离心式水泵叶栅流动研究

离心式水泵叶栅流动很复杂,必须采用试验与数据分析相结合的方法,才能真正有益于工程实践．本文主要介绍应用ＴＳＩ二维激光多普勒测速仪探测离心式水泵叶栅流场,清晰地看到轴向涡旋对叶栅流动的影响,发现离心式泵叶栅出口处液流周向分速沿圆周变化不大．简单介绍了对试验水泵进行数据计算的结果．激光测速、流场显示以及三维数值分析结果都表明试验水泵叶片压力侧有严重的回流现象．     

关于Rego-Rourke算法的注记

本注记说明搜寻同伦３－球面的ＲＲ－算法可以简化。     

临清坳陷莘县凹陷油气勘探远景评价

对莘县凹陷的构造、沉积、盆地模拟及油气勘探远景等进行了深入研究。结果表明,该凹陷具有浅、中、深３个勘探层次,浅层馆陶组和沙一段以储集次生油及低成熟油气为主;中层沙二段、沙三段以自生自储型油藏为主;深层孔二段以储集高成熟油气、石炭－二迭系以煤成气为主。此地区有着极广阔的勘探远景。     

Designing a Capability-Focused Strategic Management Model for a Turkish Public Hospital: Learning from Failure

This study aims to depict a failed strategic change initiative in a Turkish public hospital by means of an action research and it strives to explain critical factors underpinning the failure, thereby proposing how such factors should be tackled with for similar initiatives elsewhere. The study calls attention to the recent challenges ongoing in the environment of hospitals, which urge them to take on a more strategic focus. In this vein, we discredit accreditation based systems, which emphasize monitoring resources and propose a capability-focused strategic management model for hospitals. A hybrid action research protocol, which combines both traditional and participatory action research methodologies in its design, is employed to formulate and implement the model in a public hospital. The phases of the project and obstacles faced during these phases are discussed. The findings suggest that although the model offers significant potential for competitive success and better resource efficiency, path-dependent characteristics of the public sector governance in Turkey have impeded the adoption of the model in our case. Both macro-systemic characteristics related mainly to the Turkish national culture and management of public institutions and situation-specific characteristics, such as top management’s decision making orientation, professional norms and patronage relationships have blocked the way for the aspired transformation despite positive attitudes of and support from higher order public authorities and internal professional groups.     

基于GIS与AHP属性辨识模型的地质灾害危险性评价——以涪陵页岩气开采区为例

【目的】建立新的区域性地质灾害评价模型,对涪陵页岩气开采区的地质灾害危险性进行评价。【方法】根据涪陵页岩气开采区的地质、水文和气候特征,选取归一化植被指数(NDVI)、土地类型、坡度、坡高、年峰值周降雨量、年峰值日降雨量等6个主要因素作为评价指标。基于GIS平台,采用AHP属性辨识模型对研究区的地质灾害进行危险性评价。【结果】涪陵页岩气开采区的地质灾害危险性较高,极高危险区面积为1466 km2,高危险区面积为743.6 km2,两者分别占开采区总面积的9.6%和52.8%。通过开采区173个历史地质灾害点的验证表明,评价的地质灾害危险性区划与历史地质灾害点的空间分布一致,其中98个分布于极高危险区,56个分布于高危险区,分布于中危险区和低危险区的仅有19个。用受试者工作特征曲线法对上述评价结果进行精度评估,曲线下的面积百分比达82.8%,验证了评价模型的可行性。【结论】研究结果对涪陵页岩气开采区输气管线、道路和房建等的规划和防灾减灾具有重要指导意义。     

一类状态反馈控制的渔业生产模型研究

【目的】建立了具有状态反馈控制的渔业生产数学模型。【方法】借用线性近似方程、后继函数法、半连续系统几何理论、floquent乘子理论,讨论系统平衡点阶1周期解存在性及轨道稳定性。【结果】给出了系统正平衡点存在阶1周期解的若干条件,证明系统存在阶1周期情况下,阶1周期解轨道是渐近稳定的。【结论】为现实从事渔业生产活动提供一定的理论参考依据。