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Hour-to-hour variability of the ionosphere: An application of the classical multidimensional scaling method

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Science China Earth Sciences 2015年第7期58卷 1243-1250页

作者： SHI Hao ZHANG DongHe HAO YongQiang xiao zuo Department of Geophysics Peking University

The classical multidimensional scaling(MDS) method is introduced and applied in the study of the hour-to-hour ionospheric variability based on the ionospheric fo F2 observed at three ionosonde stations in East-Asia in 2002 and 2007. Results from the matrix eigen decompositions indicate that the annual part of the ionospheric variation is large in middle latitude and solar maximum period(2002) while low in the low latitude and solar minimum period(2007). The connectivity maps of the hour-to-hour ionospheric variability based on MDS method show some common diurnal features. The ionospheric connectivity between adjacent hours near noon hours and near midnight hours is high. The ionospheric connectivity between adjacent hours near sunrise hours and near sunset hours is poor, especially for the sunrise hours. Also there are latitudinal and solar activity dependences in this kind of connectivity. These results revealed from the ionospheric connectivity maps are useful physically and in practice for the ionospheric forecasting on the hour-to-hour scale.

关键词： ionospheric variability classical multidimensional scaling connectivity map

A theoretical analysis of global characteristics of spread-F

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Chinese Science Bulletin 2001年第19期46卷 1593-1595页

作者： zuo xiao Tianhua Zhang Peking Univ Dept Geophys Beijing 100871 Peoples R China

Spread-F is an important ionosphere pheonome-non and it has much effect on radio wave propogation. Taking magnetic inclination and declination into consideration, a theoretical model is deduced for the linear growth-rate of spread-F. It is a generalization of the earlier equatorial model and a relatively complete description o f the spread-F pheonomenon. This theory shows that the magnetic configuration, i.e. the magnetic strength, inclination and declination, affects the occurrence rate greatly, which forms some regional distribution characteristics of the spread-F.

关键词： spread-F irregularities global characteristics.

Study of the ionospheric TEC using GPS during the large solar flare burst on Nov. 6,1997

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Chinese Science Bulletin 2000年第19期45卷 1749-1752页

作者： Donghe Zhang zuo xiao Peking Univ Dept Geophys Beijing 100871 Peoples R China

Using the data from 15 global positioning system (GPS) stations scattered between 28° N-45° N and 90° W- 77° E we obtained the total electron content (TEC) variations with time during a large solar flare. The results indicated that the flare makes the TEC of ionosphere increasing in a large spatial area. The amounts of the TEC enhancement are mainly determined by the local time of subionospheric point, and the largest TEC enhancement is about 2.5 TECU. It is also concluded that the TEC enhancement is not symmetrical about the local noon time, the TEC enhancement values during morning hours are larger than those of the afternoon hours.

关键词： total electron content (TEC) flare subionospheric point.

基于InVEST模型的多情景下滇中城市群生境质量时空演变特征及预测

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兰州大学学报（自然科学版） 2024年第4期60卷 547-555页

作者：张露尹朱大明左小清彭秋志宋炜炜昆明理工大学国土资源工程学院昆明650093 昆明理工大学云南省高校高原山区空间信息测绘技术应用工程研究中心云南省自然资源与规划智慧创新实验室昆明650093

对滇中城市群生境质量及影响因素,通过耦合斑块生成土地利用模拟模型和生态系统服务与权衡综合评价模型,模拟不同情景下2030-2050年土地利用变化,探究生境质量的时空演变与空间相关性.结果表明,未来3种情景下,土地利用变化呈现不同趋势... 详细信息

对滇中城市群生境质量及影响因素,通过耦合斑块生成土地利用模拟模型和生态系统服务与权衡综合评价模型,模拟不同情景下2030-2050年土地利用变化,探究生境质量的时空演变与空间相关性.结果表明,未来3种情景下,土地利用变化呈现不同趋势,差异明显;自然发展情景和耕地保护情景下生境质量均值持续降低,生态保护情景生境质量均值上涨,改善效果显著;滇中城市群生境质量在县域空间上存在相关性,生境质量“热点”主要聚集在研究区西部,分布分散且面积不断缩减,“冷点”以经济较为发达的中部地区为核心区域,呈现扩张趋势.

关键词： InVEST模型生境质量多情景模拟滇中城市群

Side chain engineering on D18 polymers yields 18.74%power conversion efficiency

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Journal of Semiconductors 2021年第10期42卷 15-33页

作者： Xianyi Meng Ke Jin zuo xiao Liming Ding Center for Excellence in Nanoscience(CAS) Key Laboratory of Nanosystem and Hierarchical Fabrication(CAS)National Center for Nanoscience and TechnologyBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China

Donor-acceptor(D-A)conjugated copolymers contain-ing fused-ring acceptor units demonstrate outstanding per-formance in organic solar cells(OSCs)[1−13].We have in-vented highly efficient D-A copolymer donors D18 and D18-Cl by using a fused-ring acceptor unit,dithieno[3′,2′:3,4;2″,3″:5,6]benzo[1,2-c][1,2,5]thiadiazole(DTBT)[1,2].OSCs with D18 or D18-Cl gave power conversion efficiencies(PCEs)of 18.56%and 18.69%,respectively[3,4].Side chain engineering is an effective approach to improve the per-formance of conjugated polymers in optoelectronic devi-ces[14−16].The alkyl side chains not only determine polymers’solubility,but also influence their crystallinity and *** this work,we develop two efficient donors D18-B and D18-Cl-B via side chain engineering on D18 polymers(Fig.1(a)).These donors offer PCEs up to 18.74%(certified 18.2%)in tern-ary OSCs.

关键词： acceptor conjugated fused

Thermostable single-junction organic solar cells with a power conversion efficiency of 14.62%

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Science Bulletin 2018年第6期63卷 340-342页

作者： Hui Li zuo xiao Liming Ding Jizheng Wang Beijing National Laboratory for Molecular Sciences CAS Key Laboratory of Organic Solids Institute of Chemistry Chinese Academy of Sciences Center for Excellence in Nanoscience (CAS) Key Laboratory of Nanosystem and Hierarchical Fabrication (CAS) National Center for Nanoscience and Technology

Organic solar cells(OSCs)have drawn substantial attention in recent two decades due to their features of solution processability,low cost,and light weight[1].The active layer of OSCs is usually composed of an electron donor(D)and an electron acceptor(A).The D/A system can form interpenetrated nanoscale network,which allows efficient exciton dissociation and hence charge carrier ***,the efficiency of such binary OSCs is gen-

关键词：太阳能电池变换效率器官连接材料发展低费用振荡轻重量

STUDY ON THE INTERACTION BETWEEN POLYVINYLPYRROLIDONE AND PLATINUM METALS DURING THE FORMATION OF THE COLLOIDAL METAL NANOPARTICLES

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Chinese Journal of Polymer Science 2008年第1期26卷 23-29页

作者： Tu, Wei-xia zuo, xiao-bin Liu, Han-fan Beijing Inst Chem Technol Minist Educ Key Lab Nanomat Div Mol & Mat Simulat Beijing 100029 Peoples R China Chinese Acad Sci Inst Chem Beijing 100080 Peoples R China

Several PVP-stabilized colloidal platinum metals nanoparticles have been synthesized and characterized by FTIR and *** with the pure PVP,carbonyl groups of PVP in the mixture of PVP and the metal precursors or in the PVP-stabilized metal nanoparticles have obvious peak shifts in FTIR *** peak shifts reveal the interaction between PVP and the metal *** interaction between PVP and metal precursors has effect on the formation of the colloidal metal *** of the intera...

关键词： Colloidal metal nanoparticles Metal precursor PVP Interaction

5H-dithieno[3,2-b:20,30-d]pyran-5-one unit yields efficient wide-bandgap polymer donors

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Science Bulletin 2019年第22期64卷 1655-1657页

作者： Jinfeng Liu Ling Liu Chuantian zuo zuo xiao Yingping Zou Zhiwen Jin Liming Ding College of Chemistry and Chemical Engineering Central South UniversityChangsha 410083China Center for Excellence in Nanoscience(CAS) Key Laboratory of Nanosystem and Hierarchical Fabrication(CAS)National Center for Nanoscience and TechnologyBeijing 100190China CSIRO Manufacturing Bag 10Clayton SouthVictoria 3169Australia School of Physical Science and Technology Lanzhou UniversityLanzhou 730000China

Recently,great progress has been made in organic solar cells due to the emergence of high-performance nonfullerene acceptors[1-6].Over 16%and 17%power conversion efficiencies(PCEs)were achieved for nonfullerene-acceptor-based single-junction and tandem cells,respectively[7,8].Owing to complementary light absorption,wide-bandgap donor-acceptor(D-A)copolymers are ideal electron-donating partners for nonfullerene ***,efficient D-A copolymer donors are still limited.

关键词： acceptor donor complementary

18.69% PCE from organic solar cells

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Journal of Semiconductors 2021年第6期42卷 17-18页

作者： Ke Jin zuo xiao Liming Ding Center for Excellence in Nanoscience(CAS) Key Laboratory of Nanosystem and Hierarchical Fabrication(CAS)National Center for Nanoscience and TechnologyBeijing 100190China

The exquisite design and persistent development of fused-ring-acceptor-unit-based copolymer donors and Yseries nonfullerene acceptors(NFAs)have pushed the power conversion efficiencies(PCEs)for organic solar cells onto the18%level[1-21].Our group invented copolymer donors D18 and D18-Cl[2,3].D18:Y6,D18-Cl:N3 and D18:N3 solar cells have delivered outstanding PCEs of 18.22%,18.13%and18.56%,respectively[2-4].Ternary solar cells based on a polymer donor,a NFA and a fullerene acceptor show great potential since they combine good light-harvesting capability of NFA and good electron-mobility of fullerene[5].

关键词： acceptor harvesting fused