仪器安装板振动环境虚拟试验和验证技术研究

基于商用有限元软件MSC.Patran和Nastran,研究了导弹仪器安装板结构的振动环境预示技术。建立了仪器安装板的三维实体模型,单机仪器使用质点模拟,并通过MPC法与安装板连接;设置了多种阻尼特性,通过模态叠加法预示了该仪器安装板在振动条件下的结构动力学环境,通过振动试验验证了预示结果。研究发现,使用大阻尼能较好地预示该仪器安装板结构的动力学环境。     

PCS7自动控制系统在气烧窑上的应用

对柳钢气烧窑工艺流程及PCS7自控系统的设计特点及其在该项目上的应用做简要介绍。     

蔗糖发酵过程中无机磷含量的变化研究

无机磷与钼酸能形成磷钼酸络合物,该络合物能被还原剂α-1,2,4-氨基萘酚磺酸钠还原成钼蓝,用分光光度计确定蔗糖发酵前后无机磷的含量,观察发酵过程中无机磷的消耗。发现高浓度的磷酸盐会对微生物合成具有抑制和阻遏作用,无机磷含量的减少使葡萄糖磷酸化减慢,进而也影响糖酵解速度。研究表明在pH为6、温度为37℃、无机磷浓度为5g/L左右,发酵最佳。     

新钢10~#高炉优化高炉操作的生产实践

为稳定炉况,改善高炉操作指标,新钢10~#高炉进行了优化操作实践,取得了较好的效果。     

水热法制备粉煤灰钙基脱硫剂

文章研究了利用粉煤灰和Ca(OH)2为原料水热反应制备钙基脱硫剂。影响钙基脱硫剂钙剂利用率最主要的因素是水浴温度(TH),它的最佳值是90℃;温度上下浮动5℃,利用率将降低20%。其次还有水浴温度、粉煤灰与Ca(OH)2质量比(FC)、水固比(LS),这些因素的波动对利用率的影响相对较小。水浴时间(tH)达到8 h以上,FC在5～10的范围内变化,LS在8～18的范围内变化均能制备具有较高利用率的钙基脱硫剂。     

广州地铁黄村站联动调试工程项目管理要点

地铁站设备联动调试是项目管理的最后一关,直接关系到产品、设备功能和安装质量能否满足地铁站使用功能及各项功能的设计要求,为日后设备在最佳状态下运行创造先决条件,文中实例因涉及多个专业承包商而成为联动调试的一大难点。     

微风细雨:都江堰虹口香溪堂设计随笔

<正>都江堰虹口距成都市约80km,因避暑及漂流而成为成都的旅游胜地,生态旅游中心选址于虹口风景区深溪沟。项目分两期,一期为深溪沟接待点,由香溪行馆(别墅区)和香溪堂(服务配套建筑,190m~2)组成,二期为虹口旅游服务中心及酒店。香溪堂作为接待、休闲之用,规模很小,功能简单,但业主极为重视,把它作为二期启动前的形象展示,希望设计理念先进,独具个性。业主于2007年10月正式委托我们设计一期工程,原计划2008年6月动工。5月12日突如其来的汶川大地     

Improved ant colony optimization algorithms for determining project critical paths

In project management, a project can be represented as a network in two ways; namely, activity-on-arc (AoA) and activity-on-node (AoN). Two recent papers have shown that ant colony optimization (ACO) could find critical path(s) in projects represented as AoA networks. This paper points out that the number and placement of logical dummy activities associated with AoA-based networks can pose serious problems. To get around the problems, an ACO technique based on AoN networks is then proposed. For comparison, the two existing AoA-based ACO algorithms were reproduced and modified into AoN-based algorithms. Moreover, the proposed ACO algorithm was applied to AoA networks as well. All six algorithms were tested with several benchmark problems. The test results strongly indicate that AoN-based ACO algorithms are more effective and efficient in finding critical paths than AoA-based algorithms.     

主变保护差动比率制动曲线的测试

介绍了目前常见的主变保护装置在差动保护两侧电流的移相方式及消除主变变比和TV变比对差动保护的影响上的不同,例举了常见主变保护差动比率制动曲线的测试方法。     

Effects of Moisture on Furfural Partitioning in Oil-Paper Insulation System and Aging Assessment of Power Transformers

The furfural concentration in oil is a well-accepted chemical marker indicating the aging condition of power transformers. However, recent researches suggest that the furfural concentration in oil is affected by moisture, because moisture influences the furfural partitioning ratio in oil-paper insulation system. In this study, the correlation of moisture and furfural partitioning ratio was investigated. The accelerated thermal aging test and moisture absorption test were conducted to prepare oil-paper samples with different furfural and moisture concentrations. For samples with different moisture concentrations, the furfural partitioning ratios between oil and paper were compared. Results showed that samples with high humidity exhibited a high furfural mass fraction in oil. This finding implied that high humidity promoted the furfural diffusion from paper to oil. Further, the interference of moisture on aging assessment of insulation paper was analyzed. Results showed that the increase of moisture concentration in oil-paper system would significantly affect the accuracy of insulation paper aging assessment. A corrected equation for aging assessment of insulation paper with different moisture concentrations was established. Verification result showed that the equation could effectively correct the interference of moisture and enhance the accuracy of the aging assessment of insulation paper.