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Fusion of Ground-Based and Spaceborne Radar Precipitation Based on Spatial Domain Regularization

Journal of Meteorological Research 2024年第2期38卷 285-302页

作者： Anfan HUANG Leilei KOU Yanzhi LIANG Ying MAO Haiyang GAO Zhigang CHU School of Atmospheric Physics Nanjing University of Information Science&TechnologyNanjing 210044 Collaborative Innovation center on Forecast and evaluation of Meteorological Disasters Nanjing University of Information Science&TechnologyNanjing 210044

High-quality and accurate precipitation estimations can be obtained by integrating precipitation information measures using ground-based and spaceborne radars in the same target area.Estimating the true precipitation state is a typical inverse problem for a given set of noisy radar precipitation observations.The regularization method can appropriately constrain the inverse problem to obtain a unique and stable solution.For different types of precipitation with different prior distributions,the L_(1) and L_(2) norms were more effective in constraining stratiform and convective precipitation,respectively.As a combination of L_(1) and L_(2) norms,the Huber norm is more suitable for mixed precipitation types.This study uses different regularization norms to combine precipitation data from the C-band dual-polarization ground radar(CDP)and dual-frequency precipitation radar(DPR)on the Global Precipitation Measurement(GPM)mission core satellite.Compared to single-source radar data,the fused figures contain more information and present a comprehensive precipitation structure encompassing the reflectivity and precipitation fields.In 27 precipitation cases,the fusion results utilizing the Huber norm achieved a structural similarity index measure(SSIM)and a peak signal-to-noise ratio(PSNR)of 0.8378 and 30.9322,respectively,compared with the CDP data.The fusion results showed that the Huber norm effectively amalgamate the features of convective and stratiform precipitation,with a reduction in the mean absolute error(MAE;16.1%and 22.6%,respectively)and root-mean-square error(RMSE;11.7%and 13.6%,respectively)compared to the 1-norm and 2-norm.Moreover,in contrast to the fusion results of scale recursive estimation(SRE),the Huber norm exhibits superior capability in capturing the localized precipitation intensity and reconstructing the detailed features of precipitation.

关键词： dual-frequency precipitation radar(DPR) dual-polarization radar data fusion regularization Huber norm

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Status and developmental trends in recombinant collagen preparation technology

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Regenerative Biomaterials 2024年第2期3卷 17-36页

作者： Xiaolei Guo Yuan Ma Hang Wang Hongping Yin Xinli Shi Yiqin Chen Guobiao Gao Lei Sun Jiadao Wang Yunbing Wang Daidi Fan center for Medical Device evaluation National Medical Products AdministrationBeijing 100081China State Key Laboratory of Tribology Tsinghua UniversityBeijing 100084China school of Life science and technology China Pharmaceutical UniversityNanjing 210009China national Engineering Research center for Biomaterials&College of Biomedical Engineering Sichuan UniversityChengdu 610064China Biotech.&Biomed.Research Institute Northwest UniversityXi'an 710127China

Recombinant collagen is a pivotal topic in foundational biological research and epitomizes the application of critical bioengineer-ing technologies.These technological advancements have pro-found implications across diverse areas such as regenerative medicine,organ replacement,tissue engineering,cosmetics and more.Thus,recombinant collagen and its preparation methodologies rooted in genetically engineered celis mark pivotal milestones in medical product research.This article pro-vides a comprehensive overview of the current genetic engi-neering technologies and methods used in the production of recombinant collagen,as well as the conventional production process and gquality control detection methods for this material.Furthermore,the discussion extends to foresee the strides in physical transfection and magnetic control sorting studies,envisioning an enhanced preparation of recombinant collagen-seeded cells to further fuel recombinant collagen production.

关键词： recombinant collagen preparation genetic engineering collagen characterization physical transfection seed cell sorting

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Human influence on the duration of extreme temperature events in Asia's hotspot regions

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Advances in Climate Change Research 2024年第2期15卷 312-326页

作者： Zi-Meng WANG Hong-Yun MA Wei LI Hai-Shan CHEN Collaborative Innovation center on Forecast and evaluation of Meteorological Disasters(CIC-FEMD)/Key Laboratory of Meteorological Disaster Ministry of Education(KLME)Nanjing University of Information Science and TechnologyNanjing 210044China

Observations and models indicate that human activities exert a considerable impact on the frequency and intensity of extreme temperature events,which are associated with global warming.However,changes in the duration of extreme temperature events and their association with human influence have not been considered in most studies.Thus,the possible relationship between the observed changes in the warm and cold spell duration(WSDI and CSDI)in hotspot regions during 1960-2014 and human influence was investigated based on the NCEP/NCAR reanalysis version 1 and Coupled Model Inter-comparison Project Phase 6(CMIP6)data.Constraint projection based on these attribution results was also performed.The optimal fingerprinting technique was used to compare observed changes in WSDI and CSDI to simulated changes averaged across eight CMIP6 models.Results show that anthropogenic(ANT)forcing contributed to the observed increase in WSDI in the three hotspot regions(West Asia,South Asia and Southeast Asia),with the majority of the changes being attributed to greenhouse gas forcing.However,a generally weak ANT signal can be observed in the decreasing trend of CSDI and can be detected in South and Southeast Asia.The influence of aerosol forcing remains undetected in either WSDI or CSDI,which differs from the results for frequency and intensity of extreme temperatures.The attribution results revealed that the constrained projection of WSDI is lower than the raw projection for 2015-2100 in West Asia and Southeast Asia.However,no differences in future CSDI changes are found in Southeast Asia between the constrained and raw projections.

关键词： Extreme temperature events Duration Detection attribution Constraint projection Hotspot regions

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Differences in Variations of Long-Lived and Short-Lived Summer Heat Waves during1981–2020 over Eastern China and Their Corresponding Large-Scale Circulation Anomalies

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Journal of Meteorological Research 2024年第3期38卷 414-436页

作者： Liqun JI Haishan CHEN Collaborative Innovation center on Forecast and evaluation of Meteorological Disasters/Key Laboratory of Meteorological Disaster Ministry of Education Nanjing University of Information Science & Technology School of Atmospheric sciences Nanjing University of Information Science & Technology

Using daily maximum temperature(Tmax) data from 516 observation stations in eastern China from 1981 to 2020,this study employed a relative threshold method to define short-and long-lived heat waves（HWs） by considering regional climate differences to investigate the spatial characteristics and evolution of large-scale circulation during summer HWs. The results demonstrated spatial disparities in the frequency distribution of HWs of different durations and differences in the magnitude of duration and intensity between short-and long-lived HWs. Empirical orthogonal function analysis revealed three dominant spatial modes for both short-and long-lived HWs. The first mode showed that short-lived HWs occur prominently in both northern and southern regions, whereas long-lived HWs mainly occur in the northern region. The second mode was characterized by a meridional dipole pattern in both cases.The third mode exhibited a quadrupole pattern for short-lived HWs and a tripole pattern for long-lived HWs. Differences in the center locations of anomalies in the 500-hPa geopotential height and 850-hPa wind fields significantly influenced the temperature and precipitation anomaly distribution of typical HWs by affecting the warm column in the lower troposphere, cloud distribution, and moisture transport. Moreover, the atmospheric circulation evolution processes of typical HWs associated with the different modes of long-and short-lived HWs were linked to distinct teleconnection patterns. During the three modes of long-lived（short-lived） HWs, there was stronger（weaker） wave flux activity with multiple（single） propagation paths. Stronger westward Atlantic wave train activity at 300 hPa triggered the synergistic action of meridional and zonal wave fluxes, favoring the strengthening and maintenance of positive anomalies in geopotential height of 500 hPa. This may have contributed to the formation of long-lived HWs.These findings provide valuable insights to enhance our understanding and prediction of summer HWs.

关键词： short-lived heat waves (HWs) long-lived HWs empirical orthogonal function (EOF) modes large-scale atmospheric circulation

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Predictability of the 7·20 extreme rainstorm in Zhengzhou in stochastic kinetic-energy backscatter ensembles

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science China Earth sciences 2024年第7期67卷 2226-2241页

作者： Min YANG Peilong YU Lifeng ZHANG Xiaobing PAN Quanjia ZHONG Yunying LI College of Meteorology and Oceanography National University of Defense TechnologyChangsha 410073China Key Laboratory of High Impact Weather(Special) China Meteorological AdministrationChangsha 410073China Collaborative Innovation center on Forecast and evaluation of Meteorological Disasters/Key Laboratory of Meteorological Disaster Ministry of Education/Joint International Research Laboratory of Climate and Environment ChangeNanjing University of Information Science and TechnologyNanjing 210044China Department of Ocean science Hong Kong University of Science and TechnologyHong Kong 999077China

The scale-dependent predictability of the devastating 7·20 extreme rainstorm in Zhengzhou,China in 2021 was investigated via ensemble experiments,which were perturbed on different scales using the stochastic kinetic-energy backscatter(SKEB)scheme in the WRF model,with the innermost domain having a 3-km grid spacing.The daily rainfall(RAIN24h)and the cloudburst during 1600-1700 LST(RAIN1h)were considered.Results demonstrated that with larger perturbation scales,the ensemble spread for the rainfall maximum widens and rainfall forecasts become closer to the observations.In ensembles with mesoscale or convective-scale perturbations,RAIN1h loses predictability at scales smaller than 20 km and RAIN24h is predictable for all scales.Whereas in ensembles with synoptic-scale perturbations,the largest scale of predictability loss extends to 60 km for both RAIN1h and RAIN24h.Moreover,the average positional error in forecasting the heaviest rainfall for RAIN24h(RAIN1h)was 400 km(50-60)km.The southerly low-level jet near Zhengzhou was assumed to be directly responsible for the forecast uncertainty of RAIN1h.The rapid intensification in low-level cyclonic vorticity,mid-level divergence,and upward motion concomitant with the jet dynamically facilitated the cloudburst.Further analysis of the divergent,rotational and vertical kinetic spectra and the corresponding error spectra showed that the error kinetic energy at smaller scales grows faster than that at larger scales and saturates more quickly in all experiments.Larger-scale perturbations not only boost larger-scale error growth but are also conducive to error growth at all scales through a downscale cascade,which indicates that improving the accuracy of larger-scale flow forecast may discernibly contributes to the forecast of cloudburst intensity and position.

关键词： Stochastic kinetic-energy backscatter(SKEB) Extreme rainfall Ensemble forecast Predictability

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Synergistic effect of gradient Zn content and multiscale particles on the mechanical properties of Al-Zn-Mg-Cu alloys with coupling distribution of coarse-fine grains

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International Journal of Minerals,Metallurgy and Materials 2024年第6期31卷 1392-1405页

作者： Liangliang Yuan Mingxing Guo Yi Wang Yun Wang Linzhong Zhuang Institute of Effectiveness evaluation of Flying Vehicle Beijing 100085China State Key Laboratory for Advanced Metals and Materials University of Science and Technology BeijingBeijing 100083China Beijing Advanced Innovation center for Materials Genome Engineering University of Science and Technology BeijingBeijing 100083China Beijing Laboratory of Metallic Materials and Processing for Modern Transportation University of Science and Technology BeijingBeijing 100083China

This study investigated the influence of graded Zn content on the evolution of precipitated and iron-rich phases and grain struc-ture of the alloys,designed and developed the Al–8.0Zn–1.5Mg–1.5Cu–0.2Fe(wt%)alloy with high strength and formability.With the increase of Zn content,forming the coupling distribution of multiscale precipitates and iron-rich phases with a reasonable matching ratio and dispersion distribution characteristics is easy.This phenomenon induces the formation of cell-like structures with alternate distribu-tion of coarse and fine grains,and the average plasticity–strain ratio(characterizing the formability)of the pre-aged alloy with a high strength is up to 0.708.Results reveal the evolution and influence mechanisms of multiscale second-phase particles and the corresponding high formability mechanism of the alloys.The developed coupling control process exhibits considerable potential,revealing remarkable improvements in the room temperature formability of high-strength Al–Zn–Mg–Cu alloys.

关键词： Al–Zn–Mg–Cu alloy iron-rich phase high formability microstructure mechanisms

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Record-breaking summer-autumn drought in southern China in 2022:Roles of tropical sea surface temperature and Eurasian warming

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science China Earth sciences 2024年第2期67卷 420-431页

作者： Yuepeng HU Botao ZHOU Huijun WANG Dapeng ZHANG Collaborative Innovation center on Forecast and evaluation of Meteorological Disasters/Key Laboratory of Meteorological Disaster Ministry of Education/Joint International Research Laboratory of Climate and Environment ChangeNanjing University of Information Science and TechnologyNanjing210044China School of Atmospheric sciences Nanjing University of Information Science and TechnologyNanjing210044China

From summer to autumn in 2022,a severe drought lasted in southern China,posing serious effects on economic growth and ecological systems.This study explored the atmospheric circulations accounting for this persistent drought event.It shows that the drought in southern China during the summer of 2022 was strongly linked to the divergence of water vapor flux and descending motions,which were respectively caused by the anomalous anticyclone over the western North Pacific and the northward movement of the East Asian subtropical jet(EASJ).Differently,the atmospheric background responsible for the sustained drought in autumn is manly featured by a cyclonic circulation anomaly over the region from the Bay of Bengal to the South China Sea,which led to decreased moisture and descending motions in southern China.Further investigation suggests that the rarely strong surface warming over northern Eurasia and the extreme La Nina-like pattern over the tropical Pacific jointly resulted in the anomalous anticyclone over the western North Pacific and the northward shift of the EASJ in the summer of 2022,while the cyclonic circulation anomaly prevailing over the region from the Bay of Bengal to the South China Sea in autumn was largely attributed to the extremely negative anomalies of the tropical Indian Ocean sea surface temperature.

关键词： Summer-autumn drought Southern China Tropical sea surface temperature Eurasian warming

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Developing an atmospheric aging evaluation model of acrylic coatings:A semi-supervised machine learning algorithm

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International Journal of Minerals,Metallurgy and Materials 2024年第7期31卷 1617-1627页

作者： Yiran Li Zhongheng Fu Xiangyang Yu Zhihui Jin Haiyan Gong Lingwei Ma Xiaogang Li Dawei Zhang Beijing Advanced Innovation center for Materials Genome Engineering Institute for Advanced Materials and TechnologyUniversity of Science and Technology BeijingBeijing 100083China national Materials Corrosion and Protection Data center University of Science and Technology BeijingBeijing 100083China BRI Southeast Asia Network for Corrosion and Protection(MOE) Shunde Innovation School of University of Science and Technology BeijingFoshan 528399China

To study the atmospheric aging of acrylic coatings,a two-year aging exposure experiment was conducted in 13 representative climatic environments in China.An atmospheric aging evaluation model of acrylic coatings was developed based on aging data including11 environmental factors from 567 cities.A hybrid method of random forest and Spearman correlation analysis was used to reduce the redundancy and multicollinearity of the data set by dimensionality reduction.A semi-supervised collaborative trained regression model was developed with the environmental factors as input and the low-frequency impedance modulus values of the electrochemical impedance spectra of acrylic coatings in 3.5wt%NaCl solution as output.The model improves accuracy compared to supervised learning algorithms model(support vector machines model).The model provides a new method for the rapid evaluation of the aging performance of acrylic coatings,and may also serve as a reference to evaluate the aging performance of other organic coatings.

关键词： acrylic coatings coatings aging atmospheric environment machine learning

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Haploids can be induced in knockout mutants of OsPLA1,but not OsDMP3 or OsDMP6,in rice

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The Crop Journal 2024年第1期12卷 213-221页

作者： Zongkai Liu Yu Zhong Xiaolong Qi Tai An Shuwei Guo Dong Wang Yuwen Wang Bin Feng Zuofeng Zhu Shaojiang Chen Chenxu Liu national Maize Improvement center Engineering Research Center of Ministry of EducationChina Agricultural UniversityBeijing 100193China national center for evaluation of Agricultural Wild Plants(Rice) Department of Plant Genetics and BreedingChina Agricultural UniversityBeijing 100193China

Doubled haploid(DH)technology is an important tool in crop breeding because it can significantly accelerate the breeding process.ZmPLA1/MATL/NLD and ZmDMP are two key genes controlling haploid induction(HI)in maize,exhibiting a synergistic effect.However,it is unknown whether knock out of ZmDMP orthologs can stimulate HI in rice.In this study,a ZmPLA1 ortholog(OsPLA1)and two ZmDMP orthologs(OsDMP3 and OsDMP6)were identified in rice.All three genes encode plasma membrane-localized proteins and were highly expressed in mature anthers.Knockout of OsPLA1 in both Minghui 63 and Nipponbare resulted in reduced seed setting rate(SSR)and caused HI.The osdmp3,osdmp6 and the double mutant failed to trigger HI independently,nor increased the haploid induction rate(HIR)when combined with ospla1.Repeated pollinations operations of QX654A with the ospla1 mutant significantly improve SSR,while reducing HIR.RNA-seq profiling of mature ospla1 mutant anthers indicated that a large number of differentially expressed genes(DEGs)were enriched in redox homeostasis and lipid metabolic GO terms,plant hormone signal transduction,and MAPK signaling pathways.These findings provide important insights towards construction of an efficient DH breeding technology and study of the molecular mechanism of HI in rice.

关键词： Doubled haploid breeding Haploid induction Mutation anlaysis Rice

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Tailoring high-refractive-index nanocomposites for manufacturing of ultraviolet metasurfaces

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Microsystems & Nanoengineering 2024年第2期10卷 303-310页

作者： Hyunjung Kang Dongkyo Oh Nara Jeon Joohoon Kim Hongyoon Kim Trevon Badloe Junsuk Rho Department of Mechanical Engineering Pohang University of Science and Technology(POSTECH)PohangRepublic of Korea Graduate School of Artificial Intelligence Pohang University of Science and Technology(POSTECH)PohangRepublic of Korea Department of Chemical Engineering Pohang University of Science and Technology(POSTECH)PohangRepublic of Korea Department of Electrical Engineering Pohang University of Science and Technology(POSTECH)PohangRepublic of Korea POSCO-POSTECH-RIST Convergence Research center for Flat Optics and Metaphotonics PohangRepublic of Korea national Institute of Nanomaterials technology(NINT) PohangRepublic of Korea

Nanoimprint lithography(NIL)has been utilized to address the manufacturing challenges of high cost and low throughput for optical metasurfaces.To overcome the limitations inherent in conventional imprint resins characterized by a low refractive index(n),high-n nanocomposites have been introduced to directly serve as meta-atoms.However,comprehensive research on these nanocomposites is notably lacking.In this study,we focus on the composition of high-n zirconium dioxide(ZrO_(2))nanoparticle(NP)concentration and solvents used to produce ultraviolet(UV)metaholograms and quantify the transfer fidelity by the measured conversion efficiency.The utilization of 80 wt%ZrO_(2)NPs in MIBK,MEK,and acetone results in conversion efficiencies of 62.3%,51.4%,and 61.5%,respectively,at a wavelength of 325 nm.The analysis of the solvent composition and NP concentration can further enhance the manufacturing capabilities of high-n nanocomposites in NIL,enabling potential practical use of optical metasurfaces.

关键词： ultraviolet refractive nanocomposites

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