Efficient measurement of (3)J(N,Cgamma) and (3)J(C',Cgamma) coupling constants of aromatic residues in (13)C, (15)N-labeled proteins

An NMR pulse sequence is proposed for the simultaneous determination of side chain chi1 torsion-angle related (3)J(N,Cgamma) and (3)J(C', Cgamma) couplings in aromatic amino acid spin systems. The method is of the quantitative J correlation type and takes advantage of attenuated (15)N and (1)H transverse relaxation by means of the TROSY principle. Unlike previously developed schemes for the measurement of either of the two coupling types, spectra contain internal reference peaks that are usually recorded in separate experiments. Therefore, the desired information is extracted from a single rather than four data sets. The new method is demonstrated with uniformly (13)C/(15)N labeled Desulfovibrio vulgaris flavodoxin, which contains 14 aromatic out of 147 total amino acid residues.     

Cross-section measurement for Ni（n,x）^58（m＋g）Co, Ni（n, x）^60mCo, Ni（n,x）^61Co and Ni（n,x）^62mCo reactions induced by neutrons around 14 MeV

The cross sections of Ni(n,x)~(58(m g))Co,Ni(n,x)~(60m)Co,Ni(n,x)~(61)Co and Ni(n,x)~(62m)Co reactions induced by neutrons around 14 MeV were measured in this work and calculated by a previously developed formula in this work.The neutron flux was determined using the monitor reaction ~(27)Al(n,α)~(24)Na and the neutron energies were measured with the method of cross-section ratios for ~(90)Zr(n,2n)~(89)Zr to ~(93)Nb(n,2n)~(92m)Nb reactions.     

Synthesis, crystal structure, and spectroscopic study of K0.92(2) Zn0.08(2) H1.92(2) (PO4) (Zn-KDP)

The structure of K0.92₍₂₎ Zn_0.08(2) H_1.92(2) (PO₄) was determined using single-crystal X-ray diffraction. The crystal structure of the Zn-KDP belonged to the tetragonal space group $ \mathrm{I}\overline{4}2\mathrm{d} $ , with cell parameters of a?=?b?=?7.4487(5)?Å and c?=?6.9703(5)?Å, 386.73(5) Å3, Z?=?4, and R?=?0.023. Zn²⁺ ions were used as substitutes for K⁺ ions with hydrogen vacancy. The Zn-KDP single crystals were submitted to further Raman, infrared, and ¹H NMR studies to investigate chemical group functionalisation, possible bonding between the organic and inorganic materials, and partial substitution of K⁺ by Zn²⁺. The latter partial substitution was confirmed by the deviation of IR frequencies for O–H stretching, the variation of IR and Raman frequencies for stretching and bending vibrations ν(PO₄) of H₂PO₄, and the appearance of additional Raman (147, 386 and 481 cm^?1) vibrational bands. Electrical conductivity measurements were performed on polycrystalline pellets of Zn-KDP and pure KDP at room temperatures (RT) of up to 473K. In both cases, a conductivity jump close to 453K was observed, and a stronger increase of conductivity was measured.     

The (τ,d), (d,p) and (d,n) reactions on28Si

The model of a three-particle proton cluster coupled to the quadrupole vibrational field is applied to¹²⁹I. The energy spectrum and spectroscopic factors, as obtained in a (³He,d) stripping reaction, are calculated and compared with experimental data. With the wave functions obtained magnetic-dipole and electric-quadrupole moments are derived.     

Thermostability and magnetic properties of Sm2(Fe,M)17(C,N)y (M=Ga,Al and Si)

The effect of heat treatments on the interstitial nitrides and carbides prepared from Sm₂(Fe,M)₁₇ and Sm₂Fe₁₅Ga₂C₂ by gas–solid reaction (GSR) was investigated in order to understand more about the influence of the substitutions M=Ga, Al and Si on the thermostability of these compounds. X-ray diffraction measurements of the heat-treated samples have shown that all of these substitutions improve the thermostability of the Th₂Zn₁₇-type interstitial structure, with Al having the smallest influence and Si and Ga having a stronger influence on the thermostability. Contrary to the nitrides, the carbides prepared by GSR can be significantly stabilized with an increasing amount of the stabilizing elements. Already for a small amount of the substitution element, e.g. Sm₂Fe_16.5Ga_0.5, the 2 : 17-type interstitial phase was stabilized up to 750°C. Carburization at temperatures above 500°C was possible for the stabilized 2 : 17 compounds making possible much shorter carburization times for high C contents. Investigations on Sm₂Fe₁₅Ga₂C_y have revealed a dependence of the thermostability on the amount of absorbed C and on the processing route for the interstitial modification by GSR. A coercivity μ_0JH_c up to about 2.8 T was obtained for Sm₂Fe₁₅Ga₂C₂N showing the magnetic potential of these modified compounds.     

Light hadron, charmonium(-like) and bottomonium(-like) states

Hadron physics represents the study of strongly interacting matter in all its manifestations and understanding its properties and interactions. The interest in this field has been revitalized by the discovery of new light hadrons, charmonium- and bottomonium-like states. In this paper, the most recent experimental results from different experiments are reviewed.     

Conservation Laws of K(m, n) and mK(m, n) Equations

Based on the rank analysis method, algorithmization idea, and symbolic computation, in this paper we have presented a method to construct the conservation laws for nonlinear evolution equations. The polynomial conservation laws for K (n 2, n) equations and mnK(m, n) equations are found by using of this approach and some new results have been obtained.     

Far-infrared and mid-infrared absorption in (Bi,Pb)-Sr-(Ca,Y)-Cu-O

The reflectivities of seven films belonging to the Bi-Sr-Ca-Cu-O family, with T_c ranging from 60 to 95 K, and of a single crystal of insulating Bi-Sr-Y-Cu-O, have been measured at room temperature in the normal phase. The optical conductivity has been analyzed in terms of Drude (D), mid-infrared (MIR), and charge-transfer (CT) contributions. As T_c increases, the spectral weight within the charge-transfer gap (D+MIR) increases. Meanwhile, the peak frequency of the MIR band moves towards the far-infrared and the optical conductivity becomes more similar to that of a normal metal.     

(n,p)和(n,α)激发函数半经验计算方法

在En≤20MeV的情况下,忽略了粒子的二次发射过程,认为复合系统的形成截面是能量相关的,得到了理论模型清晰、公式形式简单的半经验计算方法.在靶核23≤A≤209的范围内,利用大量(n,p)和(n,α)反应的截面实验数据对可调参数进行了研究,得到了参数对靶核的N和Z以及入射能量的依赖关系.对得到的参数做了定性的解释,利用普适参数对(n,p)和(n,α)反应的激发函数做了预言,预言值在其误差范围内与实验数据一致. To simplify the calculation, some assumptions are considered at present work. The preequilibrium emission is the first step in the equilibrium process, which is characterized by exciton n=3 and "never come back" are considered at the preequilibrium emission process; the proton and alpha emissions are only competed with the neutron emission, the second particle emission is neglected. A semiempirical method of the cross section for (n, p ) and (n, α) reactions were obtained on the basis of evaporatio...     

The (He,p) and (d, α) reactions to states in Co

The ⁵⁶Fe(³He, p)⁵⁸Co and ⁶⁰Ni(d, α)⁵⁸Co reactions have been investigated at 12.0 and 7.0 MeV bombarding energies, respectively, using the MIT multiple-gap spectrograph. For the (³He, p) reaction, levels below 6.0 MeV of excitation were observed and analysed using the DWBA to obtain L-values. In the (d, α) reaction, levels up to 3.4 MeV of excitation were observed. A level scheme for ⁵⁸Co is proposed. The ⁵⁸Fe(0.0) analogue was observed, and candidates for the antianalogue level are identified.     

Alignment delays in the N = Z nuclei (72)Kr, (76)Sr, and (80)Zr

The ground state rotational bands of the N = Z nuclei (72)Kr, (76)Sr, and (80)Zr have been extended into the angular momentum region where rotation alignment of particles is normally expected. By measuring the moments of inertia of these bands we have observed a consistent increase in the rotational frequency required to start pair breaking, when compared to neighboring nuclei. (72)Kr shows the most marked effect. It has been widely suggested that these "delayed alignments" arise from np-pairing correlations. However, alignment frequencies are very sensitive to shape degrees of freedom and normal pairing, so the new experimental observations are still open to interpretation.     

The Zr(d,n)Nb and Zr(d,n)Nb reactions

The (d, n) reaction on ⁹⁰Zr and ⁹⁶Zr has been studied at 12 MeV deuteron bombarding energy using the neutron time-of-flight technique with an overall neutron time resolution of 1.9 ns. Angular distributions of neutron groups leading to states in ⁹¹Nb and ⁹⁷Nb were measured in the angular range between 15° and 60°. The measured cross sections were analyzed in the framework of the distorted-wave theory of stripping reactions to deduce l-values and proton spectroscopic factors of states in the residual nuclei. The results are compared with the corresponding data available from (³He, d) studies. The fractionation of the single-particle proton states and their centroid energies are determined.     

Is (3He,t) primarily A (3He,α) (α,t) reaction?

The reaction ⁴⁸Ca(³He, t)⁴⁸Sc to the low-lying even spin states has been studied as a pure sequential (³He, α) (α,t) process using an exact finite-range formalism. It is found that the strength of the cross-sections to these states is under-predicted by large factors. The consideration of second-order processes via the inelastic channels also fails to account for the strength of these states. The (³He, t) discrepancy still exists.     

Decays of σ, κ, a0(980) and f0(980)

Ratios of coupling constants for these decays are compared with qq̄ predictions and Jaffe’s q²q̄² model. In both models, the predicted ratio g²(κ→Kπ)/g²(σ→ππ) is much too small. Also, for qq̄, the predicted ratio g²(κ→Kη’)/g²(κ→Kπ) is much larger than observed. Both models fail for g²(f₀→KK)/g²(a₀→KK). This ratio requires that f₀ has a dominant KK component. It arises naturally because the f₀ pole lies very close to the KK threshold, giving its wave function a long KK tail. PACS 13.25.Gv, 14.40.Gx, 13.40.Hq     

Conservation Laws of K（m,n） and mK（m,n） Equations

Based on the rank analysis method, algorithmization idea, and symbolic computation, in this paper we have presented a method to construct the conservation laws for nonlinear evolution equations. The polynomial conservation laws for K (n 2,n) equations and mK (m,n) equations are found by using of this approach and some new results have been obtained.     

Elastic Modulus,Hardness,and Fracture Toughness of Li_(6.4)La_3Zr_(1.4)Ta_(0.6)O_(12) Solid Electrolyte

Li_(6.4)La_3 Zr_(1.4)Ta_(0.6)O_(12)(LLZTO) is a promising inorganic solid electrolyte due to its high Li+conductivity and electrochemical stability for all-solid-state batteries.Mechanical characterization of LLZTO is limited by the synthesis of the condensed phase.Here we systematically measure the elastic modules,hardness,and fracture toughness of LLZTO poly crystalline pellets of different densities using the customized environmental nanoindentation.The LLZTO samples are sintered using the hot-pressing method with different amounts of Li_2CO_3 additives,resulting in the relative density of the pellets varying from 83% to 98% and the largest grain size of 13.21 ± 5.22 μm.The mechanical properties show a monotonic increase as the sintered sample densifies,elastic modulus and hardness reach 158.47± 10.10 GPa and 11.27± 1.38 GPa,respectively,for LLZTO of 98% density.Similarly,fracture toughness increases from 0.44 to 1.51 MPa·m~(1/2),showing a transition from the intergranular to transgranular fracture behavior as the pellet density increases.The ionic conductivity reaches 4.54 × 10~(-4) S/cm in the condensed LLZTO which enables a stable Li plating/stripping in a symmetric solid-state cell for over 100 cycles.This study puts forward a quantitative study of the mechanical behavior of LLZTO of different microstructures that is relevant to the mechanical stability and electrochemical performance of all-solid-state batteries.     

Bremsstrahlung neutrino energy loss for ~(24)Mg, ~(28)Si, ~(32)S, ~(40)Ca, ~(56)Fe in strong electron screening

Based on WeinbergoSalam theory the bremsstrahlung neutrino energy loss for nuclei ~(24)Mg, ~(28)Si, ~(32)S, ~(40)Ca and ~(56)Fe are investigated in strong electron screening. Our results are compared with those of Dicus' and show that the latter are higher by 2 orders of magnitude in the density-temperature region of 10~8 g/cm~3 ≤ρ/μ_e≤10~(11) g/cm~3 and 2.5 ≤ T_9 ≤4.5. On the other hand, the factor C shows that the maximum differences are 99.16%, 99.13%, 99.12%, 99.055%, 99.040% corresponding to the nuclei ~(24)Mg, ~(28)Si, ~(32)S, ~(40)Ca and ~(56)Fe.