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基于YOLOv5s的轻量化架空输电线路鸟巢检测网络
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作者 徐业东 蔡亚恒 +2 位作者 李严 刘学雷 曹英丽 《电子测量技术》 北大核心 2024年第7期138-148,共11页
架空输电线路上的鸟巢侵占会对铁塔上的电力设备造成安全隐患,间接可能影响整个电力系统的稳定运行。针对目前架空输电线路鸟巢检测模型在复杂场景以及小目标场景下检测精度不高,检测效率低,模型复杂等问题。本研究提出一种基于YOLOv5s... 架空输电线路上的鸟巢侵占会对铁塔上的电力设备造成安全隐患,间接可能影响整个电力系统的稳定运行。针对目前架空输电线路鸟巢检测模型在复杂场景以及小目标场景下检测精度不高,检测效率低,模型复杂等问题。本研究提出一种基于YOLOv5s框架的轻量化架空输电线路鸟巢检测网络。首先在主干部分采用Fasternet重构YOLOv5s特征提取网络,降低模型复杂度,提高运行速度;然后在特征融合网络部分嵌入ConvMixer层,ConvMixer层的结构设计有助于在特征信息中更好的捕捉空间和通道的关系,提升模型对于小目标的检测能力;最后在特征融合网络部分引入ODConv模块,令送入检测头的特征图包含更多有效特征,提高模型对复杂场景和小目标的检测性能。实验结果表明,本文与基线模型YOLOv5s相比,计算量和模型体积分别减少了86%和72%,平均精度均值达到96.4%,检测速度达到104.2帧/s,验证了本文改进模型的有效性和可行性。 展开更多
关键词 轻量化 架空输电线路 YOLOv5s 鸟巢 目标检测
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The “Dead Universe” Theory: Natural Separation of Galaxies Driven by the Remnants of a Supermassive Dead Universe
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作者 Joel Almeida 《Natural Science》 2024年第6期65-101,共37页
This article explores the dead universe theory as a novel interpretation for the origin and evolution of the universe, suggesting that our cosmos may have originated from the remnants of a preceding universe. This per... This article explores the dead universe theory as a novel interpretation for the origin and evolution of the universe, suggesting that our cosmos may have originated from the remnants of a preceding universe. This perspective challenges the conventional Big Bang theory, particularly concerning dark matter, the expansion of the universe, and the interpretation of phenomena such as gravitational waves. 展开更多
关键词 Dead Universe Theory Heat Death of the Universe Big Bang Theory Universe’s Ultimate fate Universe Expansion Big Freeze Universe Cosmological Models End of Universe Theories Natural Galaxy Drift Future of the Universe Universe Cooling Down Cosmology and Entropy
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Association of <i>Ammodramus bairdii</i>A. 1844, and Other Species of Grassland Granivorous Birds in Winter Time in Northwestern Mexico 被引量:1
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作者 Jose Hugo Martinez-Guerrero Martin Emilio Pereda-Solis Christian Wehenkel 《Open Journal of Ecology》 2014年第5期281-288,共8页
During the winter of 2009 grassland birds were monitored in the region of Cuchillas de la Zarca to estimate the association betweenAmmodramus bairdiiAudubon 1844, focal species of grassland and bird species belonging ... During the winter of 2009 grassland birds were monitored in the region of Cuchillas de la Zarca to estimate the association betweenAmmodramus bairdiiAudubon 1844, focal species of grassland and bird species belonging to the trophic guild of grassland granivorous birds (n = 25 ). The study area was divided into monitoring quadrants (n = 16) where 96 transects for bird monitoring were conducted, recording 16,635 individuals of which only 32.9% were in the trophic guild of grassland granivorous birds. The association betweenA. bairdiiand other species was estimated from the nonparametric statistical index of Kendall’s coefficient of concordance (W) and the p value, through permutation analysis (n = 10,000), finding positive and significant associations (p≤0.05) of the target species for study withSturnella magna,Passerculus sandwichensisandAmmodramus savannarum, species that share habitat preferences of natural grassland in good condition, slightly grazed and with little tolerance to the shrub cover. The association W ranged from 0.072 and 0.749. These results can recognize this region as an important area for the conservation of obligate grassland birds during winter, suggesting establish training programs to better utilize this resource by means of cattle activity. 展开更多
关键词 GRAssLAND birds Kendall Coefficient Baird’s sPARROW WINTER Monitoring
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An Analysis of Pecola's Tragic Fate in The Bluest Eye
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作者 周叶函 《海外英语》 2012年第14期200-201,共2页
In The Bluest Eye,the author narrates a little black girl's strong desire to have blue eyes.At last,Pecola imagines possessing blue eyes at the cost of going insane.This paper mainly argues that it is the family&#... In The Bluest Eye,the author narrates a little black girl's strong desire to have blue eyes.At last,Pecola imagines possessing blue eyes at the cost of going insane.This paper mainly argues that it is the family's influence,the internalized racism and the whites'powerful and dominant culture that leads to Pecola's tragic fate. 展开更多
关键词 Pecola’s TRAGIC fate family’s INFLUENCE internaliz
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立足教材基础 培养学生能力——三年级下册Unit 4 Where’s the bird? (Story time)教学设计
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作者 唐莉 《小学教学研究(理论版)》 2016年第5期71-72,共2页
【教材简解】本单元的核心教学内容是"询问物品的位置"。要求学生在一定情景下能正确使用核心句型Where’s...?It’s....进行交谈。Story time共有七个场景,主要描述小鸟停在教室里的不同位置。在对话中出现了本单元的重点句... 【教材简解】本单元的核心教学内容是"询问物品的位置"。要求学生在一定情景下能正确使用核心句型Where’s...?It’s....进行交谈。Story time共有七个场景,主要描述小鸟停在教室里的不同位置。在对话中出现了本单元的重点句型,即询问及回答地点。教学应与日常生活联系起来,培养学生的主动性思维和与人交流的能力。【目标预设】1.能初步感知新的语言知识:(1)单词:a bird,a desk,a chair,in,on,under。 展开更多
关键词 初步感知 sTORY time UNIT 4 Where s the bird CHAIR 语言知识 单元的 behind CLAssROOM 整体感知
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Enzymatic recovery of glycopeptides from different industrial grades edible bird’s nest and its by-products:nutrient,probiotic and antioxidant activities,and physicochemical characteristics
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作者 Hidayati Syamimi Mohd Noor Rafi dah Mohd Ariff +5 位作者 Lee Sin Chang Xin Yi Chai Hui Yan Tan Nur’Aliah Daud Abdul Salam Babji Seng Joe Lim 《Food Science and Human Wellness》 SCIE 2022年第6期1555-1564,共10页
This study was conducted to recover edible bird’s nest(EBN)hydrolysates from different grades of EBN,including the industrial by-products,using enzymatic treatment.The nutrient,physicochemical properties and antioxid... This study was conducted to recover edible bird’s nest(EBN)hydrolysates from different grades of EBN,including the industrial by-products,using enzymatic treatment.The nutrient,physicochemical properties and antioxidant activities of the recovered hydrolysates at different hydrolysis times were evaluated.Results showed that the recovery yield of enzymatic hydrolysis was above 89%for all grades of EBN and the degree of hydrolysis increased over time.Nitrite content(0.321-0.433 mg/L)was below the permissible tolerance level for all samples.Interestingly,the antioxidant activities(DPPH and ABTS scavenging activities and ferric reducing antioxidant powder(FRAP)activity)were significantly higher(P≤0.05)in hydrolysates recovered from EBN by-products(EBNhC and EBNhD)as compared to the high grade EBN hydrolysates(EBNhA and EBNhB).The in-vitro probiotic activity of EBN and its hydrolysates were examined using the probiotic bacterium Lactobacillus plantarum.Evidently,EBN by-products hydrolysate(EBNhD)recorded the highest number of L.plantarum(1.1×1011 CFU/mL),indicating that low grade EBN has the potential as prebiotic material that promotes probiotic activity.This study demonstrated the concept of using EBN by-products hydrolysates for various applications,such as functional ingredients with enhanced bioactivities,to improve its economic value. 展开更多
关键词 Edible bird’s nest by-products Enzymatic hydrolysis GLYCOPEPTIDEs Lactobacillus plantarum Probiotic activity
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True cicadas (Cicadidae) as prey for the birds of the Western Palearctic: a review
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作者 Pere Pons 《Avian Research》 CSCD 2020年第2期174-182,共9页
Background:True cicadas(Cicadidae)are large and temporarily abundant insects.Their availability may produce demographic and behavioural effects on bird populations,as happens with forest avifauna feeding on periodical... Background:True cicadas(Cicadidae)are large and temporarily abundant insects.Their availability may produce demographic and behavioural effects on bird populations,as happens with forest avifauna feeding on periodical cicadas in North America.In Europe,the Near East and North Africa,knowledge of cicada predation by birds is sparse.Methods:To help fill this gap,I consulted Cramp’s Birds of the Western Palearctic,conducted a search of online databases and used search engines to generate a database of Western Palearctic birds known to eat cicadas.Results:A total of 105 species(16%of those occurring in the region)belonging to 13 orders,and comprising 20 of the 33 passerine families,were found to consume cicadas.I estimated that 69 of these bird species are known to consume cicadas within the limits of the Western Palearctic.Many terrestrial birds predate on cicadas,preferably on adults.Avian predators include cuckoos,owls,bee-eaters,woodpeckers,falcons,reed-warblers,larks,crows and jays,buntings,shrikes,pipits and wagtails,flycatchers and chats,tits,sparrows,leaf-warblers,starlings,warblers and thrushes,but also terns and gulls.Nymphs are consumed by some passerines,owls and herons.Cicadas can make up as much as 70%of food items delivered to nestlings.Analysis of stomach contents and neck collar samples are the most common methods used in diet studies.Conclusions:Available knowledge is biased towards species that have been more intensively studied,and often lack proper quantification of prey items.More studies about the relative importance of cicadas as prey for birds in the Western Palearctic are needed.I suggest using non-invasive studies based on pellets and droppings and prioritizing declining bird species. 展开更多
关键词 bird species CICADIDAE Cramp’s handbook Diet studies Predator-prey relationships
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A Survey of Wild Birds Trading in the Beijing Bird Markets
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作者 Xiaoqi Cheng 《Proceedings of Business and Economic Studies》 2019年第6期41-46,共6页
Birds are an indispensable part of nature andthey play an important role in maintaining an ecologicalbalance. The existence of bird markets undoubtedlyposes a threat to the population of wild birds. Thegeographical lo... Birds are an indispensable part of nature andthey play an important role in maintaining an ecologicalbalance. The existence of bird markets undoubtedlyposes a threat to the population of wild birds. Thegeographical location of Beijing is paramount to themigratory birds. The species of birds are rich in varietyand its quantity is large in scale. In addition, the birdmarket in old town Beijing has a long history - since theQing Dynasty, it has been the main bird market in thecity. Therefore, a survey of the major bird markets inthe city is highly representative. This study investigatedthe types, quantities, and prices of wild birds tradedin several major bird markets in Beijing from July16 to July 18, 2019. Data analysis and collation werealso conducted in this study. The results of the surveypresented 26 kinds of wild birds, with a total tradingvolume of an estimated 253. They are mainly birdsof the order of the passerine, 18 of which are underBeijing’s second-class protection, and one of them isunder first-class protection. 展开更多
关键词 BEIJING bird’s Market Wild birds bird Trade sURVEY
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EU's Fate after the French Election
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作者 Wu Xingtang Yang Le 《International Understanding》 2017年第2期11-15,共5页
In the second round of French presidential election,39-year-old Emmanuel Macron defeated the far-right candidate Marine Le Pen and was elected President of France.This is a historic victory to France and all EU countr... In the second round of French presidential election,39-year-old Emmanuel Macron defeated the far-right candidate Marine Le Pen and was elected President of France.This is a historic victory to France and all EU countries. 展开更多
关键词 EU’s fate after the French Election as into been of for Is
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Nation's Fate and Its Founding Principles
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作者 Mei Renyi 《Contemporary International Relations》 2004年第3期51-56,共6页
关键词 Nation’s fate and Its Founding Principles
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Cooking Class:Eight-Treasure Bird's Nest
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《China Today》 2000年第12期62-62,共1页
关键词 Cooking Class:Eight-Treasure bird’s Nest
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Effect of Six Different Acoustic Frequencies on Growth of Cowpea(Vigna unguiculata)during Its Seedling Stage 被引量:4
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作者 黄俊 姜仕仁 《Agricultural Science & Technology》 CAS 2011年第6期847-851,共5页
[Objective] The aim was to study the effects of sound waves with different types and frequency characteristics on the growth of cowpea(Vigna unguiculata)during seedling stage.[Method] The insect-music mixed sound(M... [Objective] The aim was to study the effects of sound waves with different types and frequency characteristics on the growth of cowpea(Vigna unguiculata)during seedling stage.[Method] The insect-music mixed sound(MI),cuckoo acoustic song,cricket acoustic song,single 400 Hz frequency sound wave,F5 and Fn sound waves composed of different frequencies were designed to investigate their effects on height and weight of cowpea seedling,and experimental data were statistically analyzed and multiple-compared by EXCEL.[Result] After treatment by sound waves with six different types and frequencies,the growth situations of cowpea were better than that in control.This indicated that sound waves could significantly promote height growth of plant.The treatments with good growth-promotion effect included 400 Hz frequency sound wave,cuckoo acoustic song and cricket acoustic song,followed by MI,Fn and F5.Cuckoo and cricket acoustic song treatment could promote the weight of cowpea seedling during seedling stage.[Conclusion] Sound waves with different types and frequency characteristics had significant growth-promotion effect on growth of cowpea during seedling stage,but their effects were different. 展开更多
关键词 COWPEA Acoustic frequency Music birds song Insect's sound
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天津区域鸟类活动的双偏振天气雷达回波分析
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作者 赵子杭 庄庭 +4 位作者 李建勇 李春 李宗飞 许崇海 史静 《气象》 CSCD 北大核心 2024年第9期1142-1152,共11页
利用2022年6月至2023年3月的宝坻S波段双偏振天气雷达资料,对探测到的天津区域空中生物活动进行分析,结果表明:天津区域空中生物活动存在明显的季节变化和日变化。雷达能够探测到的候鸟迁徙回波集中在2月下旬到11月下旬,其中湿地鸟类活... 利用2022年6月至2023年3月的宝坻S波段双偏振天气雷达资料,对探测到的天津区域空中生物活动进行分析,结果表明:天津区域空中生物活动存在明显的季节变化和日变化。雷达能够探测到的候鸟迁徙回波集中在2月下旬到11月下旬,其中湿地鸟类活动在夏季比较明显,候鸟迁徙活动在2月、11月特别频繁,鸟类回波出现的时刻与日出日落有明显的关联。其中,秋季鸟类活动特征较为明显,回波在反射率产品上呈现明显的类圆形特征,回波强度能达到35 dBz以上;从径向速度产品上可以看出,鸟类飞行时径向速度约在10~27 m·s^(-1);从相关系数(CC)产品上看,鸟类回波的CC整体数值较低,主要分布在0.1~0.8;从差分反射率(ZDR)产品上看,ZDR分布不均匀,最大可达3~5 dB。相比于单偏振天气雷达,S波段双偏振天气雷达对空中生物回波的识别有显著优势。 展开更多
关键词 s波段双偏振天气雷达 鸟类回波 回波强度 相关系数 差分反射率
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烯效唑(S-3307)对油菜幼苗抗寒性的生理效应 被引量:7
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作者 杨建新 胡义文 杨大旗 《西南农业大学学报(自然科学版)》 CSCD 1994年第3期256-258,共3页
用0.05μg/ml烯效唑(S-3307)浸油菜种子,能阻止其幼苗4℃,36h低温胁迫下的细胞膜电解质渗漏,提高SOD,CAT活性和游离脯氨酸、可溶性蛋白质以及Vc含量,降低MDA含量和减缓低温对幼苗叶绿素的破坏。
关键词 油菜 抗冻性 烯效唑 效应
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基于旋转LED的Flappy bird游戏设计
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作者 罗鹏 《科学技术创新》 2017年第22期118-119,共2页
利用单片机和旋转LED,设计了Flappy bird游戏。通过红外遥控器,可以控制小鸟的移动,从而完成游戏的操作。该设计具有硬件简单,显示直观,操作方便的优点。
关键词 AT89s52 旋转LED 红外遥控 Flappy bird游戏
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sms10h全自动配光测试系统在前照灯配光中的应用
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作者 何浩 晋蕾 何志军 《汽车零部件》 2013年第4期61-64,70,共5页
介绍sms10h全自动配光测试系统的结构及工作原理,采用该系统对某车型左右前照灯总成进行配光,并利用其附带的GRID扫描及分析功能,对前照灯光形进行扫描分析,模拟了实车夜间使用效果。路面试验评价结果表明,sms10h全自动配光测试系统软... 介绍sms10h全自动配光测试系统的结构及工作原理,采用该系统对某车型左右前照灯总成进行配光,并利用其附带的GRID扫描及分析功能,对前照灯光形进行扫描分析,模拟了实车夜间使用效果。路面试验评价结果表明,sms10h全自动配光测试系统软件模拟出的图形效果与实车路面测量效果基本一致。 展开更多
关键词 前照灯 配光 鸟瞰图 可见度评价
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Small objects detection in UAV aerial images based on improved Faster R-CNN 被引量:6
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作者 WANG Ji-wu LUO Hai-bao +1 位作者 YU Peng-fei LI Chen-yang 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2020年第1期11-16,共6页
In order to solve the problem of small objects detection in unmanned aerial vehicle(UAV)aerial images with complex background,a general detection method for multi-scale small objects based on Faster region-based convo... In order to solve the problem of small objects detection in unmanned aerial vehicle(UAV)aerial images with complex background,a general detection method for multi-scale small objects based on Faster region-based convolutional neural network(Faster R-CNN)is proposed.The bird’s nest on the high-voltage tower is taken as the research object.Firstly,we use the improved convolutional neural network ResNet101 to extract object features,and then use multi-scale sliding windows to obtain the object region proposals on the convolution feature maps with different resolutions.Finally,a deconvolution operation is added to further enhance the selected feature map with higher resolution,and then it taken as a feature mapping layer of the region proposals passing to the object detection sub-network.The detection results of the bird’s nest in UAV aerial images show that the proposed method can precisely detect small objects in aerial images. 展开更多
关键词 Faster region-based convolutional neural network(Faster R-CNN) ResNet101 unmanned aerial vehicle(UAV) small objects detection bird’s nest
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The foundation of the theory of the universe dark energy and its nature
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作者 Murad Shibli 《Natural Science》 2011年第3期165-185,共21页
Surprisingly recent astronomical observations have provided strong evidence that our universe is not only expanding, but also is expanding at an accelerating rate. This paper pre- sents a basis of the theory of univer... Surprisingly recent astronomical observations have provided strong evidence that our universe is not only expanding, but also is expanding at an accelerating rate. This paper pre- sents a basis of the theory of universe space- time dark energy, a solution of Einstein’s cosmological constant problem, physical interpretation of universe dark energy and Einstein’s cosmological constant Lambda and its value ( = 0.29447 × 10-52 m-2), values of universe dark energy density 1.2622 × 10-26 kg/m3 = 6.8023 GeV, universe critical density 1.8069 × 10-26 kg/m3 = 9.7378 GeV, universe matter density 0.54207 × 10-26 kg/m3 = 2.9213 GeV, and universe radiation density 2.7103 × 10-31 kg/m3 = 1.455 MeV. The interpretation in this paper is based on geometric modeling of space-time as a perfect four- dimensional continuum cosmic fluid and the momentum generated by the time. In this modeling time is considered as a mechanical variable along with other variables and treated on an equal footing. In such a modeling, time is considered to have a mechanical nature so that the momentum associated with it is equal to the negative of the universe total energy. Since the momentum associated with the time as a mechanical variable is equal to the negative system total energy, the coupling in the time and its momentum leads to maximum increase in the space-time field with 70.7% of the total energy. Moreover, a null paraboloid is obtained and interpreted as a function of the momentum generated by time. This paper presents also an interpretation of space-time tri-dipoles, gravity field waves, and gravity carriers (the gravitons). This model suggests that the space-time has a polarity and is composed of dipoles which are responsible for forming the orbits and storing the space-time energy-momentum. The tri-di- poles can be unified into a solo space-time dipole with an angle of 45 degrees. Such a result shows that the space-time is not void, on the contrary, it is full of conserved and dynamic energy-momentum structure. Furthermore, the gravity field waves is modeled and assumed to be carried by the gravitons which move in the speed of light. The equivalent mass of the graviton (rest mass) is found to be equal to 0.707 of the equivalent mass of the light photons. Such a result indicates that the lightest particle (up to the author’s knowledge) in the nature is the graviton and has an equivalent mass equals to 2.5119 x 10-52 kg. Based on the fluidic nature of dark energy, a fourth law of thermodynamics is proposed and a new physical interpretation of Kepler’s Laws are presented. Additionally, based on the fact that what we are observing is just the history of our universe, on the Big Bang Theory, Einstein’s General Relativity, Hubble Parameter, cosmic inflation theory and on NASA’s observation of supernova 1a, then a second-order (parabolic) parametric model is obtained in this proposed paper to describe the accelerated ex- pansion of the universe. This model shows that the universe is approaching the universe cosmic horizon line and will pass through a critical point that will influence significantly its fate. Considering the breaking symmetry model and the variational principle of mechanics, then the universe will witness an infinitesimally stationary state and a symmetry breaking. As result of that, our universe will experience in the near future, a very massive impulse force in the order 1083 N. Subsequently, the universe will collapse. Finally, simulation results are demonstrated to verify the analytical results. 展开更多
关键词 DARK ENERGY NATURE of DARK ENERGY Expansion of The UNIVERsE Einstein’s Cosmological Constant UNIVERsE Mass/Energy Densities space-Time DIPOLEs GRAVITONs Fourth Law of Thermodynamics fate of the UNIVERsE Kelper’s Laws
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Cyathus tenuicorticalis(Agaricales,Basidiomycota),a new species from La Selva Biological Station,Costa Rica
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作者 Góis JS Cruz RHSF +1 位作者 Ovrebo CL Baseia IG 《Studies in Fungi》 2018年第1期256-263,共8页
Cyathus tenuicorticalis was found growing on decaying wood from La Selva Biological Station,Costa Rica.Specimens were analyzed using the methodology proposed for the group and specific literature for the genus.The fun... Cyathus tenuicorticalis was found growing on decaying wood from La Selva Biological Station,Costa Rica.Specimens were analyzed using the methodology proposed for the group and specific literature for the genus.The fundamental diagnostic features for this new species are the very thin double-layered cortex in peridioles,exoperidium strongly hirsute,and a platinum bright endoperidium.Description,discussion and photographs of this new species are provided. 展开更多
关键词 Biodiversity bird’s nest fungi Gasteriod fungi Nidulariaceae Taxonomy
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基于DSP的无线伺服清除鸟巢装置
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作者 戴钦来 王宇 +1 位作者 周洪刚 沈庆赟 《电工技术》 2019年第9期68-69,72,共3页
针对变电站电气设备鸟巢清除需停电登高作业的问题,设计出一种基于DSP的无线伺服装置,可在电气设备带电情况下实施鸟巢清除作业。该装置可带电作业,避免了停电造成的负荷损失和非计划停运。
关键词 伺服驱动 鸟巢清除 无线
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