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Data driven prediction of fragment velocity distribution under explosive loading conditions 被引量:2
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作者 Donghwan Noh Piemaan Fazily +4 位作者 Songwon Seo Jaekun Lee Seungjae Seo Hoon Huh Jeong Whan Yoon 《Defence Technology(防务技术)》 2025年第1期109-119,共11页
This study presents a machine learning-based method for predicting fragment velocity distribution in warhead fragmentation under explosive loading condition.The fragment resultant velocities are correlated with key de... This study presents a machine learning-based method for predicting fragment velocity distribution in warhead fragmentation under explosive loading condition.The fragment resultant velocities are correlated with key design parameters including casing dimensions and detonation positions.The paper details the finite element analysis for fragmentation,the characterizations of the dynamic hardening and fracture models,the generation of comprehensive datasets,and the training of the ANN model.The results show the influence of casing dimensions on fragment velocity distributions,with the tendencies indicating increased resultant velocity with reduced thickness,increased length and diameter.The model's predictive capability is demonstrated through the accurate predictions for both training and testing datasets,showing its potential for the real-time prediction of fragmentation performance. 展开更多
关键词 Data driven prediction Dynamic fracture model Dynamic hardening model FRAGMENTATION Fragment velocity distribution High strain rate Machine learning
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Performance evaluation of rock fragmentation prediction based on RF-BOA,AdaBoost-BOA,GBoost-BOA,and ERT-BOA hybrid models 被引量:2
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作者 Junjie Zhao Diyuan Li +2 位作者 Jian Zhou Danial JArmaghani Aohui Zhou 《Deep Underground Science and Engineering》 2025年第1期3-17,共15页
Rock fragmentation is an important indicator for assessing the quality of blasting operations.However,accurate prediction of rock fragmentation after blasting is challenging due to the complicated blasting parameters ... Rock fragmentation is an important indicator for assessing the quality of blasting operations.However,accurate prediction of rock fragmentation after blasting is challenging due to the complicated blasting parameters and rock properties.For this reason,optimized by the Bayesian optimization algorithm(BOA),four hybrid machine learning models,including random forest,adaptive boosting,gradient boosting,and extremely randomized trees,were developed in this study.A total of 102 data sets with seven input parameters(spacing-to-burden ratio,hole depth-to-burden ratio,burden-to-hole diameter ratio,stemming length-to-burden ratio,powder factor,in situ block size,and elastic modulus)and one output parameter(rock fragment mean size,X_(50))were adopted to train and validate the predictive models.The root mean square error(RMSE),the mean absolute error(MAE),and the coefficient of determination(R^(2))were used as the evaluation metrics.The evaluation results demonstrated that the hybrid models showed superior performance than the standalone models.The hybrid model consisting of gradient boosting and BOA(GBoost-BOA)achieved the best prediction results compared with the other hybrid models,with the highest R^(2)value of 0.96 and the smallest values of RMSE and MAE of 0.03 and 0.02,respectively.Furthermore,sensitivity analysis was carried out to study the effects of input variables on rock fragmentation.In situ block size(XB),elastic modulus(E),and stemming length-to-burden ratio(T/B)were set as the main influencing factors.The proposed hybrid model provided a reliable prediction result and thus could be considered an alternative approach for rock fragment prediction in mining engineering. 展开更多
关键词 Bayesian optimization BLASTING machine learning rock fragmentation
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Fluid evolution and fragmentation characteristics under high pressure water jet impact on thermal rock 被引量:1
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作者 Jianming Shangguan Zhaolong Ge +2 位作者 Qinglin Deng Yuhuai Cui Zhi Yao 《International Journal of Mining Science and Technology》 2025年第3期483-497,共15页
In the application of high-pressure water jet assisted breaking of deep underground rock engineering,the influence mechanism of rock temperature on the rock fragmentation process under jet action is still unclear.Ther... In the application of high-pressure water jet assisted breaking of deep underground rock engineering,the influence mechanism of rock temperature on the rock fragmentation process under jet action is still unclear.Therefore,the fluid evolution characteristics and rock fracture behavior during jet impingement were studied.The results indicate that the breaking process of high-temperature rock by jet impact can be divided into four stages:initial fluid-solid contact stage,intense thermal exchange stage,perforation and fracturing stage,and crack propagation and penetration stage.With the increase of rock temperature,the jet reflection angles and the time required for complete cooling of the impact surface significantly decrease,while the number of cracks and crack propagation rate significantly increase,and the rock breaking critical time is shortened by up to 34.5%.Based on numerical simulation results,it was found that the center temperature of granite at 400℃ rapidly decreased from 390 to 260℃ within 0.7 s under jet impact.In addition,a critical temperature and critical heat flux prediction model considering the staged breaking of hot rocks was established.These findings provide valuable insights to guide the water jet technology assisted deep ground hot rock excavation project. 展开更多
关键词 Fluid evolution Fragmentation characteristics Fracture process Water jet Thermal rock
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Diabetes mellitus and glymphatic dysfunction:Roles for oxidative stress,mitochondria,circadian rhythm,artificial intelligence,and imaging
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作者 Kenneth Maiese 《World Journal of Diabetes》 SCIE 2025年第1期39-48,共10页
Diabetes mellitus(DM)is a debilitating disorder that impacts all systems of the body and has been increasing in prevalence throughout the globe.DM represents a significant clinical challenge to care for individuals an... Diabetes mellitus(DM)is a debilitating disorder that impacts all systems of the body and has been increasing in prevalence throughout the globe.DM represents a significant clinical challenge to care for individuals and prevent the onset of chronic disability and ultimately death.Underlying cellular mechanisms for the onset and development of DM are multi-factorial in origin and involve pathways associated with the production of reactive oxygen species and the generation of oxidative stress as well as the dysfunction of mitochondrial cellular organelles,programmed cell death,and circadian rhythm impairments.These pathways can ultimately involve failure in the glymphatic pathway of the brain that is linked to circadian rhythms disorders during the loss of metabolic homeostasis.New studies incorporate a number of promising techniques to examine patients with metabolic disorders that can include machine learning and artificial intelligence pathways to potentially predict the onset of metabolic dysfunction. 展开更多
关键词 Artificial intelligence Circadian rhythm Clock genes Diabetes mellitus magnetic resonance imaging Glymphatic pathway MITOCHONDRIA Oxidative stress Programmed cell death Sleep fragmentation
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Laser melting,evaporation,and fragmentation of nanoparticles:Experiments,modeling,and applications
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作者 Victor K.Pustovalov 《Nanotechnology and Precision Engineering》 2025年第2期146-191,共46页
This review examines the processes of laser heating,melting,evaporation,fragmentation,and breakdown of metal nanoparticles,as well as the dependences and values of the threshold laser parameters that initiate these pr... This review examines the processes of laser heating,melting,evaporation,fragmentation,and breakdown of metal nanoparticles,as well as the dependences and values of the threshold laser parameters that initiate these processes.Literature results are analyzed from experimental studies of these processes with gold,silver,and other nanoparticles,including laser surface melting and evaporation of nanoparticles and Coulomb fragmentation of nanoparticles by ultrashort laser pulses.A theoretical model and description of the thermal mechanisms of mentioned processes with metal(solid)nanoparticles in a liquid(solid)medium,initiated by the action of laser pulses with the threshold fluences,are presented.Comparison of the obtained results with experimental data confirms the accuracy of the model and makes it possible to use them to evaluate the parameters of laser thermal processing of nanoparticles.Applications of the processes include the laser melting,reshaping,and fragmentation of nanoparticles,the formation of nanostructures and nanonetworks,the laser processing of nanoparticles located on substrates,and their cladding on surfaces in various laser nanotechnologies.The use of laser ignition,combustion,and incandescence of nanoparticles is discussed,as is the use of nanoparticle-triggered laser breakdown for spectroscopy.These laser processes are used in photothermal nanotechnologies,nanoenergy,laser processing of nanoparticles,nonlinear optical devices,high-temperature material science,etc.In general,this review presents a modern picture of the state of laser technology and high-temperature processes with nanoparticles and their applications,being focused on the latest publications with an emphasis on recent results from 2021-2024. 展开更多
关键词 Laser HEATING MELTING EVAPORATION FRAGMENTATION NANOPARTICLE MODELING
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Sperm tRNA-derived fragments expression is potentially linked to abstinence-related improvement of sperm quality
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作者 Xi-Ren Ji Rui-Jun Wang +6 位作者 Zeng-Hui Huang Hui-Lan Wu Xiu-Hai Huang Hao Bo Ge Lin Wen-Bing Zhu Chuan Huang 《Asian Journal of Andrology》 2025年第5期638-645,共8页
Recent studies have shown that shorter periods of ejaculatory abstinence may enhance certain sperm parameters,but the molecular mechanisms underlying these improvements are still unclear.This study explored whether re... Recent studies have shown that shorter periods of ejaculatory abstinence may enhance certain sperm parameters,but the molecular mechanisms underlying these improvements are still unclear.This study explored whether reduced abstinence periods could improve semen quality,particularly for use in assisted reproductive technologies(ART).We analyzed semen samples from men with normal sperm counts(n=101)and those with low sperm motility or concentration(n=53)after 3-7 days of abstinence and then after 1-3h of abstinence,obtained from the Reproductive&Genetic Hospital of CITIC-Xiangya(Changsha,China).Physiological and biochemical sperm parameters were evaluated,and the dynamics of transfer RNA(tRNA)-derived fragments(tRFs)were analyzed using deep RNA sequencing in five consecutive samples from men with normal sperm counts.Our results revealed significant improvement in sperm motility and a decrease in the DNA fragmentation index after the 1-to 3-h abstinence period.Additionally,we identified 245 differentially expressed tRFs,and the mitogen-activated protein kinase(MAPK)signaling pathway was the most enriched.Further investigations showed significant changes in tRF-Lys-TTT and its target gene mitogen-activated protein kinase kinase 2(MAP2K2),which indicates a role of tRFs in improving sperm function.These findings provide new insights into how shorter abstinence periods influence sperm quality and suggest that tRFs may serve as biomarkers for male fertility.This research highlights the potential for optimizingART protocols and improving reproductive outcomes through molecular approaches that target sperm function. 展开更多
关键词 assisted reproductive technologies DNA fragmentation index MAPK pathway short abstinence sperm motility transfer RNA-derived fragment
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Sperm DNA fragmentation and sperm chromatin decondensation status in patients with extreme and total isolated teratospermia:A prospective study
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作者 Sonia Jellad Molka Bouricha Sarra Maatallah 《Asian pacific Journal of Reproduction》 2025年第3期137-139,共3页
Total or severe teratospermia affects the prognosis of fertility and causes serious problems for patients undergoing assisted reproduction[1].The pathophysiological mechanism of teratospermia is unclear.It has been sh... Total or severe teratospermia affects the prognosis of fertility and causes serious problems for patients undergoing assisted reproduction[1].The pathophysiological mechanism of teratospermia is unclear.It has been shown that patients with sperm parameters abnormalities and abnormal morphology have a high rate of fragmentation and sperm DNA decondensation[2,3],and that sperm DNA fragmentation analysis could be used as a predictor factor of fertility potential[4]. 展开更多
关键词 sperm dna decondensation sperm parameters sperm dna fragmentation analysis assisted reproduction sperm DNA fragmentation predictor factor sperm chromatin decondensation pathophysiological mechanism
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The Modern Paradox
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作者 Peter Takov 《Philosophy Study》 2025年第5期187-194,共8页
This paper is an attempt to explore the root of the modern paradox across multiple registers in order to uncover a persuasive pattern of contradiction that runs through the very fabric of contemporary existence.We dis... This paper is an attempt to explore the root of the modern paradox across multiple registers in order to uncover a persuasive pattern of contradiction that runs through the very fabric of contemporary existence.We discover that the very logic meant to emancipate the human subject-scientific mastery,bureaucratic order,economic growth,and many others,often recoil upon the subject,generating conditions of fragmentation,depersonalization,and spiritual aridity.Far from rejecting modernity wholesale,our task is a diagnostic one-to enter into the deep fabric of modernity and to decode its operating metaphors and interrogate what holds up the“scaffolding of collective life”.This is in a bid to find the rootedness of genuine human flourishing.Part of the answer,from our analysis,lies in a critical re-thinking within modernity without being subsumed by it. 展开更多
关键词 modernity FRAGMENTATION INDIVIDUALISM MANIPULATION CAPITALISM DOMINATION
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Messengers of Peace
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作者 ZHANG HUI 《China Today》 2025年第9期28-31,共4页
“As a global citizen,I speak to you with fear.I fear increasing unpredictability and fragmentation that can easily result in conflict.And in conflict,no one wins-we all lose,”Matias Acosta,CEO of Italian cleantech f... “As a global citizen,I speak to you with fear.I fear increasing unpredictability and fragmentation that can easily result in conflict.And in conflict,no one wins-we all lose,”Matias Acosta,CEO of Italian cleantech firm Cosysense,told the audience at the China Today•Macao Salon dialogue in Hengqin,south China’s Guangdong Province,on July 27,2025. 展开更多
关键词 UNPREDICTABILITY FRAGMENTATION global citizenship LOSS CONFLICT
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Biotite effect on the anisotropic properties of gneiss in Eastern Himalayas,China
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作者 Shijie Liu Hengxing Lan +2 位作者 Zhao Chen Langping Li Han Bao 《Journal of Rock Mechanics and Geotechnical Engineering》 2025年第8期4852-4870,共19页
Intact rocks with layered microstructures,such as gneiss,exhibit strong anisotropy.Although anisotropy in the macroscopic strength of gneiss has been widely reported,the role of microstructures in tensile mechanics re... Intact rocks with layered microstructures,such as gneiss,exhibit strong anisotropy.Although anisotropy in the macroscopic strength of gneiss has been widely reported,the role of microstructures in tensile mechanics remains largely unclear.Utilizing a range of methodologies,it was determined that the tensile strength,deformation,and fracturing behavior of Himalayan gneiss are predominantly influenced by biotite.In contrast to the behavior of other transversely isotropic rocks,the apparent tensile strength of the gneiss first decreased and then increased with anisotropic angleβ,rather than the widely reported monotonic increase or single-shoulder response.The shear sliding of biotite along cleavage planes caused stress concentrations in the surrounding brittle minerals,inducing cracks and reducing the overall tensile strength of the gneiss.Micro-observations of the relationship between cracks and biotite orientation identified three types of biotite crystal fragmentation:tensile fragmentation along cleavage planes,shear fragmentation along cleavage planes,and tensile fragmentation perpendicular to cleavage planes.Tensile and shear fragmentation of biotite along cleavage planes negatively affected the gneiss'macroscopic tensile strength.Conversely,when the tensile stress was parallel to the biotite cleavage planes,tensile fragmentation perpendicular to the cleavage planes increased the macroscopic tensile strength of the gneiss due to plastic deformation and high surface energy.Quantitative analysis of shear stress along biotite cleavage planes revealed the mechanical mechanism behind the reduced tensile strength of the East Himalayan gneisses near an anisotropic angle of 30°.These results elucidated the influence of grain-level anisotropy on the macroscopic tensile mechanical properties of intact layered rocks. 展开更多
关键词 GNEISS BIOTITE Tensile strength Induced crack Crack propagation Fragmentation characteristic
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Highway effects on artificial nest survival in a neotropical sand-coastal plain:A spatiotemporal approach
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作者 Gleidson Ramos da Silva Pedro Diniz Charles Duca 《Avian Research》 2025年第3期318-325,共8页
Roads are a leading cause of habitat fragmentation and may reduce bird populations by increasing nest predation rates.However,few studies have investigated the effects of traffic volume on the reproductive success of ... Roads are a leading cause of habitat fragmentation and may reduce bird populations by increasing nest predation rates.However,few studies have investigated the effects of traffic volume on the reproductive success of roadside birds in the neotropics.Our goal was to evaluate the effects of spatial,temporal,and vehicle flow variations on the survival of artificial open-cup nests.The study was carried out in a nature reserve on the side of a highway during the breeding season(from October to March)in two restinga(sand-coastal plain)phytophysiognomies in southeastern Brazil:non-floodable(open)and floodable(closed).One hundred thirty nests were distributed along transects ranging from 3 m to 300 m from the highway in each vegetation type(totaling 260 nests).The nests were checked every three days for their status(depredated or intact)over 12 days,and new nests were subsequently placed near sampling points of depredated or successful nests.We estimated survival using logistic exposure generalized linear and additive mixed models.At the end of the 180 days of the experiment,33%of 6202 nests were successful.Nest survival was higher in open restinga than in closed restinga.In both habitats,nest survival was lowest mid-season and highest at the beginning and end.Survival rates peaked near the highway,declined up to 50 m away,then showed a slight increase.Finally,survival increased at moderate-to-high traffic volumes(∼22,000 vehicles/day),particularly in open restinga.We suggest that spatial,temporal,and habitat-specific highway impacts(e.g.,noise,vibration,visual stimuli)can lead to variations in the activity of nest predators,generating fluctuations in nest survival associated with predator behavior. 展开更多
关键词 BIRDS Edge effect FRAGMENTATION Nest survival Traffic effect
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Effect of impact velocity on spall behaviors of nanocrystalline iron:Molecular dynamics study
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作者 Li-Qiong Chen Kui Zhao +3 位作者 Kai Zhang Ze-Zhi Wen Hou-Jin Mei Zhen-Bao Xiong 《Chinese Physics B》 2025年第9期374-384,共11页
This study investigates the effect of shock velocity(u_(p))on damage evolution mechanisms in nanocrystalline iron via molecular dynamics simulations.As u_(p)increases,shock wave propagation accelerates,and stress dist... This study investigates the effect of shock velocity(u_(p))on damage evolution mechanisms in nanocrystalline iron via molecular dynamics simulations.As u_(p)increases,shock wave propagation accelerates,and stress distribution transitions from grain boundary concentration to homogeneity.This causes a transition in fracture mode from cleavage to ductile behavior.When u_(p)exceeds 1.5 km·s^(-1),micro-spallation emerges as the dominant failure mode.During micro-spallation,localized melting within the material impedes the propagation of the shock wave.As u_(p)increases,the growth rate of the void volume fraction initially rises but then decreases.Higher u_(p)leads to earlier void nucleation.At lower u_(p),the cavitation of the model is mainly characterized by the growth and penetration of a few voids.With increasing u_(p),the number of voids grows,and their interactions expand the delamination damage region.The spall strength demonstrates stage-specific dependence on u_(p).In the classical spallation stage(C_Ⅰ),temperature softening reduces spall strength.In the plastic strengthening regime(C_Ⅱ),strain hardening enhances spall strength.In the micro-spallation stage(M_Ⅲ),further increases in u_(p)cause melting during tensile and compressive phases,reducing spall strength.Finally,in the compressionmelting regime(M_Ⅳ),local temperatures exceed the melting point,diminishing plastic damage and accelerating spall strength reduction.This study provides new insights into the dynamic response of nanocrystalline iron. 展开更多
关键词 nanocrystalline iron shock response FRAGMENTATION SPALLATION molecular dynamics
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Oxidative Degradation of Plastic Bottle Tops in an Arid, Terrestrial Environment—Identifying Oxidative Degradation by Infrared Spectroscopy
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作者 Mahra Al Kaabi Vijo Poulose Thies Thiemann 《Journal of Environmental Protection》 2025年第2期66-86,共21页
This communication looks at the photo-oxidation of polythene and polypropylene plastic bottle tops that are placed on soil in a hot arid environment. The degree of oxidation of the plastic is monitored by FT-IR spectr... This communication looks at the photo-oxidation of polythene and polypropylene plastic bottle tops that are placed on soil in a hot arid environment. The degree of oxidation of the plastic is monitored by FT-IR spectroscopy. It is noted that while different bottle top types photo-oxidize at different rates, all show an appreciable level of oxidation after half a year of exposure to the environment. The oxidation leads to brittleness of the plastic, which leads to fissure formation in bottle tops of little thickness. This leads to fragmentation of the material upon impact, making plastic bottle tops an appreciable source of microplastics. 展开更多
关键词 PLASTICS Polythene POLYPROPYLENE Plastic Bottle Tops FRAGMENTATION Microplastics Infrared Spectroscopy Oxidation Index
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Responses of steppe birds to habitat fragmentation:Insights from niche specialization and functional traits
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作者 Zheng Han Xi Yang +3 位作者 Lishi Zhang Piotr Tryjanowski Frédéric Jiguet Haitao Wang 《Avian Research》 2025年第3期353-361,共9页
Habitat fragmentation poses a significant threat to bird communities, especially those in open and semi-open ecosystems such as steppes. This study investigates how steppe birds adapt to and utilize fragmented habitat... Habitat fragmentation poses a significant threat to bird communities, especially those in open and semi-open ecosystems such as steppes. This study investigates how steppe birds adapt to and utilize fragmented habitats by combining niche modeling with ecological trait analysis. We conducted standardized point surveys to examine the habitat preferences of 32 bird species in Inner Mongolia, China, and quantified their habitat niche parameters using the Outlying Mean Index (OMI). Our results reveal distinct habitat preferences among species, with some thriving in intact environments while others are better adapted to fragmented areas. Grassland species showed high specialization along the fragmentation gradient, while others exhibited adaptability to varying levels of fragmentation. Using a Generalized Additive Model (GAM), we identified three key traits influencing habitat occupancy: hand-wing index, body mass, and range size. Specifically, species with medium hand-wing indices, moderate body mass, and larger range sizes were more likely to occupy heavily fragmented habitats. These findings provide empirical evidence on how habitat fragmentation affects bird species in steppe ecosystems. The study highlights the importance of functional traits in understanding avian responses to habitat fragmentation and offers a foundation for developing effective conservation strategies to preserve biodiversity in fragmented landscapes. 展开更多
关键词 CONSERVATION Functional traits Habitat fragmentation Niche position Response Steppe birds
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Characterization of combined blast-and fragments-induced synergetic damage in polyurea coated liquid-filled container
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作者 Chen Tao Chong Ji +3 位作者 Xin Wang Juan Gu Yuting Wang Changxiao Zhao 《Defence Technology(防务技术)》 2025年第1期201-224,共24页
Liquid-filled containers(LFC)are widely used to store and transport petroleum,chemical reagents,and other resources.As an important target of military strikes and terrorist bombings,LFC are vulnerable to blast waves a... Liquid-filled containers(LFC)are widely used to store and transport petroleum,chemical reagents,and other resources.As an important target of military strikes and terrorist bombings,LFC are vulnerable to blast waves and fragments.To explore the protective effect of polyurea elastomer on LFC,the damage characteristics of polyurea coated liquid-filled container(PLFC)under the combined loading of blast shock wave and fragments were studied experimentally.The microstructure of the polyurea layer was observed by scanning electron microscopy,and the fracture and self-healing phenomena were analyzed.The simulation approach was used to explain the combined blast-and fragments-induced on the PLFC in detail.Finally,the effects of shock wave and fragment alone and in combination on the damage of PLFC were comprehensively compared.Results showed that the polyurea reduces the perforation rate of the fragment to the LFC,and the self-healing phenomenon could also reduce the liquid loss rate inside the container.The polyurea reduces the degree of depression in the center of the LFC,resulting in a decrease in the distance between adjacent fragments penetrating the LFC,and an increase in the probability of transfixion and fracture between holes.Under the close-in blast,the detonation shock wave reached the LFC before the fragment.Polyurea does not all have an enhanced effect on the protection of LFC.The presence of internal water enhances the anti-blast performance of the container,and the hydrodynamic ram(HRAM)formed by the fragment impacting the water aggravated the plastic deformation of the container.The combined action has an enhancement effect on the deformation of the LFC.The depth of the container depression was 27%higher than that of the blast shock wave alone;thus,it cannot be simply summarized as linear superposition. 展开更多
关键词 POLYUREA Prefabricated fragment Liquid-filled container Hydrodynamic ram Cumulative effect
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Contribution of rock strength to post-fragmentation spreading and deposition of rockslides
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作者 ZHU Zhiyuan WU Yihan +2 位作者 ZHENG Lu ZHAO Siyuan BI Yuzhang 《Journal of Mountain Science》 2025年第6期1944-1965,共22页
Fragmentation is a common phenomenon in the runout process of large rockslides.Rocks have different strengths under the influence of the rock type and weathering degree,resulting in varying fragmentation characteristi... Fragmentation is a common phenomenon in the runout process of large rockslides.Rocks have different strengths under the influence of the rock type and weathering degree,resulting in varying fragmentation characteristics.However,the limited understanding of how rock strength influences the postfragmentation kinematic characteristics of rockslides is limited.Taking a natural rockslide as an example,this paper quantitatively analyzes the runout and deposition of the rockslide using the discrete element method(DEM)and examines the impacts of the rock strength on the runout and deposition characteristics of the rockslide.The results reveal that(1)Rock strength significantly influences fragmentation and runout characteristics:medium-to-high strength rocks exhibit two-stage fragmentation(10-20 s and 55-65 s),while weak-strength rocks achieve 98%fragmentation within 20 s.Optimal kinetic energy conversion occurs in medium-strength rocks,with a maximum velocity difference of 39.3 m/s between the anterior and posterior edges.(2)The sudden change in the cross-sectional dimensions of high-strength rocks under a high spreading velocity(>60 m/s)may amplify air blast hazards.(3)Deposition patterns reveal that the spatial distribution of fragments preserves original positional order;high-strength rocks produce larger fragments(nominal fragment size increases from 0.028 of weak-strength rocks to 0.607);and centroid displacement increases from 1907 m to 2117 m with rock strength in open terrains.(4)Energy dissipation analysis shows that frictional dissipation(>60%)>collisional dissipation(~37%)>>fragmentation dissipation(<2%)in the process of rockslide runout.The rock strength induces<5%variation in partitioning of energy dissipation. 展开更多
关键词 ROCKSLIDE FRAGMENTATION RUNOUT DEPOSITION Discrete element method(DEM)
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Effects of ambient temperature and 37℃on biological characteristics of processed oligoasthenoteratozoospermic spermatozoa
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作者 Sajjad Shahmohammadi Fatemeh Dehghanpour +2 位作者 Ali Nabi Moones Vasiee Mohammad Ali Khalili 《Asian pacific Journal of Reproduction》 2025年第3期129-136,共8页
Objective:To assess the biological characteristics of human spermatozoa at room temperature(RT,25℃)and 37℃at different time intervals(0,0.5,2,and 24 h)post liquefaction.Methods:Twenty oligoasthenoteratozoospermic sa... Objective:To assess the biological characteristics of human spermatozoa at room temperature(RT,25℃)and 37℃at different time intervals(0,0.5,2,and 24 h)post liquefaction.Methods:Twenty oligoasthenoteratozoospermic samples after liquefaction were incubated at 37℃or RT.Incubation was performed at 4 interval times of 0(after liquefaction),0.5,2,and 24 h.The samples were evaluated for sperm parameters,DNA fragmentation,acrosome reaction,mitochondrial integrity,and lipid peroxidation,at each time interval.Results:After 0.5 h of incubation at RT and 37℃,there were slight variations in sperm viability,normal morphology and DNA fragmentation.Similarly,mitochondrial integrity,acrosome reaction and lipid peroxidation exhibited slight differences following incubation at 0.5 h at both RT and 37℃.In addition,the assessed parameters were mostly damaged at 24 h of incubation.The results confirmed that incubation at 37℃was better than RT in terms of parameters and sperm functional tests,but the difference was not significant.Conclusions:Incubation of oligoasthenoteratozoospermic samples should be done within 0.5 h to minimize the destructive effects of prolonged incubation time(e.g.24 h)on general and specific sperm parameters.The findings declared that incubation temperature of 37℃is safer than RT on the biological characteristics of oligoasthenoteratozoospermic processed spermatozoa. 展开更多
关键词 Acrosome reaction DNA fragmentation Incubation time Mitochondrial membrane potential SPERMATOZOA Oligoasthenoteratozoospermic
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Energy transfer in dynamic fragmentation of rock-like spheres:Insights from impact experiments
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作者 Jian Huang Yuan Yuan +3 位作者 Da Huang Tan Zeng Pusheng Zhang Xiang Huang 《Journal of Rock Mechanics and Geotechnical Engineering》 2025年第10期6439-6454,共16页
Rockfall represents a significant geological hazard in mountainous regions,characterized by a sudden and unpredictable feature.The process of dynamic fragmentation and energy conversion in a rockfall event remains com... Rockfall represents a significant geological hazard in mountainous regions,characterized by a sudden and unpredictable feature.The process of dynamic fragmentation and energy conversion in a rockfall event remains complex and not fully understood.This study aims to gain a further understanding of the energy transfer mechanism during rockfall impact and fragmentation by impact tests using a variety of rock-like sphere specimens.The experiments mainly focus on the quantitative correlation between fragmentation degree and influence factors,i.e.impact angle and velocity on steel and granite slabs.The analysis focuses on the energy distribution characteristics,energy dissipation mechanisms,and the energy conversion rate of the fragments during impact and fragmentation.The results show that there is a significant correlation between the energy conversion rate and the fragmentation degree.In normal impact tests,elasto-plastic deformation energy and fracture energy are found to be two primary categories of energy dissipation.The proportion of total kinetic energy after impact is inversely proportional to the initial energy.A comparative analysis between normal and inclined slab impact tests reveals that the impact angle significantly influences the energy conversion rate,which controls the fragmentation degree as well.In addition,the fragmentation degree is inversely proportional to the restitution coefficient.These findings contribute to a better understanding of the energy conversion mechanism during rockfall impact and fragmentation,providing valuable insight for the development of effective strategies to mitigate such rockfall hazards. 展开更多
关键词 ROCKFALL Normal impact Energy conversion Fragmentation degree
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Modulation of oxidative damage and genotoxicity of biosynthesized zinc oxide nanoparticles via supplementation with modified cinnamaldehyde-loaded chitosan nanoparticles in mice
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作者 Mosaad A.Abdel-Wahhab Aziza A.El-Nekeety +4 位作者 Asmaa S.Salman Zeinab K.Hamza Engy M.Akl Soher E.Aly Wenyi Kang 《Food Science and Human Wellness》 2025年第9期3414-3427,共14页
Synthesis of zinc oxide nanoparticles(ZnO-NPs)via green method is an outstanding alternative to conventional/regular methods;however,the safety or toxicity of the biosynthesized ZnO-NPs in vivo is not fully explored.T... Synthesis of zinc oxide nanoparticles(ZnO-NPs)via green method is an outstanding alternative to conventional/regular methods;however,the safety or toxicity of the biosynthesized ZnO-NPs in vivo is not fully explored.This study was conducted to evaluate the protective efficiency of cinnamaldehyde-loaded chitosan nanoparticles(Cin@CSNPs)against oxidative damage and genotoxicity of ZnO-NPs in mice.ZnO-NPs were biosynthesized using the extract of fresh leaves of Mentha pulegium L.Cin was extracted from cinnamon essential oil,and was loaded into chitosan nanoparticle(Cin@CSNPs).Both ZnO-NPs,Cin@CSNPs and CSNPs were characterized.The in vitro release of Cin@CSNPs was determined.In the biological study,6 groups of male BALB/c mice were treated by gavage for 3 weeks as follows,control group,the group received ZnO-NPs(25 mg/kg b.w),the groups received Cin@CSNPs at low dose(50 mg/kg b.w)or high dose(100 mg/kg b.w),and the groups received ZnO-NPs plus Cin@CSNPs at the 2 tested doses.Blood and tissue samples were collected for different biochemical,genetical and histological studies.The particle size of ZnO-NPs,CSNPs,and Cin@CSNPs were(20.78±2.60),(170.0±3.7),and(218.23±2.90)nm,andξ-potential were(32.7±4.6),(8.32±0.27)and(4.80±0.21)mV,respectively.ZnO-NPs disturbed the biochemical and oxidative stress indices,AFP,CEA,TNF-α,chromosomal aberrations in somatic and germ cells,and sperm abnormality along with severe pathological changes in the hepatic,renal,and testicular tissues.Cin@CSNPs improved significantly all the parameters tested and the histological picture in a dose-dependent.Therefore,the biosynthesized ZnO-NPs exhibit oxidative damage and genotoxicity,and Cin@CSNPs have potential protective effects against the risks of ZnO-NPs and may be a promising tool to overcome the challenges of using Cin in food and pharmaceuticals applications. 展开更多
关键词 Zinc oxide nanoparticles CINNAMALDEHYDE Chitosan nanoparticles Dietary supplement GENOTOXICITY DNA fragmentation
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Development of a comprehensive framework for wetland ecosystem assessment and management
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作者 Manob Das Arijit Das Suman Singha 《Geoscience Frontiers》 2025年第3期287-300,共14页
This study focuses on the assessment of ecosystem health(EH),ecosystem services(ES),and ecosystem risk(ER)in East Kolkata Wetland(EKW).A comprehensive framework on the EH,ES and ER has been developed using remote sesn... This study focuses on the assessment of ecosystem health(EH),ecosystem services(ES),and ecosystem risk(ER)in East Kolkata Wetland(EKW).A comprehensive framework on the EH,ES and ER has been developed using remote sesning and geo-spatial techniques for the year 2000,2005,2010,2015,and 2020.The study also assessed ecosystem structure and fragmentation using landscape metrics calculated using fragstats,which showed a significant influence of land use and land cover(LULC)changes on the wetland’s ecological integrity.The study revealed that 6.86% of EKW fallen under a very low EH zone,while 20% was categorized as having very high EH.Spatio-temporal analysis of ES indicated that 30%of the area had very low ES value,with only 8% exhibiting very high ES.ER assessment revealed that 7%of the study area was highly ER,while 12%identified within a high ER zone,reflecting frequent LULC changes.The correlation analysis highlighted strong negative relationships between landscape deviation degree(LDD)and EH(−0.971),and between normalized difference water index(NDWI)and normalized difference vegetation index(NDVI)(−0.991).Additionally,landscape metrics such as the number of patches(NP)and the largest patch index(LPI)exhibited significant correlations,emphasizing the impact of fragmentation on EH and resilience.This comprehensive assessment underscores the importance of integrated approaches to monitor and manage wetland ecosystems,particularly in urban areas facing significant environmental stressors.The findings are crucial for informed decision-making and sustainable management of the wetland ecosystems,particularly in the cities of the global south. 展开更多
关键词 Ecosystem health Ecosystem services Landscape fragmentation Remote sensing URBANIZATION
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