bluuebunny/crossref_metadata_2025 huggingface dataset:
Vibrational behavior of coated microbubble in finite tube under magneto-acoustic composite field
Authors: Shi Hui-Min , Hu Jing , Wang Cheng-Hui , Feng Fei-Long , Mo Run-Yang ,   Shaanxi Key Laboratory of Ultrasonics, Shaanxi Normal University, Xi’an 710119, China
Published: August 2021

The dynamic behavior of coated microbubble in a magneto-acoustic field is very significant for its application to therapy. In this paper, the radial vibration equation of microbubble is derived by placing the coated-microbubbles in a tube filled with magnetic fluid and considering the magnetic pressure on the magnetic fluid under the magneto-acoustic field. The dynamic equation is nondimensionalized by using characteristic quantities such as Weber number and Reynolds number. The effects of magnetic-acoustic field parameters and magnetofluid characteristics on the vibration behavior of the vibration system are analyzed by the Runge-Kutta method. The results show that the magnetic field can prevent the collapse and make bubble oscillate stably. When the acoustic field is constant, the magnetic field can stabilize the oscillation of the microbubble and increase the equilibrium radius of the oscillating microbubble. The stronger the magnetic field is, the more obvious the influence of magnetofluid magnetisability χm on the vibration of the microbubble is and the stronger the nonlinear of the transient response of the microbubble is when the magnetic field is larger. In addition, the larger acoustic field parameters will enhance the response of oscillating microbubble to magnetic field. The larger the magnetic field is, the weaker the influence of acoustic parameters on the oscillations of microbubble is. Also, the transient response of microbubble is obviously nonlinear, but the steady-state response keeps the reciprocating oscillation with small amplitude. It can be seen that the adjusting of the magneto-acoustic field is beneficial to realizing the stable oscillation of microbubble in the blood vessel and avoiding collapse.
Theoretical research of time-dependent density functional on initiated photo-dissociation of some typical energetic materials at excited state
Authors: Zhao Jia-Lin , Cheng Kai , Yu Xue-Ke , Zhao Ji-Jun , Su Yan ,   Key Laboratory of Materials Modification by Laser, Ion and Electron Beams (Dalian University of Technology), Ministry of Education, Dalian 116024, China,   School of Electronic Engineering, Xi’an University of Posts and Telecommunications, Xi’an 710121, China
Published: August 2021

Nitro explosive is a main type of energetic material which can release a large amount of energy when detonated under extreme conditions. Further study of the excited state dynamics of photo-induced nitro explosive can provide an effective method to understand the complex process of ultrafast detonation physics. In this paper, the initial step of photodissociation at the first excited electron state of some typical nitro explosives including nitromethane (NM), cyclotrimethylenetrinitramine (RDX) and triaminotrinitrobenzene (TATB) is studied using the time-dependent density functional theory and the molecular dynamic method. The transient structures of energetic molecules and time evolutions of excited energy levels are observed. It is found that the structural relaxation of energetic molecules occurs immediately after the electronic excitation, and the entire photoexcitation process comes into being within a range of 200 fs. At the same time, the positions of molecular energy levels change to various degrees with the oscillations of different frequencies, such as the overlap between HOMO and LUMO, which is related to the obvious change of molecular configuration, indicating that the energy of excited carriers transfers to atoms in the form of heat through electron-phonon coupling, and the energy is redistributed through vibration relaxation in the initial stage of photodissociation which causes the chemical bonds of C—H, N—N and N—N to rupture, and the hydrogen atoms dissociated from methyl, methylene or amino groups, and the nearest nitro group to form some new intermediate states. In this process, the energy levels near the excited electron and hole energy also change significantly with time, suggesting that the coupling between electron and electron also plays a role in the dissociation process. Comparing with NM and RDX, the evolution of the excited energy level of TATB has obvious lower-frequency (phonon frequency) oscillations, showing that the coupling between electronic state and phonon of TATB is weak and thus makes it more difficult to dissociate. Our study can deepen the understanding of the structural relaxation of excited states and the time evolution of excitation energy levels in energetic materials, and provide a new understanding of the photoinduced reaction and the initial steps of laser ignition in energetic materials.
Plasmon modes of fishnet metastructure and its trapping and control of light for thin film solar cells
Authors: Jiang Yue , Wang Shu-Ying , Wang Zhi-Ye , Zhou Hua , Ka Ma-Le , Zhao Song , Shen Xiang-Qian ,   Xinjiang Key Laboratory of Solid State Physics and Devices, School of Physical Science and Technology, Xinjiang University, Urumqi 830046, China,   School of Physics, Shandong University, Jinan 250100, China
Published: August 2021

The fishnet metastructure has plane, near-optical lossless characteristic, and can excite surface plasmons in a specific light field. It has great potential in enhancing the response efficiency of photonic devices. Based on the finite difference time domain method and rigorous coupled wave analysis, in this paper, we systematically study the plasmon resonance mode of the fishnet metastructure and its light wave regulation performance on the crystalline silicon thin film solar cells. The research results show that the characteristics of absorption, scattering and extinction for the fishnet structure strongly depend on the thickness, line width, period and other characteristic parameters of the metal layer. Through optimizing the design, the resonant peak is red-shifted to 770 nm, and the relative extinction cross-section reaches 1.69, and the scattered light occupies a dominant position in the extinction spectrum. The crystalline silicon thin film solar cell with a response layer thickness of 2 μm constructed in this way has a significantly enhanced absorption efficiency in the wavelength band greater than 800 nm, and the final energy conversion efficiency of the device increases from 6.67% to 8.25%. The light intensity distribution shows that the enhanced backscattering caused by resonance and the large-angle deflection of the photon propagation direction are important reasons for the response gain of the solar cell.
Frequency doubling of acousto-optic Q-switched Nd:YVO4 cascaded Raman laser for narrow pulse-width 657 nm laser
Authors: Duan Yan-Min , Zhou Yu-Ming , Sun Ying-Lu , Li Zhi-Hong , Zhang Yao-Ju , Wang Hong-Yan , Zhu Hai-Yong ,   College of Mathematics and Physics, Wenzhou University, Wenzhou 325035, China,   College of Electrical and Electronic Engineering, Wenzhou University, Wenzhou 325035, China,   Crystech Inc., Qingdao 266100, China
Published: August 2021

Frequency doubling of second-Stokes in an acousto-optic Q-switched Nd:YVO4 cascaded self-Raman cavity is demonstrated to achieve a narrow pulse-width red laser. A three-stage bonded YVO4/Nd:YVO4/YVO4 crystal is designed by comprehensively considering the improvement of thermal effect, the performance of fundamental frequency laser and Raman conversion, to improve the Raman efficiency and output power. An LBO crystal cut for critical phase matching at room temperature is selected and used as a nonlinear optical crystal for realizing the frequency doubling of second- Stokes wave. Its phase matching angle (θ = 86.0°, φ = 0°) is very close to the non-critical phase matching angle and has a small walk-off angle, which is beneficial to the realizing of the high conversion efficiency of frequency doubling. In the experiment, the beam waist position of the pump light and the repetition frequency of the acousto-optic Q-switcher are optimized. Under an incident pump power of 14.2 W and a repetition frequency of 60 kHz, the highest average output power of 1.63 W and conversion efficiency of 11.5% are obtained for the 657 nm red laser emission. The pulse width of 657 nm red light is 11.5 ns at the maximum output power, which is much narrower than that generated by frequency doubling of ordinary neodymium-doped laser at a waveband of 1.3 μm. The result shows that the frequency doubling of the acousto-optic Q-switched Nd:YVO4 cascaded self-Ramanlaser can take advantage of the pulse-width compression characteristics of Raman process to achieve a narrower pulse-width red light laser output.
Multiwavelength corss-correlation and radio Doppler factor estimation of CGRaBS J2345-1555
Authors: Zhang Huan , Zhang Hao-Jing , Lu Lin , Ma Kai-Xuan ,   School of Physics and Electronic Information, Yunnan Normal University, Kunming 650500
Published: August 2021

In this paper, CGRaBS J2345-1555’s long-term radio band, gamma ray flux and optical V-band magnitude data are collected from Fermi/LAT, Catalina, and OVRO dataset. The correlation between multi-bands is evaluated by the discrete correlation function method. The results show that the correlation coefficient between gamma band and radio band is 0.53, and the time delay is about 90 days, a variation of the gamma band is about 90 days ahead of radio band; the correlation coefficient between radio band and optical V-band is 0.84, and the time delay is about –300 days, a variation of the optical V-band is about 300 days ahead of radio band; there is no significant correlation between gamma and optical V-band. These results show that the optical band is dominated by synchrotron radiation, and the time delay between the radio band and the optical band can be explained as the fact that the radiation region of the optical band is upstream, and the radio band is downstream. The gamma band and the radio band are both homologous. The distribution of brightness temperature is used to calculate the Doppler factor of the celestial body’s radio band. The averaged Doppler factor is 12.64, and it oscillates with the light curve. So the jet has obvious bunching effect, and the variation of radiation flux in radio band comes from the jet.
Triangular-shaped waveform generation with variable symmetry based on dual-polarization modulation
Authors: Wang Chuang-Ye , Ning Ti-Gang , Li Jing , Pei Li , Zheng Jing-Jing , Li Yu-Jian , Ai Bo ,   Key Laboratory of All Optical Network and Advanced Telecommunication Network of EMC, Institute of Lightwave Technology, Beijing Jiaotong University, Beijing 100044, China,   State Key Laboratory of Rail Traffic Control and Safety, Beijing Jiaotong University, Beijing 100044, China
Published: August 2021

Photonic generation of triangular-shaped waveform with variable symmetry based on dual-polarization modulation is proposed and demonstrated. Based on the external modulation method, a dual-polarization modulator is used to modulate the radio frequency signal to generate the needed optical signal. By setting the modulation index of the modulator and phase shift of phase shifters appropriately, the optical intensity of generated signal can equal approximately the first three terms of the Fourier series expansion of the ideal triangular-shaped waveform, so triangular-shaped waveforms with different symmetry factors can be generated. Most of previous triangular waveform generation schemes generate symmetrical triangular waveform or sawtooth waveform (sawtooth waveform can be regarded as an asymmetrical triangular waveform), and the symmetry factor is not tunable. The tunable range of symmetry factor of triangular-shaped waveform generated by this scheme can reach 0%–100%, which will greatly expand the application range of triangular-shaped waveforms. The root-mean-square error (RMSE) is introduced to measure the similarity between the generated waveform and the theoretical waveform. It can be found that theoretically the triangular-shaped waveform with a symmetry factor in a range from 14% to 86% has a good similarity to the ideal waveform (RMSE < 0.044), and the RMSE of the generated waveform in the simulation is also very close to the theoretical RMSE. Experimentally, the 4GHz triangular-shaped waveforms with different values of symmetry factor (20%–80%) are obtained by using 4GHz radio frequency signal.
Mmolecular dynamics study of glass transition and nonlinear mechanical behavior of poly(methyl methacrylate)/carbon nanotubes nanocomposites
Authors: Huang Duo-Hui , Wan Ming-Jie , Yang Jun-Sheng ,   Faculty of Science, Yibin University, Yibin 644007, China,   South China Advanced Institute for Soft Matter Science and Technology, School of Molecular Science and Engineering, South China University of Technology, Guangzhou 510640, China
Published: August 2021

The glass transition temperature and nonlinear mechanics of polymer nanocomposites are strongly influenced by the short fibers. In this paper, coarse-grained molecular dynamics simulations are used to study the effects of single-walled carbon nanotube (CNT) content on the glass transition, diffusion coefficient, viscosity and nonlinear mechanical properties of poly(methyl methacrylate) (PMMA)/CNT nanocomposites. The glass transition temperature Tg is very important for the application of the materials. The Tg is related to the specific volume of the system. Generally, the location of the discontinuity on the curve of specific volume vs. temperature is the position of Tg. Our simulation results show that the Tg of PMMA/CNT composite increases with CNT content, and the result is consistent with the experimental value (434 K). This increase of Tg is evidently due to the presence of CNTs, which imposes a limit on the mobility of the molecules of PMMA. For the free volume in the liquid state, recent experiments pointed out that the molecular mutation is relatively easy to occur because the unoccupied volume is large. Further analysis of the diffusion coefficient of the PMMA/CNT indicates that the difference in diffusion characteristic occurs above the glass transition temperature, and the diffusion coefficient of PMMA system and PMMA/CNT system are the same below the glass transition temperature. Polymer materials in the service process will inevitably suffer the deformation, and the modulus and toughness of material are inversely proportional. Based on this problem, the nonlinear mechanical properties of short CNTs added PMMA composite are studied by nonequilibrium molecular dynamics. Our results show that the yield modulus increases with the CNT content increasing. However, the toughness is almost unchanged. In order to further understand the origin of stress of PMMA/CNT nanocomposites, the stretch ratio and orientation parameters of MPPA chains are also investigated in the present work. According to the stretch ratio and orientation parameters, it is not difficult to conclude that the stress-strain curve is mainly the result of the synergistic effect of molecular chain stretching and orientation. This work provides a theoretical guidance for further experiments and processing at the atomic and molecular level.
A synchroscan streak tube with high deflection sensitivity
Authors: Liu Xue-Ling , Tian Jin-Shou , Tian Li-Ping , Chen Ping , Zhang Min-Rui , Xue Yan-Hua , Li Ya-Hui , Fang Yu-Man , Xu Xiang-Yan , Liu Bai-Yu , Gou Yong-Sheng ,   Key Laboratory of Ultra-fast Photoelectric Diagnostics Technology, State Key Laboratory of Transient Optics and Photonics, Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an 710119, China,   University of Chinese Academy of Sciences, Beijing 100049, China,   School of Network and Communication Engineering, Jinling Institute of Technology, Nanjing 211169, China,   Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan 030006, China
Published: August 2021

A synchroscan streak tube with high spatiotemporal resolution and high deflection sensitivity is proposed, which contains several innovation designs. Some measures are taken to improve the imaging performances of the streak tube. Firstly, in order to obtain a high deflection sensitivity, the difference in voltage between the photocathode and anode and the length of the equipotential region of the streak tube are reduced as much as possible. Secondly, by introducing a hyperfine grid behind the cathode, reasonably designing the voltages applied to the six-electrode electrostatic focusing system, and moving the electron beam crossing point to the entrance of the deflection plates, the temporal dispersion and the temporal distortion of the streak tube are reduced, and the spatiotemporal resolution of the streak tube is improved. Besides, the streak tube is technically analyzed by tracking the temporal and spatial distribution of electrons under an operating voltage of 7000 V with the aid of computer simulation technology (CST) software. The results show that the deflection sensitivity is 125 mm/kV, the physical temporal resolution is better than 1.83 ps @MTF = 10%, and the static spatial resolution on the photocathode is better than 38 lp/mm @MTF = 10% over the effective photocathode area with a size of 10 mm × 4 mm. By applying a synchronous scanning voltage with a repetition frequency of 250 MHz to the deflection electrode, the results show that the dynamic spatial resolution of the streak tube is better than 16 lp/mm, the limit of the dynamic temporal resolution is 1.39 ps, and two rectangular electron pulses with a size of 10 mm × 20 μm and an interval of 2.3 ps emitted from the photocathode can be well resolved by the streak tube. In addition, the experimental measurements are conducted with a streak tube developed in our laboratory. The results demonstrate that the photocathode of the streak tube can work in the entire visible light region, and the response in the short wavelength region is significantly better than that in the long wavelength region. The static spatial resolution of this streak tube is 40 lp/mm in the center of the photocathode. The temporal resolution of this streak tube is 5.55 ps measured under a synchronous scanning voltage with a repetition frequency of 75 MHz.
Novel one-dimensional optomechanical crystal nanobeam with high optomechanical coupling rate under different defect states
Authors: Xu Qi , Sun Xiao-Wei , Song Ting , Wen Xiao-Dong , Liu Xi-Xuan , Wang Yi-Wen , Liu Zi-Jiang ,   School of Mathematics and Physics, Lanzhou Jiaotong University, Lanzhou 730070, China,   Department of Physics, Lanzhou City University, Lanzhou 730070, China
Published: August 2021

Optomechanical crystals can simultaneously modulate elastic waves and electromagnetic waves as well as localizing phonons and photons to enhance the acousto-optic interaction. In this work, a new type of optomechanical crystal nanobeam cavity is designed by periodically arranging the unit cells with double holes on both sides of a hexagonal prism. Considering the moving boundary effect and the photoelastic effect as well as using the first-order electromagnetic perturbation theory and the optomechanical coupling coefficient calculation method, the optomechanical coupling rate of the structure is calculated. The result shows that the overlap between the optical mode and the mechanical mode can be improved by changing the number of defects and optimizing the geometric structure. For the nanobeam cavity structures with different numbers of the like defects, the number of defects will only affect the action mode of the moving boundary effect and photoelastic effect in the optomechanical coupling rate, but will not change the coupling rate too much. In particular, the optomechanical coupling rate of the single defect optomechanical crystal nanobeam cavity can reach –1.29 MHz, and the equivalent mass is 42.6 fg. Moreover, the designed structure is simple and easy to process and fabricate. The coupling rate of even-symmetric optomechanical crystal nanobeam cavity based on gradient defect can reach 2.25 MHz, and the coupling rate of odd symmetric structure can reach 2.18 MHz, in which the moving boundary effect is dominant. Based on the symmetry analysis of the vibration modes of the optomechanical crystal nanobeam cavity with gradient defects, it is worth noting that only the even symmetrical vibration modes of x-y, x-z and y-z can strongly couple with the optical modes. The surface density of the moving boundary effect is calculated and analyzed, and it is found that the surface density of the acoustic resonance mode with high symmetry also possesses high symmetry. However, when the surface density of the moving boundary effect in the defect state appears adjacent to each other and cancels out each other, it will destroy the coupling mode of the moving boundary effect and reduce the coupling rate, whether the symmetry is high or low. In addition, the designed optomechanical crystal nanobeam can also improve the quality factor of the resonant cavity by optimizing the defect structure while maintaining a high optomechanical coupling rate. Therefore, this research provides an effective means to find a structure with high optomechanical coupling rate, and also presents the ideas for designing the space sensors.
Stability of optical soliton in symmetrical three-quantum-dot system under high-order effects
Authors: Ren Bo , She Yan-Chao , Xu Xiao-Feng , Ye Fu-Qiu ,   School of Physics and Mechatronics Engineering, Jishou University, Jishou 416000, China,   Department of Physics and Electronic Engineering, Tongren University, Tongren 554300, China
Published: August 2021

The influence of high-order effects on the stability of the optical soliton in a semiconductor three-quantum-dot molecular system under the excitation of narrow pulse probe light is analyzed analytically by using the multi-scale method. The results show that optical soliton described by the standard nonlinear Schrödinger equation will have a large attenuation in the propagation process, while the optical soliton described by the high-order nonlinear Schrödinger equation has relatively good stability. In addition, numerical simulations of the interaction between optical solitons show that the amplitudes of the two optical solitons described by the standard nonlinear Schrödinger equation attenuate rapidly after the collisions and radiation of more serious dispersion waves, while the shapes of the two optical solitons described by the high-order nonlinear Schrödinger equation hardly changes after the collision. This is mainly because when the incident probe light pulse is narrow enough, the system must be described by a higher-order equation. The physical reason is that the higher-order effects in the equation, including non-instantaneous effects and third-order dispersion effects, cannot be ignored or treated as perturbations. This kind of stable optical soliton has potential application value for future optical information processing and transmission technology.
Amplification of optical pulse train based on Peregrine rogue wave
Authors: Wang Yan , Li Lu ,   College of Physics and Electronics Engineering, Shanxi University, Taiyuan 030006, China,   Institute of Theoretical Physics, Shanxi University, Taiyuan 030006, China
Published: August 2021

In this paper, we discuss the pulse dynamics of rational fraction based on the Peregrine rogue wave solution of nonlinear Schrödinger equation. Based on its properties and using the spectral filtering, the amplification of optical pulse train is proposed. The results show that the combination of a continuous-wave pump and a spectral filter positioned in fiber can act as an amplifier. And the idea is applied to the long-haul transmission of optical pulse train and four amplification periods are demonstrated. Particularly, the amplification of limited number of pulses can be realized by rectangular pulse truncation and the number of pulses can be adjusted by changing the parameters. The periodically modulated plane wave that can be controlled experimentally is taken as an input which can produce the maximumly amplified zero background pulse train and the location of maximumly amplified pulse train relates to the modulation intensity. The location of the maximumly amplified zero background pulse train changes with the modulation intensity. The results show that for two input signals with different frequencies, they can realize the amplification with the above method. By changing the modulation intensity the simultaneous amplification for two signals with different frequencies can be realized.
Thickness effect of Sn15Sb85 phase change film
Authors: Huang Yu-Feng , Wu Wei-Hua , Xu Sheng-Qing , Zhu Xiao-Qin , Song San-Nian , Song Zhi-Tang ,   School of Mathematics and Physics, Jiangsu University of Technology, Changzhou 213001, China,   National Laboratory of Solid State Microstructures, Nanjing University, Nanjing 210093, China,   State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Micro-system and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
Published: August 2021

Sn15Sb85 thin films with different thickness are prepared by magnetron sputtering. The evolution of Sn15Sb85 thin film from the amorphous state to the crystalline state is studied by an in-situ resistance temperature measurement system. The crystallization temperature, electrical resistance, crystallization activation energy, and data retention capacity of Sn15Sb85 thin film increase significantly with film thickness decreasing. The near infrared spectrophotometer is used to record the diffuse reflectance spectra of amorphous Sn15Sb85 film. The results show that the band gap energy increases with film thickness decreasing. The surface morphology of Sn15Sb85 film after being crystalized is observed by atomic force microscope, which shows that the thinner film has lower roughness. The analysis of X-ray diffraction indicates that the grain size becomes smaller and the crystallization may be inhibited by reducing the film thickness. T-type phase change memory cells based on Sn15Sb85 thin films with different thickness are fabricated by the CMOS technology. The electrical performances of phase change memory show that the thinner Sn15Sb85 film has a larger threshold switching voltage and smaller RESET operation voltage, which means the better thermal stability and lower power consumption. The outcomes of this work provide the guidance for designing the high-density phase change memory by reducing the size of Sn15Sb85 thin film.
Hybrid quantum-classical algorithms: Foundation, design and applications
Authors: Chen Ran-Yi-Liu , Zhao Ben-Chi , Song Zhi-Xin , Zhao Xuan-Qiang , Wang Kun , Wang Xin ,   Institute for Quantum Computing, Baidu Research, Beijing 100193, China
Published: August 2021

Quantum computing, as an emerging computing paradigm, is expected to tackle problems such as quantum chemistry, optimization, quantum chemistry, information security, and artificial intelligence, which are intractable with using classical computing. Quantum computing hardware and software continue to develop rapidly, but they are not expected to realize universal quantum computation in the next few years. Therefore, the use of quantum hardware to solve practical problems in the near term has become a hot topic in the field of quantum computing. Exploration of the applications of near-term quantum hardware is of great significance in understanding the capability of quantum hardware and promoting the practical process of quantum computing. Hybrid quantum-classical algorithm (also known as variational quantum algorithm) is an appropriate model for near-term quantum hardware. In the hybrid quantum-classical algorithm, classical computers are used to maximize the power of quantum devices. By combining quantum computing with machine learning, the hybrid quantum-classical algorithm is expected to achieve the first practical application of quantum computation and play an important role in the studying of quantum computing. In this review, we introduce the framework of hybrid quantum-classical algorithm and its applications in quantum chemistry, quantum information, combinatorial optimization, quantum machine learning, and other fields. We further discuss the challenges and future research directions of the hybrid quantum-classical algorithm.
Optical absorption and thermionic emission mechanism of multi-functional La1–x Srx B6 hexaborides
Authors: Zhang Hong-Yan , Bao Li-Hong , Chao Luo-Meng , Zhao Feng-Qi , Liu Zi-Zhong ,   College of Physics and Electronic Information, Inner Mongolia Normal University, Hohhot, 010022, China,   College of Science, Inner Mongolia University of Science Technology, Baotou 014010, China,   College of Chemistry and Environment Science, Inner Mongolia Normal University, Hohhot 010022, China
Published: August 2021

The optical absorption property of the nanocrystalline La1–x Srx B6 powder and thermionic emission property of the La1–x Srx B6 polycrystalline bulk are investigated. As a result, the transmission wavelength of LaB6 is red-shifted from 591 nm to 658 nm with the increase of Sr doping content. The emission tests indicate that the thermionic emission current density of La1–x Srx B6 polycrystalline bulk increases from 2.3 A/cm2 to 19.36 A/cm2 with the increase of La doping content under an applied voltage of 2000 V. The first-principle calculation results reveal that Sr doping LaB6 leads plasma frequency energy and Fermi level to decrease, resulting in the tunable characteristics of transmission wavelength and enhancement of thermionic emission. Therefore, the Sr-doped LaB6 as a multifunctional ceramic has a potential application in the field of optical filter or becomes a promising cathode for microwave device.
Structural control for high performance Bi2Te3–xSex thermoelectric thin films
Authors: Chen Yun-Fei , Wei Feng , Wang He , Zhao Wei-Yun , Deng Yuan ,   Hangzhou Innovation Institute, Beihang University, Hangzhou 310052, China,   Research Institute for Frontier Science, Beihang University, Beijing 100083, China
Published: August 2021

Bi2Te3-based alloys have been long regarded as the materials chosen for room temperature thermoelectric (TE) applications. With superior TE performances, Bi2Te3-based bulk materials have been commercially used to fabricate TE devices already. However, bulk materials are less suitable for the requirements for applications of flexible or thin film TE devices, and therefore the thin film materials with advanced TE properties are highly demanded. Comparing with bulk materials and P-type Bi2Te3-based thin films, the TE properties of N-type Bi2Te3-based thin films have been relatively poor so far and need further improving for practical applications. In this study, a series of N-type Bi2Te3–xSex thin films is prepared via magnetron sputtering method, and their structures can be precisely controlled by adjusting the sputtering conditions. Preferential layered growth of the Bi2Te3–xSex thin films along the (00l) direction is achieved by adjusting the substrate temperature and working pressure. Superior electrical conductivity over 105 S/m is achieved by virtue of high in-plane mobility. combining the advanced Seebeck coefficient of Bi2Te3-based material with superior electrical conductivity of highly oriented Bi2Te3–xSex thin film, a high power factor (PF) of the optimal Bi2Te3–xSex thin film can be enhanced to 42.5 μW/(cm·K2) at room temperature, which is comparable to that of P-type Bi2Te3-based thin film and bulk material.
Collective dynamics of higher-order coupled phase oscillators
Authors: Cai Zong-Kai , Xu Can , Zheng Zhi-Gang ,   College of Information Science and Engineering, Huaqiao University, Xiamen 361021, China,   Institute of Systems Science, Huaqiao University, Xiamen 361021, China
Published: August 2021

The Kuramoto model consisting of large ensembles of coupled phase oscillators serves as an illustrative paradigm for studying the synchronization transitions and collective behaviors in various self-sustained systems. In recent years, the research of the high-order coupled phase oscillators has attracted extensive interest for the high-order coupled structure playing an essential role in modeling the dynamics of code and data storage. By studying the effects of high-order coupling, we extend the Kuramoto model of high-order structure by considering the correlations between frequency and coupling, which reflects the intrinsic properties of heterogeneity of interactions between oscillators. Several novel dynamic phenomena occur in the model, including clustering, extensive multistability, explosive synchronization and oscillatory state. The universal form of the critical coupling strength characterizing the transition from disorder to order is obtained via an analysis of the stability of the incoherent state. Furthermore, we present the self-consistent approach and find the multi-cluster with their expressions of order parameters. The stability analysis of multi-cluster is performed in the subspace getting stability condition together with the stable solutions of order parameters. The discussion of all the results summarizes the mechanism of the transition from hysteresis to oscillatory states. In addition, we emphasize that the combination of the Kuramoto order parameter capturing the asymmetry of the system and the Daido order parameter representing the clustering can give a complete description of the macroscopic dynamics of the system. The research of this paper can improve the understanding of the effects of the heterogeneity among populations and the explosive synchronization occurring in higher-order coupled phase oscillators.
Deciding the Appropriate Route and Method of Hysterectomy for Women with Benign Diseases: A Cross-sectional Study at a Tertiary Care Hospital, India
Authors: Konar Hiralal , Sarkar Madhutandra , Dessa Dorothy
Published: August 2021

Introduction: Different factors may influence the route of hysterectomy for benign indications. Each of the three main approaches of hysterectomy has its own set of risks and benefits. A rational and evidence-based decision to select a right method for a particular patient is necessary to bring about the best possible outcome with least complications. Aim: To compare three groups of hysterectomy, i.e., laparotomy for Total Abdominal Hysterectomy (TAH), Non-descent Vaginal Hysterectomy (NDVH) and Total Laparoscopic Hysterectomy (TLH), with regard to the patient and clinical factors, surgical outcomes and complications, in order to decide the optimum route and method of hysterectomy in a patient with benign disease. Materials and Methods: In this hospital-based cross-sectional study, 120 women, with 40 patients each in the TAH, NDVH and TLH groups, were admitted due to benign gynaecological conditions in a tertiary care hospital in Kolkata, India from May 2013 to April 2014. They were operated, and then followed-up at 6-12 weeks after surgery. All the relevant information, e.g., clinical diagnosis, operating time, intraoperative blood loss, length of stay in hospital, postoperative pain score, intraoperative and postoperative complications, etc., were recorded. Data were analysed statistically by simple proportions and statistical tests, i.e., Chi-square test and F-test. Results: The most common indication for hysterectomy was benign diseases in all the groups, 47.5%, 40% and 37.5%, respectively in the TAH, NDVH and TLH groups. The mean operating time (minutes) was significantly higher in the TLH group (163.5) as compared to the TAH (75.03) and NDVH groups (84.88) (p=0.039). A significantly lesser mean intraoperative blood loss (mL) was observed in the NDVH (85.67) and TLH groups (98.63) as compared to the TAH group (168.47) (p=0.021). The observations in regard to other surgical outcome parameters, i.e., postoperative pain score, hospital stay, were also favourable in the NDVH or TLH group. The complication rate was higher in the TAH group (22/40 or 55%) as compared to the NDVH (14/40 or 35%) and TLH (17/40 or 42.5%) groups. Conclusion: NDVH or TLH is the preferred method over TAH in case of benign uterine disease due to lesser operative morbidity and faster recovery.
Detection of Endometrial Nerve Fibres in the Diagnosis of Endometriosis: A Case-control Study
Authors: Chikkala Hiranmayi , Prabhu Karthiga , Chandrasekaran Shanmugapriya , Shanthamani PM
Published: August 2021

Introduction: Due to non-availability of a good non-invasive or semi-invasive test for diagnosing endometriosis, there is a substantial time delay between the onset of symptoms and surgically confirmed endometriosis. Development of a simple non-invasive or semi-invasive diagnostic method can greatly help to reduce this delay and prevent severe morbidity in minimal to mild endometriosis which cannot be diagnosed clinically or by ultrasonography. Aim: To evaluate the role of nerve fibre detection in endometrial biopsy for diagnosing endometriosis Materials and Methods: In this observational study, detection of endometrial nerve fibres in endometrial biopsy in women undergoing laparoscopy/laparotomy for pelvic pain or infertility was done using polyclonal rabbit anti-protein gene product 9.5 (Dako, Australia). The results were compared between women who has laparoscopic/laparotomy visualisation of endometriotic lesions with those who don't have endometriotic lesions. Women with visual evidence of endometriosis in laparoscopy/laparotomy were taken as cases (n=32). Women without evidence of endometriosis in laparoscopy/laparotomy were taken as controls (n=29). Presence of endometrial nerve fibre was compared between women with and without evidence of endometriosis. Presence of endometrial nerve fibres and its association with painful symptoms, history of hormonal therapy, endometrial histopathology and stages of endometriosis was analysed. Results: Endometrial nerve fibres were detected in the functional layer in 21.8% of the endometriosis patients and no nerve fibres were detected in the control group. There was no significant association between endometrial nerve fibres in endometriosis and presentation of painful symptoms, history of hormonal therapy, endometrial histopathology and stages of endometriosis. Sensitivity of detecting endometriosis by the presence of nerve fibres in endometrial nerve biopsy specimen was 21.8% and specificity was 100%. Conclusion: Endometrial nerve fibre assessment for identifying endometriosis in women undergoing laparoscopy/laparotomy using routine endometrial sampling and immunohistochemical analysis was found not to be sensitive for the diagnosis of endometriosis.
Successful Management of Renal Fusion Anomaly of Kidney with Nephrolithiasis and Urinary Incontinence
Authors: Choudhury Sunirmal , Sandhu Ankit , Pal Dilip Kumar
Published: August 2021

The presence of an ectopic ureter may be indicated by continuous wetting, seen especially in girls. In majority of such cases, an ectopic ureter is associated with a duplex collecting system and complete ureteral duplication. A 32-year-old female presented with urinary incontinence with normal voiding episodes and right flank pain. On investigation, she was found to have duplex moiety on the right-side with partially duplicated ureter and quadruple moiety on the left-side with partially duplicated quadruple ureter with ectopic opening of ureters. The patient also had right upper calyceal stone. It was successfully managed with totally minimal invasive technique with retrograde intrarenal surgery for right nephrolithiasis and left laparoscopic ureteric reimplantation for ectopic ureter. Patient was continent during the follow-up period of nine months with no significant complications. Developmental anomalies of kidney and ureter though rare, can be managed with total minimal invasive techniques, requires proper planning, instruments and its implementation.
Multilocular Thymic Cyst in a Patient with Diffuse Infiltrative Lymphocytosis Syndrome
Authors: Gupta Nitin , Aggarwal Anivita , Tripathi Madhavi , Malla Sundeep , Nischal Neeraj
Published: August 2021

Diffuse Infiltrative Lymphocytosis Syndrome (DILS) is a multisystem disorder characterised by bilateral salivary gland enlargement and/or xerostomia in patients with Human Immunodeficiency Virus (HIV) infection. A 16 year old young male patient, presented with bilateral painless parotid swelling for five years. On evaluation, he was found to have oral thrush and bilateral cervical lymphadenopathy. He turned out to be positive for HIV with a cluster of differentiation 4 (CD4) count of 237/mcl. On Positron Emission Tomography- Contrast Tomography (PET-CT), a multiloculated thymic cyst (13×9×6 cm) was noted. He was diagnosed to have DILS with a large multiloculated thymic cyst. The patient was managed with tenofovir, lamivudine and efavirenz along with cotrimoxazole prophylaxis and fluconazole and was followed uptil nine months for the regress of the conditions. The case highlights the rare association between DILS and thymic cyst.
Tubercular Empyema Thoracic: An Acute Presentation with COVID-19 Co-infection
Authors: Gautam Sachin , Pandit Sanjay , Bhadoria Dharam Pal , Kumar Rahul
Published: August 2021

COVID-19 (Coronavirus Disease 2019) pandemic is caused by a novel Coronavirus, SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2, which has received worldwide attention and most COVID-19 patients have respiratory symptoms and develop a mild disease. In addition, co-infection of SARS-CoV-2 with other respiratory infections of bacterial, other viral and fungal origin needs to be validated. The clinical features, course and treatment of TB patients with COVID-19 are unclear and understudied. There is paucity of literature on this co-infection. Here, authors present a case report of a young diabetic Asian male patient who presented to the emergency department as COVID-19 positive with acute exacerbation of symptoms, who later developed respiratory distress and was eventually found to have a lung abscess with subsequent tubercular empyema thoracic on contrary to a severe COVID-19 pneumonia or a fungal infection, as thought of. Contrast Enhanced Computed Tomography (CECT) chest along with Cartridge-Based Nuclei Acid Amplification Test (CBNAAT) of pleural fluid pus confirmed the tubercular lesion timely to aid the diagnosis and further course of management.
Cefepime Induced Neurotoxicity: Case Series
Authors: Das Sukanto Kishore , Das Subodh Kumar , Panda Akhila , Parhi Laxmidhar
Published: August 2021

Cefepime is a broad-spectrum antimicrobial which is widely used for the treatment of both gram positive and gram negative pathogens, mainly in hospital setup for critically ill patients. Its half-life is around two hours and is primarily excreted via kidneys. However, in patients with renal impairment the half-life increases up to 13 hours. This may cause drug accumulation leading to several toxicities, of which neurotoxicity is of prime concern. Missing the diagnosis of these symptoms related to cefepime it may lead to increase in mortality or central nervous system dysfunction. Dose adjustment is recommended in such cases; however, several reports of neurological manifestations have been documented despite such modification. Here, is a series of six cases of cefepime induced neurotoxicity. The symptoms that the patients reported with were drowsiness, disorientation, non-convulsive epilepsy, slurred speech, tremors and myoclonic jerks. In all patients, cefepime was withdrawn and symptomatic management with anti-epileptic drug and monitoring with repeat Electroencephalogram (EEG) were done.
Vitamin-C and Mineral Composition Analysis of Some Fresh Vegetables in Patuakhali, Bangladesh
Authors: Sabuj Sadman Sakib , Faruk-E-Azam A. K. M. , Islam Md. Shahidul , Uddin Md. Nizam , Islam Md. Nazrul , Islam Md. Shajadul
Published: August 2021

Aims: This comparative study was carried out to evaluate the vitamin-C and mineral content of twenty-two different sorts of nutritious and low-cost fresh vegetables.

Methodology: The study was conducted in the agricultural chemistry laboratory, Patuakhali Science and Technology University, Patuakhali during the period of January to June 2019. Vitamin C, calcium (Ca), magnesium (Mg), sodium (Na), potassium (K), phosphorus (P) contents were determined with the flame emission spectrophotometer.

Results: Vitamin-C was higher in Momordica charantia (87.0 mg/100 g) and lower in Vigna unguiculata (0.10 mg/100g). Calcium and magnesium of the green leafy vegetables were in the range of 191.0 - 12.0 mg/100g and 210.1- 9.0 mg/100g respectively. Sodium content largely varied from 58.1- 2.1 mg/100g in which Amaranthus cruentus content higher and Cucumis sativus had the lower content. The highest potassium content was recorded in Cucurbita pepo (384.0 mg/100g) and the lowest potassium content was found in Cucumis sativus (144.20 mg / 100g). Phosphorus content was ranged between 108.0 -13.0 mg /100 g in all the green leafy vegetables. There were significant correlations between mineral contents.

Conclusion: These results revealed that selected vegetables contain an appreciable amount of vitamin C and minerals and should be included in diets as a supplement of daily allowance needed by the body.
Evolution of Dairy Cooperatives in Karnataka: A Special Focus on Women’s Dairy Cooperatives
Authors: Geetha R. S. , Murthy P. S. Srikantha
Published: August 2021

The present research is mainly based on secondary data and aimed to study dairy cooperatives’ evolution and especially those involving women in Karnataka. The indicators used in study are growth rate and percentages. In India and Karnataka, the analysis indicated that growth in milk production has increased significantly in the past 3 decades and overall, except during 2000-01 to 2009-10 period for Karnataka. As of July, 2020 there were 14 Milk Unions covering all the districts of the state with 14682 Dairy Cooperatives functioning and 25.30 lakh milk producers. Bengaluru and Kolar milk unions are larger unions in the state contributing around 25 per cent to total dairy cooperatives and milk producers in Karnataka, while contributing around 34 per cent to average milk procurement. The wide spread establishment of WDCs was possible in Karnataka through STEP scheme which was implemented by KMF with the support of Government of Karnataka. The total number of WDCs registered in Karnataka is of 4494 and currently functioning ones among them is 4046. Around 60 per cent of WDCs are set up through STEP in Karnataka over the years.
A Gender based Study on Disagreement between Parents and Adolescents for use of Social Networking Sites
Authors: Patra Kshiptimayee , Gogoi Sampreety
Published: August 2021

In today's world, social networking services are quite popular among adolescents. The usage of social networking sites is seen differently by adolescents and parents. As a result, when it comes to the use of social networking sites, there is a distinction between parents and adolescents. In today's world, parents value their adolescent's education, social life and health irrespective of their gender.

Aim: The goal of this study was to see if there was a gender difference in parent and adolescent disagreement regarding the use of social networking site.

Methodology: A multi-stage selection method was used to choose 118 adolescents and each one of their parents (a total of 236 samples) from five schools in the Jorhat Block. To gather the essential information, a self-made questionnaire was used.

Results: The results revealed from the findings that there was no significant gender difference in disagreement between parents and adolescents for use of Social networking sites.