. Madsen J. D. Robertson 《Journal of Radioanalytical and Nuclear Chemistry》2009,279(2):405-410
The toenail was examined as a biological monitor of Mg, Zn, and Cu intake using an observational case control model. The One
Source Cohort matched 63 individuals in Columbia Missouri who took the One Source multivitamin with 63 control individuals.
The matching criteria were based on age, sex, ethnicity, smoking status, and body mass index. The multivitamin contained supra-nutritional
levels of Se, Mg, Cu, and Zn. The toenail clippings were examined for these elements using instrumental neutron activation
analysis (INAA). A statistical analysis did not indicate a significant difference for Mg, Cu, or Zn between the nails of One
Source supplement users and control subjects (p<0.76, 0.55, and 0.85, respectively). The trace nutrient Se was used as an internal control. Previous studies have consistently
demonstrated that toenail Se is positively correlated with Se supplement use and the analysis did result in a significant
correlation in the toenails of One Source users and control subjects (p<1·10−4). This internal Se control suggests that the One Source Cohort is largely free from misclassification errors that could interfere
with the biomonitor response for the supranutritional intake of Mg, Cu, and Zn. 相似文献
9.
James A. Madsen Jennifer S. Brodbelt 《Journal of the American Society for Mass Spectrometry》2009,20(3):349-358
The number and types of diagnostic ions obtained by infrared multiphoton dissociation (IRMPD) and collision-induced dissociation
(CID) were evaluated for supercharged peptide ions created by electrospray ionization of solutions spiked with m-nitrobenzyl alcohol. IRMPD of supercharged peptide ions increased the sequence coverage compared with that obtained by CID
for all charge states investigated. The number of diagnostic ions increased with the charge state for IRMPD; however, this
trend was not consistent for CID because the supercharged ions did not always yield the greatest number of diagnostic ions.
Significantly different fragmentation pathways were observed for the different charge states upon CID or IRMPD with the latter
yielding far more immonium ions and often fewer uninformative ammonia, water, and phosphoric acid neutral losses. Pulsed-Q
dissociation resulted in an increase in the number of internal product ions, a decrease in sequence-informative ions, and
reduced overall ion abundances. The enhanced sequence coverage afforded by IRMPD of supercharged ions was demonstrated for
a variety of model peptides, as well as for a tryptic digest of cytochrome c. 相似文献
10.
A.L. Madsen 《International Journal of Approximate Reasoning》2010,51(5):499-514
Even though existing algorithms for belief update in Bayesian networks (BNs) have exponential time and space complexity, belief update in many real-world BNs is feasible. However, in some cases the efficiency of belief update may be insufficient. In such cases minor improvements in efficiency may be important or even necessary to make a task tractable. This paper introduces two improvements to the message computation in Lazy propagation (LP): (1) we introduce myopic methods for sorting the operations involved in a variable elimination using arc-reversal and (2) extend LP with the any-space property. The performance impacts of the methods are assessed empirically. 相似文献