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101.
Adamson P Andreopoulos C Arms KE Armstrong R Auty DJ Ayres DS Baller B Barnes PD Barr G Barrett WL Becker BR Belias A Bernstein RH Bhattacharya D Bishai M Blake A Bock GJ Boehm J Boehnlein DJ Bogert D Bower C Buckley-Geer E Cavanaugh S Chapman JD Cherdack D Childress S Choudhary BC Cobb JH Coleman SJ Culling AJ de Jong JK Dierckxsens M Diwan MV Dorman M Dytman SA Escobar CO Evans JJ Harris EF Feldman GJ Frohne MV Gallagher HR Godley A Goodman MC Gouffon P Gran R Grashorn EW Grossman N Grzelak K 《Physical review letters》2008,101(13):131802
This Letter reports new results from the MINOS experiment based on a two-year exposure to muon neutrinos from the Fermilab NuMI beam. Our data are consistent with quantum-mechanical oscillations of neutrino flavor with mass splitting |Deltam2| = (2.43+/-0.13) x 10(-3) eV2 (68% C.L.) and mixing angle sin2(2theta) > 0.90 (90% C.L.). Our data disfavor two alternative explanations for the disappearance of neutrinos in flight: namely, neutrino decays into lighter particles and quantum decoherence of neutrinos, at the 3.7 and 5.7 standard-deviation levels, respectively. 相似文献
102.
103.
Andrea Cornia Andrea Caneschi Paolo Dapporto Antonio C. Fabretti Dante Gatteschi Wanda Malavasi Claudio Sangregorio Roberta Sessoli 《Angewandte Chemie (International ed. in English)》1999,38(12):1780-1782
Carbon dioxide, formic acid, and water molecules are trapped in the crystal lattice of manganese(III ) formate (see 1 ), which was obtained by reducing permanganate with formic acid. Each CO2 guest molecule exhibits four C−H⋅⋅⋅O−C−O interactions with the three-dimensional host framework of Mn(HCOO)3 units. Compound 1 undergoes an antiferromagnetic phase transition at 27 K. 相似文献
104.
105.
106.
The effect of the type of epoxidized butadiene/styrene block copolymer [ESBS; linear (B/S) or radial (E(B/S)n), containing 0–27% of epoxy groups] on the thermal dehydrochlorination of poly (vinyl chloride) (PVC)-ESBS blends (ESBS content 10%) was investigated in the temperature range 170–180 °C, under a non-oxygen atmosphere. Thermal stability of the PVC-ESBS blends was estimated on the basis of induction time, t0, and maximum rate of hydrochloride emission, Vmax from the system. It was found that, for a similar degree of epoxidation of the SBS copolymer, the induction time i.e. the time after which emission of HCl begins, is longer in the series PVC < PVC-SBS < PVC-EB/S < PVC-E(B/S)n, and the same is true for thermal stability. However, the maximum rate of emission of HCl is lowest in the case of PVC-EB/S blends, in the range of molar ratios from 0.5 to 2.0 × 1O−2. On the basis of the dependence Vmax = f(EB/VC), it was found that there is a certain content of epoxidized butadiene (EB) units in a mixture which causes the optimum stability of poly (vinyl chloride) during heating. During thermal destruction of the PVC-ESBS blends, the HC1 evolved undergoes addition both to epoxy fragments and to double bonds. The degree of conversion of EB units in time t0 is 20% at 170 °C and 30% at 180 °C. The glass transition temperature, Tg, of PVC in the PVC-ESBS blends shifts towards higher temperatures by about 6–8 °C, proving the existence of crosslinking processes during moulding of the blends. The epoxidized butadiene/styrene radial block copolymer, E(B/S)n, is a better thermal stabilizer of PVC than the linear EB/S copolymer. 相似文献
107.
Conditions
for the preparation of light lanthanide 4-chlorophthalates were investigated
and their composition, solubility in water at 295 K, IR spectra and thermal
decomposition were determined. 4-Chlorophthalates of La–Nd(III) were
prepared as complexes with general formula NaLn[ClC6H3(CO2)2]2, whereas compounds of Sm and Eu have general formula
Ln2[ClC6H3(CO2)2]3·6H2O. During heating all complexes decompose
to oxides with intermediate formation of oxochlorides. The carboxylate groups
in the complexes studied are bidentate bridging (Sm, Eu) or bidentate chelating
and bridging (La–Nd). 相似文献
108.
Małgorzata T. Kaczmarek Maciej Kubicki Wanda Radecka-Paryzek 《Monatshefte für Chemie / Chemical Monthly》2006,137(8):997-1003
Summary. The new zinc complex of the N,N′-bis(salicylidene)-4-methyl-1,3-phenylenediamine ligand as a product of the [2 + 1] Schiff base condensation process was synthesized in the one-step metal-promoted reaction between salicylaldehyde and 4-methyl-1,3-phenylenediamine
in ethanol in the presence of zinc chloride. The two potentially tetradentate N2O2
Schiff bases function as neutral monodentate ligands involving only one oxygen atom in coordination. This rare coordination pattern
of a mononuclear salen-type zinc complex was revealed by X-ray crystallography and correlated with spectroscopic characterization. 相似文献
109.
The conditions of the formation of rare earth elementp-nitrobenzoates were studied and their quantitative composition and solubilities in water at 298 K were determined (their solubilities are of the order of 10–3 mol dm–3). The IR and X-ray spectra for the prepared complexes and the dehydrated rare earthp-nitrobenzoates were recorded. All obtained complexes are crystalline compounds. The conditions of thermal decomposition of the complexes were also studied. It was found that on heating above 573 K the complexes decompose explosively and undergo a melting process at the same time. Therefore the thermal decomposition for complexes being investigated was carried out in the temperature range 273–573 K. From the obtained results it follows that during the dehydration process no transformation of the nitro group to nitrito occurs.
Herstellung und Eigenschaften von Y, La und Lanthaniden-p-nitrobenzoaten
Zusammenfassung Die Bedingungen zur Darstellung von Y-, La- und Lanthaniden-p-nitrobenzoaten wurden untersucht. Ihre quantitative Zusammensetzung und ihre Wasserlöslichkeit bei 298 K wurden bestimmt (die Löslichkeit ist in der Größenordnung 10–3 mol dm–3). Die Infrarot- und Röntgenspektren der erhaltenen Komplexe sowie derp-Nitrobenzoate der seltenen Erden nach der Dehydratisierung wurden gemessen und dabei festgestellt, daß es sich um kristalline Verbindungen handelt. Das thermische Verhalten der erhaltenen Komplexe wurde untersucht: Sie zerfallen über 573 K explosiv und schmelzen zugleich. Der thermische Zerfall der erhaltenenp-Nitrobenzoate der seltenen Erden wurde im Temperaturbereich von 273–573 K untersucht. Es wurde festgestellt, daß die Y-, La- und Lanthaniden-p-nitrobenzoate bei Temperaturzunahme oder im Dehydratisierungsprozeß keiner Umgruppierung in entsprechende Nitritoverbindungen unterliegen.相似文献
110.
Ma?gorzata T. Kaczmarek Maciej Kubicki Wanda Radecka-Paryzek 《Monatshefte für Chemie / Chemical Monthly》2006,14(5):997-1003
The new zinc complex of the N,N′-bis(salicylidene)-4-methyl-1,3-phenylenediamine ligand as a product of the [2 + 1] Schiff base condensation process was synthesized in the one-step metal-promoted reaction between salicylaldehyde and 4-methyl-1,3-phenylenediamine
in ethanol in the presence of zinc chloride. The two potentially tetradentate N2O2
Schiff bases function as neutral monodentate ligands involving only one oxygen atom in coordination. This rare coordination pattern
of a mononuclear salen-type zinc complex was revealed by X-ray crystallography and correlated with spectroscopic characterization. 相似文献