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Status and determinants of other gainful activities by farmers in mountainous rural regions of Gilgit-Baltistan,Pakistan 被引量:1
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作者 SHAHZAD Muhammad Abid AHMED Vaqar FISCHER Christian 《Journal of Mountain Science》 SCIE CSCD 2021年第10期2520-2539,共20页
Non-farm income sources are important for livelihood sustenance,especially in the mountainous regions of developing countries.To implement effective policies to improve economic development,policymakers need insights ... Non-farm income sources are important for livelihood sustenance,especially in the mountainous regions of developing countries.To implement effective policies to improve economic development,policymakers need insights at the grassroots level.Yet,there is a lack of empirical evidence in the context of Pakistan.This study examines the current situation and the factors influencing the decision by farmers to engage in other gainful activities(OGAs)such as farm diversification and off-farm work in the northern mountainous regions of Pakistan.The study is based on quantitative survey data obtained from 459 farm managers and qualitative data from 24 key informants from five different districts in GilgitBaltistan.Utilizing a logistic regression model,a statistical analysis is conducted on farmer and farm characteristics to investigate the probability of farm managers to engage in OGAs.The survey results show that around 71%of farm managers are engaged in OGAs(with 24%in farm diversification,61%in offfarm work and 15%in both).The share of female farm managers is 51%in farm diversification while male farm managers dominate off-farm activities(69%).The most prevalent types of farm diversification are the processing of farm products and tourism-related farm work,while the main off-farm activities are setting up grocery stores outside the farm,having salaried jobs or engaging in other non-agricultural business.There are significant differences between farmers with and without OGAs particularly regarding farmer characteristics,agricultural income and some other variables.The logit model results show that farmer characteristics mainly determine off-farm work activities while farm(and other)characteristics mostly explain farm diversification.These findings suggest that OGAs primarily exist as livelihood strategies.Farm diversification is linked with the long-term sustenance of agricultural activities while off-farm work is predominantly driven by economic needs.Both types of OGAs require specific support policies while attention needs to be given not to threaten regional food supply. 展开更多
关键词 Other gainful activities Off-farm work Farm diversification Gilgit-Baltistan Pakistan
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Winter wheat yield improvement by genetic gain across different provinces in China 被引量:2
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作者 Wei Chen Jingjuan Zhang Xiping Deng 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2024年第2期468-483,共16页
The replacement of winter wheat varieties has contributed significantly to yield improvement worldwide,with remarkable progress in China.Drawing on two sets of data,production yield from the National Bureau of Statist... The replacement of winter wheat varieties has contributed significantly to yield improvement worldwide,with remarkable progress in China.Drawing on two sets of data,production yield from the National Bureau of Statistics of China and experimental yield from literature,this study aims to(1)illustrate the increasing patterns of production yield among different provinces from 1978 to 2018 in China,(2)explore the genetic gain in yield and yield relevant traits through the variety replacement based on experimental yield from 1937 to 2016 in China,and(3)compare the yield gap between experimental yield and production yield.The results show that both the production and experimental yields significantly increased along with the variety replacement.The national annual yield increase ratio for the production yield was 1.67%from 1978 to 2018,varying from 0.96%in Sichuan Province to 2.78%in Hebei Province;such ratio for the experimental yield was 1.13%from 1937 to 2016.The yield gap between experimental and production yields decreased from the 1970s to the 2010s.This study reveals significant increases in some yield components consequent to variety replacement,including thousand-grain weight,kernel number per spike,and grain number per square meter;however,no change is shown in spike number per square meter.The biomass and harvest index consistently and significantly increased,whereas the plant height decreased significantly. 展开更多
关键词 genetic gain winter wheat YIELD yield components
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Preweaning period is a critical window for rumen microbial regulation of average daily gain in Holstein heifer calves 被引量:1
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作者 Shengyang Xu Chong Jiao +1 位作者 Qiyu Diao Yan Tu 《Journal of Animal Science and Biotechnology》 SCIE CAS CSCD 2024年第1期396-411,共16页
Background Rumen bacterial groups can affect growth performance,such as average daily gain(ADG),feed intake,and efficiency.The study aimed to investigate the inter-relationship of rumen bacterial composition,rumen fer... Background Rumen bacterial groups can affect growth performance,such as average daily gain(ADG),feed intake,and efficiency.The study aimed to investigate the inter-relationship of rumen bacterial composition,rumen fermentation indicators,serum indicators,and growth performance of Holstein heifer calves with different ADG.Twelve calves were chosen from a trail with 60 calves and divided into higher ADG(HADG,high pre-and post-weaning ADG,n=6)and lower ADG(LADG,low pre-and post-weaning ADG,n=6)groups to investigate differences in bacterial composition and functions and host phenotype.Results During the preweaning period,the relative abundances of propionate producers,including g_norank_f_Butyricicoccaceae,g_Pyramidobacter,and g_norank_f_norank_o_Clostridia_vadin BB60_group,were higher in HADG calves(LDA>2,P<0.05).Enrichment of these bacteria resulted in increased levels of propionate,a gluconeogenic precursor,in preweaning HADG calves(adjusted P<0.05),which consequently raised serum glucose concentrations(adjusted P<0.05).In contrast,the relative abundances of rumen bacteria in post-weaning HADG calves did not exert this effect.Moreover,no significant differences were observed in rumen fermentation parameters and serum indices between the two groups.Conclusions The findings of this study revealed that the preweaning period is the window of opportunity for rumen bacteria to regulate the ADG of calves. 展开更多
关键词 Average daily gain CALVES Preweaning period Rumen microbiota
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Understory seedlings of Quercus mongolica survive by phenological escape
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作者 Shixiong Wu Ying Liu +2 位作者 Lulu He Wei Zeng Qijing Liu 《Forest Ecosystems》 SCIE CSCD 2024年第2期236-246,共11页
Understanding understory seedling regeneration mechanisms is important for the sustainable development of temperate primary forests in the context of increasingly intense climate warming events.The poor regeneration o... Understanding understory seedling regeneration mechanisms is important for the sustainable development of temperate primary forests in the context of increasingly intense climate warming events.The poor regeneration of dominant tree species,however,is one of the biggest challenges it faces at the moment.Especially,the regeneration of the shade-intolerant Quercus mongolica seedling is difficult in primary forests,which contrasts with the extreme abundance of understory seedlings in secondary forests.The mechanism behind the interesting phenomenon is still unknown.This study used in-situ monitoring and nursery-controlled experiment to investigate the survival rate,growth performance,as well as nonstructural carbohydrate (NSC) concentrations and pools of various organ tissues of seedlings for two consecutive years,further analyze the understory light availability and simulate the foliage carbon (C) gain in the secondary and primary forest.Results suggested that seedlings in the secondary forest had greater biomass allocation aboveground,height and specific leaf area (SLA) in summer,which allowed the seedling to survive longer in the canopy closure period.High light availability and positive C gain in early spring and late autumn are key factors affecting the growth and survival of understory seedlings in the secondary forest,whereas seedlings in the primary forest had annual negative carbon gain.Through the growing season,the total NSC concentrations of seedlings gradually decreased,whereas those of seedlings in the secondary forest increased significantly in autumn,and were mainly stored in roots for winter consumption and the following year's summer shade period,which was verified by the nursery-controlled experiment that simulated autumn enhanced light availability improved seedling survival rate and NSC pools.In conclusion,our results revealed the survival trade-off strategies of Quercus mongolica seedlings and highlighted the necessity of high light availability during the spring and autumn phenological periods for shade-intolerant tree seedling recruitment. 展开更多
关键词 Carbon gain Nonstructural carbohydrate RECRUITMENT Trade-off Biomass allocation
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Composition,function,and timing:exploring the early‑life gut microbiota in piglets for probiotic interventions
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作者 Jianping Quan Cineng Xu +14 位作者 Donglin Ruan Yong Ye Yibin Qiu Jie Wu Shenping Zhou Menghao Luan Xiang Zhao Yue Chen Danyang Lin Ying Sun Jifei Yang Enqin Zheng Gengyuan Cai Zhenfang Wu Jie Yang 《Journal of Animal Science and Biotechnology》 SCIE CAS CSCD 2024年第2期659-678,共20页
Background The establishment of a robust gut microbiota in piglets during their early developmental stage holds the potential for long-term advantageous effects.However,the optimal timeframe for introducing probiotics... Background The establishment of a robust gut microbiota in piglets during their early developmental stage holds the potential for long-term advantageous effects.However,the optimal timeframe for introducing probiotics to achieve this outcome remains uncertain.Results In the context of this investigation,we conducted a longitudinal assessment of the fecal microbiota of 63 piglets at three distinct pre-weaning time points.Simultaneously,we gathered vaginal and fecal samples from 23 sows.Employing 16S rRNA gene and metagenomic sequencing methodologies,we conducted a comprehensive analysis of the fluctuation patterns in microbial composition,functional capacity,interaction networks,and colonization resistance within the gut microbiota of piglets.As the piglets progressed in age,discernible modifications in intestinal microbial diversity,composition,and function were observed.A source-tracking analysis unveiled the pivotal role of fecal and vaginal microbiota derived from sows in populating the gut microbiota of neonatal piglets.By D21,the microbial interaction network displayed a more concise and efficient configuration,accompanied by enhanced colonization resistance relative to the other two time points.Moreover,we identified three strains of Ruminococcus sp.at D10 as potential candidates for improving piglets’weight gain during the weaning phase.Conclusions The findings of this study propose that D10 represents the most opportune juncture for the introduction of external probiotic interventions during the early stages of piglet development.This investigation augments our comprehension of the microbiota dynamics in early-life of piglets and offers valuable insights for guiding forthcoming probiotic interventions. 展开更多
关键词 Colonization resistance Intestinal microbiota PIGLET WEANING Weight gain
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Exerkine response to acute exercise:Still much to discover
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作者 Pedro L.Valenzuela Beatriz Rivas-Baeza +1 位作者 Carmen Fiuza-Luces Alejandro Lucia 《Journal of Sport and Health Science》 SCIE CAS CSCD 2024年第6期759-760,共2页
Strong evidence supports the benefits of regular physical activity/exercise for the prevention and management of numerous non-communicable diseases.^(1,2)However,despite important advances(particularly the implementat... Strong evidence supports the benefits of regular physical activity/exercise for the prevention and management of numerous non-communicable diseases.^(1,2)However,despite important advances(particularly the implementation of complex“omics”approaches),the underlying molecular mechanisms remain to be clearly elucidated.In the past decade,the role of exerkines—a myriad of signaling moieties(e.g.,mainly cytokines but also other small peptides,peptides,nucleic acids,lipids,or metabolites,among others)released by muscles(myokines)and other tissues in response to exercise that induces endocrine(at the multisystem level),paracrine,or autocrine effects—has gained attention.^(3,4)Indeed it has been proposed that some of the salutary effects of regular exercise(i.e.,repeated sessions of acute exercise)might be due,at least partly,to the progressive accumulation of frequent,acute episodes of exerkine release.^(5) 展开更多
关键词 gained multisystem PREVENTION
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Like a G6-nal:transcriptional control of G-protein coupled receptors during oligodendroglial development
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作者 Tim Aberle Michael Wegner 《Neural Regeneration Research》 SCIE CAS 2025年第7期2001-2002,共2页
Multilayered control of myelination:Quick,saltatory conduction of action potentials along nerve fibers requires the electrical insulation of axons by myelinating glia.In the central nervous system,this role is taken u... Multilayered control of myelination:Quick,saltatory conduction of action potentials along nerve fibers requires the electrical insulation of axons by myelinating glia.In the central nervous system,this role is taken up by oligodendrocytes.Oligodendrocytes are marked by the expression of the lineage determinants Sox10 and Olig2 and arise from oligodendrocyte precursor cells(OPCs)during embryonal stages.While the majority of OPCs differentiate into mature oligodendrocytes when nearby axonal segments require myelination,a small subpopulation of OPCs persist as a progenitor pool.Therefore,the timing of myelination and maintenance of the OPC pool both need to be precisely regulated.Different transcription factors either positively or negatively affect oligodendrocyte differentiation and maintenance of the OPC pool as components of a complex gene regulatory network(reviewed in Sock and Wegner,2021).Network activity is additionally influenced by extracellular signaling molecules that bind to receptors on the oligodendroglial cell surface and activate intracellular signaling pathways.How the receptors are linked to the network is poorly understood so far,but pivotal to understanding the overall regulation of central nervous system(CNS)myelination in response to environmental cues.Relevant insights were recently gained for Gpr37(Schmidt et al.,2024),a G-protein coupled receptor(GPCR)with known relevance in differentiating oligodendrocytes(Yang et al,2016). 展开更多
关键词 gained INSULATION conduction
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INTELLIGENT COVERT COMMUNICATION
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《China Communications》 SCIE CSCD 2024年第9期I0002-I0004,共3页
As increasing amounts of private and confidential information are transmitted over wireless networks,their openness and broadcast pose significant security risks.In high-security scenarios like healthcare and financia... As increasing amounts of private and confidential information are transmitted over wireless networks,their openness and broadcast pose significant security risks.In high-security scenarios like healthcare and financial activities,initial exposure of transmitted information can lead to serious threats.Covert communication,or low probability of detection(LPD)communication,has gained attention for its ability to hide transmission behaviors. 展开更多
关键词 COMMUNICATION WIRELESS gained
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Compression and stretching of ring vortex in a bulk nonlinear medium
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作者 来娴静 蔡晓鸥 +1 位作者 邵雅斌 王悦悦 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第2期264-270,共7页
We explore the nonlinear gain coupled Schrödinger system through the utilization of the variables separation method and ansatz technique.By employing these approaches,we generate hierarchies of explicit dissipati... We explore the nonlinear gain coupled Schrödinger system through the utilization of the variables separation method and ansatz technique.By employing these approaches,we generate hierarchies of explicit dissipative vector vortices(DVVs)that possess diverse vorticity values.Numerous fundamental characteristics of the DVVs are examined,encompassing amplitude profiles,energy fluxes,parameter effects,as well as linear and dynamic stability. 展开更多
关键词 vector optical vortices DISSIPATIVE nonlinear gain
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Photosynthetic response dynamics in the invasive species Tithonia diversifolia and two co-occurring native shrub species under fluctuating light conditions
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作者 Ju Li Shu-Bin Zhang Yang-Ping Li 《Plant Diversity》 SCIE CAS CSCD 2024年第2期265-273,共9页
To determine the invasiveness of invasive plants,many studies have compared photosynthetic traits or strategies between invasive and native species.However,few studies have compared the photosynthetic dynamics between... To determine the invasiveness of invasive plants,many studies have compared photosynthetic traits or strategies between invasive and native species.However,few studies have compared the photosynthetic dynamics between invasive and native species during light fluctuations.We compared photosynthetic induction,relaxation dynamics and leaf traits between the invasive species,Tithonia diversifolia and two native species,Clerodendrum bungei and Blumea balsamifera,in full-sun and shady habitats.The photosynthetic dynamics and leaf traits differed among species.T.diversifolia showed a slower induction speed and stomatal opening response but had higher average intrinsic water-use efficiency than the two native species in full-sun habitats.Thus,the slow induction response may be attributed to the longer stomatal length in T.diversifolia.Habitat had a significant effect on photosynthetic dynamics in T.diversifolia and B.balsamifera but not in C.bungei.In shady habitat,T.diversifolia had a faster photosynthetic induction response than in full-sun habitat,leading to a higher average stomatal conductance during photosynthetic induction in T.diversifolia than in the two native species.In contrast,B.balsamifera had a larger stomatal length and slower photosynthetic induction and relaxation response in shady habitat than in full-sun habitat,resulting in higher carbon gain during photosynthetic relaxation.Nevertheless,in both habitats,T.diversifolia had an overall higher carbon gain during light fluctuations than the two native species.Our results indicated that T.diversifolia can adopt more effective response strategies under fluctuating light environments to maximize carbon gain,which may contribute to its successful invasion. 展开更多
关键词 Invasive plant Photosynthetic induction Photosynthetic relaxation Carbon gain Stomatal traits Tithonia diversifolia
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Nonlinear Absorption and Low-threshold Two-photon Pumped Amplified Stimulated Emission from FAPbBr_(3) Nanocrystals
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作者 WANG Yajuan TAY Yong Kang Eugene +3 位作者 WANG Fang YU Sheng SUM Tze Chien LIU Wei 《发光学报》 EI CAS CSCD 北大核心 2024年第8期1281-1291,共11页
Formamidinium lead bromide(FAPbBr_(3))nanocrystals(NCs)have been considered to be a good optoelectronic material due to their pure green emission,excellent stability and superior carrier transport characteristics.Howe... Formamidinium lead bromide(FAPbBr_(3))nanocrystals(NCs)have been considered to be a good optoelectronic material due to their pure green emission,excellent stability and superior carrier transport characteristics.However,two-photon pumped amplified spontaneous emission(ASE)and the corresponding nonlinear optical properties of FAPbBr_(3) NCs are scarcely revealed.Herein,we synthesized colloidal FAPbBr_(3) NCs with different sizes by changing the molar ratio of FABr/PbBr_(2) in the precursor solution,using ligand assisted precipitation(LARP)technology at room temperature.Photoluminescence(PL)and time resolved photoluminescence(TRPL)spectroscopy were measured to characterize their ASE properties.And their nonlinear optical properties were studied through the Zscan technique and the two-photon excited fluorescence method.The stimulated emission properties including oneand two-photon pumped ASE have been realized from FAPbBr_(3) NCs.With large two-photon absorption coefficient(0.27 cm/GW)and high non-linear absorption cross-section(7.52×10^(5) GM),ASE with threshold as low as 9.8μJ/cm^(2) and 487μJ/cm^(2) have been obtained from colloidal FAPbBr_(3) NCs using one-and two-photon excitations.These results indicate that as a new possible green-emitting frequency-upconversion material with low thresholds,FAPbBr_(3) NCs hold great potential in the development of high-performance two-photon pump lasers. 展开更多
关键词 perovskites formamidinium lead bromide nanocrystals NONLINEAR optical gain amplified spontaneous emission
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A Stroke-Limitation AMD Control System with Variable Gain and Limited Area for High-Rise Buildings
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作者 Zuo-Hua Li Qing-Gui Wu +1 位作者 Jun Teng Chao-Jun Chen 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第1期865-884,共20页
Collisions between a moving mass and an anti-collision device increase structural responses and threaten structural safety.An active mass damper(AMD)with stroke limitations is often used to avoid collisions.However,a ... Collisions between a moving mass and an anti-collision device increase structural responses and threaten structural safety.An active mass damper(AMD)with stroke limitations is often used to avoid collisions.However,a strokelimited AMD control system with a fixed limited area shortens the available AMD stroke and leads to significant control power.To solve this problem,the design approach with variable gain and limited area(VGLA)is proposed in this study.First,the boundary of variable-limited areas is calculated based on the real-time status of the moving mass.The variable gain(VG)expression at the variable limited area is deduced by considering the saturation of AMD stroke.Then,numerical simulations of a stroke-limited AMD control system with VGLA are conducted on a high-rise building structure.These numerical simulations show that the proposed approach has superior strokelimitation performance compared with a stroke-limited AMD control system with a fixed limited area.Finally,the proposed approach is validated through experiments on a four-story steel frame. 展开更多
关键词 High-rise buildings active control stroke limitations variable gain variable limited area
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Topological laser on square lattice with gain–loss-induced higher-order corner modes
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作者 廖明杰 韦梅松 +2 位作者 王帅领 许静平 羊亚平 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第6期189-195,共7页
We investigate the higher-order topological laser in the two-dimensional(2D) coupled-cavity array. By adding staggered on-site gain and loss to the 2D Hermitian array with a trivial phase, the system will emerge degen... We investigate the higher-order topological laser in the two-dimensional(2D) coupled-cavity array. By adding staggered on-site gain and loss to the 2D Hermitian array with a trivial phase, the system will emerge degenerate topological corner modes, which are protected by bulk band gap. For such a non-Hermitian model, by adjusting the parameters of the system and introducing the pumping into the cavity at the corner, a single-mode lasing with topological protection emerges.Furthermore, single-mode lasing exists over a wide range of pumping strengths. No matter where the cavity is initially stimulated, after enough time evolution, all the cavities belonging to the topological corner mode can emit a stable laser. 展开更多
关键词 topological corner modes nonlinear saturated gain single-mode lasing
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Is Veillonella a unique marker of physical exercise?Commentary on:
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作者 Viktor Bielik Ivan Hric Riadh Hammami 《Journal of Sport and Health Science》 SCIE CAS CSCD 2024年第5期682-684,共3页
In 2020,Kostic1 published commentary on the bacterial genus Veillonella associated with the interaction between the intestinal microbiota and skeletal muscle.Since then,novel perspectives on the bidirectional gut-musc... In 2020,Kostic1 published commentary on the bacterial genus Veillonella associated with the interaction between the intestinal microbiota and skeletal muscle.Since then,novel perspectives on the bidirectional gut-muscle communication axis have gained a lot of attention.The purpose of this commentary is to explore some of the challenging issues presented in Scheiman et al. 展开更多
关键词 SKELETAL gained
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Cluster DetectionMethod of Endogenous Security Abnormal Attack Behavior in Air Traffic Control Network
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作者 Ruchun Jia Jianwei Zhang +2 位作者 Yi Lin Yunxiang Han Feike Yang 《Computers, Materials & Continua》 SCIE EI 2024年第5期2523-2546,共24页
In order to enhance the accuracy of Air Traffic Control(ATC)cybersecurity attack detection,in this paper,a new clustering detection method is designed for air traffic control network security attacks.The feature set f... In order to enhance the accuracy of Air Traffic Control(ATC)cybersecurity attack detection,in this paper,a new clustering detection method is designed for air traffic control network security attacks.The feature set for ATC cybersecurity attacks is constructed by setting the feature states,adding recursive features,and determining the feature criticality.The expected information gain and entropy of the feature data are computed to determine the information gain of the feature data and reduce the interference of similar feature data.An autoencoder is introduced into the AI(artificial intelligence)algorithm to encode and decode the characteristics of ATC network security attack behavior to reduce the dimensionality of the ATC network security attack behavior data.Based on the above processing,an unsupervised learning algorithm for clustering detection of ATC network security attacks is designed.First,determine the distance between the clustering clusters of ATC network security attack behavior characteristics,calculate the clustering threshold,and construct the initial clustering center.Then,the new average value of all feature objects in each cluster is recalculated as the new cluster center.Second,it traverses all objects in a cluster of ATC network security attack behavior feature data.Finally,the cluster detection of ATC network security attack behavior is completed by the computation of objective functions.The experiment took three groups of experimental attack behavior data sets as the test object,and took the detection rate,false detection rate and recall rate as the test indicators,and selected three similar methods for comparative test.The experimental results show that the detection rate of this method is about 98%,the false positive rate is below 1%,and the recall rate is above 97%.Research shows that this method can improve the detection performance of security attacks in air traffic control network. 展开更多
关键词 Air traffic control network security attack behavior cluster detection behavioral characteristics information gain cluster threshold automatic encoder
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Longitudinal changes in body weight of breastfeeding mothers in the first year after delivery and its relationship with human milk composition:a combined longitudinal and cross-sectional cohort study
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作者 Huijuan Ruan Yajie Zhang +6 位作者 Qingya Tang Xuan Zhao Xuelin Zhao Yi Xiang Wei Geng Yi Feng Wei Cai 《Food Science and Human Wellness》 SCIE CSCD 2024年第1期254-264,共11页
Objective:Postpartum weight retention(PPWR)is a common problem among women after childbirth.The main objectives of this study are to understand the changes in body weight of breastfeeding mothers during long-term foll... Objective:Postpartum weight retention(PPWR)is a common problem among women after childbirth.The main objectives of this study are to understand the changes in body weight of breastfeeding mothers during long-term follow-up and preliminarily explore the relationship between maternal body weight and human milk composition,including macronutrients,leptin,and adiponectin.Methods:The study included a longitudinal cohort(122 mothers),and a cross-sectional cohort(37 mothers).The human milk,maternal weight,and dietary surveys were collected in the longitudinal cohort at different follow-up time points(1-14 days postpartum,2-4 months postpartum,5-7 months postpartum,and 12-17 months postpartum).The maternal body weight was analyzed using the responses in the survey questionnaires.A milk analyzer based on the mid-infrared spectroscopy(MIRS)was used to determine milk composition,and nutrition analysis software evaluated dietary intakes.In the cross-sectional cohort,participating mothers were asked to provide blood and human milk samples and pertinent information related to maternal body composition.Maternal body composition was measured by bioelectrical impedance analysis(BIA),while ELISA analyzed leptin and adiponectin in milk and serum.Results:At 5-7 months postpartum,the PPWR of breastfeeding mothers was(2.46±3.59)kg.At 12-17 months postpartum,the PPWR was(0.98±4.06)kg.PPWR was found to be negatively correlated with milk fat content within 14 days postpartum and positively correlated at 2-4 months postpartum.In addition,the maternal weight and body muscle mass were positively correlated with leptin and adiponectin in milk.Plasma leptin was positively correlated with the mother’s body weight,body mass index(BMI),FAT percentage,and body fat mass,while plasma adiponectin did not correlate with any parameter.The results also indicate that the PPWR did not correlate with leptin and adiponectin in plasma or milk.Conclusions:Breastfeeding mothers may retain considerable weight gain one year after delivery.Human milk composition may be related to changes in maternal body weight.Leptin and adiponectin in breast milk and leptin in plasma are associated with the maternal body composition.This study supports the notion that maternal nutritional status may affect offspring health through lactation,and future research should focus on exploring weight management of postpartum mothers. 展开更多
关键词 Human milk Milk composition Body weight Body mass index(BMI) Weight gain Postpartum weight retention
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Design of a Metasurface Antenna Based on Characteristic Mode Theory
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作者 HE Huan 《电讯技术》 北大核心 2024年第10期1561-1568,共8页
A novel metasurface antenna consisting of 5×5 rectangular patch elements is presented.Thestructure with and without the central element are both analyzed by the Characteristic Mode Theory(CMT).The developed mutua... A novel metasurface antenna consisting of 5×5 rectangular patch elements is presented.Thestructure with and without the central element are both analyzed by the Characteristic Mode Theory(CMT).The developed mutually orthogonal principal modes of the optimized periodic patch structure areexcited by a center-feed dipole.A differential feeding network is employed to realize impedance matching.Prototype with profile height of 0.07λ_(0)(λ_(0)is the wavelength in free space at the lowest operatingfrequency)is fabricated and assembled to verify the simulation results.The measured results show that thereflectance coefficient of proposed matesurface antenna is less than-10 dB in the whole operating bandrange from 4.2 GHz to 5.5 GHz,a relative bandwidth of 26.8%is achieved,and the maximummeasured realized gain is more than 9 dBi with a maximum radiation efficiency of 90%.The designprovides a guideline on the application of characteristic modes(CMs)to radiation problems. 展开更多
关键词 metasurface antenna characteristic mode theory dipole antenna realized gain
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Call for Papers:Special issue“African Swine Fever”
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《Animal Diseases》 CAS 2024年第3期F0002-F0002,共1页
African swine fever(ASF)is one of the most devastating diseasesin pigs and is caused by the ASF virus(ASFV).Since its firstdiscovery in 1921 in Kenya,ASFV has spread from Africa to otherparts of the world,causing seve... African swine fever(ASF)is one of the most devastating diseasesin pigs and is caused by the ASF virus(ASFV).Since its firstdiscovery in 1921 in Kenya,ASFV has spread from Africa to otherparts of the world,causing severe economic losses to the porkindustry.Scientists have studied ASF for over 100 years,and manygovernments have tried to eradicate the disease.Nonetheless,approaches to effectively control ASF are still lacking.In recent years,ASF outbreaks have been reported in China,Belgium,Germany,Italyand many other Asian and European countries.Studies on this diseasehave gained new popularity.Under this background,we are organizingthe special issue“African swine fever”to collect the most recentknowledgeon this disease. 展开更多
关键词 SWINE SWINE gained
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ANovel Non-Isolated Cubic DC-DC Converter with High Voltage Gain for Renewable Energy Power Generation System
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作者 Qin Yao Yida Zeng Qingui Jia 《Energy Engineering》 EI 2024年第1期221-241,共21页
In recent years,switched inductor(SL)technology,switched capacitor(SC)technology,and switched inductor-capacitor(SL-SC)technology have been widely applied to optimize and improve DC-DC boost converters,which can effec... In recent years,switched inductor(SL)technology,switched capacitor(SC)technology,and switched inductor-capacitor(SL-SC)technology have been widely applied to optimize and improve DC-DC boost converters,which can effectively enhance voltage gain and reduce device stress.To address the issue of low output voltage in current renewable energy power generation systems,this study proposes a novel non-isolated cubic high-gain DC-DC converter based on the traditional quadratic DC-DC boost converter by incorporating a SC and a SL-SC unit.Firstly,the proposed converter’s details are elaborated,including its topology structure,operating mode,voltage gain,device stress,and power loss.Subsequently,a comparative analysis is conducted on the voltage gain and device stress between the proposed converter and other high-gain converters.Then,a closed-loop simulation system is constructed to obtain simulation waveforms of various devices and explore the dynamic performance.Finally,an experimental prototype is built,experimental waveforms are obtained,and the experimental dynamic performance and conversion efficiency are analyzed.The theoretical analysis’s correctness is verified through simulation and experimental results.The proposed converter has advantages such as high voltage gain,low device stress,high conversion efficiency,simple control,and wide input voltage range,achieving a good balance between voltage gain,device stress,and power loss.The proposed converter is well-suited for renewable energy systems and holds theoretical significance and practical value in renewable energy applications.It provides an effective solution to the issue of low output voltage in renewable energy power generation systems. 展开更多
关键词 Cubic DC-DC converter high voltage gain low device stress high efficiency renewable energy
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Experimental Study on Improving Performance and Productivity of Pyramid Solar StillUsing Rotation Technique
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作者 Ali Abdullah Abbas Baiee Sasan Asiaei Sayed Mostafa Hosseinalipour 《Frontiers in Heat and Mass Transfer》 EI 2024年第3期955-976,共22页
Globally,potable water scarcity is pervasive problem.The solar distillation device is a straightforward apparatus that has been purposefully engineered to convert non-potable water into potable water.The experimental ... Globally,potable water scarcity is pervasive problem.The solar distillation device is a straightforward apparatus that has been purposefully engineered to convert non-potable water into potable water.The experimental study is distinctive due to the implementation of a rotational mechanism within the pyramidal solar still(PSS),which serves to enhance the evaporation and condensation processes.The objective of this research study is to examine the impact of integrating rotational motion into pyramidal solar stills on various processes:water distillation,evaporation,condensation,heat transfer,and energy waste reduction,shadow effects,and low water temperature in saline environments.Ultimately,the study aims to enhance the production of distilled water.An economic evaluation was undertaken in order to ascertain the extent of cost reduction.Experiments measuring freshwater productivity and thermal performance were conducted over a three-month period at the University of Science and Technology in Tehran.The entire pyramid structure was rotated using a direct current motor driven by a photovoltaic cell.The research methodology entailed the operation of a PSS with varying rotational speeds(0.125,0.25,1,and 1.5 rpm)and without rotation,from 9 am to 4 pm.The findings suggested that the productivity of the distillation apparatus in terms of distilled water increased as the rotation speed rose,with the most pronounced increase occurring at 1 rpm in comparison to the other conditions.The presence of turbulence in the water enhanced the heat transfer occurring between the absorber plate and thewater.At 2:00 p.m.on an experimental day,this effect was observed when the absorber plate temperature reached 79.1°C at 1.5 rpm.In contrast,its temperature decreased to 78°C when not in a state of rotation,as the intensity of solar radiation was higher in the non-rotation state.At 1 rpm,the solar pyramid distiller achieved a 30.2%increase in output compared to its non-rotating state.At 1 rpm,the distiller achieved a 20.6%increase in output compared to 0.25 revolutions per minute.In addition to the control condition,the thermal efficiency of the solar still varied as follows:at 1,1.5,0.25,and 0.125 rpm,it was 46.2%;at 44.2%,37.8%;at 35.3%;and at 36.6%,respectively.Furthermore,distilled water generated by a pyramid solar still with rotation(PSSR)is priced at$0.03 per liter,whereas it costs$0.0317 per liter when produced by a pyramid solar still without rotation(PSS without R). 展开更多
关键词 Pyramidal solar still ROTATION solar radiation gain evaporation CONDENSATION PRODUCTIVITY thermal efficiency
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