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CRTSⅡ型板式无砟轨道水泥沥青砂浆原材料基准样对比检验的研究
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作者 黄亚敏 《四川建材》 2013年第2期31-32,共2页
原材料质量稳定性影响水泥乳化沥青砂浆性能,结合石武客专水泥乳化沥青砂浆施工经验,在满足相关规定的基础上,对原材料提出基准样对比检验管理方法,达到消除乳化沥青等原材料质量稳定波动的影响,使水泥乳化沥青砂浆质量移定可靠。
关键词 原材料 基准样 对比检验
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基于基准样地法和国产高分数据的湖南省森林植被碳储量估测 被引量:7
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作者 张沁雨 王海宾 +3 位作者 彭道黎 夏朝宗 陈健 柳文杰 《应用生态学报》 CAS CSCD 北大核心 2019年第10期3385-3394,共10页
为推广国产高分数据在大尺度范围碳储量估测计量的应用,采用覆盖湖南省的206景高分辨率遥感影像,将估测的最小单元固定为由多个像元组合成的面积为0.06hm^2的正方格,通过解译标志的建立和提纯,在森林信息提取上,利用基于像元法和面向对... 为推广国产高分数据在大尺度范围碳储量估测计量的应用,采用覆盖湖南省的206景高分辨率遥感影像,将估测的最小单元固定为由多个像元组合成的面积为0.06hm^2的正方格,通过解译标志的建立和提纯,在森林信息提取上,利用基于像元法和面向对象分类法进行比较;在乔木林碳储量估测上,利用稳健估计、偏最小二乘法和基准样地法(k-NN)估计进行比较,最后实现了对湖南省森林的碳储量估测,并生成了全省的碳密度等级分布图.结果表明:基于样地自动提取的解译标志在经过提纯后,能进一步增加乔木林提取精度;对于大尺度范围森林植被碳储量估测,无论是在森林信息提取还是乔木林碳储量建模方面,k-NN算法都体现了较大优势,是最佳估测方法;206景影像的平均分类总精度为76.8%,平均均方根误差为8.95 t·hm^-2,平均相对均方根误差为19.1%,湖南省碳储量总量为22.28 Mt.本研究结果为省级及国家级尺度的森林植被碳储量估测计量与监测提供了有效参考. 展开更多
关键词 森林植被碳储量 解译标志 基准样地法 国产高分卫星数据
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天然草地放牧系统功能优化与管理专家系统研究
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作者 董全民 杨晓霞 +5 位作者 丁路明 刘文亭 张春平 俞旸 曹铨 尚占环 《青海科技》 2023年第2期36-43,共8页
以青海三江源区联户规模化经营中草地数字化决策管理的现实需求为指导,基于草地营养生产能力和营养载畜能力,重点开展了草地监测分类、分区监测、评价、区划等研究,建立了三江源区草地监测基准样地技术体系、高寒草地放牧家畜行为信息... 以青海三江源区联户规模化经营中草地数字化决策管理的现实需求为指导,基于草地营养生产能力和营养载畜能力,重点开展了草地监测分类、分区监测、评价、区划等研究,建立了三江源区草地监测基准样地技术体系、高寒草地放牧家畜行为信息化监测技术体系和家庭联营牧场优化管理模式和技术体系,研发了三江源区草畜数字化平台和放牧管理专家系统,促进了三江源区高寒畜牧业的放牧系统信息化管理技术的发展,为实现高寒牧区以草定畜和牧区草地畜牧业生产的科学管理与决策提供了技术支撑和管理平台。 展开更多
关键词 三江源区 草畜平衡 基准样 放牧信息化管理
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Gel Microbead Cultivation with a Subenrichment Procedure Can Yield Better Bacterial Cultivability from a Seawater Sample than Standard Plating Method 被引量:2
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作者 JI Shiqi ZHAO Rui +4 位作者 YIN Qi ZHAO Yuan LIU Chenguang XIAO Tian ZHANG Xiaohua 《Journal of Ocean University of China》 SCIE CAS 2012年第1期45-51,共7页
A gel microbead (GMD) cultivation method was employed to cultivate microorganisms from an amphioxus breeding zone in Qingdao, P. R. China. The culture results were compared with those by standard plating method. In th... A gel microbead (GMD) cultivation method was employed to cultivate microorganisms from an amphioxus breeding zone in Qingdao, P. R. China. The culture results were compared with those by standard plating method. In the GMD-based method, the microcolony-forming GMDs were sorted by fluorescence-activated cell sorting (FACS). To further get pure cultures, a subsequent enrichment culture and a streaking purification procedure were conducted on marine R2A medium. Eighty bacterial strains isolated by the GMD-based method were randomly selected for sequencing. These isolates belonged to Alphaproteobacteria (33%), Gammaproteobacteria (44%), Bacteroidetes (11%), Actinobacteria (5%), Firmicutes (5%), Epsilonproteobacteria (1%), and Verrucomicrobia (1%), the last two groups being usually difficult to culture. The 16S rRNA gene sequences revealed a diverse community with 91.1%-100% of the bacterial rRNAs similarities. Thirteen strains were sharing 16S rRNA gene sequence which was less than 97% similar to any other rRNA genes currently deposited in TYP16S database. Seventy isolates derived from the standard plating method fell into 4 different taxonomic groups: Alphaproteobacteria (9%), Gammaproteobacteria (81%), Bacteroidetes (7%) and Firmicutes (3%) with a 16S rRNA gene sequence similarities between 95.8%-100%, in which only 3 strains were sharing 16S rRNA gene sequence of less than 97%. The results indicated that the GMD-based method with subenrichment culture yielded more taxonomic groups and more novel microbial strains, including members of previously rarely cultured groups, when compared with the standard plating method, and that this method markedly improved the bacterial cultivability. 展开更多
关键词 GMD cultivation marine microorganism bacterial cultivability amphioxus
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A Conceptually-Based Empirical Analysis on Quality Differences Between UK Annual Reports and US 10-K Reports
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作者 Geert Braam Ferdy van Beest 《Journal of Modern Accounting and Auditing》 2013年第10期1281-1301,共21页
The International Accounting Standards Board (IASB) and the Financial Accounting Standards Board (FASB) stress the importance of high-quality 'financial reports. From a scientific point of view, however, major me... The International Accounting Standards Board (IASB) and the Financial Accounting Standards Board (FASB) stress the importance of high-quality 'financial reports. From a scientific point of view, however, major methodological drawbacks can arise when trying to arrive at a comprehensive assessment and evaluation of the decision usefulness of financial reports. In this conceptually-based exploratory study, the authors construct a 33-item index aimed at operationalizing decision usefulness in terms of the fundamental and enhancing qualitative characteristics laid out in the conceptual framework (CF) of the IASB (2010). Using a matched-pairs sample design, which includes 70 UK annual reports and 70 US 10-K reports for 2010, the results of test-retest and inter-rater reliability tests show that these multiple items, which were based on items used in previous research, can be measured in a reliable manner. At the same time, the results of an exploratory factor analysis indicate that the IASB qualitative characteristics cannot be measured separately when the 33-item index is applied. At an aggregate level, the results of paired-sample t-tests reveal that UK reports score on average higher than US 10-K reports, which suggests that the overall quality of UK reports is better. The findings of this study add to the existing literature on the empirical evaluation of the effects of international accounting standards, showing that, as compared with 10-K reports, UK annual reports provide more information on topics such as corporate social responsibility (CSR), corporate governance, and annual bonus schemes. On the other hand, US reports outperform UK reports with respect to the content of fair value information, cash flow statements, off-balance financing, and audit reporting. 展开更多
关键词 financial reporting quality decision usefulness assessment and evaluation conceptual framework (CF) qualitative characteristics conceptually-based measurement tool
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CCD扫描检测光束准直度 被引量:8
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作者 张明丽 刘立人 +1 位作者 万玲玉 栾竹 《光学学报》 EI CAS CSCD 北大核心 2005年第8期1067-1071,共5页
提出一种检测光束准直度的新方法。在对波面矢高进行定义的基础上,提出CCD轴向扫描检测激光束准直度的方法。利用采样光波在会聚透镜后形成的衍射图样,测量两个相同基准衍射图样之间的距离,即可确定入射光波的波面矢高,进而确定入射光... 提出一种检测光束准直度的新方法。在对波面矢高进行定义的基础上,提出CCD轴向扫描检测激光束准直度的方法。利用采样光波在会聚透镜后形成的衍射图样,测量两个相同基准衍射图样之间的距离,即可确定入射光波的波面矢高,进而确定入射光波的准直度。在给出测量原理及模拟基准衍射图样的基础上,进行了实验验证。CCD轴向扫描方法具有结构简单、加工便利、操作方便的特点,是检测光束准直度的有效方法。 展开更多
关键词 衍射与光栅 准直测试 波面矢高 基准衍射罔 基准衍射平面
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