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Multi-scenario Simulation of the Impact of Land Use Change on the Ecosystem Service Value in the Suzhou-Wuxi-Changzhou Metropolitan Area,China

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Chinese Geographical Science 2024年第1期34卷 79-92页

作者： WANG Bin hu chunguang ZHANG Yushuo Department of Tourism Management Soochow UniversitySuzhou215123China Academy of Culture and Tourism Research Soochow UniversitySuzhou215123China School of Architecture and Urban Planning Huazhong University of Science and TechnologyWuhan430074China hubei Engineering and Technology Research Center of Urbanization Wuhan430074China Faculty of Culture Tourism Shanxi University of Finance and EconomicsTaiyuan030006China

As the most economically developed metropolitan area in China’s Yangtze River Delta,the rapid changing land use patterns of Suzhou-Wuxi-Changzhou(Su-Xi-Chang) metropolitan area have profound impacts on the ecosystem service value(ESV).Based on the patterns of land use change and the ESV change in Su-Xi-Chang metropolitan area from 2000 to 2020,we set up four scenarios:natural development scenario,urban development scenario,arable land protection scenario and ecological protection scenario,and simulated the impact of land use changes on the ESV in these *** results showed that:1) the area of built-up land in the Su-XiChang metropolitan area increased significantly from 2000 to 2020,and the area of other types of land *** land underwent the highest transfer-out area,and was primarily converted into built-up *** total ESV of Su-Xi-Chang metropolitan area increased initially then declined from 2000–2020,and the value of almost all individual ecosystem services decreased.2) Population density,GDP per area,night lighting intensity,and road network density can negatively impact the ESV.3) The total ESV loss under the natural development and urban development scenarios was high,and the expansion of the built-up land and the drastic shrinkage of the arable land contributed to the ESV decline under both *** total ESV under arable land protection and ecological protection scenarios increases,and therefore these scenarios are suitable for future land use optimization in *** study could provide a certain reference for land use planning and allocation,and offer guidance for the rational allocation of land resources.

关键词： multiple scenarios land use simulation ecosystem service value(ESV) Patch-Generating Land Use Simulation(PLUS)model Suzhou-Wuxi-Changzhou(Su-Xi-Chang)metropolitan area

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Simultaneous, hybrid single-molecule method by optical tweezers and fluorescence

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Nanotechnology and Precision Engineering 2019年第4期2卷 145-156页

作者： Guoteng Ma chunguang hu Shuai Li Xiaoqin Gao Hongbin Li Xiaotang hu State Key Laboratory of Precision Measuring Technology and Instruments Tianjin University300072China Nanchang Institute for Microtechnology of Tianjin University Tianjin 300072China Department of Chemistry University of British ColumbiaVancouverBC V6T 1Z1Canada

As studies on life sciences progress toward the single-molecule level,new experiments have put forward more requirements for simultaneously displaying the mechanical properties and conformational changes of *** tweezers and fluorescence microscopy have been combined to solve this *** combination of instruments forms a new generation of hybrid single-molecule technology that breaks through the limitations of traditional biochemical *** and fluorescence visualization have beenwidely used,and these techniques provide new possibilities for studying complex biochemical reactions at the singlemolecule *** paper explains the features of this combined technique,including the application characteristics of single-trap and dual-traps,the anti-bleaching method,and optical tweezers combined with epifluorescence,confocal fluorescence,total internal reflection fluorescence,and other fluorescence *** typical experiments,we analyze technical solutions and explain the factors and principles that instrument designers should *** review aims to give an introduction to this novel fusion technology process and describe important biological results.

关键词： Single-molecule Optical tweezers Confocal fluorescence FRET TIRF

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Polarization Measurement Method Based on Liquid Crystal Variable Retarder(LCVR)for Atomic Thin-Film Thickness

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Nanomanufacturing and Metrology 2022年第2期5卷 159-166页

作者： Yucong Yuan Chengyuan Yao Wanfu Shen Xiaodong hu chunguang hu State Key Laboratory of Precision Measuring Technology and Instruments Tianjin UniversityTianjin300072China

Atomic thickness thin films are critical functional materials and structures in atomic and close-to-atomic scale ***,fast,facile,and highly sensitive precision measurement of atomic film thickness remains *** reflected light has a dramatic phase change and extreme reflectivity considering the Brewster angle,indicating the high sensitivity of the optical signal to film thickness near this ***,the precision polarization measurement method focusing on Brewster angle is vital for the ultrahigh precision characterization of thin films.A precision polarization measurement method based on a liquid crystal variable retarder(LCVR)is proposed in this paper,and a measurement system with a high angular resolution is established.A comprehensive measurement system calibration scheme is also introduced to accommodate ultrahigh precision film thickness *** measurement accuracy to the subnanometer level is *** silicon oxide film samples of different thicknesses were measured around Brewster angle using the self-developed system and compared with a commercial ellipsometer to verify the measurement *** consistency of the thickness measurement results demonstrates the feasibility and robustness of the measurement method and calibration *** study also demonstrates the remarkable potential of the LCVR-based polarization method for atomic film thickness measurement in ultraprecision manufacturing.

关键词： Atomic thickness thin film Thickness Polarization measurement Brewster angle LCVR

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An optical tweezer-based microdroplet imaging technology

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Nanotechnology and Precision Engineering 2023年第3期6卷 27-33页

作者： Cong Zhai Yujian Hong Zuzeng Lin Yulu Chen Han Wang Tong Guo chunguang hu State Key Laboratory of Precision Measuring Technology and Instruments Tianjin UniversityTianjin 300072China

Microspheres can break the diffraction limit and magnify nano-structure imaging,and with its advantages of low cost and label-free operation,microsphere-assisted imaging has become an irreplaceable tool in the life sciences and for precision ***,the tiny size and limited imaging field of traditional solid microspheres cause difficulties when imaging large sample ***,droplets have similar properties to those of microspheres,with large surface curvature and refractive-index difference from the surrounding environment,and they can also serve as lenses to focus light for observation and *** work has shown that droplets with controllable size can be generated using an optical tweezer system and can be driven by optical traps to move precisely like solid ***,a novel microdroplet-assisted imaging technology based on optical tweezers is proposed that better integrates the generation,manipulation,and utilization of droplets.

关键词： Optical tweezers Photogenerated droplets Assisted imaging Controllable generation

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Sensitivity Improvements for Picosecond Ultrasonic Thickness Measurements in Gold and Tungsten Nanoscale Films

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Nanomanufacturing and Metrology 2024年第2期7卷 1-12页

作者： Jiaqi Dong Chengyuan Yao Yuanhao Zhu Shaojie Li Bowen Liu JinTao Fan chunguang hu Youjian Song Minglie hu Key Laboratory of Opto-Electronic Information Science and Technology of Ministry of Education School of Precision Instruments and Opto-Electronics EngineeringTianjin UniversityTianjin 300072China State Key Laboratory of Precision Measuring Technology and Instruments Tianjin UniversityTianjin 300072China

Picosecond ultrasonics,as a nondestructive and noncontact method,can be employed for nanoscale metallic film thickness *** sensitivity of the system,which determines the measurement precision and practicability of this technique,is often limited by the weak intensity of the ultrasonic *** solve this problem,we investigate the distinct mechanisms involved in picosecond ultrasonic thickness measurement for two types of metals,namely tungsten(W)and gold(Au).For thickness measurement in W films,theory and simulation show that optimizing the pump and probe laser wavelengths,which determine the intensity and shape of the ultrasonic signal,is critical to improving measurement sensitivity,while for Au film measurements,where acoustic-induced beam distortion is dominant,the signal intensity can be optimized by selecting an appropriate aperture size and sample *** above approaches are validated in experiments.A dual-wavelength pump-probe system is constructed based on a passively mode-locked ytterbium-doped fiber *** smoothing method and multipeak Gaussian fitting are employed for the extraction of ultrasonic *** measurement precision is achieved in a series of W and Au films with thicknesses of 43-750 *** work can be applied to various high-precision,noncontact measurements of metal film thickness in the semiconductor industry.

关键词： Picosecond ultrasonics Thickness measurement Optical pump-probe Beam distortion technique

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Sample preparation method to improve the efficiency of high-throughput single-molecule force spectroscopy

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Biophysics Reports 2019年第4期5卷 176-183页

作者： Lei Jin Li Kou Yanan Zeng chunguang hu Xiaodong hu State Key Laboratory of Precision Measuring Technology & Instruments Tianjin University Nanchang Institute for Microtechnology of Tianjin University College of Engineering and Technology Tianjin Agricultural University

Inefficient sample preparation methods hinder the performance of high-throughput single-molecule force spectroscopy(H-SMFS) for viscous damping among reactants and unstable linkage. Here, we demonstrated a sample preparation method for H-SMFS systems to achieve a higher ratio of effective target molecules per sample cell by gas-phase silanization and reactant hydrophobization. Digital holographic centrifugal force microscopy(DH-CFM) was used to verify its performance. The experimental result indicated that the DNA stretching success ratio was improved from 0.89% to 13.5%. This enhanced efficiency preparation method has potential application for force-based DNA stretching experiments and other modifying procedures.

关键词： Specific binding Digital holographic centrifugal force microscopy Sample preparation High-throughput single-molecule force spectroscopy

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Strong in-plane optical anisotropy in 2D van der Waals antiferromagnet VOCl

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Nano Research 2023年第5期16卷 7481-7488页

作者： Tianle Zhang Jiantao Du Wenjun Wang Keming Wu Shuai Yue Xinfeng Liu Wanfu Shen chunguang hu Minghui Wu Zhe Qu Shengxue Yang Chengbao Jiang School of Materials Science and Engineering Beihang UniversityBeijing 100191China Anhui Key Laboratory of Condensed Matter Physics at Extreme Conditions High Magnetic Field Laboratory Chinese Academy of SciencesHefei 230031China Science Island Branch of Graduate School University of Science and Technology of ChinaHefei 230026China CAS Key Laboratory of Standardization and Measurement for Nanotechnology CAS Center for Excellence in Nanoscience National Center for Nanoscience and Technology Beijing 100190China University of Chinese Academy of Sciences Beijing 100049China State Key Laboratory of Precision Measuring Technology and Instruments Tianjin UniversityTianjin 300072China College of Materials and Chemical Engineering MinJiang UniversityFuzhou 350108China Fujian Key laboratory of Functional marine Sensing materials Minjiang UniversityFuzhou 350108China

Two-dimensional(2D)van der Waals(vdW)magnetic materials with strong in-plane anisotropy can make possible novel applications such as optospintronics and strain *** this work,the strong in-plane optical anisotropy in 2D vdW antiferromagnet VOCl has been systematically *** optical brightness and absorption coefficient exhibit evident periodic variation with the change of incident polarization,unveiling the strong in-plane anisotropic optical *** Raman intensity in this material shows obvious dependence on the polarization angle of incident laser,demonstrating that the phonon properties possess strong in-plane ***,we have also realized in-situ visualization of in-plane optical reflection anisotropy in this ***,the strong second harmonic generation(SHG)signal can only be detected when the incident polarization is along specific in-plane crystal orientations,illustrating the presence of strong in-plane nonlinear optical *** findings will benefit the applications of VOCl in the field of polarization-dependent electronics and spintronics.

关键词： two-dimensional material vanadium oxide chloride in-plane optical anisotropy linear dichroism nonlinear optics

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Optical manipulation of ratio-designable Janus microspheres

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Photonics Research 2024年第6期12卷 1239-1249页

作者： YULU CHEN CONG ZHAI XIAOQING GAO HAN WANG ZUZENG LIN XIAOWEI ZHOU chunguang hu State Key Laboratory of Precision Measuring Technology and Instruments Tianjin UniversityTianjin 300072China

Angular optical trapping based on Janus microspheres has been proven to be a novel method to achieve controllable *** contrast to natural birefringent crystals,Janus microspheres are chemically synthesized of two compositions with different refractive ***,their structures can be artificially regulated,which brings excellent potential for fine and multi-degree-of-freedom manipulation in the optical ***,it is a considerable challenge to model the interaction of heterogeneous particles with the optical field,and there has also been no experimental study on the optical manipulation of microspheres with such designable refractive index *** the specific structure affects the kinematic properties of Janus microspheres remains ***,we report systematic research on the optical trapping and rotating of various ratio-designable Janus *** employ an efficient T-matrix method to rapidly calculate the optical force and torque on Janus microspheres to obtain their trapped postures and rotational characteristics in the optical *** have developed a robust microfluidic-based scheme to prepare Janus *** experimental results demonstrate that within a specific ratio range,the rotation radii of microspheres vary linearly and the orientations of microsphere are always aligned with the light polarization *** is of great importance in guiding the design of Janus *** their orientations flip at a particular ratio,all consistent with the *** work provides a reliable theoretical analysis and experimental strategy for studying the interaction of heterogeneous particles with the optical field and further expands the diverse manipulation capabilities of optical tweezers.

关键词： polarization ratio refractive

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Polarization-sensitive and wide-spectrum photovoltaic detector based on quasi-1D ZrGeTe_(4)nanoribbon

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InfoMat 2022年第3期4卷 109-120页

作者： Ruixue Bai Tao Xiong Jinshu Zhou Yue-Yang Liu Wanfu Shen chunguang hu Faguang Yan Kaiyou Wang Dahai Wei Jingbo Li Juehan Yang Zhongming Wei State Key Laboratory of Superlattices and Microstructures Institute of SemiconductorsChinese Academy of SciencesBeijingChina Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijingChina College of Electronic Information and Optical Engineering Nankai UniversityTianjinChina State Key Laboratory of Precision Measuring Technology and Instruments Tianjin UniversityTianjinChina Institute of Semiconductors South China Normal UniversityGuangzhouChina Guangdong Provincial Key Laboratory of Chip and Integration Technology GuangzhouChina

Low-dimensional semiconductors with in-plane anisotropy and narrow bandgap have been extensively applied to polarized detection in the near-infrared(NIR)***,the narrow bandgap can cause noise owing to the high dark current in *** article reports quasi-1D ZrGeTe_(4)nanoribbonbased photodetectors with low dark current and broadband polarization *** photodetector was fabricated by evaporating 50-nm-thick Au electrodes on a ZrGeTe_(4)*** from the photovoltaic characteristics in the ZrGeTe_(4)nanoribbon and Au electrodes,these photodetectors can operate without bias voltage,with decreased dark current,and improved device ***,the quasi-1D ZrGeTe_(4)nanoribbon-based photodetectors demonstrate a polarization sensitivity in a broadband from visible(VIS)to the NIR region,such as a high photoresponsivity of 625.65 mA W1,large external quantum efficiency of 145.9%at 532 nm,and photocurrent anisotropy ratio of 2.04 at 1064 *** exhibit a novel perpendicular optical reversal of 90in polarization-sensitive photodetection,angle-resolved absorption spectra,and azimuth-dependent reflectance difference microscopy(ADRDM)from VIS to the NIR region,as opposed to other nanoribbon-based polarization-sensitive *** work paves the way for utilizing photovoltaic photodetectors based on low-dimensional materials for broad-spectrum polarized photodetection.

关键词： linear polarization photodetector photovoltaic ZrGeTe_(4)nanoribbon

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MEMS Test System Based on Virtual Instrument Technology

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Transactions of Tianjin University 2007年第2期13卷 88-92页

作者：胡晓东栗大超郭彤胡春光胡小唐 State Key Laboratory of Precision Measuring Technology and Instruments Tianjin University

On account of the multiformity of MEMS devices, it is necessary to integrate with some optical measurement techniques for meeting static and dynamic unit test requirements. In this paper, an automated MEMS test system is built of some commercially available components and instruments based on virtual instrument technology. The system is integrated with stroboscopic imaging, computer micro-vision, microscopic Mirau phase shifting interferometry, and laser Doppler vibrometer, and is used for the measurement of full-view in-plane and out-of-plane geometric parameters and periodical motions and single spot out-of-plane transient motion. The system configuration and measurement methods are analyzed, and some applications of the measurement of in-plane and out-of-plane dimensions and motions were described. The measurement accuracy of in-plane dimensions and out-of-plane dimensional is better than 0.2 um and 5 nm respectively. The resolution of measuring in-plane and out-of-plane motions is better than 15 nm and 2 nm respectively.

关键词： MEMS optical measurement technique stroboscopic imaging virtual instrument dynamic test

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