An independent component analysis algorithm through solving gradient equation combined with kernel density estimation

A new algorithm for linear instantaneous independent component analysis is proposed based on max-imizing the log-likelihood contrast function which can be changed into a gradient equation. An iterative method is introduced to solve this equation efficiently. The unknown probability density functions as well as their first and second derivatives in the gradient equation are estimated by kernel density method. Computer simulations on artificially generated signals and gray scale natural scene images confirm the efficiency and accuracy of the proposed algorithm.     

离子型土固化材料对膨胀土的加固机理试验研究

采用离子型土固化材料对广西南宁膨胀土进行化学加固,通过试验获得不同配合比加固土的化学成分、阳离子交换量和比表面积,对加固土的物理化学性质等进行表征.同时利用扫描电镜观察加固土的微观形貌,并试验测试加固土的膨胀性和强度特性,探讨离子型土固化材料对膨胀土的加固机理.结果表明:离子型土固化材料使得膨胀土的阳离子交换能力和比表面积显著降低,土对水的吸附能力减小,土的结构稳定性得到增强;离子型土固化材料与石灰共同作用.使得膨胀土的层状结构形式改变为粒状结构,土粒之间的联结增强,土一水之间的相互作用体系发生改变,土的胀缩总率和塑性指数明显减小,土的强度和水稳定性得到有效的提高.     

如何解决汽车发电机转子绕组断线问题

简要介绍汽车发电机转子中爪极和骨架的结构设计,转子浸漆工艺参数的设置,爪极与骨架的配合尺寸。     

Alendronate affects osteoprotegerin/receptor of activator of nuclear factor κB-ligand expression in human marrow stroma cells in vitro

Objective To evaluate the effect of alendronate on osteoprotegerin (OPG) and receptor of activator of nuclear factor κB-ligand (RANKL) expression in human marrow stroma cells (hMSCs) in vitro. Methods hMSCs were isolated from haman marrow, cultured in vitro, and randomly divided into two groups: alendronate group, hMSCs culture fluid containing 1×10-7 mol/ L alendronate; control group, no special treatment but culturing hMSCs in DMEM. Two weeks after treatment, the expressions of OPG and RANKL were evaluated by RT-PCR and Western blot.Results hMSCs became uniform spindle-shaped fibroblasts. As cells proliferated, they formed colonies and showed whirlpool arrangement. After one week's treatment, hMSCs in alendronate group had reduced processes and gradually showed disc shape, which did not happen in control group but kept fibroblast shape and just increased in density. In RT-PCR, the ratio of OPG/RANKL in alendronate group and control group was 8.77±1.16 and 4.58±1.27, respec-tively. In Western blot, the ratio of OPG/RANKL in alendronate group and control group was 2.58±0.47 and 1.52±0.32, respectively. The ratio of OPG/RANKL was higher in alendronate group than in control group (P<0.01).Conclusion Alendronatc enhances OPG expression and inhibits RANKL expression of hMSCs in vitro.     

SVR算法在指数预测中的应用研究

本文阐述了回归型支持向量机（SVR）的基本结构及训练方法,并在此基础上研究了基于SVR算法的股票指数预测方法。通过应用LS—SVM软件,选用RBF核函数。利用自学模型,对超参数不断进行优化,以加快运算速度,并最终建立了该算法应用于股市预测的模型。通过股票指数的建模与仿真结果表明,支持向量回归机在股票价格的中短期预测以及整体股票趋势预测有比较好的效果。     

乌司他丁对大鼠蛛网膜下腔出血后迟发性脑血管痉挛的影响及其脑保护作用

目的通过乌司他丁(UTI)对雄性SD大鼠枕大池二次注血建造的蛛网膜下腔出血(SAH)模型的干预,观察其对迟发性脑血管痉挛(delayed cerebral vasospasm,DCVS)的防治及脑保护作用。方法将30只雄性SD大鼠随机分为空白对照组(Normal组)、假注血组(sham组)、注血组(SAH组)和乌司他丁治疗组(SAH+UTI组)。通过枕大池二次注血法建立SAH模型,光镜下观察基底动脉组织学变化和海马CA1区神经元的形态变化,计算血管舒张度(D/T)及海马CA1区神经元密度;应用免疫组化方法检测基底动脉NF-κB的表达。结果神经功能缺损评分:SAH+UTI组评分较SAH组明显改善(P<0.05);基底动脉测量发现,SAH组较Sham组血管周径及D/T值明显减低(P<0.05),SAH+UTI组较SAH组血管周径及D/T值增大(P<0.05);海马CA1区HE染色:与Normal及Sham组比较,SAH组神经元密度明显减少(P<0.05);SAH+UTI组与SAH组比较神经元密度增大(P<0.05);基底动脉NF-κB的表达:SAH组及SAH+UTI组基底动脉NF-κB的表达均较Sham组及Normal组增多(P<0.05);应用乌司他丁可以减轻SAH后NF-κB的表达(P<0.05)。结论乌司他丁可以减轻SAH后DCVS,并减轻神经细胞损伤,改善大鼠SAH后神经功能缺损症状。     

RDS-8固化酶在季冻地区公路建设中的应用分析

通过对RDS-8固化酶稳定材料在路用性能、保护环境、降低工程造价等方面的阐述,充分说明了RDS-8固化酶在季冻地区具有良好的适用性。     

抗疏力固化剂配合比设计研究

抗疏力固化剂可以改变土颗粒的结构,降低土微粒的界面活性,加速土壤石化的自然进程,提高土体的承载力。通过室内击实试验、无侧限抗压强度试验、CBR试验,研究并提出了抗疏力固化剂在实际应用中的合理掺量。     

雪芙蓉胶囊对去势雄性大鼠性功能和下丘脑室旁核一氧化氮合酶表达的影响

目的 观察补肾中成药(雪芙蓉胶囊)对去势雄性成年SD大鼠雄激素水平、性功能和下丘脑室旁核(PVN)神经元型一氧化氮合酶(nNOS)阳性神经元表达的影响.方法 制作雄性大鼠手术去势模型,术后3 d开始灌服中药,每天1次,连续28 d;检测血清睾酮水平,观察大鼠性功能;用免疫组织化学方法显示下丘脑PVN中nNOS阳性神经元的变化;用图像处理半定量方法对nNOS神经元的数量、面积及灰度进行测量和分析.结果 ①与去势组比较,雪芙蓉组大鼠血清睾酮明显增加(P<0.01),捕捉潜伏期缩短(P<0.05),捕捉次数和骑跨次数增多(P<0.05,P<0.01),捕捉率和骑跨率增高(P<0.05);②与去势组比较,雪芙蓉组大鼠PVN中的nNOS阳性细胞数量和阳性产物面积均明显增加(P<0.05),而灰度没有统计学差异(P>0.05).结论 中药雪芙蓉胶囊可提高去势雄性大鼠雄激素水平,增强去势大鼠性功能,增加下丘脑PVN中nNOS阳性神经元的表达.     

粉煤灰固化淤泥在普通干线公路路堤填筑中的应用

以231省道兴泰公路为工程依托,系统研究了粉煤灰固化淤泥的路用性能、力学性质和路堤填筑工艺。粉煤灰固化淤泥的最大干密度随粉煤灰掺入量增加而减小,最优含水量随粉煤灰掺入量增加而增大,固化淤泥的c值和无侧限抗压强度随粉煤灰含量增加而增加,φ值随粉煤灰含量增加略有增加。电渗法能有效地降低淤泥中的自由水含量。电渗法降低含水量的最低极限为32%。