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A Wideband High-Gain Sawtooth Slot Array Antenna with Frequency-Scanning at Lower Frequency and Fixed-Beam at Higher Frequency

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Chinese Journal of Electronics 2024年第2期33卷 463-471页

作者： qiang sun Yongling BAN Jun HU School of Electronic Science and Engineering University of Electronic Science and Technology of China

Exploring the multifunctional array antenna suitable for complex communication environment has very important research value. In this paper, a millimeter wave(mm-wave) double longitudinal sawtooth slot array antenna(DLSA) based on substrate integrated waveguide(SIW) technology is proposed, which has wideband, highgain and novel beam characteristics. Two irregular longitudinal slots are etched on the SIW conductor surface as the radiation structure. To improve the bandwidth of the DLSA, the metallized vias are added at the transition point of the slots to construct multiple resonant frequency points. By adjusting the size of the slots and the position of the metallized vias, the phase constant can be regulated, and the unusual beam characteristics can be obtained. That is to say, in the lower frequency band, the beam pointing angle increases with frequency. In the higher frequency band,the beam pointing angle is maintained at a fixed angle. Finally, to improve the antenna gain, a 16 × 8 DLSA is fabricated, measured and discussed. The proposed antenna has an impedance matching bandwidth close to 9.7 GHz.From 27 to 33 GHz, the beam pointing angle changes from 8° to 29°. From 33 to 37 GHz, the beam pointing angle is fixed at 29°, and the pointing angle error range is ±1°. In addition, the measured maximum gain is 22.9 d Bi at32 GHz.

关键词： Frequency-scanning Fixed beam High-gain Millimeter-wave Sawtooth slot Wideband

Analysis of pressure response at an observation well against pressure build-up by early stage of CO_(2)geological storage project

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第2期16卷 470-482页

作者： qiang sun Kyuro Sasaki Qinxi Dong Zhenni Ye Hui Wang Huan sun School of Civil Engineering and Architecture Hainan UniversityHaikou570228China Faculty of Engineering Kyushu University744 MotookaNishi-kuFukuoka819-0385Japan Key Laboratory of Equipment Safety and Intelligent Technology for Guangzhou Rail Transit System Guangzhou510430China

To ensure a safe and stable CO_(2)storage,pressure responses at an observation well are expected to be an important and useful field monitoring item to estimate the CO_(2)storage behaviors and the aquifer parameters during and after injecting CO_(2),because it can detect whether the injected CO_(2)leaks to the ground surface or the bottom of the sea.In this study,pressure responses were simulated to present design factors such as well location and pressure transmitter of the observation well.Numerical simulations on the pressure response and the time-delay from pressure build-up after CO_(2)injection were conducted by considering aquifer parameters and distance from the CO_(2)injection well to an observation well.The measurement resolution of a pressure transmitter installed in the observation well was presented based on numerical simulation results of the pressure response against pressure build-up at the injection well and CO_(2)plume front propagations.Furthermore,the pressure response at an observation well was estimated by comparing the numerical simulation results with the curve of CO_(2)saturation and relative permeability.It was also suggested that the analytical solution can be used for the analysis of the pressure response tendency using pressure build-up and dimensionless parameters of hydraulic diffusivity.Thus,a criterion was established for selecting a pressure transducer installed at an observation well to monitor the pressure responses with sufficient accuracy and resolution,considering the distance from the injection well and the pressure build-up at the injection well,for future carbon capture and storage(CCS)projects.

关键词： CO_(2)storage Saline aquifer Observation well Pressure response CO_(2)saturation

Ferroptosis mechanism and Alzheimer's disease

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Neural Regeneration Research 2024年第8期19卷 1741-1750页

作者： Lina Feng Jingyi sun Ling Xia qiang Shi Yajun Hou Lili Zhang Mingquan Li Cundong Fan Baoliang sun Shandong Key Laboratory of TCM Multi-Target Intervention and Disease Control the Second Affiliated Hospital of Shandong First Medical UniversityTaianShandong ProvinceChina Department of Internal Medicine Taian Traffic HospitalTaianShandong ProvinceChina Department of Neurology the Third Affiliated Clinical Hospital of Changchun University of Chinese MedicineChangchunJilin ProvinceChina

Regulated cell death is a genetically determined form of programmed cell death that commonly occurs during the development of living organisms.This process plays a crucial role in modulating homeostasis and is evolutionarily conserved across a diverse range of living organisms.Ferroptosis is a classic regulatory mode of cell death.Extensive studies of regulatory cell death in Alzheimer’s disease have yielded increasing evidence that fe rroptosis is closely related to the occurrence,development,and prognosis of Alzheimer’s disease.This review summarizes the molecular mechanisms of ferroptosis and recent research advances in the role of ferro ptosis in Alzheimer’s disease.Our findings are expected to serve as a theoretical and experimental foundation for clinical research and targeted therapy for Alzheimer’s disease.

关键词： Alzheimer’s disease apolipoprotein E Fe^(2+) ferroptosis glial cell glutathione peroxidase 4 imbalance in iron homeostasis lipid peroxidation regulated cell death system Xc^(-)

Cavity-enhanced photoacoustic dual-comb spectroscopy

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Light(Science & Applications) 2024年第4期13卷 610-618页

作者： Zhen Wang Qinxue Nie Haojia sun qiang Wang Simone Borri Paolo De Natale Wei Ren Department of Mechanical and Automation Engineering The Chinese University of Hong KongNew TerritoriesHong Kong SARChina. State Key Laboratory of Applied Optics Changchun Institute of OpticsFine Mechanics and PhysicsChinese Academy of Sciences130033 ChangchunChina. CNRINO-Istituto Nazionale di Ottica and LENS-European Laboratory for Nonlinear Spectroscopy50019 Sesto FiorentinoItaly

Photoacoustic dual-comb spectroscopy(DCS),converting spectral information in the optical frequency domain to the audio frequency domain via multi-heterodyne beating,enables background-free spectral measurements with high resolution and broad bandwidth.However,the detection sensitivity remains limited due to the low power of individual comb lines and the lack of broadband acoustic resonators.Here,we develop cavity-enhanced photoacoustic DCS,which overcomes these limitations by using a high-finesse optical cavity for the power amplification of dual-frequency combs and a broadband acoustic resonator with a flat-top frequency response.We demonstrate high-resolution spectroscopic measurements of trace amounts of C2H2,NH3 and CO in the entire telecommunications C-band.The method shows a minimum detection limit of 0.6 ppb C2H2 at the measurement time of 100 s,corresponding to the noise equivalent absorption coefficient of 7×10−10 cm−1.The proposed cavityenhanced photoacoustic DCS may open new avenues for ultrasensitive,high-resolution,and multi-species gas detection with widespread applications.

关键词： individual cavity spectroscopy

Quantitative geochemical reconstruction of Eocene paleoenvironment in Fushun Basin,northeast China

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Acta Geochimica 2024年第3期43卷 571-587页

作者： Yuanji Li Pingchang sun qiang Zhang Junxian Wang Department of Safety Engineering Heilongjiang University of Science and TechnologyHarbin 150022China National Professional Center Lab of Safety Basic Research for Hydrocarbon Gas Pipeline Transportation Network Harbin 150022China College of Earth Sciences Jilin UniversityChangchun 130061JilinChina Beijing Research Institute of Uranium Geology Beijing 100029China

The quantitative estimation of key parameters of paleotemperature and paleoprecipitation is crucial for paleoclimate reconstruction.Geochemical data from mod-ern sediments are highly consistent with climate data,and their relationship can provide an important reference for the quantitative reconstruction of the paleoclimate.In this study,detailed inorganic geochemical analysis was carried out using high-precision sampling of the Paleogene(LFD-1 well)Guchengzi,Jijuntun and Xiloutian Formations in the Fushun Basin located in the mid-latitudes of the Northern Hemisphere.The Eocene Guchengzi Formation(54.51–47.8 Ma)and Jijuntun Formation(47.8–41.2 Ma)in the Fushun Basin were found to have been deposited under a humid climate.The lower(41.2–40.1 Ma)and upper(40.1–37.8 Ma)parts of the Xiloutian Formation were character-ized by semiarid and semihumid–semiarid climates,respec-tively,which is very similar to the paleoclimatic information reflected by organic carbon isotopes.The Eocene Thermal Maximum 2(ETM2,~53.7 Ma),Early Eocene Climatic Optimum(EECO,~53.1–46.5 Ma),Eocene Thermal Maxi-mum 3(ETM 3,~52.8 Ma),and Middle Eocene Climatic Optimum(MECO,~40.7–40.1 Ma)events significantly enhanced chemical weathering during these periods.The rapid increase in pCO_(2)concentration leads to an increase in temperature,precipitation,and surface runoff,exhibiting strong chemical weathering.The mean annual temperature(MATa)and mean annual precipitation(MAPa,MAPb,and MAPc)were estimated using parameters,such as the corrosion index without potassium(CIA-K),CaO/Al_(2)O_(3),and(Na_(2)O+K_(2)O)/Al_(2)O_(3).Comparing MAPa,MAPb,and MAPc with the MAP estimated using pollen data,MAPa and MAPb were found to be more sensitive to the climate during high precipitation periods(precipitation>1000 mm,Guchengzi Formation),and the recovered average precipi-tation was similar to MAP.In contrast,MAPc was more sensitive to the climate during low precipitation periods(precipitation<1000 mm,Jijuntun,and Xiloutian Forma-tions),with higher accuracy.To fully co

关键词： Eocene Fushun Basin Major element Paleoclimate Geochemical reconstruction

Effects of thawing-induced softening on fracture behaviors of frozen rock

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第3期16卷 979-989页

作者： Ting Wang Hailiang Jia qiang sun Xianjun Tan Liyun Tang College of Geology and Environment Xi’an University of Science and TechnologyXi’an710054China College of Architecture and Civil Engineering Xi’an University of Science and TechnologyXi’an710054China State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan430064China

Due to the presence of ice and unfrozen water in pores of frozen rock,the rock fracture behaviors are susceptible to temperature.In this study,the potential thawing-induced softening effects on the fracture behaviors of frozen rock is evaluated by testing the tension fracture toughness(KIC)of frozen rock at different temperatures(i.e.-20℃,-15℃,-12℃,-10℃,-8℃,-6℃,-4℃,-2℃,and 0℃).Acoustic emission(AE)and digital image correlation(DIC)methods are utilized to analyze the microcrack propagation during fracturing.The melting of pore ice is measured using nuclear magnetic resonance(NMR)method.The results indicate that:(1)The KIC of frozen rock decreases moderately between-20℃ and-4℃,and rapidly between-4℃ and 0℃.(2)At-20℃ to-4℃,the fracturing process,deduced from the DIC results at the notch tip,exhibits three stages:elastic deformation,microcrack propagation and microcrack coalescence.However,at-4℃e0℃,only the latter two stages are observed.(3)At-4℃e0℃,the AE activities during fracturing are less than that at-20℃ to-4℃,while more small events are reported.(4)The NMR results demonstrate a reverse variation trend in pore ice content with increasing temperature,that is,a moderate decrease is followed by a sharp decrease and-4℃ is exactly the critical temperature.Next,we interpret the thawing-induced softening effect by linking the evolution in microscopic structure of frozen rock with its macroscopic fracture behaviors as follow:from-20℃ to-4℃,the thickening of the unfrozen water film diminishes the cementation strength between ice and rock skeleton,leading to the decrease in fracture parameters.From-4℃ to 0℃,the cementation effect of ice almost vanishes,and the filling effect of pore ice is reduced significantly,which facilitates microcrack propagation and thus the easier fracture of frozen rocks.

关键词： Frozen sandstone Different thawing temperature Fracture toughness Microcrack propagation process Unfrozen water content

Effect of phase transition during roasting of Mountain Pass rare earth concentrate on leaching efficiency of rare earths

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Journal of Rare Earths 2024年第2期42卷 409-414,I0006页

作者： Yanyan Zhao Xu sun Deliang Meng Xiangsheng Liu qiang Zhong Zongyu Feng National Engineering Research Center for Rare Earth Grirem Advanced Materials Co.Ltd.Beijing0088China Rare Earth Functional Materials(Xiong'an)Innovation Center Co. Ltd.Xiongan071700China General Research Institute for Nonferrous Metals Beijing100088China

To find a greener and more economical approach for treating the Mountain Pass rare earth concentrate(MPREC),a novel "Combination Method",including the processes of oxidizing roasting,HCI leaching and sulfuric acid roasting,is proposed in this research.In this paper,the effect of phase transition behavior in hydrochloric acid leaching during oxidative roasting at 450-600℃ was studied.During roasting,the bastnasite in MPREC is decomposed into CeLa_(2)O_(3)F_(3) and(Ce_(0.33),La_(0.33),Ca_(0.33))O_(1.5).As the CeLa_(2)O_(3)F_(3) phase has the fluorine-fixation effect,the generated CeLa_(2)O_(3)F_(3) phase can not be dissolved by HCI after roasting at 500 and 550℃,but it can be decomposed by HCI after roasting at over 600℃,resulting in the improvement of the leaching rate of total F element.The maximum leaching efficiency of rare earth elements(REEs) can reach 70.32 wt% at the roasting temperature of 550℃.After roasting at over 600℃,some F^-ions in the solution combined with RE^(3+) to form REF_(3) precipitate and enter the leaching residue,and the others are in the form of [CeF_(3)]^+ in the leaching solution during leaching,therefore,the leaching efficiency of non-ce rium REEs decreases while that of cerium element increases.This work provides basic research for optimizing the actual production process of MPREC.

关键词： Mountain pass rare earth mine Roasting Phase change Rare earths

Broadband high-efficiency plasmonic metalens with negative dispersion characteristic

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Photonics Research 2024年第4期12卷 813-820页

作者： YONG-qiang LIU YONG ZHU HONGCHENG YIN JINHAI sun YAN WANG YONGXING CHE National Key Laboratory of Scattering and Radiation Beijing 100854China

Controlling the dispersion characteristic of metasurfaces(or metalenses) along a broad bandwidth is of great importance to develop high-performance broadband metadevices. Different from traditional lenses that rely on the material refractive index along the light trajectory, metasurfaces or metalenses provide a new regime of dispersion control via a sub-wavelength metastructure, which is known as negative chromatic dispersion.However, broadband metalenses design with high-performance focusing especially with a reduced device dimension is a significant challenge in society. Here, we design, fabricate, and demonstrate a broadband highperformance diffractive-type plasmonic metalens based on a circular split-ring resonator metasurface with a relative working bandwidth of 28.6%. The metalens thickness is only 0.09λ0(λ0is at the central wavelength),which is much thinner than previous broadband all-dielectric metalenses. The full-wave simulation results show that both high transmissive efficiency above 80%(the maximum is even above 90%) and high average focusing efficiency above 45%(the maximum is 56%) are achieved within the entire working bandwidth of 9–12 GHz.Moreover, an average high numerical aperture of 0.7(NA = 0.7) of high-efficiency microwave metalens is obtained in the simulations. The broadband high-performance metalens is also fabricated and experimental measurements verify its much higher average focusing efficiency of 55%(the maximum is above 65% within the broad bandwidth) and a moderate high NA of 0.6. The proposed plasmonic metalens can facilitate the development of wavelength-dependent broadband diffractive devices and is also meaningful to further studies on arbitrary dispersion control in diffractive optics based on plasmonic metasurfaces.

关键词： resonator dispersion high

Research on a TOPSIS energy efficiency evaluation system for crude oil gathering and transportation systems based on a GA-BP neural network

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Petroleum Science 2024年第1期21卷 621-640页

作者： Xue-qiang Zhang Qing-Lin Cheng Wei sun Yi Zhao Zhi-Min Li Key Lab of Ministry of Education for Enhancing the Oil and Gas Recovery Ratio Northeast Petroleum UniversityDaqing163318HeilongjiangChina China Petroleum Pipeline Material and Equipment Co. LtdLangfang065000HebeiChina Research Institute of Petroleum Engineering and Technology Sinopec Northwest Oilfield CompanyUrumqi830011XinjiangChina

As the main link of ground engineering,crude oil gathering and transportation systems require huge energy consumption and complex structures.It is necessary to establish an energy efficiency evaluation system for crude oil gathering and transportation systems and identify the energy efficiency gaps.In this paper,the energy efficiency evaluation system of the crude oil gathering and transportation system in an oilfield in western China is established.Combined with the big data analysis method,the GA-BP neural network is used to establish the energy efficiency index prediction model for crude oil gathering and transportation systems.The comprehensive energy consumption,gas consumption,power consumption,energy utilization rate,heat utilization rate,and power utilization rate of crude oil gathering and transportation systems are predicted.Considering the efficiency and unit consumption index of the crude oil gathering and transportation system,the energy efficiency evaluation system of the crude oil gathering and transportation system is established based on a game theory combined weighting method and TOPSIS evaluation method,and the subjective weight is determined by the triangular fuzzy analytic hierarchy process.The entropy weight method determines the objective weight,and the combined weight of game theory combines subjectivity with objectivity to comprehensively evaluate the comprehensive energy efficiency of crude oil gathering and transportation systems and their subsystems.Finally,the weak links in energy utilization are identified,and energy conservation and consumption reduction are improved.The above research provides technical support for the green,efficient and intelligent development of crude oil gathering and transportation systems.

关键词： Crude oil gathering and transportation system GA-BP neural network Energy efficiency evaluation TOPSIS evaluation method Energy saving and consumption reduction