bluuebunny/crossref_metadata_2025 huggingface dataset:
Optical storage of circular airy beam in atomic vapor
Authors: Chang 常 Hong 虹 , Yang 杨 Xin 欣 , Ma 马 Yan 燕 , Yang 杨 Xinqi 鑫琪 , Cao 曹 Mingtao 明涛 , Zhang 张 Xiaofei 晓斐 , Dong 董 Ruifang 瑞芳 , Zhang 张 Shougang 首刚
Published: May 2024

The realization of quantum storage of spatial light field is of great significance to the construction of high-dimensional quantum repeater. In this paper, we experimentally realize the storage and retrieval of circular Airy beams (CABs) by using the Λ-type three-level energy system based on the electromagnetically induced transparency in a hot rubidium atomic vapor cell. The weak probe beam field is modulated with phase distribution of CABs by a spatial light modulator. We store the probe circular Airy beam (CAB) into the rubidium atomic vapor cell and retrieve it after the demanded delay. We quantitatively analyze the storage results and give corresponding theoretical explanations. Moreover, we investigate the autofocusing and self-healing effect of the retrieved CAB, which indicates that the properties and beam shape of CAB maintain well after storage. Our work will have potential applications in the storage of high-dimensional quantum information, and is also useful for improving the channel capacities of quantum internet.
Steering the energy sharing of electrons in nonsequential double ionization with orthogonally polarized two-color field
Authors: Fan 樊 Guangqi 光琦 , Yang 杨 Zhijie 志杰 , Sun 孙 Fenghao 烽豪 , Zheng 郑 Jinmei 金梅 , Han 韩 Yuntian 云天 , Huang 黄 Mingqian 明谦 , Liu 刘 Qingcao 情操
Published: May 2024

Using the semiclassical ensemble model, the dependence of relative amplitude for the recollision dynamics in nonsequential double ionization (NSDI) of neon atom driven by the orthogonally polarized two-color field (OTC) laser field is theoretically studied. And the dynamics in two typical collision pathways, recollision-impact-ionization (RII) and recollision-excitation with subsequent ionization (RESI), is systematically explored. Our results reveal that the V-shaped structure in the correlated momentum distribution is mainly caused by the RII mechanism when the relative amplitude of the OTC laser field is zero, and the first ionized electrons will quickly skim through the nucleus and share few energy with the second electron. As the relative amplitude increases, the V-shaped structure gradually disappears and electrons are concentrated on the diagonal in the electron correlation spectrum, indicating that the energy sharing after electrons collision is symmetric for OTC laser fields with large relative amplitudes. Our studies show that changing the relative amplitude of the OTC laser field can efficiently control the electron–electron collisions and energy exchange efficiency in the NSDI process.
Physics package based on intracavity laser cooling 87Rb atoms for space cold atom microwave clock
Authors: Deng 邓 Siminda 思敏达 , Ren 任 Wei 伟 , Xiang 项 Jingfeng 静峰 , Zhao 赵 Jianbo 剑波 , Li 李 Lin 琳 , Zhang 张 Di 迪 , Wan 万 Jinyin 金银 , Meng 孟 Yanling 艳玲 , Jiang 蒋 Xiaojun 小军 , Li 李 Tang 唐 , Liu 刘 Liang 亮 , Lü 吕 Desheng 德胜
Published: May 2024

This article proposes a new physics package to enhance the frequency stability of the space cold atom clock with the advantages of a microgravity environment. Clock working processes, including atom cooling, atomic state preparation, microwave interrogation, and transition probability detection, are integrated into the cylindrical microwave cavity to achieve a high-performance and compact physics package for the space cold atom clock. We present the detailed design and ground-test results of the cold atom clock physics package in this article, which demonstrates a frequency stability of 1.2 × 10−12
τ
−1/2 with a Ramsey linewidth of 12.5 Hz, and a better performance is predicted with a 1 Hz or a narrower Ramsey linewidth in microgravity environment. The miniaturized cold atom clock based on intracavity cooling has great potential for achieving space high-precision time-frequency reference in the future.
Orbit tomography in constants-of-motion phase-space
Authors: Rud M. , Moseev D. , Jaulmes F. , Bogar K. , Dong Y. , Hansen P.C. , Eriksson J. , Järleblad H. , Nocente M. , Prechel G. , Reman B.C.G. , Schmidt B.S. , Snicker A. , Stagner L. , Valentini A. , Salewski M.
Published: May 2024

Tomographic reconstructions of a 3D fast-ion constants-of-motion phase-space distribution function are computed by inverting synthetic signals based on projected velocities of the fast ions along the diagnostic lines of sight. A spectrum of projected velocities is a key element of the spectrum formation in fast-ion D-alpha spectroscopy, collective Thomson scattering, and gamma-ray and neutron emission spectroscopy, and it can hence serve as a proxy for any of these. The fast-ion distribution functions are parameterised by three constants of motion, the kinetic energy, the magnetic moment and the toroidal canonical angular momentum. The reconstructions are computed using both zeroth-order and first-order Tikhonov regularisation expressed in terms of Bayesian inference to allow uncertainty quantification. In addition to this, a discontinuity appears to be present in the solution across the trapped-passing boundary surface in the three-dimensional phase space due to a singularity in the Jacobian of the transformation from position and velocity space to phase space. A method to allow for this apparent discontinuity while simultaneously penalising large gradients in the solution is demonstrated. Finally, we use our new methods to optimise the diagnostic performance of a set of six fans of sightlines by finding where the detectors contribute most complementary diagnostic information for the future COMPASS-Upgrade tokamak.
Various Parameter Measurements in Single-Frequency Dual-ECR Heating on Electron Cyclotron Resonance Ion Source
Authors: Iwahara Kouki , Maenaka Takumu , Fujimura Yushi , Kato Yushi
Published: May 2024

We have been researching efficient generation of multi-charged ions on electron cyclotron resonance ion source (ECRIS). We can introduce microwaves from a coaxial antenna at the upstream side of the magnetic mirror field (Coaxial) and a rod antenna at the downstream side (Rod). Regardless of R-wave cutoff, ECR occurs at two resonance points by Dual-ECR heating which means introducing microwaves from both antennas and we succeeded in generating more multi-charged Ar ions. We measured beam currents and plasma parameters such as electron density and electron temperature and obtained their radial distributions. We found the beam currents of multi-charged Ar ions were highest by Dual-ECR heating.
Time-resolved measurement of optical emission line profiles from electron cyclotron resonance ion source plasma
Authors: Timonen Oskari , Koivisto Hannu , Kronholm Risto , Toivanen Ville
Published: May 2024

Optical emission spectroscopy provides a non-invasive method to probe the properties of hot and highly charged magnetically confined plasmas. The optical emission line profiles enable, for example, to identify the different species and characterize the relative population densities and temperatures of the ions and neutrals forming the plasma. The feasibility of this approach has been demonstrated at the University of Jyväskylä accelerator laboratory by measuring the light emitted by Electron Cyclotron Resonance Ion Source (ECRIS) plasma with a high-resolution spectrometer setup POSSU (Plasma Optical SpectroScopy Unit). In these previous studies, the emission line profiles were measured by scanning the desired wavelength range by rotating the diffraction grating of the spectrometer. This process is slow compared to many interesting plasma phenomena, thus limiting the applicability of the setup. Recently, POSSU has been upgraded by changing the light sensor from a photomultiplier tube to a position-sensitive imaging sensor. As a result, it is possible to measure simultaneously a 1 - 2 nm wavelength range, with a spectral resolution in the order of picometers, without moving the grating. This enables a time-resolved study of the optical emission line profiles. By turning the grating, the measured wavelength region can be chosen between 370 nm and 870 nm, which covers the visible light spectrum. The time-evolution of optical emission line profiles emitted from the JYFL 14 GHz ECRIS plasma, during shifting plasma conditions induced by changing the gas balance, has been measured to demonstrate this new capability. The time-evolution of temperatures and emission intensities of selected ion species, correlated with extracted ion beam currents, are presented.
Simulation of laser-plasma focusing using taper solenoid
Authors: Hosoya S , Kashiwagi H , Yamada K
Published: May 2024

A laser ion source can produce ion beams of various elements, including high melting point metals. Owing to its ability to switch beams rapidly by loading multiple solid targets, we are developing a laser ion source to implement it in a 400 kV ion implanter, which requires a wide range of ion species. Although a laser ion source offers above advantages, most of the plasma is lost in an ion source due to the generation of the beam from a part of the diffused plasma with a broad angular distribution. To suppress this loss and enhance beam intensity, we employ a linear solenoid to increase the amount of plasma reaching the extraction electrode by suppressing the three-dimensional plasma diffusion. However, the linear solenoid cannot suppress the loss of plasma near the target as the plasma spreads three-dimensionally from the plasma generation point. Therefore, by placing a taper solenoid near the target, it is possible to suppress the diffusion of plasma immediately after its generation and to transport most of the generated plasma to the extraction electrode. In this paper, we present the results of plasma trajectory calculations using the particle-in-cell method by the plasma simulations involving taper solenoids.
Application of Optical Emission Spectroscopy to Electron Cyclotron Resonance Ion Sources
Authors: Castro G , Reitano R , Leonardi O , Russo F , Celona L , D’Agostino G , Gammino S , Neri L , Costanzo G , Siliato D
Published: May 2024

Electron Cyclotron Resonance Ion Sources (ECRIS) are widely used for production of highly charged high intensity ion beams for research, medical and industrial applications.

ECRIS performances, especially the charge state distribution and beam intensity, depend significantly on the electron energy distribution function that ranges from a few eV to hundreds of keV. Further improvements of ECRIS performances require a deeper and deeper understanding of the plasma heating mechanisms and ion generation by means of opportune plasma diagnostics. Amongst others, optical emission spectroscopy (OES) is the most remarkable for application in ECRIS: it is a non-invasive diagnostics able to operate also in high-voltage conditions and it requires small room for operation. OES has been already tested for plasma diagnostics in proton sources.

This work presents the experimental set-up developed for the plasma diagnostics of the Advanced Ion Source for Hadrontherapy (AISHa), an ECRIS for medical applications, together with the strategy applied to relate plasma emission lines in the visible and near-infrared domain to plasma parameters for some ions of interest. Preliminary results and perspectives will be also discussed.
Work function of the caesiated converter surface at the BATMAN Upgrade H− ion source at different operational scenarios
Authors: Heiler A , Wimmer C , Berner J , Fantz U
Published: May 2024

Since negative hydrogen ion sources for neutral beam injection (NBI) systems rely on the surface production of negative hydrogen ions, Cs is injected to lower the work function of the extraction electrode surface. The adsorbed Cs layers are affected by residual gases from the given non-UHV conditions as well as by reactive hydrogen species during plasma phases, which leads to a complex surface chemistry and the occurrence of temporal changes of the work function. To control the work function and get insight into its temporal dynamics, an absolute work function diagnostic has been developed for ion sources with which measurements can be performed in vacuum phases between pulses. The diagnostic is applied at the BATMAN Upgrade test facility, which is equipped with the prototype RF ion source for the ITER NBI. It is shown that the Cs conditioning of the ion source leads to a dramatic decrease in the work function to ultra-low values < 1.5 eV. First measurements after the application of 1000 s pulses indicate that the ultra-low work function layer is not stable upon long-term plasma exposure and it is revealed that high dynamics of the Cs surface properties are given right after the pulse.
Towards ITER-Relevant CW Extraction at Negative Ion Sources for Fusion
Authors: Wünderlich D. , Wimmer C. , den Harder N. , Barnes M. , Fröschle M. , Heiler A. , Navarro A. , Riedl R. , Yordanov D. , Fantz U. , Heinemann B. ,   NNBI Team
Published: May 2024

Negative hydrogen or deuterium ion sources for neutral beam injection (NBI) systems used at fusion devices are based on the surface production process at a caesiated low work function converter surface. While producing a stable and globally homogeneous negative ion beam is not an issue, during long pulses typically a pronounced increase in the co-extracted electrons is observed, limiting the pulse length or the achievable performance. This effect is particularly pronounced in deuterium and it is attributed to an increasing work function of the converter surface. In the last years the negative ion source test facilities at IPP Garching, BATMAN Upgrade (using the small prototype source) and ELISE (using a source of the same width but only half the height of the ITER NBI source) have been converted into CW machines, making possible investigating at ITER conditions counter-measures for the increase in the co-extracted electrons. Investigations are performed, mainly at ELISE, on homogenizing and stabilizing the co-extracted electrons by affecting the ion source plasma close to the converter surface by means of biasing (additional) surfaces in the plasma.
High current positive ion source for Copernicus NBI based on a cold-cathode arc plasma generator
Authors: Shimabukuro Y , Franzen K , Korepanov S
Published: May 2024

The NBI system based on positive ions to be applied for TAE’s next-generation field reversed configuration experiment, Copernicus, has been designed. The beamlines are longer in the new system, so the required beam divergence smaller relative to the NBI system on TAE’s current device. This requirement motivates a change from slot-shaped apertures to circular in the plasma grid. The influence of changing the aperture shape on the divergence and total beam current across the extraction area has been examined. When considering spatial uniformity in calculations, it is expected that a beam current value of 173 A and a beam divergence angle of 17 mrad will be achieved, exceeding the required values by 15%. An octagonal-shaped ion source has also been developed for a future upgrade targeting 2.5 s long pulse operation, and the estimation indicates 83% source plasma uniformity with concurrent suppression of thermal loads. The development of multiple plasma diagnostics for assessing uniformity and proton ratios has been completed to validate these estimations and optimize the ion source dimensions.
Factors Influencing the Fluctuation Amplitude of the H− Ion Beam Extracted from an RF Wave Excited Ion Source Plasma
Authors: Wada Motoi , Shibata Takanori , Shinto Katsuhiro
Published: May 2024

The beam oscillation of J-PARC ion source is being studied as AC electric field at 2 MHz ion source driving frequency can directly change the extraction characteristics of both H− ions and electrons. The internal RF antenna inducing the electric field generated two peaks of plasma production during one RF cycle as confirmed by 4 MHz modulation of Balmer-alpha (Hα) emission intensity. The coupling between the plasma production at 4 MHz and the oscillation of the local plasma potential in the vicinity of the extraction hole at 2 MHz can cause 6 MHz oscillation, which was observed in the measurement of extraction current from the ion source. Phase-delay of Hα intensities from the source plasma and those of the extraction electron current were compared with the RF input signal to the amplifier.
Modelling of plasma discharge in a filament negative ion source
Authors: Candeloro V , Sartori E , Kisaki M , Kashiwagi M , Tobari H , Serianni G
Published: May 2024

Most of the currently operating Negative ion Neutral Beam Injectors (N-NBIs) exploit filament powered sources for the generation of beam ions. Being widely used in fusion experiments, the filament arc technology has been thoroughly investigated and optimized over the years, allowing to achieve excellent performances in terms of extracted beam optics. The source geometry, the magnetic field topology and the arc power strongly influence both the plasma discharge and the background gas properties and, consequently, the beam features. In this framework, this contribution describes a numerical investigation of the plasma properties in a filament-powered negative ion source, performed by means of a 2D3V Particle In Cell-Monte Carlo Collisions (PIC-MCC) code. Specifically, we discuss plasma formation by the thermionic electrons emitted by the filaments, investigating their interaction with the background gas. We also study the plasma diffusion through the magnetic filter field and how the latter modifies plasma density, electron temperature and plasma potential along the axial direction when approaching the plasma facing electrode.
Status of the High-Current Electron-Beam Ion Source Charge Breeder for the Facility for Rare-Isotope Beams
Authors: Son Hyock-Jun , Lapierre Alain , Schwarz Stefan , Villari Antonio C.C.
Published: May 2024

The Reaccelerator (ReA) of the Facility for Rare-Isotope Beams (FRIB) employs an Electron-Beam Ion Trap (EBIT) as a charge breeder to reaccelerate rare-isotope beams up to 12 MeV/u. The ReA EBIT produces an electron current of 300 – 600 mA. The maximum trap capacity of the ReA EBIT is 1010 elementary charges. FRIB production rates are expected to exceed 1010 particles/s in some cases in the future. There is also a user demand for reaccelerated stable-isotope beams of more than 1010 pps. To handle these rates and provide redundancy, a High Current Electron-Beam Ion Source (HCEBIS) has been built and is now being commissioned. An electron-beam current of 2 A with a 50 % duty cycle has been transported through a 4-T field. An upcoming upgrade to increase the electron-beam current up to 4 A will allow for a maximum trap capacity of 2.4×1011 elementary charges. We present the status of the HCEBIS, including the results of the electron-beam commissioning and systematic studies.
Upgrade and Improvement of the TRIUMF ECRIS Charge State Booster
Authors: Adegun J , Ames F , Kester O
Published: May 2024

Recently, the RF system of the TRIUMF electron cyclotron resonance ion source charge state booster (ECRIS CSB) underwent an upgrade to implement two-frequency heating using a single waveguide. The injection and extraction optics, as well as the injection and extraction systems, were carefully modelled and systematically optimized to improve the efficiency and beam quality of the charge state booster. With optimized plasma and beam optics under the single-frequency heating regime, the maximum charge state of the 133Cs isotope produced was 27+, with the peak of the charge state distribution at Cs23+ with an efficiency of 8.5 %. However, with the implementation of two-frequency heating, the maximum charge state of Cs that can be produced increased to 32+, and the charge state distribution’s peak shifted to Cs26+ with an efficiency of 9.1 %. Additionally, the two-frequency heating resulted in a total beam RMS emittance that was approximately half of the one that was measured under the single-frequency heating due to the more pronounced negative potential dip created at the plasma center.
Design and commissioning of a versatile surface ion source
Authors: Saminathan S. , Ames F. , Angus T. , Baartman R. , Charles C. , Cho J. , Dirksen P. , Hruskovec T. , Jayamanna K. , Lovera M. , Marchetto M. , Minato B. , Schultz B. , Wager D.
Published: May 2024

A compact and versatile ion source was designed and commissioned to be used with the new low energy ion beam facilities at TRIUMF. The ion source is based on the principle of surface ionization, in which ions are generated from a neutral atom by impact with a solid surface. The design of the ion source considered several factors, including the type of ions, intensity, energy and emittance of the extracted beams from the source. Commercially available alkali materials with an ionizer are used in the source; the ionizer is integrated with the in house design of extraction and transport system. The source performance was characterized using diagnostics techniques, and its key parameters, such as beam current, emittance, and beam species, were measured. The results showed that the compact surface ion source is able to achieve high ionization efficiency and stable operation, and is suitable for use in commissioning and operation of various ion beam facilities in particle accelerator laboratories.
Performance increase for a medical proton beam ECRIS through dual frequency heating at MedAustron ion therapy center
Authors: Rockenbauer R , Schmitzer C S , Gambino N
Published: May 2024

The MedAustron facility, located in Wiener Neustadt, Austria, is a state-of-the-art synchrotron-based particle therapy center that provides irradiation with proton and carbon ion beams in an energy range of 62MeV to 252MeV and 120MeV/u to 402MeV/u, respectively. In order to improve on extracted current and on long term stability, key factors for medical accelerators, the dual frequency heating mode was tested at the source level. Through the use of dual frequency heating an increase in the intensity through the accelerator sections could be achieved, without changing the optics of the overall machine. The use of dual frequency heating has also improved the transmission efficiency from LEBT to LINAC section by 4 %. Across a wider range of input power, beam transmission is elevated when comparing to single frequency heating. As a result of this increased transmission, in room particle count could be improved in comparison to single frequency heating.
Design and Experiment of a Slotted Antenna Surface Wave Plasma Flood Gun
Authors: Cui Bujian , Peng Shixiang , Ma Tenghao , Jiang Yaoxiang , Wu Wenbin , Guo Zhiyu , Chen Jiae
Published: May 2024

In a modern ion implanter, plasma flood gun (PFG) is used to neutralize wafer charge during doping process, preventing the breakdown of floating wafers caused by the space charge accumulation. In order to obtain the PFG which can produce ribbon electron beams with the characteristics of high stability, high plasma density, no metal pollution and long life, studies at Peking University (PKU) are focused on surface wave plasma flood gun (SW-PFG) recently. A 2.45 GHz SW-PFG with a quartz plate and a series of metal slotted antenna arrays was designed and tested. Theoretical studies are carried out to optimize the SW-PFG structural parameters. The quartz plate thickness is determined as 15 mm. The size of the plasma chamber is 280 mm×150 mm×40 mm with a 280 mm×2 mm extraction slit. In the experiment, a relatively uniform argon plasma is obtained under the condition of gas flow rate of 2 sccm and input power of 800 W. In this case, the plasma distribution is studied by emission spectrum diagnosis and 73 mA ribbon electron beam is measured.
Research on slope algorithm based laser welding guidance technology for 3D vision inspection of thin-walled parts
Authors: Song Ning , Zhao Yuan
Published: May 2024

Visual guidance technology advances quickly and so do the technical requirements for weld trajectory, which needs to fulfill performance indices for high precision, anti-interference and quick processing. In this study, the approach of getting 3D point cloud data by directly scanning the workpiece to be welded with a 3D scanner is used because it is more precise and reliable than processing gray-layer data obtained from a depth camera, turning it into a 3D point cloud. The weld boundary is retrieved by slope calculation for the butt weld after preprocessing the three-dimensional point cloud data (cut, down-sampling, and abnormal value removal). The center point is then determined. After that, a welding trajectory is produced by fitting the center point, which is transmitted back to the actuator to guide its welding work and realize the identification and tracking of the weld.
Effect of Nb content on the microstructure and mechanical properties of CoCrNiNbx high-entropy alloy
Authors: Hong Jialin , Li Shuang , Zhang Li , Yang Jingmei
Published: May 2024

This paper systematically studies the effect of Nb content on the microstructure and mechanical properties of CoCrNiNbx (x=0, 0.2, 0.4, 0.6, 0.8) high-entropy alloy. The results show that the secondary Laves phases start to precipitate in the alloy when the Nb element content is 0.2%. With the increase of Nb content, the shape of secondary phases changes from punctate to elongated. The maximum yield strength of the alloy is 585.88 MPa when x=0.6%, and the maximum Vickers hardness of the alloy is 688.9 HV when x=0.8%, caused by the precipitation strengthening mechanism.
Study on mechanical properties of polyurethane mixtures with different fillers combined with industrial problems
Authors: Zhang Zixiong
Published: May 2024

This paper mainly introduces the classification of polyurethane mixtures. To produce new polyurethane composites used in manufacturing, the team researched Polyurethane combined with different composites and showed the mechanical properties of the composites on a chart. When reducing-graphene oxide (GO) and multi-walled carbon nanotubes are mixed with polyurethane, the composite can increase Young’s Modulus to 615 MPa and tensile strength to 657 MPa with a weight reduction of 5%. Glass fibre filled with Polyurethane also provides a fairly Young’s Modulus (over 10000 MPa) with a high weight percent up to 20%. How to increase the content of reduced GO and carbon nanotubes in polyurethane filling will be a problem worthy of further exploration.
Design of transmission mechanism of punch feeding and discharging manipulator
Authors: Han Leilei , Jiang Di , Niu Lei , He Qin
Published: May 2024

The press loading and unloading manipulator is a kind of intelligent equipment based on automation, which is specially developed for realizing the automation and unmanned production of the press shop. It can replace the worker’s work by implementing the manual editing program and greatly improve the efficiency of production and quality. The design optimized the traditional transmission scheme comparison and molded the structure based on the solid works modeling. The key supporting parts of the manipulator are analyzed by the finite element method. The simulation results showed that the manipulator can satisfy the designed loading requirements and guarantee the designed accuracy.
High-temperature flexural mechanical properties of SiC/SiC composites
Authors: Meng Yi , Yang Shengchun , Liu Xiaochuan
Published: May 2024

To assess the flexural behavior of SiC/SiC composites in high-temperature atmospheric environments, three critical influencing factors were identified: selection of fixtures, loading and supporting roller dimensions, and span-to-thickness ratio. Subsequently, through experimental methods and finite element model simulations, the impact of these factors was investigated. The study identified the most suitable fixture materials and configuration dimensions for SiC/SiC materials. It was found that as the span-to-thickness ratio increases, the flexural strength of the material continues to rise, reaching a turning point at 543 MPa, after which it decreases. The maximum interlaminar shear stress consistently decreases with an increasing span-to-thickness ratio. Combined with the failure mode analysis of the samples, it was observed that for a span-to-thickness ratio equal to or greater than 16, the sample failure modes are all valid. Additionally, regarding the observed non-linearity in the stress-strain curve when testing with a larger span-to-thickness ratio, it is recommended to apply a large deflection correction to the flexural stress.
Optimization of reliability and sensitivity analysis for flange structures
Authors: Gong Longjia , Feng Hanlin
Published: May 2024

The study delves into the reliability-driven optimization design of the flanges, drawing from reliability design theory, advanced optimization methodologies, and comprehensive sensitivity analysis. Flanges, integral to mechanical systems, demand precise design. Reliability design theory emphasizes consistent operation under diverse conditions. A novel approach to the flange-specific reliability sensitivity analysis method is central to this research. It promises to revolutionize flange design. By understanding the first two moments of core random parameters, we expedite reliability-driven optimization designs for mechanical connections. The programs enhance our approach, streamlining the pursuit of reliability-driven designs and providing rapid, accurate sensitivity analysis data for mechanical connections. This data offers critical insights into parameter influence, enabling targeted design adjustments. In summary, this research represents a significant advancement in mechanical engineering. By integrating reliability design theory with cutting-edge methodologies, it promises to enhance the quality and reliability of mechanical connections, meeting the rigorous demands of contemporary engineering applications. This holistic approach will play a pivotal role in the future of mechanical component design.
Kinematic analysis of inverted planetary roller screw considering skew error
Authors: Zhang Changhui , Fan Yuanxun , Zhang Ming , Xu Zhiwei , Yan Cheng
Published: May 2024

To reveal the motion characteristics of inverted planetary roller screws under the influence of axial deviation error, the working principle of inverted planetary roller screws was elaborated, and a motion analysis model of inverted planetary roller screws based on deviation error was established. This paper analyzed the angle error, axial displacement error, and relative velocity error of the roller, and comprehensively analyzed the influence of errors and parameters on the motion state.
Discussion on damage of type IV hydrogen storage cylinder
Authors: Yang Bo
Published: May 2024

Aiming at the judgment that the interface joints between different material parts of high-pressure hydrogen storage cylinders are prone to fatigue damage under repeated charging and discharging conditions, the progressive damage finite element model of nonmetal-metal-nonmetal multi-dimensional composite hydrogen storage cylinders is established. Thestress distribution and static strength of composite hydrogen storage cylinders are analyzed, and the influence law of winding composite technology on the stress distribution and static strength of composite hydrogen storage cylinders is studied.
Study on reliability of gold belt welding for Aerospace Microwave Circuit
Authors: Wang Qiongjiao , Fu Yonghui , Liu Jiangtao , Song Changxu , Li Ke , Zhao Yuxin
Published: May 2024

As a highly reliable and flexible interconnection method, gold belt welding is widely used in the interconnection of aerospace microwave circuits. In this paper, to reveal the influence of the technological parameters of gold belt welding on stress, the typical aerospace electronic equipment was studied by Ansys finite element software. The result shows that the stiffness consistency of two structures which are connected by a gold belt and the winding radius of the gold belt are the crucial factors in the reliability of gold belt connection. A process-strengthening measure has been proposed based on the analysis results. The verification of the process experiment shows that using EC2216 adhesive on both sides of a gold belt can effectively reduce stress and improve mechanical reliability. Furthermore, the analytical methods and measures have been extended to other flexible interconnection methods, which provide a solution to the highly reliable interconnection in the aerospace product.
A study on the strand arrangement in 3D printing of continuous carbon fiber composite materials with multiple strands
Authors: Zhang Xinghua , Zhang Fan , Zeng Lingwei , Tu Yiwen
Published: May 2024

3D printing of continuous carbon fiber composite materials with multiple strands has significant potential for improving model forming efficiency. However, in this field, we are faced with the challenge of arranging multiple fiber strands closely without excessive overlap consolidation, to avoid damage to the original model. The inability to effectively control the arrangement of multiple strands can significantly affect the print accuracy and mechanical performance of the model. Therefore, in this study, a predictive formula for the line width of carbon fiber strands is first presented. Subsequently, a device dedicated to 3D printing with multiple strands is designed using this formula, and the interrelationship between pressure and the arrangement of multiple strands is delved into. Comparative tests are also conducted on printed parts for tension and bending to investigate the influence of strand arrangement tightness on the mechanical performance of printed samples under different pressure conditions. Through electron microscopy experiments to analyze the microstructure of fracture surfaces, the causes of differences in mechanical performance and the potential effects of different pressures on print accuracy are explained. The results of the study indicate that when pressure can be precisely controlled to ensure a tight arrangement between multiple strands, the mechanical performance of printed parts reaches its optimal state. The tensile strength can reach 360.62 MPa, and the bending strength is 311.04 MPa. At the same time, for test samples printed under the optimal printing pressure, their surface accuracy is also at its best.
Leakage of water-cooled wall tube in subcritical boiler
Authors: Gao Jun , Chen Hao , Li Tianlong , Qiao Xin , Guo Xinai , Shi Shida
Published: May 2024

Usually, heating surfaces used in thermal power plant boilers include economizers, water-cooled walls, superheaters, and reheaters, abbreviated as the “four tubes” of boilers. The leakage of the heating surface is a common form of unplanned shutdown in thermal power plants, accounting for more than 50% of abnormal shutdown accidents of units. Once the heating surface explosion occurs, the thermal power plant needs to shut down for treatment, resulting in huge losses in power generation and fuel consumption during startup and shutdown. This has a huge impact on the safety production and economic benefits of the enterprise. In this paper, the leaked water-cooled wall tube in the subcritical boiler was studied by means of microstructure analysis, hardness test, energy spectrum analysis, chemical composition test, macro-morphology inspection, and tensile test. The results revealed that the oxygen concentration difference between the area installed in ceiling pouring material and the area exposed to the air can result in significant differences in electrode potential between different areas of the front water wall tube passing through the ceiling. An oxygen concentration difference battery is formed. In this way, the water-cooled wall steel pipe continuously corroded and thinned. Finally, perforation leakage occurred under the pressure of the internal high-temperature medium.
Preparation and electrochromic performance of Nb-Doped Tungsten oxide nanowires
Authors: Zhang Zuosheng , Zhang Yong , Dong Senyu
Published: May 2024

Different niobium (Nb)-doped tungsten oxide (WO3) nanowire films were prepared by magnetron sputtering and hydrothermal methods, and their performances were analyzed. The experimental results revealed that Nb doping caused the tungsten oxide nanowire structure to become loose, increased the interplanar spacing, and raised the oxygen vacancy concentration, significantly improving the electrochromic properties. However, with increasing Nb doping levels, the cyclic stability of the samples decreased, possibly due to lattice distortion induced by Nb. The analysis demonstrated that the sample doped with 0.5% Nb exhibited optimal electrochromic performance and displayed a 5.68% coloring transmittance and an 83.3% optical modulation range at a wavelength of 633 nm. This study elucidated the influence of Nb doping on the electrochromic properties of WO3 nanowire films.
Numerical study of the seepage behavior of droplets in porous materials
Authors: Wang Zixiong , Wang Xiaoyi , Zhang Guotao , Liang Fangling
Published: May 2024

This article analyzes the spread and infiltration dynamic process of liquid droplets on the surface of porous materials and establishes a mathematical model of dynamic changes in droplets. To accurately describe the dynamic effects of droplet flow, a mathematical model of droplet dynamics was developed by applying the level-set method, and the seepage process of the droplets was also analyzed numerically. The effects of a series of control parameters on the droplet percolation process are analyzed, and the pore degree of porous materials performed a numerical study of the droplet deformation process. We observe the spread and infiltration process of liquid droplets in porous materials models. It was found that there is a competitive relationship between diffusion and penetration of droplets. The depth of penetration of droplets decreases with increasing viscosity and increases with increasing porosity. The results of the study help to understand the seepage behavior of the droplet on the surface of the porous material.
Study on the jet molding of Cu-W-Zrx alloy liner
Authors: Li Zehua , Dong Baoquan , Wang Ye , Zhao Hui , Li Mei
Published: May 2024

With the rapid development of armored weapons, the improvement of armor-breaking weapons is imminent, and the liners as the core component of armor-breaking has attracted much attention. As a result, the paper uses AUTODYN-2D kinetic simulation software to simulate the generation of jets in the erosion process of Cu-W alloy liner and Cu-W-Zr alloy liner materials. The results demonstrate that the jet created by Cu-W-Zr alloy is longer than that formed by Cu-W alloy, and it has good erosion ability with high head velocity during the jet creation process, which can be used to develop liners.
Effect of nitrate-carbonate molten salt flow rate for the 347H corrosion behavior
Authors: Gao Qi , Lu Yuanwei , Jia Jiwei , Wu Yuting , Han Xilong , Zhang Cancan
Published: May 2024

Molten salts have been widely adopted for solar thermal power stations because of their superior thermophysical properties. However, the corrosive effect on the metal material with molten salt is an important factor for the long-term operation of CSP systems. For the study of the corrosive influence on metallic materials of molten salts in dynamic conditions, the corrosion performance of the 347H sample in molten salts at different flow rates was analyzed by using nitrate-carbonate molten salt as the base salt. The findings revealed a higher corrosion rate of the 347H samples under dynamic conditions, compared to static conditions. Moreover, as the flow velocity for the molten salt increases, 347H sample corrosion rates increase. The morphological analysis of the 347H sample revealed that, under molten salt static conditions, a dense corrosion layer was mainly formed in the 347H sample, while, under molten salt dynamic conditions, a grooved structure was observed in the 347H sample. The main corrosion products of 347H samples in different flow rates are composed of Fe2O3, Fe3O4, NiFe2O4 and NaFeO2. Therefore, for changing the molten salt flow rate, the sample’s corrosion morphology changes but does not affect the sample’s corrosion product type.
Influence of cooling speeds on the microstructure and properties of A356 aluminum alloy after squeeze casting
Authors: Li Chun-Ming , Zuo Ling-Li , Li Long-Fei , Liang Jun-Ning , Zhang Yang , Chen Lin , Zhao Xue-Sheng , Han Qing-Hua
Published: May 2024

The examination focuses on the microstructural characteristics and mechanical attributes of A356 alloy subsequent to squeeze casting performed under varying cooling speeds. The findings reveal that the cooling speeds have no notable impact on the size of the grains in the A356 alloy produced through squeeze casting. However, as the cooling speeds increase, the eutectic Si phase in A356 alloy decreases, transforming it from coarse flakes to small rods or particles, thereby enhancing the mechanical characteristics of the alloy. The water-cooled alloy has the best UTS performance, whose value of A356 alloy after squeeze casting is 287 MPa.
A new hydrogen-filled Cherenkov detector for Kaon tagging at the NA62 experiment at CERN
Authors: Sanders Jack ,   the NA62 collaboration
Published: May 2024

The precision measurement of K
+ → π
+
νν̅ at the NA62 experiment requires a kaon identification detector to have a time resolution better than 100 ps, at least 95 % kaon identification efficiency, and a pion misidentification probability of less than 10-4. Since the start of NA62 data taking in 2016, kaon identification has been performed by a differential Cherenkov with achromatic ring focus (CEDAR) detector with a nitrogen gas radiator. A new CEDAR using hydrogen (CEDAR-H) as a radiator gas has been developed to reduce the material in the beamline, reducing the beam particle scattering within the detector.
CEDAR-H was validated during a two-week test beam at CERN in 2022 and was approved by the NA62 collaboration for use in data taking from 2023. The test beam results, installation and commissioning in the NA62 beamline are reported.
Thermodynamic work of partial resetting
Authors: Stølevik Olsen Kristian , Gupta Deepak
Published: May 2024

Partial resetting, whereby a state variablex(t) is reset at random times to a valueax(t),0⩽a⩽1, generalizes conventional resetting by introducing the resetting strengthaas a parameter. Partial resetting generates a broad family of non-equilibrium steady states (NESS) that interpolates between the conventional NESS at strong resetting (a = 0) and a Gaussian distribution at weak resetting (a → 1). Here such resetting processes are studied from a thermodynamic perspective, and the mean cost associated with maintaining such NESS are derived. The resetting phase of the dynamics is implemented by a resetting potentialΦ(x)that mediates the resets in finite time. By working in an ensemble of trajectories with a fixed number of resets, we study both the steady-state properties of the propagator and its moments. The thermodynamic work needed to sustain the resulting NESS is then investigated. We find that different resetting traps can give rise to rates of work with widely different dependencies on the resetting strengtha. Surprisingly, in the case of resets mediated by a harmonic trap with otherwise free diffusive motion, the asymptotic rate of work is insensitive to the value ofa. For general anharmonic traps, the asymptotic rate of work can be either increasing or decreasing as a function of the strengtha, depending on the degree of anharmonicity. Counter to intuition, the rate of work can therefore in some cases increase as the resetting becomes weaker(a→1)although the work vanishes ata = 1. Work in the presence of a background potential is also considered. Numerical simulations confirm our findings.
Hamiltonian for the Hilbert–Pólya conjecture
Authors: Yakaboylu Enderalp
Published: May 2024

We introduce a Hamiltonian to address the Hilbert–Pólya conjecture. The eigenfunctions of the introduced Hamiltonian, subject to the Dirichlet boundary conditions on the positive half-line, vanish at the origin by the nontrivial zeros of the Riemann zeta function. Consequently, the eigenvalues are determined by these nontrivial Riemann zeros. If the Riemann hypothesis (RH) is true, the eigenvalues become real and represent the imaginary parts of the nontrivial zeros. Conversely, if the Hamiltonian is self-adjoint, or more generally, admits only real eigenvalues, then the RH follows. In our attempt to demonstrate the latter, we establish the existence of a similarity transformation of the introduced Hamiltonian that is self-adjoint on the domain specified by an appropriate boundary condition, which is satisfied by the eigenfunctions through the vanishing of the Riemann zeta function. Our result can be extended to a broader class of functions whose zeros lie on the critical line.
hiPSC-derived macrophages improve drug sensitivity and selectivity in a macrophage-incorporating organoid culture model
Authors: Jo Seongyea , Park Sung Bum , Kim Hyemin , Im Ilkyun , Noh Haneul , Kim Eun-Mi , Kim Ki Young , Oelgeschläger Michael , Kim Jong-Hoon , Park Han-Jin
Published: May 2024

Accurate simulation of different cell type interactions is crucial for physiological and precise in vitro drug testing. Human tissue-resident macrophages are critical for modulating disease conditions and drug-induced injuries in various tissues; however, their limited availability has hindered their use in in vitro modeling. Therefore, this study aimed to create macrophage-containing organoid co-culture models by directly incorporating human-induced pluripotent stem cell (hiPSC)-derived pre-macrophages into organoid and scaffold cell models. The fully differentiated cells in these organoids exhibited functional characteristics of tissue-resident macrophages with enriched pan-macrophage markers and the potential for M1/M2 subtype specialization upon cytokine stimulation. In a hepatic organoid model, the integrated macrophages replicated typical intrinsic properties, including cytokine release, polarization, and phagocytosis, and the co-culture model was more responsive to drug-induced liver injury than a macrophage-free model. Furthermore, alveolar organoid models containing these hiPSC-derived macrophages also showed increased drug and chemical sensitivity to pulmonary toxicants. Moreover, 3D adipocyte scaffold models incorporating macrophages effectively simulated in vivo insulin resistance observed in adipose tissue and showed improved insulin sensitivity on exposure to anti-diabetic drugs. Overall, the findings demonstrated that incorporating hiPSC-derived macrophages into organoid culture models resulted in more physiological and sensitive in vitro drug evaluation and screening systems.
Propagation characteristics of twisted cosine-Gaussian Schell-model beams
Authors: Dong Shijie , Yang Yunzhe , Zhou Yujie , Li Xinzhong , Tang Miaomiao
Published: May 2024

We introduce a new class of twisted sources with twisted cosine-Gaussian Schell-model correlation structure. The spectral intensity and the degree of coherence of the field upon propagation are discussed. Such novel twisted field is characterized by unfamiliar twist pattern and controllable far-zone lattice profile. It exhibits a Gaussian or a lattice-like intensity distribution in the source plane, while always turns into a

2
×
2

lattice profile in the far zone. Notably, the array profile twists around the propagation axis instead of each element rotating about its own lobe center, which is different from most of the twisted array models. Moreover, the splitting tendency in the intensity distribution could be flexibly modulated by the twisted factor, the source coherence and the beam width. The coherence distribution could rotate in the same direction as the intensity with appropriate choice of parameters. Finally, the cross-spectral density’s phase distribution exhibits a spiral windmill structure and coherent singularities could be observed upon propagation.