最小元素法在露天矿排土规划中的应用

经验法确定露天矿排土规划,效率低下,且不能保证得出最优解。文章采用表上作业最小元素法求得初始可行解,经最优性检验和调整,得到最优值。通过Matlab对该方法进行验证,得出了相同的最优值计算结果。     

基于SLS系统的无底柱分段崩落法放矿方式研究

本文概述了SLS系统功能用途和分析了无底柱分段崩落法放矿方式分类，并基于SIS系统对无底柱分段崩落法放矿方式选择进行研究，得到了一些重要的结论，可为采矿工作者提供决策的依据。     

在光纤传输过程中的广义RKL方程新的孤波解

广义的RKL方程能够较好表述光子在光纤传输过程中一般特征,作者利用辅助方程法并借助计算机辅助程序构建更多的RKL方程一般精确解,结果发现这个方程的一些新孤波解.另外此方法也可用来研究其他非线性发展方程并获取新的孤波解.     

(3+1)维孤子方程的周期孤波解

扩展了Hirota法,即将Hirota法中的测试函数用新的测试函数来替代,并利用扩展了的方法来构造(3+1)维孤子方程的新的周期孤波解、周期双孤波解、双周期双孤波解.显然扩展的Hirota方法也可以解其他一些非线性发展方程.     

基于Matlab的热加工图的数值构造方法

利用热加工图(Processing Map)可以分析材料在不同区域(不同的变形温度和应变速率)的高温变形机制,从而获得热加工"安全区"和"不安全区",达到控制组织演变、避免缺陷的产生和优化工艺参数的目的.Murty提出热加工图计算方法适用于复杂本构方程的材料,但其公式中含有积分项,计算过程复杂.Matlab具有强大的矩阵计算功能,本文给出了基于Matlab平台的计算过程和简易程序,可快捷得出计算结果.并绘制出材料的热加工图.     

响应面法优化虾壳酶解的工艺

以水解度为指标,采用响应面法对虾壳酶解工艺进行了优化;根据Box-Behnken中心组合试验设计原理,选取酶解温度、酶添加量、酶解时间3因素3水平进行中心组合试验,建立水解度的二次回归方程,通过响应面分析得到优化组合条件:酶解温度53℃、酶添加量0.85%、酶解时间3.5 h,此条件下虾壳的水解度达到最大值.该条件下虾壳水解度的预测值为26.16%,验证值为26.37%,说明该优化方法可行.     

碳纤维增强矩形截面钢管梁的稳定分析

基于计算压弯构件弹塑性失稳的Jezek法,推导在轴压和弯矩共同作用下拉压侧外表面粘贴碳纤维片后矩形截面钢管梁绕强轴失稳时极限荷载的计算公式.采用有限单元法进行碳纤维增强钢管梁在压弯共同作用下的非线性屈曲分析,并得到极限承载力的数值解,该结果与解析结果吻合较好.计算结果表明,碳纤维能有效提高压弯构件的极限承载能力,改善构件屈曲状态.     

悬臂式斗轮堆取料机工作空间求解与分析

以悬臂式斗轮堆取料机为研究对象,通过分析其结构组成,将其类比为由1组滑动关节和3组转动关节构成的4自由度连杆装置。根据机器人运动学相关理论,利用目前通用的机器人运动学建模方法(D-H法)建立悬臂式斗轮堆取料机的运动学模型。在Matlab中,利用Robotic Toolbox相关函数编写程序得到其运动学仿真模型,并驱动各关节运动得到仿真结果。最后结合蒙特卡罗法在Matlab中编写程序得到悬臂式斗轮堆取料机的空间工作范围,并引入工作空间影响系数研究堆取料机关节参数变化对其工作空间的影响,从而为悬臂式斗轮堆取料机的设计和选用提供指导和参考。     

响应面法提高巨峰葡萄榨汁率的研究

通过响应面法,研究果胶酶酶用量、酶解时间和酶解温度对巨峰葡萄榨汁率的影响,并对其工艺进行条件优化.结果表明,最佳工艺条件为酶用量0.044 ml/kg,酶解时间97.5 min,酶解温度57 ℃.在此条件下,榨汁率达87.35%.     

内点法优化案例中FR共轭梯度法方向固化现象

Adams的优化分析算法未采用学生熟悉的惩罚函数法等经典算法。使用Matlab语言,采用经典算法对人字架优化案例进行实际编程计算,发现在该例中FR共轭梯度法存在着方向固化现象。深入分析该现象的成因。介绍了先进的广义简约梯度法GRG和序列二次规划SQP算法,比较分析了鲍威尔方法和惩罚函数法的适用性,让学生很好地理解了FR共轭梯度法的局限性和优化理论在机械系统运动学和动力学上的应用特点。     

转炉炉壳热应力分析

根据实际转炉建立实体模型。以有限元为手段,考虑了炉衬和炉壳材料的物性参数随温度变化的特点和炉衬与炉壳之间膨胀间隙,计算了转炉炉壳在温度载荷和炉衬膨胀压力同时作用下的热应力。所得结果可为转炉炉壳设计提供依据。     

焦炭热性能指标意义浅析

通过对焦炭在高炉内的历程及其变化规律的剖析,阐述焦炭热性能指标的意义,形象地把焦炭在高炉内的损耗分为三部分(M1,M2,M3)。指出M2对焦比及焦炭价格有一定的指导作用。     

Results of treatment of cancer of the cardia

Cancer of the cardia is traditionally discussed with cardiac cancer of the lower portion of the esophagus and upper gastric cancer invading the esophagus, and the specific characteristics of cancer of the cardia have never been clearly defined. We reviewed the outcome of 172 patients with adenocarcinoma of the cardia who had undergone radical surgery between 1949 and 1994 in the Division of Gastrointestinal Surgery of the Cancer Institute Hospital. The centers of the tumors were located within 2 cm above and below the boundary between the esophagus and the stomach, and their longitudinal diameter was less than 8 cm. We divided the patients into an early period (1949-1979; n = 79) and a late period (1980-1994; n = 93), and focused on the historical transition. There were no differences in patient gender or histology between the two periods. However, the late period was associated with fewer cases of esophageal invasion and shorter longitudinal diameter, as the age of the population advanced. The number of advanced cancers such as the localized and infiltrative type had decreased, and early cancer and early clinical stage had become more common, but despite the fact that the number of early cancers had increased, extended dissection, such as thoracic and paraaortic lymph node dissection, was performed more frequently. By clinical stage, the long-term outcome markedly improved in Stage I patient in the late period, and tended to improve in Stage II and III patients. This appears to have been attributable to the prevention of micrometastasis by extended dissection, although the number of early cancers is another major potential cause. There were no differences in the outcome of Stage IV patients between the two periods, and further advances in multimodality therapy must be awaited. The range of resection is basically proximal gastrectomy, and if there are adequate indications, the prognosis is favorable. In view of the status of lymphatic flow and lymph node metastasis, and long-term results, lateroaortic lymph node dissection is important. Since the number of early cancer patients has been increasing, if intraabdominal recurrence is prevented, intrathoracic lymph node dissection will contribute greatly to the outcome of such patients.     

The effect of amount of possession of the trait of hostility on accuracy of perception of hostility in others.

Some theories of personality hold that an individual's perception of others is influenced by his own personality characteristics; more specifically, that a trait of low social value will be projected more into others, and that insight into the possession of these characteristics reduces this distortion. These 2 hypotheses were tested by having a group of college students rate each other (including themselves) on degree of friendliness or hostility. Agreement with group rating about self yielded the insight score. In general, the hypotheses were supported; the "friendly" Ss were most accurate in their perception of others, and insight was positively associated with accurate perception. From Psyc Abstracts 36:04:4HL16M. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comparison of rates of infection of two methods of emergency ventricular drainage

The rates of infection of two methods of external ventricular drainage in use at Atkinson Morley's Hospital--namely, (a) percutaneous drainage with Rickham reservoirs and (b) tunnelled ventriculostomies--were compared in this retrospective review. Percutaneous drainage of CSF with Rickham reservoirs was associated with a 27% rate of infection as identified by positive microbiological cultures; tunnelled ventriculostomy catheters had a 10% infection rate. The difference in the infection rate between the two methods was statistically significant (P < 0.015). Other variables examined, including the age and sex of the patients and the reasons for ventricular drainage, were not associated with an increased rate of infection. Most infections from either method were caused by a coagulase negative staphylococcus. The average duration of ventricular drainage before identification of positive cultures was 5.7 days for Rickham reservoirs and 6.0 days for ventriculostomies.     

浅析《野草》的版画特征

鲁迅先生一生热爱美术作品,对版画中木刻兴趣尤甚.<野草>作为其"写心之作",亦呈现出一些与木刻版画一致的审美特征:一是具有木刻版画的色彩特征,多对比、多冷色,有阴郁的美感;二是具有木刻版画的力度特征,环境描写、人物刻画处处刀锋毕现,遒劲有力,有一种"力之美".     

四辊破碎机车刀架的改造

针对四辊破碎机车刀架车削中存在的几个问题,详细介绍了电动车刀架的结构和工作原理,建立主要设计参数的数学表达式,并进行适当的分析。改造后,这种电动车刀架运行平稳、可靠、方便、省力,取得了预期的效果。     

Effect of antibiotics of chemotaxis of human leukocytes

The effect of 20 different antibiotics on chemotaxis by human neutrophils was studied. Human leukocytes incubated with chloramphenicol, rifampin, sodium fusidate, and tetracyclines in vitro showed markedly depressed migration. The mechanisms by which these antibiotics affect leukotaxis are discussed.