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Wide Stopband Substrate Integrated Waveguide Filter Using Bisection and Trisection Coupling in Multilayer

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Chinese Journal of Electronics 2024年第2期33卷 436-442页

作者： Peng CHU jianguo FENG Peng ZHU Lei GUO Long ZHANG Leilei liu Guoqing LUO Ke WU College of Electronic and Optical Engineering Nanjing University of Posts and Telecommunications National and Local Joint Engineering Laboratory of RF Integration and Micro-Assembly Technology School of Information and Communication Engineering Dalian University of Technology Guangdong Provincial Key Laboratory of Optoelectronic Information Processing Chips and Systems Sun Yat-sen University College of Electronics and Information Engineering Shenzhen University School of Electronics and Information Hangzhou Dianzi University Poly-Grames Research Center Polytechnique Montreal

This article presents a highly efficient method for substrate-integrated-waveguide（SIW） filters to achieve very wide stopbands. By employing the proposed trisection slots in addition to the bisection slots as the inter-coupling structures, all spurious modes below TE505 of a SIW filter working in the fundamental mode TE101（f0）can be eliminated without requiring additional structure or complex theoretical analysis, without affecting the design of the fundamental passbands, and without degrading the performance of the filters. For verification, two prototype filters are designed, fabricated, and measured with wide stopbands up to 4.15f0 and 4.83f0, respectively. The proposed technique could facilitate the development of high-performance wide-stopband SIW filters for microwave/wireless circuits and systems.

关键词： Microwave measurement Couplings Filters Prototypes Nonhomogeneous media Microwave theory and techniques Microwave circuits

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Rapid synthesis of highly active Pt/C catalysts with various metal loadings from single batch platinum colloid

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Journal of Energy Chemistry 2020年第8期29卷 138-145,I0005页

作者： Yuxin Li Xiang Zhu Yawen Chen Shiqiao Zhang Jia Li jianguo liu Jiangsu Key Laboratory for Nano Technology National Laboratory of Solid State MicrostructuresCollege of Engineering and Applied Sciencesand Collaborative Innovation Center of Advanced MicrostructuresNanjing UniversityNanjing 210093JiangsuChina Kunshan Innovation Institute of Nanjing University Kunshan Sunlaite New Energy Co.Ltd.Suzhou 215347JiangsuChina

A series of Pt/C catalysts for proton exchange membrane fuel cells(PEMFCs) with various metal loadings is synthesized by a microwave-assisted polyol process via mixing an extremely stable platinum colloid(> 3 months’ shelf life) from single batch preparation with activated carbon ethylene glycol suspension.21 wt%, 42 wt% and 61 wt% Pt loadings are employed to showcase the advantages of the improved polyol process. The ultraviolet(UV)–visible spectra and ζ-potential measurements are conducted to monitor the wet chemistry process during catalyst preparation. The powder X-ray diffraction(XRD), transmission electron microscopy(TEM) and thermogravimetric analysis(TGA) characterizations are carried out on catalysts. The catalyst activities are investigated using electrochemical and single cell tests. The stability of Pt nanoparticle colloid is explored by ORR, cyclic voltammetry(CV) and ζ-potential measurements. The TEM results show the Pt particle sizes of the colloid, and the sizes of the 21 wt%, 42 wt% and 61 wt%Pt/C samples are 2.1–3.9 nm. Because of the high Pt dispersion, the Pt/C catalysts exhibit superior electroactivity toward ORR. In addition, four 61 wt% Pt/C catalysts made from the Pt colloid with 0–3 months’ shelf life show almost the same performance, which exhibits superior stability of the Pt colloid system without surfactant protection.

关键词： PEMFC Pt/C catalyst Microwave irradiation Modified polyol process Platinum nanocolloid Oxygen reduction reaction

Polluted lake restoration to promote sustainability in the Yangtze River Basin,China

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National Science Review 2022年第1期9卷 12-14页

作者： Boqiang Qin Yunlin Zhang Jianming Deng Guangwei Zhu jianguo liu David P.Hamilton Hans W.Paerl Justin D.Brookes Tingfeng Wu Kai Peng Yizhou Yao Kan Ding Xiaoyan Ji State Key Laboratory of Lake Science and Environment Nanjing Institute of Geography and Limnology Chinese Academy of Sciences School of Geography and Ocean Science Nanjing University Nanjing Zhongke Deep Insight Institute Co.Ltd. Center for Systems Integration and Sustainability Department of Fisheries and Wildlife Michigan State University Australian Rivers Institute Griffith University Institute of Marine Sciences University of North Carolina at Chapel Hill College of the Environment Hohai University Water Research Centre School of Biological Science University of Adelaide China National Environmental Monitoring Centre (CNEMC)

China has sought to address water pollution in the last decade by introducing a wide range of laws and regulations(Table S1), which led to nationwide water quality improvement [1]. However, recent quantitative assessment of progress toward Sustainable Development Goals (SDGs) in China suggests that some SDGs underpinning goals for water pollution and biodiversity have not been met [2]. Specifically,

关键词： PHOSPHORUS RATIOS NITROGEN

High-speed photodetectors in optical communication system

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Journal of Semiconductors 2017年第12期38卷 1-7页

作者： Zeping Zhao jianguo liu Yu liu Ninghua Zhu State Key Laboratory on Integrated Optoelectronics Institution of SemiconductorsChinese Academy of Sciences School of Electronic Electrical and Communication EngineeringUniversity of Chinese Academy of Sciences

This paper presents a review and discussion for high-speed photodetectors and their applications on optical communications and microwave photonics. A detailed and comprehensive demonstration of high-speed photodetectors from development history, research hotspots to packaging technologies is provided to the best of our knowledge. A few typical applications based on photodetectors are also illustrated, such as free-space optical communications, radio over fiber and millimeter terahertz signal generation systems.

关键词： high-speed photodetectors PIN photodetectors packaging integration

Aerosol observation in Fengtai area,Beijing

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Particuology 2008年第3期6卷 214-217页

作者： Zengdong liu jianguo liu Bei Wang Fan Lu Shuhua Huang Dexia Wu Daowen Hart Key Laboratory of Environmental Optics and Technology Anhui Institute of Optics and Fine Mechanics CAS Hefei 230031 China

Measurements of aerosol number concentration and particulate matter with diameter less than 10 μm （PM10） mass concentrations of urban background aerosols were performed in Fengtai area, Beijing in 2006. Black carbon （BC） was collected simultaneously from the ground and analyzed to determine the particulate matter components. To satisfy the interest in continuous monitoring of temporal and spatial distribution of aerosols, the relationship between extinction coefficient （visibility） measured by lidar remote sensing and the aerosol number concentration measured from the ground was derived by using statistical method. Vertical particle number concentration profile within the planetary boundary layer could be inversed through the lidar data as well as the statistical relation.

关键词： Number concentration Aerosol components Extinction coefficient Vertical distribution

Effects of temperature on pyrolysis products of oil sludge

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Frontiers of Environmental Science & Engineering 2008年第1期2卷 8-14页

作者： jianguo liu Wei SONG Yongfeng NIE Department of Environmental Science and Engineering Tsinghua UniversityBeijing 100084China

Temperature is the determining factor of pyro-lysis,which is one of the alternative technologies for oil sludge *** effects of final operating temper-ature ranging from 350 to 550uC on pyrolysis products of oil sludge were studied in an externally-heating fixed bed *** an increase of temperature,the mass fraction of solid residues,liquids,and gases in the final product is 67.00%–56.00%,25.60%–32.35%,and 7.40%–11.65%,and their corresponding heat values are 34.4–13.8 MJ/kg,44.41–46.6 MJ/kg,and 23.94–48.23 MJ/Nm 3,*** mass and energy tend to shift from solid to liquid and gas phase(especially to liquid phase)during the process,and the optimum temperature for oil sludge pyrolysis is *** liquid phase is mainly com-posed of alkane and alkene(C_(5)–C_(29)),and the gas phase is dominantly HC S and H 2.

关键词： oil sludge pyrolysis temperature fixed bed reactor pyrolysis products

Preparation of Mesoporous Nano-Hydroxyapatite Using a Surfactant Template Method for Protein Delivery

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Journal of Bionic Engineering 2012年第2期9卷 224-233页

作者： Xiaodong Wu Xiaofeng Song Dongsong Li jianguo liu Peibiao Zhang Xuesi Chen Department of Bone and Joint Surgery First Hospital of Jilin UniversityChangchun 130021P R.China Key Laboratory of Polymer Ecobiomaterials Changchun Institute of Applied ChemistryChinese Academy of SciencesChangehun 130022P.R.China

Mesoporous nano-hydroxyapatite （n-HA） has gained more and more attention as drug storage and release hosts. The aim of this study is to observe the effect of the ratio of surfactant to the theoretical yield of HA on the mesoporous n-HA, then to reveal the effect of the mesoporous nanostructure on protein delivery. The mesoporous n-HA was synthesized using the wet precipitation in the presence of cetyltrimethylammonium bromide （CTAB） at ambient temperature and normal atmospheric pressure. The morphology, size, crystalline phase, chemical composition and textural characteristics of the product were well characterized by X-ray Powder Diffraction （XRD）, Fourier Transform Infrared Spectroscopy （FTIR）, Scanning Electron Microscopy （SEM）, Transmission Electron Microscopy （TEM）, Dynamic Light Scattering （DLS） and N2 adsorption/desorption, respectively. The protein adsorption/release studies were also carried out by using Bovine Serum Albumin （BSA） as a model protein. The results reveal that the mesoporous n-HA synthesized with CTAB exhibits high pure phase, low crystallinity and the typical characteristics of the mesostructure. The BSA loading increases with the specific surface area and the pore volume of n-HA, and the release rates of BSA are different due to their different pore sizes and pore structures, n-HA synthesized with 0.5% CTAB has the highest BSA loading and the slowest release rate because of its highest surface area and smaller pore size. These mesoporous n-HA materials demonstrate a potential application in the field of protein delivery due to their bioactive, biocompatible and mesoporous properties.

关键词： hydroxyapatite nanoparticles mesostructure cetyltrimethylammonium bromide drug delivery

Alignment of social and ecological structures increased the ability of river management

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Science Bulletin 2019年第18期64卷 1318-1324页

作者： Shuai Wang Bojie Fu Orjan Bodin jianguo liu Mengmeng Zhang Xiaoyan Li State Key Laboratory of Earth Surface Processes and Resource Ecology Faculty of Geographical ScienceBeijing Normal UniversityBeijing 100875China State Key Laboratory of Urban and Regional Ecology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China Stockholm Resilience Centre Stockholm UniversityStockholm 10691Sweden Center for Systems Integration and Sustainability Department of Fisheries and WildlifeMichigan State UniversityEast LansingMl 48823USA

Large hydrologic basins involve multiple stakeholders, and coupled dynamic social and ecological processes. Managing such basins has long been a challenge. Balancing the demand for water from nature against that from humans is always difficult, particularly in arid watersheds. Here, we analyze potential institutional causes of ecological degradation and how it can be reversed by introducing new forms of governance. The framework and assumptions are illustrated using China’s second-largest endorheic basin, where empirical evidence shows that the introduction of a new governing authority connecting midstream and downstream actors facilitated the establishment of a new governance regime that is better aligned with the biophysical scales of the watershed. A trans-regional water allocation project initiated by the new higher-level authority successfully rescued downstream oases and restored a dried terminal lake. These outcomes suggest that when social and ecological structures are better aligned our ability to manage the interplay between social and ecological processes increases. However, the lack of direct connection between the actors of the middle and lower reaches resulted in the paradox of an increase in water demand. We therefore suggest that measures to stimulate the emergence of horizontal social ties linking different critical groups of actors across the watershed could further the alignment of the institutional and biophysical structures-without these changes sustainable management of river basins and other common pool resources will remain problematic.

关键词： River management Heihe River Social ecological system Institutional fit

Diagnostic Method and Adaptability Analysis of Multiple Water Breakthroughs in Horizontal Well in Combined Well Pattern

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Journal of Geoscience and Environment Protection 2023年第5期11卷 150-158页

作者： Zheng Lv Meinan Wang Guohao Zhang Rui Zhang jianguo liu Bohai Oilfield Research Institute of CNOOC Ltd.-Tianjin Branch Tianjin China

The combined well pattern has been widely used in reservoir development, with a common pattern being a horizontal well in the center for oil production and multiple vertical wells around for water injection. For this type of well pattern, determining the horizontal well is affected by which injection wells, especially when the injecting water breaks through, accurately determining the direction of water inflow will provide an important basis for targeted water well measures. Based on the production performance data of horizontal wells, the semi logarithmic relationship curves of water-oil ratio, derivative water-oil ratio, and cumulative production were used for the first time to determine the breakthrough problem of water injection in the surrounding water injection wells of horizontal wells based on their response characteristics. The adaptability of this method under different influencing factors was analyzed. Introducing the parameter of cumulative production not only preserves the variation trend of the derivative of water-oil ratio with time, but also facilitates the processing of actual production data.

关键词： Combined Well Pattern Multiple Water Breakthroughs in Horizontal Derivative of Water-Oil Ratio