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Numerical simulation research on hot stretch straightening of thin-walled T-shaped profile of titanium alloy assisted by resistance heating

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INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY 2022年第9-10期121卷 6483-6495页

作者： deng, xuwen Hui, Songxiao Ye, Wenjun Liu, Rui Huang, Liang GRINM Grp Co LTD State Key Lab Nonferrous Met & Proc Beijing 100088 Peoples R China GRIMAT Engn Inst Co LTD Beijing 101407 Peoples R China Gen Res Inst Nonferrous Met Beijing 100088 Peoples R China Huazhong Univ Sci & Technol Sch Mat Sci & Engn State Key Lab Mat Proc & Die & Mould Technol Wuhan 430074 Peoples R China

In accordance with the bending deformation of titanium alloy profile generated by hot extrusion, the hot stretch straightening assisted by resistance heating is an effective strategy to improve the straightness accuracy. In order to reveal the heat transfer behavior and deformation mechanism of titanium alloy profile during hot straightening, this study focuses on Ti-6.5Al-2Zr-1Mo-1 V alloy thin-walled T-shaped profile with unequal thicknesses. The flow stress curves of profile within temperatures from 400 to 800 celcius, strain rate at 5 center dot 10(-4) s(-1) were obtained by uniaxial tensile tests. The thermal boundary conditions between profile and air were determined by using inverse analysis experiment. Then, the thermal-electrical-mechanical multi-field coupling numerical simulation model was established. The temperature distribution, stress distribution, and deformation of profile were investigated systematically. The results show that the non-uniform temperature field with low temperature in thinner wall region and high temperature in thicker wall region would form during resistance heating. The stress distribution of stretch straightening process was determined by the temperature distribution and the initial bending shape of profile jointly, thereby affecting the springback deflection and direction after unloading. The established numerical simulation models, which have been verified by process experiments, could lay foundation for the prediction and process optimization in hot stretch straightening of titanium profile.

关键词： Titanium alloy thin-walled T profile Resistance heating Hot stretch straightening Numerical simulation

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Research on Flower Pattern and Roll Positioning Optimization for Roll Forming Process of TA4 Coiled Tubing

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MATERIALS 2024年第24期17卷 6164页

作者： deng, xuwen Hui, Songxiao Ye, Xiongyue Ye, Wenjun Yu, Yang Li, Yunbo GRINM Guangdong Inst Adv Mat & Technol Foshan 528051 Peoples R China GRIMAT Engn Inst Co Ltd Beijing 101407 Peoples R China Guangdong ForeWeld Corp Ltd Guangzhou 510700 Peoples R China China GRINM Grp Co LTD State Key Lab Nonferrous Met & Proc Beijing 100088 Peoples R China Univ Sci & Technol Beijing Inst Adv Mat & Technol Key Lab Adv Mat Proc MOE Beijing 100083 Peoples R China Gen Res Inst Nonferrous Met Beijing 100088 Peoples R China

Titanium alloy coiled tubing (CT) has great superiority while operating in deep wells with severe conditions, but it faces serious challenges during roll forming like high springback, edge cracking and surface wearing. In order to utilize the high precision and high efficiency production of titanium alloy CT, it is urgently necessary to develop a detailed process design. Based on the W-forming strategy and the cubic curve of the strip edge projection, the flower pattern and roll design for the 21-pass roll forming process were completed. Different tube dimensions and roll positionings were researched regarding the aspects of contact state, stress-strain distribution and geometry ovality using numerical simulation. The thickness/diameter ratio of the tube that can be formed should be within an effective range: exceeding the range leads to edge cracking, and an insufficient ratio leads to high springback. Roll positioning significantly affects the contact state and stress distribution, but leads to no major differences in the tube geometry. Finally, the trial production of the TA4 titanium CT with a size of Phi 50.8 x 4 mm was completed successfully and was consistent with the simulation results.

关键词： TA4 titanium coiled tubing roll forming flower pattern roll positioning

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Numerical Simulation and Process Optimization on Hot Twist-Stretch Straightening of Ti-6Al-4V Alloy Profile

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MATERIALS 2022年第13期15卷 4522-4522页

作者： deng, xuwen Hui, Songxiao Ye, Wenjun Liu, Rui Huang, Liang GRINM Grp Co Ltd State Key Lab Nonferrous Met & Proc Beijing 100088 Peoples R China GRIMAT Engn Inst Co Ltd Beijing 101407 Peoples R China Gen Res Inst Nonferrous Met Beijing 100088 Peoples R China Huazhong Univ Sci & Technol Sch Mat Sci & Engn State Key Lab Mat Proc & Die & Mould Technol Wuhan 430074 Peoples R China

Ti-6Al-4V profiles prepared by hot extrusion are usually accompanied by bending and twisting. The hot twist-stretch straightening is an effective strategy such that the bending deflection and twisting angle can be simultaneously decreased by a single straightening process. In addition, utilizing stress relaxation effect, the residual stress and springback can be greatly reduced by holding the straightening temperature and strain constant for a period after twist-stretch straightening. In this study, the hot deformation behaviors of the Ti-6Al-4V profile were revealed by experiments. The tensile model was obtained by uniaxial tensile tests within ranges of temperatures (500-700 degrees C) and strain rates (5 x 10(-5)-1 x 10(-3) s(-1)). The creep constitutive model was acquired with stress relaxation experiments in ranges of temperatures (500-700 degrees C) and pre-strain of 1.5%. Then, the coupled thermo-mechanical model of hot twist-stretch straightening was established. Based on orthogonal experiment strategy, the effects of straightening temperature, stretch strain, and holding time on the bending deflection and torsion angle of profile were investigated systematically and the process was optimized. The straightening accuracy is significantly affected by straightening temperature and holding time. By using optimized process parameters in practical straightening experiments, the deflection/length and angle/length after straightening does not exceed 2 parts per thousand and 2.5 parts per thousand degrees/mm, respectively, which is basically consistent with the numerical simulation result.

关键词： Ti-6Al-4V profile hot twist-stretch straightening orthogonal experiment thermo-mechanical coupling model

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Comparison and development of a metagenomic next-generation sequencing protocol for combined detection of DNA and RNA pathogens in cerebrospinal fluid

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BMC INFECTIOUS DISEASES 2022年第1期22卷 326-326页

作者： Jiang, Hanfang Xing, Zhihao Liu, Xiaorong Chai, Qiang Xin, Zefeng Zhu, Chunqing Lin, Ruihong deng, xuwen Cui, Dong Gao, HongDan Ma, Dongli Shenzhen Childrens Hosp Inst Pediat Clin Lab Shenzhen Guangdong Peoples R China Shenzhen Childrens Hosp Inst Pediat Shenzhen Guangdong Peoples R China Bengbu Med Coll Med Technol Bengbu Anhui Peoples R China

Background: The purpose of this study was to evaluate different pretreatment, extraction, amplification, and library generation methods for metagenomic next-generation sequencing (mNGS) of cerebrospinal fluid (CSF) and to develop an efficient procedure for the simultaneous detection of DNA and RNA pathogens. Methods: We generated thirteen mock CSF samples with four representative pathogens of encephalitis. Each sample was subjected to ten different methods by varying sample pretreatment/nucleic acid extraction (microbial DNA, total DNA, total NA, total RNA, Whole Transcriptome Amplification (WTA)) and library generation (Illumina or NEB). Negative extraction controls (NECs) were used for each method variation. Results: We found that the quality of mNGS sequencing reads was higher from the NEB kit for library generation. Microbial DNA and total RNA increased microbial deposition by depleting the host DNA. Methods total NA and total RNA can detect gram-positive, gram-negative, RNA and DNA pathogens. We applied mNGS, including total NA and NEB library generation, to CSF samples from five patients diagnosed with infectious encephalitis and correctly determined all pathogens identified in clinical etiological tests. Conclusions: Our findings suggested that total nucleic acid extraction combined with NEB library generation is the most effective mNGS procedure in CSF pathogen detection. The optimization of positive criteria and databases can improve the specificity and sensitivity of mNGS diagnosis.

关键词： Encephalitis Next-generation sequencing Metagenomic diagnosis

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利用慢病毒载体构建过表达人TCRP1基因的慢性髓系白血病K562细胞系及其生物学功能检测

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实用医学杂志 2023年第19期39卷 2456-2460,2468页

作者：刘孝荣何悦陈妍辛泽锋邓栩文钟惠锋陈运生深圳市儿童医院检验科广东深圳518034 深圳市儿童医院儿科研究所广东深圳518034 深圳市儿童医院血液肿瘤科广东深圳518034

目的利用慢病毒载体构建过表达人舌癌耐药相关基因(TCRP1)的慢性髓系白血病(CML)K562细胞系并检测其生物学功能。方法将TCRP1的重组质粒与包装质粒共转染293T细胞,收集病毒液测定滴度后感染K562细胞,使用嘌呤霉素筛选TCRP1过表达的细胞... 详细信息

目的利用慢病毒载体构建过表达人舌癌耐药相关基因(TCRP1)的慢性髓系白血病(CML)K562细胞系并检测其生物学功能。方法将TCRP1的重组质粒与包装质粒共转染293T细胞,收集病毒液测定滴度后感染K562细胞,使用嘌呤霉素筛选TCRP1过表达的细胞株K562/TCRP1,荧光定量PCR和Western blot方法检测TCRP1的表达,采用连续细胞计数法和CCK-8法分别对K562/TCRP1及其对照细胞株的增殖情况进行检测,并分析2个细胞株对不同浓度的伊马替尼(IM)的药物敏感性。结果TCRP1慢病毒表达载体成功转染进入K562细胞,荧光定量PCR和Western blot结果显示K562/TCRP1细胞株的TCRP1表达在mRNA水平和蛋白水平均显著高于对照组,连续细胞计数法和CCK-8法结果表明K562/TCRP1细胞的增殖能力和细胞活力增强,IM处理K562/TCRP1细胞的IC50值显著高于其对照细胞(P<0.05)。结论利用慢病毒载体成功构建了TCRP1过表达的K562细胞株,并且发现TCRP1的过表达可能增强K562细胞的增殖能力和IM耐药能力,为进一步探讨TCRP1在慢性髓系白血病发病机制中的可能作用提供基础。

关键词： TCRP1 过表达 K562细胞慢性髓系白血病

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Direct Arylation Polycondensation of Thiophene-Based C−H Monomers

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Chinese Journal of Chemistry 2023年第21期41卷 2908-2924页

作者： xuwen Zhang Yibo Shi Yunfeng deng Yanhou Geng School of Materials Science and Engineering and Tianjin Key Laboratory of Molecular Optoelectronic Science Tianjin Universityand Collaborative Innovation Center of Chemical Science and Engineering(Tianjin)Tianjin300072 China Joint School of National University of Singapore and Tianjin University International Campus of Tianjin UniversityBinhai New CityFuzhouFujian350207 China

Direct arylation polycondensation(DArP)has emerged as an eco-friendly and atom-efficient methodology for the syntheses ofπ-conjugated polymers(CPs).This approach features the direct C—H arylation of an aromatic hydrocarbon with an aryl *** the prevalence of thiophene-containing CPs,achieving efficient and defect-free DArP of thiophene-based C−H monomers is of great *** review presents a mechanistic insight into DArP and describes the development of DArP catalytic systems for varied thiophene-based C−H ***,the control of the primary defects(i.e.,branching and homo-coupling)in thiophene-based DArP is also *** emphasizing the principles behind monomer selection and catalytic system optimization,this review intends to provide a framework for future advancements in the DArP of thiophene-containing CPs.

关键词： Conjugated polymers Direct arylation polycondensation Sustainable chemistry Catalytic system Thiophene

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Quinoidal-Diketopyrrolopyrrole-Based Low-Bandgap n-Type Conjugated Polymers via Direct Arylation Polycondensation: Chalcogen Effects on Structures and Properties

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MACROMOLECULES 2024年第19期57卷 9006-9016页

作者： Rao, Mei Wang, Pai Shi, Yibo Zhang, xuwen Han, Yang deng, Yunfeng Geng, Yanhou Tianjin Univ Sch Mat Sci & Engn Tianjin Key Lab Mol Optoelect Sci Tianjin 300072 Peoples R China Tianjin Univ Key Lab Organ Integrated Circuits Minist Educ Tianjin 300072 Peoples R China Collaborat Innovat Ctr Chem Sci & Engn Tianjin Tianjin 300072 Peoples R China

Low-bandgap conjugated polymers (CPs) with strong absorption in the short-wave infrared region usually show ambipolar characteristics. Herein, three low-bandgap CPs, that is, PQF, PQT, and PQS, with unipolar n-type transport behavior were synthesized via direct arylation polycondensation (DArP) with quinoids based on terchalcogenophene-flanked diketopyrrolopyrrole (DPP) derivatives as C-Br monomers and less electron-rich (E)-1,2-bis (3,4-difluorothien-2-yl) ethene (4FTVT) as a C-H monomer, and the chalcogen effects on the isomerism of the quinoids and the properties of the resultant CPs were investigated. Thiophene-flanked DPP-containing quinoids are the mixtures of (E, E), (E, Z), and (Z, Z) isomers, while the sole (E, E) isomer is found in furan-flanked DPP-based quinoids and (Z, Z) isomer is dominant in the quinoids based on selenophene-flanked DPP. The quinoidal monomers are stable to undergo DArP. All three CPs show lower bandgaps of similar to 1.1 eV and unipolar n-type transport behavior with field-effect electron mobility (mu e) above 0.1 cm2 V-1 s(-1). Among them, the polymer PQF, comprising furan-flanked DPP, exhibits the highest mu e of 0.21 cm2 V-1 s(-1), possibly attributed to the simple chain conformation. This study provides a strategy to design low-bandgap unipolar n-type polymer semiconductors.

关键词： n-type conjugated polymers quinoidal structures low bandgap direct arylation polycondensation chalcogen effect

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Iodine-catalyzed intermolecular 1,2-thio (seleno)amination of alkenes with 1,2,3-triazoles and disulfides (diselenides) in air

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ORGANIC CHEMISTRY FRONTIERS 2024年第11期11卷 3066-3071页

作者： Ji, Jian Chen, xuwen Hu, Zongjing Guan, Cong Liu, Jinhua deng, Yaqi Liu, Shunying East China Normal Univ Shanghai Engn Res Ctr Mol Therapeut & New Drug De Sch Chem & Mol Engn Shanghai 200062 Peoples R China

An iodine-catalyzed direct radical coupling method for 1,2-thio (seleno)amination of alkenes with 1,2,3-triazoles and disulfides (diselenides) in air was developed. Products were constructed in one pot with high chemoselectivity and regioselectivity as well as a wide range of substrate scopes (including terminal and internal alkenes). Preliminary mechanistic studies indicated that formation of the C-N bond proceeded via a desulfonation-associated tandem radical cross-coupling process. Iodine-catalyzed 1,2-thio (seleno)amination of alkenes via direct N- and C-centered radical cross-coupling was established to elicit highly regioselective beta-triazolized thioalkyl compounds.

关键词： Olefins

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C-H/C-H Oxidative Direct Arylation Polycondensation to Isoindigo-Based n-Type Conjugated Polymers

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MACROMOLECULES 2024年第9期57卷 4158-4166页

作者： Shi, Yibo Zhang, xuwen Wang, Tianzuo Rao, Mei Han, Yang deng, Yunfeng Geng, Yanhou Tianjin Univ Sch Mat Sci & Engn Key Lab Organ Integrated Circuits Minist Educ Tianjin 300072 Peoples R China Tianjin Univ Tianjin Key Lab Mol Optoelect Sci Key Lab Organ Integrated Circuits Minist Educ Tianjin 300072 Peoples R China Collaborat Innovat Ctr Chem Sci & Engn Tianjin Tianjin 300072 Peoples R China Tianjin Univ Joint Sch Natl Univ Singapore & Tianjin Univ Int Campus Fuzhou 350207 Peoples R China

Two high molecular weight conjugated polymers (CPs), i.e., poly[N,N '-bis(4-tetradecyloctadecyl)-7,7 '-difluoroisoindigo-alt-2,2 '-bithiazole] (P2FI2Tz) and poly[N,N '-bis(4-tetradecyloctadecyl)-5,5 ',7,7 '-tetrafluoroisoindigo-alt-2,2 '-bithiazole] (P4FI2Tz), were synthesized via C-H/C-H oxidative direct arylation polycondensation (Oxi-DArP) using PdCl2/CuCl/Cu(OAc)(2) as catalytic system and chlorobenzene as solvent. Both polymers are unipolar n-type semiconductors with electron mobility (mu(e)) > 0.2 cm(2) V-1 s(-1), attributed to their low-lying highest occupied molecular orbitals (HOMOs) and lowest unoccupied molecular orbital (LUMOs), which are -6.01/-3.69 and -6.24/-3.82 eV for P2FI2Tz and P4FI2Tz, respectively. P2FI2Tz was also synthesized via C-Br/C-H direct arylation polycondensation (DArP) and Stille polycondensation. The resultant polymers P2FI2Tz-D and P2FI2Tz-S showed slightly lower mu(e) compared to Oxi-DArP-made polymer (P2FI2Tz-O1) with a similar molecular weight. Notably, Oxi-DArP is much faster and more efficient than DArP and Stille polycondensation. P2FI2Tz with a number-average molecular weight (M-n) above 40 kDa, was obtained in 9 h of Oxi-DArP, significantly shorter than 24 h with DArP and Stille polycondensation. P2FI2Tz with a M-n as high as 191 kDa could be synthesized via Oxi-DArP by extending the polymerization time to 16 h. Our results prove Oxi-DArP to be an efficient protocol to synthesize polymer semiconductors. This is also the first comparative study on three methods, i.e., Oxi-DArP, DArP, and Stille polycondensation.

关键词： Condensation Diffraction Monomers Organic reactions Polymers

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Beyond transcription, aryl hydrocarbon receptor plays a protective role in periodontitis by interacting with CaMKII

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JOURNAL OF PERIODONTOLOGY 2025年第1期96卷 67-81页

作者： Zeng, xuwen Feng, Meiting Lu, Jiawei Wang, Ruiling deng, Li Yang, Yanan Luo, Lijun Tongji Univ Stomatol Hosp Shanghai Engn Res Ctr Tooth Restorat & Regenerat Dept Periodontol Shanghai Peoples R China Tongji Univ Shanghai Engn Res Ctr Tooth Restorat & Regenerat Dent Sch Shanghai Peoples R China Univ Porto Inst Res & Innovat Hlth i3S Inst Invest & Inovacao Saude Porto Portugal Univ Porto Inst Mol & Cell Biol IBMC Inst Biol Mol & Celular Porto Portugal

Background: The aryl hydrocarbon receptor (AhR) has been studied as an intracellular pattern recognition receptor that can identify bacterial pigments. To identify a potential therapeutic target for periodontitis, we investigated the expression of AhR in periodontitis and its role in the pathogenesis of periodontitis. Methods: First, we analyzed AhR expression in a single-cell dataset from human periodontal tissue. Quantitative polymerase chain reaction (qPCR), immunofluorescence, and immunohistochemistry were used to verify the AhR level. Later, we determined the phenotypes of ligature-induced periodontitis in myeloid-specific AhR-deficient mice (Lyz2-Cre(+/-) AhR(fx/fx)), after which RNA sequencing (RNA-seq), qPCR, Western blot, immunofluorescence, and immunohistochemistry were used to investigate the impacts of AhR on periodontitis and its mechanism. Finally, we determined the therapeutic effect of AhR agonist 6-Formylindolo[3,2-b]carbazole (FICZ) administration on murine periodontitis and verified the effects of FICZ on macrophage polarization in vitro. Results: AhR expression was enhanced in macrophages from periodontitis patients. Deletion of AhR from macrophages aggravated ligature-induced periodontitis and promoted the inflammatory response. Calcium/calmodulin-stimulated protein kinase II (CaMKII) phosphorylation was accelerated in AhR-deficient macrophages. Inhibiting CaMKII phosphorylation ameliorated periodontitis in Lyz2-Cre(+/-) AhR(fx/fx) mice. FICZ treatment blocked alveolar bone loss and relieved periodontal inflammation. FICZ diminished M1 macrophage polarization and promoted M2 macrophage polarization upon M1 macrophage induction. Conclusion: AhR played a protective role in the pathogenesis of periodontitis by orchestrating macrophage polarization via interacting with the CaMKII signaling pathway.

关键词： aryl hydrocarbon receptor CaMKII macrophage pattern recognition receptor periodontitis

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