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An oxide layer can commonly be found between a void in and the matrix of metal materials subjected to remote mechanical loading. This paper presents an evaluation of the failure behavior of a polygonal nano-void surrounded by an oxide layer in an infinite cracked matrix under a remote anti-plane load. Based on the complex variable, conformal mapping and analytical continuation with alternating methods, the stress functions are obtained in series form and the mode-III stress intensity factors (SIFs) are derived. The results indicate that a softer oxide layer (zirconia) would cause a higher SIF compared to a stiffer oxide layer (alumina). The results of this investigation provide a quantitative description of the effects of an oxide layer and inform an optimum design method for metal forming.

The analysis of the chemical characteristics of the Middle Permian formation water in 10 wells in the northwest of Sichuan Basin indicates that: the TDS of the Middle Permian formation water in Northwest Sichuan increases longitudinally with the burial depth of the formation, and the formation water is mainly of CaCl2 type (Surin classification), Cl-Na-Ca type and Cl-Ca-Na type (Shukarev classification). The rNa+/rCl− and rSO4 2-*100/rCl− of the formation water are 0.05-0.95 and 0-5 respectively, reflecting strong water-rock interaction and strong sealing conditions. The analysis of the chemical characteristics of formation water and the preservation conditions of oil and gas shows that the overall preservation conditions of the Middle Permian in Northwest Sichuan are good, most of which is located in the “preservation zone”; longitudinally, the preservation conditions of Qixia Formation are better than those of Maokou Formation; areally, the preservation conditions of Shuangyushi and Jiulongshan regions are good; the sealing property of the strata in Hewanchang region is poor.

A novel regeneration system based on direct shoot organogenesis is described for cassava. Plants could be regenerated at high frequency by inducing shoot primordia on explants derived from cotyledons of cassava somatic embryos. After a passage on elongation medium, the regenerated shoots were easily rooted in hormone-free medium and could be successfully transplanted to soil. Using the shoot-organogenesis-based regeneration method, up to eight transplantable plantlets per explant could be regenerated. The system was optimised first for one cassava cultivar, and then its transferability to three other cultivars was demonstrated. This method widens the scope of in vitro regeneration modes of cassava, and is also compatible with Agrobacterium-mediated transformation. To develop an efficient system for production of somatic embryos for regeneration experiments, conditions for inducing primary and cycling somatic embryos were also studied, and highly efficient plant regeneration via germination of somatic embryos was achieved using maltose instead of sucrose in the culture medium, and combining paclobutrazol with 2,4-dichlorophenoxyacetic acid in the embryo induction medium.

SummaryThe late-ripening peach [Prunus persica (L.) Batsch] cultivar ‘Guibao’ was chosen in order to study the effect of different bagging treatments on the appearance, skin quality, and internal quality of fruit. Diurnal variations in temperature and relative humidity (RH) in white single-layer paper bags (WPB), white single-layer polypropylene non-woven bags (WPPB), and black single-layer paper bags (BPB) were recorded for 15 d before harvest. Bagging treatments were applied 30 d after full bloom (DAFB). The WPB and WPPB treatments continued until harvest, while the BPB were removed 7 d before harvest. Observations were recorded on skin colour and fruit quality attributes such as fruit fresh weight (FW), flesh firmness, total soluble solids concentration (TSSC), colour, skin pigments, soluble sugar concentrations (SSC) and organic acid concentrations. The average temperature and RH increased slightly in the bags. Compared with unbagged control fruit, the average temperature in WPB, WPPB, and BPB increas...

The reaction of [VO(Acac)2] with 4-methyl-N′-[(2-hydroxy-1-naphthyl)methylidene]benzohydrazide (H2L1) and 4-methyl-N′-[1-(2-hydroxynaphthyl)ethyiidene]benzohydrazide (H2L2), respectively, in methanol, affords two new oxovanadium(V) complexes [VO(OMe)L1]2 (I) and [VO(OMe)L2] (II). Both complexes have been characterized by elemental analysis, IR, and single crystal X-ray diffraction methods. Complex I is a methoxide-bridged dinuclear oxovanadium(V) compound, while complex II is a mononuclear oxovanadium(V) compound. The dinegative hydrazone ligands coordinate to the metal atoms through phenolate, imine, and deprotonated amide donor atoms. The geometry around vanadium atom in I is a distorted VNO5 octahedron, while that in II is a VNO4 square pyramid. Both complexes have effective catalytic property for the sulfoxidation reaction.

Glutathione (GSH) is a natural active tripeptide formed by glutamic acid, glycine, and cysteine, which plays a vital role in many physiological processes of the living body. The GSH contents of the sample were detected by using calcein-Cu(II) fluorescence system in our work. In a Na2HPO4-NaH2PO4 buffer with a pH of 8.0, Cu (II) could coordinate with calcein. Calcein-Cu(II) complex was not fluorescent which led to a reduction of calcein fluorescence intensity. For the strong affinity of GSH with copper (II), the addition of GSH solution would make calcein free from calcein-Cu(II) complex and recover fluorescence. Excitation spectra and emission spectra of calcein and calcein-Cu(II) system were researched. And fluorescence spectra of calcein-Cu(II) system with different GSH contents were investigated. The influence of experimental parameters such as reaction time and the addition sequence of the solution on results was also studied. We got the following conclusions: first, Cu(II) can make the calcein fluorescence be quenched, but the wavelength at the peak of fluorescence is unchanged. Second, the addition of Glutathione can make the fluorescence of calcein - Cu (II) system recover. And the change of the fluorescence intensity has a linear relationship with the concentration of GSH in the range from 2 × 10−6 to 1.0 × 10−5 mol/l. Third, response time may be extended appropriately for complete reaction in the system. At last, the experimental results have shown that calcein - GSH - Cu(II) system has higher sensitivity and better stability than calcein - Cu(II)- GSH system. This test method is of great importance in practical application.

Exchange bias in [Pt/Co]/NiO multilayers were studied as a function of film thickness and [Pt/Co] layer repetition. A strong temperature dependence of the coercivity, H c ,and exchange bias field, H ex, was observed for the thick and thinnest [Pt/Co]/NiO multilayers. While the thinnest [Pt(3 nm)/Co(1.25 nm)] 4 /NiO multilayers exhibits no in-plane exchange bias field, a perpendicular H ex⊥ ∼ -150 Oe at 80 K was measured. By contrast, the thickest [Pt(12 nm)/Co(10 nm)] 1 /NiO multilayers exhibited an in-plane H ex// ∼ -600 Oe (with H ex// ∼ -1300 Oe at 5 K) with no measurable perpendicular exchange bias field. The estimated interfacial exchange coupling energy implies the effective Co layer thickness contributing to the exchange bias is effective only in Co layer in contact with NiO bottom layer. AC susceptibility and the temperature dependence of H ex show that the a 1.25 nm thick Co component enables perpendicular exchange bias with a reduced blocking temperature T B ∼200 K, compared to that (T B ∼250 K) for the thick [Pt/Co]/NiO multilayers. This is attributed to disordered CoPt phases that formed due to intermixing between Co and Pt during deposition.

A series of [Pt(2 nm)/Co(2 nm)]10/Pt(30 nm) multilayers were deposited by using an ion-beam technique. X-ray diffraction and transmission electron microscopy results have shown that as-deposited samples consist of h.c.p. Co and f.c.c. Pt phases. Disordered CoPt3 phases were developed with increasing End-Hall voltage (VEH) that induces greater ion-beam bombardment energy during deposition. This indicates that intermixing of Co and Pt increases with ion-beam bombardment. The coercivities (ranging from 100 Oe to 300 Oe) of Co/Pt multilayers decreased with increasing VEH. After annealing, the formation of CoPt3 was observed in these ion-beam bombarded samples, resulting in lower coercivities (Hc ∼ 50 Oe). The depressed transition temperature of CoPt3 for films deposited with the largest VEH was attributed to distorted CoPt3 structures that appeared with annealing. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

In this study, the structural and magnetic properties of exchange coupled nanocomposite FePt-FePt 3 films were investigated. X-ray diffraction and transmission electron microscopy results showed that after rapid thermal annealing (600 °C for 6 minutes), a phase transformation from [Pt+Fe] into composite FePt-FePt 3 phases was obtained. Annealing created an ordered FePt phase that resulted in a large room temperature coercivity (H c ∼ 3200 Oe) compared to the as-deposited film (H c ∼ 20 Oe). While no exchange bias field (H ex ∼ 0 Oe) was measured at room temperature, the annealed sample showed significant H ex ∼ -500 Oe at lower temperatures (150 K ≤ T ≤ 250 K), indicative of exchange coupling between FePt and FePt3. The high blocking temperature (∼ 250 K) indicates FePt 3 exhibits an enhanced Neel temperature. Further increasing the annealing temperature to 700 °C resulted in a reduction of Hex which is attributed to the transformation of FePt3 into the FePt phase at this higher annealing temperature.

This paper discussed the working principle of binary channel surface acoustic wave (SAW) lithium niobate piezoelectric chip detecting mustard, established the mathematic model of beat frequency output Δf and the mustard gas density δ. The MEMS craft solved the parameters of the binary channel SAW chip such as its interdigital electrode number was 15~25 couple, width and spacing were both 25µm, degree of overlapping was 2mm, fundamental frequency was 10~35MHz, frequency-domain width was 5~20Hz, and its back pt hot film's. According to TG-DSC thermal analysis, vacuum coating craft was adopted to solve the hybrid sensitive film forming craft parameter of PdPc0.3PANI0.7(phthalocyanine palladium0.3Poiyaniline0.7). The micro-appearance of sensitive film was analyzed through SEM. The sensor's sensitivity and response characteristic were tested and analyzed: appear linear change, its response time is less than 5min while its recovery time is less than 8min.

Apparent and true values of protein digestibility (APD vs. TPD) and amino acid availability (AAAA vs. TAAA) of casein, gelatin, fish meal, shrimp meal, soybean meal and spirulina meal were determined for juvenile Chinese hairy crab Eriocheir sinensis H. Milne-Edwards. Assay diets were prepared by incorporation of 20% of a protein source into a reference diet. A protein-free diet (PFD) was used to estimate the metabolic faecal nitrogen (MFN) content and amino acid composition (MFAA). MFN content was 445.3 mg 100 g−1 PFD. MFAA ranged from 19.6 mg 100 g−1 PFD for tryptophan to 228.5 mg 100 g−1 PFD for glutamic acid. Casein and gelatin trended towards higher APD, while fish meal had the lower APD and TPD. Although there was reasonable agreement between protein digestibility and average amino acid availability, protein sources had significant effects on AAAA and TAAA. For total amino acids and most individual amino acids, casein and gelatin were relatively higher both in AAAA and in TAAA, soybean meal and spirulina meal intermediate, while fish meal was lower. Data of AAAA and TAAA suggest that soybean meal and spirulina meal could be used as substitutes for animal proteins. Individual AAAAs and TAAAs were variable within and among protein sources. Those results suggest that determination of amino acid availabilities is necessary for the more accurate and economical feed formulation.

Four successive life stages (zoea-III, zoea-IV, zoea-V and megalopa) of the Chinese mitten-handed crab, Eriocheir sinensis (H. Milne-Edwards), were exposed to ammonia in a series of short-term bioassays with the static-renewal method at 22°C, pH 8.0 and 25%o salinity. The greatest sensitivity was observed in the zoea-III stage. The 24-h LC50 values for zoea-III, zoea-IV, zoea-V and megalopa were 32.8, 73.1, 84.0 and 90.1 mg L−1 for NH3+ NH4+, and 1.11, 2.36, 2.77 and 3.18 mg L−1 for NH3, respectively. The 72-h LC50 values for zoea-III, zoea-IV and zoea-V were 11.9, 23.6 and 38.2 mg L−1 for NH3+ NH4+, and 0.40, 0.76 and 1.26 mg L−1 for NH3, respectively. The 96-h LC50 values for megalopa were 37.3 mg L−1 for NH3+ NH4+ and 1.31 mg L−1 for NH3. It was found that ammonia tolerance increased with larval development from zoea-III to megalopa, especially from zoea-III to zoea-IV and from zoea-IV to zoea-V. A comparison of safe levels of ammonia among the different life stages indicated that all stages were significantly different with respect to safe levels of ammonia (P < 0.05) except zoea-V and megalopa, which had the highest safe levels. In general, both the larvae and juveniles of E. sinensis are less resistant to ammonia than those of other crustacean species studied so far.

Poly(vinyl alcohol)-borate (PVA-borate) complexes in dilute aqueous solutions were investigated by dynamic light scattering (DLS). Two relaxation modes obtained, were scattering vector-q2 dependent and diffusive. The amplitude of slow mode was independent of borax concentration. In the very dilute PVA concentration regime ( [PVA] < 5 g/L), the PVA di-diol-borate complexation was dominated by intra-molecular reaction, and the fast mode correlation length ςf which corresponds to the polymer chain dimension increased rapidly with borax concentrations lower than 0.06 M, and reached an asymptote in the higher borax concentration regime. However, for a dilute PVA aqueous solution with higher PVA content (i.e., [PVA] = 9 g/L), both intra-and inter-molecular PVA di-diol-borate complexations might happen. The chain expansion and shrinkage of PVA-borate complex with increasing borax concentration was observed due to the balance between the electrostatic repulsion of the charged diol-borate complexes and the intra-molecular crosslink induced by the intra-molecular di-diol-borate complexation.

Static-renewal bioassays were performed to evaluate the acute toxicity of ammonia to Eriocheir sinensis (H. Milne-Edwards) at three growing stages, namely zoea-I, zoea-II, and juvenile (0.06 g wet weight per crab). The 24 h LC50 values were 13.3, 20.2, and 109.3 mg (NH3+ NH4+) 1−1 (0.47, 0.71, and 3.10 mg NH3 I−1), the 48 h LC50 values being 6.8, 10.3, and 60.9 mg (NH3+ NH4+) 1−1 (0.24, 0.36, and 1.73 mg NH31−1), while the 72 h LC50 values were 5.7, 7.6, and 45.3 mg (NH3+ NH4+) 1−1 (0.20, 0.27, and 1.29 mg NH3 1−1) for zoea-I, zoea-II, and juveniles, respectively. The 96 h LC50 value for juveniles was 31.6 mg (NH3+ NH4+) 1−1(0.90 mg NH31−1). It was evident that the tolerance to ammonia increased during the same exposure time as the larvae developed to juveniles and decreased with prolonged exposure time. Compared with larvae, juveniles were more sensitive to the fluctuation of ambient ammonia concentrations in the certain range within which partial kills took place. The ‘safe level’ of ammonia based on the 96 h LC50 value and an application factor of 0.1 was 3.16 mg (NH3+NH4+)1−1 (0.09 mg NH3 1−1) for juveniles and those for zoea-I and zoea-II were 0.57 and 0.76 mg (NH3+ NH4+) 1−1 (0.02 and 0.03 mg NH3 1−1) based on 72 h LC50 values.

A study is reported of the formation of ultrafine SiC powder through the reaction of elemental silicon and CH4 in an induction plasma. The reaction route used involved in the first place the vaporization of a fine elemental silicon powder axially injected into the center of the discharge followed by the carburization reaction through the coinjection of CH4. The powder obtained was composed of a mixture of α- and β-SiC with varying amounts of free carbon and free silicon. The particle size distribution was typically in the range of 40–60 nm with a corresponding specific surface area of 30–50 m2/g. A parametric study showed that the quality of the powder obtained varied with the plasma plate power and the position of the injection probe. The plasma gas composition employed was found to influence the proportions of α- and β-SiC in the synthesized SiC powder. With an Ar/N2 mixture as the plasma gas, the ratio of the α to β phases was less than 1.0, whereas the ratio was greater than 1.5 when using a mixture of Ar/H2 as plasma gas. The Si powder feed rate and the input C/Si molar ratio in the injected reactants significantly affected both the formation of the SiC and the free Si and free C content in the synthesized powder. Lining the cylindrical reactor wall with graphite resulted in improved conversion of Si to SiC. The weight fraction of the powder collected at different sections of the reactor system varied with the reactor operating conditions. The experimental results support the view that the formation mechanism for ultrafine SiC is dominated by the reaction of Si vapor with the thermal decomposition products of CH4.

Ultrafine SiC powders have been synthesized from elemental silicon and methane using induction plasma technology. The powder products were characterized by X-ray diffraction, thermogravimetric analysis, scanning and transmission electron microscopy, electron probe microanalysis, infrared spectroscopy, and surface area measurement. The powders collected from various sections of the reactor system showed different features reflecting different compositions and powder morphologies. The purest SiC powder was collected in the metallic filter. It was composed of both α-and β-phase of SiC with small levels of free silicon and carbon. The reaction route used is based on the evaporation of the injected pure silicon starting powder, followed by carburization of the silicon vapour using methane. The silicon evaporation rate was found to depend strongly on the particle size of the silicon powder. Using silicon powder with a mean particle diameter of 100 μm, at a plasma power level of P=43.2 kW, the conversion of silicon to SiC and the overall SiC content in the product powder was 44.2% and 50.8 wt%, respectively. The injection probe position was Z=9.3 cm, the silicon feed rate was 4 g min−1, and the C/Si molar ratio was 0.7. Using silicon particles with a mean diameter of 45 μm, the conversion and overall content of SiC increased to 70.4% and 73.9 wt%, respectively, under the same plasma operating conditions and powder feed rates. By appropriate selection of experimental conditions, ultrafine SiC powder of high quality was achieved.

We have studied the correlation between the ion-beam bombardment and exchange bias effects in NiFe/NiO bilayers. The dependence of the exchange bias field, H ex , with increasing V EH suggests strongly that the Ar ion-beam bombardment process may increase the spin misalignment in FM/AF interfaces (resulting in a decrease of H ex ) or create uncompensated NiO spins (shown by a shift from negative to positive H ex ), depending on the energy used. The polarity switch from −H ex to +H ex occurred with increasing ion-beam bombardment time (t bom. ≫ 5 mins).

C16H28N8O8S2, orthorhombic, Pbca (no. 61), a = 10.646(1) Å, b = 8.185(1) Å, c = 26.402(4) Å, V = 2300.6 Å3, Z = 4, Rgt(F) = 0.038, wRref(F2) = 0.093, T = 293 K.

C10H13NO10, monoclinic, P121/n1 (no. 14), a = 7.351(2) Å, b = 22.077(5) Å, c = 8.129(2) Å, β = 99.907(4)°, V = 1299.5 Å3, Z = 4, Rgt(F) = 0.041, wRref(F2) = 0.106, T = 294 K.

The exchange bias field dependence on the Mn-oxide and its microstructure in NiFe/Mn-oxide bilayers was investigated. Transmission electron microscopy results have shown that the bilayer bottom consisted of either α-Mn, rocksalt MnO, or a composite of tetragonal Mn3O4+MnO, depending on the ratio of O2/Ar used during dual ion-beam deposition. Magnetometry results at 5 K indicate that the exchange bias field (Hex∼−300 Oe) is largest in a NiFe/Mn (0%O2/Ar) bilayer. The MnO formation by in situ Mn oxidation results in a decrease in Hex in a NiFe/Mn-oxide (21%O2/Ar) bilayer. In contrast, a further increase in the O2/Ar ratio during deposition results in larger Hex and Hc. This is attributed to the oxidation of MnO into a harder ferrimagnet, Mn3O4. Our results indicate that the antiferromagnetic Mn enabled stronger coupling with NiFe than MnO. In addition, we find that the MnO–Mn3O4 coupling dominates the exchange bias effects at high oxygen concentrations.