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Extended Nested Array with a Filled Sensor for DOA Estimation of Non-circular Signals
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作者 LI Xiaolong ZHANG Xiaofei SHEN Zihan 《Transactions of Nanjing University of Aeronautics and Astronautics》 2025年第1期90-100,共11页
Sparse array design has significant implications for improving the accuracy of direction of arrival(DOA)estimation of non-circular(NC)signals.We propose an extended nested array with a filled sensor(ENAFS)based on the... Sparse array design has significant implications for improving the accuracy of direction of arrival(DOA)estimation of non-circular(NC)signals.We propose an extended nested array with a filled sensor(ENAFS)based on the hole-filling strategy.Specifically,we first introduce the improved nested array(INA)and prove its properties.Subsequently,we extend the sum-difference coarray(SDCA)by adding an additional sensor to fill the holes.Thus the larger uniform degrees of freedom(uDOFs)and virtual array aperture(VAA)can be abtained,and the ENAFS is designed.Finally,the simulation results are given to verify the superiority of the proposed ENAFS in terms of DOF,mutual coupling and estimation performance. 展开更多
关键词 non-circular signal extended nested array sparse array direction of arrival(DOA)estimation sum-difference coarray
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Design and assembly of a nested imaging X-ray telescope for the Hot Universe Baryon Surveyor mission 被引量:1
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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
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Nested Levels of Hybrid Cryptographical Technique for Secure Information Exchange
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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
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具有荧光增强性能的负载Ag/SDS nested-network的铜网制备
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作者 田硕 袁志鹏 张延芳 《山东大学学报(理学版)》 CAS CSCD 北大核心 2024年第11期93-99,共7页
适宜的金属离子与荧光团的距离是获得高效荧光强度的关键,但对二者距离的调控通常比较繁琐。针对此问题,本文采用铜网上的碳膜充当金属银与荧光团之间的隔离层,利用硝酸银AgNO_(3)与铜网之间发生置换反应以制备得到负载在铜网上的银/十... 适宜的金属离子与荧光团的距离是获得高效荧光强度的关键,但对二者距离的调控通常比较繁琐。针对此问题,本文采用铜网上的碳膜充当金属银与荧光团之间的隔离层,利用硝酸银AgNO_(3)与铜网之间发生置换反应以制备得到负载在铜网上的银/十二烷基硫酸钠(Ag/SDS)nested-network结构,获得了高效的荧光增强效果。 展开更多
关键词 Ag/SDS nested-network 铜网 碳膜 荧光强度
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Optimization of Nesting Systems in Shipbuilding:A Review
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作者 Sari Wanda Rulita Gunawan Muzhoffar Dimas Angga Fakhri 《哈尔滨工程大学学报(英文版)》 2025年第1期152-175,共24页
This review article provides a comprehensive analysis of nesting optimization algorithms in the shipbuilding industry,emphasizing their role in improving material utilization,minimizing waste,and enhancing production ... This review article provides a comprehensive analysis of nesting optimization algorithms in the shipbuilding industry,emphasizing their role in improving material utilization,minimizing waste,and enhancing production efficiency.The shipbuilding process involves the complex cutting and arrangement of steel plates,making the optimization of these operations vital for cost-effectiveness and sustainability.Nesting algorithms are broadly classified into four categories:exact,heuristic,metaheuristic,and hybrid.Exact algorithms ensure optimal solutions but are computationally demanding.In contrast,heuristic algorithms deliver quicker results using practical rules,although they may not consistently achieve optimal outcomes.Metaheuristic algorithms combine multiple heuristics to effectively explore solution spaces,striking a balance between solution quality and computational efficiency.Hybrid algorithms integrate the strengths of different approaches to further enhance performance.This review systematically assesses these algorithms using criteria such as material dimensions,part geometry,component layout,and computational efficiency.The findings highlight the significant potential of advanced nesting techniques to improve material utilization,reduce production costs,and promote sustainable practices in shipbuilding.By adopting suitable nesting solutions,shipbuilders can achieve greater efficiency,optimized resource management,and superior overall performance.Future research directions should focus on integrating machine learning and real-time adaptability to further enhance nesting algorithms,paving the way for smarter,more sustainable manufacturing practices in the shipbuilding industry. 展开更多
关键词 Cutting plate nesting algorithms nesting optimization Shipbuilding efficiency Algorithmic optimization
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Visual cues modulate nest defense behavior in Japanese Tits:Insights from the appearance,posture and size of snake dummies
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作者 Dake Yin Jiangping Yu +4 位作者 Romain Lorrilliere Jiangping Jin Mingju E Longru Jin Haitao Wang 《Avian Research》 2025年第4期713-720,共8页
Predator dummies are usually used to explore the impact of predator features on the anti-predator behavior of birds.Previous studies have shown that the morphology and behavior of aerial predators can signal different... Predator dummies are usually used to explore the impact of predator features on the anti-predator behavior of birds.Previous studies have shown that the morphology and behavior of aerial predators can signal different threat levels to birds.However,whether subtle changes in ground predator dummies cause changes in the nest defense behavior of parent birds is unclear.In this study,we aimed to investigate whether Japanese Tits(Parus minor)exhibit different nest defense behaviors in response to experimentally manipulated variations in the appearance,posture,and size of virtual snake proxies(common nest predators).During the incubation period,we observed the nest defense behaviors of the parent tits against taxidermized Siberian Ratsnakes(Elaphe schrenckii)with varied characteristics and rubber-made model snakes.The tits exhibited more intense responses to taxidermized large(body length about 120 cm)coiled ratsnakes than to large coiled model snakes.They exhibited weaker responses to taxidermized small(body length about 20 cm)coiled ratsnakes than to taxidermized small sinusoidal ratsnakes.In addition,they exhibited more intense responses to taxidermized large coiled ratsnakes than to taxidermized small coiled ratsnakes,and more intense responses to taxidermized small sinusoidal ratsnakes than to large model snakes.However,there was no difference in the response of tits to taxidermized small sinusoidal ratsnakes and taxidermized large coiled ratsnakes,or to taxidermized small coiled ratsnakes and model snakes.Thus,the presence of scales,a sinusoidal posture,and a large body size of snake dummies can induce more intense behavioral responses in Japanese Tits.We suggested that Japanese Tits can discriminate subtle differences in ground predator dummies of nests and exhibit different nest defense behaviors. 展开更多
关键词 Ground predator of nest Japanese Tits nest defense behavior Predator dummies
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Highway effects on artificial nest survival in a neotropical sand-coastal plain:A spatiotemporal approach
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作者 Gleidson Ramos da Silva Pedro Diniz Charles Duca 《Avian Research》 2025年第3期318-325,共8页
Roads are a leading cause of habitat fragmentation and may reduce bird populations by increasing nest predation rates.However,few studies have investigated the effects of traffic volume on the reproductive success of ... Roads are a leading cause of habitat fragmentation and may reduce bird populations by increasing nest predation rates.However,few studies have investigated the effects of traffic volume on the reproductive success of roadside birds in the neotropics.Our goal was to evaluate the effects of spatial,temporal,and vehicle flow variations on the survival of artificial open-cup nests.The study was carried out in a nature reserve on the side of a highway during the breeding season(from October to March)in two restinga(sand-coastal plain)phytophysiognomies in southeastern Brazil:non-floodable(open)and floodable(closed).One hundred thirty nests were distributed along transects ranging from 3 m to 300 m from the highway in each vegetation type(totaling 260 nests).The nests were checked every three days for their status(depredated or intact)over 12 days,and new nests were subsequently placed near sampling points of depredated or successful nests.We estimated survival using logistic exposure generalized linear and additive mixed models.At the end of the 180 days of the experiment,33%of 6202 nests were successful.Nest survival was higher in open restinga than in closed restinga.In both habitats,nest survival was lowest mid-season and highest at the beginning and end.Survival rates peaked near the highway,declined up to 50 m away,then showed a slight increase.Finally,survival increased at moderate-to-high traffic volumes(∼22,000 vehicles/day),particularly in open restinga.We suggest that spatial,temporal,and habitat-specific highway impacts(e.g.,noise,vibration,visual stimuli)can lead to variations in the activity of nest predators,generating fluctuations in nest survival associated with predator behavior. 展开更多
关键词 BIRDS Edge effect FRAGMENTATION nest survival Traffic effect
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Unsaturated cobalt single-atoms stabilized by silanol nests of zeolites for efficient propane dehydrogenation
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作者 Liwen Guo Dao Shi +4 位作者 Tianjun Zhang Yanhang Ma Guodong Qi Jun Xu Qiming Sun 《Chinese Journal of Catalysis》 2025年第5期323-333,共11页
Propane dehydrogenation(PDH)has emerged as a key on-purpose technology for the production of propylene,but it often depends on toxic chromium and expensive platinum catalysts,highlighting the need for environmentally ... Propane dehydrogenation(PDH)has emerged as a key on-purpose technology for the production of propylene,but it often depends on toxic chromium and expensive platinum catalysts,highlighting the need for environmentally friendly and cost-effective alternatives.In this study,we developed a facile impregnation method to fabricate unsaturated Co single-atoms with a tricoordinated Co_(1)O_(3)H_(x) structure by regulating silanol nests in purely siliceous Beta zeolites.Detailed PDH catalytic tests and characterizations revealed a positive correlation between the presence of silanol nests and enhanced catalytic activity.Additionally,the unsaturated Co single-atoms exhibited a carbon deposition rate more than an order of magnitude slower than that of Co nanoparticles.Notably,the optimized Co_(0.3%)/deAl-meso-Beta catalyst achieved a record-high propylene formation rate of 21.2 mmol_(C3H6) g_(cat)^(-1) h^(-1),with an exceptional propylene selectivity of 99.1%at 550℃.Moreover,the Co_(0.3%)/deAl-meso-Beta catalyst demonstrated excellent stability,with negligible deactivation after 5 consecutive regeneration cycles.This study emphasizes the pivotal role of silanol nests of zeolites in stabilizing and modulating the coordination environment of metallic active sites,providing valuable insights for the design of high-activity,high-stability,and low-cost PDH catalysts. 展开更多
关键词 Propane dehydrogenation Unsaturated cobalt Single-atoms Silanol nest Zeolite
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Testing urban edge effects:Nest predation rates are higher in areas further from the boundary of a suburban park
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作者 Ailun Wang Tara J.Pirie Mark D.E.Fellowes 《Avian Research》 2025年第3期311-317,共7页
Urban green spaces and parks offer opportunities for retaining and increasing bird richness, diversity, and species abundance. However, urbanisation influences predator–prey interactions, leading to high predation ra... Urban green spaces and parks offer opportunities for retaining and increasing bird richness, diversity, and species abundance. However, urbanisation influences predator–prey interactions, leading to high predation rates in urban areas, in the UK notably through the presence of large populations of domestic cats and increased populations of synanthropic species, such as rats and squirrels. These high predation rates are assumed to be a significant cause of reproductive failure in birds. Some ecologists advocate for the use of buffer zones with reduced human influence to reduce potential hunting pressure in eco-sensitive areas. However, the buffer effect on predation rates of nesting birds in suburban areas is rarely investigated. In this study, we investigated how edge effects (how close nest sites are to housing) and nest height (i.e., ground vs. above-ground) affected nest predation rates in a suburban park using camera traps to monitor artificial nests containing quail eggs. Our hypothesis was that nests in the buffer area (<300 m inward from university boundary) and at low height would suffer higher predation rates than nests in the core area (>300 m from the university boundary) and at height, as the buffer zone effect, and ease of access to ground predators would result in higher predation rates. We found no significant effect of nest height in nest predation rates. However, contrary to our expectations, nests in the core zone suffered higher predation rates than those in the buffer zone, and corvids were responsible for almost half of the egg loss events. We speculate that this may be a consequence of higher levels of anthropogenic disturbance (e.g., pedestrians, dog walking, vehicles) adjacent to our buffer zone acting as a deterrent to avian nest predators. This work suggests that protecting urban sites from disturbance may not always act to support bird abundance. 展开更多
关键词 Edge effect Greenspace nest predation Urbanisation Urban park
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Nest attentiveness does not impact incubation duration across different bird species
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作者 D.Charles Deeming 《Avian Research》 2025年第3期338-344,共7页
Avian incubation is characterised by the contact between the eggs and the bird's skin to transfer heat to increase egg temperature above ambient conditions. Birds can be attentive to the clutch all of the time or,... Avian incubation is characterised by the contact between the eggs and the bird's skin to transfer heat to increase egg temperature above ambient conditions. Birds can be attentive to the clutch all of the time or, particularly if only one parent incubates, attentiveness may be quite low. Attentiveness is related to egg size with large eggs having high attentiveness, whereas small eggs (<10 g) can have attentiveness ranging from 50% to 100%. Previous studies have suggested that incubation duration is a function of attentiveness albeit for small birds. This study tested the hypothesis that, after controlling for egg size and phylogeny, incubation duration would be a function of attentiveness. Data for 444 bird species representing 24 orders were analysed. Whilst egg mass had a significant relationship with incubation duration, there was no relationship with attentiveness for all of the species or a subset of the passerines. Despite egg temperature drops during an incubation recess, average day-time and night-time temperatures are similar in a range of species. Re-examination of previously reported temperature profiles recorded by dummy eggs over a 24-h period shows that after an incubation recess there seems to be an additional heat flux that raises egg temperature above that seen during night-time periods of constant incubation. The reasons why eggs under intermittent incubation are not considerably cooler than eggs during constant incubation are discussed. 展开更多
关键词 Egg temperature Heat flux Incubation duration nest attentiveness PHYLOGENY
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Nestlings of two parrotbill species can independently evaluate the presenceof predators based on acoustic cues
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作者 Jiaojiao Wang Peng Pan +4 位作者 Haijie Zhang Laikun Ma Qindong Zhou Longwu Wang Jianhua Hou 《Avian Research》 2025年第1期83-88,共6页
Nest predation is the leading cause of reproductive failure in birds and a major driving force in the evolution of anti-predation strategies.Current studies on the anti-predation strategies of birds driven by predatio... Nest predation is the leading cause of reproductive failure in birds and a major driving force in the evolution of anti-predation strategies.Current studies on the anti-predation strategies of birds driven by predation pressure have mainly focused on adults.However,the detection and behavioral responses of nestlings toward predation risk require further investigation.In this study,we examined nestling responses to predator sounds.Two species of nestlings,the Reed Parrotbill(Paradoxornis heudei)and Vinous-throated Parrotbill(Sinosuthora webbiana),were exposed to the Sparrowhawk(Accipiter nisus,less common)and Oriental Magpie(Pica serica,more common),which are predator species,the Oriental Turtle Dove(Streptopelia orientalis),which is a commonly found harmless species,and background noise.Our findings revealed that compared to pre-playback of natural begging and playback of background noise and Oriental Turtle Dove sounds,playback of the two predator types decreased the total begging time and total number of calls of the two nestlings species,with the calls of the Sparrowhawk leading to greater suppression of nestling begging behavior than those of the Oriental Magpie.Therefore,our results indicated that these nestlings were able to distinguish predators from harmless species based on auditory cues. 展开更多
关键词 Anti-predation behavior nest predation Predator recognition Sound playback SYMPATRIC
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NEST:与时俱进的创新与实践
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作者 Ricky 《电子竞技》 2025年第5期80-81,共2页
腊月冬日里的福建晋江,并不算暖和。在五店市的状元戏台上,NEST全国电子体育大赛(以下简称NEST)的工作人员正在抓紧检查舞台内外的比赛设备。这是NEST来到晋江的第三年,之所以引进NEST,一定程度上是希望借助赛事的落地推广当地文旅产业... 腊月冬日里的福建晋江,并不算暖和。在五店市的状元戏台上,NEST全国电子体育大赛(以下简称NEST)的工作人员正在抓紧检查舞台内外的比赛设备。这是NEST来到晋江的第三年,之所以引进NEST,一定程度上是希望借助赛事的落地推广当地文旅产业发展,同时结合晋江传统体育产业的优势发展数字体育经济。 展开更多
关键词 数字体育经济 电子体育大赛 文旅产业 晋江 nest
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Erratum: Fermi Surface Nesting with Heavy Quasiparticlesin the Locally Noncentrosymmetric Superconductor CeRh2As2
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作者 Yi Wu Yongjun Zhang +15 位作者 Sailong Ju Yong Hu Yanen Huang Yanan Zhang Huali Zhang Hao Zheng Guowei Yang Evrard-Ouicem Eljaouhari Baopeng Song Nicholas CPlumb Frank Steglich Ming Shi Gertrud Zwicknagl Chao Cao Huiqiu Yuan Yang Liu 《Chinese Physics Letters》 2025年第4期188-188,共1页
In the acknowledgements,[1]the first acknowledged grant number(2022YFA140220)is incorrect and should be changed to 2022YFA1402200.
关键词 fermi surface nesting locally noncentrosymmetric superconductor cerh heavy quasiparticles
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To Explore the Application Effect of Bird’s Nest Nursing in Neonatal Nursing
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作者 Xiaoling Liu 《Journal of Clinical and Nursing Research》 2025年第4期377-383,共7页
Objective:To observe and study the practical value of adopting nest nursing in neonatal nursing.Methods:From January 2023 to January 2024,a total of 382 newborns that were admitted to the hospital were selected to car... Objective:To observe and study the practical value of adopting nest nursing in neonatal nursing.Methods:From January 2023 to January 2024,a total of 382 newborns that were admitted to the hospital were selected to carry out this study.They were divided into two groups,the routine group and the observation group,with 191 cases in each group.Newborns in the routine group were given basic nursing intervention,while those in the observation group were given bird’s nest nursing intervention.The growth and development indexes,the occurrence of adverse reactions,the improvement of gastrointestinal function,and the nursing satisfaction rate of their families were analyzed and studied.Results:The growth and development indexes of newborns in the observation group were significantly better than those in the routine group(P<0.05).The incidence of adverse neonatal reactions in the observation group was significantly lower than that in the routine group(P<0.05).The improvement of gastrointestinal function of newborns in the observation group was significantly better than that in the routine group(P<0.05).The nursing satisfaction rate of newborns’families in the observation group was significantly higher than that in the routine group(P<0.05).Conclusion:As for the key points of clinical newborn care,the actual effect of adopting the bird’s nest nursing intervention is more prominent,and its main function is to promote the growth and development of newborns.It can not only avoid the risk of adverse reactions in many aspects but also improve the gastrointestinal function of newborns,so that the nursing satisfaction rate of family members is obviously improved.It is recommended to be applied and popularized in clinical practice. 展开更多
关键词 Neonatal care Bird’s nest nursing Application effect
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Study on the Effect of Improved“Bird’s Nest”Nursing in the Out-of-hospital Transport of Premature Infants
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作者 WenJing Li Dan Zhao Huiyu Zhou 《Journal of Clinical and Nursing Research》 2025年第7期137-144,共8页
Objective:To explore the application effect of improved“Bird’s nest”nursing in the transport of premature infants.Methods:Collecting 100 cases of premature infants,randomly divided into experimental group and contr... Objective:To explore the application effect of improved“Bird’s nest”nursing in the transport of premature infants.Methods:Collecting 100 cases of premature infants,randomly divided into experimental group and control group,two groups of premature 50 cases each.The control group received the traditional“Bird’s nest”nursing.Experimental group in modified the“bird’s nest”nursing intervention,compared two groups of premature monitoring vital signs during the transfer process,transport after the body development indicators,the time and cure warmers intervention.Results:Compared with control group,experimental group premature temperature fluctuation is small,apnea and fewer times of low body temperature and oxygen saturation is higher,the contrast results with statistical significance(P<0.05).There was no significant difference in physical development,time to get out of the incubator,and cure rate.Conclusion:Modified the“bird’s nest”care in outside the hospital application,help to improve premature transfer process safety,and security for premature success implementation of transshipment is of great significance. 展开更多
关键词 Improved“bird’s nest”nursing Premature infants Out-of-hospital transport
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应用PCR及Nested-PCR技术检测柑橘黄龙病病原研究 被引量:35
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作者 丁芳 易干军 王国平 《园艺学报》 CAS CSCD 北大核心 2004年第6期803-806,共4页
以采自田间和广东省农业科学院果树研究所防虫隔离网室内嫁接并感染黄龙病的5个柑橘品种叶片为材料,以草本指示植物长春花(Catharanthusroseas)和木本指示植物柑(CitrusreticulataBlanco)鉴定为基础,采用改良的CTAB法提取总DNA,在此... 以采自田间和广东省农业科学院果树研究所防虫隔离网室内嫁接并感染黄龙病的5个柑橘品种叶片为材料,以草本指示植物长春花(Catharanthusroseas)和木本指示植物柑(CitrusreticulataBlanco)鉴定为基础,采用改良的CTAB法提取总DNA,在此基础上进行常规PCR与NestedPCR检测,并对特异目的片段进行克隆、测序。试验证明NestedPCR比常规PCR的灵敏度更高。这两种方法均可以检测出未显症的黄龙病材料,但NestedPCR可以在木本指示植物嫁接后40d左右、草本指示植物摩擦接种1个月左右检测到病原;而常规PCR在木本植物嫁接后60d左右、草本植物摩擦接种近2个月左右才能检测到病原。常规PCR所能检测到的最低DNA的量为pg数量级;NestedPCR检测病原DNA灵敏度约为常规PCR的104倍。 展开更多
关键词 柑橘 黄龙病 PCR nested—PCR 检测
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广西砂糖橘黄龙病亚洲种的Nested-PCR检测 被引量:8
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作者 黄宏明 王茜 +2 位作者 徐宁 韦宗便 廖惠红 《南方农业学报》 CAS CSCD 北大核心 2013年第12期1997-2000,共4页
【目的】利用柑橘黄龙病病原亚洲种16S rDNA序列的特异引物检测疑似黄龙病的砂糖橘叶片样品,为砂糖橘黄龙病的综合防控提供理论依据。【方法】选取采自广西9市17个采样点的214份疑似黄龙病及无症状砂糖橘叶片样品,用试剂盒法提取叶脉基... 【目的】利用柑橘黄龙病病原亚洲种16S rDNA序列的特异引物检测疑似黄龙病的砂糖橘叶片样品,为砂糖橘黄龙病的综合防控提供理论依据。【方法】选取采自广西9市17个采样点的214份疑似黄龙病及无症状砂糖橘叶片样品,用试剂盒法提取叶脉基因组DNA,采用柑橘黄龙病亚洲种16S rDNA特异引物进行PCR扩增,扩增结果在1%琼脂糖凝胶电泳上检测,统计待检样品柑橘黄龙病病原菌亚洲种的带菌率。【结果】对214份样品的Nested-PCR扩增结果,部分样品可得到1160 bp左右的特异条带,与预期大小相符但条带明暗不同。来自广西9市17个采样点的砂糖橘叶片样品均检测出黄龙病亚洲种病原,平均检出率均在66.0%以上,其中检出率最高的是来自东兴市的样品,检出率为100.0%,检出率最低的是来自南宁市的样品,检出率为66.9%;斑驳、缺素型黄化、叶脉黄化、小叶和无症状叶片样品中均可检测出黄龙病亚洲种。【结论】Nested-PCR技术具有灵敏度高、特异性强的特点,能够快速、准确检测出各种症状样品的黄龙病病原,可用于柑橘黄龙病的早期诊断。 展开更多
关键词 砂糖橘 黄龙病病原 检测率 nested—PCR 广西
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基于Nested Logit模型的铁路旅客客运产品选择研究 被引量:14
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作者 王文宪 陈钉钧 +1 位作者 吕红霞 江峰 《交通运输系统工程与信息》 EI CSCD 北大核心 2015年第4期140-146,共7页
通过成都—武汉既有线出行旅客的问卷调查,以及样本数据的归纳分析,对旅客客运产品选择行为特征进行描述.基于随机效用最大化理论,以乘车方式与客运产品作为选择肢,旅客主体、出行特性及列车服务特性的各项指标作为效用变量,构建了乘车... 通过成都—武汉既有线出行旅客的问卷调查,以及样本数据的归纳分析,对旅客客运产品选择行为特征进行描述.基于随机效用最大化理论,以乘车方式与客运产品作为选择肢,旅客主体、出行特性及列车服务特性的各项指标作为效用变量,构建了乘车方式位于上层、客运产品位于下层的Nested Logit模型.模型的上下层参数标定结果表明,旅客的收入状况、出行目的、出行距离、列车票价及运行时间对其乘车方案选择具有显著影响,旅客的年龄、出行费用来源、收入状况、出行距离,以及列车票价、运行时间对其客运产品选择具有显著影响.模型能较为准确地反映铁路客运产品的实际需求,从而为其合理设计与调整提供理论依据. 展开更多
关键词 铁路运输 效用变量 乘车方式 客运产品 nested LOGIT模型
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大豆油中转基因成分的Nested PCR和Semi-nested PCR检测方法研究 被引量:10
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作者 闻伟刚 崔俊霞 赵秀玲 《生物技术通报》 CAS CSCD 2005年第6期84-87,共4页
对大豆油中DNA提取方法进行了研究,结果表明CTAB、SDS和Wizard试剂盒提取大豆油DNA均具有良好的效果。利用nested PCR和semi-nested PCR检测大豆(Roundup Ready)油中的转基因成分发现,该方法能够检测到大豆原油中的Lectin基因(112bp)、C... 对大豆油中DNA提取方法进行了研究,结果表明CTAB、SDS和Wizard试剂盒提取大豆油DNA均具有良好的效果。利用nested PCR和semi-nested PCR检测大豆(Roundup Ready)油中的转基因成分发现,该方法能够检测到大豆原油中的Lectin基因(112bp)、CaMV35S基因(147bP)和CP4-EPSPS基因(205bp),检测灵敏度达到10-6ng/μl;但该方法未能从人豆成品油(一级)中扩增到上述基因,当中的转基因成分DNA含量低于10-12ng/μl。 展开更多
关键词 大豆油 转基因成分 nested PCR Semi-nested PCR检测
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RP/SP融合数据的Mixed Logit和Nested Logit模型估计对比 被引量:14
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作者 张天然 杨东援 +1 位作者 赵娅丽 叶亮 《同济大学学报(自然科学版)》 EI CAS CSCD 北大核心 2008年第8期1073-1078,1084,共7页
分析了RP/SP(revealed preference/stated preference)融合数据对交通行为研究的重要性,通过实际调查的RP/SP融合数据,对比了用Mixed Logit和Nested Logit模型的估计结果.得出了以下结论:RP/SP融合数据中,有时同类型交通方式的关联性要... 分析了RP/SP(revealed preference/stated preference)融合数据对交通行为研究的重要性,通过实际调查的RP/SP融合数据,对比了用Mixed Logit和Nested Logit模型的估计结果.得出了以下结论:RP/SP融合数据中,有时同类型交通方式的关联性要比RP和SP数据之间的关联性强,应用不同的Nested Logit模型分层方法进行估计对比;Mixed Logit考虑了个体的异质性,假定参数为随机分布,同时体现了RP/SP数据的关联性和同类型交通方式的关联性,能够得到更好的参数估计结果;Mixed Logit模型能更现实地反映不同交通方式使用者对时间和费用敏感性的不同(时间价值的不同),体现小汽车使用者比公共交通使用者具有更高时间价值的现实情况. 展开更多
关键词 RP/SP融合数据 MIXED Logit(RPL/RCL)模型 异质性 nested LOGIT模型
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