Experiments in Fluids最新文献

{"title":"Quantitative schlieren with physics-informed neural networks","authors":"Lennart Rohlfs,&nbsp;Julien Weiss","doi":"10.1007/s00348-026-04268-1","DOIUrl":"10.1007/s00348-026-04268-1","url":null,"abstract":"<div><p>This article introduces physics-informed quantitative schlieren (PIQS), a data-assimilation framework that transforms standard qualitative schlieren images into quantitative flow fields. By leveraging physics-informed neural networks (PINNs), the method treats the unknown calibration factor between image intensity and density gradient as a learnable parameter that is inferred during the training process. The solution is anchored using Rankine–Hugoniot jump relations across identified shock waves to solve the inherent scale ambiguity. The framework is validated against a numerical ground truth for inviscid supersonic flow over a rhombus airfoil, where it recovers the true calibration factor and density field with high accuracy (<span>(R^2 &gt; 0.99)</span>). Application to a turbulent Mach 2 shock-wave/boundary-layer interaction (SBLI) demonstrates that PIQS yields reconstructions consistent with independent quantitative background-oriented schlieren (BOS) measurements. Finally, the method is applied to previously published schlieren imagery of a supersonic projectile, successfully recovering quantitative density profiles that match analytical Taylor–Maccoll solutions. These results demonstrate that PIQS offers a robust pathway for extracting quantitative data from both contemporary and historical schlieren visualizations without requiring dedicated calibration hardware.</p></div>","PeriodicalId":554,"journal":{"name":"Experiments in Fluids","volume":"67 8","pages":""},"PeriodicalIF":2.7,"publicationDate":"2026-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00348-026-04268-1.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148433690","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterization of the laminar–turbulent transition in helically coiled reactors: an experimental study using high-speed PIV and LDV","authors":"Conrad Müller,&nbsp;Péter Kováts,&nbsp;Dominique Thévenin,&nbsp;Katharina Zähringer","doi":"10.1007/s00348-026-04251-w","DOIUrl":"10.1007/s00348-026-04251-w","url":null,"abstract":"<div><p>Helically coiled reactors (HCRs) are increasingly employed in industrial applications due to their enhanced heat and mass transfer characteristics, compact design and improved mixing performance compared to straight tube systems. Despite their widespread use, a significant gap remains in the literature regarding the transition from laminar to turbulent flow within such geometries. Most existing studies rely primarily on pressure drop measurements for flow characterization, while comprehensive velocity-based investigations remain scarce. In this work, a detailed qualitative and quantitative characterization of the laminar–turbulent transition in a helical reactor is presented. An experimental set-up was developed to perform high-speed particle image velocimetry (PIV) measurements across a wide range of Reynolds numbers (Re = 500…9500). Various markers are employed to identify and analyse the onset of turbulence: visual flow patterns represented through carpet plots and pseudo-3D visualizations, statistical quantities such as standard deviation and turbulence intensity and the root mean square (RMS) of vorticity as a Lyne vortex indicator. Additionally, spectral analyses are conducted using power spectral density (PSD) evaluation, along with the estimation of dissipation rates and Kolmogorov time <span>(tau)</span> and length scales <span>({eta}_{tau })</span> to assess the small-scale turbulent structures. Pseudo-3D visualizations reveal first turbulent structures at <span>({text{R}text{e}}_{text{c}text{r}text{i}text{t}}=2400)</span> and a constant presence of additional vortex structures at <span>({text{R}text{e}}_{text{c}text{r}text{i}text{t}}=6000)</span>. Analysis of the standard deviation and turbulence intensity reveals a transition between <span>({text{R}text{e}}_{text{c}text{r}text{i}text{t}}=2400dots 4800)</span>. The frequency analysis with PSD shows full turbulence at <span>({text{R}text{e}}_{text{c}text{r}text{i}text{t}}=7000)</span>. Vorticity analysis and dissipation rates support a transition area between <span>({text{R}text{e}}_{text{c}text{r}text{i}text{t}}=2400dots 5000)</span>. These various ranges reveal that predicting exactly the transition point of course depends on the retained definition, with many different approaches documented in the literature. Keeping this in mind, it is still possible to give a lower boundary for the onset of transition around <span>({text{R}text{e}}_{text{c}text{r}text{i}text{t}}=2400)</span> and an upper boundary to a fully turbulent flow within the whole cross section at <span>({text{R}text{e}}_{text{c}text{r}text{i}text{t}}=7000)</span> for the considered geometry (curvature ratio <span>(delta =0.847)</span>, inner tube diameter <span>({d}_{i}=10 text{m}text{m})</span>).</p><h3>Graphical abstract</h3><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":554,"journal":{"name":"Experiments in Fluids","volume":"67 8","pages":""},"PeriodicalIF":2.7,"publicationDate":"2026-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00348-026-04251-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148433763","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Lateral vortex structures in open-channel turbulence over a non-uniform staggered cube rough bed","authors":"Liang Zhong,&nbsp;Xinming Yan,&nbsp;Yibo Tan,&nbsp;Jiangxiu Yu","doi":"10.1007/s00348-026-04264-5","DOIUrl":"10.1007/s00348-026-04264-5","url":null,"abstract":"<p>To reveal the statistical characteristics of lateral vortex structures in open-channel turbulence over a non-uniform rough bed, seven sets of open-channel experiments were conducted using particle image velocimetry. The rough bed was formed by staggered cubes of two distinct sizes. The Reynolds number <i>Re</i> ranged from 4736 to 11,839. Based on experimental data, the spatial distribution and statistical properties of lateral vortex structures in the longitudinal section were analyzed. The results showed that a shear layer formed near the cube tops. In this region, prograde vortices were characterized by high density, large size, and strong rotational intensity, whereas retrograde vortices exhibited the opposite trend. In the upper flow region away from the cubes, the density of prograde vortices decreases with distance from the bed, while the density of retrograde vortices increases. The rotation intensity of both types decreases toward the free surface. In this region, the relative submergence <i>h</i>/<i>D</i> strongly affects all statistical vortex parameters. The friction Reynolds number <i>Re</i>_<i>τ</i> appears to influence only the rotation intensity. Suitable scaling relations were obtained for the dependence of vortex density and radius on <i>h</i>/<i>D</i>, and for the dependence of rotation intensity on <i>Re</i>_<i>τ</i>. Prograde vortices contribute up to 35% to the Reynolds stress, while retrograde vortices contribute about 6%. Near the sidewall, the contribution of retrograde vortices can reach 20%. Linear stochastic estimation revealed linearly aligned vortical structures with an inclined orientation near the cubes, with larger structures observed near the large cube.</p>","PeriodicalId":554,"journal":{"name":"Experiments in Fluids","volume":"67 8","pages":""},"PeriodicalIF":2.7,"publicationDate":"2026-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148433691","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"4D LPT study of the mixing of a Newtonian fluid in the laminar regime","authors":"Ernest Simon,&nbsp;Jérôme Morchain,&nbsp;Frédéric Augier,&nbsp;Sébastien Cazin,&nbsp;Alain Liné","doi":"10.1007/s00348-026-04202-5","DOIUrl":"10.1007/s00348-026-04202-5","url":null,"abstract":"<div><p>This study presents a time-resolved three-dimensional investigation of the mixing of a Newtonian fluid in the laminar regime using 4D Lagrangian particle tracking (4D LPT) based on Shake-The-Box algorithm. To the authors’ knowledge, this is the first application of 4D LPT to characterize the periodic flow structures throughout the impeller area and in the volume of fluid below it, down to the wall. The experimental setup enabled high-resolution Lagrangian measurements of particle trajectories (<span>(160times 10^{3})</span> particles tracked for 12,453 time steps), which were subsequently used to reconstruct Eulerian velocity fields. A detailed comparison with direct numerical simulations shows excellent agreement across all velocity components, confirming the accuracy of the method. This technique makes it possible to detect fluid velocities greater than the tip velocity of the blades, which had been identified in turbulent flow, but is shown to occur in laminar flow. In addition, modal analyses on the three-velocity components in the investigated volume (Proper Orthogonal Decomposition and Direct Fourier Transform) reveal that the flow is governed by the periodic passage of the impeller blades, and coherent structures, namely trailing vortices, are detected via the λ_₂-criterion. The Lagrangian data further allow for the identification of laminar mixing characteristics, highlighted through Poincaré sections and lineal stretch. These results demonstrate the unique capabilities of 4D LPT to investigate both coherent structures and mixing dynamics at a low Reynolds number in a stirred tank reactor.</p><h3>Graphical Abstract</h3><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":554,"journal":{"name":"Experiments in Fluids","volume":"67 8","pages":""},"PeriodicalIF":2.7,"publicationDate":"2026-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00348-026-04202-5.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148433569","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A meshless data-tailored approach to compute statistics from scattered data with adaptive radial basis functions.","authors":"Damien Rigutto,&nbsp;Manuel Ratz,&nbsp;Miguel A. Mendez","doi":"10.1007/s00348-026-04257-4","DOIUrl":"10.1007/s00348-026-04257-4","url":null,"abstract":"<div><p>Constrained radial basis function (RBF) regression has recently emerged as a powerful meshless tool for reconstructing continuous velocity fields from scattered flow measurements, particularly in image-based velocimetry. However, existing formulations based on isotropic kernels often suffer from spurious oscillations in regions with sharp gradients or strong flow anisotropy. This work introduces an anisotropic, gradient-informed, and adaptively sampled extension of the constrained RBF framework for regression of scattered data. Gradient information is estimated via local polynomial regression at collocation points, smoothed, and used to (1) re-sample data, maximizing sampling density near steep gradients while downsampling in smooth regions, and (2) construct a local anisotropic metric that shapes each basis function according to the flow directionality. In addition, a gradient-informed regularization is introduced by embedding observed gradients into the least-squares system as weighted soft constraints. The resulting formulation is fully meshless, linear, and computationally efficient, while significantly improving reconstruction quality in challenging regions. The method is evaluated on both synthetic and experimental datasets, including direct numerical simulation (DNS) data of a turbulent channel and time-resolved particle tracking velocimetry of a turbulent jet. Results show that the proposed approach outperforms isotropic and gradient-free RBF formulations in accuracy, smoothness, and physical consistency—particularly near shear layers and boundaries—while reducing the number of bases by an order of magnitude. To support the application, we have created a repository that provides access to the investigated datasets (https://github.com/mendezVKI/SPICY_VKI).</p></div>","PeriodicalId":554,"journal":{"name":"Experiments in Fluids","volume":"67 8","pages":""},"PeriodicalIF":2.7,"publicationDate":"2026-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148433571","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Identification and evolution of microbubbles within cloud cavitation over twisted hydrofoil","authors":"Wenbiao Huang,&nbsp;Yuwei Wang,&nbsp;Hao Zhang,&nbsp;Lianghao Xu,&nbsp;Hongbo Huang,&nbsp;Guoping Zhang,&nbsp;Qingqing Ye","doi":"10.1007/s00348-026-04231-0","DOIUrl":"10.1007/s00348-026-04231-0","url":null,"abstract":"<div><p>Cloud cavitation over twisted hydrofoils involves complex multiscale bubble distributions. In this study, a microscale bubble measurement technique and identification method based on high-speed imaging are developed to analyze the evolution of bubble clusters and size distributions ranging from micrometers to millimeters under various cavitation numbers. The algorithm integrates adaptive denoising and watershed segmentation to efficiently capture the densely distributed microbubble clusters. The method is validated through comparison with fiber-optic probe measurements, showing discrepancies of less than 6%. Temporal and spatial analyses capture the evolution of cloud cavitation and the emergence of the U-shaped structure. The microbubble density exhibits a clear decay in both the streamwise and wall-normal directions. Periodic variations in bubble number and diameter reveal a fragmentation process, which is strongly influenced by the U-shaped structure. Proper orthogonal decomposition (POD) identifies the dominant unstable mode associated with cavity shedding of vapor cloud and the temporal variation of microbubble number. The bubble size distribution follows a -10/3 power-law beyond a critical size, indicating shear-driven fragmentation mechanisms.</p></div>","PeriodicalId":554,"journal":{"name":"Experiments in Fluids","volume":"67 8","pages":""},"PeriodicalIF":2.7,"publicationDate":"2026-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148433570","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An absorption-based sensor system for accurate in situ examination of liquid film formation upon spray–wall interaction at elevated temperatures","authors":"Matthias Bonarens,&nbsp;Clemens Hansemann,&nbsp;Gabriele Goet,&nbsp;Leon Schuhmann,&nbsp;Kyle J. Daun,&nbsp;Steven Wagner","doi":"10.1007/s00348-026-04236-9","DOIUrl":"10.1007/s00348-026-04236-9","url":null,"abstract":"<div><p>Thin liquid films critically influence the performance of a wide range of processes. In situ examination of these types of films is currently hindered by the limitations of available non-intrusive measurement techniques, particularly with respect to robustness and working distance. Differential absorption enables non-intrusive measurements of various film parameters in simplified laboratory configurations, but has rarely been applied under realistic process conditions due to signal contamination by spurious reflections at the film interface that severely perturb measurements. Their influence is particularly pronounced when the wetted surface is rough, as is the case for many technical surfaces. To overcome this susceptibility and enable accurate measurements, an imaging-based measurement system is proposed that allows reflections at the film interface to be identified and filtered from the signal. The concept is validated using Monte Carlo simulations and demonstrated experimentally by using it to characterize a film that forms when water is injected into a flow bench designed to facilitate experiments in the context of selective catalytic reduction (SCR). In contrast to the established sensor concept that utilizes an area-integrating detector, the newly developed system provides meaningful estimates for film temperature and thickness.</p></div>","PeriodicalId":554,"journal":{"name":"Experiments in Fluids","volume":"67 7","pages":""},"PeriodicalIF":2.7,"publicationDate":"2026-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00348-026-04236-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148380667","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Estimating the flow dynamics from instantaneous wall heat transfer in an impinging sweeping jet","authors":"Víctor Duro,&nbsp;Marco Raiola,&nbsp;Rodrigo Castellanos,&nbsp;Carlos Sanmiguel Vila","doi":"10.1007/s00348-026-04255-6","DOIUrl":"10.1007/s00348-026-04255-6","url":null,"abstract":"<div><p>Despite recent advances in impinging sweeping jets, it remains unclear whether a linear correlation between momentum and heat transfer holds locally across the impingement region, and whether this coupling permits the temporal reconstruction of the dominant velocity dynamics solely from wall measurements. This study investigates whether the unsteady velocity dynamics of an impinging sweeping jet can be inferred from non-intrusive wall heat transfer measurements. The flow is characterised by strong spatial inhomogeneity and large-scale, aperiodic motion associated with the sweeping dynamics. Particle Image Velocimetry snapshots are combined with time-resolved convective heat transfer fields acquired on the impingement surface, modelled with a heat flux sensor, and measured using high-speed infrared thermography. We use Extended Proper Orthogonal Decomposition as a reduced-order linear correlation framework to assess and exploit the temporal coupling between wall thermal signatures and the impinging velocity field measured on orthogonal planes. The method successfully enriches the temporal description of the large-scale velocity dynamics. These findings indicate that the primary energy-carrying structures of the flow are encoded in the wall heat transfer dynamics. The modal analysis provides evidence of a low-rank linear coupling between wall heat transfer and the dominant velocity dynamics in this configuration.\u0000</p></div>","PeriodicalId":554,"journal":{"name":"Experiments in Fluids","volume":"67 7","pages":""},"PeriodicalIF":2.7,"publicationDate":"2026-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00348-026-04255-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148380383","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Variable time step (VTS) based PTV-LIF measurements of stratified jet transitions: from plunging flows and dense bottom jets to internal hydraulic jumps","authors":"Chiun-Chau Su,&nbsp;Sin-Ru Liang,&nbsp;Hervé Capart,&nbsp;Steven Yueh Jen Lai","doi":"10.1007/s00348-026-04250-x","DOIUrl":"10.1007/s00348-026-04250-x","url":null,"abstract":"<div><p>Stratified flows driven by density differences exhibit diverse dynamic regimes, yet transitions between plunging flows, internal hydraulic jumps, and gravity plumes remain poorly characterized, particularly in confined geometries. This study addresses this gap by introducing a Variable Time Step (VTS) enhanced Particle Tracking Velocimetry-Laser Induced Fluorescence (PTV-LIF) methodology to investigate saline bottom jets in a narrow sloping channel. Isopropanol was employed as a refractive index matching agent to eliminate optical distortions, enabling simultaneous measurement of velocity and density fields using a single high-speed camera. The VTS method effectively reduced quantization errors inherent in traditional fixed-time-step algorithms, significantly improving measurement accuracy of flow and density fields. By systematically varying ambient water depths, clear transitions from plunging flows through submerged jumps and internal hydraulic jumps to gravity plumes were observed and classified for the first time. Results confirmed that flow regimes varied significantly with ambient fluid depth. Both subaerial and subaqueous hydraulic jump heights were well described by existing theoretical frameworks, though significant differences in jump lengths were observed, likely due to turbulent shear at the stratified interface. These findings extend existing regime maps and provide new experimental evidence elucidating the critical role of confinement and buoyancy in controlling stratified flow transitions, with important implications for understanding dense discharge behavior in submarine outfalls, sediment-laden river plumes, and ocean current dynamics.</p></div>","PeriodicalId":554,"journal":{"name":"Experiments in Fluids","volume":"67 7","pages":""},"PeriodicalIF":2.7,"publicationDate":"2026-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00348-026-04250-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148380699","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Subpixel-accurate real-time BOS measurement via GPU-optimized optical flow algorithms","authors":"Borui Zheng,&nbsp;Shixian Yang,&nbsp;Jiayin Chen,&nbsp;Hanyang Shen,&nbsp;Wengang Zhang,&nbsp;Liangyue Ji","doi":"10.1007/s00348-026-04277-0","DOIUrl":"10.1007/s00348-026-04277-0","url":null,"abstract":"<div><p>Background-oriented schlieren (BOS), owing to its simple optical setup, low cost, and applicability to large-field-of-view measurements in complex environments, has become a widely used technique for flow-field visualization. However, current BOS methods still face several limitations, including insufficient real-time capability, difficulties in quantitative analysis, and high computational cost. To address these limitations, this study proposes a real-time gradient-based BOS method which enhances optical flow estimation by introducing a constant gradient assumption in place of the conventional brightness-constancy constraint. This assumption is incorporated into both the Dense Inverse Search (DIS) and Farneback algorithms, based on the premise that local image structures remain relatively stable over short temporal intervals despite intensity variations. Furthermore, the preprocessing pipeline integrates subpixel interpolation and three-layer progressive temporal smoothing to improve image quality while preserving schlieren details. To enable real-time processing, a GPU-based parallel architecture is developed together with an optimized data pipeline. This design enables concurrent execution of multiple processing modules and improves GPU resource utilization, thereby accelerating the overall BOS workflow. Experimental results show that the proposed method achieves 30 frames per second in tested scenarios, indicating its potential for real-time industrial BOS applications.</p></div>","PeriodicalId":554,"journal":{"name":"Experiments in Fluids","volume":"67 7","pages":""},"PeriodicalIF":2.7,"publicationDate":"2026-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148380141","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}