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Cold metal transfer arc additive manufacturing technique was used to produce 5356 aluminum alloy by adding refining agents to solve the problems of coarse grains and poor performance. Metallic powd...

Ramie is of low cost, non-toxic, degradable but the use of ramie in garments manufacturing is limited due to a large amount of hairiness bringing scratchiness to skin. Herein, a facile and efficient surface micro-dissolution technology was used to eliminate the hairiness of ramie fabrics. SEM, Mirrorless Digital Camera, FTIR, XRD, and TG were used to investigate the morphology and structure of treated ramie fabrics. Softness, hydrophilicity, breaking strength, whiteness, moisture absorption, dye uptake, and air permeability were also studied. The results proved that surface micro-dissolution technology eliminate hairiness effectively while its physical properties were retained. In particular, the softness of the fabric was well maintained, which makes it suitable for clothing production. The surface micro-dissolution technology of ramie fabric based on copper ammonia solution system has the advantages of short treatment time and low process requirements, which provides a new idea for improving the wearability of ramie fabric.

In this paper, we propose a cross-correlation algorithm for correction of common phase error (CPE) in orthogonal frequency division multiplexing (OFDM) systems with high implementation efficiency. CPE resulting from the impairment of orthogonality among subcarriers is due to phase noise. It leads to the offset of demodulated data and increases the bit error rate (BER) of the receivers. As a result, it significantly degrades the performance of wireless communication systems that use OFDM. Therefore, offset compensation algorithm must be adopted in the OFDM system. The phase offset is traditionally estimated and compensated by introducing pilots in each OFDM symbol. However, the BER performance of the traditional algorithm PCP is poor because it is limited by the quantity of the pilot constraints of the wireless communication standard. A novel CPE correction algorithm involved in time and frequency domain can be developed to solve this problem. The proposed algorithm takes advantage of preamble sequences to remove the limitation of the pilots and improve the BER performance. Numerical analyses show that the proposed algorithm presents better estimation performance in additive white Gaussian noise (AWGN) channel. And the mean square error (MSE) is reduced to 10−3, which is lower than that of the traditional algorithm (10−2) at 10 dB signal-to-noise ratio (SNR). The BER is approximately down to10−5 at 12 dB SNR. The proposed algorithm can be easily implemented with low complexity of hardware for practical applications.

Al–Li alloy has been widely used in the aerospace field owing to its high strength and low density. In this study, alternating current cold metal transfer (AC CMT) along with a high-frequency pulse current technique was used to weld a 2060 Al–Li alloy using an ER5356 wire. The effect of pulse frequency on the arc shape, microstructure, and mechanical properties of the welded joints was examined, and mechanical performance testing was conducted. The results revealed that the arc diameter, arc length, and arc volume showed a trend of increasing first and then decreasing with an increase in the pulse frequency and reached their peak values when the pulse frequency was 50 kHz. Coupling the welding process with a high-frequency pulse resulted in grain refinement, which was attributed to the stirring action of the arc force. Both the porosity levels and grain size decreased with increasing frequency. When the pulse frequency was 70 kHz, the porosity level was the lowest, and the grain size was refined to 24.1 μm. The tensile strength of the welded joints also increased with the pulse frequency, and a maximum tensile strength of 249 MPa was observed at 70 kHz.

Wool felt, a kind of natural biomass material, is usually discarded directly after industrial application. However, wool felt with an overhead network and open-channel architecture can be utilized as electrode materials for energy storage. In the present work, we converted wool felt into conductive materials via in situ polymerization of pyrrole and a hot-pressing process. The morphology and structure of the prepared PPy@wool felt were characterized by Scanning Electronic Microscopy (SEM), Energy Dispersive Spectrometry (EDS), Fourier Transfer Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD) and X-ray Photoelectron Spectroscopy (XPS). Compared with other biomass fiber sources, such as cotton and silk fabrics, the prepared PPy@wool felt with interconnected structure exhibited a higher electrical conductivity of 3.94 Ω □−1. As an electrode application for supercapacitors, the hot-pressed PPy@2D wool presented excellent areal specific capacitance of 6502.3 mF cm−2 and a high energy density of 577.99 μW h cm−2 at 0.25 mA cm−2. When the current density was 5 mA cm−2, the capacitance retention rate remained 80.23% of its initial areal specific capacitance after 1000 cycles. The enhanced electrochemical performance can be attributed to the unique network structure and thermal setting characteristics of wool felt. The production of electronic devices, sourced from waste wool felt, will create the premise for circular economy systems in the electronics sector.

Recent years have witnessed the explosive progress of functional materials, which are made by loading various metal oxides onto fabrics. A cost-effective, facile, and simple approach of loading hexagonal zinc oxide (ZnO) sheets onto fabrics is highly desired. Here, the fabrication of the multifunctional ZnO@cotton fabrics is demonstrated using a surface micro-dissolution method by sodium hydroxide/urea (NaOH/urea) and zinc chloride (ZnCl2) aqueous solution. The hexagonal sheet ZnO forms the reflective layer to ultraviolet and near-infrared rays. The UV reflectivity of ZnO@cotton fabric is higher than the raw fabric in the range of 10.9–18.8% and UPF value of treated fabric was 100 + . Infrared barrier results were obtained through the phenomenon of heat radiation transfer obstruction, when fabrics being placed on the hot plate of 120 °C, the temperature difference between raw and treated fabrics is 6.6 °C. Also, the high antibacterial activity against Escherichia coli and Staphylococcus aureus cultures of ZnO@cotton fabric was testified.

Freshwater contamination by spilling oil and scarcity have progressively exasperated the global water crisis. Developing a facile method to remediate polluted water as well as converting the abundant oily wastewater to freshwater has become a matter of urgency. Here we developed a cotton fabric based membrane (ZnO@CF) with special wettability and excellent anti-contamination ability by using zinc chloride aqueous solution as a micro-dissolving agent and zinc source, and using gaseous ammonia as alkali source. Micro/nano structure zinc oxide was in-situ grown on the fibers as superhydrophilic matter as well as enabling the membrane with photocatalytic property. The resulting cotton fabrics (ZnO@CF) are superhydrophilic and superoleophobic underwater with a water droplet spread of 0.3 s and an underwater oleophobic angle of 156.3°. ZnO@CF could separate different oil-water mixtures with separation efficiency higher than 99.3% and a permeate flux up to 940 L m−2 h−1 solely driven by gravity. After three cycles of separation, ZnO@CF still maintained a separation efficiency of about 99.2% and little flux variety, suggesting its fantabulous stability for repeated application. Impressively, ZnO@CF also demonstrated great anti-contamination abilities, including resistance to oil contamination and degradation of dyes staining. Even immersed in the dye aqueous solution, ZnO@CF was capable to separate oil-water mixture containing dyestuff after UV assisted degradation, and did not show any worsening in separation performances. These obvious advantages together with the potential for facile production make the membrane promising toward efficient oil-water separation in practical applications.

Optimization of mass loading and intrinsic structure of polypyrrole (PPy) materials plays decisive roles in the development of energy storage systems to meet the increasing requirements. A di-oxidant sandwich-type polymerization (designated as DOSP) method was developed to synthesize PPy on the surface of CNTs@wool felt to construct composites (CNTs/PPy-2@wool) by using FeCl3∙6H2O and MnO2 as di-oxidant. Under acidic conditions, MnO2 acts as both a sacrificial template and oxidant to initiate the polymerization of pyrrole (Py) monomers on its freshly activated surface to obtain CNTs/PPy-2@wool. Furthermore, MnO2 could effectively adsorb Py monomers, and the adsorbed Py monomers were oxidatived to PPy, resulting in the efficient adsorption and high mass loading of PPy (13.44 mg cm−2) on the CNTs@wool felt surface. As a result, the CNTs/PPy-2@wool electrode showed an areal capacitance of 2303.9 mF cm−2 at a current density of 0.25 mA cm−2 in 1 M H2SO4 solution, delivering a max energy density of 204.79 μWh cm−2 at a power density of 457.93 μW cm−2. Moreover, the device exhibited good rate capability with capacitance retentions over 65% when the current density increased from 0.25 mA cm−2 to 2 mA cm−2 and a long-term life with 84.29% of initial capacitance after 1000 cycles. The potential application of the proposed CNTs/PPy@wool felt as electrode materials for various integrated energy storage devices.

Silicon (Si)-based materials have emerged as promising anode materials owing to the theoretical capacity as high as 4200 mAh g−1 and satisfying working potential for lithium insertion. However, silicon-based anode materials inevitably face the dilemmas of huge volume variation and poor electric conductivity. In this study, three-dimensional (3D) hierarchically porous SiOx/C and carbon materials have been designed and fabricated from one renewable biomass precursor (i.e., bamboo shoot hulls) through low-temperature activated treatment and mildly aluminothermic reduction. The SiOx/C anode after pre-lithiation treatment achieves an initial discharge capacity of 1332 mAh g−1 and a high capacity of 1289 mAh g−1 after 400 cycles at 200 mA g−1 as anode electrode for half lithium-ion batteries (LIBs). When employed for full LIBs, the SiOx/C exhibits a specific capacity of 142 mAh g−1 at 0.1 C with prominent cyclic stability and exceptionally low volume expansion. Moreover, hierarchically porous carbons are also prepared from the same precursor through activation of CuCl2 and further removal of SiO2, exhibiting excellent electrochemical performances for lithium/sodium ion batteries.

In the paper, a grey forecasting model and a population growth model are established for forecasting water resources supply and demand situation in the region, and evaluating the scarcity of water resources thereof in order to solve the problem of water shortage in North China. A concrete plan for alleviating water resources pressure is proposed with AHP as basis, thereby discussing the feasibility of the plan. Firstly, water resources supply and demand in the future 15 years are predicted. There are four sources for the demand of water resources mainly: industry, agriculture, ecology and resident living. Main supply sources include surface water and underground water resources. A grey forecasting method is adopted for predicting in the paper aiming at water resources demands since industrial, agricultural and ecological water consumption data have excessive decision factors and the correlation is relatively fuzzy. Since residents’ water consumption is determined by per capita water consumption and local ...

Some parameters are introduced to evaluate the completeness of a partial multifractal spectrum with the shape of a bell or a hook, calculated using a statistical method due to a finite range of moment q. From the results of two kinds of Cantor sets, p/0/1-p and p/1-2p/p, and some examples of random fractals, it shows that the more homogeneous the probability distribution of the quantity studied is, the larger the range of q in the partial multifractal spectrum with the same evaluation parameters.

Solid-state reactions and amorphous Ge crystallization for various ratios of thickness (or composition) in Pd–Ge alloy thin films after annealing have been investigated by transmission electron microscopy. Besides polycrystalline Pd (p-Pd) and amorphous Ge (a-Ge), polycrystalline Pd2Ge (p-Pd2Ge) phase is also formed in as-evaporated films. During annealing at 250 °C, polycrystalline Pd2Ge and PdGe are formed. The experimental results indicate that the formation of Pd2Ge and PdGe compounds may be dominant at low annealing temperatures, and also affect amorphous Ge crystallization. The reactions are sensitively dependent on the annealing temperatures and the thickness ratio of Pd and Ge films. The reactions and amorphous Ge crystallization are mutually competitive in Pd–Ge alloy thin films.

The daily Hang Seng index in the Hong Kong stock market has been analyzed in this paper. Two kinds of sign sequences as given conditions have been used to predict the future price movements. One is the parameter of multifractal spectrum Δ f based on the indexes recorded in every minute, and the other is the variation of the close index Δ i . Results show that correlation between large fluctuations of the close price and the condition in these two methods is strong and some sign sequences of the parameter Δ f can be used to predict the probability of the near future price movements.

We report a perplexing behavior of fractal shape transition that results from a change in the annealing temperature and time or the film thickness ratio. We find that a compact-to-open fractal shape transition can be induced by increasing the annealing temperature and time or decreasing the thickness ratio of the Au and Ge films. This behavior is not completely consistent with what is predicted by theories based on diffusion-limited aggregation and previous experimental observations. In this new system, we find that fractal shape transitions are truly dominated by the random-successive nucleation and growth mechanism.

The surface topographies of as-sputtered and annealed ZnO films were measured by atomic force microscope (AFM). Multifractal behavior of AFM images has been analyzed by box-counting method. It is found that the scaling range can be extended from the image size to the smallest pixel (about 3 decades) by selecting an appropriate method for determining height probability and neglecting smallest probabilities (totally

Fractal image processing has been applied to characterize the surface roughness of ZnO films as measured by atomic force microscopy. The simple fractal analysis suggests that the fractal dimension D can be used to describe the change of the whole grain morphology along the growth direction. Multifractal analysis shows that the scaling range is close to three orders of magnitude, which is larger than that of a simple fractal and most empirical fractals. The width of the multifractal spectrum can be used to characterize the roughness of the film surface quantitatively and the shape of multifractal spectrum can describe the ratio between the number of the lowest valleys and the highest peaks statistically.

In this paper, the daily Hang Seng index in Hong Kong stock market is studied by multifractal analysis. The main parameter of multifractal spectra used is Δf, which can be used to characterize the ratio of number of highest index moments to that of lowest ones. The dependence of today's gain probability (G%) and the day's index increase probability (n%) with Δf of the previous 3 days are studied. It is found that G% and n% can reach 70–80% at the large positive Δf region and can be very close to 20% at the big negative Δf region. The predictability decreases with the increasing number of the previous days.

Fractal growth of thin films at low temperature (75–200 K) is simulated by kinetic Monte Carlo method, using realistic growth model — Ag on Pt(111) surface and physical parameters. It is shown that the fractal growth of thin films is nonlinear, i. e., the island size S(t) grows with time t as tk, where the growth exponent k is slightly less than 1 because of the growth competition of islands and the competition between nucleation and growth of islands. The further results indicate that the branch width of islands b increases with increasing island size Sas b ≈ Sα, where α is approximately equal to 1 3 because of the geometrical structure of the triangular substrate.

In this paper, the daily Hang Seng index in Hong Kong stock market is analyzed by multifractal. The correlation of the parameters of the multifractal spectra with the variation of close return Z is studied statistically. It is found that the amount of the variation of return is correlated with the amount of Δα of that day. The increase or decrease of the return is related to the positive or negative value of Δf. The gain probability and the increasing day's probability can be higher than 70% at the larger Δf region and be lower than 20% at the more negative region.

The kinetic behavior of fractal crystallization in amorphous semiconductor/metal bilayer films has been studied by in situ transmission electron microscopy. The fractal growth process exhibits three stages: rapid growth, steady growth, and slow growth. During the initial rapid growth stage, the fractal crystallization is controlled by both diffusion and reaction processes. With increasing annealing time, fractal growth is obstructed and becomes slower because more and more other fractal patterns approach from the neighborhood. The growth kinetics analysis indicates that both diffusion-limited aggregation and random successive nucleation mechanisms play an important role in fractal crystallization in the amorphous Ge/Au films.

The highly c-axis oriented ZnO films were deposited on Si substrates with Zn buffer layers. The intense cathodoluminescence, including UV, blue, and green emissions, was observed in these films at room temperature. According to X-ray diffraction analysis and cathodoluminescence spectra, it is found that the Zn buffer layer plays an important role for improving crystal quality of films and for getting intense cathodoluminescence.

Thin films of ${\mathrm{C}}_{60}/\mathrm{Ag}$ were prepared by codeposition of ${\mathrm{C}}_{60}$ and Ag onto (001) NaCl substrates. The surface roughness depends strongly on the substrate temperature, and a transition from kinetically roughening to thermally roughening was observed by using atomic force microscopy. Multifractal spectra of the film surfaces have been studied in the length scale of 30 nm to 5 $\ensuremath{\mu}\mathrm{m}.$ Compared with the conventional root-mean-square method, the multifractal spectrum provides more information about the spatial distribution of the surface roughness.

The growth morphology of C 60 films grown on a NaCl (0 0 1) substrate is significantly affected by the substrate temperature and the predepositing of surfactant Sb. With increasing substrate temperature from 130°C to 185°C, a compact-fractal-cornpact growth transition occurred in the Sb-mediated C 60 film. Possible growth mechanisms are discussed.

A technique for growth of layered silver nano-crystallites and C 60 by vapor co-deposition is reported. It is found that the epitaxial relationship and growth morphology of Ag films on NaCl substrate were significantly affected by co-deposition of small amounts of C 60 . The temperature of the source of C 60 was 350 °C, and a layer of Ag nano-crystallites all with (110) orientation was grown on a hot (001) NaCl substrate. Moreover, co-deposition of C 60 prevented coalescence of Ag nano-particles into large grains. Thus, granular films were obtained with high density of oriented Ag nano-crystallites with a narrow size distribution.

A simplified model of interface roughening is presented. As a special case, the roughening process of a grain boundary has been simulated. This process is based on random walks of atoms across the grain boundary with a restoring effect induced by neighbouring atoms to reduce the roughness. The root-mean-square roughness σ decreases with the increasing restoring effect. The Hausdorff dimension of the rough interface increases from 2.1 to 2.45 with the decreasing restoring effect. The rough interface can be also described by the multifractal spectra. The results show that the larger the restoring effect, the wider the singularity spectrum.

To investigate the differential expression pattern of hsa-miR-9 between EBV-positive and -negative Burkitt lymphoma cell lines and its association with BCL-6.The expression of hsa-miR9 and BCL-6 mRNAs in EBV(+) Raji and EBV-Ramous cells in mRNA levels were detected using fluorescence quantitative PCR (QRT-PCR). The two cells lines were transiently transfected with hsa-mir9-inhibitor and hsa-mir9-minicsvia Oligofectamine 2000, and the changes in BCL6 expressions was detected using QRT-PCR and Western blotting. Annexin V/PI staining was used to analyze the apoptosis and morphological changes of the transfected cells.The expression of Hsa-miR9 and BCL-6 was significantly higher in EBV(+) Raji cells than EBV(-) Ramous cells (P0.01). BCL-6 mRNA and protein expression was reduced in EBV(+) Raji cells after transfection with hsa-miR9-inhibitor but up-regulated in EBV(-) Ramous cells transfected with hsa-miR9-minics. Flow cytometry revealed a significantly decreased apoptosis rate in EBV(+) Raji cells transfected with hsa-miR9-inhibitor but an increased rate in EBV(-) Ramous cells transfected with hsa-miR9-minics, and the results were confirmed by microscopic observations.Hsa-miR9 positively regulate the expression of BCL-6 and apoptosis of EBV(+) Raji cells and EBV(-) Ramous cells.

An amorphous Ge‐Au(a‐Ge‐Au) film prepared by vacuum deposition was studied in situ and irradiated by an electron beam in a transmission electron microscope. The amorphous Ge‐Au film can be crystallized rapidly and locally by electron beam irradiation, forming polycrystalline metastable Ge0.4Au0.6 tetragonal phase and then decomposing to polycrystalline Ge and polycrystalline Au at increased irradiation dose. The results suggest that the crystallization of a‐GeAu film, the formation of Ge0.4Au0.6 and the decomposition of the metastable Ge0.4Au0.6 are dependent on the temperature rise of the irradiation process.

Ultrathin single quantum well (about one monolayer) grown on GaAs(001) substrate with GaAs cap layer has been studied by high resolution x‐ray diffractometer on a beamline of the Beijing Synchrotron Radiation Facility. The interference fringes on both sides of the GaAs(004) Bragg peak are asymmetric and a range of weak fringes in the higher angle side of the Bragg peak is observed. The simulated results by using the kinematical diffraction method shows that the weak fringe range appears in the higher angle side when the phase shift introduced by the single quantum well is very slightly smaller than mπ (m:integer), and vice versa. After introducing a reasonable model of single quantum well, the simulated pattern is in good agreement with the experiment.

Cross‐sectional transmission electron microscopy, selected area electron diffraction, and small‐angle x‐ray diffraction have been used to observe the systematic deviations of period in W/Si and W/C multilayers. The mean periods decreased gradually as the detected regions were located farther away from the substrate. To avoid destroying the multilayer, a method is suggested to measure the systematic deviation of period by using soft x rays with wavelengths below and above an absorption edge and hard x rays such as Cu Kα1.

We present a novel computer simulation of bacterial-colony growth. The ingredients of the simulation are two local conditions: multiplication rate of bacteria in the interface, depending on agar concentration and agar plate moisture, and occupation rate of the sites of the cluster inside a small circle around the potential growth site, representing the nutrient concentration. Varying growth conditions, fractal, dense-branching morphology and compact-growth patterns have been observed, which is consistent with the experimental demonstrations.

Ge‐22 at. %Au/Au bilayer films annealed at various temperatures have been observed by transmission electron microscopy. The as‐deposited bilayer film is composed of crystalline Ge,Au and metastable Ge0.4Au0.6 phases. The Au grain size is nonuniform, and no amorphous Ge is observed. During annealing at 60–350 °C, patterns with several wide branches are generated that are different from the dense branching fractals induced by crystallization of amorphous Ge in a‐Ge/Au films. The fractal dimension of the pattern (measured by the box‐counting method) increases with the annealing temperature. The agglomeration of small Au grains to coarse Au grains in the Ge‐Au/Au bilayer film may be the mechanism for the fractal structure formation.

The simulation of soft‐x‐ray (λ=1.33–14.0 nm) ‐diffraction behavior at 2θ=90° of W/C and W/Si multilayers with sublayer thickness ratio (composition) deviation in periods is presented. The results show that when the deviation Δx≥0 (which means that the thickness fraction x=d1/d increases from the top to the bottom of the multilayers, where d1 is the thickness of the heavy element sublayer and d the period of the multilayer), (i) in the case of W/Si where the W and Si absorption coefficients are close the diffraction intensities decrease in general, while in the case of W/C where the W and C absorption coefficients are close the increase of the diffraction intensities can reach about 20%; (ii) the full‐width at half‐maximum of the diffraction peak always decreases; (iii) the peak position tends to move to the small‐angle side.

The fractal character of anneal-induced aggregation in three kinds of bilayer films of the Ge-Au and Ge-Ag systems has been studied in this paper: amorphous germanium (a-Ge)/polycrystalline metal (p-metal), heated deposited a-Ge/p-metal, and (a-Ge + p-metal)/p-metal bilayer films. By means of transmission electron microscopy observation, component analysis of X-ray energy-dispersive spectroscopy and the measurement of fractal dimension for the aggregation regions it has been found that the morphology of the anneal-induced aggregation is divided into different types: the snowflake-like aggregation (SA) region, the equiaxial-like aggregation (EA) region and the randomly distributed aggregation (RDA) region. If the annealing temperature is high enough (exceeds the eutectic temperature of the metal-Ge system), interface co-melting and recrystallization (MR) occur in the annealed film. This depends on the metallic properties, those of the a-Ge film (especially on the a-Ge crystallization temperature T c ), and on the annealing conditions (the annealing temperature T a and the annealing time t a ). The value of the fractal dimension D f could serve as a parameter for describing the morphology of the aggregated region: D f ≈ 1.7−1.85 for the SA region; D f ≈ 2 for the EA region; D f ≈ 1.7−1.85 for the RDA region; D f ≈ 2 for the MR region. The results are discussed in terms of the equilibrium diagrams of the Au-Ge and Ag-Ge systems and the relationship between properties of the semiconductor germanium and metals gold and silver.

A simulation of Cu Lα and Cu Kα diffractions from W/Si multilayers with a local layer‐thickness deviation at various depths of the multilayers has been presented. The results show that the peak intensity decreases rapidly at first while increasing the depth of the local deviation, and then the peak splits into double peaks. But, afterward, the double peaks coincide again. These changes are affected by the ratios (x) of heavy‐atom layer thickness to total period thickness. The intensities of the double peaks are nearly equal when x is 0.5, but are quite different when x is 0.22. The changes due to the local deviation are different from those due to random fluctuations or systematic deviations in periods. An explanation has been carried out by the amplitude‐phase diagrams.

A helical cellular automata (HCA) model constructed on a two-dimensional grid of cells with a helical structure is presented and the pattern formation of this model studied by numerous computer simulations. It is found that the evolutions of the HCA are sensitive to the circumference of the helix p. With various p, the initial growth of the model generates various patterns ranging from Sierpinski triangle gasket, complex textured pattern, to lateral quasiperiodic structure. A sudden transition from regular fractal to compact pattern occurs near the point where p is equal to a positive integer power of 2. With increasing height of the patterns (increasing growth time), the model also exhibits different growth behaviors in the vertical direction for various p, including the formation of regular periodic patterns and the evolution from initial regular patterns to eventual random structures. Fractal dimension analysis is used to characterize these different evolution processes quantitatively.