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Deformability characteristics of jointed rock masses under uniaxial compression 被引量:47
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作者 Chen Xin Liao Zhihong Peng Xi 《International Journal of Mining Science and Technology》 2012年第2期213-221,共9页
We investigated the combined influence of joint inclination angle and joint continuity factor on deforma- tion behavior of jointed rock mass for gypsum specimens with a set of non-persistent open flaws in uni- axial c... We investigated the combined influence of joint inclination angle and joint continuity factor on deforma- tion behavior of jointed rock mass for gypsum specimens with a set of non-persistent open flaws in uni- axial compression. Complete axial stress-strain curves were classified into four types, i.e., single peak, softening after multi-peak yield platform, hardening after multi-peak yield platform and multi-peak dur- ing softening. Observation of crack evolution on the specimen surface reveals that the deformation behavior is correlated to the closure of pre-existing joint, development of fractures in rock matrix and teeth shearing of the shear plane. To investigate the brittleness of the specimens, the ratio of the residual strength to the maximum peak strength as well as the first and last peak strains were studied. At the same joint inclination angle, the ratios between residual strength and the maximum peak strength and the last peak strains increased while the first peak strain decreased with the increase of joint continuity factor. At the same joint continuity factor, the curves of the three brittleness parameters vs. joint inclina- tion angle can either be concave or convex single-oeak or wave-shaoed. 展开更多
关键词 Rock mass Joint inclination angle Joint connectivity Uniaxial compression test Axial stress-strain curve
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Study on Direct Synthesis of Diphenyl Carbonate with Heterogeneous Catalytic Reaction (V) Screening Catalysts and Optimizing Synthesis Conditions 被引量:7
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作者 张光旭 吴元欣 +4 位作者 马沛生 田崎峰 吴广文 李定或 王存文 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2003年第5期526-530,共5页
Pd/LaxPbyMnOz, Pd/C, Pd/molecular sieve and Pd-heteropoly acid catalysts for direct synthesis of diphenyl carbonate (DPC) by heterogeneous catalytic reaction were compared and the results of DPC synthesis indicated th... Pd/LaxPbyMnOz, Pd/C, Pd/molecular sieve and Pd-heteropoly acid catalysts for direct synthesis of diphenyl carbonate (DPC) by heterogeneous catalytic reaction were compared and the results of DPC synthesis indicated that the catalyst Pd/LaxPbyMnOz had higher activity. The Pd/LaxPbyMnOz catalyst and the support was characterized by XRD, SEM and TEM, the main phase was Lao.szPbo.asMnOa and the average diameter could be about 25.4nm. The optimuna conditions for synthesis of DPC with Pd/LasPbyMnOz were determined by orthogonal experiments and the experimental results showed that reaction temperature was the first factor of effect on the selectivity and yield of DPC, and the concentration of O2 in gas phase also had significant effect on selectivity of DPC. The optimum reaction conditions were catalyst/phenol mass ratio l to 50, pressure 4.5MPa, volume concentration of O2 25%, reaction temperature 60℃ and reaction time 4 h. The maximum yield and average selectivity could reach 13% and 97% respectively in the batch operation. 展开更多
关键词 diphenyl carbonate supported catalyst heterogeneous catalytic reaction optimum conditions
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Mechanisms of Enhancement of Photocatalytic Properties and Activity of Nd^(3+)-Doped TiO_2 for Methyl Orange Degradation 被引量:6
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作者 侯梅芳 李芳柏 +3 位作者 李瑞丰 万洪富 周国逸 谢克昌 《Journal of Rare Earths》 SCIE EI CAS CSCD 2004年第4期542-546,共5页
Nd^(3+)-doped TiO_2 powders were prepared by the sol-gel method. Their crystal pattern and parameter, the specific surface area, the surface chemical state of Ti and the ratio of O/Ti were characterized. The results s... Nd^(3+)-doped TiO_2 powders were prepared by the sol-gel method. Their crystal pattern and parameter, the specific surface area, the surface chemical state of Ti and the ratio of O/Ti were characterized. The results show that Nd impurity hinders the crystal transformation, and decreases the relative intensity of (101) peak. The crystallite sizes of Nd^(3+)-doped TiO_2 powders decrease while their specific surface area increase owing to the Nd^(3+) doping. The XPS measurement shows that the content of Ti(Ⅲ) and ratio of O/Ti on their surfaces increase significantly with the increase of Nd^(3+) dosage. The adsorption and photodegradation experiments show that the optimum molar content of Nd^(3+) is 1.2%. 展开更多
关键词 catalytic chemistry PHOTOCATALYSIS TiO_2 neodymium methyl orange rare earths
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Preparation of Diphenyl Oxalate from Transesterification of Dimethyl Oxalate with Phenol over TS-1 Catalyst 被引量:2
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作者 Xin Bin MA Sheng Ping WANG +1 位作者 Hong Li GUO Gen Hui XU 《Chinese Chemical Letters》 SCIE CAS CSCD 2003年第5期461-464,共4页
Diphenyl oxalate was synthesized from transesterification of dimethyl oxalate with phenol over TS-1 ( 2.5 wt% Ti ) catalyst. TS-1 catalyst, as a heterogeneous catalyst, showed excellent selectivity of diphenyl oxalat... Diphenyl oxalate was synthesized from transesterification of dimethyl oxalate with phenol over TS-1 ( 2.5 wt% Ti ) catalyst. TS-1 catalyst, as a heterogeneous catalyst, showed excellent selectivity of diphenyl oxalate and methylphenyl oxalate compared with other homogeneous catalysts. Lewis acid sites on TS-1 catalyst were the active sites for transesterification of dimethyl oxalate with phenol. The high selectivity was closely related to the weak acid sites over TS-1. 展开更多
关键词 Diphenyl oxalate TRANSESTERIFICATION dimethyl oxalate weak acid sites TS-1.
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Effects of Cerium Dopant on Ni-B Amorphous Alloy Catalysts Used in 2-Ethylanthraquinone Hydrogenation 被引量:2
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作者 侯永江 王亚权 +3 位作者 王莅 米镇涛 吴巍 闵恩泽 《Journal of Rare Earths》 SCIE EI CAS CSCD 2004年第5期628-631,共4页
A series of Ce-doped Ni-B amorphous alloy catalysts were prepared by a KBH_4 reduction method, characterized by ICP, BET, XRD, H_2-chemisorption, H_2-TPD, etc., and tested in the hydrogenation of 2-ethylanthraquinone.... A series of Ce-doped Ni-B amorphous alloy catalysts were prepared by a KBH_4 reduction method, characterized by ICP, BET, XRD, H_2-chemisorption, H_2-TPD, etc., and tested in the hydrogenation of 2-ethylanthraquinone. The results of characterization show that with the addition of Ce the amount of H_2-chemisorption and H_2-TPD areas first increases markedly and then decreases with the maximum appears at the atomic ratio of Ce to Ni of 0.036. The hydrogenation activity also shows the same trend. The effects of Ce are attributed to its dispersion of Ni particles, resulting in the formation of more surface Ni centers. However, much higher Ce contents may result in the decrease of the surface Ni contents. After heat treatment at higher temperatures, the amorphous structure of Ni-B is destroyed. 展开更多
关键词 catalytic chemistry Ni-B amorphous alloy CERIUM catalysts ANTHRAQUINONE HYDROGENATION hydrogen (peroxide ) rare earths
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Study on Coke Formation and Stability of Nickel-Based Catalysts in CO_2 Reforming of CH_4 被引量:2
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作者 黎先财 吴敏 +1 位作者 杨沂凤 何琲 《Journal of Rare Earths》 SCIE EI CAS CSCD 2004年第6期854-858,共5页
CO_2 reforming of CH_4 over nickel-based catalysts was investigated by using a fixed-bed reactor. Catalytic activity and amount of carbon deposition effects by nickel loading content, rare earth promoter and promoter ... CO_2 reforming of CH_4 over nickel-based catalysts was investigated by using a fixed-bed reactor. Catalytic activity and amount of carbon deposition effects by nickel loading content, rare earth promoter and promoter contents were evaluated. It is found that nickel loading as well as reaction temperature can influence the activity and carbon deposition amounts,and with the addition of rare earth promoter, it can greatly improve the catalytic activity and exert a strong effect on the anticoking performance of the catalysts. The 5.0%(mass fraction)Ni-0.75%La-BaTiO_3 catalyst shows great resistance to coke formation and higher thermal stability as well as the catalytic activity. 展开更多
关键词 NICKEL BaTiO_3 REFORMING carbon deposition rare earths
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High-Pressure Plasma Deposition of a-C:H Films by Dielectric-Barrier Discharge 被引量:1
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作者 刘昌俊 李阳 +1 位作者 杜海燕 艾宝都 《Plasma Science and Technology》 SCIE EI CAS CSCD 2003年第1期1597-1602,共6页
The fabrication of a-C:H films from methane has been performed using dielectric-barrier discharges at atmospheric pressure. The effect of combined-feed gas, such as carbon dioxide, carbon monoxide or acetylene on the ... The fabrication of a-C:H films from methane has been performed using dielectric-barrier discharges at atmospheric pressure. The effect of combined-feed gas, such as carbon dioxide, carbon monoxide or acetylene on the formation of a-C:H films has been investigated. It has been demonstrated that the addition of carbon monoxide or acetylene into methane leads to a remarkable improvement in the fabrication of a-C:H films. The characterization of carbon film obtained has been conducted using FT-IR, Raman and SEM. 展开更多
关键词 METHANE DEPOSITION a-C:H films dielectric-barrier discharge
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Characters and structures of the nucleobase-ascorbate transporters(NAT)family genes in Gossypium hirsutum and their roles in responding to salt and drought stresses 被引量:1
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作者 GUO Lixue ZHAO Lanjie +9 位作者 LU Xuke CHEN Xiugui WANG Shuai WANG Junjuan WANG Delong YIN Zujun CHEN Chao FAN Yapeng ZHANG Yuexin YE Wuwei 《Journal of Cotton Research》 2022年第2期115-129,共15页
Background: Nucleobase-ascorbate transporters(NAT), synonymously called nucleobase-cation symporter 2(NCS2) proteins, were earlier reported to be involved in plant growth, development and resistance to stress. Previou... Background: Nucleobase-ascorbate transporters(NAT), synonymously called nucleobase-cation symporter 2(NCS2) proteins, were earlier reported to be involved in plant growth, development and resistance to stress. Previous studies concluded that s a polymorphic SNP associated with NAT12 was significant di erent between salt-tolerant and salt-sensitive materials of upland cotton. In current study, a comprehensive analysis of NAT family genes was conducted for the first time in cotton.Results: In this study, we discovered 32, 32, 18, and 16 NAT genes in Gossypium hirsutum, G. barbadense, G. raimondii and G. arboreum, respectively, which were classified into four groups(groups I–IV) based on the multiple sequence analysis. These GhNAT genes were unevenly distributed on At and Dt sub-genome in G. hirsutum. Most GhNAT members in the same group had similar gene structure characteristics and motif composition. The collinearity analysis revealed segmental duplication as well as tandem duplication contributing to the expansion of the GhNATs. The analysis of cis-acting regulatory elements of GhNATs showed that the function of GhNAT genes in cotton might be related to plant hormone and stress response. Under di erent conditions, the expression levels further suggested the GhNAT family genes were associated with plant response to various abiotic stresses. GhNAT12 was detected in the plasma membrane. And it was validated that the GhNAT12 gene played an important role in regulating cotton resistance to salt and drought stress through the virus-induced gene silencing(VIGS) analysis.Conclusions: A comprehensive analysis of NAT gene family was performed in cotton, including phylogenetic analysis, chromosomal location, collinearity analysis, motifs, gene structure and so on. Our results will further broaden the insight into the evolution and potential functions of NAT genes in cotton. Current findings could make significant contribution towards screening more candidate genes related to biotic and abiotic resistance for the improvement in cotton. 展开更多
关键词 Gossypium hirsutum NAT gene family VIGS Salt and drought stresses
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Synthesis and Characterization of Ultra-fine Si_3N_4 by Electric Arc Plasma
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作者 邹吉军 G P.Vissokov +3 位作者 何琲 刘昌俊 杜海燕 崔兰 《Plasma Science and Technology》 SCIE EI CAS CSCD 2002年第1期1127-1134,共8页
Under conditions of electric-arc low-temperature plasma (LTP), ultra-finely dis- persed Si3N4 particles have been synthesized by using silicon powder and nitrogen as raw materi- als. The prepared samples are character... Under conditions of electric-arc low-temperature plasma (LTP), ultra-finely dis- persed Si3N4 particles have been synthesized by using silicon powder and nitrogen as raw materi- als. The prepared samples are characterized by X-ray diffraction (XRD), scanning electron spec- troscopy (SEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The result indicates that the basic phase in Si3N4 produced is α- and β-Si3N4. The particle size of Si3N4 sample is in the range of 30-500 nm. 展开更多
关键词 SI Synthesis and Characterization of Ultra-fine Si3N4 by Electric Arc Plasma ARC
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Assembly and phylogenomic analysis of cotton mitochondrial genomes provide insights into the history of cotton evolution
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作者 Yanlei Feng Yukang Wang +10 位作者 Hejun Lu Jun Li Delara Akhter Fang Liu Ting Zhao Xingxing Shen Xiaobo Li James Whelan Tianzhen Zhang Jianping Hu Ronghui Pan 《The Crop Journal》 SCIE CSCD 2023年第6期1782-1792,共11页
Cotton is a major crop that provides the most important renewable textile fibers in the world.Studies of the taxonomy and evolution of cotton species have received wide attentions,not only due to cotton’s economic va... Cotton is a major crop that provides the most important renewable textile fibers in the world.Studies of the taxonomy and evolution of cotton species have received wide attentions,not only due to cotton’s economic value but also due to the fact that Gossypium is an ideal model system to study the origin,evolution,and cultivation of polyploid species.Previous studies suggested the involvement of mitochondrial genome editing sites and copy number as well as mitochondrial functions in cotton fiber elongation.Whereas,with only a few mitogenomes assembled in the cotton genus Gossypium,our knowledge about their roles in cotton evolution and speciation is still scarce.To close this gap,here we assembled 20 mitogenomes from 15 cotton species spanning all the cotton clades(A–G,K,and AD genomes)and 5 cotton relatives using short and long sequencing reads.Systematic analyses uncovered a high level of mitochondrial gene sequence conservation,abundant sequence repeats and many insertions of foreign sequences,as well as extensive structural variations in cotton mitogenomes.The sequence repeats and foreign sequences caused significant mitogenome size inflation in Gossypium and its close relative Kokia in general,while there is no significant difference between the lint and fuzz cotton mitogenomes in terms of gene content,RNA editing,and gene expression level.Interestingly,we further revealed the specific presence and expression of two novel mitochondrial open reading frames(ORFs)in lint-fiber cotton species.Finally,these structural features and novel ORFs help us gain valuable insights into the history of cotton evolution and polyploidization and the origin of species producing long lint fibers from a mitogenomic perspective. 展开更多
关键词 Cotton evolution Cotton phylogeny Lint fiber cotton Mitochondrial genome Mitochondrial genes
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Catalysis Conversion Methane into C_(2) Hydrocarbons via Electric Field Enhanced Plasma 被引量:5
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作者 Bao Wei WANG Gen Hui XU 《Chinese Chemical Letters》 SCIE CAS CSCD 2003年第12期1236-1238,共3页
In this paper the effect of catalyst and carrier in electric field enhanced plasma on methane conversion into C2 hydrocarbons was investigated. Methane coupling reaction was studied in the system of continuous flow r... In this paper the effect of catalyst and carrier in electric field enhanced plasma on methane conversion into C2 hydrocarbons was investigated. Methane coupling reaction was studied in the system of continuous flow reactor on Ni, MoO3, MnO2 catalysts and different ZSM-5 carriers. The per pass conversion of methane can be as high as 22%, the selectivity of ethylene can be as high as 23.8%, of acetylene 60.8%, of ethane 5.4% and of total C2 hydrocarbons was more than 90%. ZSM-5-25 was the better carrier and MnO2 was the better active component. The efficiency of energy was as high as 7.81%. 展开更多
关键词 METHANE electric field enhanced PLASMA CATALYSIS C_(2) hydrocarbons.
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Investigation on Interaction between Cold Plasma with Catalysts
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作者 Bao Wei WANG Gen Hui XU 《Chinese Chemical Letters》 SCIE CAS CSCD 2003年第3期316-318,共3页
The characteristic parameters were measured with floating double probe method when cold plasma was interacting with catalysts, such as MoO3/Al2O3, NiY, Pd/Al2O3, which were used in the conversion of natural gas to C2 ... The characteristic parameters were measured with floating double probe method when cold plasma was interacting with catalysts, such as MoO3/Al2O3, NiY, Pd/Al2O3, which were used in the conversion of natural gas to C2 hydrocarbons through electrical field enhanced plasma catalysis. These parameters were compared in different input voltage, different atmosphere, before and after reaction in plasma field. The interaction between catalysts and cold plasma was also investigated. This confirm that cold plasma can enhanced catalysis effect. 展开更多
关键词 Cold plasma floating double probe catalyst.
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Preface for machine learning and artificial intelligence in geotechnics : Opportunities and challenges
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作者 PAN Qiu-jing CHEN Xi +3 位作者 ZHANG Jin-zhang LI Feng-wei ZHANG Dong-ming TANG Chong 《Journal of Central South University》 CSCD 2024年第11期3819-3822,共4页
The rapid evolution of the digital economy has brought significant opportunities and challenges to the field of geotechnical and underground engineering.As the scale of these projects continues to grow,their planning,... The rapid evolution of the digital economy has brought significant opportunities and challenges to the field of geotechnical and underground engineering.As the scale of these projects continues to grow,their planning,design,construction,and maintenance generate extensive multi-source and heterogeneous data.These data include site investigation reports,design blueprints,and structural deformation monitoring records,all of which capture the intricate and diverse characteristics of geotechnical systems.Additionally,risks and hazards during the construction phase pose potential threats to engineering safety,enhancing the need for effective risk management strategies. 展开更多
关键词 DEFORMATION artificial UNDERGROUND
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Synthesis and Surface Tension Properties of Polyethyleneimine-Polyethylene Oxide Block Copolymers 被引量:1
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作者 张剑 LONNIE Bryant 《Chinese Journal of Chemistry》 SCIE CAS CSCD 2003年第4期460-465,共6页
This paper describes the synthesis, surface tension and dispersancy properties of block copolymer nonionic surfactants comprised of polyethyleneimine (PEI) and polyethylene oxide (PEO) blocks of selected lengths. Thes... This paper describes the synthesis, surface tension and dispersancy properties of block copolymer nonionic surfactants comprised of polyethyleneimine (PEI) and polyethylene oxide (PEO) blocks of selected lengths. These block copolymers were prepared by a three step synthetic sequence. Firstly, PEO glycol was converted to its dimethanesulphonylester (dimesyl) derivative by reacting with methanesulphonyl chloride. Then a tri block polymer was prepared by the ring opening polymerization of 2 methyl 2 oxazoline (MeOZO) with the dimesyl PEO derivative. Lastly, linear PEI blocks were obtained by subsequent hydrolysis and purification. 1H NMR spectra confirmed the structures of the intermediate, final products and their purities (>99%). The utility of these block copolymers is described in terms of their surface tension and clay dispersancy measurements as a function of copolymer chain and block length. 展开更多
关键词 block copolymer polyethylene oxide poly^ethyle^nei^mine surface tension clay dispersancy
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AXIN1 boosts antiviral response through IRF3 stabilization and induced phase separation
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作者 Dan-Ling Dai Chu Xie +27 位作者 Lan-Yi Zhong Shang-Xin Liu Le-Le Zhang Hua Zhang Xing-Ping Wu Zhou-Ming Wu Kexin Kang Yan Li Ya-Meng Sun Tian-Liang Xia Chen-Song Zhang Ao Zhang Ming Shi Cong Sun Mei-Ling Chen Ge-Xin Zhao Guo-Long Bu Yuan-Tao Liu Kui-Yuan Huang Zheng Zhao Shu-Xin Li Xiao-Yong Zhang Yun-Fei Yuan Shi-Jun Wen Lingqiang Zhang Bin-Kui Li Qian Zhong Mu-Sheng Zeng 《Signal Transduction and Targeted Therapy》 SCIE CSCD 2024年第11期5166-5182,共17页
Axis inhibition protein 1(AXIN1),a scaffold protein interacting with various critical molecules,plays a vital role in determining cell fate.However,its impact on the antiviral innate immune response remains largely un... Axis inhibition protein 1(AXIN1),a scaffold protein interacting with various critical molecules,plays a vital role in determining cell fate.However,its impact on the antiviral innate immune response remains largely unknown.Here,we identify that AXIN1 acts as an effective regulator of antiviral innate immunity against both DNA and RNA virus infections.In the resting state,AXIN1 maintains the stability of the transcription factor interferon regulatory factor 3(IRF3)by preventing p62-mediated autophagic degradation of IRF3.This is achieved by recruiting ubiquitin-specific peptidase 35(USP35),which removes lysine(K)48-linked ubiquitination at IRF3 K366.Upon virus infection,AXIN1 undergoes a phase separation triggered by phosphorylated TANK-binding kinase 1(TBK1).This leads to increased phosphorylation of IRF3 and a boost in IFN-I production.Moreover,KYA1797K,a small molecule that binds to the AXIN1 RGS domain,enhances the AXIN1-IRF3 interaction and promotes the elimination of various highly pathogenic viruses.Clinically,patients with HBV-associated hepatocellular carcinoma(HCC)who show reduced AXIN1 expression in pericarcinoma tissues have low overall and disease-free survival rates,as well as higher HBV levels in their blood.Overall,our findings reveal how AXIN1 regulates IRF3 signaling and phase separation-mediated antiviral immune responses,underscoring the potential of the AXIN1 agonist KYA1797K as an effective antiviral agent. 展开更多
关键词 IRF3 IMMUNITY SEPARATION
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