轧制计划的优化模型及其应用

对于钢铁企业热轧生产控制计算机系统中的实际轧制计划初选问题,即板坯库倒垛问题,提出了一个新的非线性０－１整数规划数学模型,通过实际应用表明,该数学模型与原有的启发式经验模型相比,效果显著。     

亚伯拉罕·棣莫弗的概率思想与正态概率曲线

目的系统地探讨和分析正态概率曲线的发现过程及棣莫弗(Abraham De Moivre,1667- 1754)概率思想的创新点。方法历史分析和文献考证。结果棣莫弗在前人的基础上,经过10 余年的努力最终导出了正态概率曲线的数学表达式。结论正态分布是概率论中最重要的分布, 其发现揭示了棣莫弗概率思想的发展过程及其对概率论发展所做的奠基性工作。     

甘氨酸在电沉积铁铬合金中的作用

研究不同浓度甘氨酸对电沉积铁铬合金过程的影响,分析了甘氨酸在电沉积过程中的作用.加入甘氨酸后,可得到优良的镀层,而不含甘氨酸时,镀层中夹杂铬的化合物,造成镀层质量低劣.甘氨酸浓度为0.4～0.8 mol·L-1时,镀层中铬含量较稳定.甘氨酸的加入使得阴极极化增加,电位负移.在此镀液中,甘氨酸与Fe(Ⅱ)络合,使其析出电位负移,达到铁铬共沉积的目的.     

Persistence of soil organic matter as an ecosystem property

Globally, soil organic matter (SOM) contains more than three times as much carbon as either the atmosphere or terrestrial vegetation. Yet it remains largely unknown why some SOM persists for millennia whereas other SOM decomposes readily--and this limits our ability to predict how soils will respond to climate change. Recent analytical and experimental advances have demonstrated that molecular structure alone does not control SOM stability: in fact, environmental and biological controls predominate. Here we propose ways to include this understanding in a new generation of experiments and soil carbon models, thereby improving predictions of the SOM response to global warming.     

Experience-dependent plasticity of dendritic spines in the developing rat barrel cortex in vivo

Do changes in neuronal structure underlie cortical plasticity? Here we used time-lapse two-photon microscopy of pyramidal neurons in layer 2/3 of developing rat barrel cortex to image the structural dynamics of dendritic spines and filopodia. We found that these protrusions were highly motile: spines and filopodia appeared, disappeared or changed shape over tens of minutes. To test whether sensory experience drives this motility we trimmed whiskers one to three days before imaging. Sensory deprivation markedly (approximately 40%) reduced protrusive motility in deprived regions of the barrel cortex during a critical period around postnatal days (P)11-13, but had no effect in younger (P8-10) or older (P14-16) animals. Unexpectedly, whisker trimming did not change the density, length or shape of spines and filopodia. However, sensory deprivation during the critical period degraded the tuning of layer 2/3 receptive fields. Thus sensory experience drives structural plasticity in dendrites, which may underlie the reorganization of neural circuits.     

一种碳酸盐岩流体替换新方法

针对碳酸盐岩的基质矿物类型非单一且孔隙结构复杂多变的特点,提出一种适用于碳酸盐岩的流体替换方法。以常规Gassmann方程为基础,采用流体因子分析的基质矿物体积模量反演方法和碳酸盐岩岩石物理模型的孔隙结构反演方法,得到岩石基质矿物的体积模量,并考察复杂孔隙结构的影响,实现碳酸盐岩的流体替换。岩石物理测试分析数据和实际测井资料的计算结果均证明了新方法的正确性和有效性。     

正交胶合竹板单面火损后力学性能试验研究

为研究正交胶合竹板单面火损后的力学性能,通过对12块试件进行承载力试验,分析了不同火损时长、不同阻燃处理方式对正交胶合竹板炭化性能和残余承载力的影响.结果表明,相同阻燃处理方式下正交胶合竹板的炭化程度随火损时长增加而增加,残余承载力随火损时长增加而降低.当火损时长相同时,不同阻燃处理方式下正交胶合竹板的炭化速度由高到低...     

A novel method for improving cerussite sulfidization

Evaluation of flotation behavior, solution measurements, and surface analyses were performed to investigate the effects of chloride ion addition on the sulfidization of cerussite in this study. Micro-flotation tests indicate that the addition of chloride ions prior to sulfidization can significantly increase the flotation recovery of cerussite, which is attributed to the formation of more lead sulfide species on the mineral surface. Solution measurement results suggest that the addition of chloride ions prior to sulfidization induces the transformation of more sulfide ions from pulp solution onto the mineral surface by the formation of more lead sulfide species. X-ray diffraction and energy-dispersive spectroscopy indicate that more lead sulfide species form on the mineral surface when chloride ions are added prior to sulfidization. These results demonstrate that the addition of chloride ions prior to sulfidization can significantly improve the sulfidization of cerussite, thereby enhancing the flotation performance.     

承钢高炉炉缸沉积物矿相的研究

针对承钢高炉在冶炼炼钒钛矿过程中炉缸中生成大量沉积物，影响高炉顺行这一情况，对承钢高炉沉积物进行了矿物组成和矿相分析，结合承钢生产具体情况，提出减少承铜高炉炉缸沉积物的措施。     

铜铁共催化烯烃串联加成/环化合成异喹啉二酮

发展了一种铜/铁协同催化的N-烯丙酰基苯甲酰胺串联加成/环化/偶联合成叔烷基化异喹啉二酮的反应.在廉价金属Cu/Fe协同催化作用下,烷基偶氮试剂介导N-丙烯酰基-N-烷基氯代苯甲酰胺发生串联加成/环化,区域选择性地切断C-Cl键而发生进一步交叉偶联,以41%~78%的产率合成了一系列远端双重α-官能团化叔烷基取代的异喹啉二酮骨架.该反应首次利用卤代苯甲酰胺去芳构化而形成的超共轭自由基为偶联体与偶氮试剂发生交叉偶联,选择性地在碳-卤键位置构建碳（叔）-碳键.此偶联策略将为深入拓展叔烷基-芳基交叉偶联提供新的思路.