碱熔法从硼精矿中提取硅的研究

以硼镁铁矿磁选得到的硼精矿为原料,通过单因素实验和正交实验,采用碱熔法研究硼精矿在提取硅过程中焙烧温度、焙烧时间、碱矿比对硅提取率的影响。结果表明,实验过程中各个因素对硅提取率的影响由大到小的顺序依次为碱矿比、焙烧温度、焙烧时间;最佳的实验条件为:焙烧温度550℃,焙烧时间30min,碱矿比4∶1。在最佳条件下,硅提取率可达到92%以上,硼和硅元素以可溶盐的形式富集在提取液中,而铁和镁等元素则富集在渣中,实现了硼、硅与铁、镁的分离。     

煅烧高岭土-TiO_2复合材料的制备及表征

以煅烧高岭土和TiO2为原料,采用机械力化学法制备煅烧高岭土-TiO2复合材料。以遮盖力和吸油量为指标,优化煅烧高岭土-TiO2复合材料的制备工艺,并表征其颜料性能。结果表明:复合过程中共混研磨时间、球料质量比和搅拌磨转速对复合材料的颜料性能影响显著。制备的煅烧高岭土-TiO2复合材料遮盖力为纯钛白粉的88.4%,白度也与其接近,且吸油量适中。该材料用于内墙涂料显示出较好的颜料性能,能以一定比例替代钛白粉使用。     

纳米氧化锌-煅烧高岭土复合材料的制备

以煅烧高岭土和纳米氧化锌为主要原料,用水解沉淀法在煅烧高岭土表面包覆纳米氧化锌,制备一种无机复合型抗紫外材料;采用分光光度计分别测定在波长325、350、375、400nm紫外光下复合材料的紫外光吸光度。结果表明:反应温度、氧化锌包覆量、改性时间、改性剂滴加速度、矿浆浓度、煅烧温度等对纳米氧化锌-煅烧高岭土复合粉体材料的紫外光吸收性能有重要影响。在制备条件为:氧化锌包覆量为8%、反应温度为90℃、改性时间为10min、改性剂滴加速度为3mL/min、矿浆中m(水)∶m(煅烧高岭土)=10∶1、煅烧温度为400℃时,所制备的纳米氧化锌-煅烧高岭土复合粉体材料的紫外光吸收性能较好。     

煅烧表面载钴煤系高岭土的色度学研究

由于高岭土中含铁杂质的存在,很大程度上影响了其煅烧产物的白度和色调,而现有技术很难经济地将含铁杂质除尽,因而使高岭土的应用受到很大限制.选择铁含量较低的山西煤系高岭土,研究了化学沉积法实现煤系高岭土表面载钴,并经过煅烧,改善煅烧产物色度指标.研究表明,与未处理样品比较,载钴处理后的样品煅烧产物白度值可提高2～5度,并能...     

铌酸锶钡陶瓷材料的制备及介电性能研究

以BaCO3，SrCO3和Nb205作为原料，采用高能球磨工艺制备SBN50陶瓷粉体。球磨后的粉体不经煅烧，直接压片成型，在1250～1350℃下保温1．5～12h可制备出SBN50陶瓷材料，并对此进行了X射线衍射分析、扫描电镜观察和性能测试。结果表明：球磨30h的粉体在1100℃时合成SBN50单相；随着烧结温度的升高和保温时间的延长，SBN50陶瓷的介电常数先增大后减小，晶粒大小呈有规律的变化。1300℃下保温3h制得的陶瓷样品介电常数最高（εmax=1447），居里温度（L）为130℃。     

强磁选和流态化磁化焙烧联合工艺回收赤泥中的铁

以山东省某赤泥高阶磁选过程中的底流(铁品位31. 07%)、粗精(铁品位42. 73%)为原料,采用流态化磁化焙烧-弱磁选工艺进行实验研究。结果表明:该赤泥过细流化困难,但经过高阶磁选工艺"抛细留粗"处理的底流、粗精均可以实现连续、稳定的流态化。底流在采用流态化磁化焙烧-弱磁选工艺后,铁品位可以提高至62. 04%,铁回收率可以提高至68. 35%;粗精在采用流态化磁化焙烧-弱磁选工艺后,铁品位可以提高至63. 88%,铁回收率可以提高至85. 47%。     

废纸脱墨优化工艺条件研究

主要研究了常用脱墨剂及其脱墨工艺条件对废纸脱墨效果的影响,通过优化试验确定脱墨剂的最佳用量和脱墨工艺条件.试验表明:应用HC脱墨剂可得到较好的脱墨效果(脱墨后浆的白度有58.58%ISO).其脱墨时的最佳工艺条件为:碎浆条件:脱墨剂用量为0.1%(质量分数,后同),浓度10%(质量分数,后同),温度55℃,时间20min;熟化条件:浓度10%,温度55℃,时间30min;浮选条件:脱墨剂用量为0.2%,浓度1.0%,温度55℃,时间7min,pH值为8.0.     

丙烯酸酯类乳液胶黏剂的制备及其应用

目的制备出多元共聚型丙烯酸酯乳液,并应用于纸塑复合膜中。方法采用乳液共聚合法,优化合成工艺,制备丙烯酸酯乳液胶黏剂。结果制备胶黏剂的最优工艺条件中乳化剂十二烷基硫酸钠和乳化剂OP-10的质量比为1∶3,总质量分数为4.5%;引发剂过硫酸铵质量分数为0.6%;丙烯酸质量分数为5%;丙烯酸丁酯与醋酸乙烯酯的质量比为13∶6;乙酸锌质量分数为0.2%;选择预乳化种子滴加方法,预乳化时间为30 min,温度为50℃,搅拌速度为440 r/min;滴加与保温时的搅拌速度为400 r/min,保温时间为1 h,单体滴加时间为3 h,滴加温度为80℃,保温温度为83℃;反应结束时加入对苯二酚,其质量分数为0.3%。结论合成的胶黏剂有良好的粘接性能。     

钨矿选矿工艺研究

对滇南某钨矿物与褐铁矿连生,两部分相互穿插的钨矿选矿工艺进行了研究.利用化学分离法进行选矿,研究制定了掺碱焙烧-浸煮-酸沉的选矿工艺.考察了不同的焙烧温度、浸煮时间、浸煮液固比、NaCO3加入量、NaNO3加入量对WO3含量及回收率的影响.结果表明,当焙烧温度在800℃,浸煮时间为50 min,浸煮液固比取4:1,NaCO3加入量为25 g,NaNO3为0.75g时,钨的回收率最高,可达24.02%,WO3的含量最高可达49.89%.     

吉林省靖宇县二道阳岔铁矿矿石可选性分析及探究

总体来看,原矿矿石成分比较单一,选矿试验证明矿石为易选矿石,采用磁选法进行选别,单一磁选工艺流程,经过一次磨矿、一次初选,粗精矿再磨后再次精选,获得的精矿品位TFe67.20%,回收率72.66%。除磁铁矿及少量的磁黄铁矿外,其他非磁性矿物均进入尾矿,其他含铁矿物分布局限,质量分数低,且不易利用,不需另行选矿。     

Design method and scientific method

A recurring theme in recent design theory has been a desire to relate design method to scientific method: to create the ‘science of design’ or a ‘design science’. There is an inherent paradox in such a desire since design and science are clearly very dissimilar kinds of activities. Further, the concept of ‘scientific method’ now seems to be in epistemological chaos. For these reasons, attempts to model design method on scientific method seem misplaced. It is proposed that it would be more fruitful to regard design as a technology, rather than as a science. The paper seeks to establish the basis for such a view, drawing especially on the idea that both design and technology involve the application of types of knowledge other than the purely ‘scientific’ kind.     

基于APEX方法的湍流退化图像复原算法

在目标探测过程中,为了消除大气湍流带来的影响,提出了一种基于APEX方法的盲去卷积图像复原算法.该算法是一种非迭代的盲图像复原算法,以湍流退化系统具有G类点扩展函数为假设前提,通过模糊图像的频谱信息直接估计点扩展函数,并采用SECB方法实现目标图像的重建.本文对该算法的原理及其对湍流退化图像复原的可行性进行了深入研究,进行了真实的湍流退化图像的复原实验,其结果表明,该算法能够快速实现对湍流退化图像的重建,并具有一定的稳定性,能满足目标探测过程中的实时性要求.     

无机纳米材料的水热合成及其衍生方法

综述了纳米材料水热合成法的研究进展,并总结了水热合成法的优点和缺点,对水热合成法的反应机理作了初步的探讨,对水热反应中水的状态作了简要分析;对由水热法衍生出来的溶剂热和微波水热法也做了分析,介绍了溶剂热反应中经常使用的有机溶剂和微波反应中微波的加热机理;同时论述了目前这几种实验方法的实验进展和应用情况.     

基于拉格朗日乘子法的空间圆弧拟合优化方法

针对传统的空间圆弧拟合方法鲁棒性低、拟合精度不高等问题,提出了一种鲁棒性较强的空间圆弧拟合优化方法。首先,以拉格朗日乘子法为基础,基于平面条件约束建立目标函数,从而得出空间圆弧拟合方程;其次,采用RANSAC（random sample consensus,随机抽样一致）算法剔除错误跟踪点,将RANSAC算法的高稳定性应用到空间圆弧拟合的点云优化中,进而提高拟合精度。最后,通过实验分析验证了所提空间圆弧拟合优化方法的可行性,并与传统拟合方法进行比较,分析所提方法的拟合精度。实验结果表明：普通圆弧点云拟合的相对精度在0.003左右,复杂圆弧点云拟合的相对精度在0.01左右;相较于传统拟合方法,所提方法有效解决了拟合精度低及鲁棒性差等问题。研究结果表明提出的空间圆弧拟合优化方法一方面可运用拉格朗日乘子法增强鲁棒性,另一方面可通过采用RANSAC方法剔除错误点以提高拟合精度,具有广泛的工程实际应用价值。     

基于分解法的最大熵随机有限元法

摘要：提出了一种新的基于分解法的最大熵随机有限元方法,利用单变量分解将多维随机响应函数表述为单维随机响应函数的组合形式,从而将求解随机结构响应统计矩的多维积分表达式转化为单维积分式,对单维积分采用高斯-埃尔米特积分格式求解。在获得结构响应的统计矩之后,利用最大熵原理求得结构响应的概率密度函数解析表达式。该法不涉及求导运算,对于非线性随机问题非常适用。算例结果表明,本文方法具有较好的精度与计算效率。
     

Numerical manifold method based on the method of weighted residuals

Usually, the governing equations of the numerical manifold method (NMM) are derived from the minimum potential energy principle. For many applied problems it is difficult to derive in general outset the functional forms of the governing equations. This obviously strongly restricts the implementation of the minimum potential energy principle or other variational principles in NMM. In fact, the governing equations of NMM can be derived from a more general method of weighted residuals. By choosing suitable weight functions, the derivation of the governing equations of the NMM from the weighted residual method leads to the same result as that derived from the minimum potential energy principle. This is demonstrated in the paper by deriving the governing equations of the NMM for linear elasticity problems, and also for Laplaces equation for which the governing equations of the NMM cannot be derived from the minimum potential energy principle. The performance of the method is illustrated by three numerical examples.     

动态测量不确定度贝叶斯评定的改进方法研究

动态测量不确定度的评定一直是比较复杂的问题,到目前为止,国内外有许多学者对这一问题进行了探索与研究,给出了一些评定的方法,但这些方法都存在自身的缺点与不足,还不能给出十分精确的评定结果。因此,通过对现有基于贝叶斯理论的动态测量不确定度评定方法进行分析,用最大熵原理改进其先验分布的选择与计算方法,从而有效提高计算后验分布的精度,最终提高不确定度的计算准确度。     

Combination of Newmark method and natural element method for elastodynamics

The natural element method (NEM) is a meshless method. The trial and test functions of the NEM are constructed using natural neighbor interpolations which are based on the Voronoi tessellation of a set of nodes. The NEM interpolation is linear between adjacent nodes on the boundary of the convex hull, which makes imposition of essential boundary conditions easy to implement. We investigate the performance of the NEM combined with the Newmark method for problems of elastodynamics in this article. Applications are considered for a cantilever beam with different initial load conditions. The NEM numerical results are compared with the finite element method. NEM shows promise for these applications.     

Finite cell method

A simple yet effective modification to the standard finite element method is presented in this paper. The basic idea is an extension of a partial differential equation beyond the physical domain of computation up to the boundaries of an embedding domain, which can easier be meshed. If this extension is smooth, the extended solution can be well approximated by high order polynomials. This way, the finite element mesh can be replaced by structured or unstructured cells embedding the domain where classical h- or p-Ansatz functions are defined. An adequate scheme for numerical integration has to be used to differentiate between inside and outside the physical domain, very similar to strategies used in the level set method. In contrast to earlier works, e.g., the extended or the generalized finite element method, no special interpolation function is introduced for enrichment purposes. Nevertheless, when using p-extension, the method shows exponential rate of convergence for smooth problems and good accuracy even in the presence of singularities. The formulation in this paper is applied to linear elasticity problems and examined for 2D cases, although the concepts are generally valid. The first author would like to appreciate the financial support of his stay in Germany, where this research has been carried out, by the Alexander von Humboldt foundation.     

Body force method

The body force method is based on the principle of superposition. The solution in the body force method is obtained by the superposition of fundamental solutions so as to satisfy a given boundary condition. By means of these fundamental solutions all problems can be solved in principle. In this paper, first the fundamental principle of the body force method is illustrated and then its application to crack problems, elastic–plastic problems and elastodynamic problems are shown. This revised version was published online in July 2006 with corrections to the Cover Date.