检索结果-内蒙古大学图书馆

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

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

来源：评论

学校读者我要写书评

暂无评论

Memristive Artificial Synapses for Neuromorphic Computing

引用

Nano-Micro Letters 2021年第5期13卷 218-245页

作者： Wen Huang xuwen Xia Chen Zhu Parker Steichen Weidong Quan Weiwei Mao Jianping Yang liang Chu Xing’ao Li New Energy Technology Engineering Laboratory of Jiangsu Province and School of Science Nanjing University of Posts and Telecommunications(NJUPT)Nanjing 210023People’s Republic of China Key Laboratory for Organic Electronics and Information Displays and Institute of Advanced Materials Jiangsu National Synergistic Innovation Center for Advanced MaterialsSchool of Materials Science and EngineeringNanjing University of Posts and Telecommunications(NUPT)9 Wenyuan RoadNanjing 210023People’s Republic of China College of Electronic and Optical Engineering and College of Microelectronics Nanjing University of Posts and Telecommunications(NJUPT)Nanjing 210023People’s Republic of China Department of Materials Science and Engineering University of WashingtonSeattleWA 98195‑2120USA

Neuromorphic computing simulates the operation of biological brain function for information processing and can potentially solve the bottleneck of the von Neumann *** computing is realized based on memristive hardware neural networks in which synaptic devices that mimic biological synapses of the brain are the primary *** synaptic functions with these devices is critical in neuromorphic *** the last decade,electrical and optical signals have been incorporated into the synaptic devices and promoted the simulation of various synaptic *** this review,these devices are discussed by categorizing them into electrically stimulated,optically stimulated,and photoelectric synergetic synaptic devices based on stimulation of electrical and optical *** working mechanisms of the devices are analyzed in *** is followed by a discussion of the progress in mimicking synaptic *** addition,existing application scenarios of various synaptic devices are ***,the performances and future development of the synaptic devices that could be significant for building efficient neuromorphic systems are prospected.

关键词： Synaptic devices Neuromorphic computing Electrical pulses Optical pulses Photoelectric synergetic effects

来源：评论

学校读者我要写书评

暂无评论

Capsule structured Al/FeF3/AP energetic microspheres with enhanced combustion performance and energy release efficiency by a microexplosion reaction

引用

FUEL 2023年第1期340卷

作者： Wang, xuwen Hu, Yinghui Zhang, Jian liang, Jiayan Yang, Yulin Lin, Kaifeng Pang, Aimin Shuai, Yong Harbin Inst Technol Sch Chem & Chem Engn MIIT Key Lab Crit Mat Technol New Energy Convers & Harbin 150001 Peoples R China Harbin Inst Technol Sch Energy Sci & Engn Harbin 150001 Peoples R China Hubei Inst Aerosp Chemotechnol Sci & Technol Aerosp Chem Power Lab Xiangyang 441003 Peoples R China

The agglomeration and sintering of aluminum (Al) metal fuels lead to inadequate combustion and low energy release efficiency in the solid propellant systems. Herein, we assemble Al particles with gas generator of ferric trifluoride (FeF3) into capsule structured microspheres to detonate a microexplosion reaction by the evaporation -induced self-assembly technique, with encapsulating by ammonium perchlorate (AP) oxidant. The generated ternary Al/FeF3/AP microspheres achieved superior heat of combustion (12719.75 J g-1) and combustion temperature (1639.6 degrees C) owing to the full contact between components, reduced reaction transport distance, and the fierce shattering microexplosion combustion. Combustion mechanism analysis indicated that Al2O3 layer that hindered the oxidation reaction of Al was etched by the hydrogen fluoride (HF) from FeF3 decomposition, which caused the rapid splashing of nano Al clusters to detonate shattering microexplosion combustion. Furthermore, the ternary Al/FeF3/AP microspheres dramatically improve the combustion performance of hydroxy-terminated polybutadiene (HTPB)-based propellants and achieve a burning rate of 2.975 mm s-1, higher than most of the published HTPB/AP/Al propellants to date. The construction of Al/FeF3/AP microspheres exhibits a huge po-tential for the improvement of the propulsion power of rockets and weapons.

关键词： Energetic capsule microspheres Al FeF3 AP Shattering microexplosion combustion Al combustion efficiency HTPB solid propellants

来源：评论

学校读者我要写书评

暂无评论

A new rapid and accurate synchronization scheme based on PMF-FFT for high dynamic GPS receiver

A new rapid and accurate synchronization scheme based on PMF...

引用

作者： Hou, Huiling Wu, Kang Chen, Yijun liang, xuwen Shanghai Institute of Microsystem and Information Technology Chinese Academy of Sciences Shanghai China Shanghai Engineering Center for Microsatellites Chinese Academy of Sciences Shanghai China Authoriswith University of Chinese Academy of Sciences Beijing China

In this letter, a new rapid and accurate synchronization scheme based on PMF-FFT for high dynamic GPS receiver is proposed, with a fine Doppler frequency estimation inserted between the acquisition and tracking modules. Fine Doppler estimation is firstly achieved through a simple interpolation of the PMF-FFT outputs in terms of LSE criterion. Then a high dynamic tracking loop based on UKF is designed to verify the synchronization speed and accuracy. Numerical results show that the fine frequency estimation can closely approach the CRB, and the high dynamic receiver can obtain fine synchronization rapidly just through a very narrow bandwidth. The simplicity and low complexity give the proposed scheme a strong and practical-oriented ability, even for weak GPS signals. Copyright © 2017 The Institute of Electronics, Information and Communication Engineers.

关键词： Synchronization

来源：评论

学校读者我要写书评

暂无评论

Comparison of health-related quality of life measures in asthma-COPD overlap

引用

CHRONIC RESPIRATORY DISEASE 2023年 20卷

作者： Liu, Meishan Yang, xuwen Wang, Ying Lu, Yong liang, Lirong Zhang, Hong Huang, Kewu Capital Med Univ Beijing Inst Resp Med Dept Resp & Crit Care Med Beijing Peoples R China Capital Med Univ Beijing Chao Yang Hosp Beijing Peoples R China Capital Med Univ Beijing Inst Resp Med Dept Clin Epidemiol Beijing Peoples R China Capital Med Univ Beijing Inst Resp Med Dept Resp & Crit Care Med 8 Gongti South Rd Beijing 100020 Peoples R China Capital Med Univ Beijing Chao Yang Hosp 8 Gongti South Rd Beijing 100020 Peoples R China

Objective: The Asthma Quality of Life Questionnaire (AQLQ) and COPD assessment test (CAT) are used to assess the health status of asthma and chronic obstructive pulmonary disease (COPD), respectively. However, whether these questionnaires are appropriate in patients with asthma-COPD overlap (ACO) has not been reported. This study aimed to evaluate the performance of the AQLQ and CAT in subjects with ***: Subjects were enrolled from two previously described observational studies in Beijing, China. ACO was defined by a consensus definition from a roundtable discussion. All subjects completed the AQLQ, CAT, St George's Respiratory Questionnaire (SGRQ), pulmonary function tests, and the Asthma Control Questionnaire (ACQ)-5. Cross-sectional construct validity was evaluated by correlating the AQLQ and CAT with SGRQ score and other measures of asthma and COPD ***: 147 subjects with ACO were recruited. There were floor effects on non-respiratory components of the CAT, and ceiling effects on emotion domains of the AQLQ. Both questionnaires were significantly correlated with ACQ-5 score but were not correlated with FEV1% predicted or FVC% predicted. The AQLQ and CAT were strongly correlated with SGRQ score (r = -0.657 and r = 0.623, respectively). Multivariable linear regression analysis showed that the AQLQ (standardized beta-coefficient = -0.449, p < .001) had a stronger association with SGRQ score compared with CAT (standardized beta-coefficient = 0.211, p = .023).Discussion: The AQLQ and CAT were both valid for assessing the health-related quality of life in subjects with ACO, but the AQLQ performed better than CAT.

关键词： asthma-chronic obstructive pulmonary disease overlap health-related quality of life chronic obstructive pulmonary disease assessment test asthma quality of life questionnaire validity

来源：评论

学校读者我要写书评

暂无评论

Direct Arylation Polycondensation toward Water/Alcohol-Soluble Conjugated Polymers: Influence of Side Chain Functional Groups

引用

ACS MACRO LETTERS 2021年第4期10卷 419-425页

作者： Zhao, Bowen liang, Ziqi Zhang, Ying Sui, Ying Shi, Yibo Zhang, xuwen Li, Miaomiao Deng, Yunfeng Geng, Yanhou Tianjin Univ Sch Mat Sci & Engn Tianjin 300072 Peoples R China Tianjin Univ Tianjin Key Lab Mol Optoelect Sci Tianjin 300072 Peoples R China Tianjin Univ Joint Sch Natl Univ Singapore & Tianjin Univ Int Campus Fuzhou 350207 Peoples R China

Direct arylation of 2,7-dibromofluorene with n-octyl, 6-diethoxylphosphorylhexyl, 6-(N,N-diethylamino)hexyl or 6-bromohexyl side chains and 1,2,4,5-tetrafluorobenzene (TFB) were conducted to investigate the effect of side chain functional groups on the coupling, and the resulting TFB-substituted fluorene derivatives were used as C-H monomers for the synthesis of water/alcohol soluble conjugated polymers (WSCPs) by direct arylation polycondensation (DArP). The direct arylation and DArP of the monomers carrying phosphonate and amino groups went on smoothly in typical DArP conditions, that is, Pd(OAc)(2)/(PBu2Me)-Bu-t-HBF4/base/DMAc and Pd-2(dba)(3)center dot CHCl3/P(o-MeOPh)(3)/pivalic acid/base/THF, and high molecular weight polymers with these groups were successfully synthesized. However, for fluorenemonomers with bromohexyl side chains, the target products could not be obtained from the above conditions but could be prepared in the absence of carboxylic acid additives in low polar solvents. With the above DArP-made polymers as cathode interfacial layers, high performance organic solar cells (OSCs) were successfully fabricated.

关键词： Monomers Organic reactions Organophosphorus compounds Condensation Polymers

来源：评论

学校读者我要写书评

暂无评论

YTHDC2 inhibits rat bone mesenchymal stem cells osteogenic differentiation by accelerating RUNX2 mRNA degradation via m6A methylation

引用

HELIYON 2023年第8期9卷 e18876页

作者： Ma, Bo Cao, Pei Zhang, Lichen Zhu, Hongyi Ye, xuwen Wang, Lingjun Chen, liang Peking Univ Dept Trauma & Orthoped Peoples Hosp Beijing Peoples R China Nankai Univ Sch Med Tianjin Peoples R China Soochow Univ Affiliated Hosp 1 Dept Gen Surg Suzhou 215006 Jiangsu Peoples R China Soochow Univ Affiliated Hosp 1 Orthoped Inst Dept Orthoped Suzhou 215006 Jiangsu Peoples R China

As the most abundant internal mRNA modification, N6-methyladenosine (m6A) RNA methylation has been found to influence many biological events including bone mesenchymal stem cells (BMSCs) osteogenic differentiation. YTH N6-methyladenosine RNA binding protein C2 (YTHDC2) is an m6A reading protein with the ability to mediate the decay of combined methylated mRNA, however its role in BMSCs osteogenic differentiation remains unknown. In this study, we first found an increase of RUNX family transcription factor 2 (RUNX2) expression and a decrease of YTHDC2 expression during the process of BMSCs osteogenic dif-ferentiation. Furthermore, we transfected BMSCs with YTHDC2 interference fragment, resulting in an increased content of RUNX2 mRNA and protein inside BMSCs. Finally, through RNA Immunoprecipitation experiments, we confirmed that YTHDC2 protein can bind to RUNX2 mRNA and accelerate its decomposition. Moreover, the immunofluorescence staining also showed a negative correlation between YTHDC2 and RUNX2. In conclusion, during BMSCs osteogenic differentiation, YTHDC2 protein showed decreased expression, resulting in a higher level of RUNX2 (mRNA and protein) expression inside cells, indicating YTHDC2 as a promising molecular target for the regulation of BMSCs osteogenic differentiation.

关键词： BMSCs Osteogenic differentiation m6A YTHDC2 RUNX2

来源：评论

学校读者我要写书评

暂无评论

Direct Arylation Polycondensation-Derived Polythiophene Achieves Over 16% Efficiency in Binary Organic Solar Cells via Tuning Aggregation and Miscibility

引用

ADVANCED ENERGY MATERIALS 2024年第47期14卷

作者： Zhang, xuwen Zhang, Tao liang, Ziqi Shi, Yibo Li, Saimeng Xu, Chenhui Li, Miaomiao Ye, Long Hou, Jianhui Geng, Yanhou Tianjin Univ Sch Mat Sci & Engn Tianjin Key Lab Mol Optoelect SciKey Lab Organ In Minist EducCollaborat Innovat Ctr Chem Sci & Engn Tianjin 300350 Peoples R China Chinese Acad Sci Inst Chem CAS Res Educ Ctr Excellence Mol Sci State Key Lab Polymer Phys & ChemBeijing Natl Lab Beijing 100190 Peoples R China

Polythiophenes are the most appealing donor materials in organic solar cells (OSCs) due to their simple chemical structures. However, the top-performance polythiophenes are typically synthesized via Stille polycondensation, which is problematic due to significant toxicity and poor atom economy. By contrast, direct arylation polycondensation (DArP) is an eco-friendly, and atom-efficient alternative for synthesizing conjugated polymers, while the best efficiency for DArP-derived polythiophenes is below 12%. This study reports a series of polythiophene-based donors synthesized via DArP. Among these, PT4F-Th reaches a power conversion efficiency (PCE) of 16.4%, which not only matches the current record for polythiophene-based donor materials, but also marks the highest PCE achieved by DArP-derived donors to date. The superior performance of PT4F-Th is largely attributed to its optimal temperature-dependent aggregation behavior and moderate miscibility with acceptors, along with the highest crystallinity among the candidates, resulting in the most favorable blend film morphology. This study underscores the significant potential of DArP-derived polythiophenes in developing high-performance and eco-friendly OSCs. A series of polythiophene-based donors are synthesized using direct arylation polycondensation (DArP), highlighting PT4F-Th, which achieves an outstanding power conversion efficiency (PCE) of 16.4% in binary organic solar cells (OSCs). This efficiency sets a new record for DArP-derived donors. Blend film morphology is characterized by X-ray scattering and microscopy, emphasizing the synergistic effects of temperature-dependent aggregation behavior and miscibility. image

关键词： direct arylation polycondensation miscibility organic solar cells polythiophene power conversion efficiency

来源：评论

学校读者我要写书评

暂无评论

Polyphenols-inspired interface modification and reduced agglomeration of solid propellants via a functionalized fluorine-containing organic substance coating layer

引用

SURFACE & COATINGS TECHNOLOGY 2024年 477卷

作者： Li, Jiao Zhang, Jian Zhang, Hongyu Wang, xuwen Lu, Taojie liang, Jiayan Yang, Yulin Lin, Kaifeng Xia, Debin Harbin Inst Technol Sch Chem & Chem Engn MIIT Key Lab Crit Mat Technol New Energy Convers & Harbin 150001 Heilongjiang Peoples R China Harbin Inst Technol Sch Chem & Chem Engn Harbin 150001 Peoples R China

Interface modification of aluminum particles plays a crucial part in reducing the agglomeration during the combustion of solid propellants. In this study, the aluminum (Al) particles are pretreated with gallic acid (GA) to get Al@GA with an adhesion-favorable surface, which facilitates the further coating procedure. One new fluorine-containing organic substance is prepared, namely p-HFBA. The p-HFBA further coats the Al@GA to produce Al@GA/p-HFBA. The interface between Al@GA and the coating layer p-HFBA forms Al-F bonds and induces a pre-ignition reaction with an aluminum oxide shell. Hence, the agglomerate size of propellants containing Al@GA/p-HFBA significantly decreases from 176.30 mu m to 84.72 mu m. The agglomerates volume is reduced by approximately 97 %. Additionally, more gaseous products investigated by TG-MS provide the Al particles with greater impetus (aerodynamic forces, Fae), enabling them to leave the burning surface and reduce the residence time. The rise in Fae and drop in adhesion force (Fad) effectively reduce the agglomeration intensity according to the skeleton layer model. This work proves that interface modification can effectively enhance the combustion performance of aluminized solid propellants.

关键词： Interface modification Fluorine-containing organic substance Coatings Pre-ignition reaction Agglomeration Skeleton layer model

来源：评论

学校读者我要写书评

暂无评论

Platelet microparticles-derived miR-25-3p promotes the hepatocyte proliferation and cell autophagy via reducing B-cell translocation gene 2

引用

JOURNAL OF CELLULAR BIOCHEMISTRY 2020年第12期121卷 4959-4973页

作者： Xu, Yuyuan Li, Wenfei liang, Guangyu Peng, Jie Xu, xuwen Southern Med Univ Nanfang Hosp Dept Infect Dis 1838 North Guangzhou Ave Guangzhou 510515 Guandong Peoples R China

Platelets are critical regulators of liver regeneration, but the mechanisms are still not fully understood. Platelets have been shown to contain a wide variety of microRNAs (miRNAs) and play an important role in many diseases. However, the mechanism that how the platelet microparticles (PMPs)-derived miRNA regulate the hepatocyte proliferation is not very clear. In this study, we have successfully isolated and identified PMPs. We also found that PMPs, which could be well integrated into the HHL-5 cells, could upregulate the level of miR-25-3p in HHL-5 cells. Meanwhile, we found that PMPs-derived miR-25-3p promoted HHL-5 cells proliferation by accelerating cells into the S phase, and enhanced the autophagy by increasing the LC3II expression and reducing the P62 expression. Then, we proved that the miR-25-3p could target the B-cell translocation gene 2 (BTG2) and downregulate the expression levels of the BTG2 gene in HHL-5 cells. In addition, the overexpression of BTG2 significantly inhibited the proliferation and autophagy abilities of HHL-5 cells, while cotransfected miR-25-3p mimics or PMPs could partially rescue HHL-5 cells proliferation and autophagy. Furthermore, we proved that PMPs accelerated hepatocyte proliferation by regulating autophagy pathways. Therefore, PMPs-derived miR-25-3p promoted HHL-5 cell proliferation and autophagy by targeting BTG2, which may be a new therapeutic method for liver regeneration.

关键词： autophagy B-cell translocation gene 2 liver regeneration miR-25-3p platelet microparticles proliferation

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：