检索结果-南通市图书馆

Needs and challenges of optical atmospheric monitoring on the background of carbon neutrality in China

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Environmental science & Engineering 2024年第6期18卷 49-62页

作者： Wenqing Liu Chengzhi Xing Anhui institute of Optics and Fine Mechanics Hefei Institutes of Physical ScienceChinese Academy of SciencesHefei 23001China

The achievement of the targets of coordinated control of PM2.5 and O3 and the carbon peaking and carbon neutrality depend on the development of pollution and greenhouse gas monitoring *** monitoring technology,based on its technical characteristics of high scalability,high sensitivity and wide-targets detection,has obvious advantages in pollution/greenhouse gases monitoring and has become an important direction in the development of environmental monitoring *** present,a system of environmental optical monitoring technology with differential optical absorption spectroscopy(DOAS),cavity ring-down spectroscopy(CRDS),light detection and ranging(LIDAR),laser heterodyne spectroscopy(LHS),tunable diode laser absorption spectroscopy(TDLAS),fourier transform infrared spectroscopy(FTIR)and fluorescence assay by gas expansion(FAGE)as the main body has been ***,with the promotion of“reduction of pollution and carbon emissions”strategy,there have been significant changes in the sources of pollution/greenhouse gases,emission components and emission concentrations,which have put forward new and higher requirements for the development of monitoring *** the future,we should pay more attention to the development of new optical monitoring techniques and the construction of stereoscopic monitoring system,the interdisciplinarity(among mathematics,physics,chemistry and biology,etc.),and the monitoring of greenhouse gases and research on atmospheric chemistry.

关键词： Pollution Greenhouse gas Optical atmospheric monitoring Needs and challenges

Atomically self-healing of structural defects in monolayer WSe2

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics B 2024年第9期33卷 53-59页

作者：李康舒李俊贤韩小藏周武赵晓续 School of Materials science and Engineering Peking University School of physical sciences University of Chinese Academy of Sciences AI for science institute

Minimizing disorder and defects is crucial for realizing the full potential of two-dimensional transition metal dichalcogenides(TMDs) materials and improving device performance to desired properties. However, the methods in defect control currently face challenges with overly large operational areas and a lack of precision in targeting specific defects. Therefore,we propose a new method for the precise and universal defect healing of TMD materials, integrating real-time imaging with scanning transmission electron microscopy(STEM). This method employs electron beam irradiation to stimulate the diffusion migration of surface-adsorbed adatoms on TMD materials grown by low-temperature molecular beam epitaxy(MBE),and heal defects within the diffusion range. This approach covers defect repairs ranging from zero-dimensional vacancy defects to two-dimensional grain orientation alignment, demonstrating its universality in terms of the types of samples and defects. These findings offer insights into the use of atomic-level focused electron beams at appropriate voltages in STEM for defect healing, providing valuable experience for achieving atomic-level precise fabrication of TMD materials.

关键词： atom manipulation design fabrication nanoscale materials and structures: fabrication and characterization new materials: theory scanning transmission electron microscopy (STEM)

Nanofluidic memristor based on the elastic deformation of nanopores with nanoparticle adsorption

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

National science Review 2024年第4期11卷 46-54页

作者： Xi Zhou Yuanyuan Zong Yongchang Wang Miao Sun Deli Shi Wei Wang Guanghua Du Yanbo Xie Department of chemistry and Chemical Engineering Northwestern Polytechnical University School of physical science and Technology Northwestern Polytechnical University School of Aeronautics and institute of Extreme Mechanics Northwestern Polytechnical University institute of Modern Physics Chinese Academy of Sciences

The memristor is the building block of neuromorphic computing. We report a new type of nanofluidic memristor based on the principle of elastic strain on polymer nanopores. With nanoparticles absorbed at the wall of a single conical polymer nanopore, we find a pinched hysteresis of the current within a scanning frequency range of 0.01–0.1 Hz, switching to a diode below 0.01 Hz and a resistor above 0.1 Hz. We attribute the current hysteresis to the elastic strain at the tip side of the nanopore, caused by electrical force on the particles adsorbed at the inner wall surface. Our simulation and analytical equations match well with experimental results, with a phase diagram for predicting the system transitions. We demonstrate the plasticity of our nanofluidic memristor to be similar to a biological synapse. Our findings pave a new way for ionic neuromorphic computing using nanofluidic memristors.

关键词： nanofluidics memristor neurocomputing elastic deformation

Sustainable all-weather CO2 utilization by mimicking natural photosynthesis in a single material

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

National science Review 2024年第2期11卷 177-187页

作者： Xianjin Shi Yu Huang Ran Long Zhenyu Wang Liqin Wang Junji Cao Gangqiang Zhu Yujie Xiong State Key Laboratory of Loess and Quaternary Geology(SKLLQG) Key Laboratory of Aerosol Chemistry and Physics Institute of Earth EnvironmentChinese Academy of Sciences Center of Excellence in Quaternary science and Global Change Chinese Academy of Sciences University of Chinese academy of sciences Hefei National Research Center for physical sciences at the Microscale School of Chemistry and Materials Science and National Synchrotron Radiation Laboratory University of Science and Technology of China institute of Atmospheric Physics Chinese Academy of Sciences School of Physics and Information Technology Shaanxi Normal University

Solar-driven CO2conversion into hydrocarbon fuels is a sustainable approach to synchronously alleviating the energy crisis and achieving net ***,the dependence of the conversion process on solar illumination hinders its practical application due to the intermittent availability of sunlight at night and on cloudy or rainy ***,we report a model material of Pt-loaded hexagonal tungsten trioxide（Pt/h-WO3） for decoupling light and dark reaction processes,demonstrating the sustainable CO2conversion under dark conditions for the first *** such a material system,hydrogen atoms can be produced by photocatalytic water splitting under solar illumination,stored together with electrons in the h-WO3through the transition of W6+to W5+and spontaneously released to trigger catalytic CO2reduction under dark ***,we demonstrate using natural light that CH4production can persist at night and on rainy days,proving the accomplishment of all-weather CO2conversion via a sustainable way.

关键词： sustainable CO2 utilization artificial photosynthesis all-weather application charge storage

An improved analysis method for assessing the nuclear-heating impact on the stability of toroidal field magnets in fusion reactors

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Nuclear science and Techniques 2024年第6期35卷 163-176页

作者： Yu-Dong Lu Jin-Xing Zheng Xu-Feng Liu Huan Wu Jian Ge Kun Xu Ming Li Hai-Yang Liu Lei Zhu Fei Liu institute of Plasma Physics Hefei Institutes of Physical ScienceChinese Academy of SciencesHefei 230031China University of science and Technology of China Hefei 230026China

The superconducting magnet system of a fusion reactor plays a vital role in plasma confinement,a process that can be dis-rupted by various operational factors.A critical parameter for evaluating the temperature margin of superconducting magnets during normal operation is the nuclear heating caused by D-T *** study investigates the impact of nuclear heat-ing on a superconducting magnet system by employing an improved analysis method that combines neutronics and thermal *** the magnet system,toroidal field(TF)magnets are positioned closest to the plasma and bear the highest nuclear-heat load,making them prime candidates for evaluating the influence of nuclear heating on *** enhance the modeling accuracy and facilitate design modifications,a parametric TF model that incorporates heterogeneity is established to expedite the optimization design process and enhance the accuracy of the computations.A comparative analysis with a homogeneous TF model reveals that the heterogeneous model improves accuracy by over 12%.Considering factors such as heat load,magnetic-field strength,and cooling conditions,the cooling circuit facing the most severe conditions is selected to calculate the temperature of the *** selection streamlines the workload associated with thermal-hydraulic *** approach enables a more efficient and precise evaluation of the temperature margin of TF ***,it offers insights that can guide the optimization of both the structure and cooling strategy of superconducting magnet systems.

关键词： Superconducting magnet Nuclear heating Neutronics Thermal hydraulics

维普期刊数据库

Unusual Single Electron Transfer Reactions between Alkenes and Iodine Electrophiles

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of chemistry 2024年第5期42卷 471-477页

作者： Zhengzhao Lou Jingyu Hu Chuanfa Ni Xiu Wang Jinbo Hu Key Laboratory of Organofluorine chemistry Shanghai Institute of Organic ChemistryUniversity of Chinese Academy of SciencesChinese Academy of Sciences345 Ling Ling RoadShanghai200032 China School of physical science and Technology ShanghaiTech University100 Haike RoadShanghai201210 China

The electrophilic addition to an alkene with an electrophile has been widely studied and applied in organic *** organic chemistry textbook describes the classical reaction between an alkene and an iodine electrophile(such as elemental iodine and N-iodosuccinimide(NIS))as a typical ionic reaction,in which an iodonium ion is formed and then attacked by a ***,in this article,we report a new and unusual reaction mode between an alkene and NIS;that is,a single electron transfer(SET)process occurs between these two reactants by forming an electron-donor acceptor *** only does this unusual single electron transfer reaction between an alkene and NIS add fundamentally important knowledge to organic chemistry,it also provides a valuable synthetic method as the new SET reaction mode with opposite regioselectivity as compared with the traditional ionic mode.

关键词： Electrophilic addition Radical ions Reaction mechanisms Alkenes Fluorine

Multi-objective global optimization approach predicted quasi-layered ternary TiOS crystals with promising photocatalytic properties

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics B 2024年第8期33卷 447-454页

作者：向依婕高思妍王春雷方海平段香梅郑益峰张越宇 Shanghai institute of Applied Physics Chinese Academy of Sciences University of Chinese academy of sciences School of Materials science and Engineering East China University of Science and Technology College of science Shanghai University School of Physics East China University of Science and Technology School of physical science and Technology Ningbo University Wenzhou institute University of Chinese Academy of Sciences (UCAS)

Titanium dioxide（TiO2） has attracted considerable research attentions for its promising applications in solar cells and photocatalytic ***,the intrinsic challenge lies in the relatively low energy conversion efficiency of TiO2,primarily attributed to the substantial band gaps（exceeding 3.0 eV） associated with its rutile and anatase *** multi-objective global optimization,we have identified two quasi-layered ternary Ti-O-S crystals,composed of titanium,oxygen,and *** calculations of formation energy,phonon dispersions,and thermal stability confirm the chemical,dynamical and thermal stability of these newly discovered *** the state-of-art hybrid density functional approach and many-body perturbation theory（quasiparticle GW approach and Bethe-Salpeter equation）,we calculate the optical properties of both the TiOS ***,both phases show favorable photocatalytic characteristics,featuring band gaps suitable for visible optical absorption and appropriate band alignments with water for effective charge carrier ***,ternary compound TiOS holds the potential for achieving high-efficiency photochemical conversion,showing our multi-objective global optimization provides a new approach for novel environmental and energy materials design with multicomponent compounds.

关键词： first principles calculations multi-objective global optimization photocatalysis

Li-promoted C3N4 catalyst for efficient isomerization of glucose into fructose at 50℃ in water

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Green Energy & Environment 2024年第9期9卷 1419-1426页

作者： Wang Liu Yanfei Zhang Mengya Sun Xinpeng Zhao Shenggang Li Xinqing Chen Liangshu Zhong Lingzhao Kong CAS Key Laboratory of Low-Carbon Conversion science and Engineering Shanghai Advanced Research Institute Chinese Academy of Sciences University of Chinese academy of sciences School of physical science and Technology Shanghai Tech University School of Environmental science and Engineering Suzhou University of Science and Technology

Efficient and selective glucose-to-fructose isomerization is a crucial step for production of oxygenated chemicals derived from sugars,which is usually catalyzed by base or Lewis acid heterogeneous ***,high yield and selectivity of fructose cannot be simultaneously obtained under mild conditions which hamper the scale of application compared with enzymatic ***,a Li-promoted C3N4catalyst was exploited which afforded an excellent fructose yield （40.3 wt%） and selectivity （99.5%） from glucose in water at 50~oC,attributed to the formation of stable Li–N bond to strengthen the basic sites of ***,the so-formed N6–Li–H2O active site on Li–C3N4catalyst in aqueous phase changes the local electronic structure and strengthens the deprotonation process during glucose isomerization into *** superior catalytic performance which is comparable to biological pathway suggests promising applications of lithium containing heterogeneous catalyst in biomass refinery.

关键词： Glucose Fructose Isomerization Li–C 3 N 4 Density functional theory calculations

Iron oxide/CNT-based artificial nacre for electromagnetic interference shielding

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2024年第7期17卷 6560-6566页

作者： Cheng-Xin Yu Yu-Feng Meng Bo Yang Jun Pang Xiang-Sen Meng Zi-Ye Zhao Qing-Yue Wang Li-Bo Mao Zhi-Kun Wu Shu-Hong Yu institute of physical science and Information Technology Anhui UniversityHefei 230601China Key Laboratory of Materials Physics Anhui Key Laboratory of Nanomaterials and NanotechnologyCAS Center for Excellence in NanoscienceInstitute of Solid State PhysicsHFIPSChinese Academy of SciencesHefei 230031China Department of chemistry New Cornerstone Science LaboratoryInstitute of Biomimetic Materials&ChemistryAnhui Engineering Laboratory of Biomimetic MaterialsDivision of Nanomaterials&ChemistryHefei National Research Center for Physical Sciences at the MicroscaleUniversity of Science and Technology of ChinaHefei 230026China

Biological structural materials,despite consisting of limited kinds of compounds,display multifunctionalities due to their complex hierarchical *** some biomimetic strategies have been applied in artificial materials to enhance their mechanical stability,the simultaneous optimization of other functions along with the mechanical properties via biomimetic designs has not been thoroughly ***,iron oxide/carbon nanotube(CNT)-based artificial nacre with both improved mechanical and electromagnetic interference(EMI)shielding performance is fabricated via the mineralization of Fe_(3)O_(4)onto a CNTincorporated *** micro-and nano-structures of the artificial nacre are similar to those of natural nacre,which in turn improves its mechanical *** alternating electromagnetic wave-reflective CNT layers and the wave-absorptive iron oxide layers can improve the multiple reflections of the waves on the surfaces of the reflection layers,which then allows sufficient interactions between the waves and the absorption ***,compared with the reflection-dependent EMI-shielding of the non-structured material,the artificial nacre exhibits strong absorption-dependent shielding behavior even with a very low content of wave-absorptive *** to the high mechanical stability,the shielding effectiveness of the artificial nacre that deeply cut by a blade is still maintained at approximately 70%−96%depending on the incident wave *** present work provides a new way for designing structural materials with concurrently enhanced mechanical and functional properties,and a path to combine structural design and intrinsic properties of specific materials via a biomimetic strategy.

关键词： artificial nacre electromagnetic interference shielding biomineralization biomimetic material hierarchical structure