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Cedar Pollen and Cedar Pollinosis 被引量:1
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作者 Yin Min(殷 敏) Cheng Lei(程 雷) Akira Miyoshi 1 Peng Jieren(彭解人) 2 Chen Zhibin(陈智斌)\ Shi Haibo(时海波)\ T Sambe 3\ Y Taguchi 4\ N Sahashi 5 Department of Otolaryngology, the First Affiliated Hospital of Nangjing Medical University, Nanj 《Journal of Nanjing Medical University》 2000年第1期41-44,共4页
Objective To investigate the prevalence of cedar pollinosis in China, and compare Cryptomeria fortunei(Cf) with Cryptomeria japonica (Cj) morphologically. Methods\ An epidemiological survey on nasal allergy was carri... Objective To investigate the prevalence of cedar pollinosis in China, and compare Cryptomeria fortunei(Cf) with Cryptomeria japonica (Cj) morphologically. Methods\ An epidemiological survey on nasal allergy was carried out among 1 660 primary and middle school students and 1 620 university students, including questionnaire investigation, nasal inspection by the same doctor and scratch test with the allergen extract of Cj. The pollen of Cf and Cj were observed by optical and electron microscope. The genes of chloroplast of them were analysed. Results ①The total positive rate of cedar pollen scratch test was 4.2%. 55 cases of nasal allergy were confirmed according to the criteria of diagnosis, in which 8 cases showed positive reaction to Cj and only 1 case was hypersentive to it. ②No significant distinction between Cf and Cj was found by optical and electron microscope and no difference in gene analysis was found. Conclusion\ ①Cedar pollinosis does exist in China. It′s low prevbalence is related to the low quantity of cedar pollen.②Cf and Cj are of the same family and genus. ③There may be an increasing tendency of cedar pollinosis in China.\; 展开更多
关键词 cedar cedar pollen cedar pollinosis EPIDEMIOLOGICAL
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Spatial Variations in Particle Size and Magnetite Concentration on Cedar Beach:Implications for Grain-Sorting Processes,Western Lake Erie,Canada 被引量:4
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作者 ZHANG Shuwei Maria T. CIOPPA ZHANG Shihong 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2010年第6期1520-1532,共13页
This study examined spatial variations in the concentration,grain size and heavy mineral assemblages on Cedar Beach(Lake Erie,Canada).Magnetic studies of heavy mineral-enriched,dark-reddish sands present on the beac... This study examined spatial variations in the concentration,grain size and heavy mineral assemblages on Cedar Beach(Lake Erie,Canada).Magnetic studies of heavy mineral-enriched,dark-reddish sands present on the beach showed that magnetite(~150μm) is the dominant magnetic mineral.Surficial magnetic susceptibility values defined three zones:a lakeward region close to the water line(Zone 1),the upper swash zone(Zone 2) and the region landwards of the upper swash zone (Zone 3).Zone 2 showed the highest bulk and mass susceptibility(κ,χ) and the highest mass percentage of smaller grain-size(250μm) fractions in the bulk sand sample.Susceptibility(i.e.κandχ) values decreased and grain size coarsened from Zone 2 lakewards(into Zone 1) and landwards (into Zone 3),and correlated with the distribution of the heavy mineral assemblage,most probably reflecting preferential separation of large,less dense particles by waves and currents both along and across the beach.The eroded western section of Cedar Beach showed much higher concentrations of heavy minerals including magnetite,and finer sand grain sizes than the accreting eastern section, suggesting that magnetic techniques could be used as a rapid,cost-effective way of examining erosion along sensitive coastline areas. 展开更多
关键词 magnetic susceptibility magnetite concentration grain size grain-sorting processes cedar Beach Lake Erie
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基于分布式数据库Cedar的高效工单管理系统设计与实现
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作者 潘宇晨 李宇明 +2 位作者 张春熙 张蓉 洪道诚 《华东师范大学学报(自然科学版)》 CAS CSCD 北大核心 2018年第3期88-96,共9页
随着互联网发展,企业随之转型,积极开展基于互联网的业务.传统业务系统架构基于集中式数据管理系统如MySQL之上,在封闭使用状态向开放使用状态转换的过程中,逐渐在可用性上暴露出弊端,故而不能很好地支持业务拓展规模化、分布式处理的要... 随着互联网发展,企业随之转型,积极开展基于互联网的业务.传统业务系统架构基于集中式数据管理系统如MySQL之上,在封闭使用状态向开放使用状态转换的过程中,逐渐在可用性上暴露出弊端,故而不能很好地支持业务拓展规模化、分布式处理的要求.网络业务的开展对工单系统提出了在支持大数据、高并发、高冲突、高可用下保证处理高效性的新需求.在深入分析当前业务特征的基础上,利用分布式数据库Cedar,基于Netty通信框架,以海尔的工单业务为实例,设计并实现了支持工单存储、派单以及工程师抢单业务的高效、可扩展工单管理系统,详述了系统的可靠性和可扩展实现.经实验表明,该工单系统在保证高吞吐和低延迟的同时具有良好的可扩展性和可用性. 展开更多
关键词 cedar 分布式计算 工单管理 share-nothing架构
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Impact of a Low Severity Fire on Soil Organic Carbon and Nitrogen Characteristics in Japanese Cedar Soil, Yamagata Prefecture, Japan 被引量:1
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作者 Felix Seidel M. Larry Lopez C +1 位作者 Georg Guggenberger Yoshihiro Nobori 《Open Journal of Forestry》 2017年第2期270-284,共15页
Slash and burn practices are widely used around the globe with different degrees of success which are mostly related to the impact of fire on soil properties. In Japan slash and burn practises, known as Yakihata, have... Slash and burn practices are widely used around the globe with different degrees of success which are mostly related to the impact of fire on soil properties. In Japan slash and burn practises, known as Yakihata, have a long history and are still used in Yamagata Prefecture today. The purpose of this study was to determine the impact of a low severity controlled fire underneath Japanese cedar (Cryptomeria japonica) on brown forest soil (Cambisol). Japanese Cedar is the dominant species among plantations in Japan. We measured organic carbon and nitrogen content as well as changes in carbon (δ13C) and nitrogen (δ15N) stable isotope composition in a steep west facing slope under heavy precipitation (~2600 mm/a) and heavy snowfall (~3 to 4 m/a). The accumulation of Ctotal and Ntotal at the bottom of the slopes was remarkably higher at the slash and burned site than in the control forest site. After slash and burn δ15N isotopes in the slope in general became significantly lighter than in the control forest while the δ13C did not show any significant difference between the two sites except at the bottom of the slopes where δ13C was heavier in the forest. The results show that Ctotal and Ntotal values as well as the isotopes ratios of C and N change with decreasing elevation in the forest as well as in the burned site being consistent with leaching and erosion. The changes in soil nitrogen and carbon isotopes at the bottom of the slope appear to be related to the transport of material with different isotopic composition from the upper slope. The effect of the low severity fire (as part of the slash and burn practice) on soil organic carbon and nitrogen movement was enhanced by the steepness of the slopes and the high precipitation of Shonai region. 展开更多
关键词 High Precipitation Japanese cedar Forest SOIL LOW SEVERITY FIRE Stable Isotopes STEEP Slopes
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Spatial Variations in Particle Size,Heavy Mineral Assemblage and Magnetic Concentration of Dark-reddish Sands on Cedar Beach,Western Lake Erie,Ontario,Canada
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作者 Maria T.Cioppa 《地学前缘》 EI CAS CSCD 北大核心 2009年第S1期124-124,共1页
Environmental magnetic research on beaches and shoreline processes is limited.Therefore,we carried out environmental magnetic studies on the heavy mineral-enriched,dark-reddish sands on Cedar Beach of western Lake Eri... Environmental magnetic research on beaches and shoreline processes is limited.Therefore,we carried out environmental magnetic studies on the heavy mineral-enriched,dark-reddish sands on Cedar Beach of western Lake Erie(41.68°N,82.40°W).Magnetite has been identified as the dominant magnetic mineral of these sands.This study reveals a spatial variation in concentration of magnetite particles,distribution of 展开更多
关键词 heavy mineral MAGNETIC CONCENTRATION grain size dark-reddish SANDS cross-shore and lonshore variation cedar BEACH Lake Erie
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Impacts of Land Cover Changes on Runoff and Sediment in the Cedar Creek Watershed,St.Joseph River,Indiana,United States
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作者 JIANG Xiaobo Chi-hua Huang Fushui Ruan 《Journal of Mountain Science》 SCIE CSCD 2008年第2期113-121,共9页
The relation between runoff and sediment and land cover is investigated in the Cedar Creek Watershed (CCW), located in Northeastern Indiana, United States. The major land cover types in this watershed are cultivated... The relation between runoff and sediment and land cover is investigated in the Cedar Creek Watershed (CCW), located in Northeastern Indiana, United States. The major land cover types in this watershed are cultivated land, woodland and pasture /Conservation Reserve Program (CRP), which account for approximate 90 % of the total area in the region. Moreover, land use was changed tremendously from aooo to 9004, even without regarding the effect of the crop rotation system (corn & soybean). At least 49 % of land cover types were changed into other types in this period. The land cover types, ranking by changing area from high to low series, are rye, soybean, corn, woodland and pasture/CRP. The CCW is divided into 21 subwatersheds, and soil and water loss in each sub-watershed is computed by using Soil and Water Assessment Tool (SWAT). The results indicate that the variations in runoff and sediment have positive relation to the area of crops (especially corn and soybean); sediment is more sensitive to land cover changes than runoff; more heavy rainfall does not always mean more runoff because the combination of different land cover types always modify runoff coefficient; and rye, soybean and corn are the key land cover types, which affected the variation in runoff and sediment in the CCW. 展开更多
关键词 cedar Creek watershed Soil and Water Assessment Tool land cover change RUNOFF SEDIMENT
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Microwave Assisted Acid Digestion of Biomorphic Ceramic Obtained from Cedar Wood Infiltrated with ZrO2
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作者 F. Sánchez Rojas C. Bosch Ojeda J. M. Cano Pavón 《American Journal of Analytical Chemistry》 2011年第1期66-74,共9页
This work proposes the use of experimental design for optimization of microwave-assisted digestion of bio- morphic ZrO2-ceramic. Cedar wood is used as template and it was infiltrated with ZrO2 via sol-gel process. XPS... This work proposes the use of experimental design for optimization of microwave-assisted digestion of bio- morphic ZrO2-ceramic. Cedar wood is used as template and it was infiltrated with ZrO2 via sol-gel process. XPS, SEM and XRD have been used to verify the effectiveness of the synthesis. The effects of different combination of acids in the digestion of this sample have been optimized taking as response the concentra- tion of several metallic ions measured by ICP-MS. 展开更多
关键词 cedar WOOD Microwave DIGESTION ICP-MS Metallic IONS Experimental Design
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Estimation of Carbon Sequestration;Using Allometric Equations;in Azrou Cedar Forests (Cedrus atlantica Manetti) in the Central Middle Atlas of Morocco under Climate Change
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作者 Mohamed El Mderssa Bakhyi Belghazi +3 位作者 Hassan Benjelloun Omar Zennouhi Laila Nassiri Jamal Ibijbijen 《Open Journal of Forestry》 2019年第3期214-225,共12页
The topic of carbon sequestration in forest ecosystems has recently taken a lot of attention due to concerns about global climate change. As a spontaneous species of the Central Middle Atlas, the Atlas Cedar was the s... The topic of carbon sequestration in forest ecosystems has recently taken a lot of attention due to concerns about global climate change. As a spontaneous species of the Central Middle Atlas, the Atlas Cedar was the subject of our study. Thus, a total of 30 sample trees were subjected to the weight measurements for the estimation of biomass and organic carbon stock in a logging lot in the Azrou forest. The amount of sequestered carbon was then extrapolated in all stand forests studied from the developed carbomass models. The results obtained show that the largest allocation of carbon stock (93%) is in the stem, followed by branches (5%) and foliage (2%). The average carbon storage in this cedar forest is 99.42 tC/ha (aboveground and belowground), or 364.58 t/ha of CO2, a value significantly higher than that found in other Moroccan forest ecosystems. 展开更多
关键词 ATLAS cedar Carbon CLIMATE Change SEQUESTRATION STOCK
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Study of Atlas Cedar Growth (<i>Cedrus atlantica</i>Manetti) in El M’sid Mountains (East Algeria): Productivity and Growth According to Planting Methods
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作者 Amina Keriem Mohamed Sbabdji Luc Lambs 《Open Journal of Forestry》 2018年第2期182-195,共14页
The Atlas cedar (Cedrus atlantica) is one of the more valuable reforestation species in the Mediterranean areas. But this species suffers from rainfall limitation and climate changes, particularly in its originated ar... The Atlas cedar (Cedrus atlantica) is one of the more valuable reforestation species in the Mediterranean areas. But this species suffers from rainfall limitation and climate changes, particularly in its originated area, North Africa. Therefore, any knowledge about the plantation practices to improve the tree water availability and the reforestation success has great importance. The current study has been undertaken in this view, i.e. to compare the growth of cedar plots located in El M’Sid Mountains, Souk Ahras department (700 km east of Algiers), according to different planting methods. The radial growth and the productivity have been measured on a cedar plot with a total surface of 165 ha. 150 ha has been planted in 1970 on hillside ditches, and 15 ha of which the majority is planted in a simple hole and some bouquets on terraces, both are originated from a complementary reforestation achieved during 1980. The results show that most of the trees planted in 1970 reach a height ranging between 10 and 17 m and a diameter between 23 and 44 cm. Even some trees were 20 m high with diameter of 65 cm. The productivity fluctuates between 3 and 8 m3/ha/year, values close to the one of natural native plots. Trees planted in 1980 reach a height ranging between 5. 5 to 7 m, and diameter between 11.5 to 23 cm. The radial growth improves that the hillside ditches help the roots anchoring and trees growth during the first season after plantation. These results indicate that the cedar tree can be used with success in areas outside the natural cedar forest presence, and that appropriate planting techniques can compensate in part the lower rainfall occurring in these chosen regeneration areas. 展开更多
关键词 ATLAS cedar EL M’Sid MOUNTAINS Tree PRODUCTIVITY Radial GROWTH Hillside Ditches
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Non-Contact Velocity Measurement of Japanese Cedar Columns Using Air-Coupled Ultrasonics
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作者 Masumi Hasegawa Misaki Mori Junji Matsumura 《World Journal of Engineering and Technology》 2016年第1期45-50,共6页
The ultrasonic wave velocities of Japanese cedar columns were measured using a non-contact method. An air-coupled ultrasonic wave was propagated through the axial and lateral directions of wood. The velocities in the ... The ultrasonic wave velocities of Japanese cedar columns were measured using a non-contact method. An air-coupled ultrasonic wave was propagated through the axial and lateral directions of wood. The velocities in the axial direction (V<sub>L</sub>) showed the minimum values around the pith. The averaged V<sub>L</sub> increased from 3600 m/s towards the outside of measurement area and attained the maximum values (=4010 m/s). The velocities in the lateral direction (V<sub>RT </sub>) showed no tendency among measurement points. The averaged V<sub>RT </sub> was 1450 m/s. The velocities obtained using the non-contact method showed a significant positive relationship with those obtained using the contact method. The averaged ratio of V<sub>L</sub> to V<sub>RT </sub> was measured to be approximately 2.2 to 2.8. These ratios were in agreement with those from a contact method. These findings suggest that it is possible to measure the velocity in Japanese cedar columns with the non-contact method by using air-coupled ultrasonics. 展开更多
关键词 Air-Coupled Ultrasonics VELOCITY Non-Contact Method Nodestructive Evaluation Japanese cedar
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Plantation management history and coarse woody debris characteristics influence the diversity of saproxylic beetles associated with Chinese cedar in Tianmushan, Zhejiang, East China
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作者 WU Jie PAN Hui +1 位作者 YANG Shu-Zhen NIU Xiao-Ling 《昆虫学报》 CAS CSCD 北大核心 2013年第2期173-185,共13页
关键词 天目山自然保护区 人工林经营 粗木质残体 多样性 甲虫 雪松 中国 浙江
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Development and evaluation of a quadruple real-time fluorescence-based quantitative reverse transcription polymerase chain reaction assay for detecting Langya, Mojiang, Nipah, and Cedar viruses 被引量:1
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作者 Wenjun He Tian Ma +5 位作者 Yalan Wang Weifang Han Jun Liu Wenwen Lei Le Zhang Guizhen Wu 《Biosafety and Health》 CAS CSCD 2024年第2期80-87,共8页
The emerging viruses within the genus Henipavirus in the family Paramyxoviridae pose a great threat to public biosafety.To develop a quadruple real-time fluorescence-based quantitative reverse transcription polymerase... The emerging viruses within the genus Henipavirus in the family Paramyxoviridae pose a great threat to public biosafety.To develop a quadruple real-time fluorescence-based quantitative reverse transcription polymerase chain reaction(qRT-PCR)assay is pivotal for the early warning of the potential of zoonotic infectious diseases.Specific primers and probes were designed for the relatively conserved regions based on whole genome sequences of Langya virus(LayV),Mojiang virus(MojV),Nipah virus(NiV),and Cedar virus(CedV),followed by the establishment of a quadruple real-time fluorescence-based qRT-PCR detection method.No cross-reactivity was observed with other viral nucleic acids.The optimal linear detection range for LayV,MojV,NiV,and CedV was 10^(1)-10^(8)copies/μL,and the lower limit of detection was 10 copies/μL.Three different DNA concentrations of LayV,MojV,NiV,and CedV(10^(4),10^(5),and 10^(6)copies/μL)were tested 14 times,achieving good repeatability.The standard deviation of the cycle threshold values for each concentration was<0.5 and the coefficient of variation was<3%.Furthermore,the amplification efficiency of quadruple real-time fluorescence-based qRT-PCR was>90%,and the correlation coefficient was>0.99.The established quadru-ple real-time fluorescence-based qRT-PCR assay for the detection of LayV,MojV,NiV,and CedV exhibits good sensitivity,specificity,and repeatability.Therefore,it can be used to detect Henipavirus and other related clinical specimens. 展开更多
关键词 Real-time fluorescence-basedq RT-PCR Langyavirus Mojiang virus Nipahvirus cedar virus
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土壤氮与微生物调控对毛竹和日本柳杉生长的影响——毛竹扩张潜在机制
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作者 张茜 方海富 +4 位作者 赵红 申家成 刘亮英 徐昕彤 张令 《植物研究》 北大核心 2025年第5期755-768,共14页
毛竹(Phyllostachys edulis)向周边林分扩张影响植物和土壤稳定性,而其成功扩张机制尚不明确。通过研究不同氮形态和土壤微生物对毛竹和日本柳杉(Cryptomeria japonica)生长的影响,揭示全球变化背景下毛竹扩张的养分与微生物机制。该研... 毛竹(Phyllostachys edulis)向周边林分扩张影响植物和土壤稳定性,而其成功扩张机制尚不明确。通过研究不同氮形态和土壤微生物对毛竹和日本柳杉(Cryptomeria japonica)生长的影响,揭示全球变化背景下毛竹扩张的养分与微生物机制。该研究采用盆栽试验,设置8 g?m-2氮输入处理(对照,Con;铵态氮,N1,施用硫酸铵溶液;硝态氮,N2,施用硝酸钾溶液),并调控土壤微生物群落(对照,Con;细菌抑制,B,施用3 g·L^(-1)链霉素溶液;真菌抑制,F,施用1 g·L^(-1)扑海因溶液),探讨单一和混合种植下毛竹和日本柳杉幼苗对氮输入和微生物的响应。结果表明:相比于对照,无论在单一种植还是混合种植下,氮输入可显著提高毛竹和日本柳杉幼苗的生物量和苗高,但显著降低根冠比。微生物处理中,在2种种植模式下,细菌和真菌抑制均降低2个物种的生物量和苗高(P<0.01),植物生长受限。与对照相比,细菌抑制下毛竹和日本柳杉生物量分别降低13.93%和11.57%,苗高分别降低9.41%和4.56%;真菌抑制下生物量分别降低15.84%和10.46%,苗高分别降低6.90%和3.20%。与单一种植相比,混合种植显著提高毛竹生物量和苗高,但同时将毛竹和日本柳杉根冠比分别降低6.01%和5.77%(P<0.05),混合种植下毛竹表现出较强的生长优势。氮输入处理中,与单种日本柳杉相比,单种毛竹和混合种植下土壤有机碳和全氮含量显著降低。N1、N2形态氮输入均显著降低各种植模式下土壤pH,混合种植土壤pH高于单一种植。在全球变化背景下,氮沉降导致的生态系统氮输入可能与毛竹扩张相互作用,形成正反馈,进而促进毛竹成功扩张。随着氮沉降加剧,土壤养分有效性与土壤微生物群落通过促进植物养分吸收和资源分配,促使植物竞争能力增强,导致毛竹向周边林分成功扩张。 展开更多
关键词 日本柳杉 氮输入 微生物调控 毛竹扩张
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西安城区弱势雪松大树生长状况调查与分析
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作者 张亚玲 杨群力 +4 位作者 余鸽 任磊 卫玮 郭亚君 李娜 《陕西林业科技》 2025年第5期97-101,109,共6页
为解决西安地区雪松大树“生长势衰弱、濒危甚至死亡”的问题,笔者在西安城区选择三处代表性的城市绿地,即道路绿地、公园绿地、附属绿地,按照等比例随机抽样的方式,对60株衰弱雪松大树的地径、冠幅、生长势、生长环境等进行测量、观察... 为解决西安地区雪松大树“生长势衰弱、濒危甚至死亡”的问题,笔者在西安城区选择三处代表性的城市绿地,即道路绿地、公园绿地、附属绿地,按照等比例随机抽样的方式,对60株衰弱雪松大树的地径、冠幅、生长势、生长环境等进行测量、观察和记录,通过主要因素分析法,从“人为因素、环境因素、病虫害”等三类情况入手,将引起雪松大树“生长势衰弱、濒危甚至死亡”的具体原因归结为“根系受损、覆土过厚、人为踩踏、密度过大、硬化铺设、积水、干旱、蛀干害虫和蚜虫等”9个方面,并对其危害性进行排序,为西安城区雪松大树的救治、复壮和后期管养提供参考。 展开更多
关键词 城市绿地 雪松大树 生长势 调查分析 复壮 救治
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雪松松针多糖结构及热变性研究
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作者 马晓彦 李泷帆 +3 位作者 李宇涵 段冰洁 吉一帆 于宏伟 《煤炭与化工》 2025年第3期145-152,共8页
研究了雪松松针多糖结构及热变性。开展了中红外(MIR)及变温MIR光谱实验。结果发现,雪松松针多糖结构的红外吸收模式主要包括:ν_(O-H-游离-雪松松针多糖)、ν_(O-H-缔合-雪松松针多糖)和ν_(C-O-雪松松针多糖)。在303~393 K的温度范围... 研究了雪松松针多糖结构及热变性。开展了中红外(MIR)及变温MIR光谱实验。结果发现,雪松松针多糖结构的红外吸收模式主要包括:ν_(O-H-游离-雪松松针多糖)、ν_(O-H-缔合-雪松松针多糖)和ν_(C-O-雪松松针多糖)。在303~393 K的温度范围内,随着测定温度的升高,炒决明子结构主要官能团(ν_(O-H-游离-雪松松针多糖)、ν_(O-H-缔合-雪松松针多糖)和ν_(C-O-雪松松针多糖))对应的红外吸收频率及强度均有明显的改变。进一步对其热变性机理进行了研究,MIR光谱及变温MIR光谱可以有效开展重要的天然产物(雪松松针多糖)结构及热变性研究。 展开更多
关键词 雪松松针多糖 中红外光谱 结构 热变性
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国内外数字资源长期保存研究现状与进展 被引量:30
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作者 黄旭 毕强 《图书馆学研究》 CSSCI 北大核心 2009年第1期25-28,共4页
本文首先对数字资源长期保存国际会议(IPRES)以及国外具有代表性的启动项目进行简要介绍,进而分析我国数字资源长期保存的研究现状,通过比较国内外研究现状及进展情况,找出我国与国外的差距,并提出我国数字资源长期保存的几点建议。
关键词 数字资源 保存方式 研究进展 NDIIPP项目 cedarS项目 图书馆
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关于数字信息长期保存的元数据 被引量:30
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作者 梁娜 张晓林 《四川图书馆学报》 2002年第1期24-32,共9页
在简要介绍数字信息长期保存体系框架OAIS的基础上 ,介绍了CEDARS、PANDORA/NLA。
关键词 元数据 数字信息长期保存 cedarS PANDORA/NLA NEDLIB
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MANET中基于蚁群的网络核心提取分布路由协议 被引量:1
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作者 何炎祥 文卫东 +1 位作者 金辉 刘浩文 《计算机工程》 CAS CSCD 北大核心 2006年第14期83-84,106,共3页
提出了一个用于移动Ad Hoc网络(MANET)的基于蚁群的核心提取分布路由协议——Ant-CEDAR,该协议使用类似蚁群的移动代理获得高效的路由,从而可加强核心提取分布Ad Hoc路由算法(CEDAR)。对Ant-CEDAR协议进行了模拟实验,实验数据表明该协... 提出了一个用于移动Ad Hoc网络(MANET)的基于蚁群的核心提取分布路由协议——Ant-CEDAR,该协议使用类似蚁群的移动代理获得高效的路由,从而可加强核心提取分布Ad Hoc路由算法(CEDAR)。对Ant-CEDAR协议进行了模拟实验,实验数据表明该协议具有高效性和低耗性。 展开更多
关键词 MANET 蚁群 cedar
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林龄对秃杉人工林土壤碳氮储量的影响
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作者 刘婧岩 《林业科技情报》 2025年第1期13-15,共3页
为了解不同林龄阶段下秃杉人工林土壤碳氮储量状况,探讨林龄对人工林土壤有机碳以及全氮含量及储量的影响。选择地理位置毗邻、立地条件相似的区域,以5种林龄(10年生、16年生、22年生、29年生和35年生)秃杉人工林作为研究对象,采集分析... 为了解不同林龄阶段下秃杉人工林土壤碳氮储量状况,探讨林龄对人工林土壤有机碳以及全氮含量及储量的影响。选择地理位置毗邻、立地条件相似的区域,以5种林龄(10年生、16年生、22年生、29年生和35年生)秃杉人工林作为研究对象,采集分析林地土壤有机碳与全氮含量及储量的变化特征,以及碳氮储量之间关系。结果表明:林龄不断增加情况下,土壤密度逐渐下降,土壤有机碳质量分数以及全氮质量分数逐渐上升。10、16、22、29和35年生秃杉人工林土壤0~100 cm土层,有机碳储量分别达到161.33、165.6、171.04、175.93和185.24 t·hm^(-2),全氮储量分别达到18.30、20.64、24.20、25.94和28.26 t·hm^(-2)。因此,秃杉人工林不断健康生长过程,对土壤有机碳以及全氮的生物积累所提供的有益作用也不断提升,促进土壤碳氮储量同步提升。 展开更多
关键词 林龄 秃杉 人工林 碳氮储量
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多孔异形闸墩混凝土无缝施工技术
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作者 张帅 张兴旺 张俊 《云南水力发电》 2025年第10期60-63,共4页
针对传统分缝闸墩二次浇筑法存在的施工效率低、层间质量差等问题,以鄱阳湖分洪闸工程为背景,提出异形闸墩整体浇筑施工技术。通过研发定型钢模-精轧螺纹钢组合支撑体系,实现双缝墩一次成型;创新采用“T型钢筋+沥青杉板”结构缝加固工艺... 针对传统分缝闸墩二次浇筑法存在的施工效率低、层间质量差等问题,以鄱阳湖分洪闸工程为背景,提出异形闸墩整体浇筑施工技术。通过研发定型钢模-精轧螺纹钢组合支撑体系,实现双缝墩一次成型;创新采用“T型钢筋+沥青杉板”结构缝加固工艺,解决沥青杉木板变形控制难题。工程应用表明,该技术使闸墩施工周期缩短40%,垂直度偏差控制在H/2000以内,结构缝渗漏率降低至0.5%以下。 展开更多
关键词 异形闸墩 整体浇筑 结构缝处理 沥青杉木板
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