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Research of changing characteristics and control factors of farmland topsoil organic carbon in China

XU Xin-wang,PAN Gen-xing,WANG Yan-lin,CAO Zhi-hong,

地理研究 , 2009,
Abstract: Through collecting 966 samples of measured data of farmland topsoil organic carbon,as well as temperature and precipitation data from 1980 to 2006 of China,this paper analyzed changing characteristics of farmland soil organic carbon of China,discussed the reasons of change and development trends,and analyzed the differences of carbon sequestration ability of the temperature and rainfall on the paddy soil and dry soil,and the affection of temperature and rainfall on the soil organic carbon in different regio...
Analysis of the output to input ratio in farmland ecosystem in Shouguang Experimental Area,the prevention and cure of seawater intrusion project in Laizhou Bay
莱州湾海水入侵防治寿光试区农 田 生 态 系 统 产 投 比 分 析

Luo Hong-yi,

中国生态农业学报 , 1999,
Abstract: Energy and material flux in Lijia village farmland ecosystem were analysed and evaluated.The results showed that the Lijia village,which used to be affected by seawater intrusion,after harnessed by agro-eco-engineering,its system function has been strenthened up,and its structure tends to reach rationalization.Then some problems which should be paid attention to are pointed out concerning eco-agricultural development in the region.
响叶杨(populusadenopoda)种子的形成及其寿命  [PDF]
南京林业大学学报(自然科学版) , 1984, DOI: 10.3969/j.jssn.1000-2006.1984.01.014
Abstract: <正>用显微技术及软x射线摄影,定位观察响叶杨种子发育过程中的形态变化与胚胎发育的对应关系。根据观察、试验的结果,讨论了环境条件与种子寿命的关系;还测定了响叶杨种子寿命的变化规律及其影响因素,探索延长这种子寿命的方法。
动物学研究 , 1995,
Abstract: 1994年10月15日马中翼等人在云南省泸水县的老窝捕获到1只雄鸟,经中国科学院昆明动物研究所鉴定为黄腰响蜜lie,为我国鸟类科的新记录。标本保存在中国科学院昆明动物研究所鸟类标本室。科的特征体形较小。嘴形似雀,短而粗实,上嘴稍弯曲;尾羽12枚;翅形长而尖,仅具9枚初级飞羽;脚呈对趾型,第2、3趾向前,第1、4趾向后,似啄木鸟。
响蜜lie科的新记录  [PDF]
动物学研究 , 1995,
Abstract: 1994年10月15日马中翼等人在云南省泸水县的老窝捕获到1只雄鸟,经中国科学院昆明动物研究所鉴定为黄腰响蜜lie,为我国鸟类科的新记录。标本保存在中国科学院昆明动物研究所鸟类标本室。科的特征体形较小。嘴形似雀,短而粗实,上嘴稍弯曲;尾羽12枚;翅形长而尖,仅具9枚初级飞羽;脚呈对趾型,第2、3趾向前,第1、4趾向后,似啄木鸟。
液压减振器液压模型与气穴异响研究  [PDF]
重庆交通大学学报(自然科学版) , 2014, DOI: 10.3969/j.issn.1674-0696.2014.01.34
Abstract: :?为了降低液压减振器气穴异响,分析了压缩和复原过程中液压油的运动状态和气穴的生成过程,建立了气穴系数与节流孔直径之间的关系模型,以及双筒液压减振器的参数模型;通过Simulink对液压减振器压缩和复原过程的仿真分析,确定了减振器气穴异响与节流孔直径和油液运动黏度的关系。结果表明:减振器的异响可以通过增加节流阀的有效节流直径和降低油液运动黏度来减轻。
汽车发动机异响模糊诊断  [PDF]
南京林业大学学报(自然科学版) , 1998, DOI: 10.3969/j.jssn.1000-2006.1998.02.005
Abstract: <正>论述了基于模糊数学理论的汽车发动机异响模糊诊断方法,提出了模糊诊断数学模型、模糊关系矩阵的建立方法及模糊推理诊断过程。据此建立的汽车故障诊断专家系统,提高了对发动机异响故障诊断的准确性和可信度。
Is Farmland As Good As Gold?  [PDF]
Marvin J. Painter
Economics Research International , 2011, DOI: 10.1155/2011/924708
Abstract: An analysis of Canadian farmland risk and its return on investment shows that a Farmland Real Estate Investment Trust (F-REIT) and gold would have significantly enhanced portfolio performance over the past 35 years. Investors who desire low-risk portfolios would not have benefited from an F-REIT or gold investment. However, investors in the medium-risk category could have improved the financial performance of their portfolios by including an F-REIT investment rather than gold. The financial gains from F-REIT result from a level of risk that is lower than gold, REITs, and stocks, an expected yield that is greater than for bonds, and a low correlation with other financial asset returns.
斜置旋耕刀和国标旋耕刀的对比分析  [PDF]
南京农业大学学报 , 1999, DOI: 10.7685/j.issn.1000-2030.1999.04.025
Abstract: 在斜置旋耕条件下,从理论和试验上对比分析了国标旋耕刀和自行研制的斜置旋耕刀的耕作特点,从而证实斜置旋耕刀较国标旋耕刀更适宜于进行斜置旋耕耕作。
Effects of Irrigation and Nitrogen Supply on Grain Yield,Water Use Efficiency and Apparent Nitrogen Recovery Fraction of Spring Wheat on No-tillage Farmland with Standing Stubble

LIU Qing-lin,ZHANG En-he,WANG Qi,WANG Tian-tao,LIU Chao-wei,YU Hua-lin,YIN Hui,

中国沙漠 , 2011,
Abstract: A controlled experiment was conducted in oases of the Shiyanghe river basin to investigate the effects of different irrigation and nitrogen supply levels on grain yield,straw yield,harvest index(HI),water use efficiency(WUE) and apparent nitrogen recovery fraction(NF) of spring wheat on no-tillage farmland with standing stubble.A complete randomized block split-plot design was employed with different irrigation regimes,namely conventional irrigation of 327 mm,20% water-saving irrigation of 261 mm,40% water-...
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