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The Flow of Gauge Transformations on Riemannian Surface with Boundary

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Communications in Mathematics and Statistics 2017年第3期5卷 277-316页

作者： Wanjun ai School of Mathematical Sciences University of Science and Technology of ChinaHefeiChina

We consider the gauge transformations of a metricG-bundle over a compact Riemannian surface with *** employing the heat flow method,the local existence and the long time existence of generalized solution are proved.

关键词： Heat flow Coulomb gauge Blow-up analysis

Single Emulsion Microfluidic Production of Janus and Core-Shell Particles via Off-chip Polymerization

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Chinese Journal of Polymer Science 2016年第3期34卷 367-377页

作者： ai-di zhu 郭明雨 Suzhou Key Laboratory of Macromolecular Design and Precision Synthesis Jiangsu Key Laboratory of AdvancedFunctional Polymer Design and Application College of Chemistry Chemical Engineering and Materials Science Soochow University Suzhou 215123 China

In this work, we describe a straightforward approach to produce monodisperse Janus and core-shell particles by using organic solvent free single emulsion droplet-based microfluidic device combining with off-chip polymerization. To accomplish this, methyl methacrylate（MMA） was used as both the oil phase and solvent to dissolve a polymerizable PEGbased macromolecular surfactant, instead of traditional surfactant, and the photo-initiator. Janus particles can be easily obtained by off-chip UV polymerization due to polymerization induced phase separation between PEG and the formed poly（methyl methacrylate）. At the same time, core-shell particles can also be easily attained by inverting the original collecting tube several times and then exposing to UV light. These results may extend the scope of microfluidic technology and the studies on polymerization induced self-assembly/phase-separation into easy fabrication of various new functional materials.

关键词： Microfluidics Single emulsion Core-Shell spheres Janus particles Polymerization-induced phase-separation

Composition-tuned optical properties of CdSe_(x)S_(1-x) and CdSe_(x)S_(1-x)/ZnS QDs

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Optoelectronics Letters 2022年第8期18卷 479-483页

作者： WU Feng ZHANG siwen TIAN Zhu YU Wenhui SUN Shishuai LI Xiaolan Department of Physics School of ScienceTianjin University of TechnologyTianjin 300384China

The different compositions of the ternary alloyed CdSe_(x)S_(1-x)quantum dots(QDs)and CdSe_(x)S_(1-x)/ZnS core/shell quantum dots(CSQDs)have been synthesized by the chemical *** radii of these QDs were determined by transmission electron microscope(TEM).The optical properties of these QDs were investigated by the absorption and fluorescent *** was found that the absorption and fluorescent emissions were tuned by the component ratio,and the Commission Internationale de l´Eclairage(CIE)coordinates of the fluorescent spectra also depended on the *** with the CdSe_(x)S_(1-x)QDs,the CdSe_(x)S_(1-x)/ZnS CSQDs exhibit the fluorescence enhancement due to the surface passivation by shell *** composition-tuned optical properties may allow them to be used as fluorescent markers in biological imaging and to fabricate multicolor light emitting diode(LED).

关键词： CdSe_(x)S_(1-x) CdSe_(x)S_(1-x)/ZnS QDs

Satellite UV-Vis spectroscopy:implications for air quality trends and their driving forces in China during 2005-2017

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Light(Science & Applications) 2019年第1期8卷 246-257页

作者： Chengxin Zhang Cheng Liu Qihou Hu Zhaonan Cai Wenjing Su Congzi Xia Yizhi Zhu siwen Wang Jianguo Liu School of Earth and Space Sciences University of Science and Technology of China230026 HefeiChina Department of Precision Machinery and Precision Instrumentation University of Science and Technology of China230026 HefeiChina Key Laboratory of Environmental Optics and Technology Anhui Institute of Optics and Fine MechanicsChinese Academy of Sciences230031 HefeiChina Center for Excellence in Regional Atmospheric Environment Institute of Urban EnvironmentChinese Academy of Sciences361021 XiamenChina Key Laboratory of Precision Scientific Instrumentation of Anhui Higher Education Institutes University of Science and Technology of China230026 HefeiChina Key Laboratory of Middle Atmosphere and Global Environment Observation Institute of Atmospheric PhysicsChinese Academy of Sciences100029 BeijingChina Multiphase Chemistry Department Max Planck Institute for Chemistry55128 MainzGermany

Abundances of a range of air pollutants can be inferred from satellite UV-Vis spectroscopy measurements by using the unique absorption signatures of gas ***,we implemented several spectral fitting methods to retrieve tropospheric NO_(2),SO_(2),and HCHO from the ozone monitoring instrument(OMI),with radiative simulations providing necessary information on the interactions of scattered solar light within the *** analyzed the spatial distribution and temporal trends of satellite-observed air pollutants over eastern China during 2005-2017,especially in heavily polluted *** found significant decreasing trends in NO_(2) and SO_(2) since 2011 over most regions,despite varying temporal features and turning *** contrast,an overall increasing trend was identified for tropospheric HCHO over these regions in recent ***,generalized additive models were implemented to understand the driving forces of air quality trends in China and assess the effectiveness of emission *** results indicated that although meteorological parameters,such as wind,water vapor,solar radiation and temperature,mainly dominated the day-to-day and seasonal fluctuations in air pollutants,anthropogenic emissions played a unique role in the long-term variation in the ambient concentrations of NO_(2),SO_(2),and HCHO in the past 13 ***,recent declines in NO_(2) and SO_(2) could be attributed to emission reductions due to effective air quality policies,and the opposite trends in HCHO may urge the need to control anthropogenic volatile organic compound(VOC)emissions.

关键词： driving forces spectroscopy

Attitude Tracking Control for Rigid Spacecraft with Arbitrary Convergence Time

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Journal of Systems Science & Complexity 2024年第6期37卷 2579-2594页

作者： XU Yu-Tian WU ai-Guo Guangdong Provincial Key Laboratory of Intelligent Morphing Mechanisms and Adaptive Robotics Harbin Institute of Technology(Shenzhen)Shenzhen 518055China Key University Laboratory of Mechanism&Machine Theory and Intelligent Unmanned Systems of Guangdong Harbin Institute of Technology(Shenzhen)Shenzhen 518055China Department of Automation Harbin Institute of Technology(Shenzhen)Shenzhen 518055China HIT Wuhu Robot Technology Research Institute Wuhu 241060China

In this paper,attitude tracking control with arbitrary convergence time for rigid spacecraft is ***,a novel time-varying sliding function is proposed to achieve free-will arbitrary time convergence when the system states reside on the sliding *** such a sliding function,an attitude tracking controller is designed to guarantee that the states of the closed-loop system converge to the sliding surface within a predetermined time in the presence of external *** free-will arbitrary time convergences of the closed-loop system and sliding function are illustrated by numerical simulations.

关键词： Attitude tracking free-will arbitrary time stability rigid spacecraft sliding mode control

Photonic MEMS tunable laser sources

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The Journal of China Universities of Posts and Telecommunications 2009年第3期16卷 1-3页

作者： LIU ai-qun School of Electrical and Electronic Engineering Nanyang Technological University 50 Nanyang Avenue 639798 Singapore

This article covers laser configurations, design and experiments of photonic microelectromechanical systems （MEMS） tunable laser sources. Three different types of MEMS tunable lasers such as MEMS coupled-cavity lasers, injection-locked laser systems and dual-wavelength tunable lasers are demonstrated as examples of natural synergy of MEMS with photonics. The expansion and penetration of the MEMS technology to silicon optoelectronic creates on-chip optical systems at an unprecedented scale of integration. While producing better integration with robustness and compactness, MEMS improves the functionalities and specifications of laser chips. Additionally, MEMS tunable lasers are featured with small size, high tuning speed, wide tuning range and CMOS compatible integration, which broaden their applications to many fields.

关键词： photonic MEMS tunable laser photonics silicon optoelectronics

Optimizing feeding regimen of replacement gilts to improve their reproductive performance and retention rate of their first 2 parities

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Animal Nutrition 2023年第1期12卷 227-235页

作者： Jiajian Tan Miaomiao Wang Haiqing Sun Chao Wang Hongkui Wei siwen Jiang Yuanfei Zhou Jian Peng Department of Animal Nutrition and Feed Science College of Animal Science and TechnologyHuazhong Agricultural UniversityWuhan 430070China Key Lab of Agricultural Animal Genetics Breeding and Reproduction of Ministry of Education&Key Lab of Swine Genetics and Breeding of Ministry of AgricultureHuazhong Agricultural UniversityWuhan 430070China The Cooperative Innovation Center for Sustainable Pig Production Wuhan 430070China Guangxi Yang Xiang Joint Stock Company Guigang 537000China

The effects of age,body weight(BW),and backfat thickness(BF)of replacement gilts at first estrus and first mating on their subsequent reproductive performance and retention of their first 2 parities as sows was evaluated.A total of 3,025 Danish replacement gilts were categorized by farm(allocated to 4 farms),cross combination,age,BW and BF at first estrus and first mating,estrous cycle number at first mating,and flush feeding before first *** result shows that all the factors mentioned above were significantly associated with reproductive performance and retention rates of the first 2 *** 3 had more piglets born alive per litter(BA)(Paits differed,we used 100 replacement gilts as a unit and the total number of weaned piglets from the first 2 parities as a new *** gilts undergoing their first estrus between 180 and 210 d of age at 115 to 124.9 kg BW and 14 to 15 mm BF had significantly higher reproductive indexes for their first 2 parities per 100 replacement *** gilts that mated between 210 and 230 d of age at 140 to 149.9 kg BW and 15 to 16 mm BF had optimal reproductive *** results provide a new insight into the complex relationships among these reproductive performance traits and may help guide successful management of replacement gilts as a pivotal starting point for future fertility and longevity of rearing herds.

关键词： Replacement gilts Rearing parameter Reproductive performance Retention rate

Impulse-coupling coefficients from a pulsed-laser ablation of semiconductor GaAs

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Nuclear Science and Techniques 2006年第4期17卷 217-221页

作者： LIU ai-Hua College of Physics and Electronics Shandong Normal University Jinan 250014 China

Impulse-coupling coefficients from 1.06 - μ m, 10-ns Nd:YAG pulsed-laser radiation to GaAs targets with different areas were measured using the ballistic pendulum method in the laser power density ranging from 4.0 × 108 to 5.0 × 109 W·cm-2. A detonation wave model of the plasma was established theoretically. The expansion process of plasma after the laser pulse ends is described in detail, and the impulse-coupling coefficients from pulsed laser with different energies to GaAs with different areas were calculated using the given model. It is found that the theoretical results agree well with the experimental data.

关键词：激光-材料相互作用冲击式联接镓砷半导体激光爆破

Research on the scatter features of the PKiKP/PcP amplitude ratio and the inner core boundary density contrasts beneath Northeast Asia

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Science China Earth Sciences 2021年第5期64卷 716-727页

作者： Haodong ZHANG Yinshuang ai Yumei HE Key Laboratory of Earth and Planetary Physics Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China CAS Center for Excellence in Tibetan Plateau Earth Sciences Beijing 100049China University of Chinese Academy of Sciences Beijing 100101China

Quantifying the density contrasts of the Earth’s inner core boundary(ICB)is crucial to understand core-mantle coupling and the generation of the *** PKiKP/PcP amplitude ratio is commonly used to obtain the density contrast at the ICB,but its applications are limited by scattered observed *** this study,we selected the PKiKP and PcP phases reflected at the same region of inner-core and core-mantle boundaries beneath Northeast Asia from different earthquakes for the first time,and the observations suggested that the PKiKP/PcP amplitude ratio is widely *** also compared the PKiKP and PcP amplitudes,which demonstrated that the scatter cannot be attributed only to ICB anomalies but might also arise from raypath differences and heterogeneities throughout the crust and *** fitting the observed PKiKP/PcP amplitude ratio,we obtained a density contrast of approximately 0.65 g cm^(-3) and a compressional velocity contrast of approximately 0.87 km s^(-1) at the ICB beneath Northeast *** larger contrast values indicate the possible occurrence of local crystallization occurring at the inner core surface.

关键词： Northeast Asia Inner core boundary PKiKP/PcP amplitude ratio Density contrast