检索结果-南通市图书馆

Improving creep strength of the fine-grained heat-affected zone of novel 9Cr martensitic heat-resistant steel via modified thermo-mechanical treatment

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2024年第5期31卷 1037-1047页

作者： Jingwen Zhang liming yu Yongchang Liu Ran Ding Chenxi Liu Zongqing Ma Huijun Li Qiuzhi Gao Hui Wang State Key Lab of Hydraulic Engineering Simulation and Safety Tianjin Key Lab of Composite and Functional MaterialsTianjin UniversityTianjin 300072China School of Resources and Materials Northeastern University at QinhuangdaoQinhuangdao 066004China School of Mechanical Engineering Chengdu UniversityChengdu 610106China

The infamous type Ⅳ failure within the fine-grained heat-affected zone (FGHAZ) in G115 steel weldments seriously threatens the safe operation of ultra-supercritical (USC) power *** this work,the traditional thermo-mechanical treatment was modified via the replacement of hot-rolling with cold rolling,i.e.,normalizing,cold rolling,and tempering (NCT),which was developed to improve the creep strength of the FGHAZ in G115 steel *** NCT treatment effectively promoted the dissolution of preformed M_(23)C_(6)particles and relieved the boundary segregation of C and Cr during welding thermal cycling,which accelerated the dispersed reprecipitation of M_(23)C_(6) particles within the fresh reaustenitized grains during post-weld heat *** addition,the precipitation of Cu-rich phases and MX particles was promoted evidently due to the deformation-induced *** a result,the interacting actions between precipitates,dislocations,and boundaries during creep were reinforced *** this strategy,the creep rupture life of the FGHAZ in G115 steel weldments can be prolonged by 18.6%,which can further push the application of G115 steel in USC power plants.

关键词： G115 steel fine-grained heat-affected zone creep strength element segregation nano-sized precipitates

Study on Clogging Mechanism and Water Sediment Movement Mechanism of Patch-Type Drip Irrigation Emitters

在线全文

学校读者我要写书评

暂无评论

排灌机械工程学报 2024年

作者： ZHU Ximao yu liming WANG Dan WANG Changman WU Dali YCIC Ecological Environment Engineering Co.， LTD 4. Yanshan Manyue Berry Agriculture Co.， LTD Faculty of Modern Agriculture Engineering， Kunming University of Science and Technology Research Institute of Highway Ministry of Transport， Key Laboratory of Environmental Protection Technology on Road

As one of the key components of drip irrigation technology， the existence of sediment particles seriously affects the service life of emitters and restricts the popularization of drip irrigation technology. In this paper， two kinds of patch drip irrigation emitters are used as research object， and the anti-clogging performance experiment is carried out in the laboratory. The dynamic changes in emitters’ clogging characteristics (Dra， Cu) were statistically analyzed. The movement mechanism of emitter clogging and discharging sediment was studied. The effects of emitter structure and position factors on emitter clogging were analyzed. The results show that: (1) The pressure-compensated emitter has better anti-clogging performance， and its service life is 227.8% of the labyrinth channel emitter. (2) Single structural factor can not evaluate the anti-clogging performance of emitters. All factors causing emitter clogging should be considered comprehensively. (3) All emitters have sensitive clogging sediment inside， but only when sediment content is high can it easily cause blockage. The results show that when the sensitive sediment content is 5.46% and 5.54%， it does not affect the clogging characteristics of the emitters. (4) The discharge of sediment V90 from the emitter is affected by the accumulation effect of clogged sediment. The experimental results show that the emitter can discharge up to 50% of the accumulated clogged sediment without clogging. In comparison， the emitter with clogging can only discharge up to 25% of the accumulated clogged sediment. These results could provide references for the application and promotion of drip irrigation technology.

关键词：

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

中药活性成分治疗多发性骨髓瘤的研究进展

中华中医药杂志 2024年第6期39卷 2997-3001页

作者：于丽明崔思远山东中医药大学济南250399 山东第一医科大学第三附属医院济南250031 山东中医药大学附属医院济南250014 山东莱博生物科技有限公司济南250100 山东大学临床医学院济南250012

随着蛋白酶体抑制剂、免疫调节剂和单克隆抗体等临床新药的不断问世,多发性骨髓瘤(MM)患者的生存较前有了较大改善,但MM仍然是一种不可治愈性的血液肿瘤,其发病机制仍然不明,同时也面临难治、耐药等诸多问题,因此一些新的、更加有效的... 详细信息

随着蛋白酶体抑制剂、免疫调节剂和单克隆抗体等临床新药的不断问世,多发性骨髓瘤(MM)患者的生存较前有了较大改善,但MM仍然是一种不可治愈性的血液肿瘤,其发病机制仍然不明,同时也面临难治、耐药等诸多问题,因此一些新的、更加有效的治疗方法仍是重要的临床需求。近年来中医药技术在促进MM细胞凋亡,抑制细胞增殖、侵袭,提高传统化疗药物的敏感性、逆转耐药等方面表现出较大的优势和潜力,尤其对中药活性成分的作用研究成为热点,相关研究不断增加,开发应用前景广阔。文章综述了近年来中药姜黄、黄芩、藤黄、淫羊藿、冬凌草、青蒿、雷公藤等其活性成分干预MM作用机制的研究进展,以期进一步明确中药活性成分抗MM的作用机制,为中医药靶向治疗MM提供新的方向。

关键词：中药活性成分多发性骨髓瘤作用机制血液肿瘤研究进展

在线全文

学校读者我要写书评

暂无评论

南京市典型道路交通噪声三维分析

中国资源综合利用 2024年第1期42卷 150-152页

作者：俞黎明江苏省南京环境监测中心南京210000

作为一种非稳态、不连续的流动污染源,交通噪声影响范围广,时间长,程度深。本文以南京市为例,从水平分布、垂直分布和24 h连续监测三个维度分析典型道路交通噪声。结果表明,随着距慢车道水平距离的扩大,非高架段道路昼夜声级逐步衰减;... 详细信息

作为一种非稳态、不连续的流动污染源,交通噪声影响范围广,时间长,程度深。本文以南京市为例,从水平分布、垂直分布和24 h连续监测三个维度分析典型道路交通噪声。结果表明,随着距慢车道水平距离的扩大,非高架段道路昼夜声级逐步衰减;高架段道路夜间噪声受居民生活噪声的影响显著,距离增加导致声级下降;高架道路和非高架道路混合路段,噪声水平和垂直分布变化呈现一定规律,24 h声源状况与车流量存在一定相关性。

关键词：典型道路交通噪声水平分布垂直分布连续监测南京市

高Cr马氏体耐热钢的协同强化机制及形变热处理应用

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

金属学报 2024年第6期60卷 713-730页

作者：张竟文余黎明刘晨曦丁然刘永长天津大学材料科学与工程学院水利工程智能建设与运维全国重点实验室天津300354

高Cr(9%~12%,质量分数)马氏体耐热钢因其较高的热导率、较低的热膨胀系数以及优异的高温蠕变强度等优点而被认为是超超临界火电机组关键设备升级改造的主选材料。然而,服役过程中高Cr马氏体耐热钢高温蠕变强度的不断弱化严重影响了其安... 详细信息

高Cr(9%~12%,质量分数)马氏体耐热钢因其较高的热导率、较低的热膨胀系数以及优异的高温蠕变强度等优点而被认为是超超临界火电机组关键设备升级改造的主选材料。然而,服役过程中高Cr马氏体耐热钢高温蠕变强度的不断弱化严重影响了其安全可靠性。以往提升高Cr马氏体耐热钢高温蠕变强度的主要手段是通过合金成分优化设计来促进沉淀相弥散析出,但单一析出强化效应对蠕变强度的提升效果非常有限。近年来,位错-沉淀相-界面协同强化效应在提升高Cr马氏体耐热钢高温蠕变性能方面表现出显著效果。其原理是通过形变热处理引入位错来促进多种沉淀相弥散析出,同时通过控制相变来细化板条组织,增强位错、沉淀相及界面3者之间的交互作用,从而实现多类蠕变强化效应的协同提升。本文总结了高Cr马氏体耐热钢的协同强化机制及形变热处理组织调控,从高温蠕变强度提升角度回顾了合金成分的优化历程,阐述了热处理过程中的相变行为及高温组织退化机理,对比分析了单一析出强化效应及形变热处理后位错-沉淀相-界面协同强化效应对其高温蠕变强度的影响规律,并基于焊接接头蠕变失效行为探索了形变热处理对焊接热影响区的组织调控机制,以期为高Cr马氏体耐热钢及其他火电机组用沉淀型强化耐热钢的材料设计及工程应用提供指导。

关键词：高Cr马氏体耐热钢高温蠕变强度协同强化形变热处理组织调控

资质过剩感和工作重塑在临床护士平台型领导与职业召唤间的链式中介效应

在线全文

学校读者我要写书评

暂无评论

中国实用护理杂志 2024年第5期40卷 350-356页

作者：姜虹陈浩杰杨英于立明青岛大学附属青岛市海慈医院(青岛市中医医院)妇科青岛266000 青岛大学附属青岛市海慈医院(青岛市中医医院)小儿二科青岛266000

目的探讨临床护士的平台型领导、资质过剩感、工作重塑与职业召唤的关系,为制订临床护士职业召唤策略提供参考。方法采用便利抽样法,于2023年4—5月选取青岛大学附属青岛市海慈医院(青岛市中医医院)、山东大学齐鲁医院、青岛市市立医院... 详细信息

目的探讨临床护士的平台型领导、资质过剩感、工作重塑与职业召唤的关系,为制订临床护士职业召唤策略提供参考。方法采用便利抽样法,于2023年4—5月选取青岛大学附属青岛市海慈医院(青岛市中医医院)、山东大学齐鲁医院、青岛市市立医院共488名临床护士作为研究对象。采用一般资料调查表、平台型领导量表、资质过剩感量表、工作重塑量表和职业召唤量表对研究对象进行横断面调查,分析平台型领导、资质过剩感、工作重塑与职业召唤之间的关系及中介效应。结果488名临床护士中男79名,女409名,年龄23~51(30.37±6.40)岁。临床护士的平台型领导、资质过剩感、工作重塑和职业召唤得分分别为(86.12±9.99)、(21.79±7.29)、(70.61±14.54)、(38.70±7.54)分。平台型领导对职业召唤总效应为0.316。平台型领导对职业召唤的中介路径:平台型领导→资质过剩感→职业召唤;平台型领导→工作重塑→职业召唤;平台型领导→资质过剩感→工作重塑→职业召唤,3个中介效应依次占总效应的17.99%、9.50%和4.56%。结论资质过剩感和工作重塑在临床护士平台型领导与职业召唤间存在链式中介效应。护理管理者应实施平台型领导,缓解临床护士资质过剩感和提高工作重塑水平,进而提高其召唤水平。

关键词：护士平台型领导资质过剩感工作重塑职业召唤

Effect of ultrasonic pretreatment on anaerobic digestion and its sludge dewaterability

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2011年第9期23卷 1472-1478页

作者： Huacheng Xu Pinjing He Guanghui yu liming Shao State Key Laboratory of Pollution Control and Resource Reuse Key Laboratory of Yangtze River Water Environment College of Environmental Science and Engineering Tongji University Shanghai 200092 China

To investigate the effect of ultrasonic pretreatment on anaerobic digestion and sludge dewaterability and further to probe into the influencing factors on sludge dewaterability,sludge flocs were stratified into four fractions：（1） slime;（2） loosely bound extracellular polymeric substances （LB-EPS）;（3） tightly bound EPS （TB-EPS）;and （4） EPS-free *** results showed that ultrasonic pretreatment increased the anaerobic digestion efficiency by 7%–8%.Anaerobic digestion without ultrasonic pretreatment deteriorated the sludge dewaterability,with the capillary suction time （CST） increased from 1.42 to 47.3 （sec·L）/*** application of ultrasonic pretreatment firstly deteriorated the sludge dewaterability （normalized CST increased to 44.4 （sec·L）/g-TSS）,while subsequent anaerobic digestion offset this effect and ultimately decreased the normalized CST to 23.2 （sec·L）/*** dewaterability of unsonicated sludge correlated with protein （p = 0.003） and polysaccharide （p = 0.004） concentrations in the slime fraction,while that of sonicated sludge correlated with protein concentrations in the slime and LB-EPS fractions （p 0.05）.Fluorescent excitationemission matrix analysis showed that the fluorescence matters in the LB-EPS fraction significantly correlated with sludge dewaterability during anarobic digestion.

关键词： anaerobic digestion capillary suction time extracellular polymeric substances sludge dewaterability ultrasonic pretreatment

Multi-level virtual prototyping of electromechanical actuation system for more electric aircraft

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2018年第5期31卷 892-913页

作者： Jian FU Jean-Charles MARE liming yu Yongling FU School of Mechanical Engineering and Automation Beihang University Institut Clement Ader (CNRS UMR 5312) INSA-Toulouse Flying College Beihang University

Electromechanical actuators（EMAs） are becoming increasingly attractive in the field of more electric aircraft because of their outstanding benefits, which include reduced fuel burn and maintenance cost, enhanced system flexibility, and improved management of fault detection and isolation. However, electromechanical actuation raises specific issues when being used for safetycritical aerospace applications like flight controls： huge reflected inertia to load, jamming-type failure, and increase of backlash with service due to wear and local dissipation of heat losses for thermal balance. This study proposes an incremental approach for virtual prototyping of EMAs. It is driven by a model-based system engineering process in order to enable simulation-aided *** practices supported by Bond graph formalism are suggested to develop a model＇s structure efficiently and to make the model ready for use（or extension） by addressing the above mentioned issues. Physical effects are progressively introduced, and the realism of lumped-parameter models is increased step-by-step. In particular, multi-level component models are architected to ensure continuity between engineering activities. The models are implemented in the AMESim simulation environment, and simulation responses are given to illustrate how they can be used for preliminary sizing, control design, thermal balance verification, and faults to failure analysis. The proposed best practices intend to provide engineers with fast, reusable, and efficient means to assess performance virtually and enhance maturity, performance, and robustness.

关键词： Bond graph Electromechanical actuator Flight control Model-based system engi-neering More electric aircraft Power-by-wire

The simultaneous improvements of strength and ductility in additive manufactured Ni-based superalloy via controlling cellular subgrain microstructure

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2021年第9期68卷 184-190页

作者： Yanan Zhao Zongqing Ma liming yu Ji Dong Yongchang Liu State Key Lab of Hydraulic Engineering Simulation and Safety.School of Materials Science and Engineering Tianjin UniversityTianjin 300072China Tianjin Sino-German University of Applied Sciences TianjinChina

Fine cellular subgrain structure was formed in the Selective Laser Melting(SLM) manu factured IN718 alloy via optimizing the processing *** the subsequent homogenization heat treatment process,the Laves phase dispersed at the subgrain boundaries can be eliminated while the cellular subgrain structure is reserved in the printed samples after holding at 1080℃ for 50 *** the prolongation of the holding time,the subgrain boundaries undergo low angle rotation via the motion ofdislocation,which leads to the annihilation of the cellular subgrain ***,during the subsequent double aging heat treatment process,the reserved cellular subgrain structure in the homogenized samples promotes the precipitation of γ" second phase nanoparticles,and these precipitated γ" phase nanoparticles prefer to distribute at subgrain *** was found that these unique subgrain boundaries with γ" phase precipitates can hinder but not fully terminate the motion of dislocation during the plastic deformation process,which contributes to increasing the strength as well as holding the stable plastic ***,the strength and ductility of final prepared IN718 alloy with cellular subgrain microstructure were improved simultaneously compared to the prepared alloy without cellular subgrain structure,which even exceed the mechanical properties standards(AMS 5662) of wrought IN718 *** results in our work suggest that controlling the subgrain structure is a promising effective strategy to improve the mechanical properties of SLM manu factured nickel-based superalloy.

关键词： Selective laser melting Superalloy Subgrain structure Strengthening and toughening