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Projections of summer light rain frequency in typical terrain over eastern china under wind speed constraint

Science china Earth Sciences 2024年第6期67卷 1885-1894页

作者： Xuechen DONG Daoyi GONG Cuicui SHI Institute of Disaster Risk Science Faculty of Geographical ScienceBeijing Normal UniversityBeijing 100875China Key Laboratory of Environmental Change and Natural Disaster MOEFaculty of Geographical ScienceBeijing Normal UniversityBeijing 100875China School of National Safety and Emergency Management Beijing Normal UniversityBeijing 100875China School of Systems Science Beijing Normal UniversityBeijing 100875China

The variation in near-surface wind speed is a key dynamic parameter in the orographic effect of precipitation over eastern *** this study,we used the latest high-resolution outputs from six GCMs in CMIP6-HighResMIP to evaluate the performance of high-resolution models in simulating the orographic precipitation characteristics of typical mountainous areas in summer over eastern *** orographic precipitation under warming scenarios was projected and constrained according to observational *** results indicated that during the contemporary climate reference period(1979-2009),although the relationship between model-simulated near-surface wind speed and orographic light rain frequency was consistently stable,the sensitivity of the orographic light rain frequency to surface wind variability was generally underestimated,with a deviation approximately 24.1% lower than the observational *** estimated orographic light rain frequency corrected based on the observed near-surface wind speed under a 1.5℃ warming scenario,was 36.1% lower than that of the contemporary period;this reduction was 8.6 times that without the wind speed constraint(4.2%).The MRI-AGCM3-2-S model,with a longer dataset,demonstrated relatively stable reductions in orographic light rain frequency under different warming scenarios(1.5℃,2℃,3℃,and 4℃)after the application of wind speed *** all cases,the reductions exceeded those for the predictions made without the wind speed constraint.

关键词： Frequency of orographic light rain HighResMIP High-resolution projection Observational constraint Eastern china

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Acoustofluidics-enhanced biosensing with simultaneously high sensitivity and speed

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Microsystems & Nanoengineering 2024年第3期10卷 335-346页

作者： Yuang Li Yang Zhao Yang Yang Wenchang Zhang Yun Zhang Sheng Sun Lingqian Zhang Mingxiao Li Hang Gao Chengjun Huang Institute of Microelectronics of the Chinese Academy of Sciences Beijing 100029P.R.China University of Chinese Academy of Sciences Beijing 101408P.R.China Department of Medicine Brigham and Women’s HospitalHarvard Medical SchoolBostonMA 02115USA

Simultaneously achieving high sensitivity and detection speed with traditional solid-state biosensors is usually limited since the target molecules must passively diffuse to the sensor surface before they can be *** techniques have been applied to shorten the diffusion time by continuously moving molecules through the biosensing ***,the binding efficiencies of the biomolecules are still limited by the inherent laminar flow inside microscale *** this study,focused traveling surface acoustic waves were directed into an acoustic microfluidic chip,which could continuously enrich the target molecules into a constriction zone for immediate detection of the immune reactions,thus significantly improving the detection sensitivity and *** demonstrate the enhancement of biosensing,we first developed an acoustic microfluidic chip integrated with a focused interdigital transducer;this transducer had the ability to capture more than 91%of passed ***,polystyrene microbeads were pre-captured with human IgG molecules at different concentrations and loaded for detection on the *** representative results,~0.63,2.62,11.78,and 19.75 seconds were needed to accumulate significant numbers of microbeads pre-captured with human IgG molecules at concentrations of 100,10,1,and 0.1 ng/mL(~0.7 pM),respectively;this process was faster than the other methods at the hour level and more sensitive than the other methods at the nanomolar *** results indicated that the proposed method could significantly improve both the sensitivity and speed,revealing the importance of selective enrichment strategies for rapid biosensing of rare molecules.

关键词： fluid continuously simultaneous

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Study on the Chlorination Leaching of Gold and Copper from High Gold-Containing Material Based on Variable Stirring Speed

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JOM 2025年第5期77卷 3151-3166页

作者： Ling, Qingfeng Zhou, Shiwei Li, Bo Wei, Yonggang Dong, Haigang Wang, Hua Kunming Univ Sci & Technol State Key Lab Complex Nonferrous Met Resources Cle Kunming 650093 Peoples R China Kunming Univ Sci & Technol Fac Met & Energy Engn Kunming 650093 Peoples R China Sino Platinum Met Co Ltd Kunming 650106 Peoples R China

High gold-containing material (HGCM) is the product of waste printed circuit boards (WPCBs) by pyrometallurgy and electrolytic refining. This paper proposes a mixing method based on variable stirring speed to enhance the leaching of gold and copper. The leaching behavior of gold and copper in the chlorination system from HGCM under variable stirring speed was studied, and the results showed that a variable stirring speed can enhance liquid flow and save reaction time. Temperature and acid concentration affect the leaching of metals. Under optimum conditions, gold and copper can be completely leached. Moreover, the gold leaching process was found to conform to the surface chemical-controlled shrinking core model, according to the kinetic curve and an activation energy of 49.47 kJ/mol. In addition, combined with XRD analysis of the raw material and leaching residue, the main phases in HGCM are AuCu3, Au, and Au3Cu. This process delivered complete copper and gold leaching from HGCM under laboratory conditions, and provided a more efficient and fast method for chlorination leaching of metals.

关键词： Activation energy

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Carbon nanofibers embedded with Fe-Co alloy nanoparticles via electrospinning as lightweight high-performance electromagnetic wave absorbers

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Rare Metals 2024年第6期43卷 2769-2783页

作者： Wen-Jun Cai Jian-Guo Jiang Zi-Dong Zhang Zi-Xuan Liu Lu-JieZhang Zhen-Kun Long Ke Bi Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials(Ministry of Education) Shandong UniversityJinan 250061China School of Materials Science and Engineering Shandong UniversityJinan 250061China Energy Institute Qilu University of Technology(Shandong Academy of Sciences)Jinan 250014China State Key Laboratory of Information Photonics and Optical Communications School of ScienceBeijing University of Posts and TelecommunicationsBeijing 100876China

As a lot of electromagnetic pollution and interference issues have emerged,to overcome electromagnetic interference,prevent electromagnetic hazards,and develop new high-performance electromagnetic wave(EMW)absorbers have become a significant task in the field of materials *** this paper,a three-dimensional(3D)carbon nanofibers network with core-shell structure,embedded with varied molar ratios of iron and cobalt(4:0,3:1,2:2,1:3,0:4),was effectively synthesized(Fe/Co@C-CNFs)via *** phase,microstructure,magnetic and EMW absorption properties were *** is discovered that Fe/Co@C-CNFs doped with iron:cobalt=1:1 have excellent EMW absorption *** the matching thickness is 1.08 mm,the minimum reflection loss(RL)value is-18.66 dB,while the maximum effective absorption bandwidth(EAB)reaches 4.2 GHz(13.9-18 GHz)at a thickness of 1.22 *** is owing to the absorbers'superior impedance matching and multiple reflections as well as the conductivity,dielectric,and magnetic losses of carbon nanofibers embedded with Fe-Co alloy *** addition,the radar cross section(RCS)of the absorbers has been calculated by CST Studio Suite,showing that the absorbing coating can effectively reduce the RCS at various angles,especially for Fe/Co@C-CNFs doped with iron:cobalt=1:*** findings not only provide new insights for the preparation of light-weight and high-performance electromagnetic wave absorbers,but also contribute to energy storage and conversion.

关键词： Electromagnetic wave(EMW)absorbers Fe/Co@C-CNFs Core-shell structure EMW absorbing mechanism Radar cross section(RCS)

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Modeling of High-frequency Electromagnetic Oscillation for DC Fault in MMC-HVDC Systems

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CSEE Journal of Power and Energy Systems 2023年第3期9卷 1151-1160页

作者： Hong Shen Zhonghao Dongye Lei Qi Muxue Wang Xiangyu Zhang Peng Qiu Xiaoguang Wei State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources North China Electric Power UniversityBeijing 102206China Electric Power Research Institute State Grid Zhejiang Electric Power CompanyHangzhou 310014China State Key Laboratory of Advanced Power Transmission Technology Global Energy Interconnection Research Institute Co.Ltd.Beijing 102209China

DC short-circuit faults pose a hazard to the operation of a modular multilevel converter(MMC)-based high voltage direct current(HVDC)system,necessitating reliable fault clearing solutions with rapid ***,because the parasitic capacitances of the main equipment oscillate with the lumped inductances of the HVDC system,strong electromagnetic oscillations with multiple frequencies occur during clearance *** oscillations will disturb the HVDC system’s protection and control ***,this paper focuses on the modeling of these ***,an equivalent circuit for the MMC-based HVDC system is proposed,taking into account the parasitic capacitances of the system’s major components,such as DC reactors,connecting cables,and DC circuit breakers(DCCBs).Second,four distinct oscillation stages are postulated based on action coordination of MMCs and DCCBs,and the associated analytical equations for the oscillation frequencies are ***,a 200 kV MMC-based DC converter station is subjected to an 6ms/6kA pole-to-pole(PTP)short-circuit *** oscillations have a frequency range of several kHz to several hundreds of *** measured waveforms correspond well with simulated results,including the parasitic ***,the relative errors between the simulated and measured frequencies are less than 5%.

关键词： DC short-circuit fault electromagnetic oscillation MMC-HVDC parasitic parameter wide-band model

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Advances in air pollution control for key industries in china during the 13th five-year plan

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Journal of Environmental Sciences 2023年第1期35卷 446-459页

作者： Xuecheng Wu Yanping Yang Yue Gong Zhiwen Deng Ying Wang Weihong Wu Chenghang Zheng Yongxin Zhang State Key Laboratory of Clean Energy Utilization College of Energy EngineeringZhejiang UniversityHangzhou 310027China Jiaxing Research Institute of Zhejiang University Jiaxing 314051China

Industrial development is an essential foundation of the national economy,but the industry is also the largest source of air pollution,of which power plants,iron and steel,building materials,and other industries emit large amounts of ***,the Chinese government has promulgated a series of stringent emission regulations,and it is against this backdrop that research into air pollution control technologies for key industrial sectors is in full *** particular,during the 13th Five-Year Plan,breakthroughs have been made in pollution control technology for key industrial sectors.A multi-pollutant treatment technology system of desulfurization,denitrification,and dust collection,which applies to key industries such as power plants,steel,and building materials,has been ***-performance materials for the treatment of different pollutants,such as denitrification catalysts and desulfurization absorbers,were *** the same time,multi-pollutant synergistic removal technologies for flue gas in various industries have also become a hot research topic,with important breakthroughs in the synergistic removal of NO_(x),SO_(x),and *** to the increasingly stringent emission standards and regulations in china,there is still a need to work on the development of multi-pollutant synergistic technologies and further research and development of synergistic abatement technologies for CO_(2) to meet the requirements of ultra-low emissions in industrial sectors.

关键词： key industries Desulfurization Denitrification Dust collection Multi-pollutant control

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Design of luminescence in(Sr,Gd)Li(Al,Mg)_(3)N_(4):Eu^(2+)deep red phosphors via crystal field engineering for full-spectrum WLEDs

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Journal of Rare Earths 2023年第8期41卷 1127-1134,I0001页

作者： Qing Lin Tongyu Gao Yuanhong Liu Ronghui Liu Siwei Chen Xiaole Ma Chunlei Zhao National Engineering Research Center for Rare Earth GRINM Group Co.Ltd.Beijing 100088China GRIREM Advanced Materials Co. Ltd.Beijing 100088China General Research Institute for Nonferrous Metals Beijing 100088China

Red phosphor,with longer wavelength,is highly desirable for full-spectrum *** deep red phosphors(Sr,Gd)Li(AI,Mg)_(3)N_(4):Eu^(2+)were designed from the initial model of SrLiAl_(3)N_(4):Eu^(2+)by structural *** correlations among structural evolution,crystal-field environment,and luminescence properties were *** Sr^(2+)with Gd^(3+)in(Sr,Gd)LiAl_(3)N_(4):Eu^(2+)leads to the enhanced crystal field splitting,larger Stokes shift,and increased structural polyhedron distortion differences,consequently resulting in spectral red-shift and *** further spectral tuning,Mg,with lower electronegativity,was also introduced to modify the local crystal structure,consequently resulting in a further red-shift towards 675 nm and enhanced photoluminescence intensity in(Sr,Gd)Li(AI,Mg)_(3)N_(4):Eu^(2+).What’s more,w-LEDs were fabricated by using blue LED chip,blue,green,red and deep red((Sr,Gd)Li(Al,Mg)_(3)N_(4):Eu^(2+))phosphors whose color rendering index were Ra 96.0 and *** above results demonstrate that the partial replacements of Sr^(2+)by Gd^(3+)and Al^(3+)by Mg^(2+)are effective methods for spectral modulation and(Sr,Gd)Li(AI,Mg)_(3)N_(4):Eu^(2+)phosphors are suitable for highquality full-spectrum WLEDs.

关键词： Full-spectrum WLEDs Structural modulation Deep red phosphor Rare earths

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Efficient construction of calcium fluoride nanoaggregates for enhanced water vapor adsorption

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Particuology 2024年第6期89卷 191-197页

作者： Dan-Lei Yang Jing Cao Rong-Kun Liu Jie-Xin Wang School of Life Sciences and Chemical Engineering Jiangsu Second Normal UniversityNanjing210013China State Key Laboratory of Organic-Inorganic Composites Beijing University of Chemical TechnologyBeijing 100029China Research Center of the Ministry of Education for High Gravity Engineering and Technology Beijing University of Chemical TechnologyBeijing100029China Petrochemical Research Institute PetroChinaBeijing102206China

Calcium fluoride(CaF_(2))is an ideal adsorbent for the dehydration of gaseous hydrogen fluoride(HF)containing water *** this work,a novel CaF_(2)absorbent,spherical CaF_(2)nanoaggregates(NAs)with a closely packed structure,was proposed and efficiently fabricated by spray drying *** the building blocks of CaF_(2)NAs,the CaF_(2)nanoparticles(NPs)were prepared by the addition of excess calcium ions(Ca^(2+))or fluorine ions(F−)in the *** results indicated that the CaF_(2)NPs synthesized by excess Ca^(2+)and the corresponding NAs exhibited much better water vapor adsorption properties than their counterparts by excess F−,owing to higher zeta *** importantly,whether excess Ca^(2+)or F^(−),CaF_(2)NAs had further enhanced water vapor adsorption capacity compared to primary CaF_(2)NPs,possibly owing to their unique nano-micro secondary structures and higher surface *** work has great potential in the development of high-performance absorbents for separating moisture from corrosive gas HF.

关键词： CaF_(2)nanoaggregates Water vapor adsorption Spray drying

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Synthesis of hierarchical porous carbon with high surface area by chemical activation of(NH_(4))_(2)C_(2)O_(4) modified hydrochar for chlorobenzene adsorption

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Journal of Environmental Sciences 2023年第4期126卷 123-137页

作者： Jie Wen Zewei Liu Hongxia Xi Bichun Huang School of Environment and Energy South China University of TechnologyGuangzhou Higher Education Mega CentreGuangzhou 510006China School of Chemistry and Chemical Engineering South China University of TechnologyGuangzhou 510640China The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters Ministry of EducationSouth China University of TechnologyGuangzhou Higher Education Mega CentreGuangzhou 510006China

In this work,hydrothermal technique combined with KOH activation were employed to develop a series of porous carbons (NPCK-x) using tobacco stem as a low-cost carbon source and (NH_(4))_(2)C_(2)O_(4)as a novel nitrogen-doping *** properties of NPCK-x were characterized by Brunauer-Emmett-Teller,field emission scanning electron microscopy,X-ray diffraction,Raman microscope,elemental analysis,and X-ray photoelectron *** showed that the NPCK-x samples possessed large surface areas (maximum:2875 m^(2)/g),hierarchical porous structures,and high degree of disorder.N-containing functional groups decomposed during activation process,which could be the dominant reason for appearance of abundant mesopores and well-developed pore *** chlorobenzene adsorption experiments demonstrated that carbon materials with(NH_(4))_(2)C_(2)O_(4)modification exhibited higher adsorption capacity (maximum:1053 mg/g) than those without modification (maximum:723 mg/g).The reusability studies of chlorobenzene indicated that the desorption efficiency of (NH_(4))_(2)C_(2)O_(4)modified porous carbon reached90.40%after thermal desorption at 100℃ under *** model fitting results exhibited that the existence of mesopores accelerated the diffusion rate of chlorobenzene in porous ***,Grand Canonical Monte Carlo simulation was conducted to verify that micropores with pore sizes of 1.2–2 nm of the optimized porous carbon were the best adsorption sites for chlorobenzene and mesopores with pore sizes of 2–5 nm were also highly active sites for chlorobenzene adsorption.

关键词： Tobacco stem Hierarchical porous carbon N-containing groups Dynamic adsorption Chlorobenzene

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Community Incidence Estimates of Five Pathogens Based on Foodborne Diseases Active Surveillance—china,2023

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china CDC weekly 2024年第24期6卷 574-579,I0002页

作者： Penghui Fan Haihong Han Jikai Liu Xiaochen Ma Ronghua Zhang Hong Liu Yijing Zhou Zunhua Chu Jian Wen Li Lin Weiwei Li Yunchang Guo NHC Key Laboratory of Food Safety Risk Assessment China National Center for Food Safety Risk AssessmentBeijingChina Beijing Center for Disease Prevention and Control BeijingChina Zhejiang Provincial Center for Disease Control and Prevention Hangzhou CityZhejiang ProvinceChina Shanghai Center for Disease Control and Prevention ShanghaiChina Jiangsu Provincial Center for Disease Control and Prevention Nanjing CityJiangsu ProvinceChina Shandong Province Center for Disease Control and Prevention Jinan CityShandong ProvinceChina Guangdong Province Center for Disease Control and Prevention Guangzhou CityGuangdong ProvinceChina Sichuan Province Center for Disease Control and Prevention Chengdu CitySichuan ProvinceChina

What is already known about this topic?Foodborne diseases,representing significant food safety and public health challenges globally,are not welldocumented in terms of incidence,particularly for cases characterized by acute gastroenteritis(AGI)in *** is added by this report?This study developed a pyramid model to estimate the incidence of five pathogens,stratified by gender and *** estimated incidences per 100,000 people with 95%uncertainty intervals(UI)are as follows:Norovirus,3,188.28(95%UI:2,518.03,7,296.96);Salmonella spp.,1,295.59(95%UI:1,002.62,1,573.11);diarrheagenic ***(DEC),782.62(95%UI:651.19,932.05);Vibrio parahaemolyticus,404.06(95%UI:342.19,468.93);and Shigella spp.,26.73(95%UI:21.05,33.46).What are the implications for public health practice?This study elucidates the incidence rates across various gender and age groups,thereby identifying priority populations for targeted preventive interventions aimed at reducing disease *** insights are crucial for the development of public health policies and management of food safety risks.

关键词： acute diseases stratified

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