检索结果-南通市图书馆

Science China Chemistry 2011年第5期54卷 812-815页

作者： li qingning WU XiaoJing ZHAO Juan WU ChangYu WANG XueMei State Key Laboratory of Bioelectronics Southeast University Nanjing 210096China Medical School Ningbo UniversityNingbo 315211China

In this study,we have prepared the blending of gold nanoparticles-multiwalled nanotubes (Au-MCNTs) and then applied the new nanocomposites to modify the glassy carbon electrode (GCE) for highly sensitive detection of the interaction between anticancer drug daunorubicin (DNR) and cancer cells. Electrochemical analysis indicates that the Au-MCNT modified GCE shows high sensitivity and could track the real time response of cancer cells under DNR treatments. Therefore,this new nano-interface and Au-MCNT modified electrode could be explored as a rapid,highly sensitive,and convenient real-time detection strategy in cancer related research and would have prospect in other biomedical applications.

关键词： pharmaceutical analysis electrochemical detection anticancer drugs gold nanoparticles multi-walled carbon nanotubes

A new insight into structural complexity in ferroelectric ceramics

在线全文

学校读者我要写书评

暂无评论

Journal of Advanced Ceramics 2017年第3期6卷 262-268页

作者： Weidong ZENG qingning li Changrong ZHOU Jiwen XU Changlai YUAN Guohua CHEN School of Material Science and Engineering Guilin University of Electronic Technology Guilin 541004 China

The structure of the ferroelectrics has been widely studied in order to pursuing the origin of high electromechanical responses. However, some experiments on structure of ferroelectrics have yielded different results. Here, we report that the controversial phase structure is due to the adaptive diffraction of nanodomains which hides the natural crystal structure, and the electric-field-induced phase transition is that the natural crystal structure reappears due to the coalescent nanodomains or ordering nanodomains by applying a high electric field. The temperature dependence of dielectric constant with different measurement frequencies and X-ray diffraction (XRD) patterns of unpoled, poled, and annealing after poled ceramics in Bi0.5Na0.5TiO3–BaTiO3 (BNT–BT) ceramics authenticate the statement. These results provide a new insight into the origin of structural complexity in ferroelectric ceramics, which is related to the key role of nanodomains.

关键词： crystal structure adaptive diffraction ferroelectricity phase transitions

Propane Dehydrogenation over PtSnNa Catalyst Supported on La-ZSM-5 Zeolite

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

China Petroleum Processing & Petrochemical Technology 2010年第3期12卷 18-24页

作者： Huang li Zhou Yuming Zhang Yiwei li qingning Tian Xiaoming (School of Chemistry and Chemical Engineering,Southeast University,Nanjing 211189) Southeast Univ Sch Chem & Chem Engn Nanjing 211189 Peoples R China

The La-ZSM-5 zeolite with different contents of La was synthesized by the hydrothermal method. The physico-chemical properties of the materials were studied. The results of FT-IR analyses indicated that La might be incorporated into the framework of ZSM-5 zeolite. The NH3-TPD analyses showed that the amount of weak acid sites of the zeolite decreased with a continuously increasing La content. Afterwards, the La-ZSM-5 zeolite was used as the support of PtSnNa catalyst for propane dehydrogenation. The test results revealed that the utilization of La- ZSM-5 zeolite could achieve a high propene conversion, and effectively inhibit the coke formation on the catalyst surface. When the content of La was 0.16%, the catalytic activity and stability of the catalyst got the best of its performance. Besides, the PtSnNa/La （0.16%）-ZSM-5 catalyst is more stable than the conventional PtSnNaLal ZSM-5 catalysts.

关键词： La-ZSM-5 propane dehydrogenation propene.

Effects of thermal and electrical histories on structure and dielectric behaviors of(li_(0.5)Nd_(0.5))^(2+)-modified(Bi_(0.5)Na_(0.5))TiO_(3)-BaTiO_(3) ceramics

在线全文

学校读者我要写书评

暂无评论

Journal of Materiomics 2017年第2期3卷 121-129页

作者： Jiwen Xu qingning li ling Yang Weidong Zeng Changrong Zhou Changlai Yuan Guohua Chen Guanghui Rao Guangxi Key Laboratory of Information Materials Guilin University of Electronic TechnologyGuilinGuangxi541004China

The effect of thermal and electrical histories on structure and dielectric behaviors is studied using 0.95(Bi_(0.5)Na_(0.5))_(0.97)(li_(0.5)Nd_(0.5))_(0.03)TiO_(3)-0.05BaTiO_(3)(abbreviated as BNTLN0.03-BT5)ceramic as a selected *** structure change caused by annealing treatment,and pronounced phase transition and domain switching by electrical poling,are observed to occur,*** dielectric constant and its strong frequency dispersion in unpoled samples decrease evidently by electrical poling due to electric field-induced ordered *** high temperature Maxwell-Wagner relaxor behavior vanishes by annealing treatment due to the loss of electrical inhomogeneity with interface charging *** properties are improved evidently by annealing treatment at 900℃,implying a new appropriate method to improve piezoelectric properties.

关键词： Ceramics Dielectric properties Ferroelectricity Piezoelectricity

案例整合情景模拟教学模式在急性上消化道出血见习教学中的应用

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

现代医院 2024年第8期24卷 1306-1308,1312页

作者：赖晓波英嵩崧梁培智黎庆宁唐文娟周永健广州市第一人民医院广东广州510180

目的探讨案例整合情景模拟教学模式应用于急性上消化道出血见习教学的教学成效。方法选取广州医科大学临床医学(南山班)2021级40名医学生为研究对象,随机分为两组,其中22名为实验组,采用案例整合情景模教学模式;另18名同学为对照组,采... 详细信息

目的探讨案例整合情景模拟教学模式应用于急性上消化道出血见习教学的教学成效。方法选取广州医科大学临床医学(南山班)2021级40名医学生为研究对象,随机分为两组,其中22名为实验组,采用案例整合情景模教学模式;另18名同学为对照组,采用传统床旁见习教学模式。教学内容为急性非静脉曲张性上消化道出血。结果实验组和对照组消化内科学总得分无统计学差异(P>0.05),涉及消化道出血相关内容的得分情况实验组得分明显优于对照组,两组间有统计学意义(P<0.05)。在课后满意度调查中,大部分实验组同学对新教学模式满意度较高并积极参与。结论案例整合情景模拟教学模式在激发学习兴趣、培养医学职业素养、活跃课堂气氛等方面明显优于传统床边教学模式,适于消化内科的实践教学,可作为医学本科见习的常规教学方法进行推广及使用。

关键词：以案例为基础的教学情景模拟消化内科急性非静脉曲张性上消化道出血

Dielectric behaviors and relaxor characteristics in Bi_(0.5)Na_(0.5)TiO_(3)-BaTiO_(3) ceramics

在线全文

学校读者我要写书评

暂无评论

Journal of Advanced Dielectrics 2019年第5期9卷 57-64页

作者： Pei Chen Jun Wang Weidong Zeng Changrong Zhou Yongsheng Zhang qingning li Jiwen Xu Guohua Chen Changlai Yuan Guangxi Key Laboratory of Information Materials Guilin University of Electronic Technology Guilin Guangxi 541004P.R.China School of Material Science and Engineering Guilin University of Electronic Technology Guilin Guangxi 541004P.R.China

Microstructure and dielectric behaviors of heating/cooling and bias-field were investigated in lead-free ceramics(1-x)Bi_(0.5)Na_(0.5)TiO_(3)-xBaTiO_(3)(BNT-xBT,x=0,0.02,0.04,0.06,0.08 and 0.10).The relaxor characters and the Vogel–Fulcher law of frequency-dependent dielectric properties were *** dielectric anomalies with pronounced frequency dispersion at Td,a maximum dielectric with variable frequency-dispersion at Tm and a third Maxwell–Wagner-type relaxation over a wide temperature range in high-temperature region were *** significant dielectric thermal hysteresis,low barrier energy,high freezing temperature in heating process and the maximum dielectric tunability appeared in x=0.4 ceramic.

关键词： Bismuth sodium titanate dielectric relaxor Vogel-Fulcher law dielectric tunability

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

多肢剪力墙自振频率传递矩阵法简化计算

地震工程与工程振动 2010年第2期30卷 99-104页

作者：李桅李青宁西安建筑科技大学土木工程学院陕西西安710055

基于连续体系模型与传递矩阵法的结合,提出了一种简化方法来计算多肢剪力墙的动力特性。整个结构体系等效模拟为一个夹层结构梁;建立了相应的基本微分方程;通过求解微分方程得到了楼层间变形函数;利用边界条件及层间变形函数导出了层间... 详细信息

基于连续体系模型与传递矩阵法的结合,提出了一种简化方法来计算多肢剪力墙的动力特性。整个结构体系等效模拟为一个夹层结构梁;建立了相应的基本微分方程;通过求解微分方程得到了楼层间变形函数;利用边界条件及层间变形函数导出了层间传递矩阵;据此计算出了体系的振型与自振频率。算例分析表明本文方法计算结果与文献给出的解是比较吻合的。

关键词：多肢剪力墙连续体系模型动力分析自振频率传递矩阵法

求解曲线箱梁空间振动特性的Cayley-Hamilton传递矩阵法

在线全文

学校读者我要写书评

暂无评论

振动与冲击 2017年第8期36卷 138-143页

作者：闫仙丽李青宁山西大学土木工程系太原030013 西安建筑科技大学土木工程学院西安710055

将传递矩阵法与Cayley-Hamilton定理相结合,以微分方程和矩阵分析理论为基础,提出了一种新的Cayley-Hamilton传递矩阵法。应用该方法,考虑曲线箱梁桥的空间弯曲、剪切、扭转、拉压、翘曲及其相互间的耦合作用,推导了曲线箱梁桥离散模型... 详细信息

将传递矩阵法与Cayley-Hamilton定理相结合,以微分方程和矩阵分析理论为基础,提出了一种新的Cayley-Hamilton传递矩阵法。应用该方法,考虑曲线箱梁桥的空间弯曲、剪切、扭转、拉压、翘曲及其相互间的耦合作用,推导了曲线箱梁桥离散模型的振动空间传递矩阵。以某单跨简支曲线箱梁桥为例,采用所推导矩阵,对其进行计算机编程运算,得到该桥梁的自振频率与振型,并与有限元法计算结果相比较,二者吻合良好,表明本文方法有效。

关键词：桥梁工程振动特性 Cayley-Hamilton传递矩阵法曲线箱梁

在线全文

学校读者我要写书评

暂无评论

曲线箱梁桥的空间传递矩阵

哈尔滨工程大学学报 2014年第10期35卷 1212-1218页

作者：闫仙丽李青宁西安建筑科技大学土木工程学院陕西西安710055

为了分析曲线箱梁桥的受力情况,将传递矩阵法用于曲线箱梁桥的受力分析,以变化固定端的悬臂梁作为单元基本计算体系,利用平衡方程、卡式定理及虚功原理推导了弹性曲线箱梁的显式空间传递矩阵,并考虑了截面剪切中心与形心不重合的影响。... 详细信息

为了分析曲线箱梁桥的受力情况,将传递矩阵法用于曲线箱梁桥的受力分析,以变化固定端的悬臂梁作为单元基本计算体系,利用平衡方程、卡式定理及虚功原理推导了弹性曲线箱梁的显式空间传递矩阵,并考虑了截面剪切中心与形心不重合的影响。为验证公式的正确性,分别采用传递矩阵法与有限元法对某一单跨曲线箱梁桥进行空间受力分析,结果显示2种方法计算结果基本吻合,而传递矩阵法划分较少单元却可达到很高的精度,计算效率大大提高。表明该公式正确,推导方法可行,可推广应用于其他结构在不同荷载情况下传递矩阵的推导。

关键词：曲线桥箱梁空间传递矩阵卡式定理虚功原理

多点地震输入下结构地震反应分析的频域精细传递矩阵法

在线全文

学校读者我要写书评

暂无评论

建筑结构学报 2010年第2期31卷 48-54页

作者：孙建鹏李青宁西安建筑科技大学土木工程学院陕西西安710055

正确的地震输入方式是研究工程结构抗震性能的首要因素。结构的地震反应分析,需要考虑多点地震输入的影响。将精细传递矩阵理论与拟静力原理相结合,建立多点地震输入下结构地震反应分析的频域精细传递矩阵法。首先,根据梁单元的几何物... 详细信息

正确的地震输入方式是研究工程结构抗震性能的首要因素。结构的地震反应分析,需要考虑多点地震输入的影响。将精细传递矩阵理论与拟静力原理相结合,建立多点地震输入下结构地震反应分析的频域精细传递矩阵法。首先,根据梁单元的几何物理关系,建立梁单元的状态传递矩阵;其次,根据傅里叶变换,建立集中质量两侧的状态传递矩阵;然后,根据转折处及分支点处的结构特点,建立转折处及分支点处的状态传递矩阵;最后,根据结构的实际特点,建立结构总的传递矩阵。在上述算法的基础上,编制了计算程序,并进行了相应的算例计算。算例计算结果表明,结构在水平方向地震力的作用下,边柱的地震反应考虑一致激励较为合理;中柱水平方向考虑一致激励较为合理,而竖直方向应考虑多点激励的不利影响。

关键词：精细传递矩阵法地震反应频域多点输入瑞雷阻尼