检索结果-南通市图书馆

Microstructure evolution and mechanical properties of brazing joint for ultra-thin-walled Inconel 718 considering grain size effect and brazing temperature

引用

Chinese Journal of Aeronautics 2024年第2期37卷 541-556页

作者： Rui zhao Yueshuai SONG hui KANG Min WAN School of Mechanical Engineering and Automation Beihang UniversityBeijing 100191China Jiangxi Research Institute of Beihang University Jiangxi 330000China

The systematic investigation of the mechanical properties and microstructure evolution process of ultra-thin-walled Inconel 718 capillary brazing joints is of great significance because of the exceptionally high demands on its *** achieve this objective,this study investigates the impact of three distinct brazing temperatures and five typical grain sizes on the brazed joints’mechanical properties and microstructure evolution *** evolution analysis was conducted based on Electron Back Scatter Diffraction(EBSD),Scanning Electron Microscopy(SEM),X-Ray Diffraction(XRD),High-Resolution Transmission Electron Microscopy(HRTEM),and Focused Ion Beam(FIB).Besides,the mechanical properties and fracture behavior were studied based on the uniaxial tension tests and in-situ tension *** findings reveal that the brazing joint’s strength is higher for the fine-grain capillary than the coarse-grain one,primarily due to the formation of a dense branch structure composed of G-phase in the brazing *** effects of grain size,such as pinning and splitting,are amplified at higher brazing ***,micro-cracks initiate around brittle intermetallic compounds and propagate through the eutectic zone,leading to a cleavage fracture *** fracture stress of fine-grain specimens is higher than that of coarse-grain due to the complex micro-crack ***,this study contributes significantly to the literature by highlighting the crucial impact of grain size on the brazing properties of ultra-thin-walled Inconel 718 structures.

关键词： EYWORDS Ultra-thin-walled structure Brazing Inconel 718 Grain size effect Brazing temperature

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Berberine alleviates ovarian tissue damage in mice with hepatolenticular degeneration by suppressing ferroptosis and endoplasmic reticulum stress

引用

Journal of Integrative Medicine 2024年第4期22卷 493-502页

作者： qian-zhuo Liu hui Han Xin-ru Fang Lu-yao Wang Dan zhao Miao-zhu Yin Nian Zhang Peng-yu Jiang Zhi-hui Ji Li-min Wu Department of Neurology the First Affiliated Hospital of Anhui University of Chinese MedicineHefei 230031Anhui ProvinceChina Center for Reproduction and Genetics the First Affiliated Hospital of USTCDivision of Life Sciences and MedicineUniversity of Science and Technology of ChinaHefei 230031Anhui ProvinceChina

Objective:Hepatolenticular degeneration (HLD) is an autosomal recessive disorder that manifests as multiorgan damage due to impaired copper (Cu) metabolism. Female patients with HLD often experience reproductive impairments. This study investigated the protective effect of berberine against ovarian damage in toxic-milk (TX) mice, a murine model for ***:Mice were categorized into control group, HLD TX group (HLD group), penicillamine (Cu chelator)-treated TX group and berberine-treated TX group. Body weight, ovary weight and the number of ovulated eggs were recorded. Follicular morphology and cellular ultrastructure were examined. Total iron, ferrous iron (Fe2+) and trivalent iron (Fe3+) levels, as well as malondialdehyde (MDA), glutathione(GSH) and oxidized glutathione (GSSG), were measured in the ovaries. Western blot analysis was used to analyze the expression of proteins related to ferroptosis and endoplasmic reticulum (ER) ***:Ovarian tissue damage was evident in the HLD group, with a significant increase in ferroptosis and ER stress compared to the control group. This damage was inhibited by treatment with penicillamine,a Cu chelator. Compared with the HLD group, berberine increased the number of ovulations, and improved ovarian morphology and ultrastructure. Further, we found that berberine reduced total iron,Fe2+, MDA and GSSG levels, elevated GSH levels, decreased the expression of the ferroptosis marker protein prostaglandin-endoperoxide synthase 2 (PTGS2), and increased glutathione peroxidase 4 (GPX4)expression. Furthermore, berberine inhibited the expression of ER stress-associated proteins mediated by the protein kinase RNA-like ER kinase (PERK) ***:Ferroptosis and ER stress are involved in Cu-induced ovarian damage in TX mice. Berberine ameliorates ovarian damage in HLD TX mice by inhibiting ferroptosis and ER stress.

关键词： Berberine Hepatolenticular degeneration Copper deposition Ferroptosis Endoplasmic reticulum stress

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Effect of tungsten carbide particles on microstructure and mechanical properties of Cu alloy composite bit matrix

引用

Journal of Iron and Steel Research(International) 2024年第2期31卷 519-530页

作者： Ding-qian Dong Feng-yuan He Xin-hui Chen hui Li Kai-hua Shi hui-wen Xiong Xin Xiang Li Zhang College of Mechanical Engineering Sichuan University of Science and EngineeringZigong643000SichuanChina State Key Laboratory of Powder Metallurgy Central South UniversityChangsha410083HunanChina Zigong Cemented Carbide Co. Ltd.Zigong643011SichuanChina Material Corrosion and Protection Key Laboratory of Sichuan Province Sichuan University of Science and EngineeringZigong643000SichuanChina

Copper alloy composite bit matrix was prepared by pressureless vacuum infiltration,using at least one of the three kinds of tungsten carbide particles,for example,irregular cast tungsten carbide,monocrystalline tungsten carbide and sintered reduced tungsten carbide *** effects of powder particle morphology,particle size and mass fraction of tungsten carbide on the microstructure and mechanical properties of copper alloy composite were investigated by means of scanning electron microscopy,X-ray diffraction and abrasive wear test in *** results show that tungsten carbide morphology and particle size have obvious effects on the mechanical properties of copper alloy *** tungsten carbide partially dissolved in the copper alloy binding phase,and layers of Cu_(0.3)W_(0.5)Ni_(0.1)Mn_(0.1)C phase with a thickness of around 8–15μm were formed on the edge of the cast tungsten *** 45%irregular crushed fine cast tungsten carbide and 15%monocrystalline cast tungsten carbide were used as the skeleton,satisfactory comprehensive performance of the reinforced copper alloy composite bit matrix was obtained,with the bending strength,impact toughness and hardness reaching 1048 MPa,4.95 J/cm^(2) and 43.6 HRC,*** main wear mechanism was that the tungsten carbide particles firstly protruded from the friction surface after the copper alloy matrix was worn,and then peeled off from the matrix when further wear occurred.

关键词： Polycrystalline diamond compact Pressureless vacuum infiltration Copper alloy composite bit matrix Microstructure characterization Abrasive wear behavior

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Significant annealing-induced hardening effect in nanolaminate d-nanotwinne d(CrCoNi)_(97.4)Al_(0.8)Ti_(1.8)me dium-entropy alloy by severe cold rolling

引用

Journal of Materials Science & Technology 2024年第3期170卷 156-166页

作者： Shuqing Yuan hui Fu Lei qian Chi Fai Cheung Xu-Sheng Yang State Key Laboratory of Ultra-precision Machining Technology Department of Industrial and Systems EngineeringThe Hong Kong Polytechnic UniversityHung HomKowloonHong KongChina Hong Kong Polytechnic University Shenzhen Research Institute Shenzhen 518060China

Due to the easy coarsening caused by poor thermal stability,the verified annealing-induced hardening in nanograined metals can only maintain at a relatively low-temperature *** this study,a nanolam-inated(CrCoNi)_(97.4)Al_(0.8)Ti_(1.8)medium-entropy alloy with an average lamellae thickness of∼20 nm embedded by thinner nanotwins was fabricated by severe cold rolling to achieve superior thermal *** with the conventional nanotwinned CrCoNi with nanotwins inside ultra-fined grains,the hier-archical nanolaminated-nanotwinned(CrCoNi)_(97.4)Al_(0.8)Ti_(1.8) exhibits a significant annealing-induced hard-ening effect,i.e.,hardness increasing from∼250 HV in the original specimen to∼500 HV in the cold-rolled status and finally∼630 HV after annealing at 600℃for 1 *** microstructure characterizations reveal that the reduced dislocation density and formation of L1_(2)ordered domain are mainly responsible for such hardening effect,which is facilitated by the effectively suppressed coarsening with annealing temperature,i.e.,slow detwinning process and well-retained low-angle nanolamellar *** coarsening mechanisms from the cold-rolled nanolamellae to the fully recrystallized micro-equiaxed structures under the annealing temperatures ranging from 400 to 800℃ were also elucidated by atomic observations.

关键词： Annealing-induced hardening Thermal stability Nanolaminated-nanotwinned structure CrCoNi Detwinning Grain boundary migration

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Leader-follower Optimal Selection Method for Distributed Control System in Active Distribution Networks

引用

CSEE Journal of Power and Energy Systems 2024年第1期10卷 314-323页

作者： Jian Le Liangang zhao Cao Wang qian Zhou Yang Wang School of Electrical Engineering and Automation Wuhan UniversityWuhan 430072China

Aiming at the shortcomings of a traditional centralized control in an active distribution network(AND),this paper proposes a leader-follower distributed group cooperative control strategy to realize multiple operation and control tasks for an *** distributed information exchange protocols of the distributed generation(DG)group devoted to node voltage regulation or exchange power control are developed using a DG power utilization ratio as the consensus *** these bases,this study further investigates the leader optimal selection method for a DG group to improve the response speed of the distributed control ***,a single or multiple leader selection model is established to minimize the constraints of the one-step convergence factor and the number of leaders to improve the response speed of the distributed control *** simulation results of the IEEE 33 bus standard test system show the effectiveness of the proposed distributed control *** addition,the response speed of a DG control group can be improved effectively when the single or multiple leaders are selected optimally.

关键词： Active distribution1network consensus algorithm leader-follower system mixed-integer semidefinite programming optimal distributed control

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Comparison of nonlinear modeling methods for the composite rubber clamp

引用

Applied Mathematics and Mechanics(English Edition) 2024年第5期45卷 763-778页

作者： Yiming CAO hui MA Xumin GUO Bingfeng zhao hui LI Xin WANG Bing WANG School of Mechanical Engineering and Automation Northeastern UniversityShenyang 110819China Key Laboratory of Vibration and Control of Aero-Propulsion Systems of Ministry of Education of China Northeastern UniversityShenyang 110819China AVIC Shenyang Engine Design Institute Shenyang 110013China Dalian Mengyu Machinery Co. Ltd.Dalian 116317Liaoning ProvinceChina

The cubic stiffness force model(CSFM)and Bouc-Wen model(BWM)are introduced and compared *** unknown coefficients of the nonlinear models are identified by the genetic algorithm combined with *** fitting the identified nonlinear coefficients under different excitation amplitudes,the nonlinear vibration responses of the system are *** results show that the accuracy of the BWM is higher than that of the CSFM,especially in the non-resonant ***,the optimization time of the BWM is longer than that of the CSFM.

关键词： pipeline system nonlinear clamp model composite rubber clamp amplitude-dependent characteristic vibration response experiment

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Remote copper-catalyzed enantioselective substitution of yne-thiophene carbonates

引用

Science China Chemistry 2024年第4期67卷 1175-1180页

作者： Hao-Dong qian Xiang Li Tingrui Yin Wei-Feng qian Chunhui zhao Cuiju Zhu Hao Xu CCNU-uOttawa Joint Research Centre Key Laboratory of Pesticides&Chemical Biology of Ministry of EducationInternational Joint Research Center for Intelligent Biosensing Technology and HealthCollege of ChemistryCentral China Normal UniversityWuhan 430079China

Here,we describe a strategy for the copper-catalyzed asymmetric heteroarylation of yne-thiophene carbonates with indoles via remote *** key to the success of this strategy lies in the design of the alkynyl group at the ortho-position of the heterocycle thiophene,enabling the formation of a triarylmethane moiety via very remote ***,the concept of remote copper-catalyzed asymmetric transformation extends not only to yne-allylic esters but also to yne-aryl *** reaction readily provides a diverse array of chiral triarylmethanes with high efficiency,enantioselectivity,and excellent functional group ***,facile follow-up transformations underscore their potential utility in the synthesis of various enantioenriched building *** mechanistic studies support the plausibility of the remote substitution pathway.

关键词： remote substitution copper catalyst asymmetric catalysis triaryl methanes

来源：

维普期刊数据库

同方期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Critical Role of Ethylene-Propylene Block Copolymer in Impact Polypropylene Copolymer

引用

Chinese Journal of Polymer Science 2024年第3期42卷 344-351,I0007页

作者： Yu-hui Tang Na Zhang Wei Bao Wei Jiang Yuan Lin zhao-hui Su State Key Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China School of Applied Chemistry and Engineering University of Science and Technology of ChinaHefei 230026China

Ethylene-propylene block copolymer(EbP) is a vital component in impact polypropylene copolymer(IPC), yet its distribution in the multiphase composite material and how it influences the phase structure and the mechanical properties are not well understood. In this work,four IPCs were investigated by atomic force microscopy-infrared(AFM-IR) to assess the phase compositions in situ, based on which in conjunction with the chain microstructure information obtained ex situ the distributions of the copolymer components were derived for each alloy. For the IPCs whose EbP comprises long P and long E segments, the EbP fraction was found to phase separate from the rubber and the PP matrix to form the cores of the disperse particles with the E-P segmented copolymer(EsP). In contrast, in the IPC with EbP composed of long P and short E segments, the EbP fraction formed an outer shell for the rubber particles with the cores comprising the EsP alone, and this IPC, containing a lower E comonomer content than its counterpart, exhibited both better impact resistance and higher flexural modulus. These results clarify how the chain structure of EbP governs the phase morphology in IPC, which in turn impacts the properties of the composite material.

关键词： Impact polypropylene copolymers AFM-IR Ethylene-propylene block copolymers Core-shell rubber particles

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

The mechanisms of thermal solidification agent promoting steam diversion in heavy oil reservoirs

引用

Petroleum Science 2024年第3期21卷 1902-1914页

作者： Zhan-Xi Pang qian-hui Wang qiang Meng Bo Wang Dong Liu State Key Laboratory of Petroleum Resources and Engineering China University of Petroleum(Beijing)Beijing102249China Liaohe Oilfield Institute CNPC ChinaPanjin124000LiaoningChina Henan Oilfield Institute Sinopec ChinaNanyang473400HenanChina Tianjin Branch of China National Offshore Oil Company(CNOOC)Ltd. Tianjin300452China

At high cycles of steam huff&puff,oil distribution in reservoirs becomes stronger heterogeneity due to steam *** solidification agent can be used to solve this *** solution is a lowviscosity liquid at normal temperature,but it can be solidified above 80℃.The plugging degree is up to 99%at 250℃.The sweep efficiency reaches 59.2%,which is 7.3%higher than pure steam *** addition,simultaneous injection of viscosity reducer and/or nitrogen foams can further enhance oil *** mechanism of this technology depends on its strong plugging ability,which changes the flowing pattern of steam to effectively mobilize remaining *** reducer and nitrogen foams further expand the sweep range and extends the effective ***,thermal solidification agent can plug steam channeling paths and adjust steam flowing direction to significantly enhance oil recovery at high cycles of steam huff&puff.

关键词： Heavy oil reservoir Steam huff&puff Steam channeling Steam diversion Plugging performance Mechanism analysis

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Systematic review and network meta-analysis of different nonsteroidal anti-inflammatory drugs for juvenile idiopathic arthritis

引用

World Journal of Clinical Cases 2024年第12期12卷 2056-2064页

作者： Tao Zeng Jian-Zhong Ye hui Qin qian-qian Xu College of Medicine Jingchu University of Technology JingmenJingmen 448000Hubei ProvinceChina

BACKGROUND Various non-steroidal anti-inflammatory drugs(NSAIDs)have been used for juvenile idiopathic arthritis(JIA).However,the optimal method for JIA has not yet been *** To perform a systematic review and network meta-analysis to determine the optimal *** We searched for randomized controlled trials(RCTs)from PubMed,EMBASE,Google Scholar,CNKI,and Wanfang without restriction for publication date or language at August,*** RCTs that comparing the effectiveness of NSAIDs with each other or placebo for JIA were included in this network *** surface under the cumulative ranking curve(SUCRA)analysis was used to rank the treatments.P value less than 0.05 was identified as statistically *** We included 8 RCTs(1127 patients)comparing 8 different instructions including meloxicam(0.125 qd and 0.250 qd),Celecoxib(3 mg/kg bid and 6 mg/kg bid),piroxicam,Naproxen(5.0 mg/kg/d,7.5 mg/kg/d and 12.5 mg/kg/d),inuprofen(30-40 mg/kg/d),Aspirin(60-80 mg/kg/d,75 mg/kg/d,and 55 mg/kg/d),Tolmetin(15 mg/kg/d),Rofecoxib,and *** were no significant differences between any two NSAIDs regarding ACR Pedi 30 *** SUCRA shows that celecoxib(6 mg/kg bid)ranked first(SUCRA,88.9%),rofecoxib ranked second(SUCRA,68.1%),Celecoxib(3 mg/kg bid)ranked third(SUCRA,51.0%).There were no significant differences between any two NSAIDs regarding adverse *** SUCRA shows that placebo ranked first(SUCRA,88.2%),piroxicam ranked second(SUCRA,60.5%),rofecoxib(0.6 mg/kg qd)ranked third(SUCRA,56.1%),meloxicam(0.125 mg/kg qd)ranked fourth(SUCRA,56.1%),and rofecoxib(0.3 mg/kg qd)ranked fifth(SUCRA,56.1%).CONCLUSION In summary,celecoxib(6 mg/kg bid)was found to be the most effective NSAID for treating ***,piroxicam,and meloxicam may be safer options,but further research is needed to confirm these findings in larger trials with higher quality studies.

关键词： Non-steroidal anti-inflammatory drugs Juvenile idiopathic arthritis Network meta-analysis Systematic review

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

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

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

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

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

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：