Research on the rheological properties of pesticide suspension concentrate

This study reports research on pesticide suspension rheology and a new rheological parameter, the relative value of approach, which has great advantage for judging the physical stability of a pesticide suspension concentrate. Experiments showed that the system can form stable dispersions when the value of the relative value of approach (Sr) is less than 0.1.     

关于求解无界区域上Helmholz方程的Hermite-Galerkin谱方法

考虑直接用Hermite-Galerkin谱方法求解无界区域上的Helmholz方程.一般来说,由于无界区域上的Laplace算子不是紧算子,因此无法得到离散格式的稳定性.但分析表明,在适当的参数选取下,可以使用Hermite-Galerkin谱方法而取得较高的数值精度.数值结果也验证了上述结论.     

Optimum design of large span concrete filled steel tubular arch bridge based on static,stability and modal analysis

A three-dimensional finite element model was established for a large span concrete filled steel tubular (CFST) arch bridge which is currently under construction. The arch rib, the spandrel columns, the prestressed concrete box-beam, the cast-in-situ concrete plate of bridge deck, the steel box-beam and the crossbeams connecting the two pieces of arch ribs, were modeled by three-dimensional Timoshenko beam elements (3DTBE). The suspenders were modeled by three-dimensional cable elements (3DCE). Both geometric nonlinearity and prestress effect could be included in each kind of element. At the same time a second finite element model with the same geometric and material properties excepted for the sectional dimension of arch rib was set up. Static dynamic analyses were performed to determine the corresponding characteristics of the structure. The results showed that the arch rib's axial rigidity could be determined by static analysis. The stability and vibration of this system could be separated into in-plane modes, out-of-plane modes and coupled modes. The in-plane stability and dynamic characteristics are determined by the arch rib's vertical stiffness and that of out-of-plane is determined by the crossbeams' stiffness and arch rib's lateral stiffness mainly. The in-plane stiffness is much greater than that of out-of-plane for this kind of bridge . The effect of geometric nonlinearity and prestress effect on bridge behavior is insignificant.     

具时滞电磁轴承系统的稳定性和分支存在性分析

研究了具时滞电磁轴承系统的数学模型.从对系统线性化方程的特征方程根的分布分析入手,讨论了系统平衡点的稳定性条件,进而确定了系统平衡点的线性稳定性区域,然后又讨论了系统Hopf分支的存在性.最后,通过数值模拟验证了得到的结论.     

紫芋花色苷的抗氧化活性及其稳定性研究

采用铁离子还原法测定了紫芋中花色苷的总抗氧化能力,及防腐剂、金属离子和温度因素对其总抗氧化能力的影响.结果表明紫芋花色苷提取物的总抗氧化能力随加热时间延长而下降,温度越高,下降速度越快.防腐剂苯甲酸钠对紫芋花色苷提取物总抗氧化能力的影响不明显,四种金属离子（K＋、Mg2＋、Ca2＋、Zn2＋）对其总抗氧化能力有不同程度...     

某公路滑坡的稳定性分析及防治

公路滑坡治理对保护人民的生命财产、保证交通畅通具有重要意义,目前治理公路高陡边坡的措施有SNS柔性防护技术、喷锚网支护技术、抗滑桩墙体系等。而抗滑桩工程则由于抗滑桩具有适应性强、特别适用于滑面较深的大型滑坡,因有滑坡稳定性和地质环境干扰小、可多桩同时施工、工期较短、抗滑能力强等多方面的突出优点成为滑坡地质灾害治理中一种主要的方法。本文将介绍某公路滑坡的治理经验,阐述了滑坡的形成原因,重点分析了滑坡的地质情况,提出了”抗滑桩＋削坡＋锚杆支护＋挡土墙＋截、排水工程”的滑坡体综合治理方案。     

Research on the rheological properties of pesticide suspension concentrate

This study reports research on pesticide suspension rheology and a new rheological parameter, the relative value of approach, which has great advantage for judging the physical stability of a pesticide suspension concentrate. Experiments showed that the system can form stable dispersions when the value of the relative value of approach (Sr) is less than 0.1.     

从《淮南子》到《诫子书》——“淡泊明志，宁静致远”解读

“非淡泊无以明志，非宁静无以致远”，最早出于西汉刘安编撰的《淮南子·主术训》。后经诸葛亮注入新的思想含义而引用入《诫子书》，遂成为“诸葛亮精神”的重要组成部分之一，并成为中华文明的精神财富得以传承与弘扬。“淡泊明志，宁静致远”的思想，博大精深，它的精髓至少能从哲理性、真理性和进取性诸方面凸现出来。     

碱金属硝酸盐的热稳定性讨论

碱金属的硫酸盐、碳酸盐和氯化物比较稳定不易分解，而碱金属硝酸盐却不稳定。本用热力学原理和方法讨论了这类盐不稳定性的热力学原因，并从理论上分析了碱金属系列热稳定性的变化规律。     

弹跳球运动的研究

建立了弹跳球运动的二维映射关系式，利用非线性动力学的原理和方法，在不同控制参数条件下，研究了系统二维映射式不动点的稳定性．