基于灰色GM（1，1）模型的城市生活用水量预测

介绍灰色理论建模原理和模型参数辨识方法,并以上海市为实例建立灰色GM（1,1）预测模型,运用残差检验、后验差检验以及关联度检验3种方法对模型进行精度检验,其模型拟合精度达97．25％。用所建立的模型对上海市2003～2007年城市生活用水量进行预测。结果表明,该灰色模型用于城市生活用水量预测,符合其灰色特性,通用性好,并且所需数据少,计算量适中,预测结果与实际情况比较吻合。     

Accurate and Precise Elemental Abundance of Zinc in Reference Materials by an Isotope Dilution Mass Spectrometry TIMS Technique

A thermal ionisation mass spectrometric technique enabled the abundance of Zn in geological and biological reference materials and water samples to be measured by double spiking isotope dilution mass spectrometry enriched in the ⁶⁷Zn and ⁷⁰Zn isotopes. In the past, thermal ionisation mass spectrometry proved to be difficult for low-level zinc isotopic measurements. The size of Zn samples used for isotopic determination, in particular the biological RMs, represents an important breakthrough. These results represent the most accurate and precise concentrations measured for Zn in these samples. The maximum fractional uncertainty was that for TILL-3 (2%), while the minimum fractional uncertainty was 0.7% for both BCR-1 and W-2. The inhomogeneity of Zn in HISS-1 was revealed while other reference materials appeared homogeneous at the 95% confidence uncertainty. The certified concentration of Zn in HISS-1 and IMEP-19 by their producers are 28% and 3.8% higher than the values measured in this work. These are the first Zn concentration measurements in these materials by the isotope dilution-TIMS technique, except for BCR-1, NIES N^o 9 and IMEP-19. Reducing the blank enabled accurate measurement in water at the ng g^-1 level demonstrating the applicability of the technique for low-level Zn samples.     

Quantitative Research Performing other Worlds: lessons from sustainable agriculture in the Philippines

For those interested in ethical research, quantitative methods are often dismissed as apolitical; as unreflective exercises in ‘mere counting’. If, however, in doing research, we bring into being the very worlds we purport to describe, the question begs: what kinds of worlds might quantitative methods bring into being? Is there space for a reflexive, quantitative research agenda? In this paper, I will discuss an action-based predominantly quantitative research project that aimed to investigate the diverse impacts of sustainable agriculture on small-scale farmers in the Philippines. The study, one of the largest ever undertaken on organic rice production, was consciously designed, not merely to describe, but to perform organic agriculture differently. While most quantitative, and indeed much qualitative, research ignores its performativity, this research was intended to enact a reality of sustainable agriculture as a viable and vital alternative to mainstream, capitalist agriculture.     

Patterns of Irrigated Agricultural Land Conversion in a Western U.S. Watershed: Implications for Landscape-Level Water Management and Land-Use Planning

In irrigated agricultural landscapes, land-use conversion may have landscape-level social, hydrological, and ecological effects. We used geographic information systems (GIS) and interviews to analyze development effects on irrigation in the Henry's Fork Watershed, Idaho. Farmers developed irrigation there in the 19th century, and incidental recharge from canal seepage and flood irrigation raised groundwater levels and expanded wetlands. Cohesive culture in agricultural communities sustained irrigation systems until amenity-driven demographic shifts beginning in the 1970s led to development approved by local governments with land-use planning but no water-management authority. Although only 5% of irrigated land has been converted, development has fragmented irrigated landscapes and made canal-system operation more difficult, potentially reducing groundwater levels, wetland extent, and return flows critical to downstream irrigators and fish and wildlife. We discuss future scenarios, highlighting the need for increased communication among local and state governments regarding land use and water management in irrigated landscapes across the West.     

浅谈如何做好为农服务类气象节目

文章通过分析农村受众对电视气象节目的心理需求,结合近几年内蒙古气象影视所开展的为农气象服务和自身工作体会,对如何利用影视平台做好为农气象服务进行探讨。     

基于GPS PPK技术的远距离高精度验潮方法研究

为实现远岸潮汐精确监测,基于GPS PPK技术开展了远距离高精度GPS验潮方法研究。研究给出了GPS潮位测量方法,其次联合GPS定位信息和IMU姿态信息,通过坐标转换原理得到瞬时水面的精确高程。在此基础上,研究利用基于FFT的低通滤波技术提取潮位信息。最后在烟台港进行了实际工程试验。试验结果表明,当GPS PPK验潮距离达98km时,潮位误差可控在!15cm以内,验潮精度仍可优于10cm。     

Effects of corridor networks on plant species composition and diversity in an intensive agriculture landscape

The development of modern agriculture has resulted in much homogenization of the landscape consisting of large patches of farmland,so small remnant non-crop habitats especially linear corridors play an important role in the conservation of species and the maintenance of ecosystem functions.However,little attention has been paid to the effects of corridors structural characteristics on the plant species restricted to such habitats.In this study,we selected three types of corridors including ditch,hedgerow and road,and ana-lyzed their structural characteristics.The plant species presented in these corridors were investigated,and the species diversity,abun-dance and frequency were estimated.Moreover,spatial arrangements of corridors were classified into different types to discuss whether there were significant effects of corridor network on plant distribution.The results show that three types of corridors have different ef-fects on plant species composition and diversity.The one-one combined corridor networks and total network associated by three corri-dors have more complex structural features than each single type of corridor.However,there is no strong correlation between the corri-dor networks with their plant species.We suggest that carrying out a pointed vegetation survey at corridor intersections to further test the relationships between structural features of corridor and plants is necessary.     

一种I3S标准的倾斜摄影服务精度动态控制方法

针对倾斜摄影数据服务共享保密要求高、倾斜摄影数据包SLPK不同精度数据制作复杂的问题,本文基于开源I3S标准规范与解析倾斜摄影在线服务结构特征,研究实现了一种I3S标准的倾斜摄影服务精度动态控制方法。该方法可根据服务需求,通过控制索引树节点级别,基于一套数据实现多种精度的在线服务;作为实景三维建设的重要技术支撑,具有良好的实用价值。     

新疆比勒提地区断裂构造磁异常信息提取及解释简

比勒提地区位于新疆西南天山,以该区1∶50000高精度磁测数据为基础,采用解析延拓、方向导数等技术手段提取与断裂构造有关的磁异常信息,对区域内构造进行识别,结合标本物性参数统计,对引起磁异常的原因进行分析。对区域磁异常向上延拓及求一阶导数后进行对比,圈定4个特征异常带A1~A4,结合地质资料,识别出4条断裂构造FW1~FW4,FW1和FW2对应喀拉铁克断裂及其次级断裂,FW3为构造动力作用产生的强片理化带,FW4为隐伏断裂,表明高精度磁法测量在本区能有效识别断裂并反映其分布。     

新疆比勒提地区断裂构造磁异常信息提取及解释

比勒提地区位于新疆西南天山,以该区1：50000高精度磁测数据为基础,采用解析延拓、方向导数等技术手段提取与断裂构造有关的磁异常信息,对区域内构造进行识别,结合标本物性参数统计,对引起磁异常的原因进行分析。对区域磁异常向上延拓及求一阶导数后进行对比,圈定4个特征异常带A1-A4,结合地质资料,识别出4条断裂构造FW1-FW4,FW1和FW2对应喀拉铁克断裂及其次级断裂,FW3为构造动力作用产生的强片理化带,FW4为隐伏断裂,表明高精度磁法测量在本区能有效识别断裂并反映其分布。