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排序方式: 共有659条查询结果,搜索用时 15 毫秒
1.
Edward G. Sheetz Zhao Zhang Alyssa Marogil Minwei Che Dr. Maren Pink Dr. Veronica Carta Prof. Dr. Krishnan Raghavachari Prof. Dr. Amar H. Flood 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(60):e202201584
The recognition of boron compounds is well developed as boronic acids but untapped as organotrifluoroborate anions (R−BF3−). We are exploring the development of these and other designer anions as anion-recognition motifs by considering them as substituted versions of the parent inorganic ion. To this end, we demonstrate strong and reliable binding of organic trifluoroborates, R−BF3−, by cyanostar macrocycles that are size-complementary to the inorganic BF4− progenitors. We find that recognition is modulated by the substituent's sterics and that the affinities are retained using the common K+ salts of R−BF3− anions. 相似文献
2.
The Constraint Molecular Dynamics approach is illustrated together with calculation on different heavy ion collisions. In particular the charge-mass distribution produced in the collision 124Sn + 64Ni and 112Sn + 58Ni at 35 MeV/nucleon is discussed. By comparing the Y = (N ? Z)/A distributions for fragments produced in central collisions it results that this observable can be sensitive to the dynamic effects induced on the two systems by the different charge/mass ratio. 相似文献
3.
A new sample business survey for agriculture, the REA survey, and a project of integration with the FADN network (RICA in
Italy) have significantly changed the production of statistical information nowadays available with reference to the agricultural
sector. On the basis of this relevant information, new economic analyses are being developed on farms’ performance, agricultural
households’ income and the Common Agricultural Policy (CAP). In this paper the authors estimate the relationship between the
levels of variables of interest and their sampling errors using models in order to improve the accessibility of the information
on estimates accuracy to the final users (agricultural analysts, policy makers).
The paper is the result of a joint research of the three authors. Sections 1–3 and 6 by Pizzoli, Sects. 4 and 5 by Rondinelli,
Sect. 7 by Filiberti, conclusions joint to the three authors. 相似文献
4.
Veronica Felli Susanna Terracini 《Calculus of Variations and Partial Differential Equations》2006,27(1):25-58
This paper deals with a class of nonlinear elliptic equations involving a critical power-nonlinearity as well as a potential featuring multiple inverse square singularities. When the poles form a symmetric structure, it is natural we wonder how the symmetry affects such mutual interaction. The present paper means to study this aspect from the point of view of the existence of solutions inheriting the same symmetry properties as the set of singularities.
Mathematics Subject Classification (2000) 35J60, 35J20, 35B33 相似文献
5.
The composting of organic solid waste, the mixture of fruit and vegetable leftovers enriched with night soil, was investigated
in a closed thermally insulated reactor. It was found that 80.9 % of the original substrate biodegraded after 14 days. A mathematical
model of the column reactor was proposed where the biodegradation rate of the organic solid waste was described using simple
n-thorder kinetics. A good prediction of process performance was obtained using the proposed kinetics and experimentally obtained
reaction heat.
Presented at the 33rd International Conference of the Slovak Society of Chemical Engineering, Tatranské Matliare, 22–26 May
2006. 相似文献
6.
Veronica?StigssonEmail author G?ran?Kloow Ulf?Germg?rd Niclas?Andersson 《Cellulose (London, England)》2005,12(4):395-401
Controlling the reduction in molecular weight of the cellulose chains is essential in the production of carboxymethyl cellulose
(CMC). Such a reduction can be achieved by the addition of cobalt during the process of cobalt(II) ions, which act as a catalyst
for oxidative cleavage, and the influence thereof has been studied under a variety of conditions. This study has resulted
in a model that summarises the effects of the added amount of cobalt, the time for the cobalt reaction, the temperature in
the mercerisation stage of the CMC-manufacturing process and finally the effect of the temperature in the etherification stage.
It is shown that it is important for cobalt to be present during the mercerisation stage in order to achieve the desired viscosity. 相似文献
7.
8.
The bond dissociation enthalpies (BDE) of several phenols containing electron-withdrawing substituents in the para position have been determined by means of the EPR radical equilibration technique. It has been found that CN, NO(2), CHO, COOR, and COOH induce an increase of the BDE value of the O-H bond, thus producing a worsening of the antioxidant activity of phenols, while Cl, Ph, and CH[double bond]CHPh show an opposite effect. The contributions of these substituents for the calculation of the BDE values in polysubstituted phenols by using the group additivity rule have also been derived. It is shown that this rule provides quite reliable predictions of bond strengths, so that the method can be conveniently used to estimate new data on substituted phenols. 相似文献
9.
Roman E. Enrique Castro W. Veronica Camus O. Margarita 《Journal of organometallic chemistry》1985,293(1):93-101
The reactions between the phosphine-organoiron [CpFeII-η6-C6Me5CH2PPh2]+ PF6? (1) and [RhCl(η4-diolefin)(μ-Cl)]2 in CH2Cl2 at reflux give the new heterobinuclear air-stable crystalline complexes [CpFeII-η6-C6Me5CH2)P(Ph)2Rh(η4-diene)Cl]PF6,(D'*-diene=cyclooctadiene (COD): 65%, 2; trimethylfluorobenzobicyclo[2.2.2]octadiene (Me3TFB): 48%, 3). Complexes 2 and 3 have been studied by 1H, 13C and 31P NMR spectroscopy and they are carbonylated (CO, 1 atm). Cyclic voltammetry experiments with addition of MeOH show electron transfer FeIRhI → FeIIRh0, the presence of a catalytic wave FeI/FeII and the possible formation of Rh hydrides. Under normal conditions 2 is a catalyst for hydrogenation of cyclohexene, but it is less efficient than the known mononuclear Rh1 analogues. 相似文献
10.
Many gas-phase anions react with carbonyl sulfide by sulfur atom transfer to form RS? ions. The properties of H2NS?, formed in this way from H2N? and OCS, are described. 相似文献