期刊文献+
共找到7,242篇文章
< 1 2 250 >
每页显示 20 50 100
Implementation of a Nesting Repair Technology for Transportation Pipeline Repair
1
作者 Yijun Gao Yong Wang +2 位作者 Qing Na Jiawei Zhang Aixiang Wu 《Fluid Dynamics & Materials Processing》 EI 2024年第11期2443-2458,共16页
Filling methods in the mining industry can maximize the recovery of mineral resources and protect the underground and surface environments.In recent years,such methods have been widely used in metal mines where pipeli... Filling methods in the mining industry can maximize the recovery of mineral resources and protect the underground and surface environments.In recent years,such methods have been widely used in metal mines where pipeline transportation typically plays a decisive role in the safety and stability of the entirefilling system.Because thefilling slurry contains a large percentage of solid coarse particles,the involved pipeline is typically eroded and often damaged during such a process.A possible solution is the so-called nesting repair technology.In the present study,nesting a 127 mm outer diameter pipeline in 151 mm inner diameter borehole is considered to meet the repair objective.First,by using the rheological theory,the pipeline transmission resistance and self-flow conveying range are calculated under different working conditions.It is shown that the pipeline transmission resistance is larger when the inner diameter of casing is 80 mm,and the limitflow rate of vertical pipeline self-flow is 120 m^(3)/h;moreover,when the pipeline diameter is 100 mm and theflow rate is 140 m^(3)/h,the self-flow conveying can be satisfied in most of the underground−455 m stage.Accordingly,a plan is presented for the nesting repair strategy,based on the installation of a drill bit under the casing and lowering the casing into the borehole as if it were a drill pipe.Finally,the outcomes of such a strategy are verified.Thefillingflow rate range using the new pipelines is found to be in the range from 188.60 to 224.39 m^(3)/h,and its averagefillingflow rate reaches 209.83 m^(3)/h when conveying 2319.6 m long-distance quarry. 展开更多
关键词 BOREHOLE nesting repair pipeline transmission resistance flow rate
下载PDF
Kentish Plover(Charadrius alexandrinus) and Little Tern(Sternula albifrons) prefer shells for nesting:A field experiment
2
作者 Macarena Castro Andrés De la Cruz +1 位作者 Nuria Martin-Sanjuan Alejandro Pérez-Hurtado 《Avian Research》 SCIE CSCD 2024年第1期55-59,共5页
Shorebird populations are declining worldwide,mainly due to human disturbances and loss of coastal wetlands.However,supratidal habitats as saltpans could play a role in buffering human impact.Saltpans have shown to be... Shorebird populations are declining worldwide,mainly due to human disturbances and loss of coastal wetlands.However,supratidal habitats as saltpans could play a role in buffering human impact.Saltpans have shown to be important as feeding or breeding sites of some shorebird species.A potential conservation strategy to increase shorebird populations in saltpans is to manipulate the cues that birds use to select optimal breeding habitat.Here it is hypothesized that shorebirds are attracted to bivalve shells due to the advantages they offer.Following this hypothesis,we supplemented a restored saltpan in 2019 and 2021 with bivalve shells,expecting an increase in the number of breeding birds’ nests.More than 75% of Kentish Plover(Charadrius alexandrinus) and Little Tern(Sternula albifrons) nests were found in patches with shells in both years.The best model for both species indicates that the presence of shells is the factor that most correlates with the location of nests.The probability of choosing one place over another to settle their nest increases in areas with an abundance of shells,double in the case of the Kentish Plover and triple in the case of the Little Tern.The result of this study may constitute a valuable tool for attracting birds to restored saltpans and could contribute to the success of expensive restoration projects where time is usually a constraint. 展开更多
关键词 Habitat management nest site selection Saltpan restoration Shell supplementation SHOREBIRDS
下载PDF
Seasonal increase in nest defense,but not egg rejection,in a cuckoo host 被引量:1
3
作者 Bo Zhou Wei Liang 《Avian Research》 SCIE CSCD 2024年第1期50-54,共5页
The interactions between avian brood parasites and their hosts provide an informative and easy-to-handle system for studying coevolution.Avian brood parasitism reduces the reproductive success of hosts,and thus,hosts ... The interactions between avian brood parasites and their hosts provide an informative and easy-to-handle system for studying coevolution.Avian brood parasitism reduces the reproductive success of hosts,and thus,hosts have evolved anti-parasitic strategies,such as rejecting parasitic eggs and adopting aggressive nest defense strategies,to avoid the cost brought on by brood parasitism.To test whether host anti-parasitic strategies are adjusted with the risk of being parasitized when the breeding seasons of brood parasites and hosts are not synchronous,we conducted a field experiment assessing nest defense and egg recognition behaviors of the Isabelline Shrike(Lanius isabellinus),a host of the Common Cuckoo(Cuculus canorus).In the local area,the host Isabelline Shrike begins to breed in April,whereas the summer migratory Common Cuckoo migrates to the local area in May and begins to lay parasitic eggs.Results showed that nest defense behaviors of the Isabelline Shrike increases significantly after cuckoo arrival,showing higher aggressiveness to cuckoo dummies,with no significant difference in attack rates among cuckoo,sparrowhawk and dove dummies,but their egg rejection did not change significantly.These results imply that Isabelline Shrikes may adjust their nest defense behavior,but not egg rejection behavior,with seasonality. 展开更多
关键词 AGGRESSION Anti-parasite strategy Egg rejection Mismatch cuckoo parasitism nest defense
下载PDF
The effects of climate and land use change on the potential distribution and nesting habitat of the Lesser Adjutant in Nepal
4
作者 Hem Bahadur Katuwal Hari Prasad Sharma +10 位作者 Prashant Rokka Krishna Prasad Bhusal Bishnu Prasad Bhattarai Sabina Koirala Sandeep Chhetri Luitel Shailendra Yadav Ganesh Sah Hem Sagar Baral Laxman Prasad Poudyal Lin Wang Rui-Chang Quan 《Avian Research》 SCIE CSCD 2023年第3期326-335,共10页
Climate change and land use change pose a threat to the world’s biodiversity and have significant impacts on the geographic distribution and composition of many bird species,but little is known about how they affect ... Climate change and land use change pose a threat to the world’s biodiversity and have significant impacts on the geographic distribution and composition of many bird species,but little is known about how they affect threatened large-sized waterbird species that rely on agricultural landscapes.To address this gap,we investigated how climate and land use changes influence the distribution and nesting habitats of the globally vulnerable Lesser Adjutant(Leptoptilos javanicus) in Nepal.Between 2012 and 2023,we collected distribution data from 24 districts and nesting site information from 18 districts.In a nation-wide breeding survey conducted in 2020,we documented a total of 581 fledglings from 346 nests in 109 colonies.The ensemble model predicted a current potential distribution of 15%(21,637 km2) and a potential nesting habitat of 13%(19,651 km2) for the species in Nepal.The highest predicted current suitable distribution and nesting habitat was in Madhesh Province,while none was predicted in Karnali Province.The majority of this predicted distributional and nesting habitat falls on agricultural landscapes(>70%).Our model showed a likely range expansion of up to 15%(21,573 km2) for the distribution and up to 12%(17,482 km2) for the nesting habitat under SSP5-8.5 scenarios for the 2070s.The range expansion is expected to occur mainly within the current distribution and breeding range(Tarai and some regions of Siwalk),particularly in Lumbini and Sudurpashchim provinces,and extend to the northern portions(Siwalik and Mid-hill regions) in other provinces.However,the current Protected Areas and Important Bird and Biodiversity Areas are inadequate for providing optimal habitats for the species.Although the model suggests range expansion,the use of such novel habitats is primarily contingent on the availability and protection of large-sized trees(particularly Bombax ceiba,observed in 65% of colonies) in agricultural regions where nesting occurs.Therefore,our research suggests that agricultural landscapes should be prioritized in management plans for the conservation of the Lesser Adjutant in Nepal. 展开更多
关键词 Agricultural landscapes Bombax ceiba Ensemble modeling Farmland bird IBA nest site
下载PDF
Modelling the nesting-habitat of threatened vulture species in the caucasus:An ecosystem approach to formalising environmental factors in species distribution models
5
作者 Rustam Pshegusov Victoria Chadaeva 《Avian Research》 SCIE CSCD 2023年第4期572-585,共14页
Abiotic factors play an important role in species localisation,but biotic and anthropogenic predictors must also be considered in distribution modelling for models to be biologically meaningful.In this study,we formal... Abiotic factors play an important role in species localisation,but biotic and anthropogenic predictors must also be considered in distribution modelling for models to be biologically meaningful.In this study,we formalised the biotic predictors of nesting sites for four threatened Caucasian vultures by including species distribution models(wild ungulates,nesting tree species)as biotic layers in the vulture Maxent models.Maxent was applied in the R dismo package and the best set of the model parameters were defined in the R ENMeval package.Performance metrics were continuous Boyce index,Akaike's information criterion,the area under receiver operating curve and true skill statistics.We also calculated and evaluated the null models.Kernel density estimation method was applied to assess the overlap of vulture ecological niches in the environmental space.The accessibility of anthropogenic food resources was estimated using the Path Distance measure that considers elevation gradient.The availability of pine forests(Scots Pine)and wild ungulates(Alpine Chamois and Caucasian Goat)contributed the most(29.6%and 34.3%)to Cinereous Vulture(Aegypius monachus)nesting site model.Wild ungulate distribution also contributed significantly(about 46%)to the Bearded Vulture(Gypaetus barbatus)model.This scavenger nests in the highlands of the Caucasus at a minimum distance of 5–10 km from anthropogenic facilities.In contrast,livestock as a food source was most important in colony distribution of Griffon Vulture(Gyps fulvus).The contribution of distances to settlements and agricultural facilities to the model was 45%.The optimal distance from Egyptian Vulture(Neophron percnopterus)nesting sites to settlements was only 3–10 km,to livestock facilities no more than 15 km with the factor contribution of about 57%.Excluding the wild ungulate availability,the ecological niches of studied vultures overlapped significantly.Despite similar foraging and nesting requirements,Caucasian vultures are not pronounced nesting and trophic competitors due to the abundance of nesting sites,anthropogenic food sources and successful niche sharing. 展开更多
关键词 Caucasian vultures Ecological niche differentiation Maxent nesting sites Species distribution models
下载PDF
Nesting Biology and Site Selection of Olive Ridley—A Coherence of Nature
6
作者 Arun Malarvizhi P. M. Mohan 《Open Journal of Marine Science》 2023年第2期29-39,共11页
Nesting behaviour of sea turtles remains a subject to study, due to their enigmatic pattern of seasonal breeding activities. In the present study, characteristics of the breeding turtle, Olive Ridley (Lepidochely... Nesting behaviour of sea turtles remains a subject to study, due to their enigmatic pattern of seasonal breeding activities. In the present study, characteristics of the breeding turtle, Olive Ridley (Lepidochelys olivacea) at Ramnagar along N-E coast of North Andaman Islands were investigated, for the nesting periods 2016-2017. Olive Ridley is the dominant sea turtles, with more than 300 individuals nesting every season with at least a 75% hatching success rate. It is one of the conducive, highly protective and undisturbed nesting sites for Olive Ridley on North Andaman coast. In the present study an initiative is made, to identify nature’s cues and the biological characteristics of Olive Ridley, which leads it to nest at Ramnagar beach, with a high hatchling success rate. 展开更多
关键词 Sea Turtle Olive Ridley Ramnagar Beach nesting Beach Sand Grain Hatch-ling North Andaman
下载PDF
The Probable Cause for Nesting Pattern of Olive Ridley (Lepidochelys olivacea) at Ramnagar Beach, North East Coast of Andaman Island, India
7
作者 Arun Malarvizhi M. M. Ilaamurughu P. M. Mohan 《Open Journal of Marine Science》 2023年第1期7-27,共21页
The nesting behaviour of sea turtles remains a subject to study, due to their enigmatic pattern of seasonal breeding activities. Over a period of time, several reports have been made in this context associated with th... The nesting behaviour of sea turtles remains a subject to study, due to their enigmatic pattern of seasonal breeding activities. Over a period of time, several reports have been made in this context associated with the nesting behaviour of the Olive Ridley turtles. In the present study, characteristics of the breeding beach and nesting pattern of Olive Ridley (Lepidochelys olivacea) at Ramnagar along N-E coast of Andaman Islands were investigated, during the nesting periods 2016-2017. The study area hosts Olive Ridley, the dominant sea turtles with more than 300 individuals nesting each year. For this study, the number of sea turtles visited, nested, the sediment characters, salinity, and temperature were taken. The exposed sandy nesting beach characteristics are prone to varying degrees of morphological changes every day. The results depict that even though similar grain size (Coarse Sand to Fine Sand and Very well sorted to Poorly Sorted), with an ambient incubating temperature, pH and salinity with wide nesting area, the selective nesting in the particular location of the beach identified because of comfortable energy conditions in the waters (1.5 m/s) favours the female turtles to reach the beach at the preferable site of Ramnagar and nest. 展开更多
关键词 Sea turtle Olive Ridley Ramnagar Beach nesting Environment Morphological Changes Sand Grain HATCHLING North Andaman
下载PDF
Nest decoration:Black feathers prevent Crested Mynas from nest usurpation
8
作者 Jinmei Liu Wei Liang 《Avian Research》 SCIE CSCD 2024年第2期292-297,共6页
Nests are important structures for birds to raise their offspring and for signaling.Many birds incorporate feathers into the nest,since feathers were traditionally thought to serve the function of insulation.Hypothese... Nests are important structures for birds to raise their offspring and for signaling.Many birds incorporate feathers into the nest,since feathers were traditionally thought to serve the function of insulation.Hypotheses in recent years have considered that some birds place feathers in conspicuous locations in the nest for decoration to trigger a fear response in the competitors.In this study,we investigated whether decorative feathers could deter nest usurpation by Crested Mynas(Acridotheres cristatellus)by manipulating nest box contents.The results revealed that Crested Mynas preferred black feathers to white feathers as decorations and occupied nest boxes decorated with black feathers significantly less than those decorated with white feathers,suggesting that black decorative feathers in the nest could be more effective in preventing nest usurpation by Crested Mynas and that white decorative feathers may have other functions.The black feathers in the nest are prominently placed at the edge of the nest to convey the message that“this nest is occupied”or“the owner of this nest has been preyed upon”to visitor Crested Mynas,thus effectively preventing them from usurping the nest at a later stage. 展开更多
关键词 Extended phenotype FEATHERS nest decoration nest usurpation
下载PDF
Habitat preferences and nest site selection by sympatric populations of Middle Spotted Woodpecker(Dendrocoptes medius) and Syrian Woodpecker(Dendrocopos syriacus) in natural mountain forests of Southwest Iran
9
作者 Arya Shafaeipour Jerzy Michalczuk Behzad Fathinia 《Avian Research》 SCIE CSCD 2024年第1期81-90,共10页
We examined habitat preferences and nesting requirements of sympatric populations of Middle Spotted Woodpecker(Dendrocoptes medius) and Syrian Woodpecker(Dendrocopos syriacus).We carried out our study in 2015–2018 in... We examined habitat preferences and nesting requirements of sympatric populations of Middle Spotted Woodpecker(Dendrocoptes medius) and Syrian Woodpecker(Dendrocopos syriacus).We carried out our study in 2015–2018 in natural mountain forests of Southwest Iran.We compared selected features of nesting,territory,and outside territory tree stands of the studied woodpeckers.The Middle Spotted Woodpecker occupied only oak forests,but the Syrian Woodpecker inhabited heterogenic forests that included the preferred tree of this species,the Mount Atlas Mastic.We recorded that in the breeding territories of the Middle Spotted Woodpecker,a greater area covered by tree crowns,as well as a larger number of trees,and a larger trunk basal area were observed in comparison to the territories occupied by the more plastic Syrian Woodpecker.Different habitat preferences demonstrated by both species could be a result of the selection of tree stands that provide the necessary food resources for each woodpecker species.Adaptation of Syrian Woodpecker to use heterogenic forest stands including tree species that produce fruits and as Mount Atlas Mastic trees,which likely allowed this species to colonise in Asia and Europe non-forest tree stands as orchards or gardens.Our results showed that poor tree condition and large tree trunk dimensions had a positive impact on the selection of nesting sites by both species.The presence of trees with large trunk dimensions was associated with multiple years of use of woodpecker breeding sites in the studied forests.Maintaining habitats in suitable condition for both studied woodpeckers can be achieved by preserving natural forests in the mountain regions of Iran. 展开更多
关键词 Habitat conservation nesting requirements Primary cavity nesters Species co-occurrence
下载PDF
Design and assembly of a nested imaging X-ray telescope for the Hot Universe Baryon Surveyor mission
10
作者 Jun Yu Ruohui Xian +8 位作者 Xiaoqiang Wang Yifan Wang Zhanshan Wang Wei Zhang Yibo Cai Jing Yang Xi Lu Wei Wang Wei Cui 《Astronomical Techniques and Instruments》 CSCD 2024年第3期157-165,共9页
The Hot Universe Baryon Surveyor (HUBS) mission will carry a nested X-ray telescope capable of observing an energy range from 0.5 keV to 2 keV to study hot baryon evolution. In this paper, we report the latest progres... The Hot Universe Baryon Surveyor (HUBS) mission will carry a nested X-ray telescope capable of observing an energy range from 0.5 keV to 2 keV to study hot baryon evolution. In this paper, we report the latest progress in the design and construction of nested X-ray telescopes which were designed to use a three-stage conic-approximation type assembly to simplify the manufacturing process. The mirror substrate is made using the thermal glass slumping method, with mirrors characterized by a root-mean-square roughness of 0.3 nm, with expected high reflectivity and good thermal stability. We also discuss methods of telescope construction and conduct a deformation analysis of the manufactured mirror. The in situ measurement system program is developed to guide the telescope assembly process. 展开更多
关键词 nested X-ray telescope Thermal glass slumping Telescope assembly In situ measurement
下载PDF
Nested Levels of Hybrid Cryptographical Technique for Secure Information Exchange
11
作者 Pawan Kumar Vipin Saxena 《Journal of Computer and Communications》 2024年第2期201-210,共10页
Data security is a very important part of data transmission over insecure channels connected through high-speed networks. Due to COVID-19, the use of data transmission over insecure channels has increased in an expone... Data security is a very important part of data transmission over insecure channels connected through high-speed networks. Due to COVID-19, the use of data transmission over insecure channels has increased in an exponential manner. Hybrid cryptography provides a better solution than a single type of cryptographical technique. In this paper, nested levels of hybrid cryptographical techniques are investigated with the help of Deoxyribonucleic Acid (DNA) and Paillier cryptographical techniques. In the first level, information will be encrypted by DNA and at the second level, the ciphertext of DNA will be encrypted by Paillier cryptography. At the decryption time, firstly Paillier cryptography will be processed, and then DAN cryptography will be processed to get the original text. The proposed algorithm follows the concept of Last Encryption First Decryption (LEFD) at the time of decryption. The computed results are depicted in terms of tables and graphs. 展开更多
关键词 ENCRYPTION DECRYPTION DNA Paillier Cryptography nested Levels Hybrid Cryptography
下载PDF
一种基于NeSTiNg的TSN强实时流量调度和自动配置方法 被引量:2
12
作者 王波 高文炜 +1 位作者 徐丹妮 贺新乐 《微电子学与计算机》 2022年第11期62-68,共7页
流量调度是时间敏感网络(Time Sensitive Networking, TSN)技术的核心.在大型工业嵌入式系统应用中,TSN流量调度的设计和仿真阶段需要对链路、流、门控等调度信息进行复杂且苛刻的配置.现有的基于仿真框架的配置方法多采用手动配置,这... 流量调度是时间敏感网络(Time Sensitive Networking, TSN)技术的核心.在大型工业嵌入式系统应用中,TSN流量调度的设计和仿真阶段需要对链路、流、门控等调度信息进行复杂且苛刻的配置.现有的基于仿真框架的配置方法多采用手动配置,这阻碍了这些框架对大型TSN网络的适用性.基于TSN强实时流量传输机制和NeSTiNg(Network Simulator for Time-Sensitive Networking)框架,提出一种适用于大型网络的强实时流量调度和自动配置方法.首先,该方法区别于传统的手动配置输入方式,实现了对流偏移、门状态和路由表等信息的自动配置;其次,该方法提取了流的端到端时延,验证了大型网络中TSN传输的强实时性;最后,通过计算拓扑变化后选择新路径的运算时间,评估了该方法对动态拓扑的适用性.结果表明:该方法保证了大型网络中大量流传输的强实时性,且当拓扑改变时,相比于静态路由有更低的运算时间. 展开更多
关键词 TSN IEEE 802.1Qbv nesting 流量调度 自动配置 TSN评估 运算时间
下载PDF
眼针对脑缺血再灌注损伤大鼠Nesting、GAP43蛋白表达影响 被引量:4
13
作者 宓丹 潘冲 陈雪 《辽宁中医药大学学报》 CAS 2018年第10期119-122,共4页
目的:通过观察眼针治疗对脑缺血再灌注损伤大鼠大脑皮层巢蛋白(Nesting)、生长相关蛋白43(Growth associated protein 43,GAP43)蛋白表达的影响,探讨眼针治疗对脑缺血后神经再生作用。方法:SD大鼠随机分为空白组、假手术组、模型... 目的:通过观察眼针治疗对脑缺血再灌注损伤大鼠大脑皮层巢蛋白(Nesting)、生长相关蛋白43(Growth associated protein 43,GAP43)蛋白表达的影响,探讨眼针治疗对脑缺血后神经再生作用。方法:SD大鼠随机分为空白组、假手术组、模型组(3 h、24 h、72 h)、眼针组(3 h、24 h、72 h),每组6只。采用改良线栓法制备大脑中动脉缺血2 h再灌注损伤模型,眼针组给予眼针治疗方法,每12 h 1次,每次20 min。各组大鼠在治疗点结束后,对大鼠神经功能缺损进行评分,用Westblot法检测缺血侧大脑皮层Nesting、GAP43蛋白含量。结果:(1)眼针组24 h、72 h神经功能评分低于同时间点的模型组(P〈0.05)。(2)脑缺血后模型组Nesting蛋白表达升高并随着缺血时间延长持续升高,与空白组比较,P〈0.05;眼针组Nesting蛋白表达趋势与模型组相似,与模型组同时间点比较,眼针组Nesting蛋白表达升高更明显(P〈0.05)。(3)脑缺血后模型组GAP43蛋白表达升高并随着缺血时间延长持续升高,与空白组比差异明显(P〈0.05);眼针组GAP43蛋白表达趋势与模型组相似,与模型组同时间点比较,眼针组GAP43蛋白表达升高更明显(P〈0.05)。结论:眼针治疗可以促进脑缺血后Nesting、GAP43蛋白的表达,从而具有促进脑缺血后神经发生的作用。 展开更多
关键词 脑缺血 眼针 神经发生 nesting GAP43
下载PDF
Does nest sanitation elicit egg rejection in an open-cup nesting cuckoo host rejecter? 被引量:4
14
作者 Tongping Su Chanchao Yang +1 位作者 Shuihua Chen Wei Liang 《Avian Research》 CSCD 2018年第4期294-298,共5页
Background: Nest sanitation behavior is one of the most important means to ensure high reproductive efficiency. In avian brood parasitism, nest sanitation behavior may be a pre-adaptation of host birds that allows the... Background: Nest sanitation behavior is one of the most important means to ensure high reproductive efficiency. In avian brood parasitism, nest sanitation behavior may be a pre-adaptation of host birds that allows them to identify the parasitic eggs, so that egg discrimination behavior may have evolved from nest sanitation behavior. However, whether nest sanitation behavior could improve egg rejection in cuckoo hosts was inconclusive.Methods: In this study, we investigated the relationship between nest sanitation and egg discrimination behavior in a potential cuckoo host, the Brown-breasted Bulbul(Pycnonotus xanthorrhous) with two experimental groups. In the first group, we added a blue, non-mimetic egg to the nest of the host, while in the second group we added a blue, non-mimetic egg and a peanut half-shell.Results: The results showed that in the first group, the probability of rejecting the non-mimetic eggs was 53.8%(n = 26 nests). In comparison, all of the Brown-breasted Bulbuls in the second group were able to rapidly remove the peanut shells from the nest, but only 52.6%(n = 19 nests) rejected the non-mimetic eggs. The rejection rates of the non-mimetic eggs in both experimental groups were not significantly different.Conclusions: Our study indicated that nest sanitation behavior of Brown-breasted Bulbuls did not influence their egg recognition and that egg discrimination ability of Brown-breasted Bulbuls was not directly related to nest sanitation behavior. 展开更多
关键词 BROOD PARASITISM Brown-breasted Bulbul Egg discrimination nest SANITATION behavior CUCKOO HOST
下载PDF
HABITAT SUITABILITY INDEX MODELS: GREY HERON NESTING IN ZHALONG NATIONAL NATURE RESERVE 被引量:1
15
作者 孙洪志 高中信 王丹 《Journal of Northeast Forestry University》 SCIE CAS CSCD 1995年第2期61-64,共4页
Grey heron (Ardea cimerca) is one kind of the great birds which are often seen in the northeast marsh area of P.R.China, and there are many grey herons to reproduce in Zhalong Nature Reserve from March to August annua... Grey heron (Ardea cimerca) is one kind of the great birds which are often seen in the northeast marsh area of P.R.China, and there are many grey herons to reproduce in Zhalong Nature Reserve from March to August annually. In this paper, through the inveingation of the grey herons nesting habitat and according to the water depth, vegetation type, cover density and plan heigh of the nesting place, the grey heron’s nesting habitat suitability index medes are established. The main model is s=(s1xs2xs3xs4)1/4,where s1 is the water depth suitability index, s2 is the vegetation type suitability index, s3 is the cover density index, sa is the plant height suitability index. These models provide a kind of reliable method for evaluating the habitat quality of the grey heron’s nesting. 展开更多
关键词 GREY HERON nesting HABITAT INDEX MODEL
下载PDF
Nesting patterns of raptors;White backed vulture (<i>Gyps africanus</i>) and African fish eagle (<i>Haliaeetus vocifer</i>), in Lochinvar National Park on the kafue flats, Zambia 被引量:2
16
作者 Chansa Chomba Eneya M’Simuko 《Open Journal of Ecology》 2013年第5期325-330,共6页
This study assessed the nesting patterns of raptors, Gyps africanus and Haliaeetus vocifer in Lochinvar National Park. The main objective of the study was to determine whether tree species, height, girth size, and hab... This study assessed the nesting patterns of raptors, Gyps africanus and Haliaeetus vocifer in Lochinvar National Park. The main objective of the study was to determine whether tree species, height, girth size, and habitat influenced raptor’s nest placement within Lochinvar National Park. Two species were selected as indicator species for the raptors. Habitat types and tree species were identified and measurements of tree species with nests measured. It was found that the minimum height of nest placement was 10 meters above ground and Acacia woodland was found to be the most preferred habitat for nest placement. Raptors avoided human disturbance by placing their nests at least 100 meters away from human disturbance and from the National park boundary inwards or abandoning if human encroachment comes close to the nest. More research is required to assess nesting materials used, and to determine whether raptors can swap nets or return to the abandoned nests when human disturbance ceases. 展开更多
关键词 RAPTORS nest Placement Tree Height Lochinvar Kafue Flats Habitat
下载PDF
Algorithm for 2D irregular-shaped nesting problem based on the NFP algorithm and lowest-gravity-center principle 被引量:5
17
作者 LIU Hu-yao HE Yuan-jun 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2006年第4期570-576,共7页
The nesting problem involves arranging pieces on a plate to maximize use of material. A new scheme for 2D ir- regular-shaped nesting problem is proposed. The new scheme is based on the NFP (No Fit Polygon) algorithm a... The nesting problem involves arranging pieces on a plate to maximize use of material. A new scheme for 2D ir- regular-shaped nesting problem is proposed. The new scheme is based on the NFP (No Fit Polygon) algorithm and a new placement principle for pieces. The novel placement principle is to place a piece to the position with lowest gravity center based on NFP. In addition, genetic algorithm (GA) is adopted to find an efficient nesting sequence. The proposed scheme can deal with pieces with arbitrary rotation and containing region with holes, and achieves competitive results in experiment on benchmark datasets. 展开更多
关键词 nesting Cutting stock No Fit Polygon (NFP) Genetic algorithm (GA) Lowest gravity center
下载PDF
Light matters:Nest illumination alters egg rejection behavior in a cavity-nesting bird 被引量:3
18
作者 Canchao Yang Anders Pape Møller Wei Liang 《Avian Research》 SCIE CSCD 2022年第1期64-67,共4页
Egg discrimination by cavity-nesting birds that build nests under dim light conditions was presumed to depend on nest luminance,although this hypothesis has rarely been tested.Tests of egg discrimination ability by ca... Egg discrimination by cavity-nesting birds that build nests under dim light conditions was presumed to depend on nest luminance,although this hypothesis has rarely been tested.Tests of egg discrimination ability by cavity-nesting tits under dim light conditions may reveal the selection pressure from brood parasitism that they encounter under natural interactions.We manipulated the intensity of luminance of nests of the Green-backed Tit(Parus monticolus),a potential cuckoo host that possesses a strong discrimination ability of non-mimetic foreign eggs.We performed experiments to test their egg discrimination ability under different light conditions.Our results showed that Green-backed Tits discriminate against non-mimetic foreign eggs under normal light conditions in nest boxes,and this ability persisted at nest luminance as low as 4.78±1.31 lux that is several times lower than normal luminance(38.11±24.02 lux).However,egg discrimination by Green-backed Tits disappeared when nest luminance was reduced to a minimum of 0.35±0.15 lux.The latter value represents total darkness for humans.The present study shows that nest luminance plays a key role in egg discrimination by Green-backed Tits that build nests under dim light conditions.This study provides strong experimental evidence for nest illumination altering egg rejection behavior in cavity-nesting birds. 展开更多
关键词 Brood parasitism Cryptic egg Egg rejection Luminance manipulation nest light condition
下载PDF
Developing and validating a nestling photographic aging guide for cavity-nesting birds: an example with the European Bee-eater(Merops apiaster) 被引量:1
19
作者 Joana S.Costa Afonso D.Rocha +1 位作者 Ricardo A.Correia Jose A.Alves 《Avian Research》 CSCD 2020年第1期57-64,共8页
Background: Accurate estimation of nestlings’ age is essential in avian demography studies as well as in population ecology and conservation. For example, it can be useful for synchronizing nest visits with events of... Background: Accurate estimation of nestlings’ age is essential in avian demography studies as well as in population ecology and conservation. For example, it can be useful for synchronizing nest visits with events of particular interest, such as the age at which young can be safely ringed, or in choosing the best period to attain the most accurate calculation of laying or hatching dates.Methods: We constructed a photographic guide for aging European Bee-eaters(Merops apiaster) nestlings to 3-day age classes and evaluated the aging method by performing a validation exercise with several observers with no previous experience in aging bee-eater nestlings.Results: The aging guide for bee-eater nestlings allowed estimating age to within 3 days with an average accuracy of 0.85. We found the optimal period for aging nestlings was between days 13-18(with accuracy between 0.94 and 0.99), during which the status of feather development was more easily distinguishable from the preceding and subsequent age classes. During the first 3 days after hatching, nestlings could also be aged with high accuracy(0.93). The small size of the nestling in relation to the eggs and the nestling’s inability to raise its head during these first days allowed for good discrimination from the subsequent age class. Between days 25 and 28, nestlings were correctly aged in only half of assignments(0.55 sensitivity) and nestlings belonging to class 7(days 7-9) were the least correctly identified(0.38 sensitivity). However, by visiting the nests at 12 days intervals it is possible to achieve the highest accuracy in age estimation with the smallest disturbance and logistic investment.Conclusions: This study highlighted how indirect methods and a simple protocol can be established and employed to quickly estimate nestling age in cases where handling nestlings is challenging or impossible, while minimizing disturbance in and around the nest. 展开更多
关键词 Age estimation CHICK development FEATHER growth Image GUIDE nest visit PLUMAGE colour
下载PDF
Green Turtle, <i>Chelonia mydas</i>, Nesting and Temperature Profile of the Nesting Beach at Huyong Island, the Similan Islands in Andaman Sea 被引量:1
20
作者 Sarawoot Gomuttapong Winai Klom-In +3 位作者 Jirarach Kitana Putsatee Pariyanonth Kumthorn Thirakhupt Noppadon Kitana 《Natural Resources》 2013年第4期357-361,共5页
Global change in temperature is regarded as a serious natural disaster that may cause extinction of organisms. Green turtle, Chelonia mydas, is not only an endangered species but also a species with temperature depend... Global change in temperature is regarded as a serious natural disaster that may cause extinction of organisms. Green turtle, Chelonia mydas, is not only an endangered species but also a species with temperature dependent sex determination that could be affected by the global warming. In this study, nesting and temperature profile of C. mydas nesting beach at HuyongIsland, the most important nesting site of C. mydas in Andaman Sea of Thailand, were studied in order to monitor a potential effect of regional climate change on the green turtle nesting activity and habitat. Nesting activities were surveyed during May-August 2011 and temperature profiles of the nesting beach were monitored for 58 days during the normal incubation period of this species. The total of 25 nests with clutch size of 105 ± 25 eggs was found during this study period suggesting normal nesting activity of the green turtle. Temperature profile of the nesting beach showed similar trend among nests with no clear influence of the vegetation cover. Mean nest temperature at the middle-third period, corresponding to the temperature-sensitive period of C. mydas, ranged from 28.3°C to 28.9°C, suggesting a slightly male-biased sex ratio of the offspring. Overall, temperature profile of the nesting beach showed little or no indication of adverse effects of regional increase in temperature on nesting activity and egg incubation of the green turtle at this period. 展开更多
关键词 Conservation nesting Ecology Sea TURTLE Thermal Profile
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部