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The pseudospectrum and spectrum(in)stability of quantum corrected Schwarzschild black hole

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Science China(Physics,Mechanics & Astronomy) 2024年第10期67卷 55-75页

作者： Li-Ming Cao Jia-ning Chen Liang-Bi Wu Libo Xie Yu-Sen zhou School of Fundamental Physics and Mathematical Sciences Hangzhou Institute for Advanced StudyUCASHangzhou 310024China Peng Huanwu Center for Fundamental Theory Hefei 230026China Interdisciplinary Center for Theoretical Study and Department of Modern Physics University of Science and Technology of ChinaHefei 230026China

In this study,we investigate the pseudospectrum and spectrum(in)stability of quantum corrected Schwarzschild black ***,we use the hyperboloidal framework to cast the quasinormal mode(QNM)problem into an eigenvalue problem associated with a non-selfadjoint operator,and then the spectrum and pseudospectrum are ***,the invariant subspace method is exploited to improve the computational efficiency for *** investigation into the spectrum(in)stability entails two main *** the one hand,we calculate the spectra of the quantum corrected black hole,then by the means of the migration ratio,the impact of the quantum correction effect on the Schwarzschild black hole has been *** results indicate that the so-called“migration ratio instability”will occur for small black holes with small angular momentum number *** the eikonal limit,the migration ratios remain the same for each *** the other hand,we study the spectrum(in)stability of the quantum corrected black hole by directly adding some particular perturbations into the effective potential,where perturbations are located at the event horizon and null infinity,*** are two interesting observations under the same perturbation energy ***,perturbations at infinity are more capable of generating spectrum instability than those at the event ***,we find that the peak distribution can lead to the instability of QNM spectrum more efficiently than the average distribution.

关键词： quasinormal modes pseudospectrum hyperboloidal coordinate

Quantification of CO_(2) Emissions from Three Power Plants in China Using OCO-3 Satellite Measurements

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Advances in Atmospheric Sciences 2024年第11期41卷 2276-2288页

作者： Yang YAng Minqiang zhou Wei WAng Zijun ning Feng ZHAng Pucai WAng College of Data Science Jiaxing UniversityJiaxing 314000China LAGEO Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China CNRC Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Key Laboratory of Atmospheric Environment and Extreme Meteorology Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Shanghai Ecological Forecasting and Remote Sensing Center Shanghai 200030China Department of Atmospheric and Oceanic Sciences/Institute of Atmospheric Sciences Fudan UniversityShanghai 200082China

Coal-fired power plants are a major carbon source in China. In order to assess the evaluation of China's carbon reduction progress with the promise made on the Paris Agreement, it is crucial to monitor the carbon flux intensity from coal-fired power plants. Previous studies have calculated CO_(2) emissions from point sources based on Orbiting Carbon Observatory-2 and-3(OCO-2 and OCO-3) satellite measurements, but the factors affecting CO_(2) flux estimations are uncertain. In this study, we employ a Gaussian Plume Model to estimate CO_(2) emissions from three power plants in China based on OCO-3 XCO_(2) measurements. Moreover, flux uncertainties resulting from wind information, background values,satellite CO_(2) measurements, and atmospheric stability are discussed. This study highlights the CO_(2) flux uncertainty derived from the satellite measurements. Finally, satellite-based CO_(2) emission estimates are compared to bottom-up *** satellite-based CO_(2) emission estimates at the Tuoketuo and Nongliushi power plants are ~30 and ~10 kt d^(-1) smaller than the Open-Data Inventory for Anthropogenic Carbon dioxide(ODIAC) respectively, but ~10 kt d^(-1) larger than the ODIAC at Baotou.

关键词： OCO-3 power plant CO_(2)emission Gaussian Plume Model

Low-temperature NH_(3)-SCR performance of a novel Chlorella@Mn composite denitrification catalyst

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Journal of Environmental Sciences 2024年第3期137卷 271-286页

作者： Hengheng Liu Fengyu Gao Songjin Ko ning Luo Xiaolong Tang Erhong Duan Honghong Yi Yuansong zhou School of Energy and Environmental Engineering University of Science and Technology BeijingBeijing 100083China Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants Beijing 100083China School of Environmental Science and Engineering University of Science and Technology HebeiHebei 050018China Department of Chemistry Pyongyang University of ArchitecturePyongyangDemocratic People’s Republic of Korea

The synthesis process of conventional Mn-based denitrification catalysts is relatively complex and *** this paper,a resource application of chlorella was proposed,and a Chlorella@Mn composite denitrification catalyst was innovatively synthesized by electrostatic *** Chlorella@Mn composite denitrification catalyst prepared under the optimal conditions(0.54 g/L Mn^(2+)concentration,20 million chlorellas/mL concentration,450℃ calcination temperature)exhibited a well-developed pore structure and large specific surface area(122 m^(2)/g).Compared with MnOx alone,the Chlorella@Mn composite catalyst achieved superior performance,with~100%NH_(3)selective catalytic reduction(NH_(3)-SCR)denitrification activity at 100-225℃.The results of NH_(3)temperature-programmed desorption(NH_(3)-TPD)and H_(2)temperature-programmed reduction(H_(2)-TPR)showed that the catalyst had strong acid sites and good redox *** potential testing showed that the electronegativity of the chlorella cell surface could be used to enrich with Mn^(2+).X-ray photoelectron spectroscopy(XPS)confirmed that Chlorella@Mn had a high content of Mn^(3+)and surface chemisorbed ***-situ diffuse refectance infrared Fourier transform spectroscopy(in-situ DRIFTS)experimental results showed that both Langmuir-Hinshelwood(L-H)and Eley-Rideal(E-R)mechanisms play a role in the denitrification process on the surface of the Chlorella@Mn catalyst,where the main intermediate nitrate species is monodentate *** presence of SO_(2)promoted the generation and strengthening of Bronsted acid sites,but also generated more sulfate species on the surface,thereby reducing the denitrification activity of the Chlorella@Mn *** Chlorella@Mn composite catalyst had the characteristics of short preparation time,simple process and low cost,making it promising for industrial application.

关键词： Chlorella@Mn catalyst NH_(3)-SCR Poisoning resistance Reaction mechanism Infuence of SO_(2)

Phosphine-Built-In Porous Organic Cage Supported Ultrafine Pd Nanoclusters Enable Highly Efficient and Regioselective Hydrogenation of Epoxides

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CCS Chemistry 2024年第10期6卷 2476-2488页

作者： Xin zhou Zhaozhan Wang Zhe-ning Chen Yong Yang CAS Key Laboratory of Bio-Based Materials Qingdao Institute of Bioenergy and Bioprocess TechnologyChinese Academy of SciencesQingdao 266101 Shandong Energy Institute Qingdao 266101 College of Environment and Safety Engineering Qingdao University of Science and TechnologyQingdao 266101 State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002 University of Chinese Academy of Sciences Beijing 100049 Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry Xiamen UniversityXiamen 361005

Selective hydrogenation of epoxides has been regarded as an atom-economical and straightforward method for the synthesis of ***,it remains a big challenge in the precise control of *** date,the reaction enabled by a reusable and high-performance heterogeneous catalyst with excellent regioselectivity is very ***,we develop highly loaded and ultrafine Pd nanoclusters(NCs)encapsulated on a phosphinebuilt-in porous organic cage(FPPOC)for the catalytic hydrogenation of epoxides by molecular *** from the unique characters of uniform dispersion and strong interaction between Pd NCs and FPPOC,the resultant Pd NCs exhibited superior catalytic activity and excellent regioselectivity for the hydrogenation of epoxides under milder conditions.A diverse set of terminal and internal epoxides was efficiently reduced to the corresponding linear or branched alcohols in an extremely regioselective manner,well tolerating diverse functional ***,the catalyst demonstrates high stability and could be reused up to 10 times with marginal decay in activity and ***,the catalyst is applicable for scale-up synthesis with a record turnover number as high as 16,111,to the best of our knowledge,outperforming those previous state-of-the-art *** experiments and characterizations in combination with density functional theory calculations provide insight into the superior activity and excellent regioselectivity.

关键词： porous organic cage phosphine-built-in palladium nanoclusters regioselective hydrogenation epoxides

Peripheral carbazole units-decorated MR emitter containing B−N covalent bond for highly efficient green OLEDs with low roll-off

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Journal of Semiconductors 2024年第8期45卷 59-66页

作者： Danrui Wan Jianping zhou Guoyun Meng ning Su Dongdong Zhang Lian Duan Junqiao Ding School of Chemical Science and Technology Yunnan UniversityKunming 650091China Key Laboratory of Organic Optoelectronics and Molecular Engineering of Ministry of Education Department of ChemistryTsinghua UniversityBeijing 100084China Southwest United Graduate School Kunming 650092China

Boron−nitrogen doped multiple resonance(BN-MR)emitters,characterized by B−N covalent bonds,offer distinctive advantages as pivotal building blocks for facile access to novel MR emitters featuring narrowband spectra and high ***,there remains a scarcity of exploration concerning synthetic methods and structural derivations to expand the library of novel BN-MR ***,we present the synthesis of a BN-MR emitter,tCz[B−N]N,through a one-pot borylation reaction directed by the amine group,achieving an impressive yield of 94%.The emitter is decorated by incorporating two 3,6-di-tbutylcarbazole(tCz)units into a B−N covalent bond doped BN-MR parent molecule via para-C−π−D and para-N−π−D *** peripheral decoration strategy enhances the reverse intersystem crossing process and shifts the emission band towards the pure green region,peaking at 526 nm with a narrowband full-width at half maximum(FWHM)of 41 ***,organic light emitting diodes(OLEDs)employing this emitter achieved a maximum external quantum efficiency(EQEmax)value of 27.7%,with minimal efficiency *** at a practical luminance of 1000 cd·m^(−2),the device maintains a high EQE value of 24.6%.

关键词： multi-resonance narrowband emission B−N covalent bond organic light emitting diodes

Dietary crude protein time-dependently modulates the bacterial community and metabolites and changes dietary nutrient efficiency in growing pigs

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Animal Nutrition 2024年第2期17卷 1-10页

作者： Yuming Wang Junyan zhou ning Cao Lu Wang Jiayu Tu Xiangfang Zeng Shiyan Qiao State Key Laboratory of Animal Nutrition and Feeding Institute of Animal Sciences of Chinese Academy of Agricultural Sciences Animal Science and Technology College Beijing University of Agriculture State Key Laboratory of Animal Nutrition and Feeding Ministry of Agriculture Feed Industry CentreChina Agricultural University

The reduced nutrient digestibility of low-protein(LP) diets has been shown to be caused by the weakened fermentative capacity of the post-gut flora. The dynamic regulation of dietary protein contents on post-gut microbial population and fermentative metabolism is unclear. Twelve growing barrows(19.9 ± 0.8 kg) fitted with a T-cannula at the blind end of the cecum were randomly administered a highprotein(HP, 21.5% crude protein [CP]) diet or an LP(15.5% CP) diet for 28 d. The cecal content and feces were collected at d 1, 14, and 28 of the experiment for microflora structures and metabolite concentrations analysis. The nutrient digestibility coefficient and plasma biochemical parameters were also determined. Compared with the HP treatment, the LP treatment showed decreased plasma urea nitrogen concentration and apparent total tract digestibility of dry matter, gross energy, and CP(P 28, which may be mainly related to the elevated abundance of SCFA-producing bacteria, such as Ruminococcus, Lactobacillus, and Prevotella(P 24-7, and Rikenella, enriched in the LP treatment possibly contributed to reduced plasma endotoxin content. The differences in the abundances of almost all the above-mentioned flora appeared on d 28 but not d 14. Likewise, differences in the Simpson and Shannon indices and clustering patterns of the microbiota between treatments were also only observed on d 28. To sum up, in a time-dependent manner, the LP diet increased probiotics with gut-improving functions a

关键词： Low-protein diet Microorganism Nutrient digestibility Pig Short-chain fatty acid

Karstsinnectes cehengensis(Cypriniformes:Nemacheilidae),a new species of cave fish from Guizhou,China

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Zoological Systematics 2024年第2期49卷 101-115页

作者： Xinrui Zhao Changting Lan Tao Luo Jing Yu Jiajun zhou ning Xiao Jiang zhou School of Karst Sciences Guizhou Normal UniversityGuiyang 550025China School of Life Sciences Guizhou Normal UniversityGuiyang 550001China Zhejiang Forest Resource Monitoring Center Hangzhou 310020China Zhejiang Forestry Survey Planning and Design Company Limited Hangzhou 310020China Guiyang Healthcare Vocational University Guiyang 550081China

Four species of the genus Karstsinnectes,which live in dark,low-energy groundwater ecosystems,are currently recorded,mainly distributed in the upstream of the Pearl River,the Youjiang River and the Hongshui *** biodiversity surveys is particularly difficult due to the particular cave habitats inhabited by these *** this work,we describe a new cave fish of the genus Karstsinnectes,namely *** Luo,Zhao&zhou,***.,collected from the Beipanjiang River,the upstream of the Hongshui ***,the four individuals of the new species form a phylogenetically separate lineage,as the sister clade of ***,with a 9.4–9.5%genetic difference in mitochondrial Cyt ***,the new species can be distinguished from its congeners by a combination of the following morphological characteristics:body naked,without body color;eyes reduced,diameter 1.4–3.8%of head length;anterior and posterior nostrils adjacent,anterior nostril not elongated to a barbel-like tip;lateral line incomplete;caudal fin forked;dorsal-fin rays iii-7,pectoral-fin rays i-11–12,pelvic-fin rays i-7,anal-fin rays iii-5,with 14 branched caudal-fin *** discovery of this new species represents the northernmost distribution of species within the genus Karstsinnectes and the first record from Guizhou *** currently known species of this genus inhabited in caves,making them ideal organisms for studying historical river connectivity and cave formation process.

关键词： Diversity karst cave morphology phylogeny Karstsinnectes

Aerodynamic Features of High-Speed Maglev Trains with Different Marshaling Lengths Running on a Viaduct under Crosswinds

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Computer Modeling in Engineering & Sciences 2024年第7期140卷 975-996页

作者： Zun-Di Huang Zhen-Bin zhou ning Chang Zheng-Wei Chen Su-Mei Wang School of Rail Transportation Wuyi UniversityJiangmen529020China National Rail Transit Electrification and Automation Engineering Technology Research Center(Hong Kong Branch) The Hong Kong Polytechnic UniversityHong Kong999077China Department of Civil and Environmental Engineering The Hong Kong Polytechnic UniversityHong Kong999077China

The safety and stability of high-speed maglev trains traveling on viaducts in crosswinds critically depend on their aerodynamic ***,this paper uses an improved delayed detached eddy simulation(IDDES)method to investigate the aerodynamic features of high-speed maglev trains with different marshaling lengths under *** effects of marshaling lengths(varying from 3-car to 8-car groups)on the train’s aerodynamic performance,surface pressure,and the flow field surrounding the train were investigated using the three-dimensional unsteady compressible Navier-Stokes(N-S)*** results showed that the marshaling lengths had minimal influence on the aerodynamic performance of the head and middle ***,the marshaling lengths are negatively correlated with the time-average side force coefficient(CS)and time-average lift force coefficient(Cl)of the tail *** to the tail car of the 3-car groups,the CS and Cl fell by 27.77%and 18.29%,respectively,for the tail car of the 8-car *** is essential to pay more attention to the operational safety of the head car,as it exhibits the highest time average ***,the mean pressure difference between the two sides of the tail car body increased with the marshaling lengths,and the side force direction on the tail car was opposite to that of the head and middle ***,the turbulent kinetic energy of the wake structure on the windward side quickly decreased as marshaling lengths increased.

关键词： High-speed maglev train marshaling lengths crosswinds aerodynamic features

Biomedical rare-earth magnesium alloy:Current status and future prospects

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Journal of Magnesium and Alloys 2024年第4期12卷 1260-1282页

作者： Mingli Yang Cheng Chen Dongsheng Wang Yinjin Shao Wenhao zhou Cijun Shuai Youwen Yang Xinghai ning Institute of Additive Manufacturing Jiangxi University of Science and TechnologyNanchang 330013China Key Laboratory of Construction Hydraulic Robots of Anhui Higher Education Institutes Tongling UniversityTongling 244061China Department of Rehabilitation Ganzhou People’s HospitalGanzhou 341099China Shaanxi Key Laboratory of Biomedical Metallic Materials Northwest Institute for Non-Ferrous Metal ResearchXi’an 710016China State Key Laboratory of High Performance Complex Manufacturing Central South UniversityChangsha 410083China School of Mechanical and Electrical Engineering Jiangxi University of Science and TechnologyGanzhou 341000China College of Engineering and Applied Science Nanjing University210089China

Biomedical magnesium(Mg)alloys have garnered significant attention because of their unique biodegradability,favorable biocompatibility,and suitable mechanical *** incorporation of rare earth(RE)elements,with their distinct physical and chemical properties,has greatly contributed to enhancing the mechanical performance,degradation behavior,and biological performance of biomedical Mg ***,a series of RE-Mg alloys are being designed and investigated for orthopedic implants and cardiovascular stents,achieving substantial and encouraging research *** this work,a comprehensive summary of the state-of-the-art in biomedical RE-Mg alloys is *** physiological effects and design standards of RE elements in biomedical Mg alloys are ***,the degradation behavior and mechanical properties,including their underlying action are studied ***,the preparation techniques and current application status of RE-Mg alloys are ***,we address the ongoing challenges and propose future prospects to guide the development of high-performance biomedical Mg-RE alloys.

关键词： Magnesium alloy Rare earth elements Biodegradation behavior Mechanical performance Biological properties