“2016·7”清江流域洪水调度方案分析

2016年7月,清江流域发生了特大洪水,湖北省防汛抗旱指挥部认真研究、贯彻、落实防洪决策部署,把保障人民群众生命财产安全放在首位,反应迅速、调度灵活。经过对汛情进行研究分析,制定出了相应的措施,即采取预泄腾库迎洪、汛中错峰拦洪、汛末适时收水等,取得了清江特大洪水防御的阶段性胜利。对"2016·7"清江洪水调度方案及措施的制定、落实情况进行了总结分析,可为今后清江流域防洪调度工作提供借鉴与参考。     

Plastic deformation of ZnO thin films through edge and screw dislocation movements

Columnar wurtzite grains were formed in sputtered ZnO thin films deposited on a plastic polyethylene terephthalate substrate. Selected-area diffraction patterns reveal that the columnar grains in the sputtered films present two preferred growth planes, namely, the basal (0002) and prismatic (100) growth planes. The diffraction patterns obtained also confirm that the microstructure of sputtered indium tin oxide thin films is amorphous in nature. Tensile tests indicate that the fracture strain of the ZnO thin film occurs between 1.73% and 2.14%, while the fracture strain of the indium tin oxide thin film occurs between 0.24% and 0.67%. Thus, the fracture toughness of the sputtered ZnO thin film is greater than that of the sputtered indium tin oxide thin film. High-resolution transmission electron microscopic images demonstrate that edge and screw dislocations could be identified in the sputtered ZnO thin films. Moreover, edge and screw dislocation movements may, respectively, be observed in the basal- and prismatic-oriented ZnO columnar grains of the sputtered ZnO thin films. Our results indicate that movements of the edge and screw dislocations in the basal- and prismatic-oriented ZnO columnar grains account for the plastic deformation of the investigated ZnO thin films under tensile stress.     

小江调水调蓄水库方案研究

小江调水是引江济渭入黄方案中的重要方案之一.小江调水方案是从三峡库区支流小江取水,水源丰富,调水量保证率高,Ⅰ期调水40亿m3,引水流量300 m3/s.在综合分析各种调蓄水库的可能性后,推荐采用沣河平原水库方案来调蓄小江来水,并对该方案的作用和效果进行了分析.结果表明:该方案冲淤效果得到改善,减淤量在平水系列比无水库时提高19.6%,在枯水系列提高32.4%.     

LED激发叶绿素荧光探测仪的设计研究

对蓝光激发叶绿素的荧光光谱进行了分析,讨论了叶绿素荧光光谱的来源,采用调制式470nm绿光LED激发叶绿素,制成叶绿素荧光光谱仪,线性范围0—100μg／L,检出限0．1μg／L,该方法快速、灵敏、有很好的特异性．     

Effect of variation in gas distribution on explosion propagation characteristics in coal mines

In order to investigate the effect of variation in the distribution of gas on explosion propagation characteristics in coal mines, experiments were carried out in two different channels with variation in gas concentration and geometry. Flame and pressure transducers were used to track the explosion front velocity. The flame speed (Sf) showed a slight downward trend while the methane concentration varied from 10% to 3% in the experimental channel. The peak overpressure (Pmax) dropped dramatically when com-pared with normal conditions. As well, the values of Pmax and Sf decreased when the methane concentration dropped from 8% to 6%. The flame speed in the channel, connected to a cylinder with a length varying from 0.5 to 2 m, was greater than that in the normal channel. The peak overpressure was also higher than that under normal conditions because of a higher flame speed and stronger pressure piling up. The values of Pmax and Sf increased with an increase in cylinder length. The research results indicate that damage caused by explosions can be reduced by decreasing the gas concentration, which should be immediately detected in roadways with large cross-sections because of the possibility of greater destruction caused by more serious explosions.     

Microscopic characterization of semi-solid aluminium alloys

The microstructural evolution and element distribution of the Al-4Cu-Mg alloy during semi-solid compression were investigated,and the precipitate behavior and dislocation morphology were discussed.The experimental results show that the microstructure,the number of CuAl2(θ phase) precipitates,and the dislocation density of the Al-4Cu-Mg alloy depend apparently on the process parameters.More segregation of Cu at the grain boundary happens with an increase of deformation temperature and a decrease of strain ra...     

再生混凝土单轴受压变形性能的试验研究

对再生混凝土与普通混凝土的单轴受压性能进行了对比试验研究,主要包括弹性模量、应力应变曲线上升段以及峰值应变.研究结果表明,再生混凝土的弹性模量比普通混凝土低,用普通混凝土弹性模量计算公式不再适用于再生混凝土,在对试验数据进行了回归分析的基础上,提出了再生混凝土弹性模量的计算公式.应力应变曲线的上升段与普通混凝土相似,都是用3次多项式拟合,其峰值应变比普通混凝土高.     

短期洪水预报在磨盘山水库洪水调度中的应用

阐述和分析了拉林河干流磨盘山水库20070801#洪水的降水情况和洪水特点,结合《磨盘山水库洪水及兴利调度系统》所提供的数据资料进行2007年主汛期首次洪水调度。     

(1102)γ面蓝宝石生长的(1120)α面氮化镓研究

自发极化和压电极化是氮化镓制作光电器件没有解决的问题,对非极性GaN材料的研究解决了极化现象.采用低温AIN作为缓冲层,在(1102)γ面蓝宝石和(0001)с面蓝宝石上分别生长了(1120)非极性α面和(0001)极性с面GaN,用原子力显微镜和高分辨X射线衍射、光致发光谱比较了生长在γ面蓝宝石上的α面GaN和с面蓝宝石上的с面GaN,α面GaN材料质量和с面GaN相差较大,在α面GaN上发现了三角坑的表面形貌,这和传统的с面生长的极性GaN截然不同.对α面GaN的缺陷形成原因进行了讨论,并且确定了三角坑缺陷的晶向.     

一种基于改进层次聚类的Hough空间峰值检测方法

运用Hough变换对序列图像中的弱小点目标运动轨迹进行直线检测时,常规的Hough变换参数空间峰值检测方法难以区分相近的目标运动轨迹。为满足多目标有效跟踪的应用需求,文章根据目标Hough变换参数空间的狭长型特点,结合改进的层次聚类方法,给出一种基于层次聚类的Hough变换参数空间峰值检测方法。通过实验分析,验证了文章所提方法的有效性。