不同功率532 nm激光诱导棕色挪威大鼠脉络膜 新生血管模型的实验研究

目的 采用532 nm激光的不同功率诱导棕色挪威大鼠脉络膜新生血管模型,以探求成模率最高的激光功率。方法 将45只挪威棕色大鼠随机分为3个实验组,每组15只,激光功率依次为400 mW、300 mW、200 mW,光斑直径100 μm,曝光时间100 ms,每眼光凝10～12个点。对各实验组大鼠激光造模后的第1周、2周、3周、4周行眼底彩照、荧光素血管造影和光学相干断层扫描,对实验数据进行统计。结果 眼底彩照可见激光诱导后的视网膜因玻璃膜的破坏呈现水肿状态;荧光血管造影显示功率200 mW的激光与300 mW、400 mW的激光诱导后第1～4周的渗漏率对比,差异有统计学意义(P0.05),第2、4周对比渗漏率有统计学意义(P0.05),而第1、3周和第2、3周的渗漏率差异有统计学意义(P0.05)。光学相干断层扫描显示视网膜破坏后结果紊乱,然后诱发脉络膜新生血管形成,最终趋于稳定,部分视网膜结构萎缩变薄。结论 200 mW、300 mW、400 mW的532 nm激光均可以诱导挪威棕色大鼠形成脉络膜新生血管模型,其中300 mW的成模率最高,脉络膜新生血管于1周后开始形成,第3周达到高峰,第4周趋于稳定。     

时效时间对6063铝合金准静态压缩性能的影响

以6063铝合金汽车吸能型材为研究对象,采用准静态轴向加载方式,从组织、力学性能等方面研究不同时效制度对6063铝合金型材准静态压缩性能的影响。结果表明：当时效温度为200 ℃时,随着时效时间的延长,合金组织中大尺寸析出相的数量呈先增加后减少的趋势,粗晶层厚度基本不变;随着时效时间的延长,6063铝合金型材的强度、硬度升高,同时准静态压缩的承载能力增强,时效时间6 h时承载能力达到峰值;6063铝合金型材的吸能性能随时效时间的延长而提高,时效时间6 h的吸收功较2 h的提高了48%。     

A coupled model of TiN inclusion growth in GCr15SiMn during solidification in the electroslag remelting process

TiN inclusions observed in an ingot produced by electroslag remelting (ESR) are extremely harmful to GCr15SiMn steel. There-fore, accurate predictions of the growth size of these inclusions during steel solidification are significant for clean ESR ingot production. On the basis of our previous work, a coupled model of solute microsegregation and TiN inclusion growth during solidification has been estab-lished. The results demonstrate that compared to a non-coupled model, the coupled model predictions of the size of TiN inclusions are in good agreement with experimental results using scanning electron microscopy with energy disperse spectroscopy (SEM-EDS). Because of high cooling rate, the sizes of TiN inclusions in the edge area of the ingots are relatively small compared to the sizes in the center area. Dur-ing the ESR process, controlling the content of Ti in the steel is a feasible and effective method of decreasing the sizes of TiN inclusions.     

砂砾岩地层三维地应力场研究

以西部某地区砂砾岩储层为研究对象,基于丰富的压裂改造资料、地球物理测井资料,分析深部地层实测地应力的大小与方向,建立了适用于砂砾岩储层的地应力评价模型并计算地应力单井剖面.在此基础上,利用地震构造模型构建合理的三维空间数值模型,以单井地应力为基本约束,利用有限元法对工区现今三维地应力场进行反演.研究结果表明:工区地应力...     

Fault-Tolerant Design for Data Efficient Retransmission in WiNoC

There is a sharp decline in the network performance when the wireless link fails as a data path in the Wireless Network-on-Chip(WiNoC).To counteract this problem,we propose a fault-tolerance mechanism for the efficient retransmission of data in the WiNoC.When an error is detected in the data transmission process,this mechanism works to feed back the fault information to the source node in real time via fault signal lines.In the source node,the highest transmission priority is assigned to the backup retransmitted data,and the corresponding direct link is positioned to enable the data packet for its efficient retransmission to the destination node,thereby ensuring efficiency in fault tolerance.Additionally,we have improved the receiving port of the wireless router,added the corresponding redundant buffers and mux,and dynamically selected the retransmitted non-faulty data packets to be written to the local router in order to avoid the disorderly retransmission of the data packets.The evaluation results of this paper demonstrate that compared with the methods which are under different fault conditions,this fault-tolerant method drastically improves the data throughput rate,reduces the delay,effectively guarantees the reliability of the network,and improves the system performance.     

p38丝裂原活化蛋白激酶和核因子-κB促进创面血管化的机制探讨

目的:探讨p38丝裂素活化蛋白激酶(MAPK)信号转导通路和核因子-κB(NF-κB)/抑制因子(IκB)通路在调控血管内皮细胞生长因子(VEGF)产生及血管化等方面的作用及其相互关系.方法:将32只Wistar大鼠完全随机分为4组各8只:假烫组、烫伤组、烫伤+p38MAPK抑制剂组和烫伤+NF-κB抑制剂组.除假烫组以外,其余各组均制作深Ⅱ°烫伤模型,其中烫伤+p38MAPK抑制剂组和烫伤+NF-κB抑制剂组于烫伤后15 min和12 h分别静脉注射SB203580和PDTC;各组大鼠均于伤后48 h处死并取材.酶联免疫吸附法(ELISA)测定创面组织中VEGF的含量和血管微密度(MVD),蛋白印迹(Western blotting)法检测p38MAPK和IκBα的表达.结果:和假烫组相比,伤后48 h,烫伤组创面组织中VEGF的质量浓度明显上升,为(0.81±0.19)ng/m L和(2.88±0.32)ng/m L,(P0.05);MVD值明显增加,为(3.12±0.72)和(8.08±2.10),(P0.05);p38 MAPK含量升高,为(966±176)和(4778±332),(P0.05);IκBα含量下降,为(2 327±310)和(1 278±149),(P0.05).使用SB203580和PDTC均能抑制烧伤后创面组织中VEGF含量的上升和血管化.预先给予SB203580能抑制烧伤后创面组织中p38MAPK含量升高,但对IκBα含量无显著影响;预先给予PDTC可以防止烧伤后创面组织中IκBα含量的下降,而对p38MAPK表达无影响.结论:在烧伤后创面愈合过程中,p38 MAPK信号转导通路和NF-κB/IκB通路是两个平行和独立的信号转导通路,两者间无直接的联系,但共同调节着烧伤后VEGF的产生与创面血管化.     

非线性矩阵方程X+A~* X~(-q) A=Q的Hermite正定解

非线性矩阵方程X+A*X-qA=Q,这里A是n阶非奇异复数阵,Q为q≥1阶Hermite正定距阵.在q≥1时上面矩阵方程有正定解,或者是此正定解唯一,并给出它们的充分以及必要条件,接着又给出了求上面方程正定解的迭代法.     

鄂尔多斯盆地大牛地气田山1段沉积微相研究

通过钻井岩心观察,剖面结构及岩性组合特征分析,对大牛地气田山西组山1段沉积体系进行系统研究,认为山1段为辫状河三角洲沉积体系,并进一步识别出分流河道、分流间洼地、泛滥平原等微相。     

观音场-大塔场地区须六段储层特征及主控因素

通过钻井岩心观察、薄片鉴定及实测孔渗资料分析,分别研究了观音场—大塔场地区须六段储层岩性、物性表明:须六段储层(发育在须六1亚段和须六3亚段)主要为长石岩屑砂岩、岩屑长石砂岩和岩屑砂岩,为低孔、低渗的孔隙型、孔隙-裂缝型储层。残余粒间孔、颗粒边缘和粒间胶结物溶孔较发育。环边绿泥石胶结和构造破裂作用为建设性成岩作用,改善了储集空间、提高了储集性。     

释“八卦”新义

“八卦”是最近几年使用频率颇高的一个时尚词语。它的含义有了新的发展。从语义、语源、流行成因等方面论述“八卦”一词的新义新用法。