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Will the 2022 compound heatwaveedrought extreme over the Yangtze River Basin become Grey Rhino in the future?

Advances in Climate Change Research 2024年第3期15卷 547-556页

作者： Ai-Qing FENG Qing-Chen CHAO Lu-Lu liu Ge GAO Guo-Fu WANG Xue-jun ZHANG Qi-guang WANG China Meteorological Administration Key Laboratory for Climate Prediction Studies National Climate CentreBeijing 100081China Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China China Institute of Water Resources and Hydropower Research Beijing 100038China China Meteorological Administration Training Centre China Meteorological AdministrationBeijing 100081China

The increasingly frequent and severe regional-scale compound heatwave-drought extreme events(CHDEs),driven by global warming,present formidable challenges to ecosystems,residential livelihoods,and economic ***,uncertainty persists regarding the future trend of CHDEs and their insights into regional spatiotemporal *** integrating daily meteorological data from observations in 1961-2022 and global climate models(GCMs)based on the Shared Socioeconomic Pathways,the evolution patterns of CHDEs were compared and examined among three sub-catchments of the Yangtze River Basin,and the return periods of CHDE in 2050s and 210Os were *** findings indicate that the climate during the 2022 CHDE period was the warmest and driest recorded in 1961-2022,with precipitation less than 154.5 mm and a mean daily maximum temperature 3.4°C higher than the average of 1981-2010,whereas the char-acteristics in the sub-catchments exhibited temporal and spatial *** July-August 2022,the most notable feature of CHDE was its extremeness since 1961,with return periods of~200-year in upstream,80-year in midstream,and 40-year in downstream,*** 2050,the return periods witnessed 2022 CHDE would likely be reduced by *** towards 2100,under the highest emission scenario of SSP585,it was projected to substantially increase the frequency of CHDEs,with return periods reduced to one-third in the upstream and downstream,as well as halved in the *** findings provide valuable insights into the changing risks associated with forthcoming climate extremes,emphasizing the urgency of addressing these challenges in regional management and sustainable development.

关键词： Compound extreme event Joint return period Drought Heatwave Climate change Yangtze River Basin

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Cuproptosis mediates copper-induced testicular spermatogenic cell death

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Asian Journal of Andrology 2024年第3期26卷 295-301页

作者： Jing-Yi Zhang Xu-jun Yu jun-jun Li Yao Xiao guang-Sen Li Fang Yang Liang Dong Chengdu University of Traditional Chinese Medicine Chengdu 611137China Chengdu Fifth People’s Hospital The Fifth People’s Hospital of Chengdu University of Traditional Chinese MedicineChengdu 611130China TCM Regulating Metabolic Diseases Key Laboratory of Sichuan Province Hospital of Chengdu University of Traditional Chinese MedicineChengdu 610072China Department of Surgery The Reproductive and Women-Children HospitalChengdu University of Traditional Chinese MedicineChengdu 610041China

Cuproptosis,a novel mechanism of programmed cell death,has not been fully explored in the context of spermatogenic *** investigated the potential involvement of cuproptosis in spermatogenic cell death using a mouse model of copper *** male Institute of Cancer Research(ICR)mice were randomly divided into four groups that received daily oral gavage withsodium chloride(control)or copper sulfate(CuSO_(4))at 50 mg kg^(−1),100 mg kg^(−1),or 200 mg kg^(−1),for 42 consecutive *** to copper overload exhibited a disruption in copper ***,significant upregulated expression of keycuproptosis factors was accompanied by a significant rise in the rates of testicular tissue cell *** revealed the presence of ferredoxin 1(Fdx1)in Sertoli cells,Leydig cells,and spermatogenic cells at various stages oftesticular development,and the Fdx1-positive staining area was significantly increased in copper-overloaded *** and decreased adenosine triphosphate levels were also observed,further implicating mitochondrial damage *** analyses revealed pathological lesions and blood−testis barrier destruction in the testicular tissue,accompaniedby decreased sperm concentration and motility,in copper-overloaded *** summary,our results indicate that copper-overloadedmice exhibit copper homeostasis disorder in the testicular tissue and that cuproptosis participates in spermatogenic cell *** findings provide novel insights into the pathogenic mechanisms underlying spermatogenic cell death and provide initialexperimental evidence for the occurrence of cuproptosis in the testis.

关键词： blood−testis barrier cuproptosis ferredoxin 1 spermatogenic cell death

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Evolution of pore systems in low-maturity oil shales during thermal upgrading--Quantified by dynamic SEM and machine learning

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Petroleum Science 2024年第3期21卷 1739-1750页

作者： jun liu Xue Bai Derek Elsworth Key Laboratory of Deep Underground Science and Engineering(Ministry of Education) Institute of New Energy and Low-Carbon TechnologySichuan UniversityChengdu610065SichuanChina International Quantum Academy Shenzhen518048GuangdongChina Shenzhen Institute of Advanced Electronic Materials Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhen518055GuangdongChina Department of Energy and Mineral Engineering Pennsylvania State University ParkPA 16802USA

In-situ upgrading by heating is feasible for low-maturity shale oil,where the pore space dynamically *** characterize this response for a heated substrate concurrently imaged by *** systematically follow the evolution of pore quantity,size(length,width and cross-sectional area),orientation,shape(aspect ratio,roundness and solidity)and their anisotropy—interpreted by machine *** indicate that heating generates new pores in both organic matter and inorganic ***,the newly formed pores are smaller than the original pores and thus reduce average lengths and widths of the bedding-parallel pore ***,the average pore lengths and widths are increased in the bedding-perpendicular ***,heating increases the cross-sectional area of pores in low-maturity oil shales,where this growth tendency fluctuates at300℃.In addition,the orientation and shape of the newly-formed heating-induced pores follow the habit of the original pores and follow the initial probability distributions of pore orientation and ***,limited anisotropy is detected in pore direction and shape,indicating similar modes of evolution both bedding-parallel and *** propose a straightforward but robust model to describe evolution of pore system in low-maturity oil shales during heating.

关键词： Low-maturity oil shale Pore elongation Organic matter pyrolysis In-situthermal upgrading Scanning electron microscopy(SEM) Machine learning

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Synthesis of highly stable Ni nanoparticles via electrostatic self-assembly for enhanced hydrogen storage of MgH2

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Rare Metals 2024年第9期43卷 4356-4366页

作者： Qin-Ke Tang Jiang-Chuan liu Rui Shi Yun-Feng Zhu Ji-guang Zhang Ya-Na liu jun Wang Yao Zhang Xiao-Hui Hu Zhi-Bin liu Li-Quan Li College of Materials Science and Engineering Jiangsu Collaborative Innovation Centre for Advanced Inorganic Function CompositesNanjing Tech University School of Materials Science and Engineering Southeast University

Magnesium-based hydrides have been widely recognized as an appropriate choice for solid-state hydrogen ***,its undesirable thermodynamics and sluggish hydrogenation/dehydrogenation kinetics are major bottlenecks for its ***,a highly stable and highly dispersed Ni-based catalyst （Ni/Al2O3/GN） was fabricated to promote the hydrogen storage performance of MgH2via the electrostatic effect of NiAl-LDH/GN precursor with a co-calcination reduction ***2-5wt % Ni/Al2O3/GN exhibits excellent hydrogen storage performance,releasing about 5.7 wt % hydrogen in 3500 s at 250℃,and can reach a saturation hydrogen absorption of about 6.15 wt% in 3000 s at 100℃.Furthermore,it also shows low dehydrogenation apparent activation energy of 89.1 and 118.2 kJ·***,the catalyst ensures the stability of both the physical phase and structure during ball milling and cycling *** role of each phase in Ni/Al2O3/GN on the hydrogen storage performance of MgH2was also discussed through experiments and theoretical calculation,and the synergistic catalytic mechanism of Ni/Al2O3/GN was clearly *** work provides a unique perspective for the preparation of highly stable and highly dispersible catalysts.

关键词： Catalytic mechanism Hydrogen storage performance Magnesium hydride Ni/Al2O3/GN

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Time-history performance optimization of flapping wing motion using a deep learning based prediction model

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Chinese Journal of Aeronautics 2024年第5期37卷 317-331页

作者： Tianqi WANG liu liu jun LI Lifang ZENG School of Aeronautics and Astronautics Zhejiang UniversityHangzhou 310027China Huanjiang Laboratory Zhuji 311800China

Flapping Wing Micro Aerial Vehicles(FWMAVs)have caused great concern in various fields because of their high efficiency and *** wing motion is a very important factor that affects the performance of the aircraft,and previous works have always focused on the time-averaged performance ***,the time-history performance is equally important in the design of motion mechanism and flight control *** this paper,a time-history performance optimization framework based on deep learning and multi-island genetic algorithm is presented,which is designed in order to obtain the optimal two-dimensional flapping wing ***,the training dataset for deep learning neural network is constructed based on a validated computational fluid dynamics *** aerodynamic surrogate model for flapping wing is obtained after the convergence of *** surrogate model is tested and proved to be able to accurately and quickly predict the time-history curves of lift,thrust and ***,the optimization framework is used to optimize the flapping wing motion in two specific cases,in which the optimized propulsive efficiencies have been improved by over 40%compared with the ***,a dimensionless parameter C_(variation)is proposed to describe the variation of the time-history characteristics,and it is found that C_(variation)of lift varies significantly even under close time-averaged *** the importance of time-history performance in practical applications,the optimization that integrates the propulsion efficiency as well as C_(variation)is carried *** final optimal flapping wing motion balances good time-averaged and time-history performance.

关键词： FWMAV Flapping wing motion Deep learning Unsteady aerodynamic performance Optimization Time-history curve

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Resolution Enhancement of SOHO/MDI Magnetograms

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Research in Astronomy and Astrophysics 2024年第6期24卷 358-367页

作者： Ying Qin Kai-Fan Ji Hui liu Xiao-guang Yu Yunnan Observatories Chinese Academy of SciencesKunming 650011China University of Chinese Academy of Sciences Beijing 100049China Yunnan Key Laboratory of Solar Physics and Space Science Kunming 650216China Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of SciencesKunming 650216China

Research on the solar magnetic field and its effects on solar dynamo mechanisms and space weather events has benefited from the continual improvements in instrument resolution and measurement *** augmentation and assimilation of historical observational data timelines also play a significant role in understanding the patterns of solar magnetic field *** the realm of astronomical data processing,super-resolution(SR)reconstruction refers to the process of using a substantial corpus of training data to learn the nonlinear mapping between low-resolution(LR)and high-resolution(HR)images,thereby achieving higherresolution astronomical *** paper is an application study in high-dimensional nonlinear *** learning models were employed to perform SR modeling on SOHO/MDI magnetograms and SDO/HMI magnetograms,thus reliably achieving resolution enhancement of full-disk SOHO/MDI magnetograms and enhancing the image resolution to obtain more detailed *** this study,a data set comprising 9717pairs of data from 2010 April to 2011 February was used as the training set,1332 pairs from 2011 March were used as the validation set and 1034 pairs from 2011 April were used as the test *** data preprocessing,we randomly cropped 128×128 sub-images as the LR cases from the full-disk MDI magnetograms,and the corresponding 512×512 sub-images as HR ones from the HMI full-disk magnetograms for model *** tests conducted have shown that the study successfully produced reliable 4×SR reconstruction of full-disk MDI *** MESR model's results(0.911)were highly correlated with the target HMI magnetographs as indicated by the correlation coefficient ***,the method achieved the best PSNR,SSIM,MAE and RMSE values,indicating that the MESR model can effectively reconstruct magnetograms.

关键词： magnetic fields techniques:image processing virtual observatory tools Sun:magnetic fields

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DLF-YOLOF:an improved YOLOF-based surface defect detection for steel plate

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Journal of Iron and Steel Research(International) 2024年第2期31卷 442-451页

作者： guang-hu liu Mao-xiang Chu Rong-fen Gong Ze-hao Zheng School of Electronic and Information Engineering University of Science and Technology LiaoningAnshan114051LiaoningChina

Surface defects can affect the quality of steel *** methods based on computer vision are currently applied to surface defect detection of steel ***,their real-time performance and object detection of small defect are still *** improved object detection network based on You Only Look One-level Feature(YOLOF)is proposed to show excellent performance in surface defect detection of steel plate,called ***,the anchor-free detector is used to reduce the network ***,deformable convolution network and local spatial attention module are introduced into the feature extraction network to increase the contextual information in the feature ***,the soft non-maximum suppression is used to improve detection accuracy ***,data augmentation is performed for small defect objects during training to improve detection *** show the average precision and average precision for small objects are 42.7%and 33.5%at a detection speed of 62 frames per second on a single GPU,*** shows that DLF-YOLOF has excellent performance to meet the needs of industrial real-time detection.

关键词： Steel surface defects detection YOLOF Anchor-free detector Small object detection Real-time detection

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Understand the Temperature Sensing Behavior of Solid-state Polymerized PEDOT Hybrid Based on X-ray Scattering Studies

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Chinese Journal of Polymer Science 2024年第1期42卷 105-112,I0010页

作者： Zhen-Hang He guang-Feng liu Ze-Kun Zhou Zhen liu Yi-Shu Zeng Peng Zhang School of Materials Science and Engineering Key Laboratory for Polymeric Composite and Functional Materials of Ministry of EducationSun Yat-sen UniversityGuangzhou 510275China Shanghai Advanced Research Institute(Zhangjiang Laboratory) Chinese Academy of SciencesShanghai 201204China

Poly(3,4-ethylenedioxythiophene)(PEDOT) is one of the most successful conductive polymers that recently has been used in wearable sensors for human health monitoring. In this work, we prepared a series of PEDOT hybrids consisting of PEDOT, sodium poly(styrene sulfonate)(PSSNa) and polyethylene oxide(PEO), and their preparation could be scaled-up via an adapted solid-state polymerization process. The resistance of the as-prepared PEDOT:PSS/PEO hybrid shows clear temperature response, i.e., it decreases almost linearly with the temperature increase. To understand this phenomenon, the in situ synchrotron radiation wide-and small-angle X-ray scattering(WAXS/SAXS) characterizations were undertaken to study the temperature-dependent microstructure change of the PEDOT:PSS/PEO hybrid. It demonstrated that PEDOT formed conductive paths in the hybrids, which were not destroyed by the PEO crystallization. As temperature increased, the PEO crystals' melting and the accompanying reorganization of PEDOT chains endowed the hybrid sample temperature responsiveness. Based on these fundamental knowledges, the hybrid materials were used to fabricate flexible wearable sensor that showing temperature sensing performance with an accuracy of 1 ℃. These findings shed lights on the scalable manufacturing of wearable sensors for body temperature monitoring.

关键词： Solid-state polymerization PEDOT hybrid Structure-property correlation X-ray scattering

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Advances in depressants for flotation separation of Cu–Fe sulfide minerals at low alkalinity:A critical review

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International Journal of Minerals,Metallurgy and Materials 2024年第1期31卷 1-17页

作者： Qicheng Feng Wenhang Yang Maohan Chang Shuming Wen Dianwen liu guang Han State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization Faculty of Land Resource EngineeringKunming University of Science and TechnologyKunming 650093China Yunnan Key Laboratory of Green Separation and Enrichment of Strategic Mineral Resources Kunming University of Science and TechnologyKunming 650093China

The flotation separation of Cu–Fe sulfide minerals at low alkalinity can be achieved using selective *** the flotation system of Cu–Fe sulfide minerals,depressants usually preferentially interact with the pyrite surface to render the mineral surface hydrophilic and hinder the adsorption of the *** review summarizes the advances in depressants for the flotation separation of Cu–Fe sulfide minerals at low *** advances include use of inorganic depressants (oxidants and sulfur–oxygen compounds),natural polysaccharides (starch,dextrin,konjac glucomannan,and galactomannan),modified polymers (carboxymethyl cellulose,polyacrylamide,lignosulfonate,and tricarboxylate sodium starch),organic acids (polyglutamic acid,sodium humate,tannic acid,pyrogallic acid,salicylic acid,and lactic acid),sodium dimethyl dithiocarbamate,and *** potential application of specific inorganic and organic depressants in the flotation separation of Cu–Fe sulfide minerals at low alkalinity is *** advances in the use of organic depressants with respect to the flotation separation of Cu–Fe sulfide minerals are comprehensively ***,the depression performances and mechanisms of different types of organic depressants on mineral surfaces are ***,several perspectives on depressants vis-à-vis flotation separation of Cu–Fe sulfide minerals at low alkalinity are proposed.

关键词： Cu–Fe sulfide minerals flotation separation selective depressants depression mechanism

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A novel small-signal equivalent circuit model for GaN HEMTs incorporating a dual-field-plate

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Journal of Semiconductors 2024年第5期45卷 61-68页

作者： Jinye Wang jun liu Zhenxin Zhao School of Integrated Circuit Science and Engineering Hangzhou Dianzi UniversityHangzhou 310018China

An accurate and novel small-signal equivalent circuit model for GaN high-electron-mobility transistors(HEMTs)is proposed,which considers a dual-field-plate(FP)made up of a gate-FP and a *** equivalent circuit of the overall model is composed of parasitic elements,intrinsic transistors,gate-FP,and source-FP *** equivalent circuit of the gate-FP is identical to that of the intrinsic *** order to simplify the complexity of the model,a series combination of a resistor and a capacitor is employed to represent the *** analytical extraction procedure of the model parameters is presented based on the proposed equivalent *** verification is carried out on a 4×250μm GaN HEMT device with a gate-FP and a source-FP in a 0.45μm *** with the classic model,the proposed novel small-signal model shows closer agreement with measured S-parameters in the range of 1.0 to 18.0 GHz.

关键词： small-signal model dual field-plate(FP) GaN high-electron-mobility transistors(HEMT) parameter extraction

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