bluuebunny/crossref_metadata_2025 huggingface dataset:
The importance of internal climate variability in climate impact projections
Authors: Schwarzwald Kevin , Lenssen Nathan
Published: October 2022

Uncertainty in climate projections is driven by three components: scenario uncertainty, intermodel uncertainty, and internal variability. Although socioeconomic climate impact studies increasingly take into account the first two components, little attention has been paid to the role of internal variability, although underestimating this uncertainty may lead to underestimating the socioeconomic costs of climate change. Using large ensembles from seven coupled general circulation models with a total of 414 model runs, we partition the climate uncertainty in classic dose–response models relating county-level corn yield, mortality, and per-capita gross domestic product to temperature in the continental United States. The partitioning of uncertainty depends on the time frame of projection, the impact model, and the geographic region. Internal variability represents more than 50% of the total climate uncertainty in certain projections, including mortality projections for the early 21st century, although its relative influence decreases over time. We recommend including uncertainty due to internal variability for many projections of temperature-driven impacts, including early-century and midcentury projections, projections in regions with high internal variability such as the Upper Midwest United States, and impacts driven by nonlinear relationships.
Tau neutrinos in the next decade: from GeV to EeV
Authors: Abraham Roshan Mammen , Alvarez-Muñiz Jaime , Argüelles Carlos A , Ariga Akitaka , Ariga Tomoko , Aurisano Adam , Autiero Dario , Bishai Mary , Bostan Nilay , Bustamante Mauricio , Cummings Austin , Decoene Valentin , de Gouvêa André , De Lellis Giovanni , De Roeck Albert , Denton Peter B , Di Crescenzo Antonia , Diwan Milind V , Farzan Yasaman , Fedynitch Anatoli , Feng Jonathan L , Fields Laura J , Garcia Alfonso , Garzelli Maria Vittoria , Gehrlein Julia , Glaser Christian , Grzelak Katarzyna , Hallmann Steffen , Hewes Jeremy , Indumathi D , Ismail Ahmed , Jana Sudip , Jeong Yu Seon , Kelly Kevin J , Klein Spencer R , Kling Felix , Kosc Thomas , Kose Umut , Koskinen D Jason , Krizmanic John , Lazar Jeff , Li Yichen , Martinez-Soler Ivan , Mocioiu Irina , Nam Jiwoo , Niess Valentin , Otte Nepomuk , Patel Sameer , Petti Roberto , Prechelt Remy L , Prohira Steven , Rajaoalisoa Miriama , Reno Mary Hall , Safa Ibrahim , Sarasty-Segura Carlos , Senthil R Thiru , Stachurska Juliana , Tomalak Oleksandr , Trojanowski Sebastian , Wendell Roger Alexandre , Williams Dawn , Wissel Stephanie , Yaeggy Barbara , Zas Enrique , Zhelnin Pavel , Zhu Jing-yu
Published: October 2022

Tau neutrinos are the least studied particle in the standard model. This whitepaper discusses the current and expected upcoming status of tau neutrino physics with attention to the broad experimental and theoretical landscape spanning long-baseline, beam-dump, collider, and astrophysical experiments. This whitepaper was prepared as a part of the NuTau2021 Workshop.
CMB constraints on DHOST theories
Authors: Hiramatsu Takashi
Published: October 2022

We put constraints on the degenerate higher-order scalar-tensor (DHOST) theories using the
Planck 2018 likelihoods. In our previous paper, we developed a Boltzmann solver incorporating the
effective field theory parameterised by the six time-dependent functions, αi
(i = 
B, K, T, M, H) and β
1, which can describe the DHOST theories.
Using the Markov-Chain Monte-Carlo method with our Boltzmann solver, we find the viable parameter
region of the model parameters characterising the DHOST theories and the other standard
cosmological parameters. First, we consider a simple model with α
=
ΩDE(t)/ΩDE(t
0), α
B = α
T = α
M = α
H = 0
and β
1 = β
1,0ΩDE(t)/ΩDE(t
0) in the ΛCDM background
where t
0 is the present time and obtain β
1,0 = 0.032-0.016
+0.013 (68% c.l.).
Next, we focus on another theory given by ℒDHOST = X + c
3
X□ϕ/Λ3 +
(M
pl
2/2 + c
4
x
2/Λ6)R + 48c
4
2
X
2/
(M
pl
2Λ12 + 2c
4Λ6
X
2)ϕμ

ϕμρ

ϕρν

ϕν
with
X := ∂μϕ∂μϕ and two positive constant parameters, c
3 and c
4. In
this model, we consistently treat the background and the perturbations, and obtain c
3 =
1.59+0.26
-0.28 and the upper bound on c
4, c
4 < 0.0088 (68% c.l.).
Soliton-like optical pulse in a gain medium with dissipation under conditions of intra-pulse Raman scattering
Authors: Sazonov S V
Published: October 2022

The propagation of an optical pulse in a nonresonant gain medium with the Raman nonlinearity is studied. A nonlinear integro-differential equation for the envelope of the pulse electric field is derived. The solution of this equation in the form of a superluminal soliton-like pulse is obtained and analyzed.
Single-molecular methodologies for the physical biology of protein machines
Authors: Wang Shuang , Lu Ying , Li Ming
Published: October 2022

Physical biology is an interdisciplinary field that bridges biology with physical sciences and engineering. Single-molecule physical biology focuses on dynamics of individual biomolecules and complexes, aiming to answering basic questions about their functions and mechanisms. It takes advantages of physical methodologies to gain quantitative understanding of biological processes, often engaging precise physical measurements of reconstructed objects to avoid interference from unnecessary complications. In this review, we (i) briefly introduce concepts of single-molecule physical biology, (ii) describe extensively used single-molecule methodologies that have been developed to address key questions in two important objects of single-molecule physical biology, namely, nucleic acid-interacting proteins and membrane-interacting proteins, and (iii) show by a few successful examples how one may use single-molecule methods to deepen our understanding of protein machines.
Dynamical behavior and optimal impulse control analysis of a stochastic rumor spreading model
Authors: Huo Liang’an , Chen Xiaomin
Published: October 2022

The Internet era has brought great convenience to our life and communication. Meanwhile, it also makes a bunch of rumors propagate faster and causes even more harm to human life. Therefore, it is necessary to perform effective control mechanisms to minimize the negative social impact from rumors. Thereout, firstly, we formulate a rumor spreading model considering psychological factors and thinking time, then, we add white noise (i.e., stochastic interference) and two pulse control strategies which denote education mechanism and refutation mechanism into the model. Secondly, we obtain the global positive solutions and demonstrate the global exponential stability of the unique positive periodic rumor-free solution. Thirdly, we discuss the extinction and persistence of rumor. Moreover, we use Pontriagin’s minimum principle to explore the optimal impulse control. Finally, several numerical simulations are carried out to verify the effectiveness and availability of the theoretical analysis. We conclude that the pulse control strategies have a great influence on controlling rumor spreading, and different control strategies should be adopted under different transmission scenarios.
FAST Observations of an Extremely Active Episode of FRB 20201124A: I. Burst Morphology
Authors: Zhou D. J. , Han J. L. , Zhang B. , Lee K. J. , Zhu W. W. , Li D. , Jing W. C. , Wang W. -Y. , Zhang Y. K. , Jiang J. C. , Niu J. R. , Luo R. , Xu H. , Zhang C. F. , Wang B. J. , Xu J. W. , Wang P. , Yang Z. L. , Feng Y.
Published: October 2022

We report the properties of more than 600 bursts (including cluster-bursts) detected from the repeating fast radio burst (FRB) source FRB 20201124A with the Five-hundred-meter Aperture Spherical radio Telescope during an extremely active episode on UTC 2021 September 25–28, in a series of four papers. The observations were carried out in the band of 1.0–1.5 GHz by using the center beam of the L-band 19-beam receiver. We monitored the source in sixteen 1 hr sessions and one 3 hr session spanning 23 days. All the bursts were detected during the first four days. In this first paper of the series, we perform a detailed morphological study of 624 bursts using the two-dimensional frequency-time “waterfall” plots, with a burst (or cluster-burst) defined as an emission episode during which the adjacent emission peaks have a separation shorter than 400 ms. The duration of a burst is therefore always longer than 1 ms, with the longest up to more than 120 ms. The emission spectra of the sub-bursts are typically narrow within the observing band with a characteristic width of ∼277 MHz. The center frequency distribution has a dominant peak at about 1091.9 MHz and a secondary weak peak around 1327.9 MHz. Most bursts show a frequencydownward-drifting pattern. Based on the drifting patterns, we classify the bursts into five main categories: downward drifting (263) bursts, upward drifting (3) bursts, complex (203), no drifting (35) bursts, and no evidence for drifting (121) bursts. Subtypes are introduced based on the emission frequency range in the band (low, middle, high and wide) as well as the number of components in one burst (1, 2, or multiple). We measured a varying scintillation bandwidth from about 0.5 MHz at 1.0 GHz to 1.4 MHz at 1.5 GHz with a spectral index of 3.0.
Thin flexible arrays for long-term multi-electrode recordings in macaque primary visual cortex
Authors: Merken Lara , Schelles Maarten , Ceyssens Frederik , Kraft Michael , Janssen Peter
Published: October 2022

Objective. Basic, translational and clinical neuroscience are increasingly focusing on large-scale invasive recordings of neuronal activity. However, in large animals such as nonhuman primates and humans—in which the larger brain size with sulci and gyri imposes additional challenges compared to rodents, there is a huge unmet need to record from hundreds of neurons simultaneously anywhere in the brain for long periods of time. Here, we tested the electrical and mechanical properties of thin, flexible multi-electrode arrays (MEAs) inserted into the primary visual cortex of two macaque monkeys, and assessed their magnetic resonance imaging (MRI) compatibility and their capacity to record extracellular activity over a period of 1 year. Approach. To allow insertion of the floating arrays into the visual cortex, the 20 by 100 µm2 shafts were temporarily strengthened by means of a resorbable poly(lactic-co-glycolic acid) coating. Main results. After manual insertion of the arrays, the ex vivo and in vivo MRI compatibility of the arrays proved to be excellent. We recorded clear single-unit activity from up to 50% of the electrodes, and multi-unit activity (MUA) on 60%–100% of the electrodes, which allowed detailed measurements of the receptive fields and the orientation selectivity of the neurons. Even 1 year after insertion, we obtained significant MUA responses on 70%–100% of the electrodes, while the receptive fields remained remarkably stable over the entire recording period. Significance. Thus, the thin and flexible MEAs we tested offer several crucial advantages compared to existing arrays, most notably in terms of brain tissue compliance, scalability, and brain coverage. Future brain-machine interface applications in humans may strongly benefit from this new generation of chronically implanted MEAs.
Linear, resistive stability studies for Wendelstein 7-X-type equilibria with external current drive
Authors: Strumberger E. , Günter S. , Wendelstein 7-X team the
Published: October 2022

Comprehensive linear stability studies of resistive modes are presented for Wendelstein 7-X-type stellarator equilibria with electron cyclotron current drive (ECCD). The external co-current drive leads to an increase of the rotational transform and the formation of one or two ι = 1 rational flux surfaces. Using the 3D linear stability CASTOR3D code, low n
*-type resistive modes (n
* = 1,2...,8 with n
* being the dominant toroidal Fourier harmonic contributing to the mode) are investigated. We studied the dependence of their growth rates on plasma resistivity, parallel viscosity, and shape of the rotational transform profile (especially various distances between two ι = 1 flux surfaces). Similarly to tokamak configurations, single and double tearing modes, and internal resistive kink modes are found. In addition, modes oscillating between two n
*-types of the same mode family are observed. The frequencies of those modes are in the range of ≈ 10–260 Hz. Equilibria with either a large distance between the ι = 1 flux surfaces, or a single ι = 1 surface are most unstable with respect to n
* = 1 resistive kink modes. The latter finding fits to the experimental observation of sawtooth-like oscillations followed by a thermal quench in W7-X discharges with ECCD.
A reduced model for the ITER divertor based on SOLPS solutions for ITER Q = 10 baseline conditions: A. identifying options for the control parameters*
Authors: Stangeby P.C. , Lore J.D. , Pitts R.A. , Canik J.M. , Bonnin X.
Published: October 2022

Edge codes such as SOLPS coupled to neutral codes such as EIRENE have become so comprehensive and sophisticated that they now constitute, in effect, ‘code-experiments’ that, as for actual experiments, can benefit from interpretation using simple models and conceptual frameworks, i.e. reduced models. The first task is the identification of options for the reduced model control parameters that are best suited for control of the action of the divertor, i.e. for control of target power loading and sputter-erosion, primarily. A strong correlation between the electron temperature at the divertor target, T
e,t, and the neutral deuterium D2 density at the target, n
D2,t, flux-tube resolved, has recently been reported for a number of code studies including SOLPS-4.3 modeling of a set of ∼50 ITER baseline cases: Q
DT = 10, q
95 = 3, P
SOL = 100 MW, metallic walls, and Ne seeding (Pitts et al 2019 Nucl. Mater. Energy
20 100696). This part A of the present study reports new results for largely the same ITER cases, confirming the strong correlations reported earlier between local values of T
e,t, and (i) n
D2,t, and (ii) normalized volumetric losses of power and pressure in the divertor. Strong correlations have now also been found, and are reported here for the first time, between T
e,t and all of the divertor target quantities of practical interest. A physical explanation for this surprising result has not been fully identified; nevertheless it has encouraging implications for reduced modeling of the ITER divertor. For such ITER conditions, (i) the global Ne injection rate, InjNe (Ne s−1), and (ii) the electron temperature at the location on the target where the peak power deposition occurs, T
e,t
@q
⊥,pk (eV), are found to be promising reduced model control parameters. In the companion report, part B, a reduced model for the ITER divertor is developed and described in detail, based on reversed-direction 2 point modelling, Rev2PM. The input to the reduced model is a value of the variable pair

T

e
,
t

@

q

⊥
,
p
k

,
I
n

j

Ne

and the output are values of the various target as well as divertor-entrance quantities of practical interest, e.g. q
⊥,pk, n
e,Xpt (the electron density at the poloidal location of the X-point), etc. In part B the reduced model is quantitatively characterized using one half of the code cases; it is then used to successfully predict (replicate) the code values of e.g. n
e,Xpt for the other half of the cases.
Optimization of offshore wind turbines layout considering wake effect
Authors: Li Li-Xia , Liu Wen-Bo
Published: October 2022

In the actual construction of an offshore wind farm, the layout of wind turbines directly affects the flow characteristics of each wind turbine. When the wind passes through the upstream unit, the work done at the hub of the downstream fan decreases, resulting in the wake effect. Therefore, on the premise of considering the wake flow, it is of great significance to study the optimization of fan arrangement. The research and selection of reasonable wind turbine arrangements have a significant effect on power generation efficiency and power output. In this paper, the improved Gauss model is used to simulate the wake flow, and the cost model that is more close to the actual construction is selected. By taking the number and distance of wind turbines as variables and the cost generated as the objective function, the research is carried out. The research is carried out in the process of automatic optimization through a particle swarm optimization algorithm.
Fault Location of Hybrid Transmission Line Based on Zero Sequence Current and EMTR
Authors: Shang LiQun , Zang Peng , Xu HaiYang
Published: October 2022

In order to better solve the problems of current cable-overhead hybrid lines that are affected by transition resistance, fault phase angle, and fault type in fault location, this paper proposes to use the zero-sequence current method to determine the large fault section first, and then according to the electromagnetic time reversal theory (EMTR) to realize the accurate location of faults in small sectionsa. A simulation model of a cable-overhead hybrid transmission line was established using ATP-EMTP, and the program was verified in MATLAB. The simulation results show that the method is not only not affected by the transition resistance and the phase angle of the fault, but also the type of fault has no effect on the results of the distance measurement, and it has higher positioning accuracy. With the allowable relative error, different types of faults can be accurately located.
Study on the optimal allocation of comprehensive energy in the park
Authors: Zhao Qingqi , Yang Lin , Li Wenwen , Shi Xulei , Ji Yanchen , Wang Miaomiao
Published: October 2022

According to the demand response mode of the user side, this paper divides the flexible load into translational, reducible and transferable loads, briefly analyzes and introduces the operation characteristics of the three loads, and constructs the park comprehensive energy source system including wind power generation, photovoltaic, gas turbine and gas boiler. Considering the system investment cost, operation cost, fuel cost and compensation cost, this paper constructs the optimal allocation model of electric heating system in the park with the optimal total cost, and optimizes it through YALMIP in MATLAB. The final results show that the participation of flexible load and electric heating energy storage can not only effectively reduce the initial investment cost and total system cost in the early stage of the park, but also reasonably adjust the load curve, the optimal output point of energy storage equipment is obtained to determine the capacity of energy storage equipment.
Discussion on Three-dimensional Design of Overhead Transmission Line Based on Tilt Photogrammetry Technolog
Authors: Wang Ting , Jing Yan , Li Shuo , Li Jianfeng , Niu Rui
Published: October 2022

With the rapid development of modern social economy, the continuous expansion of urban land and the increasing scale of power system construction, there are many problems in cable transmission and routing in overhead transmission lines. This paper mainly introduces the tilt photogrammetry technology, and studies its application in the three-dimensional design of overhead transmission lines. Firstly, this paper introduces the concept, basic principle and key technology of tilt photogrammetry technology, expounds the importance of three-dimensional design of overhead transmission line, and then tests the error value of three-dimensional software of overhead transmission line. Finally, the test results show that the maximum plane error is 0.253 m and the mean square error is 0.168 M. The maximum error of elevation is 0.247m and the mean square error of elevation is 0.128 M. Its accuracy shall meet the requirements that the error shall not exceed 0.2m and the mean square error of elevation shall not exceed 0.2m.
The study on high temperature exhaust orifice infrared suppression
Authors: Wang Ning , Lv Zhun , Wang Ying
Published: October 2022

A type of gas turbine generator unit has lots of advantages, such as small size, light weight, advanced technical performance, strong environment adaptability, rapid start. However, the high temperature exhaust gas generated during the operation of the machine leads to the high temperature and obvious infrared radiation characteristics near the exhaust port. The objective of this paper is to investigate the infrared suppression of the exhaust orifice of the gas turbine generator unit. Meanwhile, some schemes about infrared suppression are proposed, that is, redesigning the exhaust cover or adding grid regenerator of high temperature phase change materials(HTPCMs). The method of computer simulation experiment, relying on Gambit and Fluent for modeling, is used to demonstrate the feasibility of the scheme. Results indicate that the first enrichment of gas turbine exhaust heat can be completed and the exhaust temperature can be reduced by about 200°C when the grid is set as a three-layer pattern crisscrossed up and down.
Adopting Differential Lightning Protection Measures to Reduce Simultaneous Trip Probability of 220 kV Double-Circuit Transmission Line on the Same Tower
Authors: Pang Wei
Published: October 2022

Double-circuit lines on the same tower are more widely used due to the increasing shortage of transmission corridors. If lightning strikes cause simultaneous tripping, it will cause severe economic losses and safety problems. Transmission lines with 220 kV voltage level are an essential part of the main grid. Reducing the simultaneous tripping rate of 220 kV lines is extremely important for the safe operation of the power grid. This paper analyses the advantages and disadvantages of several typical lightning protection methods for double-circuit lines on the same tower by simulation calculation. Combined with the characteristics of several typical double-circuit towers, lightning protection design for double-circuit lines is studied, and the differentiated lightning protection methods and basic protection processes for typical lines are proposed.
Fault Line Selection with Correlation Analysis of Zero Sequence Current and Voltage under High-Low Frequency
Authors: Yan Xing , Ma Chenghu , Han Hui
Published: October 2022

When a single-phase ground fault occurs near the zero or maximum point, the fault line selection of resonance grounding system is not sensitive enough. After analyzing the transient current and line impedance characteristics of zero sequence network, and making full use of the decaying DC component, power frequency component and high frequency component of the transient zero sequence current of the feeder, a fault line selection method based on correlation analysis of zero sequence current and bus zero sequence voltage derivative in high and low frequency band is proposed. The effectiveness of the method is verified by the examples from the aspects of fault closing angle, transition resistance.
Modeling of Photovoltaic modules under shading condition and an error evaluation criterion
Authors: Lai GuangZhi , Wang Dong , Li HaoRan , Zhao Yi , Ni WeiChen , Wen JiaHao
Published: October 2022

Energy is the focus of recent years. As one of the most representative new energy sources, solar energy has the characteristics of large reserves and no pollution. The main way to use solar energy is photovoltaic (PV) power generation, and the PV module in the PV power generation system is the component that converts solar energy into electric energy. In the actual power generation process, PV modules often receive uneven solar illumination due to the shadow caused by clouds, trees, buildings, etc., resulting in changes in the output characteristics of PV modules and reduced output efficiency. Therefore, modeling of PV modules under shading condition is very important. This paper presents two simple methods for solving the parameters of PV module models, which require few parameters and are easy to obtain. A modeling method of PV modules under shading condition is also presented. And then the modeling method is verified with the experiment result. Finally, an error criterion for PV module modeling under shading condition is proposed to measure the goodness of the modeling. Combining with the two parameter solving methods, the errors of this PV module modeling method under shading condition of the error criterion proposed in this paper are 3.24% and 2.51%, respectively, which meet the requirements for engineering use.
Dynamic Capacitance Measurement of SF6 Circuit Breaker During Opening Operation
Authors: Qin Jian , Wang Jialin , Zhou Xiong , Qian Shuaiwei , Chen Jianxi , Huang Yongqiang , Dong Hailiang
Published: October 2022

In order to mine the state information of SF6 circuit breakers (CBs) interruption chamber and evaluate the contacts state, a method of measuring and calculating the dynamic capacitance between contacts in CBs opening process was proposed. The test CB is connected in series with a high frequency AC power supply, and the voltage and current of the circuit breaker are measured during the opening process. The fundamental frequency components of the voltage and current are extracted by the short-time Fourier transform, and the dynamic capacitance curve as a function of time is calculated. The results show that due to the variation of capacitance, there are a large number of harmonics with frequencies close to the fundamental frequency in terminal voltage and current. During the first two cycles after contacts separation, the capacitance drops sharply to 33.25 pF, then with the increase of the contact distance, the capacitance decreases much more slowly and tends to be constant, and the capacitance is 20.70pF after the completion of the opening.
Power Allocation in Smart Grid Aided Cell Free Massive MIMO Systems for URLLC Applications
Authors: Ou Qinghai , Wang Yanbo , Bao La , Wang Yanru , She Rui , Zhang Ningchi , Ma Wenjie
Published: October 2022

This paper investigates power allocation in cell-free massive MIMO for URLLC applications, where each access point is powered by smart grid or solar panels/wind-turbines. In particular, the closed-form achievable rate for URRLC is derived. By exploiting the derived results, a non-convex and non-smooth optimization problem is formulated for maximizing the minimum URRLC rate of all multicast group, and is NP-hard. To deal with this problem, the formulated optimization problem is transformed into a tractable version, then the classical CVX tool is adopted to solve the resultant problem. Numerical simulation verifies the practicability of the derived theoretical results and the proposed algorithm.
Electric field numerical analysis and structure optimization of grounding switch in GIS based on finite element analysis
Authors: Feng Miao , Wang Ming , Zhang Qingxian , Tan Heyi , Li Xiaozhe , Zeng Dehua , Yang Tao , Zhang Mao
Published: October 2022

The grounding switch is an important component to ensure safety on its GIS and maintenance personal. In this paper, the COMSOL Multiphysics software is used to carry out electrostatic field analysis on grounding switch in GIS by the finite element method. This study also did a lot of research including drawing 3D models of key parts, gridding division and post-processing the data of electric field. The field intensity distribution diagrams and the maximum value of field intensity concentration area of key insulation position at 1100kV and 500kV are obtained. The electric field intensity distribution of GIS near the static contactor of the grounding switch is discussed, and the design of appropriately increasing the radius of the conductor in the part the great abrasion is proposed, and it provides a theoretical basis for the electric field distribution of electrical equipment.
Object-oriented extraction research under multiple scenarios based on Sentinel-2A satellite images
Authors: Liu Chao-Qun , Liu Min , Li Zhen , Zhu Yun-Quan
Published: October 2022

In order to solve the problem of information extraction from Sentinel-2A satellite remote sensing images, four scene images of mountainous landscape with complex forests, flat cultivated rural landscape suburban coastal landscape and complex urban landscape were selected as experimental objects, and three algorithms of KNN, CART and SVM of object-oriented method are used to extract the main feature information, so as to compare the extraction accuracy of different methods in different scenes. The experimental results show that the overall accuracy of object-oriented feature classification of Sentinel-2A image in four scenes is greater than 75.47%, and the kappa coefficient is greater than 0.72 except that the overall accuracy of KNN in Scenes 4 is 0.66. Through the comprehensive comparative analysis of the four scenes, it can be seen that the average overall accuracy of rural landscape of Sentinel-2A image is 84.65%, the average kappa coefficient is 0.79, which is better than the average overall accuracy of urban landscape classification of 78.1%, the average kappa coefficient is 0.7, and the flat terrain scene is better than the mountainous area with large topographic elevation difference. In terms of classification methods, SVM algorithm has better classification accuracy than CART algorithm, and CART has better classification accuracy than KNN.
Feasible Region Calculation Method of Tie-line in Interconnected Regions in Day-ahead Dispatch Scenarios
Authors: Li Baoju , Sun Yong , Fu Xiaobiao , Zhang Jiquan , Yang Rui , Sun Yujun
Published: October 2022

To improve the reliability of the output and input power planning in interconnected regions in day-ahead dispatch scenarios, it is necessary to reasonably measure the feasible region of tie-line cross-region power exchanges. Due to the large number of day-ahead dispatch periods, it is difficult to solve the tie-line feasible region. Therefore, this paper first selects the adjacent periods to reconstruct the feasible region model and proposes a method to synthesize the feasible region of each day-ahead dispatch period. Then, the tie-line feasible regions are obtained considering the internal operation constraints of the output and input terminal regions. Finally, the final tie-line feasible region is synthesized according to the interconnection relationship of sub-regions. Based on the IEEE 39-bus system, the influence of the regional interconnection relationship on the calculation of tie-line feasible region and the evaluation results of power transmission and receiving capacity are analyzed, and the effectiveness of the method is verified.
Flow field characteristics analysis of Venturi tube with cavity
Authors: Li Peng , Ma Liang , Wang Miaomiao , Zhao Xin , Zhang Lixin
Published: October 2022

Venturi tube flow is prone to cavitation at high flow rate. In this paper, based on the study of the cavitation flow field in Venturi tube, the authors improve the throat structure of Venturi tube with cavity and carry out analysis of numerical simulation Flow field characteristics by Large eddy simulation (LES), analyze the pressure pulsation in Venturi tube to explore the change of pressure and velocity in different positions, study on the change of cavitation volume fraction, explore the changes of cavitation number and cavitation length under different pressure ratios. Through the previous research and analysis, the flow field characteristics of Venturi tube with cavity are understood, which lays the foundation for cavitation application of Venturi tube.
Synthesis of Single Crystal Perovskite MAPbBr3by Using Anti-solvent Vapor-assisted Crystallization Method for X-Ray Photodetector Application
Authors: Muslimawati Rossyaila Matsna , Manawan Maykel , Bahtiar Ayi
Published: October 2022

Perovskite methylammonium lead tri-bromide (MAPbBr3) has been extensively studied for active material of X-ray photodetector, due to its suitable bandgap with the X-ray energy range and its high value of charge carrier diffusion to produce both high efficiency and sensitivity of photodetector. However, the high resistivity due to the large crystal defect density caused by its polycrystalline crystal structure will reduce the charge carrier mobility and lifetime and therefore produce less sensitive photodetector. The solution to overcome these problems is the perovskite MAPbBr3material must be in the form of single crystal to produce low crystal defect density. Another practical problem for X-ray photodetector application is the most of the reported perovskite crystals have the size less than 1 cm2. For the practical purposes of X-ray photodetector devices, a cubic structure and large crystal dimension (larger than 1 cm2) are required to adjust into the flat-panel detector. In this research, MAPbBr3perovskite crystals were synthesized by using Anti-solvent Vapor-assisted Crystallization (AVC) method. The precursor MAPbBr3was prepared by dissolving MABr and PbBr2with molar ratio of 1.25 and 1.0 in dimethylformamide (DMF). Dichloromethane (DCM) was used as anti-solvent. The diffusion of anti-solvent DCM into precursor solution was controlled by providing a small hole on the top of vial which contains the precursor. The crystal growth rate was controlled by varying the volume ratio of DCM and MAPbBr3precursor solution. The obtained largest crystal size of 7mm × 7mm was prepared with a volume ratio of DCM and precursor of 2.67 and a volume of 3 mL precursor solution. The energy gap MAPbBr3crystal is 2.14 eV derived from UV-Vis absorbance spectrum. The XRD pattern of the crystal showed that the perovskite MAPbBr3had cubic crystal structure with a lattice constant of 5.99 Å. The diffraction pattern of the crystal showed a dominant peak of crystal plane (100). This result confirmed that the synthesized MAPbBr3crystal has a single crystal oriented in x-axis direction.
Performance Chitosan Membranes to Filter Humic Acid (HA) Waste from Aquatic Environment
Authors: Rupiasih Ni Nyoman , Sumadiyasa Made , Nita Wolfharditia Oktaviana
Published: October 2022

Various pollutants can directly and indirectly threaten the health and safety of our aquatic environment. To overcome this, various methods needed for more efficient wastewater treatment. Wastewater treatment using natural polymer matrix membranes can provide an excellent alternative that is environmentally friendly. For this purpose, a study on filtering humic acid (HA) waste frompolluted water using chitosan membranes has been carried out. The membranes used are chitosan membranes 1%, 2%, 3%, and 4%. The filtration was carried out by using the dead-end filtration method, and the analysis of humic acid was done by using UV-Vis spectrophotometer. The ability of the membrane to screen humic acid waste is indicated by pure water flux (PWF), waste (product) flux (PF), and rejection coefficient (R). The results obtained that the chitosan membrane 2% showed the highest filtration ability 99.87% with pure water flux and product flux of 2938.14 L/m2h and 1678.93 L/m2h, respectively. While the chitosan membranes 3% and 4% gave rejection coefficient of 83.76% and 79.38%, respectively. The chitosan membrane 1%, on the pressure of 100 kPa did not produce flow. So, chitosan membrane 2% can be used as a method to reduce humic acid waste from the aquatic environment, which is environmentally friendly method. So, chitosan membrane 2% can be used as a method to reduce humic acid waste from the aquatic environment, which is environmentally friendly method.
Effect of Cellulose Fiber from Coconut Coir as Filler For Dental Flowable Composite
Authors: Isnaini Steella Ilham , Cevanti Twi Agnita , Sari Nur Shiyama Purnama , Rois Mahardika F. , Widiyastuti W. , Setyawan Heru
Published: October 2022

The composite restorations in posterior teeth have recently received an increasing interest due to the improvement of their physical and mechanical properties. However, compositing by the most common polymerization procedure tends to deform the tooth structure that may cause some damage in the marginal seal due to the imperfect interfacial attachment. Several techniques have been used to overcome this problem, one of them is using a flowable composites on the bottom of the cavity as the first layer. The purpose of this study is to develop fiber-reinforced composite (FRC) material made of coir fiber (Cocos nucifera) with matrix (Bis-GMA, TEGDMA, DGEBA, and camphorquinone). Cellulose fiber was formed by an anti-solvent method from an aqueous NaOH-urea cellulose solution dropped into ethanol-water mixture. The resulting cellulose fibers were then mixed with the matrix using a magnetic stirrer. The composition of nanocellulose in the matrix was varied 10:90 and their characteristics were compared with the commercial nanofiller composite (Z 350 and 3M) as control. The sample was tested for cross-linked using a scanning electron microscope (SEM) and Fourier transform infrared (FTIR). The morphology of nanocellulose look like a fiber as cross-linked with matrix. Therefore, the formation of a crosslink bond between cellulose and matrix C-O-C with a new wavenumber in 890 cm-1. The nanocellulose composite also form fibers that binds the matrix, while flowable composites from manufacturers from fibers and particulates. From this experimental method it can be suggested coconut fiber has high potential as raw material to be filler in a dental flowable composite.
Study on Surface Properties of Unalloyed Copper Implanted with Different Transition Metal ions
Authors: Cui Haoxiong , Wang Jianguang , Cheng Wei , Cheng Guoan , Wu Xiaoling , Zheng Ruiting
Published: October 2022

Copper is widely used in Integrated Circuits and electronic components. Its corrosion performance and service performance have been paid much attention. We implanted Ti, Cr, Fe, Ni, Zn and other fourth period transition metal ions into unalloyed copper. After that, zeta potential test, electrochemical test and density functional theory calculation were used to study the surface properties of the implanted samples. We found that for copper samples, the zeta potential of implanted samples is related to the type of implanted transition metal ions, that is, the charge state at the solid-liquid interface is related to the type of implanted ions. We use density functional theory calculations to explain this change in surface properties of metal samples before and after ion implantation. We find that the d-band center of the transition metal has a similar trend to zeta potential.
Controllable Synthesis of Hierarchical Dendrite-Like Iron-Based Hybrids with Boosting Microwave Absorption Performance
Authors: Wei Tian , Xian Jian , Longjiang Deng
Published: October 2022

Fabricating high-performance microwave absorption materials with excellent attenuation property covering low frequency ranges are urgently needed for applications in our daily life. Herein, we put forward the controllable synthesis of hierarchical dendrite-like iron-carbon hybrids (Fe-C based hybrids) through three steps, including the hydrothermal method, chemical vapor deposition strategy and hydrogen reduction using K3[Fe(CN)6] and C2H2 as Fe and C source, respectively. Due to the existence of interface polarization effect, natural resonance, and exchange resonance generated from Fe-C based hybrids, the microwave absorption property in low frequency bands of the as-fabricated Fe-C based hybrids are growing as the filler loading increases. The Fe-C based hybrids achieved the minimum reflection loss value (RLmin) at 2.95 GHz as low as -31.73 dB at 4.5 mm, and the effective absorption bandwidth can reach up to 9.19 GHz in the range of thickness from 1.5 to 5.0 mm, covering the entire L, S, C, and X-band frequency bands. The novel structure design provides a facile and meaningful strategy for fabricating two-dimensional hierarchical dendrite-like Fe-C based hybrids as high-performance microwave absorbers.
Structure design and optimization of oil-contaminated microplastic combination cleaning vessel
Authors: Ma Yuchen , Zhang Siyang
Published: October 2022

This paper based on the analysis of existing oil removal boats, a new practical, simple and economic oil treatment boat is designed, while using magnetic fluid, adsorption and collection of microplastics, and this solution can replace the manual completion of the sea surface oil cleaning work. The main contents include: design of motion mechanism for collecting oil pollution, microplastic filtering device. The 3D modeling of the hull was established and the motion simulation was carried out by using SolidWorks. Finite element analysis of various load-bearing structures was carried out using ANSYS to verify the rationality of each structure. The control system was designed, and the hardware part was designed with circuitry for the operating system according to the actual needs.
Virtual machine optimization setting of ship public computer platform
Authors: Zhou Yin
Published: October 2022

Ship public computer platform is a shared platform built for ship users by using public hardware resources and equipment. Users of public computer platform can directly call the hardware resources of public computer platform through network, virtual machine and other media to create their own virtual computing environment. With the development of computer technology and virtualization technology, ship public computing platform technology has also received extensive attention in the industry. Firstly, this paper introduces the key points of cloud computing technology. Based on cloud platform computing, this paper introduces the virtual machine design, database redundancy design, CPU and network optimization setting of ship public computer platform in detail. Finally, the virtual machine construction of ship public computer platform is realized based on VMware software platform, which has very important application significance.
Design and simulation verification of aircraft altitude control based on pitch angle estimation
Authors: Wang Lingling , Sun Yanli
Published: October 2022

In the conventional aircraft attitude control, the pitch angle is usually used as the inner loop to complete the control of the longitudinal channel. However, when the pitch angle sensor fails and its measurement data is unreliable, how to use a certain algorithm to ensure the effective control task of the attitude control loop. In this paper, a filtering algorithm based on pitch angle estimation is proposed to solve the shortcomings of aircraft in safety and reliability when the conventional altitude is controlled by pitch angle signal. The algorithm design and simulation results show that the filtering algorithm based on pitch angle estimation can effectively complete the control task and ensure better control quality.
An aggregation strategy of air conditioning loads considering diversity of the load
Authors: Zuo Nannan , Gao Guige
Published: October 2022

Through the reasonable aggregation and control of air conditioning loads (ACLs), the peak load of power grid can be reduced and the contradiction between supply and demand can be alleviated without affecting or less affecting the comfort of users. In order to further tap the demand response ability of aggregated loads, an aggregation strategy of ACLs considering diversity of the load is proposed. Firstly, grey relational analysis method is used to extract the thermal environmental characteristic parameters with high correlation to different categories of ACLs. Then, ACLs are classified by KNN algorithm; Finally, according to different control modes of ACLs, k-means algorithm is used to aggregate the load to obtain aggregated power. Through simulation verification, the aggregation strategy that retains the diversity of ACLs has high accuracy and can improve the aggregated active power capacity effectively. The strategy has higher practical application value.
Low noise amplifier with adaptive gain setting — (AWAGS) ASIC
Authors: Wieczorek P. , Flemming H. , Deppe H.
Published: October 2022

The ASIC design group at GSI developed an Amplifier With Adaptive Gain Setting (AWAGS) chip. The input stage based on a folded cascode architecture is followed by a single-ended to differential conversion and output buffers. To the contrary to usual ASIC designs, the capacitive feedback is divided into five capacitances with different values. Starting with the smallest one the capacitances are added to the feedback depending on the input charge. This concept allows to measure over a high dynamic range (>200000) with the highest precision in the individual gain setting. The AWAGS ASIC is produced in a UMC 180 nm UMC multi-project wafer (MPW) run 2020.
Development of Compton-PET hybrid imaging system with CeBr3-SiPM arrays
Authors: Uenomachi M. , Shimazoe K. , Orita T. , Kamada K. , Takahashi M. , Takahashi H.
Published: October 2022

Positron emission tomography (PET) and single photon emission computed tomography (SPECT) are both established imaging technologies in nuclear medicine that are clinically available. However, simultaneous PET and SPECT nuclide imaging is difficult to accomplish with current equipment because of their distinct principles. In light of this, we have developed and demonstrated a GAGG scintillator based Compton-PET hybrid imaging system capable of performing PET and Compton imaging simultaneously. Alternatively, the CeBr3 scintillator possesses more desirable properties, including a high light yield (>60000 photons/MeV), a fast decay time (∼19 ns), and an excellent energy resolution (<4%@662 keV). Herein, we developed an 8 × 8 array of CeBr3 detector based instrumentation by using 64 channel fast signal processing slew rate limited Time over Threshold (ToT) based application-specific integrated circuits and a field programmable gate array ToT data acquisition system with a 62.5 ps accuracy. Furthermore, we evaluated the system’s basic performances. The mean and greatest energy resolutions were 10.1% and 6.0% (FWHM) for 662 keV. The time resolution was 239 ps (FWHM) after offset calibration. We also achieved a proof-of-concept based on single source.
Construction, operations, and performance of the CMS phase-1 silicon pixel detector
Authors: Choudhury S.
Published: October 2022

The CMS phase-1 pixel detector was designed to cope with an instantaneous luminosity of 2 × 1034 cm−2 s−1 and 25 ns bunch spacing with very small efficiency loss. The upgraded detector has 124 million channels that features a 4-hit coverage in the tracking volume with an additional layer in the barrel and one extra disk in both the endcaps. DC-DC converters have been used to deliver more power to the detector without the need of replacing the cable plant. A CO2 based cooling system was implemented and carbon fibre based support structures were used to reduce the material budget in the tracking volume. The data acquisition system was upgraded to cope with higher collision rates with a digital data format from the detector front-ends. The detector was installed in early 2017 and has been successfully operated since then. In this paper, the design and construction, operational experience and the performance of the phase-1 pixel detector at LHC Run 2 will be summarised.