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1.
A procedure is described for the resolution of two-component mixtures by use of data from variable-angle fluorescence spectrometry. The experimental data are treated by multilinear regression. The method is applied to the resolution of mixtures of fluorescein and dichlorofluorescein at the ng ml?1 level; mean errors are < 4%. 相似文献
2.
The application of a program written in BASIC for an IBM/PC interfaced with a commercial spectrofluorimeter enables variable-angle scanning fluorescence spectra to be obtained, without modification of the instrument. The technique is effective for determinations of the components of mixtures of carbaryl, fuberidazol and warfarin, all of which are pesticides with intrinsic fluorescence and closely overlapping profiles. The proposed method permitted simultaneous determinations with RSD of less than 2.5% and recoveries of 99–110%. 相似文献
3.
Stephen MT Hoke Gaoyang Liang A Irina Mutiu Julie Genereaux Christopher J Brandl 《BMC biochemistry》2007,8(1):16
Background
Spt7 is an integral component of the multi-subunit SAGA complex that is required for the expression of ~10% of yeast genes. Two forms of Spt7 have been identified, the second of which is truncated at its C-terminus and found in the SAGA-like (SLIK) complex. 相似文献4.
Sequential Synthesis of 3 d–3 d, 3 d–4 d,and 3 d–5 d Hybrid Polyoxometalates and Application to the Electrocatalytic Oxygen Reduction Reactions
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Dr. Guillaume Rousseau Shuangshuang Zhang Dr. Olivier Oms Dr. Anne Dolbecq Dr. Jérôme Marrot Dr. Rongji Liu Xinke Shang Prof. Guangjin Zhang Prof. Pierre Mialane 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(34):12153-12160
The Co7(AlePy)2 polyoxometalate, which encloses a {(PW9)2CoII7} core covalently bound to two free aminopyridine groups through bisphosphonate ligands ( AlePy ), has been isolated. It can be used as a precursor, allowing the synthesis of heterometallic hybrid compounds, as illustrated by the characterization of cobalt/zinc ( Co7(AlePyZn)2 ), cobalt/palladium ( Co7(AlePyPd)2 ), and cobalt/platinum ( Co7(AlePyPt)2 ) species. A composite based on the water‐insoluble precious metal‐free Co7(AlePyZn)2 compound and the low‐cost carbon material Vulcan XC‐72 has been selected as a cathode material ( Co7Zn/C ) for oxygen reduction reaction studies. The electrocatalytic performances of the Co7Zn/C hybrids were assessed at neutral and basic pH, showing that Co7Zn/C exhibits high selectivity for the four‐electron reduction of O2. Moreover, its durability is superior to that of a commercial Pt/C catalyst with 20 % loading. Also, comparative studies performed in the presence of methanol have indicated that Co7Zn/C has a much better tolerance to the crossover effect than Pt/C . Altogether, these results indicate for the first time that, even in neutral media, polyoxometalate/carbon composites can represent low‐cost oxygen reduction catalysts that can function stably, for a long time, and with high performance. 相似文献
5.
B. Roussière E. Le Blanc G. Savard H. T. Duong J. Pinard S. Liberman J. K. P. Lee J. E. Crawford G. Thekkadath P. Kilcher J. Obert J. Oms J. C. Putaux J. Sauvage ISOCELE Collaboration 《Hyperfine Interactions》1988,43(1-4):473-476
Isotope shift (IS) and hyperfine structure (HFS) measurements have been performed for185, 187, 189, 191, 195Pt using the PILIS (Post ISOCELE Laser Isobar Separator) apparatus installed at the ISOCELE facility. Magnetic and quadrupole
moments have been deduced from the HFS results. The charge radius changes determined for these odd nuclei from the IS results,
added to the σ<r2> values of the even-A nuclei are compared to the results of lattice Hartree-Fock+BCS calculations for asymmetric solutions:185Pt is confirmed to be prolate shaped whereas187, 189, 191Pt are likely triaxial in their ground states. 相似文献
6.
B. Roussière F. Le Blanc J. Pinard L. Cabaret J. Crawford H. T. Duong J. Genevey G. Huber F. Ibrahim M. Krieg J. K. P. Lee J. Obert J. Oms J. C. Putaux C. Richard-Serre J. Sauvage V. Sebastian 《Acta Physica Hungarica A》1998,7(1):97-100
Isotope shift and hyperfine structure measurements have been performed on the short lived184Au nucleus using the COMPLIS apparatus installed at ISOLDE. The charge radius change and the magnetic and quadrupole moments of both isomeric and ground states have been deduced. The184Au ground state appears to be slightly more deformed than the isomeric state. 相似文献
7.
J. Sauvage J. Libert B. Roussière D. Verney L. Cabaret J. E. Crawford J. Genevey G. Huber F. Ibrahim F. Le Blanc J. K. P. Lee J. Oms J. Pinard 《Physics of Atomic Nuclei》2001,64(6):1134-1140
Nuclear and atomic spectroscopy measurements have provided a great number of data on the neutron-deficient Pt and Hg nuclei. The odd-A Pt and Hg with A<186 have a prolate shape, and the even-even isotopes have a triaxial shape, while the nuclear shape of the odd-A Pt and Hg with A>186 is still an open question. The energy of the low-lying levels and the nuclear moments have been calculated in the framework of a semimicroscopic “axial-rotor + 1 quasiparticle” coupling model. The predictions are compared with the experimental data and discussed. The results strongly suggest a prolate shape for the negative-parity low-lying states of the odd-A 187–191Pt and 187–193Hg isotopes. 相似文献
8.
D. Verney L. Cabaret J. E. Crawford H. T. Duong B. Fricke J. Genevey G. Huber F. Ibrahim M. Krieg F. Le Blanc J. K. P. Lee G. Le Scornet D. Lunney J. Obert J. Oms J. Pinard J. C. Puteaux K. Rashid B. Roussière J. Sauvage V. Sebastian 《The European Physical Journal A - Hadrons and Nuclei》2006,30(3):489-518
Laser spectroscopy measurements have been performed on neutron-deficient and stable Ir isotopes using the COMPLIS experimental
setup installed at ISOLDE-CERN. The radioactive Ir atoms were obtained from successive decays of a mass-separated Hg beam
deposited onto a carbon substrate after deceleration to 1kV and subsequently laser desorbed. A three-color, two-step resonant
scheme was used to selectively ionize the desorbed Ir atoms. The hyperfine structure (HFS) and isotope shift (IS) of the first
transition of the ionization path 5d
76s
24
F
9/2 → 5d
76s6p
6
F
11/2 at 351.5nm were measured for 182-189Ir, 186Ir
m
and the stable 191, 193Ir. The nuclear magnetic moments μI and the spectroscopic quadrupole moments Qs were obtained from the HFS spectra and the change of the mean square charge radii from the IS measurements. The sign of μI was experimentally determined for the first time for the masses 182≤A≤189 and the isomeric state 186Ir
m
. The spectroscopic quadrupole moments of 182Ir and 183Ir were measured also for the first time. A large mean square charge radius change between 187Ir and 186Ir
g
and between 186Ir
m
and 186Ir
g
was observed corresponding to a sudden increase in deformation: from β2 ≃ + 0.16 for the heavier group A = 193, 191, 189, 187 and 186m to β2≥ + 0.2 for the lighter group A = 186g, 185, 184, 183 and 182. These results were analyzed in the framework of a microscopic treatment of an axial rotor plus one
or two quasiparticle(s). This sudden deformation change is associated with a change in the proton state that describes the
odd-nuclei ground state or that participates in the coupling with the neutron in the odd-odd nuclei. This state is identified
with the π3/2+[402] orbital for the heavier group and with the π1/2-[541] orbital stemming from the 1h
9/2 spherical subshell for the lighter group. That last state seems to affect strongly the observed values of the nuclear moments. 相似文献
9.
Sequential injection system for on-line analysis of total nitrogen with UV-mineralization 总被引:2,自引:0,他引:2
An automatic method for the determination of total nitrogen in wastewater by sequential injection analysis and mineralization with UV radiation has been developed. The method is based on the mineralization of the samples with sodium persulphate in basic medium under UV radiation. Small volumes of sample and reagents are firstly aspirated into a single channel and then propelled by flow reversal to the UV reactor and then to the detector. The organic and inorganic nitrogen compounds are oxidized to nitrate that is then measured at 226 nm. The sequential injection procedure has been optimized and the factors affecting the efficiency of the oxidation have been studied with a number of test substances with different chemical structures and properties. Solutions in the concentration range 1-56 g l−1 of nitrogen can be analyzed with the described procedure. The sample rate is of 30-40 samples h−1. The LOD is 0.6 mg l−1 N and the reproducibility is 1.8% (28 mg l−1 N). Organic carbon in the form of glucose was added to a number of test solutions to study the potential interference of organic matter.The method was compared with the Kjeldahl digestion method by analyzing 15 wastewater samples with both methods. The nitrate and nitrite content of the non-oxidized samples were subtracted from the corresponding nitrogen content determined after photo-oxidation and the value compared with the Kjeldahl nitrogen content. 相似文献
10.
M. T. Oms R. Forteza V. Cerdà F. García A. L. Ramos 《International journal of environmental analytical chemistry》2013,93(1-4):1-14
Abstract The use of variable-angle fluorescence spectra together with multilinear curve-fitting techniques for the resolution of mixtures of polycyclic aromatic hydrocarbons (PAHs), is described. Only one spectrum is necessary to determine four compounds in a mixture even when a severe overlap occurs. The PAHs are quantified at ng/ml levels. 相似文献