Powder Technology最新文献

{"title":"Particulate matter emissions and exposure assessment in stone carving: A study of controlled and real-world conditions","authors":"Shubham Sharma,&nbsp;Nivedita Kaul,&nbsp;Sumit Khandelwal","doi":"10.1016/j.powtec.2026.122242","DOIUrl":"10.1016/j.powtec.2026.122242","url":null,"abstract":"<div><div>The stone carving industry routinely exposes workers to high concentrations of airborne particulate matter (PM). Limited studies have quantified exposure characteristics in real occupational settings. This study addresses this gap by investigating the concentration, size distribution, and particle counts generated during typical stone carving operations.</div><div>Monitoring was conducted in two phases using a Grimm Environmental Dust Monitor (EDM264). Separate monitoring for active and non-active periods of stone carving under semi-controlled conditions (Phase 1) revealed sharp contrasts. Concentrations of PM₄-₁₀, PM₂.₅-₄, and PM₁-₂.₅ during non-active periods dropped to about 1–2% of their active-period levels. In contrast, fine particles (PM₁) persisted up to 70% of active-period concentrations even after carving ceased, indicating their prolonged airborne presence. Phase 2, conducted at a stone carving site, showed lower average levels than Phase 1, with PM₄-₁₀ and PM₂.₅-₄ around 10% and 7% of corresponding fractions in Phase 1. Notably, maximum and minimum PM levels in Phase 2 closely aligned with average concentrations for active and non-active periods of Phase 1, respectively. However, the particle size ratio for fine PM in Phase 2 (PM₁/PM₂.₅ = 0.62) was higher, indicating a greater relative contribution of finer particles.</div><div>Overall, fine fractions, particularly PM₁, remained consistently elevated across both experimental and field settings. These findings highlight the intense and variable exposure faced by stone carving workers and underscore the urgent need for dust control measures and personal protective equipment to mitigate exposure and reduce respiratory health risks.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"474 ","pages":"Article 122242"},"PeriodicalIF":4.6,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146187094","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The mechanism of radial airflow in enhancing dry high-gradient magnetic separation","authors":"Honghao Chang ,&nbsp;Jiangang Ku ,&nbsp;Dongfang Lu ,&nbsp;Zhicheng Hu ,&nbsp;Xiubin Wang ,&nbsp;Hongfan Qin","doi":"10.1016/j.powtec.2026.122270","DOIUrl":"10.1016/j.powtec.2026.122270","url":null,"abstract":"<div><div>In our previous study, a novel pneumatic magnetic separator that integrates radial airflow was introduced to address the challenge of low separation efficiency due to particle agglomeration during dry high-gradient magnetic separation (dry HGMS) of powder materials. However, the specific mechanisms of airflow remain inadequately understood. In the present study, a specially designed radial airflow matrix was employed to perform visualization separation experiments and conduct CFD-DEM simulations for various airflow configurations in dry HGMS. Results indicate that mixed ore particles sized −0.038+0.013 mm cannot easily overcome adhesion-related challenges when separation depends solely on gravity feed. The use of airflow feed increases the TFe grade of material accumulated on the matrix surface from 49.48% to 56.59%. When radial airflow is introduced, the maximum TFe grade reaches 69.01%. A comparative analysis of the simulation results indicates that when the TFe grade of the accumulations is around 61%, the corresponding recoveries are 59.47%, 65.42%, and 86.36% for airflow feed alone, gravity feed coupled with radial airflow, and airflow feed coupled with radial airflow, respectively. Furthermore, when the TFe grade of the concentrate is around 65%, the corresponding recoveries are 36.75%, 59.82%, and 60.53% under the same operating conditions. The application of radial airflow effectively promotes the dispersion of powder materials, dislodges adhered quartz particles, and significantly enhances selectivity. Thus, it achieves better separation performance than the traditional airflow feed methods.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"474 ","pages":"Article 122270"},"PeriodicalIF":4.6,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146187439","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A contact detection algorithm for DEM simulation of mixed cylindrical and polyhedral particles based on the common plane method","authors":"Yue Wang ,&nbsp;Jun Liu ,&nbsp;Zheng Liu ,&nbsp;Kai Dong ,&nbsp;Mingqing Liu ,&nbsp;Zhange Bi ,&nbsp;Li Liu","doi":"10.1016/j.powtec.2026.122247","DOIUrl":"10.1016/j.powtec.2026.122247","url":null,"abstract":"<div><div>Accurate narrow-phase contact detection is a computational bottleneck in discrete element method (DEM) simulations of granular systems containing particles of different shapes. The common-plane (CP) method, originally developed for polyhedron–polyhedron contact, is extended here to particle systems that include cylindrical elements: a cylinder-to-plane distance metric is introduced to enable CP-based treatment of cylinder–cylinder contact, and a unified procedure is established for cylinder–polyhedron contact with explicit formulations for the contact normal, penetration depth, and contact point. To improve robustness and efficiency, an adaptive rotation strategy and step-halving termination scheme are used in the CP iteration to prevent stagnation. The algorithm is implemented in a three-dimensional DEM code and validated by gravity-driven packing experiments on three systems: cylinders only, cubes only (the cube representing a convex polyhedron), and mixed cylinder–cube assemblies. The simulations reproduce the observed deposition process and final packing structure, and the predicted final packing height agrees with experiments within 8%. The results indicate that the proposed approach is feasible for DEM simulation of cylindrical–polyhedral mixtures within the tested parameter range.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"474 ","pages":"Article 122247"},"PeriodicalIF":4.6,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146187095","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reduced-order modeling of multiphase flow in fluidized beds using proper orthogonal decomposition and neural ODEs","authors":"Matthew J. Schulz,&nbsp;Joe Standridge,&nbsp;Paul G.A. Cizmas","doi":"10.1016/j.powtec.2026.122187","DOIUrl":"10.1016/j.powtec.2026.122187","url":null,"abstract":"<div><div>A reduced-order model (ROM) was used to parametrize flow solutions of a two-dimensional fluidized bed. This ROM consists of a set of proper orthogonal decomposition (POD) modes. Instead of using the Galerkin projection to reduce the governing partial differential equations to a smaller set of ordinary differential equations whose unknowns are the time coefficients, a neural ordinary differential equation (NODE) was used to predict these time coefficients. A set of full-order model (FOM) solutions was used to define the POD modes and train the NODE. Given a sufficient dataset, this reduced-order modeling approach can be applied to any parametrized flow problem. With computational speeds over four orders of magnitude faster than the full-order model, the ROM was shown to efficiently predict flow behavior when supplied with new values of flow parameters. The speed and accuracy of this POD and NODE-based ROM allow for real-time control methods and accelerated design.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"474 ","pages":"Article 122187"},"PeriodicalIF":4.6,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146187097","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of ion species and particle surface properties on electric-field-dependent particle electrophoresis","authors":"Tomonori Fukasawa,&nbsp;Naoki Maruyama,&nbsp;Takuma Kanatani,&nbsp;Yasuto Michimori,&nbsp;Toru Ishigami,&nbsp;Kunihiro Fukui","doi":"10.1016/j.powtec.2026.122257","DOIUrl":"10.1016/j.powtec.2026.122257","url":null,"abstract":"<div><div>The effects of ionic species (Li⁺, Cs⁺, and guanidinium (Gdm⁺)), particle surface modification (alkyl-OH, SO₃H, and acrylate), and applied electric field strength on the zeta potential, fraction of charge in the slipping layer, and thickness of the slipping layer of polystyrene spheres were investigated using microscopic electrophoresis. Focusing on the hydrophilicity/hydrophobicity of ions and particle surfaces, we found that, regardless of surface modification, the zeta potentials of all particles were negative in electrolytes containing Li⁺, Cs⁺, or Gdm⁺. The absolute values of the zeta potential increased with increasing applied electric field strength up to 2 V cm⁻¹ and subsequently plateaued. For hydrophilic particles (alkyl-OH and SO₃H), electrolytes containing Li⁺ and Cs⁺ yielded smaller absolute zeta potential values than those observed in Gdm⁺-containing electrolytes. In contrast, for hydrophobically modified particles (acrylate), the presence of Gdm⁺ resulted in smaller absolute zeta potential values than those of Li⁺ and Cs⁺. Measurements under a weak applied electric field (0.5 V cm⁻¹) revealed that the slipping layer thickness in LiCl solutions decreased with increasing particle hydrophobicity, whereas that in GdmCl solutions increased. These results indicate that zeta potential measurements under weak applied electric fields, which are less likely to delaminate the ion-accumulated layer, enable evaluation of the slipping layer thickness and interfacial ion-accumulated layer structure. In addition, stability ratio measurements suggest that characteristic interfacial states reflected in the slipping layer are related to aggregation behavior. The results provide insight into the electrokinetic origins of ion effects and offer a basis for evaluating particle surface hydrophilicity/hydrophobicity.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"474 ","pages":"Article 122257"},"PeriodicalIF":4.6,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146187098","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Maximising the computational efficiency of the neural physics discrete element method","authors":"Tongan Yang ,&nbsp;Boyang Chen ,&nbsp;Jiansheng Xiang ,&nbsp;Sadjad Naderi ,&nbsp;Claire E. Heaney ,&nbsp;Mikio Sakai ,&nbsp;John-Paul Latham ,&nbsp;Yanghua Wang ,&nbsp;Christopher C. Pain","doi":"10.1016/j.powtec.2026.122254","DOIUrl":"10.1016/j.powtec.2026.122254","url":null,"abstract":"<div><div>Traditional Discrete Element Method (DEM) simulations face significant computational challenges, primarily due to high memory demands and long execution times when modelling systems with large numbers of particles. These limitations restrict the scalability of DEM and hinder its application to complex or industrial-scale problems. To overcome these challenges, this study improves the performance of the NN4DEM solver (Neural Networks for the Discrete Element Method), part of the novel Neural Physics framework. In Neural Physics, DEM kernels are written as discrete convolutions and programmed as convolutional layers whose weights are prescribed analytically by the chosen contact laws and discretisation. Requiring no training, the Neural Physics approach preserves the underlying DEM contact physics. This contrasts with machine-learning approaches, which train neural networks to approximate contact detection or force prediction. Our contribution is twofold. First, we develop an octree data structure based on linear octree compression which transforms cell-based motion state grids into particle-based representations. This reduces memory consumption and accelerates computation for large problems. Second, we introduce Morton-order partitioning, which optimises memory utilisation and enables substantially larger particle counts. We present two dynamic benchmarks: a rotary drum test case, to investigate the influence of the Froude number on particle motion, and a granular landslide benchmark that develops large void regions and strong spatial heterogeneity. GPU profiling is carried out for particle-packing cases to evaluate the fine-grain single-GPU parallel performance of the implementation. The results demonstrate that the proposed Neural Physics framework achieves computational efficiency comparable with state-of-the-art DEM codes.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"474 ","pages":"Article 122254"},"PeriodicalIF":4.6,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146187103","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study on powder physical and compression properties of mannitol: Similarity, variation, and classification","authors":"Lijun Lin ,&nbsp;Xiao Lin ,&nbsp;Lan Shen ,&nbsp;Yanlong Hong ,&nbsp;Lijie Zhao","doi":"10.1016/j.powtec.2026.122256","DOIUrl":"10.1016/j.powtec.2026.122256","url":null,"abstract":"<div><div>The global supply of mannitol offers diverse grades, typically categorized by manufacturers into “spray-dried” or “granulated” types for direct compression (DC). However, relying solely on these nominal process labels can be misleading for formulation development. This study established a quantitative, functionality-based classification system by systematically evaluating thirteen commercial mannitol grades through multivariate statistical analysis. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) revealed that the manufacturing process label does not strictly dictate functional performance. Notably, three specific granulated grades were found to functionally cluster with spray-dried materials (Cluster 1) due to their shared porous micromorphology and high specific surface area, exhibiting superior tabletability (<em>k</em>_a) and compressibility (<em>k</em>_<em>G</em>). In contrast, Cluster 2, characterized by dense crystalline structures, demonstrated distinct mechanical behaviors dominated by high elasticity (<em>k</em>_<em>FES</em>) and fragmentation tendency (<em>f)</em>. Partial least squares (PLS) regression further elucidated the critical mechanisms governing tablet quality, identifying yield pressure (<em>P</em>_<em>y</em>) and tabletability (<em>k</em>_a) as the primary positive determinants for tensile strength, while excessive fragmentation and elastic recovery negatively impacted mechanical integrity. A trade-off was also observed where enhanced compressibility facilitated rapid disintegration, whereas excessive interparticle bonding could delay it. In summary, this property-driven classification framework provides a more rational strategy for excipient selection than commercial labels, enabling the identification of optimal materials for robust DC formulations based on intrinsic functional attributes.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"474 ","pages":"Article 122256"},"PeriodicalIF":4.6,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146187096","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Preparation of phosphor bronze powders by arc erosion of wires: Microstructure and mechanical properties","authors":"Baohang Ling,&nbsp;Chenhui Wang,&nbsp;Jintao Luo,&nbsp;Fengchen Chen,&nbsp;Bingge Zhao","doi":"10.1016/j.powtec.2026.122273","DOIUrl":"10.1016/j.powtec.2026.122273","url":null,"abstract":"<div><div>The rapid development of the new-energy industry has placed increasing demands on connectors. Additive manufacturing provides an effective strategy for fabricating complex connector contact components, for which phosphor bronze powder is a promising feedstock owing to its excellent mechanical strength and electrical conductivity. To meet these requirements, high-quality phosphor bronze powders were prepared in this study using the arc erosion of wires (AEW) method. Spherical QSn6–0.1, QSn7–0.2, and QSn8–0.3 powders with smooth surface and low satellite content were successfully produced. Their solidification structure and mechanical properties were systematically examined using X-ray diffraction, scanning electron microscopy, and single-powder compression testing. All powders consist primarily of α-Cu and δ-Cu₄₁Sn₁₁ phases despite the difference in composition. The ultrahigh cooling rate during AEW promotes uniform solidification structure without apparent defects and effectively suppresses Sn inverse segregation. Powder diameter, rather than composition, dominates the solidification behavior: smaller powders experience faster cooling, resulting in finer solidification structures and smaller secondary dendrite arm spacing. Single-powder compression tests reveal that powder hardness increases with decreasing diameter. Analysis of the strain-hardening rate indicates a size-dependent deformation mechanism: larger powders exhibit a pronounced hardening peak associated with the formation of stacking faults due to the alloy's low stacking-fault energy, whereas this effect is suppressed in smaller powders. This study presents a novel method for producing phosphor bronze powders, and the findings offer valuable insights into tailoring their solidification and mechanical behavior for additive manufacturing applications.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"474 ","pages":"Article 122273"},"PeriodicalIF":4.6,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146187453","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study on extinguishing wood crib fires using ammonium polyphosphate-modified dry water","authors":"Jianshe Xu ,&nbsp;Quan Wang ,&nbsp;Yaoyong Yang ,&nbsp;Dingyu Feng ,&nbsp;Rui Li ,&nbsp;Kaiyan Lu ,&nbsp;Yingjian Cao","doi":"10.1016/j.powtec.2026.122261","DOIUrl":"10.1016/j.powtec.2026.122261","url":null,"abstract":"<div><div>To develop efficient forest fire extinguishing agents, this study optimized the preparation process of core-shell structured dry water (DW) using high-speed dispersion. Flame-retardant ammonium polyphosphate (APP) was introduced to modify the DW. The physical properties of the resulting materials, including bulk density, fluidity, particle size, moisture retention, and thermal stability, were characterized. The extinguishing efficiency and flame retardancy were evaluated by analyzing temperature data collected along the central axis of a wood crib using a thermocouple monitoring system. The results indicated that the optimal preparation parameters-a solid-to-liquid ratio (m_SiO₂:m_sol) of 1:10, a dispersion speed of 6000 rpm, and a dispersion time of 90 s yielded uniform DW particles without agglomeration. Compared to pure water-based dry water (Pure-DW), the ammonium polyphosphate-modified dry water (APP-DW) exhibited a slightly higher bulk density, smaller and more concentrated particle size, superior fluidity, improved moisture retention, and a multi-stage mass loss profile in the TG curve. Regarding the wood crib surface temperature, the APP-DW demonstrated a 9.76% increase in the instantaneous cooling rate and a 61.43% increase in the average cooling rate within 10 s compared to Pure-DW. Furthermore, upon deliberate reignition attempts, the modified DW made ignition more difficult, reduced the intense combustion duration by 40%, and prolonged the smoldering time by 30%. The enhanced performance is attributed to the mechanisms of isolation, heat absorption, interruption of chain reactions, and capture of free radicals by the APP-DW. This study provides a theoretical foundation for developing rapid-extinguishing and highly efficient flame-retardant forest firefighting agents.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"474 ","pages":"Article 122261"},"PeriodicalIF":4.6,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146187437","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Research on the regulation of rheological properties of 3D printed recycled concrete and multi-objective optimization of printer parameters","authors":"Yuanxun Zheng ,&nbsp;Yate Li ,&nbsp;Xinyue Xi ,&nbsp;Zhenghan Sun ,&nbsp;Guanqin Guo ,&nbsp;Yuxin Zhao ,&nbsp;Qianqian Cao","doi":"10.1016/j.powtec.2026.122265","DOIUrl":"10.1016/j.powtec.2026.122265","url":null,"abstract":"<div><div>The technology of 3D printed recycled aggregate concrete (3DPRAC) offers dual benefits by advancing the intelligent transformation of the construction industry and promoting sustainable development, which has garnered considerable research interest. This study first investigated the effects of resting time and recycled fine aggregate (RFA) replacement rate on the fluidity of 3DPRAC through fluidity tests, and explored the regulatory mechanisms of its rheological properties. The correlation between fluidity and both buildability and mechanical performance was established, with the underlying mechanisms further elucidated via microstructural analysis. Subsequently, response surface methodology (RSM) was employed to systematically examine the influence of key printing parameters, including extrusion speed, horizontal printing speed, and vertical movement speed, on the material's performance. Through multi-objective optimization, an optimal parameter combination was identified. The results demonstrate that controlling the fluidity within 160–180 mm enables stable shaping without collapse, achieving a buildability height of up to 205 mm. Moreover, under the optimized parameters, namely an extrusion speed of 0.77 r/s, a horizontal printing speed of 40.8 mm/s, and a vertical movement speed of 10.3 mm/s, the material exhibits superior printing quality and structural stability, with both buildability and mechanical performance reaching their optimum. This study provides a theoretical basis and technical support for the engineering application of 3DPRAC.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"474 ","pages":"Article 122265"},"PeriodicalIF":4.6,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146187006","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}