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PEN/BADCy Interlayer Dielectric Films with Tunable Microstructures via an Assist of Temperature for Enhanced Frequency Stability

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Chinese Journal of Polymer Science 2020年第11期38卷 1258-1266,I0009页

作者： xi-Ting Lei Li-Fen Tong Ming-Zhen Xu Yong You xiao-bo Liu School of Materials and Energy University of Electronic Science and Technology of ChinaChengdu 610054China

Low dielectric in terlayer films have become an important element to ensure the development of the microelectr onics industry.A kind of flexible interlayer dielectrics,polyarylene ether nitrile/bisphenol A cyanate ester(PEN/BADCy)film,with good thermal stability and low frequency dependence,has been developed by solution casting ***,materials were designed to incorporate bisphenol A cyanate ester as a part of blend,contributing to the frequency stability and structural *** morphological study combined with electron microscopy revealed the uniform and flexible microstructure information with controllable morphology through self-polymerization of cyanate esters with different prepolymerization time and curing *** dielectric films could present high thermal stability with Tg>180℃.Significant improvement in the dielectric properties was achieved for the dielectric constant and loss was much stabler than neat PEN over the frequency range from 100 Hz to 5 *** the prepolymerization time was 3h and final curing temperature reached 230℃,the dielectric constant and dielectric loss of the films were 3.36 and 0.013 at 100 kHz,*** dimensional stability(CTE=53.67×10^-6 K^-1)was confirmed and con sidered beneficial to use as an in terlayer dielectrics.

关键词： Polyarylene ether nitrile Bisphenol A cyanate ester Interlayer dielectrics Tunable microstructures

Engineering electronic structures of titanium vacancies in Ti_(1-x)O_(2)nanosheets enables enhanced Li-ion and Na-ion storage

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Green Energy & Environment 2022年第4期7卷 734-741页

作者： Huiqin Wang Fengchu Zhang Jing xia Fei Lu bo Zhou Ding Yi xi Wang Key Laboratory of Luminescence and Optical Information Ministry of EducationDepartment of PhysicsSchool of ScienceBeijing Jiaotong UniversityBeijing100044China Institute of Molecular Plus Tianjin UniversityTianjin300072China Chemistry and Chemical Engineering Guangdong Laboratory Shantou515031China

Up to now,three kinds of ion-storage mechanisms are summarized towards anode materials in lithium/sodium-ion batteries,but they have low capacity and poor cyclic ***,it is necessary to develop a new approach to optimize ion ***,we report an adsorption/desorption storage route through engineering electronic structure of cation-deficient Ti_(1-x)O_(2)***_(1-x)O_(2)nanosheets indeed exhibit higher capacity(332.1 mA h g^(-1)vs.137.7 mA h g^(-1)for LIBs,195.7 mA h g^(-1)vs.111 mA h g^(-1)for SIBs),and more stable cyclic performance(296 mA h g^(-1)vs.99 mA h g^(-1)for LIBs,178.1 mA h g^(-1)vs.80.2 mA h g^(-1)for SIBs after 100 cycles)at 0.1 A g^(-1)than TiO_(2)*** analysis and density functional theory(DFT)calculations reveal that electronic structures of vacancy within Ti_(1-x)O_(2) nanosheets encourage a novel adsorption-desorption storage *** results highlight the benefits of the engineered electronic structures within electrode material and implement novel ion-storage mechanism towards broad energy storage applications.

关键词： Titanium vacancy Titania nanosheet Electronic structure Ion storage Storage mechanism

Effects of Enclosure on Grassland Ecological and Economic Benefits in Northern China

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Chinese Geographical Science 2024年第1期34卷 67-78页

作者： HU bo WEN Qingke xi Fengjiang LI Mengyao WANG Libing REN Yuejuan Aerospace Information Research Institute Chinese Academy of SciencesBeijing100094China University of Chinese Academy of Sciences Beijing100049China Inner Mongolia Remote Sensing Center Co. Ltd.Huhhot010000China xilinhot the Maodeng pasture Xilinhot026000China China University of Mining and Technology Xuzhou221116China Shanxi Provincial Key Lab of Resources Environment and Disaster MonitoringCoal Geological Geophysical Exploration Surveying&Mapping Institute of Shanxi ProvinceJinzhong030600China

Grasslands in northern China serve the country as both an ecological barrier and a livestock production ***,installing enclosures has been becoming the major grassland restoration measure adopted by many local ***,the effects of restoration on both ecological and production benefits of grassland remain unclear for implemented grassland restoration ***,a representative rangeland in northern China,the Maodeng pasture in Inner Mongolia Autonomous Region was selected as the study area,and remote sensing monitoring analyses were carried out to quantify the ecological benefits and economic benefits from 2015 to *** results showed that:1) in terms of ecological benefits,the grassland area with a grassland coverage rate of more than 60% accounts for 32.3% of the regional area,and 86.4% of its grassland grew significantly better than the same period in2015,showing a significant improvement in grassland *** the average amount of carbon per unit area as the ecological benefit evaluation index,it increased by 27.1% to 32.48Tg C/yr from 2015 to 2021.2) In terms of economic benefits,both theoretical grass production and livestock carrying capacity increased from 2015 to *** to 2015,the theoretical grass production in 2021 increased by 24.8% to 71 900 *** livestock carrying capacity reached 52 100 sheep units in 2021,nearly 11 000 sheep units more than that in *** the study period,multiple economic indicators(on a per capita basis of permanent residents) for the pastoral area of xilinhot City to which the Maodeng pasture belongs,have grown *** capita total income rose from 29 630 yuan(RMB) in2015 to 62 859 yuan(RMB) in *** on grassland resources to develop the pastoral ecology also broadens the potential economic development ***,the establishment of the reserve and the experiment of implanting an enclosure policy have had a significant and positive impact on Maodeng pasture’s develo

关键词： enclosure grassland ecological benefit economic benefit Maodeng pasture Inner Mongolia northern China

Techniques of microwave permeability characterization for thin films

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Chinese Physics B 2019年第9期28卷 37-49页

作者： xi-Ling Li Jian-bo Wang Guo-Zhi Chai Key Laboratory for Magnetism and Magnetic Materials of the Ministry of Education Lanzhou UniversityLanzhou 730000China Key Laboratory for Special Function Materials and Structural Design of the Ministry of Education Lanzhou UniversityLanzhou 730000China National Demonstration Center for Experimental Physics Education Lanzhou UniversityLanzhou 730000China

We review the microwave methods to characterize the material properties, including the established and the emerging techniques in material characterization, especially the permeability spectra of the magnetic thin *** all aspects of the microwave techniques for characterizing the permeability of thin films at microwave frequencies, including the new methods developed by our group, are ***, the introduction part is ***, the coaxial-line with transmission/reflection methods and the pickup coil with electromagnetic induction method are ***, the most widely used shorted microstrip technique is discussed in detail by the equivalent circuit method, transmission line method,and electromagnetic induction ***, the coplanar waveguide method and the near-field probe method are also ***, the high temperature permeability characterization by using the shorted microstrip line, the near-field microwave probe, and the shorted microstrip line probe are described in *** paper may be useful for researchers or engineers who will build up such measurement fixture to make full use of the existing methods or to develop original methods to meet the requirements for ever-rising measurements.

关键词： high frequency permeability coaxial-line methods induction coil method shorted microstrip technique coplanar waveguide method

Microscopic characterization and formation mechanisms of deep-water sandy-debris-flow and turbidity-current sandstones in a lacustrine basin： a case study in the Yanchang Formation of the Ordos Basin, China

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Petroleum Science 2018年第1期15卷 28-40页

作者： Jian-bo Liao Ai-Hua xi Zhi-Yong Li Hua-Qing Liu xiang-bo Li Rong Wanyan School of Geoscience and Technology Southwest Petroleum University Chengdu 610500 Sichuan China Petro China Research Institute of Petroleum Exploration &Development-Northwest Lanzhou 730020 Gansu China Key Laboratory of Reservoir Description CNPCLanzhou 730020 Gansu China

Deep-water deposition is a current issue in sedimentological research. Sandy-debris-flow sandstones and turbidity-current sandstones are the main types of sandstone that are the focus of considerable disputes in this research. Previous studies mainly focused on description of the macroscopic sedimentary structure and theoretical derivation of the formation mechanisms. The microscopic petrological characteristics, reservoir properties, and formation mechanisms of deep-water sandy-debris-flow and turbidity-current sandstones have been studied in the Yanchang Formation of the Ordos Basin,China, by means of field outcrop surveys, thin-section identification, geochemical element analysis, and porosity and permeability measurements under overburden pressure. The content of detrital grains in the sandy-debris-flow sandstones is high, whereas the contents of mica sheets and matrix are low. The fine-grained matrix is distributed unevenly within the pores. A considerable number of residual intergranular pores are preserved in the middle of single sand bodies, resulting in relatively better reservoir properties. The total number of detrital grains in the turbidite sandstone is low, while it contains abundant mica sheets and matrix. The mica sheets and fine-grained matrix are distributed evenly within the pores, resulting in serious damage to pores and poor reservoir properties. The sandy-debris-flow sandstones in the center of the lake basin form a high-quality reservoir; thus, this area is suitable for oil and gas exploration.

关键词： Sandy debris flow Turbidite Ordos Basin Petrology Reservoir properties

The role of exercise in rehabilitation of discharged COVID-19 patients

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Sports Medicine and Health Science 2021年第4期3卷 194-201页

作者： Wenyan bo Yue xi Zhenjun Tian Institute of Sports and Exercise Biology School of Physical EducationShaanxi Normal UniversityXi'an710119China

Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)mainly caused pneumonia and pulmonary fibrosis through upper respiratory tract infection,which resulted in acute respiratory distress syndrome(ARDS)and multiorgan damage of cardiovascular,nervous,digestive,and genitourinary *** the virus test turned negative after the patient recovered,the damage to multiorgan caused by SARS-CoV-2 may ***,the health status of the recovered patients has gradually become the focus of people's *** coronavirus disease 2019(COVID-19)patients can receive exercise rehabilitation training after discharge?and what's the basis?We try to analyze and answer these questions,will provide some ideas about the patients to develop a reasonable and effective exercise rehabilitation program.

关键词： SARS-CoV-2 COVID-19 Exercise rehabilitation Inflammation cytokine storm Exercise response factor

Hot Compression Behavior of Mg-Gd-Y-Zn-Zr Alloy Containing LPSO with Different Morphologies

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Acta Metallurgica Sinica(English Letters) 2023年第10期36卷 1680-1698页

作者： Rui Guo xi Zhao bo-Wen Hu Xue-Dong Tian Qiang Wang Zhi-Min Zhang School of Material Science and Engineering North University of ChinaTaiyuan030051China School of Aeronautics and Astronautics North University of ChinaTaiyuan030051China

In this study,hot compression behavior of as-homogenized Mg-9Gd-4Y-2Zn-0.5Zr alloys containing long period ordered(LPSO)phases with different initial morphologies was investigated under a strain rate of 0.01 s−1 at 450°*** microstructure,texture evolution and dynamic recrystallization(DRX)mechanism under different strains(0.1,0.3,0.5,0.7,and 1.4)were *** compression conditions,the block-shape phase and deformedα-Mg matrix were regularly arranged vertically in the compression direction(CD).The particle phase(Mg5RE)and amount of kink bands were *** degree of kink increased initially and decreased significantly when the deformation strain reached *** DRX mechanisms were produced during the compression process:(i)The block LPSO,Mg5RE and Zr-Zn phase activated DRX through the particle stimulated nucleation(PSN)mechanism.(ii)Several DRX activated on the serrated grain boundary between the two parent grains through discontinuous DRX(DDRX)mechanism.(iii)A large number of kink bands and larger spacing of lamellar LPSO increased the nucleation of DRX through continuous DRX(CDRX)*** combination of different recrystallization mechanisms has evident effects on grain *** increased as compression proceeds,and the texture was gradually weakened.

关键词： Mg-Gd-Y-Zn-Zr alloy Compression Long period ordered(LPSO)phase Recrystallization mechanism

Total ionizing dose effects on graphene-based charge-trapping memory

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Science China(Information Sciences) 2019年第12期62卷 207-214页

作者： Kai xi Jinshun BI SANDip MAJUMDAR bo LI Jing LIU Yannan XU Ming LIU Laboratory of Microelectronics Devices and Integrated Technology Institute of MicroelectronicsChinese Academy of Sciences School of Microelectronics University of Chinese Academy of Sciences

This study investigates the total ionizing dose effects in graphene-based charge-trapping memory(GCTM) capacitors by using60 Co γ-irradiation. Electrical properties including C-V hysteresis window,gate leakage current, and flat band voltage shifts are evaluated with ionizing dose levels up to 1 Mrad(Si).The C-V hysteresis memory window is hardly affected by the irradiation. The gate leakage current increases with the increase of ionizing dose due to the multiple-trap assisted tunneling mechanism. Significant electrical degrade of the devices in programmed and erased states has been observed with the increase of the dose levels. Mechanisms behind the degradation are attributed to the photo-emission in the graphene nanodisc charge-trapping sets, radiation-induced holes trapping in the peripheral oxides, and the recombination of the stored electrons with the radiation-induced holes.

关键词： graphene non-volatile memories radiation trap-assisted tunneling leakage current

Highly catalytic metal–organic framework coating enabled by liquid superwetting and confinement

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Nano Research 2023年第5期16卷 7716-7723页

作者： bo Yi Yan-Lung Wong Kedi Li Changshun Hou Tengrui Ma Zhengtao Xu xi Yao Department of Biomedical Sciences City University of Hong KongHong Kong 999077China Department of Chemistry City University of Hong KongHong Kong 999077China Institute of Materials Research and Engineering Agency for ScienceTechnology and Research(A*STAR)Singapore 138634Singapore City University of Hong Kong Shenzhen Research Institute Shenzhen 518057China

In this work,we report that high catalytic performance of metal–organic frameworks(MOFs)can be obtained through a synergistic effect of postsynthetic modification of MOF nanoparticles and liquid superwetting and confinement in the MOF ***,2-ureido-4[1H]pyrimidinone(UPy)functionalized polysiloxanes were covalently appended onto the UiO-66 nanoparticles via a postsynthetic approach,which were further anchored onto different porous films through multivalent hydrogen bonding of the UPy *** hydrophobic MOF coating can preserve the porosity of the solid substrates,enable rapid liquid superwetting and confinement within the porous *** the Knoevenagel condensation as a modeled system,robust and highly catalytic performances of the MOF coating were observed on a range of aldehyde ***-scale production of chromene,a pharmaceutical which is typically synthesized via expensive catalysis,was successfully demonstrated on the MOF coating with high yielding rates,demonstrating the great potential of the MOF coating in pharmaceutical synthesis.

关键词： metal–organic framework postsynthetic modification hydrogen bonding superwetting liquid confinement