Experimental ivnestigation on flow fields of viscous fluid around two-dimensional wings and comparison with computational results

To examine the flow field of a viscous fluid around the trailing edge of a wing with respect to the Kutta condition or the Joukowski hypothesis, an experimental investigation into the velocity fields around two-dimensional (2D) wings NACA0012 and NACA4412 was carried out using an X-type hot-wire anemometer in a wind tunnel and the method of colored milk injection in a circulating water channel. The results of these investigations revealed that the flow of a viscous fluid at the trailing edge of a 2D wing is tangential to the face on the pressure side, and that the flow is very slow or reversed on the suction side due to separation when the angle of attack is greater than 7.5°. By flow visualization, a Kármán vortex street was found in the wake of both wings (NACA0012 and NACA4412) when the angle of attack was 5°. These results show that the ordinary Kutta condition with respect to the direction of outflow at the trailing edge is not necessarily satisfied in a viscous fluid, but the Kutta condition with respect to the pressure at the trailing edge is satisfied as usual. Numerical results, which have been obtained as the solution of Reynolds-averaged Navier-Stokes equations, show good agreement with above-mentioned experimental results. Therefore, CFD (Computational Fluid Dynamics) simulation has proved to be very effective for studying steady viscous flow around the trailing edge of a 2D wing.     

宁夏回族高脂血症患者CYP2C9*3、MSA2756G基因多态性的研究

目的 研究高脂血症治疗的药物相关基因CYP2C9*3、甲硫氨酸合成酶(MSA2756G)在宁夏回族高脂血症患者中的分布及其与高脂血症的关系.方法 通过扩增引进限制性酶切位点(ACRS)和应用聚合酶链式反应-限制性片段长度多态性(PCR-RFLP)技术对高脂血症患者进行基因型分析.结果 180名宁夏回族高脂血症患者中,CYP2C9*3等位基因频率为3.33%,突变频率男性(3.05%)高于女性(0.28%),差异有显著性(P<0.01),而与健康对照组(3.00%)比较,差异无显著性(P>0.05);MSA2756G等位基因频率为15.83%,显著高于健康对照组(10.25%)(P<0.05),未发现性别差异.结论 宁夏回族人群携带CYP2C9*3基因型的男性患高脂血症风险更大;MSA2756G可能是高脂血症的危险因子.     

Correlation of expression of ER, PR and c-erbB-2 with ultrasonographic features in invasive ductal cancer of breast

Objective To analyze the relationship of the expression level of estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor-2 (HER-2, c-erbB-2) of breast invasive ductal carcinoma (IDC) with ultrasonographic characteristics. Methods Totally 104 patients with IDCs confirmed pathologically were involved in this study. ER, PR and c-erbB-2 expression in the IDC specimens was determined by immunohistochemical staining technique. The correlation between the ultrasonographic features and the positive expression of ER, PR or c-erbB-2 was analyzed. Results The positive expression rate of ER and PR in the group with tumor spiculation sign and posterior acoustic attenuation was higher than that in the group without. The positive expression rate of ER differed significantly (P<0.05) while that of PR did not (P>0.05). The over-expression rate of c-erbB-2 in the group of microcalcification, sufficient blood flow and axillary lymph node metastasis was higher than that in the group of non-microcalcification, deficient blood flow or without axillary lymph node metastasis (P<0.05). The expression of ER, PR and c-erbB-2 was not related to the size of tumor (P>0.05). Conclusion The expression of ER and c-erbB-2 is closely related to the ultrasonographic characteristics of IDC, which may, to some extent, reflect the expression level of ER and c-erbB-2.     

基于AEMM法的大跨度预制T梁存梁中的变形分析

大跨度预制预应力T梁具有建设成本低、不影响交通的优点,但其存梁过程中的变形在加载龄期、预应力损失、截面特性变化及存放时间差异等各种因素影响下呈非线性变化,难以控制。以高精度的按龄期调整的有效模量法(AEMM)法为理论基础,运用MATLAB编制其相应的徐变分析模块,计算出最佳加载龄期及存放时间,并推荐预制时最优预拱度设置线形,从而使存梁中的复杂徐变问题得到完美解决。     

骨转录因子Runx2和骨桥蛋白OPN在人乳腺癌组织中的表达及其与乳腺癌微钙化的关系

目的观察骨转录因子Runx2、骨桥蛋白(osteopontin,OPN)在人乳腺癌组织中的表达,并进一步探讨其与乳腺癌微钙化形成间的关系。方法利用免疫组化方法观察骨转录因子Runx2和骨桥蛋白OPN在62例乳腺癌组织中的表达。根据乳腺癌患者钼靶X线片中微钙化的有无与数量多少,将62例乳腺癌分为3组,即无钙化组、少量钙化组以及大量钙化组,观察Runx2和OPN蛋白表达与不同乳腺癌微钙化之间的关系。结果 Runx2蛋白在人类乳腺癌组织中表达阳性率为72.6%(45/62)。OPN蛋白在人类乳腺癌组织中表达阳性率为79.0%(49/62)。Runx2和OPN蛋白的阳性表达与乳腺癌钼靶X线片中微钙化的出现和数量密切相关,随着微钙化从无到有以及由少至多,Runx2(χ2=15.686,P<0.05)和OPN(χ2=16.161,P<0.05)蛋白的阳性表达率呈逐步增高的趋势。但Runx2和OPN阳性表达与乳腺癌钼靶片中微钙化形态无关。结论 Runx2和OPN蛋白在人类乳腺癌组织中高表达,其可能参与了乳腺癌微钙化的形成过程。     

基于节点兴趣的混合P2P网络

针对P2P网络在搜索资源时往往无法快速准确的定位目标,提出一种节点兴趣分组以及分层结构的P2P网络结构.网络拓扑在分布时将兴趣相似度高的节点放到一个兴趣组中,节点在搜索资源时就会更准确的定位在离自己距离近的同时也是兴趣最相似的节点上,减少了查询消息的路由转发.同时应用分层的管理,对整个网络中的节点功能细化,使得网络的稳定性和可扩展性得到优化.实验结果表明,采用兴趣分组和结构分层的网络访问延时得到有效控制,搜索成功率也得到提高.该算法在缩短路由跳数的同时还提高了搜索的精准率.     

高职院校思想政治理论课教学现状的调查与分析

本文在对武汉船舶职业技术学院思想政治理论课教学情况进行抽样调查的基础上,分析了以90后高职生群体为教学对象的思想政治理论课程建设中存在的问题,并提出了相关对策,期待以点带面,对高职院校思想政治理论课教学改革提供一定的借鉴。     

基于FPGA的数字相位调制系统的设计与实现

对2DPSK及QDPSK数字调制信号进行了分析,采用FPGA在QuartusⅡ环境下,利用VHDL语言及图形输入方式对调制系统进行了设计,用Altera公司的芯片EPlC3T144C-8为核心器件组建的系统进行了功能测试,得到了满意的验证波形.     

谈服务区“后浇带”施工

详细论述了高速公路服务区综合楼后浇带的施工方法,对后浇带浇注时间的确定、后浇带支撑与拆除方法及成品保护、安全措施提出了详细要求和理论依据,对后浇带施工有一定指导意义.     

海洛因暴露对子代小鼠海马凋亡相关基因表达的影响

目的 观察子宫内海洛因暴露对小鼠海马caspase-3、Bcl-2和Bax表达的影响,探讨线粒体凋亡通路在海洛因暴露引起子代小鼠神经、行为发育异常中的作用.方法 于小鼠胚龄(embryonic day)E9～E18d时,每天给孕鼠皮下注射海洛因10mg/kg,建立子宫内海洛因暴露的小鼠模型.按出生前处理将仔鼠分为空白组(Con)、盐水组(Sal)和海洛因组(Her).待仔鼠14d时取海马,应用RT-PCR和Western Blot检测caspase-3、Bcl-2和Bax的表达情况.结果 与Con和Sal组相比,Her组仔鼠的caspase-3和Bax的蛋白表达明显增加(P＜0.05),而Bcl-2蛋白表达明显下降(P＜0.05).结论 海洛因暴露可引起子代小鼠海马caspase-3和Bax表达上调,Bcl-2表达下调,提示线粒体凋亡通路可能参与了海洛因损伤小鼠神经行为发育的分子机制.