检索结果-南通市图书馆

Improving Corrosion Resistance of Friction Stir Welding Joint of 7075 Aluminum Alloy by Micro-arc Oxidation

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2014年第12期30卷 1251-1254页

作者： yue yang Leilei Zhou Key Laboratory of Advanced Structural Materials Ministry of Education Changchun University of Technology

An attempt has been made to improve the corrosion resistance of friction stir welded joints of 7075 aluminum alloys by micro-arc oxidation（MAO）, and the effects of Na2Si O3 concentration in electrolyte on the corrosion resistance of the coatings were discussed. Morphology and phase constituents of the MAO coatings produced in electrolyte with different Na2SiO3 concentrations were analyzed by scanning electron microscopy, confocal laser scanning microscopy and X-ray diffraction. Electrochemical tests were conducted to evaluate the corrosion resistance of the coatings. The results show that the corrosion resistance of the coated joints is much better than that without the ceramic coating, and the ceramic coating produced in the electrolyte with Na2SiO3 concentration 20 g/L showed better corrosion resistance than the others.

关键词： Aluminum alloy Micro-arc oxidation Friction stir welding joint Corrosion resistance

在线全文

学校读者我要写书评

暂无评论

构建永生化细胞的研究进展

中国输血杂志 2024年第9期37卷 1081-1090页

作者：杨玥顾海慧中国人民解放军海军军医大学第一附属医院输血科上海200433

人类细胞在正常增殖分裂过程中会到达衰老期(M1期)和致死期(M2期),细胞会停止分裂并凋亡,这种不可逆的生理过程是机体内在的一种抗肿瘤机制。然而细胞有限的增殖能力限制了细胞在基础实验、临床应用和生物工程等领域的研究。建立稳定、... 详细信息

人类细胞在正常增殖分裂过程中会到达衰老期(M1期)和致死期(M2期),细胞会停止分裂并凋亡,这种不可逆的生理过程是机体内在的一种抗肿瘤机制。然而细胞有限的增殖能力限制了细胞在基础实验、临床应用和生物工程等领域的研究。建立稳定、持续增殖且结构功能正常的永生化细胞系是当前细胞生物学研究的热点和难点。永生化细胞也是生产工程化血细胞的重要来源。本综述总结了永生化细胞的构建技术和可逆转性永生化细胞的研究进展。

关键词：永生化细胞可逆转永生化细胞衰老端粒酶工程化血细胞

α1-抗胰蛋白酶对未成熟脑白质损伤小鼠运动功能的影响

在线全文

学校读者我要写书评

暂无评论

中国当代儿科杂志 2024年第2期26卷 181-187页

作者：李文冬宋娟张含杨禄祥岳宇阳张新玲王永郑州大学第三附属医院小儿内科/河南省小儿脑损伤重点实验室河南郑州450052

目的探讨α1-抗胰蛋白酶(α1-antitrypsin,AAT)对未成熟脑白质损伤小鼠成年期运动功能的影响。方法将5日龄C57BL/6J幼鼠随机分为假手术组(n=27)、缺氧缺血(hypoxia-ischemia,HI)+生理盐水组(n=27)、HI+AAT组(n=27)。通过HI法建立未成熟... 详细信息

目的探讨α1-抗胰蛋白酶(α1-antitrypsin,AAT)对未成熟脑白质损伤小鼠成年期运动功能的影响。方法将5日龄C57BL/6J幼鼠随机分为假手术组(n=27)、缺氧缺血(hypoxia-ischemia,HI)+生理盐水组(n=27)、HI+AAT组(n=27)。通过HI法建立未成熟脑白质损伤小鼠模型。HI+AAT组分别于HI前24 h、HI后立即及HI后72 h腹腔注射AAT(50 mg/kg);HI+生理盐水组在相同时间腹腔注射相同剂量生理盐水。造模后7 d和55 d进行头颅磁共振T2加权成像扫描。2月龄时利用Catwalk步态分析系统评估成年期小鼠的静态、动态和协调性参数。结果与假手术组小鼠相比,HI损伤小鼠造模后7 d头颅磁共振T2加权像呈现高信号,可见脑白质明显损伤;造模后55 d脑白质损伤仍存在。与假手术组小鼠相比,HI+生理盐水组小鼠爪印面积、最大接触面积、平均压强、最大压强、爪印宽度、平均速度、身体速度、步幅长度、摆动速度、步态模式AA占比、爪印耦合(左后爪→左前爪)占比降低(P<0.05);HI+生理盐水组爪间距离、步态模式AB占比、位相滞后(左前爪→左后爪)占比升高(P<0.05)。与HI+生理盐水组小鼠相比,HI+AAT组小鼠平均速度、身体速度、步幅长度、摆动速度(右前爪)升高(P<0.05)。结论未成熟脑白质损伤小鼠在成年期可表现出明显运动功能障碍,而应用AAT可改善其部分运动功能。

关键词：缺氧缺血脑白质损伤 α1-抗胰蛋白酶 Catwalk步态分析小鼠

在线全文

学校读者我要写书评

暂无评论

退火温度对温轧高锰钢组织性能的影响

材料热处理学报 2024年第1期45卷 131-137页

作者：李敬杨跃辉张晓娟苑少强河北省智能装备数字化设计及过程仿真重点实验室唐山学院河北唐山063000

测定了中碳25Mn钢经温轧及退火处理后的拉伸性能及-196℃时的低温韧性,并对不同处理条件下的显微组织及冲击断口进行了观察,讨论了试验钢退火过程中的再结晶行为及其对力学性能的影响机制。结果表明:试验钢在550℃保温1 h后已经基本完... 详细信息

测定了中碳25Mn钢经温轧及退火处理后的拉伸性能及-196℃时的低温韧性,并对不同处理条件下的显微组织及冲击断口进行了观察,讨论了试验钢退火过程中的再结晶行为及其对力学性能的影响机制。结果表明:试验钢在550℃保温1 h后已经基本完成再结晶,再提高退火温度,再结晶组织逐渐粗化,导致奥氏体的稳定性变差,因此在变形过程中更易于发生马氏体相变,即相变诱导塑性(TRIP)机制逐渐增强,这虽然能够在一定程度上缓解裂纹形核与扩展过程中产生的应力集中,但马氏体的产生也会导致钢的韧性与塑性恶化。同时,结果也表明即便再结晶已经充分,细小的奥氏体晶粒中仍然存在一定量的高密度位错胞和层错,因此产生了比单一细晶强化更高的强度增量。

关键词：高锰钢温轧再结晶变形机制

Efficient dynamic pruning on largest scores first (LSF) retrieval

在线全文

学校读者我要写书评

暂无评论

Frontiers of Information Technology & Electronic Engineering 2016年第1期17卷 1-14页

作者： Kun JIANG yue-xiang yang College of Computer National University of Defense Technology

Inverted index traversal techniques have been studied in addressing the query processing performance challenges of web search engines, but still leave much room for improvement. In this paper, we focus on the inverted index traversal on document-sorted indexes and the optimization technique called dynamic pruning, which can efficiently reduce the hardware computational resources required. We propose another novel exhaustive index traversal scheme called largest scores first(LSF) retrieval, in which the candidates are first selected in the posting list of important query terms with the largest upper bound scores and then fully scored with the contribution of the remaining query terms. The scheme can effectively reduce the memory consumption of existing term-at-atime(TAAT) and the candidate selection cost of existing document-at-a-time(DAAT) retrieval at the expense of revisiting the posting lists of the remaining query terms. Preliminary analysis and implementation show comparable performance between LSF and the two well-known baselines. To further reduce the number of postings that need to be revisited, we present efficient rank safe dynamic pruning techniques based on LSF, including two important optimizations called list omitting(LSF_LO) and partial scoring(LSF_PS) that make full use of query term importance. Finally, experimental results with the TREC GOV2 collection show that our new index traversal approaches reduce the query latency by almost 27% over the WAND baseline and produce slightly better results compared with the Max Score baseline, while returning the same results as exhaustive evaluation.

关键词： Inverted index, Index traversal, Query latency, Largest scores first (LSF) retrieval, Dynamic pruning

踝关节置换术治疗终末期创伤性踝关节炎的疗效分析

在线全文

学校读者我要写书评

暂无评论

中华创伤骨科杂志 2024年第4期26卷 286-292页

作者：路彤梁晓军杨杰杨鑫权赵宏谋李帅杜洋岳洋金淼洛董浩解伟鹏西安医学院西安710021 西安交通大学附属红会医院足踝外科诊疗中心西安710054 陕西中医药大学西安712046

目的探讨踝关节置换术(TAA)治疗终末期创伤性踝关节炎的疗效。方法回顾性分析2014年1月至2022年12月西安交通大学附属红会医院足踝外科诊疗中心接受TAA治疗的41例(41踝)终末期创伤性踝关节炎患者资料。男19例,女22例;年龄(58.5±8.9)岁... 详细信息

目的探讨踝关节置换术(TAA)治疗终末期创伤性踝关节炎的疗效。方法回顾性分析2014年1月至2022年12月西安交通大学附属红会医院足踝外科诊疗中心接受TAA治疗的41例(41踝)终末期创伤性踝关节炎患者资料。男19例,女22例;年龄(58.5±8.9)岁;体重指数(23.6±2.3)kg/m 2;左踝17例,右踝24例。比较患者术前、末次随访时的美国足踝外科协会(AOFAS)踝-后足评分、疼痛视觉模拟评分(VAS)、健康评估12项简表(SF-12)、后足力线(HFA)角、踝关节活动度(ROM),并观察并发症的发生情况。结果41例患者术后均获随访,时间(52.2±10.9)个月。本组患者末次随访时的AOFAS踝-后足评分(85.1±4.8)分、疼痛VAS评分1.0(0.5,1.0)分、SF-12生理得分(46.9±3.9)分、SF-12心理得分(53.9±2.0)分、HFA角0.1°±4.3°、踝关节活动度39.0°±5.1°均较术前[(45.8±8.2)分、6.0(5.0,6.5)分、(27.9±3.1)分、(49.6±4.0)分、-6.8°±13.9°、20.5°±4.6°]显著改善,差异均有统计学意义(P<0.05)。术后12例患者发生并发症,其中主要为踝关节周围疼痛(6例),还有伤口愈合不良、骨囊肿、足背外侧麻木或感觉异常、术中截骨骨折,随访期间无翻修病例。结论TAA是治疗终末期创伤性踝关节炎的有效手段,能显著缓解患者的踝关节疼痛,并保留部分踝关节活动功能。

关键词：骨关节炎关节成形术假体植入创伤性踝关节炎疗效

Modeling of the turbulent burning velocity for planar and Bunsen flames over a wide range of conditions

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Sinica 2022年第3期38卷 10-25,I0001页

作者： Zhen Lu yue yang State Key Laboratory for Turbulent and Complex Systems College of EngineeringPeking UniversityBeijing 100871China BlC-ESAT Peking UniversityBeijing 100871China HEDPS-CAPT Peking UniversityBeijing 100871China

We develop and assess a model of the turbulent burning velocity ST over a wide range of *** aim is to obtain an explicit ST model for turbulent combustion modeling and flame *** model consists of sub models of the stretch factor and the turbulent flame *** stretch factor characterizes the flame response of turbulence stretch and incorporates detailed chemistry and transport effects with a lookup table of laminar counterflow *** flame area model captures the area growth based on Lagrangian statistics of propagating surfaces and considers the effects of turbulence length scales and fuel *** present model predicts sT via an algebraic expression without free *** assess the model using 490 cases of the direct numerical simulation or experiment reported from various research groups on planar and Bunsen flames over a wide range of conditions,covering fuels from hydrogen to n-dodecane,pressures from 1 to 30 atm,lean and rich mixtures,turbulence intensity ratios from 0.1 to 177.6,and turbulence length ratios from 0.5 to *** the scattering sT data in the literature,the comprehensive comparison shows that the proposed ST model has an overall good agreement over the wide range of conditions,with the averaged modeling error of 28.1%.

关键词： Turbulent burning velocity Turbulent premixed flame Flame speed

应用型本科院校“334”课程质量保障体系建设研究

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

农业工程与装备 2024年第1期51卷 36-39页

作者：高明华杨玥杨岚沈阳工学院质量管理与评估处辽宁抚顺113122 沈阳工学院机械工程与自动化学院辽宁抚顺113122

随着高等教育内涵式发展和高校分类发展的推进,课程质量保障体系建设已成为高等院校推动学科发展的重要内容之一。沈阳工学院基于应用型本科专业特色,把人才培养目标和人才培养方针融入课程实施全过程,构建了由3个层级、3个独立机构、4... 详细信息

随着高等教育内涵式发展和高校分类发展的推进,课程质量保障体系建设已成为高等院校推动学科发展的重要内容之一。沈阳工学院基于应用型本科专业特色,把人才培养目标和人才培养方针融入课程实施全过程,构建了由3个层级、3个独立机构、4个工作系统组成的“334”课程质量保障体系,形成了有机构、有目标、有标准、有查评、有反馈、有改进的教学机制,为教学效果和课程质量的持续提升提供了保障。

关键词：应用型本科课程质量保障体系学科建设

A Reliability Assessment of an Integrated Energy System Based on Coupling Energy Flow and Thermal Inertia

在线全文

学校读者我要写书评

暂无评论

CSEE Journal of Power and Energy Systems 2022年第6期8卷 1772-1783页

作者： Wenxia Liu Tie Ma yue yang North China Electric Power University Beijing 102206China

With the wide application of integrated energy systems(IES),the degree of coupling between different types of energy sources is further strengthened,and the mechanism of fault development tends to be ***,in order to improve the accuracy and practicability of the reliability assessment of IESs,a sequential simulation reliability assessment method considering multi-energy flow and thermal inertia is proposed in this *** this method,the IES structure model is constructed with the combined cooling,heating and power(CCHP)unit as the core equipment,combining with the new energy source to realize the comprehensive energy power flow calculation considering any ***,a load reduction optimization model is established,considering the importance of load and operational economy,in the system status ***,the heat supply reliability index is corrected taking into account the transmission delay characteristics and terminal thermal inertia.A case study based on the 20-node and the analysis of the influence factors demonstrates the validity of the proposed method.

关键词： Combined cooling heating and power(CCHP) integrated energy system multi-energy flow calculation reliability assessment thermal inertia