bluuebunny/crossref_metadata_2025_split huggingface dataset:
Aerodynamic Characteristic Analysis of V-22 Tilt-Rotor Aircraft in Hover
Authors: Xu Peimin , Yang Yueyue , Zhou Jie , Zhou Guiyu 
Published: June 2022

Abstract
Tilt-rotor aircraft combines the vertical take-off and landing function of helicopters with the high-speed cruise function of fixed-wing aircraft, which has given rise to extensive attention in the aviation field, but the complex aerodynamic characteristics of the rotor flow field and the interference of rotor/fuselage have always been tough problems. In recent years, the continuous development of high-performance computer and the combination of high-precision CFD method and dynamic overset grid technology, make it possible to perform fine numerical simulation of tilt-rotor aircraft’s flow field. In this paper, the low-dissipation fifth-order Roe-WENO scheme and overset grid method are used to solve the unsteady N-S equation, and the hovering state of tilt-rotor aircraft is numerically simulated. The result shows: under the interference of ground effect and fountain effect, the lift coefficient of blade when the azimuth angle is 180° to 360° is obviously smaller than that when the azimuth angle is 0° to 180°. The vortex structure of the hovering flow field of V-22 tilt-rotor aircraft is mainly composed of the fountain effect recirculation zone, the tip vortex wake and the root vortex wake. The tip vortex wake develops downwards, shrinks inward and approaches the fuselage. After the root wake falls off, it converges and fuses on the surface of nacelles. The root vortex wake is strong and moves towards the front of the fuselage and the plane of symmetry.
Numerical Investigation of Round-to-Slot Holes on Film-Cooling Performance in a Turbine Vane
Authors: Huang Ying , Peng Can , Zhang Jingzhou , Zhu Xingdan 
Published: June 2022

Abstract
The numerical investigation of single row holes on suction surface and pressure surface of a scaled turbine guide vane is carried out. In particular, the effects of round-to-slot holes (RTSHs) on film cooling performance are illustrated. Four RTSHs with different exit-to-inlet area ratios are considered under different blowing ratios. The results show that RTSHs can suppress the normal penetration of cooling jet and broadening the lateral coverage of film layer. With the increase of slot aspect ratio, the anti-kidney vortices pair is generally strengthened, making the film cooling improvement more significantly. The film cooling improving effects of shaped holes on the pressure surface is better than that on the suction surface, particularly under high blowing ratios. A key factor affecting the bleed pressure of coolant flow is exit-inlet area ratio of RTSH. The equivalent-area RTSH achieves nearly the same discharge coefficient (Cd) as the cylindrical hole. Viewed from the comprehensive effects of the Cd and adiabatic film cooling effectiveness on shaped hole, the RTSH-3 with a slot aspect of 9 and an exit-inlet area ratio of 1.27 is suggested to be the most favorable film-hole geometry among the current shaped-holes, either on the pressure surface or on the suction surface.
Study on optical scattering detection method of bubbly wake of targets in water
Authors: Wang Yun , Gu Wei , Shen Zhiben , Shi Weihua , Wu Jianwei , Dong Liang 
Published: June 2022

Abstract
A method for the detection of the bubbly wake of targets in water is presented, which is based on the features of optical frequency domain of the scattering optical signal. A simulation on the optical frequency domain characteristics of the bubbly wake scattering signal is performed by statistical test method. The influence of the bubble population and the velocity distribution on the optical frequency domain characteristics is analyzed. On this basis, a test platform for the characteristics of optical frequency domain of the bubbly wake scattering signal is designed and established. The characteristics of the bubbly wake scattering signal are studied experimentally. Experimental results agree with the theoretical analysis. The results show that the amplitude and the cut-off frequency of the shift spectra will increase with the increasing bubble population and range of velocity distribution. It indicates the effectiveness of the detection method.
Effects of blade curvature on flow and heat transfer characteristics of internal cooling at trailing edge
Authors: Yan Yan , Zhu Jianqin , Cheng Zeyuan 
Published: June 2022

Abstract
In modern turbine blade designs, a large number of internal cooling technologies have been developed and blade curvature is one of the most important factors. This paper numerically simulates the heat transfer process of the internal cooling channel with flat plate and wall curvature at the trailing edge and analyses Nu distribution and deviation between these two structures. The results show that due to the disruptive and reorganising effects of blade curvature on the vortex structure, blade curvature strengthens the heat transfer. There are significant heat transfer differences at the individual surface of each path.
Analysis on Welding Temperature Field and Stress Field of Boring Bar of New Boring Machine
Authors: Han Liang , Song Yuning 
Published: June 2022

Abstract
Ansys software is used to simulate the welding process of the boring bar of the new cylinder head boring machine. The indirect coupling method is used to analyze the temperature field, then the stress field and deformation. It is found that for the double support structure, the highest temperature occurs at the outer stiffened plate of the small diameter end, and the lowest temperature occurs at both ends of the inner support structure. The deformation of the whole structure mainly comes from the axial deformation, and the maximum deformation occurs at the large diameter end of the outer rib plate. Because the role of the supporting web is to limit the large deformation of the whole structure, the structure at the small diameter end is firmer and has the ability of anti-deformation. In terms of technology, the influence caused by deformation can be compensated by the compensation design of machining amount.
Analysis of rainwater overflow in underground pipe network
Authors: Zhou Tian , Yang Fan , Liu Wei , Tan Yue 
Published: June 2022

Abstract
Urban rainwater pipe network is a direct way to resist urban waterlogging, and its safe and stable operation is the premise to ensure the normal operation of the city. However, in China and even around the world, the monitoring means for the operation of urban rainwater pipe network are very limited. For the occurrence and solution of urban waterlogging, it often mainly depends on the means of personnel inspection to monitor where the rainwater pipe network overflows, and then take measures. There is no effective monitoring method for the whole rainwater pipe network. Therefore, an accurate and efficient rainwater pipe network monitoring method is urgently needed. To solve the current problem of real-time monitoring of rainwater pipe network, the core problem is how to monitor the liquid level data of any pipe section of the whole rainwater pipe network in real time, so it is necessary to introduce hydrodynamic model. The traditional hydrodynamic model mainly simulates the hydraulic and hydrological, and does not simulate the rainwater pipe network, but makes a generalized estimation of the drainage of the rainwater pipe network. In addition, some hydrodynamic models for drainage pipe network are not established for the problem of rainwater pipe network monitoring. The ultrasonic liquid level gauge with real-time acquisition function is not introduced into the calculation simulation, and it does not have the ability of adaptive correction. Therefore, the traditional rainwater monitoring methods and hydrodynamic models can not fundamentally solve the problem of real-time monitoring of the whole rainwater pipe network. Using hydrodynamic model calculation, combined with rain gauge and liquid level gauge to monitor and modify model parameters, so as to intelligently monitor the whole rainwater pipe network, which can greatly improve the current monitoring level of urban rainwater pipe network and reduce the work cost of manual patrol monitoring.
Operational Effectiveness Evaluation of UAV Cluster Based on Bayesian Networks
Authors: Wang J J , zhang Y Y , Ma J , Hou J , Wang F M , Li N 
Published: June 2022

Abstract
This paper focuses on the requirements of operational efficiency evaluation for UAV cluster, and establishes an evaluation index system for UAV cluster operations, and establishes evaluation index system from the aspects of cooperative attack capability, autonomous reconnaissance capability, instant messaging capability, rapid planning capability and autonomous formation capability. The evaluation network model is built by using Bayesian network, and the corresponding prior and conditional probabilities are calculated. The effectiveness values of each capability are calculated and verified by experiments. This paper provides an applicable quantitative evaluation method for UAV cluster operational effectiveness evaluation.
The Positive Integer Solutions of Ternary Euler Function Equation φ(x
1
x
2
x
3) = k(φ
2(x
1) + φ
2(x
2) + φ
2 (x
3)) + l
Authors: Zheng Hui 
Published: June 2022

Abstract
Let φ(n) be Euler function. In this work we discuss the solvability of Euler function equation φ(x
1
x
2
x
3) = k (φ
2(x
1) + φ
2(x
2) + φ
2(x
3)) +l, and give more accurate upper bounds of all positive integer solutions of this equation with elementary method. As an application, we find all the positive integer solutions of this equation for the given k and l.
The Lagrange’s method in dynamic spacetime
Authors: He Po-shan 
Published: June 2022

Abstract
The Lagrange’s method is a kind of commen method in physics on motion particle. Usually, the field is nonconsevative if it had constraint condition vary in time, it lead to the Lagrange’s equaition have inhomogeneous term and many integral. The dynamic spacetime can be constraint the situation of motion of particle, because of this kind of spacetime had the gravitational wave. This paper will be discuess the form of Lagrange’s method in dynamic spacetime.
S1 attractor bifurcation analysis for a three-species cooperating model
Authors: Li Junyan , Wu Ruili 
Published: June 2022

Abstract
In this paper, the dynamic bifurcation of the three-species cooperating model is considered. It worth noting that the main theory of this paper is the Center manifold reduction and attractor bifurcation theory, which is developed by Ma [1,2]. The main work of this paper shows that if the algebraic multiplicity of the first eigenvalue is 2, there exists an S1 attractor bifurcation, and the number of its singular points can only be eight. Besides, we show that the simplified governing equations bifurcate to an S1 attractor, when the Control parameter λ crosses a critical value λ
0.
Acoustic Radiation Characteristics from Shell Structure for Different Depth State
Authors: Dong Lei , Li HanXu , Chen YanYu 
Published: June 2022

Abstract
As a naval warship, submarine is a typical complex combined system. The excitation source of its vibration has the characteristics of large amplitude and wide frequency spectrum, and the prediction of vibro-acoustic radiation needs to be carried out in a wide frequency band. How to accurately predict the vibro-acoustic radiation of submarines in the whole frequency band has become a problem of practical significance. Elastic cylindrical shell is the typical structure of underwater vehicle. Studying acoustic radiation characteristics from shell structure for different depth state has a certain significance for studying submarine acoustic stealth characteristics. As an important acoustic performance metrics, the radiation sound power of underwater structure is significant for researching vibration and sound radiation characteristics. In this article, based on the FEM and BEM method, by using ANSYS and SYSNOISE software shell structure for different depth state is modeled and its vibration and radiation characteristics are researched. Numerical calculation shows that with immersed depth increasing, the vibration response and sound radiation power from shell structure gradually tend to the ones from under free field.
The influence of structural features on the acoustic scattering characteristics of array transducers
Authors: Deng Fang-zhou 
Published: June 2022

Abstract
In order to study the sound scattering characteristics of array transducers on different shell structures, based on the COMSOL finite element simulation calculation method, this paper analyzes the scattered sound field characteristics of the array transducer in the single-shell structure, the single-double transition shell structure, and the double-shell structure. A quantitative comparison between the radiated sound field and the scattered sound field is made, the law of the scattered sound field is analyzed, the scattering characteristics of the array transducer under different shells are explained, and the simulation basis for the engineering application of the array transducer is provided.
The Large Deflection Solution of Circular Elastic Membrane under Composite Loads
Authors: Zhou Can , Fang Shuting , Liu Changjiang 
Published: June 2022

Abstract
In this paper, the large deflection problem of axisymmetric isotropic elastic membranes subjected to the composite loads is studied. The Hencky transformation is extended and the general solution of large deflection of the membranes under the composite loads is obtained. The general solution is given in different forms in different values of loads. The obtained results of the numerical values of elastic characters can be applied in practice.
Research Status and Development Trend of UAV Path Planning Algorithms
Authors: Zeng Sha , Liu Kang 
Published: June 2022

Abstract
This paper introduces the basic concepts of UAV track planning, the relationship between track planning and algorithms, and focuses on the analysis and induction of several commonly used algorithms at home and abroad in recent years. The advantages and disadvantages of current path planning algorithms in different application scenarios are summarized. Finally, the future development trend of UAV path planning algorithm is prospected, and it is pointed out that real-time online path planning algorithm research, multi-UAV swarm planning algorithm, perfect path planning problem model and algorithm hybrid optimization are the next research trends.
Adaptive RBF Neural Network Backstepping Control for Two-Link Robot Manipulators
Authors: Wang Chao 
Published: June 2022

Abstract
In this paper, an adaptive radial basis function neural network(RBFNN) backstepping controller is presented for a two-link robot manipulator in the presence of uncertainty and external interferences. RBFNNs are applied to approximate uncertain nonlinear functions, and considering the backstepping technique, an adaptive RBFNN backstepping control strategy is proposed. It is proved by the Lyapunov function that tracking errors converge to a small neighborhood of the equilibrium point and the closed-loop system variables are bounded. The simulation results demonstrate the effectiveness of the presented design method.
The Research of Asymptotic Average Shadowing Property and Pointwise Lipschitz Shadowing Property
Authors: Bei Caixia , Ji Zhanjiang 
Published: June 2022

Abstract
We investigated the dynamical relationship between asymptotic average shadow ing property and pointwise Lipschitz shadowing property on the sequence map and the limit map. Then, we have: (1)Suppose {gn
} strongly uniformly converge to g · gn
has asymptotic average shadowing property implies g has asymptotic average shadowing property. (2) Suppose {gn
} strongly uniformly converge to g · gn
has fine pointwise shadowing property implies g has pointwise Lipschitz shadowing property. The above results promote the theory development of asymptotic average shadowing property and pointwise Lipschitz shadowing property.
Numerical study on variable aperture extraction grids of a titanium hydride cathodic vacuum arc ion source
Authors: Wu W.B. , Zhou H.J. , Zhou Q.H. , Yang W. , Dong Y. , Yang W.Y. 
Published: June 2022

Abstract
Titanium hydride cathodic vacuum arc ion sources are widely
used in particle accelerators, neutron sources, etc. For the
application in neutron sources, higher H+/D+ fraction and
higher beam uniformity are preferred. In this work, to improve the
beam uniformity of a miniature titanium hydride cathodic vacuum arc
ion source, a new scheme of variable aperture extraction grids is
proposed. A 2D numerical model is developed for the investigation of
the variable aperture extraction grids. Numerical results indicate
that the extraction grid plays important roles in the titanium
hydride cathodic vacuum arc ion source that can improve the
stability of ion source. Moreover, simulated results show that the
designed variable aperture extraction grids can reduce the beam
nonuniformity to less than ±10%, while the beam nonuniformity
of the fixed aperture extraction grids are between ±22% and
±37%. Thus, the presented work can provide a potential
reference for the improvement of beam uniformity of the vacuum arc
ion sources.
Design of PLC and EPICS based control system for a deuteron RFQ
Authors: Liu S. , Wei Y.X. , Lu Y.R. , Wang Z. , Han M.Y. , Wei T.H. , Zheng P.F. 
Published: June 2022

Abstract
Peking University and Southwestern Institute of Physics are
jointly developing a new deuteron RFQ to study the migration and
deposition of impurities on the first wall of a tokamak
facility. This RFQ will accelerate a 10-mA deuteron beam from
40 keV up to 1.5 MeV at a duty factor of 1%. In this paper, the
detailed design of the prototype control system based on a Siemens
PLC and EPICS/CSS software environment for the RFQ accelerator is
presented. The system is composed by many kinds of sub-systems
developed using different hardware solutions. The interlock
protection mechanism is introduced into the control system. The
EPICS Archiver Appliance is used to provide the service of data
archiving and retrieval. The system has been successfully
implemented for RF conditioning and beam commissioning.
Effect of Positional Changes on Skin Landmarks in Midface Filling
Authors: Du Yuyang , Ye Yajie , Wang Qing , Li Meijia , Chen Xinyao , Li Rou , Hao Lijun , Luo Sai 
Published: June 2022

Abstract

Background
The design lines for midfacial filling shift upward with a patient’s position changes from upright to supine during operation. This will cause the actual filled part to deviate from the target area.

Objectives
This authors aimed to evaluate the effect of positional changes on midfacial landmarks and find the optimal body position for midface filling.

Methods
The process involved the grading and evaluation stages. The midfacial laxity of each sample in the evaluation stage was graded into minimal, moderate, and severe by the system established in the grading stage. Measured through the 3-dimensional images in each grade, the vertical distances from landmarks C, D, and E (representing the region of the tear trough, infraorbital area, and nasolabial fat pad, respectively) to the horizontal line of the inner canthus and depth of nasolabial fold at an angle of 90° were separately compared with those from the other angles (60°, 45°, 30°, and 0°) of the operating table.

Results
In the minimal midfacial laxity group, all 3 landmarks significantly moved upward when the angle decreased to 30°. However, landmark E of the moderate and severe and landmark D of the severe midfacial laxity groups both significantly moved upward when the angle decreased to 45°. The depth of the nasolabial fold at a 45° angle was significantly less than that at a 90° angle in the moderate and severe groups.

Conclusions
In midface filling, a patient’s body position should be optimally selected according to the midfacial laxity and filling area.
A yeast suppressor screen links Coa4 to the mitochondrial copper delivery pathway for cytochrome c oxidase
Authors: Swaminathan Abhinav B , Soma Shivatheja , Vicary Alison C , Zulkifli Mohammad , Kaur Harman , Gohil Vishal M 
Published: June 2022

Abstract
Cytochrome c oxidase (CcO) is a multimeric copper-containing enzyme of the mitochondrial respiratory chain that powers cellular energy production. The two core subunits of cytochrome c oxidase, Cox1 and Cox2, harbor the catalytic CuB and CuA sites, respectively. Biogenesis of each copper site occurs separately and requires multiple proteins that constitute the mitochondrial copper delivery pathway. Currently, the identity of all the members of the pathway is not known, though several evolutionarily conserved twin CX9C motif-containing proteins have been implicated in this process. Here, we performed a targeted yeast suppressor screen that placed Coa4, a twin CX9C motif-containing protein, in the copper delivery pathway to the Cox1 subunit. Specifically, we show that overexpression of Cox11, a copper metallochaperone required for the formation of CuB site, can restore Cox1 abundance, cytochrome c oxidase assembly, and mitochondrial respiration in coa4Δ cells. This rescue is dependent on the copper-coordinating cysteines of Cox11. The abundance of Coa4 and Cox11 in mitochondria is reciprocally regulated, further linking Coa4 to the CuB site biogenesis. Additionally, we find that coa4Δ cells have reduced levels of copper and exogenous copper supplementation can partially ameliorate its respiratory-deficient phenotype, a finding that connects Coa4 to cellular copper homeostasis. Finally, we demonstrate that human COA4 can replace the function of yeast Coa4 indicating its evolutionarily conserved role. Our work provides genetic evidences for the role of Coa4 in the copper delivery pathway to the CuB site of cytochrome c oxidase.
David Against Goliath: Direct Comparison of Handheld Bowel Sonography and Magnetic Resonance Enterography for Diagnosis of Crohn’s Disease
Authors: Rispo Antonio , de Sire Roberto , Mainenti Pier Paolo , Imperatore Nicola , Testa Anna , Maurea Simone , Ricciolino Simona , Nardone Olga Maria , Olmo Oriana , Castiglione Fabiana 
Published: June 2022

AbstractBackgroundDiagnosis of Crohn’s disease (CD) requires ileo-colonoscopy (IC) and cross-sectional evaluation. Recently, “echoscopy” has been used effectively in several settings, although data about its use for CD diagnosis are still limited. Our aim was to evaluate the diagnostic accuracy of handheld bowel sonography (HHBS) in comparison with magnetic resonance enterography (MRE) for CD diagnosis.MethodsFrom September 2019 to June 2021, we prospectively recruited consecutive subjects attending our third level IBD Unit for suspected CD. Patients underwent IC, HHBS, and MRE in random order with operators blinded about the result of the other procedures. Bivariate correlation between MRE and HHBS was calculated by Spearman coefficient (r). To test the consistency between MRE and HHBS for CD location and complications, the Cohen’s k measure was applied.ResultsCrohn’s disease diagnosis was made in 48 out of 85 subjects (56%). Sensitivity, specificity, positive predictive values, and negative predictive values for CD diagnosis were 87.50%, 91.89%, 93.33%, and 85% for HHBS; and 91.67%, 94.59%, 95.65%, and 89.74% for MRE, without significant differences in terms of diagnostic accuracy (89.41% for HHBS vs 92.94% for MRE, P = NS). Magnetic resonance enterography was superior to HHBS in defining CD extension (r = 0.67; P &lt; .01) with a better diagnostic performance than HHBS for detecting location (k = 0.81; P &lt; .01), strictures (k = 0.75; P &lt; .01), abscesses (k = 0.68; P &lt; .01), and fistulas (k = 0.65; P &lt; .01).ConclusionHandheld bowel sonography and MRE are 2 accurate and noninvasive procedures for diagnosis of CD, although MRE is more sensitive in defining extension, location, and complications. Handheld bowel sonography could be used as effective ambulatory (or out-of-office) screening tool for identifying patients to refer for MRE examination due to high probability of CD diagnosis.