西阜高速公路石家庄段弃渣场水保措施探析

针对西阜高速公路石家庄段建设过程中弃渣量大的实际情况,在分析弃渣场选址与治理思路的基础上,提出了工程措施、植物措施和临时拦挡措施相结合的综合防治体系,并对弃渣场水保措施进行典型设计。     

农业用水及土壤水资源分析研究

在现行水资源评价中,只把地表水和地下水作为水资源看待,但我国华北平原地区降水的70%转化成土壤水,成为农业生产最重要的水源。依据华北平原土壤特性,从农业用水的角度分析了土壤水的水文特征,提出土壤水资源分析研究的建议。     

Isolation and identification of (3-methoxyphenyl)acetonitrile as a phytotoxin from meadowfoam (Limnanthes alba) seedmeal

Ethyl ether, ethanol, and water extracts of meadowfoam (Limnanthes alba Hartweg ex. Benth.) seedmeal were prepared and bioassayed against velvetleaf (Abutilon theophrasti Medicus) and wheat (Triticum aestivum L. Cardinal). Both the ethyl ether and ethanol fractions, but not the water extract, inhibited velvetleaf and wheat radicle elongation. Fractionation of the extracts indicated that (3-methoxyphenyl)acetonitrile (3-MPAN) was the active compound from both extracts, comprising >97% of the active ethanol fraction. 3-Methoxybenzyl isothiocyanate, which had been previously shown to be the major breakdown product of glucolimnanthin, the majorL. alba glucosinolate, was not detected in either extract. Radicle elongation of velvetleaf and wheat were inhibited by 3-MPAN with I₅₀ (the concentration required to inhibit growth by 50%) values of approximately 4 × 10^–4 M (velvetleaf) and 7×10^–4 M (wheat).Mention of firms or products does not imply endorsement by the U.S. Department of Agriculture over other firms or products not mentioned.     

大规模地形建模的研究

针对目前各种大规模地形建模的优缺点,并结合目前流行的地形建模方法,提出一种较为真实的地形建模方案。为达到更真实的模拟,对地形泥土腐蚀现象做了研究,提出了一种基于细胞自动机的腐蚀模拟方法。     

Closed-loop drip irrigation control using a hybrid wireless sensor and actuator network

In this research, a closed-loop drip irrigation control hybrid wireless sensor and actuator network (HWSAN) prototype were developed and deployed in a crop field for soil property precise measurement and precision irrigation in accordance with the measured soil property. The HWSAN was composed of a wireless sensor and actuator network (WSAN) used for in-field soil property monitoring and irrigation control and a laboratory supervising system. The WSAN included ten sensor nodes, five irrigation control nodes...     

砂质潮土施用有机肥后效研究

采用长期定位试验 ,研究了砂质潮土一次性施入不同数量有机肥对数年小麦的产量效应、产量构成、品质、水分利用和土壤肥力的变化和影响 .结果表明 ,有机肥不仅能显著增加当季小麦产量、单位面积穗数和穗粒数 ,提高耕层土壤有机质、全氮、有效磷、有效钾含量和水分利用效率 ,而且有较长的后效 .小麦产量与有机肥用量的关系 ,随着时间的推移 ,由二次曲线回归效应转变为直线相关 ;小麦粗蛋白质、干湿面筋含量与有机肥用量呈显著正相关     

水田施用涂层尿素对氮素挥发抑制效果的模拟试验

水田土壤施用涂层尿素抑制氮素挥发损失的研究结果表明,涂尿素素肥料在全层混施,8cm深施和表面撒施3种施肥方式下均有抑制NH3和NOx挥发损失的作用,涂层尿素与普通尿素相比,表面撒施降低氮素（NH3＋NOx)挥发损失率达32．8％,8cm深施降低氮素（NH3＋NOx)挥发失率达19．9％,全层混施降低氮素（NH3＋NOx)挥发损失率达6．9％。     

南京河西地区软土场地地震动参数研究

根据南京河西地区所处的地震地质环境、地震活动环境及基岩地震动衰减规律 ,对所选取的某个典型工程软土场地 ,进行了地震危险性分析 ,给出了基岩地震动参数 ;对场地的地震动效应进行了研究 ,给出了 5 0a及10 0a超越概率水平为 6 3%、10 %和 3%的场地地震动参数。该成果对河西地区的工程抗震设计有一定的参考价值     

Comparison of Skidding Performance of Small Track-type Experimental Prototype Skidder and J-50 Skidding Tractor

In this paper, field experimental comparison is made between a small track-type experimental prototype skidder and a J-50 skidding tractor. Experimental data, including skidding productivity, soil compaction on skidding trails, and damage rate of the residual trees, are analyzed. The results indicate that with the condition of scattered skidding area and low skidding volume per cycle, small track-type experimental prototype skidder has advantage on working and a higher skidding productivity. It makes lower soil compaction to the skidding trails in the depth of 0-5 cm, 5-10 cm, and 10-15 cm. Under the same work conditions, the damage rate of the residual trees made by small track-type experimental prototype skidder is only 1/5 of those made by J-50 type skidding tractor. The damage rate is reduced by 80%.