Based on the general displacement method and the basic hypothesis of the trial load method, a new advanced trial load method, the general displacement arch-cantilever element method, was proposed to derive the transfo...Based on the general displacement method and the basic hypothesis of the trial load method, a new advanced trial load method, the general displacement arch-cantilever element method, was proposed to derive the transformation relation of displacements and loads between the surface nodes and middle plane nodes. This method considers the nodes on upstream and downstream surfaces of the arch dam to be exit nodes （master nodes）, and the middle plane nodes to be slave nodes. According to the derived displacement and load transformation matrices, the equilibrium equation treating the displacement of middle plane nodes as a basic unknown variable is transformed into one that treats the displacement of upstream and downstream nodes as a basic unknown variable. Because the surface nodes have only three degrees of freedom （DOF）, this method can be directly coupled with the finite element method （FEM）, which is used for foundation simulation to analyze the stress of the arch dam with consideration of dam-foundation interaction. Moreover, using the FEM, the nodal load of the arch dam can be easily obtained. Case studies of a typical cylindrical arch dam and the Wudongde arch dam demonstrate the robustness and feasibility of the proposed method.展开更多
近年来重金属的污染已经成为危害最大的水污染之一。镍是一种有毒的重金属元素，镍造成的环境污染受到广泛关注。合成了一种镍（Ⅱ）印迹吸附剂来去除水样中的Ni（Ⅱ），并采用电感耦合等离子体质谱（Inductively Coupled Plasma Mass S...近年来重金属的污染已经成为危害最大的水污染之一。镍是一种有毒的重金属元素，镍造成的环境污染受到广泛关注。合成了一种镍（Ⅱ）印迹吸附剂来去除水样中的Ni（Ⅱ），并采用电感耦合等离子体质谱（Inductively Coupled Plasma Mass Spectrometry,ICP-MS）测定水中Ni（Ⅱ）浓度。研究了水体pH值、洗脱条件、吸附时间以及循环使用次数等影响因素。方法的检出限为0．021ug／L。该方法的相对标准偏差为1.13％。地表水样中Ni（Ⅱ）的加标回收率在98％～101％，说明运用Ni（Ⅱ）印迹吸附剂对水中Ni（Ⅱ）的去除效果较好，建立的方法准确可靠。展开更多
基金supported by the National Natural Science Foundation of China (Grant No. 90510017)
文摘Based on the general displacement method and the basic hypothesis of the trial load method, a new advanced trial load method, the general displacement arch-cantilever element method, was proposed to derive the transformation relation of displacements and loads between the surface nodes and middle plane nodes. This method considers the nodes on upstream and downstream surfaces of the arch dam to be exit nodes （master nodes）, and the middle plane nodes to be slave nodes. According to the derived displacement and load transformation matrices, the equilibrium equation treating the displacement of middle plane nodes as a basic unknown variable is transformed into one that treats the displacement of upstream and downstream nodes as a basic unknown variable. Because the surface nodes have only three degrees of freedom （DOF）, this method can be directly coupled with the finite element method （FEM）, which is used for foundation simulation to analyze the stress of the arch dam with consideration of dam-foundation interaction. Moreover, using the FEM, the nodal load of the arch dam can be easily obtained. Case studies of a typical cylindrical arch dam and the Wudongde arch dam demonstrate the robustness and feasibility of the proposed method.
文摘近年来重金属的污染已经成为危害最大的水污染之一。镍是一种有毒的重金属元素，镍造成的环境污染受到广泛关注。合成了一种镍（Ⅱ）印迹吸附剂来去除水样中的Ni（Ⅱ），并采用电感耦合等离子体质谱（Inductively Coupled Plasma Mass Spectrometry,ICP-MS）测定水中Ni（Ⅱ）浓度。研究了水体pH值、洗脱条件、吸附时间以及循环使用次数等影响因素。方法的检出限为0．021ug／L。该方法的相对标准偏差为1.13％。地表水样中Ni（Ⅱ）的加标回收率在98％～101％，说明运用Ni（Ⅱ）印迹吸附剂对水中Ni（Ⅱ）的去除效果较好，建立的方法准确可靠。
