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试析市政工程排水管网施工质量控制措施
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作者 石红宇 雷旭 《工程设计与施工》 2024年第6期16-18,共3页
城市排水体系作为中国发展过程中的一项重要基础设施,其整体运营结果的好坏,能够直接影响到中国城市的正常运行,以及国民的日常生活。从当前实际情况上看,市政项目排水管网施工作业还有以下几个方面的问题有待解决,如规划方案不健全、... 城市排水体系作为中国发展过程中的一项重要基础设施,其整体运营结果的好坏,能够直接影响到中国城市的正常运行,以及国民的日常生活。从当前实际情况上看,市政项目排水管网施工作业还有以下几个方面的问题有待解决,如规划方案不健全、排水体系问题等。因此,有关部门必须对市政排水管网的规划与施工作业开展科学的剖析,并给出可行的优化方案,从而确保其正常运营。基于此,论文主要分析了市政工程排水管网施工质量控制措施,以期给有关工作人员提供参考。 展开更多
关键词 市政工程 排水管网 施工质量 控制措施
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Research Status and Key Technologies of Geo-Electromagnetic Magnetic Induction Sensor
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作者 Yanzhang Wang Yunxia Wan +3 位作者 Chen Chen hongyu shi Jun Lin Defu Cheng 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2017年第4期38-49,共12页
According to different applications,the performance parameters of the several Geo-Electromagnetic Magnetic Induction Sensors( GEMISs) which are the most representative in the world are compared. After discussing the s... According to different applications,the performance parameters of the several Geo-Electromagnetic Magnetic Induction Sensors( GEMISs) which are the most representative in the world are compared. After discussing the several key technologies for improving the performance of GEMISs,the main conclusions are as follows: the application bandwidth can be expanded by adopting flux negative feedback( 1 m Hz-10 k Hz);"laminated"core structure is useful for suppressing eddy current loss; the effective permeability of the core has increased observably after adding flux concentrators to the two ends of the core; the chopper amplifier is a useful method to suppress 1/f noise for reducing the GEMIS's output noise; the indoor calibration scheme based on"long straight solenoid"proposed to obtain sensor sensitivity. Accordingly,the problem how to reduce the noise of GEMIS is urgent need to be solved,which will improve the performance of GEMIS. And there is plenty of work requires further study on parameters ' optimization of coil and core. In the future,miniaturization,intelligence and three-axis measurement are the development directions of GEMIS. 展开更多
关键词 GEMIS key technologies FLUX NEGATIVE feedback “Laminated” corestructure FLUX CONCENTRATORS
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Electric field controlled superlubricity of fullerene-based host–guest assembly 被引量:1
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作者 Shanchao Tan hongyu shi +6 位作者 Xin Du Kunpeng Wang Haijun Xu Junhua Wan Ke Deng Qingdao Zeng Yuhong Liu 《Nano Research》 SCIE EI CSCD 2023年第1期583-588,共6页
Controlling friction by the electric field is a promising way to improve the tribological performance of a variety of movable mechanical systems.In this work,the assembly structure and microscale superlubricity of a h... Controlling friction by the electric field is a promising way to improve the tribological performance of a variety of movable mechanical systems.In this work,the assembly structure and microscale superlubricity of a host–guest assembly are effectively controlled by the electric field.With the help of the scanning tunneling microscopy(STM)technique,the host–guest assembly structures constructed by the co-assembly of fullerene derivative(Fluorene-C60)with macrocycles(4B2A and 3B2A)are explicitly characterized.Combined with density functional theory(DFT),the distinct different assembly behaviors of fullerene derivatives are revealed at different probe biases,which is attributed to the molecular polarity of the fullerene derivative.Through the control on the adsorption behavior,the friction coefficient of host–guest assembly is demonstrated to be controllable in the electric field by using atomic force microscopy(AFM).At positive probe bias,the friction coefficient of the host–guest assembly is significantly reduced and achieves superlubricity(μmin=0.0049).The efforts not only help us gain insight into the host–guest assembly mechanism controlled by the electric field,but also promote the further application of fullerene in micro-electro-mechanical systems(MEMS). 展开更多
关键词 SUPERLUBRICITY electric field friction control fullerene derivative host-guest assembly
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Hierarchical self-assembled structure and frictional response of phthalocyanine molecules 被引量:1
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作者 Yijun QIAO Jian SONG +3 位作者 hongyu shi Hongdong WANG shizhu WEN Yuhong LIU 《Friction》 SCIE EI CAS CSCD 2023年第3期354-368,共15页
Solid evidence is needed to demonstrate the effect of molecular orientation and structure on the frictional property of boundary lubricants.In this work,the frictional properties of phthalocyanine self-assembled monol... Solid evidence is needed to demonstrate the effect of molecular orientation and structure on the frictional property of boundary lubricants.In this work,the frictional properties of phthalocyanine self-assembled monolayers(SAMs)with face-on(aromatic cores parallel to the substrate)and edge-on(aromatic cores stand on the substrate)orientations have been compared and the in situ structural variation of edge-on SAMs under frictional shear has been revealed by atomic force microscope(AFM).Face-on oriented SAMs show lower adhesion,lower friction,and stronger wear resistance,compared with edge-on oriented SAMs.Hierarchical structures of edge-on oriented SAMs have been revealed by frictional topography,which are consisted of nanoscale columns,micron-scale stripes,and centimeter-scale monolayer.The column structure deforms under increasing load force,leading to a stepwise friction force curve and a transition among three friction states(ordered friction,collapsed friction,and worn friction).The structural deformation depends on both the order degree and anisotropic stiffness of columns.Columns in phthalocyanine SAMs show a larger stiffness when shearing against molecular plane than shearing along the molecular plane.The presented study on the interfacial structure and frictional mechanism promisingly supports the designing of novel boundary lubricants and their application in engineering. 展开更多
关键词 hierarchical assembly molecular orientation frictional mechanism PHTHALOCYANINE
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2D-to-3D buckling transformability enabled reconfigurable metamaterials for tunable chirality and focusing effect 被引量:1
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作者 DONGHAI HAN WENKANG LI +7 位作者 TAO SUN MIN LIU XIAOMING CHEN hongyu shi ZHENGJIE FAN FANQI MENG LIUYANG ZHANG XUEFENG CHEN 《Photonics Research》 SCIE EI CAS CSCD 2023年第10期1770-1780,共11页
Recently,multifarious deformation approaches in nature have promoted dynamic manipulation for electromagnetic(EM)waves in metamaterials,and those representative strategies are mainly focused on the modulation of spect... Recently,multifarious deformation approaches in nature have promoted dynamic manipulation for electromagnetic(EM)waves in metamaterials,and those representative strategies are mainly focused on the modulation of spectral parameters.Several works have also achieved tunable phase-gradient meta-devices.Here,to broaden the modulation freedom of mechanical deformation,we initially propose two reconfigurable metamaterials consisting of mirrored S-shaped meta-atoms selectively bonded on biaxially pre-stretched substrates.Planar meta-atoms with spin-insensitive transmittance are buckled into 3D morphologies to break residual symmetries by releasing the stress and to facilitate spin-dependent transmittance under circularly polarized incidence.Owing to the geometric anisotropy of S-shaped meta-atoms along the x and y axes,3D chiral meta-atoms exhibit discriminate circularly cross-polarized transmittance under opposite spins.The underlying physical mechanism reveals that EM resonance originates from the excitation of electric dipoles and magnetic dipoles,and their cross coupling finally triggers the chiral effects of 3D meta-atoms.By introducing the gradient-phase design that keeps unchanged under various strains,two types of meta-atoms with specified orientations are interleaved to design a double-foci metalens,and its 2D-to-3D morphology transformation shortens the focusing length and facilitates the intensity change of two foci.Our approach in designing reconfigurable EM metamaterials with 2D-to-3D buckling transformability can be further extended toward terahertz even optical wavebands,and it may assist with deriving more applicable multi-functionalities in the aspects of imaging,sensing,and holograms. 展开更多
关键词 BUCKLING POLARIZED circular
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An annually laminated stalagmite from the eastern Qinghai-Tibetan Plateau provides evidence of climate instability during the early MIS5e in the Asian summer monsoon
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作者 Tao GAO Pingzhong ZHANG +7 位作者 Hai CHENG Leilei ZHANG Xinhu LI hongyu shi Wei JIA Youfeng NING Hanying LI R.Lawrence EDWARDS 《Science China Earth Sciences》 SCIE EI CAS CSCD 2023年第5期1147-1164,共18页
The Marine Isotope Stage(MIS5e)is characterized by a warmer climate than that of the pre-industrial period,and serves as an analog for the Current Warm Period(CWP).However,uncertainties persist regarding its climatic ... The Marine Isotope Stage(MIS5e)is characterized by a warmer climate than that of the pre-industrial period,and serves as an analog for the Current Warm Period(CWP).However,uncertainties persist regarding its climatic stability.Here,we retrieved a stalagmite(WXB075)from Wanxiang Cave in the eastern Qinghai-Tibetan Plateau,and employed abs-olute^(230)Th dating and relative annual layer data to establish a high-precision chronological framework for reconstructing the history of the Asian summer monsoon(ASM)and environmental evolution during early MIS5e with multiple proxies.The findings indicate that the annually laminated stalagmite was formed during Cooling Event 27(C27).The deposition of WXB075 experienced a hiatus(~125.58 ka BP)due to a significant cooling event in the North Atlantic,which may be linked to the unstable climate in the Northern Hemisphere.Additionally,the impact of meltwater discharge in high northern latitudes results in a two-phase evolution of the ASM,i.e.,an initial weaker stage followed by a gradual increase(with exception of deposition hiatus).The climatic instability of ASM is generally characterized by a quasi-60 year cycle that affects vegetation conditions,biological productivity,and karst hydroclimate dynamics.However,the increase in meltwater and decrease in temperature in the Northern Hemisphere have led to a weakened ASM and subsequent reduction in precipitation.Consequently,vegetation degradation above the cave has occurred along with a slowdown of karst hydroclimate.The vegetation conditions,organic matter content,and wet/drought of the karst hydroclimate were affected by both the large-scale monsoon circulation and local environment during extreme weakening(strengthening)of the monsoon when high-frequency climatic events of ASM occurred.A comparison ofδ^(18)O records between early MIS5e and the past 2000 years reveals that the climate during early MIS5e differed significantly from that of CWP,Medieval Warm Period(MWP),and Dark Age Cold Period(DACP)but was similar to Little Ice Age(LIA).Comparison with other geological records from the Northern Hemisphere indicates that climate instability was a widespread phenomenon during MIS5e.The power spectrum analysis of WXB075δ^(18)O reveals significant quasi-60 and 35 a cycles during the early MIS5e,which is consistent with the Atlantic Multidecadal Oscillation(AMO).The comprehensive results demonstrate that the ASM in the early MIS5e was closely linked to solar activity,Intertropical Convergence Zone(ITCZ)position,and Atlantic Meridional Overturning Circulation(AMOC). 展开更多
关键词 Eastern Qinghai-Tibetan Plateau Climate instability Wanxiang Cave stalagmite Asian summer monsoon Environmental response Deposition hiatus
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Transmissive metasurface for multi-channel and full-polarization modulation of electromagnetic wavefronts
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作者 LINDA SHAO ZHENFEI LI +4 位作者 JIALIN FENG JIN ZHANG hongyu shi XUDONG BAI WEIREN ZHU 《Photonics Research》 SCIE EI CAS CSCD 2023年第2期245-251,共7页
Metasurfaces have great potential for flexible manipulation of electromagnetic wave polarizations and wavefronts.Here, we propose a general method for achieving independent wavefront manipulation in a single polarizat... Metasurfaces have great potential for flexible manipulation of electromagnetic wave polarizations and wavefronts.Here, we propose a general method for achieving independent wavefront manipulation in a single polarizationmultiplexing transmissive metasurface. As a proof of concept, we design a transmission-type anisotropic metasurface for independent wavefront manipulation in full-polarization channels. An x-polarized wave transmitted through such a metasurface could be converted into four outgoing beams with delicately designed polarization states that converge to specific positions for holographic imaging. The measured results are in good agreements with simulated ones, verifying the independent wavefront manipulations with arbitrary polarization conversions.Compared with the existing traditional meta-devices with single-polarization modulation, we achieve polarization-multiplexed metasurfaces with mixed polarization and phase control, which can greatly improve the functional richness of the system. 展开更多
关键词 surface. PROOF HOLOGRAPHIC
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Influence of functional groups on the self-assembly of liquid crystals 被引量:1
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作者 Shanchao Tan Jiayu Tao +5 位作者 Wendi Luo Hao Jiang Yuhong Liu Haijun Xu Qjngdao Zeng hongyu shi 《Chinese Chemical Letters》 SCIE CAS CSCD 2021年第3期1149-1152,共4页
Functional groups in the molecule play an important role in the molecular o rganization process.To reveal the influence of functional groups on the self-assembly at interface,herein,the self-assembly structures of thr... Functional groups in the molecule play an important role in the molecular o rganization process.To reveal the influence of functional groups on the self-assembly at interface,herein,the self-assembly structures of three liquid crystal molecules,which only differ in the functional groups,are explicitly characterized by using scanning tunneling microscopy(STM).The high-resolution STM images demonstrate the difference between the supramolecular assembly structures of three liquid crystal molecules,which attribute to the hydrogen bonding interaction andπ-πstacking interaction between different functional groups.The density functional theory(DFT)results also confirm the influence of these functional groups on the self-assemblies.The effort on the self-assembly of liquid crystal molecules at interface could enhance the understanding of the supramolecular assembly mechanism and benefit the further application of liquid crystals. 展开更多
关键词 SELF-ASSEMBLY Liquid crystal Functional group Hydrogen bond π-πStacking interaction
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Cross-polarization suppression in C-shaped microstrip patch antenna employing anisotropic dielectrics
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作者 hongyu shi shitao Zhu +2 位作者 Jianxing Li Anxue Zhang Zhuo Xu 《Journal of Advanced Dielectrics》 CAS 2017年第4期29-33,共5页
An anisotropic dielectric realized by layered ceramic structures was adopted to design a low cross-polarization C-shaped patch antenna.The anisotropic dielectric performs as a substrate and can cause additional cross-... An anisotropic dielectric realized by layered ceramic structures was adopted to design a low cross-polarization C-shaped patch antenna.The anisotropic dielectric performs as a substrate and can cause additional cross-polarized fields which are able to cancel the cross-polarized fields generated by the C-shaped patch itself,and then reduce the cross-polarization level.Compared to the C-shaped patch antenna with an isotropic substrate,the cross-polarization of the proposed antenna is suppressed by more than 15 dB with a little gain enhancement at 2.4 GHz.The anisotropic dielectric has a little impact on the direction of the C-shaped patch antenna.The gain of the proposed C-shaped patch antenna is 6.8 dB with a cross-polarization of28 dB. 展开更多
关键词 Anisotropic dielectrics layered ceramic structures low cross-polarization patch antennas
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Wideband polarization-independent anomalous reflection metasurface with multiple resonance modes
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作者 Guoxiang Dong Song Xia +6 位作者 Yongyong Zhuang hongyu shi Zhan Zhang Yuchen He Anxue Zhang Xiaoyong Wei Zhuo Xu 《Journal of Advanced Dielectrics》 CAS 2017年第2期17-20,共4页
An ultra-thin metasurface is proposed to realize wideband polarization-independent anomalous reflection. The sub-wavelengthresonator can produce different resonance modes, which are the result of the combined effect o... An ultra-thin metasurface is proposed to realize wideband polarization-independent anomalous reflection. The sub-wavelengthresonator can produce different resonance modes, which are the result of the combined effect of dielectric and the metallic structure.The gradient metasurface is done by six discrete orientation of the local sub-wavelength resonator which provides a phase gradient.The simulation and measured results show that 9 GHz bandwidth of the anomalous reflection is achieved. 展开更多
关键词 Metasurface anomalous reflection polarization
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