bluuebunny/crossref_metadata_2025 huggingface dataset:
POLÍTICAS PÚBLICAS DE TURISMO NO BRASIL: UMA ANÁLISE DOS PLEITOS DIRECIONADOS PARA O DESENVOLVIMENTO DO TURISMO NO ESTADO DE SÃO PAULO
Authors: Rigoldi Aracelis Gois Morales , Pôrto Júnior Francisco Gilson Rebouças , Vieira Marli Teresinha , Spers Valéria Rueda Elias
Published: October 2023

O estado de são Paulo apresenta uma política pública de turismo diferenciada perante aos demais estados brasileiros, que a partir de legislações específicas, por meio do Departamento de Apoio ao Desenvolvimento dos Municípios Turísticos da Secretaria Estadual de Turismo (DADETUR), o Estado disponibiliza recursos financeiros para aplicação de projetos para infraestrutura focada para o desenvolvimento do turismo para os municípios decretados estâncias. Nesse sentido, a pesquisa tem como objetivo analisar os pleitos procedentes dos recursos do DADETUR, focando a importância das obras direcionadas ao fomento do turismo. Metodologicamente, o estudo é descritivo e exploratório, com uma abordagem qualitativa. A pesquisa utilizou-se dos instrumentos de triangulação de análises da coleta de dados e da técnica de análise de Bardin (2016), construindo categorias e subcategorias definidas para uma análise interpretativa. As coletas das informações ocorreram nos anos de 2017 a 2021 na sede da Secretaria de Turismo do estado de São Paulo. Os resultados demonstraram que a principal política pública de turismo do estado de São Paulo não cumpre com os objetivos da proposta de fomentar o turismo para o desenvolvimento da atividade, revelando que a maioria dos peitos são destinados para execução de obras de infraestrutura básica urbana.
Rights to the Result of Intellectual Activity of Artificial Intelligence in Terms of the Dualism of Intellectual Law
Authors: Akhramkina Kira Anatol'evna
Published: October 2023

This article reveals the author's view on the issues arising in the field of intellectual property rights in connection with the development of artificial intelligence systems. The topic of the research is touched upon due to the fact that the modern technological renewal in the modern world is so large-scale that many scientists are inclined not only to historical changes, but also to anthropological ones: technology becomes dominant in an inextricable connection with the human operator. In the modern Russian legislation there is no institutional fixation of norms of law regulating the relations connected with creation and use of results of artificial intelligence. In the global legal field the recognition of artificial intelligence as the author of the invention has been an open question for a long time. The article considers different points of view on the definition of artificial intelligence, including foreign sources. The author argues about the applicability of the concept of "inventor" in relation to artificial intelligence. The author's position in relation to the results of artificial intelligence is presented on the basis of the principle of intellectual property duality, where the main idea is the separation of non-property and property rights to the results of artificial intelligence. Methods of analysis, synthesis, modeling, comparative-legal were used. In the end conclusions are made about the recognition of authorship on the result of artificial intelligence, based on the creative contribution to its creation and work, the emergence and transfer of exclusive rights.
Topology optimization design of dual-channel metasurface structure with controllable amplitude of retroreflection and mirror reflection
Authors: Shi Peng-Fei , Ma Xin-Ying , Xiang Chuan , Zhao Hong-Ge , Li Yuan , Gao Ren-Jing , Liu Shu-Tian ,   School of Marine Electrical Engineering, Dalian Maritime University, Dalian 116023, China,   National Engineering Research Center of Fiber Optic Sensing Technology and Networks, Wuhan University of Technology, Wuhan 430070, China,   State Key Laboratory of Structural Analysis, Optimization and CAE Software for Industrial Equipment, Dalian University of Technology, Dalian 116023, China
Published: October 2023

For oblique incident electromagnetic waves, the generation of double reflection channels including retroreflection channel is of great significance in improving target recognition performance and navigation performance. In double channel reflection, controlling the ratio of retroreflection to specular reflection is the key to realizing reflection power distribution. In order to realize the control of the proportion of the reflected power in each channel, a topology optimization method for designing the reflective metasurface microstructure with dual channel is proposed in this paper. The implementation mechanism is investigated, physical model of metasurface with dual reflection channel including retroreflection channel is established, and the topology optimization model of metasurface microstructure with specific power ratio of the retroreflection to specular reflection is established. As a numerical example, a dual channel metasurface reflector with a 1∶1 ratio of retroreflection power to specular reflection power is designed for a 10 GHz plane wave in the TE mode with a pitch angle of –30°. The designed metasurface exhibits strong directionality in the retroreflective direction, and the reflection amplitudes in both directions are similar. The retroreflective metasurface with the maximum retroreflection ratio is designed. The retroreflection ratio of the designed metasurface is 0.093. There is no specular reflection or other singular reflection, and the strong reflection on the metasurface is concentrated at –30°. The ratio of the main beam power to the total reflection power is 0.900. The simulated and experimental results verify the feasibility of the proposed method.
Research progress of measurement of propagators in path integrals
Authors: Tian Li-Man , Wen Yong-Li , Wang Yun-Fei , Zhang Shan-Chao , Li Jian-Feng , Du Jing-Song , Yan Hui , Zhu Shi-Liang ,   Key Laboratory of Atomic and Subatomic Structure and Quantum Control (Ministry of Education), School of Physics, South China Normal University, Guangzhou 510006, China,   Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials,South China Normal University, Guangzhou 510006, China,   Guangdong-Hong Kong Joint Laboratory of Quantum Matter, Frontier Research Institute for Physics, South China Normal University, Guangzhou 510006, China
Published: October 2023

The propagator plays a central role in path integral theory and therefore has significant value in various fields of modern quantum physics, where path integral representations can be used. However, owing to the fact that it has not been directly measured in experiment, progress of experimental studies of quantum systems based on path integral representations has been seriously limited. Recently, we proposed a propagator measurement scheme based on the direct measurement of the wave function and successfully performed the first experimental measurement of the propagator by using a single photon experiment. Furthermore, in this study, the quantum principle of least action is demonstrated for the first time. This research successfully addresses the technical challenges of path integral experimental studies. In this work, we review the research progress in this field, including a brief introduction to the basic concepts and research progress of direct wave function measurement, and a detailed description of the theoretical model, experimental design, and experimental results of propagator measurement. Finally, we introduce an important application example, which can serve as the experimental demonstration of the quantum principle of least action through propagator measurement. The research progress of propagator measurement reviewed in this work will provide important references for future experimental studies by using this method.
Numerical analysis and optimization of 2.8 μm lightly-erbium-doped fluoride fiber laser based on cascaded transition
Authors: Xia Wen-Xin , Fu Shi-Jie , Zhang Jun-Xiang , Zhang Lu , Sheng Quan , Luo Xue-Wen , Shi Wei , Yao Jian-Quan ,   Key Laboratory of Optoelectronic Information Technology (Ministry of Education), School of Precision Instrument and Optoelectronics Engineering, Tianjin University, Tianjin 300072, China
Published: October 2023

Er3+-doped ZBLAN fiber laser is a promising approach to producing 2.8 μm mid-infrared (MIR) laser. The long lifetime of the lower-laser-level 4I13/2 often results in serious self-terminating effect which harms the laser power and efficiency significantly, especially for the active fiber with low dopant concentration which is preferred for weak thermal issues but cannot depopulate the lower-laser-level effectively via the up-conversion process. The 1.6 μm lasing (4I13/2 → 4I15/2) in Er-ZBLAN fiber could deplete the population on 4I13/2. Therefore, cascaded 2.8 μm and 1.6 μm lasing in Er3+-doped ZBLAN fiber provides a promising solution to the self-termination effects on laser power scaling. Moreover, the 4I13/2 → 4I15/2 1.6 μm laser also has some overlap with the 4I13/2 → 4I9/2 excited state absorption (ESA) spectrum. The ions on the 4I9/2 level would then relax to the upper-laser-level of 2.8 μm lasing (4I11/2), and results in enhanced laser efficiency. In general, the 1.6 μm cascaded lasing in 2.8 μm Er-ZBLAN fiber laser involves both lasing and ESA. The two processes have different spectra and different influences on the 2.8 μm laser gain. Therefore, there should exist an optimal wavelength of the 1.6 μm laser, which would balance the two processes, ensuring the lower-laser-level depopulation while maximizing the ion recycling. Therefore, we develop a comprehensive numerical model of cascaded 2.8 μm and 1.6 μm lasers based on Er-ZBLAN fiber. After the numerical model is verified by the previous experimental results, the effects of MIR and 1.6 μm lasing wavelengths on the power and conversion efficiency of 2.8 μm laser are investigated in depth. The results show that a suitable trade-off between the two processes can be reached with the cascaded lasing wavelength of 1610 nm, for the optimized 2.8 μm laser power/efficiency. Moreover, the influence of 1.6 μm laser cavity feedback on the power/efficiency characteristics of the 2.8 μm laser is also investigated. It is found that the feedback at 1.6 μm is very low, even only 4% is provided by the Fresnel reflection of the fiber facet, which can effectively generate 1.6 μm laser and significantly improve the efficiency of 2.8 μm laser.
Simulation and experimental analysis of aspherical double-liquid lens based on parallel plate electrode
Authors: Kong Mei-Mei , Dong Yuan , Xu Chun-Sheng , Liu Yue , Xue Yin-Yan , Pan Shi-Cheng , Zhao Rui ,   College of Electronic and Optical Engineering & College of Flexible Electronics (Future Technology), Nanjing University of Posts and Telecommunications, Nanjing 210023, China,   NARI Information & Communication Technology Co., Ltd., Nanjing 211100, China
Published: October 2023

According to the principle of dielectrophoresis, an aspherical double-liquid lens based on parallel plate electrodes is designed. In comparison with the liquid lenses based on patterned-electrodes, the aspherical double-liquid lens structure uses continuous electrodes, which have the advantages of simpler processing, lower cost, easier realization and more practicability. The droplet in the dielectric electrophoretic liquid lens is polarized in the electric field and moves towards the higher electric field intensity under the action of the dielectrophoretic force. With the change of applied voltage, the dielectrophoretic force varies, thus the contact angle of the droplet at the liquid-liquid interface is changed. Firstly, the models of aspherical double-liquid lenses under different voltages are established with Comsol software, and the data of interfacial profile are derived. Then using Matlab software, the derived interface surface data are fitted by polynomial, and the aspherical coefficients are obtained. Finally, the optical models are built with Zemax software, and the variation range of focal length and root mean square (RMS) radius of aspherical double-liquid lens under different voltages are analyzed. In order to further study the characteristics of aspherical double-liquid lens, it is compared with spherical double-liquid lens model. The liquid material, cavity structure and droplet volume of spherical double-liquid lens are consistent with those of aspherical double-liquid lens. The corresponding spherical double-liquid lens model is established by using the Zemax software, the range of focal length and RMS radius of spherical double-liquid lens under different voltages are obtained. The results show that the focal length variation range of aspherical double-liquid lens is larger than that of spherical double-liquid lens, and the imaging quality of the former is better than that of the latter. The experimental preparation of the designed aspherical double-liquid lens device is carried out, and its focal length and imaging resolution are measured. When the operating voltage is in a range of 0–280 V, the focal length varies from 54.2391 to 34.5855 mm, which is basically consistent with the simulation result. The feasibility of the liquid lens structure is verified experimentally. The imaging resolution can reach 45.255 lp/mm. The designed aspherical double-liquid lens based on the parallel plate electrode can provide a new scheme for the high-quality imaging of liquid lens and its application, and can expand the application scope of liquid lens.
Orbital angular momentum mode femtosecond fiber laser with over 100 MHz repetition rate
Authors: Hang Wu  , Liao Chen  , Shuai Li  , Yvfan Du  , Chi Zhang  , Xinliang Zhang  ,   Wuhan National Laboratory for Optoelectronics and School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, China
Published: October 2023

Orbital Angular Momentum (OAM) lasers have potential demand in many applications such as large capacity communication systems, laser processing, particle manipulation and quantum optics. OAM mode femtosecond fiber laser has become the research focus with the advantages of simple structure, low cost and high peak power. The current OAM mode femtosecond fiber lasers have made breakthroughs in the repetition frequency, pulse width, spectrum width and other key parameters, but it is difficult to achieve good overall performance. Besides, the repetition rate is currently in tens of MHz. In this paper, a large-bandwidth mode coupler is made based on the mode phase matching principle. Among them, the first order mode coupler with 3dB polarization dependent loss is made by the technology of strong fused biconical taper, and the second order mode coupler with 0.3dB polarization dependent loss is made by the technology of weak fused biconical taper. Combined with the nonlinear polarization rotation mode-locking mechanism, OAM mode femtosecond fiber lasers with over 100 MHZ repetition rate are built. The achievement of the key parameters is attributed to the selection of dispersion shifted fibers that can accurately adjust intracavity dispersion. Compared to traditional dispersion compensation fibers (DCF), the group velocity dispersion is reduced by an order of magnitude, so it can better adjust intracavity dispersion to achieve the indicators of large spectral bandwidth and narrow pulse width. In addition, the diameter of the fiber is 8μm, which is the same as that of a single mode fiber. Compared to DCF, the fusion loss can be ignored, so only a shorter gain Erbium-doped fiber is required that ensure a shorter overall cavity length and achieve high repetition frequency. The experimental results show that the first order OAM mode fiber laser has 113.6 MHz repetition rate, 98 fs half-height full pulse width, and 101nm 10-dB bandwidth. Second-order OAM mode fiber laser has 114.9 MHz repetition rate, 60 fs half-height full pulse width, and 100nm 10-dB bandwidth. Compared with the reported schemes, our scheme has better performance in key parameters such as repetition rate, pulse width and spectral width. We believe that the OAM mode fiber laser with good over performance is expected to be more widely used in OAM communication, particle manipulation and other research fields.
Invesigation of the electronic structure and Optoelectronic properties of Si-doped β-Ga2O3 using GGA+U method based on first-principle
Authors: Zhang Ying-Nan  , Zhang Min  , Zhang Pai  , Hu Wen-Bo  ,   School of Physics and Electronic Technology, Liaoning Normal University, Dalian 116029, China
Published: October 2023

In this work, the formation energy, band structure, state density, differential charge density and optoelectronic properties of undoped and Si doped β-Ga2O3 are calculated using GGA+U method based on density functional theory. The results show that the Si-substituted tetrahedron Ga(1) is more easily synthesized in experiments, and the obtained β-Ga2O3 band gap and Ga 3d state peak are in good agreement with the experimental results, and the effective doping is more likely to be obtained under oxygen-poor conditions. After Si doping, the total energy band moves to the low-energy end, and Fermi level enters the conduction band, showing n-type conductive characterastic. Si 3s orbital electrons occupy the bottom of the conduction band, the degree of electronic coocupy is strengthened, and the conductivity is improved. The dielectric function ε2(ω) results show that with the increase of Si doping concentration, the ability to stimulate conductive electrons first increases and then decreases, which is in good agreement with the quantitative analysis results of conductivity. The optical band gap increases and the absorption band edge rises slowly with the increase of Si doping concentration. The results of absorption spectra show that Si-doped β-Ga2O3 has strong deep ultraviolet photoelectric detection ability. The calculated results provide a theoretical reference for the further experimental investigation and the optimization innovation of Si-doped β-Ga2O3 and relative device design.
Spintronic devices based on topological and two-dimensional materials
Authors: Longxing Jiang  , Qingchao Li  , Xu Zhang  , Jingfeng Li  , Jing Zhang  , Zuxin Chen  , Min Zeng  , Hao Wu  ,   1. School of Semiconductor Science and Technology, South China Normal University, Guangzhou 510631, China;,   2. Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China;,   3. School of Materials Science and Engineering, Beihang University, Beijing 100191, China
Published: October 2023

Novel quantum materials such as topological materials, two-dimensional materials, create new opportunities for the spintronic devices. These materials can improve the charge-spin conversion efficiency, provide high-quality interface, and enhance the energy efficiently for spintronic devices. In addition,they have rich interactions and coupling effects, which provides a perfect platform to find new physics and novel methods to control the spintronic properties. Many inspiring results have been reported regarding the research on topological materials and two-dimensional materials, especially the layered topological and two-dimensional magnetic materials, and their heterostructures. This review will discuss recent achievements with these novel quantum materials on spintronic applications, firstly introduce the breakthroughs that topological materials have been made in spin-orbit torque devices, then present two-dimensional magnetic materials and their performance in spintronic devices, finally discuss the research progress in topological materials/two-dimensional magnetic materials heterostructures. This review can help to get a comprehensive understanding of the development of these novel quantum materials in the field of spintronics and inspire new research ideas with these novel materials.
Progress of Two-Dimensional Magnetic Materials for Spin Orbit Torque
Authors: Yinong Xiong  , Chuangwen  , Chuantong Ren  , Dequan Meng  , Shiwei Chen  , Shiheng Liang  ,   1. Faculty of Physics and Electronic Science, Hubei University, Wuhan 430062, China;,   2. Key Laboratory of Intelligent Sensing System and Security, Ministry of Education, Wuhan 430062, China
Published: October 2023

The rapid development of information technology has put forward higher requirements for the performance of information processing and storage devices. At the same time, with the continuous reduction of device size, traditional semiconductor devices based on electron charge properties face the problems and challenges of thermal dissipation and quantum size effect, and semiconductor technology has entered the post-molar era. Unlike traditional charge-based electronic devices, spin-based non-volatile Spintronic devices not only have high integrated density, read and write speed and read and write times, but also can effectively avoid heat dissipation, establishing a new technical platform for the development of information storage, processing and communication. In recent years, two-dimensional materials have attracted a lot of attention due to their unique band structure and rich physical properties. Two-dimensional magnetic materials have shown great research and application potential in the field of Spintronics. Compared to traditional block materials, the atomic thickness, ultra-clean interface and flexible stacking of two-dimensional materials provide great opportunities for exploring novel physical effects and ultra-low-power devices. At the same time, with the rise of topological materials (TMs), their topological protected band structures, diversified crystal structures and symmetries, strong spin-orbit coupling and adjustable electrical conductivity provide an ideal physical research platform for spintronics research. In this paper, we first introduce the common methods of preparing two-dimensional materials, then focus on the research progress of two-dimensional magnetic materials in the field of spin-orbit electronics, and finally look forward to the research challenges in this field. In the future, with continuous in-depth research on the preparation, physical properties and device applications of two-dimensional magnetic materials, two-dimensional magnetic materials will show more extensive research prospects and application value in the field of spintronics. Two-dimensional magnetic materials will provide more material systems for spintronics development.
Transition state searching for complex biomolecules: Algorithms and machine learning
Authors: Yang Jian-Yu , Xi Kun , Zhu Li-Zhe ,   Warshel Institute for Computational Biology, School of Medicine, The Chinese University of Hong Kong, Shenzhen 518172, China
Published: October 2023

Transition state is a key concept for chemists to understand and fine-tune the conformational changes of large biomolecules. Due to its short residence time, it is difficult to capture a transition state via experimental techniques. Characterizing transition states for a conformational change therefore is only achievable via physics-driven molecular dynamics simulations. However, unlike chemical reactions which involve only a small number of atoms, conformational changes of biomolecules depend on numerous atoms and therefore the number of their coordinates in our 3D space. The searching for their transition states will inevitably encounter the curse of dimensionality, i.e. the reaction coordinate problem, which invokes the invention of various algorithms for solution. Recent years, new machine learning techniques and the incorporation of some of them into the transition state searching methods emerged. Here, we first review the design principle of representative transition state searching algorithms, including the collective-variable (CV)-dependent gentlest ascent dynamics, finite temperature string, fast tomographic, travelling-salesman based automated path searching, and the CV-independent transition path sampling. Then, we focus on the new version of TPS that incorporates reinforcement learning for efficient sampling, and we also clarify the suitable situation for its application. Finally, we propose a new paradigm for transition state searching, a new dimensionality reduction technique that preserves transition state information and combines gentlest ascent dynamics.
Theoretical prediction of C- and O-doped Hittorf’s violet phosphorene as bipolar magnetic semiconductor material
Authors: Lu Yi-Lin , Dong Sheng-Jie , Cui Fang-Chao , Zhang Kai-Cheng , Liu Chun-Mei , Li Jie-Sen , Mao Zhuo ,   Institute of Ocean, College of Physical Science and Technology, Bohai University, Jinzhou 121007, China,   Faculty of Electronic Information Engineering, Guangdong Baiyun University, Guangzhou 510450, China,   College of Food Science and Engineering, Bohai University, Jinzhou 121007, China,   School of Environment and Chemical Engineering, Foshan University, Foshan 528000, China,   Peking Union Medical College, Chinese Academy of Medical Sciences, Tianjin 300192, China
Published: October 2023

Hittorf’s violet phosphorene is a novel two-dimensional material with stable structure and excellent optoelectronic properties. Studying the doping effect helps to understand its physical essence and is of great significance in further developing nanoelectronic devices. In this paper, the first-principles method based on density functional theory is used to study the electromagnetic properties of the non-metallic element B-, C-, N-, and O-doped single-layer violet phosphene. The results show that there is no magnetism after having doped boron and nitrogen, and the system still behaves as a nonmagnetic semiconductor, while carbon doping and oxygen doping cause spin splitting, and the violet phosphorene transforms from a nonmagnetic semiconductor to a bipolar magnetic semiconductor, and its spin density is mainly distributed in the P atom and gap region, rather than on the impurity. The direction of spin polarization of its carrier can be reversed by adjusting the electric field of O-doped violet phosphorene. When a certain size of forward or reverse electrostatic field is applied, the band dispersion becomes stronger, and the O-doped violet phosphorene transforms into a half-metallic magnet with 100% downward or upward spin polarization at the Fermi level. The field effect spin filter based on O-doped violet phosphorene can reverse the direction of spin-polarized current by changing the direction of the gate voltage. This study shows that O-doped violet phosphorene is expected to be an ideal candidate material for two-dimensional spin field-effect transistors, bipolar magnetic spintronic devices, dual channel field effect spin filters, and field-effect spin valves.
Topological phase transitions and topological quantum states modulated by the counter-rotating wave terms in a one-dimensional superconducting microwave cavity lattice
Authors: Zheng Zhi-Yong  , Chen Li-Jie  , Xiang Lü  , Wang He  , Wang Yi-Ping  ,   College of Science, Northwest A & F University, Yangling, 712100, China
Published: October 2023

We propose a one-dimensional lattice theory scheme based on superconducting microwave cavities, which includes two different types of microwave cavity unit cells. The coupling between unit cells is controlled by flux qubits to simulate and study their topological insulator characteristics. Specifically, a one-dimensional superconducting microwave cavity lattice scheme with a p-wave superconducting pairing term is achieved by mapping the counter-rotating wave terms to the p-wave superconducting pairing term. We found that the p-wave superconducting pairing term can modulate the topological quantum state of the system, allowing for the creation of topological quantum information transmission channels with four edge states. In addition, when the p-wave superconducting pairing term and the nearest-neighbor interaction exist, we find that the energy band undergoes fluctuations, inducing the generation of new energy bands, but the degeneracy of the edge states remains stable, which can achieve multiple topological quantum state transmission paths. However, when its regulatory value exceeds the threshold, the energy gap of the system will close, causing the edge states to annihilate in new energy bands. Furthermore, when considering the existence of defects in the system, we found that when the strength of the defects are small, the edge state produces small fluctuations, but it can be clearly distinguished, indicating its robustness. When the strength of the defect exceeds the threshold, the edge state and energy band cause irregular fluctuations, allowing the edge state to integrate into the energy band. Our research results have important theoretical value and practical significance, and can be applied in quantum optics and quantum information processing in the future.
Migration behavior of space charge packet researched by using electron beam irradiation and real-time space charge distribution measurement in piezo-pressure wave propagation (PWP) method
Authors: Pan Jia-Ping , Zhang Ye-Wen , Li Jun , Lü Tian-Hua , Zheng Fei-Hu ,   Department of Electrical Engineering, Tongji University, Shanghai 201804, China
Published: October 2023

The space charge packet is a special sort of space charge phenomenon that is characterized by the migration of aggregated space charge in the form of a packet in the sample. Currently, most of the experimental and simulation studies on the generation and migration of space charge packets focus on the space charge packets with positive polarity in polyethylene and their cross-linking products, while the characteristics of the space charge packets with negative polarity still need studying. This paper presents an integrated experimental system for studying space charge packet with negative polarity, which enables experimental studies combining electron beam irradiation technique and real-time space charge distribution measurement. The beam flux for electron beam irradiation is controlled by a metal grid with an optical fiber-electric relay, and the space charge distribution measurement is performed by the piezo- pressure wave propagation method. The system achieves a withstand voltage value of 17 kV and a measuring resolution of 25 ns for space charge distribution measurement and is suitable for experimental studies of various material samples with different thickness ranges under different electric fields. In this work, the migration behaviors of space charge packets with negative polarity in polypropylene (PP) and polymethyl methacrylate (PMMA) samples under different applied electric fields (15, 20, 25, 30 kV/mm) are studied by using the experimental system. The relationship between the migration properties of carriers with negative polarity (electrons) and the electric field can be extracted from the experimental results. The “negative differential mobility” phenomenon is found for both materials, i.e. the migration rate decreases with the increase of the electric field. The threshold electric field for the “negative differential mobility” phenomenon of electrons in PP sample is about 26.0 kV/mm while the threshold electric field for the “negative differential mobility” phenomenon of electrons in PMMA sample is 19.5 kV/mm, and the phenomenon disappears at an electric field of 27.5 kV/mm. The electric field where the "negative differential mobility" phenomenon of electrons appears and disappears in different materials can be extracted by using the experimental system proposed in this paper.
Heavy ion single event effect in double-trench SiC metal-oxide-semiconductor field-effect transistors
Authors: Li Yang-Fan , Guo Hong-Xia , Zhang Hong , Bai Ru-Xue , Zhang Feng-Qi , Ma Wu-Ying , Zhong Xiang-Li , Li Ji-Fang , Lu Xiao-Jie ,   School of Materials Science and Engineering, Xiangtan University, Xiangtan 411105, China,   Northwest Institute of Nuclear Technology, Xi’an 710024, China,   State Key Laboratory of Science and Technology on Reliability Physics and Application of Electronic Component, China Electronic Product Reliability and Environmental Research Institute, Guangzhou 510610, China
Published: October 2023

In this paper, experiments on 208 MeV Ge ion irradiation with different source-drain bias voltages are carried out for the double-trench SiC metal–oxide–semiconductor field-effect transistors, and the physical mechanism of the single event effect is analyzed. The experimental results show that the drain leakage current of the device increases more obviously with the increase of the initial bias voltage during irradiation. When the bias voltage is 400 V during irradiation, the device has a single event burned at a fluence of 9×104 ion/cm2, and when the bias voltage is 500 V, the device has a single event burned at a fluence of 3×104 ion/cm2, so when the LET value is 37.3 MeV·cm2/mg, the SEB threshold of DUT does not exceed 400 V, which is lower than 34% of the rated operational voltage. The post gate-characteristics test results show that the leakage current of the device with a bias voltage of 100 V does not change significantly during irradiation. When the bias voltage is 200 V, the gate leakage and the drain leakage of the device both increase, so do they when the bias voltage is 300 V, which is positively related to bias voltage. In order to further analyze the single particle effect mechanism of device, the simulation is conducted by using TCAD tool. The simulation results show that at low bias voltage, the heavy ion incident device generates electron-hole pairs, the electrons are quickly swept out, and the holes accumulate at the gate oxygen corner under the effect of the electric field, which combines the source-drain bias voltage, leading to the formation of leakage current channels in the gate oxygen layer. The simulation results also show that at high bias voltage, the electrons generated by the incident heavy ion move towards the junction of the N– drift layer and the N+ substrate under the effect of the electric field, which further increases the electric field strength and causes significant impact ionization. The local high current density generated by the impact ionization and the load large electric field causes the lattice temperature to exceed the melting point of silicon carbide, causing single event burnout. This work provides a reference and support for studying the radiation effect mechanism and putting silicon carbide power devices into aerospace applications.
A preclinical model of THC edibles that produces high-dose cannabimimetic responses
Authors: English Anthony , Uittenbogaard Fleur , Torrens Alexa , Sarroza Dennis , Slaven Anna Veronica Elizabeth , Piomelli Daniele , Bruchas Michael R , Stella Nephi , Land Benjamin Bruce
Published: October 2023

No preclinical experimental approach enables the study of voluntary oral consumption of high-concentration Δ9-tetrahydrocannabinol (THC) and its intoxicating effects, mainly owing to the aversive response of rodents to THC that limits intake. Here, we developed a palatable THC formulation and an optimized access paradigm in mice to drive voluntary consumption. THC was formulated in chocolate gelatin (THC-E-gel). Adult male and female mice were allowed ad libitum access for 1 and 2 hr. Cannabimimetic responses (hypolocomotion, analgesia, and hypothermia) were measured following access. Levels of THC and its metabolites were measured in blood and brain tissue. Acute acoustic startle responses were measured to investigate THC-induced psychotomimetic behavior. When allowed access for 2 hr to THC-E-gel on the second day of a 3-day exposure paradigm, adult mice consumed up to ≈30 mg/kg over 2 hr, which resulted in robust cannabimimetic behavioral responses (hypolocomotion, analgesia, and hypothermia). Consumption of the same gelatin decreased on the following third day of exposure. Pharmacokinetic analysis shows that THC-E-gel consumption led to parallel accumulation of THC and its psychoactive metabolite, 11-OH-THC, in the brain, a profile that contrasts with the known rapid decline in brain 11-OH-THC levels following THC intraperitoneal (i.p.) injections. THC-E-gel consumption increased the acoustic startle response in males but not in females, demonstrating a sex-dependent effect of consumption. Thus, while voluntary consumption of THC-E-gel triggered equivalent cannabimimetic responses in male and female mice, it potentiated acoustic startle responses preferentially in males. We built a dose-prediction model that included cannabimimetic behavioral responses elicited by i.p. versus THC-E-gel to test the accuracy and generalizability of this experimental approach and found that it closely predicted the measured acoustic startle results in males and females. In summary, THC-E-gel offers a robust preclinical experimental approach to study cannabimimetic responses triggered by voluntary consumption in mice, including sex-dependent psychotomimetic responses.
Theta cycle dynamics of spatial representations in the lateral septum
Authors: Bzymek Katarzyna , Kloosterman Fabian
Published: October 2023

An internal representation of the environment – or map – allows animals to evaluate multiple routes and adapt their navigation strategy to current needs and future goals. The hippocampal formation plays a crucial role in learning a spatial map and using the map for goal-directed navigation. The lateral septum forms a major node for connections between the hippocampus and subcortical brain regions that could link the spatial map to motivation and reward processing centers such as the ventral tegmental area and hypothalamus. It is not known, however, how the lateral septum contributes to the processing of spatial information and route planning.In this study, we investigated the temporal dynamics of spatial representations in the lateral septum. Neuropixels probes were used to record cellular activity along the dorsal-ventral extent of the lateral septum while rats performed one of two spatial navigation tasks in a Y-maze. The activity of a large fraction of cells was theta rhythmic and a subset of cells showed evidence of being active on alternate theta cycles (theta cycle skipping). Both theta rhythmicity and cycle skipping were strongest in the dorsal lateral septum. Similarly, spatially selective firing was most prominent in the dorsal lateral septum. Using neural decoding, we show that the lateral septum cell population encodes both the current location and alternatingly the possible future paths within single theta cycles when rats approach the choice point in the maze.Our data further shows that the alternating expression of spatial representations in the lateral septum is task-dependent, such that it is strongest when the task also requires the animals to alternate between rewarded goal arms. These data suggest that task demands and experience shape which representations are activated near a choice point. The lateral septum receives strong input from hippocampal place cells, and while there may be integration and transformation of incoming spatial signals, our findings support the idea that hippocampal spatial representations and their temporal dynamics are conveyed to subcortical projection areas through the lateral septum.
Transformation of value signaling in a striatopallidal circuit
Authors: Lee Donghyung , Liu Lillian , Root Cory M.
Published: October 2023

The ways in which sensory stimuli acquire motivational valence through association with other stimuli is one of the simplest forms of learning. Though we have identified many brain nuclei that play various roles in reward processing, a significant gap remains in understanding how value encoding transforms through the layers of sensory processing. To address this gap, we carried out a comparative investigation of the olfactory tubercle (OT), and the ventral pallidum (VP) - 2 connected nuclei of the basal ganglia which have both been implicated in reward processing. First, using anterograde and retrograde tracing, we show that both D1 and D2 neurons of the OT project primarily to the VP and minimally elsewhere. Using 2-photon calcium imaging, we then investigated how the identity of the odor and reward contingency of the odor are differently encoded by neurons in either structure during a classical conditioning paradigm. We find that VP neurons robustly encode value, but not identity, in low-dimensional space. In contrast, OT neurons primarily encode odor identity in high-dimensional space. Though D1 OT neurons showed larger response vectors to rewarded odors than other odors, we propose this is better interpreted as identity encoding with enhanced contrast rather than as value encoding. Finally, using a novel conditioning paradigm that decouples reward contingency and licking vigor, we show that both features are encoded by non-overlapping VP neurons. These results provide a novel framework for the striatopallidal circuit in which a high-dimensional encoding of stimulus identity is collapsed onto a low-dimensional encoding of motivational valence.
Neurophysiological trajectories in Alzheimer’s disease progression
Authors: Kudo Kiwamu , Ranasinghe Kamalini G. , Morise Hirofumi , Syed Faatimah , Sekihara Kensuke , Rankin Katherine P. , Miller Bruce L. , Kramer Joel H. , Rabinovici Gil D. , Vossel Keith , Kirsch Heidi E. , Nagarajan Srikantan S.
Published: October 2023

Alzheimer’s disease (AD) is characterized by accumulation of amyloid-
β
and misfolded tau proteins causing synaptic dysfunction and progressive neurodegeneration and cognitive decline. Altered neural oscillations have been consistently demonstrated in AD. However, the trajectories of abnormal neural oscillations in AD progression and their relationship to neurodegeneration and cognitive decline are unknown. Here, we deployed robust event-based sequencing models (EBMs) to investigate the trajectories of long-range and local neural synchrony across AD stages, estimated from resting-state magnetoencephalography. Increases in neural synchrony in the delta-theta band and decreases in the alpha and beta bands showed progressive changes along the EBM stages. Decreases in alpha and beta-band synchrony preceded both neurodegeneration and cognitive decline, indicating that frequency-specific neuronal synchrony abnormalities are early manifestations of AD pathophysiology. The long-range synchrony effects were greater than the local synchrony, indicating a greater sensitivity of connectivity metrics involving multiple regions of the brain. These results demonstrate the evolution of functional neuronal deficits along the sequence of AD progression.
Stumpy forms are the predominant transmissible forms of Trypanosoma brucei
Authors: Ngoune Jean Marc Tsagmo , Sharma Parul , Crouzols Aline , Rotureau Brice
Published: October 2023

Recently, Schuster
et al
. demonstrated that bloodstream slender forms of African trypanosomes are readily transmissible to young tsetse flies where they can complete their complex life cycle (1). In their experimental conditions, a single slender parasite was sufficient for productive infection. Here, we compared the infectivity of slender and stumpy bloodstream forms in adult flies with a mature immune system, and without using any chemical compounds that would alter the insect immune response and/or promote the infection. After ingestion of slender forms, infected flies were observed only in one out of 24 batches of non-immunocompetent teneral flies and with a high number of parasites. In contrast, infected flies were detected in 75% (18/24) of the batches infected with stumpy parasites, and as few as 10 stumpy parasites produced mature infections in immune adult flies. We discuss that, although Schuster
et al
. have demonstrated the intrinsic capacity of slender form trypanosomes to infect young and naive tsetse flies, highlighting the remarkable plasticity and adaptability of these protists, this phenomenon is unlikely to significantly contribute to the epidemiology of African trypanosomiases. According to both experimental and field observations, stumpy forms appear to be the most adapted forms for African trypanosome transmission from the mammalian host to the tsetse fly vector in natural conditions.
Optimizing e-commerce warehousing through open dimension management in a three-dimensional bin packing system
Authors: Yang Jianglong , Liang Kaibo , Liu Huwei , Shan Man , Zhou Li , Kong Lingjie , Li Xiaolan
Published: October 2023

In the field of e-commerce warehousing, maximizing the utilization of packing bins is a fundamental goal for all major logistics enterprises. However, determining the appropriate size of packing bins poses a practical challenge for many logistics companies. Given the limited research on the open-size 3D bin packing problem as well as the high complexity and lengthy computation time of existing models, this study focuses on optimizing multiple-bin sizes within the e-commerce context. Building upon existing research, we propose a hybrid integer programming model, denoted as the three dimensional multiple option dimensional rectangular packing problem (3D-MODRPP), to address the multiple-bin size 3D bin packing problem. Additionally, we leverage well-established hardware and software technologies to propose a 3D bin packing system capable of accommodating multiple bin types with open dimensions. To reduce the complexity of the model and the number of constraints, we introduce a novel assumption method for 0–1 integer variables in the overlap and rotation constraints. By applying this approach, we significantly streamline the computational complexity associated with the model calculations. Furthermore, we refine the dataset by developing a customized version based on the classical Three-Dimensional One-Size Dependent Rectangular Packing Problem (3D-ODRPP) dataset, leading to improved outcomes. Through comprehensive analysis of the research results, our model exhibits remarkable advancements in addressing the strong heterogeneous bin packing problem, the weak heterogeneous bin packing problem, the actual bin packing problem, and the bin packing problem with multiple bin types and open sizes. Specifically, it significantly reduces model complexity and computation time and increases space utilization. The system designed in this study paves the way for practical applications based on the proposed model, providing researchers with broader research prospects and directions to expand the scope of investigation in the field of 3D bin packing. Consequently, this system contributes to solving complex 3D packing problems, reducing space waste, and enhancing transportation efficiency.