检索结果-南通市图书馆

High-stability spherical lanthanide nanoclusters for magnetic resonance imaging

National Science Review 2023年第4期10卷 123-132页

作者： Hai-Ling Wang Donglin Liu Jian-Hua Jia Jun-Liang Liu Ze-Yu Ruan Wei Deng Shiping Yang Si-Guo Wu Ming-Liang Tong Key Laboratory of Bioinorganic and Synthetic chemistry of Ministry of Education School of Chemistry Sun Yat-sen University College of chemistry and Materials Science Shanghai Normal University

High-nuclear lanthanide clusters have shown great potential for the administration of high-dose mononuclear gadolinium chelates in magnetic resonance imaging(MRI). The development of high-nuclear lanthanide clusters with excellent solubility and high stability in water or solution has been challenging and is very important for expanding the performance of MRI. We used N-methylbenzimidazole-2-methanol(HL) and LnCl3·6H2O to synthesize two spherical lanthanide clusters, Ln32(Ln = Ho, Ho32; and Ln =Gd, Gd32), which are highly stable in solution. The 24 ligands L-are all distributed on the periphery of Ln32and tightly wrap the cluster core, ensuring that the cluster is stable. Notably, Ho32can remain highly stable when bombarded with different ion source energies in HRESI-MS or immersed in an aqueous solution of different pH values for 24 h. The possible formation mechanism of Ho32was proposed to be Ho(Ⅲ),(L)-and H2O → Ho3(L)3/Ho3(L)4→ Ho4(L)4/Ho4(L)5→ Ho6(L)6/Ho6(L)7→ Ho16(L)19→Ho28(L)15→ Ho32(L)24/Ho32(L)21/Ho32(L)23. To the best of our knowledge, this is the first study of the assembly mechanism of spherical high-nuclear lanthanide clusters. Spherical cluster Gd32, a form of highly aggregated Gd(Ⅲ), exhibits a high longitudinal relaxation rate(1 T, r1= 265.87 mM-1·s-1). More notably, compared with the clinically used commercial material Gd-DTPA, Gd32has a clearer and higher-contrast T1-weighted MRI effect in mice bearing 4T1 tumors. This is the first time that high-nuclear lanthanide clusters with high water stability have been utilized for MRI. High-nuclear Gd clusters containing highly aggregated Gd(Ⅲ) at the molecular level have higher imaging contrast than traditional Gd chelates; thus, using large doses of traditional gadolinium contrast agents can be avoided.

关键词： T1-weighted MRI lanthanide clusters high stability low toxicity assembly mechanism

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

高碘酸根分子钙钛矿作为新型含能杀菌剂

引用

Science China Materials 2023年第4期66卷 1641-1648页

作者：余志鸿刘德轩凌钰怡陈晓娴尚宇陈劭力叶子铭张伟雄陈小明 MOE Key Laboratory of Bioinorganic and Synthetic chemistry School of ChemistrySun Yat-Sen UniversityGuangzhou 510275China

近年来,病原体引起的流行病频发,对含能杀菌剂提出了迫切需求;它们可通过爆炸性反应快速地大面积抛洒以单质碘为主的高效广谱杀菌物质,但其高碘含量与高爆性能难以同时兼得.在此,我们报道了一类新型含能杀菌剂——多碘分子钙钛矿:(H_(2)... 详细信息

近年来,病原体引起的流行病频发,对含能杀菌剂提出了迫切需求;它们可通过爆炸性反应快速地大面积抛洒以单质碘为主的高效广谱杀菌物质,但其高碘含量与高爆性能难以同时兼得.在此,我们报道了一类新型含能杀菌剂——多碘分子钙钛矿:(H_(2)dabco)M(IO_(4))_(3)(dabco=1,4-二氮杂双环[2.2.2]辛烷,M=Na^(+)/K^(+)/Rb^(+)/NH_(4)^(+)分别对应DAI-1/2/3/4)和(H_(2)dabco)Na(H_(4)IO_(6))_(3)(DAI-X1).这些化合物具有立方钙钛矿结构,不仅具有高碘含量(49–54wt%),而且具有较高的爆速(6.331–6.558 km s^(-1))和爆压(30.69–30.88 GPa).特别地,DAI-4具有高达54.0 wt%的碘含量,以及6.558 km s^(-1)的爆速.激光扫描共聚焦显微镜观察和标准微量肉汤稀释法实验表明,DAI-4的爆炸产物对细菌(大肠杆菌、金黄色葡萄球菌和铜绿假单胞菌)具有广谱杀菌性.这类基于高碘酸根的分子钙钛矿具有易于放大合成、低成本、高爆轰性能和高碘含量的优点,是极具潜力的新型含能杀菌剂.

关键词：激光扫描共聚焦显微镜广谱杀菌碘含量钙钛矿碘分子爆炸产物爆轰性能单质碘

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

PCK Study of Middle school chemistry Teachers in Yan'an Based on the Core Quality of chemistry Subject

引用

Journal of Contemporary Educational Research 2020年第11期4卷 15-19页

作者： Hua Yang Meng-jiao Tuo Rui-zhu Xu Shu-jun Hou School of Chemistry and Chemical Engineering Yan'an UniversityYan'an 716000Shaanxi ProvinceChina

The new round of curriculum reform requires the promotion on the development of students'core literacy,and how the core literacy of chemistry can take root in the chemistry classroom is inseparable from the guidance and nurture of teachers in the teaching process.The"Professional Standards for Secondary school Teachers"clearly stipulates that pedagogical content knowledge(PCK)is regarded as the professional knowledge of teachers.PCK is the core content of teachers'professional knowledge and an important guarantee for teachers to carry out teaching activities.Teachers5 PCK level is not only a direct measure of their teaching achievements,but also an important criterion for guiding novice teachers to become experienced teachers.The research subjects selected for this study are the middle school chemistry teachers in Yan'an City.By using the Delphi method to investigate the understanding of Yan'an middle school chemistry teachers on the core literacy of chemistry and to explore the PCK mastery of middle school chemistry teachers at different stages,it serves to deepen the Yan'an middle school chemistry teachers5 own knowledge and learning of PCK while help to promote the improvement of the teaching level and professional development of chemistry teachers in Yan'an middle schools.At the end of the paper,the relevant suggestions made based on the investigation of the chemistry PCK study of middle school chemistry teachers in Yan'an City on the core literacy of the chemistry subject will improve the overall building level of the middle school chemistiy teachers of Yan'an City.

关键词： Chemistiy subject core literacy Middle school chemistry teacher Pedagogical content knowledge

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

New progress in zeolite synthesis and catalysis

引用

National Science Review 2022年第9期9卷 102-119页

作者： Hao Xu Peng Wu Shanghai Key Laboratory of Green chemistry and Chemical Processes School of Chemistry and Molecular Engineering East China Normal University

The rational design synthesis of zeolite catalysts with effective,environmentally benign and atom-economic routes is a major topic in the field of microporous materials,as it would avoid the high labor cost and inefficiency of traditional trial-and-error methods in developing new structures and dispel environmental concerns regarding the industrial mass production of zeolites.Catalytic applications of zeolite materials have expanded from conventional single functionalities,such as solid acids or selective oxidation catalysts to bi/multifunctionalities through combination with metals or metal oxides.This is a response to new re quirements from petro chemical and fine chemical industries,such as precise control of product distribution,conversion of low-carbon resources for chemical production,and solutions to increasingly severe environmental problems related to CO2and NOx.Thus,based on the systematic knowledge of zeolite chemistry and science that researchers have acquired in the past half-century and the development re quirements,remarkable progress has been made in zeolite synthesis and catalysis in the past 10 years.This includes the manipulation of zeolitic monolayers derived from layered zeolites and germanosilicates to construct novel zeolite materials and effective and green zeolite syntheses as well as the synergistic interaction of zeolites and metal/metal oxides with different space distributions in the conversion of low-carbon resources.With many zeolite catalysts and catalytic processes being developed,our understanding of the close relationship between zeolite synthesis,structure and catalytic properties has deepened.Researchers are gradually approaching the goal of rationally designing zeolite catalysts with precisely controlled activity and selectivity for particular applications.

关键词： layered zeolite germanosilicates green synthesis fast synthesis bifunctional catalytic system metal confined in zeolite

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

Photodegradable polar-functionalized polyethylenes

引用

National Science Review 2023年第7期10卷 124-133页

作者： Chaoqun Wang Jian Xia Yuxing Zhang Xiaoqiang Hu Zhongbao Jian State Key Laboratory of Polymer Physics and chemistry Changchun Institute of Applied Chemistry Chinese Academy of Sciences school of Applied chemistry and Engineering University of Science and Technology of China

The degradation of plastics has attracted much attention from the global community.Polyethylenes(PEs),as the most abundant synthetic plastics,are most frequently studied.PE is non-degradable and non-polar because of the sole presence of the pure hydrocarbon components.Concurrent incorporation of both in-chain cleavable and functional groups into the PE chain is an effective pathway to overcome the non-degradable and non-polar issue;however,the method for achieving this pathway remains elusive.Here,we report a strictly non-alternating(>99%) terpolymerization of ethylene with CO and fundamental polar monomers via a coordination-insertion mechanism using late transition metal catalysts,which effectively prevents the formation of undesired chelates originating from both co-monomers under a low CO concentration.High-molecular-weight linear PEs with both in-chain isolated keto(>99%) and main-chain functional groups are prepared.The incorporation of key low-content isolated keto groups makes PEs photodegradable while retaining their desirable bulk material properties,and the introduction of polar functional groups considerably improves their surface properties.

关键词： degradable plastic homogeneous catalysis C1 chemistry non-alternating copolymerization polyolefin

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

Sn-doped BiOCl nanosheet with synergistic H^(+)/Zn^(2+)co-insertion for“rocking chair”zinc-ion battery

引用

Journal of Energy chemistry 2023年第6期81卷 623-632,I0014页

作者： Yuzhu Qian Hongrui Wang Xinni Li Ting Song Yong Pei Li Liu Bei Long Xiongwei Wu Xianyou Wang School of Chemistry Xiangtan UniversityXiangtan 411105HunanChina School of Chemistry and Materials Science Hunan Agricultural UniversityChangsha 410128HunanChina

The development of insertion-type anodes is the key to designing“rocking chair”zinc-ion batteries.However,there is rare report on high mass loading anode with high performances.Here,{001}-oriented Bi OCl nanosheets with Sn doping are proposed as a promising insertion-type anode.The designs of cross-linked CNTs conductive network,{001}-oriented nanosheet,and Sn doping significantly enhance ion/electron transport,proved via experimental tests and theoretical calculations(density of states and diffusion barrier).The H^(+)/Zn^(2+)synergistic co-insertion mechanism is proved via ex situ XRD,Raman,XPS,and SEM tests.Accordingly,this optimized electrode delivers a high reversible capacity of 194 m A h g^(-1)at 0.1 A g^(-1)with a voltage of≈0.37 V and an impressive cyclability with 128 m A h g^(-1)over 2500 cycles at 1 A g^(-1).It also shows satisfactory performances at an ultrahigh mass loading of 10 mg cm^(-2).Moreover,the Sn-Bi OCl//MnO_(2)full cell displays a reversible capacity of 85 m A h g^(-1)at 0.2 A g^(-1)during cyclic test.

关键词： Sn-doped BiOCl nanosheet High mass loading anode Synergistic H^(+)/Zn^(2+)co-insertion Fast ionic/electronic diffusion “Rocking chair”zinc-ion battery

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

导热/吸波一体化高分子复合材料的研究进展和机理分析

引用

Science Bulletin 2023年第11期68卷 1195-1212,M0004页

作者：郭永强阮坤鹏王广胜顾军渭 School of Chemistry Beihang UniversityBeijing 100191China Shaanxi Key Laboratory of Macromolecular Science and Technology School of Chemistry and Chemical EngineeringNorthwestern Polytechnical UniversityXi’an 710072China

高分子复合材料由于其功能多样、性能稳定、可加工性强等优点,在电子电气领域具有重要的应用.随着5G时代电子产品的小型化和高功率化发展,导致其狭小内部空间的热积聚和电磁波辐射问题愈发严重,传统解决方法是分别使用导热和电磁波吸收... 详细信息

高分子复合材料由于其功能多样、性能稳定、可加工性强等优点,在电子电气领域具有重要的应用.随着5G时代电子产品的小型化和高功率化发展,导致其狭小内部空间的热积聚和电磁波辐射问题愈发严重,传统解决方法是分别使用导热和电磁波吸收功能高分子复合材料,但是难以满足电子产品的小型化、轻薄化发展趋势对多功能一体化材料的迫切需求.因此,设计制备导热/吸波一体化高分子复合材料对于解决电子产品热积聚和电磁污染问题、适应电子产品发展趋势至关重要.本综述总结了导热/吸波一体化高分子复合材料的最新研究成果,分析了影响其导热/吸波性能的因素,并对其导热/吸波机理做了深入的剖析.着重讨论了制约导热/吸波一体化高分子复合材料发展的若干因素,并针对性地提出了解决方案和发展方向,旨在为高性能导热/吸波一体化高分子复合材料发展提供参考价值.

关键词：高分子复合材料电子产品吸波机理多功能一体化电磁波吸收电磁波辐射电磁污染电子电气

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

Nature-inspired design of droplet-synthesized polymeric nanoelectrode for photoelectrochemical microRNA sensing within single cells

引用

Science Bulletin 2024年第2期69卷 159-162页

作者： Si-Yuan Yu Yi-Li Liu Zheng Li Dechen Jiang Jing-Juan Xu Hong-Yuan Chen Wei-Wei Zhao State Key Laboratory of Analytical chemistry for Life Science School of Chemistry and Chemical EngineeringNanjing UniversityNanjing 210023China

Nanoelectrodes have been shown to be powerful tools for nanoscopic research on single entities,deepening the understanding of heterogeneity and stochastics for single molecules,nanoparticles and cells[1–3].However,despite their importance,current nanoelectrode preparations are highly restrained to flame/electrochemical etching,metal sputtering,electrochemical deposition,etc.[3],resulting in a limited range of materials(mainly gold,platinum and carbon)for potential-resolved detection of redox-active species(Table S1 online).The enrichment of preparation methods to introduce novel materials and mechanisms should prove significant for the development of nanoelectrodes.

关键词： electrode deepening restrained

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

Aggregation-induced emission polymers via reversible-deactivation radical polymerization Special Collection:Distinguished Australian Researchers

Aggregate

引用

Aggregate 2024年第1期5卷 16-46页

作者： Nicholas Kai Shiang Teo Bo Fan Aditya Ardana San H.Thang School of Chemistry Monash UniversityClaytonVictoriaAustralia

Aggregation-induced emission(AIE)is a unique phenomenon whereby aggregation of molecules induces fluorescence emission as opposed to the more commonly known aggregation-caused quenching(ACQ).AIE has the potential to be utilized in the large-scale production of AIE-active polymeric materials because of their wide range of practical applications such as stimuli-responsive sensors,biological imaging agents,and drug delivery systems.This is evident from the increasing number of publications over the years since AIE was first discovered.In addition,the evergrowing interest in this field has led many researchers around the world to develop new and creative methods in the design of monomers,initiators and crosslinkers,with the goal of broadening the scope and utility of AIE polymers.One of the most promising approaches to the design and synthesis of AIE polymers is the use of the reversible-deactivation radical polymerization(RDRP)techniques,which enabled the production of well-controlled AIE materials that are often difficult to achieve by other methods.In this review,a summary of some recent works that utilize RDRP for AIE polymer design and synthesis is presented,including(i)the design of AIE-related monomers,initiators/crosslinkers;the achievements in preparation of AIE polymers using(ii)reversible addition–fragmentation chain transfer(RAFT)technique;(iii)atom transfer radical polymerization(ATRP)technique;(iv)other techniques such as Cu(0)-RDRP technique and nitroxide-mediated polymerization(NMP)technique;(v)the possible applications of these AIE polymers,and finally(vi)a summary/perspective and the future direction of AIE polymers.

关键词： aggregation-induced emission atom transfer radical polymerization nitroxide-mediated polymerization reversible addition–fragmentation chain transfer reversible-deactivation radical polymerization

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

Compositional evolution for mixed aerosols containing gluconic acid and typical nitrate and the effect of multiply factors on hygroscopicity

引用

Journal of Environmental Sciences 2024年第5期139卷 206-216页

作者： Yue Zhu Shufeng Pang Yunhong Zhang School of Chemistry and Chemical Engineering Beijing Institute of TechnologyBeijing 100081China

The aging process of atmospheric aerosols usually leads to a mixture of inorganic salts and organic compounds of anthropogenic origin.In organic compounds,polyhydroxy organic acids are important components,however,the study on composition and hygroscopic properties of the mixture containing inorganics and polyhydroxy organic acids is scanty.In this study,gluconic acid,the proxy of polyhydroxy organic acids,is mixed with the representative nitrate(Mg(NO_(3))_(2),Ca(NO_(3))_(2))to form aerosols.ATR-FTIR and optical microscopy are employed to study the component changes and hygroscopicity as a function of relative humidity.As relative humidity fluctuates,the FTIR-ATR spectra display that the internal mixed gluconic acid(CH_(2)(CH)_(4)(OH)_(5)COOH)and nitrate can react to release acidic gases,forming relevant gluconate and further affecting the hygroscopicity.The specific presentation is particles cannot be recovered to their original size after the dehydration-hydration process and there will be some disparities in GF for mixed particles.For the gluconic acid-Ca(NO_(3))_(2)/Mg(NO_(3))_(2)mixtures with molar ratios of 1:1,higher degree of reaction resulting in the production of large amounts of gluconate should be responsible to the lower hygroscopicity compared to ZSR model.For 1:2 gluconic acid-nitrate mixed systems(with higher nitrate content),the hygroscopicity of mixtures are higher than the ZSR prediction.A possible reason could be‘salt-promoting effect’on the organic fractions of the surplus inorganic salt in the mixture.These data can improve the chemical composition list evaluation,in turn hygroscopic properties and phase state of atmospheric aerosol,and then the climate effect.

关键词： Hygroscopicity Gluconic acid Reaction ZSR simulation Size growth factors

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：