Search

Nano-ZnO has the characteristics of photocatalytic performance and excellent transparency and conductivity. Because of its many excellent properties, it also occupies a very important position in the types of semiconductor materials. Nano-ZnO film preparation technology has been researched and developed and applied in many fields, but there are few applied researches on the protection of paper artworks. The main content of this article is the study of the application and enhancement effect of nano-ZnO film preparation technology on the protection of paper cultural relics. In this paper, the sol-gel process is selected in the common film preparation process, and the configured sol is dipped and lifted. By comparing the paper covered with nano ZnO film and the paper not covered with nano ZnO film in the anti-aging performance test, anti-ultraviolet aging performance test, aging appearance change and the experimental results of the mechanical performance test of the application effect of different papers, the results are investigated. The application and enhancement effect of nano-ZnO film preparation technology in the protection of paper art works. Experimental studies have shown that under the same aging time, the mechanical properties of rice paper covered with nano-Zno film are higher than those of blank rice paper without nano-Zno film. The transverse tensile strength of the paper is increased by 5.88 m/N, an increase of 98%. The vertical tensile strength increased by 3.93 m/N, an increase of about 87%, the vertical folding resistance increased by 16 times, the horizontal folding resistance increased by 15 times, and the vertical tearing strength increased by 4.15 m/N, an increase of about 125%, and the transverse tearing degree is enhanced by 2.21 m/N, which is about 64%. The two kinds of rice paper were subjected to warm-heat aging, and the final results showed that the mechanical properties of the two kinds of rice papers showed a decreasing trend, but the mechanical properties of the rice paper covered by the nano-Zno film decreased at a slower rate, and the final mechanical properties were also lower than that of untreated rice paper. Blank rice paper covered with film is better. The experimental results of ultraviolet light on paper aging show that the nano-Zno film covering the paper will delay the paper aging, and the appearance of the nano-Zno film after ultraviolet light does not change significantly. Under the mechanical performance test of nano Zno film on different types of paper application, the tensile strength, folding resistance and tearing degree of the three papers participating in the experiment have been improved, which shows that the nano Zno film has the advantage of strengthening paper. [ABSTRACT FROM AUTHOR]

Aging behavior occurs in the storage process of paper archives, which accelerates the aging process of the paper. Therefore, it is important for paper archives management to explore the aging behavior of acidified paper (AP) and to delay or prevent its further aging. The aging behavior of the commonly used university archives paper with artificial acidification were studied by measuring pH value, electrical conductivity, mechanical properties and whiteness. The results show that the pH value, conductivity, mechanical properties and whiteness of AP change significantly compared with the non-acidified raw paper (P). After dry-heat aging treatment, the pH value of AP decreased more obviously than P, which shows more obvious aging degradation and further acidification of AP. During the aging process of AP, the molecular and structural degradation are promoted by the presence of acidic substances, which increase the electrical conductivity of the system. The microstructures of the paper are changed by acidification and aging treatment, and more fiber fracture, etching and microscopic holes are found in the surface SEM images. The reductions of the tensile index and whiteness of AP are also more significant because of the degradation acceleration of the acid. [ABSTRACT FROM AUTHOR]

The aging and acidification behavior of paper archives affect their long-term preservation. Therefore, delaying or preventing aging and acidification has become an important topic in the field of paper archives management. the aging and acidification behavior of commercial archival paper were studied by measuring pH value, electrical conductivity, mechanical properties and whiteness in this work. The results show that the aging and acidification phenomena are obvious after dry-heat aging treatment. The molecular degradation of cellulose, hemicellulose, lignin and other components results in the decrease of pH value of the system, which decrease with the increase of the treatment temperature and time. The electrical conductivity of the system increases because of the molecular degradation and structural degradation, and with the increase of the treatment temperature and time, the electrical conductivity increases more significantly. After aging treatment, the paper appears etching and increasing microcosmic pores. With the occurrence of molecular degradation and structural degradation, the tensile index and whiteness of the paper decrease, and with the increase of the treatment temperature and time, the tensile index and whiteness decrease more significantly. [ABSTRACT FROM AUTHOR]

A novel, simple and low-cost method for fabricating paper-based microfluidic device was presented. A soldering wire was used for making a template with specific pattern, and transfer printing to a filter paper by help of polydimethylsiloxane (PDMS). The device was mounted on an YX-128° LiNbO3 piezoelectric substrate. The entire fabrication process could be finished less than one minute without using any complicated equipments. Important parameter in the fabrication of paper-based microfluidic device such as transfer printing time was discussed. To verify the function of the paper-based microfluidic device, color development reactions of starch were implemented. [ABSTRACT FROM AUTHOR]

A new paper-based microfluidic device is fabricated on a piezoelectric substrate. A polydimethylsiloxane channel filled with cotton threads is mounted on the piezoelectric substrate with an interdigital transducer. A testing filter paper with dried reaction solution is coated on the end of the cotton thread. Sample solution is driven to the cotton thread channel and transported to testing area for microfluidic analysis. Red ink solution and color development reaction of starch are demonstrated for microfluidic operation and analysis. Results show that the linear velocity of microfluidic transportation in the cotton thread channel is 4.558 mm/s, and color development reaction of starch is successfully implemented. [ABSTRACT FROM AUTHOR]

A new paper-based microfluidic switch activated by surface acoustic wave (SAW) was presented. The switch was comprised of two folded paper microchannels and an unfolded paper microchannel. One of the folded paper microchannels was connected with the unfolded paper microchannel. Two interdigital transducers (IDTs) and two reflectors were fabricated on 128° yx-LiNbO3substrate using microelectrical technology. When an amplified RF signal was applied to the IDTs, a droplet on the piezoelectric substrate was actuated to the unfolded paper microchannel by SAW. Folded angle of a folded paper microchannel was increased and connected with the other folded paper microchannel to implement ‘on’ function of the microfluidic switch. The switch was examined using red dye solution microfluids and mixed indicating solution of 330 mmol/L Citric acidmonohydrate, 10 mmol/L N-(1-Naphthyl) ethylenediamine dihydrochloride and 50 mmol/L Sulfanilamide. The presented switch is valuable for programmable paper-based microfluidic device for multiple sample analyses. [ABSTRACT FROM AUTHOR]

A new method for dispatching microfluid is presented. A steel ball of 2mm diameter is placed on a 128 degrees YX LiNbO3 substrate. A PDMS frame is mounted on the piezoelectric substrate for defining the movement trajectory of the steel ball. Paper testing zone is fixed on a PDMS block for the target of the microfluidic dispatch. The steel ball is driven by surface acoustic wave, and carried microfluid at the outlet of the PDMS microchannel to the paper testing zone. Red ink solution is used to demonstrate the fluid dispatch. [ABSTRACT FROM AUTHOR]

A new method for fabricating a paper based microfluidic device in a printed circuit board is presented. The printed circuit board is hollowed out to form a pattern of paper channels. When a polydimethylsiloxane (PDMS) film is mounted on the bottom of the PCB, liquid PDMS is filled in the areas having been hollowed out, and solidified in a constant temperature oven. Paper pattern is then mounted on the solidified PDMS, while a piezoelectric device with an interdigital transducer is embedded into the PCB. At last, PDMS film is covered on the surface of paper channels. Microfluidic transportation and color development reaction are demonstrated in presented microfluidic platform. Results show paper channels and the piezoelectric device can be integrated into the printed circuit board, and surface acoustic wave can drive a microfluid to the paper channels for microfluidic analysis. [ABSTRACT FROM PUBLISHER]

In this paper, four low-melting alloy materials, Sn-3.5Ag, Sn-1.6Cu, Sn-Zn-0.7Cu and Sn-8Zn-3Bi, were used to study the wettability of these materials on copper substrates. Using the Image Pro Plus software to calculate the spread area and analyze the spread-ability of low-melting alloy materials with different compositions on the copper substrate. The calculation results show that the low-melting alloy material with strong spreading property is Sn-1.6Cu. The interface morphology of Sn-1.6Cu on the copper substrate after wetting equilibrium was observed by SEM and EDX instruments. The interface quality was judged according to the interface morphology, and the interface element distribution and element penetration were analyzed. The experimental results show that the interface between Sn-1.6Cu and the copper substrate is reliable, and there are no interface defects such as porosity, slag inclusion and crack. The research work in this paper provides a theoretical basis for the subsequent material improvement research. [ABSTRACT FROM AUTHOR]

Ba(NdxTi(1-2x)Nbx)O3 (x=0.025, 0.05, 0.1 & 0.2) and (Na0.5Bi0.5)(NdyTi(1-2y) Nby)O3 (y=0.0125, 0.025 & 0.05) ceramics were prepared through solid state sintering route. In the present paper X-ray diffraction (XRD) data was obtained using (Philips X-pert Pro Pan Analytical: Model PW3040/60). The XRD data was simulated using modified Arrhenius and Lorentz equation using ORIGIN 6.1 software which was proposed by us earlier. In the case of Ba(NdxTi(1-2x)Nbx)O3 ceramics the values of lattice parameter obtained using modified Arrhenius and Lorentz equations are 3.9597Ao, 4.2534Ao, 5.2364Ao & 5.2690Ao for x=0.025, 0.05, 0.1 & 0.2 respectively. The average values of activation energy for x-ray scattering are 74.47 meV, 85.21 meV, 90.20 meV & 95.79 meV for x=0.025, 0.05, 0.1 & 0.2 respectively. Similar simulation studies were also carried on (Na0.5Bi0.5)(NdyTi(1-2y)Nby)O3 ceramics and the results are presented in this paper. [ABSTRACT FROM AUTHOR]

In this paper, an unexplored solid solution (1-x)Bi(Cu1/2Ti1/2)O3-(x)PbTiO3 has been synthesized and characterized for its crystal structure, dielectric and ferroelectric properties aimed at a selected composition, i.e., 0.30 Bi(Cu1/2Ti1/2)O3-0.70PbTiO3. The paper unveils the different synthesis approaches to achieve pure-phase in Pb-based perovskite-structured materials that are prone to produce impurities during synthesis. The Rietveld refinement of the XRD pattern confirms a tetragonal crystal structure (P4mm) of the composition. The ferroelectric properties of the as-prepared composition are also discussed using P-E hysteresis and PUND characteristics. The composition shows a high Tc (480 °C) and low dielectric losses, making it suitable for high-temperature applications. [ABSTRACT FROM AUTHOR]

One of the most frequent malignant tumors seen in clinics is primary liver cancer, also referred to as the "king of cancers." Therefore, the necessity for an effective and precise detection technique is urgent. Compared with the cantilever beam, the double-ended clamped beam has the characteristics of higher resonance frequency and stronger noise immunity, so it has a good application prospect as a biosensor. This paper takes the double-ended clamped beam biosensor as the object and focuses on the method that can be applied to the early diagnosis and detection of liver cancer. The manufacturing process of the double-ended clamped beam and the biofunctional modification of the beam surface were introduced. Meantime, this paper introduces the integration of the composite double-ended clamped beam biosensor system. As a result, a high-sensitivity, high-reliability in situ real-time monitoring technology for early-stage liver cancer is proposed. A composite double-ended clamped beam made of silicon and silicon nitride is used. The size of the double-ended clamped beam is 280 µm × 50µm × 5µm. This paper provides a low-cost, portable, and rapid early diagnosis method for liver cancer, which has very significant application value in the field of early cancer screening. [ABSTRACT FROM AUTHOR]

The progress of science and technology makes the birth of nanometer material. In order to study the application of nanometer material in disaster prevention and mitigation, this paper proposes the research on the disaster information integration technology of disaster prevention and mitigation system based on nanometer material. This paper introduces the disaster information integration technology of the disaster prevention and mitigation system based on nanometer material. In order to highlight the advantages of the disaster prevention and mitigation system based on nanometer material, this paper carries out the function test and performance test. In the aspect of performance test, this paper compares it with the disaster prevention and mitigation system of other two materials from the aspects of response time and accuracy research. In this paper, we find that the response time of the disaster prevention and mitigation system based on nanometer material is faster than that of the other two systems, and the accuracy of the system in this paper will not be greatly reduced with the increase of task amount, which is relatively stable. Among them, when the task amount is 10, the accuracy of the system in this paper is 0.96, and when the task amount is 150, the accuracy of this system is 0.94. The results of this paper show that the disaster prevention and mitigation system based on nanometer material is relatively superior. [ABSTRACT FROM AUTHOR]

At present, coal mine tunneling technology is developing in the direction of intelligence and unmanned. The piezoelectric vibration energy harvester can convert the vibration energy generated by the cutting part of roadheader into electrical energy and realize the energy self-sufficiency of the low-power wireless sensor. In practical applications, the vibration frequency of the cutting part of roadheader is different, and the working condition is complex, resulting in the energy recovery efficiency of the vibration energy harvester is not ideal. In order to improve its adaptability and reliability, a separated excitation broadband piezoelectric vibration energy harvester is proposed in this paper. [ABSTRACT FROM AUTHOR]

To find out the effect of the rare earth doping element Holmium (Ho) on CuInS2 thin films, various studies have been carried out and the results have been reported in this paper. The PL study shows that intensity of doped film is more than undoped film. The PL emission peak appears at 570–580 nm. SEM images of CIS:Ho (4 ml) film shows agglomeration on the surface. Both synthesized film of CuInS2 appears to be amorphous in nature with chalcopyrite structure as clear from XRD. Hall measurement and optical studies were also performed. [ABSTRACT FROM AUTHOR]

A new method for transporting droplets is presented to avoid directive radiation of surface acoustic wave (SAW). An interdigital transducer (IDT) is fabricated on a 128°-YX LiNbO3 piezoelectric substrate using microelectric technology. A droplet to be transported is placed on a steel ball, which is driven by SAW. The droplet on the steel ball is then transported together with the steel ball. 0.5ul red ink solution was successfully transported by help of the steel ball with 2 mm diameters at 30.9 dBm electric signal power. Color development reaction is also implemented by transporting reaction solution using presented method to a paper-based device. [ABSTRACT FROM AUTHOR]

In our earlier studies we have shown procedure for the estimation of activation energy and relaxation times directly from the dielectric and AC conductivity data simultaneously dependant on T and ω using modified Lorentz equation instead of well-known Arrhenius, modified Arrhenius and Vogel-Fulcher laws. In the present paper we have carried out similar experimental and simulation studies on the dielectric and AC conductivity data using modified Lorentz equations on the ceramic compound (Ba0.997Pr0.003TiO3). The obtained results on the activation energy and relaxation times are presented in this paper. [ABSTRACT FROM AUTHOR]

We argue that the "N-aeetyl glycine phosphite " crystal grown and characterized in the title paper actually is glycine phosphite. [ABSTRACT FROM AUTHOR]

In this paper, a composite excitation method is used to optimize the design of an existing cantilevered cylindrical ultrasonic motor to avoid vibration interference. Modal and transient simulation analysis of the stator structure was carried out by the finite element method. Optimized stator structure is simpler than the original motor. Simulation analysis results show that the circumferential amplitude is increased by more than 35% with 55.7% reduction in ceramic usage. [ABSTRACT FROM AUTHOR]

To find out the effect of the rare earth doping element Holmium (Ho) on CuInS2 thin films, various studies have been carried out and the results have been reported in this paper. The PL study shows that intensity of doped film is more than undoped film. The PL emission peak appears at 570–580 nm. SEM images of CIS:Ho (4 ml) film shows agglomeration on the surface. Both synthesized film of CuInS2 appears to be amorphous in nature with chalcopyrite structure as clear from XRD. Hall measurement and optical studies were also performed. [ABSTRACT FROM AUTHOR]

In this paper, detailed studies of effect of small amount of manganese substitution (at the zirconium site) on the structural, micro-structural, and electrical characteristics of lead zirconate titanate of Pb(Zr0.35–xMnxTi0.65)O3;x = 0, 0.02, 0.06, 0.10 (PZMT)) have been reported. The materials were prepared by using standard ceramic technology. The formation of the compounds and their basic crystal data have been studied through X-ray diffraction (XRD) method. The crystallite size and lattice strain of the compounds, evaluated from Scherrer's and Hall Williamson (H-W) equations, is found to be in the range of 40–50 nm and 11 × 10−4 to 50 × 10−4, respectively. Microstructures of different magnifications, revealing the surface nature of the compounds, have been recorded by field emission scanning electron microscope (FESEM). Effect of Mn+4 ions on electrical behavior (electrical impedance (Z*), electrical modulus (M*), conduction and relaxation phenomenon) of PZMT systems, over wide range of temperature and frequency, has been studied. [ABSTRACT FROM AUTHOR]

Rare earth yttrium substituted lithium ferrites Li0.5Zn0.1Ti0.1YxFe2.3–xO4 with nominal composition x = 0.00 to 0.10 in steps of 0.02 was prepared by the conventional ceramic method. The samples were sintered at 1050 °C for 6 h using resistive conventional heating. X-ray diffraction (XRD) patterns confirmed the formation of a single phase with a spinel structure. FTIR studies also confirmed the tetrahedral and octahedral metal-oxygen bonding of the spinel structure. Structural parameters like density, lattice constant, and crystallite size, site distances, bond length distances were measured from XRD data. The crystallite size reduces while the density increased with the progressive substitution of Y3+ ions. The Fe3+ ions at the A and the B sites mainly contributes to the electromagnetic properties of ferrites. Y3+ ions preferably entering the B sites can significantly interfere with the conduction mechanism of lithium ferrites. The objective of the present work is to find out the effect of Y3+ substitution on the structural and electrical conduction response Li-Zn-Ti ferrites. The DC resistivity initially is found to increase for concentration x = 0.04 and then decrease with further substitution. The study of the temperature dependence of DC resistivity depicts two types of conduction mechanisms in the range studied. The results obtained are analyzed and presented in the paper. [ABSTRACT FROM AUTHOR]

Potassium sodium niobate (KNN) is an environmentally compatible piezoelectric material for substituting harmful lead-based ceramics. KNN-based ceramics have excellent piezoelectric properties with high Curie temperature. But, KNN faces difficulties during the processing like volatilization of alkali elements, chemical inhomogeneity, low densification, etc. The objective of this research is to investigate the impact of certain metal oxides additions like ZnO and MnO2 as sintering aids to solve the problems of the preparation and hence study the structural and electric properties of K0.5N0.5NbO3 (KNN) ceramics. ZnO and MnO2 added potassium sodium niobate, K0.5N0.5NbO3 was prepared by using the ceramic method. The prepared samples were sintered at 1000 °C for 2h conventionally. The structural properties of the ceramics have been analyzed by using X-Ray Diffractometer. The study demonstrates the formation of the orthorhombic-symmetric perovskite phase in all the prepared samples. The microstructural behavior of the ceramics has been characterized by techniques such as scanning electron microscopy (SEM) and compositional properties were studied by energy dispersive x-ray (EDAX). The effects of metal oxide additions on the electronic properties such as dielectric constant, dielectric loss, impedance properties, Nyquist plot, etc., were studied. The results have been analyzed and discussed in the paper. [ABSTRACT FROM AUTHOR]

Through a typical solid-state reaction followed by planetary ball milling, ABO3 structured perovskite Bi0.5Na0.5ZrO3 (BNZ) was employed as an additive to create the lead-free piezoceramic composite having compositional formula K0.47Na0.47Li0.06NbO3+(x)Bi0.5Na0.5ZrO3 where x = 0.0 wt% to 0.5 wt%. The prepared composites were characterized with the help of XRD, SEM, and FTIR. The XRD results indicated manifestation of morphotropic phase boundary (MPB), i.e. orthorhombic-tetragonal (O-T) phase boundary, for 0.4 wt% and 0.5 wt%. The SEM pictures revealed the microstructural properties of grain-grain size distribution and the average grain size of the composites. The elemental composition examination using EDAX revealed no foreign element contamination. The FTIR examination verified the development of perovskite, indicating that the BNZ has correctly fused into the KNLN matrix. The DC resistivity (ρdc) behavior was determined from IV and IR curves measured at room temperature together with varied temperature line up from 30 °C to 150 °C and a high dc resistivity ρdc of order ≈ 109 Ω cm was obtained for all the ceramics. The results have been analyzed and the mechanism pertaining to the results has been discussed in the paper. Thus the main idea was to develop a lead-free piezoceramic composite by incorporating Bi0.5Na0.5ZrO3 as an additive and investigating its effect on the above mentioned properties of the composite material. [ABSTRACT FROM AUTHOR]

Synthesis (via solid-state reaction) and characterization (structure, microstructure, dielectric, electrical, and ferroelectric behavior) of brownmillerite polycrystalline material NaBiFe2O5 (NBFO) are discussed in this paper. The formation of a triclinic structure has been analyzed by the X-ray diffraction method. The morphology of the ceramic sample was analyzed using a field emission scanning electron microscope (FESEM) and energy-dispersive X-ray analysis (EDX). It is found that the grains are uniformly distributed through well-defined grain boundaries of the sample containing all the constituent elements (Na, Bi, Fe, and O). The study of both frequency (1 kHz–1MHz) and temperature (25–450 °C) dependent dielectric and AC-conductivity predicts the presence of Maxwell-Wagner type of dielectric dispersion and thermally activated relaxation mechanism of NBFO. The impedance spectra support the semiconducting behavior of the brownmillerite NBFO at high temperature. The resistance of the material falls with a rise in temperature favors the negative temperature coefficient resistance behavior of the material. The study of electric polarization suggests the possibility of the ferroelectric properties of the studied sample. The high dielectric constant and low tangent loss suggest the possibility of the material for device applications. [ABSTRACT FROM AUTHOR]

Lead-free K0.47Na0.47Li0.06NbO3 added with different oxides such as ZnO, Na2SiO3, Bi2O3, NiO, and CoO were prepared with conventional two steps sintering ceramic method where the samples were sintered at 1050 °C(5 min) and 950 °C(4h). The phase structures and crystallite sizes were studied using X-ray diffraction analysis. A dispersive behavior is observed when dielectric constant and dielectric loss were studied with variation in frequency in the range from 20 Hz to 5 MHz at room temperature. It is seen that addition of oxides improved the dielectric properties. The a. c. conductivity and impedance characteristics for the samples were also measured for a wide range of frequencies using an impedance analyzer. The Nyquist impedance plot for these samples studied for the conduction mechanism. The results were analyzed and presented in the paper. [ABSTRACT FROM AUTHOR]

Tetravalent titanium substituted lithium zinc manganese ferrite having chemical formula Li0.35+x/2Zn0.1Mn0.1TixFe2.35 − 3x/2O4 where x = 0.00, 0.15, 0.30, 0.45, 0.60, 0.75 were prepared by using the solid-state ceramic technique. Using additives V2O5 and Na2SiO3 as sintering aids, the samples were calcined and sintered at 900 °C and 950 °C, respectively for 1 h each, at a regulated heating rate of 10 °C/min. The X-ray diffraction (XRD) studies showed a single-phase spinel structure. XRD data were used to assess the structural information including density, lattice constant, and crystallite size. The additives reduced the sintering temperature and time and an increase in porosity has been observed with the increase of Ti4+ substitution. Scanning electron microscopy (SEM) was used to analyze the samples' microstructure, while Energy-dispersive X-ray (EDAX) analysis was used to identify the different elemental makeup. The fluctuation of the initial permeability and permeability loss at room temperature with a change in frequency was investigated using an impedance analyzer and found that higher substitution reduced the resonance frequency. The magnetic hysteresis studies showed that saturation magnetization reduced with an increase of Ti4+ substitution. The results obtained were analyzed and discussed systematically in the paper. [ABSTRACT FROM AUTHOR]

In view of the shortcomings of the traditional electromagnetic current transformer in the detection of pulsating DC and smooth DC, a leakage current detection method based on fluxgate magnetic field sensor is proposed in this paper. The leakage current is detected by the size of the magnetic field induced by the DRV425 fluxgate magnetic field sensor. At the same time, the magnetic core is designed to improve the sensitivity of the magnetic field sensor. Finally, the FFT is run in STM32 to identify the waveform of the leakage current from the frequency domain, and the tripping of the action mechanism is realized under different leakage current waveforms and different leakage current thresholds. The experimental results show that the method can effectively detect and identify the leakage current waveform, and can effectively improve the current status of the leakage protector. [ABSTRACT FROM AUTHOR]

Electrodeionization (EDI) is a popular method of water treatment in the current field of water treatment. EDI module mainly absorbs the charged ions in water through the cation exchange resin and realizes the ion removal of water by applying an electric field to make the charged ions move in a directional way and pass through the cation exchange membrane with selective permeability. The existing EDI module has a low integration degree and the working current cannot be adjusted intelligently according to the field environment. In order to solve the problem of low integration degree, this paper designs an EDI module that integrates the EDI module, sensor, controllable constant current source module, and main controller. Meanwhile, in order to solve the problem that the current EDI working current cannot be adjusted in real-time with the environmental water quality, an EDI module output current control method based on fuzzy PID and a main controller hardware circuit based on the adjustable constant current source circuit of a microcontroller digital-to-analog converter (DAC) are designed to adjust the output current of EDI module intelligently. Then the control model of the control system is established by Matlab respectively using the PID control method and fuzzy PID control method, and the simulation is compared. In this paper, the hardware and software of the module are developed based on STM32. The experimental results show that the designed EDI module can realize accurate and fast control of water quality. [ABSTRACT FROM AUTHOR]

The spindle system is important in the machine tool. The vibration signal generated by the spindle system in the machine tool has a great influence on the machining accuracy of the product and the abrasion and lifetime of the tool. Therefore, it is necessary to monitor the vibration signal in the machining process of the machine tool spindle in real time. The vibration sensor is used to monitor the vibration signal of the machine tool spindle in this paper. The data collected by the sensors are transmitted to the Bluetooth module by the serial port for wireless communication. The vibration signal and its frequency domain transformation of the spindle are received by LabVIEW software platform, and the original waveform is displayed, the threshold alarm and the storage of data are realized. The experimental results show that the designed system can realize the online monitoring of the vibration state of the machine tool spindle effectively. [ABSTRACT FROM AUTHOR]

In order to develop the preparation process of sand blank for NC milling requirements, the study of the material and the formula of sand blank are performed by experiment method. In order to obtain the optimal cutting parameters combination, the study is performed to evaluate the NC milling accuracy influence of sand mold for different cutting parameters by orthogonal experiment method. And the NC milling problems of sand mold such as avalanche angle, crack and uneven surface etc are solved by the above studies. The feasibility and effectiveness of the research findings are finally verified by the specific machining example. So, the whole technology solution of the preparation of sand blank and the NC precision milling of complex sand mold could be provided in this paper. [ABSTRACT FROM AUTHOR]

This paper presents tracking control method for wheeled mobile robots (WMRs) with state, sensor and control delays. The differential equations are obtained from the kinematic model of WMR with Pfaffian constraint. Thus, the state-space representations of WMR motion system and the target path system can be achieved. And the tracking error system with state, sensor and control delays is got. A nonlinear tracking control is designed with not only the state of future time but also that of past time. The exponential stability of the closed-loop system under the tracking control is proved. Since the control has the predictive states, it cannot be physically implemented. A high-gain observer (HGO) is constructed to solve this physical implement problem. Moreover, the exponential stability of the errors between the original states and the generated states from HGO is demonstrated. The simulation experiments verified the effectiveness, convenience and simplicity of the designed state-feedback control (SFC) and the output feedback control (OFC) via HGO, which illustrates that the target paths of a circle and a figure-of-8 can be successfully tracked by WMR under the proposed controllers by this paper. [ABSTRACT FROM AUTHOR]

This paper has proposed a multi-piezoelectric input synchronized switch harvesting on inductor (MI-SSHI) circuit. The MI-SSHI circuit is mainly composed of an extreme detector unit and synchronized switch harvesting on inductor (SSHI) units. The extreme detector unit generates real-time control signals. Since the principle of SSHI circuit, each voltage on piezoelectric element can be switched at different instant in a period. In this paper, two piezoelectric element inputs are selected as an example. The experimental result validates that the output power of the MI-SSHI circuit is improved by 11.67%, in comparison to the traditional S-SSHI circuit. [ABSTRACT FROM AUTHOR]

With the rapid development of various industries, the machinery manufacturing industry has been constantly carrying out reform and innovation, among which the introduction and use of technology is constantly increasing, so as to promote the development level of the machinery manufacturing industry. As the most cutting-edge and most potential technology, 3 D printing technology is an important direction of the development of mechanical automation processing. The purpose of this paper is to study the application of 3 D printing technology based on nanomaterials in automatic machining. This paper first introduces the basic concept and working principle of 3 D printing technology, and analyzes the types of 3 D printing technology. Then the classification and preparation of nanomaterials are introduced. This paper also studies the application of 3 D printing technology based on nanomaterials in mechanical automation. The experimental materials in this paper select gold nanoparticles of nanomaterials, and use SLS technology of 3 D printing to degrease and sintering gold nanoparticles. In this paper, the performance of the embryo was tested through two processes of degreasing and sintering, and the experimental results showed that the application of 3 D printing technology based on nanomaterials in mechanical automatic processing has certain practical significance. In this paper, the degreasing rate of the billet at different degreasing temperature is analyzed. When the degreasing temperature is 500 °C, the degreasing rate of the billet reaches 94%. [ABSTRACT FROM AUTHOR]

In this paper, an unexplored solid solution (1-x)Bi(Cu1/2Ti1/2)O3-(x)PbTiO3 has been synthesized and characterized for its crystal structure, dielectric and ferroelectric properties aimed at a selected composition, i.e., 0.30 Bi(Cu1/2Ti1/2)O3-0.70PbTiO3. The paper unveils the different synthesis approaches to achieve pure-phase in Pb-based perovskite-structured materials that are prone to produce impurities during synthesis. The Rietveld refinement of the XRD pattern confirms a tetragonal crystal structure (P4mm) of the composition. The ferroelectric properties of the as-prepared composition are also discussed using P-E hysteresis and PUND characteristics. The composition shows a high Tc (480 °C) and low dielectric losses, making it suitable for high-temperature applications. [ABSTRACT FROM AUTHOR]

This paper proposed a double-sided staggered conical teeth traveling wave rotating ultrasonic motor based on in-plane bending mode, which reduces the difficulty of rotor preload application and improves the output characteristics of in-plane bending mode traveling wave rotating ultrasonic motor. The motor has four sets of drive teeth alternately distributed on both the inner and outer sides of the vibrator, with the drive teeth gap dedicated to accommodate the piezoelectric ceramic piece, and the staggered drive teeth on both sides of the vibrator are used to drive the rotor rotation. The motor operates in two in-plane third-order bending modes with the same frequency and orthogonal to each other, and is excited by four sets of piezoelectric ceramic disks spaced 90 degrees apart from the inner and outer sides. After the prototype was completed, its vibration characteristics and output performance were experimentally tested, and the actual effects of the three excitation schemes were compared. The experimental results show that the motor can provide a maximum output torque of 1.82N-mm and a maximum no-load speed of 96.4 rpm when the excitation voltage is 300 V and the excitation frequency is 20.60 kHz. [ABSTRACT FROM AUTHOR]

Molybdenum disulfide (MoS2) is a typical two-dimensional material, which is widely used in many fields because of its excellent electrical and optical properties. In recent years, the high-quality growth of MoS2 has attracted more and more attention from researchers. Many studies have reported a two-step method for the production of MoS2 by pre-deposition of molybdenum (Mo) source and then vulcanization, which is cumbersome and time-consuming, and the preparation temperature is mostly above 800 °C, increasing energy consumption and experimental risk. In this paper, S source and Mo source can be distinguished by double temperature zone tube furnace to prepare MoS2 material in one-step method. The temperatures of S and Mo sources were designed separately, and the effect of each temperature on the quality of MoS2 was investigated. And the monolayer MoS2 with high crystalline quality was obtained at a S source temperature of 165 °C and a Mo source temperature of 680 °C. We produce MoS2 in one-step method at low temperature, which provides a reference for the synthesis of high-quality monolayer MoS2. [ABSTRACT FROM AUTHOR]

In this paper, NiCo2S4 nanoelectrode materials were prepared by a two-step hydrothermal method. Physical and morphological characterization and electrochemical testing revealed that the prepared NiCo2S4 has a sea urchin-like layered three-dimensional network structure, which can fully increase the contact area with the electrolyte, increase the active sites and improve the electrochemical performance. The specific capacitance of the prepared NiCo2S4 nanomaterials reached 717.32 F/g. The cyclic voltammetry test curve as well as galvanostatic charge-discharge (GCD) test curve have perfect symmetry, good material reversibility. Electrochemical impedance spectroscopy (EIS) indicates materials with low impedance. The specific capacitance remained 76.8% after 3000 cycles and the electrochemical stability was good. NiCo2S4 electrode material has excellent electrochemical properties and has a promising application in supercapacitor electrodes. [ABSTRACT FROM AUTHOR]

In the present work, pure and bismuth-doped barium titanates have been prepared using the sol-gel method. The chemical formula used for the synthesis of bi-doped barium titanate is Ba1-xBixTiO3, where the values of x have been chosen to be 0.00, 0.05, 0.075, 0.10, and 0.15. Barium acetate [Ba(CH3COO)2] and titanium (IV) isopropoxide [Ti{OCH(CH3)2}4] have been used as barium and titanium precursors, respectively. For bismuth doping, bismuth (III) nitrate pentahydrate [Bi(NO3)3)5H2O] has been used. The paper discusses the preparation mechanism, tolerance factor, and the thermal characterization (TGA/DSC) results of pure and bi-doped barium titanate ceramics. [ABSTRACT FROM AUTHOR]

Sleep apnea hypoventilation syndrome (SAHS) is a potentially dangerous and common disease that can affect the patient's health and even lead to sudden death during sleep, making it necessary to monitor changes in respiratory status in real time. Traditional medical devices are mainly concentrated in hospitals and are not conducive to widespread use, while wearable medical devices are well suited to this task. Occasional transient respiratory obstruction is common during sleep for normal people, but it is pathological if SAHS occurs very frequently and severe. In this paper, a respiration monitoring system based on piezoelectric film sensor was fabricated, which can make real-time monitoring, record and display the respiration rate, and automatically recognize it and sound a warning. The proposed system shows great potential for wearable SAHS monitoring instrument. [ABSTRACT FROM AUTHOR]

In this paper, we illustrate the structural, electronic, and optoelectronic properties of LiMgZ (Z=N, P or Sb) half-materials using two methods: DFT and TDDFT. To achieve this goal, we have performed the DFT method under the Quantum Espresso package. Both calculation methods have been done under the approximations: GGA-PBE. In order to determine the optimized lattice parameters of each studied compound, the total energies have been calculated as a function of this parameter. The obtained results show that all the studied compounds are indirect band gap semiconductors, except for the LiMgSb material which shows a direct band gap. Moreover, the calculated band gap energy values are 2.30 eV, 2.15 eV, and 1.1 eV for LiMgP, LiMgN, and LiMgSb respectively. It is clear that this latter compound is more suitable for photovoltaic applications. [ABSTRACT FROM AUTHOR]

The paper investigates the mechanical properties of nanocomposites based on high-density polyethylene (PE) with nanoclay (NC) additives after exposure to an electric field and compares them with changes occurring in the structure. It has been shown that C = C groups are formed as a result of the rupture of macromolecules under the action of an electric field. Depending on the exposure time, the mechanical strength of the nanocomposite and PE decreases, while the tensile strain (ε) and optical density (D) increase. The rate of strength reduction in nanocomposite is lower than that of PE. [ABSTRACT FROM AUTHOR]

This paper aims to investigate the different properties of cobalt-doped and undoped tin oxide thin films. The tin oxide thin films were doped with different atomic percentages of cobalt, ranging from 0% (undoped) to 2% and 4%, using a cost-effective and easily accessible technique known as spray pyrolysis with a moving nozzle at 490 °C. The phase identification of the different thin layers was carried out using X-ray diffraction, which indicated that the compound is homogeneous has a polycrystalline structure and is, with preferential orientation growth at the (211) level. The optical properties of the synthesized thin films were investigated using UV-visible spectroscopy in the range from 300 to 900 nm, which allowed the estimation of both linear and nonlinear optical properties. The results of the investigations into the linear optical properties indicated that the samples have a direct band gap energy between 3.75 to 3.81 eV, permittivity between 2.67 to 3.266, photoelectrons between 0.2 to 3.35 = 1025, and refractive index between 1.778 to 1.875. The results also indicated that the absorption cross section changes with photon energy and the number of photoelectrons, where it has an approximately constant value at low energies. Moreover, the nonlinear optical properties were determined using the Sheik-Bahae model, which revealed that the samples have the same maximum two-photon absorption (TPA) process coefficient of 3.63 cm/W and the same maximum nonlinear refractive index (NRI) value of 6.91 × 10−8 cm2/W. [ABSTRACT FROM AUTHOR]

This paper presents an application of Legendre polynomial approach to solve the wave propagation in a piezoelectric ZnO planar resonator subjected to stress-free boundary conditions and excited using two thin electrodes connected to an electrical source. The method is able to take into account the boundary conditions, the presence of electrical source and the different dissimilarities of the physical properties. Resonance frequencies of longitudinal modes are calculated in case of an open and short-circuit brunch. Dispersion characteristics are also calculated such as mechanical displacement and stress profiles for different resonance frequencies. The electromechanical coupling coefficient is also calculated. [ABSTRACT FROM AUTHOR]

In this paper, we studied the magnetism of Fe2N, using the ab initio and Monte Carlo studies. The magnetic moment and the exchange couplings are deduced by ab initio calculations. The obtained density of states is not symmetrical with respect to the axis of energy proving the ferromagnetic character of this compound. Any gap energy, at the Fermi level, is found confirming the metallic character of this compound. The Hamiltonian of this system consists of several physical parameters. Both the magnetic entropy and the maximum magnetic entropy are obtained. The relative cooling power and the magnetic hysteresis cycle are illustrated. The transition temperature TC value has been deduced and found to be about 252.01 K. This value is in good agreement with the experimental results presented. Also, we found that the magnetizations decrease rapidly to zero with increasing temperature. This is due to the ferromagnetic-paramagnetic phase transition caused by thermal energy. [ABSTRACT FROM AUTHOR]

The liquid crystal microfluid drive is a fast-growing field with potential breakthroughs. In this paper, the microdrive experimental platform and the simulation platform were designed. The influence of drive parameters (electric field strength and frequency) and material parameters (stretching elastic constant, bending elastic constant and viscosity coefficient) on the microdrive effect of liquid crystal was explored. The drive parameters mainly affect the tilt angle range of dielectric molecules. When the tilt angle of the molecule approaches 90°, 4'-(Octyloxy)-4-biphenylcarbonitrile liquid crystal material has the maximum drive speed which can reach 19 µm/s. Among the three medium materials studied, the material 4'-(Octyloxy)-4-biphenylcarbonitrile with a small viscosity coefficient, small elastic coefficient and medium dielectric anisotropy coefficient has the best drive effect. The viscosity coefficient and the dielectric coefficient have a great influence on the drive performance. This research conclusion will lay a theoretical foundation for the synthesis of medium materials driven by liquid crystal microfluid. [ABSTRACT FROM AUTHOR]

In this paper, the interfacial electronic structures of the monolayer, bilayer, and magic-angle graphene/LiNbO3 heterostructures are calculated. The density, energy band, differential charge density, effective mass are calculated and analyzed for the model of structure. The results show that the interface material can adjust the state density, band width, electron concentration and effective mass of the electrons around the Fermi energy level. Therefore, we predict that this structure is feasible in principle for experimental preparation, and can improve the transfer efficiency of carrier, which can provide a high-speed carrier basis for the solar cells. [ABSTRACT FROM AUTHOR]

Resistive random access memory is promising for next-generation nonvolatile memory, which has high memory density, low power consumption, and fast read/write speed. However, the resistive switching (RS) mechanism in oxide ferroelectric thin film devices is still unclear. In this paper, Pt/BiFeO3/La0.5Sr0.5CoO3(Pt/BFO/LSCO) heterostructures were deposited on (111)SrTiO3(STO) substrates by magnetron sputtering. X-ray diffraction confirmed the epitaxial relationship between (111)BFO//(111)LSCO//(111)STO. Atomic force microscopy (AFM) showed that (111)BFO had an island structure with uniform grain distribution. The Pt/(111)BFO/(111)LSCO heterostructures exhibit obvious ferroelectricity and RS effects. The results of C-V analysis and I-V fitting indicate that the RS is caused by the space-charge-limited conduction mechanism. [ABSTRACT FROM AUTHOR]

China is a big oil country, and its oil production and storage are in the forefront of the world. However, China's oil resources are mainly low-permeability reservoirs. It is characterized by small porosity, which leads to the increase of injection pressure and seriously affects the production rate. The main solution is to use polysilicon nano injection enhancer. Polysilicon nano materials can solve the problem of high injection pressure from the micro level. At present, there are many researches on polysilicon nano injection technology at home and abroad, but the research on the application of polysilicon nano materials in natural gas pipeline materials is still blank. In order to solve this problem, this paper will further study the injection enhancement effect of polysilicon nano materials in natural gas pipeline materials. First of all, through theoretical research and analysis, this paper believes that polysilicon nano injection technology has good application, good effect in oilfield injection pressure drop, and obvious advantages over other traditional injection additives. In order to further analyze the injection enhancement effect of polysilicon nanomaterials, the corresponding experimental model is established. The experiment is divided into two parts, one is the preparation of reagents and solvents. In this paper, nano polysilicon solution and corrosion inhibitor are re optimized. The other part is the specific test steps. In order to ensure the quality and verifiability of the test, this paper explains and records the test principle and steps in detail. After sampling and analysis of many core factors such as adsorption time and permeability, it can be seen from the analysis data that when polysilicon nanomaterials are injected, when the injection volume is about 1pv, the effect of depressurization is the best, and the comprehensive effect of depressurization is good. This study has achieved ideal results, which is of great significance to the related research of oil field. [ABSTRACT FROM AUTHOR]