Research on product size and grinding dynamics of vibration mills

In order to improve vibration mills grinding effect and increase productive efficiency, prime factors of vibration mills were gained much attention. The purpose of this study is to reveal product size distribution and grinding dynamics of vibration mills by orthogonal experi-ments. The metallurgical refractory materials were used as research object. In order to explore the relationships between grinding effect and primary factors, lots of milling experiments were carried out. Based on the results, the conclusions can be summarized： as time runs, the size distri-bution shows exponential trend, and range becomes more and more narrow. Also the quantitative analysis result between grinding effect and primary factors was obtained by non-linear regres-sion： high frequency, high amplitude and low fill ratio can increase grinding speed.     

抚顺西露天矿北帮边坡综合治理方案的研究

针对西露天矿北帮地表出现的裂缝及可能产生滑坡现象,对其变形原因以及边坡变形机理进行深入、透彻的研究,并实施一系列预防性抗滑措施。     

供电对地方煤矿井下电动机热破坏原因及处理

本文从理论上分析电压过低是造成地方煤矿井下电动机热破坏的主要原因。通过分析并提出解决问题的方法。     

Study on cogging force of permanent magnet linear synchronous motor

Presented the methods to obtain the cogging force of permanent magnet linear synchronous motors(PMLSMs), analyzed the characteristics of the cogging force,and provided a basis for reducing the effect of the cogging force. 2-dimensional finite element method(2D FEM) was used to solve the whole motor when its mover was at different position, so that the relation was derived between the cogging force and the mover position. The analysis results show that the cogging force between the two ends of the primary iron-core and the secondary permanent magnets (PMs) is sinusoidal function of the mover position under certain conditions only. Two proposed methods,namely direct and indirect methods, are applied to calculate the cogging force between the primary iron-core teeth and the secondary PMs. The agreement of the two methods is validated.     

五大战略培育中国大企业

国资委主任李荣融日前在“2004年中国企业高峰会”上演讲时说．加快中国经济结构的战略性调整，加快经济增长方式的转变，就必须大力实施大公司大企业集团战略、为此，他提出，国资委将采取五大措施来实现这一战略。     

纳米粉体粒度特性表征方法讨论

实验中采用不同的方法对四种ZrO2纳米粉体的颗粒特性进行了表征。对颗粒呈现球形、不发生硬团聚的微小粒子，例如YSZ—KD试样，一次颗粒粒度为10～15nm，比表面为64．2m^2／g，采用XRD获得的微晶粒子尺寸与TEM和BET方法获得的颗粒尺寸相一致。由于比表面高，颗粒之间容易发生静电力、范德华力和液桥力的作用而软团聚在一起，其团聚系数较大为62．5，粒度分布宽度为14．58。TEM和BET与XRD方法获得的颗粒尺寸出现偏差，说明YSZ—HW1、YSZ—TH试样中出现了基元为2～3的多晶颗粒，多晶颗粒存在使得颗粒体偏离球形。团聚系数为25．71，粒度分布宽度为18．94的YSZ—HW1试样中仍存在较多的软团聚体，团聚系数为6．89，粒度分布宽度为8．91的YSZ—TH试样中软团聚状况明显较少。YSZ—HW2试样中TEM和BET与XRD方法获得的颗粒尺寸出现很大偏差，说明其中存在较多的硬团聚体，硬团聚体使得颗粒呈现不规则外形，其比表面小，活性低，表现为团聚系数小，粒度分布窄。     

煤炭企业安全培训工作分析与对策

指出安全教育培训是当前煤炭企业安全管理工作的重要议题和主要措施,分析了培训效果的不足及原因,提出了解决安全教育培训低效的对策。只有通过科学有效的企业内部培训才能够切实提高职工的安全意识和技能,为保证安全生产与各项工作的顺利实施打下坚实的基础。     

矿产资源形势分析与预测的理论与方法

结合矿产资源形势分析与预测的基本理论，综合介绍了目前比较流行的几种分析与预测的方法，旨在为政府和企业提供预测方法和决策依据，以促进资源的合理开发和利用。     

异型柱框架、框-剪结构在高层建筑中的应用

结合一住宅小区的结构设计．对异型柱框架、框一剪结构的破坏机理、计算理论和结构构造进行了探讨，供设计同仁参考。     

灰色理论和回归分析在滑坡预测中的应用

通过对灰色系统GM(1，1)模型的介绍，把灰色理论和回归分析结合起来应用于滑坡的预测中，分析滑坡的发展趋势，对滑坡的预防有一定的帮助，根据某高速公路滑坡实际情况．对部分监测点位移进行了建模和预测，与回归分析的方法进行了结合，具有较高的精度．可以应用于实际工程。