期刊文献+
共找到3,882篇文章
< 1 2 195 >
每页显示 20 50 100
Morphology and valence state evolution of Cu:Unraveling the impact on nitric oxide electroreduction 被引量:1
1
作者 Ting Sun Fengyu Gao +4 位作者 Ya Wang Honghong Yi Qingjun Yu Shunzheng Zhao Xiaolong Tang 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第4期276-286,共11页
Ammonia(NH3)serves as a critical component in the fertilizer industry and fume gas denitrification.However,the conventional NH3production process,namely the Haber-Bosch process,leads to considerable energy consumption... Ammonia(NH3)serves as a critical component in the fertilizer industry and fume gas denitrification.However,the conventional NH3production process,namely the Haber-Bosch process,leads to considerable energy consumption and waste gas emissions.To address this,electrocatalytic nitric oxide reduction reaction(NORR)has emerged as a promising strategy to bridge NH3consumption to NH3production,harnessing renewable electricity for a sustainable future.Copper(Cu)stands out as a prominent electrocatalyst for NO reduction,given its exceptional NH3yield and selectivity.However,a crucial aspect that remains insufficiently explored is the effects of morphology and valence states of Cu on the NORR performance.In this investigation,we synthesized CuO nanowires(CuO-NF)and Cu nanocubes(Cu-NF)as cathodes through an in situ growth method.Remarkably,CuO-NF exhibited an impressive NH3yield of 0.50±0.02 mg cm^(-2)h^(-1)at-0.6 V vs.reversible hydrogen electrode(RHE)with faradaic efficiency of29,68%±1,35%,surpassing that of Cu-NF(0.17±0.01 mg cm^(-2)h^(-1),16.18%±1.40%).Throughout the electroreduction process,secondary cubes were generated on the CuO-NF surface,preserving their nanosheet cluster morphology,sustained by an abundant supply of subsurface oxygen(s-O)even after an extended duration of 10 h,until s-O depletion ensued.Conversely,Cu-NF exhibited inadequate s-O content,leading to rapid crystal collapse within the same timeframe.The distinctive current-potential relationship,akin to a volcano-type curve,was attributed to distinct NO hydrogenation mechanisms.Further Tafel analysis revealed the exchange current density(i0)and standard heterogeneous rate constant(k0)for CuO-NF,yielding 3.44×10^(-6)A cm^(-2)and 3.77×10^(-6)cm^(-2)s^(-1)when NORR was driven by overpotentials.These findings revealed the potential of CuO-NF for NO reduction and provided insights into the intricate interplay between crystal morphology,valence states,and electrochemical performance. 展开更多
关键词 NORR Ammonia Synthesis COPPER morphology Valence States Mechanism
下载PDF
Responses of growth performance,antioxidant function,small intestinal morphology and mRNA expression of jejunal tight junction protein to dietary iron in yellow-feathered broilers 被引量:1
2
作者 Kaiwen Lei Hao Wu +4 位作者 Jerry W Spears Xi Lin Xi Wang Xue Bai Yanling Huang 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2024年第4期1329-1337,共9页
This study aimed to investigate the dose-effect of iron on growth performance,antioxidant function.intestinal morphology,and mRNA expression of jejunal tight junction protein in 1-to21-d-old yellow-feathered broilers.... This study aimed to investigate the dose-effect of iron on growth performance,antioxidant function.intestinal morphology,and mRNA expression of jejunal tight junction protein in 1-to21-d-old yellow-feathered broilers.A total of 7201-d-old yellow-feathered maleb roilers were allocated to 9 treatments with 8 replicate cages of 10 birds per cage.The dietary treatments were consisted of a basal diet(contained 79.6 mg Fe kg^(-1))supplemented with 0,20,40,60,80,160,320,640,and 1,280 mg Fe kg^(-1)in the form of FeSO_(4)·7H_(2)O.Compared with the birds in the control group,birds supplemented with 20mg Fe kg^(-1)had higher average daily gain(ADG)(P<0.0001).Adding 640 and 1,280 mg Fe kg^(-1)significantly decreased ADG(P<0.0001)and average daily feed intake(ADFI)(P<0.0001)compared with supplementation of 20mg Fe kg^(-1).Malondialdehyde(MDA)concentration in plasma and duodenum increased linearly(P<0.0001),but MDA concentration in liver and jejunum increased linearly(P<0.05)or quadratically(P<0.05)with increased dietary Fe concentration.The villus height(VH)in duodenum and jejunum,and the ratio of villus height to crypt depth(V/C)in duodenum decreased linearly(P?0.05)as dietary Feincreased.As dietary Fe increased,the jejunal relative mRNA abundance of claudin-1 decreased linearly(P=0.001),but the jejunal relative mRNA abundance of zona occludens-1(ZO-1)and occludin decreased linearly(P?0.05)or quadratically(P?0.05).Compared with the supplementation of 20 mg Fe kg^(-1),the supplementation of640 mg Fe kg^(-1)or higher increased(P?0.05)MDA concentrations in plasma,duodenum,and jejunum,decreased VH in the duodenum and jejunum,and the addition of 1,280 mg Fe kg^(-1)reduced(P?0.05)the jejunal tight junction protein(claudin-1,ZO-1,occludin)mRNA abundance.In summary,640 mg of supplemental Fe kg^(-1)or greater was associated with decreased growth performance,increased oxidative stress,disrupted intestinal morphology,and reduced mRNA expression of jejunal tight junction protein. 展开更多
关键词 IRON yellow-feathered broiler antioxidant function intestinal morphology tight junction protein
下载PDF
Droplet morphology analysis of drop-on-demand inkjet printing 被引量:1
3
作者 Hu-xiang Xia Takechi Kensuke +2 位作者 Tajima Shin Kawamura Yoshiumi Qing-yan Xu 《China Foundry》 SCIE EI CAS CSCD 2024年第1期20-28,共9页
As an accurate 2D/3D fabrication tool,inkjet printing technology has great potential in preparation of micro electronic devices.The morphology of droplets produced by the inkjet printer has a great impact on the accur... As an accurate 2D/3D fabrication tool,inkjet printing technology has great potential in preparation of micro electronic devices.The morphology of droplets produced by the inkjet printer has a great impact on the accuracy of deposition.In this study,the drop-on-demand(DoD)inkjet simulation model was established,and the accuracy of the simulation model was verified by corresponding experiments.The simulation result shows that the velocity of the droplet front and tail,as well as the time to disconnect from the nozzle is mainly affected by density(ρ),viscosity(μ)and surface tension(σ)of droplets.When the liquid filament is about to disconnect from the nozzle,the filament length and filament front velocity are found to have a linear correlation withσ/ρμand ln(ρ/(μσ1/2)). 展开更多
关键词 microdevice fabrication inkjet printing droplet morphology modeling and simulation
下载PDF
Lineaperpetua gen.nov.:a new diatom genus in the Thalassiosirales supported by morphology and molecular data
4
作者 Pan YU Lin YANG +4 位作者 Qingmin YOU John Patrick KOCIOLEK Kangyu WANG Yonghong BI Quanxi WANG 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2024年第1期277-290,共14页
Based on a combination of morphology and molecular data of ribosomal DNA genes,a new diatom genus Lineaperpetua gen.nov.Yu,You,Kociolek&Wang is described.The features that help define Lineaperpetua at the level of... Based on a combination of morphology and molecular data of ribosomal DNA genes,a new diatom genus Lineaperpetua gen.nov.Yu,You,Kociolek&Wang is described.The features that help define Lineaperpetua at the level of genus include:a tangentially undulated valve face;continuous cribra areolae on the valve interior consisting of pores arranged as strips;single rimoportula located inside the ring of marginal fultoportulae.Additionally,phylogenetic analysis based on nuclear small subunit(SSU)rDNA sequences and nuclear large subunit(LSU)rDNA gene placed the three strains of L.lacustris in a single,monophyletic clade at a considerable sequence distance from the other genera(Thalassiosira,Conticribra,Planktoniella,Shinodiscus,and other genera)belonging to Thalassiosirales.Despite the similarities with some species of Thalassiosira,Conticribra,and Spicaticribra,the suite of features found in Lineaperpetua differentiate it from these other genera.These molecular data and morphological characters suggest an affinity of the new genus to the Thalassiosiraceae. 展开更多
关键词 DIATOM morphology new genus PHYLOGENY TAXONOMY Thalassiosiraceae
下载PDF
The interaction between KIF21A and KANK1 regulates dendritic morphology and synapse plasticity in neurons
5
作者 Shi-Yan Sun Lingyun Nie +5 位作者 Jing Zhang Xue Fang Hongmei Luo Chuanhai Fu Zhiyi Wei Ai-Hui Tang 《Neural Regeneration Research》 SCIE CAS 2025年第1期209-223,共15页
Morphological alterations in dendritic spines have been linked to changes in functional communication between neurons that affect learning and memory.Kinesin-4 KIF21A helps organize the microtubule-actin network at th... Morphological alterations in dendritic spines have been linked to changes in functional communication between neurons that affect learning and memory.Kinesin-4 KIF21A helps organize the microtubule-actin network at the cell cortex by interacting with KANK1;however,whether KIF21A modulates dendritic structure and function in neurons remains unknown.In this study,we found that KIF21A was distributed in a subset of dendritic spines,and that these KIF21A-positive spines were larger and more structurally plastic than KIF21A-negative spines.Furthermore,the interaction between KIF21A and KANK1 was found to be critical for dendritic spine morphogenesis and synaptic plasticity.Knockdown of either KIF21A or KANK1 inhibited dendritic spine morphogenesis and dendritic branching,and these deficits were fully rescued by coexpressing full-length KIF21A or KANK1,but not by proteins with mutations disrupting direct binding between KIF21A and KANK1 or binding between KANK1 and talin1.Knocking down KIF21A in the hippocampus of rats inhibited the amplitudes of long-term potentiation induced by high-frequency stimulation and negatively impacted the animals’cognitive abilities.Taken together,our findings demonstrate the function of KIF21A in modulating spine morphology and provide insight into its role in synaptic function. 展开更多
关键词 ACTIN CYTOSKELETON dendrite KANK1 KIF21A MICROTUBULE spine morphology SPINE synaptic plasticity talin1
下载PDF
A new species of Discostella guiyangensis sp.nov.(Bacillariophyta,Stephanodiscales)from Guiyang,China:morphology and phylogeny
6
作者 Yandan XIANG Fangru NAN +3 位作者 Xudong LIU Shulian XIE John Patrick KOCIOLEK Qi LIU 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2024年第4期1312-1324,共13页
We describe a new species of Discostella from Guiyang based on light and scanning electron microscopic observations,as well as molecular analysis.This species is morphologically distinguished from other species by a r... We describe a new species of Discostella from Guiyang based on light and scanning electron microscopic observations,as well as molecular analysis.This species is morphologically distinguished from other species by a relatively smooth and slightly recessed central area with marginal striae of unequal lengths forked near the margin.Marginal fultoportulae and a single rimoportula are situated between every two costae or on the costae.Both morphological characters and the concatenated data of rbc L and SSU rDNA indicate that Discostella guiyangensis is a unique and new species.According to divergence time estimation analysis,Discostella guiyangensis is the oldest species among the Discostella species sequenced currently.In addition,we complement molecular data of Discostella asterocostata and Discostella stelligera. 展开更多
关键词 Discostella morphology molecular analysis divergence time estimation new species
下载PDF
Flower morphology of Allium(Amaryllidaceae)and its systematic significance
7
作者 Ju Eun Jang Shukherdorj Baasanmunkh +5 位作者 Nudkhuu Nyamgerel Seung-Yoon Oh Jun-Ho Song Ziyoviddin Yusupov Komijlon Tojibaev Hyeok Jae Choi 《Plant Diversity》 SCIE CAS CSCD 2024年第1期3-27,共25页
Allium is a complicated genus that includes approximately 1000 species.Although its morphology is well studied,the taxonomic importance of many morphological traits,including floral traits,are poorly understood.Here,w... Allium is a complicated genus that includes approximately 1000 species.Although its morphology is well studied,the taxonomic importance of many morphological traits,including floral traits,are poorly understood.Here,we examined and measured the floral characteristics of 87 accessions of 74 Allium taxa(belonging to 30 sections and nine subgenera)from Central to Eastern Asian countries.We then examined the taxonomic relationships between select flower characteristics and a phylogenetic tree based on ITS sequences.Our results confirm that floral morphology provides key taxonomic information to assess species delimitation in Allium.We found that perianth color is an important characteristic within the subg.Melanocrommyum,Polyprason,and Reticulatobulbosa.In subg.Allium,Cepa,and Rhizirideum,significant characteristics include ovary shape,perianth shape,and inner tepal apex.For species in subg.Angunium,the key taxonomic character is ovule number(only one ovule in per locule).In the subg.Allium,Cepa,Polyprason,and Reticulatobulbosa,which belong to the third evolutionary line of Allium,hood-like appendages occur in the ovary,although these do not occur in subg.Rhizirideum.Our results also indicated that the flower morphology of several species in some sections are not clearly distinguished,e.g.,sect.Sacculiferum(subg.Cepa)and sect.Tenuissima(subg.Rhizirideum).This study provides detailed photographs and descriptions of floral characteristics and information on general distributions,habitats,and phenology of the studied taxa. 展开更多
关键词 ALLIUM Flower morphology Pistil character Statistical analysis Significant characteristic Species level
下载PDF
Leaf Morphology Genes SRL1 and RENL1 Co-Regulate Cellulose Synthesis and Affect Rice Drought Tolerance
8
作者 LIU Dan ZHAO Huibo +18 位作者 WANG Zi’an XU Jing LIU Yiting WANG Jiajia CHEN Minmin LIU Xiong ZHANG Zhihai CEN Jiangsu ZHU Li HU Jiang REN Deyong GAO Zhenyu DONG Guojun ZHANG Qiang SHEN Lan LI Qing QIAN Qian HU Songping ZHANG Guangheng 《Rice science》 SCIE CSCD 2024年第1期103-117,I0020-I0022,共18页
The morphological development of rice(Oryza sativa L.)leaves is closely related to plant architecture,physiological activities,and resistance.However,it is unclear whether there is a co-regulatory relationship between... The morphological development of rice(Oryza sativa L.)leaves is closely related to plant architecture,physiological activities,and resistance.However,it is unclear whether there is a co-regulatory relationship between the morphological development of leaves and adaptation to drought environment.In this study,a drought-sensitive,roll-enhanced,and narrow-leaf mutant(renl1)was induced from a semi-rolled leaf mutant(srl1)by ethyl methane sulfonate(EMS),which was obtained from Nipponbare(NPB)through EMS.Map-based cloning and functional validation showed that RENL1 encodes a cellulose synthase,allelic to NRL1/OsCLSD4.The RENL1 mutation resulted in reduced vascular bundles,vesicular cells,cellulose,and hemicellulose contents in cell walls,diminishing the water-holding capacity of leaves.In addition,the root system of the renl1 mutant was poorly developed and its ability to scavenge reactive oxygen species(ROS)was decreased,leading to an increase in ROS after drought stress.Meanwhile,genetic results showed that RENL1 and SRL1 synergistically regulated cell wall components.Our results revealed a theoretical basis for further elucidating the molecular regulation mechanism of cellulose on rice drought tolerance,and provided a new genetic resource for enhancing the synergistic regulation network of plant type and stress resistance,thereby realizing simultaneous improvement of multiple traits in rice. 展开更多
关键词 CELLULOSE cell wall drought tolerance leaf morphology RICE
下载PDF
Influences of clean fracturing fluid viscosity and horizontal in-situ stress difference on hydraulic fracture propagation and morphology in coal seam
9
作者 Gang Wang Shuxin Wang +5 位作者 Yixin Liu Qiming Huang Shengpeng Li Shuliang Xie Jinye Zheng Jiuyuan Fan 《International Journal of Coal Science & Technology》 EI CAS CSCD 2024年第3期159-175,共17页
The viscosity of fracturing fluid and in-situ stress difference are the two important factors that affect the hydraulic fracturing pressure and propagation morphology. In this study, raw coal was used to prepare coal ... The viscosity of fracturing fluid and in-situ stress difference are the two important factors that affect the hydraulic fracturing pressure and propagation morphology. In this study, raw coal was used to prepare coal samples for experiments, and clean fracturing fluid samples were prepared using CTAB surfactant. A series of hydraulic fracturing tests were conducted with an in-house developed triaxial hydraulic fracturing simulator and the fracturing process was monitored with an acoustic emission instrument to analyze the influences of fracturing fluid viscosity and horizontal in-situ stress difference on coal fracture propagation. The results show that the number of branched fractures decreased, the fracture pattern became simpler, the fractures width increased obviously, and the distribution of AE event points was concentrated with the increase of the fracturing fluid viscosity or the horizontal in-situ stress difference. The acoustic emission energy decreases with the increase of fracturing fluid viscosity and increases with the increase of horizontal in situ stress difference. The low viscosity clean fracturing fluid has strong elasticity and is easy to be compressed into the tip of fractures, resulting in complex fractures. The high viscosity clean fracturing fluids are the opposite. Our experimental results provide a reference and scientific basis for the design and optimization of field hydraulic fracturing parameters. 展开更多
关键词 Clean fracturing fluid Hydraulic fracturing VISCOSITY Horizontal in-situ stress difference Hydraulic fracture morphology Acoustic emission
下载PDF
On the evolution and formation of discharge morphology in pulsed dielectric barrier discharge
10
作者 陈星宇 李孟琦 +3 位作者 王威逸 张权治 彭涛 熊紫兰 《Plasma Science and Technology》 SCIE EI CAS CSCD 2024年第4期101-113,共13页
The discharge morphology of pulsed dielectric barrier discharge(PDBD) plays important roles in its applications. Here, we systematically investigated the effects of the voltage amplitude,discharge gap, and O_(2)conten... The discharge morphology of pulsed dielectric barrier discharge(PDBD) plays important roles in its applications. Here, we systematically investigated the effects of the voltage amplitude,discharge gap, and O_(2)content on the PDBD morphology, and revealed the possible underlying mechanism of the U-shaped formation. First, the morphological evolution under different conditions was recorded. A unique U-shaped region appears in the middle edge region when the gap is larger than 2 mm, while the entire discharge region remains columnar under a 2 mm gap in He PDBD. The width of the discharge and the U-shaped region increase with the increase in voltage, and decrease with the increase of the gap and O_(2)content. To explain this phenomenon,a two-dimensional symmetric model was developed to simulate the spatiotemporal evolution of different species and calculate the electric thrust. The discharge morphology evolution directly corresponds to the excited-state atomic reduction process. The electric thrust on the charged particles mainly determines the reaction region and strongly influences the U-shaped formation.When the gap is less than 2 mm, the electric thrust is homogeneous throughout the entire region,resulting in a columnar shape. However, when the gap is larger than 2 mm or O_(2)is added, the electric thrust in the edge region becomes greater than that in the middle, leading to the U-shaped formation. Furthermore, in He PDBD, the charged particles generating electric thrust are mainly electrons and helium ions, while in He/O_(2)PDBD those that generate electric thrust at the outer edge of the electrode surface are mainly various oxygen-containing ions. 展开更多
关键词 low-temperature plasma dielectric barrier discharge discharge morphology particle distribution electric thrust
下载PDF
An Implementation of Multiscale Line Detection and Mathematical Morphology for Efficient and Precise Blood Vessel Segmentation in Fundus Images
11
作者 Syed Ayaz Ali Shah Aamir Shahzad +4 位作者 Musaed Alhussein Chuan Meng Goh Khursheed Aurangzeb Tong Boon Tang Muhammad Awais 《Computers, Materials & Continua》 SCIE EI 2024年第5期2565-2583,共19页
Diagnosing various diseases such as glaucoma,age-related macular degeneration,cardiovascular conditions,and diabetic retinopathy involves segmenting retinal blood vessels.The task is particularly challenging when deal... Diagnosing various diseases such as glaucoma,age-related macular degeneration,cardiovascular conditions,and diabetic retinopathy involves segmenting retinal blood vessels.The task is particularly challenging when dealing with color fundus images due to issues like non-uniformillumination,low contrast,and variations in vessel appearance,especially in the presence of different pathologies.Furthermore,the speed of the retinal vessel segmentation system is of utmost importance.With the surge of now available big data,the speed of the algorithm becomes increasingly important,carrying almost equivalent weightage to the accuracy of the algorithm.To address these challenges,we present a novel approach for retinal vessel segmentation,leveraging efficient and robust techniques based on multiscale line detection and mathematical morphology.Our algorithm’s performance is evaluated on two publicly available datasets,namely the Digital Retinal Images for Vessel Extraction dataset(DRIVE)and the Structure Analysis of Retina(STARE)dataset.The experimental results demonstrate the effectiveness of our method,withmean accuracy values of 0.9467 forDRIVE and 0.9535 for STARE datasets,aswell as sensitivity values of 0.6952 forDRIVE and 0.6809 for STARE datasets.Notably,our algorithmexhibits competitive performance with state-of-the-art methods.Importantly,it operates at an average speed of 3.73 s per image for DRIVE and 3.75 s for STARE datasets.It is worth noting that these results were achieved using Matlab scripts containing multiple loops.This suggests that the processing time can be further reduced by replacing loops with vectorization.Thus the proposed algorithm can be deployed in real time applications.In summary,our proposed system strikes a fine balance between swift computation and accuracy that is on par with the best available methods in the field. 展开更多
关键词 Line detector vessel detection LOCALIZATION mathematical morphology image processing
下载PDF
Engineering fibrillar morphology for highly efficient organic solar cells
12
作者 Chengcheng Xie Bin Zhang +1 位作者 Menglan Lv Liming Ding 《Journal of Semiconductors》 EI CAS CSCD 2024年第2期7-9,共3页
The power conversion efficiency(PCE)for single-junction organic solar cells(OSCs),wherein the photoactive layer is a typical bulk-heterojunction containing donor and acceptor materials,has surpassed 19%[1−4].The advan... The power conversion efficiency(PCE)for single-junction organic solar cells(OSCs),wherein the photoactive layer is a typical bulk-heterojunction containing donor and acceptor materials,has surpassed 19%[1−4].The advance is ascribed to the development of Y-series non-fullerene acceptors(NFAs)[5,6]and polymer donors[7−13],and the refined control of the blend film morphology. 展开更多
关键词 morphology refined DONOR
下载PDF
Clinical validation of the early embryo viability assessment system: Analysis for the blastocyst morphology and pregnancy outcomes
13
作者 Vu D Hop An M Cuong +3 位作者 Phi T T Anh Nguyen T L Huong Le Hoang Nguyen V Hanh 《Asian pacific Journal of Reproduction》 CAS 2024年第5期219-227,共9页
Objective:To determine the relationship between the early embryo viability assessment(EEVA)and blastocyst morphological parameters and pregnancy outcomes.Methods:This retrospective cohort study was conducted on 291 in... Objective:To determine the relationship between the early embryo viability assessment(EEVA)and blastocyst morphological parameters and pregnancy outcomes.Methods:This retrospective cohort study was conducted on 291 intracytoplasmic sperm injection cycles including 2522 embryos with indications of prolonging embryo culture to the blastocyst stage in the Genea embryo review incubator,and 511 single vitrified-warmed blastocyst transfer cycles from January 2020 to June 2023.The EEVA system produced an EEVA score from E1(best)to E5(worse)for the potential of blastocyst formation.Blastocyst morphology was evaluated.The association between the EEVA score and each type of blastocyst morphology,implantation rate,clinical pregnancy,and ongoing pregnancy were assessed using generalized estimating equations.Results:The inner cell mass A(ICM A),trophectoderm A(TE A),blastocoele expansion degree of 3,4,5,6,7 rates were higher with lower the EEVA score.The adjusted odd ratio(aOR)(E5 vs E1)was 0.3 for ICM A,0.174 for TE A and 0.210 for BL3,4,5,6,7(all P<0.001),suggesting a significant association between lower EEVA scores and improved embryo quality.The implantation,clinical pregnancy,and ongoing pregnancy rate were also higher with lower the EEVA score.The aOR of E5 vs E1 was 0.245 for implantation,0.185 for clinical pregnancy and 0.200 for ongoing pregnancy rate(P<0.001).Conclusions:There were associations between blastocyst morphology,pregnancy outcome and EEVA scores.The good blastocyst morphology and pregnancy outcomes are higher with lower the EEVA score. 展开更多
关键词 Automated embryo assessment BLASTOCYST Early embryo viability assessment Genea embryo review incubator morphology Pregnancy outcomes Timelapse
下载PDF
Recognition of Organizational Morphology of Mesoscale Convective Systems Using Himawari-8 Observations
14
作者 SHOU Yi-xuan ZHANG Su-zhao LU Feng 《Journal of Tropical Meteorology》 SCIE 2024年第3期289-305,共17页
The onset,evolution,and propagation processes of convective cells can be reflected by the organizational morphology of mesoscale convective systems(MCSs),which are key factors in determining the potential for heavy pr... The onset,evolution,and propagation processes of convective cells can be reflected by the organizational morphology of mesoscale convective systems(MCSs),which are key factors in determining the potential for heavy precipitation.This paper proposed a method for objectively classifying and segmenting MCSs using geosynchronous satellite observations.Validation of the product relative to the classification in radar composite reflectivity imagery indicates that the algorithm offers skill for discriminating between convective and stratiform areas and matched 65%of convective area identifications in radar imagery with a false alarm rate of 39%and an accuracy of 94%.A quantitative evaluation of the similarity between the structures of 50 MCSs randomly obtained from satellite and radar observations shows that the similarity was as high as 60%.For further testing,the organizational modes of the MCS that caused the heavy precipitation in Northwest China on August 21,2016(hereinafter known as the“0821”rainstorm)were identified.It was found that the MCS,accompanied by the“0821”rainstorm,successively exhibited modes of the isolated cell,squall line with parallel stratiform(PS)rain,and non-linear system during its life cycle.Among them,the PS mode might have played a key role in causing this flooding.These findings are in line with previous studies. 展开更多
关键词 mesoscale convective system SATELLITE organizational morphology extremely heavy precipitation
下载PDF
Effect of process parameters on the morphology of aluminum/copper alloy lap joints by red and blue hybrid laser welding
15
作者 宋曜祥 肖梦智 +4 位作者 黄德才 张瑞华 尹燕 茹恩光 吴怡霖 《China Welding》 CAS 2024年第2期23-30,共8页
In order to overcome the problems of many pores,large deformation and unstable weld quality of traditional laser welded aluminumcopper alloy joints,a red-blue dual-beam laser source and a swinging laser were introduce... In order to overcome the problems of many pores,large deformation and unstable weld quality of traditional laser welded aluminumcopper alloy joints,a red-blue dual-beam laser source and a swinging laser were introduced for welding.T2 copper and 6063 aluminum thin plates were lap welded by coaxial dual-beam laser welding.The morphology of weld cross section was compared to explore the influence of process parameters on the formation of lap joints.The microstructure characteristics of the weld zone were observed and compared by optical microscope.The results show that the addition of laser beam swing can eliminate the internal pores of the weld.With the increase of the swing width,the weld depth decreases,and the weld width increases first and then decreases.The influence of welding speed on the weld cross section morphology is similar to that of swing width.With the increase of welding speed,the weld width increases first and then decreases,while the weld depth decreases all the time.This is because that the red laser is used as the main heat source to melt the base metals,with the increase of red laser power,the weld depth increases.As an auxiliary laser source,blue laser reduces the total energy consumption,consequently,the effective heat input increases and the spatter is restrained effectively.As a result,the increase of red laser power has an enhancement effect on the weld width and weld depth.When the swing width is 1.2 mm,the red laser power is 550 W,the blue laser power is 500 W,and the welding speed is 35 mm/s,the weld forming is the best.The lap joint of T2 copper and 6063 aluminum alloy thin plate can be connected stably with the hybrid of blue laser.The effect rules of laser beam swing on the weld formation were obtained,which improved the quality of the joints. 展开更多
关键词 laser welding aluminum/copper alloy dual beam process parameters weld morphology
下载PDF
Contribution to the Knowledge of the Afrotropical Spilomelinae (Lepidoptera, Crambidae): A New Genus in the Tribe Nomophilini Kuznetzov & Stekolnikov 1979 Based on Morphology and DNA Barcoding
16
作者 Michael Seizmair 《Advances in Entomology》 2024年第3期155-169,共15页
The new genus Parathrausta gen.n. in the subfamily Spilomelinae (Lepidoptera, Crambidae) is erected based on a series of specimens collected in the Afrotropical region of Saudi Arabia. The new genus is monotypical, wi... The new genus Parathrausta gen.n. in the subfamily Spilomelinae (Lepidoptera, Crambidae) is erected based on a series of specimens collected in the Afrotropical region of Saudi Arabia. The new genus is monotypical, with Parathrausta internervalis sp.n. its type species. The adults of the type species, the male genitalia, the female genitalia and the tympanal organs are described and figured. The new genus is recognized as related by characters in the male and female genitalia with genera in the tribes Steniini Guine, 1854 and Nomophilini Kuznetzov & Stekolnikov, 1979, namely with Bradina Lederer, 1863, Perisyntrocha Meyrick, 1894, Diathrausta Lederer, 1863, Diasemiopsis Munroe, 1957, Diasemiodes Munroe, 1957 and with the genera in the Duponchelia Zeller, 1847 group comprising Duponchelia Zeller, 1847, Penestola Mschler, 1890, Tatobotys Butler, 1880 and Hymenoptychis Zeller, 1852. The character states differentiating the new genus from the comparative genera are discussed. Potential autapomorphies of the new genus are listed. The tribal assignment of the new genus to the Nomophilini Kuznetzov & Stekolnikov, 1979 based on morphological characters is discussed. The support of the tribal and cladistic assignment of the new genus as a sister clade to Diathrausta Lederer, 1863 based phylogenetic analyses (NJ, MP and ML) is shown. An unusually strong genetic divergence of the genus in the COI segment of the mt-DNA based on the Tamura-Nei distance measure from the morphologically related genera is recognized and addressed. 展开更多
关键词 PYRALOIDEA Taxonomy morphology COI New Genus New Species Arabian Peninsula
下载PDF
Biosynthesis of Silver Nanoparticles with Clerodendron phlomoides Leave Extract:Particle Morphology,Antimicrobial Potential and Application
17
作者 Kirubanandan Shanmugam Subha Veeramani Renganathan Sahadevan 《Journal of Clinical and Nursing Research》 2024年第1期51-64,共14页
Silver nanoparticles are versatile nanomaterials that have found numerous applications in various fields.The use of plant extract for the synthesis of silver is a green and sustainable approach.Clerodendron phlomoides... Silver nanoparticles are versatile nanomaterials that have found numerous applications in various fields.The use of plant extract for the synthesis of silver is a green and sustainable approach.Clerodendron phlomoides leaves extract has been found to contain various phytochemicals,such as phenols,flavonoids,tannins,and alkaloids,which possess reducing and stabilizing properties that can aid the production of silver particles.In this paper,morphological and topographical analyses were performed on silver nanoparticles.The biosynthesized silver nanoparticles showed antimicrobial potential against wound pathogens.SEM and TEM micrographs revealed that the particles were sphere and nanosized,which makes them suitable for various biomedical applications. 展开更多
关键词 Silver nanoparticles Clerodendron phlomoides BIOSYNTHESIS morphology SEM TEM FTIR Antimicrobial activity and wound pathogens
下载PDF
Spatial Morphology Evolution Characteristics Analysis of the Resident Population Distribution in Henan, China
18
作者 Kaiguang Zhang Hongling Meng +1 位作者 Mingting Ba Danhuan Wen 《Journal of Geoscience and Environment Protection》 2024年第3期163-180,共18页
The population spatial distribution pattern and its evolving pattern play an important role in regional allocation of social resources and production factors, formulation of regional development plans, construction of... The population spatial distribution pattern and its evolving pattern play an important role in regional allocation of social resources and production factors, formulation of regional development plans, construction of a better life society, and promotion of regional economic development. Based on the resident population statistics data of Henan province from 2006 to 2021, with county as the basic study unit, the paper studies the spatial morphology characteristics and its evolution patterns of resident population distribution, by using spatial analysis methods such as population distribution center, standard deviation ellipse, and spatial auto correlation analysis. The results show that: the resident population spatial distribution shows unbalanced state, the population agglomeration areas mainly distribute in the northeast part and north part, where the resident population growth rate is significantly higher than other regions, over time, this trend is gradually becoming significant. The resident population distribution has a trend of centripetal concentration, with the degree and trend of centripetal gradually strengthening. The resident population distribution has obvious directional characteristics, but the significance is not high, the weighted resident population average center is approximately located at (4.13740˚N, 113.8935˚E), and the azimuth of the distribution axis is approximately 11.19˚. The population distribution has obvious agglomeration characteristics, with the built-up areas of Zhengzhou and Luoyang as their centers, where have a significant siphon effect on the surrounding population. The southern and southwestern regions in the province form a relatively stable belt area of Low-Low agglomeration areas. 展开更多
关键词 Resident Population Spatial Distribution Spatial morphology Temporal and Spatial Evolution Center Migration Standard Deviation Ellipse Spatial Autocorrelation
下载PDF
Research on Defect Detection of Wind Turbine Blades Based on Morphology and Improved Otsu Algorithm Using Infrared Images
19
作者 Shuang Kang Yinchao He +1 位作者 Wenwen Li Sen Liu 《Computers, Materials & Continua》 SCIE EI 2024年第10期933-949,共17页
To address the issues of low accuracy and high false positive rate in traditional Otsu algorithm for defect detection on infrared images of wind turbine blades(WTB),this paper proposes a technique that combines morpho... To address the issues of low accuracy and high false positive rate in traditional Otsu algorithm for defect detection on infrared images of wind turbine blades(WTB),this paper proposes a technique that combines morphological image enhancement with an improved Otsu algorithm.First,mathematical morphology’s differential multi-scale white and black top-hat operations are applied to enhance the image.The algorithm employs entropy as the objective function to guide the iteration process of image enhancement,selecting appropriate structural element scales to execute differential multi-scale white and black top-hat transformations,effectively enhancing the detail features of defect regions and improving the contrast between defects and background.Afterwards,grayscale inversion is performed on the enhanced infrared defect image to better adapt to the improved Otsu algorithm.Finally,by introducing a parameter K to adjust the calculation of inter-class variance in the Otsu method,the weight of the target pixels is increased.Combined with the adaptive iterative threshold algorithm,the threshold selection process is further fine-tuned.Experimental results show that compared to traditional Otsu algorithms and other improvements,the proposed method has significant advantages in terms of defect detection accuracy and reducing false positive rates.The average defect detection rate approaches 1,and the average Hausdorff distance decreases to 0.825,indicating strong robustness and accuracy of the method. 展开更多
关键词 Morphological enhancement improved Otsu algorithm infrared image grayscale inversion adaptive iterative thresholding
下载PDF
Active phase morphology engineering of NiMo/Al2O3 through La introduction for boosting hydrodesulfurization of 4,6-DMDBT 被引量:3
20
作者 Ji-Xing Liu Xiang-Qi Liu +7 位作者 Ri-Xin Yan Ling-Feng Ji Hui-Fang Cheng Hui Liu Yan Huang Ming-Qing Hua Hua-Ming Li Wen-Shuai Zhu 《Petroleum Science》 SCIE EI CAS CSCD 2023年第2期1231-1237,共7页
Herein,we designed and constructed a mesoporous LaAlOx via a solvent evaporation induced self-assembly protocol.The structure and physicochemical property of the corresponding NiMo supported catalyst was analyzed by a... Herein,we designed and constructed a mesoporous LaAlOx via a solvent evaporation induced self-assembly protocol.The structure and physicochemical property of the corresponding NiMo supported catalyst was analyzed by a set of characterizations,and its catalytic activity was investigated for hydrodesulfurization(HDS)of 4,6-dimethyldibenzothiophene.It has confirmed that the incorporation of La profoundly facilitate the generation of“Type II”NiMoS phase by weakening the interaction of Mo–O–Al leakage and promoting the sulfidation of both Ni and Mo oxides as well as changing the morphology of Ni promoted MoS2 slabs,thereafter boosting the HDS performance substantially.The finding here may contribute to the fundamental understanding of structure-activity in ultra-deep desulfurization and inspire the advancement of highly-efficient HDS catalyst in future. 展开更多
关键词 NiMo supported Catalyst LaAlOx composites HYDRODESULFURIZATION morphology Reaction kinetics
下载PDF
上一页 1 2 195 下一页 到第
使用帮助 返回顶部