检索结果-南通市图书馆

Exceptional catalytic effect of novel rGO-supported Ni-Nb nanocomposite on the hydrogen storage properties of MgH_(2)

引用

Journal of Materials Science & Technology 2024年第5期172卷 83-93页

作者： Samuel Guemou liuting Zhang Shuai li Yiqun Jiang Tao Zhong Zichuan Lu Ren Zhou Fuying Wu qian li School of Energy and Power Instrumental Analysis CenterJiangsu University of Science and TechnologyZhenjiang 212003China National Engineering Research Center for Magnesium Alloys&National Key Laboratory of Advanced Casting Technologies&College of Materials Science and Engineering Chongqing UniversityChongqing 400044China Chongqing Institute of New Energy Storage Materials and Equipment Chongqing 401135China Max Planck Institute for Iron Research Düsseldorf 40237Germany

The design of an excellent active catalyst to improve the sluggish kinetic and thermodynamic properties of magnesium hydride(MgH_(2))remains a great challenge to achieve its practical *** this study,a novel Ni-Nb/rGO nanocomposite catalyst was successfully prepared by one-spot hydrothermal and sub-sequent calcination *** novel Ni-Nb/rGO nanocomposite exhibits an exceptional catalytic effect on improving MgH_(2) sorption ***,the onset desorption temperature of MgH_(2)+10 wt%Ni-Nb/rGO composite is reduced to 198℃,much lower than that of undoped MgH_(2)(330℃).In-terestingly,the composite can release 5.0,5.9,and 6.0 wt%H_(2) within 10 min at 245,260,and 275℃,***,the dehydrogenated MgH_(2)+10 wt%Ni-Nb/rGO composite starts to absorb hydrogen even at room temperature with approximate 2.75 wt%H_(2) uptake at 75℃under 3 MPa H_(2) pressure within 30 min and exhibits excellent stability by maintaining 6.0 wt%hydrogen content after 20 cycles at 300℃.Chou’s model suggests that the de/hydrogenation kinetics of Ni-Nb/rGO-modified MgH_(2) switches from surface penetration model to diffusion model at lower ***,the ac-tivation energies(E a)for the de/hydrogenation of MgH_(2)+10 wt%Ni-Nb/rGO are reduced to 57.8 kJ/mol and 33.9 kJ/mol,which are significantly lower than those of undoped MgH_(2).The work demonstrates that the addition of a novel ternary Ni-Nb/rGO catalyst is an effective strategy to not only boost the sorption kinetics of MgH_(2) but also maintain its cycling property.

关键词： Hydrogen storage materials Magnesium hydride Ni-Nb/rGO Kinetic analysis Catalytic mechanism

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

Photocatalytic oxidation of methane to methanol over zinc titanate supported silver catalysts

引用

Journal of Rare Earths 2024年第5期42卷 899-906,I0004页

作者： Yuyan Gan Jinbi Huang qian Lv Yanru li lizhi Wu YU Tang Yuanxing Fang Pengfei Zhu li Tan Institute of Molecule Catalysis and In-Situ/Operando Studies State Key Laboratory of Photocatalysis on Energy and EnvironmentCollege of ChemistryFuzhou UniversityFuzhou350108China School of Environmental Science and Engineering Shaanxi University of Science and TechnologyXi'an 70021China

The direct activation of methane under mild condition to achieve highly selective of oxygenates is a challenging *** this study,a well dispersed silver supported ZnTiO_(3) catalyst was prepared to achieve selective preparation of methanol from methane and water under mild condition.X-ray diffraction,transmission electron microscopy and X-ray photoelectron spectroscopy characterizations demonstrate that silver species are uniformly dispersed on ZnTiO_(3) surface in the form of metallic silver *** photoelectric characterizations reveal that the addition of silver species enhances light absorption and promotes charge separation of the *** the reaction conditions of 50℃and 3 MPa,the methanol is obtained as the only liquid product over the designed Ag/ZnTiO_(3) catalyst under light *** this photocatalytic process,the holes generated by ZnTiO_(3) activate water to produce intermediate·OH,which further reacts with methane to synthesize *** silver species as co-catalysts extend the light absorption range of ZnTiO_(3) as well as promote charge separation.

关键词： Photocatalytic Methane oxidation Zinc titanate Silver Methanol

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

Construction of core@double-shell structured energetic composites with simultaneously enhanced thermal stability and safety performance

引用

Defence Technology（防务技术） 2024年第4期34卷 134-142页

作者： Peng Wang Wen qian Ruolei Zhong Fangfang He Xin li Jie Chen li Meng Yinshuang Sun Guansong He Institute of Chemical Materials China Academy of Engineering PhysicsMianyang 621900China State Key Laboratory of Environment-friendly Energy Materials School of Materials and ChemistrySouthwest University of Science and TechnologyMianyang 621010China

The poor thermal stability and high sensitivity severely hinder the practical application of hexanitrohexaazaisowurtzitane(CL-20).Herein,a kind of novel core@double-shell CL-20 based energetic composites were fabricated to address the above *** coordination complexes which consist of natural polyphenol tannic acid(TA) and Fe~Ⅲ were chosen to construct the inner shell,while the graphene sheets were used to build the outer *** resulting CL-20/TA-Fe~Ⅲ/graphene composites exhibited simultaneously improved thermal stability and safety performance with only 1 wt% double-shell content,which should be ascribed to the intense physical encapsulation effect from inner shell combined with the desensitization effect of carbon nano-materials from outer *** phase transition(ε to γ) temperature increased from 173.70 ℃ of pure CL-20 to 191.87℃ of CL-20/TA-Fe~Ⅲ/graphene ***,the characteristic drop height(H_(50)) dramatically increased from 14.7 cm of pure CL-20 to112.8 cm of CL-20/TA-Fe~Ⅲ/graphene composites,indicating much superior safety performance after the construction of the double-shell *** general,this work has provided an effective and versatile strategy to conquer the thermal stability and safety issues of CL-20 and contributes to the future application of high energy density energetic materials.

关键词： CL-20 Double-shell structure Thermal stability Safety performance Tannic acid Graphene sheets

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

Biomimetic chitin hydrogel via chemical transformation

引用

Nano Research 2024年第2期17卷 771-777页

作者： Rui-Rui liu qian-qian Shi Yu-Feng Meng Yong Zhou li-Bo Mao Shu-Hong Yu Division of Nanomaterials&Chemistry Hefei National Research Center for Physical Sciences at the MicroscaleDepartment of ChemistryInstitute of Biomimetic Materials&ChemistryAnhui Engineering Laboratory of Biomimetic MaterialsUniversity of Science and Technology of ChinaHefei 230026China College&Hospital of Stomatology Key Laboratory of Oral Diseases Research of Anhui ProvinceAnhui Medical UniversityHefei 230032China Department of Dental Implantology College&Hospital of StomatologyAnhui Medical UniversityHefei 230032China

Chitin hydrogel has been recognized as a promising material for various biomedical applications because of its biocompatibility and ***,the fabrication of strong chitin hydrogel remains a big challenge because of the insolubility of chitin in many solvents and the reduced chain length of chitin regenerated from *** herein introduce the fabrication of chitin hydrogel with biomimetic structure through the chemical transformation of chitosan,which is a water-soluble deacetylated derivative of *** reacetylation of the amino group in chitosan endows the obtained chitin hydrogel with outstanding resistance to swelling,degradation,extreme temperature and pH conditions,and organic *** chitin hydrogel has excellent mechanical properties while retaining a high water content(more than 95 wt.%).It also shows excellent antifouling performance that it resists the adhesion of proteins,bacteria,blood,and ***,as the initial chitosan solution can be feasibly frozen and templated by ice crystals,the chitin hydrogel structure can be either nacre-like or wood-like depending on the freezing method of the precursory chitosan *** to these anisotropic structures,such chitin hydrogel can exhibit anisotropic mechanics and mass transfer *** current work provides a rational strategy to fabricate chitin hydrogels and paves the way for its practical applications as a superior biomedical material.

关键词： chitin hydrogel biomimetic structure chemical stability mechanical strength antifouling

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

Two material removal modes in chemical mechanical polishing:mechanical plowing *** bonding

引用

Friction 2024年第5期12卷 897-905页

作者： Yuan WU liang JIANG Wenhui li Jiaxin ZHENG Yushan CHEN linmao qian Tribology Research Institute State Key Laboratory of Rail Transit Vehicle SystemSouthwest Jiaotong UniversityChengdu610031China

With the rapid development of semiconductors,the number of materials needed to be polished sharply *** material properties vary significantly,posing challenges to chemical mechanical polishing(CMP).Accordingly,the study aimed to classify the material removal *** on the CMP and atomic force microscopy results,the six representative metals can be preliminarily classified into two groups,presumably due to different material removal *** the tribology perspective,the first group of Cu,Co,and Ni may mainly rely on the mechanical plowing *** adding H_(2)O_(2),corrosion can be first enhanced and then suppressed,affecting the surface mechanical ***,the material removal rate(MRR)and the surface roughness increase and *** comparison,the second group of Ta,Ru,and Ti may primarily depend on the chemical bonding *** H_(2)O_(2)can promote oxidation,increasing interfacial chemical ***,the MRR increases,and the surface roughness decreases and levels *** addition,CMP can be regulated by tuning the synergistic effect of oxidation,complexation,and dissolution for mechanical plowing,while tuning the synergistic effect of oxidation and ionic strength for chemical *** findings provide mechanistic insight into the material removal mechanism in CMP.

关键词： Chemical mechanical polishing corrosion wear material removal mode mechanical plowing chemical bonding

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

Equilibrium Reinsurance Strategy and Mean Residual life Function

引用

Acta Mathematicae Applicatae Sinica 2024年第3期40卷 758-777页

作者： Dan-ping li Lv CHEN lin-yi qian Wei WANG School of Statistics Key Laboratory of Advanced Theory and Application in Statistics and Data Science-MOEEast China Normal UniversityShanghai 200062China Academy of Statistics and Interdisciplinary Sciences Key Laboratory of Advanced Theory and Application in Statistics and Data Science-MOEEast China Normal UniversityShanghai 200062China School of Mathematics and Statistics Ningbo UniversityNingbo 315211China

In this paper,we analyze the relationship between the equilibrium reinsurance strategy and the tail of the distribution of the *** Mean Residual life(MRL)has a close relationship with the tail of the distribution,we consider two classes of risk distributions,Decreasing Mean Residual life(DMRL)and Increasing Mean Residual life(IMRL)distributions,which can be used to classify light-tailed and heavy-tailed distributions,*** assume that the underlying risk process is modelled by the classical CramérLundberg model *** the mean-variance criterion,by solving the extended Hamilton-Jacobi-Bellman equation,we derive the equilibrium reinsurance strategy for the insurer and the reinsurer under DMRL and IMRL,***,we analyze how to choose the reinsurance premium to make the insurer and the reinsurer agree with the same reinsurance *** find that under the case of DMRL,if the distribution and the risk aversions satisfy certain conditions,the insurer and the reinsurer can adopt a reinsurance premium to agree on a reinsurance strategy,and under the case of IMRL,the insurer and the reinsurer can only agree with each other that the insurer do not purchase the reinsurance.

关键词： mean residual life excess-of-loss reinsurance insurer reinsurer stochastic control

来源：

维普期刊数据库

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

Causal temporal graph attention network for fault diagnosis of chemical processes

引用

Chinese Journal of Chemical Engineering 2024年第6期70卷 20-32页

作者： Jiaojiao Luo Zhehao Jin Heping Jin qian li Xu Ji Yiyang Dai School of Chemical Engineering Sichuan UniversityChengdu 610065China China Three Gorges Corporation Beijing 100038China

Fault detection and diagnosis(FDD)plays a significant role in ensuring the safety and stability of chemical *** the development of artificial intelligence(AI)and big data technologies,data-driven approaches with excellent performance are widely used for FDD in chemical ***,improved predictive accuracy has often been achieved through increased model complexity,which turns models into black-box methods and causes uncertainty regarding their *** this study,a causal temporal graph attention network(CTGAN)is proposed for fault diagnosis of chemical processes.A chemical causal graph is built by causal inference to represent the propagation path of *** attention mechanism and chemical causal graph were combined to help us notice the key variables relating to fault *** in the Tennessee Eastman(TE)process and the green ammonia(GA)process showed that CTGAN achieved high performance and good explainability.

关键词： Chemical processes Safety Fault diagnosis Causal discovery Attention mechanism Explainability

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

Effects of combustion temperature on the optical properties of brown carbon from biomass burning

引用

Journal of Environmental Sciences 2024年第3期137卷 302-309页

作者： Peng Gao Rule Deng Song Jia Yue li Xuefei Wang qian Xing School of Chemistry Sciences University of Chinese Academy of SciencesBeijing 100049China College of Chemistry and Materials Engineering Beijing Technology and Business UniversityBeijing 100048China

Biomass burning has been known as one of main sources of Brown Carbon(BrC)in *** this study,by controlling the combustion temperature at 250℃,350℃,and 450℃,the methanol soluble organic carbon(MSOC)and methanol insoluble carbon(MISC)from pine wood burning was collected by ***–Vis,excitation emission matrix(EEM),TEM and FTIR spectra were applied to investigate the properties of BrC *** MSOC at 250℃ and 350℃,all the spectral profiles of UV–Vis absorption and excitation emission matrix are almost the same,while the EEM of MSOC at 450℃ are different from that of the other *** MISC fuorescence was observed only in the case of 450℃.In the FTIR spectra,with the temperature increasing the peaks associated to the oxygen-contained functions was weakened,indicating the formation of the fuorophores with larger conjugated system,especially aromatic *** results show that biomass combustion at low temperature produces more oxygen-riched BrC,which possesses relatively lower light absorption,while at high temperature produces more aromatics hydrocarbons with relatively strong light *** results of this work are helpful to trace the source of brown carbon and optimize biomass energy utilization.

关键词： Biomass burning Combustion temperature Methanol-soluble brown carbon EEM Impinger

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

An improved positioning model of deep-seafloor datum point at large incidence angle

引用

Journal of Oceanology and limnology 2024年第1期42卷 90-100页

作者： qianqian li Shoulian CAO Fanlin YANG Yu LUO qian TONG College of Underwater Acoustic Engineering Harbin Engineering UniversityHarbin 150000China College of Geodesy and Geomatics Shandong University of Science and TechnologyQingdao 266590China Key Laboratory of Ocean Geomatics Ministry of Natural ResourcesQingdao 266590China

The inhomogeneous sound speed in seawater causes refraction of sound waves,and the elimination of the refraction effect is essential to the accuracy of underwater acoustic *** raytracing method is an indispensable tool for effectively handling ***,this method has a conflict between localization accuracy and computational *** equivalent sound speed profile(ESSP)method uses a simple sound speed profile(SSP)instead of the actual complex SSP,which can improve positioning precision but with residual *** residual error is especially non-negligible in deep water and at large beam incidence *** analyzing the residual error of the ESSP method through a simulation,an empirical formula of error is *** data collected in the sailing circle mode(large incidence angle)of the South China Sea are used for *** experiments show that compared to the ESSP method,the improved algorithm has higher positioning precision and is more efficient than the ray-tracing method.

关键词： underwater acoustic positioning seafloor datum points large incident angle equivalent sound speed profile(ESSP) deep water

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

Impacts of Water-Sediment Regulation Scheme on Chromophoric Dissolved Organic Matter in the Lower Yellow River

引用

Journal of Ocean University of China 2024年第2期23卷 455-466页

作者： liU Xiao JIANG Xueyan liU qian SUI Juanjuan ZOU li Key Laboratory of Marine Chemistry Theory and Technology of Ministry of Education Ocean University of ChinaQingdao 266100China College of Chemistry and Chemical Engineering Ocean University of ChinaQingdao 266100China School of Earth Sciences University of BristolBristolBS81RJUK North China Sea Environmental Monitoring Center State Oceanic AdministrationQingdao 266033China Key Laboratory of Ecological Prewarning Protection and Restoration of Bohai SeaMinistry of Natural ResourcesQingdao 266033China Key Laboratory of Marine Environment and Ecology of Ministry of Education Ocean University of ChinaQingdao 266100China College of Environmental Science and Engineering Ocean University of ChinaQingdao 266100China

As a river with more than 3000 reservoirs in its watershed,the Yellow River has been affected by dams not only on the sediment load,but also on the water ***-sediment regulation scheme(WSRS),which has been carried out annually in the Yellow River since 2002,is a typical human activity affecting river water *** dissolved organic matter(CDOM)in river is susceptible to changes in ecological and environmental conditions as well as human ***,we report variations in dissolved organic carbon concentrations,compositions and sources of CDOM in time series samples in the lower Yellow River during *** addition,a parallel factor fluorescence analysis(PARAFAC)method is applied to identify different fluorescent components in water samples during WRSR,showing four major components including tryptophan-like component(C1),microbial humic-like component(C2),terrestrial humic-like component(C3)and tyrosine-like component(C4).In general,C1 increased after water regulation,while C2 and C3 increased after sediment regulation,indicating that the water and sediment released by the dam have different effects on CDOM *** the impacts of the dam,source of CDOM in the lower Yellow River is mainly autochthonous related to microbial activities,and is regulated by the terrestrial input during WSRS *** resuspension inhibits microbial activities and reduces the production of autochthonous ***,human activities especially WSRS,as exemplified here,significantly alter the quality and quantity of CDOM in the lower Yellow River,affecting CDOM dynamics and biogeochemical processes in the estuarine environment.

关键词： chromophoric dissolved organic matter(CDOM) water-sediment regulation scheme(WSRS) Yellow River optical properties

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：