bluuebunny/crossref_metadata_2025 huggingface dataset:
Properties of In2O3:Sb Thin Films Deposited on Quartz Substrates by Radio-Frequency Magnetron Sputtering
Authors: Cho Shinho
Published: September 2021

Antimony-doped indium oxide thin films were deposited on quartz substrates by radio-frequency (RF) magnetron sputtering at various growth temperatures in the range of 25–400 °C. The effects of growth temperature on the structural, morphological, optical, and electrical properties
of the In2O3:Sb thin films were investigated using X-ray diffraction, scanning electron microscopy, ultraviolet-visible spectrophotometry, and a Hall effect measurement system. The thin films showed a cubic structure with a dominant (222) diffraction peak, and a large
number of spherical particles with an average size of approximately 100 nm and a thickness of 190 nm were evolved at a growth temperature of 400 °C. Growing the thin film at higher growth temperatures resulted in an increase in the figure of merit, grain size, and electron concentration,
and a decrease in the optical band gap, electrical resistivity, and average transmittance in the wavelength range of 450–1100 nm. The results suggest that the optimal growth temperature for fabricating high-quality RF-sputtered In2O3:Sb thin films is 400 °C.
Enhancement of Perovskite Solar-Cell Efficiency Using FAPbBr3/I3 with Methylammonium Chloride
Authors: Joo Sung Hwan , Bark Chung Wung , Choi Hyung Wook
Published: September 2021

Organic/inorganic metal halide formamidinium lead iodide (FAPbI3) perovskites exhibit excellent optical properties, a suitable band gap, a wide light-absorption range, and superior electron-hole mobility. However, it is difficult to fabricate high-quality α-phase FAPbI3
film due to the relatively easy formation of the more stable δ-FAPbI3 (hexagonal structure). To overcome this, in this study, formamidinium lead bromide (FAPbBr3) was used to induce the synthesis of stable α-phase FAPbI3. The resulting light-absorbing
layer was composed of (FAPbI3)0.95 (FAPbBr3)0.05, but δ-phase FAPbI3 could be still observed. To suppress the formation of δ-phase FAPbI3 , methylammonium chloride (MACl) was added to the (FAPbI3)0.95
(FAPbBr3)0.05 precursor solution. At an optimal MACl content of 40 mol%, perovskites with improved crystallinity and large crystallite size could be fabricated, resulting in a perovskite solar-cell efficiency of 18.204%.
Characteristics of Palladium Doped Amorphous Carbon Films Fabricated by Unbalanced Magnetron Sputtering System
Authors: Park Yong Seob , Kim Young-Baek , Hwang Sung Hwan , Lee Jaehyeong
Published: September 2021

Generally, hydrogenated amorphous carbon (a-C:H) has been shown to have a low friction coefficient, high hardness, and low abrasive wear rate. In this study, Pd doped hydrogenated amorphous carbon (a-C:H:Pd) fabricated by the closed-field unbalanced magnetron sputtering (CFUBMS) system
with two targets of carbon and palladium in Ar/C2H2 plasma. The tribological and lubricant characteristics for a-C:H:Pd fabricated with various DC bias voltage from 0 to −200 V were investigated. We obtained a hardness up to 27.5 GPa and friction coefficient lower
than 0.1. The atomic percentage of Pd related to the lubricant properties increased up to 22% at −200 V. In the results, the Pd doping in the a-C:H films improved the tribological and lubricant properties. The friction coefficient value of a-C:H:Pd films was decreased, the hardness and
elastic modulus were increased, and also the adhesion properties was improved with the increase of negative DC bias voltage.
Characteristics of HfO2 Thin Film Capacitor Deposited by RF Magnetron Sputtering
Authors: Bak Yang Gyu , Park Ji Woon , Lee Hee Young
Published: September 2021

High-k HfO2 thin films were assessed as a gate dielectric for possible oxide thin-film transistor applications. A HfO2 gate dielectric layer was deposited by radio frequency magnetron sputtering (RF-MS) of a sintered ceramic target at the working pressure
of 5 mTorr and annealed at various annealing conditions. X-ray diffraction (XRD) and UV-Vis transmission spectroscopy were carried out to determine the structure and optical transparency of the sputtered HfO2 films, respectively. The electrical characteristics of the HfO2
films were evaluated using the metal-oxide-semiconductor (MOS) capacitor structure of Ti/HfO2/n++-Si. The capacitance-voltage (C-V) and current-voltage (I-V) measurements were taken using an impedance analyzer (Keysight, E4990A) and semiconductor parameter
analyzer (Keithley, 4200-SCS), respectively. A dielectric constant of up to 8 with a leakage current as low as 1.0 × 10−9 A/cm2 at 2.0 V were observed.
The Extraction of Polyoxometalate Flash Compact Model and Corresponding Circuit Simulation
Authors: Ding Jie , Yan Guoliang , Adamu-Lema Fikru , Dou Yinke , Chen Yan , Ding Bing , Georgiev Vihar P. , Asenov Asen
Published: September 2021

The main component of the POM flash memories is a polyoxometalates (POMs) layer which is used as the floating gate. As a competitive candidate of NAND Flash, POM flash memories attract significant interest and intensive investigations which have been conducted on modelling its physical
characteristics and electrical properties. In this paper, we report the development of a specific compact model extraction strategy for POM flash memory based on BSIM4 compact model, allowing the corresponding circuit performance investigation. POM flash compact models are extracted and optimized
using genetic algorithm (GA) at the three POM flash redox states. The extracted models are in good agreement with both high drain and low drain bias TCAD simulations. For the first time, the extracted compact models are applied in the circuit simulation to investigate the circuit behaviour
of POM flash cells. This will provide valuable guidance for the practical design using POM flash cells.
Preparation of Carbon Fiber-Polyacrylamide Composite Hydrogel Based on Surface Electric-Initiated Polymerization
Authors: Lv Mengge , Wei Xinfang , Peng Liwen
Published: September 2021

Conductive hydrogels have shown excellent application prospects in the fields of bioelectronics, tissue engineering, wearable devices, etc. However, its poor compatibility at the organic-inorganic interface affects its mechanical strength and limits its wide application. We prepared
carbon fiber-polyacrylamide organic-inorganic composite material by electrochemical polymerization using N,N-methylenebisacrylamide as the crosslinking agent, acrylamide as the monomer, and carbon fiber as the conductive filler. It forms a conductive hydrogel after absorbing water.
The effects of monomer concentration, reaction time, and current on the composite material were investigated in this article. The experimental results show that a large number of irregular bumps are produced on the surface of carbon fiber, and various characterization tests show that it is
polyacrylamide (PAM) that successfully attached to carbon fiber. Under the same electrochemical polymerization time, the current density and monomer concentration have little effect on the molecular weight which mainly concentrated around 6.2 × 105. The graft modification
of PAM reduces the defects on the surface of the carbon fiber, and the composite effect is good.
A Novel Preparation of Mn/NiCo2O4 Catalyst with High Catalytic Activity on Methane
Authors: Peng Liwen , Wang Haiwang , Lv Mengge
Published: September 2021

In this paper, a Mn/NiCo2O4 catalyst was prepared for the complete oxidation of low-concentration methane. When the ratio of Mn: Co is 1:4, the catalyst has the best catalytic activity, and the best methane conversion temperature Feis 400 °C. In addition, the
catalytic activity remains stable during the long-term reaction, showing adequate thermal stability. The catalyst is grown on FeCrAl alloy by hydrothermal method to complete the catalytic oxidation of methane. In the catalysis process, the Mn/NiCo2O4-FeCrAl catalyst is
energized and the current is directly passed through the alloy substrate to generate Joule heat, reaching the optimal catalytic temperature for complete oxidation of methane.
Modification of Polyhedral Oligomeric Silsesquioxane (Epoxy Resin-Polyhedral Oligomeric Silsesquioxane) by Inorganic Nanoparticles
Authors: Fang Yanhong , Wang Ping
Published: September 2021

As a kind of green and clean energy, solar energy has attracted more and more attention. Among them, the antifouling treatment on the surface of photovoltaic panels is the key to improve the photoelectric conversion efficiency. EP-POSS (epoxy resin-polyhedral oligomeric silsesquioxane)
has good hydrophobicity and has potential application value in the field of protective coating of photovoltaic panels. UV-vis tests show EP-POSS light transmittance about 85%, have good pervious to light quality, through the ZnO and SiO2 inorganic nanoparticles to modification of
EP-POSS, in order to improve the wearability of EP-POSS coating and bacteriostasis, the EP-POSS microstructure was tested by TEM, XRD characterization of nano particles and the compatibility of EP-POSS, again with TGA, adhesion and wear resistance test the performance of the EP-POSS found
inorganic nanoparticles can better improve the use performance of EP-POSS.
Hybrid Supercapacitors Based on Self-Assembled Electrochemical Deposition of Reduced Graphene Oxide/Polypyrrole Composite Electrodes
Authors: Ma Jun , Syed Junaid Ali , Su Dongyun
Published: September 2021

Conductive polymers (CPs) have potential application to commercial energy storage because of their high electrochemical activity and low cost. However, an obstacle in developing CP-based supercapacitors is the degradation in their capacitance during the charge-discharge process that
leads to poor rate performance. This study fabricates layers of a high-performance self-assembled polypyrrole/reduced graphene oxide (PPY/RGO) composite material on a carbon cloth through electrochemical deposition. The layered graphene improved the electrochemical properties of PPY. Carbon
fiber rods were coated with the PPY/RGO composite layer, the thickness of which depends on the deposition time. Adequate capacitive behaviors were achieved by using 16 layers of polypyrrole/reduced graphene oxide, with a specific capacitance of 490 F g−1 (0.6 A g−1)
and good rate performance. The results here provide a novel means of preparing graphene-based nanocomposites films for a variety of functions. A symmetric device was subsequently assembled by using electrodes featuring 16 layers of the polypyrrole/reduced graphene oxide composite. It yielded
a specific capacitance of 205 F g−1 and a high energy density of 16.4 Wh kg−1. It also exhibited good cycle stability, with a capacitance retention rate of 85% for 5,000 cycles.
Co3S4/NiCo2S4 Nano-Arrays on Nickel Foam as Energy Storage for Supercapacitors
Authors: Meng Xiang-Sen , Xiang Jun , Bu Nan , Guo Yan , Loy Sroeurb , Yang Wen-Duo , Chen Hong-Quan , Zhao Rong-Da , Wu Fu-Fa
Published: September 2021

In this work, Co3S4/NiCo2S4 nano-arrays electrode with Co3S4 nanocones and NiCo2S4 nanosheets interlaced arrangement are prepared by the promising hydrothermal method. Compared with single Co3S4/NF
or NiCo2S4/NF electrode, the prepared Co3S4/NiCo2S4/NF electrode exhibits excellent specific capacitance. At a current density of 2 mA cm−2, the surface capacitance is as high as 9036 mF cm−2,
and it still maintains a surface capacitance of 5664 mF cm−2 at a current density of 8 mA cm−2. Co3S4/NiCo2S4/NF||ASC has a high electrochemical performance with a maximum energy density of 0.62 Wh cm−3
and a power density of 15.94 W cm−3. At a current density of 5 mA cm−2, the capacity retention rate is 83.75% after 3000 cycles.
Experimental Research on the Sensitivity of Partial Discharge Ultra High Frequency Sensor Structure Parameters
Authors: Li Wen-Yi
Published: September 2021

With the development of intelligent high voltage switch, online gas insulated switchgear discharge detection technology has been more and more widely applied. Because of the high sensing sensitivity and good antiinterference performance of build-in partial discharge sensor, it is currently
required to install them on gas insulated switchgear products with voltage levels of 220 kV and above at the factory. The structural parameters of the build-in partial discharge sensor is of great importance to its sensing sensitivity. Therefore, in this paper, the influence of the structure
change on the sensitivity of axisymmetric gas insulated switchgear build-in partial discharge sensor is experimentally studied. A practical gas insulated switchgear test model was established in the laboratory, and the frequency domain measurement system based on Spectrogram analyzer and synchronous
sweep signal generator was adopted. By comparing the insertion loss generated by the build-in sensor when receiving sweep signal, the influence of structural parameter changes on the sensing sensitivity was analyzed. The results show that the diameter of the build-in sensor should be matched
with the diameter of the hand-hole. The match of the larger diameter of the hand-hole and the smaller diameter of the sensor can increase the sensing sensitivity, but when the diameter of the sensor is close to the diameter of the hand-hole, the sensitivity will be significantly reduced. In
addition, metal bolts with the sensor electrode and its insulating support fixed to the hand-hole cover can also result in a significant reduction in sensing sensitivity. Using the same measuring principle and system, the propagation attenuation characteristics of partial discharge ultra high
frequency signal in gas insulated switchgear typical structures (linear and L-shaped structures) are also experimentally studied. The results show that the average attenuation of partial discharge ultra high frequency signal in gas insulated switchgear along the linear distance is 0.3 dB/m,
and the attenuation through every L-shaped structure is 4.2 dB.
The Preparation of Ag Nanopaste with Silver-Plated Diamond by Low-Temperature Pressureless Sintering
Authors: Tang Rongjiang , He Hong , Jiang Xiong , Zeng Fabing , Yan Haidong , Zhang Ping
Published: September 2021

Diamond/Ag nanopaste has been prepared by mixing Ag nanoparticles, silver-plated diamond particles, and an organic solvent system. Then, we characterized and studied the sintering properties of diamond/Ag nanopaste. Meanwhile, the impact factor of sintering temperature on the sintered
microstructure of the diamond/Ag nanopaste on direct bonding copper (DBC) substrate was investigated. The influences of sintering temperature on the shear strength of diamond/Ag nanopaste connection layer for attaching silicon chip on the silver-plated copper substrate were analyzed. The results
show that silver plating on the surface of the diamond can significantly strengthen the bonding ability between the diamond and nano-silver. When the pressureless sintering temperature increased from 150 °C to 350 °C, the porosity of diamond/Ag nanopaste decreased from 29.8% to 8.9%,
and the sintered diamond/Ag joint with uniform and dense connection layer showed the maximum shear strength of 15.26 MPa as sintering at 350 °C.
Molecular Logic Gate Based on DNA Strand Displacement Reaction
Authors: Ma Jingjing
Published: September 2021

In this paper, I construct an XOR logic gate based on DNA strand displacement reaction, and verify our design through corresponding biochemical experiment. I designed several different DNA strands. Based on two basic DNA strand displacement reaction mechanisms, by adding different input
strands and taking the signal of FAM fluorescent group as the output, the XOR logic gate is realized. The result shows that DNA strand displacement technology has important application value in DNA computing, especially in the construction of DNA molecular logic gates.
Research on Power Consumption Model of Permanent Magnet Direct Drive Belt Conveyor System Based on Fruit Fly Optimization Algorithm-Generalized Regression Neural Network-Particle Swarm Optimization
Authors: Wang Gui-Mei , Zhang Li-Chen , Liu Jie-Hui , Yang Li-Jie
Published: September 2021

The permanent magnet direct drive electric drum is used to replace the driving device of the traditional belt conveyor, which simplifies the structure. However, the permanent magnet direct drive electric drum still operates in a high speed and stable state after starting, and cannot
transport materials reasonably, belt speed cannot match the coal quantity reasonably; the problem of energy waste is still severe. Thus, based on fruit fly optimization algorithm-generalized regression neural network-particle swarm optimization algorithm, the power consumption network model
of the permanent magnet direct drive belt conveyor system is established. The relationship among belt velocity, coal transport quantity and power is obtained, and the optimal belt velocity is found with the power consumption network model. Thus, the minimum power is obtained. The algorithm
selects the optimal smoothing factor by fruit fly optimization algorithm, inputs the optimal smoothing factor into generalized regression neural network and establishes the optimal power consumption model. Then establishes the matching relationship of coal quantity, optimal power, and optimal
belt speed in the power consumption model by the adaptive weight particle swarm optimization. The model is compared with the network model with smoothing factors of 0.7 and 0.4. The comparisons show that the optimized model performs better, which can be better applied to establish the energy
consumption model of the system.
Demagnetization Modeling and Characteristic Analysis of Belt Conveyor Permanent Magnet Electric Roller Based on Back Electromotive Force
Authors: Yang Lijie , Deng Caiming , Wang Guimei
Published: September 2021

The demagnetization of permanent magnet electric roller of coal mine belt conveyor will reduce the comprehensive performance of electric roller. In serious cases, the belt conveyor will stop suddenly or burn down, leading to the failure of normal production and safety accidents on the
site. In this paper, starting from the A-phase current and output torque angles under different degrees of loss of magnetic fault, the B–H curve is fitted by linear ratio, and the reverse electromotive force is modeled by numerical analysis method. A diagnosis method for the degree of
demagnetization of permanent magnet electric roller on account of the mathematical model of back electromotive force is presented. In this paper, a 200 KW permanent magnet electric roller used in a mine is taken as the research object. The finite element model is established by ANSYS Electronics
Desktop and the demagnetization simulation of model is carried out. The model of mathematics on account of the back electromotive force is compared with a model of finite element simulation, and the back electromotive force waveform of the two methods is basically the same, and the error is
less than 5%. The mathematical model based on the reverse electromotive force proposed in this paper can accurately reflect the degree of loss of magnetization of the motor, and the calculation results are accurate, which is conducive to determining the state of the permanent magnet electric
roller more effectively, and provides a theoretical basis for predicting and diagnosing the failure of loss of magnetization of the permanent magnet electric roller.
Research on Temperature Compensation of the Fiber Bragg Grating Sensor and the Resistance Strain Gauge
Authors: Zhu Feng , Liu Min , Xu Chengjun , Zou Sheng , Chen Chentong , Xiao Xinyi
Published: September 2021

The fiber Bragg grating sensor is widely used in strain monitoring of large metal structure and trend to replace the resistance strain gauge due to its advantages of strong stability, high measurement accuracy, multiple points measuring, strong environmental suitability and long transmission
distance. The temperature-induced strain, which can have the same order of magnitudes as the mechanically-induced strain, will cause great errors in the strain monitoring. Therefore, the temperature compensation for the sensors is essential to guarantee the measurement accuracy. The existing
theoretical models and experiment platforms for analyzing the temperature compensation are established by assuming that the testing temperature is constant. However, the surrounding temperature of some large metal structure is not stable, and the effect of temperature change cannot be neglected.
This paper aims to establish an analytic model and an experiment platform to compare the temperature compensation of the fiber bragg grating sensor and the resistance strain gauge. The superiority of the temperature compensation for the fiber bragg grating sensor is verified. The result provides
theoretical support for choosing the fiber bragg grating sensor in the long-time strain monitoring.
Preparation, Characterization, and Microwave Absorption Properties of Cobalt-Doped SrFe12O19 Nanoparticles
Authors: Liu Yuan , Lai Jie , Liu Yun
Published: September 2021

Ferrite is the major absorbing components of conventional radar absorbing materials (RAM). However, conventional RAM made of the single-absorbing components cannot meet the comprehensive requirements of “thin, wide, light, and strong.” To overcome this limitation, a composite
compound of cobalt-doped SrFe12O19 nanoparticles is currently exploited to improve absorbing ability. SrFe12−xCoxO19 (x = 0, 0.05, 0.1, 0.15, 0.20, 0.25) composite ferrites were prepared using the sol-gel method. Results
show that the powders obtained are pure lead-magnetite ferrite, and the properties of the samples are improved evidently after Co substitution. At room temperature, the samples substituted using Co exhibit typical permanent magnetism. When x = 0.2, the maximum saturation magnetization and
coercivity of the powders are 55.8 A·2/kg and 302.4 kA/m, respectively. The real complex permittivity part of SrFe12−xCoxO19 first increases and then decreases with the increase in x and has a maximum value of x = 0.2.
The complex imaginary permittivity part fluctuates with the increase in x; it first decreases, then increases, and finally decreases. With the increase in x, the complex permeability real part of the sample does not change much between 2 GHz to 16 GHz but first increases and then decreases
in the range of 16-18 GHz. The imaginary part of the complex permeability first increases and then decreases, reaching its maximum at x = 0.2. The attenuation constants and absorbing properties of the samples before and after substitution were analyzed. The matching thickness of strontium
ferrite (SrFe12O19) is 5.2 mm, the matching thickness of SrFe11,8Co0.2O19 (x = 0.2) is reduced to 2.4 mm, the minimum reflectivity is −24.7 dB (13.8 GHz), and the microwave absorption bandwidth lower than −10 dB is 4.7 GHz
(11.6-16.3 GHz). These results indicate that an appropriate amount of Co substitution could greatly improve the absorbing performance of SrFe12O19. This study provides a simple method for the preparation of Co doped strontium ferrite. The microwave absorbing properties
of the composite powders are excellent and have potential engineering application value.
Morphology and Structure Induced Co3O4 Nanowires High-Performance Supercapacitor Electrode Material
Authors: Wang Jian , Zhao Yan , Li Yucai , Song Shiwei
Published: September 2021

The electrochemical performance of the material depends heavily on the morphologies and structural characteristics of the material. Co3O4 samples show the remarkable electrochemical performance owing to the high porosity, appropriate pore size distribution and
novel architecture and the effect of NH4F for morphology. Co3O4 nanowires grown on Ni foam have been synthesized through a facile hydrothermal approach, revealing large capacitance of 2178.4 mF cm−2 at the current density of 2 mA cm−2
and superior cycling stability.
A Highly Efficient Volatile Organic Compounds Gas Sensor Based on Molybdenum Oxide Applied in Air Detection Inside Vehicles
Authors: Zhou Jinying , Liu Yan , Xu Lei , Long Jun
Published: September 2021

Volatile organic compounds (VOCs) are the major air pollutants inside vehicles. In this research, a highly sensitive gas sensor was developed based on an excellent sensing material and explored for VOCs sensing application. The X-ray diffraction and scanning electron microscopy were
performed to evaluate the detailed structural features of sensing material. From the gas-sensing property tests to the three representative VOCs vapors, containing xylene, toluene and formaldehyde, the gas sensor fabricated from the exceptional sensing material significantly responses to the
three VOCs vapors. In particular, the xylene response of the sensor is slightly larger than the other two gas response. Thus, the fabricated sensor could be a promising application for VOCs detection inside vehicles.
A Formaldehyde Indoor Gas Sensor Based on Hierarchical α-Molybdenum Trioxide
Authors: Zhu Yujun , Zhang Fan , Wang Kaifang , Zhang Yawen , Gu Xiuzhi , fa Yuan Zheng , Liu Xin
Published: September 2021

The detection of indoor formaldehyde gas is important because of its highly toxic nature. Herein, the two-dimensional α-MoO3 nanosheets and three-dimensional α-MoO3 hierarchical flowers have been prepared by simple hydrothermal strategy and used as
the formaldehyde sensing materials. Their microstructures, morphologies and gas sensing characteristics towards formaldehyde were studied. The test results exhibited that, at the optimal temperature of 250 °C, the sensor performances were enhanced due to the assembly of 2D nanosheets into
3D hierarchical structure. The improved properties were contributed to the formation of the hierarchical microstructure constructed by nanosheets. The hierarchical microstructure based gas sensor has significant potential in indoor air sensing application.
Transverse Vibration Analysis of Axially Moving Trapezoidal Plates
Authors: Zhang Man , Dong Ji-Xian
Published: September 2021

Transverse vibration of axially moving trapezoidal plates is investigated. The differential equation of transverse vibration for a axially moving trapezoidal plate is established by D'Alembert principle. The original trapezoid region can be replaced by regular square region by the medium
parameter method for the convenience of calculation. A generalized complex eigenvalue equation is derived by a discrete method (the differential quadrature method). The complex frequency curve of trapezoidal plate is obtained by calculating the eigenvalue equation. The change of the complex
frequencies of the axially moving trapezoidal plates with the dimensionless axially moving speed is analyzed. The effects of the aspect ratio and the trapezoidal angle on instability type of the trapezoidal plate are discussed under different boundary conditions. The results of numerical analysis
show that there are two main instability types of axially moving trapezoidal plate: divergence and flutter. The modal orders of the two types of instability are also different, which is related to the trapezoidal angle, aspect ratio and boundary condition of the trapezoidal plate.
The Synthesis and Optical Properties of Zinc-Nitrogen Co-Doped TiO2 Thin Films Using Sol–Gel Derived Spin-Coating Method
Authors: Zhao Shuai , Lin Dong-Xue , Wang Yu-Xin
Published: September 2021

All of the TiO2 films including intrinsic TiO2 film, Zn single doped film with 2.0 at% content and N doped films with 4.0 at%, 6.0 at%, 8.0 at% and 10.0 at% content, were obtained by butyl titanate (Ti(OC4H9)4) as a titanium source,
zinc nitrate (Zn(NO3)2·6H2O) as zinc source and urea (H2 NCONH2) as nitrogen source, which was calcined at 600 °C on the glass substrate and Si substrate using sol–gel spin coating method. The structures, morphology and
optical properties of various films were analyzed and studied by X ray diffract meter (XRD), ultraviolet-visible spectrophotometer (UV-Vis) and scanning electron microscope (SEM). The results indicated that the main crystal plane of TiO2 film was (101) and any impurity crystal plane
didn't appear. All samples had obvious red shifts in the absorbing edge overall and reduced significantly the width of forbidden band, especially, the N doping content with 8.0 at% was surprised to investigate the strongest (101) peak intensity, the sharpest peak type, the best meritocratic
orientation, the greatest red shift of the absorption spectrum, the lowest optical band gap value of 3.356 eV, and the highest utilization rate of visible light of the sample. However, the surface morphology of the others films except the N doping content with 8.0 at% is not further improved
by co-doping, that is, their surfaces were still rough, had obvious voids and uneven distribution between the grains. Meanwhile, the intensity of the (101) crystalline diffraction peaks of these samples were reduced and the crystalline spacing generally increased after co-doping.
Integrated Method for Road Extraction: Deep Convolutional Neural Network Based on Shape Features and Images
Authors: Wang Feng-Ping , Xu Zheng-Chao , Shi Qi-Shuai
Published: September 2021

As a significant application in RS images, road detection is still a challenging task due to the presence of complex surroundings and multiple false objects. To achieve a satisfying result, a road detection method based on residual learning and saliency sampling is developed in this
paper. First, a multistrapdown module is designed with double residual learning blocks that have low computational complexity and time consumption. Second, to improve the classification accuracy and learning ability of the method, a saliency sampling set is established by fusing brightness,
orientation and texture maps. The sampling set is imported and merged into the model through the pooling layer. Finally, the cross entropy loss function is carried out in a Softmax classifier. Extensive experiments show that our proposed integrated method is much better than the state-of-the
art methods in detection accuracy.
Comparative Bioactivity Analysis for Off-the-Shelf and Culture–Rescued Umbilical Cord-Derived Mesenchymal Stem/Stromal Cells in a Xeno- and Serum-Free Culture System
Authors: Nguyen Minh Quang , Bui Hue T. H. , Tuyet Anh Nguyen Thi , Nhung Trinh Thi Hong , Hoang Duc M. , Liem Nguyen Thanh , Hoang Van T.
Published: September 2021

We recently reported a standardized xeno- and serum-free culture platform to isolate and expand umbilical cord-derived mesenchymal stem/stromal cells (UC-MSCs). Comparing populations from the same passage, cells that were cryopreserved and culture-rescued exhibited characteristics similar to those of their fresh counterparts, continuously cultured cells without interim cryopreservation. The culture rescue after thawing allowed for the cells to be fully recovered. However, since it would be more cost-effective and timesaving if cryopreserved cells can be used as an off-the-shelf product, we set out to compare the bioactivity of freshly thawed UC-MSCs versus culture-rescued UC-MSCs of the same batch that were recultured for an additional passage under our xeno- and serum-free protocol. UC-MSCs showed high viability in both the freshly thawed and the re-cultured group. Both populations displayed a similar proliferation capacity which is indicated by a comparable population doubling time and colony-forming ability. Both freshly thawed and culture-rescued UC-MSCs expressed the characteristic immunophenotype and were capable of differentiating into osteocytes, chondrocytes, and adipocytes. On the other hand, culture-rescued cells appeared to be more potent in immunosuppression than freshly thawed cells. In conclusion, freshly thawed and culture-rescued cell products share comparable bioactivity in cell growth and proliferation, immunophenotype, and differentiation potential. However, the culture-rescued cells that were allowed to grow for an additional passage appear to display a more favorable immunomodulatory potential when compared to their freshly thawed parent cells.
Oscillation Modes of Weld Pool in Stationary GTA Welding Using Structure Laser Method
Authors: Wu Xingpei , Huang Jiankang , He Jing , Liu Shien , Liu Guangyin , Fan Ding
Published: September 2021

Researchers have recently attempted to monitor pool oscillations using the three-dimensional laser vision method. However, the deficiency of simulation software will result in significant capital expenditure. Both simulations and experiments are performed in this study, and the Bessel equation is used to analyze the oscillation mode of a weld pool. The laser dot matrix images of (0, 1), (1, 1), (2, 1), and (0, 2) oscillation modes at different times are obtained via structured laser optical measurement simulation. The oscillation mode of a stationary gas tungsten arc weld pool is analyzed based on laser dot matrix images obtained from a structure laser experiment. Results show that the simulated laser dot matrix images are consistent with the experiment results. The oscillation mode of the weld pool can be recognized based on the laser dot matrix image. This study not only provides conditions for assessing the penetrating state of a weld pool, but also enable a further understanding of the oscillation mode of a weld pool and the development of more effective observation methods and measurement tools to effectively control and improve welding quality.
Influence of Ultrasonic Surface Rolling Process and Shot Peening on Fretting Fatigue Performance of Ti-6Al-4V
Authors: Wang Ning , Zhu Jinlong , Liu Bai , Zhang Xiancheng , Zhang Jiamin , Tu Shantung
Published: September 2021

At present, there are many studies on the residual stress field and plastic strain field introduced by surface strengthening, which can well hinder the initiation of early fatigue cracks and delay the propagation of fatigue cracks. However, there are few studies on the effects of these key factors on fretting wear. In the paper, shot-peening (SP) and ultrasonic surface rolling process (USRP) were performed on Ti-6Al-4V plate specimens. The surface hardness and residual stresses of the material were tested by vickers indenter and X-ray diffraction residual stress analyzer. Microhardness were measured by HXD-1000MC/CD micro Vickers hardness tester. The effects of different surface strengthening on its fretting fatigue properties were verified by fretting fatigue experiments. The fretting fatigue fracture surface and wear morphology of the specimens were studied and analyzed by means of microscopic observation, and the mechanism of improving fretting fatigue life by surface strengthening process was further explained. After USRP treatment, the surface roughness of Ti-6Al-4V is significantly improved. In addition, the microhardness of the specimen after SP reaches the maximum at 80 μm from the surface, which is about 123% higher than that of the AsR specimen. After USRP, it reaches the maximum at 150 μm from the surface, which is about 128% higher than that of AsR specimen. It is also found that the residual compressive stress of the specimens treated by USRP and SP increases first and then decreases with the depth direction, and the residual stress reaches the maximum on the sub surface. The USRP specimen reaches the maximum value at 0.18 mm, about − 550 MPa, while the SP specimen reaches the maximum value at 0.1 mm, about − 380 MPa. The fretting fatigue life of Ti-6Al-4V effectively improved after USRP and SP. The surface integrity of specimens after USRP is the best, which has deeper residual compressive stress layer and more refined grain. In this paper, a fretting wear device is designed to carry out fretting fatigue experiments on specimens with different surface strengthening.
Is the simple webbed penis a contraindication to circumcision?
Authors: Bawazir Osama Abdullah , Alhallaq Obada Alladh , Albayhani Bashair , Bawazir Abdullah
Published: September 2021

Background

Surgical correction of the webbed penis is challenging. We presented the safety and feasibility of webbed penis correction for neonates under local anesthesia using a simple principle of leaving equal cylindrical shaft skin.

Methods

This retrospective study included 530 patients who presented for circumcision to three pediatric surgery centers between May 2017 and January 2020. We included male patients aged less than four weeks old who had circumcision with a minimum of 6 months follow-up. We compared patients with normal penile anatomy (n = 451, Group 1) to a simple webbed penis (n = 79, Group 2).

Results

There were no differences in age and weight between groups. The procedure time was significantly longer in Group 2 (8.05 ± 3.11 vs. 7.48 ± 2.07 min;P = 0.04). There were no differences in bleeding (P = 0.38), redundant foreskin (P > 0.99), need for corrective surgery (P = 0.38), and re-suturing (P = 0.28) between groups. The procedure success was significantly higher in Group 1 (449 (99.56%) vs. 70 (88.6%);P < 0.001). Parents' satisfaction was measured at two weeks with no difference between both groups.

Conclusion

Simple penoscrotal web is not a contraindication for neonatal circumcision. Circumcision of the penoscrotal web had good esthetic results with comparable outcomes to those with a normal penis without a web.
Proteomics reveals the effects of drought stress on the kernel development and starch formation of waxy maize
Authors: Guo Jian , Qu Lingling , Hu Yifan , Lu Weiping , Lu Dalei
Published: September 2021

Background

Kernel development and starch formation are the primary determinants of maize yield and quality, which are considerably influenced by drought stress. To clarify the response of maize kernel to drought stress, we established well-watered (WW) and water-stressed (WS) conditions at 1–30 days after pollination (dap) on waxy maize (Zea mays L. sinensis Kulesh).

Results

Kernel development, starch accumulation, and activities of starch biosynthetic enzymes were significantly reduced by drought stress. The morphology of starch granules changed, whereas the grain filling rate was accelerated. A comparative proteomics approach was applied to analyze the proteome change in kernels under two treatments at 10 dap and 25 dap. Under the WS conditions, 487 and 465 differentially accumulated proteins (DAPs) were identified at 10 dap and 25 dap, respectively. Drought induced the downregulation of proteins involved in the oxidation–reduction process and oxidoreductase, peroxidase, catalase, glutamine synthetase, abscisic acid stress ripening 1, and lipoxygenase, which might be an important reason for the effect of drought stress on kernel development. Notably, several proteins involved in waxy maize endosperm and starch biosynthesis were upregulated at early-kernel stage under WS conditions, which might have accelerated endosperm development and starch synthesis. Additionally, 17 and 11 common DAPs were sustained in the upregulated and downregulated DAP groups, respectively, at 10 dap and 25 dap. Among these 28 proteins, four maize homologs (i.e., A0A1D6H543, B4FTP0, B6SLJ0, and A0A1D6H5J5) were considered as candidate proteins that affected kernel development and drought stress response by comparing with the rice genome.

Conclusions

The proteomic changes caused by drought were highly correlated with kernel development and starch accumulation, which were closely related to the final yield and quality of waxy maize. Our results provided a foundation for the enhanced understanding of kernel development and starch formation in response to drought stress in waxy maize.
Ileostomy or ileal pouch-anal anastomosis for ulcerative colitis: patient participation and decisional needs
Authors: Cohan Jessica N. , Ozanne Elissa M. , Hofer Rebecca K. , Kelly Yvonne M. , Kata Anna , Larsen Craig , Finlayson Emily
Published: September 2021

Background

Up to 30% of patients with ulcerative colitis will undergo surgery resulting in an ileal pouch-anal anastomosis (IPAA) or permanent end ileostomy (EI). We aimed to understand how patients decide between these two options.

Methods

We performed semi-structured interviews with ulcerative colitis patients who underwent surgery. Areas of questioning included the degree to which patients participated in decision-making, challenges experienced, and suggestions for improving the decision-making process. We analyzed the data using a directed content and thematic approach.

Results

We interviewed 16 patients ranging in age from 28 to 68 years. Nine were male, 10 underwent IPAA, and 6 underwent EI. When it came to participation in decision-making, 11 patients felt independently responsible for decision-making, 3 shared decision-making with the surgeon, and 2 experienced surgeon-led decision-making. Themes regarding challenges during decision-making included lack of support from family, lack of time to discuss options with the surgeon, and the overwhelming complexity of the decision. Themes for ways to improve decision-making included the need for additional information, the desire for peer education, and earlier consultation with a surgeon. Only 3 patients were content with the information used to decide about surgery.

Conclusions

Patients with ulcerative colitis who need surgery largely experience independence when deciding between IPAA and EI, but struggle with inadequate educational information and social support. Patients may benefit from early access to surgeons and peer guidance to enhance independence in decision-making. Preoperative educational materials describing surgical complications and postoperative lifestyle could improve decision-making and facilitate discussions with loved ones.
The association between malaria prevalence and COVID-19 mortality
Authors: Anyanwu Michael U.
Published: September 2021

Background

The number of persons infected with COVID-19 continues to increase with deaths reported daily across the globe. High income countries such as the US, the UK, Italy and Belgium have reported high COVID-19 related deaths but low-and-middle-income countries have recorded fewer deaths despite having poor healthcare system. This study aimed to investigate the association between malaria prevalence and COVID-19 mortality.

Methods

An ecological study was conducted with data from 195 countries. Spearman’s correlation was used to test the association between the population variables and COVID-19 mortality. Generalized linear model with Poisson distribution was used to determine the significant predictors of COVID-19 mortality.

Results

There was a significant positive correlation between median age, life expectancy, 65+ mortality and COVID-19 mortality while malaria prevalence, sex ratio and cardiovascular mortality were negatively correlated with COVID-19 mortality. Malaria prevalence, life expectancy and mortality rate were significant on multivariate regression analysis.

Conclusion

The results of this study support the hypotheses that there are reduced COVID-19 deaths in malaria endemic countries, although the results need to be proved further by clinical trials.
Physical activity and sedentary behaviors (screen time and homework) among overweight or obese adolescents: a cross-sectional observational study in Yazd, Iran
Authors: Hadianfard Ali Mohammad , Mozaffari-Khosravi Hassan , Karandish Majid , Azhdari Maryam
Published: September 2021

Background

The growing number of adolescents who are overweight or obese (OW / OB) is a public concern. The present study was aimed to evaluate physical activity (PA) and sedentary behaviors (SB) (screen time (ST) and homework time (HT)) among Yazd OW/OB adolescents.

Methods

This cross-sectional study was performed among 510 students aged 12-16 in Yazd, Iran. The general information, PA, and SB (ST and HT) were collected by interview based on the WHO standard questionnaire. Anthropometric data were assessed by precise instruments. Daily energy intake (Energy) was obtained from a 7-day food record. Nutritionist 4 software (version I) was run to estimate the energy.

Results

There was a high prevalence of SB > 2h/day (97.6), ST > 2h/day (70.3%), overweight or obesity (40%), abdominal obesity (36.9%), physical inactivity (29.8%) among the students. The younger age (p = 0.014), energy (p < 0.001), no access to the yard (p < 0.001), family size ≤ 2 (p = 0.023), passive transportation, (p = 0.001), the highest school days’ HT (p = 0.033) and SB (p = 0.021), and the highest weekends’ HT among the students were the risk factors for OW/OB. The highest PA level was associated with a lower risk of OW/OB (p < 0.001). The findings were not the same in both sexes. Compared to the normal weight students, OW / OB spent more time on school days and weekdays for ST (P <0.001), HT (P <0.001, P = 0.005) and SB (P <0.001), respectively. OW/OB students showed a higher weekends’ ST (p < 0.001) and lower HT (p = 0.048) than normal-weight students.

Conclusion

The prevalence of SB, ST, OW/OB, and physical inactivity were common. The school days and weekends’ HT, the school days’ SB and HT, age, energy, PA, and access to the yard, family size, and passive transportation were related to the greater chances of OW/OB students. Given that the expansion of online education and self-isolation in a new situation with COVID-19, it seems we will meet the worrying results.
Factor structure and measurement invariance of the Chinese version of the Center for Epidemiological Studies Depression (CES-D) scale among undergraduates and clinical patients
Authors: Niu Lishui , He Jiayue , Cheng Chang , Yi Jinyao , Wang Xiang , Yao Shuqiao
Published: September 2021

Background

The Center for Epidemiologic Studies Depression scale (CESD) was widely used for screening of depressive symptoms. The purpose of the current study was to investigate the factor structure and measurement invariance of the CESD across genders and groups in a sample of Chinese undergraduates and clinical patients.

Methods

Participants included 3093 undergraduates from the Hunan province and 336 patients from psychological clinics. The structure of the CESD scale was analyzed by confirmatory factor analysis (CFA). Multiple sets of CFAs were used to test measurement invariance across genders among undergraduates and clinical patients. Internal consistency reliability was also evaluated.

Results

The five-factor model achieved satisfactory fit (in the undergraduate sample: WLSMVχ2 = 1662.385, df = 160, CFI = 0.973, TLI = 0.968, RMSEA = 0.055; in the clinical patients: WLSMVχ2 = 502.089, df = 160, CFI = 0.962, TLI = 0.955, RMSEA = 0.072). The measurement invariance of the five-factor model across genders was supported fully assuming different degrees of invariance. The CESD also showed acceptable internal consistency.

Conclusion

Due to its sound structure and measurement invariance, the five-factor model of the CESD is best suited for testing in Chinese mainland college students and clinical patients.