近距侧爆情况下马蹄形隧道动态响应特点的研究

在数值模拟和动光弹试验研究的基础上 ,对马蹄形隧道在邻近爆破作用下的动态响应特点进行了分析 ,并在综合考虑入射应力波波长、隧道直径、爆源与隧道的相对距离的基础上 ,提出了隧道迎爆一侧的动应力集中因子的近似确定方法 ,为今后邻近隧道的爆破施工安全提供了有益的参考。     

钢构件应力集中区低周疲劳分析及实验研究

针对两个具有应力集中区的特定钢构件的低周疲劳问题进行理论分析和实验研究。文中提出了一套低周疲劳分析的相关近似方法 :由材料静力参数估算其疲劳参数 ,并利用实验数据加以修正 ,获得了循环应力 -应变曲线和应变 -疲劳寿命曲线 ;进而把非线性有限元法和局部应力应变分析结合在一起计算疲劳寿命。理论结果和实验结果作了比较 ,从而证明本文提出的分析方法是行之有效的。     

动态预浓缩法富集变压器油中溶解的C2烃

利用动态预浓缩方法对溶解在变压器油中的乙炔、乙烯和乙烷进行了富集,在１０ｍＬ顶空气体的进样量下得到了１００倍的富集效果,因此可以用热导检测器替代氢火焰离子化检测器,使在线检测成为可能,通过比较溶解气体从变压器油中脱出的方法发现,超声振荡比机械振荡的脱气效率提高几十至上百倍。     

高效液相色谱法测定人血浆中的辛伐他汀

 建立了高效液相色谱法监测人口服辛伐他汀药物后的血药浓度。血样用环己烷-二氯甲烷(体积比为3.5∶1)提取,以洛伐他汀为内标,在237nm波长下检测;色谱柱:LichrospherC18(200mm×4.6mmi.d.,5μm),流动相:乙腈-水(体积比为70∶30);流速:1.2mL/min。血药浓度在0.25～50.0μg/L范围内与峰面积和内标峰面积的比值之间线性关系良好,日内及日间相对标准偏差(n=5)分别低于7.94%和8.58%,回收率高于93.3%。方法灵敏、准确、快速,适用于药物动力学和药效学研究。     

Finding the critical path in an activity network with time-switch constraints

An activity network is an acyclic graph with non-negative weights and with a unique source and destination. A project consisting of a set of activities and precedence relationships can be represented by an activity network and the mathematical analysis of the network provides useful information for managing the project. In a traditional activity network, it is assumed that an activity always begins after all of its preceding activities have been completed. This assumption may not be adequate enough to describe some practical applications where some forms of time constraints are attached to an activity. In this paper, we investigate one type of time constraint called time-switch constraint which assumes that an activity begins only in a specified time interval of a cycle with some pairs of exclusive components. Polynomial time algorithms are developed to find the critical path (or longest path) and analyze the float of each arc in this time-constrained activity network. The analysis shows that the critical path and float in this context differ from those of a traditional activity network in some management perspectives and thus, consideration of the time-switch constraint leads to enhanced project management through more effective use of budgets and resource allocation.     

Buckling of a von Kármán Plate Adhesively Connected to a Rigid Support Allowing for Delamination: Existence and Multiplicity Results

The present paper deals with an eigenvalue problem for a hemivariational inequality, arising in the study of a mechanical problem: the buckling of a von Kármán plate adhesively connected to a rigid support with delamination effects. For this eigenvalue problem an existence result is obtained by applying a critical point method suitable for nonconvex nonsmooth functions. Further, a result concerning the multiplicity of solutions is proved. The mechanical interpretation of these results is briefly discussed.     

微晶酚酞-乙基紫分离富集镉(Ⅱ)

微晶酚酞-乙基紫分离富集镉(Ⅱ);微晶酚酞;乙基紫;分离富集;镉(Ⅱ)     

原位聚合阴离子交换型固相萃取（SPE）微柱

原位聚合阴离子交换型固相萃取（SPE）微柱;原位聚合;SPE微柱;分离富集     

硅烷浓度对微晶硅太阳电池的影响

采用甚高频等离子化学气相沉积技术(VHF-PECVD)制备了系列p-i-n型微晶硅太阳电池,研究了电池有源层硅烷浓度的变化对电池性能的影响.结果发现:随着硅烷浓度的提高电池的短路电流密度先提高然后降低,转换效率与之有相同的变化趋势,而开路电压随硅烷浓度的提高而增加,这些变化来源于有源层材料结构的改变.电池的填充因子几乎不受硅烷浓度的影响,但受前电极的影响很大.不同系列电池转化效率的最高点虽然处于非晶到微晶的过渡区,但对应电池的晶化率不同.另外,研究结果也给出非晶/微晶过渡区随着辉光功率的提高和沉积气压的降低向高硅烷浓度方向转移.     

壬基酚聚氧乙烯醚型Gemini季铵盐表面活性剂的合成 及其表面性质的研究

合成了系列壬基酚聚氧乙烯醚型Gemini季铵盐表面活性剂(GNPQA), 用核磁、红外和元素分析对它们的结构进行了表征, 考察了反应条件对转化率的影响, 并用表面张力法和稳态荧光探针法对GNPQA的表面性能及胶束聚集数(N)进行了研究. 结果表明, 较优的反应条件: 反应时间为12 h, 反应温度为70 ℃, 反应原料摩尔比为n(双聚壬基酚聚氧乙烯醚)∶n(三乙胺)∶n(环氧氯丙烷)＝1∶1∶1; GNPQA的临界胶束浓度(CMC)值较相应的单体壬基酚聚氧乙烯醚型季铵盐表面活性剂(NPQA)降低了1～2个数量级, 显示了较高的表面活性; 当GNPQA溶液浓度为5～9倍CMC时, N值随浓度增大而线性增大; 随着氧乙烯(EO)单元数的增长, GNPQA的CMC和N值均逐渐减小; 结合GNPQA的表面性能参数和N值的变化规律, 探讨了这类表面活性剂表面及胶束聚集体的结构形态.