检索结果-南通市图书馆

Photo-Activated Snap-Through of Nematic Shallow Spherical Shells

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Solida Sinica 2022年第2期35卷 239-247页

作者： yanli lin linghui He Renhuai Liu MOE Key Lab of Disaster and Control in Engineering Institute of Applied MechanicsJinan UniversityGuangzhou 510632China CAS Key Laboratory of Mechanical Behavior and Design of Materials University of Science and Technology of ChinaHefei 230026China

Photo-responsive nematic polymers can transduce light into mechanical work,but the rate is limited by the quasi-static *** enhance the work output,a strat・egy of exploiting photo-triggered snap-through of glassy nematic shallow spherical shells with hemeotropic director alignment is examined *** criterion for the nonlinear instability is derived analytically by using the modified iteration *** is shown that,for thin shells of small height and large basal radius,snap-through can be caused by an incident light with moderate irradiation *** phenomenon may inspire some new designs of contactless and ultra-fast actuation devices with high-rate output of mechanical work.

关键词： Nematic shell Snap-through Ultra-fast actuation

Isothermal corrosion Fe_3Si alloy in liquid zinc

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

Journal of University of Science and Technology Beijing 2007年第1期14卷 52-55页

作者： Wenjun Wang Junping lin yanli Wang Guoliang Chen State Key Laboratory for Advanced Metals and Materials University of Science and Technology Beijing Beijing 100083 China

The isothermal corrosion testing, microscopic examination and the performance of Fe3Si alloy as materials of construction for bath hardware in continuous hot-dipping lines were studied. The corrosion of Fe3Si alloy in molten zinc was controlled by attacking the grain boundaries preferentially. Aluminum reacted with iron of Fe3Si alloy firstly while the samples were immersed in molten zinc, although aluminum contents in the molten zinc were very low. The phase of reaction product was thought to be Fe2Al5. The corrosion rate of the Fe3Si alloy in molten zinc was determined to be approximately 2.9×10^-3 mm/h, therefore the liquid zinc corrosion resistance of Fe3Si alloy was very weak.

关键词： Fe3Si alloy liquid zinc corrosion galvanizing intermetallics

在线全文

学校读者我要写书评

暂无评论

授课时长改革后大学生课余自学状况调查

中国高等医学教育 2024年第8期 50-51页

作者：石凯凯林艳丽宋鹏河北医科大学口腔医学院河北石家庄050017

目的:课余自学是大学生专业课学习的重要方式,直接影响学习效果。本校在2020年第1学期进行了授课时长的改革,为学生提供了更多的自主学习时间。方法:通过线上和线下问卷调查,从学习动机、学习内容、学习方法、学习计划性、学习时间的有... 详细信息

目的:课余自学是大学生专业课学习的重要方式,直接影响学习效果。本校在2020年第1学期进行了授课时长的改革,为学生提供了更多的自主学习时间。方法:通过线上和线下问卷调查,从学习动机、学习内容、学习方法、学习计划性、学习时间的有效利用等方面调查分析授课时长改革对学生的影响。结果:医学生在专业课的课余自学情况良好,并根据调查结果,提出了一些思考与建议。结论:授课时长改革后,大部分医学生具备了利用自主时间进行学习的自我意识,认识到自主学习的重要性,并能根据个人兴趣选择自主学习内容。

关键词：大学生专业课自学授课时长改革医学教育

Homogenization treatment of high Nb containing TiAl alloys with as-cast and as-forged microstructures

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2008年第2期27卷 181-186页

作者： XU Zhengfang XU Xiangjun lin Junpin ZHANG Yong WANG yanli lin Zhi CHEN Guoliang State Key Laboratory for Advanced Metals and Materials University of Science and Technology Beijing Beijing 100083 China

The effect of heat treatment on the microstructure evolution of a high Nb containing TiAl alloy has been studied. The results indicate that β-segregation, β-segregation and S-segregation in the as-cast and as-forged alloys can be effectively eliminated at the temperature above Tα （1350-1400℃） for long holding time （12-24 h） and the full lamellar （FL） microstructure is gained. For the two alloys, the lamellar colony sizes are 120 μm and 2000 μm, respectively after heat treatment at 1400℃ for 12 h. Meanwhile, the sizes are 210 μm and 3000 μm, respectively at 1350℃ for 24 h. To get a fine homogenous microstructure, the primary as-cast alloy is first subjected to preheat treatment for eliminating the segregations. After the preheat treatment, the ailoy is processed by the multi-step canned forging to attain the microstructure with fine grain size.

关键词： TiAl-based alloy Nb-containing FL microstructure heat treatment rnicrosegregation

胆总管结石患者腹腔镜胆总管探查术中应用“三针法”缝合方案的临床研究

在线全文

学校读者我要写书评

暂无评论

中华普外科手术学杂志（电子版） 2024年第5期18卷 531-534页

作者：姜宁宁蔺艳丽陈惠明陕西省康复医院普外科西安710065

目的:探讨胆总管结石患者腹腔镜胆总管探查术中应用“三针法”缝合方案的效果。方法:前瞻性选取2020年6月至2023年5月接受腹腔镜胆总管探查术的胆总管结石患者105例,依据随机数字表法分为常规组(采用常规胆总管缝合术)53例与三针组(采... 详细信息

目的:探讨胆总管结石患者腹腔镜胆总管探查术中应用“三针法”缝合方案的效果。方法:前瞻性选取2020年6月至2023年5月接受腹腔镜胆总管探查术的胆总管结石患者105例,依据随机数字表法分为常规组(采用常规胆总管缝合术)53例与三针组(采用“三针法”缝合胆总管)52例。采用SPSS25.0软件分析数据,手术相关指标、术后恢复情况、术后疼痛情况等计量资料采用(x±s)表示,行独立样本t检验;计数资料并发症发生情况行χ^(2)检验。P0.05),但三针组胆瘘发生率低于常规组(P<0.05)。结论:采用“三针法”缝合方案可缩短胆总管结石患者腹腔镜胆总管探查术的缝合时间及手术时间,降低术后胆瘘发生率,且不会增加医疗费用,值得临床推广应用。

关键词：胆总管结石腹腔镜胆总管探查术三针法缝合胆瘘

Dynamic recrystallization during hot torsion of Al-4Mg alloy

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

Journal of University of Science and Technology Beijing 2003年第2期10卷 45-48页

作者： Junpin lin, yanli Wang, Zhi lin, and Guoliang ChenState Key Laboratory of Advanced Metal Materials, University of Science and Technology Beijing, Beijing 100083, China Lab. of Adv. Metal Mat. Univ. of Sci. and Technol. Beijing Beijing 100083 China

Binary Al-4Mg alloy have been deformed by hot torsion at 300-500 deg C andstrain rates of 0.006-1.587 s^(-1) to a true strain of 5.5. The specimens were annealed in vacuumfor 1.5 h at 500 deg C and then water quenched. The study indicates that the dynamicrecrystallization occurs during hot torsion of Al-4Mg alloy in a certain range of Z parameter(Zener-Hollmon Parameter), i.e. 19.3 <= lnZ <=24.8. Increasing the strain rate at higher deformationtemperature or reducing the strain rate at lower deformation temperature accelerates the occurrenceof dynamic recrystallization in the alloy.

关键词： Al-4Mg alloy dynamic recrystallization hot torsion

Influence of sample surface condition on nano indentation experiment

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2002年第2期21卷 131-132页

作者： WANG yanli, lin Zhi, lin Junpin, PENG Jihua, and CHEN GuoliangState Key laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083, China University of Science and Technology Beijing State Key Laboratory for Advanced Metals and Materials 北京 100083

The microhardness and elastic modules of the materials weremeasured using the Nano Indenter II, which is a new measuring systemfor the mechanical properties of materials on nano-scale. It candetermine themicrohardness, elastic modules and other mechanicalproperties of materials through measuring applied load and depthunder indenter tip. The results indicated that surface condition ofsample such as the surface roughness affects the experimental preci-sion.

关键词： microhardness elastic modules Nano Indenter

外泌体环状RNA在胃癌中作用机制的研究进展

在线全文

学校读者我要写书评

暂无评论

天津医药 2024年第10期52卷 1110-1115页

作者：姚和林艳丽崔雨萌阎新龙北京工业大学化学与生命科学学院 100124 军事科学院军事医学研究院

胃癌是世界上高发且病死率较高的肿瘤之一,诊断时的临床分期与患者的预后息息相关,寻找灵敏的诊断标志物以提高早期诊断准确率便成为十分迫切的议题。外泌体是由多种细胞分泌的纳米级胞外囊泡,通过在肿瘤微环境中转运生物活性物质,从而... 详细信息

胃癌是世界上高发且病死率较高的肿瘤之一,诊断时的临床分期与患者的预后息息相关,寻找灵敏的诊断标志物以提高早期诊断准确率便成为十分迫切的议题。外泌体是由多种细胞分泌的纳米级胞外囊泡,通过在肿瘤微环境中转运生物活性物质,从而在细胞通讯中发挥重要作用。环状RNA是一类具有特定结构的非编码RNA,由于不易降解得以富集在外泌体中并参与到其介导的各种病理生理过程。外泌体环状RNA可以影响肿瘤细胞的增殖、侵袭、转移及耐药等过程,在临床上具有比常规诊断标志物更显著的优势,可能成为诊断胃癌潜在的生物标志物。该文分别介绍了外泌体和环状RNA的特征、形成机制及在胃癌中的作用,详细论述了外泌体来源的环状RNA在胃癌发生发展中的作用,讨论了其在胃癌诊断与治疗中潜在的临床应用价值和面临的挑战。

关键词：胃肿瘤外泌体 RNA 环状生物标志物

Determination of both jasmonic acid and methyl jasmonate in plant samples by liquid chromatography tandem mass spectrometry

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

Chinese Science Bulletin 2010年第21期55卷 2231-2235页

作者： LIU Xia YANG yanli lin WanHuang TONG JianHua HUANG ZhiGang XIAO LangTao Hunan Provincial Key Laboratory of Phytohormones and Growth Development Hunan Agricultural University Changsha 410128 China

An efficient method for the simultaneous extraction and quantification of both jasmonic acid(JA)and methyl jasmonate(MeJA) from a single plant sample was *** tissues were firstly extracted by using 100%cold methanol,then the Sep-pak C18 solid-phase extraction(SPE)cartridges were adopted for the purification of sample extract,and finally JA and MeJA were determined by the liquid chromatography tandem mass spectrometry(LC-MS-MS)*** was found that the accuracy was improved by using the extra standard for the estimation and correction of JA and MeJA losses in the extraction and purification *** detection limits for JA and MeJA were 0.03 and 0.075 ng mL-1,respectively,and the average recovery rate of JA and MeJA was 92.48%and 94.30%.The method was found to be reproducible and selective,yielding well isolated and easily detectable peaks for both JA and MeJA and simplifying the time-consuming extraction and ***-performance liquid chromatography(HPLC)system was employed as the control detection method for the LC-MS-MS *** two systems were compared in their specificity and accuracy.

关键词：高效液相色谱法茉莉酸甲酯串联质谱法植物样品测定同时提取 HPLC 提取纯化