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Physical mechanism of the rapid increase in intense and long-lived extreme heatwaves in the Northern Hemisphere since 1980

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Science china Earth Sciences 2024年第7期67卷 2103-2121页

作者： Yuqing wang wen ZHOU chunzai wang Key Laboratory of Polar Atmosphere-ocean-ice System for Weather and climate of the MOE Department of Atmospheric and Oceanic Sciences&Institute of Atmospheric SciencesFudan UniversityShanghai 200438China Key Laboratory for Polar Science of the MNR Polar Research Institute of ChinaShanghai 201209China State Key Laboratory of Tropical Oceanography South China Sea Institute of OceanologyChinese Academy of SciencesGuangzhou 510301China Global Ocean and climate Research center South China Sea Institute of OceanologyChinese Academy of SciencesGuangzhou 510301China

Since 1980,both the intensity and duration of summer heatwaves in the middle and high latitudes of the Northern Hemisphere have significantly increased,leading this region to become a critical area for a significant increase in the frequency of intense and long-lived extreme *** found that stronger and more persistent high-pressure systems and lower soil moisture before the events were the main drivers of intense and long-lived extreme heatwaves in western Europe and the middle and high latitudes of North ***,in eastern Europe and Siberia,lower cloud cover before events is also a main driver of this type of extreme heatwave,in addition to the above *** factors are coupled with each other and can change heatwave intensity and duration by influencing surface radiation processes during *** the self-organizing map classification method,we found that 6 weather patterns with increased frequency,intensity,and duration were the main dynamic reasons leading to the increase in intense and long-lived extreme heatwaves after *** addition,the decrease in summer average soil moisture in most areas of the mid-high latitudes of the Northern Hemisphere and the decrease in average cloud cover in eastern Europe and Siberia are found to be the main thermodynamic reasons leading to the increase in these extreme heatwaves.

关键词： High intensity Long duration Extreme heatwaves High pressure system Soil moisture cloud cover

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Unconditionally stable crank-Nicolson algorithm with enhanced absorption for rotationally symmetric multi-scale problems in anisotropic magnetized plasma

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Journal of Systems Engineering and Electronics 2024年第1期35卷 65-73页

作者： wen Yi wang Junxiang XU Hongbing School of Automatic Engineering University of Electronic Science and Technology of ChinaChengdu 611731China Beijing Institute of Aerospace Systems Engineering Beijing 100076China

Large calculation error can be formed by directly employing the conventional Yee’s grid to curve *** order to alleviate such condition,unconditionally stable crankNicolson Douglas-Gunn(cNDG)algorithm with is proposed for rotationally symmetric multi-scale problems in anisotropic magnetized *** the cNDG algorithm,an alternative scheme for the simulation of anisotropic plasma is proposed in body-of-revolution *** perfectly matched layer(cPML)formulation is proposed to efficiently solve the open region *** example is carried out for the illustration of effectiveness including the efficiency,resources,and *** the results,it can be concluded that the proposed scheme shows considerable performance during the simulation.

关键词： anisotropic magnetized plasma body-of-revolution(BOR) crank-Nicolson Douglas-Gunn(cNDG) finite-difference time-domain(FDTD) perfectly matched layer(PML) rotationally symmetric multi-scale problems

Low profile cavity-embedded ultra-wideband UHF array antenna with end-fire beams

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Journal of Electronic Science and Technology 2024年第2期22卷 24-35页

作者： Huan He wen-Song wang Southwest china Institute of Electronic Technology Chengdu610036China School of Electrical and Electronic Engineering Department Nanyang Technological UniversitySingapore639798Singapore

A low-profile,vertically polarized,ultra-wideband array antenna with end-fire beams operating in an ultra-high frequency(UHF)band is developed in this *** array antenna consists of 1×16 log-periodic top-hat loaded monopole antenna arrays and is feasible to embed into a shallow cavity to further reduce the array *** is introduced in the proposed antenna element to reduce profile height and the rectangular top hats are carefully designed to minimize the transverse *** results show that when the antenna array operates in a frequency range of 300 MHz-900 MHz,the end-fire radiation pattern achieves±45°scanning range in the horizontal *** prototypes of the proposed end-fire antenna element and a uniformly spaced linear array(1×2)are fabricated and *** end-fire antenna array should be suitable for airborne applications where low-profile and conformal scanning phased antenna arrays with end-fire radiations are *** design is attractive for airborne platform applications that are used to search,discover,identify,and scout the aerial target with vertically polarized beams.

关键词： End-fire radiation Low-profile Vertical polarization Log-periodic array

A generalization of Banach's lemma and its applications to perturbations of bounded linear operators

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Applied Mathematics(A Journal of chinese Universities) 2024年第2期39卷 363-369页

作者： wang Zi DING Jiu wang Yu-wen School of Mathematics Sciences Harbin Normal UniversityHarbin 150025China School of Mathematics and Natural Sciences The University of Southern MississippiHattiesburg MS 39406-5043USA Academic committee Harbin Institute of PetroleumHarbin 150027China

Let X be a Banach space and let P:X→X be a bounded linear *** an algebraic inequality on the spectrum of P,we give a new sufficient condition that guarantees the existence of(I-P)^(-1) as a bounded linear operator on X,and a bound on its spectral radius is also *** generalizes the classic Banach *** apply the result to the perturbation analysis of general bounded linear operators on X with commutative perturbations.

关键词： Banach lemma spectral radius generalized inverse perturbation analysis

Galerkin-based quasi-smooth manifold element(QSME)method for anisotropic heat conduction problems in composites with complex geometry

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Applied Mathematics and Mechanics(English Edition) 2024年第1期45卷 137-154页

作者： Pan wang Xiangcheng HAN Weibin wen Baolin wang Jun LIANG School of civil Engineering Central South UniversityChangsha 410083China Institute of Advanced Structure Technology Beijing Institute of TechnologyBeijing 100081China School of Science Harbin Institute of TechnologyShenzhen 518055Guangdong ProvinceChina

The accurate and efficient analysis of anisotropic heat conduction problems in complex composites is crucial for structural design and performance evaluation. Traditional numerical methods, such as the finite element method(FEM), often face a trade-off between calculation accuracy and efficiency. In this paper, we propose a quasi-smooth manifold element(QSME) method to address this challenge, and provide the accurate and efficient analysis of two-dimensional(2D) anisotropic heat conduction problems in composites with complex geometry. The QSME approach achieves high calculation precision by a high-order local approximation that ensures the first-order derivative *** results demonstrate that the QSME method is robust and stable, offering both high accuracy and efficiency in the heat conduction analysis. With the same degrees of freedom(DOFs), the QSME method can achieve at least an order of magnitude higher calculation accuracy than the traditional FEM. Additionally, under the same level of calculation error, the QSME method requires 10 times fewer DOFs than the traditional FEM. The versatility of the proposed QSME method extends beyond anisotropic heat conduction problems in complex composites. The proposed QSME method can also be applied to other problems, including fluid flows, mechanical analyses, and other multi-field coupled problems, providing accurate and efficient numerical simulations.

关键词： anisotropic heat conduction quasi-smooth manifold element(QSME) composite with complex geometry numerical simulation finite element method(FEM)

Enrichment of anammox biomass during mainstream wastewater treatment driven by achievement of partial denitrification through the addition of bio-carriers

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Journal of Environmental Sciences 2024年第3期137卷 181-194页

作者： Yuqing Ma Bo wang Xiaodi Li Shuo wang wen wang Yongzhen Peng National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology Engineering Research Center of BeijingBeijing University of TechnologyBeijing 100124China

Anammox is widely considered as the most cost-effective and sustainable process for nitrogen ***,how to achieve the enrichment of anammox biomass remains a challenge for its large-scale application,especially in mainstream wastewater *** this study,the feasibility of enrichment of anammox biomass was explored through the realization of partial denitrification and the addition of *** using ordinary activated sludge,a sequencing batch reactor(SBR)followed by an up-fow anaerobic sludge bed(UASB)was operated at 25±2℃ for 214 *** long-term operation was divided into five phases,in which SBR and UASB were started-up in Phases I and II,*** eliminating oxygen and adjusting the infow ratios in Phases III-V,advanced nitrogen removal was achieved with the effuent total nitrogen being 4.7 mg/L and the nitrogen removal efficiency being 90.5%in Phase *** in-situ and ex-situ activity tests demonstrated the occurrence of partial denitrification and ***,16S rRNA high-throughput sequencing analysis revealed that candidatus Brocadia was enriched from below the detection limit to in biofilms(0.4%in SBR,2.2%in UASB)and the foc sludge(0.2%in SBR,1.3%in UASB),while Thauera was mainly detected in the foc sludge(8.1%in SBR,8.8%in UASB),which might play a key role in partial ***,this study provides a novel strategy to enrich anammox biomass driven by rapid achievement of partial denitrification through the addition of bio-carriers,which will improve large-scale application of anammox processes in mainstream wastewater treatment.

关键词： Enrichment Anammox biomass Bio-carriers Partial denitrification Mainstream wastewater

BL03HB: a Laue microdiffraction beamline for both protein crystallography and materials science at SSRF

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Nuclear Science and Techniques 2024年第7期35卷 68-78页

作者： Zhi-Jun wang Si-Sheng wang Zheng-Huang Su Li Yu Yu-Zhu wang Bo Sun wen wen Xing-Yu Gao Shanghai Advanced Research Institute Chinese Academy of SciencesShanghai201210China University of chinese Academy of Science Beijing100049China

A Laue microdiffraction beamline (BL03HB) was constructed at the Shanghai SynchrotronRadiation Facility (SSRF). This beamline featu res two consecutive focusing points in twodifferent sectors within its end station, the first dedicated to protein crystallography and theother tailored to materials science applications. Based on a superbend dipole magnet with amagnetic field of 2.29 T, a two-stage focusing design was implemented with two sets of Kirkpatrick- Baez mirrors to achieve a micro white beam as small as 4.2 um X4.3 pμm at the firstsector and 09 pum X 1.3 pum at the second sector in the standard beamline operation mode at *** X-ray microbeam in the two sectors can be easily switched between monochromatic andwhite beams by moving a four-bounce monochromator in or out of the light path, respectively. Inthe protein crystallography sector, white-beam Laue microdifraction was dermonstrated tosuccessully determine the structure of protein crystals from only a few images of diffraction data .collected by a Pilatus 2 M area detector. In the materials science sector, the white -beam Lauediffraction was collected in a reflection geometry using another Pilatus 2 M area detector, whichcould map the microstructural distribution on the sample surface by scanning the samples. Ingeneral, the BL03HB beamline promotes the application of Laue microdiffraction in both proteincrystallgraphy and materials science. This paper presents a comprehensive overview of theBL03HB beamline, end station, and the first commission results.

关键词： crystallography White-beam Laue microdiffraction Beamline Synchrotron

Single-atom Ag-loaded carbon nitride photocatalysts for efficient degradation of acetaminophen:The role of Ag-atom and O_(2)

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Journal of Environmental Sciences 2024年第5期139卷 12-22页

作者： Yi Yuan wen-Long wang Zhi-Wei wang Jin wang Qian-Yuan Wu Key Laboratory of Microorganism Application and Risk control of Shenzhen Guangdong Provincial Engineering Research Center for Urban Water Recycling and Environmental SafetyInstitute of Environment and EcologyShenzhen International Graduate SchoolTsinghua UniversityShenzhen 518055China Shenzhen Environmental Science and New Energy Technology Engineering Laboratory Tsinghua-Berkeley Shenzhen InstituteShenzhen 518055China college of Materials Science and Engineering Shenzhen UniversityShenzhen 518071China

carbon nitride has been extensively used as a visible-light photocatalyst,but it has the disadvantages of a low specific surface area,rapid electron-hole recombination,and relatively low light *** this study,single-atom Ag was successfully anchored on ultrathin carbon nitride(UTcN)via thermal polymerization,the catalyst obtained is called *** Ag hardly changed the carbon nitride's layered and porous physical *** exhibited efficient visible-light photocatalytic performances in the degradation of various recalcitrant pollutants,eliminations of 85% were achieved by visible-light irradiation for *** with Ag improved the photocatalytic performance of UTcN by narrowing the forbidden band gap from 2.49 to 2.36 e V and suppressing electron-hole pair *** addition,Ag doping facilitated O_(2) adsorption on UTcN by decreasing the adsorption energy from -0.2 to -2.22 e V and favored the formation of O_(2)^(·-).Electron spin resonance and radical-quenching experiments showed that O_(2)^(·-)was the major reactive species in the degradation of Acetaminophen(paracetamol,APAP).

关键词： Ag single atom carbon nitride Photocatalysis Visible light Adsorption energy Reactive species

Effect of BaO and MgO on structure and properties of aluminate slag with various caO/Al_(2)0_(3)ratios

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Journal of Iron and Steel Research(International) 2024年第1期31卷 204-214页

作者： Yu-qi Kong Ting Wu wen-zhi Xia wen Yang Hai-chuan wang School of Metallurgical Engineering Anhui University of TechnologyMa’anshan243032AnhuiChina Key Laboratory of Metallurgical Emission Reduction and Resource Recycling(Ministry of Education) Anhui University of TechnologyMa’anshan243002AnhuiChina

To provide theoretical guidance for performance stability control of low-reactive mold fluxes,the effects of BaO and MgO on the structure and properties of aluminate slag with various caO/Al_(2)0_(3)(c/A)ratios were investigated using the Fourier transform infrared spectrometer,Raman spectroscope,hemispherical melting point instrument,rotational viscometer and X-ray *** results indicated that with BaO and MgO addition,the structure polymerization was first weakened and then enhanced at c/A of 1.1,and the transition contents corresponded to 8 wt.%BaO and 2 wt.%MgO,respectively,while the structure polymerization decreased continuously at c/A of *** the viscosity change was well consistent with the structure evolution,the polymerization degree played a more prominent role in the slag viscosity than superheat degree when the melting temperature difference was within 40℃.The break temperature decreased initially and then increased with augment of BaO and MgO at c/A of 1.1,while it manifested a decrease trend with BaO addition,and it decreased obviously but then turned to increase with MgO increment at c/A of *** crystallization phase and crystallization ratio kept stable with BaO increment,while the crystallization ratio rose greatly with MgO promoting LiAlO_(2)precipitation at c/A of *** crystal types of all experimental slags were mainly ca_(12)Al_(14)O_(33)and caF_(2)at c/A of 1.3,and the precipitation of crystalline phase BaAl2O4 demonstrated a rising trend,while that of ca_(12)Al_(14)O_(33)gradually declined with BaO augment.

关键词： Aluminate slag Structure MgO BaO Viscosity Property