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Extensive researches have been conducted over the decades to investigate the effects of seawater on many crop plants, either by irrigation or foliar spray, in an attempt to enhance yield and quality, but there are few studies on the effects of seawater irrigation on soil properties. The purpose of this study was to determine the effects of seawater irrigation on the fruit quality of Cabernet Sauvignon grapevines, soil pH, soil salinization, soil bulk density properties and soil microbial diversity. Field experiments were conducted using seawater (10% concentrations) during the fruit expansion period, the early veraison period, the veraison period and the late veraison period in Penglai (pH 6.5–6.7). Seawater irrigation led to increased levels of fruit soluble solids, phenolic content, anthocyaninand sugar/acid ratio, resulting in slowly-increased pH values of soils. After 4 years of continuous seawater irrigation, the pH value of the 0–20 cm soil layer increased 0.24 units at the vineyard of the Guobin Winery and increased 0.17 and 0.18 units after one and two years of seawater irrigation, respectively, at the vineyard of the COFCO Winery. Moreover, seawater irrigation did not affect soil properties, since soil bulk density, specific gravity and porosity did not differ significantly from the control soil. Furthermore, seawater irrigation had less effect on the types of soil microbial communities. The results suggest that combined with rainfall, seawater irrigation could be useful for improving fruit quality and soil pH without inducing secondary soil salinization problems, and seawater irrigation could be used in acidic vineyard soils.

A multi-function switched filters MMIC is designed and measured based on $0.25\mu\mathrm{m}$ GaAs E/D pHEMT process, which could be employed in wideband receivers. The switched filters work at 3∼8.4 GHz, and it comprises two low-insertion-loss SP4Ts (single pole quadruple throw), four bandpass filters, and several TTL (transistor-transistor-logic) digital drivers. Measured and simulated results are found in good agreement with each other. The measured results show that the insertion loss of the switched filters is less than 9dB, the ripple of the passband is less than 2 dB and the return loss is less than −13 dB.

To explore the effect and possible mechanism of serum hepcidin on malignant tumor patients combined with anemia of chronic disease (ACD). ELISA method was used to measure the concentrations of serum hepcidin, interleukine-6 (IL-6), and tumor necrosis factor α (TNF-α) in 40 malignant tumor patients with ACD. Meanwhile, the concentrations of serum hepcidin, IL-6, and TNF-α in 20 malignant tumor patients without ACD were measured. The differences in above indices between the two groups were compared. Meanwhile, the correlations of hemoglobin (Hb) value with hepcidin, IL-6, and TNF-α in the anemia group were analyzed, and the correlations of hepcidin with IL-6 and TNF-α were analyzed. The serum hepcidin, IL-6 and TNF-α levels in the patients from the anemia group were higher than those in the non-anemia group, which were 49.48±18.38 ng/mL vs. 10.36±5.28 ng/mL, 11.79±4.11 pg/mL vs. 5.46±2.37 pg/mL, and 10.73±3.94 pg/mL vs. 6.48±3.26 pg/mL, respectively(P＜0.05). Besides, Hb value in the patients from the anemia group had negative correlations with serum hepcidin and IL-6 (r values were -0.739 and -0.379, and P＜0.05), but had no correlation with TNF-α (r=-0.213, P>0.05). The serum hepcidin in the patients from the anemia group had a positive correlation with IL-6 (r=0.377, P＜0.05), but had no correlation with TNF-α (r=0.268, P>0.05). Conclusion: Hepcidin plays a critical role in the ACD onset of malignant tumor, and may happen mainly under the participation of IL-6.

The property of biomaterials to control the sequential release of growth factors has been widely concerned in the field of bone repair and regeneration. Double-factor sustained-release scaffolds have good biocompatibility and bioactivity. O‑Carboxymethyl chitosan microspheres (O-CMCS) has antimicrobial activity, biodegradability, biocompatibility and film formation. This study developed scaffolds materials with microspheres with a purpose of forming a controlled slow release secondary structure. O-CMCS were used as drug carrier to construct the compound sustained-release system with rhBMP-2 and VEGF double factors release. The O-CMCS were loaded with rhBMP-2 and the hydroxyapatite collagen (HC) scaffolds were loaded with VEGF to prepare the scaffolds. These were double factors composite sustained-release system scaffolds. The biocompatibility of the sustained-release system was evaluated by in vitro and in vivo experiments. HC composite scaffolds were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction detection (XRD), in vitro sustained release test, in vitro cell culture and in vivo animal experiments. The results showed that rhBMP-2/VEGF in HC composite scaffolds (HCBV) successfully achieved the sequential release of the double factors, which could benefit bone regeneration.

To study the relationship between the mechanical properties of sintered NdFeB magnets and composition of the Nd-rich phase, sintered NdFeB magnets with different mechanical properties and composition of Nd-rich phases were prepared by spark plasma sintering technology (SPS). Several correlations including the bending strength of the magnet to sintering temperature (σbb-t), the rare earth content in the Nd-rich phase to the sintering temperature (nRE-t), and the iron content in the Nd-rich phase to the sintering temperature (nFe-t) were investigated. Several empirical formulas for these relationships ware obtained by fitting these experimental curves. It is found that there is almost no change in the sum of Re and Fe content, revealing that the diffusion direction of RE and Fe atoms in the boundary phase between the main phases during sintering is opposite, and the relationship of σbb to nRE are approximately linear. Based on these, the mechanism of improving the mechanical properties of sintered NdFeB materials via changing the composition of Nd-rich phase was discussed.

β -FeOOH nanoparticles have been prepared in a microemulsion system with nonionic surfactant polyoxyethylene(4)nonylphenylether CH 3 (CH 2 ) 8 C 6 H 4 O(CH 2 OCH 2 ) 4 H. The powder X-ray diffraction, infrared spectra, and transmission electron microscopic images indicate that the products are 20–30 nm length nanorods with a crystal structure belonging to monoclinic β -FeOOH and lattice parameters of a =0.9981, b =0.2948, c =1.0485 nm and β =92.26°. The size and shapes of β -FeOOH nanoparticles can be manipulated by the surfactant. The modified β -FeOOH nanoparticles are paramagnetic at room temperature and may be antiferromagnetic or weakly ferrimagnetic at lower temperatures. The 57 Fe Mossbauer spectra show that the magnetic structure transforms below 150 K and two kinds of Fe–O octahedra exist in the lattice of the modified β -FeOOH nanoparticles. The numbers of each kind of Fe–O octahedra are not the same at room temperature or at low temperatures.

We have investigated the magnetic, electrical transport and electron spin resonance (ESR) properties of polycrystalline Fe-doped manganite LaMn 0.7 Fe 0.3 O 3+ δ prepared by sol–gel method. A typical cluster-glass feature is presented by DC magnetization and AC susceptibility measurements and a sharp but shallow memory effect was observed. Symmetrical Lorentzian lines of the Mn/Fe spectra were detected above 120 K, where the sample is a paramagnetic (PM) insulator. When the temperature decreases from 120 K, magnetic clusters contributed from ferromagnetic (FM) interaction between Mn 3+ and Mn 3+ /Fe 3+ ions develop and coexist with PM phase. At lower temperature, these FM clusters compete with antiferromagnetic (AFM) ones between Fe 3+ ions, which are associated with a distinct field-cooled (FC) effect in characteristic of cluster-glass state.

The quadrupole splitting distributions (QSDs) from the Mossbauer spectra of triphylite, ferrisicklerite and purpurite at 298 K and 80 K were obtained by the use of the Voigt-based quadrupole splitting distribution (QSD) method for the first time. QSDs of Fe2+ and Fe3+ are attributed to Fe2+ and Fe3+ at the corresponding octahedrally coordinated sites in the crystal structures of the three phosphate minerals. The influence on the distortion of the M2 site by different next-nearest neighbor (NNN) configurations was discussed based on the Jahn–Teller effect in purpurite, and the authors propose two M2 subsites with different distortions in purpurite. Two QSDs of Fe3+ in the Mossbauer spectra of purpurite are tentatively assigned to Fe3+ at the two M2 subsites, and next-nearest neighbor (NNN) effects were used to interpret the Mossbauer spectra of purpurite.

A laboratory-scale EMS-based HTS maglev vehicle operating over a 1.5 m guideway has been successfully constructed. The fully integrated system consists of a vehicle chassis, four dependent magnetic circuits, four distance sensors, and control and power amplification circuits. As key component of the system, each magnetic circuit includes a U-shape iron core with one HTS coil forming each pole. Eight HTS coils made of Bi-2223 multi-filamentary tape were used to provide the magnetic motive force. Several questions relating to the unique characteristics of the HTS material in a controlled magnetic circuit are discussed. The most important consideration for such applications is that the anisotropic critical current of the Bi-2223/Ag tape depends strongly on the magnetic field. The commercially available FEA software ANSYS was used to simulate the field distribution along the magnetic circuit and HTS coil winding, and thereby identify how the magnetic circuit alters the field distribution in the coil winding and therefore also the critical current. A general optimization process is described for finding the best position in the U-shape iron core to hold the HTS coils. In this process the critical current of the HTS tape and the force–current characteristic of the magnetic circuit are considered synthetically. The results demonstrate the feasibility and stability of HTS material in a typical maglev system and other similar controllability applications. � 2005 Elsevier B.V. All rights reserved. PACS: 84.71.Ba

The amorphous iron boron alloy can be prepared very easily by a room temperature solid–solid reaction of the FeCl 3 ·6H 2 O, CrCl 3 ·6H 2 O and KBH 4 powders. The characterizations show that the product is mainly composed of amorphous iron boron alloy nanoparticles. 57 Fe Mossbauer spectra at 84 and 295 K show that there are three kinds of Fe-containing components in the sample. There are the superparamagnetic relaxation in Mossbauer spectra and the continuous distribution of internal magnetic field in the iron boron alloy.

AC losses in multi-filamentary tapes depend on various parameters. Among them, the overall tape width and thickness are expected to have an important influence. In order to study this geometrical effect, five Bi-2223/Ag tapes with different aspect ratios from 5 to 26 have been prepared. AC losses have been measured at 77 K when a perpendicular AC magnetic field is applied. It has been found that at any frequencies the magnetic loss per cycle increases as the aspect ratio increases. For AC magnetic loss, with increasing frequency from 3 to 9000 Hz the losses as a function of frequency show a maximum if the field amplitude is much less than the full penetration field or increase continuously if the field amplitude is larger.

On five Bi-2223/Ag tapes with different aspect ratios from 5 to 26, AC losses have been measured at 77 K while a parallel AC magnetic field or a perpendicular AC magnetic field or a longitudinal AC transport current is applied. It has been found that at any frequency the perpendicular magnetic losses per cycle increase, but the parallel magnetic losses per cycle and the transport losses per cycle decrease as the aspect ratio increases. These experimental results are in accord with theoretical results. Meanwhile, we investigated the geometry dependence of the decay time constant of coupling current and that of full penetration field.

This paper presents a novel approach of modeling the delamination phenomenon experienced by laminated composite plate and shell structures by using a previously developed layerwise shell finite element in conjunction with some transformations. This layerwise element is formulated by stacking some single-layered shell elements through a transformation of displacements of the mid-surface of a layer to those on the mid-surface of the laminated composite shell structure. It can accurately model the overall displacements and interlaminar stresses of a laminated composite shell structures whose layers are perfectly (rigidly) bonded. The novelty of the present approach, however, lies in the fact that two different transformations are used so that interlaminar displacements as well as interlaminar stresses can be represented in the finite element model. The transformations allow for displacement mismatches across the normal direction of the layer interfaces (the normal mode of delamination) and between layers (the shear mode). As a result, the proposed methodology can be used to model the open and shear modes of delamination. A two-layered simply supported composite beam and a two-layered simply supported cross-ply square plate are then chosen for numerical studies. These examples demonstrate how the present approach can be applied to accurately model delamination phenomena such as shear slip and normal separation. The paper concludes with suggestions for future work.

The effect of oxygen content on the electrical transport properties of La 0.4 Ca 0.6 MnO 3-y was studied. Upon decreasing oxygen content, the lattice parameters a, b and c of the samples increase and the electrical resistivity of the samples also increases abruptly, contradicting what is expected in terms of Mn 4+ /Mn 3+ ratio. This work suggests that other factors rather than the ratio of Mn 4+ /Mn 3+ may play a role in determining the properties of La 0.4 Ca 0.6 MnO 3-y with less oxygen contents.

The morphology of the silver films deposited and annealed on laser ablated YBa2Cu3O7−δ thin films and the corresponding contact resistivity have been systematically investigated. A minimum contact resistivity of 6 × 10−8 Ω cm2 was reached at 77 K by annealing Ag/YBa2Cu3O7−δ contact at the optimum temperature. The effect of the annealing temperature on the contact resistivity was explained by considering the morphology of the silver films and the diffusion of silver into YBa2Cu3O7−δ film, etc. The difference of the contact resistivity for Ag contact to polycrystalline, single crystal and thin film of YBa2Cu3O7−δ were also explained.

La 0.75 M 0.25 Cr 0.75 Fe 0.25 O 3 (M = Sr, Ba) compounds are synthesized by a wet chemical method, the crystal structure of the compounds belongs to the orthorhombic system. The Mossbauer spectra of 57 Fe reveal that all the iron ions in the compounds are trivalent and in high-spin state. There is a linear relationship between the quadrupole splitting of the 57 Fe nucleus and the electronegativity of the M ion in La 0.75 M 0.25 Cr 0.75 Fe 0.25 O 3 (M = Ca, Sr, Ba). Unlike in La 1-x Sr x FeO 3 , the substitution of the divalent alkaline earth ion for the trivalent lanthanum ion does not lead to an increasing valence state of the Fe 3+ ion in La 0.75 M 0.25 Cr 0.75 Fe 0.25 O 3 (M = Sr, Ba). Doping the alkaline earth ion will more likely lead to an increasing valence state of the Cr 3+ ion.

The nickel ferrite ultrafine powders with different grain sizes (8, 12, 20, 40 and 80 nm) have been synthesized. Mossbauer spectra of Fe-57 nucleus in the samples composed of the nickel ferrite ultrafine powder before and after the high pressure treatments have been measured. The superparamagnetic relaxation is markedly suppressed by high pressure. The intensity of the sextets in Mossbauer spectra increases with increasing the grain size or pressure. The effect of high pressure on Mossbauer spectra of the samples may involve not only the physical changes, but also the chemical or structural ones in the ultrafine particles during the high pressure treatment, such as the formation of the interfacial region between the ultrafine particles and the rearrangements of the atoms in the surface layers of the ultrafine particles. (C) 2000 Elsevier Science S.A. All rights reserved.

La 1− x Ca x Cr 1− x Fe x O 3 ( x = 1/4, 1/3) are synthesized by wet chemical method and the crystal structure of the compounds belongs to orthorhombic system. Mossbauer spectra of 57 Fe nucleus show that all the iron ions in the compounds are trivalent and in high-spin state. A tight-bending method on the basis of EHMO approximation has been performed to calculate the average valence states of various ions in La 3/4 Ca 1/4 Cr 3/4 Fe 1/4 O 3 . The results indicate that the average valence state of chromium ion increases with doping calcium ion, but that of iron ion still is trivalent in the compound. Doping calcium and iron ions may have a certain effect on energy band structure and on conduction mechanism in lanthanum chromite.

New compounds Eu 2 Co 2/3 Nb 4/3 O 7 and Eu 2 Ni 2/3 Nb 4/3 O 7 have been synthesized. The crystal structure of the new compounds belongs to a hexagonal system. The assignments for the absorption bands in the region of 400 to 1000 cm -1 of the infrared spectra for the compounds have also been given. A new absorption band (v' 1 = 816 or 832 cm -1 ) may arise from the stretching vibration of the Co-O or Ni-O bond in the compounds. The results of the infrared spectra can demonstrate the pyrochlore structure of Eu 2 Co 2/3 Nb 4/3 O 7 and Eu 2 Ni 2/3 Nb 4/3 O 7 . The results of Mossbauer spectra at room temperature indicate that the Eu cation is trivalent in the compounds and there has been a certain distortion in the lattice of the compounds due to the substitution of the cobalt or nickel cation for the niobium cation. This kind of pyrochlore compounds with formula RE 2 B' 2/3 B 4/3 O 7 belongs to a hexagonal system, not to a cubic one.

Change in the quadrupole splitting of 151 Eu nucleus in the Mossbauer spectra of an EuBa 2 Cu 3 O 7− x thick film at 105 K has been observed when an AC electric current passes the thick film. It has been found that the quadrupole splitting of 151 Eu nucleus increases with increasing the frequency of the electric current passing the thick film and that the relationship between the quadrupole splitting of Eu nucleus in the superconducting thick film and temperature before the superconducting transition can also obey the formula presented by Heubes and Christiansen. This phenomenon may be attributed to the hysteresis loss of the alternating current passing the superconducting regions in the EuBa 2 Cu 3 O 7− x thick film.

Mossbauer spectra of Fe-57 in a thick film YBa2(Cu0.97Fe0.03)(3)O7-x irradiated by a large dose of gamma-rays from Co-60 have been measured. The variation of the relative intensities of some subspectra of Fe-57 in the. Mossbauer spectra of the thick film YBa2(Cu0.97Fe0.03)(3)O7-x after irradiation can be observed. This variation indicates that the change of the coordination environment around some Fe atoms in the lattice occurs due to irradiation. The relative intensity of subspectrum D1(Fe) at the Cu(1) site decreases and that of subspectrum D4(Fe) at the Cu(1) site increases. This may be because of the possible oxygen atom hopping between the coordination environments of D1(Fe) and D4(Fe) in the lattice caused by irradiation. The effect of irradiation on the coordination environment around the Fe atom at the Cu(2) site is not appreciable. (C) 1997 Elsevier Science B.V.

Finite elements that are capable of representing vibration behaviour of general plate and shell structures have been developed and presented in this paper. The formulations and derivation of the explicit stiffness matrices of the elements have already been proposed and obtained earlier by the authors. These three-node 18-d.o.f. flat triangular shell elements have proved to be accurate and reliable for general shell structures under static loads. In the present paper, explicit expressions for corresponding consistent mass matrices are derived. The shell elements are of the hybrid strain type and degenerate in nature. This degenerate nature allows for applications to thin as well as to moderately thick to thick shells and makes extension to non-linear analysis simple. The hybrid strain feature, however, provides continuity of displacements and strains. Efforts are also directed to address the issue of normal rotation. The presented elements are capable of reflecting true normal rotation as well as desirable membrane and bending behaviour. Computed results of several problems that were considered in the obstacle course of the static analysis are included to demonstrate the accuracy and capability of the elements.

Aspects and theories of nonlinear analysis of structures, with special emphasis on structures that are discretized by the finite element method, are discussed. The updated Lagrangian formulation and the incremental Hellinger-Reissner variational principle are adopted. The independently assumed fields employed are the incremental displacements and incremental strains. Accordingly, the incremental second Piola-Kirchhoff stress and the incremental Washizu strain are selected as the incremental stress and strain measures. Various schemes for the transformation of the second Piola-Kirchhoff stress to Cauchy stress are included. Two versions of linear and nonlinear element stiffness and mass matrices are considered. These are the director and simplified versions. Variable thickness of the shell is considered so as to account for the ‘thinning effect’ due to large strain. Material nonlinearity studied in this paper is of elasto-plastic type with isotropic strain hardening. Cases in which small elastic but large plastic strain condition applies are considered and the J2 flow theory of plasticity, in conjunction with Ilyushin's yield criterion, is employed. To simplify the derivation of (small displacement) stiffness matrix and to facilitate the derivation of explicit expressions for the element matrices, the non-layered approach has been applied.