超重核素94～102同位素链上的位能曲面研究

采用宏观-微观模型对原子核系数在94～102之间偶偶核素同位链上原子核的位能曲面进行了系统的研究,给出了这些同位素链上原子核的位能曲面图。在此基础上讨论了超重核素的形变随核子数之间的变化规律,研究了该区域可能存在的形状共存现象和超重核素的稳定性。最后对超重核区域原子核的同质异能态进行了讨论。     

Existence of single-peaked solution of a semilinear elliptic problem

We discussed the Dirichlet problem of semilinear elliptic equationin (Pβ,α)D;-β△u=uε+εu,u>0,in Ω u=0, on(e),Ω where Ω(∪)RN(N≥4) is smooth and bounded domain,P=N+2/N-2,β,ε>0. We have proved that there exist positive ε0 and ε1 , such that when 0≤ε≤ε0,β>√ε1,(P0,1)has a single-peaked solution uβ, furthermore, |▽μβ|-0in the sense of measure as ε→0 and β→0.     

Heteroseneous oxidation of carbonyl sulfide on mineral oxides

Heterogeneous oxidation of carbonyl sulfide （OCS） on mineral oxides including SiO2, Fe2O3, CaO, MgO, ZnO and TiO2, which are the main components of atmospheric particles, were investigated using in situ diffuse reflectance infrared Fourier transform spectroscopy （in situ DRIFTS）, ion chromatography （IC）, temperature-programmed desorption （TPD）, X-ray diffraction （XRD） and Brunauer-Emmett-Teller （BET） methods. The main products and intermediates of the heterogeneous oxidation of OCS on these oxides were identified with in situ DRIFTS and IC. The reaction mechanism and kinetics were also discussed. It is found that the reaction mechanism on these mineral oxides is the same as that on Al2O3 for the same final products and the intermediates at room temperature. Namely, OCS can be catalytically oxidized to produce surface SO4^2- species and gaseous CO2 through the surface hydrogen thiocarbonate （HSCO2-） and HSO; species. The activity series for heterogeneous oxidation of OCS follows： Al2O3 ≈ CaO 〉 MgO 〉 TiO2 ≈ ZnO 〉 Fe2O3 〉 SiO2. The specific area, basic hydroxyl and surface basicity of these oxides have effect on the reactivity. This study suggests that heterogeneous reactions of OCS on mineral dust may be an unneglectable sink of OCS.     

The composition and distribution of metal clusters in the MoFe protein from a nifZ deletion strain （DJ 194） of Azotobacter vinelandii

Through the anaerobic chromatography on the columns of DEAE 52, Q-Sepharose and Sephacryl S-200, a nitrogenase MoFe protein (△nifZ Av1) was obtained from a nifZ deleted mutant of Azotobacter vinelandii (stain DJ194).The results of Western blotting after anoxic native electrophoresis and SDS-PAGE showed that △nifZ Av1 was similar to wild type MoFe protein (OP Av1) at the electrophoretic mobility, molecular weight and subunit composition. Furthermore, △nifZ Avl was also similar to OP Av1 at the molybdenum content, EPR signal (g≈4.3, 3.65 and 2.01), and the molar extinction coefficient (△ε) of circular dichroism (CD)at 660 nm region. All of these indicated that, besides having the same α2β2 composition as OP Av1, the △nifZ Av1 also contained equal amount of reductive FeMoco in the spin state of S=3/2 to OP Av1. However, the iron content and substrate (C2H2, H^ and N2)-reduction activity of △nifZ Av1 were 74% and 46%-50% of those of OP Av1, respectively. Furthermore, the △ε at around 450 nm, which reflects P-cluster in Av1, was obviously lower than that of OP Av1. It suggested that the difference between △nifZ Avl and OP Av1 resulted from P-cluster rather than FeMoco, and from the half number of P-cluster in △nifZ Av1, but the composition or redoxstate of P-cluster in △nifZ Av1 were not changed. Thus it could propose that △nifZ Av1 is composed of two different αβsubunit pairs. One is a FeMoco-and P-cluster-containing pair, and the other is a P-cluster-deficient but FeMoco-containing pair. Since the deletion of nifZ gene leads to the deficiency of only one of two P-clusters in a α2β2 tetramer, the assembly of P-cluster may not simply depend on one gene product, and so a possible mechanism of NifZ is supposed here.     

Theoretical characterization of single-electron iodine-bond weak interactions in CH3…I-Y（Y=BH2,H,CH3,C2H3,C2H,CN,NC）systems

Iodine-involved single-electron halogen bonds (SEXBs) weak interactions in the systems of CH3···I-Y(Y = BH2, H, CH3, CH==CH2, C≡CH, CN, NC) were investigated for the first time using B3LYP/6-311++G(d,p) and MP2/aug-cc-pVTZ computational levels (the relativistic effective core potential basis set of Lanl2dz was used on iodine atom). The interaction energies between two moieties with basis set super-position error corrections for the seven complexes are -0.57, -1.36, -3.80, -2.17, -4.49,-6.33 and -8.64 kJ mol-1 (MP2/aug-cc-pVTZ ), respectively, which shows that SEXBs interactions are all weak. Natural bond orbital theory analysis revealed that charges flow from CH3 to the I-Y moiety. The total amount of natural bond orbital charge transfer (ΔNC) from the CH3 radical to I-Y increases in the order CH3…IBH2 < CH3…IH ≈ CH3…ICH3 ≈ CH3···IC2H3 < CH3…ICCH< CH3…ICN< CH3…INC. Atoms-in-molecules theory was used to investigate the topological properties of the bond critical points in the seven SEXB structures.     

Pairing problem of generators in Kac-Moody algebras

The following result is proved: in any Kac Moody algebra g(A) , (ⅰ) given any non central element h in the Cartan subalgebra  , or (ⅱ) given any real root vector x β, β∈Δ re . There exists y∈g(A) such that the subalgebra generated by y and h or y and x β contains the derived algebra g′(A) of g(A) .     

Monte Carlo simulations for two-dimensional Ising system far from equilibrium

With a dynamic Monte Carlo simulation, which is free of critical slowing down, the critical behavior of two-dimensional Ising model at non-equilibrium states is investigated. We focus on the two-time autocorrelation function A(t, t' ) to identify the dynamic exponent z in two different evolution stages, quenched from a high temperature state and a completely ordered state to the critical state at TC, re-spectively. By using the heat-bath algorithm, the dynamic critical exponent is estimated as z ≈ 2.16. As a result, the universality of the scaling behavior is verified numerically, and the exponent λC is deter-mined complete by λC = β /ν for the evolutions from an initial completely ordered state.     

NMR and IR investigations of ternary inclusion complexes among β-cyclodextrin, rare earth metal ions, and naphthalenediamines

Ternary inclusion complexes β-cyclodextrin (β-CD), rare earth metal ions (YbCl₃, YCl₃), and 1,8-naphthalene- diamine/1,5-naphthalenediamine are synthesized in basic aqueous media, which are characterized via ¹H NMR and IR spectroscopy. The stoichiometric proportion of β-CD:YbCl₃:1,5-naphthalenediamine is 2:1:2, that of β-CD:YCl₃:1,8-naphthalenediamine is 2:1:1, and that of β-CD:YbCl₃:1,8-naphthalenediamine is 2:1:1. The IR spectroscopy of the ternary inclusion complexes in the range of 935–1 000 cm⁻¹ reveals the existence of the coordinate bond M—O or M—N. The possible conformations of the ternary inclusion complexes are depicted. Biography: JIANG Huiming(1972–), male, Associate professor, research direction: molecular complex chemistry, supramolecular chemistry.     

New method on constructing analytic potential function of diatomic molecules

A new method on constructing analytical potential energy functions is presented, and then a relatively universal analytical potential energy function for precisely calculating the spectra of diatomic molecules and ions is derived. Furthermore, six kinds of common potential energy curves containing three main potential curves i.e. steady state, metastable state and repulsive state are obtained from this potential energy function. Finally, spectroscopic parameters of thirteen diatomic molecules and ions including BeD-X ² Σ ⁺, BeT-X ² Σ ⁺ and Na₂-X ¹ Σ _g ⁺ etc are calculated by using the potential function, as a consequence, all calculation results are in good agreement with experimental data. Biography: YU Changfeng (1962–), male, Associate professor, research direction: theoretical physics.     

Molecule modification and mass deposition induced by the implantation of low energy Fe+ ion beams into amino acids

Fe⁺ ion beams with the energy of 110 keV were implanted into films of L(+)-cysteine (HSCH₂CH(NH₂)COOH). One of the single crystals grown in hydrochloric acid solution with the implanted samples through slow evaporation was structurally characterized by the X-ray crystallography. The crystal is monoclinic, space group C2, with a = 1.8534(4) nm, b = 0.5234(1) nm, c = 0.7212(1) nm, β= 103.72°, V = 0.67965(3) nm³, Z = 4, F(000) = 144.0, D{clac} = 1.763 g · cm⁻³, μ(MoK _a = 1.06 mm⁻¹, T = 293(2) K. R = 0.0379, wR = 0.0835 for 660 observed reflections (I > 2σ(I)). The structural formula of the crystal compound is (CH₂CH(NH₂)NO₂)ClFe (M _r = 180.38 u). Products of heavy ion beam irradiation were purified and it was directly confirmed that the implanted Fe⁺ ions had been deposited in the novel molecules. The same doses of Fe⁺ ion beams of the same energy were implanted into films of L(+)-cysteine hydrochloride monohydrate. FTIR spectroscopy of the implanted samples proved that some of the original molecules were seriously damaged and significant modifications were induced.     

β2-Adrenoceptor affinity chromatography and its application in the screening of the active compounds from Semen Armeniacae Amarum

β2-Adrenoceptor （β2-AR） was purified from the rabbit lung tissue by sepherose-salbutamol affinity chromatographic column. To prepare the β2-AR stationery phase, β2-AR was evenly immobilized on the surface of macro-pore silica with e mild chemical coupling method through covalent bond. The retention properties of β2-AR stationery phase were characterized by four ligends, selbutamol sulfate, noredreneline bitartrete, adrenaline hydrochloride end proprenolol hydrochloride, to establish the β2-AR affinity chromatography. Then, the method was used to screen the active compounds from the total extracts of Semen Armeniacae Amarum. The results showed that β2-AR on the surface of the stationary phase could keep its original bioectivity end selectivity. Amygdalin retained in the chromatographic column was proved to be the active compound of the total extracts of Semen Armeniacae Amarum. Compared with the existing chromatographic screening approaches, this method showed e good stability end high selectivity. The active compounds which could interact with β2-AR in traditional Chinese medicine （TCM） could be screened efficiently by this method, providing e new way to screen the active compounds in complicated samples such as TCM.     

Preparation,crystal structure and quantum chemical investigation of [Li(NTO) (H2O)]

[Li(NTO)(H₂O)₂] was prepared by mixing the aqueous solution of 3-nitro-1,2,4-triazol-5-one (NTO) and lithium hydroxide. The crystal structure of [Li(NTO)(H₂O)₂] was determined by single crystal diffraction analysis. The crystal is monoclinic, space group P2₁/n with crystal parameters of a = 0.742 0(2) nm, b = 0.344 9(1) nm,c = 2.490 6(3) nm, β= 94.89(1)°, Z = 4,D _c , = 1.799 g cm⁻³,V = 0.635 nm³, μ = 1.591 cm⁻¹, F(000) = 392. The finalR is 0.051. The MNDO MO calculation shows that the coordinate bonds of title compound possess certain extent of covalent character. O₂ atom of NTO anion is bonded to Li atom; the nitro group will be lost first when NTO is decomposed.     

Separation and analysis of the soluble trimer of Aβ1-40 and its effects on the rise in intracellular calcium

Alzheimer’s disease (AD) is one of the progressive neurodegenerative diseases associated with protein conformational transition, generally known as protein conformational disorders[1]. The general characteriza- tions of AD are the intracellular fibrillar…     

Investigation on the synthesis mechanism of β-FeSi2 prepared by pulsed laser deposition

The FeSi2 target alloy was fabricated by conventional powder metallurgy technology, and then, β-FeSi2 thin films was successfully prepared by pulsed laser deposition (PLD). X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM) were used to characterize the structure, composition, and their changes in the process of β-FeSi2 preparation. In addition, a laser sintering process was also employed to prepare FeSi2 alloy. The analysis of radiation heat transfers in different-sized FeSi2 melt indicates that the cooling rate of the melt depends on the size, i.e., the cooling rate of the micron sized melt is 103 times greater than that of the millimeter-sized melt. The product α-FeSi2 by laser sintering and β-FeSi2 by PLD reveals the different phase transition process in crystallization of milli-meter-sized and micron-sized (or submicron-sized) FeSi2 melt. The results of PLD preparation process shows that β-FeSi2 could be pre-pared through a liquid-phase sintering, followed by a rapid cooling.     

On the Pólya conjecture and the weak Weyl-Berry conjecture

The Pólya conjecture and its connection with the weak Weyl-Berry conjecture are studied Specifically let Ω⊆R ⁿ (n≥1) be a non-empty bounded open set with boundary ∂Ω. LetN ₀(λ, −Δ,Ω) be the Dirichlet counting function and φ(λ) the associated Weyl term. If the interior Minkowski dimension of ∂Ω is δ∈[n−1,n], then under certain realisable conditions we prove that for λ sufficiently large the Pólya conjecture φ(λ) −N ₀(λ,−Δ,Ω)≥0 is true. Under related conditions we also prove thatϕ(λ)−N ₀(λ,−Δ, Ω)≈λ^5/2, as λ→+∞. That is, the Weak Weyl-Berry conjecture is true. Similar results are obtained for the Neumann counting function. Partially supported by the National Natural Science Foundation of China and the Royal Society of London Chen Hua: born in March 8, 1956, Professor     

Formation of the inclusion complex of Orange II with β-Cyclodextrin and its photostability

Inclusion complex of Orange II with β-Cyclodextrin (β-CD) and the anti-photolysis effect under UV-light were investigated. The molar ratio of inclusion complex of β-Cyclodextrin and Orange II is 1∶1. The formation constantK = 1.236×10³ L/mol was determined by the UV and Fluorescence spectra respectively, which was quite in accordance with the calculation with a modified Benesi-Hildbrand equation. The inclusion complex was characterized by the IR spectra and the molar ratio of inclusion complex is 1∶1 too. The formation constantK = 1.266×10³ L/mol was determined by¹H NMR analysis and was nearly the same by UV and fluorescence spectra. The photocatalytic decolorization rate of Orange II solutions containing β-CD and TiO₂ was smaller by 51.9% than that of the Orange II solutions only containing TiO₂, while in the case of direct photolysis of Orange II solutions, β-CD can lower the photolysis rate by 48.1% under UV-light. This result indicates β-CD can inhibit the photolysis and photocatalytic decolorization of Orange II under UV-light. The β-CD inclusion complex was found to be persistent to UV-light photolysis. Foundation item: Supported by the National Natural Science Foundation of China (20177017) Biography: Lu Ping (1958), male. Associate professor, research direction: environmental photochemistry.     

Instability of relativistic electron beam with strong magnetic field

Stability criteria for a weak relativistic beam-plasma interaction in a strong magnetic field are found. Two beam modes occur,ω≈k _zC andω≈k _zC-ω_c. The dispersion equation of electrostatic two-stream is exactly solved with analytical method.     

Quantum chemical studies on tuning the second-order nonlinear optical molecular switching of triarylborane derivatives

In this work, density functional theory (DFT) combined with the finite field (FF) method has been adopted to analyze the second-order nonlinear optical (NLO) properties of the triarylborane (TAB) derivatives obtained by introducing different inductive electron groups into the phenylene ring of the TAB (RTAB, where R=2-C6H5-C2B10H10(1),R=F(2), R=Me(3),R=NO2(4),R=NH2(5)). The static first hyperpolarizabilities (βtot) of the RTAB molecules can be switched by binding one F- to the boron center (RTAB′) or one-electron reduction (RTAB"). The DFT-FF calculations show that the βtot values of 2′, 3′ and 5′ decrease while those of 1′ and 4′ increase compared with the values of their neutral molecules, which was attributed to the fact that the charge transfers of 2, 3 and 5 become smaller and those of 1 and 4 become larger by binding one F- ion to the boron center, according to time-domain DFT (TD-DFT) analysis. However, the incorporation of one electron enhances the second-order NLO properties of the RTAB molecules remarkably, especially for system 1. It is notable that the βtot value of reduced form 1″ is 508.69×10-30 esu, i.e. about 578 times larger than that of system 1. Frontier molecular orbital (FMO) and natural bond orbital (NBO) analyses suggest that the reversal of the charge distribution between the neutral molecules and their reduced forms leads to low HOMO-LUMO energy gaps (E0) and thus large βtot values for the reduced forms.     

Synthesis, crystal structure and properties of binuclear manganese complex [(bipy)2Mn2(μ-O)(μ-Ac)2(H2O)2](ClO4)2

Binuclear manganese complex [(bipy)₂Mn₂(μ-O)(μ-Ac)₂(H₂O)₂](ClO₄)₂ was synthesized by the reaction of MnAc₃ · 2H₂O with 2,2′-bipyridine in the HAc-NaAc buffer (pH = 4.0). X-ray diffraction result for the single crystal shows that the crystal is monoclinic, space group C₂/C, with a = 3.408 2(7),b = 0.864 4(2),c = 2.174 9(4) nm, β= 105.2∘, V=6.186(2) nm³, Z= 8. There are two very strong peaks of UV-Vis spectrum in the range of 400–600 nm, which are similar to those of Mn catalase and Mn ribonuleotide reductase extracted from organisms. Cyclic voltammogram shows that the complex in CH₃CN undergoes quasi-reversible one-electron reduction and oxidation at E_1/2=1.15V.     

Crystal structure and magnetism of the binuclear Gd(III) complex Gd2(C12H8N2)2(C6H5COO)6

In the medium of H₂O, C₂H₅OH and HAC, the reaction of Gd(NO₃)₃·6H₂O with C₆H₅COONa and C₁₂H₈N₂ produced a novel binuclear Gd(III) complex in formula [Gd₂(C₁₂H₈N₂)₂ (C₆H₅COO)₆]. Crystallographic data: crystal system, triclinic; space group, P1; unit cell dimensions, a=1.191 9(2) nm,b =1.244 2(2) nm,c = 1.080 4(2) nm, α = 93.57(3)°, β= 113.33(3)°, γ= 105.06(3)°, Z=l. The finalR =0.037 6. The magnetic measurement of the crystal powder in the temperature region of 1.5–300 K shows that this complex possesses antiferromagnetic property with fitting magnetic parametersJ = −0.471 andg =1.975.