bluuebunny/crossref_metadata_2025_split huggingface dataset:
Thermo-mechanical response of the twisted and coiled polymer actuator (TCPA): a finite element analysis (FEA)
Authors: Hunt Robert , Olsen Zakai , Kim Kwang 
Published: April 2021

Abstract
Twisted and coiled polymer actuators (TCPAs) are a recently discovered thermally driven artificial muscle, fabricated from a polymer fiber coiled into a helix. They produce axial contraction or torsion when heated above glass transition temperature and relaxes to their previous state when cooled back to their initial temperature. Studies have shown the actuator to produce enormous tensile strain (49%), power densities (27.12 kW kg−1), and specific work (2.48 kJ kg−1) [Haines (2014 Science
343 868–72)]. The remarkable capabilities of TCPAs have raised interest in the applications of smart materials, soft robotics, and artificial muscles. Recently, Yang et al investigated the physical phenomena of TCPA’s actuation through a top-down multiscale model, validated through experimental works [Yang and Li (2016 J. Mech. Phys. Solids
92 237–59)]. This paper extends Yang’s approach to a finite element analysis simulation for predicting the thermo-mechanical response of a TCPA, validated by experimental comparison. Currently, there are little to no studies done in the numerical simulation of TCPAs, which is an essential tool in all fields of engineering. A numerical simulation is imperative for increasing the model’s adaptability in real-life physical systems, where analytical solutions become too complex, and for predictive simulations for designing prototype robotic actuators. The equations developed by Yang et al are implement into a three-dimensional COMSOL Multiphysics model. The results of the numerical simulation displacement response show great accuracy when compared to the experimental data tested by a dynamic mechanical analyzer.
Anomalous isotope effect in BCS superconductors with two boson modes
Authors: Sun Gan , Lou Pan-Xiao , Lai Sheng-Qiang , Wang Da , Wang Qiang-Hua 
Published: April 2021

Abstract
The isotope effect in the superconducting transition temperature is anomalous if the isotope coefficient α < 0 or α > 1/2. In this work, we show that such anomalous behaviors can naturally arise within the Bardeen–Cooper–Schrieffer framework if both phonon and non-phonon modes coexist. Different from the case of the standard Eliashberg theory (with only phonon) in which α ⩽ 1/2, the isotope coefficient can now take arbitrary values in the simultaneous presence of phonon and the other non-phonon mode. In particular, most strikingly, a pair-breaking phonon can give rise to large isotope coefficient α > 1/2 if the unconventional superconductivity is mediated by the lower frequency non-phonon boson mode. Based on our studies, implications on several families of superconductors are discussed.
The Perfect Hyperfluid of Metric-Affine Gravity: the foundation
Authors: Iosifidis Damianos 
Published: April 2021

Abstract
We set the foundation and formulate the Perfect (Ideal) Hyperfluid. The latter represents the natural generalization of the usual perfect fluid structure where now the microscopic characteristics of matter (spin, shear, dilation) are also taken into account, sourcing a non-Riemannian arena (i.e spacetime torsion and non-metricity) for Metric-Affine Gravity. We derive the energy tensors of this Hyperfluid structure and subsequently present the conservation laws obeyed by them. Finally, we consider a Cosmological application of this Perfect Hyperfluid and classify some possible forms of this fluid structure.
NBFTP: a dedicated data transfer system for remote astronomical observation at Dome A*
Authors: Huang Si-Yuan , Yu Ce , Sun Chao , Hu Yi , Shang Zhaohui , Ma Bin , Che Ming , Lu Xiao-Xiao 
Published: April 2021

Abstract
Dome A, Antarctica, has been thought to be one of the best astronomical sites on the Earth for decades. Since it was first visited by astronomers in 2008, dozens of facilities for astronomical observation and site testing were deployed. Due to its special geographical location, the data and message exchange between Dome A and the domestic control center could only depend on Iridium. Because the link bandwidth of Iridium is extremely limited, the network traffic cost is quite expensive and the network is rather unstable, the commonly used data transfer tools, such as rsync and scp, are not suitable in this case. In this paper, we design and implement a data transfer tool called NBFTP (narrow bandwidth file transfer protocol) for the astronomical observation of Dome A. NBFTP uses a uniform interface to arrange all types of data and matches specific transmission schemes for different data types according to rules. Break-point resuming and extensibility functions are also implemented. Our experimental results show that NBFTP consumes 60% less network traffic than rsync when detecting the data pending to be transferred. When transferring small files of 1KB, the network traffic consumption of NBFTP is 40% less than rsync. However, as the file size increases, the network traffic consumption of NBFTP tends to approach rsync, but it is still smaller than rsync.
Reflections and standing waves on the Tianlai cylinder array
Authors: Li Ji-Xia , Wu Feng-Quan , Sun Shi-Jie , Yu Zi-Jie , Zuo Shi-Fan , Liu Ying-Feng , Wang You-Gang , Zhang Cong , Ansari Reza , Timbie Peter , Chen Xuelei 
Published: April 2021

Abstract
In 21 cm intensity mapping, the spectral smoothness of the foreground is exploited to separate it from the much weaker 21 cm signal. However, the non-smooth frequency response of the instrument complicates this process. Reflections and standing waves generate modulations on the frequency response. Here we report the analysis of the standing waves in the bandpass of the signal channels of the Tianlai Cylinder Array. By Fourier transforming the bandpass into the delay time domain, we find various standing waves generated on the telescope. A standing wave with time delay at ∼142 ns is most clearly identified which is produced in the 15-meter feed cable. We also identify a strong peak at a shorter delay of τ < 50 ns, which may be a mix of the standing wave between the reflector and feed, and the standing wave on the 4 m intermediate frequency (IF) cable. We also show that a smoother frequency response could be partially recovered by removing the reflection-inducted modulations. However, the standing wave on the antenna is direction-dependent, which poses a more difficult challenge for high precision calibration.
Temporal variation of solar flare index during solar cycles 21 − 24
Authors: Roy Soumya , Prasad Amrita , Panja Subhash Chandra , Patra Sankar Narayan 
Published: April 2021

Abstract
The present investigation attempts to quantify the temporal variation of Solar Flare Index (SFI) with other activity indices during solar cycles 21 – 24 by using different techniques such as linear regression, correlation, cross-correlation with phase lag-lead, etc. Different Solar Activity Indices (SAI) considered in this present study are Sunspot Number (SSN), 10.7 cm Solar Radio Flux (F10.7), Coronal Index (CI) and MgII Core-to-Wing Ratio (MgII). The maximum cycle amplitude of SFI and considered SAI has a decreasing trend from solar cycle 22, and cycle 24 is the weakest solar cycle among all other cycles. The SFI with SSN, F10.7, CI and MgII shows hysteresis during all cycles except for solar cycle 22 where both paths for ascending and descending phases are intercepting each other, thereby representing a phase reversal. A positive hysteresis circulation exists between SFI and considered SAI during solar cycles 22 and 23, whereas a negative circulation exists in cycles 21 and 24. SFI has a high positive correlation with coefficient values of 0.92, 0.94, 0.84 and 0.81 for SSN, F10.7, CI and MgII respectively. According to cross-correlation analysis, SFI has a phase lag with considered SAI during an odd-number solar cycle (solar cycles 21 and 23) but no phase lag/lead during an even-numbered solar cycle (solar cycles 22 and 24). However, the entire smoothed monthly average SFI data indicate an in-phase relationship with SSN, F10.7 and MgII, and a one-month phase lag with CI. The presence of those above characteristics strongly confirms the outcomes of different research work with various solar indices and the highest correlation exists between SFI and SSN as well as F10.7 which establishes that SFI may be considered as one of the prime activity indices to interpret the characteristics of the Sun’s active region as well as for more accurate short-range or long-range forecasting of solar events.
Timing analysis of the black hole candidate EXO 1846–031 with Insight-HXMT monitoring
Authors: Liu He-Xin , Huang Yue , Xiao Guang-Cheng , Bu Qing-Cui , Qu Jin-Lu , Zhang Shu , Zhang Shuang-Nan , Jia Shu-Mei , Lu Fang-Jun , Ma Xiang , Tao Lian , Zhang Wei , Chen Li , Song Li-Ming , Li Ti-Pei , Xu Yu-Peng , Cao Xue-Lei , Chen Yong , Liu Cong-Zhan , Cai Ce , Chang Zhi , Chen Gang , Chen Tian-Xiang , Chen Yi-Bao , Chen Yu-Peng , Cui Wei , Cui Wei-Wei , Deng Jing-Kang , Dong Yong-Wei , Du Yuan-Yuan , Fu Min-Xue , Gao Guan-Hua , Gao He , Gao Min , Ge Ming-Yu , Gu Yu-Dong , Guan Ju , Guo Cheng-Cheng , Han Da-Wei , Huo Jia , Jiang Lu-Hua , Jiang Wei-Chun , Jin Jing , Jin Yong-Jie , Kong Ling-Da , Li Bing , Li Cheng-Kui , Li Gang , Li Mao-Shun , Li Wei , Li Xian , Li Xiao-Bo , Li Xu-Fang , Li Yang-Guo , Li Zheng-Wei , Liang Xiao-Hua , Liao Jing-Yuan , Liu Bai-Sheng , Liu Guo-Qing , Liu Hong-Wei , Liu Xiao-Jing , Liu Yi-Nong , Lu Bo , Lu Xue-Feng , Luo Qi , Luo Tao , Meng Bin , Nang Yi , Nie Jian-Yin , Ou Ge , Sai Na , Shang Ren-Cheng , Song Xin-Ying , Sun Liang , Tan Ying , Tuo You-Li , Wang Chen , Wang Guo-Feng , Wang Juan , Wang Ling-Jun , Wang Weng-Shuai , Wang Yu-Sa , Wen Xiang-Yang , Wu Bai-Yang , Wu Bo-Bing , Wu Mei , Xiao Shuo , Xiong Shao-Lin , Xu He , Yang Jia-Wei , Yang Sheng , Yang Yan-Ji , Yang Yi-Jung , Yi Qi-Bin , Yin Qian-Qing , You Yuan , Zhang Ai-Mei , Zhang Cheng-Mo , Zhang Fan , Zhang Hong-Mei , Zhang Juan , Zhang Tong , Zhang Wan-Chang , Zhang Wen-Zhao , Zhang Yi , Zhang Yi-Fei , Zhang Yong-Jie , Zhang Yuan-Hang , Zhang Yue , Zhang Zhao , Zhang Zhi , Zhang Zi-Liang , Zhao Hai-Sheng , Zhao Xiao-Fan , Zheng Shi-Jie , Zheng Yao-Guang , Zhou Deng-Ke , Zhou Jian-Feng , Zhu Yu-Xuan , Zhuang Ren-Lin , Zhu Yue 
Published: April 2021

Abstract
We present the observational results from a detailed timing analysis of the black hole candidate EXO 1846–031 during its outburst in 2019 with the observations of Insight-HXMT, NICER and MAXI. This outburst can be classified roughly into four different states. Type-C quasi-periodic oscillations (QPOs) observed by NICER (about 0.1–6 Hz) and Insight-HXMT (about 0.7–8 Hz) are also reported in this work. Meanwhile, we study various physical quantities related to QPO frequency. The QPO rms–frequency relationship in the energy band 1–10 keV indicates that there is a turning pointing in frequency around 2 Hz, which is similar to that of GRS 1915+105. A possible hypothesis for the relationship above may be related to the inclination of the source, which may require a high inclination to explain it. The relationships between QPO frequency and QPO rms, hardness, total fractional rms and count rate have also been found in other transient sources, which can indicate that the origin of type–C QPOs is non-thermal.
GRB 130310A: very high peak energy and thermal emission
Authors: Qin Song-Mei , Jiang Lu-Yao , Wang Xiang-Gao 
Published: April 2021

Abstract
The special GRB 130310A was observed by Fermi Gamma-Ray Burst Monitor and Large Area Telescope, with T
90∼ 2.4 s. With a combination of a Band function and a blackbody (BB) function, the time-resolved spectral analysis of GRB 130310A confirmed that there is a sub-dominate thermal component in the early period (e.g., slice T
0 + [4.03 – 4.14] s) spectrum with BB temperature (kT) being ∼7∼5 keV, which can be interpreted as photosphere emission. The precursor of GRB 130310A can be fitted well with a BB component with kT ∼ 45 keV, which is higher than that of the main burst. It suggests that the radiation of GRB 130310A is in transition from thermal to non-thermal. Such a transition is an indication of the change in jet composition from a fireball to a Poynting-flux-dominated jet. A very high peak energy is obtained in the first time bin, with the peak energy Ep
of the Band component for Band+BB and Band model being ∼8.5∼5.2 MeV and ∼11.1∼7.4 MeV, respectively. Afterwards, the Ep
drops to ∼ 1 MeV. The Ep
evolution patterns with respect to the pulses in the GRB 130310A light curves show a hard-to-soft evolution. The interpretation of the high peak energy Ep
within the photosphere and internal shock model is difficult. It also suggests that at least for some bursts, the Band component must invoke a non-thermal origin in the optically thin region of a GRB outflow. Assuming the redshift is z ∼ 0.1 ∼ 8, the radius of the jet base r
0 ∼ 109 cm to allow (1 + σ
15) > 1 in line with the calculation results of the magnetization parameter at ∼1015 cm (σ
15). However, the value of (1 + σ
15) is ≃ 1 in the zone z around 3 for r
0 ∼ 109 cm, suggesting the non-excluded possibility that the origin is from ICMART with a low value. The photosphere-internal shock seems capable of interpreting the high peak energy, which requires electron Lorentz factor γe
∼ 60 and εe
∼ 0.06.
PtSe2 phototransistors with negative photoconductivity
Authors: Di Bartolomeo A , Urban F , Faella E , Grillo A , Pelella A , Giubileo F , Askari M B , McEvoy N , Gity F , Hurley P K 
Published: April 2021

Abstract
Platinum diselenide (PtSe2) is one of the most studied materials of the emerging group-10 transition-metal dichalcogenides. We investigate the electrical conduction and the photoconduction of PtSe2 ultrathin films exploited as the channel of back-gated field-effect transistors. The channel resistance decreases with the rising temperature and shows that the films have semiconducting behaviour. The gate modulation confirms a p-type conductivity with field-effect mobility up to 30 cm2/(Vs). Under exposure to the radiation from a super-continuous white light source, a reduction of the PtSe2 electrical conductivity (negative photoconductivity) is observed in low vacuum, while a positive photoconductivity emerges only under high-power illumination conditions. Although, the positive photoconductivity arises from conventional photoconductive effect, the negative photoconductivity can be explained as the combination of the photogating effect caused by charge accumulation in the SiO2 dielectric and the photo-induced desorption of adsorbates.
Time-Frequency Bandpass Filter with Nonstationary Signal Decomposition Application
Authors: Yu Xiaoluo , Yang Yang , He Qingbo , Peng Zhike 
Published: April 2021

Abstract
In various applications such as speech processing, underwater sound, radar application and mechanical fault diagnosis, there are large number of nonstationary signals. In order to achieve nonstationary signal decomposition, the instantaneous frequency ridge is extracted through interactive mode, and a time-frequency bandpass filter (TFBPF) method is proposed. This method is the modified version of Intrinsic Chirp Component Decomposition (ICCD) and has the physical essence of time-frequency domain bandpass filter. The superiority and application potential of TFBPF in complex engineering signal decomposition are demonstrated through two numerical examples. In the first one, we prove that TFBPF can decompose the weak signal component directly through analyzing the vibration signal of hydraulic turbine; While in the second one, we prove that TFBPF can effectively overcome the drawbacks of ICCD through analyzing the vibration signal during the speed-up process of a complex equipment. TFBPF is still very effective even for complex signal decomposition in a strong noise environment.
Design and Implementation of Wireless Identification and Sensing Platform in Structure Monitoring
Authors: Qiu Xunchao , Yuan Jianqing , Hou Lijun , Gao Wei , Xi Wangyuan , Yan Wei 
Published: April 2021

Abstract
In the process of structure monitoring, active wireless sensor devices are often used. In order to replace the energy limitation bottleneck of the power supply unit, the Wireless Identification and Sensing Platform (WISP) with real-time data transmission function is adopted to realize the collection of structural vibration acceleration data. Firstly, the various functional modules of the WISP with three-axis acceleration are introduced. Then, through software programming of the low-power MSPF430F2132 microprocessor on it, the drive and control of the external three-axis acceleration sensor ADXL330 is realized. Finally, it was tested through comparative experiments. The research results show that the acceleration data monitored by the WISP is accurate, effective and reliable. Compared with the active wireless Narada unit, the similarity is more than 83%. Compared with the OpenSEES system, the accuracy of the structure frequency monitored by the WISP is 99.07%. Therefore, it is feasible and reliable to use the WISPs to perform multi-point deployment control in structural dynamic monitoring.
Anomaly Detection in Text Data Sets using Character-Level Representation
Authors: Mohaghegh Mahsa , Abdurakhmanov Amantay 
Published: April 2021

Abstract
This paper proposes a character-level representation of unsupervised text data sets for anomaly detection problems. An empirical examination of the character-level text representation was conducted to demonstrate the ability to separate outlying and normal records using an ensemble of multiple classic numerical anomaly classifiers. Experimental results obtained on two different data sets confirmed the applicability of the developed unsupervised model to detect outlying instances in various real-world scenarios, providing the opportunity to quickly assess a large amount of textual data in terms of information consistency and conformity without knowledge of the data content itself.
Big Data Technology of Precision Poverty Alleviation Tracking Audit System under the Internet
Authors: Wang Wei 
Published: April 2021

Abstract
As our country’s poverty alleviation has entered a decisive moment, it has become an urgent task to count the poor. Based on the Internet perspective, this article combs the basic theories and related overviews of the precision poverty alleviation policy, and on this basis, carries out the follow-up audit evaluation system construction; In order to improve the audit effect, this paper uses big data technology, case analysis method, literature analysis method and other methods to collect data from databases such as CNKI, Wanfang database, SSCI, etc., build a tracking audit system model, and pass The literature survey method reads and analyzes a large number of related literature. The study found that through the introduction of big data calculations, the tracking audit effect has been improved, the accuracy has increased by 30%, and the classification and tracking of the poor have been greatly improved. The index is above 0.8, an increase of about 40%. This shows that under the follow-up audit of precision poverty alleviation, big data technology can play an important role and greatly improve poverty alleviation work.
Single-scale Residual Dense Dehazing Network
Authors: Wang Nian , Li Aihua , Cui Zhigao , Su Yanzhao , Lan Yunwei 
Published: April 2021

Abstract
Recently, image dehazing algorithm has been widely used in the preprocessing of target tracking and pattern recognition. A large number of end-to-end convolutional networks have achieved good results in dehazing by image translation. In this paper, we use Residual Dense structure, which has been prove effective in high resolution reconstruction, to build feature extract block, and stack these block to form a single-scale dehazing network. In order to further enhance the performance, we convey the feature of shallow layer to deep layer by channel concatenation. The results show that our network has achieved good results in both the synthetic haze removal and the real haze removal.
Application of Big Data Processing Technology in Human Resource Management Information System
Authors: Zeng Jiayi 
Published: April 2021

Abstract
As an important part of the high-level management model, human resource management has attracted much attention in all fields. Human resource management faces a large number of data problems, and it is urgent to discover valuable knowledge and provide decision-making support for enterprises to develop talent training strategies. The purpose of this article is to analyze the application of big data processing technology in human resource management information system. This paper proposes a literature research method, a case research method and a comparative research method to conduct a comprehensive analysis of the human resource management information system of a company. In addition, this paper takes the human resource data of a company as an example, through a large amount of data preprocessing work, design a human resource data mining system based on association rules is implemented, which realizes the application of incremental association rule mining algorithm to human resource data mining, realizes visualization, and finally mines valuable information. The experimental results of this paper show that the number of users of the client and server in the human resource management information system is less than 100, and the performance of the system can fully meet the needs of actual work in actual use.
Sustainable Development of Leisure Tourism Agriculture in Guangzhou Based on Data Hierarchical Modeling
Authors: Wang Ning , Zhou Jinyu , Liu Liming 
Published: April 2021

Abstract
Hierarchical modeling breaks down the problem of multiple input and multiple output modeling into a series of single input multiple output data modeling problems. This method can improve the efficiency and accuracy of multi-input multi-output system modeling. The model is suitable for describing a system with a complex structure and can contain more input variables, which is conducive to making full use of the existing system information. The problem of data modeling is to get this kind of mapping relationship. Usually a set of basic functions is selected for linear combination, an expression of F with a parameter is given, and then the coefficient of the parameter is determined by least square method or other methods. Urban agriculture was proposed in the process of industrialization and urbanization, with the rapid development of the urban economy, the increasingly severe environmental problems, and the deepening of the idea of sustainable development. Urban agriculture tourism is developed based on urban agriculture by developing various functions of urban agriculture. It makes the development of urban tourism more plentiful and novel, and further expands the space for agricultural development. Therefore, to find the efficient way, this paper proposes the pattern of the sustainable development of leisure tourism agriculture in Guangzhou based on data hierarchical modeling. Numerical analysis and the sample overview are provided to test he performance of the proposed methodology.