一种提高检测效率的V-detector优化算法的设计

实值阴性选择算法V-detector在产生检测器时不能确保检测器具有较大的覆盖范围,其结果是检测器集合中的检测器数量过多,检测效率较低。为提高检测效率,提出了V-detector优化算法,一方面,通过合理确定检测器的中心点位置及检测半径,扩展了检测器的覆盖范围;另一方面,优化算法采用假设检验的判定方法判断检测器集合对非自体空间的覆盖率。假设检验融合到检测器集合的生成进程中,在确保检测器集合满足覆盖率要求的条件下,减少了检测器集合中的检测器数量。实验结果表明,与原算法相比,优化算法使检测器集合中检测器的数量大幅度下降,检测效率得到提高。     

对偶超群

设Ｐ（Ｇ）为群Ｇ的幂集,Ｐ０（Ｇ）＝Ｐ（Ｇ）－｛Х｝关于运算：ＡＢ＋｛ａｂａ∈Ａ,ｂ∈Ｂ｝,↓ＡＡ,Ｂ∈Ｐ（Ｇ）作成一个半群。若Ｑ≤Ｐ（Ｇ）关于此运算为一个群,则称Ｑ为Ｇ上的超群。利用群Ｇ的正规子半群的性质,将Ｇ的幂集进行了完整地刻画,得到了单位群、对偶超群等概念。并讨论了超群与对偶超群与对偶超群之间的关系。     

应用判断矩阵对绛县粮食生产发展战略的分析

应用判断矩阵法对绛县粮食生产发展战略的定量分析表明,调动农民种粮积极性、增加农用物资投入、增加科技含量、改善农业生产条件等是该县商品粮基地建设的关键,并为地方政府决策提供了科学依据.     

Oxidative modifications of low-density lipoproteins (LDL) by the human endothelial cell line EA.hy 926

Modifications of LDL by the EA.hy 926 cell line were compared to those generated by human umbilical vein endothelial cells (HUVEC). Thiobarbituric acid reactive substances (TBARS) index values (TBARS sample/TBARS cell-free control ratio) were 2.64±0.18 (m±SE, n=11) and 3.12±0.24 (n=11), for HUVEC and EA.hy 926, respectively. The percentage of the most electronegative modified LDL fraction (fraction C), assessed by using an ion-exchange chromatographic method based on fast protein liquid chromatography (FPLC), represented 14±3% (n=34) and 22±13% (n=10) of total modified LDL in HUVEC and EA.hy 926, respectively. LDL modified by both cell lines showed increased agarose electrophoretic mobility and apo B100 fragmentation on SDS-PAGE. None of the results were significantly different between the two cell lines. Superoxide anion production was 0.12±0.04 (n=11) and 0.07±0.01 nmol/min/mg cell protein (n=11) in HUVEC and EA.hy 926, respectively. Cell-specific effects on LDL were abrogated in cysteine-free medium. Moreover, cell-modified LDL were similarly degraded by J774 macrophage-like cells. We conclude that EA.hy 926 cells are a good model for investigating endothelial cell-induced modifications of LDL. Advantages include ready availability and less individual variability than with HUVEC.     

Improved hydrogenation-dehydrogenation characteristics of nanostructured melt-spun Mg-10Ni-2Mm alloy pr ocessed by rapid solidification

The as-cast Mg-10Ni-2Mm (mole fraction, %) alloy was prepared by a simple and low-cost two-step method of pre-alloying and vacuum induction melting. The nanocrystalline alloy was obtained by the melt-spun process with the surface velocity of copper wheel of 10.5 m/s. The hydrogen storage properties were examined by PCT measurement. The enthalpy ( ΔH) and entropy ( ΔS) of the alloy determined by van’t Hoff plots indicate that the thermodynamic performance of the nanocrystalline alloy is improved by fast diffusion ability of hydrogen in the nanocrystalline microstructure embedding nano-particles of intermetallics compounds Mg2Ni and MmMg12. The reaction kinetics of the melt-spun alloy is greatly improved due to short diffusion path of hydrogen in the nanocrystalline microstructure, resulting in bett er overall hydrogen storage properties. The hydrogen storage capacity is 5.09% (mass fraction, hereinafter the same), and the amount of hydrogen desorption is 4.86%. The hydrogen desorption rate of 95.5% in the alloy is available.     

高糖高胆固醇诱导EA.hy926细胞凋亡中对HSPD1基因表达的影响

用高糖（25mmol/L葡萄糖）和胆固醇（0.8, 1.6, 3.2mmol/L）处理EA.分析高糖高胆固醇诱导EA.hy926细胞凋亡中对HSPD1基因表达的影响,研究表明随胆固醇浓度的增加,EA.hy926细胞活性下降,呈浓度依赖性.0.8mmol/L胆固醇低糖培养液培养12h的细胞活性与正常对照组无显著差异（P>0.05）,而0.8mmol/L胆固醇高糖培养液培养12h的细胞活性与正常对照组（高糖培养液+0mmol/L胆固醇）具显著性差异(P<0.01).低糖或高糖培养液+0.8mmol/L胆固醇处理EA.hy926细胞不同时间后,细胞活性呈时间依赖性下调,48h后细胞大部分变圆,脱落.高糖高胆固醇处理的细胞大部分发生凋亡（50%）,HSPD1基因表达显著上调.     

等静压和温度作用下Pb(Zr,Sn,Ti)O3陶瓷的介电性能研究

对反铁电-铁电相界附近的Nb掺杂Pb(Zr,Sn,Ti)O3陶瓷，采用2GPa等静压装置测试了其在不同等静压力下的介电温度性能，分析了各种介电异常，发现了精细的相变特性，指出随着温度升高，在较低的等静压范围内发生反铁电-铁电-顺电相变，而在较高的等静压范围内发生反铁电-顺电相变，其中，铁电相分为微弱频率弥散的弛豫型铁电相和正常铁电相两个不同的介电性能区域，最后，得到了该组分材料的温度-等静压相图。     

连续流好氧颗粒污泥反应器水力特性及亚硝化影响因素

为确定连续流好氧颗粒污泥反应器水流特性及亚硝化影响因素,脉冲加入示踪剂NaCl,测定出水电导率.试验结果表明,反应器流态接近推流型,属非理想流态.对温度、pH值、溶解氧DO、碳氮比C/N、水力停留时间HRT等影响亚硝化的主要操作条件进行了单因素试验.在此基础上,根据数学最优化原理对影响因素进行正交试验.结果表明,对亚硝化产生影响的各操作条件依次为pH值、温度、HRT、DO、C/N比,各因子最优水平组合为pH=8.0、t=29℃、DO=1.0 mg/L、HRT=15 h、C/N=5.在此操作条件下,反应器连续运行1个月,亚硝酸氮累积率平均达到90%以上,氨氮、COD去除率分别达到85%及90%以上.     

PMMA的失稳断裂与断口形态

用超声波断口图和扫描电镜(SEM)研究了聚甲基丙烯酸甲酯(PMMA)的失稳断裂与断口形态,发现了两个断裂临界速度。当裂纹速度达到第一临界值时,出现二次曲线记号;裂纹扩展速度超过第二临界速度时,断口表面留下二级微裂纹丛。这两个临界速度都是试件厚度的函数。     

对《中图法》第4版TN类—无线电电子学、电信技术类目修订的分析

本文对《中图法》第 3版、第 4版中的无线电电子学、电信技术类目进行了比较 ,总结出第 4版对无线电电子学、电信技术类目修订的几个特点