bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of annealing atmosphere on the structure and spectral properties of GdScO3 and Yb:GdScO3 crystals
Authors: Li Jia-Hong , Sun Gui-Hua , Zhang Qing-Li , Wang Xiao-Fei , Zhang De-Ming , Liu Wen-Peng , Gao Jin-Yun , Zheng Li-Li , Han Song , Chen Zhao , Yin Shao-Tang ,   The Key Laboratory of Photonic Devices and Materials, Anhui Province, Anhui Institute of Optics and Fine Mechanics, Hefei institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031,  China,   University of Science and Technology of China, Hefei 230026, China,   Advanced Laser Technology Laboratory of Anhui Province, Hefei 230031, China
Published: May 2022

GdScO3 and Yb:GdScO3 single crystals are grown by the chzochralski method in nitrogen atmosphere, and they are characterized by X-ray diffraction(XRD), Raman spectra and transmission spectra . Their lattice parameters, atomic coordinates and temperature factors are determined by Rietveld refinement. It is found that the cell volume of GdScO3 and Yb:GdScO3 annealed in air atmosphere increase, but after these sample are annealed in H2 atmosphere their cell volumes decrease. Based on these results, we demonstrate that the crystal grown in nitrogen atmosphere has interstitial oxygen atoms, and the number of interstitial oxygen atoms in the sample annealed in air atmosphere increases, but that annealed in H2 atmosphere decreases. The Raman peaks of 155 cm–1, 298 cm–1, 351 cm–1 of GdScO3 are weakened or even disappear when Yb3+ ions are doped into it. The Raman spectra of the Yb:GdScO3 unannealed and annealed in H2 and air atmosphere are nearly consistent with each other, which indicates that Raman spectrum is insensitive to the defects such as oxygen interstitial caused by annealing. It is suggested that the optical loss of GdScO3 in the visible wavelength originates mainly from the defect energy level absorption of oxygen interstitial, and transmissivity of Yb:GdScO3 increases when it is annealed in hydrogen atmosphere, which results from the fact that ytterbium ion can reduce some interstitial oxygen atoms. When GdScO3 and Yb:GdScO3 are annealed in air or hydrogen atmosphere, the optical absorption loss of GdScO3 and Yb:GdScO3 in a wavelength range of 1000–3000 nm increase due to the trap level produced near the conduction or valence band. The effect on structure and spectral properties of Yb:GdScO3 and GdScO3 are explored preliminarily, which is useful for further studying and optimizing laser performance of rare earth doped GdScO3 crystal.
Growth of monolayer MoS2 films dual-assisted by NaCl
Authors: Wang Fen-Tao , Fan Teng , Zhang Shi-Xiong , Sun Zhen-Hao , Fu Lei , Jia Wei , Shen Bo , Tang Ning ,   Key Laboratory of Interface Science and Engineering for Advanced Materials, Ministry of Education, Taiyuan University of Technology, Taiyuan 030024, China,   State Key Laboratory of Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871, China
Published: May 2022

In recent years, transition metal dichalcogenides materials represented by monolayer molybdenum disulfide (MoS2) have aroused great interest due to their excellent optical and electrical properties. The synthesis method of high-quality monolayer MoS2 film is a key problem for scientific research and industrial application. Recently, researchers have proposed a salt-assisted chemical vapor deposition method for growing the monolayer films, which greatly promotes the growth rate and quality of monolayer film. By using this method, we design a growth source of semi-enclosed quartz boat, and successfully obtain high-quality monolayer MoS2 films by using the double auxiliary action of sodium chloride (NaCl). Scanning electron microscopy shows the excellent film formation, and the photoluminescence spectra show that the luminescence intensity is significantly higher than that of the sample grown without NaCl. The NaCl double-assisted growth method proposed in this study can reduce the growth temperature of MoS2, shorten the growth time, and improve the optical properties of the films. Besides, the operation is simple and the cost is low, which provides an idea for growing the large-scale two-dimensional materials.
Influence of interface kinetics parameters on the overall fluctuation instability of the interface morphology of deep cell crystal
Authors: Niu Di , Jiang Han ,   School of Mathematics & Computing Science, Guilin University of Electronic Technology, Guilin 541004, China
Published: May 2022

The effect of interface kinetics on the stability of deep cell morphology in directional solidification is studied. By using the multiple variable method and the matching asymptotic methodandby finding the mode solution of the system,the dispersion relation satisfied by the change rate of the disturbance amplitude of the cell-crystal interface is derived , and the quantization condition of the interface morphology is obtained. The results show that there are two global instability mechanisms in the directional solidification system with considering the growth of deep cell crystal with interfacial dynamic parameters : global oscillation instability mechanism and low-frequency instability. The stability analysis shows that the interface stability parameter \begin{document}$\mathrm{\varepsilon }$\end{document}is related to the cell relative parameter \begin{document}$ {\mathrm{\lambda }}_{0} $\end{document}, and thatthe larger the interface dynamic parameter \begin{document}$ {M}_{\text{*}} $\end{document}, the larger the stable region of the overall fluctuation instability of the dendrite structure in the overall oscillation modeis.
Progress of defect and defect passivation in perovskite solar cells
Authors: Wang Cheng-Lin , Zhang Zuo-Lin , Zhu Yun-Fei , Zhao Xue-Fan , Song Hong-Wei , Chen Cong ,   State Key Laboratory of Reliability and Intelligence of Electrical Equipment, School of Materials Science and Engineering, Hebei University of Technology, Tianjin 300130, China,   State Key Laboratory on Integrated Optoelectronics, College of Electronic Science & Engineering, Jilin University, Changchun 130012, China
Published: May 2022

Research on perovskite solar cells is prevalent because of their excellent photovoltaic performance. Most of the perovskite films are prepared by polycrystalline perovskite films and low-temperature solution method, thus inevitably creating a high density of defects, including point defects and extended defects. These defects can also be divided into two types: shallow-level defects and deep-level defects. The multiple types of defects are the main cause of nonradiative recombination, which will limit the enhancement of photovoltaic properties and stability of solar cell devices. In this paper, we review the latest advances in defect passivation and describe in detail the mechanisms of different methods to passivate defects at the surface and interface of perovskite films to reduce nonradiative recombination. We also summarize the research results about the defect passivation to reduce the deep energy level traps by Lewis acid and base, anion and cation, and the results about the conversion of defects into wide band gap materials as well. The effects of various strategies to modulate the mechanism of passivation of perovskite surface/interface defects are also elaborated. In addition, we discuss the intrinsic link between crystal defects and device stability, and provide an outlook on the feasibility of defect passivation strategies in future research.
Effect of inserted AlxGa1–xN layer on characteristic of double-channel n-Al0.3Ga0.7N/GaN/i-AlxGa1–xN/GaN HEMT
Authors: Cai Jing , Yao Ruo-He , Geng Kui-Wei ,   School of Microelectronics, South China University of Technology, Guangzhou 510640, China,   Sino-Singapore International Joint Research Institute, Guangzhou 510700, China
Published: May 2022

With the demand for high-temperature, high-frequency, and high-power microwave applications increasing, AlGaN/GaN high electron mobility transistors (HEMT) have attracted much attention in recent years. Two-dimensional electron gas (2DEG) induced by spontaneous polarization and piezoelectric polarization caused by the uneven charge distribution on Ga-N bond and the large tensile strain guarantees the high performance of AlGaN/GaN HEMT. Compared with single-channel devices, dual-channel AlGaN/GaN HEMT has great application prospects in enhancing the electronic confinement, current drive and alleviating the current collapse. In order to study the physical characteristics, the carrier state and transportation characterization of n-Al0.3Ga0.7N/GaN/i-AlxGa1–xN/GaN multilayer structure are investigated. By calculating the one-dimensional self-consistent Poisson-Schrödinger, the energy band diagram, electric field and charge distribution in the devices are obtained. The 2DEG, alloy disorder and dislocation scattering mechanism in the device are also analyzed by analytical models in which the wave function in finite barriers and Fermi’s rule are used.

With AlxGa1–xN layer thickness increasing from 0 nm to 30 nm and Al content rising from 0.1 to 0.2, the concentration of 2DEG localized in the heterointerface is diminished in the first channel. Simultaneously, mobility limited by alloy disorder scattering increases monotonically with the r composition occupation number and the AlxGa1–xN thickness proportion increasing. Besides, dislocation scattering on carriers is strengthened in the same quantum well, resulting in the lower mobility. In the second channel, 2DEG density gets growing when the variables mentioned above is enlarged. The mobility restricted by alloy disorder scattering shows a reverse trend with the variation of the AlxGa1–xN thickness and Al fraction, which more greatly affect the carriers in the parasitic channel due to the lower barrier height and high permeable carriers. Furthermore, the effect of dislocation scattering on channel electrons is gradually weakened, resulting in an increasing mobility. In general, The dislocation scattering effect in the second channel is intenser than that in the first channel.
Effect of Pr80Cu20 grain boundary addition on microstructure and magnetic properties of (Pr, Nd, Dy)32.2Co13Cu0.4FebalB0.98M1.05 magnet
Authors: Zhang Jia-Teng , Xu Ji-Yuan , Jin Jia-Ying , Meng Rui-Yang , Dong Sheng-Zhi ,   Division of Functional Materials, Central Iron & Steel Research Institute, Beijing 100081, China,   School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, China
Published: May 2022

With the aim of increasing Cu concentration to regulate the distribution of Co elements in RE-rich phase, the low-melting-point Pr80Cu20 intergranular alloy is introduced into the (Pr, Nd, Dy)32.2Co13Cu0.4FebalB0.98M1.05 (M = Al, Ga, Zr) magnet. Comparing with the original magnet, the remanence of PrCu-doped magnet is basically unchanged, and the coercivity is increased by approximately 1.3 kOe. Simultaneously, the Curie temperature, remanence temperature coefficient and irreversible flux loss are slightly improved. Microstructural study reveals that the Co-lean phase and the Co-rich phase coexist in the grain boundary in the 2nd-annealed original magnet. However, for the PrCu-doped magnet, the uniform distribution of Cu and Co elements in the intergranular phase are evidently improved, resulting in the elimination of the Co-rich phase. Since the R2(Fe, Co)17 (R = Pr, Nd, Dy) soft magnetic phase easily coexist with the Co-rich phase and are detrimental to the coercivity, the elimination of Co-rich intergranular phase may be an important reason for the higher coercivity of the 2nd-annealed PrCu-doped magnet than that of the original magnet.
Effect of flow rate of shielding gas on distribution of particles in coaxial double-tube helium atmospheric pressure plasma jet
Authors: Chen Zhong-Qi , Zhong An , Dai Dong , Ning Wen-Jun ,   School of Electric Power, South China University of Technology, Guangzhou 510641, China,   College of Electrical Engineering, Sichuan University, Chengdu 610065, China
Published: May 2022

In the application of atmospheric pressure plasma jet, the influence of ambient gas cannot be ignored, especially in some specific scenarios which are highly sensitive to ambient particles. Coaxial double-tube plasma jet device is a promising method of controlling the chemical properties of jet effluent by restraining the mutual diffusion between jet effluent and ambient gas. In this work, the discharge characteristics and chemical properties of coaxial double-tube helium atmospheric pressure plasma jet at different flow rates of shielding gas are studied numerically, and the model is validated by experimental optical images. The results illustrate the enhanced discharge at the high flow rate, the weaker discharge at the low flow rate, and discharge behaviors without shielding gas as well. With the increase of shielded gas flow rate, the particle density increases in the discharge space, which can be attributed to the wider main discharge channel caused by the increase of shielding gas flow rate. In addition, the analysis shows the great difference in ion fluxes affected by the flow rate of the SG between the contour lines of different helium mole fractions. This study further reveals that different discharge positions have a great influence on the generation of nitrogen and oxygen particles, thus deepening the understanding of influence of shielding gas flow rate on discharge behavior, and may open up new opportunities for the further application of plasma jet.
Generation of four-mode cluster states based on cascade four-wave mixing process
Authors: Dong An-Qi , Zhang Kai , Jing Jie-Tai , Liu Wu-Ming ,   State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, China,   Center for Excellence in Ultra-intense Laser Science, CAS, Shanghai 201800, China,   Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan 030006, China,   Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China,   School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China,   Songshan Lake Materials Laboratory, Dongguan 523808, China
Published: May 2022

As a crucial quantum resource for quantum computing and quantum information processing, cluster state has attracted extensive attention due to its unique entanglement properties and rich structures. In this work, we theoretically propose a scheme for generating four-mode entangled states based on cascaded four-wave mixing (FWM) process. The internal entanglement characteristics are studied by using the positivity under partial transposition criterion and eigenmode decomposition. In addition, the output entangled states are reconstructed and optimized by adjusting the relative phase of balanced homodyne detection and postprocessing the signal noise, and finally three four-mode cluster states with different structures are generated. Such a method can effectively reduce the excess noise induced by finite squeezing. Our theoretical results provide a reliable way of generating scalable continuous variable cluster states based on FWM process in atomic ensemble.
High-precision co-phase method for segments based on a convolutional neural network
Authors: Zhao Wei-Rui , Wang Hao , Zhang Lu , Zhao Yue-Jin , Chu Chun-Yan ,   School of Optics and Photonics, Beijing Institute of Technology, Beijing 100081, China,   Beijing Key Laboratory for Precision Optoelectronic Measurement Instrument and Technology, Beijing 100081, China
Published: May 2022

In order to achieve the resolution comparable to the resolution of a monolithic primary mirror telescope and make the imaging quality of the imaging system reach or approach to the diffraction limit, the submirrors of the segments telescope should ensure co-phase splicing. To solve the problem of phase error detection, a high-precision piston error detection method is proposed based on convolutional neural network (CNN). By setting a mask with a sparse multi-subpupil configuration on the exit pupil of the imaging system, a point spread function (PSF) image dataset that is extremely sensitive to the piston error is constructed. According to the characteristics of this dataset, a high-performance CNN model is built. And the best detection range of CNN is tested. The simulation results show that a single network can accurately output the piston error of one or more submirrors in the capture range slightly less than one wavelength. When the single network is applied to the six-submirror imaging system, the detection precision of the piston error reaches an RMS value of 0.0013λ (here, RMS stands for root mean square). And the method has good robustness to residual tip-tilt error, wavefront aberration, and CCD noise, light source bandwidth. The method is simple and fast, and can be widely used to detect the piston error of the segments.
Effect of surface modification of metallic nanorod on spontaneous emission enhancement
Authors: Su Yu-Feng , Peng Jin-Zhang , Yang Hong , Huang Yong-Gang ,   College of Physics and Electromechanical Engineering, Jishou University, Jishou 416000, China
Published: May 2022

Metal nanorods show excellent optical properties, since the plasmonic resonance frequency can be tuned by its aspect ratio and the optical field can be confined within a region of subwavelength, even within a nanometer region. It has the ability to flexibly modify the spontaneous emission properties of a nearby quantum emitter. However, it is unclear how the emission property changes when the metal nanorod has been deposited at the tips or coated on all sides with metal. In this work, the spontaneous emission enhancements of a two-level atom around a tailored nanorod with a wide variety of shapes, dimensions or materials are systematically investigated by the finite element method. Three different optical response models are adopted, including the classical local response approximation (LRA), the nonlocal hydrodynamic model (HDM), and the generalized nonlocal optical response model (GNOR). For a cylindrical nanorod with two endcaps, it is found that the resonance frequency shows large redshift and the emission enhancement peak increases as the endcap gradually changes from cone to cylinder of the same height. The resonance frequency shows small blueshift and the emission enhancement peak decreases slightly as the deposited metal of the conical endcaps changes from gold to silver. However, as the material of the cylinder also changes from gold to silver, becoming an all-silver nanostructure, an obvious blueshift can be detected at the resonance frequency and the emission enhancement peak rises sharply. For bimetal core-shell nanostructure, the shell can screen the surface plasmon of the core from being excited, and the plasmonic resonance associated with shell increases in proportion to the thickness of the shell. The emission enhancement peak for gold nanostructure appears to be blue-shifted when coated with silver. In contrast, it is red-shifted for silver nanostructure coated with gold.
Phase regulation of lightwave transmission in inhomogeneous atmospheric medium using plane acoustic field
Authors: Wang Ming-Jun , Wang Wan-Rou , Li Yong-Jun ,   School of Automation and Information Engineering, Xi’an University of Technology, Xi’an 710048, China
Published: May 2022

Based on the acousto-optic effect and the Gladstone–Dale relationship, the relationship about variations of the refractive index of the isotropic homogeneous atmospheric medium and the inhomogeneous atmospheric medium with the sound pressure under the disturbance of the plane sound field is derived. Models for the transmission of plane light waves and Laguerre-Gaussian beams through homogeneous atmospheric medium and inhomogeneous atmospheric medium disturbed by plane acoustic waves are established. The results show that the refractive index distribution of the homogeneous atmospheric medium exhibits a homogeneous periodic distribution after being disturbed by the plane sound field. For large-scale angles of longitudinal variation of atmospheric pressure, the plane sound field has little effect on the distribution of the refractive index of the inhomogeneous atmosphere. For small-scale angles, the inhomogeneous atmospheric refractive index gradually decreases with height and fluctuates with the influence of sound pressure. When the plane acoustic wave disturbs the homogeneous atmospheric medium, the isophase plane of the plane light wave will fluctuate significantly due to the influence of the acoustic wave. The phase of the LG beam rotates and always returns to the original phase. When the plane acoustic wave disturbs the inhomogeneous atmospheric medium, the phase change of the plane light wave will change periodically with the change law of the sound wave. The overall optical path is an inclined plane, but due to the disturbance of the sound wave, the optical path will fluctuate. The phase of the LG beam still rotates, but unlike the homogeneous medium, its phase does not return to its original phase due to the change of its refractive index with height.
Properties of Photoluminescence and mechanoluminescence of KxNa1–xNbO3:Pr3+ ferroelectric
Authors: Liang Ai-Hua , Wang Xu-Sheng , Li Guo-Rong , Zheng Liao-Ying , Jiang Xiang-Ping , Hu Rui ,   Key Laboratory of Inorganic Functional Materials and Devices, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China,   Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China,   Jiangxi Key Laboratory of Advanced Ceramic Materials, School of Materials Science and Engineering, Jingdezhen Ceramic University, Jingdezhen 333403, China,   Functional Materials Research Laboratory, School of Materials Science and Engineering, Tongji University, Shanghai 201804, China
Published: May 2022

Mechanoluminescent (ML) materials have mechanical-light conversion properties and can generate luminescence under mechanical stress, which makes the ML materials have high application value in optical information display. In this work, the crystal structure and defect distribution are adjusted by changing the K+/Na+ ratio of the ferroelectric matrix KxNa1–xNbO3∶0.5%Pr3+ (KxNNOP), and the effects of K+ content on the photoluminescence (PL) and ML properties are systematically investigated. The research results indicate that as the K+ content increases, the symmetry of the crystal is enhanced, leading the PL intensity of the KxNNOP samples to decrease. It is worth noting that the emission peaks caused by the 3P1→3H5 and 3P0→3H5 transition at the Pr3+ electron level appear in the PL spectra of the components with higher K+ content under the light excitation of 450 nm, which is attributed to the different energy level positions of the internal valence electron charge transfer states within Pr-O-Nb, caused by the change in the distance between Pr3+ and Nb5+. Under the compressive stress, the KxNNOP (x = 0, 0.01, 0.02, 0.1) components exhibit the bright red ML, and the ML intensity increases with the K+ content increasing. The K0.1NNOP component exhibits the highest ML intensity emission. In particular, the ML behavior has the characteristics of repeatability and recoverability. The trap energy levels in the KxNNOP samples are investigated by thermoluminescence curves, revealing that the enhancement of ML in K0.1NNOP may be related to the differences in trap density and trap depth, caused by changes in K+ content. Based on these results, a model is established to elucidate the possible ML mechanism in KxNNOP.
Laser parameters requirement for third-generation ground-based gravitational wave detection
Authors: Li Qing-Hui , Li Wei , Sun Yu , Wang Ya-Jun , Tian Long , Chen Li-Rong , Zhang Peng-Fei , Zheng Yao-Hui ,   State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Opto-Electronics, Shanxi University, Taiyuan 030006, China,   Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan 030006, China,   School of Physical and Electronic Engineering, Shanxi University, Taiyuan 030006, China
Published: May 2022

Gravitational waves (GWs), predicted by the general relativity of Albert Einstein, are ripples in space-time caused by massive accelerating objects. Since the first direct observation of GWs in 2015, more and more binary black hole mergers and neutron star merger were detected by the laser interferometer gravitational-wave observatory (LIGO) and the Virgo interferometric detector. The construction of the third-generation (3G) gravitational wave detector(GWD), whose sensitivity is ten times that of the second-generation (2G) GWD (Advanced LIGO and Virgo), can not only push the gravitational wave astronomy towards the edge of the observable universe, but also test the fundamental laws of physics and study the nature of matter. By utilizing the abandoned underground mines, Shanxi university proposes to construct a 3G ground-based gravitational wave detector with an arm length of 10 km and a strain sensitivity of 10–24 Hz–1/2, improving the location accuracy of wave source by participating in the global GWD network. The construction of 3G GWD has many technical challenges, including ultrahigh large-scale vacuum system, ultrastable seismic isolation system, high-precision control system, high-quality laser and quantum source. Theoretically, the sensitivity of GWD with equal arm length is not limited by the laser source noise. However, in the actual scenario, the sensitivity is limited by the differences in arm length, arm cavity linewidth, arm reflectivity, arm mass, arm power, and the laser parameters. In this work, based on the design sensitivity (10–24 Hz–1/2) of dual-recycled Fabry-Perot Michelson interferometer, we propose the requirements for an ultra low-noise laser, including wavelength, amplitude noise, frequency noise, beam pointing noise and fundamental mode purity. The results show that in order to achieve the design sensitivity at the Fourier frequency of 100 Hz, the wavelength of the laser source should be 1.5 μm, the output power should be higher than 200 W, the amplitude noise should be better than 10–8 Hz–1/2, and the frequency noise should be better than 100 Hz/Hz1/2. To achieve the sensitivity of 10–24 Hz–1/2 at 10 Hz analysis frequency, the requirements for the amplitude and frequency noise of the laser source are much more stringent. This study lays a solid foundation for the analysis of laser source noise and the decomposition of interferometer indexes .
Analysis and implementation of simple four-dimensional memristive chaotic system with infinite coexisting attractors
Authors: Qin Ming-Hong , Lai Qiang , Wu Yong-Hong ,   ECJTU Tianyou College, East China Jiaotong University, Nanchang 330013, China,   School of Electrical and Automation Engineering, East China Jiaotong University, Nanchang 330013, China,   School of Science, Wuhan University of Technology, Wuhan 430074, China
Published: May 2022

Using memristors to construct special chaotic systems is highly interesting and meaningful. A simple four-dimensional memristive chaotic system with an infinite number of coexisting attractors is proposed in this paper, which has a relatively simple form but demonstrates complex dynamical behavior. Here, we use digital simulations to further investigate the system and utilize the bifurcation diagrams to describe the evolution of the dynamical behavior of the system with the influence of parameters. We find that the system can generate an abundance of chaotic and periodic attractors under different parameters. The amplitudes of the oscillations of the state variables of the system are closely dependent on the initial values. In addition, the experimental results of the circuit are consistent with the digital simulations, proving the existence and feasibility of this memristive chaotic system.
Giant coercivity in single crystal Ta3FeS6 film
Authors: Liu Xiao-Wei , Xiong Jun-Lin , Wang Li-Zheng , Liang Shi-Jun , Cheng Bin , Miao Feng ,   School of Physics, Nanjing University, Nanjing 210093, China,   Institute of Interdisciplinary Physical Sciences, School of Science, Nanjing University of Science and Technology, Nanjing 210094, China
Published: May 2022

Van der Waals (vdW) layered ferromagnetic materials provide a unique platform for fundamental spintronic research, and have broad application prospects in the next-generation spintronic devices. In this study, we synthesize high-quality single crystals of vdW intrinsic ferromagnet Ta3FeS6 by the chemical vapor transport method. We obtain thin layer samples of Ta3FeS6 with thickness values ranging from 19 to 100 nm by the mechanical exfoliation method, and find that their corresponding Curie temperatures are between 176 and 133 K. The anomalous Hall measurement shows that the Ta3FeS6 has out-of-plane ferromagnetism with the coercivity reaching 7.6 T at 1.5 K, which is the largest value in those of the layered vdW ferromagnetic materials reported so far. In addition, we observe that the reversal polarity of the hysteresis loop changes sign with temperature increasing. Our work provides an opportunity to construct stable and miniaturized spintronic devices and present a new platform for studying spintronics based on van der Waals magnetic materials.
Labial Agglutination in Different Age Groups: A Case Series
Authors: Mitra Sukumar , Banerjee Damayanti , Chakrabarty Debdatta , Das Seema
Published: May 2022

Labial adhesion or agglutination is varying degree of apposition between the labia minora which may be complete or partial. Here, a case series of five patients of different age groups ranging from toddler, prepubertal, postpartum and postmenopausal age groups were included. Most often, labial adhesions are encountered in prepubertal age group due to hypoestrogenic state. Parents most often diagnose incidentally while changing diapers. Similar hypoestrogenic environment encountered in postmenopausal state where in addition to apposition, women have co-existent genitourinary symptoms for which they seek care. Old people may be delayed in seeking care due to uncertainty. Labial adhesions among reproductive age group are quite rare. Most of the case has a past history of trauma which was not adequately managed and the agglutination developed as a remote complication. All the five patients were managed as per the severity of adhesions. Treatment included from conservative approach of oestrogen cream application to surgical adhesiolysis.
Diagnostic Accuracy of Rapid Antigen Test for COVID-19 Infection: A Retrospective Analysis
Authors: Chauhan Dhwani N , Verma Shambhavi , Jadhav Kishor V , Kumar M Kiran , Chauhan Naresh T , Kavishvar Abhay B , Kosambiya Jayesh K
Published: May 2022

Introduction: For the diagnosis of Coronavirus Disease 2019 (COVID-19) disease, Real-Time Reverse Transcriptase-Polymerase Chain Reaction (RT-PCR) is a laboratory-based technique and is considered a gold standard test, but is time consuming. A Rapid Antigen Test (RAT) is used for screening which is an immunoassay that identifies the presence of a viral antigen causing infection at the point of care. The RAT is quick, inexpensive, easily accessible and doesn’t need lab handling or sample preprocessing. Aim: To measure the sensitivity, specificity, Negative Predictive Value (NPV) and Positive Predictive Value (PPV) of RAT in comparison to RT-PCR. Materials and Methods: This retrospective study was conducted in Department of Community Medicine at Government Medical College (tertiary care centre), Surat, Gujarat, India, using secondary data from 1st July 2020 to 5th Dec 2020. The samples were collected from all the patients of Acute Respiratory Illness (ARI), Severe Acute Respiratory Illness (SARI), Influenza Like Illness (ILI), the suspected COVID-19 cases and all walk in patients for testing or treatment purposes. A total of 264 participants enrolled in the study underwent both the RAT and RT-PCR tests. The sensitivity, specificity, Positive Predictive Value (PPV) and Negative Predictive Value (NPV) were calculated using MS Excel Statistical Package for the Social Sciences (SPSS) version 17.0. Results: Total 264 cases were analysed, amongst which 161 (60.9%) were males and 103 (39.1%) were females and the mean age of the patient was 41.6 years and 36.8 years for males and females, respectively. The overall sensitivity was 52.47%, specificity was 87.11%, PPV was 71.62% and the NPV was 74.73%. While among symptomatic patients sensitivity was 55.55%, specificity was 88.54%, PPV was 76.97% and NPV was 74.35%. Conclusion: Because of the low sensitivity of the RAT, if used alone a high number of false negative cases will be resulted. Hence, it is employed in community and clinical settings as sequential screening in conjunction with RT-PCR, which results in improved net gain and aids in disease transmission control.
Macular Thickness- An Early Predictor of Diabetic Macular Oedema
Authors: Sareddy Chandrika , Nagpal Shubha , Muzumdar Deepa
Published: May 2022

Introduction: Diabetic Macular Oedema (DME) accounts for visual morbidity in about three fourth of Diabetic Retinopathy (DR) patients. Traditional examination on 90D slit lamp or stereoscopic fundus photograph may not be able to identify early maculopathy. Optical Coherence Tomography (OCT) is a sensitive, non invasive modality which may detect early retinal thickness changes in DME. Aim: To identify any increase in macular thickness in diabetic patients with early DR without any clinically detectable macular oedema. Materials and Methods: This cross-sectional analytical study was conducted from September 2018 to July 2020 in the Ophthalmology Department at Bharati Vidyapeeth Medical College and Hospital, Pune, Maharashtra, India. A total of 277 eyes of 184 subjects were evaluated. Of these 182 eyes were of diabetic patients (124 patients) and 95 eyes belonged to controls (60 subjects). Amongst the diabetic eyes evaluated, group I consisted of 100 eyes with no evidence of DR and group II consisted of 82 eyes with mild Non Proliferative Diabetic Retinopathy (NPDR). Group III included 95 eyes of non diabetic age matched controls. Macular thickness was measured using the Topcon 3D OCT-1 Maestro System. The central 1mm macular thickness of the three groups was analysed and compared using student's t-test. Results: The mean Central Macular Thickness (CMT) showed no statistically significant difference (p-value<0.7) between group III (222.4±10.8) and group I (223.0±13.7 μm). However, a significant increase in CMT (p-value<0.0001 and, p-value<0.0006) was noted in group II (230.7±15.6 μm) when compared with group III (222.4±10.8 μm) and group I (223.0±13.7 μm). Macular thickness amounting to Subclinical Macular Oedema (SCME) was seen in only in 6.09% of eyes in group II, five eyes of the total number of 82 eyes with mild NPDR. Conclusion: Increased CMT was detected in mild NPDR patients on Optical Coherence Topography (OCT) even without any clinical evidence of macular oedema. Since eyes with SCME, diagnosed at base line assessment, are at a higher risk of developing clinical macular oedema subsequently, it is recommend that a base line OCT be performed in all patients detected to have mild NPDR irrespective of the absence of clinical findings suggestive of DME.
Virtual Events in the Post-COVID-19 Pandemic Era in Medical Profession: A Narrative Review
Authors: Gupta Amit , Chenatt Jaine John , Singla Tanuj , Rajput Deepak , Gupta Sweety
Published: May 2022

The Coronavirus Disease 2019 (COVID-19) pandemic wreaked havoc on almost all aspects of life and has undeniably altered the landscape of the world forever. In the medical profession, everything from education to scheduling operations was affected. Educational events such as conferences, Continuing Medical Education (CME) and other events had to be converted into virtual conferences and meetings. However, now that the pandemic is slowly coming to an end and countries and borders have started to reopen, the question now remains- should we go back to our old ways or has this become the new normal? This review discusses the advantages and limitations of conducting virtual events and discusses future trends of holding such events in these uncertain times.
A Cross-sectional Study on Adherence to Personal Protective Equipment among Healthcare Workers during COVID-19 Pandemic in a Tertiary Care Centre, Tamil Nadu, India
Authors: Purushotham R , Raja, Veena , Javeedh SPJ Salim , Ramamurthy Balaji Ramraj , Ramamurthy Bhuvanamha Devi
Published: May 2022

Introduction: Personal Protective Equipment (PPE) provides physical barrier against hazardous injury or infectious agents. With the outbreak of COVID-19 pandemic, PPE plays a vital role with face mask and gloves are being most essential. The frontline Healthcare Workers (HCW) utilizes them to minimize the risk of contaminated contact or infected droplet exposure. Aim: To evaluate the appropriate use of personal protective equipment among healthcare workers in tertiary care hospital. Materials and Methods: This cross-sectional study was conducted in SRM Medical College Hospital and Research Centre, Potheri, Chengalpet district, Chennai, Tamil Nadu, India, from February 2021 to May 2021, on utility of PPE among the healthcare workers. There were a total of 273 participants including doctors, residents (postgraduate)/interns, nurses and laboratory technicians. A predesigned questionnaire was utilized to collect information, apart from observation of their PPE practice and 360 degree observation from peers were also used to evaluate. Statistical analysis was done using Chi-square test, Fisher’s-exact test and logistic regression model. Results: Among 273 HCWs, there were 58 (21.24%) doctors, 163 (59.71%) residents and interns, 19 (6.96%) nurses and 33 (12.09)% technicians. There was no association in the frequency of mask with the type of HCW (p-value=0.217). However, the usage frequency of gloves (p-value=0.003), face shield/goggles (p-value=0.004), disposable gown (p-value=0.001) and doffing according to protocol (p-value=0.001) showed statistically significant difference between the category of HCWs. Conclusion: In this study, PPE adherence was high among HCW; however, there was a subtle difference in compliance across the varied groups of healthcare professional and type of PPE used. The PPE compliance among HCW cannot be assumed to be good blindly; frequent official training programs, availability of PPE logistics along with scrutinization regarding its appropriate usage and discarding at regular intervals minimizes the non compliance and also helps in curtaining the COVID-19 transmission.
Income and Employment Generation Activities among Farmer Beneficiaries through a Crop-based Module of Farmer First Programme
Authors: Maran Kapil , Dubey M. K. , Shrivastava Sanjana
Published: May 2022

This paper is concerned with analyzing the impact of the Farmer First Programme in generating the income and employment of the farmers through a crop-based module of the farmer first Programme in Balaghat district of Madhya Pradesh State, the Farmer First Programme (FFP) is a concept of  Indian Council of Agricultural Research (ICAR) where the farmer plays a centric role for research problem identification, prioritization, and conduct of experiments and its management at farmer’s conditions. Its focus is on Farmer's Farm, Innovations, Resources, Science, and Technology (FIRST). A sample of 129 farmers from the Lalbarra block of Balaghat district was purposively selected because it's having a maximum area under Farmer First Programme. A total of five modules are going on in the Lalbarra block. out of which only Crop Based Module was selected because it consists of a high number of Beneficiaries. The purpose of this research was to determine the impact of the Farmer FIRST programme on the farming community in terms of income and employment generation during 2020-21, for finding the research issue, Ex- post facto research design was used. We employed absolute changes for assessing the Impact of the Crop Based Module of the Farmer First Programme by gaining the additional income of individuals which were computed by ascertaining pre and post-income and employment generation of individuals through FFP. It may be concluded that there is a significant and positive difference found in income and employment generation among the farmers through Farmer First Programme.
Homobrassinolide on Growth, Minerals and Vitamins of Curcuma longa L. (Turmeric) Rhizome
Authors: Rajesh G. , Vardhini B. V.
Published: May 2022

The application of homobrassinolide on the growth, mineral content and vitamin content of Curcuma longa L. (turmeric) rhizome grown in Nizamabad, Telangana State, India was studied. Homobrassinolide application as foliar spray to turmeric on the 20th, 40th and 60th day from sowing resulted in enhanced growth of turmeric rhizome in terms of fresh and dry weights. The promotion of growth was associated with increased levels of minerals in terms of calcium (Ca), Manganese (Mn), potassium (K), phosphorus (P), copper (Cu), zinc (Zn) and iron (Fe) of turmeric rhizome. Further, the contents of Vitamin B fractions [Thiamine (Vitamin B1), Niacin (Vitamin B2), and Riboflavin (Vitamin B3)] and Vitamin C/Ascorbic Acid of the turmeric rhizome were also found enhanced indicating the ability of homobrassinolide in positively monitoring nutrient value in turmeric rhizome.
Assessment of the Effect of Ethanolic Leaf Extract of Lemon Grass (Cymbopogon citratus) on Lung Histology of Treated Wistar Rats
Authors: Obioma Nweke Elizabeth , Ugboaja Chijioke, I. , U. Ogwo, E. , Miracle Nweke Tochukwu
Published: May 2022

The aim of this study was to evaluate the effect of ethanolic leaf extract of lemongrass on body lung histology of treated wistar rats. Freshly harvested leaves of lemongrass were dried at room temperature and afterwards ground into fine powder. 250 g of powdered plant sample was suspended in 1000 mL of 95% ethanol for 72 hours and agitated thrice daily. The resulting extract was concentrated. Twenty adult male wistar rats were divided into four groups of five rats. Group I was the Normal Control, Group II was administered with 100 mg/kg b.w of ethanolic extract of lemongrass, Group III was administered with 300 mg/kg b.w of ethanolic extract of lemongrass, and Group IV was administered with 600 mg/kg b.w of ethanolic extract of lemongrass. Treatment lasted for 14 days after which subsequently sacrificed. The lungs were harvested for histological examination which was carried out using standard procedures. Oral administration of ethanolic leaf extract of lemongrass significantly (P<0.05) decreased body weight of treated rats compared to their untreated counterpart. The histopathological report showed a mild to moderate congestion of blood vessels and inflammatory cells around the bronchioles in the treated groups when compared to control. In conclusion, it can be deduced from this study that extract of lemongrass has the capacity to inflict harm to the lungs at high doses.
Measuring Tourists' Intention to use Digital Platform in Selecting Travel Products: A Study on Bangladesh
Authors: Halim Md. Abdul
Published: May 2022

The different digital platforms assist tourists to share and collect travel information which effects their purchasing and selection patterns. The prime intention of conducting this study was to measure tourists’ preference in using different digital technologies while they make their travel decisions. The study used a quantitative approach to gather data from Bangladeshi travelers through an online questionnaire called Google form. The non-probability convenience sampling method was used to select 246 individuals to conduct this study. The study was destined based on primary and secondary data collection methods. SPSS 26.0 was used to examine the data. The descriptive statistics were used to analyze the demographic features of the respondents, and Multiple Linear Regression and Pearson correlation were also used to support the association between the dependent and independent variables. R=.737 forecasted the variance of preferring digital technologies in selecting travel products with a goodness-of-fit level of roughly 54.3%. The digital platforms assist tourists to share and collect travel information (M=4.26) which affects their purchasing and selection patterns. The last travel plan patterns stated they usually research online (62%), mainly using/on the social media sites (41.10%), for travel information. The study highlighted the importance of these digital platforms among travelers and spotted the gap between the customer requirement and accessible digital sites for reservation and payment. So, viable and accessible payment methods should be implemented, emphasizing Bangladeshi tourists.
Tissue Specific Antioxidant Response of Cirrhinus mrigala (Hamilton, 1822) Exposed to Lead Chloride
Authors: Abbas Amna , Zahra Andleeb , Anwar Ammar , Roy Hafeez , Liaquat Umer , Khan Fatima , Ullah Kalleem , Saleem Sahar , Ghafoor Filza
Published: May 2022

In the present study, the effect of Lead chloride (PbCl2) on the peroxidase and catalase activity in the tissues (liver, kidney, gills and muscles) of Cirrhinus mrigala was studied. Cirrhinus mrigala were observed at sub-lethal concentrations viz. 1/3rd LC50 and 1/7th LC50 for 28 days. After chronic exposure fishes were dissected and sampling weekly. The activity of peroxidase enzyme was increased significantly (p<0.01) in experimental fish’s organs as compared to control group. Through metal stressed maximum peroxidase activity was found as 0.997±0.011 UmL-1, 0.676±0.016 UmL-1, 0.489±0.005 UmL-1 and 0.339±0.006 UmL-1 in liver, kidney, gills and muscles of fishes exposed to 1/3rd LC50 respectively. The catalase enzyme activity was decreased significantly in experimental fish organs as compared to control group. Minimum catalase enzyme activity was measured as 592.55±3.76 UmL-1, 577.32±8.64 UmL-1, 547.10±12.65 UmL-1   and 488.21± 28.57 UmL-1in the metal stressed liver, gills, kidney and muscles   respectively, in fishes exposed to 1/3rd LC50. Catalase activity was found significantly higher in the control fish.
Assessment of Population Abundance, Density and Habitat Preference of Sclater’s Guenon (Cercopithecus sclateri Pocock 1904) in Aboh-Mbaise Communal Forest, Imo State, Nigeria
Authors: Ovat O. I. , Tyowua B. T. , Orsar T. J.
Published: May 2022

Aims: We assessed the population abundance, density and habitat preference of sclater’s guenon (Cercopithecus sclateri) in Aboh-Mbaise communal forest to inform conservation efforts for the species now and in the future.

Study Design: We used the point count sampling method to estimate population size.

Place and duration of study: The study was carried out in Lagwa communal forest, Aboh-Mbaise Local Government Area, Imo State, between December 2019 and November 2021.

Methodology: We laid-out eight 2.5-km transects in a land area of 28,500km2. We enumerated and measured trees using the point-centered quarter method. 

Results: Results of this study indicated that they were 738 individual monkeys, 392 in dry and 346 in the wet seasons. The population density was 0.04 ± 0.01 individuals/km2, with troop sizes of 4.09±0.83 and 3.68 ± 0.75 for dry and wet seasons, respectively. The monkeys were sighted mostly in secondary forest, sacred groves, and economic trees. Most of the trees were within the diameter-at-breast-height class of 21cm-30 cm. A total of (304) plant species were used by the monkeys for cover in both seasons; these included Dacryodes edulis, Elaeis guinensis, Magnifera indica, Treculia africana and Pterocarpus erinaceous.

Conclusion: The findings of this research is a prelude to understanding the population dynamics and habitat structure of the sclater’s guenon in the study area. Massive sensitization of the locals, regeneration of the remaining fragmented habitat and establishment of a wildlife sanctuary are needed to allow conservation of the species and its habitat.