检索结果-南通市图书馆

Hydrogenation of CO_(2) to p-xylene over ZnZrO_(x)/hollow tubular HZSM-5 tandem catalyst

Journal of Energy Chemistry 2024年第12期99卷 725-737页

作者： Haifeng Tian zhiyu chen Haowei Huang Fei Zha Yue Chang Hongshan chen College of Chemistry&Chemical Engineering Northwest Normal UniversityLanzhou 730070GansuChina Key Laboratory of Eco-functional Polymer Materials of the Ministry of Education Lanzhou 730070GansuChina College of Physics and Electronic Engineering Northwest Normal UniversityLanzhou 730070GansuChina

The conversion of CO_(2) into specific aromatics by modulating the morphology of zeolites is a promising ***-5 zeolite with hollow tubular morphology is *** morphology of zeolite was precisely controlled,and the acid sites on its outer surface were passivated by steam-assisted crystallization method,so that the zeolite exhibits higher aromatic selectivity than sheet HZSM-5 zeolite and greater p-xylene selectivity than chain HZSM-5 *** tandem catalyst was formed by combining hollow tubular HZSM-5 zeolites with ZnZrO_(x)metal *** para-selectivity of p-xylene reached 76.2%at reaction temperature of 320℃,pressure of 3.0 MPa,and a flow rate of 2400 mL g^(-1)h^(-1)with an H_(2)/CO_(2) molar ratio of 3/*** research indicates that the high selectivity of p-xylene is due to the pore structure of hollow tubular HZSM-5 zeolite,which is conducive to the formation of ***,the passivation of the acid site located on the outer surface of zeolite effectively prevents the isomerization of *** reaction mechanism of CO_(2) hydrogenation over the tandem catalyst was investigated using in-situ diffuse reflectance Fourier transform infrared spectroscopy and density functional *** results showed that the CO_(2) to p-xylene followed a methanol-mediated route over ZnZrO_(x)/hollow tubular HZSM-5 tandem *** addition,the catalyst showed no significant deactivation in the 100 h stability *** present study provides an effective strategy for the design of catalysts aimed at selectively preparing aromatics through CO_(2)hydrogenation.

关键词： Hollow tubular HZSM-5 zeolite Tandem catalyst CO_(2)hydrogenation P-xylene Reaction mechanism

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

Microstructure Evolution and Mechanical Properties of Friction Stir Welded Al-Cu-Li Alloy

引用

Acta Metallurgica Sinica(English Letters) 2024年第5期37卷 855-871页

作者： Peng chen Wenhao chen Jiaxin chen zhiyu chen Yang Tang Ge Liu Bensheng Huang Zhiqing Zhang School of New Energy and Materials Southwest Petroleum UniversityChengdu 610500China Sichuan Provincial Engineering Research Center of Advanced Materials Manufacturing Technology for Shale Gas High-Efficient Exploitation Southwest Petroleum UniversityChengdu 610500China College of Materials Science and Engineering Chongqing UniversityChongqing 400045China School of Mechatronic Engineering Southwest Petroleum UniversityChengdu 610500China School of Robot Engineering Yangtze Normal UniversityChongqing 408100China

The investigation concentrates on friction stir welded(FSW)Al-Cu-Li alloy concerning its local microstructural evolution and mechanical *** grain features were characterized by electron back scattered diffraction(EBSD)technology,while precipitate characterization was conducted by using transmission electron microscopy(TEM)aligned along[011]Al and[001]Al zone *** mechanical properties are evaluated through micro-hardness and tensile *** can be found that nugget zones exhibit finely equiaxed grains evolved through complete dynamic recrystallization(DRX),primarily occurring in continuous dynamic recrystallization(CDRX)and discontinuous dynamic recrystallization(DDRX).In the thermal-mechanically affected zone(TMAZ),numerous sub-structured grains,exhibiting an elongated morphology,were created due to partial DRX,signifying the dominance of CDRX,DDRX,and geometric dynamic recrystallization(GDRX)in this region.T_(1)completely dissolves in the nugget zone(NZ)leading to the formation of Guinier-Preston zones and increase ofδ′,β′and S′.Conversely,T_(1)partially solubilizes in TMAZ,the lowest hardness zone(LHZ)and heat affected zone(HAZ),and the residual T_(1)undergoes marked coarsening,revealing various T_(1)*** solubilization and coarsening of T_(1)are primary contributors to the degradation of hardness and strength.θ′primarily dissolves and coarsens in NZ and TMAZ,whilst this precipitate largely coarsens in HAZ and LHZ.σ,TB,grain boundary phases(GBPs)and precipitate-free zone(PFZ)are newly generated during FSW.σexists in the TMAZ,LHZ and HAZ,whereas TB nucleates in *** and PFZ mostly develop in LHZ and HAZ,which can cause strain localization during tensile deformation,potentially leading to LHZ joint fracture.

关键词： Al-Cu-Li alloy Friction stir welding Microstructure evolution Mechanical properties

来源：

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

Common-mode radiation characteristic analysis of connections between cables and metal cases

引用

Frontiers of Electrical and Electronic Engineering in China 2008年第3期3卷 353-357页

作者： Haifeng SONG zhiyu chen Institute of Electronics Chinese Academy of SciencesBeijing 100080China China Academy of Electronics and Information Technology Beijing 100041China

In this paper,the common-mode radiation characteristic of the connection between a cable and a conductor is analyzed by the electric field integral function(EFIF)and the method of moment(MoM).The RWG basis function is adopted as the conductor basis function,the pulse basis function as the wire basis function and the juncture employs Costa basis function.A scheme of singular region separation is proposed to overcome the integration singularity of juncture matrix *** new conclusions of the common-mode radiation characteristics with the metal case are obtained by numeration.

关键词： method of moment(MoM) common-mode radiation metal case electromagnetic compatibility(EMC)

来源：

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

Boosting thermoelectrics by alloying Cu_(2)Se in SnTe-CdTe compounds

引用

Journal of Materials Science & Technology 2021年第30期89卷 45-51页

作者： zhiyu chen Juan Li Jing Tang Fujie Zhang Yan Zhong Hangtian Liu Ran Ang Key Laboratory of Radiation Physics and Technology Ministry of EducationInstitute of Nuclear Science and TechnologySichuan UniversityChengdu610064China Interdisciplinary Materials Research Center School of Materials Science and EngineeringTongji UniversityShanghai201804China Institute of New Energy and Low-Carbon Technology Sichuan UniversityChengdu610065Chin

The discovery of band convergence has opened an effective avenue for significantly enhancing thermoelectric performance of SnTe,while alloying CdTe in SnTe is evidenced efficient for improving the valley ***,the thermoelectric transport properties are limited due to the low solubility of CdTe in SnTe(~3%).Inspired by the improvement of dimensionless figure of merit zT in Cu or Se-doped SnTe,investigating the effect of Cu_(2)Se on the electronic and phonon transport properties of SnTe-CdTe alloys is highly ***,improving the quality factor can trigger an increase of the potential of a compound for higher zT,which is of importance for design of thermoelectric ***,alloyed 3%Cu_(2)Se in SnTe-3%CdTe system enables an increased peak zT,which is attributed by the optimization of electronic performance(~21μW cm^(-1)K^(-2)at 800 K),as well as the decreased lattice thermal conductivity owing to the enhanced mass and strain *** importantly,alloying Cu_(2)Se not only improves the quality factor from~0.25 to~0.45,resulting in a higher maximum potential zT,but also effectively preserves the Fermi energy in a relative optimized *** current findings demonstrate the role of Cu_(2)Se for manipulating thermoelectrics in SnTe.

关键词： SnTe Thermoelectrics Quality factor Fermi level

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

Optimal Energy Efficiency Resource Allocation Strategy for Cognitive Clustering Network under PUEA Attack

引用

China Communications 2020年第10期17卷 249-263页

作者： Linna Hu Ning Cao Rui Shi Xue Cai Minghe Mao zhiyu chen Computer&Information College Hohai UniversityNanjing 210098China Nanjing University of Science&Technology Zijin College Nanjing 210023China State Grid Information&Telecommunication Branch State Grid Corporation of ChinaBeijing 100761China School of Electronic and Information Engineering Suzhou universitySuzhou 215006China

5G has pushed the use of radio spectrum to a new level,and cognitive clustering network can effectively improve the utilization of radio spectrum,which is a feasible way to solve the growing demand for wireless ***,cognitive clustering network is vulnerable to PUEA attack,which will lead to the degradation of system detection performance,thereby reducing the energy *** at these problems,this paper investigates the optimal energy efficiency resource allocation scheme for cognitive clustering network under PUEA attack.A cooperative user selection algorithm based on selection factor is proposed to effectively resist PUEA user attack and improve detection *** construct the energy efficiency optimization problem under multi-constraint conditions and transform the nonlinear programming problem into parametric programming problem,which is solved by Lagrangian function and Karush-Kuhn-Tucker *** the sub-gradient iterative algorithm based on optimal energy efficiency under PUEA attack is proposed and its complexity is *** results indicate that proposed method is effective when subjected to PUEA attacks,and the impact of different parameters on energy efficiency is analyzed.

关键词： cognitive clustering network energy efficiency resource allocation PUEA cooperative user selection

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

Optimal Energy-Efficient Transmission for Hybrid Spectrum Sharing in Cooperative Cognitive Radio Networks

引用

China Communications 2019年第6期16卷 150-161页

作者： Linna Hu Rui Shi Minghe Mao zhiyu chen Hongxi Zhou Weiliang Li Computer&Information College Hohai UniversityNanjing 210098China Nanjing University of Science&Technology Zijin College Nanjing 210023China State Grid Information&Telecommunication Branch State Grid Corporation of ChinaBeijing 100761China

In order to improve the energy efficiency(EE)in cognitive radio(CR),this paper investigates the joint design of cooperative spectrum sensing time and the power control optimization problem for the secondary user systems to achieve the maximum energy efficiency in a cognitive network based on hybrid spectrum sharing,meanwhile considering the maximum transmit power,user quality of service(QoS)requirements,interference limitations,and primary user *** optimization of energy efficient sensing time and power allocation is formulated as a non-convex optimization *** Dinkelbach’s method is adopted to solve this problem and to transform the non-convex optimization problem in fractional form into an equivalent optimization problem in the form of ***,an iterative power allocation algorithm is proposed to solve the optimization *** simulation results show the effectiveness of the proposed algorithms for energy-efficient resource allocation in the cognitive network.

关键词： cognitive radio networks cooperative spectrum sensing energy-efficiency hybrid spectrum sharing power control sensing time optimization

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

WEAR AND SEALING CHARACTERISTICS OF ENGINE VALVE GUIDE

引用

Chinese Journal of Mechanical Engineering 2005年第3期18卷 434-438页

作者： Qu Shengguan Xia Wei Han Lifa Xiao zhiyu chen Weiping LiYuanyuan College of Mechanical Engineering South China University of Technology Guangzhou 510640 China

A novel powder metallurgy （P/M） material with high wear resistance is developed in order to decrease the wear and lubricant-leakage of a diesel engine valve guide. The friction and wear tests of this material are conducted. It indicates that the wear resistance of the newly developed P/M material has been improved and much better than that of the formerly used alloy steel. Moreover, three different sealing structures are designed and theoretically analyzed with respect to the characteristic of hydrodynamic sealing. Through comparative experiments of component leakage and engine run-in for different valve guide structures, it proves that the structure with a machined sealing groove but not installed with a seal-ring cannot only reduce the specific lubricant consumption （SLC） of cylinder head, but also decrease the wear of valve stern and valve guide.

关键词： Engine valve guide Powder metallurgy material Friction and wear Sealing

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

Negative effects of artiffcial nest boxes on birds:A review

引用

Avian Research 2023年第2期14卷 257-266页

作者： Luchang Zhang Xingjian Ma zhiyu chen Chunying Wang Zicheng Liu Xiang Li Xiaoying Xing College of Wildlife and Protected Area Northeast Forestry UniversityHarbin150040China Northeast Asia Biodiversity Research Center Harbin150040China Heilongjiang Luobei Dulu River Wetland Nature Reserve Administration Hegang154200China Heilongjiang Taipinggou National Nature Reserve Administration Hegang154200China Dalian Environmental Monitoring Center Dalian116023China

Artificial nest boxes are placed to attract birds to nest and breed in a specific location,and they are widely used in avian ecology research and in the attraction of insectivorous *** is evidence that artificial nest boxes can adversely affect breeding fitness but no great focus has been placed on this issue by ***,we retrieved 321 research papers regarding artificial nest boxes published from 2003 to 2022 and used the'Biblioshiny'program to extract and integrate keywords;we then summarized the adverse effects of artificial nest boxes on avian breeding *** studies highlighted many drawbacks and misuses in the designing and placement of nest boxes;furthermore,bird attraction was decreased by their inappropriate selection,thus reducing breeding *** nest box production,there were shortcomings in the construction material,color,smell,and structural design of the boxes *** boxes were also placed at inappropriate densities,locations,orientations,heights,and managed ***,we propose suggestions for more efficient and safer artificial nest boxes for future use in avian ecology research and bird conservation.

关键词： Artificial nest box Avian breeding Management Negative effect Nest box hanging Nest box location Nest box structure

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

Reusable electrochemical non-enzymatic glucose sensors based on Au-inlaid nanocages

引用

Nano Research 2022年第7期15卷 6490-6499页

作者： Lu Shen Zhen Liang zhiyu chen Can Wu Xuefeng Hu Jieyu Zhang Qing Jiang Yunbing Wang National Engineering Research Center for Biomaterials Sichuan UniversityChengdu 610065China

Mass detection of glucose,which is required in many applications,remains *** commercial enzyme-based glucose test strips cannot be reused,and current non-enzymatic glucose sensors exhibit a narrow range of detection and slow glucose oxidation ***,controlled etching of Prussian blue analogue(PBA)nanocubes at the vertices is conducted and Au nanoparticles(Au NPs)are subsequently inlaid in the etched cavities by in-situ reduction of *** unique AuNP-PBA nanocomplexes exhibit low electrochemical potential for glucose oxidation,high electrocatalytic activity,and rapid redox electron transfer *** immobilization of the Au-inlaid nanomaterials on a fine Au wire leads to a non-enzymatic glucose sensor with a particularly wide linear detection range(10μM to 16 mM),excellent anti-interference,and fast *** importantly,the sensor is reusable,and its sensitivity is well maintained even after 150 times of *** new-concept material promises to enable high-throughput glucose detection at a low cost,which is essential in diabetic management and other healthcare applications.

关键词： non-enzymatic glucose sensors Prussian blue analogues gold nanoparticles electrochemistry reusable sensors

来源：

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

Real-time effects of nicotine exposure and withdrawal on neurotransmitter metabolism of hippocampal neuronal cells by microfluidic chip-coupled LC-MS

引用

Chinese Chemical Letters 2022年第6期33卷 3101-3105页

作者： zhiyu chen Lei Fu Xin-An Liu Zhiyi Yang Wenbo Li Fang Li Qian Luo Institute of Biomedical and Health Engineering Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhen 518055China University of Chinese Academy of Sciences Beijing 100049China Shenzhen Engineering Laboratory of Single-molecule Detection and Instrument Development Shenzhen 518055China Guangdong Provincial Key Laboratory of Brain Connectome and Behavior CAS Key Laboratory of Brain Connectome and Manipulationthe Brain Cognition and Brain Disease Institute(BCBDI)Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research InstitutionsShenzhen 518055China

Nicotine ingested from smoking exerts neuroprotection and developmental neurotoxicity in central nervous *** can produce several changes of cognitive behaviors through regulating the release of different neurotransmitters in the ***,the effects of nicotine exposure or withdrawal on neurotransmitter metabolism of hippocampus are still *** this study,we real-time evaluated the dynamic alterations in neurotransmitter metabolism of hippocampal neuronal(HT22)cells induced by nicotine exposure and withdrawal at relevant exposure levels of smoking and secondhand smoke by using a microfluidic chip-coupled with liquid chromatography-mass spectrometry(MC-LC-MS)*** found HT22 cells mainly released related neurotransmitters of tryptophan and choline metabolism,both nicotine exposure and withdraw altered its neurotransmitters and their metabolites *** to nicotine mainly altered the secretion of serotonin,kynurenic acid,choline and acetylcholine of HT22 cells to improve hippocampal dependent cognition,and the change are closely related to the dose and duration of ***,the altered metabolites could rapidly recover after nicotine withdrawal,but picolinic acid was ***-LC-MS system used in present study showed a greater advantage to detect unstable metabolites than conventional method by using in vitro model,and the results of dynamic alterations of neurotransmitter metabolism induced by nicotine might provide a potential targets for drug development of neuroprotection or cognitive improvement.

关键词： Nicotine Microfluidic chip-coupled LC-MS Hippocampal neuronal cells Neurotransmitter metabolism Cognition

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

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：