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An electrophoretic deposition system was used to deposit graphene oxide (GO) or alkali-functionalized GO (GONa) on the surface of graphite fiber cloth (GFC). The morphology and structure of the obtained products were examined by scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR) and Raman spectrum. The SEM images showed the GO or GONa sheets tightly covered on GFC. However, the GONa was easier to be deposited on the GFC than GO and the loading ratio could be up to 20.58 wt%. The composites showed the best electrochemical performance with specific capacitance of 27.32 F/g at 0.5 A/g when loading ratio of GONa was 8.54 wt%, synthesized at 27 V in 0.35 g/L GONa solution for 2.5 h. Moreover, the specific capacitance of the composites decreased slower with increasing current and was higher than that of the GO at 5.0 A/g. The relative specific capacitance of the GO or GONa in their composites was respectively a dozen times higher than that of the GO alone (33.39 F/g at 0.5 A/g), i.e. 427.63 F/g in GO-GFC and 355.41 F/g in GONa-GFC at 0.5 A/g. After the reduction, the specific capacitance of the reduced GO-GFC was enhanced while the reduced GO lowered, indicating that the composites prevented the most GO molecules agglomerating or restacking.

Graphical abstractDisplay Omitted We explore subwavelength imaging of the isolated triangular nanostructures.We use a modified self-assembly method to fabricate triangular array mask.The superlens structure provides an enhanced imaging resolution. Superlens nanolithography is a promising technique for patterning nanoscale structures because of its ability to overcome the diffraction limit. In this paper, subwavelength imaging of triangular particle array through a silver superlens is investigated. The superlens structure was optimized by means of the transfer transmission matrix method. The triangular array was obtained by self-assembly of nanoscale polystyrene spheres (PSS) and was successfully replicated into the photoresist. Experimental results show that the superlens structure provides at least 50nm resolution, about 1/7 of the incidence wavelength.

It has been proposed that a planar silver layer could be used to project a super-resolution image in the near field when illuminated near its plasma frequency. The planar silver layer is called as a superlens. In this paper, we design a superlens structure for nanolithography purpose. The imaging comparisons of single and layered silver/dielectric stacks are made. The design details of the superlens structure are presented. An experiment for demonstrating the focusing effect of the silver layer is performed which shows the superlens supports the imaging of a grating with 1 μm pitch at an exposure source with 365 nm wavelength.

Mask less surface plasmon interference lithography provides potential to obtain nanoscale feature size with large area at low cost. In this paper, we present a novel structure for mask less surface plasmon interference lithography. It is an enhanced Kretschmann structure in which a dielectric layer with low refractive index is added between the prism and metal layer. Numerical results show that the additional dielectric layer eliminates the inherent limit in classic Kretschmann structure that requires use of a prism with high refractive index for lithography purpose. Also, the structure exhibits more flexibility in tuning the spatial resolutions than classic Kretschmann structure. Both advantages lead to the structure more practical in real use.

The near-field perfect lens (NFPL) in imaging chrome gratings is investigated by using finite difference time domain (FDTD) method. The surface plasmon focused effect in and beneath the NFPL layer is demonstrated. The effects of the grating parameters and NFPL permittivity on image fidelity are explored. It is found that the excitation of surface plasmons results in frequency-increased images at large duty cycles and small imaginary part of NFPL permittivities. It is also shown that maximum intensity distributions on image plane occur at some specified pitches and duty cycles. The physics mechanisms are presented to explain these phenomena.

Plasmonic lithography can be used to pattern subwavelength nanostructures. In this paper, long-range surface-plasmon (LRSP) interference lithography is proposed to obtain large exposure depth and high pattern contrast. Finite-time-domain-difference (FDTD) simulation results show the proposed approach provides over 20% increase in the exposure depth while maintaining the same pattern contrast as compared with the Kretschman SP (KSP) interference at 431nm wavelength.

The Notch signalling pathway in the mammalian ovary regulates granulosa cell proliferation. However, the effects of Notch signalling on steroidogenesis are unclear. In this study we cultured mouse ovarian granulosa cells from preantral follicles invitro and observed the effect of Notch signalling on steroidogenesis through overexpression, knockdown and inhibition of Notch signalling. Activation of Notch signalling decreased progesterone and oestrogen secretion. In contrast, inhibition of Notch signalling increased the production of progesterone and oestrogen. Expression of the genes for steroidogenic-related enzymes, including 3β-hydroxysteroid dehydrogenase, p450 cholesterol side-chain cleavage enzyme and aromatase, was repressed after stimulation of Notch signalling. The expression of upstream transcription factors, including steroidogenic factor 1 (SF1), Wilms’ tumour 1 (Wt1), GATA-binding protein 4 (Gata4) and Gata6, was also inhibited after stimulation of Notch signalling. Production of interleukin (IL)-6 was positively correlated with Notch signalling and negatively correlated with the expression of these transcription factors and enzymes. In conclusion, Notch signalling regulated progesterone and oestrogen secretion by affecting the expression of upstream transcription factors SF1, Wt1, Gata4 and Gata6, as well as downstream steroidogenic-related enzymes. IL-6, which may be regulated directly by Notch signalling, may contribute to this process. Our findings add to the understanding of the diverse functions of Notch signalling in the mammalian ovary.

The effects of different solution methods on aging microstructure and properties of Cu–Cr–Sn–Zn alloy have been studied. The grain size of rapid solidification is much smaller than solid-solution grain size. Strengthening of smaller grain size is obvious. There are much more fine precipitates in the rapidly solidified aging than in the solid-solution aging which accounts for the increase in hardness and conductivity of Cu–Cr–Sn–Zn alloy. Under 920 °C for 1 h solid solution and 500 °C aging for 15 min, the hardness and electrical conductivity can reach 102 HV and 51.4%IACS, respectively. On rapid solidification and the same aging condition, the hardness and electrical conductivity can reach 178 HV and 60.6%IACS, respectively.

After solid solution treatment, the effects of aging processes on the microstructure and electrical conductivity of Cu–Cr–Zr–Mg lead frame alloy were investigated in order to determine the phase transformation and the time–temperature-transformation (TTT) behavior. The results show that aged at 470 °C the fine precipitation of an ordered CrCu2(Zr,Mg) phase is found in copper matrix as well as fine Cr and Cu4Zr, aged at 550 °C the phase CrCu2(Zr,Mg) is decomposed into Cu4Zr and Cr phase, aged at 600 °C the precipitates is bcc Cr only. The phase transformation kinetics equation was deduced from the Avrami empirical formula based on the linear relationship between the electrical conductivity and the volume fraction of the phase transformation.

Recrystallization and precipitation behaviors after cold rolling and aging are investigated for Cu-0.7Cr-0.13Zr alloy. The processed alloy was characterized using the measurement of Vickers hardness, scanning electron microscopy, and transmission electron microscopy. The resultant complex microstructures are interpreted in terms of the interactions between precipitation and recrystallization. Upon aging at 500 °C for 1 h, the 45% rolled alloy exhibits a retarded recrystallization process and therefore an efficient hardening response, which are attributed to the pinning effect of fine dispersed precipitates on the dislocation. When heavily deformed and aged at high temperature, the alloy shows an accelerated process of recrystallization, and precipitates are found to coarsen.

A multi-objective optimization methodology for the aging process parameters is proposed which simultaneously considers the mechanical performance and the electrical conductivity. An optimal model of the aging processes for Cu–Cr–Zr–Mg is constructed using artificial neural networks and genetic algorithms. A supervised artificial neural network (ANN) to model the non-linear relationship between parameters of aging treatment and hardness and conductivity properties is considered for a Cu–Cr–Zr–Mg lead frame alloy. Based on the successfully trained ANN model, a genetic algorithm is adopted as the optimization scheme to optimize the input parameters. The result indicates that an artificial neural network combined with a genetic algorithm is effective for the multi-objective optimization of the aging process parameters.

Sympathetic innervations exist in mammalian CL. The action of catecholaminergic system on luteal cells has been the focus of a variety of studies. Norepinephrine (NE) increased progesterone secretion of cattle luteal cells by activating β-adrenoceptors. In this study, murine luteal cells were treated with NE and isoprenaline (ISO). We found that NE increased the viability of murine luteal cells and ISO decreased the viability of luteal cells. Both NE and ISO promoted the progesterone production. Nonselective β-adrenergic antagonist, propranolol reversed the effect of ISO on cell viability but did not reverse the effect of NE on cell viability. Propranolol blocked the influence of NE and ISO on progesterone production. These results reveal that the increase of luteal cell viability induced by NE is not dependent on β-adrenergic activation. α-Adrenergic activation possibly contributes to it. Both NE and ISO increased progesterone production through activating β-adrenergic receptor. Further study showed that CyclinD2 is involved in the increase of luteal cell induced by NE. 3β-Hydroxysteroid dehydrogenase, LHR, steroidogenic acute regulatory protein (StAR), and PGF2α contribute to the progesterone production induced by NE and ISO.

Notch signaling is an evolutionarily conserved pathway, which involves in various cell life activities. Other studies and our report showed that the Notch signaling plays very important role in follicle development in mammalian ovaries. In luteal cells, Notch ligand, delta-like ligand 4, is involved in normal luteal vasculature. In this study, murine luteal cells were cultured in vitro and treated with Notch signaling inhibitors, L-658,458 and N-[N-(3,5-difluorophenacetyl)-l-alanyl]-S-phenylglycinet-butyl ester (DAPT). We found that L-658,458 and DAPT treatment decrease basal and human chorionic gonadotropin (hCG)-stimulated progesterone secretion. On the contrary, overexpression of intracellular domain of Notch3 increased basal and hCG-stimulated progesterone secretion. Further studies demonstrated that Notch signaling regulated the expression of steroidogenic acute regulatory protein and CYP11A, 2 key enzymes for progesterone synthesis. In conclusion, Notch signaling plays important role in regulating progesterone secretion in murine luteal cells.

This paper uses an artificial neural network (ANN) and Levenberg–Marquardt training algorithm to model the non-linear relationship between parameters of rapidly solidified aging processes and mechanical and electrical properties of Cu–Cr–Sn–Zn alloy. The predicted values of the ANN are in accordance with the testing data. A basic repository on the domain knowledge of rapidly solidified age processes is established. Rapidly solidified aging processes can greatly enhance the hardness and electrical conductivity for Cu–Cr–Sn–Zn alloy. At 500 °C for 15 min aging the hardness and conductivity can reach 170 HV and 64% IACS respectively.

Internal oxidation is a commercial method for producing oxide dispersion strengthened copper (ODS Cu). In this paper, the dilute Cu–Al alloy powders containing 0.26 wt% of Al have been internally oxidized at temperatures (T) from 700 to 1000 °C, for holding times (t) up to 10 h. The alumina particle size has been observed and determined by electron microscopy using the two-stage preshadowed carbon replica method. By the use of backpropagation network, the non-linear relationship between internal oxidation process parameters (T,t) and alumina particle size has been established on the base of dealing with the experimental data. The results show that the well-trained backpropagation neural network can predict the alumina particle size during internal oxidation precisely and the prediction values have sufficiently mined the basic domain knowledge of internal oxidation process. Therefore, a new way of optimizing process parameters has been provided by the authors.

The effects of aging processes on the properties and microstructure of Cu–0.3Cr–0.15Zr–0.05Mg lead frame alloy were investigated. Aging precipitation phase was dealt with by transmission electronic microscope (TEM). After solid solution was treated at 920 °C and aged at 470 °C for 4 h, the fine precipitation of an ordered compound CrCu 2 (Zr, Mg) is found in copper matrix as well as fine Cr and Cu 4 Zr. Along the grain boundary, there are larger chromium. The hardness and electrical conductivity can reach 109 HV and 80% IACS, respectively. Sixty percent cold-rolled deformation prior to aging at 470 °C enhances the hardness of the alloy. The coherent precipitates Cr in copper matrix and the dislocations pinned by the fine precipitates are responsible for maximum strengthening of the alloy. So the hardness 165 HV and electrical conductivity 79.2% IACS are available.

The mechanisms responsible for the nucleation, growth and coarsening of Al2O3 particles in dilute Cu–Al alloys during internal oxidation have been investigated, and the alumina morphologies produced have been studied by electron microscopy using two-stage preshadowed carbon replica method. The alumina particle size has been observed to increase with increasing temperature of oxidation, with increasing time of oxidation, and with decreasing oxygen resource coefficient over the experimental range. These results indicate that the alumina particle size is determined by a competition between the rate of nucleation as the internal oxidation front passes and the subsequent growth and coarsening rates of the particles.