Energetic Materials Frontiers最新文献

{"title":"Synthesis, characterization, and thermal decomposition performance of 1,2,3-triazolyl-substituted 1,3,5-triazines with carbonyl, ester, and azide functional groups","authors":"Tat'yana V. Sokolnikova, Maxim V. Penzik, Alexey G. Proidakov, Valery N. Kizhnyaev","doi":"10.1016/j.enmf.2023.12.001","DOIUrl":"https://doi.org/10.1016/j.enmf.2023.12.001","url":null,"abstract":"<p>Based on the organocatalytic reaction of enamine azide addition of 2,4,6-triazido-1,3,5-triazine to acetylacetone acetoacetic ester, we synthesized a series of previously unknown mono-, di-, and tri(1,2,3-triazolyl)-substituted-1,3,5-triazines that additionally carried carbonyl, ester, and azide groups. The structure of the obtained compounds was proved by NMR (¹H, ¹³C) and IR spectroscopy, and the composition was confirmed by elemental analysis. With the aid of differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) coupled to mass spectrometry (TG-MS), we obtained data on the thermal behavior and decomposition mechanism for these compounds. We demonstrated that di(1,2,3-triazolyl)-substituted 1,3,5-triazines have an increased thermal stability and have higher values of decomposition onset temperature (220–250 °C) in comparison with tri(1,2,3-triazolyl)-substituted 1,3,5-triazines (180 °C and 160 °C, respectively).</p>","PeriodicalId":34595,"journal":{"name":"Energetic Materials Frontiers","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138688451","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Synthesis and characterization of 2-amino-4,5-bis(tetrazol-5-yl)-1,2,3-triazole: A high-nitrogen energetic material with low sensitivities and high thermal stability","authors":"Xun Huang, Long Chen, Hai-feng Huang, Jun Yang","doi":"10.1016/j.enmf.2023.12.002","DOIUrl":"https://doi.org/10.1016/j.enmf.2023.12.002","url":null,"abstract":"<p>In this study, a high-nitrogen insensitive energetic material, 2-amino-4,5-bis(tetrazole-5-yl)-1,2,3-triazole (H₂ABTT), was successfully synthesized by introducing the <em>N</em>-amino group on the 1,2,3-triazole ring. This compound exhibits excellent properties in many aspects. Compared to 4,5-bis(tetrazol-5-yl)-1,2,3-triazole (H₃BTT), which has a decomposition temperature (<em>T</em>_d) of 277 ^oC, nitrogen content of 75.11 %, density of 1.69 g cm⁻³, a detonation velocity of 8630 m s⁻¹, a detonation pressure of 26.3 GPa, an impact sensitivity (<em>IS</em>) of 2 J, and a friction sensitivity (<em>FS</em>) of 240 N, H₂ABTT exhibits higher thermal stability of <em>T</em>_d:303 ^oC, higher nitrogen content of N%:76.35 %, higher density of 1.86 g cm⁻³, more desirable detonation properties (detonation pressure <em>Dv</em>: 9185 m s⁻¹; detonation pressure <em>p</em>: 31.7 GPa), and lower mechanical sensitivities (<em>IS</em> &gt; 100 J; <em>FS</em> &gt; 360 N). Furthermore, H₂ABTT outperforms insensitive explosive TATB (<em>Dv</em> = 8179 m s⁻¹; <em>p</em> = 30.5 GPa; <em>IS</em> = 50 J; <em>FS</em> &gt; 360 N) in some properties, making it a potential high-performance insensitive explosive. Besides, energetic salts <strong>4–6</strong> were successfully synthesized based on H₂ABTT. The calculated results show that some of these salts even possess higher detonation performance compared to H₂ABTT.</p>","PeriodicalId":34595,"journal":{"name":"Energetic Materials Frontiers","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138688733","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of nitroamino−nitroimino tautomerism: A useful theoretical supplement for nitroamino-based energetic materials","authors":"Ya-xi Wang, Xun Zhang, Jun-liang Liu, Meng-xin Xue, Lu Hu, Si-ping Pang","doi":"10.1016/j.enmf.2023.11.002","DOIUrl":"https://doi.org/10.1016/j.enmf.2023.11.002","url":null,"abstract":"Nitroamino is an ideal high-energy group for constructing energetic compounds. The skeletal isomerization of nitroamino to nitroimino forms intramolecular HBs, thus resulting in better density, thermal stability and sensitivity. However, it is difficult to find nitroamino and nitroimino in the same environment for comparative analysis. A new compound, 5-Nitroamino-8-nitroimino-1,4-dihydropyrazino [2,3-d]pyridazine-2,3-dione (3), was designed and synthesized. The symmetric skeleton of pyrazino [2,3-d]pyridazine provides the same environment for both nitroamino and nitroimino groups. By using a variety of computational and graphical methods, a theoretical support for nitroamino-based energetic materials was produced by thoroughly examining the influence between nitroamino and nitroimino.","PeriodicalId":34595,"journal":{"name":"Energetic Materials Frontiers","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135763505","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Preparation of NCh-B and NCh-B-Ti nanocomposites and their ignition and combustion performances","authors":"Yu-shu Xiong, Yong-qi Wang, Chong Wan, Wen-zhen Zhang, Zhao Qin, Su-hang Chen, Kang-zhen Xu","doi":"10.1016/j.enmf.2023.11.001","DOIUrl":"https://doi.org/10.1016/j.enmf.2023.11.001","url":null,"abstract":"To overcome the agglomeration and insufficient combustion of nano-boron (n-B) powders, this study successfully prepared two novel types of boron-based nanocomposites using the acoustic resonance technology, namely high-substitute nitrochitosan/nano-boron (NCh-B) with ratios of 1:3, 1:5, 1:7, and 1:9 and nitrochitosan/nano-boron powder/nano-titanium (NCh-B-Ti) with Ti contents of 5 wt%, 10 wt%, 15 wt%, and 20 wt%. The structural morphologies, laser ignition, and combustion properties of the composites were systematically investigated. The results suggest that the addition of NCh can significantly improve the dispersion of n-B. NCh-B exhibited a higher combustion performance than n-B, as evidenced by their ignition delay and flame areas. When the laser power density was 81 W, NCh-B5-Ti15% exhibited a combustion time and an ignition delay of 240 ms and 5.5 ms respectively, which were higher and lower than those of NCh-B5 (199 ms and 17 ms, respectively). Furthermore, NCh-B5-Ti15% displayed a lower ignition delay than both n-B powders (12 ms) and NCh-B (11 ms), as well as brighter flames and a larger combustion area. Therefore, the addition of n-Ti can promote the combustion of the n-B powders, with the combustion products of NCh-B-Ti including H3BO3, B2O3, TiB2, and TiO. This study provides a new method for improving the ignition performance and combustion efficiency of n-B powders.","PeriodicalId":34595,"journal":{"name":"Energetic Materials Frontiers","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135516019","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of Al powder on the reaction process and reactivity of B/KNO3 energetic sticks","authors":"Chen-yang Li, Min-jie Li, Hao-yu Song, Chuan-hao Xu, Lei Gao, Bao-yun Ye, Jing-yu Wang, Chong-wei An","doi":"10.1016/j.enmf.2023.10.004","DOIUrl":"https://doi.org/10.1016/j.enmf.2023.10.004","url":null,"abstract":"Boron/potassium nitrate (B/KNO3) is a type of critical energetic composite material (ECM). However, the inert oxide layer on the B surface of B/KNO3 hinders the contact between pure fuel and oxidant, thus limiting energy release This limitation could be eliminated by adding highly reactive Al powder. To discern the effects of Al powder size on the reaction process and reactivity of B/KNO3, this study prepared Al/B/KNO3/polyvinylidene fluoride (PVDF) energetic sticks using the direct ink writing (DIW) technology. This study characterized the macroscopic morphology and structure of the energetic sticks using a laser scanning microscope and a scanning electron microscope, examined the reaction process of the composites using a differential scanning calorimeter and a thermogravimetric analyzer, and observed the flame propagation behavior of energetic sticks and energetic architectures using a high-speed camera. Furthermore, it tested the pressure output characteristics of the energetic composites using a closed volume tank. The results show that adding Al powder can improve the combustion efficiency of B/Al composite fuels and reduce the agglomeration of the combustion products. The Al powder with various particle sizes affects various reaction stages of the composite. The combustion and pressure output tests suggest that adding Al powder with a particle size of 1 μm yielded high reactivity and that flame jump propagation appeared in energetic architectures when the channel spacing was below 10 mm. These findings provide a guide for modifying the B/KNO3 energetic composites and regulating the reactivity of energetic sticks.","PeriodicalId":34595,"journal":{"name":"Energetic Materials Frontiers","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135809626","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Achieving superior thermal conductivity in polymer bonded explosives using a preconstructed 3D graphene framework","authors":"Guan-song He,&nbsp;Yu Dai,&nbsp;Peng Wang,&nbsp;Chao-yang Zhang,&nbsp;Cong-mei Lin,&nbsp;Kun Yang,&nbsp;Jian-hu Zhang,&nbsp;Ruo-lei Zhong,&nbsp;Shi-jun Liu,&nbsp;Zhi-jian Yang","doi":"10.1016/j.enmf.2023.07.002","DOIUrl":"10.1016/j.enmf.2023.07.002","url":null,"abstract":"<div><p>When subjected to complicated thermal alternation, the low thermal conductivity (<em>k</em>) of polymerbonded explosives (PBXs) will induce high thermal stress, which will undermine the safety and reliability of the explosives by causing cracks or damage. However, it has been proven to be a challenge to efficiently increase the <em>k</em> of PBXs due to the high interfacial thermal resistance (<em>ITR</em>) and intrinsic defects of their conductive nanofillers. By introducing AgNWs with a high aspect ratio into graphene, this study constructed a novel multi-dimensional high-<em>k</em> nanofiller composed of one-dimensional (1D) silver nanowires (AgNWs) and two-dimensional (2D) graphene, namely gra@AgNWs. The AgNWs decorated could remedy the intrinsic defects of graphene by passing through the interspaces within graphene nanosheets to form connections as bridges. Consequently, the <em>k</em> of energetic polymer composites increased significantly by 89% from 0.425 ​W ​m⁻¹ ​K⁻¹ to 0.805 ​W ​m⁻¹ ​K⁻¹ at ultralow filler loading of 0.5 ​wt%. Furthermore, the temperature gradients and thermal stress in the composite cylinder decreased significantly under complicated thermal changes owing to the enhanced <em>k</em>. As quantitatively demonstrated through the fitting of experimental data using a theoretical model, AgNWs significantly decreased the <em>ITR</em>, paving highways” for phonon transfer between adjacent graphene nanosheets. Hence an expected synergistic effect of heat transfer was produced in the composites. This study provides new insights into the design and preparation of highly thermally conductive composites.</p></div>","PeriodicalId":34595,"journal":{"name":"Energetic Materials Frontiers","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44527502","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Machine learning-assisted quantitative prediction of thermal decomposition temperatures of energetic materials and their thermal stability analysis","authors":"Zhi-xiang Zhang, Yi-lin Cao, Chao Chen, Lin-yuan Wen, Yi-ding Ma, Bo-zhou Wang, Ying-zhe Liu","doi":"10.1016/j.enmf.2023.09.004","DOIUrl":"https://doi.org/10.1016/j.enmf.2023.09.004","url":null,"abstract":"In this study, machine learning (ML)-assisted regression modeling was conducted to predict the thermal decomposition temperatures and explore the factors that correlate with the thermal stability of energetic materials (EMs). The modeling was performed based on a dataset consisting of 885 various compounds using linear and nonlinear algorithms. The tree-based models established demonstrated acceptable predictive abilities, yielding a low mean absolute error (MAE) of 31°C. By analyzing the dataset through hierarchical classification, this study insightfully identified the factors affecting EMs’ thermal decomposition temperatures, with the overall accuracy improved through targeted modeling. The SHapley Additive exPlanations (SHAP) analysis indicated that descriptors such as BCUT2D, PEOE_VSA, MolLog_P, and TPSA played a significant role, demonstrating that the thermal decomposition process is influenced by multiple factors relating to the composition, electron distribution, chemical bond properties, and substituent type of molecules. Additionally, descriptors such as Carbon_contents and Oxygen_Balance proposed for characterizing EMs showed strong linear correlations with thermal decomposition temperatures. The trends of their SHAP values indicated that the most suitable ranges of Carbon_contents and Oxygen_Balance were 0.2–0.35 and −65 to −55, respectively. Overall, the study shows the potential of ML models for decomposition temperature prediction of EMs and provides insights into the characteristics of molecular descriptors.","PeriodicalId":34595,"journal":{"name":"Energetic Materials Frontiers","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135348903","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Deuterated energetic materials: Syntheses, structures, and properties","authors":"Zheng-hang Luo ,&nbsp;Jia-jun Zhou ,&nbsp;Hao Li ,&nbsp;Yuan-hua Xia ,&nbsp;Liang-fei Bai ,&nbsp;Hai-jun Yang","doi":"10.1016/j.enmf.2023.08.001","DOIUrl":"10.1016/j.enmf.2023.08.001","url":null,"abstract":"<div><p>The deuteration of energetic materials contributes to high signal-to-noise ratios (SNRs) in neutron diffraction, thus allowing the structures of energetic materials to be effectively investigated. This study developed the synthesis methods of deuterated energetic materials through chemical synthesis or newly developed one-pot H/D exchange. Using these methods, it synthesized nine deuterated energetic materials in a concise and low-cost manner: deuterated 1,3,5-triamino-2,4,6-trinitrobenzene (TATB-<em>d</em>₆, <strong>1</strong>), 1,3,5,7-tetranitro-1,3,5,7-tetraazacyclooctane (HMX-<em>d</em>₈, <strong>2</strong>), 1,3,5-trinitro-1,3,5-triazacyclohexane (RDX-<em>d</em>₆, <strong>3</strong>), dihydroxylammonium 5,5′-bis(tetrazole-1-oate) (TKX-50-<em>d</em>₈, <strong>4</strong>), nitroguanidine (NQ-<em>d</em>₄, <strong>5</strong>), 1,1-diamino-2,2-dinitroethylene (FOX-7-<em>d</em>₄, <strong>6</strong>), 2,6-diamino-3,5-dinitropyrazine-1-oxide (LLM-105-<em>d</em>₄, <strong>7</strong>), trinitrotoluene (TNT-<em>d</em>₃, <strong>8</strong>), and 3-nitro-1,2,4-triazol-5-one (NTO-<em>d</em>₂, <strong>9</strong>). Furthermore, the single crystals of HMX-<em>d</em>₈ (<strong>2</strong>) and RDX-<em>d</em>₆ (<strong>3</strong>) were obtained, and the <em>α-</em>, <em>β-</em>, <em>γ-</em>, and <em>δ-</em>polymorphs of HMX-<em>d</em>₈ (<strong>2</strong>) were prepared accordingly. The deuterated energetic materials were characterized and analyzed using infrared spectroscopy (IR), nuclear magnetic resonance (NMR) spectroscopy, differential scanning calorimetry (DSC), thermogravimetry (TG), X-ray diffraction (XRD), and neutron diffraction. Besides, this study determined the decomposition activation energy (<em>E</em>_a), pre-exponential factor (A), decomposition rate constant (<em>k</em>), and critical explosion temperature (<em>T</em>_b) of TATB-<em>d</em>₆ (<strong>1</strong>), HMX-<em>d</em>₈ (<strong>2</strong>), and RDX-<em>d</em>₆ (<strong>3</strong>) via DSC experiments at different heating rates. The NMR and neutron diffraction data show that these deuterated energetic materials have high deuteration rates of more than 95%. The DSC and TG analyses indicate that the deuterated energetic materials exhibit slightly higher decomposition temperatures than their nondeuterated counterparts. Furthermore, neutron diffraction shows that the deuterated energetic materials feature high SNRs.</p></div>","PeriodicalId":34595,"journal":{"name":"Energetic Materials Frontiers","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49376150","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cover Story","authors":"","doi":"10.1016/S2666-6472(23)00049-0","DOIUrl":"https://doi.org/10.1016/S2666-6472(23)00049-0","url":null,"abstract":"","PeriodicalId":34595,"journal":{"name":"Energetic Materials Frontiers","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71761255","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Recent progress in research on the dynamic process of high-energy explosives through pump-probe experiments at high-intensity laser facilities","authors":"Gen-bai Chu ,&nbsp;Tao Xi ,&nbsp;Shao-yi Wang ,&nbsp;Min Shui ,&nbsp;Yong-hong Yan ,&nbsp;Guo-qing Lv ,&nbsp;Yao Wang ,&nbsp;Ming-hai Yu ,&nbsp;Xiao-hui Zhang ,&nbsp;Fang Tan ,&nbsp;Jian-ting Xin ,&nbsp;Liang Wang ,&nbsp;Yu-chi Wu ,&nbsp;Jing-qin Su ,&nbsp;Wei-min Zhou","doi":"10.1016/j.enmf.2023.06.003","DOIUrl":"10.1016/j.enmf.2023.06.003","url":null,"abstract":"<div><p>To accurately predict the detonation and safety performances of high-energy explosives, it is necessary to investigate their reaction mechanisms on different scales, which, however, presents a challenge due to the complex reaction kinetics of the explosives and a lack of experimental methods presently. This work introduces the time-resolved pump-probe experiments capabilities aiming at high-energy explosives based on large-scale laser facilities and presents the recent progress in research on the dynamic process of the explosives, obtaining the following understandings: (1) First, the micron-sized single-crystal 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) can be compressed to an overdriven detonation state at a laser facility, followed by the shock Hugoniot measurements of TATB; (2) Second, high resolution transient X-ray radiography makes it possible to achieve the dynamic imaging of the internal deformation, damage, and reaction dynamics of high-energy explosive under dynamic loading; (3) Third, the phase transformation and chemical reaction products of the shock-compressed explosives can be investigated using dynamic X-ray diffraction or scattering spectra; (4) Finally, the structural changes, molecular reactions, molecular bond cleavage, and intermediate product components of explosives under ultrafast pumping can be explored using ultrafast laser spectroscopy. Large-scale laser facilities can provide various flexible pump-probe methods, including laser shock loading, transient X-ray imaging, dynamic X-ray diffraction, and ultrafast spectroscopy, allowing a series of experiments to be carried out to evaluate different levels of ignitions from low-pressure to overdriven detonations. Furthermore, the facilities also enable <em>in situ</em>, real-time investigations of the internal deformation, phase transition, and ultrafast dynamics of explosives under dynamic loading at high spatial and temporal resolutions. The study of the reaction kinetics and mechanisms of high-energy explosives on microscopic-mesoscopic scales provides an efficient means to unravel the mystery of explosive reactions.</p></div>","PeriodicalId":34595,"journal":{"name":"Energetic Materials Frontiers","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44839147","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}