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101.
Ohne Zusammenfassung 相似文献
102.
103.
Irina Puci? Tadija Mad?ar Milko Jak?i? 《Monatshefte für Chemie / Chemical Monthly》2006,25(6):953-961
Anti-corrosion polymer films used for 0 to 6 years were investigated to determine the type and content of volatile corrosion
inhibitors (VCI) and how long the films emit it to protect the metal surface encased by the film. By FTIR and DSC low density
polyethylene (LDPE) was identified as the polymer carrier. Particle induced X-ray emission (PIXE) spectroscopy of anti-corrosion
polymer films revealed significant concentration of molybdenum implying that corrosion inhibitor was molybdate based. The
films were divided into three groups according to different rate of the VCI concentration decrease with increasing age. The
division of films into groups and diffusion of VCI was confirmed by significant decrease of Mo content determined by PIXE
spectroscopy after accelerated ageing in vacuum at 50°C. It was concluded that films with initial concentration of Mo above
6000 ppm emit VCI for at least 6 years while the films with less than 4000 ppm of molybdenum do not emit the VCI in the ambient
conditions. 相似文献
104.
105.
Piotr Jakóbczak 《Israel Journal of Mathematics》1997,97(1):175-181
In this note we construct the functionf holomorphic in the unit ballB in ℂ
N
such that for every positive-dimensional subspace Π of ℂ
N
,f|П⋂B is notL
2-integrable. We present also some possible generalizations of this result.
Partially supported by the KBN Grant 2 PO3A 060 08. 相似文献
106.
Gyula Argay Alajos Kálmán Béla Ribár Zoltán Djarmati Nikola Tot Ernö Schwirtlich Ratko M. Jankov 《Journal of chemical crystallography》1991,21(5):625-628
The title compound: 2H-10,4a-(epoxy-methano)-phenantren-12-one-1,3,4,9,10,10a-hexahydro-5,6-dihydroxy-9-etoxy-1,1-dirnethyl-7-(1-methylethyl), was isolated fromSalvia officinalis L. andHyssopus officinalis L. C22H30O5, orthorhombic, P212121, (No. 19)a=8.309(1),b=11.320(2),c=22.060(3) Å,V=2075.0(9) Å3,Z=4,D
x=1.199 g·cm–3, (CuK)=1.54184 Å,=6.43 cm–1, F(000)=808,T=296(1) K. The structure was solved by direct methods and refined toR=0.047 for 1824 observed reflections collected on a CAD-4 diffractometer. In the course of structure refinement conformational disorder of the isopropyl moiety and the terminal methyl group pertaining to the ethoxy ligand was established. They result altogether in four different conformers.Alternatively it can be termed 9-ethoxyrosmanol. 相似文献
107.
Vassil I. Ognyanov Marietta A. Haimova Nikola M. Mollov 《Monatshefte für Chemie / Chemical Monthly》1982,113(8-9):993-998
The title compounds5 were synthetized in two steps from the corresponding isoindolo[2,1–b]isoquinoline-5(7H)-ones3, obtained in high yields from 3-ethoxy-1H-isoindoles2 and homopthalic anhydrides1. TheStevens rearrangement of5 gave 2-methyl-2,3-dihydro-1H-isoindole-1-spiro-2-indanes6.
Synthese von 5,7,11 b,12-Tetrahydro-isoindolo[2,1-b]isochinolinium Methiodiden und ihre Stevens-Umlagerung
Zusammenfassung Die Titelverbindungen5 wurden in zwei Stufen aus den entsprechenden Isoindolo[2,1–b]isochinolin-5(7H)-onen (3) dargestellt, die ihrerseits in hohen Ausbeuten aus 3-Ethoxy-1H-isoindolen (2) und Homophthalsäureanhydriden erhältlich sind. DieStevens-Umlagerung von5 führte zu 2-Methyl-2,3-dihydro-1H-isoindol-1-spiro-2-indanen (6).相似文献
108.
Vassil I. Ognyanov Orlin S. Petrov Emil P. Tiholov Nikola M. Mollov 《Helvetica chimica acta》1989,72(2):353-360
Two gossypol analogues 2a and 2b were synthesized for biological evaluation as male contraceptive agents. The naphthol 8c was prepared by analogy with a known procedure starling from 3-isopropylcatechol ( 3 ). (t-Bu)2O2-Mediated phenolic coupling of 8c furnished the binaphthol 9c which, after pyrane ring closure, deprotection. and selective bisformylation with SnCl4/Cl2CHOCH3, gave the target compound 2a . The corresponding tetrahydroxy analogue 2b was prepared in a similar way. 相似文献
109.
Yuliya Prokopenko Valdas Jakštas Vaidotas Žvikas Victoriya Georgiyants Liudas Ivanauskas 《Natural product research》2019,33(13):1961-1963
The aim of research was to study the content of amino acids using in extracts of Fumaria schleicheri L., Ocimum basilicum L., and Corylus avellana L. by HILIC MS/MS method. Separation of amino acids in the samples was carried out with Acquity H-class UPLC system (Waters, Milford, USA) equipped with SeQuant ZIC-Hilic collumn (2.1 × 150 mm, 3.5 μm) (Merck Millipore, Darmstadt, Germany). The MS/MS fragment ion chromatograms of the test solutions established the presence of 19 amino acids. The obtained results have shown that O. basilicum L. characterized the highest concentrations of different neurogenic amino acids (128.1 mg/kg), comparing with F. schleicheri L. and C. avellana L. (57.72 and 52.91 mg/kg, respectively). 相似文献
110.
Analysis of calcium, oxalate, and citrate interaction in idiopathic calcium urolithiasis in children
Milosević D Batinić D Konjevoda P Blau N Stambuk N Nizić L Vrljicak K Batinić D 《Journal of chemical information and computer sciences》2003,43(6):1844-1847
The majority of urinary stones in children are composed of calcium oxalate. To investigate the interaction between urinary calcium, oxalate, and citrate as major risk factors for calcium stones formation, their 24-h urinary excretion was determined in 30 children with urolithiasis and 15 normal healthy children. The cutoff points between children with urolithiasis and healthy children, accuracy, sensitivity, and specificity for each risk factor alone as well as for all three taken together were determined. OneR and J4.8 classifiers as parts of the larger data mining software Weka, based on machine learning algorithms, were used for the determination of the cutoff points for differentiation of the children. The decision tree based on J4.8 classifier analysis of all three risk factors together proved to be the best for differentiating stone formers from normal children. In comparison to the accuracy of the differentiation after calcium and oxalate of 80% and 75.6%, respectively, the decision tree showed an accuracy of 97.8%. Even when its stability was tested by the leave-one-out cross-validation procedure, the accuracy remained at a very acceptable percentage of 93.2% correctly classified patients. J4.8 classifier analysis gave a look inside urinary calcium, oxalate, and citrate interaction. Urinary calcium excretion was shown as the most informative in discrimination of the children with urolithiasis from healthy children. However, it was shown that oxalate and citrate excretions might influence the stone formation in a subpopulation of the stone formers. In patients with low urinary calcium, a major role in lithogenesis belongs to oxalate, in some of them alone and in others in conjunction with citrate. Decreased urinary citrate excretion in the presence of increased oxalate excretion may lead to stone formation. 相似文献