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In this paper, ultralong ZnO nanowires were prepared on the surfaces of nickel foams and zinc foils by a hydrothermal method. The photocatalytic activities of ZnO nanowires grown on nickel foams have been tested by the degradation of Rhodamine B solution and using ZnO nanowires grown on zinc foils as the reference. The results indicate that the photocatalytic performance of ZnO nanowires grown on nickel foams is better than those grown on zinc foils. The results are mainly due to the fact that nickel foam is a three-dimensional scaffold structure, which provides large surface area for ZnO nanowire growth. More importantly, the photocatalytic circulation experiments indicate that ZnO nanowires grown on nickel foams are stable and reusable. In addition, the photocatalytic reaction rates can be enhanced by the use of multi-layer of nickel foams with ZnO nanowires grown on their surfaces.

Mg-based materials are very promising candidates for hydrogen storage. In this paper, the graphene supported Ni was introduced to the Mg90Al10 system by hydrogenation synthesis (HS) and mechanical milling (MM). The 80 wt%Ni@Gn catalyst was synthesized by a facile chemical reduction method. The microstructures of the catalyst and composite show that Ni nanoparticles are well supported on the surface of graphene and they are dispersed uniformly on the surface of MgH2 particles. After heating to 450 °C and holding at 340 °C for 2 h subsequently under 2.0 MPa hydrogen pressure, all the samples are almost completely hydrogenated. According to the temperature programmed desorption test, the Mg90Al10-8(80 wt%Ni@Gn) composite could desorb 5.85 wt% H2 which comes up to 96% of the theoretical hydrogen storage capacity. Moreover, it shows the optimal hydriding/dehydriding performance, absorbing 5.11 wt% hydrogen within 400 s at 523 K, and desorbing 5.81 wt% hydrogen within 1800 s at 573 K.

Considering the fact that large surface areas and fast electron transport properties of photoanodes play an essential role in determining dye sensitized solar cell efficiency. A centrifugation-assisted method was designed to fabricate nanoparticle decorated hierarchical nanowire arrays. The hierarchical nanostructure arrays enable the fast charge transport properties of the photoanode. At the same time, the nanoparticles and the hierarchical nanostructures work together to guarantee the large surface areas of the photoanodes. During the fabrication process, TiO2 hierarchical nanowire arrays were firstly fabricated on fluorine doped tin oxide substrates via a hydrothermal method and then nanoparticles were deposited subsequently in the interval spaces among the neighboring nanostructures. Field-emission scanning electron microscopy and X-ray diffraction were used to characterize the morphology and structure of the obtained products, respectively. The results show that the nanoparticles do deposit in the interval spaces among the hierarchical nanowires forming a hybrid structure composed of anatase and rutile TiO2. The obtained nanoparticle decorated hierarchical nanowire arrays have been successfully applied in dye sensitized solar cells. A power conversion efficiency of 5.52% was achieved with the photoanode film thickness of about 20 µm.

A novel embedded Mg-based hydrogen storage nanocomposite was prepared by mechanical milling of hydriding combustion synthesized (HCS) Mg-based hydride and hydrogen permissive/oxygen prohibitive polymer. The Mg-based hydride was mechanically milled with tetrahydrofuran solution of polymethyl methacrylate (PMMA) under argon atmosphere. It is determined by X-ray diffraction (XRD) analysis that the average grain size of all the milled nanocomposites become smaller and the nanocomposites exhibit a good air-stable property. The microstructures of the nanocomposites obtained by Field emission scanning electron microscopy (FESEM) and High-resolution transmission electron microscopy (HRTEM) analyses show that Mg95Ni5 particles embedded by PMMA have a diameter of smaller than 100 nm, approximately. The nanocomposites show the optimal hydriding/dehydriding properties, requiring 60 min to absorb 3.37 wt.% hydrogen at low temperature of 473 K, and desorbing as high as 1.02 wt.% hydrogen within 120 min at the same temperature. The onset dehydriding temperature of the composites is about 373 K, which is 150 K lower than that of HCS products Mg95Ni5.

Purpose To investigate the condylar morphology after closed treatment of unilateral intracapsular condylar fracture in children and adolescents through three-dimensional evaluation and to explore the influence of age, types of fracture, follow-up period, treatment methods, and concomitant fractures on the treatment effectiveness. Materials and methods The medical records of patients who underwent closed treatment for condylar fractures from January 2006 to December 2018 were reviewed. The fractured sides were included in the study group and the opposite healthy joints were included in the control group. The height of articular eminence, depth of glenoid fossa, length & width & thickness of condylar process, length & width of the ramus, and deviation of pogonion were measured three-dimensionally. Results 31 participants were included in the study. The length of condylar process was 2.10±3.77 mm (P=0.004) shorter, the depth of glenoid fossa was 1.09±2.13 mm (P=0.040) shallower, and the length of ramus was 1.55±2.49 mm (P=0.002) longer in fractured side than the ones in healthy side after closed treatment. The pogonion deviated 0.48±1.7 mm to the fractured side, but no statistical significance was found (P=0.129). Conclusions Children had great growth potential to compensate the shortening of condylar process after intracapsular condylar fracture, so closed treatment could be an effective therapy for young children and adolescents.

This study investigated the effect of different specific surface area micronized zinc oxide (ZnO) on growth performance, zinc (Zn) tissue content, jejunal morphology, jejunal antioxidative status, and intestinal mucosa barrier-related gene expression in meat ducks. A total of 480 one-day-old Cherry Valley ducks were randomly divided into 4 dietary treatments, which each had 12 replicates; therefore, each replicate consisted of 10 ducks. Experimental diets included the basal diet supplemented with ZnSO4 (control group) and 3 different treatments of specific surface area micronized ZnO, in which the specific surface area was either 11.30 m2/g (S-mZnO), 20.90 m2/g (M-mZnO), or 34.02 m2/g (L-mZnO). The amount of Zn extra supplementation in the 4 diets was 120 mg/kg of diet. The experiment lasted for 35 D. The results showed that supplementation of M-mZnO significantly increased (P0.05) the BW (35 D), the BW gain (14 to 35 and 1 to 35 D), the jejunal crypt depth, and mRNA expression of zonula occludens-3, mucin 2, and secretory immunoglobulin A of ducks, while the feed-to-gain ratio (14 to 35 and 1 to 35 D) significantly decreased (P0.05) when compared to the control and the other 2 supplementation groups. Furthermore, compared with control group, the hepatic Zn content and the jejunal superoxide dismutase activity in the 3 micronized ZnO groups were significantly increased (P0.05), and the Zn content in the pancreas tended to increase (P = 0.051). In conclusion, this study demonstrates that M-mZnO as a dietary supplement can improve the growth performance of meat ducks by increasing the Zn tissue content and improving intestinal morphology, antioxidative status, and physical, chemical, and immunological barrier function.

The filtration characteristics of untreated sewage sludge, thermal alkaline pretreated and anaerobic fermented sewage sludge were investigated in the process of fatty acids production. The filtration resistance, viscosity, particle size, extracellular polymeric substances (EPS) and soluble microbial products (SMP) were determined to identify the filtration characteristics of the sewage sludge. The results indicated that thermal alkaline pretreatment significantly increased the filtration resistance and viscosity of the sewage sludge, while anaerobic fermentation decreased the filtration resistance. The particle size of the sewage sludge decreased after pretreatment and fermentation. Moreover, the EPS concentration in the sludge sharply decreased after thermal alkaline pretreatment and then increased after the following fermentation. The mechanism of the increase of sludge filtration resistance after pretreatment could be attributed to the release of EPS from the microbial cells of the sludge. The degradation and conversion of SMP into volatile fatty acids could explain the decrease in the filtration resistance after fermentation.

A very cheap solvent, ethanol, was successfully applied to control ZnO crystal growth for fabricating a series of ZnO composite nanostructures. During the experimental process, a two-step chemical route was adopted. In step-one, ZnO nanowire arrays were grown on fluorine-doped tin oxide coated glass substrate. In step-two, the step-one prepared samples were used as substrates for composite nanostructure deposition. The morphologies of the obtained products were characterized by field emission scanning electron microscopy. The results indicate that the morphologies of the final products can be effectively controlled by changing the water/ethanol ratios in the chemical solution. The obtained ZnO composite nanostructures with various morphologies were successfully employed in dye-sensitized solar cells. The light-to-electricity conversion results show that the composite nanostructures consisting of nanowires and pseudospherical nanostructures enable 80% improvement in solar energy conversion efficiency as compared with the nanowire arrays. These results indicate that the synthesized ZnO composite nanostructures are more suitable for application as photoelectrodes in solar cells.

Precipitation strengthening in nanostructured metallic multilayer (NMM) films of Cr/Cu–Cr was studied using nanoindentation and electron microscopy. Magnetron-sputtered NMM films having layer thicknesses of 10, 20 and 30 nm were prepared at room temperature (RT) and 100 °C. Some of the RT-deposited films were annealed at 100 °C for 30 min. Cr was introduced in the Cu–Cr layers by using a Cu–Cr target (95 at.% – 5 at.%) target. A significant increase in nanoindentation hardness was observed in the Cr/Cu–Cr. A reduction of hardness dependence on layer thickness was also observed in the Cr/Cu–Cr, such that sample having a layer thickness of 30 nm provides the equivalent strength of a 10/10 nm Cr/Cu. Uniformly distributed Cr particles in the Cu–Cr layers are key strengthening features in these new Cr/Cu–Cr NMM films. A single dislocation-based model was used to correlate the observed mechanical behaviours and microstructure. The model predicts similar trend observed from the experimental results, suggesting t...

In order to improve the performance of ZnO-based solar cells, ZnO/CdS core/shell heterostructures were synthesized via a facile chemical conversion route. Large area and quasi-aligned ZnO nanowire arrays were firstly fabricated on conductive glass substrates, and then the synthesis of ZnO/ZnS and ZnO/CdS heterostructures were realized by a chemical conversion method. The morphology and structure of the obtained products has been confirmed by field-emission scanning electron microscopy and X-ray diffraction measurements. The synthesized ZnO/CdS core/shell heterostructures were successfully applied in solar cells. The photovoltaic performance investigation demonstrates that the synthesized ZnO/CdS heterostructure-based solar cell shows a higher short-circuit current density compared with the N719 dye-sensitized ZnO nanowire array counterpart. The enhancement in current density may be due to the fact that the surface coverage of the light absorption layer in the ZnO/CdS core/shell heterostructure is very high. These results indicate that the synthesized ZnO/CdS heterostructures by the present method are very suitable for the application as photoelectrode in solar cells.

In recent years, with the development of the researches on aviation, space and energy fields, integral impeller, blisk, shrouded turbine blisk and hooded impeller have been used more and more broadly. The construction of these key parts is complex. Their weight is lighter than before. Their structural strength is enhanced. Their reliability and efficiency are greatly improved. And these parts are made of anti-high temperature and corrosion resistance materials. These characters make it difficult to machine them precisely. In this paper, five-axis EDM equipment is developed to solve this problem. Based on this equipment, the processing techniques of integral impeller, blisk, shrouded turbine blisk and hooded impeller are researched. And the electrodes are designed. The discharge conditions and machining trajectories are optimized. Finally, the eligible work pieces such as shrouded turbine blisk and hooded impeller have been made by using the research result.

The strategy to manipulate nanoscale building blocks into well-organized heterostructures is very important to both material synthesis and nanodevice applications. In this work, highly-ordered ZnO/PbS core/shell nanowire arrays were fabricated by a facile and low temperature chemical route. Large area and well-aligned ZnO nanowire arrays were firstly fabricated on conductive glass substrates, and then the synthesis of ZnO/ZnS and ZnO/PbS core/shell nanowire arrays were realized by a chemical conversion method. The morphology, structure, and composition of the obtained nanostructures were confirmed by field-emission scanning electron microscopy, energy-dispersive X-ray analysis, and X-ray diffraction measurements. The optical properties of the synthesized nanostructures were investigated by micro-Raman and photoluminescence spectroscopy. In the synthesized ZnO/PbS core/shell nanowire arrays, the ZnO cores can provide direct conduction pathways for electron transport and PbS shells possess superior photoelectric performance. Therefore, the obtained ZnO/PbS core/shell nanostructures may have potential application in photovoltaic devices.

National High Technology Research and Development Program of China [2009AA03Z327]; Scientific and Technological Innovation Flat of Fujian Province [2009J1009]

The strategy to manipulate nanoscale building blocks into well-organized hierarchical architectures is very important to both material synthesis and nanodevice applications. In this work, hierarchical ZnO nanostructures with controllable morphology were synthesized by a two-step chemical route. At step-one, hexagonal- and spherical-shaped ZnO nanostructures were deposited on glass slide substrates. At step two, the morphology of hierarchical ZnO nanostructures could be effectively controlled by changing the composition of solutions. The method described here is a simple and reproducible process, which does not require any templates, catalysts, or surfactants, but can control the morphology of ZnO crystals from simple to complex. The morphologies and structures of the products were characterized by field-emission scanning electron microscopy and X-ray diffraction measurements. Room-temperature photoluminescence spectra demonstrate that the variety of nanostructures can cause the variation of the photoluminescence intensity, suggesting that the controlled morphologies can be used to modulate the optical properties of ZnO nanostructures.

Water-soluble CdSe nanoparticles have been synthesized from aqueous solution of selenosulfate by using mercaptocarboxylic acid as stabilizer. A comprehensive investigation is presented on the growth mechanism of CdSe nanoparticles and the factors determining the size. The growth mechanism of CdSe nanoparticles composed two kinds of growth mode, aggregation and Ostwald ripening. The growth rate and product properties can be controlled by changing the reaction conditions. The best conditions, for synthesis of CdSe nanoparticles in the current system, are the pH value in the range of 9-10 and a large excess of the cadmium precursor. The structure of CdSe nanoparticles has been studied by using XRD, TEM, and HRTEM.

The temperature-dependent self-diffusion coefficient D ( T ) in liquid metals between the melting temperature T m and boiling point T b is modeled in terms of the relationship among D , liquid viscosity η , and liquid–vapor surface tension γ lv . The model predictions for D ( T ) correspond to available experimental and molecular dynamics (MD) simulations results for liquid alkali metals Li, Na, Rb and Cs, semi-metal Al, transition and noble metals Ni, Cu, Ag and Au.

Ni nanocontacts have been grown by electrodeposition using a self-terminating technique in a single electrolyte bath based on nickel sulfate, nickel chloride and boric acid. Resistance measurements performed on different samples presented two kinds of obviously different magnetoresistance effects. The analysis of the data sets showed that magnetostriction might play a key role in magnetoresistance of the electrodeposited Ni nanocontacts.

The attraction force between the AFM tip and the surface of sputtered dielectric thin films (SiO2 and ZrO2) was measured with atomic force microscope (AFM) by applying DC-bias between the AFM tip and the n-Si substrate. Under 0 electric field, there exists van der Waals interaction between the AFM tip and the surface of dielectric films. When DC voltages are applied, the attraction force increases obviously for thin SiO2 (5.2 nm) and ZrO2 (6.8 nm) films due to the columbic interaction between them. A parallel-plate model has been developed to evaluate the ideal columbic tip-surface force for SiO2 and ZrO2 films. Contrary to the calculation result, the columbic force for ZrO2 film (6.8 nm) is lower than that for SiO2 film (5.2 nm), indicating the poor dielectric properties of the ZrO2 film. The poor dielectric properties of ZrO2 film should be due to the interfacial SiOx-containing layer formed between ZrO2 and Si, supporting the conclusion reached in the literature that the interfacial SiOx-containing layer can deleteriously influence the dielectric properties of high-k films.

In design of aqueduct structure, natural frequency calculation is the basis of earthquake response analysis. In this paper, the dynamic characteristic of Gegou U shape aqueduct is calculated by the finite element software ANSYS. And in this software, the interaction between water and aqueduct wall is simulated with added mass method. Natural vibration frequencies and principal modes of Gegou U shape aqueduct are analyzed and calculated in four different water level which include empty tank water level, semi tank water level, design water level and bank-full water level. The calculation results show that the water level has a great influence on the natural frequencies of the aqueduct and the frequencies decrease with the increase of water level. The research results can provide basis for its protection and seismic design of U shape aqueduct. Keywords-Gegou aqueduct; ANSYS; natural frequency; vibration mode; added mass

In this paper, the finite element method was used to analysis the modal characters of a reinforced concrete pedestrian bridge structures. The relationship between parameters and structural vibration frequency was found by parametric analysis. Structural dynamic conditions corresponding state occurred was mainly determined by main modes. In practice, simulated operation, bridges can be analyzed by the previous stage of the natural frequencies and the mode shapes in order to assess. Keywords-pedestrian bridge; modal analysis; dynamic characteristics; natural frequencies; mode shapes

One of the most important findings in the recent study of deformation and fracture in ordered intermetallics is that many intermetallic alloys with high crystal symmetries (such as L1{sub 2} and B2) are intrinsically quite ductile at ambient temperatures, and that their commonly observed low ductility and brittle fracture are caused mainly by extrinsic factors. Environmental embrittlement has been identified as a major extrinsic factor that embrittles many intermetallic alloys. In this case, the alloys showed brittle fracture and low ductilities when tested in moist air, but they exhibited distinctly high ductilities when tested in high-vacuum or dry-oxygen environments. In order to have a mechanistic understanding of moisture-induced hydrogen embrittlement, it is essential to have a direct measurement of trapped hydrogen atoms with position resolution. In this study, the authors try to develop a laser desorption mass spectrometric method to measure hydrogen atoms in a position-sensitive way. They also compare the amount of trapped hydrogen, with and without exposure to water, for FeAl containing 35.8 at. % Al.

TiO 2 was prepared by the oxidation of TiCl 4 at relatively low deposition temperatures using spray pyrolysis. For a fixed carrier gas (N 2 ) flow rate, the substrate temperature is the critical parameter determining the film properties. Films made near 595 K contain only the anatase phase, adhere well to the glass substrate, and have a relative optical transmission of about 75% (between 450 and 850 nm), the value one calculates for the non-absorbing anatase phase in this region. These films have an absorption edge characteristic of a direct gap semiconductor with allowed transitions and optical gaps of 3.5–3.7 eV, depending on the porosity. At higher substrate temperatures (above 635 K), the resulting films have a cloudy appearance and they contain both the rutile and the anatase modifications, confirmed by X-ray diffraction. Lower temperature substrates reduce the deposition rate and yield more porous films. For the pure anatase films, the dark conductivities are about one order of magnitude larger, and the photoconductivity is about one order of magnitude smaller when measured with the sample in air, than those observed when the sample is in a vacuum. When the samples are in a vacuum, the conductivities of the clear films increase by about two orders of magnitude (from about 10 −10 to about 10 −8 S cm −1 ) when illuminated with light from an electrically programmable read-only memory eraser (mercury light), which gives an intensity of about 30 μW cm −2 at the sample. The photoresponse has two parts; the fast portion rises in less than 1 s to 99% of its final value, followed by a small slow rise portion. The slow response, which is more pronounced in the decay process, is interpreted as being due to the presence of surface trapping states.

The paper combines the least squares support vector machines (LS-SVM) with the system output oversampling technique to realize the blind nonlinear system identification. The given distribution of the inputs is employed to perform this novel algorithm. The LS-SVM based mathematical approximation provides an adequate modeling of the unknown nonlinear system given the distribution knowledge of the system inputs. Simulation results demonstrate the effectiveness of this approach.