bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preparation of β-Ga2O3 films on off-angled sapphire substrates and solar-blind ultraviolet photodetectors
Authors: Zhu Yuxia , Li Yuewen , Xiu Xiangqian , Sun Xinyu , Xie Zili , Tao Tao , Chen Peng , Liu Bin , Ye Jiandong , Zhang Rong , Zheng Youdou 
Published: July 2022

Abstract

β-Ga2O3 films have been prepared on (0001) sapphire substrates with different off-axis angles toward

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11

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by sol–gel method and the solar-blind ultraviolet photodetectors (PDs) with metal-semiconductor-metal structure have been fabricated on these films. The effects of off-angled sapphire substrates on the surface morphology and crystal quality of β-Ga2O3 films have been systematically investigated. All the results indicate that to some extent the larger off-angled sapphire substrate could lead to the smoother surface morphology and higher crystal quality of β-Ga2O3 films. Reduction in the numbers of in-plane rotational domains for β-Ga2O3 films on off-angled substrates may result in the above-mentioned improvement, which have been confirmed by x-ray diffraction ϕ-scan. β-Ga2O3 film grown on ∼7° off-angled sapphire substrate has (

400

) preferred orientation with the single-domain growth mode. Besides, the performance of β-Ga2O3 PDs fabricated on different off-angled substrates show the same trend with changing the off-axis angles. The β-Ga2O3 PD fabricated on ∼7° off-angled sapphire substrate has excellent optical characteristics with large photocurrent to dark current ratio of 430.53 and high UV–visible rejection ratio of 1.42 × 103. These results would be helpful for improving the crystal-quality of hetero-epitaxy β-Ga2O3 films by using off-angled sapphire substrates and fabricating the cost-effective mass-producible solar-blind ultraviolet PDs by sol–gel method.
Pressure effect on magnetism and valence in ferromagnetic superconductor Eu(Fe0.75Ru0.25)2As2
Authors: Nix Zachary , Zhao Jiyong , Alp Esen E , Xiao Yuming , Zhang Dongzhou , Cao Guang-Han , Vohra Yogesh K , Bi Wenli 
Published: July 2022

Abstract
Eu(Fe0.75Ru0.25)2As2 is an intriguing system with unusual coexistence of superconductivity and ferromagnetism, providing a unique platform to study the nature of such coexistence. To establish a magnetic phase diagram, time-domain synchrotron Mössbauer experiments in 151Eu have been performed on a single crystalline Eu(Fe0.75Ru0.25)2As2 sample under hydrostatic pressures and at low temperatures. Upon compression the magnetic ordering temperature increases sharply from 20 K at ambient pressure, reaching ∼49 K at 10.1 GPa. With further compression, the magnetic order is suppressed and eventually collapses. Isomer shift values from Mössbauer measurements and x-ray absorption spectroscopy data at Eu L
3 edge show that pressure drives Eu ions to a homogeneous intermediate valence state with mean valence of ∼2.4 at 27.4 GPa, possibly responsible for the suppression of magnetism. Synchrotron powder x-ray diffraction experiment reveals a tetragonal to collapsed-tetragonal structural transition around 5 GPa, a lower transition pressure than in the parent compound. These results provide guidance to further work investigating the interplay of superconductivity and magnetism.
Optimized photoelectric characteristics of MAPbCl3 and MAPbBr3 composite perovskite single crystal heterojunction photodetector
Authors: Liu Chao , Chen Hang , Lin Ping , Hu Haihua , Meng Qingyu , Xu Lingbo , Wang Peng , Wu Xiaoping , Cui Can 
Published: July 2022

Abstract
MAPbBr3 single crystal (SC) thin layer was successfully grown on MAPbCl3 SC substrate to form perovskite SC heterojunction. Planar structure electrodes are deposited by thermal evaporation on the surfaces of MAPbCl3, MAPbBr3, and SCs heterojunction, respectively to evaluate their photoelectric performance. The SC heterojunction device exhibits excellent unidirectional conductivity in the voltage-current curves. Meanwhile, the current–time curves prove that SC heterojunction devices can effectively utilize the advantages of MAPbCl3 and MAPbBr3, possessing relatively low dark current (∼300 nA), which is comparable to the dark current of MAPbCl3, but very high photocurrent (∼3500 nA), which is equivalent to the photocurrent of MAPbBr3. Rather than the photocurrent overshot and decay occurring at the exposure of light illumination in the MAPbBr3 device, the photocurrent is extremely stable without overshot and decay in the SC heterojunction device. The light-to-dark ratio of the SC heterojunction device is twice that of MAPbCl3 device and three times that of MAPbBr3 device. Furthermore, the detectivity of the heterojunction device reaches as high as

∼

7

×

1

0

11

Jones

, an order of magnitude higher than MAPbCl3 and MAPbBr3. The excellent characteristics of SC heterojunction further expand the practical application prospect of perovskite materials.
Simulating the Dicke lattice model and quantum phase transitions using an array of coupled resonators
Authors: Leng Si-Yun , Lü Dong-Yan , Yang Shuang-Liang , Ma Ming , Dong Yan-Zhang , Zhou Bo-Fang , Zhou Yuan 
Published: July 2022

Abstract
A proposal for simulating the Dicke-Lattice model in a mechanics-controlled hybrid quantum system is studied here. An array of coupled mechanical resonators (MRs) can homogeneously interact with a group of trapped Bose–Einstein condensates (BECs) via the gradient magnetic field induced by the oscillating resonators. Assisted by the classical dichromatic radio-wave fields, each subsystem with the BEC-MR interaction can mimic the Dicke type spin-phonon interaction, and the whole system is therefore extended to a lattice of Dicke models with the additional adjacent phonon-phonon hopping couplings. In view of this lattice model with the Z
2 symmetry, its quantum phase transitions behavior can be controlled by this periodic phonon-phonon interactions in the momentum space. This investigation may be considered as a fresh attempt on manipulating the critical behaviors of the collective spins through the external mechanical method.
Patient behavior detection based on time-frequency fusion of FMCW radar
Authors: Xu Zhimeng , Zhang Shanshan , Chen Liangqin , Wu Zhenbin 
Published: July 2022

Abstract
This paper proposes a novel time-frequency feature fusion method to recognise patients’ behaviours based on the Frequency Modulated Continuous Wave (FMCW) radar system, which can locate patients as well as recognise their current actions and thus is expected to solve the shortage of medical staff caused by the novel coronavirus pneumonia (COVID-19). To recognise the patient’s behaviour, the FMCW radar is utilised to acquire point clouds reflected by the human body, and the micro-Doppler spectrogram is generated by human motion. Then features are extracted and fused from the time-domain information of point clouds and the frequency-domain information of the micro-Doppler spectrogram respectively. According to the fused features, the patient’s behaviour is recognised by a Bayesian optimisation random forest algorithm, where the role of Bayesian optimisation is to select the best hyper-parameters for the random forest, i.e. the number of random forest decision trees, the depth of leaves, and the number of features. The experimental results show that an average accuracy of 99.3% can be achieved by using the time-frequency fusion with the Bayesian optimisation random forest model to recognise six actions.
Characterization of absolute cavity radiometers for traceability to SI of solar irradiance
Authors: Balenzategui J L , de Lucas J , Cuenca J , González-Leiton A , Molero M , Fabero F , Silva J P , Mejuto E , Muñoz R , Arce A , Prieto E 
Published: July 2022

Abstract
Solar-type cavity radiometers are instruments of the highest metrological level for measuring solar direct normal irradiance. To ensure their traceability and performance, they are periodically compared to the World Group of Standards, which realizes the World Radiometric Reference (WRR), in the International Pyrheliometer Comparisons (IPCs). Additionally, they can be characterized in an absolute way, with direct traceability to SI units and with their measurement uncertainty calculated. This paper describes the different techniques and procedures applied for the characterization and calibration of solar cavity radiometers, with the main results obtained to date in the case of an Automatic Hickey–Frieden (AHF) radiometer. Voltmeters, resistors, temperature sensors and the area of the precision apertures have been calibrated, while the effective absorptance, temperature coefficients, optical scattering and non-equivalence factor have been evaluated. The temperature dependence of the electrical current in the cavity heater has also been analysed. The resulting corrections obtained for the AHF by characterization are compatible with the WRR factors obtained by this instrument in the past IPCs. An uncertainty of 0.42% (k = 1) has been obtained, and this paper discusses further improvements that may be able to reduce this figure to the desired expanded uncertainty of U = 0.1% (k = 2).
Bayesian approach to pyrometry during intercritical annealing of advanced high strength steel
Authors: Suleiman Fatima K , Lin Kaihsiang , Tsang Roger , Daun Kyle J 
Published: July 2022

Abstract
Precise thermal control during intercritical annealing is essential to the production of advanced high strength steels (AHSS). Measuring the temperature of the steel strip through pyrometry requires detailed knowledge of the spectral emissivity of the steel strip, which is imperfectly known since it varies with wavelength, direction, temperature, surface roughness, and oxidation, the latter depending on alloy composition and processing conditions. This study presents a Bayesian pyrometry methodology in which temperature and spectral emissivity are described as unknown stochastic variables that are inferred simultaneously. Additional information about the spectral emissivity obtained through ex situ characterization are incorporated into the inference through maximum likelihood priors. While standard pyrometry methods provide a point estimate of surface temperature, the Bayesian framework infers the posterior probability density, which will allow galvanizers to better assess the reliability of the pyrometrically-inferred temperature.
Optimal placement of distribution-level synchrophasor sensors for distribution system
Authors: Chen Tengpeng , Liu Fangyan , Chen Xuebing , Sun Lu , Amaratunga Gehan A J 
Published: July 2022

Abstract
This paper proposes a new method for the placement of the important synchrophasor sensors, the distribution-level phasor measurement units (DPMUs). A new objective function is developed to achieve minimization of distribution system state estimation errors where the limited number of DPMUs, the zero injection buses, the limited DPMU channels and the supervisory control and data acquisition measurements are taken into account. The A-optimal experimental design criterion is used to formulate the proposed objective function and constraints. The state estimates are obtained by using the maximum likelihood estimator where both Gaussian and non-Gaussian measurement noise scenarios are studied. The performance of the proposed method is demonstrated by simulations on IEEE 34-bus and 123-bus distribution systems.
Stable and flexible photodetector based on liquid-phase exfoliated titanium disulfide nanosheets
Authors: Liao Yanmo , Huang Zongyu , Qiao Hui , Zhou Yang , Yang Han , Qi Xiang 
Published: July 2022

Abstract
Herein, the TiS2 nanosheets (NSs) are prepared from the TiS2 bulk by the liquid-phase exfoliation to fabricate photoelectrochemical-type (PEC) photodetector. SEM images and Raman spectra show the successful acquisition of the TiS2 NSs. The as-prepared TiS2 photodetector shows self-powered ability with an applicable photoresponsivity that is about 0.37 μA W−1 under zero bias potential and 80 mW cm−2 visible light, and the response time of rise is 0.67 s and the decay time is 2.81 s. In this case, the photodetector is made of ITO-coated polyethylene terephthalate (PET), so it can maintain stable performance under the bending conditions. These results display that the as-prepared photodetector has excellent photoelectric properties, which facilitates the development of TiS2 NSs in optoelectronic devices.
Third quadrant overvoltage ruggedness of p-gate GaN HEMTs
Authors: Yuan Lifeng , Zhou Feng , Jin Yulei , Yang Qunsi , Xu Weizong , Ren Fangfang , Zhou Dong , Chen Dunjun , Zhang Rong , Zheng Youdou , Lu Hai 
Published: July 2022

Abstract
Overvoltage ruggedness is an essential reliability requirement for non-avalanche AlGaN/GaN power devices against inductive transient spikes in the OFF-state breakdown events. In this work, we first report the 3rd-quadrant (i.e. source-to-drain reverse operation) overvoltage ruggedness of the p-gate GaN high-electron-mobility transistors (HEMTs) by performing static current–voltage (I–V) sweeps and dynamic unclamped inductive switching (UIS) experiments. Both experimental results reveal an inferior breakdown performance of the device under 3rd-quadrant blocking conditions, including a low static voltage of 57 V and a dynamic breakdown voltage (BV) of 155 V. In particular, this transient voltage is evidently degraded from 155 V to 114 V (i.e. a 26% reduction) by increasing the load current, which is significantly different from the stable BV (1.4 kV) achieved in the 1st-quadrant dynamic breakdown. Such unusual degradation behavior can be explained by the trapping-related carrier transport mechanism, which is supported by temperature-dependent breakdown characteristics. Further numerical simulations, de-capsulation failure analyses and repeated UIS experiments are carried out to study the failure mechanism and gain insight into the overvoltage capability of the device. These results suggest that the rational design of the p-gate GaN HEMTs with the desired 3rd-quadrant overvoltage ruggedness requires careful consideration, especially in reverse conduction events.
Frequency stabilization of multiple wavelength lasers based on a broadband spectrum
Authors: Zhang Shuang , Qiao Hao , Ai Di , Zhou Min , Xu Xinye 
Published: July 2022

Abstract
We report on frequency stabilization of multiple wavelength lasers operating at 1389 and 1695 nm simultaneously on a broadband spectrum. These lasers are implemented in ytterbium optical lattice clock experiments, which need to have a narrow enough linewidth and maintain high long-term frequency stability. A 1560 nm femtosecond mode-locked laser with a narrow mode spacing of 250 MHz is used as a master laser, which is referenced to a local ultrastable optical cavity with the instability better than 1 × 10−15 at 1 s averaging time. Through the combination of erbium-doped fiber amplifier and high nonlinear fiber, the spectral width of the maser laser is broadened from 10 nm to more than 300 nm. The range of the broadened spectrum can cover 1389 and 1695 nm. Meanwhile, the spectral intensity at the corresponding wavelength can ensure that the signal-to-noise ratio of the beat signals between the two lasers and the broadened spectrum is about 30 dB at a resolution bandwidth (RBW) of 100 kHz. After phase locking the 1389 and 1695 nm lasers on the broadband spectrum, the residual linewidths are obtained to be about 0.8 Hz at 1 Hz RBW, and the stabilities are 3.5 × 10−16 and 4.7 × 10−16 at 1 s averaging time respectively, improving about six orders of magnitude. Our result can be conducive to obtaining the stabilized laser sources for the atomic optical clock, and will be of great significance for simplifying and miniaturizing the optical clock system.
Calibration of a precision current measurement system for high AC voltages using an AC quantum voltmeter
Authors: Ilić Damir , Heinrich Alexander , Meisner Johann , Behr Ralf 
Published: July 2022

Abstract
This paper describes the calibration of a high precision AC current measurement device which is required in a system to measure AC voltages up to 800 kV in the frequency range of 10 Hz to 400 Hz. The AC current measurement unit of such a system requires the calibration of the input current in the milliampere range at a frequency of approximately 50 Hz, and all measurements have been made at a suitable frequency of 62.5 Hz. An AC quantum voltmeter (AC-QVM) is used to achieve a traceability chain from DC resistance calibration, when it works as DC quantum standard, and as AC quantum standard for the AC current measurement. All DC and AC measurements needed for one calibration point (one current level) can be done in a rapid sequence within 30 min using the same AC-QVM, such that the combined uncertainty is at a level of 1 μA A−1 (k = 1).
An unexpected negative feedback between climate change and eutrophication: higher temperatures increase denitrification and buffer nitrogen loads in the Po River (Northern Italy)
Authors: Gervasio Maria Pia , Soana Elisa , Granata Tommaso , Colombo Daniela , Castaldelli Giuseppe 
Published: July 2022

Abstract
Temperature is one of the most fundamental drivers governing microbial nitrogen (N) dynamics in rivers; however, the effect of climate change-induced warming on N processing has not been sufficiently addressed. Here, annual, and seasonal (spring and summer) N loads exported from the Po River watershed (Northern Italy), a worldwide hotspot of eutrophication and nitrate pollution, are investigated in relation to water temperature trends over the last three decades (1992–2019). Despite large inter-annual variations, from the early 1990s, the Po River experienced a significant reduction in total N loads (−30%) represented mainly by nitrate, although agricultural N surplus in croplands and other watershed conditions have remained constant. In parallel, the Po River water is steadily warming (+0.11 °C yr−1, for average annual temperature) and the number of warm days is increasing (+50%, in the spring–summer period). The inverse relationship between water temperature and N loads strongly indicated that the higher temperatures have boosted the denitrification capacity of river sediments along the lowland reaches. Overall, over the last three decades, annual total N loads declined by around one-third due to a near 3 °C increase in temperature and this evidence was even more marked for the summer season (−45% for total N loads and +3.5 °C for temperature). Based on these observations, it is suggested that near-term effects of climate change, i.e. warming and an increase in the duration of low-flow periods in rivers, may have negative feedback on eutrophication, contributing to partially buffer the N export during the most sensitive period for eutrophication.
Diversity and distribution of fish species in Upper Watershed of Citanduy, West Java, Indonesia
Authors: Haryono  , Wahyudewantoro G , Gustiano R , Mulyadi  
Published: July 2022

Abstract
Citanduy is one of the major rivers in West Java, Indonesia, which empties into the Segara Anakan Lagoon. This river has streams originating from the Galunggung and Sawal Mountains. Information about freshwater fish in this area has not been fully documented and explored regarding fish diversity and distribution. This study aims to assess the fish diversity, abundance, distribution, and potential uses. The survey method was conducted upstream of the Citanduy River in the Regency of Tasikmalaya and Ciamis from 2012 to 2013. The sampling stations were grouped into the primary forest (1), secondary forest (2), shrubs (3), and (4) rice fields or plantations. In total, there are four stations in Sawal Mount and three groups of stations in Galunggung Mount. The collected fish were caught using electrofishing equipped with cast nets at each station. The results showed that there were 12 families with 24 species. Cichlidae is the dominant family with six species, followed by Cyprinidae with five species, and the remaining families only have one or two species. Both the Sawal and Galunggung Mountains have diverse habitats in rice fields or plantations. Based on the species, Barbodes binotatus was the most abundant species (128 ind./st.), followed by Nemacheilus fasciatus (64 ind./st.), Rasbora lateristriata (48 ind./st.) and the rest species with a range of 1-38 ind./st. Barbodes binotatus and Poecillia reticulata were widely distributed at 85.7%, followed by Channa gachua 71.4%; and the remaining species with a range of 14.3-57.1%. Most species have the potential as consume fish. Based on the species authenticity status, nine species (37.5%) were detected as introduced species.
The impact of aeration rate on Mahseer, Tor soro seed culture biological performance and blood profile
Authors: Setijaningsih L , Puspaningsih D 
Published: July 2022

Abstract
Water quality is the main factor that should have been considered in the part of aquaculture where the fish will grow in the optimal environment circumstances that suit biological demands. Adding the aeration aims to increase dissolved oxygen and turbulence. The objectives of this study is to see how different aeration rates affect the survival and growth of Mahseer Tor soro. The research used 12 aquariums, each sizing of 66x24x30 cm. Fish’s stocking density was three individuals per Liter for each aquarium. The randomization design was completed with four treatments and three replicates. The different aeration rate as a treatment were A) 0; B) 1000; C) 2000; and D) 3000 ml/minute. The results show that the highest absolute length (1.73±0.611 cm) and survival rate (98.33%) at 1000 ml/minute were the highest where the blood profile such as blood glucose, the hematocrit, haemoglobin, and erythrocyte values at 1000 ml/minute was the lowest compared to other treatments (P<0.05). The best of aeration rate for seed culture of masher, Tor soro is 1000 ml/minute, which has resulted in dissolved oxygen is ranging from 7.05–7.71 mg/L.
Application of Biofloc Technology in Indonesian Eel Anguilla bicolor bicolor Fish Culture: Water Quality Profile
Authors: Sadi NH , Agustiyani D , Ali F , Badjoeri M , Triyanto  
Published: July 2022

Abstract
Nowadays biofloc technology which utilizes organic matter decomposition activity of heterotrophic bacteria through C/N ratio setting has been widely applied in aquaculture but has never been applied in eel farming. Water quality is a crucial factor in eel aquaculture, one of the prestigious fish commodities. Therefore, this study was conducted to determine the feasibility of biofloc technology to be applied in eel fish culture. The study was conducted using two different pond systems, i.e with and without a water recirculation system. Air in both systems was injected into the water to reach 7-8 mg/L of dissolved oxygen. Molasses and activated charcoal as a carbon source were added so as to achieve a C/N ratio of 20:1. Water quality and microbiology parameters were monitored weekly. The results showed that both biofloc systems were able to maintain water quality very well up to the eleventh week without water replacement, which was characterized by low content of total organic nitrogen and toxic compounds nitrite. Therefore the biofloc technology is suitable to be applied in eel aquaculture.