基于梯度提升决策树的变形宏病毒检测

宏病毒在高级持续性威胁中被广泛运用.其变形成本低廉且方式灵活,导致传统的基于病毒规则库的反病毒系统难于有效对抗.提出一种基于梯度提升决策树的变形宏病毒检测方法.该方法以病毒专家经验为指导,实施大规模特征工程,基于词法分析对变形宏病毒做细粒度建模,并使用海量样本训练模型.实验表明,该方法能够准确检测企业级用户网络中传播的真实变形宏病毒和主流变形工具生成的变形宏病毒;对400万个宏程序样本进行10折交叉验证,准确率和召回率分别达到99.41％和97.34％,优于现有其他方法.     

Eugenol-Containing Siloxane Synthesized Via Heterogeneous Catalytic Hydrosilylation and its Application in Preparation of Superb Viscoelastic Low Modulus Gels

Silicon - Eugenol is widely used as bio-based raw materials, based on functional groups such as hydroxyl, methoxy, and allyl contained in the molecule that has van der Waals forces or chemical...     

基于堆叠去相关自编码器和支持向量机的窃电检测

已有窃电检测模型的准确率尚无法满足应用需求,是因其均将建模重点放在了分类算法的选择或改进上,而相对地忽视了特征提取过程。因此,提出一种基于深度学习的特征提取方法,即堆叠去相关自编码器。得益于深层结构和高度非线性,其能够从用户用电数据中提取到高度抽象和简明的特征。随后支持向量机将这些特征映射到指示是否窃电的标签。基于真实数据的算例测试,验证了所提窃电检测模型具有较高的检出率和较低的虚警率,同时也验证了堆叠去相关自编码器能够提取到有效的特征。     

Improving the resilience of maritime supply chains: The integration of ports and inland transporters in duopoly markets

The adverse impact of the outbreak of COVID-19 has reduced ports’ operational efficiency. In addition, ports and inland logistics providers are generally independent of each other and difficult to work together, which leads to time loss. Thus, as the core player, ports can integrate with inland logistics providers to improve the efficiency and resilience of maritime supply chains. This study examines the strategic options of two competing maritime supply chains consisting of ports and inland logistics providers. We investigate the impact of cooperation between ports and inland logistics providers and government regulation on the maritime supply chain by comparing members’ optimal pricing and overall social welfare under centralized, decentralized, and hybrid scenarios. Results indicate that the hybrid scenario is an equilibrium strategy for maritime supply chain, although this strategy is not optimal for governments seeking to improve supply chain resilience and maximize social welfare. Furthermore, observations show that through government economic intervention, both seaborne supplies can be incentivized to adopt an integrated strategy, and business and society can achieve a win–win situation.     

倾斜内螺纹管中亚临界及超临界水传热特性研究

为探究超（超）临界锅炉机组内螺纹管水冷壁的传热特性,在倾角5°~90°的?35 mm×7.75 mm倾斜上升内螺纹管中进行了实验研究,实验参数为压力15~28 MPa,质量流速600~1000 kg?m^-2?s^-1,热通量300~500 kW?m^-2。实验对比了内螺纹管与?25 mm×3 mm光管的壁温特性;讨论了倾斜角度、质量流速和压力的变化对内螺纹管中亚临界、近临界和超临界水传热的影响;拟合了不同倾斜角度下超临界水的传热关联式。结果表明：所用内螺纹管有明显的推迟传热恶化、强化传热的性能;不同倾斜角度的内螺纹管传热特性存在差异;亚临界压力下质量流速对气液两相区传热系数影响很小,近临界和超临界压力下,随质量流速的增加,整体上传热系数增大;压力为15 MPa时的传热系数最大。超临界压力下,随压力的增大,大比热容区的传热系数减小。     

生物油金属水热原位加氢提质技术研究进展

水热液化技术可以将秸秆等木质纤维素类生物质转化为生物油,生物油提质可制备液体燃料和高附加值化学品。但生物油成分复杂,研发适宜的提质方法与工艺是当前的热点。金属水热原位加氢提质是一种新兴生物油提质技术,具有原料适应性广、成本低和效率高等优势,受到国内外广泛关注。本文从木质纤维素类生物质水热加氢提质原理、金属水热原位加氢最新研究进展及相关数值模拟方法三方面进行了综述,在此基础上指出目前该技术存在的主要问题,并指明未来研究方向。目前金属水热原位加氢提质过程活性氢和氢气作用机制尚不明晰;明确加氢催化剂与金属/金属氧化物的相互作用是制备高效加氢催化剂的关键;集总动力学和分子模拟等方法是金属水热原位加氢提质技术在理论计算领域未来的发展方向,有待进行深入研究。     

基于格式塔心理学的视觉符号“开眼”认知度测量

目的 通过定量的实验研究,分析设计的直觉性,解答“什么样的图形更能吸引人的注意”的问题。方法 采用心理学经典的点探测范式进行实验设计,测量视觉符号的“开眼”认知度。结果 虽然得出的数据曲线随图形的形状变化略有不同,但总体来看图形缺失1/3时反应时间最短。结论 基本图形缺失1/3时,图形认知度最高、识别最迅速,不同图形间的差异较小,判断较稳定,吸引人注意的同时又不会对完全形态产生困惑,能够对视觉符号设计产生积极影响。     

Statistical analysis of performance degradation of lead—acid battery under simulated electric vehicle operations

Controlled laboratory tests were conducted to evaluate the effects of selected electric-vehicle application factors on the performance and life of lead     

High active and ultra-stable bifunctional FeNi/CNT electrocatalyst for overall water splitting

Efficient non-noble metal catalysts are desirable to greatly improve the efficiency of anodic oxygen evolution and cathodic hydrogen evolution reactions. Herein, iron-nickel/carbon nanotube composites are synthesized as efficient bifunctional electrocatalysts for water splitting. The catalyst is homogeneously distributed, while the formation of iron-nickel alloy is confirmed. Because of the synergism of iron and copper and the contribution of carbon nanotubes, the Fe–Ni/CNT electrocatalyst shows excellent oxygen evolution reaction performance with the overpotential of 221 mV at 10 mA cm^?2 and maintains stable at 0.48 V for 150 h. It expedites overall water splitting at 10 mA cm^?2 with 1.50 V and show excellent stability at 20 mA cm^?2 for 65 h, providing great potential for large-scale applications.