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STUDYONRESIDUESOF~(14)C-FENITROTHIONINMODELRICE-FISHECOSYSTEMANDFIELDRICE-FISHECOSYSTEMZhangZhongliang(张仲良);WangHuaxin(王化新);G?.. 相似文献
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甲状腺在动物体内具有控制产热、调节蛋白质等物质的代谢和促进生长发育等多种功能。有关菜籽饼对甲状腺活动的影响已有不少研究报导。Hussar等观察到菜籽饼(作为蛋白质补充料)喂猪时,其甲状腺发生肿大,血清中甲状腺激素浓度降低。其后Bowland、Maransos、Grandhi和Mckinnon等也报导了菜籽饼对猪甲状腺的损伤作用,但对猪的生长、发育的影响则不尽相同。不同喂量的菜籽饼对甲状腺功能影响如何,尚不清楚。可作为饲料添加剂的土霉素、黄连素和穿心莲对猪甲状腺功能的影响,报导甚少。 相似文献
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Residues of 14C- carbofuran were studied in model late- rice ecosystem (LRE) and early- rice ecosystem (ERE). The treatment consisted of two rates of the pesticide (1x) and 2.5x). At day 56 after application, 7.3% (1x) and 2.9% (2.5x) of the pesticide and its degradative products remained in the water of the LRE, and 1.8% (1x) and 2.4% (2.5x) of them remained in the water of the ERE. At harvest, 37.5% (LRE) and 24.0% (ERE) of the pesticide applied were detected in the upper layer of the soil; and 40.6% (LRE) and 26.9% (ERE) remained in the lower layer of the soil. The residues in the rice plants increased at the first stage, reached maximum levels during day 14 to 28 after application, and decreased thereafter. At harvest, residues in the stems and leaves in the two treatments (1x and 2.5x) were 3.91μ g/g and 7.78μ g/g (LRE) and 5.04 μg/g and 17.29 μ g/g (ERE) respectively. Residues in the ears were about 1/8 to 1/12 of that in the other parts of the plants. The pesticide residues in fish bodies in both experiments were also determined. 相似文献
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刚性承载板下弹性多层连续体应力和位移分析 总被引:3,自引:0,他引:3
本文根据笔者提出的弹性多层体系“系数递推法”,导得刚性承载板作用下弹性多层连续体系的应力和位移表达式。 相似文献
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多层粘弹性半空间轴对称问题的理论解 总被引:4,自引:0,他引:4
利用积分变换和传递矩阵的方法推导了多层粘弹半空间轴对称问题的理论争。引入F.Durbin的方法实现Laplace逆变换,通过实例计算路表弯沉表明初始时段所得结果与弹性解基本一致。随着时间的推移,多层粘弹体系表面弯沉增大,这种现象说明随时间的推移,材料的粘性起到更大的作用,与实际情况相附。本文的方法可以很容易推广到多层粘弹体系的动力学问题之中。 相似文献
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轴对称弹性半空间问题一般解的新方法 总被引:4,自引:0,他引:4
本文从轴对称弹性半空间问题的平衡方程出发,利用拉普拉斯和亨格尔积分变换,直接求出该课题的一般解,避免了采用应力函数,概念清晰易懂。为层状轴对称弹性半空间课题的求解开辟了新的途径。 相似文献
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