bluuebunny/crossref_metadata_2025_split huggingface dataset:
Design of a Flextensional Transducer with Adjustable Prestress
Authors: Fang Houlin , Liu Yang , Zhao Tianqing , Liu Yunzhe , Li Kaikai , Sun Deyu , Zhang Dezhi 
Published: September 2021

Abstract
Prestress has a great bearing on the performance of flextensional transducer. In order to enhance the adjustability of prestress, a design method for the flextensional transducer with adjustable prestress was proposed in this study. Through the conversion design of rotational and rectilinear motions of the transition block, the clamping length of major axis of class IV flextensional transducer shell was changed, enabling the adjustment of prestress. Next, the related experiment was further carried out. The results show that the return displacement of adjustable transition block is slightly greater than the travel displacement, and both displacements show high overlap ratios in the two tests. Because of the prestress adjustment, the frequency response of flextensional transducer is reduced to some extent, within one frequency band (40-63 Hz), but its sound pressure level (SPL) substantially increases nearby the resonant frequency (about 75 Hz).
Research on hull pressure distribution of amphibious landing on water based on RANS method
Authors: Hu Qi , Wu Bin , Wang Ming-Zhen , Huang Miao , Jiao Jun 
Published: September 2021

Abstract
Aiming at the strength problem of amphibious landing on water, the pressure distribution of ship bottom is studied. RANS multi-phase flow method is used to solve the coupling problem of gas, liquid and solid in the process of amphibious landing on the water surface. Overlapping grid technology is used to simulate the landing under different initial horizontal velocity and vertical velocity. The influence of initial conditions on the motion response of amphibious is analyzed, and the variation law of pressure on each section of ship bottom with time is obtained, This paper analyzes the variation of pressure with time and position, and provides technical reference for the design and application of water loads in the development of amphibious.
Research on Optimal Design and Construction Technology of Prefabricated Load-bearing Pier Structure
Authors: Chen H. , Han S.Y. , Zhang P. H. , Kang D.Y. 
Published: September 2021

Abstract
The prefabricated pier structure has the advantages of low energy consumption, high mechanized level, which meets the green development trend of the construction industry, with broad application prospects. This paper analyzes the process and construction principle of the prefabricated pier structure and the pier and the top platform of the prefabricated bearing pier, which describes the principle of the prefabricated bearer structure, and the structural operation of the prefabricated bearer structure, and proposed a new type of prefabricated pier structure.
The Study on Selection of Evaluation Criterion for Slope Instability
Authors: Cheng Yongfeng , Kong Xiaoang , Zhao Binbin , Liu Yi , Yang Zhi 
Published: September 2021

Abstract
How to select an appropriate instability evaluation criterion is a key issue in the application of the finite element strength reduction method. Commonly used evaluation criteria for slope instability mainly include non-convergence criterion of finite element numerical calculation, displacement saltation criterion at characteristic point, and penetration criterion of plastic zone. The researches on these three types of instability criteria are still continuing, but there is no uniform conclusion yet. Based on the different characteristics of the three types of instability evaluation criteria, this paper compares and analyzes the evaluation results of three criteria on the slope stability by trial calculations, and then discusses the characteristics and effectiveness of three types of instability evaluation criteria. In actual numerical calculation, it is necessary to minimize the influence of human factors and comprehensively consider the three types of instability evaluation criteria to improve the consistency of the evaluation results. when the evaluation results are inconsistent, priority should be given to the feature point displacement saltation criterion at characteristic point or penetration criterion of plastic zone. In addition, a reasonable dilatancy angle is needed to accurately consider the influence of dilatancy on slope stability.
Very High Cycle Fatigue Properties of 2024 Aluminum Alloy Samples in Three Sizes
Authors: Wang Changkai , Chen Xuan , Cheng Li , Ding Junliang , Wang Bohan 
Published: September 2021

Abstract
An ultrasonic fatigue testing system was used to carry out very high cycle fatigue (VHCF) tests on 2024 aluminum alloy in three different sizes of specimens. The influence of specimen size and optimization on the experimental results was discussed and the VHCF properties of 2024 aluminum alloy were obtained at the same time. The results show that: The S-N curves of all specimens show a continuous decreasing tendency and the curve of the dog-bone-shaped specimen (the half-length of the testing volume L0 > 0) is lower than that of the hourglass-shaped specimen (L0 = 0) at low-cycle and high-cycle fatigue stages, which is opposite at the VHCF stage; The optimized specimen solves the problem of fracture position deviation and effectively improves the accuracy of experimental data; 2024 aluminum alloy will still fracture when the fatigue life exceed 107, and there exist no fatigue limit; All cracks initiate at surface and the fracture morphologies show characteristics of the crack initiation and propagation.
Compact biosensors based on thin film silicon nitride microring resonators
Authors: Hong Yixiao , Ge Hua , Hong Jianxun 
Published: September 2021

Abstract
We presented a silicon microring resonator based on thin film silicon nitride waveguide for biosensor applications. Design and fabrication were conducted. The device was fabricated on a silicon nitride wafer with 250 nm top film on 3 μm buried oxide by using electron-beam lithography and inductively coupled plasma etching. The radius of the microring is as smaller as 50 μm. The quality factor of the resonator is 8610. The spectra and resonance shift for bulk sensing were measured by flowing sodium chloride solutions with different concentrations on the surface of the sensor. The sensitivity and the LOD of the sensor are 384.58 nm/RIU and 4.68×10−4 RIU, respectively.
A Study on the Harmfulness of Tire Fragments Impact on Panel Structure Angle and Postures
Authors: Wu Xiaoyang , Chen Qing , Zhang Ke , Wang Peiyan , Yue Zhufeng 
Published: September 2021

Abstract
When a tire bursts, the flying fragments may break through the wing, damage the precision instruments inside it, and cause huge economic losses. In this paper, the impact of tire fragments on the fuselage structure is simulated, and the dynamic response of the structure under different postures of impacting different structures and fragments is analyzed. The damage caused by different impact modes is analyzed and compared, the harshest impact conditions are selected, and the corresponding improvement measures are given according to the impact results. It is found that the strain of the frame truss structure is the smallest when the fragments impacts on the front side, but it may lead to the fracture of the frame truss on the back side, resulting in secondary fragments splashing. When impacting in different postures, the edge impact is the most dangerous. Although it penetrates the skin, it is very close to the failure value.
Present status and development trend of Acoustic releaser
Authors: Jianqiang Song 
Published: September 2021

Abstract
Acoustics releaser plays an important role in the recovery of marine surveying system. This paper analyses and introduces present situation of the acoustics releaser in our country. Finally, main technology development direction and strategy of localization are put forward in the paper. The paper mainly includes research status quo outside and in China as well as key technical problems in design of underwater acoustic releasers.
The integral of complex variables on three defined contours
Authors: Li Hankun , Wang Weiyue , Zhang Yuhan 
Published: September 2021

Abstract
Complex variables have aroused strong interest in the community of mathematics in the past few decades. Our aim is to obtain the integral results of a particular equation

f
(
Z
)
=

z
3

+
(
1
+
2

i
)
z

2

−
7
z
+
1
−
2
i

z
4

−
1

,

in three defined contours. To determine the value of integral, the information we need to find is the residue values ABCD on four specific points and find out what residue values each contour includes. After finding the residue values and analysing four contours, we should use Cauchy integral formula to find the integral value. Firstly, by using the partial fraction to separate the equation into four independent parts, we obtain four values on each of the four fractions are the value of integral. Thus we can find exactly the four residue values, which are -1 on (1,0), 3 on (0,i), -2 on (-1.0) and 1 on (-I,0) as shown in the following expression.

f(Z)=

z
3

+
(
1
+
2

i)z

2

−
7
z
+
1
−
2
i

z
4

−
1

=

−
1

Z
−
1

+

3

Z
−
i

+

−
2

Z
+
1

+

1

Z
+
i

,

and then we must analyse each contour and find out the residue values they include. By drawing a diagram of each of the three contours. We find that contour 1 contains A, contour 2 contains A and D, and contour 3 contains ABCD. The final step to obtaining the value of residue is to use Cauchy integral formula

∫

y

f
(
z
)
d
z

=
2
π
i

∑

k
=
1

n

Res

f
(
z
)

.

According to Cauchy integral formula, the value of integral of the equation on a specific contour is obtained by multiplying the sum of the residue values included in that contour by 2πi, the value of integral of the equation can be found as we now have all the necessary information. For the first contour

y
(
t
)
=
1
+

e

i
t

,

where

0
≤
t
≤
2
π
,

the value of integral is calculated by using 2πi multiply by -1. We can get the result -2πi. For the second contour

y
(
t
)
=

1
−
i

2

+

2

e

i
t

,

where

0
≤
t
≤
2
π
,

the value of integral is calculated by using 2πi multiply by the sum of -1 and 1. As we can see, the sum is 0. We can get the result 0. For the third contour

y
(
t
)
=
2

e

i
t

,

where

0
≤
t
≤
2
π
,

the value of integral is calculated by using 2πi multiply by the sum of -1,3, -2, and 1.
As we can see, the sum of these residue values 1. We can get the result 2πi. Hence all of the values of integral of the equation

f
(
z
)
=

z
3

+
(
1
+
2

i)z

2

−
7
z
+
1
−
2
i

z
4

−
1

,

is found.
Derivation and classical solutions for the Wave equation
Authors: Ji Chunyu , Li Kaiyang , Liu Qiyuan 
Published: September 2021

Abstract
The problem of string vibration prompted mathematicians to find a suitable equation to express this phenomenon, which led to the birth of the Fourier series and integrals. The physical law of string vibration can be expressed by wave equation and solved by Fourier series. The study on the wave equation is fraught with mathematical and physical controversy. D.Bernoulli based on results from physical experiments to make a bold conjecture that the shape of a vibrating string can be described as a combination of trigonmetric series, which was inspired and validated by work from Fourier on study on heat equation. This study reviews the wave equation using Fourier as a tool. This paper not only gives the derivation of the wave equation but also explores its solution and corresponding properties.
A note on the entire functions: theorems, properties and examples
Authors: Huo Xiaodan , Zhan Yufei 
Published: September 2021

Abstract
In this work, we summarized several fundamental theorems of the entire functions and explored how their zeros determine those functions. The background of this work is based on Elias M. Stein and Rami Shakarachi, and their lectures about functions that are holomorphic in the whole complex plane that once were taught at Princeton University. First, we introduced Jensen’s formula and gave detailed proof. This relates the values of a meromorphic function inside a disk with its boundary values on the circumference and with its zeros and poles. Next, we studied the proof of Weierstrass infinite products and the definition of canonical factors. Last, Hadamard’s factorization theorem and a few main lemmas were introduced. We showed the proof of the Hadamard factorization theorem and solved its several applications through using examples. Hadmard’s theory is well demonstrated in this article, and we showed the rigor and scientific validity of the theory through examples.
Mathematical Modeling of Traffic
Authors: Sun Jiayang 
Published: September 2021

Abstract
This mathematical exploration is around the topic of traffic. Traffic is a constant problem for many small and large cities with a significant population density and costs people efficiency. Traffic congestion adversely impacts metropolitan cities’ living standards, reflecting on travelers’ time cost, the number of resulting accidents, and trivially fuel consumption. Therefore good transportation is called for contributions everywhere today in the modern world. In this essay, mathematical theory is used to integrate the most influential cause - the culprit of traffic congestions.
Research on Regional Innovation Capability Based on Grey Relation Analysis
Authors: Wang Junchuan , Zou Du 
Published: September 2021

Abstract
Regional innovation ability evaluation is a powerful engine to promote high-quality economic development, and also an important part of the strategy ofstrengthening the province through innovation. In this paper, the regional innovation capacity evaluation index system is constructed from three dimensions of regional innovation input, regional innovation environment and regional innovation output. By using the grey correlation analysis method, the regional innovation capacity of 13 cities and states in Hubei Province in 2019 is evaluated and ranked. The results show that the regional innovation capacity of Hubei Province is roughly distributed in ladder shape. In this paper, 13 cities and prefectures in Hubei province are divided into three levels, and some suggestions are put forward to improve the overall ability of scientific and technological innovation and to balance the development of regional innovation in Hubei province.
Numerical simulation of flow field in a Laval nozzle based on one-dimensional Euler equation
Authors: Cai Han , Jiang Zirun 
Published: September 2021

Abstract
Numerical simulation refers to a computer research method which runs calculation based on a specific mathematical model to simulate actual physical processes. It is a powerful tool to analyse complex engineering problems. In this paper, a numerical method for solving the steady one-dimensional Euler equations using a two-step second-order difference scheme is developed. The method is implemented by a Python code. The method is applied to numerical simulation of flows in a Laval nozzle and used to investigate the influence of shapes of Laval nozzle. It is found that the physical quantities of the nozzle flow show a positive correlation trend with different throat positions. In terms of the temperature, density, and pressure, they increase during the initial evolutions, then reach the maximum point and produce significant fluctuations, indicating the flow flows into the transonic stage. Subsequently, those physical properties gradually tend to a stable value during the supersonic stage. Moreover, it is observed that the closer the throat is to the exit, the lower the Mach number at which it eventually stabilizes. Finally, a suggestion about the best shape of the nozzle which can realize the max efficiency is concluded. Despite using an inviscid flow model, the steady pressures are quite satisfactorily predicted over the range of frequencies studied.
Interpretation of TeV electron and positron data with a single source
Authors: Xie Bohan 
Published: September 2021

Abstract
In recent years, many experiments, for example, like AMS-02, CALET, DAMPE, HESS and Fermi-LAT, have enhanced their precision in detecting the flux of cosmic rays, especially for high energy particles. We aim to interpret the electrons and positrons data above 1 TeV by using a model considering supernova remnants (SNRs) and the single pulsar as the major sources of electrons and positrons. We explain the rationality of applying the continuous scenario model for the single pulsar. We use the data above and choose seven parameters (d, t, γe, Etot, Q0,SNR, γSNR, Ec,SNR
) to perform the best fit for electrons and positrons flux at Earth. We perform the fit for the data above 1 Tev and 10 GeV to analyze how the single pulsar and SNRs contribute to the total flux. We also find that the fit ranges we choose for the parameters have a significant influence on the result. By considering this effect, a further analysis on the best fit by constraining γe
and Ec,SNR
shows that the pulsar PSR B0656+14 can provide most of the flux to the data above 1 TeV.
Research on Furnace Temperature Curve
Authors: Zhang Jieya , Jing Yijun , Chao Yongzheng , Mao Yuanyuan 
Published: September 2021

Abstract
The furnace temperature curve of the reflow furnace records the temperature changes during the soldering process of the printed circuit board components, which is the main factor influencing the quality of component soldering. Given the temperature of each temperature zone and the furnace passing speed, use the conveyor belt model, Fourier’s law and Newton’s law of cooling to establish a mathematical model to find the midpoint temperature of each temperature zone and obtain the furnace temperature curve. A search algorithm is further set up to obtain the maximum conveyor belt passing speed.
Numerical Study on Subsonic-Supersonic Laval Nozzle Using MacCormack Scheme
Authors: Li Boyang , Wu Jingbo , Liu Yuzhou 
Published: September 2021

Abstract
Due to the wide application of the Delaware nozzle in many fields, the flow characteristics of the subsonic-supersonic isentropic flow in the De-Laval nozzle are analyzed numerically. The flow in the nozzle can be simplified to a quasi-one-dimensional flow problem. First, the MacCormack format is employed to discretize the control equations in conservative form. Then, the results with and without artificial viscosity are compared. Grid independence is also discussed. The results show that the numerical solution and the theoretical solution agree very well, indicating that the numerical simulation results are very reliable. In addition, a higher pressure will reduce the peak and valley values of Mach number, pressure, density, temperature and velocity in the nozzle, and these extreme values of subsonic supersonic isentropic nozzle appear earlier. Additionally, the shock wave is accurately captured, and the shock wave is behind the throat. This research is of great significance to understand the flow characteristics in the nozzle.
Research on fracture parameters of asphalt mixture based on XFEM and J Integral method
Authors: Zeng Guowei , Zhou Peng 
Published: September 2021

Abstract
The fracture toughness and load displacement relationship of the three point bending (3pb) asphalt mixture specimens with different notch position were experimentally and numerical investigated. Firstly, the extended finite element was used to simulate the three-point bending and fracture process of asphalt mixture beam, and the load and displacement curves were obtained, which were compared with the test results to verify the accuracy of the XFEM model. Secondly, J contour integral method in ABAQUS software was used to solve the stress intensity factor under the three-point bending of asphalt mixture, and the fracture parameters of asphalt mixture were provided by the numerical calculation results. The results showed that the offset distance increases, the influence of the type II crack in the fracture process increases, but the type I crack still was dominant.
Gödel’s Incompleteness Theorem and Problems Outside Quantum Mechanics
Authors: Yan Yutong 
Published: September 2021

Abstract
Gödel’s Incompleteness Theorem is considered a significant finding in logic and mathematics and has many indications in physics. This paper analyzes and concludes that Gödel’s Incompleteness theorem potentially parallels problems of reference frame in classical physics and other issues considering self-inclusion with regard to consciousness, which not necessarily relevant to quantum mechanics. It also demonstrates further investigations on Gödel’s Incompleteness theorem, which can add to our understanding of problems in classical physics and philosophy of mind that still require in-depth research.
Study on the Relationship between Quantum Entanglement and Spacetime
Authors: Zhu Peiyu 
Published: September 2021

Abstract
Quantum entanglement and spacetime are strongly associated fields in modern physics. This paper investigated the connection between quantum entanglement and spacetime, particularly focusing on how they mutually form one another. The quantum mechanics and relativity theory cannot peacefully coexist in some cases, so it is difficult to combine them together. This article analyzes studies which suggest quantum entanglement can fabricate the continuous spacetime, and studies that imply spacetime geometry can explain quantum entanglement. These findings may bring us a better vision of the relation between quantum mechanics and relativity, as well as pave a path to the unification of quantum mechanics and relativity.
The challenge of the new theoretical system of physics in the 21st century to the popular views of physics in the world
Authors: Zhou Jiang Hua 
Published: September 2021

Abstract
This paper is based on the new theoretical system of physics in the 21st century published by the British Physical Society IOP Journal of physics in 2020. It is a challenge to some popular views of physics today! It negates the big bang theory, general relativity, epistemology of gravitational wave existence and epistemology of antimatter existence. It denies the research method of relying on the electron Collider to find the smallest particle in the material world! It is put forward that “the state of matter light” is the epistemology of the fifth physical state; stars are not composed of hydrogen and helium, nor are they nuclear reactions; the formation reason of Galactic System and the epistemology of cosmic unit. This paper is a summary and deduction of the new theoretical system of physics in the 21st century.
Five Methods of Exoplanet Detection
Authors: Dai Ziqi , Ni Dong , Pan Lizhuang , Zhu Yiheng 
Published: September 2021

Abstract
The study of exoplanetary systems can help us understand the formation and evolution of the solar system itself and search for terrestrial planets in the habitable and extrasolar lives in exoplanetary systems. Exoplanets have become an important area of astrophysics in the last two decades. This paper reviews five different methods to detect exoplanets, including direct imaging, astrometry, radial velocity, transit event observation, and microlensing. These approaches could expand the sample size of exoplanets and further our understanding of the types, formation and evolution of exoplanets.