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Effects of land use change on the spatiotemporal variability of soil organic carbon in an urban-rural ecotone of Beijing,China

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Journal of Integrative Agriculture 2016年第4期15卷 918-928页

作者： YE Hui-chun huang yuan-fang CHEN Peng-fei huang Wen-jiang ZHANG Shi-wen huangShan-yu HOU Sen Key Laboratory of Digital Earth Science Institute of Remote Sensing and Digital EarthChinese Academy of SciencesBeijing 100094P.R.China Hainan Key Laboratory of Earth Observation Sanya 572029P.R.China College of Resources and Environment China Agricultural UniversityBeijing 100193P.R.China State Key Laboratory of Resources and Environment Information System Institute of Geographic Science and Natural Resources ResearchChinese Academy of SciencesBeijing 100101P.R.China College of Earth and Environment Anhui University of Science and TechnologyHuainan 232001P.R.China Institute of Geography University of CologneKoln 50923Germany

Understanding the effects of land use changes on the spatiotemporal variation of soil organic carbon （SOC） can provide guidance for low carbon and sustainable agriculture. In this paper, based on the large-scale datasets of soil surveys in 1982 and 2009 for Pinggu District -- an urban-rural ecotone of Beijing, China, the effects of land use and land use changes on both temporal variation and spatial variation of SOC were analyzed. Results showed that from 1982 to 2009 in Pinggu District, the following land use change mainly occurred： Grain cropland converted to orchard or vegetable land, and grassland converted to forestland. The SOC content decreased in region where the land use type changed to grain cropland （e.g., vegetable land to grain cropland decreased by 0.7 g kg-1; orchard to grain cropland decreased by 0.2 g kg-l）. In contrast, the SOC content increased in region where the land use type changed to either orchard （excluding forestland） or forestland （e.g., grain cropland to orchard and forestland increased by 2.7 and 2.4 g kg-1, respectively; grassland to orchard and forestland increased by 4.8 and 4.9 g kg-1, respectively）. The organic carbon accumulation capacity per unit mass of the soil increased in the following order： grain cropland soil〈vegetable land/grassland soil〈orchard soil〈forestland soil. Therefore, to both secure supply of agricultural products and develop low carbon agriculture in a modern city, orchard has proven to be a good choice for land using.

关键词： land use change soil organic carbon spatiotemporal variability urban-rural ecotone

Spatial Interpolation of Soil Texture Using Compositional Kriging and Regression Kriging with Consideration of the Characteristics of Compositional Data and Environment Variables

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Journal of Integrative Agriculture 2013年第9期12卷 1673-1683页

作者： ZHANG Shi-wen SHEN Chong-yang CHEN Xiao-yang YE Hui-chun huang yuan-fang LAI Shuang China Agricultural University/Key Laboratory of Arable Land Conservation (North China) Minstry of Agriculture/Key Laboratory of Agricultural Land Quality MonitoringMinistry of Land and Resources School of Earth and Environment Anhui University of Science and Technology Afforestation Management Office Sichuan Forestry Department

The spatial interpolation for soil texture does not necessarily satisfy the constant sum and nonnegativity constraints. Meanwhile, although numeric and categorical variables have been used as auxiliary variables to improve prediction accuracy of soil attributes such as soil organic matter, they （especially the categorical variables） are rarely used in spatial prediction of soil texture. The objective of our study was to comparing the performance of the methods for spatial prediction of soil texture with consideration of the characteristics of compositional data and auxiliary variables. These methods include the ordinary kriging with the symmetry logratio transform, regression kriging with the symmetry logratio transform, and compositional kriging （CK） approaches. The root mean squared error （RMSE）, the relative improvement value of RMSE and Aitchison＇s distance （DA） were all utilized to assess the accuracy of prediction and the mean squared deviation ratio was used to evaluate the goodness of fit of the theoretical estimate of error. The results showed that the prediction methods utilized in this paper could enable interpolation results of soil texture to satisfy the constant sum and nonnegativity constraints. Prediction accuracy and model fitting effect of the CK approach were better, suggesting that the CK method was more appropriate for predicting soil texture. The CK method is directly interpolated on soil texture, which ensures that it is optimal unbiased estimator. If the environment variables are appropriately selected as auxiliary variables, spatial variability of soil texture can be predicted reasonably and accordingly the predicted results will be satisfied.

关键词： compositional kriging auxiliary variables regression kriging symmetry logratio transform

Spatial distribution prediction and benefits assessment of green manure in the Pinggu District,Beijing,based on the CLUE-S model

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Journal of Integrative Agriculture 2016年第2期15卷 465-474页

作者： ZHANG Li-ping ZHANG Shi-wen ZHOU Zhi-ming HOU Sen huang yuan-fang CAO Wei-dong College of Resources and Environment China Agricultural University/Key Laboratory of Arable Land Conservation(North China)Minstry of Agriculture/Key Laboratory of Agricultural Land Quality MonitoringMinistry of Land and Resources School of Earth and Environment Anhui University of Science and Technology Institute of Agricultural Resources and Regional Planning Chinese Academy of Agricultural Sciences

Green manure use in China has declined rapidly since the 1980 s with the extensive use of chemical *** deterioration of field environments and the demand for green agricultural products have resulted in more attention to green *** intervention and policy-oriented behaviors likely have large impacts on promoting green manure ***,little information is available regarding on where,at what rates,and in which ways（i.e.,intercropping green manure in orchards or rotating green manure in cropland） to develop green manure and what benefits could be gained by incorporating green manure in fields at the county *** paper presents the conversion of land use and its effects at small region extent（CLUE-S） model,which is specifically developed for the simulation of land use changes originally,to predict spatial distribution of green manure in cropland and orchards in 2020 in Pinggu District located in Beijing,*** types of land use for planting or not planting green manure were classified and the future land use dynamics（mainly croplands and orchards） were considered in the *** scenarios were used to predict the spatial distribution of green manure based on data from 2011：The promotion of green manure planting in orchards（scenario 1） and the promotion of simultaneous green manure planting in orchards and croplands（scenario 2）.The predictions were generally accurate based on the receiver operating characteristic（ROC） and Kappa indices,which validated the effectiveness of the CLUE-S model in the *** addition,the spatial distribution of the green manure was acquired,which indicated that green manure mainly located in the orchards of the middle and southern regions of Dahuashan,the western and southern regions of Wangxinzhuang,the middle region of Shandongzhuang,the eastern region of Pinggu and the middle region of Xiagezhuang under scenario *** manure planting under scenario 2 occurred in orchards in the middle re

关键词： CLUE-S model green manure spatial distribution prediction benefits assessment

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中国河流沙粒对水轮机磨损影响的研究与实践

水力发电 2005年第12期31卷 56-58页

作者：黄源芳中国长江三峡工程开发总公司湖北宜昌443002

多泥沙河流的水电站,进入水轮机的水流含有不同程度的泥沙,对水轮机的过流部件常常造成严重的磨损。在实际工程中,空蚀和磨损两者相互作用造成严重后果。中国的江河水流含泥沙较多,在这些河流上修建的水电站,水轮机受泥沙磨损的侵害比... 详细信息

多泥沙河流的水电站,进入水轮机的水流含有不同程度的泥沙,对水轮机的过流部件常常造成严重的磨损。在实际工程中,空蚀和磨损两者相互作用造成严重后果。中国的江河水流含泥沙较多,在这些河流上修建的水电站,水轮机受泥沙磨损的侵害比较严重。50多年来,我国的科技工作者对水轮机防泥沙磨损作了大量的研究工作,并积累了一些行之有效的工程实践经验,同时也借鉴了国外同行的应用实践,在水轮机的抗磨损方面已不同程度地取得了一些成效。

关键词：多泥沙河流水轮机磨损研究

用AVR单片机实现的矿井顶板离层容栅位移测量系统

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煤炭技术 2013年第4期32卷 144-146页

作者：黄仿元贵州大学职业技术学院信息工程系贵阳550001

本文详细分析了容栅传感器的结构和工作原理,在此基础上设计了一套容栅传感器测量矿井顶板离层位移的系统,并利用单片机C语言实现了对容栅传感器输出信号的采集。该系统可以实现容栅传感器和上位机的通信,极大的丰富了容栅传感器的功能... 详细信息

本文详细分析了容栅传感器的结构和工作原理,在此基础上设计了一套容栅传感器测量矿井顶板离层位移的系统,并利用单片机C语言实现了对容栅传感器输出信号的采集。该系统可以实现容栅传感器和上位机的通信,极大的丰富了容栅传感器的功能,使测量到的数据便于保存、处理和分析。

关键词：顶板离层容栅位移传感器 AVR单片机

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三峡机组设计性能及结构特点

人民长江 2001年第5期32卷 1-3页

作者：黄源芳中国长江三峡工程开发总公司湖北宜昌443002

目前，三峡左岸电站１４台水轮发电机组已进入制造和安装阶段。从前期建安情况看也显现出机组的设计性能和结构难点。如在水轮机设计制造方面存在水头变幅大、最优效率保证值以及高水头区稳定性要求高、尾水管压力脉动指标范围小等，在... 详细信息

目前，三峡左岸电站１４台水轮发电机组已进入制造和安装阶段。从前期建安情况看也显现出机组的设计性能和结构难点。如在水轮机设计制造方面存在水头变幅大、最优效率保证值以及高水头区稳定性要求高、尾水管压力脉动指标范围小等，在水轮机结构设计方面，还存在结构尺寸大、泥沙磨损、材质选择和加工运输等特点要求；在发电机设计制造上也存在电网参数要求、推力负荷大、定于绕组冷却方式、定子机座及转子支架结构复杂等难点。针对上述技术问题，通过技术咨询与联络协商，加强监造控制，并借助其他大型机组的制造经验和最新科技成果，已经找到了解决众多复杂难题的办法，我们相信，只要控制好每一个环节，最终将实现设计性能和结构设计优化成果的目标。

关键词：三峡水利枢纽水轮发电机组设计性能结构设计

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浅析水电机组修复改造的目的

大电机技术 2008年第5期 31-34页

作者：黄源芳中国三峡总公司湖北宜昌443002

水电是可再生的绿色能源,开发新水电和改造老水电是同等重要相辅相成地增加发电量的途径。为后者,需对老水电站的核心设备——水电机组进行修复和现代化改造。本文列举国内外若干实例,对其改造的原因、目的进行了初步归纳浅析。

关键词：水电机组修复改造

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不同样本数量下土壤属性空间预测比较

中国农业科学 2013年第22期46卷 4716-4725页

作者：柴旭荣黄元仿山西师范大学城市与环境科学学院中国农业大学资源与环境学院

【目的】通过不同样本数量情形下土壤属性空间预测精度的对比,探讨样本数对预测精度的影响。【方法】以土壤有机质、土壤质量含水量、土壤速效钾和土壤有效锰4个土壤属性作为研究对象,采用矩量法(MoM)和有限最大似然法(REML)两种变异函... 详细信息

【目的】通过不同样本数量情形下土壤属性空间预测精度的对比,探讨样本数对预测精度的影响。【方法】以土壤有机质、土壤质量含水量、土壤速效钾和土壤有效锰4个土壤属性作为研究对象,采用矩量法(MoM)和有限最大似然法(REML)两种变异函数计算方法,对比分析在不同样本数情形下各土壤属性空间预测精度。【结果】(1)不论是利用MoM法还是REML法计算变异函数,样本点数从50增加到70,各土壤变量预测精度都有了明显提高;样本数从70逐步增加到150过程中,预测精度没有明显提高;(2)在不同样本数情形下,REML法相对于MoM法的预测精度的提高率具有明显的变化,而且在有些情况下,REML法的预测精度比MoM低,而且对于不同土壤变量,表现结果也不相同。【结论】样本数对土壤空间预测准确性具有显著影响,在本研究区域尺度下,当样本数小于70个时,无论用哪种变异函数计算方法进行预测,预测结果的可信度都比较低。

关键词：样本数变异函数矩量法有限最大似然法

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浅淡对原型水轮机的研究方法

大电机技术 2011年第5期 35-43页

作者：黄源芳刘洁中国长江三峡工程开发总公司湖北宜昌443002 华中科技大学武汉430074

文章在介绍水力机械三大类研究方法后,着重阐述对已成为存在事实的原型水轮机研究方法。文章以较丰富的实例介绍了统计分析法、试验分析法和综合分析法的内容和要点。最后,对水力机械领域在研究中存在的一些问题,及对研究应用这种研究... 详细信息

文章在介绍水力机械三大类研究方法后,着重阐述对已成为存在事实的原型水轮机研究方法。文章以较丰富的实例介绍了统计分析法、试验分析法和综合分析法的内容和要点。最后,对水力机械领域在研究中存在的一些问题,及对研究应用这种研究方法提出了建议。

关键词：存在事实水力机械研究方法