检索结果-南通市图书馆

Effect of noble metal nanoparticle size on C–N bond cleavage performance in hydrodenitrogenation: a study of active sites

引用

Frontiers of Chemical Science and Engineering 2023年第12期17卷 1986-2000页

作者： Yi-Fan Xue Jie Feng yun-cai song Wen-Ying Li State Key Laboratory of Clean and Efficient Coal Utilization Taiyuan University of TechnologyTaiyuan 030024China

Breakage of the C-N bond is a structure sensitive process,and the catalyst size significantly affects its *** the active metal nanoparticle scale,the role of catalyst size in C-N bond cleavage has not been clearly ***,Ru catalysts with variable nanoparticle sizes were obtained by modulating the reduction temperature,and the catalytic activity was evaluated using 1,2,3,4-tetrahydroquinoline and o-propylaniline with different C-N bond hybridization patterns as *** showed a 13 times higher reaction rate for sp3-hybridized C-N bond cleavage than sp2-hybridized C-N bond cleavage,while the reaction rate tended to increase first and then decrease as the catalyst nanoparticle size *** concentrations of terrace,step,and corner sites were found in different sizes of Ru *** relationship between catalytic site variation and C-N bond cleavage activity was further investigated by calculating the turnover frequency values for each *** analysis indicates that the variation of different sites on the catalyst is the intrinsic factor of the size dependence of C-N bond cleavage activity,and the step atoms are the active sites for the C-N bond *** Ru nanoparticles are smaller than 1.9 nm,they have a strong adsorption effect on the reactants,which will affect the catalytic performance of the Ru ***,these findings were also confirmed on other metallic Pd/Pt *** role of step sites in C-N bond cleavage was proposed using the density function theory *** reactants have stronger adsorption energies on the step atoms,and step atoms have d-band center nearer to the Fermi *** this case,the interaction with the reactant is stronger,which is beneficial for activating the C-N bond of the reactant.

关键词： sp3 sp2-hybridized C–N bond noble metal nanoparticle catalytic active site turnover frequency DFT

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Flat Currents of Green-Schwarz Superstring in AdS2 × S^2 Background

引用

Communications in Theoretical Physics 2006年第4期45卷 663-668页

作者： WANG Xiao-Hui WANG Zhan-yun cai Xiao-Lin song Pei HOU Bo-Yu SHI Kang-Jie Institute of Modern Physics Northwest University Xi＇an 710069 China

From the κ symmetric action of IIB string in AdS2 × S^2 background given by Zhou, we derive the equations of motion. By using the twisted dual transformation which was introduced by Hou, we construct the flat curren... 详细信息

关键词： Green-Schwarz superstring integrability AdS2 × S^2

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

基于自适应多尺度超螺旋算法的无人机集群姿态同步控制

引用

自动化学报 2023年第8期49卷 1656-1666页

作者：蔡运颂许璟牛玉刚华东理工大学信息科学与工程学院上海200237 华东理工大学能源化工过程智能制造教育部重点实验室上海200237

四旋翼无人机(Unmanned aerial vehicle, UAV)系统姿态角和角速度分别为运行在不同时间尺度上的慢、快动态.由于输入扰动的上界难以精确估计,本文提出一种基于自适应多尺度超螺旋(Super-twisting, STW)滑模算法的无人机集群一致性控制策... 详细信息

四旋翼无人机(Unmanned aerial vehicle, UAV)系统姿态角和角速度分别为运行在不同时间尺度上的慢、快动态.由于输入扰动的上界难以精确估计,本文提出一种基于自适应多尺度超螺旋(Super-twisting, STW)滑模算法的无人机集群一致性控制策略.首先,建立无人机集群系统的姿态角模型,并通过奇异摄动理论将其化为两时间尺度形式.基于系统的快慢特性,本文设计两时间尺度的超螺旋滑模算法,并采用自适应增益处理无人机集群系统的未知边界非线性.此外,还提出一种改进型自适应多尺度超螺旋滑模算法,进一步减少系统的一致性收敛时间,实现无人机集群姿态角有限时间内同步.最后通过仿真分析,验证两种自适应多尺度超螺旋算法的正确性和有效性.

关键词：奇异摄动超螺旋算法多尺度姿态协同四旋翼无人机

来源：

维普期刊数据库博看期刊

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Dissecting the cell microenvironment of ovarian endometrioma through single-cell RNA sequencing

引用

Science China Life Sciences 2025年第1期 116-129页

作者： Jiangpeng Wu Siyu Xia Wenting Ye Yan Sun Jing cai Fubing Yu Haiping Wen Xiuwei Yi Taikang Li Mingwei Chen Jiayun Chen Ge song Chuanbin Yang Yali song Jigang Wang Department of Reproductive Medicine Dongguan Maternal and Child Health Care Hospital Department of Urology and Shenzhen Clinical Research Centre for GeriatricsShenzhen People's HospitalSouthern University of Science and Technology State Key Laboratory for Quality Ensurance and Sustainable Use of Dao-di Herbs Artemisinin Research Centerand Institute of Chinese Materia MedicaChina Academy of Chinese Medical Sciences Reproductive Medicine Center Foshan Women and Children Hospital State Key Laboratory of Antiviral Drugs School of PharmacyHenan University

Ovarian endometrioma（OE）, also known as “chocolate cysts,” is a cystic mass that develops in the ovaries due to endometriosis and is a common gynecological condition characterized by the growth of endometrial tissue outside the uterus, leading to symptoms such as dysmenorrhea, pelvic pain, and infertility. However, the precise molecular and cellular mechanisms driving this pathophysiology remain largely unknown, posing challenges for diagnosis and treatment. Here, we employed integrated single-cell transcriptomic profiling of over 52,000 individual cells from endometrial tissues of OE patients and healthy donors and identified twelve major cell populations. We identified notable alterations in cell type-specific proportions and molecular signatures associated with OE. Notably, the activation of IGFBP5+macrophages with pro-inflammatory properties, NK cell exhaustion, and aberrant proliferation of IQCG+and KLF2+epithelium are key features and may be the potential mechanisms underlying the pathogenesis of OE. Collectively, our data contribute to a better understanding of OE at the single cell level and may pave the way for the development of novel therapeutic strategies.

关键词： ovary high-throughput sequencing transcriptomics gene expression analysis ligand-receptor analysis

来源：

同方期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Compressed data separation via dual frames based split-analysis with Weibull matrices

引用

Applied Mathematics(A Journal of Chinese Universities) 2013年第4期28卷 427-437页

作者： cai yun LI song Department of Mathematics Zhejiang University

In this paper, we consider data separation problem, where the original signal is composed of two distinct subcomponents, via dual frames based Split-analysis approach. We show that the two distinct subcomponents, which are sparse in two diff erent general frames respectively, can be exactly recovered with high probability, when the measurement matrix is a Weibull random matrix （not Gaussian） and the two frames satisfy a mutual coherence property. Our result may be significant for analysing Split-analysis model for data separation.

关键词： Compressed sensing data separation dual frames split-analysis Weibull random matrices

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Convergence analysis of projected gradient descent for Schatten-p nonconvex matrix recovery

引用

Science China Mathematics 2015年第4期58卷 845-858页

作者： cai yun LI song Department of Mathematics Zhejiang University

The matrix rank minimization problem arises in many engineering applications. As this problem is NP-hard, a nonconvex relaxation of matrix rank minimization, called the Schatten-p quasi-norm minimization(0 < p < 1), has been developed to approximate the rank function closely. We study the performance of projected gradient descent algorithm for solving the Schatten-p quasi-norm minimization(0 < p < 1) *** on the matrix restricted isometry property(M-RIP), we give the convergence guarantee and error bound for this algorithm and show that the algorithm is robust to noise with an exponential convergence rate.

关键词： low rank matrix recovery nonconvex matrix recovery projected gradient descent restricted isometry property

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

R380空间过渡圆弧面齿条UGNXCAM造型及数控加工

引用

装备制造技术 2011年第4期 168-170,182页

作者：蔡云松杨顺田蒋士博四川工程职业技术学院四川德阳618000

新日铁5M改造项目中的齿条是由圆弧修形面构成的,其局部结构的特殊性,用一般的数控编程方法难以解决,采用UGNX4.0造型与自动编程的方法,并在XK2414数控龙门铣镗床上成功制造,其设计思路新颖独特,该方法对其他复合形面的加工,也有借鉴意义。

关键词：齿条圆弧修形面 UG建模后置处理数控龙门铣

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Visualization of COVID-19 spread based on spread and extinction indexes

引用

Science China(Information Sciences) 2020年第6期63卷 220-222页

作者： song-Hai ZHANG yun cai Jian LI Department of Computer Science and Technology Tsinghua University Beijing National Research Center for Information Science and Technology(BNRist)

From December 2019, Coronavirus disease 2019(COVID-19) rapidly spread from the city of Wuhan (Hubei Province) to all of China, which was exacerbated by mass population movements associated with the Chinese Spring Festival. To date, more than 80000 people have been infected,and more than 3000 have died. In addition,COVID-19 has already spread to 142 countries,

关键词： Visualization of COVID-19 spread based on spread and extinction indexes

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

45钢表面渗硼在夹具导引元件中的应用

引用

湘潭矿业学院学报 2001年第2期16卷 22-23,26页

作者：赵运才李颂文肖一夫湘潭工学院机械工程及自动化工程系湖南湘潭411201 益阳滨湖柴油机总厂湖南益阳413000

分析了 45钢表面渗硼的工艺及性能 ,特别将渗硼钻套在工厂进行了使用试验试验结果表明 :45钢钻套工作表面渗硼的磨损量随加工件数的变化曲线基本上遵循机械零件磨损的一般规律 ,在相同工况条件下 ,45钢渗硼钻套的耐磨性是T9淬硬钻套的... 详细信息

分析了 45钢表面渗硼的工艺及性能 ,特别将渗硼钻套在工厂进行了使用试验试验结果表明 :45钢钻套工作表面渗硼的磨损量随加工件数的变化曲线基本上遵循机械零件磨损的一般规律 ,在相同工况条件下 ,45钢渗硼钻套的耐磨性是T9淬硬钻套的 5 .3 7倍 ,大大延长了导引元件的使用寿命图 3 ,表 1,参

关键词：表面渗硼耐磨性钻套 45钢夹具使用寿命

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Determination of thalidomide in human plasma by liquid chromatography-tandem mass spectrometry

Determination of thalidomide in human plasma by liquid chrom...

引用

加快转变医药发展方式，占领科学技术制高点——2011年中国药学大会暨第11届中国药师周

作者： Nan Bai a,Xiangyong Cui b,Jingkai Gu b,Beibei Liang a,yun cai a,Xiujie song a,Chunguang Sun a,Hao Liu a,Rui Wang a,a Department of Clinical Pharmacology,Chinese PLA General Hospital,Beijing100853,PR China b Research Center for Drug Metabolism,Jilin university,Changchun 130023,PR China

A rapid,sensitive,and specific analytical method based on high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) has been developed for the determination of thalidomide in human *** analyte and internal standard were extracted by liquid-liquid extraction with ether-dichloromethane (3:2,v/v) and separated on a TC-C 18 column using methanol-10mM ammonium acetate-formic acid (60:40:0.04,v/v/v) as the mobile phase at a flow rate of 0.9 mL·min -*** detection was performed using an API 4000 triple quadrupole mass spectrometer under positive ESI mode and completed within *** multiple reaction monitoring (MRM) transitions were m/z 259.1→84.0 for analyte and m/z 195.9 →138.9 for *** calibration curve exhibited a linear dynamic range of 2-1500 ng·mL -1 (r>0.999 1).Intra- and inter-day precisions (as RSD) were 6.8-13.5% and 4.3-5.0% respectively,and accuracy (as RE) was 2.0-3.5%.The recoveries and matrix effects were satisfactory in all the biological matrices *** method was successfully used in a pharmacokinetic study of thalidomide in Chinese healthy male volunteers receiving an oral administration of 200mg dose.

关键词： human plasma thalidomide multiple reaction monitoring (MRM) LC-MS/MS

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：