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Water droplet impact on superhydrophobic surfaces with microstructures and hierarchical roughness

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Science China(Physics,Mechanics & Astronomy) 2014年第7期57卷 1376-1381页

作者： HAO PengFei lv CunJing NIU FengLei YU Yu Department of Engineering Mechanics Tsinghua University State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources North China Electric Power University

Quantitative correlation between the critical impact velocity of droplet and geometry of superhydrophobic surfaces with microstructures is systematically *** data shows that the critical impact velocity induced wetting transition of droplet on the superhydrophobic surfaces is strongly determined by the perimeter of single micropillar,the space between the repeat pillars and the advancing contact angle of the sidewall of the *** proposed model agrees well with the experimental results,and clarifies that the underlying mechanism which is responsible for the superhydrophobic surface with hierarchical roughness could sustain a higher liquid pressure than the surfaces with microstructures.

关键词：微观结构疏水表面层结构超疏水性表面撞击水滴冲击速度表面粗糙度

Wetting property of smooth and textured hydrophobic surfaces under condensation condition

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Science China(Physics,Mechanics & Astronomy) 2014年第11期57卷 2127-2132页

作者： HAO PengFei lv CunJing YAO ZhaoHui NIU FengLei Department of Engineering Mechanics Tsinghua University State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources North China Electric Power University

Static and dynamic wetting behaviors of sessile droplet on smooth,microstructured and micro/nanostructured surface under condensation condition are systematically *** contrast to the conventional droplet wetting on such natural materials by dropping,we demonstrate here that when dropwise condensation occurs,the sessile droplet will transit from the Cassie-Baxter wetting state to the Wenzel wetting state or partial Cassie-Baxter wetting state on the microstructured surface or the micro/nanostructured surface,which leads to a strong adhesion between the droplet and the *** contrast,the apparent contact angle and the sliding angle on the smooth surface changes a little before and after the condensation because of small *** analysis shows that the roughness factor controls the adhesion force of the droplet during condensation,and a theoretical model is constructed which will be helpful for us to understand the relationship between the adhesion force and the geometry of the surface.

关键词：表面特性光滑表面湿润疏水织构缩合滴状冷凝纳米结构

System-Level EMC Assessment for Military Vehicular Communication Systems Based on a Modified Four-Level Assessment Model

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China Communications 2018年第8期15卷 39-53页

作者： Ping Zhou Yinghua lv Zhihong Chen Hongping Xu School of Electronic Engineering Beijing University of Posts and Telecommunications Beijing Institute of Astronautic System Engineering China Academy of Launch Vehicle Technology

With the development of EMC technology, EMC assessment has become increasingly important in EMC design. Although numerous EMC assessment models are available today, few of them can provide a tradeoff between efficiency and accuracy for the specific case of military vehicular communication systems. Face to this situation, a modified four-level assessment model is proposed in the paper. First, the development of EMC assessment technology is briefly reviewed, and the theoretical mechanism of EMI environment is introduced. Then, the architecture of the proposed model is outlined, and the assessment methods are explored. To demonstrate the application of it, an example involving a communication system in a military vehicle is presented. From the physical layer to the signal layer, a hierarchical assessment on the entire system is successfully performed based on the proposed model, and we can make a qualitative EMC assessment on the EMC performance of the system. Based on a comparison with the traditional model, we conclude that the proposed model is more accurate, more efficient and less time-consuming, which is suitable for the EMC assessment on militaryvehicular communication systems. We hope that the proposed model will serve as a useful reference for system-level EMC assessments for other systems.

关键词：评价模型通讯系统军事车辆 EMC 修改水评价技术理论机制

Preparation,characterization and combustion properties of Zr/ZrH_2 particles coated with α-FeOOH crystal grains

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Particuology 2009年第3期7卷 169-174页

作者： Baoliang lv Yao Xu Bo HOU Dong Wu Yuhan Sun State Key Laboratory of Coal Conversion Institute of Coal Chemistry Chinese Academy ofSdences Taiyuan 030001 China Graduate School of the Chinese Academy of Sciences Beijing 100049. China

Zr/ZrH2 particles with irregular morphologies and broad size distribution were uniformly coated with acicular α-FeOOH crystal grains via a facile route without using polymers or surfactants. The as-synthesized material was characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, energy dispersive X-ray （EDX）, UV-vis diffusion reflection （UV-vis） and Raman spectrometry. Based on these characterizations, the synthesis mechanism was explained in terms of combined heterogeneous nucleation and solid state transformation reaction. The presence of α-FeOOH coating greatly changed the combustion behavior of Zr/ZrH2 particles： the combustion lasting time decreased from 32 s for un-coated Zr/ZrH2 particles to 0.2 s for coated particles while the maximum temperature in the combustion process increased from 1510 ℃ to 2036℃.

关键词： Composite materials Coating Zr/ZrH2 α-FeOOH Solid state transformation Combustion

Syntheses,Crystal Structures and Fluorescent Properties of Two Zinc Complexes Assembled by Bis(imidazol)Ligands

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Chinese Journal of Structural Chemistry 2020年第10期39卷 1885-1891,1745页

作者：吕梦影吕丛闫国松周实姜维刘博李秀梅 Key Laboratory of Preparation and Applications of Environmental Friendly Materials(Jilin Normal University) Ministry of EducationChangchun 130103China Faculty of Chemistry Tonghua Normal UniversityTonghua 134002China

Two new complexes[Zn(nph)(bix)]n·nH2O(1)and[Zn(nba)2(bix)]n(2)(H2nph=4-nitrophthalic acid,Hnba=4-nitrobenzoic acid,bix=1,4-bis(imidazol-1-yl)-benzene)have been hydrothermally synthesized and structurally characterized by elemental analysis,IR spectrum,fluorescence spectrum,single-crystal and power X-ray *** 1 exhibits a three-dimensional(3D)framework,which is stabilized through C–H…O hydrogen bonds andπ-πstacking *** 2 shows a zero-dimensional structure,which is further extended into a three-dimensional supramolecular structure through C–H…O and C–H…N hydrogen bonding interactions.

关键词： hydrothermal synthesis crystal structure Zn(Ⅱ)complex 1 4-bis(imidazol-1-yl)-benzene

Abundance and diversity of ammonia-oxidizing archaea in response to various habitats in Pearl River Delta of China, a subtropical maritime zone

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Journal of Environmental Sciences 2013年第6期25卷 1195-1205页

作者： Zhixin Li Wenbiao Jin Zhaoyun Liang yangyang Yue Junhong lv Shenzhen Key Laboratory of Water Resource Utilization and Environmental Pollution Control Harbin Institute of Technology Shenzhen Graduate School Shenzhen Institute of Advanced Technology Chinese Academy of Sciences

Ammonia-oxidizing archaea （AOA） are widely considered key to ammonia oxidation in various environments. However, little work has been conducted to simultaneously investigate the abundance and diversity of AOA as well as correlations between archaeal amoA genotypes and environmental parameters of different ecosystems at one district. To understand the abundance, diversity, and distribution of AOA in Pearl River Delta of China in response to various habitats, the archaeal amoA genes in soil, marine, river, lake, hot spring and wastewater treatment plant （WWTP） samples were investigated using real-time fluorescent quantitative PCR and clone libraries. Our analyses indicated that the diversity of AOA in various habitats was different and could be clustered into five major clades, i.e., estuary sediment, marine water/sediment, soil, hot spring and Cluster 1. Phylogenetic analyses revealed that the structure of AOA communities in similar ecological habitats exhibited strong relation. The canonical correspondence method indicated that the AOA community structure was strongly correlated to temperature, pH, total organic carbon, total nitrogen and dissolved oxygen variables. Assessing AOA amoA gene copy numbers, ranging from 6.84× 10^6 to 9.45 × 10^7 copies/g in dry soil/sediment, and 6.06× 10^6 to 2.41 ×10^7 copies/L in water samples, were higher than ammonia-oxidizing bacteria （AOB） by 1-2 orders of magnitude. However, AOA amoA copy numbers were much lower than AOB in WWTP activated sludge samples. Overall, these studies suggested that AOA may be a major contributor to ammonia oxidation in natural habitats but play a minor role in highly aerated activated sludge. The result also showed the ratio of AOA to AOB amoA gene abundance was positively correlated with temperature and less correlated with other environmental parameters. New data from our study provide increasing evidence for the relative abundance and diversity of ammonia-oxidizing archaea in the global nitrogen cyc

关键词： ammonia-oxidizing archaea abundance community structure real-time quantitative PCR clone library Pearl River Delta

Theory-orientated discovery of high-temperature superconductors in superhydrides stabilized under high pressure

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Matter and Radiation at Extremes 2020年第6期5卷 88-90页

作者： Jian lv Ying Sun Hanyu Liu yanming Ma International Center for Computational Method and Software College of PhysicsJilin UniversityChangchun 130012People’s Republic of China State Key Laboratory of Superhard Materials College of PhysicsJilin UniversityChangchun 130012People’s Republic of China International Center of Future Science Jilin UniversityChangchun 130012People’s Republic of China

A dream long held by physicists has been to raise the critical temperature(Tc)—the temperature below which the material exhibits no electrical resistance—of a superconductor to room *** most recent excitement in tha... 详细信息

关键词： temperature. stabilized superconductors

Logic-signal output of fluorescent proteins for screening antibiotic combinations

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Science China Chemistry 2014年第12期57卷 1696-1702,1-2页

作者： lv Feng Ting LIU Li Bing WANG Shu Beijing National Laboratory for Molecular Science Key Laboratory of Organic Solids Institute of ChemistryChinese Academy of Sciences

A new method to screen antibiotic combinations is demonstrated,which takes advantage of the logic-signal output of genetically engineered drug-resistant *** strains expressing different fluorescent ***-six antibiotic combinations for nine antibiotics were *** operation of different logic gates can reveal the susceptibility,resistance,or synergistic effect of the antibiotic combinations in a rapid(7–8 h versus 24–28 h for typical growth-based assays),simple,quantitative and high-throughput *** logic-signal-based output patterns provide the basis for novel and reliable screening of antibiotic combinations and help us to both gain insight into the mechanisms of multi-drug action.

关键词：荧光蛋白质信号输出逻辑信号抗生素筛选基因工程药物大肠杆菌协同作用

Implementing fractional Fourier transform and solving partial differential equations using acoustic computational metamaterials in space domain

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Acta Mechanica Sinica 2021年第9期37卷 1371-1377,I0001页

作者： Zengyao lv Peng Liu Yuanshuai Ding Hangyu Li Yongmao Pei Department of Engineering Mechanics Center for Flexible Electronics TechnologyApplied Mechanics LaboratoryTsinghua UniversityBeijing100084China State Key Laboratory for Turbulence and Complex Systems Department of Mechanics and Engineering ScienceCollege of EngineeringPeking UniversityBeijing100871China Locomotive and Car Research Institute China Academy of Railway Sciences Corporation LimitedBeijing100081China

Metamaterials can control incident waves in the sub-wavelength range through the design of artificial structures, and realize the functions that natural materials cannot achieve. The study of metamaterials has important theoretical value and application prospects. In recent years, the proposal of computational metamaterials has opened up a brand-new direction for analog computing, providing high-throughput, energy-free computing methods for special computing tasks. However, the development of acoustic computing metamaterials is relatively preliminary, and it is necessary to develop design theories. There is no work to solve partial differential equations and realize fractional Fourier transform in spatial domain acoustic computing metamaterials. In this paper, the acoustic wave computational metamaterial is designed, and the simulation realizes the spatial domain fractional Fourier transform and partial differential equation calculation. It is expected that acoustic computational metamaterials will enable new capabilities in signal acquisition and processing, network computing, and drive new applications of sound wave.

关键词： Fractional Fourier transform Partial differential equations Acoustic computational metamaterials