磨机磁性衬板的开发和应用

新型磁性衬板寿命长,重量轻,降低磨机的能耗,增加了磨机生产能力．衬板的永磁体可重复使用,运转成本低．     

Retinoblastoma protein contains a C-terminal motif that targets it for phosphorylation by cyclin-cdk complexes

Stable association of certain proteins, such as E2F1 and p21, with cyclin-cdk2 complexes is dependent upon a conserved cyclin-cdk2 binding motif that contains the core sequence ZRXL, where Z and X are usually basic. In vitro phosphorylation of the retinoblastoma tumor suppressor protein, pRB, by cyclin A-cdk2 and cyclin E-cdk2 was inhibited by a short peptide spanning the cyclin-cdk2 binding motif present in E2F1. Examination of the pRB C terminus revealed that it contained sequence elements related to ZRXL. Site-directed mutagenesis of one of these sequences, beginning at residue 870, impaired the phosphorylation of pRB in vitro. A synthetic peptide spanning this sequence also inhibited the phosphorylation of pRB in vitro. pRB C-terminal truncation mutants lacking this sequence were hypophosphorylated in vitro and in vivo despite the presence of intact cyclin-cdk phosphoacceptor sites. Phosphorylation of such mutants was restored by fusion to the ZRXL-like motif derived from pRB or to the ZRXL motifs from E2F1 or p21. Phospho-site-specific antibodies revealed that certain phosphoacceptor sites strictly required a C-terminal ZRXL motif whereas at least one site did not. Furthermore, this residual phosphorylation was sufficient to inactivate pRB in vivo, implying that there are additional mechanisms for directing cyclin-cdk complexes to pRB. Thus, the C terminus of pRB contains a cyclin-cdk interaction motif of the type found in E2F1 and p21 that enables it to be recognized and phosphorylated by cyclin-cdk complexes.     

铜绿山矿面临的问题与对策分析

从历史发展的角度,阐述了铜绿山矿生产中存在的主要问题,并针对这些问题提出了相应的对策。     

关于状态空间方法的一个注记

本注记给出了在状态空间方法中常用的几个特殊矩阵的特征多项式和特征值的精确计算。     

换半线圈法在运行现场修复电机时的应用

本文应用换半线圈法对广钢公司损坏的发电机定子绕组进行修复,给出了修复过程中的实施重点,表明了换半线圈法是一种在运行现场修复电机的行之有效的方法。     

Effects of Ce on the hydrogen storage properties of TiFe0.9Mn0.1 alloy

The hydrogenation properties and the microstructures of TiFe_0.9Mn_0.1Ce_x (x = 0, 0.02, 0.04, 0.06) alloys were investigated by PCT, XRD and SEM/EDX. The results showed that the addition of small amount of Ce remarkably improved the activation properties of TiFe_0.9Mn_0.1 alloys. The alloys could start to absorb hydrogen at 353 K under the initial hydrogen pressure of 4.0 MPa without noticeable incubation time. XRD profiles and SEM observation indicated that Ce dispersing in TiFe matrix played an important role for the improvement of activation properties. The addition of Ce didn't affect the thermodynamics and the cycling properties of TiFe_0.9Mn_0.1 alloy. The degradation of hydrogen capacity after cycles of hydrogenation was recovered by a heat treatment at 623 K.     

自己造就的污水应让自己喝了回去--读郑光复先生《拂去泼在中国建筑师身上的污水--细品《中国建筑师缺乏修养》及其附文《细读……》》有感

人不可以有傲气,但不可以无傲骨 ——徐悲鸿 一个国家、一个民族、一个群体乃至一个个人,可能会受到别人的嘲弄、欺负乃至宰割,但这并不可怕。可怕的是受到了欺负,不以为耻,不以为忧,反以为乐,反以为荣;奴颜婢膝,并不知道自己也是人,这才是最大的可悲。     

基于启发式算法的自动化立体仓库拣货路径优化研究

为了对自动化立体仓库拣货系统进行优化,本文根据自动化仓库订单拣货问题的特点,以拣货时间最小化为目标建立了相应的数学模型,设计了基于启发式规则的求解算法,并用MATLAB实现了算法,经仿真验证以及将启发式算法与文献其它算法进行比较,结果表明,应用本文模型以及改进的启发式算法进行拣选路径的设计,能够有效地缩短拣选时间和距离,从而提高拣选效率,本算法具有一定的实用性。     

水泥与偏高岭土地聚物砂浆碱骨料反应对比研究

为减少环境污染,近年来对碱激发胶凝材料的研究逐渐增加,而目前研究大多集中在地质聚合物机理方面,较少涉及其碱骨料反应。本文试图探究高温高碱环境下,碱激发胶凝材料砂浆与传统水泥砂浆碱骨料反应的不同,以推进碱激发胶凝材料的工程应用。通过测量试件不同龄期长度变化,研究掺不同骨料的水泥砂浆和偏高岭土基地聚物砂浆在高温高碱溶液中的变形行为,同时采用XRD、SEM等微观手段分析二者不同龄期产物的组成和微观结构。研究结果表明：地聚物与水泥的碱骨料反应历程存在明显区别,地聚物中不会发生严重的碱骨料反应,工程中能使用碱活性强的骨料;地聚物浆体最终形成(类)沸石结构,其笼式结构能吸附和固溶大量有害碱,能适应海工等强腐蚀性环境。     

气流流路对高压SF_6断路器介质强度混沌影响

高压SF6断路器的开断性能主要取决于灭弧室内的介质恢复能力。开断过程中,气流在可变流路中呈跨音速流动,将不可避免地产生湍流与激波,气流参数变化存在混沌特征,且灭弧室内部各气流参数在毫秒级时间与毫米级空间内气流运动行为复杂多变。采用有限体积法对550k V单断口高压SF6断路器开断容性小电流情况下的气流场进行数值求解,通过改变喷口长度及型面可调控气流流路,改变气流参数时空行为;采用有限元法得到灭弧室内电场分析;基于流注理论得到不同喷口结构下灭弧室内的介质恢复特性。由于断路器开断过程中介质强度恢复存在混沌,影响断路器的开断性能,通过改变喷口气流流路可以有效调控断路器内气流参数的混沌特性,以增强介质恢复能力,提高开断性能。