bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of plasma surface treatment on embedded n-contact for GaN-based blue light-emitting diodes grown on Si substrate
Authors: Feng Bo  , Deng Biao  , Liu Le-Gong  , Li Zeng-Cheng  , Feng Mei-Xin  , Zhao Han-Min  , Sun Qian  ,   National Institute of LED on Silicon Substrate, Nanchang University, Nanchang 330047, China;,   Lattice Power (Jiangxi) Corporation, Nanchang 330029, China;,   Key Laboratory of Nanodevices and Applications, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou 215123, China
Published: December 2020

Unlike the finger-like n-contact that is prepared after the wafer bonding and the N-polar GaN surface roughening for GaN-based vertical structure light-emitting diodes (LEDs) grown on Si substrates, the embedded via-like n-contact is formed prior to the wafer bonding. The high temperature process of the wafer bonding often causes the electrical characteristics of the via-like embedded n-contact to degrade. In this paper, we study in detail the effect of plasma treatment of the n-GaN surface on the forward voltage of GaN-based LED grown on Si substrate. It is shown that with no plasma treatment on the n-GaN surface, the forward voltage (at 350 mA) of the 1.1 mm1.1 mm chip with a highly reflective electrode of Cr (1.1 nm)/Al is 3.43 V, which is 0.28 V higher than that of the chip with a pure Cr-based electrode. The LED forward voltages for both kinds of n-contacts can be reduced by an O2 plasma treatment on the n-GaN surface. But the LED forward voltage with a Cr/Al-based electrode is still 0.14 V higher than that of the chips with a pure Cr-based electrode. However, after an Ar plasma treatment on the n-GaN surface, the LED forward voltage with a Cr/Al-based electrode is reduced to 2.92 V, which is equal to that of the chip with a pure Cr-based electrode. The process window of the n-GaN surface after the Ar plasma treatment is broader. X-ray photoelectron spectroscopy is used to help elucidate the mechanism. It is found that Ar plasma treatment can increase the concentration of N-vacancies (VN) at the n-GaN surface. VN acts as donors, and higher VN helps improve the thermal stability of n-contact because it alleviates the degradation of the n-contact characteristics caused by the high temperature wafer bonding process. It is also found that the O content increases slightly after the Ar plasma treatment and HCl cleaning. The O atoms are mainly present in the dielectric GaOx film before the Ar plasma treatment and the HCl cleaning, and they exist almost equivalently in the conductive GaOxN1-x film and the dielectric GaOx film after Ar treatment and HCl cleaning. The conductive GaOxN1-x film and the VN donors formed during the plasma treatment can reduce the contact resistance and the LED forward voltage.
Spectral radiant characteristic of airborne optoelectronic system detecting aerial maneuver target
Authors: Kou Tian  , Yu Lei  , Zhou Zhong-Liang  , Wang Hai-Yan  , Ruan Cheng-Wei  , Liu Hong-Qiang  ,   Aeronautics and Astronautics Engineering College, Air Force Engineering University, Xi'an 710038, China
Published: December 2020

Spectral radiation detection in deep space background is an important fundamental research in the field of infrared target detection and identification. Based on the spectral radiation and scattering theory, the spatial distribution model of aerial target reflecting background radiation under complex environment is first built. Then the horizontal and pitch spectral radiation models of target are built based on target skin temperature distribution caused by aerodynamic heating. Combining the target motion equation and relative rotation matrix between target matrix and detector matrix, the process-oriented characteristic of spectral response signal with spatiotemporal variation is emphatically analyzed. The simulation results indicate that different target maneuver modes cause different characteristics of spectral response signal, which shows that a remarkable mapping relationship exists between the target maneuver mode and spectral response signal characteristic. Thus using the spectral response signal to identify target maneuver mode provides a feasible method, and the target posture and relative position are the main factors to affect the spectral response signal characteristic.
Structural optimization of Fen-Ptm (5 n+m 24) alloy clusters based on an improved Basin-Hopping Monte Carlo algorithm
Authors: Liu Tun-Dong  , Li Ze-Peng  , Ji Qing-Shuang  , Shao Gui-Fang  , Fan Tian-E  , Wen Yu-Hua  ,   Department of Automation, Xiamen University, Xiamen 361005, China;,   Department of Physics, Xiamen University, Xiamen 361005, China
Published: December 2020

Alloy nanoclusters have received extensive attention because they can achieve bifunctional properties by making good use of the cooperative effect of two metals. In this paper, an improved Basin-Hopping Monte Carlo (BHMC) algorithm is proposed to investigate the structural stabilities of Fe-Pt alloy nanoclusters. Different cluster sizes and chemical compositions are considered. Moreover, a similarity function is introduced to analyze the structural similarity between the stable structures of alloy clusters and those of their monometallic clusters. Meanwhile, the atomic distributions of Fe-Pt alloy clusters are considered for their stable structures. The results indicate that for Fe-Pt alloy clusters with the size N 24, there is no significant structural evolution with the increase of cluster size. Fe atoms prefer to segregate at the peripheral positions of the clusters, while Pt atoms tend to occupy the interior. The same distribution result can be obtained for the structures of clusters with different compositions. With Fe composition increasing, this distribution trend is more pronounced for the Fe-Pt alloy clusters.
In addition, by calculating the structural similarity function between alloy and monometallic clusters, we find that the stable structures of Fe-Pt alloy clusters gradually vary with composition ratio. Moreover, when the Fe atoms or Pt atoms are added into the Fe-Pt alloy system, they change the stable structures of Fe-Pt alloy clusters, resulting in a different structure from Fe and Pt monometallic ones. Also, the structural similarity is different when the Fe composition varies. Furthermore, the best stable structures of Fe-Pt clusters with different compositions and sizes are obtained by calculating the second-order finite difference in energy of Fe-Pt alloy clusters.
Conversion relationships between several parameter groups of completely polarized electromagnetic waves
Authors: Liu Jun-Qun  , Liu Yao-Wen  ,   Nanjing Research Institute of Electronics Technology, Nanjing 210039, China
Published: December 2020

It is known that polarization as the third characteristic of electromagnetic waves plays substantial roles which are comparable with the wave amplitude and phase, in describing the tempo and spatial properties of electromagnetic waves. Various parameter groups for characterizing the polarization state of electromagnetic waves with different initial states and boundary conditions have been proposed. However, a full-scale set of conversion relationships between these parameter groups with specific initial phases is not yet available. In this work, the initial phases as additional parameters for the orthogonal linear polarization and the polarization ellipse parameter groups and the digitized elliptical angle ' as a complementary parameter to the polarization ellipse parameter group are taken into account respectively. Consequently, a full-scale set of conversion relationships between these parameter groups has been rigorously derived out. The validity of these conversion relationships are confirmed by the numerical calculations in terms of mathematical completeness and one-to-one correspondence. These conversion relationships make the tedious computation of the wave polarization much simpler and straightforward, benefiting practical implementation of the polarization theory of electromagnetic waves.
Parallel magneticcontrolled THz modulator based on two-dimensional magnetized plasma photonic crystal
Authors: Zhou Wen  , Ji Ke  , Chen He-Ming  ,   School of Opto-Electronics, Nanjing University of Posts and Telecommunications, Nanjing 210023, China;,   Bell Honors School, Nanjing University of Posts and Telecommunications, Nanjing 210023, China
Published: December 2020

THz waves are very good candidates for high-capacity wireless links since they offer a much higher bandwidth than RF frequencies. Photonic crystal (PC) offers a new opportunity for integrated THz wave devices. It permits the integrated devices to be miniaturized to a scale comparable to the wavelength of the electromagnetic wave. Considering their governing properties such as photonic band gap (PBG) and photon localization effect to control electromagnetic wave propagations, PC-based THz modulator has attracted much attention. Tunability strategies include mechanical control, electrical control, magneto static control, temperature control and optical pumping. However, the development of high-speed THz wireless communication system is limited by the low modulation depth and rate of previously reported modulators. In this paper, we propose a novel magnetic-controlled THz modulator based on a magnetized plasma PC consisting of line defects and a point defect. InSb, a semiconductor with high electron mobility, is introduced into the point defect. According to the magneto-optical effect, the refractive index of InSb changes rapidly under the control of the applied magnetic field (MF) intensity. Then the mode frequency in the point defect changes dynamically. The structure is based on a two-dimensional PC constructed by triangular lattice of Si rods in air. Based on the magneto-optic effect, the magnetized plasma defect mode in the THz regime can be decomposed into the left- and right-handed circularly polarized light when the applied magnetic field is parallel to the direction of the THz wave. And the difference in effective refractive index between the left- and right-handed circularly polarized light increases with the applied uniform magnetic field increasing. Therefore the on/off modulation of left- and right-hand circularly polarized light can be realized. The steady-state field intensity distribution and the time domain steady state response of TE wave propagating parallelly to the external magnetic field are simulated by the finite-difference-time-domain and finite element method. The simulation results show that PC-based mode transfer modulator has the potential application to THz wireless broadband communication system with a good performance of high contrast ratio (25.4 dB), low insertion loss (0.3 dB) and high modulation rate (～4 GHz). It is convenient to load the modulation signals in an easy MF application way. The device designed is leading the way to extend the application of THz wireless communication filed with advantages of small size, low insertion loss, and high extinction ratio.
Characteristics of metal ablation product by intense pulsed ion beam irradiation
Authors: Zhang Jie  , Zhong Hao-Wen  , Shen Jie  , Liang Guo-Ying  , Cui Xiao-Jun  , Zhang Xiao-Fu  , Zhang Gao-Long  , Yan Sha  , Yu Xiao  , Le Xiao-Yun  ,   School of Physics and Nuclear Energy Engineering, Beihang University, Beijing 100191, China;,   Beijing Key Laboratory of Advanced Nuclear Energy Materials and Physics, Beihang University, Beijing 100191, China;,   Institute of Heavy Ion Physics, Peking University, Beijing 100871, China
Published: December 2020

Intense pulse ion beam (IPIB) has been extensively used in material surface modification. The ablation effect plays an important role in the interaction between IPIB and material. Therefore, the understanding of ablation mechanism is of great significance for IPIB application. Here, to investigate the ablation process and the characteristics of ablation products, pure zinc targets are bombarded by IPIB of 1.2-1.5 J/cm2 energy density at TEMP-4M accelerator. The ablation products are collected by monocrystalline silicon substrates in the IPIB irradiation process. By using the scanning electron microscopy, energy dispersive spectrometer and high precision balance, the surface morphology of the substrate and the characteristics of ablation products are obtained. The majority of observed ablation products are nearly circular particles with diameters of 0.03-2.00 m. There are a small number of zinc droplets and solid debris with large irregular shapes on the silicon substrate. Combining Monte Carlo method and infrared imaging diagnostic results, a heat conduction model is constructed by finite element method to describe the distribution and evolution of thermal field formed by IPIB on a zinc target. The results show that the zinc target can be melted and evaporated under a 1.2 J/cm2 IPIB irradiation. By comparing the experimental resuls with the simulation results, it is found that the gaseous, liquid and solid ablation products are generated collectively in the zinc ablation process. The causes of the different ablation products are also studied.
A stereo photographic physical model for ocean wave measurement
Authors: Wang Ying-Xia  , Jiang Wen-Zheng  , Qiao Fang-Li  , Chen Si-Yu  ,   College of Oceanic and Atmospheric Sciences, Ocean University of China, Qingdao 266100, China;,   Ocean Environment and Numerical Simulation Laboratory, The First Institute of Oceanography, SOA; Laboratory of Marine Science and Numerical Model in SOA, Qingdao 266061, China;,   Laboratory for Regional Oceanography and Numerical Modeling, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China
Published: December 2020

Unlike the traditional models, a new stereo photographic model requiring no sea control points that are difficult to lay on a sea surface is developed in this paper. It is realized according to the order of camera intrinsic parameters calibration, relative orientation and absolute orientation based on average sea surface, and we give the governing equations and its algorithms. First of all, in the paper we present an imaging model that adopts non-measurement camera with considering only the radial distortion coefficients, and then give the method that calculates the camera intrinsic parameters by combining the co-planar equations and the distance equations to form a closed system of equations. For verifying the convergence of the governing equations, we lay four parallel sand ridges on a level ground in laboratory, measure seven lines of different heights and take a pair of the images by two cameras. The intrinsic parameters are successfully calculated by using the method, and further analysis shows that the results are highly precise. When observing the ocean waves in offshore sea, we need to recalculate the relative orientation parameters. At this time the governing equations are the co-planar equations, but the accuracy of the image matching is seriously related to the accuracy of the relative orientation parameters. However, as the mirror reflection of the sea surface, the matching accuracy of the sea image is often low, so we select 407 optimal matching points from among 1600 conjugate points and calculate the parameters. It needs a sequence of sea image pairs to obtain the absolute orientation parameters, 256 pairs in the paper. For each pair, we select firstly 300300 feature points on the left image approximately evenly, then find the conjugate points on the right image by image matching, calculate the coordinates of the corresponding sea surface points in the left camera coordinate system, and then fit the points into a plane; thus a plane sequence can be obtained. We establish a special object coordinate system on the average sea surface that is obtained by summing the plane sequence, and calculate the absolute orientation parameters by the geometric relationship between the two coordinate systems. And it is proved that the methods of relative orientation and absolute orientation proposed in this paper are feasible by reconstructing sea surface height field. The model greatly reduces the difficulty in calibrating the stereoscopic photography for ocean wave measurement, which is beneficial to its popularization and application.
Partial component consensus of leader-following multi-agent systems
Authors: Wu Bin-Bin  , Ma Zhong-Jun  , Wang Yi  ,   School of Mathematics and Computing Science, Guilin University of Electronic Technology, Guilin 541004, China;,   Guangxi Colleges and Universities Key Laboratory of Data Analysis and Computation, Guilin University of Electronic Technology, Guilin 541004, China;,   School of Mathematics and Statistics, Zhejiang University of Finance and Economics, Hangzhou 310012, China
Published: December 2020

Consensus problems, as basic topics in distributed coordination of multi-agent systems, have drawn a great deal of attention from different research fields. Generally, consensus refers to the asymptotic convergence of state variables of all agents with time evolution. In this paper, a concept on partial component consensus in multi-agent system is first given, which is a weaker dynamic behavior of group than the consensus in general, and then the problem of partial component consensus in leader-following first-order multi-agent system with the directed network topology is discussed. By designing an appropriate pinning control protocol and building corresponding error system, partial component consensus in multi-agent system is transformed into the partial variable stability of the error system. Using matrix theory and stability theory, a sufficient condition is given to realize partial component consensus in multi-agent system. Numerical simulations are given to illustrate the theoretical results.
Day-to-day dynamical evolution of network traffic flow with elastic demand
Authors: Liu Shi-Xu  , Chen Wen-Si  , Chi Qi-Yuan  , Yan Hai  ,   School of Civil Engineering, Fuzhou University, Fuzhou 350116, China;,   Beijing Collaborative Innovation Center for Metropolitan Transportation, Beijing University of Technology, Beijing 100124, China
Published: December 2020

Network traffic flow is an aggregated result of a huge number of travelers' route choices, which is influenced by the travelers' choice behaviors. So day-to-day traffic flow is not static, but presents a complex and tortuous day-to-day dynamic evolution process. Studying day-to-day dynamic evolution of network traffic flow, we can not only know whether the traffic network equilibrium can be reached and how the process is achieved, but also can know what phenomenon will occur in the evolution of network traffic flow if the equilibrium is not reached. In a real traffic system, taking day as scale unit, the day-to-day network traffic demand is variable and changes with everyday's traffic network state. The travelers' route choices are also influenced by the previous day's behaviors and network state. Then, will the day-to-day network traffic flow evolution be stable? If it is unstable, when will bifurcation and chaos occur? In this paper we discuss the day-to-day dynamic evolution of network traffic flow with elastic demand in a simple two-route network. The dynamic evolution model of network traffic flow with elastic demand is formulated. Based on a nonlinear dynamic theory, the existence and uniqueness of the fixed point of dynamic evolution model are proved, and an equilibrium stability condition for the dynamic evolution of network traffic flow with elastic demand is derived. Then, the evolution of network traffic flow is investigated through numerical experiments by changing the three parameters associated with travelers, which are the sensitivity of travelers' travel demand to travel cost, the randomness of travelers' route choices, and travelers' reliance on the previous day's actual cost. Our findings are as follows. Firstly, there are three kinds of final states in the evolution of network traffic flow: stability and convergence to equilibrium, periodic motion and chaos. The final state of the network traffic flow evolution is related to the above three parameters. It is found that under certain conditions the bifurcation diagram of the network traffic flow evolution reveals a complicated phenomenon of period doubling bifurcation to chaos, and then period-halving bifurcation. Meanwhile, the chaotic region is interspersed with odd periodic windows. Moreover, the more sensitive to cost the travelers' travel demand the more likely the system evolution is to be stable. The smaller the randomness of travelers' route choices, the less likely the system evolution is to be stable. The lower the degree of travelers' reliance on the previous day's actual cost, the more likely the system evolution is to be stable.
Propagation matrix of plane wave incident obliquely on stratified lossy chiral medium
Authors: Wang Fei  , Wei Bing  ,   School of Physics and Optoelectronic Engineering, Xidian University, Xi'an 710071, China;,   Collaborative Innovation Center of Information Sensing and Understanding at Xidian University, Xi'an 710071, China
Published: December 2020

The real and imaginary parts of the eigen complex wave vector in a stratified lossy chiral medium for the case of oblique incidence are derived by using the phase-matching condition. Due to the fact that the real and imaginary parts are nonparallel, the eigen wave propagating in the medium is inhomogeneous. Then the refraction angle of the eigen wave can be deduced via the real part of the wave vector. Finally the propagation matrix of the obliquely incident wave in a stratified lossy chiral medium is derived based on the boundary conditions and the field equations of eigen wave in each region. By using the proposed method, the reflection, transmission, and propagation characteristics of plane wave with arbitrary incident angle in a stratified chiral medium can be analyzed.
Liquid-solid phase transition of Cu-Zr eutectic alloy under microgravity condition
Authors: Chen Ke-Ping  , Lü Peng  , Peng Wang  ,   Department of Applied Physics, Northwestern Polytechnical University, Xi'an 710072, China
Published: December 2020

Eutectic phase transition involves the competitive nucleation and coupled growth of two solid phases within one liquid phase. Phase selection especially under unequilibrium condition, may result in novel microstructures and thus affects the performances of eutectic alloys. Liquid Cu-10 wt.% Zr hypoeutectic, Cu-12.27 wt.% Zr eutectic and Cu-15 wt.% Zr hypereutectic alloys are rapidly solidified in the containerless process in a 3 m drop tube. During the experiments, the Cu-Zr alloys are heated by induction heating in an ultrahigh vacuum chamber and further overheated to 200 K above their liquidus temperatures for a few seconds. Then the liquid alloys are ejected out from the small orifice and dispersed into tiny droplets after adding the argon gas flow. The solidified samples are analyzed by Phenom Pro scanning electron microscope and HXD-2000 TMC/LCD microhardness instrument. The competitive nucleation and growth among (Cu) dendrite, Cu9Zr2 dendrite and (Cu+Cu9Zr2) eutectic phase become more and more intensive as droplet diameter decreases. The layer spacing in Cu-12.27 wt.% Zr eutectic alloy decreases when the undercooling increases. And the microstructural transition takes place from lamellar eutectic to anomalous eutectic. The microstructure of Cu-10 wt.% Zr hypoeutectic alloy is characterized by (Cu) dendrite and lamellar eutectic. Whereas the microstructure in Cu-15 wt.% Zr hypereutectic alloy consists of Cu9Zr2 dendrite and lamellar eutectic. For the Cu-10 wt.% Zr hypoeutectic alloy, with the decrease of droplet size, the primary (Cu) phase transforms from coarse dendrites into equiaxed grains, and the volume fraction of (Cu) dendrite becomes larger and larger. As for Cu-15 wt.% Zr hypereutectic alloy, the primary Cu9Zr2 intermetallic compound grows in a band manner, and with the decrease of droplet size and increase of cooling rate, the solidified microstructure transforms from band Cu9Zr2 dendrite plus lamellar eutectic into spherical cell structure. The three alloys reach maximal undercooling at 177 K, 156 K and 204 K, respectively. The Trivedi-Magnin-Kurz and Lipton-Kurz-Trivedi/Boetinger-Coriell-Trivedi models are used to analyze the dendritic and eutectic growth as a function of undercooling. Theoretical analysis indicates that both dendritic growth and eutectic growth are controlled by solute diffusion during liquid-solid phase transition. To further investigate the effects of cooling rate and undercooling on the mechanical properties of Cu-Zr eutectic alloys, the microhardness of each of different phases is determined. The microhardness of the primary (Cu) phase within Cu-10 wt.% Zr hypoeutectic alloy is strengthened with the increase of cooling rate. The microhardness of eutectic within the three alloys also increases with increasing the cooling rate and the initial alloy composition of the alloy.
Study of the two dimensional imaging performance for the gas electron multiplier using the resistive anode readout method
Authors: Ju Xu-Dong  , Dong Ming-Yi  , Zhou Chuan-Xing  , Dong Jing  , Zhao Yu-Bin  , Zhang Hong-Yu  , Qi Hui-Rong  , Ouyang Qun  ,   Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China;,   State Key Laboratory of Particle Detection and Electronics, Beijing 100049, China;,   University of Chinese Academy of Sciences, Beijing 100049, China
Published: December 2020

The new type of micro-pattern gaseous detector (MPGD) like the gas electron multiplier (GEM), features the advantage of good spatial resolution ( 100 m). However, abundant and high density electronic channels are needed to obtain the high spatial resolution, which will lead to a great pressure on the detector construction, power consumption, spatial utilization, etc. The resistive anode readout method can help to obtain a good spatial resolution comparable to the pixel readout structure with an enormous reduction of the electronic channels. By using the thick film resistor technology, a new type of resistive structure, composed of high resistive square pad array with low resistive narrow border strips, is developed and applied to the readout anode of the triple GEM detector. For the resistive anode readout board used in the experiment, there are 66 resistive cells, which means that the detector needs only 49 electronics channels. To obtain a good spatial resolution, the cell size is set to be 6 mm6 mm. The surface resistivity of the pads and the strips are 150 k/□ and 1 k/□, respectively. The performances of the detector, especially the two-dimensional imaging performance, are studied by using a 55Fe (5.9 keV) source and an X ray tube (8 keV). The test results show that the spatial resolution of the detector is better than 80 m () by using the imaging of a 40 m wide slot, and the nonlinearity is better than 1.5% by the scanning along the x-axis of the readout board in the steps of 1 mm. Furthermore, quite a good two-dimensional imaging capability is achieved by the detector. These good performances of the detector show the feasibility of the resistive anode readout method for the GEM detector with large area and other detectors with similar structures in the two-dimensional imaging applications.
A theoretical study on collision mechanisms for low energy electron impact ionization of helium in the perpendicular geometry
Authors: Yang Huan  , Zhang Sui-Meng  , Xing Ling-Ling  , Wu Xing-Ju  , Zhao Min-Fu  ,   The Department of Experiment and Practical Training Management, West Anhui University, Liu'an 237012, China;,   Research Center of Atmos and Molecules and Optical Applications, West Anhui University, Liu'an 237012, China;,   School of Electrical and Optoelectronic Engineering, West Anhui University, Liu'an 237012, China
Published: December 2020

Under the condition of ten different incident energies ranging from 3 eV to 80 eV above the ionization potential of helium and the outgoing electrons having equal energies, by making use of 3C model and modified 3C model, the triple differential cross sections of electron-impact single ionization of the ground state of helium in the perpendicular geometry are calculated. The result is compared with corresponding experimental result to systematically investigate the influences of various screening effects on the triple differential cross sections for helium. The collision mechanisms of the triple differential cross sections are explored. The result shows that the effects of dynamic screening in the final state can directly affect the structures of the triple differential cross sections at lower incident energy, which will unavoidably affect the angular distribution and relative amplitude of side peaks at angles =90 and =270. The screening effects of residual electron in the final state of He+ have a similar significant effect on the amplitude of triple differential cross section of helium and angular distributions and relative amplitudes of side peaks at angles =90 and =270. When the incident energy is over 84.6 eV, the screening effect of residual electron in the final state of He+ has a slight effect on the amplitude of triple differential cross section, which can be overlooked. But the effects of dynamic screening in the final state on side peaks at angles =90 and =270 need considering. In addition, by taking advantage of DS3C-Z model, the results of collision mechanism of various peaks at angles =180, =90 and =270 show that the middle peak at angle =180 is produced by a process called triple scattering mechanism and then the side peaks at angles =90 and =270 are produced by a process called double scattering mechanism. Such a collision mechanism has a direct influence on the generation and variation law of triple differential cross sections.
General image encryption algorithm based on deep learning compressed sensing and compound chaotic system
Authors: Chen Wei , Guo Yuan , Jing Shi-Wei ,   School of Computer and Control Engineering, Qiqihar University, Qiqihar 161006, China
Published: December 2020

Many image compression and encryption algorithms based on traditional compressed sensing and chaotic systems are time-consuming, have low reconstruction quality, and are suitable only for grayscale images. In this paper, we propose a general image compression encryption algorithm based on a deep learning compressed sensing and compound chaotic system, which is suitable for grayscale images and RGB format color images. Color images can be directly compressed and encrypted, but grayscale images need copying from 1 channel to 3 channels. First, the original image is divided into multiple 3 × 33 × 33 non-overlapping image blocks and the bilinear interpolation Bilinear and convolutional neural network are used to compress the image, so that the compression network has no restriction on the sampling rate and can obtain high-quality compression of image. Then a composite chaotic system composed of a two-dimensional cloud model and Logistic is used to encrypt and decrypt the compressed image (sliding scrambling and vector decomposition), and finally the decrypted image is reconstructed. In the reconstruction network, the convolutional neural network and bilinear interpolation Bilinear are mainly responsible for reconstructing the contour structure information, and the fully connected layer is mainly responsible for reconstructing and combining the color information to reconstruct a high-quality image. For grayscale images, we also need to calculate the average value of the corresponding positions of the 3 channels of the reconstructed image, and change the 3 channels into 1 channel. The experimental results show that the general image encryption algorithm based on deep learning compressed sensing and compound chaos system has great advantages in data processing quality and computational complexity. Although in the network the color images are used for training, the quality of grayscale image reconstruction is still better than that of other algorithms. The image encryption algorithm has a large enough key space and associates the plaintext hash value with the key, which realizes the encryption effect of one image corresponding to one key, thus being able to effectively resist brute force attacks and selective plaintext attacks. Compared with it in the comparison literature, the correlation coefficient is close to an ideal value, and the information entropy and the clear text sensitivity index are also within a critical range, which enhances the confidentiality of the image.
A Drosophila screen identifies NKCC1 as a modifier of NGLY1 deficiency
Authors: Talsness Dana M , Owings Katie G , Coelho Emily , Mercenne Gaelle , Pleinis John M , Partha Raghavendran , Hope Kevin A , Zuberi Aamir R , Clark Nathan L , Lutz Cathleen M , Rodan Aylin R , Chow Clement Y
Published: December 2020

N-Glycanase 1 (NGLY1) is a cytoplasmic deglycosylating enzyme. Loss-of-function mutations in the NGLY1 gene cause NGLY1 deficiency, which is characterized by developmental delay, seizures, and a lack of sweat and tears. To model the phenotypic variability observed among patients, we crossed a Drosophila model of NGLY1 deficiency onto a panel of genetically diverse strains. The resulting progeny showed a phenotypic spectrum from 0 to 100% lethality. Association analysis on the lethality phenotype, as well as an evolutionary rate covariation analysis, generated lists of modifying genes, providing insight into NGLY1 function and disease. The top association hit was Ncc69 (human NKCC1/2), a conserved ion transporter. Analyses in NGLY1-/- mouse cells demonstrated that NKCC1 has an altered average molecular weight and reduced function. The misregulation of this ion transporter may explain the observed defects in secretory epithelium function in NGLY1 deficiency patients.
Constructions of Vulnerability by Different Groups of Welfare Professionals
Authors: Theilmann Birgitte , Laursen Erik
Published: December 2020

This article has examined the various ways vulnerability among children is constructed by four groups of welfare professionals (teachers, daycare workers, social workers, and health care workers) within a Danish welfare context. Based on an empirical research project that featured a large number of interviews, the article has demonstrated how professionals construct vulnerability from a combination of their professional background and experiences in their working practice related to vulnerability among children. The research findings have revealed that professional employees in general tend to link vulnerability among children to either diagnoses and deviant behavior or a child’s family context. At the same time, professional employees tend to ignore the possibility that vulnerability might be produced inside an institutional context like a school or kindergarten. In linking vulnerability to the child’s family context, professional employees generally point to classic forms of risk and social problem factors related to children’s families.
February 1st in Ireland (Imbolc and/or LáFhéile Bride): From Christian Saint to Pagan Goddess
Authors:   Department of Germanic and Celtic Studies, Philological Faculty, Moscow State University, Russia, Mikhailova Tatyana ,   Institute of Linguistics, Russian Academy of Sciences
Published: December 2020

Like in many countries of Europe, the 1st of February (Imbolk, the Brigid’day) in Ireland marks the beginning of Spring and is connected with some fertility rites. In old rural Ireland the people spent time watching hedgehogs (to see one was a good weather sign), preparing and eating special food, making straw girdles and caps, putting red ribbons on their houses (Brat Bride ‘Brigit’s cloak’), making special Brigit’s crosses and straw dolls, called Brideog, to visit a sacred spring which had a magic healing and anti-sterile power (wells and springs, worshiped in pagan Ireland, were prohibited by St. Patrick), and finally singing protective charms. In modern urban Ireland all these rites remind in the past, but the Brigid’day is not forgotten or abandoned. In this article, the author tries to outline three main ‘tracks’ of the old tradition: 1. Pseudo-folkloric (fake-lore): singing, dancing, making crosses, storytelling etc. 2. Pseudo (Vernacular)-Catholic: early mass and pilgrimages to the places connected with St. Brigit, especially – sacred wells. 3. “Neo-paganic”: special dresses, red ribbons, ritual dancing, fires, divinations of the future, bath in the sacred water etc. (in the most part – performed by women). Collecting material for the classification, the author outlined a special new direction of ‘shared spirituality’ representing presumably a new mode of collective behavior in modern urban societies.
GjirokastraFolklore Festival as the Main Ritual Event in Albanian Cultural Life at the Beginning of the 21st Century
Authors:   Peter the Great Museum of Anthropology and Ethnography (Kunstkamera), Russian Academy of Sciences, St. Petersburg, Russia, Novik Alexander
Published: December 2020

The paper presents an overview and analysis of the Gjirokastra National Folklore Festival (NFFoGj), one of the most important events in the cultural life of Albania. Global transformations that have affected all aspects of life have inevitably brought changes to traditional culture, traditional values and relations with the outside world, including across the Balkans. The majority of program issues were inspired by a common European practice of holding mass folklore events and measures aimed at nurturing and preserving cultural heritage. It is deeply connected to the process of revitalisation of old ritual practices and folk costume and to the socialisation of people who have professional and semi-professional associations with ethnic culture. Having analysed the materials collected in the run-up to the festival and during the event as well as during field studies in the Western Balkans in 1992–2019, I can acknowledge revitalisation of many, if not all, elements of folk culture. In this case revitalisation does not mean following the tradition literally, but rather an attempt to preserve it while adopting a modern perspective and advances in technology. The essential part of this process is the attempt to breathe new life into the components of traditional culture, and adapt them to the here and now. The NFFoGj has also become a major attempt to museificate the cultural heritage of the Albanians. Contests that have been held regularly over the past 70 years to reveal the best examples of folk art and support independent artists have encouraged interest in the roots of national culture and helped many generations not to forget what their predecessors valued. Thus, folk dance, music, songs and costume were reproduced – at times artificially – in various regions of the country to showcase the achievements of a locality (village, district, town, region) at the national festival as the main ritual cultural event.
Analysis of Institutional Factors Affecting Optimization of Coffee Yields in Chuka Sub-County, Tharaka-Nithi County, Kenya
Authors: Kihoro David M. , Gathungu Geofrey K.
Published: December 2020

The importance of coffee production in the world economy cannot be ruled out due to its contribution in the developing countries in areas such as creation of employment and rise in foreign exchange. Most of the coffee producing countries in the world have come up with strategies to increase their quantity and improve the quality of their produce. In Kenya, the government have also come with numerous policies to support coffee production at the farm level but production of coffee in Kenya has since 1989 crop year been declining. There has been emergence of other enterprises that are profitable than coffee production such as real estate and dairy sector in most of the coffee-growing zones, but there are many farmers who have been determined to maintain coffee production. Despite the efforts made by the government to maximise coffee production in terms of quality and quantity, production has shown a downward trend, with some farmers completely doing away with production This study was aimed at assessing the factors that affect optimization of coffee production in Chuka sub-County, Tharaka-Nithi County. Proportional stratified random sampling was used to select a sample of 153 respondents from a population of 7,428 small-scale coffee farmers from ten cooperatives in the sub-County. The findings of the study indicated that access to extension, access to research and management of coffee cooperative were essential in coffee production with a mean agreement of 58.33%. The research established that access to extension (5%) and management of cooperatives (5%) were statistically significant while access to research at (5%) was statistically insignificant. Similarly, access to extension services increased optimization by 91%, poor management of coffee cooperatives reduced production by 45.1%, while access to research increased coffee production by 51%. Therefore, it is important to ensure farmers access extension services, research and there is improved management of coffee cooperatives.
Effects of Different Socio-economic Characteristics of Rural Households on Their Saving Decision in Pabna District of Bangladesh: A Binary Logistic Regression Analysis
Authors: Al-Amin Md.
Published: December 2020

Household saving ensures a smooth future by softening the potential insecurities arise from uncertainty at the cost of present consumption. Moreover, the volume of national investment determines the actual health of an economy which is intensively associated with national savings. This study aimed at determining the effects of different socio-economic characteristics of rural households on their saving decision in Pabna district of Bangladesh. This research used a set of cross-sectional data from 250 households from three upazilas in Pabna district namely Pabna Sadar, Iswardi and Sujanagar on the relevant variables for the empirical analysis. A multistage random sampling technique involving simple, purposive and stratified random sampling was used to draw the sample. The study employed a binary logistic regression model to assess the influences of different socio-economic and demographic characteristics of rural household on their saving decision. The findings of the current study asserted that gender, family size and dependency ratio of household have significant and negative effects on their decision to start saving or not to start saving. Contrarily, the effects of the variables age, education level, marital status, income, secondary earner and liabilities on the decision of households to participate in saving were positive and significant. Moreover, the results revealed that social status has a strong but insignificant effect, but the variables access to bank and credit facilities have almost no significant effect on the household saving decisions. Since, private savings is essential for both the micro and macro level of an economy, therefore the study tried to suggest some recommendations with a view to increase private savings.
Financial Risk and Adoption of Public-Private Partnerships in Kenyan Public Universities
Authors: Asakania Francis Mukatia , Namusonge Gregory S. , Sakwa Maurice
Published: December 2020

Employment of public-private partnerships as a way of delivery of public utilities has been on the rise in the recent past. This has been driven by a number of factors, key among them being the ability of the public entity to transfer financial risk to private sector players who are better placed to mitigate such risks. The study purposed to assess the effect of financial risk on adoption of public-private partnerships in Kenyan public universities. The specific study objectives were to evaluate the influence of interest rate variability, revenue streams variability and exchange rate variability on adoption of public-private partnerships. The study employed a descriptive research design while targeting a population of 223 comprising of purposively selected employees from nine public universities. A sample size of 143 was used from whom data was collected using structured questionnaire. Data analysis employed use of both descriptive and inferential statistics. The results obtained show that interest rate variability, revenue stream variability and exchange rate variability have a statistically significant influence on adoption of public-private partnerships. On the basis of the study findings it was concluded that financial risk transfer had a significant positive influence on adoption of public-private partnerships in Kenyan public universities. It is therefore recommended that Kenyan public universities should thoroughly evaluate financial risk involved in any project before entering into public-private partnership arrangement in order to enhance value for money.
Comparative Advantages of Conservation Agriculture Practice in Coastal Areas of Chattogram Division: A Productivity and Profitability Analysis
Authors: Majumder Kausar Ahmed , Ahmed Jasim Uddin , Fatema Kanij
Published: December 2020

The study was conducted to assess comparative advantages of the productivity and profitability for conservation agriculture practice in Chattogram. A total of 120 farmers (60 farmers adopting conservation agriculture (CA) and 60 farmers non-adopting CA) from two districts (Feni and Noakhali) of Chattogram division were selected. Descriptive statistics like sum, averages, percentages, and ratios were calculated to evaluate the nature and extent of use of advanced machinery and fertilizer data. Farmers were categorized on the basis of farm size (small, medium and large) and selected by multistage stratified sampling. Crop productivity was measured using the Enyedi’s crop productivity index. The profitability of crop production was measured in terms of gross return, gross margin, net margin and benefit-cost ratio (BCR). The crop productivity of rice, mustard and soybean were increased by 0.18, 26, and 0.19 percent, respectively in respect to non-practicing conservation agriculture.  BCR increased by 42.43%, 40.78% and 36.61% for rice, mustard and soybean cultivation respectively with respect to the entire region for adopting conservation agriculture practice. Ultimately, the farmers who adopted conservation agriculture were gaining more profit than the farmer whose were not adopting the conservation agriculture practice. As Bangladesh is a labour intensive country and the availability of capital is short. The expense of purchasing the machines cannot be afforded by the farmers. In Feni and Noakhali are located in the coastal region. Climatic problem is another problem of the people of this area. The uses of advanced machineries are still limited. The quality of soil is decreasing day by day because of excessive use of synthetic fertilizers.