Subjects: Geosciences >> Cartography submitted time 2023-03-13 Cooperative journals: 《干旱区研究》
Abstract： Carrying out the optimal allocation of land use is aimed at promoting the scientific use of regional land resources and achieving carbon emission reduction targets. In this paper, the Fenhe River Basin is taken as the research area. Based on the data on land use and resistance factors in 2015 and 2020, the FLUS-MCR model and the carbon budget coefficient method are used to verify the accuracy of the model. Five simulation scenarios, such as low- carbon development priority, economic development priority, cultivated land protection priority, ecological protection priority, and natural development in 2030, are set up to compare the layout characteristics of land use types under different scenarios in the future, and an optimized layout scheme is proposed. The results showed that: (1) In 2020, the areas of four land use functional zoning of the prohibited, restricted, key, and optimized development zones in Fenhe River Basin were 2491.76 km2, 6445.99 km2, 16325 km2, and 14477 km2, respectively. The net carbon emission of the basin is 2002.46 × 104 t. The prohibited development zone is the carbon sink area of the basin, and the total carbon absorption is 0.76×104 t. The remaining three areas are carbon source areas, and the total carbon emission is 2003.22 × 104 t. (2) In 2030, the carbon balance of land use in each scenario from high to low is low- carbon development priority, ecological protection priority, cultivated land protection priority, natural development priority, and economic development priority. (3) In 2030, under different scenarios, in addition to the relatively reasonable land use structure of the prohibited development zone, the restricted development zone still needs to appropriately reduce the proportion of cultivated land and construction land in the area. To support the coordinated development of land use, production, living conditions, and ecological functions and to accomplish low-carbon land use goals, the key and optimal development zones should take arable grassland development into consideration.
Subjects: Geosciences >> Other Disciplines of Geosciences submitted time 2022-09-26 Cooperative journals: 《干旱区研究》
Abstract：土壤水分特征曲线是土壤的重要水分运动参数之一，受土壤质地、容重、结构、温度等影响。为探明初始 容重对土壤水分特征曲线及相应水分运动参数的影响，选取3种类型土壤，分别设置5个初始容重处理，利用van Genuchten模型拟合获取土壤水分特征曲线及其水分运动参数，分析初始容重对不同类型土壤水分特征曲线及相 应水分运动参数的影响。结果表明：（1）近饱和段（SS>100 kPa），黑土的水分特征曲面随 着初始容重的增加平缓上升，红壤的水分特征曲面在初始容重由1.3 cm3cm-3 增加到1.4 cm3cm-3 的过程中呈下降 趋势，塿土的水分特征曲面在初始容重由1.3 cm3cm-3 增加到1.4 cm3cm-3 时上升的更加陡直。（2）van Genuchten模 型对土壤水分特征曲线拟合效果较好（R2>0.99），适用于这3种类型土壤不同初始容重条件下的水分特征曲线的拟 合。（3）3种土壤的水分运动参数、s与初始容重均表现为显著的负相关关系（P在不 同初始容重间差异显著（Pr与初始容重表现为显著的负相关关系（Pn表现为显著的正相关关系（Pn呈负相关关系，但关系不显著（P>0.01），且3种土壤不同初始容重处理间水分运动参数n的变化幅度 较小，变化幅度维持在0.1左右。研究结果可为不同类型土壤、不同初始容重条件下土壤水分运动参数的获取及水 文过程模拟提供参考。
Subjects: Geosciences >> Other Disciplines of Geosciences submitted time 2019-09-11 Cooperative journals: 《干旱区研究》
Abstract：以渭河流域为研究区，获取流域内21个气象站1978—2002年20 cm口径蒸发皿和1985—2015年E-601型蒸发器日观测资料，采用线性回归模型重构各站点蒸发皿蒸发数据资料，Mann-Kendall趋势检验与空间插值法分析流域蒸发皿蒸发量的时空变换特征，敏感性分析法定量评估各气象要素对蒸发皿蒸发量变化的贡献。结果表明：流域多年平均蒸发皿蒸发能力低于黄河流域的平均水平，蒸发皿蒸发量介于1 015.5~1 705.6 mm，其空间分布状况表现为由北向南逐渐减少；年蒸发皿蒸发量总体呈增加趋势，变化率为1.371 mm·a-1；蒸发皿蒸发量对实际水汽压最敏感；气温是影响蒸发皿蒸发量的主导因子，其贡献率为304.5%。
Subjects: Biology >> Zoology submitted time 2018-12-25 Cooperative journals: 《动物营养学报》
Abstract：黄花蒿是一种草本植物，在我国传统医学中被广泛应用，具有抗炎、抗氧化、抗疟疾、驱虫和免疫调节等多种生物活性。此外，黄花蒿无毒无害、无耐药性，在动物生产方面具有极高的利用价值。本文综述了黄花蒿中生物活性物质的生理功能及其在动物生产中的具体应用，为黄花蒿的进一步研究提供参考。
Subjects: Biology >> Zoology submitted time 2018-12-24 Cooperative journals: 《动物营养学报》
Abstract：本试验旨在研究饲粮中添加不同水平壳聚糖对蛋种鸡血清中脂类物质及脂肪细胞因子含量的影响。试验选择26周龄健康海兰褐蛋种鸡450只，随机分为5组，每组6个重复，每个重复15只鸡。对照组饲喂不添加壳聚糖的基础饲粮，4个试验组分别饲喂在基础饲粮中添加250、500、1 000和2 000 mg/kg壳聚糖的试验饲粮。试验期为56 d。结果表明：与对照组相比，饲粮添加250、500、1 000和2 000 mg/kg壳聚糖可不同程度地降低试验第28天和第56天蛋种鸡血清中总胆固醇（TC）、低密度脂蛋白胆固醇（LDL-C）、游离脂肪酸（FFA）的含量及肝脏FFA含量。试验第28天时，与对照组相比，饲粮添加250、500和1 000 mg/kg壳聚糖可显著降低蛋种鸡血清中甘油三酯（TG）含量（P≤0.05），添加500 mg/kg壳聚糖可显著降低血清中极低密度脂蛋白（VLDL）含量（P≤0.05），添加250、500、1 000和2 000 mg/kg壳聚糖可显著降低蛋种鸡血清中瘦素（LEP）含量（P≤0.05），添加250 mg/kg壳聚糖可显著增加血清中高密度脂蛋白胆固醇（HDL-C）含量（P≤0.05）。试验第28天和第56天时，蛋种鸡血清TC含量与壳聚糖添加水平均呈现显著的线性下降关系（P<0.01）；试验第28天时，蛋种鸡血清TG（P<0.01）、HDL-C（P<0.01）、FFA（P=0.04）和VLDL含量（P<0.01）与壳聚糖添加水平呈显著的二次曲线关系，通过回归分析得出壳聚糖添加水平在652.56~967.18 mg/kg时对上述指标有较好的调节效果。由此可见，饲粮添加壳聚糖可改善蛋种鸡体内脂质代谢的健康水平，且其对蛋种鸡血清脂类物质含量及肝脏FFA含量的影响与其添加水平有关。
Subjects: Biology >> Zoology submitted time 2017-11-07 Cooperative journals: 《动物营养学报》
Abstract：本试验旨在研究饲粮中添加不同水平的艾蒿水提物对肉仔鸡血清细胞因子含量及小肠诱导型一氧化氮合成酶（iNOS）mRNA表达量的影响。选取192只健康的1日龄爱拔益加（AA）肉仔鸡，随机分为4个组，每组6个重复，每个重复8只鸡。对照组饲喂基础饲粮，试验组分别饲喂在基础饲粮中添加500、1 000、2 000 mg/kg艾蒿水提物的试验饲粮。试验期42 d。结果表明：1）与对照组相比，21日龄时，2 000 mg/kg添加组的血清白细胞介素-1β（IL-1β）、白细胞介素-2（IL-2）和白细胞介素-4（IL-4）的含量显著升高（P0.05），1 000 mg/kg添加组的血清NO含量和回肠iNOS mRNA表达量显著升高（P<0.05），2 000 mg/kg添加组的回肠iNOS mRNA表达量极显著升高（P<0.01）；42日龄时，500、1 000和2 000 mg/kg添加组血清NO含量和iNOS活性及空肠iNOS mRNA表达量显著或极显著升高（P<0.05或P<0.01）。由此可见，饲粮中添加艾蒿水提物可以促进肉仔鸡免疫细胞因子的分泌和NO的生成，且与iNOS mRNA的表达增强有关。
Subjects: Geosciences >> Space Physics submitted time 2016-05-04
Abstract： The inherent shortcoming of most regional models is the lack of altitude information. In order to overcome this, the objective of this study is to establish the three-dimensional (3D) model of element X, Y, Z, and F over Chinese and its adjacent regions in 2010.0 at the height of about 300 km. Based on the vector and scalar geomagnetic measuring data of CHAMP satellite, associated with 3D Taylor polynomial method, we try to create the 3D model over China and calculate the spatial distribution of geomagnetic field region. 3D model not only has the advantages like simple calculation and convenient to use, but also takes into account the height. In addition, the selection of truncation level of 3D model was also discussed. In order to verify the constructed 3D model, a comparison between 3D and Taylor polynomial (2D) model was taken, we analyzed the Root-mean-square error (RMSE) and the residual distributions between 3D and 2D models in different truncation level. Results showed RMSE and the mean absolute residuals of each level of the 3D model are about 45% smaller than that of 2D model. The 3D model of degree 5 basically has the same precision as that of 2D model of degree 8 in this study. Geomagnetic distributions and residuals of 3D and 2D models have high consistency. After comparing with 2D model, the 3D model considers the altitude information, so the precision is really improved; the coefficients show that 3D model of low degree can reflect more information and has the similar precision when compared to 2D model of high degree. � 2015, Science Press. All right reserved.
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