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Phase Equilibria of Hydrogen Bonding Fluid in a Slit Pore with Broken Symmetry

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Chinese Journal of Chemical Physics 2015年第3期28卷 288-294,I0001页

作者： Xiao-yu Liu Jiang-tao Li Fang gu Hai-jun Wang College of Chemistry and Environmental Science Hebei University Baoding 071002 China Chemical Biology Key Laboratory of Hebei Province Hebei University Baoding 071002 China Key Laboratory of Medical Chemistry and Molecular Diagnosis Ministry of Education BaodinE 071002 China

Phase equilibria of hydrogen bonding （HB） fluid confined in a slit pore with broken symmetry were investigated by the density functional theory incorporated with modified fundamental measure theory, where the symmetry breaking originated from the distinct interactions between fluid molecules and two walls of the slit pore. In terms of adsorption-desorption isotherms and the corresponding grand potentials, phase diagrams of HB fluid under various conditions are presented. Furthermore, through phase coexistences of laying transition and capillary condensation, the effects of HB interaction, pore width, fluid-pore interaction and the broken symmetry on the phase equilibrium properties are addressed. It is shown that these factors can give rise to apparent influences on the phase equilibria of confined HB fluid because of the competition between intermolecular interaction and fluid-pore interaction. Interestingly, a significant influence of broken symmetry of the slit pore is found, and thus the symmetry breaking can provide a new way to regulate the phase behavior of various confined fluids.

关键词： Hydrogen bonding fluid Broken symmetry Phase equilibria Density functional theory

LegoDroid: flexible Android app decomposition and instant installation

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Science China(Information Sciences) 2023年第4期66卷 155-173页

作者： Yi LIU yun MA Xusheng XIAO tao XIE Xuanzhe LIU School of Computer Science Peking University Key Laboratory of High Confidence Software Technologies(Peking University) Ministry of Education Institute for Artificial Intelligence Peking University Department of Computer and Data Sciences Case Western Reserve University

Current mobile applications(apps) have become increasingly complicated with increasing features that are represented on the graphical user interface associated with application programming interfaces(APIs) to access backend functionality and data. Meanwhile, apps suffer from the “software bloat” in volume. Some app features may be redundant, with respect to those features(from other apps) that the users already desirably and frequently use. However, the current app release model forces users to download and install a full-size installation package rather than optionally choosing only their desired features. Large-size apps can not only increase the local resource consumption, such as CPU, memory, and energy, but also inevitably compromise the user experience, such as the slow load time in the app. In this article, we first conduct an empirical study to characterize the app feature usage when users interact with Android apps,and surprisingly find that users access only a very small subset of app features. Based on these findings,we design a new approach named Lego Droid, which automatically decomposes an Android app for flexible loading and installation, while preserving the expected functionality with a fast and instant app load. With such a method, a slimmer bundle will be downloaded and host the target APIs inside the original app to satisfy users’ requirements. We implement a system for Lego Droid and evaluate it with 1000 real-world Android apps. Compared to the original full-size apps, apps optimized by Lego Droid can substantially improve the load time by reducing the base bundle and feature bundles by 13.06% and 10.93%, respectively,along with the app-package installation size by 44.17%. In addition, we also demonstrate that Lego Droid is quite practical with evolving versions, as it can produce substantial reusable code to alleviate the developers’ efforts when releasing new app versions.

关键词： performance software bloat instant installation mobile applications program analysis

Suitability projection for Chinese ski areas under future natural andsocioeconomic scenarios

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Advances in Climate Change Research 2021年第2期12卷 224-239页

作者： DENG Jie CHE tao JIANG Tong DAI Li-yun Heihe Remote Sensing Experimental Research Station Key Laboratory of Remote Sensing of Gansu ProvinceNorthwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou730000China Center for Excellence in Tibetan Plateau Earth Sciences Chinese Academy of SciencesBeijing100101China University of Chinese Academy of Sciences Beijing100049China Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disaster School of Geographic SciencesNanjing University of InformationScience&TechnologyNanjing210044China Jiangsu Center of Collaborative Innovation in Geographical Information Resource Development and Application Nanjing210000China

Ski tourism is extremely sensitive to climate change and is also heavily affected by socioeconomic *** some ski areas arestill profitable under current climate and socioeconomic conditions,they will become difficult to operate in the face of rising winter temper-atures,which will result in further economic losses,resource waste and environmental *** study projects variability in the suitability ofski area development across China in the coming *** suitability under three representative concentration pathway emission sce-narios(RCP2.6,RCP4.5 and RCP8.5),socioeconomic suitability under four shared socioeconomic pathways(SSP1,SSP2,SSP3,and SSP5)andintegrated suitability under four climatic-socioeconomic scenarios(RCP2.6-SSP1,RCP4.5-SSP2,RCP8.5-SSP3,and RCP8.5-SSP5)are ***,the suitability of 731 existing ski areas in China is *** results show a substantial decline in integrated suitabilityfor most regions of China except for some very cold areas,where higher air temperatures will make visitors feel more comfortable and therelatively poor socioeconomic conditions will improve in the 2030s,2050s and *** average higher integrated suitability area(integratedsuitability values greater than 0.5)under four climatic-socioeconomic scenarios decreases from the current 29.9%e14.4%,5.0%and 4.5%bythe 2030s,2050s and 2090s,*** RCP2.6-SSP1,the higher integrated suitability area is projected to decrease from the current28.0%e5.2%by the 2050s and then increase to 5.3%by the *** RCP4.5-SSP2,RCP8.5-SSP3,and RCP8.5-SSP5,the higher inte-grated suitability area is projected to continuously decrease from 30.3%,30.6%and 30.6%in the 2010s to 4.1%,4.4%and 4.4%in the 2090s,*** the 2090s,41,138 and 277 existing ski areas are projected to be closed under RCP2.6-SSP1,RCP4.5-SSP2,and RCP8.5-SSP3/RCP8.5-SSP5,*** is clear that emission pathways and climate change adaptation and mitigation

关键词： Suitability Ski tourism Climate change Socioeconomic development China

Diketopyrrolopyrrole-based Conjugated Polymers as Representative Semiconductors for High-Performance Organic Thin-Film Transistors and Circuits

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Chinese Journal of Polymer Science 2023年第5期41卷 671-682,I0006页

作者： Kai-Qing Liu Yuan-He gu Zheng-Ran Yi yun-Qi Liu Zhuhai Fudan Innovation Institution Zhuhai 518057China Department of Environmental Science and Engineering Faculty of Innovation EngineeringMacao University of Science and TechnologyMacao 999078China Key Laboratory of Organic Solids Beijing National Laboratory for Molecular SciencesInstitute of ChemistryChinese Academy of SciencesBeijing 100190China

Since the first report of diketopyrrolopyrrole(DPP)-based conjugated polymers for organic thin-film transistors(OTFTs),these polymers have attracted great attention as representative semiconductors in high-performance *** unremitting efforts in molecular-structure regulation and device optimization,significant mobilities exceeding 10 cm2·V–1·s–1 have been achieved in OTFTs,greatly promoting the applied development of organic *** this review,we summarize our progress in molecular design,synthesis and solution-processing of DPP-based conjugated polymers for OTFT devices and circuits,focusing on the roles of design strategies,synthesis methods and processing ***,the remaining issues and future outlook in the field are briefly discussed.

关键词： Diketopyrrolopyrrole Polymer semiconductors Organic thin-film transistor Organic circuits

The visual fiducial based pose estimation of mobile manipulator in large-scale components manufacturing

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Science China(Technological Sciences) 2021年第10期64卷 2186-2199页

作者： GONG ZeYu YU SuPu tao Bo gu ZhenFeng WANG JinShan DING Han State Key Laboratory of Digital Manufacturing Equipment and Technology School of Mechanical Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074China

The accurate estimation of the end-effector’s pose in large operating spaces is the key for the mobile manipulator to realize efficient manufacturing of large and complex *** propose a novel pose tracking method in large-range using visual fiducial markers,and further propose the layout optimization method for the encoded fiducial markers.A metric named orientational dilution of precision(ODOP)is proposed to evaluate the magnification of the pose estimation error compared with the measurement error of the coded fiducial *** distribution pattern of the coded markers is analyzed based on ODOP,and the square-shaped layout is determined to be a satisfactory distribution pattern for the minimum positioning unit of markers,and the side length of the square-shaped layout is further *** simulations and experiments prove the effectiveness of the ODOP ***,the square-shaped layout and the designed distribution density for positioning coded markers are adopted to realize the high-precision measurement of large components by the mobile manipulator.

关键词： pose estimation orientational dilution of precision mobile manipulator visual fiducial layout optimization

Numerical Investigation of Flow Separation Control on a Highly Loaded Compressor Cascade by Plasma Aerodynamic Actuation

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Chinese Journal of Aeronautics 2012年第3期25卷 349-360页

作者： ZHAO Xiaohu LI Yinghong WU yun ZHU tao LI Yiwen Science and Technology on Plasma Dynamics Laboratory Air Force Engineering UniversityXi'an 710038China

To discover the characteristic of separated flows and mechanism of plasma flow control on a highly loaded compressor cascade, numerical investigation is conducted. The simulation method is validated by oil flow visualization and pressure distribution. The loss coefficients, streamline patterns, and topology structure as well as vortex structure are analyzed. Results show that the numbers of singular points increase and three pairs of additional singular points of topology structure on solid surface generate with the increase of angle of attack, and the total pressure loss increases greatly. There are several principal vortices inside the cascade passage. The pressure side leg of horse-shoe vortex coexists within a specific region together with passage vortex, but finally merges into the latter. Corner vortex exists independently and does not evolve from the suction side leg of horse-shoe vortex. One pair of radial coupling-vortex exists near blade trailing edge and becomes the main part of backflow on the suction surface. Passage vortex interacts with the concentrated shedding vortex and they evolve into a large-scale vortex rotating in the direction opposite to passage vortex. The singular points and separation lines represent the basic separation feature of cascade passage. Plasma actuation has better effect at low freestream velocity, and the relative reductions of pitch-averaged total pressure loss coefficient with different actuation layouts of five and two pairs of electrodes are up to 30.8% and 26.7% while the angle of attack is 2~. Plasma actuation changes the local topology structure, but does not change the number relation of singular points. One pair of additional singular point of topology structure generates with plasma actuation and one more reattachment line appears, both of which break the separation line on the suction surface.

关键词： plasma aerodynamic actuation cascade oil flow visualization topology structure vortex singular point

Torque Limit-based Inertial Control Method Based on Delayed Support for Primary Frequency Control of Wind Turbines

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Journal of Modern Power Systems and Clean Energy 2024年第2期12卷 561-570页

作者： Wei gu Zaiyu Chen Qun Li Minghui Yin Qiang Li yun Zou School of Automation Nanjing University of Science and TechnologyNanjing 210094China State Grid Jiangsu Electric Power Co. Ltd.Research InstituteNanjing 211103China

To avoid the secondary frequency dip caused by the steep drop of the electrical power of wind turbines(WTs)at the end of frequency support stage,the torque limit-based iner-tial control(TLIC)method sets the power reference as a linear function of rotor speed,rather than the step form for the step-wise inertial ***,the compensation effect on the frequency nadir(FN)caused by the load surge is weakened as the TLIC power is no longer in the step ***,the maximum point of the frequency response component(FRC)contributed by TLIC occurs earlier than the minimum point of FRC corresponding to the load surge,so that the FN cannot be adequately ***,this paper first investigates the relation between the peak and nadir times of FRCs stimulated by the TLIC and load *** this basis,with the compensation principle of matching the peak and nadir times of FRCs,the improved TLIC method based on delayed support is ***,the effectiveness of the proposed method is validated via the experiments on the test bench of wind-integrated power system.

关键词： Wind turbine frequency response component torque limit inertial control delayed support

Long-term flexible penetrating neural interfaces:materials, structures, and implantation

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Science China(Information Sciences) 2021年第12期64卷 5-22页

作者： Chi gu Jianjuan JIANG Tiger H.tao Xiaoling WEI Liuyang SUN State Key Laboratory of Transducer Technology Shanghai Institute of Microsystem and Information TechnologyChinese Academy of Sciences University of Chinese Academy of Sciences School of Physical Science and Technology Shanghai Tech University Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of Science 52020 X-Lab Shanghai Institute of Microsystem and Information TechnologyChinese Academy of Sciences Shanghai Research Center for Brain Science and Brain-Inspired Intelligence Center for Excellence in Brain Science and Intelligence Technology Chinese Academy of Sciences

Penetrating neural interface, which collects the neural electrophysiological signal and serves as a key component in brain-computer interface, has drawn great attention recently. The instability of chronic recording is the main challenge for the conventional neural interface. Novel neural probes with improved long-term performance have been developed based on advanced materials and engineered structures. Here, we review these emergent innovations contributing to chronic stable recording from the perspectives of materials,structures, and implantation methods. These advances make possible further developments in neuroscience research related to neural decoding, neural circuit mechanism analysis, and neurological disease treatment.

关键词： neural interface long-term flexible minimally invasive biocompatibility

Enhanced electromagnetic wave absorption properties of ZIF-67 modified polymer-derived SiCN ceramics by in situ construction of multiple heterointerfaces

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Rare Metals 2023年第5期42卷 1635-1644页

作者： tao-Bo Geng Gao-Yuan Yu Gao-Feng Shao Xiao-gu Huang School of Chemistry and Materials Science Nanjing University of Information Science&TechnologyNanjing210044China

Multiphase polymer-derived ceramics have the advantages of thermal stability and adjustable dielectric properties,which exhibit significant potential for use in high-temperature microwave absorbing ***,Co-containing polymer-derived SiCN(Co-SiCN)ceramics were successfully synthesized by the physical mixing of zeolitic imidazolate framework(ZIF)-67 and polysilazane precursors and subsequent *** phase and chemical compositions,microstructures,dielectric properties,electromagnetic wave absorption(EWA)performance,and mechanism of the ceramics were *** results showed that the introduction of ZIF-67 promoted the in situ formation of dielectric loss phases,including SiC nanocrystals,CoSi nanocrystals,and free *** phase composition can be regulated by controlling the pyrolysis temperature to achieve ideal EWA *** Co-SiCN ceramic pyrolyzed at 1500℃demonstrated excellent EWA performance,with a maximum effective absorption band(EAB_(max))of 3.0 GHz at an ultralow thickness of 1.05 mm and minimum reflection loss(RL_(min))of-46.4 dB at a low frequency of 6 *** with other reported SiCN-based ceramics containing magnetic metals,the ceramics prepared in this study stand out because of their low RL and high EAB at low *** superior microwave absorption performance of the Co-SiCN ceramics is attributed to the heterointerface polarization,and impedance matching induced by the synergistic effects of their co-existing electromagnetic transparent/absorption *** study provides new insights into the development of high-performance SiCNbased microwave absorbers.

关键词： Polymer-derived SiCN ceramic Multiple heterointerfaces Zeolitic imidazolate framework(ZIF-67) Electromagnetic wave absorption(EWA)