Upper and Lower Bounds on Maximum Nonlinearity of n-input m-output Boolean Function

The paper presents lower and upper bounds on the maximumnonlinearity for an n-input m-output Booleanfunction. We show a systematic construction method for a highlynonlinear Boolean function based on binary linear codes whichcontain the first order Reed-Muller code as a subcode. We alsopresent a method to prove the nonexistence of some nonlinearBoolean functions by using nonexistence results on binary linearcodes. Such construction and nonexistence results can be regardedas lower and upper bounds on the maximum nonlinearity. For somen and m, these bounds are tighter than theconventional bounds. The techniques employed here indicate astrong connection between binary linear codes and nonlinear n-input m-output Boolean functions.     

Molality as a unit of measure for expressing 1H MRS brain metabolite concentrations in vivo

Absolute concentrations of cerebral metabolite in in vivo 1H magnetic resonance spectroscopy studies (1H-MRS) are widely reported in molar units as moles per liter of tissue, or in molal units as moles per kilogram of tissue. Such measurements require external referencing or assumptions as to local water content. To reduce the scan time, avoid assumptions that may be invalid under specific pathologies, and provide a universally accessible referencing procedure, we suggest that metabolite concentrations from 1H-MRS measurements in vivo be reported in molal units as moles per kilogram of tissue water. Using internal water referencing, a two-compartment water model, a simulated brain spectrum for peak identification, and a spectroscopic bi-exponential spin-spin relaxation segmentation technique, we measured the absolute concentrations for the four common 1H brain metabolites: choline (Cho), myo-inositol (mIno), phosphocreatine + creatine (Cr), and N-acetyl-aspartate (NAA), in the hippocampal region (n = 26) and along the Sylvian fissure (n = 61) of 35 healthy adults. A stimulated echo localization method (20 ms echo time, 10 ms mixing time, 4 s repetition time) yielded metabolite concentrations, uncorrected for metabolite relaxation or contributions from macromolecule resonances, that were expectantly higher than with molar literature values. Along the Sylvian fissure the average concentrations (coefficient of variation (CV)) in mmoles/kg of tissue water were 17.6 (12%) for NAA, 14.2 (9%) for Cr, 3.6 (13%) for Cho, and 13.2 (15%) for mIno. Respective values for the hippocampal region were 15.7 (20%), 14.7 (16%), 4.6 (19%), and 17.7 (26%). The concentrations of the two regions were significantly different (p 相似文献   

The ̅K N → π Σ decay threshold effect in 3He(in-flight K –, n) reaction spectrum

The formation of a deeply-bound K?? ^–? pp state by the ³He(in-flight K? ^–, n) reaction is investigated theoretically in a distorted-wave impulse approximation using the Green’s function method. The expected inclusive and semi-exclusive spectra at $p_{K^-} = 1.0$ GeV/c and $\theta_n = 0^{\circ}$ are calculated for the forthcoming J-PARC E15 experiment. We discuss these spectra with some K? ^–-“pp” optical potentials, taking into account the energy-dependence of the imaginary part of the potentials by a phase space suppression factor.     

Improved book-embeddings of incomplete hypercubes

In this paper, we show that any incomplete hypercube with, at most, 2ⁿ+2ⁿ⁻¹+2ⁿ⁻² vertices can be embedded in n−1 pages for all n≥4. For the case n≥4, this result improves Fang and Lai’s result that any incomplete hypercube with, at most, 2ⁿ+2ⁿ⁻¹ vertices can be embedded in n−1 pages for all n≥2.Besides this, we show that the result can be further improved when n is large — e.g., any incomplete hypercube with at most 2ⁿ+2ⁿ⁻¹+2ⁿ⁻²+2ⁿ⁻⁷ (respectively, 2ⁿ+2ⁿ⁻¹+2ⁿ⁻²+2ⁿ⁻⁷+2ⁿ⁻²³⁰) vertices can be embedded in n−1 pages for all n≥9 (respectively, n≥232).     

Labeling bipartite permutation graphs with a condition at distance two

An L(p,q)-labeling of a graph G is an assignment f from vertices of G to the set of non-negative integers {0,1,…,λ} such that |f(u)−f(v)|≥p if u and v are adjacent, and |f(u)−f(v)|≥q if u and v are at distance 2 apart. The minimum value of λ for which G has L(p,q)-labeling is denoted by λ_p,q(G). The L(p,q)-labeling problem is related to the channel assignment problem for wireless networks.In this paper, we present a polynomial time algorithm for computing L(p,q)-labeling of a bipartite permutation graph G such that the largest label is at most (2p−1)+q(bc(G)−2), where bc(G) is the biclique number of G. Since λ_p,q(G)≥p+q(bc(G)−2) for any bipartite graph G, the upper bound is at most p−1 far from optimal.     

微量吸附量热法研究氧化物催化剂的酸碱性质

利用微量吸附量热技术定量地表征了Eu₂O₃、CeO₂、MgO、ZnO、Al₂O₃和NiO等氧化物表面酸碱中心的强度和数量,结果表明,样品的NH₃和CO₂起始吸附热与其Sanderson电负性相关.     

Phosphanimin- und Phosphaniminato-Komplexe von Eisen. Die Kristallstrukturen von [FeCl3(Me3SiNPEt3)], [FeCl2(Me3SiNPEt3)]2, [FeCl2(NPEt3)]2 und [Fe(O2C?CH3)2(NPEt3)]2

Phosphanimine and Phosphoraneiminato Complexes of Iron. The Crystal Structures of [FeCl₃(Me₃SiNPEt₃)], [FeCl₂(Me₃SiNPEt₃)]₂, [FeCl₂(NPEt₃)]₂, and [Fe(O₂C? CH₃)₂(NPEt₃)]₂ The phosphanimine complexes [FeCl₃(Me₃SiNPEt₃)] (red-orange) and [FeCl₂(Me₃SiNPEt₃)]₂ (colourless) have been prepared by reactions of Me₃SiNPEt₃ with FeCl₃ and FeCl₂, respectively, in CH₂Cl₂ suspensions. Thermal decomposition of these donor-acceptor complexes in boiling toluene leads to the phosphoraneiminato complex [FeCl₂(NPEt₃)]₂ (black), whereas [Fe(O₂C? CH₃)₂(NPEt₃)]₂ (brown) is formed from iron(II) acetate and Me₃SiNPEt₃ in boiling acetonitrile. The complexes are characterized by IR spectroscopy and by crystal structure determinations. [FeCl₃(Me₃SiNPEt₃)] (1) : Space group P2₁/c, Z = 8, structure determination with 4 673 unique reflections, R = 0.033. Lattice dimensions at ?15°C: a = 1 607.8, b = 1 602.0, c = 1 417.2 pm, β = 106.56°. 1 forms monomeric molecules with tetrahedrally coordinated iron atoms. Bond lengths in average: Fe? N = 196.9 pm, Fe? Cl = 219.7 pm. [FeCl₂(Me₃SiNPEt₃)]₂ (2) : Space group P2₁/c, Z = 4, structure determination with 4 992 unique reflections, R = 0.048. Lattice dimensions at 20°C: a = 1 457.9, b = 1 685.4, c = 1 507.3 pm, β = 116.74°. 2 forms dimeric molecules, which are associated by chloro bridges. The iron atoms are tetrahedrally coordinated with trans positions of the phosphanimine ligands. Both lengths in average: Fe? N = 202.2 pm, Fe? Cl_terminal = 224.7 pm, Fe? Cl bridge = 241.0 pm. [FeCl₂(NPEt₃)]2 (3): Space group P2₁/n, Z = 2, structure determination with 2763 unique reflections, R = 0.039. Lattice dimensions at ?70°C: a = 799.1, b = 1009.0, c = 1441.9 pm, β = 93.45°. 3 forms centrosymmetric dimeric molecules, in which the tetrahedrally coordinated iron atoms are associated by the nitrogen atoms of the phosphoraneiminato ligands. Bond lengths in average: Fe? N = 191.4 pm, Fe? Cl = 222.7 pm. [Fe(O₂C? CH₃)₂(NPEt₃]2 (4): Space group P2₁/n, Z = 2, structure determination with 3005 observed unique reflections, R = 0.034. Lattice dimensions at -65°C: a = 886.4, b = 1444.6 pm, β = 90.60°. 4 forms centrosymmetric dimeric molecules, in which the octahedrally coordinated iron atoms are associated by the nitrogen atoms of the phosphoraneiminato ligands with bond lengths Fe? N of 191.9 and 195.0 pm. The acetate groups are coordinated in a chelating fashion.     

First-principles calculations of stable local structures and electronic structures of magnesium secondary battery cathode materials,MgCo2−xMnxO4 (x = 0, 0.5), in second charged state after first discharge

Journal of Solid State Electrochemistry - The stable structures associated with the second charge of MgCo2−xMnxO4 (x = 0, 0.5), where Mg is removed from the stable first-discharge...     

Self‐Replication and Amplification of Enantiomeric Excess of Chiral Multifunctionalized Large Molecules by Asymmetric Autocatalysis

Self‐replication of large chiral molecular architectures is one of the great challenges and interests in synthetic, systems, and prebiotic chemistry. Described herein is a new chemical system in which large chiral multifunctionalized molecules possess asymmetric autocatalytic self‐replicating and self‐improving abilities, that is, improvement of their enantioenrichment in addition to the diastereomeric ratio. The large chiral multifunctionalized molecules catalyze the production of themselves with the same structure, including the chirality of newly formed asymmetric carbon atoms, in the reaction of the corresponding achiral aldehydes and reagent. The chirality of the large multifunctionalized molecules controlled the enantioselectivity of the reaction in a highly selective manner to construct multiple asymmetric stereogenic centers in a single reaction.     

Synthesis, photophysical and electrochemical properties of perfluoroisopropyl substituted binuclear phthalocyanine conjugated with a butadiyne linker

Synthesis of 1,3-butadiyne-bridged perfluoroisopropyl binuclear phthalocyanine 2 has been successfully achieved from unsymmetrical A₃B-type iodo-perfluoroisopropyl phthalocyanine by palladium-catalyzed cross-coupling with trimethylsilylacetylene and copper-catalyzed Glaser homo-coupling as key reactions. The dyad 2 essentially remains non-aggregated irrespective of solvent and concentration. Electrochemical analysis suggests oxidation is not possible whereas the molecule is more easily reduced. All the results are advantages for photodynamic therapy (PDT).