检索结果-南通市图书馆

Impacts of permafrost degradation on streamflow in the northern Himalayas

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2024年第6期67卷 1990-2000页

作者： linfeng FAN Fang JI Xingxing KUANG Zhilin guo Rui ZHANG Chunmiao ZHENG State Key Laboratory of Mountain Hazards and Engineering Resilience Institute of Mountain Hazards and EnvironmentChinese Academy of SciencesChengdu 610299China Yangtze Institute for Conservation and Development Hohai UniversityNanjing 210024China School of Environmental Science and Engineering Southern University of Science and TechnologyShenzhen 518055China Eastern Institute for Advanced Study Ningbo 315200China

The Himalayan water tower provides crucial water resources for Asia.Permafrost degradation is deemed to exert important impacts on streamflow in the Himalayan rivers.Yet,the magnitudes of such impacts remain poorly quantified.Here,we established a robust hydrological model that incorporated active layer deepening and ground ice melt for the drainage basin of the largest river in the northern Himalayas-the Yarlung Zangbo River(YZR).We estimated that permafrost degradation led to~0.65 km^(3)/yr decrease in surface runoff and~0.35 km^(3)/yr increase in baseflow and ground ice melt contributed~0.25% to the annual streamflow in the YZR for the period 2001-2022.The“fill-and-spill”mechanism helps explain the seeming contradiction of observed increasing versus decreasing baseflow in different permafrost regions worldwide.We propose that the dilution of riverine dissolved organic carbon(DOC)concentrations by baseflow may lead to the riverine DOC hysteresis patterns.This study not only lays solid scientific basis for water resources management in the Himalayas,but also yields new insights into how to interpret measured river discharge and nutrient flux in permafrost regions over the globe.

关键词： Permafrost degradation Hydrology Streamflow Surface runoff Groundwater Himalayas

Highly ordered crystallization ofα-FAPbl_(3) films via homogeneous seeds for efficient perovskite solar cells

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2024年第7期94卷 625-634页

作者： guohui Luo linfeng Zhang Liyun guo Xiuhong Geng Penghui Ren Yi Zhang Haihua Hu Xiaoping Wu Lingbo Xu Ping Lin Haiyan He Xuegong Yu Peng Wang Can Cui Key Laboratory of Optical Field Manipulation of Zhejiang Province Department of PhysicsZhejiang Sci-Tech UniversityHangzhou 310018ZhejiangChina Zhejiang Provincial Key Laboratory of Fiber Materials and Manufacturing Technology Zhejiang Sci-Tech UniversityHangzhou 310018ZhejiangChina Hangzhou City University Hangzhou 310015ZhejiangChina Key Laboratory of Solar Energy Utilization and Energy Saving Technology of Zhejiang Province Zhejiang Baima Lake Laboratory Co.Ltd.Hangzhou 310012ZhejiangChina State Key Laboratory of Silicon Materials and School of Materials Science and Engineering Zhejiang UniversityHangzhou 310027ZhejiangChina

Formamidine lead triodide(FAPbI_(3))perovskites have become the most promising photovoltaic materials for perovskite solar cells with record power conversion efficiency(PcE).However,random nucleation,phase transition,and lattice defects are still the key challenges limiting the quality of FAPbI_(3)films.Previous studies show that the introduction or adding of seeds in the precursor is effective to promote the nucleation and crystallization of perovskite films.Nevertheless,the seed-assisted approach focuses on heterogeneous seeds or hetero-composites,which inevitably induce a lattice-mismatch,the genera-tion of strain or defects,and the phase segregation in the perovskite films.Herein,we first demonstrate that high-quality perovskite films are controllably prepared usingα-and δ-phases mixed FAPbI_(3) micro-crystal as the homogeneous seeds with the one-step antisolvent method.The partially dissolved seeds with suitable sizes improve the crystallinity of the perovskite flm with preferable orientation,improved carrier lifetime,and increased carrier mobility.More importantly,theα-phase-containing seeds promote the formation of α-phase FAPbI_(3) films,leading to the reduction of residual lattice strain and the suppres-sion of I-ion migration.Besides,the adding of dimethyl 2,6-pyridine dicarboxylate(DPD)into the pre-cursor further suppresses the generation of defects,contributing to the PCE of devices prepared in air ambient being significantly improved to 23.75%,among the highest PCEs for fully air-processed FAPbl_(3) solar cells.The unpackaged target devices possess a high stability,maintaining 80%of the initial PCE under simulated solar illumination exceeding 8o0 h.

关键词： Perovskite solar cells FAPbI_(3) Homogeneous seeds Strain Phase stability

Innovations in metallurgical and materials processes:advancing liquid theory and honoring Prof.Han-jie guo's contributions to physical chemistry in metallurgy

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research(International) 2024年第1期31卷 1-2页

作者： Shuai Liu Jing guo Han-jie guo School of Artificial Intelligence Beijing Technology and Business UniversityBeijing100048China School of Metallurgical and Ecological Engineering University of Science and Technology Beijing(USTB)Beijing100083China

Spanning three decades,Prof.Han-jie guo's research group has dedicated itself to exploring the fundamental theories and practical applications of physical chemistry within the realm of metallurgy.Operating under the a... 详细信息

关键词： chemistry liquid complexes

Light People:Prof.Eric Mazur speaks about ultrafast optics and education

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Light(Science & Applications) 2024年第3期13卷 402-406页

作者： Chenzi guo Yang Li Changchun Institute of Optics Fine Mechanics and PhysicsChinese Academy of SciencesChangchunChina State Key Laboratory of Precision Measurement Technology and Instrument Department of Precision InstrumentTsinghua UniversityBeijingChina

Prof.Eric Mazur is a great influencer over and beyond the optics community.As a physicist,he is a pioneer of ultrafast optics and was one of the inventors of colliding-pulse mode-locked laser.As an educator,he not only gave talks to thousands,but also revolutionized teaching with his globally renowned methodology“Peer Instruction”.As a leader and entrepreneur,he co-founded several companies and was President of Optica(formerly the Optical Society)and currently is the Chair of the Optica Foundation.Here,Light:Science&Applications talked with Prof.Eric Mazur about his opinions on research,education and industry.The full interview video can be found in the Supplementary File.

关键词： optics education companies

Emerging direct current triboelectric nanogenerator for high-entropy mechanical energy harvesting

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2024年第5期67卷 1297-1316页

作者： CHEN Jie guo RuiLong guo HengYu College of Physics and Electronic Engineering Chongqing Normal UniversityChongqing 401331China Department of Applied Physics Chongqing UniversityChongqing 401331China

In the era of the Internet of Things(IoT),the provision of sustainable power to distributed,mobile,and low-power-consumption electronic devices is a critical challenge.To overcome this challenge,the triboelectric nanogenerator(TENG),a highly efficient high-entropy mechanical energy harvesting device,was developed in 2012.This device enables the direct conversion of irregular and low-frequency mechanical energy into pulsed alternating current(AC)signals.However,the incompatibility of most electronic devices with AC signals necessitates rectifier circuits or generators that deliver direct current(DC)signals.In recent years,DC-TENGs have undergone extensive development,achieving significant milestones in various application fields while also facing crucial challenges that require solutions.In this review,three categories of DC-TENG devices with distinct operating mechanisms are comprehensively explored:multiphase coupling,mechanical rectification,and air breakdown.Their typical structures and working mechanisms are thoroughly discussed,and specific output performance limitations,along with corresponding optimization strategies,are identified.Furthermore,the applications of DC-TENGs in various scenarios are summarized.Finally,the challenges faced by DC-TENGs and potential solutions are analyzed to guide further advancements in this technology.

关键词： TENG direct current working mechanisms output performance limitations optimization strategies

Light People:Prof.Kei May Lau,newly elected US NAE member in Hong Kong,talks about future of photonics and women in science

在线全文

学校读者我要写书评

暂无评论

Light(Science & Applications) 2024年第4期13卷 602-608页

作者： Yating Wan Chenzi guo Electrical and Computer Engineering the ComputerElectrical and Mathematical Sciences and Engineering DivisionKing Abdullah University of Science and Technology23955-6900 ThuwalSaudi Arabia Changchun Institute of Optics Fine Mechanics and PhysicsChinese Academy of SciencesChangchunChina

Editorial Photonics technology remains a driving force in today’s scientific landscape,marked by continuous innovation and crossdisciplinary relevance.In an enlighting conversation with Light:Science&Applications,Prof.Kei May Lau,a pioneer in photonics research,shares her deep insights on the evolution of technologies of LEDs,lasers,challenges of hetero-epitaxy,and the future of micro-LEDs and quantum dot lasers.Recently honored as a member of the US National Academy of Engineering(NAE)for her significant contributions to photonics and electronics using III-V semiconductors on silicon,Prof.Lau stands out as the sole Hong Kong scholar inducted into the NAE this year,joining 114 new and 21 international members.In this exclusive Light People interview,Prof.Lau shares her journey as a pioneering woman in engineering,her commitment to mentorship and academia,and her perspective on advancing female representation in science.The summary provided is distilled from Prof.Lau’s thoughtful responses during the interview.For a deeper exploration of Prof.Lau’s experiences and advice,the full interview is available in the Supplementary material.

关键词： interview lighting driving

Improving benzene catalytic oxidation on Ag/Co_(3)O_(4) by regulating the chemical states of Co and Ag

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2024年第9期143卷 201-212页

作者： Hao guo Tao guo Mengqi Zhao Yaxin Zhang Wenfeng Shangguan Yinnian Liao State Key Laboratory of Chemistry and Utilization of Carbon Based Energy Resources Xinjiang UniversityXinjiang 830017China Xinjiang Key Laboratory of Coal Clean Conversion&Chemical Engineering Process Xinjiang UniversityXinjiang 830017China School of Chemical Engineering and Technology Xinjiang UniversityXinjiang 830017China Research Center for Combustion and Environmental Technology Shanghai Jiao Tong UniversityShanghai 200240China School of Applied Chemistry and Materials Zhuhai College of Science and TechnologyGuangdong 519041China

Silver(9 wt.%)was loaded on Co_(3)O_(4)-nanofiber using reduction and impregnation methods,respectively.Due to the stronger electronegativity of silver,the ratios of surface Co^(3+)/Co^(2+) on Ag/Co_(3)O_(4) were higher than on Co_(3)O_(4),which further led to more adsorbed oxygen species as a result of the charge compensation.Moreover,the introducing of silver also obviously improved the reducibility of Co_(3)O_(4).Hence the Ag/Co_(3)O_(4) showed better catalytic performance than Co_(3)O_(4) in benzene oxidation.Compared with the Ag/Co_(3)O_(4) synthesized via impregnation method,the one prepared using reduction method(named as Ag Co-R)exhibited higher contents of surface Co^(3+) and adsorbed oxygen species,stronger reducibility,as well as more active surface lattice oxygen species.Consequently,Ag Co-R showed lowest T_(90) value of 183℃,admirable catalytic stability,largest normalized reaction rate of1.36×10^(-4)mol/(h·m^(2))(150℃),and lowest apparent activation energy(E_(a))of 63.2 kJ/mol.The analyzing of in-situ DRIFTS indicated benzene molecules were successively oxidized to phenol,o-benzoquinone,small molecular intermediates,and finally to CO_(2) and water on the surface of Ag Co-R.At last,potential reaction pathways including five detailed steps were proposed.

关键词： Reduction method Co_(3)O_(4)-supported Ag catalyst,VOCs Benzene oxidation Reaction mechanism

Physicochemical principles of hydrogen metallurgy in blast furnace

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research(International) 2024年第1期31卷 46-63页

作者： Han-jie guo School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing100083China Beijing Key Laboratory of Special Melting and Preparation of High-End Metal Materials Beijing100083China

Based on the stoichiometric method and the free energy minimization method,an ideal model for the reduction of iron oxides by carbon and hydrogen under blast furnace conditions was established,and the reduction efficiency and theoretical energy consumption of the all-carbon blast furnace and the hydrogen-rich blast furnace were compared.The results show that after the reduction reaction is completed at the bottom of the blast furnace,the gas produced by reduction at 1600℃still has a certain excessive reduction capacity,which is due to the hydrogen brought in by the hydrogen-rich blast as well as the excess carbon monoxide generated by the reaction of the coke and the oxygen brought in by the blast.During the process of the gas with excessive reduction capacity rising from the bottom of the blast furnace and gas reduction process,the excessive reduction capacity of the gas gradually decreases with the increase in the dydrogen content in the blast.In the all-carbon blast furnace,the excess gas reduction capacity is the strongest,and the total energy consumption per ton of iron reduction is the lowest.This shows that,for the current operation mode of the blast furnace,adding hydrogen in the blast furnace cannot reduce the consumption of carbon required for reduction per ton of iron,but rather increases the consumption of carbon.

关键词： Hydrogen metallurgy Excess gas reduction capacity Theoretical energy consumption Hydrogen-rich blast furnace Thermodynamic model Gibbs minimum free energy method

Control Strategies for Digital Twin Systems

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

IEEE/CAA Journal of Automatica Sinica 2024年第1期11卷 170-180页

作者： guo-Ping Liu IEEE the Center for Control Science and Technology Southern University of Science and TechnologyShenzhen 518055China

With the continuous breakthrough in information technology and its integration into practical applications, industrial digital twins are expected to accelerate their development in the near future. This paper studies various control strategies for digital twin systems from the viewpoint of practical applications.To make full use of advantages of digital twins for control systems, an architecture of digital twin control systems, adaptive model tracking scheme, performance prediction scheme, performance retention scheme, and fault tolerant control scheme are proposed. Those schemes are detailed to deal with different issues on model tracking, performance prediction, performance retention, and fault tolerant control of digital twin systems. Also, the stability of digital twin control systems is analysed. The proposed schemes for digital twin control systems are illustrated by examples.

关键词： Digital twin control systems fault tolerant control model tracking performance prediction performance retention