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1.
2.
The study focuses on the 2H/H, 13C/12C, 15N/14N, 18O/16O and 34S/32S values of defatted dry matter (DFDM) and on the 2H/H, 13C/12C and 18O/16O values of the fat fraction of meat samples from various lamb types reared in seven Italian regions, following different feeding regimes (forage, concentrate, milk). The 13C/12C (r = 0.922), 2H/H (r = 0.577) and 18O/16O (r = 0.449) values of fat and DFDM are significantly correlated, the fat values being significantly lower for C and H and higher for O than for DFDM values and the differences between the two fractions not being constant for different lamb types. The feeding regime significantly affected the 13C/12C, 15N/14N, 18O/16O and 2H/H of fat. The DFDM 2H/H, and 18O/16O values, excluding an outlier, are significantly correlated with the corresponding values in meteoric waters, thus allowing us to trace the variability of geoclimatic factors. 15N/14N is influenced by pedoclimatic conditions, whereas 34S/32S is influenced by the sea spray effect and the surface geology of the provenance area. By applying stepwise linear discriminant analysis only the 2H/H of fat was found not to be significant and 97.7% of the samples were correctly assigned to the lamb type and more than 90% cross‐validated. With the feeding regime, 97.7% of the samples were both correctly assigned and cross‐validated using a predictive model including 13C/12C, 15N/14N, 18O/16O, 34S/32S of DFDM and 18O/16O of fat. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

3.
脯氨酸类衍生物结构独特,鲜有报道利用核磁共振(nuclear magnetic resonance,NMR)技术对氨基酸的手性进行鉴别.利用多种NMR技术:1H NMR、1H-1H同核位移相关谱(1H-1H COSY)、1H-1H质子全相关谱(1H-1H TOCSY)、1H-1H核Overhauser效应谱(1H-1H NOESY)、13C NMR、无畸变的极化转移增强法(DEPT135°)、1H-13C检出1H的异核单量子相干(1H-13C HSQC)和1H-13C检出1H的异核多键相关(1H-13C HMBC),对脯氨酸类N-酰胺衍生物两种构象异构体的1H和13C NMR进行了全归属,确定了室温下在二甲基亚砜(DMSO)中L型和D型的顺反异构体以相同的比例同时存在.  相似文献   

4.
Potential energy curves of 22 electronic states of RhN have been calculated by the complete active space second‐order perturbation theory method. The X1Σ0+ is assigned as the ground state, and the first excited state a3Π0+ is 978 cm?1 higher. The 1Δ(I) and B1Σ+ states are located at 9521 and 13,046 cm?1 above the ground state, respectively. The B1Σ+ state should be the excited state located 12,300 cm?1 above the ground state in the experimental study. Moreover, two excited states, C1Π and b3Σ+, are found 14,963 and 15,082 cm?1 above the X1Σ+ state, respectively. The transition C1Π1–X1Σ0+ may contribute to the experimentally observed bands headed at 15,071 cm?1. There are two excited states, D1Δ and E1Σ+, situate at 20,715 and 23,145 cm?1 above the X1Σ+ state. The visible bands near 20,000 cm?1 could be generated by the electronic transitions D1Δ2–a3Π1 and E1Σ+0–X1Σ+0 because of the spin–orbit coupling effect. © 2013 Wiley Periodicals, Inc.  相似文献   

5.
A recently discovered phenomenon of excessively high X-ray production is discussed. The high yield is attributed to the build-up of potential on non-conducting targets irradiated with accelerated ion beams, and the subsequent discharge. Ion-beams of1H+,1H2 +,2H+,2H2 +,3He+,3He2+,4He+,14N+,14N2+,16O+ and20Ne+ were used. A new mechanism of X-ray excitation is proposed. The increased X-ray fluxes produced by this process are suitable for analytical applications of high specificity. The mechanism of excitation associated with the process, factors affecting the high X-ray yields, applications and a general overview of the studies undertaken with the various ion beams are given.  相似文献   

6.
Sensitive and selective nuclear reaction methods have been sought for the nuclear microprobe measurement of the spatial distributions of13C and13C/12C ratios. The13C(α, n)16O reaction, with neutron detection, is the most selective for13C, and has a sensitivity of ca. 100 ppm. The reactions13C(d, p)14C and12C(d, p)13C, with proton detection, are the most sensitive for the simultaneous measurement of13C and12C, with detection limits of 30 and 2 ppm respectively. Less sensitive alternative reaction pairs are;13C(3He, p)15N and12C(3He, p)14N;13C(d, nγ)14N and12C(d, pγ)13C;13C(3He, pγ)15N and12C(3He, pγ)14N. The conditions governing their use, particularly light element interferences, are detailed.  相似文献   

7.
The vibrational spectra of a number of transition-metal complexes containing terminal or bridging nitrido (N3?) and oxo (O2?) ligands are reported. Full assignments of fundamental modes are given for (OsO314N)?, (OsO315N)?, (Os14NX4)?, (Os15NX4)?, (Ru14NX4)?, (Os14NX5)2?, (Os15NX5)2? and (Ru14NX5)2? (X = Cl, Br), and also for the oxo complexes (Mo16OCl4, (Mo18OCl4)?, (Mo16OCl5)2? and (Mo18OCl5)2?. Force constants have been evaluated for the four- and five-coordinate complexes. The significance of the results is discussed in terms of the metalligand bonding involved in these species.  相似文献   

8.
We have measured the ionic conductivities of pressed pellets of the layered compounds MUO2PO4 · nH2O, and correlated the results with TGA data. The conductivities (in ohm?1 m?1), at temperatures increasing with decreasing water content over the range 20 to 200°C, were approximately as follows: Li+4H2O, 10?4; Li+, Na+, K+, and NH4+3H2O, 10?4, 10?2, 10?4, and 10?4; H+, Li+, and Na+1.5H2O, 10?2, 10?4, and 10?4; Na+1H2O, 10?5; H+, K+, and NH4+0.5H2O, all 10?5; and H+, Li+, Na+, K+, NH+4, and 12Ca2+OH2O, 10?5, 10?5, 10?4, 10?5, 10?5, and 10?6. A ring mechanism is proposed to account for the high conductivity found in NaUO2PO4 · 3.1H2O. The accurate TGA data showed that most of the hydrates had water vacancies of the Schottky type, and should be represented as MUO2PO4(A ? x)H2O, where x can be between 0 and 0.3.  相似文献   

9.
Summary The chelation behaviour of the complexes of La3+, Ce3+, Pr3+, Nd3+, Sm3+, Eu3+, Gd3+, Y3+, Tb3+, Dy3+, Ho3+ with biologically active 2-Hydroxy-1-naphthaldehyde semicarbazone (HNAS) has been studied potentiometrically in 75% (v/v) dioxane-water medium at various ionic strengths. The method of Bjerrum and Calvin, as modified by Irving and Rossotti has been used to find out the values of n andpL. The formation constants of metal chelates and the values ofS min have been calculated. The order of formation constants of chelates was found to be: La3+3+3+3+3+3+3+3+3+3+3+.
Physikochemische Untersuchungen zur Komplexierung von biologisch aktivem 2-Hydroxy-1-naphthaldehyd-Semicarbazon (HNAS) mit Lanthanoiden
Zusammenfassung Das Chelierungsverhalten von La3+, Ce3+, Pr3+, Nd3+, Sm3+, Eu3+, Gd3+, Y3+, Tb3+, Dy3+ und Ho3+ mit 2-Hydroxy-1-naphthaldehydsemicarbazon (HNAS) wurde potentiometrisch in 75% (v/v) Dioxan-Wasser bei verschiedenen Ionenstärken untersucht. Die Werte für n undpL wurden nach der Methode von Bjerrum und Calvin in der Modifikation von Irving und Rossotti bestimmt. Die Komplexbildungskonstanten der Metallchelate und die WerteS min wurden ermittelt. Die Reihung der Komplexbildungskonstanten war La3+3+3+3+3+3+3+3+3+33+.
  相似文献   

10.
In the wavelength range of 231-275 nm, we have studied the mass-resolved dissociation spectra of OCS+ via B2+←X23/2(000) and B2+←X21/2(000, 001) transitions by preparing OCS+ ions in the well-defined spin-orbit states. The spectroscopic constants ofυ1(CS stretch)=828.9 (810.4) cm-1, υ2(bend)=491.3 cm-1 and υ3(CO stretch)=1887.2 cm-1 for OCS+(B2+) are deduced. The observed dependence of the υ2(bend) mode excitation of B2+ on the spin-orbit splitting of X2∏(Ω=1/2, 3/2) in the B2+←X2∏ transition can be attributed to the K coupling between the (000)21/2 and (010)2+1/2 vibronic levels of X2∏ state, which makes the B2+(010)←X21/2(000) transition possible.  相似文献   

11.
Coordination Chemistry of P‐rich Phosphanes and Silylphosphanes XXI The Influence of the PR3 Ligands on Formation and Properties of the Phosphinophosphinidene Complexes [{η2tBu2P–P}Pt(PR3)2] and [{η2tBu2P1–P2}Pt(P3R3)(P4R′3)] (R3P)2PtCl2 and C2H4 yield the compounds [{η2‐C2H4}Pt(PR3)2] (PR3 = PMe3, PEt3, PPhEt2, PPh2Et, PPh2Me, PPh2iPr, PPh2tBu and P(p‐Tol)3); which react with tBu2P–P=PMetBu2 to give the phosphinophosphinidene complexes [{η2tBu2P–P}Pt(PMe3)2], [{η2tBu2P–P}Pt(PEt3)2], [{η2tBu2P–P}Pt(PPhEt2)2], [{η2tBu2P–P}Pt(PPh2Et)2], [{η2tBu2P–P}Pt(PPh2Me)2], [{η2tBu2P–P}Pt(PPh2iPr], [{η2tBu2P–P}Pt(PPh2tBu)2] and [{η2tBu2P–P}Pt(P(p‐Tol)3)2]. [{η2tBu2P–P}Pt(PPh3)2] reacts with PMe3 and PEt3 as well as with tBu2PMe, PiPr3 and P(c‐Hex)3 by substituting one PPh3 ligand to give [{η2tBu2P1–P2}Pt(P3Me3)(P4Ph3)], [{η2tBu2P1–P2}Pt(P3Ph3)(P4Me3)], [{η2tBu2P1–P2}Pt(P3Et3)(P4Ph3)], [{η2tBu2P1–P2}Pt(P3MetBu2)(P4Ph3)], [{η2tBu2P1–P2}Pt(P3iPr3)(P4Ph3)] and [{η2tBu2P1–P2}Pt(P3(c‐Hex)3)(P4Ph3)]. With tBu2PMe, [{η2tBu2P–P}Pt(P(p‐Tol)3)2] forms [{η2tBu2P1–P2}Pt(P3MetBu2)(P4(p‐Tol)3)]. The NMR data of the compounds are given and discussed with respect to the influence of the PR3 ligands.  相似文献   

12.
Radioactivity of coals and fly ashes   总被引:1,自引:0,他引:1  
The level and the behavior of the naturally occurring primordial radionuclides 238U, 226Ra, 210Pb, 232Th, 228Ra and 40K in coals and fly ashes are described. The activity concentrations of the examined coals and originated from coal mines in Greece ranged from 117 to 435 Bq·kg−1 for 238U, from 44 to 255 Bq·kg−1 for 226Ra, from 59 to 205 Bq·kg−1 for 210Pb, from 9 to 41 Bq·kg−1 for 228Ra and from 59 to 227 Bq·kg−1 for 40K. These levels are comparable to those appeared in coals of different countries worldwide. The activity concentrations of the examined fly ashes and produced in coal-fired power plants in Greece ranged from 263 to 950 Bq·kg−1 for 238U, from 142 to 605 Bq·kg−1 for 226Ra, from 133 to 428 Bq·kg−1 for 210Pb, from 27 to 68 Bq·kg−1 for 228Ra and from 204 to 382 Bq·kg−1 for 40K. The results showed that there is an enrichment of the radionuclides in fly ash relative to the input coal during the combustion process. The enrichment factors (EF) ranged from 0.60 to 0.76 for 238U, from 0.69 to 1.07 for 226Ra, from 0.57 to 0.75 for 210Pb, from 0.86 to 1.11 for 228Ra and from 0.95 to 1.10 for 40K.  相似文献   

13.
Summary Extremely low activity levels of cosmic ray induced nuclides have been measured in freshly precipitated rainwater by quick chemical separation coupled with ultra low background gamma-spectrometry. The nuclides detected were 38S (T1/2 = 2.83 h)-38Cl (37.2 m), 39Cl (55.6 m), 24Na (14.96 h), 28Mg (20.9 h), 7Be (53.3 d) and 22Na (2.602 y). The number of atoms in rain water were evaluated to be ranging from 400-1900 l-1 for 39Cl (n = 6, mean: 1200), 30-1500 l-1 for 24Na (n = 16, mean: 520), 80-600 l-1 for 28Mg (n = 13, mean: 260), 1 . 106-4 . 107 l-1 for 7Be (n = 16, mean: 7 . 106) and 2 . 103-1 . 105 l-1 for 22Na (n = 9, mean: 2 . 104). Measurements of activity levels and activity ratios of short-lived cosmic-ray induced short-lived nuclides will open new method to understand atmospheric processes occurred at the altitude of rain cloud.  相似文献   

14.
The ΔJ = 0,l-doublet transitions of OCS isotopes (16O12C32S, 16O12C33S, 16O12C34S, 16O13C32S and 18O12C32S) in the (0110) vibrational state have been measured in a molecular-beam electric-resonance spectrometer equipped with a nozzle source. Rotation-vibration coupling constants and electric dipole moments have been determined for all isotopes, and the spin-rotation and the quadrupole coupling constants for the 33S nucleus in 16O12C33S in the υ2=0 and υ2=1 states.  相似文献   

15.
The composition of nickel hexacyanoferrate(II) complexes depends on the ratios of sodium hexacyanoferrate(II) and nickel nitrate solutions mixed. The adsorption behavior of nickel hexacyanoferrate(II) is described; acid treatment of Ni2Fe(CN)6 accelerates the adsorption rate of cesium, but does not increase the adsorption capacity. The Ni—Cs exchange ratios of Ni2Fe(CN)6 are discussed. In concentrated salt solutions, the distribution coefficients of 59Fe, 60Co, 65Zn. 137Cs, 95Zr and 144Ce are determined together with those of 85Sr and 106Ru. A simple determination of 137Cs in sea water containing 59Fe, 60Co, 65Zn, 95Zr, 144Ce, 85Sr and 106Ru is described.  相似文献   

16.
The CASPT2 potential energy curves (PECs) for O‐loss dissociation from the X2Π, A2Π, B2Σ+, C2Σ+, 14Σ?, 12Σ?, and 14Π states of the OCS+ ion were calculated. The PEC calculations indicate that X2Π, 14Σ?, 12Σ?, and 14Π correlate with CS+(X2Σ+) + O(3Pg); A2Π and B2Σ+ correlate with CS+(A2Π) + O(3Pg); and C2Σ+ probably correlates with CS+(X2Σ+) + O(1Dg). The CASSCF minimum energy crossing point (MECP) calculations were performed for the C2Σ+/14Σ?, C2Σ+/14Π, A2Π/14Σ?, A2Π/12Σ?, A2Π/14Π, and B2Σ+/12Σ? state pairs and the spin‐obit couplings were calculated at the located MECPs. A conical intersection point between the B2Σ+ and C2Σ+ potential energy surfaces was found at the CASSCF level. Based on our calculations, seven O‐loss predissociation processes of the C2Σ+ state are suggested and an appearance potential value of 7.13 eV for the CS+ + O product group is predicted. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011  相似文献   

17.
The 17O and 2H quadrupole coupling constants of rovibrational levels of 17O1H+, 17O2H+, and 16O2H+ in their X3Σ state have been calculated from molecular wave functions that explicitly describe nuclear motion. The 17O quadrupole coupling is predicted to be strong and its vibrational dependence differs from that known for other nuclei A in the first-row hydrides AH or AH+. The deuterium coupling in 17O2H+ and 16O2H+ is found to be weak and its behavior is similar to that of other first-row hydrides. The change with rotational excitation is unimportant. The quadrupole hyperfine patterns of 17O2H+ in its ground state are dominated by the strong oxygen coupling. © 1996 John Wiley & Sons, Inc.  相似文献   

18.
In this study, the titanyl and vanadyl phthalocyanine (Pc) salts (Bu4N+)2[MIVO(Pc4?)]2? (M=Ti, V) and (Bu3MeP+)2[MIVO(Pc4?)]2? (M=Ti, V) with [MIVO(Pc4?)]2? dianions were synthesized and characterized. Reduction of MIVO(Pc2?) carried out with an excess of sodium fluorenone ketyl in the presence of Bu4N+ or Bu3MeP+ is exclusive to the phthalocyanine centers, forming Pc4? species. During reduction, the metal +4 charge did not change, implying that Pc is an non‐innocent ligand. The Pc negative charge increase caused the C?N(pyr) bonds to elongate and the C?N(imine) bonds to alternate, thus increasing the distortion of Pc. Jahn–Teller effects are significant in the [eg(π*)]2 dianion ground state and can additionally distort the Pc macrocycles. Blueshifts of the Soret and Q‐bands were observed in the UV/Vis/NIR when MIVO(Pc2?) was reduced to [MIVO(Pc . 3?)] . ? and [MIVO(Pc4?)]2?. From magnetic measurements, [TiIVO(Pc4?)]2? was found to be diamagnetic and (Bu4N+)2[VIVO(Pc4?)]2? and (Bu3MeP+)2[VIVO(Pc4?)]2? were found to have magnetic moments of 1.72–1.78 μB corresponding to an S=1/2 spin state owing to VIV electron spin. As a result, two latter salts show EPR signals with VIV hyperfine coupling.  相似文献   

19.
In this article, the angular correlated configuration interaction method previously introduced by some of the authors is extended to three‐body atomic systems with general masses. A recently proposed angularly correlated basis set is used to construct ground state wave functions which: (i) satisfy exactly Kato cusp conditions at the two‐body coalescence points; (ii) have only linear coefficients; and (iii) show a fast convergency rate for the energy. The efficiency of the construction is illustrated by the study of the negatively charged hydrogen‐like systems (H?, T?, D?, 1H?, and Mu?), neutral helium‐like systems (e?e? He+2,e?e? 4He+2, e?e? 3He+2, e?μ? He+2, e?μ ?4He+2, and e?μ? 3He+2), and positively charged lithium‐like systems (e?e? Li+3, e?e? 7Li+3, e?e? 6Li+3, e?μ? Li+3, e?μ? 7Li+3, and e?μ? 6Li+3). The ground state energies and other mean values are compared with those given in the literature, when available. Wave functions with a moderate number of (20 maximum) linear coefficients are given explicitly; they are sufficiently simple and accurate to be used in practical calculations of atomic collision in which multidimensional integrations are involved. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2010  相似文献   

20.
The addition of54Mn and65Zn to a nine-radionuclide standard (containing241Am.,109Cd.57Co,139Ce,203Hg.113Sn,137Cs,88Y, and60Co) provides the capability to determine the extent of coincidence summing for gamma rays from88Y and60Co. A method for correcting the efficiency points at 1332 keV (60Co) and 1836 keV (88Y) for coincidence summing is presented.  相似文献   

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