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饮用天然高钼水诱发的钼中毒耕牛主要生物酶测定 总被引:8,自引:0,他引:8
本研究对高钼饮水诱导钼中毒的耕牛及对照牛的血浆及组织(肝脏、肺脏、肾脏、脾脏、心脏、肌肉)中超氧化物歧化酶(SOD)、黄嘌呤氧化酶(XOD)及谷胱甘肽过氧化物酶(GSH-PX)等3种生物酶活性进行了对比分析测定。结果表明,血浆和组织中SOD、XOD及GSH-PX均随着钼中毒的加重其活性显著下降。这3种生物酶是钼中毒比较灵敏且相关较大的生化指标,对钼中毒具有一定诊断价值;测定SOD。XOD、GSH-PX可作为钼中毒监测的重要手段。 相似文献
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Agricultural implement draft requirements show considerable spatial variability due to variations in soil properties and fracturing of soil. A large sample size is necessary to obtain a representative mean draft value for a given soil type and condition because of this variability. Moreover, empirical polynomial/multi-linear regression models for implement draft are often subjected to multi-collinearity problems. Proper design of experiments can assist in the complete elimination of these multicollinearity problems. An implement test procedure has been developed which addresses the problems of soil variability and multi-collinearity. Proper choice of values for independent variables in the experimental design phase can assist in transforming these variables to an orthogonal domain which completely overcomes multi-collinearity problems. The orthogonal regression technique using transformed variables and the conventional polynomial/multi-linear regression techniques using real variables were used to analyze draft data for a moldboard plow in a Capay clay soil to illustrate advantages of the orthogonal technique. 相似文献
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J. Doland Nichols 《Small-Scale Forestry》2007,6(2):127-140
Until recently the focus of forestry regulations in New South Wales (NSW) was on public rather than private lands. This paper
describes the process of developing legislation to control where and how private native forestry takes place. To date, the
lead agency in attempting to formulate a clear policy has been the Department of Natural Resources. First, through a series
of committee meetings of representatives of key stakeholder groups, a draft private native forestry code was devised and was
released for public comment. After a period of intense negative reaction from both those in favour of continuing timber production
in native forests and those in favour of requiring that private lands be managed as nature reserves, the draft code was withdrawn
and a government-appointed committee then began again the process of drawing up a code acceptable to most stakeholders. 相似文献
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本文分析了影响深松机具牵引阻力的因素。深松作业的牵引阻力与作业速度的平方以及松土深度成正比。铲头形状影响切土、碎土阻力,铲柄形状影响土壤惯性阻力、土壤与铲柄的摩擦阻力及碎土阻力。在粘土地上,园孤形铲柄较前倾直线形铲柄的牵引阻力小,但在沙壤土中,则前倾45度的直线形铲柄较园孤形铲柄的牵引阻力小。因此,应根据土壤类型合理选用深松部件的形状以减小牵引阻力。 相似文献
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Very little research has been done to investigate soil loosening as a function of the geometry of the tillage tool and of the original soil properties and moisture content. A field experiment was conducted to observe the effects of the geometric parameters of flat tillage tools on their draft, cutting efficiency and loosening of a moist clay soil. The test tool variables included rake angles to the horizontal of 30, 60 and 90°, widths of 75 and 150 mm and depths of operation of 100, 150 and 200 mm. Measurements were taken of draft, disturbed soil cross sectional profiles and the initial area of soil disturbed by the tools. The resulting draft requirement increased with width, depth and rake angle of the tool. The cross sectional area of soil disturbed did not change appreciably with rake angle, but the significant increase in draft with angle resulted in markedly diminished soil cutting efficiency (area divided by draft). The degree of soil loosening was generally smaller at a rake angle of 60° than at 30 or 90°, and tended to be higher at greater depths of operation. In addition, a larger depth to width ratio generally increased the degree of loosening. Results for the soil studied indicate that the best implement design for low draft, high cutting efficiency and superior soil loosening should have a rake angle of about 30° and should be fairly narrow with a depth to width ratio of 2 or more. 相似文献
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介绍了国内外燃煤电厂“烟塔合一”技术的应用现状,阐述了“烟塔合一”的工艺流程及技术特点,重点进行了“烟塔合一”排烟方案与常规的烟囱排烟方案对环境影响的对比分析,并针对燃煤电厂“烟塔合一”技术在环评过程中存在的问题进行探讨。 相似文献
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从50年来在《Science》发表的蚕丝学文献看中国家蚕基因组研究 总被引:1,自引:0,他引:1
检索、概括了50年来在《Science》杂志刊登的10篇蚕丝学文献的基本情况和内容,介绍了家蚕基因组框架图在家蚕全基因组序列分析、比较基因组学和丝腺、激素及发育相关基因等功能基因研究方面取得的重要进展,显示了中国家蚕基因组研究对世界蚕业科学的重大贡献。 相似文献
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