Geochemical characteristics of Jurassic coal and significance for the evolution of the environment, Yanqi Basin, China

The Mesozoic strata of the Yanqi Basin consists of coarse debris with coal beds, characterized by the developments of coal seams of the Jurassic sediments whose main petrologic contents are glutenite, fine sandstone, mudstone, carbonaceous shale and coal. Based on the analyses of the minerals, trace elements and REEs, we try to find geochemical characteristics of the coal seam formation process. The analysis results indicate that the contents of ash and sulfur are low while the content of phosphor is comparatively high, and that the specific value of Al2O3/SiO2 is relatively high and that of （Al2O3+SiO2）／（Fe2O3+CaO+MgO） is near 1. All these results indicate that the coal seams are formed in the relatively deep marsh, which is favorable for the evolvement of hydrocarbon at the diagenesis stage.     

改性B72文物保护材料耐光老化性能研究

目的研究改性后的B72(Paraloid B72)文物保护材料的耐光老化性能。方法采用紫外线吸收剂UV326对目前广泛使用的文物保护材料B72进行改性。通过傅立叶变换红外光谱、反射光谱、光失重来表征改性材料的耐光老化性能。结果在光老化过程中,B72材料比UV326紫外线吸收剂改性B72材料的红外光谱曲线变化更快,特别是羰基和酯基谱带强度减小更明显。改性材料能够有效阻止B72变黄,并且实现对基质材料和壁画的保护作用。改性B72比纯B72有更好的耐光老化性能。结论光老化过程对材料表面的亮度改变不大,而B72材料泛黄程度远大于UV326改性B72。改性B72材料比原材料的耐光老化性能有了明显改善,是一种大有潜力的文物保护材料。     

回火温度对高Cr马氏体耐热钢组织与性能的影响

利用光学显微镜(OM)、透射电镜(TEM)、扫描电镜(SEM)及电子探针(EPMA)等手段,系统研究了不同回火温度下9%Cr马氏体耐热钢的组织及力学性能变化.结果表明:回火后位错网络化、析出相形态、板条马氏体破碎化等是影响力学性能变化的主要因素.正火并760℃回火后在室温和550℃条件下抗拉强度分别达到657和556MPa,0℃冲击功达到285J,此回火温度下实验钢具有最佳综合力学性能.700, 820,850℃回火,韧性大幅降低.高温服役条件下不发生粗化的MX相弥散分布在铁素体和马氏体中,与马氏体高温回复形成的亚稳态多边形结构有效提升耐热钢抗高温蠕变性能.     

多特征融合的交通标识视认性评测方法

针对目前交通标识视认性评测方法误差过大的缺点,提出了一种高精度交通标识视认性评测方法。该方法根据道路环境中不同因素对交通标识视认性的影响,计算了标志牌图像中的颜色特征、亮度特征、复杂度特征,并考虑标志牌背景的影响,计算了标志牌和背景之间的颜色对比特征、亮度对比特征和复杂度对比特征,综合考虑以上6种特征及特征相互之间的影响,利用自顶向下(top-down)和自底向上(bottom-up)视觉模型建立多特征融合的交通标识视认性评测模型。通过模型实现了对识别出的标志牌进行视认性评测,反馈模型推测的视认性值。通过实验对多特征融合的视认性评测模型的有效性及模型精度进行了评测。结果表明,该模型能够高精度推测标志牌视认性值,且达标率在89%以上。     

基于群决策的基础设施可持续性影响因素评价

针对基础设施可持续性影响因素复杂,传统的可持续性评价方法难以客观评估基础设施可持续性影响因素的权重,构建了基于关联度的多属性群决策模型,引入综合权重修正矩阵,从信息偏差、一致性和信息熵三个方面对可持续性影响因素权重进行优化,并以实际项目数据为依据,通过实证分析验证了模型的有效性.该评价模型的应用有助于提高基础设施可持续性评价的客观性.     

二维方柱绕流阻塞效应的大涡模拟

在均匀流条件下对阻塞比(R)分别为4.2%、10%、16.7%、20%和25%的二维方柱绕流进行了大涡模拟(LES)研究,对比了各工况下柱体的整体气动力和表面风压分布随阻塞比的变化规律,分析了阻塞比对柱体附近区域内流场特性和瞬时涡量的影响.研究表明,当阻塞比由4.2%增大到25%,柱体的平均阻力系数、脉动升力系数和Strouhal数分别增加了27.6%、43.6%和31%.随着阻塞比的增大,侧面及背风面负风压系数的均值绝对值以及脉动值均显著增加,柱体两侧附近流场特性也有明显的变化.在大阻塞比工况中,洞壁附近会生成二次旋涡,并与柱体脱落的旋涡相互掺混.     

Distributed Fault Detection for Consensus in Second-Order Discrete-Time Multi-agent Systems with Adversary

This paper is concerned with distributed fault detection of second-order discrete-time multi-agent systems with adversary,where the adversary is regarded as a slowly time-varying signal.Firstly,a novel intrusion detection scheme based on the theory of unknown input observability（ UIO） is proposed. By constructing a bank of UIO,the states of the malicious agents can be directly estimated. Secondly,the faulty-node-removal algorithm is provided.Simulations are also provided to demonstrate the effectiveness of the theoretical results.     

Molecularly Imprinted Polymer Based on GO-QDs as Enhanced Fluorescent Nanoscale Device for Specific Recognition of Target Protein

In this work the enhanced molecularly imprinted optosensing material based on graphene oxide-quantum dots （ GO- QDs） was synthesized for highly selective and sensitive specific recognition of the target protein, bovine serum albumin （BSA）. Here, GO was introduced to enhance the efficiency of mass-transfer in recognition of target protein. Molecularly imprinted polymer coated GO-QDs using BSA as template （BMIP-coated GO-QDs ） exhibited a fast mass-transfer speed, which could be ascribed to the high volume of efficient surface area and high target recognition efficiency of the synthesized nanoscale device. Under optimal conditions, it was found that the BSA as target protein could remarkably quench the relative fluorescence intensity of BMIP- coated GO-QDs linearly in a concentration-dependent manner that was best described by a Stern-Volmer equation. The Ksv （Stern- Volmer constant） for template BSA was much higher than bovine hemoglobin （BHb） and lysozyme （Lyz）, implying a highly selective recognition ability of the BMIP-coated GO-QDs to BSA. This enhanced fluorescent nanoscale device may provide opportunities to develop a system that is efficient and effective and has potential in the design of highly effective fluorescent receptor for recognition of target protein in Droteomics studies.     

黄河源区湿地及邻近草甸土壤糖类含量比较

通过分析黄河源区湿地及其邻近草甸土壤糖类含量差异用于评价源区湿地的健康状态。试验采用苯酚—硫酸法测定了黄河源区不同湿地和邻近草甸0~20 cm土壤的单糖含量和0~30 cm土壤的多糖含量。结果表明:湿地土壤0~20 cm的单糖含量为20.01~133.52 mg/kg;邻近草甸土壤0~20 cm的单糖含量为35.53~120.81 mg/kg。湿地土壤0~30 cm的多糖含量为78.01~805.21 mg/kg;邻近草甸土壤0~30 cm的多糖含量为109.93~553.89 mg/kg。不同类型湿地及其邻近湿地土壤单糖含量均随土壤深度的增加而减少,而湿地和草甸同一层的差异随湿地类型而异。河流湿地和沼泽湿地土壤多糖含量高于邻近草甸的,但湖泊湿地中邻近草甸多糖含量均高于湿地土壤含量。     

基于PCA和PSO-SVM在葡萄酒分类中的应用研究

针对葡萄酒的物理化学成分冗余数据,提出了一种基于主成分分析(PCA)和粒子群优化—支持向量机(PSO-SVM)的模型用于葡萄酒的分类.首先,对葡萄酒的物理化学成分进行主成分分析,提取主要影响因素,减少输入维数,再利用粒子群优算法寻找支持向量机的最佳参数,并用支持向量机完成对训练集样本的学习和测试集样本的预测分类.结果表明,该模型与其他模型相比较,具有较高的准确性,有一定的适用价值.