检索结果-南通市图书馆

Enhanced tribological properties of aligned graphene-epoxy composites

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

Friction 2022年第6期10卷 854-865页

作者： Yuefeng DU Zhenyu ZHANG Dong WANG Lezhen ZHANG junfeng cui Yapeng CHEN Mingliang WU Ruiyang KANG Yunxiang LU Jinhong YU Nan JIANG Key Laboratory for Precision and Non-Traditional Machining Technology of Ministry of Education Dalian University of TechnologyDalian 116024China Beijing Spacecrafts Manufacturing Factory Co. Ltd.China Academy of Space TechnologyBeijing 100094China Weichai Power Co. Ltd.Weifang 261061China Key Laboratory of Marine Materials and Related Technologies Zhejiang Key Laboratory of Marine Materials and Protective TechnologiesNingbo Institute of Materials Technology and Engineering(NIMTE)Chinese Academy of SciencesNingbo 315201China

The random distribution of graphene in epoxy matrix hinders the further applications of grapheneepoxy composites in the field of tribology.Hence,in order to fully utilize the anisotropic properties of graphene,highly aligned graphene-epoxy composites(AGEC)with horizontally oriented structure have been fabricated via an improved vacuum filtration freeze-drying method.The frictional tests results indicated that the wear rate of AGEC slowly increased from 5.19x10^(-6)mm^(3)/(N-m)to 2.87x10^(-5)mm^(3)/(N-m)with the increasing of the normal load from 2 to 10 N,whereas the friction coefficient(COF)remained a constant of 0.109.Compared to the neat epoxy and random graphene-epoxy composites(RGEC),the COF of AGEC was reduced by 87.5%and 71.2%,and the reduction of wear rate was 86.6%and 85.4%at most,respectively.Scanning electron microscope(SEM)observations illustrated that a compact graphene self-lubricant film was formed on the worn surface of AGEC,which enables AGEC to possess excellent tribological performance.Finally,in light of the excellent tribological properties of AGEC,this study highlights a pathway to expand the tribological applications of graphene-epoxy composites.

关键词： graphene aligned epoxy composite tribological performance

科幻叙事尺度到生活经验的复归——从电视剧《三体》说起

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

电影评介 2024年第4期 103-108页

作者：崔俊峰郑州大学美术学院

自2008年小说《三体》首度发行以来,刘慈欣的《三体》三部曲便一直作为中国长篇科幻小说的代表而备受瞩目。这部作品在科幻领域掀起热潮后,影响力逐渐扩散至互联网等其他领域;英文版《三体》荣获雨果奖后,其影响力更为广泛——无论是时... 详细信息

自2008年小说《三体》首度发行以来,刘慈欣的《三体》三部曲便一直作为中国长篇科幻小说的代表而备受瞩目。这部作品在科幻领域掀起热潮后,影响力逐渐扩散至互联网等其他领域;英文版《三体》荣获雨果奖后,其影响力更为广泛——无论是时任全国人大发言人傅莹引用《三体》阐述朝核问题^([1]).

关键词：《三体》科幻小说雨果奖刘慈欣科幻叙事朝核问题互联网电视剧

Deformation mechanism and in-situ TEM compression behavior of TB8βtitanium alloy with gradient structure

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

Journal of Materials Science & Technology 2021年第25期84卷 105-115页

作者： Dan Liu Daoxin Liu junfeng cui Xingchen Xu Kaifa Fan Amin Ma Yuting He Sara Bagherifard College of Civil Aviation Northwestern Polytechnical UniversityXi’an710072China Key Laboratory for Precision and Non-Traditional Machining Technology of Ministry of Education Dalian University of TechnologyDalian116024China Department of Aeronautics and Astronautics Air Force Engineering UniversityXi’an710038China Department of Mechanical Engineering Politecnico di MilanoMilan20156Italy

Severe plastic deformation is known to induce grain refinement and gradient structure on metals’surfaces and improve their mechanical properties.However,the fundamental mechanisms behind the grain refinement and micromechanical properties of materials subjected to severe plastic deformation are not still well studied.Here,ultrasonic surface rolling process(USRP)was used to create a gradient microstructure,consisting of amorphous,equiaxed nano-grained,nano-laminated,ultrafine laminated and ultrafine grained structure on the surface of TB8βtitanium alloy.High energy and strain drove element co-segregation on sample surface leading to an amorphous structure during USRP processing.In situ transmission electron microscope compression tests were performed in the submicron sized pillar extracted from gradient structure and coarse grain,in order to reveal the micromechanics behavior of different grain morphologies.The ultrafine grained layer exhibited the lowest yield stress in comparison with single crystal and amorphous-nanocrystalline layers;the ultrafine grained layer and single crystal had an excellent strain hardening rate.The discrepancy among the grain sizes and activated dislocation sources led to the above mentioned different properties.Dislocation activities were observed in both compression test and microstructure evolution of USRP-treated TB8 alloy.An evolution of dislocation tangles and dislocation walls into low angle grain boundaries and subsequent high angle grain boundaries caused the grain refinement,where twinning could not be found and no phase transformation occurred.

关键词： TB8 alloy Ultrasonic surface rolling process Gradient microstructure Microstructure evolution In situ transmission electron microscope compression test

在线全文

学校读者我要写书评

暂无评论

中低速磁浮列车制动过程的时滞补偿预测控制

铁道科学与工程学报 2024年第2期21卷 735-747页

作者：崔俊锋王长远王琦周艳丽熊光华杨辉北京全路通信信号研究设计院集团有限公司北京100070 华东交通大学电气与自动化工程学院江西南昌330013

中低速磁悬浮列车制动过程中具有非线性强、时滞大、时滞特性难处理等特性,传统列车制动控制方法难以实现对磁浮列车制动过程的精准速度控制。为解决中低速磁悬浮列车制动过程的时滞问题,提高制动控制精度,提出一种中低速磁浮列车制动... 详细信息

中低速磁悬浮列车制动过程中具有非线性强、时滞大、时滞特性难处理等特性,传统列车制动控制方法难以实现对磁浮列车制动过程的精准速度控制。为解决中低速磁悬浮列车制动过程的时滞问题,提高制动控制精度,提出一种中低速磁浮列车制动过程的时滞补偿预测控制方法。首先,根据中低速磁悬浮列车实际运行数据,利用带有遗忘因子的递推最小二乘法辨识列车模型参数,建立列车自回归模型。然后,根据得到的受控自回归积分滑动平均模型和Smith预估器构建带时滞补偿的广义预测控制器并分析其控制律更新过程,实现对中低速磁悬浮列车制动过程的纯滞后补偿,降低列车制动过程中时滞特性的影响。最后,基于某磁浮线现场数据,以中低速磁悬浮列车制动过程为被控对象进行实验仿真,并比较时滞补偿广义预测控制方法与传统广义预测控制方法对于中低速磁悬浮列车制动过程速度跟踪控制的效果。仿真结果表明:所设计的时滞补偿广义预测控制器能够以更高的精度实现对中低速磁悬浮列车制动过程的速度跟踪,且与传统广义预测控制方法相比,系统跟踪误差更小并具有更好的控制性能。所提出的时滞补偿广义预测控制算法不仅解决了中低速磁悬浮列车制动过程的时滞问题,而且有效提高了列车制动控制的精度,验证了该方法的有效性。

关键词：中低速磁悬浮列车制动过程时滞补偿广义预测控制 Smith预估器

变容与平衡:西药东渐背景下近代中国汤剂改良之争

在线全文

学校读者我要写书评

暂无评论

南京中医药大学学报（社会科学版） 2024年第1期25卷 7-14页

作者：朱睿思崔军锋浙江师范大学人文学院浙江金华321025

近代大量西药入华,对中国传统医药市场产生持续冲击,中药的不足之处日显。部分中医药界人士顺应时代潮流,向西方学习,力图革新中药。汤剂与中医诊疗观念联系紧密,其革新过程不仅受到医界关注,还多次成为中西医论争的焦点。由于近代中国... 详细信息

近代大量西药入华,对中国传统医药市场产生持续冲击,中药的不足之处日显。部分中医药界人士顺应时代潮流,向西方学习,力图革新中药。汤剂与中医诊疗观念联系紧密,其革新过程不仅受到医界关注,还多次成为中西医论争的焦点。由于近代中国现实政治与客观研究能力的不足,汤剂改良未能实现科学化发展,但关于其改良过程的争论,亦展现了近代中西医在制药方面的平衡与近代中医药界对于西医学知识的收受与变容。

关键词：汤剂改良中药科学化西药剂型

小儿热速清口服液HPLC指纹图谱的建立及多指标成分的含量测定

在线全文

学校读者我要写书评

暂无评论

中国药房 2024年第7期35卷 801-806页

作者：崔俊凤崔帅梁秀坤李东旭王鑫瑞高鹏滨州市检验检测中心山东滨州256600 滨州市化学药物研发与质量控制重点实验室山东滨州256600 山东中医药大学药学院济南250355

目的建立小儿热速清口服液高效液相色谱(HPLC)指纹图谱,并对其中12种指标成分进行含量测定。方法采用HPLC法。以Venusil MP C18为色谱柱;以乙腈-0.1%磷酸溶液为流动相进行梯度洗脱;流速为1.0 mL/min;检测波长为210 nm;柱温为30℃;进样量... 详细信息

目的建立小儿热速清口服液高效液相色谱(HPLC)指纹图谱,并对其中12种指标成分进行含量测定。方法采用HPLC法。以Venusil MP C18为色谱柱;以乙腈-0.1%磷酸溶液为流动相进行梯度洗脱;流速为1.0 mL/min;检测波长为210 nm;柱温为30℃;进样量为10μL。采用《中药色谱指纹图谱相似度评价系统(2012版)》建立13批小儿热速清口服液的HPLC指纹图谱,并进行相似度评价,测定12种指标成分,即(R,S)告依春、3,5-二-O-咖啡酰奎宁酸、葛根素、连翘苷、连翘酯苷A、绿原酸、黄芩苷、柴胡皂苷d、汉黄芩苷、黄芩素、大黄素、大黄酚的含量。结果13批小儿热速清口服液指纹图谱的相似度均大于0.97,指认了14个共有峰。13批小儿热速清口服液中上述12种指标成分的含量分别为0.078~0.172、1.564~2.736、1.338~2.578、0.426~0.872、1.477~2.628、1.396~2.447、4.052~9.146、0.367~0.692、1.974~4.674、1.274~2.969、0.085~0.167、0.155~0.307 mg/mL。结论本研究建立的HPLC指纹图谱及含量测定方法准确度高、专属性好,可用于小儿热速清口服液的质量评价。

关键词：小儿热速清口服液高效液相色谱法指纹图谱含量测定

In situ real-time study buckling behavior of boron nitride nanotubes with axial compression by TEM

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2019年第7期30卷 1401-1404页

作者： Guoxin Chen Huanming Lu junfeng cui Haitao Yu Bo Wang Yan Liu He Li Nan Jiang Key Laboratory of Marine Materials and Related Technologies CAS Zhejiang Key Laboratory of Marine Materials and Protective Technologies Ningbo Institute of Materials Technology and Engineering Chinese Academy of Sciences Ningbo 315201 China University of Chinese Academy of Sciences Beijing 100049 China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of Sciences Beijing 100049 China

Boron nitride nanotubes(BNNTs)were treated as brittle materials and could be used to enhance the composite mechanical properties.Many approaches were used to verify the theoretical prediction experimentally,but how to in situ real-time characterize nanomechanical properties of BNNTs was still interested to the researchers.An in situ transmission electron microscopy(TEM)equipped with a force transducer holder had been used to study the structure evolution behavior of BNNTs with axial compression.Real-time video and the force transducer had been used synchronously to record the whole force loading process where the mechanical deformation of BNNT began,buckled and ended with fracture.An in dividual ultrathin BNNT was employed to con duct the loading test.The results showed that the elastic deformation happened on the BNNT.Young's modulus?1.05-1.37 Tpa and elasticity coefficient?198.7-255.9 N/m of BNNT were calculated by Euler formula and Hooker's law,respectively.

关键词： BNNTs Buckling behavior Real-time In situ TEM Young's modulus Axial compression

Types and microstructures of pores in shales of the Ordovician Wulalike Formation at the western margin of the Ordos Basin, China

在线全文

学校读者我要写书评

暂无评论

能源地球科学(英文)

能源地球科学(英文) 2023年第3期4卷 100-112页

作者： Wuling Mo Min Wang Fangwen Chen Zhengliang Huang Ying Li Yu Yan Ren Jiang Tong Lin junfeng cui Research Institute of Petroleum Exploration and Development Beijing100083China China University of Petroleum(East China) QingdaoShangdong266580China Exploration and Development Research Institute of Petro China Changqing Oilfield Company Xi'anShaanxi710018China

Shale samples from the Ordovician Wulalike Formation at the western margin of the Ordos Basin are studied to define the types, microstructures and connectivity of pores as well as the relationships between the pore structures and gas content of the samples by using experimental techniques such as high-resolution field emission scanning electron microscopy (FESEM), mercury injection capillary pressure (MICP), low-temperature nitrogen adsorption (LTNA), CO_(2) adsorption, and focused ion beam scanning electron microscopy (FIB-SEM). The results show that the shale has 10 different lithofacies, typical mixed sedimentary characteristics, and poorly developed pores. The reservoir space mainly consists of intercrystalline pores, dissolution pores, intergranular pores, and micro-fissures, with organic pores occasionally visible. The pore size is mostly within 0.4–250 nm range but dominated by micropores and mesopores less than 20 nm, with pore numbers peaking at pore sizes of 0.5 nm, 0.6 nm, 0.82 nm, 3 nm, and 10 nm, respectively. The pores are poorly connected and macropores are rarely seen, which may explain the low porosity and low permeability of the samples. Samples with high content of organic matter and felsic minerals are potential reservoirs for oil and gas with their favorable physical properties and high connectivity. The pores less than 5 nm contribute significantly to the specific surface area and serve as important storage space for adsorbed gas.

关键词： Shale Pore type Microstructure Ordovician Ordos Basin

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

荧光MIRA法快速检测食品中产气荚膜梭菌

中国食品卫生杂志 2024年第2期36卷 139-146页

作者：张士财丁卫平伊廷存张瑞朱富强崔俊凤霍胜楠滨州市检验检测中心山东滨州256600 山东省食品药品检验研究院山东济南250101

目的基于荧光多酶恒温快速扩增(MIRA)技术,建立一种快速准确检测食品中产气荚膜梭菌的方法。方法利用产气荚膜梭菌共有α毒素编码基因plc保守序列设计引物探针,并建立和优化荧光MIRA方法;提取17种非目标菌基因组DNA进行方法特异性验证;... 详细信息

目的基于荧光多酶恒温快速扩增(MIRA)技术,建立一种快速准确检测食品中产气荚膜梭菌的方法。方法利用产气荚膜梭菌共有α毒素编码基因plc保守序列设计引物探针,并建立和优化荧光MIRA方法;提取17种非目标菌基因组DNA进行方法特异性验证;梯度稀释目标菌基因组DNA和菌液用于方法灵敏度评价;选取4种食品进行基质干扰试验,评估方法的稳定性;检测实际样品并与国家标准方法进行比较,以验证该方法的实用性。结果该方法特异性强,检测多种非目标致病菌均呈阴性反应;灵敏度高,以基因组DNA为模板和菌液为模板时最低检测限分别为1.05×10^(1) fg/μL和7.5×10^(0) CFU/mL;该方法不受基质影响,抗干扰能力强;耗时短,约20 min即可完成检测。结论本研究中的荧光MIRA方法快速准确、灵敏度高、特异性强,可用于食品中产气荚膜梭菌的快速检测。

关键词：多酶恒温快速扩增产气荚膜梭菌 plc基因分子检测食源性致病菌