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A simple and convenient route for the synthesis of the ferrocenyl-cyclopentenone compounds (3 and 7) and ferrocenyl-cyclopentenedione compounds (4 and 8) has been developed. Compounds 3 and 7 were obtained by a selective oxidating reaction of the ferrocenyl-cyclopenta[d]pyridazine species of 2 and 6 in CH2Cl2 in air, respectively. Compounds 4 and 8 were generated by a hydrolysis reaction of 3 and 7 in a H2O/EtOH mixed solvent system in the presence of SnCl2, respectively. The substituted ferrocenyl group plays a central role in the formation of the ferrocenyl-cyclopentenone (3 and 7) and ferrocenyl-cyclopentenedione (4 and 8) derivatives, which is demonstrated well by the current experimental data as well as the theoretical calculations. All the new ferrocene-containing complexes have been characterized by elemental analysis, IR spectra, and 1H NMR spectroscopy, as well as for 3, 4, 5, 7, 8, and 9 by X-ray diffraction analysis. In addition, the luminescent properties of 1−4 were investigated preliminarily...

The Co-doped TiO2 films (Co0.1Ti0.9O2−δ) are prepared on silicon substrates by sol-gel method and post annealing. The Co0.1Ti0.9O2−δ film annealed in air is non-ferromagnetic at room temperature. After further annealed in a vacuum, the room-temperature ferromagnetism (RTFM) is observed. Experimental evidences show that the RTFM in the Co0.1Ti0.9O2−δ film may come from the Co-doped TiO2 matrix and is related to the oxygen vacancies created by vacuum annealing.

We have evaluated the effects of recombination processes in a charge storage layer, either between trapped electrons and trapped holes or between trapped carriers and free carriers, on charge trapping memory cell's performances by numerical simulation. Recombination is an indispensable mechanism in charge trapping memory. It helps charge convert process between negative and positive charges in the charge storage layer during charge trapping memory programming/erasing operation. It can affect the speed of programming and erasing operations.

A new nickel-macrocyclic complex [Ni(L)]·CH2Cl2 (1, L = C24H22N4O3) was synthesized based on a bent oxadiazole bridging ligand terminated by tetradentate N2O2 Schiff-base units. Two novel Ni−Ag mixed-metal, mixed-valence, and cluster-containing coordination polymers, namely, [Ag2Ni(L)](ClO4)2.5 (2) and [Ag2Ni(L)](BF4)2.5 (3), generated from 1 and AgX (X = ClO4−, BF4−) were synthesized. During the reactions, unexpected metal-exchange and metal valence-change were observed. These two Ni−Ag coordination polymers are isostructural. They all feature a two-dimensional double-layered concavo-convex structure which is composed of a dual-bowl unit and mixed-valent NiII2NiIII2 cluster node. Compounds 1−3 were fully characterized by infrared spectroscopy, elemental analysis, and single-crystal X-ray diffraction. In addition, the luminescent properties of 1−3 were investigated primarily.

The Monte Carlo simulation is performed to investigate the quantum mechanical (QM) effects on heat generation in nano-scale metal oxide semiconductor field effect transistors (MOSFETs) by solving the quantum Boltzmann equation. The influence of QM effects both in real space and K space on the heat generation is investigated.

Two new symmetric and unsymmetrical semirigid organic ligands 2,5-bis(4-(1H-1,2,4-triazol-1-ylmethyl)phenyl)-1,3,4-oxadiazole (L1) and 4-(1H-1,2,4-trizol-1-ylmethyl)benzoic acid (L2) have been prepared. L2 was generated from L1 by a hydrothermal reaction via the hydrolysis of the central oxadiazole ring of L1. The solution and hydrothermal reactions of L1 with various inorganic M(II) (M = Cd, Co, Zn, and Cu) ions have been investigated. Compounds [Cd(L1)2](NO3)2 (1), [Cu(L1)2](NO3)2 (2), and [Cu(L1)]Cl2·2(H2O) (3) were obtained in solution by a combination of L1 with corresponding metal salts, while compounds Zn(L2)2 (4), Co(L2)2 (5), and [Co(L2)2]·H2O (6) were synthesized by a hydrothermal technique with in situ generated unsymmetrical L2 ligand. In addition, compounds 4−6 could also be prepared by direct combination of L2 with corresponding metal salts under the same hydrothermal conditions. All six new coordination polymers were fully characterized by infrared spectroscopy, elemental analysis, single-c...

We have synthesized a ferrocene-based 1,3-alternate thiacalix[4]arene ditopic receptor 3 that contains four identical polyether arms terminated with the ferrocene amide moieties. Our studies have revealed that this redox-active receptor can be used as an electrochemical sensor to recognize both europium (Eu3+) and dihydrogen phosphate (H2PO4-) ions with a high selectivity.

Rutin is a common dietary flavonoid with important antioxidant and pharmacological activities. However, its application in the food industry is limited mainly because of its poor water solubility. The subcritical water (SW) treatment provides an efficient technique to solubilize and achieve the enrichment of rutin in soy protein isolate (SPI) by inducing their complexation. The physicochemical, interfacial, and emulsifying properties of the complex were investigated and compared to the mixtures. SW treatment had much enhanced rutin-combined capacity of SPI than that of conventional method, ascribing to the well-contacted for higher water solubility of rutin with stronger collision-induced hydrophobic interactions. Compared to the mixtures of rutin with proteins, the complex exhibited an excellent surface activity and improved the physical and oxidative stability of its stabilized emulsions. This improving effect could be attributed to the targeted accumulation of rutin at the oil-water interface accompanied by the adsorption of SPI resulting in the thicker interfacial layer, as evidenced by higher interfacial protein and rutin concentrations. This study provides a novel strategy for the design and enrichment of nanovehicle providing water-insoluble hydrophobic polyphenols for interfacial delivery in food emulsified systems.

Conjugates of β-conglycinin and dextran were prepared by heating in solution under macromolecular crowding environment and dry-heating methods, and then fractionated by solubility at pH 4.8 and pH 6.5 and characterized. The results showed that the degree of glycation of the conjugates extracted from pH 4.8 were higher than the conjugates extracted from pH 6.5. Corresponding to the higher degree of glycation, it was supposed that the β-conglycinin of groups 4.8 of macromolecular crowding environment was completely surrounded by the dextran molecular while that of groups 6.5 were encircled partially with a lower degree of glycation. Compared to β-conglycinin, groups 4.8 demonstrated a decreasing surface hydrophobicity and sulfhydryl group content while groups 6.5 increased. The secondary structure of β-conglycinin soluble at pH 4.8 after conjugating under macromolecular crowding environment tended to stretch out and the highly ordered structure turn to random structures. The differences between the extraction of pH 4.8 and pH 6.5 conjugated by dry-heating methods were not as remarkable as the difference between the extraction conjugated by macromolecular crowding environment.

Four new oxadiazole-bridging ligands (L1-L4) were designed and synthesized by the reaction of 2,5-bis(2-hydroxyphenyl)-1,3,4-oxadiazole with isonicotinoyl chloride and nicotinoyl chloride, respectively. L1 and L3 are unsymmetric single-armed ligands (4- or 3-pyridinecarboxylate arm), and L2 and L4 are symmetric double-armed ligands (4- or 3-pyridinecarboxylate arms). Nine new complexes, [Ag(L1)]PF6.CH3OH (1), [Ag(L1)]ClO4.CH3OH (2), Cu(L2)(NO3)2.2(CH2Cl2) (3), [Cu(L2)2](ClO4)2.2(CH2CCl2) (4), Cu(L2)Cl2 (5), [Cu4(L3)2(H2O)2](L3)4(ClO4)4 (6), [Ag(L4)(C2H5OH)]ClO4 (7), [Ag(L4)(C2H5OH)]BF4 (8), and [Ag(L4)(CH3OH)]SO3CF3 (9), were isolated from the solution reactions based on these four new ligands, respectively. L1, L2, and L3 act as convergent ligands and bind metal ions into discrete molecular complexes. In contrast, L4 exhibits a divergent spacer to link metal ions into one-dimensional coordination polymers. New coordination compounds were fully characterized by infrared spectroscopy, elemental analysis, and single-crystal X-ray diffraction. In addition, the luminescent and electrical conductive properties of these new compounds were investigated.

A double Schiff-base ligand 1,4-bis(2-thiazolyl)-2,3-diaza-1,3-butadiene (L8) has been synthesized, and its coordination chemistry with various silver salts AgX (X = SbF6-, SO3CF3-, H2PO4-, and NO3-) has been investigated. The resulting molecular structures are delicately dependent on the nature of the counterions and the solvent intermedia. Uncoordinating counterions (X = SbF6- and SO3CF3-) generated the hydrogen-bonded frameworks based on discrete molecular complex building blocks, whereas coordinating anions (X = H2PO4- and NO3-) formed polymeric complexes driven by the metal−anion interactions. Furthermore, the luminescent and electrical conductive properties of some new complexes were investigated.

Using Monte Carlo simulations, we have investigated the classical XY model on triangular lattices of ultra-thin film structures with middle ferromagnetic layers sandwiched between two antiferromagnetic layers. The internal energy, the specific heat, the chirality and the chiral susceptibility are calculated in order to clarify phase transitions and critical phenomena. From the finite-size scaling analyses, the values of critical exponents are determined. In a range of interaction parameters, we find that the chirality steeply goes up as temperature increases in a temperature range; correspondingly the value of a critical exponent for this change is estimated.

Seven new conjugated symmetric and unsymmetric fulvene ligands L1−L7 were synthesized. Thirteen new organometallic coordination polymers and supramolecular complexes were obtained through self-assembly based on these new fulvene ligands in the benzene/toluene mixed solvent system. Compounds 1−13 have been fully characterized by infrared spectroscopy, elemental analysis, and single-crystal X-ray diffraction. The results indicate that the coordination chemistry of new fulvene ligands is versatile. They can adopt either a cis or a trans conformation to bind Ag(I) ion through not only the terminal −CN and thiophene functional groups but also the fulvene carbon atoms into organometallic coordination polymers or discrete complexes. In addition, the luminescent properties of L1, L3, L5, and L7 and some of their Ag(I) complexes were investigated preliminarily in EtOH and the solid state.

Two new bent oxadiazole bridging benzoacetylene ligands 2,5-bis(4-ethynylphenyl)-1,3,4-oxadiazole (L9) and 2,5-bis(3-ethynylphenyl)-1,3,4-oxadiazole (L10) were synthesized. The coordination chemistry of them with various inorganic Ag(I) salts has been investigated. Seven new coordination polymers were prepared by solution reactions and fully characterized by infrared spectroscopy, elemental analysis, and single-crystal X-ray diffraction. [Ag2(L9)](SO3CF3)2 (1) (triclinic, P; a =10.292(4), b = 10.794(4), c = 11.399(5) A; alpha = 98.894(5), beta = 102.360(6), gamma = 90.319(5) degrees ; Z = 2), [Ag(L9)]SbF6 (2) (orthorhombic, Cmca; a = 19.059(9), b = 12.922(6), c = 15.609(7) A; Z = 8), [Ag(L9)]BF4 (3) (orthorhombic, Cmca; a = 19.128(3), b = 12.6042(18), c = 28.003(4) A; Z = 16), [Ag(L9)]ClO4 (4) (monoclinic, P2(1)/c; a = 8.5153(16), b = 19.722(4), c = 10.320(2) A; beta = 105.307(3) degrees ; Z = 4), [Ag(L10)]SO3CF3 (5) (triclinic, P; a = 9.0605(13), b = 10.4956(15), c = 10.8085(16) A; alpha = 101.666(2), beta = 109.269(2), gamma = 100.944(2) degrees ; Z = 2), [Ag(L10)(H2O)(0.5)]BF4.0.5H2O (6) (monoclinic, C2/m; a = 32.180(6), b = 17.027(3), c = 8.1453(15) A; beta = 102.541(3) degrees ; Z = 8), and {[Ag2(L10)2(H2O)](ClO4)2}.o-xylene (7) (monoclinic, P2(1)/c; a = 8.1460(10), b = 17.326(2), c = 30.345(4) A; beta = 97.71 degrees ; Z = 4) were obtained by the combination of L9 and L10 with various Ag(I) salts in a benzene/methylene chloride mixed solvent system. In addition, the luminescent and electrical conductive properties of these new compounds were investigated.

The new double Schiff base ligand L7 (2,5-bis(2-benzodiazine)-3,4-diaza-2,4-hexadiene) with disubstituted quinoxaline diazenes was synthesized. Four new polymeric Ag(I) complexes based on L7, namely {Ag3(L7)3(BF4)3(CH2Cl2)3(H2O)}n (1), {Ag2.5(L7)1.5(ClO4)2.5(H2O)2}n (2), {Ag4(L7)3(PF6)4}n (3), and {Ag4(L7)3(SbF6)4}n (4), have been synthesized successfully. They were fully characterized by infrared spectroscopy, elemental analysis, and single-crystal X-ray diffraction. In compound 1, two Ag(I) atoms are held together by two L7 ligands through the inside middle chelating N donors to generate a binuclear “X-shaped” helical secondary building block. In compounds 2−4, three Ag(I) atoms are held together by three L7 ligands through the inside middle chelating N donors to afford a trinuclear crownlike secondary building block. These spontaneous self-organized supramolecular secondary building blocks were further linked together into the higher extended hierarchy through outside N−Ag(I) coordination interactions....

Two one-dimensional Cu(II) coordination polymers and one hydrogen-bonded supramolecular complex were synthesized based on a new unsymmetrical oxadiazole bridging ligand L7 (2-[(3-pyridyl)]-5-[(4-pyridyl)]-1,3,4-oxadiazole). In addition, the luminescent properties of L7 and its Cu(II) coordination polymers were investigated preliminarily in the solid state.

Two new bent bis(cyanophenyl)oxadiazole ligands, 2,5-bis(4-cyanophenyl)-1,3,4-oxadiazole (L7) and 2,5-bis(3-cyanophenyl)-1,3,4-oxadiazole (L8), were synthesized. The coordination chemistry of these ligands with various Ag(I) salts has been investigated. Seven new coordination polymers, namely, {[Ag(L7)(H2O)]ClO4}n) (1) (triclinic, P1, a = 9.342(4) A, b = 9.889(4) A, c = 10.512(4) A, alpha = 68.978(6) degrees, beta = 78.217(6) degrees, gamma = 81.851(7) degrees, Z = 2), {[Ag(L7)]SO3CF3}n (2) (monoclinic, P2(1)/n, a = 7.559(2) A, b = 23.739(6) A, c = 10.426(3) A, beta = 108.071(4) degrees, Z = 4), {[Ag(L8)]BF4 x 0.5(C6H6) x H2O}n (3) (triclinic, P1, a = 7.498(3) A, b = 10.649(4) A, c = 13.673(5) A, alpha = 98.602(5) degrees, beta = 100.004(5) degrees, gamma =110.232(5) degrees, Z = 2), {[Ag(L8)SbF6] x H2O}n (4) (triclinic, P1, a = 8.2621(9) A, b = 10.6127(12) A, c = 13.3685(15) A, alpha = 98.012(2) degrees, beta = 106.259(2) degrees, gamma = 112.362(2) degrees, Z = 2), {[Ag2(L8)2(SO3CF3)] x H2O}n (5) (triclinic, P1, a = 10.713(4) A, b = 13.449(5) A, c = 15.423(5) A, alpha = 65.908(5) degrees, beta = 74.231(5) degrees, gamma = 83.255(5) degrees, Z = 2), {[Ag2(L8)(C6H6)(ClO4)] x ClO4}n (6) (monoclinic, P2(1)/n, a = 6.9681(17) A, b = 20.627(5) A, c = 17.437(4) A, beta = 95.880(4) degrees, Z = 4), and {[Ag2(L8)(H2PO4)2]}n (7) (triclinic, P1, a = 7.956(2) A, b = 9.938(3) A, c = 14.242(4) A, alpha = 106.191(4) degrees, beta = 97.322(4) degrees, gamma = 107.392(4) degrees, Z = 1), were obtained by the combination of L7 and L8 with Ag(I) salts in a benzene/methylene chloride mixed-solvent system and fully characterized by infrared spectroscopy, elemental analysis, and single-crystal X-ray diffraction. In addition, the luminescence and electrical conductance properties of compounds 1-6 and the host-guest chemistry of compound 3 were investigated.

One new conjugated symmetric fulvene ligand L1 and two new unsymmetric fulvene ligands L2 and L3 were synthesized. Five new supramolecular complexes, namely Ag2(L1)3(SO3CF3)3 (1) (1, monoclinic, P2(1)/c; a = 12.702(3) A, b = 26.118(7) A, c = 13.998(4) A, beta = 96.063(4) degrees, Z = 4), [Ag(L1)]ClO4 (2) (monoclinic, C2/c; a = 17.363(2) A, b = 13.2794(18) A, c = 13.4884(18) A, beta = 100.292(2) degrees, Z = 8), [Ag(L1)(C6H6)SbF6] x 0.5C6H6 x H2O (3) (monoclinic, P2(1)/c; a = 6.8839(11) A, b = 20.242(3) A, c = 18.934(3) A, beta = 91.994(3) degrees, Z = 4), Ag(L2)(SO3CF3) (4) (triclinic, P1; a = 8.629(3) A, b = 10.915(3) A, c = 11.178(3) A, alpha = 100.978(4) degrees, beta = 91.994(3) degrees, gamma = 105.652(4) degrees, Z = 2), and Ag(L3)(H2O)(SO3CF3) (5) (triclinic, P1; a = 8.914(5) A, b = 10.809(6) A, c = 11.283(6) A, alpha = 69.255(8) degrees, beta = 87.163(9) degrees, gamma = 84.993(8) degrees, Z = 2) were obtained through self-assembly based on these three new fulvene ligands in a benzene/toluene mixed-solvent system. Compounds 1-5 have been fully characterized by infrared spectroscopy, elemental analysis, and single-crystal X-ray diffraction. The results indicate that the coordination chemistry of new fulvene ligands is versatile. They can adopt either cis- or trans-conformation to bind soft acid Ag(I) ion through not only the terminal -CN and furan functional groups but also the fulvene carbon atoms into organometallic coordination polymers or discrete complexes. In addition, the luminescent properties of L1-L3 and their Ag(I) complexes were investigated preliminarily in EtOH and solid state.

The coordination chemistry of the oxadiazole-bridged 4,4‘- and 3,3‘-biphenylamine ligands, namely, 2,5-bis(4-aminophenyl)-1,3,4-oxadiazole (L3) and 2,5-bis(3-aminophenyl)-1,3,4-oxadiazole (L4), wit...

One novel fulvene ligand HL was synthesized successfully by an aroylation reaction of substituted cyclopentadienyl anion. The coordination chemistry of fulvene ligand HL is investigated. The study demonstrated that the fulvene-type ligand HL could be used as multidentate or chelating ligand to coordinate transition metal ions into a coordination polymer or a supramolecular complex. One novel one-dimensional Ag(I)−fulvene organometallic coordination polymer, namely, [Ag(HL)(H2O)]SbF6 (1) and one Co(II) complex, namely, Co(L)2·2C2H5OH (2), with an unusual seven-membered metallo-ring unit were synthesized successfully based on HL and L, respectively. In the solid state, complex 2 adopts a novel hydrogen bonded one-dimensional chain motif.

The coordination chemistry of the oxadiazole-containing rigid bidentate ligands 2,5-bis(4-pyridyl)-1,3,4-oxadiazole (L2) and 2,5-bis(4-aminophenyl)-1,3,4-oxadiazole (L3) with inorganic Ag(I) salts ...

Two new fulvene ligands, L1 and L2, have been synthesized by an aroylation reaction of the cyclopentadienyl anion. The coordination chemistry of L1 and L2 was investigated. Two novel CpAg(I)-containing polymeric compounds, 1 ([Ag4(L1)2(μ-H2O)2(SO3CF3)4]·(μ-bis-η1-C6H6))·H2O) and 2 ([Ag2(L2)(H2O)(SO3CF3)2]·0.5(C6H6)), have been synthesized. Compounds 1 and 2 have been fully characterized by infrared spectroscopy, elemental analysis, and single-crystal X-ray diffraction. The solid state structure of 1 features a macro-ring-containing one-dimensional chain motif. The solid state structure of 2 features a one-dimensional double-chain motif. These double chains are further cross-linked to each other via CpAg(SO3CF3)2AgCp (Ag···Ag contact of 4.215(15) A) linkage into a novel 2-D network with large cavities (effective cross-section of ca. 21 × 9 A), in which the benzene guest molecules are located.

We investigate phase transitions of the XY model on a two-layer square lattice which consists of a Villain plane (J) and a ferromagnetic plane (I), using Monte Carlo simulations and a histogram method. Depending on the values of interaction parameters (I,J), the system presents three phases: namely, a Kosterlitz–Thouless (KT) phase in which the two planes are critical for I predominant over J, a chiral phase in which the two planes have a chiral order for J predominant over I and a new phase in which only the Villain plane has a chiral order and the ferromagnetic plane is paramagnetic with a small value of chirality. We clarify the nature of phase transitions by using a finite size scaling method. We find three different kinds of transitions according to the values of (I,J): the KT transition, the Ising transition and an XY-Ising transition with ν = 0.849(3). It turns out that the Ising or XY-Ising transition is associated with the disappearance of the chiral order in the Villain plane.

Two novel fulvene-type organic ligands L1 and L2 have been synthesized by aroylation reaction of substituted cyclopentadienyl anions. L1 crystallized in the monoclinic space group P21, a = 6.7498(4), b = 20.5769(11), c = 8.9532(5) A, β = 109.5060(10)°, and Z = 2. L2 crystallized in the triclinic space group P , a = 11.4126(10), b = 11.4763(10), c = 11.7719(10) A, α = 67.050(2), β = 74.509(2), γ = 61.148(2)°, and Z = 2. The coordination chemistry of L1 and L2 has been investigated. One novel AgI-containing organometallic coordination polymer 3, based on both AgI−C and AgI−N interactions, has been synthesized by combination of L1 and AgClO4 in a benzene/dichloromethane mixed-solvent system. Two new MII-containing [M = CuII (4) and CoII (5)] supramolecular complexes with seven-membered metalla-ring unit have been prepared by combination of L2 and the corresponding M(OAc)2·2H2O (M = CuII and CoII) salts in ethanol. The isostructural compounds 4 and 5 crystallized in the triclinic space group P [4: a = 8.8808(5), b = 10.9928(7), c = 14.2196(9) A, α = 99.9750(10), β = 95.8190(10), γ = 93.5610(10)°, and Z = 1; 5: a = 8.7964(10), b = 10.8103(12), c = 14.3765(15) A, α = 99.681(2), β = 95.930(2), γ = 93.429(2)°, and Z = 1]. In the solid state, molecular complexes 4 and 5 are bound by strong intermolecular N···O−H hydrogen bonds in a hand-in-hand fashion to give a novel one-dimensional chain motif. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)

In this paper, by applying a simplified version of Lieb's spin-reflection-positivity method, which was recently developed by one of us [G.S. Tian and J.G. Wang, J. Phys. A: Math. Gen. 35 (2002) 941], we investigate some general properties of the boson-fermion Hamiltonian, which has been widely used as a phenomenological model to describe the real-space pairing of electrons. On a mathematically rigorous basis, we prove that for either negative or positive coupling V, which represents the spontaneous decay and recombination process between boson and fermion in the model, the pairing energy of electrons is nonzero. Furthermore, we also show that the spin-excitation gap of the boson-fermion Hamiltonian is always larger than its charged gap, as predicted by the pre-paired electron theory.

The coordination chemistry of the oxadiazole-containing rigid bidentate ligands 2,5-bis(4-pyridyl)-1,3,4-oxadiazole (L1) and 2,5-bis(3-pyridyl)-1,3,4-oxadiazole (L2) with inorganic M(II) (M = Zn and Cu) salts has been investigated. Two new coordination polymers (1 and 2) and two new bimetallic macrocyclic supramolecular complexes (3 and 4) were synthesized from solution reactions of L1 and L2 with inorganic M(II) (M = Zn and Cu) salts, respectively. {[Zn(L1)(H2O)2(CH3CN)2](ClO4)2·(L1)(CH3CN)1.5(CH2Cl2)0.5}n (1; monoclinic, P21/m, a = 7.5755(4) A, b = 8.3120(16) A, c = 9.6449(6) A, β = 99.9920(10)°, Z = 2) was obtained by combination of L1 with Zn(ClO4)·6H2O in a CH2Cl2/CH3CN mixed-solvent system. The structure features one-dimensional chains that are cross-linked to each other by weak noncovalent π−π interactions (alternating face-to-face stacking of coordinated and uncoordinated L1 molecules) to generate a novel two-dimensional network. {[Zn(L1)(H2O)2(NO3)2]·2(CH3CN)2}n (2; monoclinic, C2/c, a = 27.2789(...

By using either numerical calculations or analytical methods, such as the bosonization technique, the ground state of the Penson–Kolb model has been previously studied by several groups. Some physicists argued that, as far as the existence of superconductivity in this model is concerned, it is canonically equivalent to the negative-U Hubbard model. However, others did not agree. In the present paper, we shall investigate this model by an independent and rigorous approach. We show that the ground state of the Penson–Kolb model is nondegenerate and has a nonvanishing overlap with the ground state of the negative-U Hubbard model. Furthermore, we also show that the ground states of both the models have the same good quantum numbers and may have superconducting long-range order at the same momentum q = 0. Our results support the equivalence between these models.

We study the effects of the energy band structure of conduction-electron on the transport properties of an interacting quantum dot system. By applying the nonequilibrium Keldysh Green function technique, we show that the finite width of electron band in leads causes the negative differential conductance in some regions of the applied voltage. We also show that the van Hove singularities in the density of states of conduction-electron do not qualitatively change the differential conductance of the system, and hence can be safely ignored. Therefore, the wide band approximation used in the previous investigations is partially justified.

The coordination chemistry of the oxadiazole-containing ligand 2,5-bis(4-pyridyl)-1,3,4-oxadiazole (L5) with inorganic Cu(II) and Co(II) salts has been investigated. Three new coordination polymers (1–3) and one H-bonded polymer (4) were prepared by solution reactions. [Cu(L5)(H2O)(SO4)]·2(H2O) (1) adopts a novel chiral three-dimensional motif with rhombus channels (ca. 6.04 × 14.09 A). [Co(L5)(CH3OH)2(SO4)](CH3OH)(H2O)3.5 (2) features a novel two-dimensional network. [Cu(L5)2(H2O)2](L5)2(ClO4)2(CH3OH)(H2O) (3) features a two-dimensional rhombus-grid-type layer with inner grid cavity dimensions of 13.22 × 13.22 A2. Compound 4, however, is a molecular complex that is bound together by strong N⋯H–O and O⋯H–O hydrogen bonds into a three-dimensional H-bonded network.

A novel fulvene-type bidentate ligand 1 has been synthesized by an aroylation reaction of cyclohexyl-substituted cyclopentadienyl anions. Compound 1 crystallizes in the triclinic space group P1, with a = 7.0419(5) A, b = 11.9360(8) A, c = 15.6470(11) A, α = 85.1440(10)°, β = 78.1140(10)°, γ = 74.5360(10)°, V = 1239.76(15) A3, and Z = 2. The coordination chemistry of 1 was investigated, and a novel Ag-containing coordination polymer (2), linked by both Ag−heteroatom and Ag−carbon interactions, has been synthesized. The coordination polymer has been fully characterized by infrared spectroscopy, elemental analysis, and single-crystal X-ray diffraction. Compound 2 crystallizes in the triclinic space group P1, with a = 7.1654(5) A, b = 15.7277(11) A, c = 18.8157(13) A, α = 73.5150(10)°, β = 89.0410(10)°, γ = 89.0970(10)°, V = 1355.19(14) A3, and Z = 2. The solid-state structure of 2 features a one-dimensional double-chain motif. These double chains are in turn cross-linked to each other via strong interchain...

The new asymmetric ligand 2-{5-[(pyridin-4-ylmethyl)sulfanyl]-1,3,4-oxadiazol-3-yl}phenol (HL) has been used to synthesize the novel discrete title binuclear metallocycle, [Cu(2)(C(14)H(10)N(3)O(2)S)(2)(C(5)H(7)O(2))(2)] or Cu(2)L(2)(acac)(2) (acac is acetylacetonate). Each Cu(II) centre is five-coordinate and adopts a square-pyramidal geometry. Two ligands are connected by two Cu(II) cations to form the dinuclear metallocycle, which lies across a crystallographic inversion centre. Discrete molecules are linked into a two-dimensional structure through weak Cu···S, C-H···π and π-π interactions.

Soy lipophilic protein nanoparticles (LPP), which present a novel delivery vehicle for conjugated linoleic acid (CLA), were fabricated by ultrasonication of the soy lipophilic protein (LP), which exhibits unique characteristics including a high loading capacity, oxidation protection and a sustained releasing profile in vitro for CLA. The CLA-loaded LPP exhibited a mean diameter of 170 ± 0.63 nm and a loading capacity of 26.3 ± 0.40% (w/w). A coating of sodium caseinate (SC) on the surface improved the colloidal stability of the CLA-loaded LPP. This encapsulation conferred protection against the oxidation of CLA, by which the head space-oxygen consumption and hydrogen peroxide value were obviously decreased in comparison with the SC-encapsulated CLA and CLA alone. The delivery system enables a sustained releasing profile of CLA in a simulated gastrointestinal tract (GIT). These findings illustrate that the LPP could act as an effective delivery device for CLA, which could provide oxidation stability and a sustained release property.

An improved physical model for the collector current in the SOI submicrometre gate-controlled hybrid transistor (GCHT) is presented in this paper, with the bias-dependent dynamic threshold voltage of the GCHT redefined and evaluated, considering the impact of carrier injection on the inversion degree of the surface in the base. Many physical effects are taken into account in this model, including channel length modulation effect, mobility degradation effect, as well as high injection effect, source/drain series resistance and body-contact resistance effect, which may result in additional gate-body bias. The model is verified by comparison between calculated results, PISCES simulated results and experimental data.

Two different tautomeric forms of a new Schiff base, C17H19N3O2·C17H19N3O2, are present in the crystal in a 1:1 ratio, namely the enol–imine form 4-(1-{[4-(dimethyl­am­ino)benzyl­idene]­hydra­zono}­eth­yl)benzene-1,3-diol and the keto–amine form 6-[(E)-1-{[4-(dimethyl­amino)benzyl­idene]hy­dra­zino}ethyl­­idene]-3-hydroxy­cyclo­hexa-2,4-dien-1-one. The tautomers are formed by proton transfer between the hydr­oxy O atom and the imine N atom and are hydrogen bonded to each other to form a one-dimensional zigzag chain along the crystallographic b axis via inter­molecular hydrogen bonds.

Ag-doped and pure ZrO2 thin films are prepared on Pt/Ti/SiO2/Si substrates by sol-gel process for resistive random access memory application. The highly reproducible resistive switching is achieved in the 10% Ag-doped ZrO2 devices. The improved resistive switching behaviour in the Ag doped ZrO2 devices could be attributed to Ag doping effect on the formation of the stable filamentary conducting paths. In addition, dual-step reset processes corresponding to three stable resistance states are observed in the 10% Ag doped ZrO2 devices, which may be implemented for the application of multi-bit storage.

Background. T-cell response to alloantigen is dependent on T-cell receptor activation and costimulation through the CD28 receptor, because T-cell receptor activation alone is insufficient for optimal immune response. The CD28 receptor on helper T cells interacts with its ligand B7 on activated B cells-macrophages as costimulus to support T-cell activity. CTLA4Ig is a recombinant inhibitor of CD28 receptor activation. In vivo studies with a rat major histocompatibility complex mismatch heterotopic cardiac transplant model demonstrate that CTLA4Ig prolongs cardiac allograft survival. This CTLA4Ig survival benefit is enhanced with prior donor-specific antigen exposure. Methods. To investigate CTLA4Ig mechanisms, we examined the differential expression of B7 and cytokine mRNAs for interferon-γ (IFN-γ), interleukin-2 (IL-2), IL-4, and IL-10 (Th1 or Th2 activation) in cardiac allografts after treatment with CTLA4Ig and donor-specific antigen exposure versus conventional immunotherapy (cyclosporine, cyclophosphamide, or antilymphocyte serum). In the above major histocompatibility complex mismatch model, hearts (on day 5 after transplantation at peak rejection) had cytokine mRNA expression determined by semiquantitative reverse transcriptase-polymerase chain reaction. Results. Inhibition of B7 expression was observed in CTLA4Ig animals. Expression of IL-2 and IFN-γ was near undetectable in CTLA4Ig and cyclophosphamide rats but was only moderately reduced by cyclosporine and antilymphocyte serum. IL-4 mRNA expression was reduced equally in all animals. Finally, IL-10 levels were unchanged by CTLA4Ig but were decreased by other therapies. Conclusions. The beneficial effect of CTLA4Ig, inhibiting expression of B7, alters Th1 cytokines IL-2 and IFN-γ, with a resultant predominant IL-10 driven, Th2 tolerogenic response.

The chiral 3-fold interpenetrating diamondoidlike Cu(II)-containing coordination polymer [Cu(2,5-bis(4-pyridyl)-1,3,4-oxadiazole)2(H2O)](ClO4)2]n (1a) is reported. It undergoes a temperature-driven reversible single-crystal-to-single-crystal structural transformation between room- (293 K, 1a) and low-temperature (150 K, 1b) forms.