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1.
In this paper we determine the forcing linearity numbers for semisimple modules over integral domains.  相似文献   
2.
New, rapid, and inexpensive methods that monitor the chemical composition of corn stover and corn stover-derived samples are a key element to enabling the commercialization of processes that convert stover to fuels and chemicals. These new techniques combine near infrared (NIR) spectroscopy and projection to latent structures (PLS) multivariate analysis to allow the compositional analysis of hundreds of samples in 1 d at a cost of about $10 each. The new NIR/PLS rapid analysis methods can also be used to support a variety of research projects that would have been too costly to pursue by traditional methods.  相似文献   
3.
[reaction: see text] The first examples of free radical-mediated vinyl amination are described by nonconventional vinyl radical addition to azomethine nitrogen. This new vinyl amination protocol is mild and provides convenient synthetic access to nonstabilized N,N-dialkyl enamines and tandem bond-forming processes.  相似文献   
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This review examines the most recent electrochemical developments for nitrate, nitrite and ammonium detection for on-site water monitoring. There remains a high demand for effective field-based detection of the dissolved inorganic nitrogen (DIN) analytes to aid in mitigating nitrogen loading. Electrochemical approaches show increasing potential to fill this role as advancements in nanotechnology continually improve analytical performance and on-site applicability. However, translating these improvements into the field still faces the resonating challenges of reaching analytical proficiency (selectivity, sensitivity, robustness, stability), practical end-user functionality, minimal matrix interferences and cost effectiveness. Herein, we elaborate on these challenges via a critical evaluation of current studies and examine how realistic the prospects of on-site nitrate, nitrite and ammonium are. We also present recommendations in addressing these gaps to conclude the review.  相似文献   
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A direct kinetics study of the product‐forming channels of the reaction of isoprene‐derived hydroxyalkylperoxy radicals with NO has been performed at 100 Torr pressure and 298 K using the turbulent flow technique with high‐pressure chemical ionization mass spectrometry for the detection of reactants and products. For comparative purposes, a similar study was also performed for the reaction of 1‐ and 2‐butene‐derived hydroxyalkylperoxy radicals with NO. The measured hydroxyalkylnitrate product channel branching ratios were determined to be 0.061, 0.068, and 0.070 for the 1‐butene, 2‐butene, and isoprene systems, respectively. The results are compared to previous measurements of the hydroxyalkylnitrate‐branching ratios for these systems, and the atmospheric significance of the results is discussed. © 2007 Wiley Periodicals, Inc. Int J Chem Kinet 39: 353–361, 2007  相似文献   
8.
The projection shadow moiré technique was employed to determine an out-of-plane contouring history of aluminum, [(+45/–45)]3S , [(0/903,0] S and [(0/90/+45/–45)]2S fiberglass epoxy pin-loaded specimens experimentally. The contouring interval was limited to 0.0254 mm by experimental concerns. Qualification of the projection shadow moiré optical arrangement was initially accomplished by the out-of-plane contouring of a clamped, centrally loaded, circular aluminum plate. Experimental results indicate significant out-of-plane displacements in the bearing region of the coupon at load levels well below ultimate. Effects of material anisotropy could be seen in the fiber-oriented shape of the displacement contours. Comparisons with three-dimensional finite-element results indicate that experimental out-of-plane contours were significantly larger than their finite-element counterparts in the region above the pin for the [(+45/–45)]3S , [(0/90)3, 0] S laminates. These deviations increased with increasing pin-load level. These variations could be attributed to linear-elastic through-thickness moduli assumptions as well as through-thickness finite-element mesh coarseness.  相似文献   
9.
[Structure: see text] An advanced intermediate in our planned synthesis of mitomycin C has been acquired in nine steps from tert-butyl glyoxylate. The aziridinyl pyrrolidine and quinone subunits are coupled regioselectively to arrive at an enamine that is prepared for C10 homologation.  相似文献   
10.
Zusammenfassung Es werden einige Methoden zur Bestimmung des Hydrazids der Iso-Nicotinsäure beschrieben. Folgende Reaktionen werden hierfür verwendet: Die Oxydation des Hydrazinrestes, die Überführung des Hydrazids in das Azid sowie die Bestimmung der sauren und basischen Gruppen durch Titration in nichtwäßriger Lösung.Der Endpunkt der jeweiligen Reaktion wird entweder mit Indikatoren, besser und genauer aber elektrometrisch bestimmt.
Summary Several methods for the determination of the hydrazide of iso-nicotinic acid are described. The following reactions were used for this purpose: oxidation of the hydrazine radical; conversion of the hydrazide to the azide; determination of the acidic and basic groups by titration in non-aqueous solution. The endpoint of the particular titration is determined either by means of indicators, or better and more accurately electrometrically.

Résumé On décrit quelques méthodes pour le dosage de l'hydrazide de l'acide isonicotinique. Les réactions suivantes ont été utilisées pour cela: l'oxydation du reste hydrazide, la transformation de l'hydrazide en azide ainsi que le dosage des groupements acides et basiques par titrage en milieu non aqueux. Le point d'équivalence est déterminé suivant le cas soit avec des indicateurs, soit mieux et d'une façon plus précise électrométriquement.


Mit 4 Abbildungen.  相似文献   
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