无皂核壳乳液的研究进展

无皂核壳乳液聚合是在传统乳液聚合基础上发展起来的一种聚合新技术,综合了无皂乳液聚合技术和核/壳乳液聚合技术的优点,并且得到广泛的应用及发展。围绕国内外无皂核壳乳液聚合方面的研究进展,对无皂核壳乳液聚合的方法、机理及应用现状进行介绍,并对无皂核壳乳液存在的问题和未来研究趋势进行展望。     

基于文本挖掘的电力运维服务项目智能辅助管理

为了提高电力系统对运维服务项目的计划申报和管理效率,设计并实现基于文本挖掘技术的电力系统运维服务项目的智能辅助管理系统。构建一个适用于电力系统运维项目计划的智能管理框架,在该框架下基于智能分词和文本特征表示设计一种层级融合分类方法,有效提高申报项目分类准确率,稽查分类错误。该辅助系统有效解决了电力运维服务项目的分类错误和重复立项等问题,提高了电力运维服务项目的计划管理效率和资金使用效率。     

Study of flame-retarded silicone rubber with ceramifiable property

Fire-resistant ceramifiable silicone rubber composites with excellent comprehensive property were prepared in this paper. Silicone rubber was used as the base polymer, aluminum hydroxide, magnesium hydroxide, zinc borate, and glass frits were additives. The flammability and thermal stability properties, essentially focusing on the use of the limiting oxygen index and thermogravimetric analysis, were all studied. Besides, the ceramic residues were also studied by mechanical testing, scanning electron microscopy, and X-ray diffraction. The ceramifying silicone rubber could achieve a limiting oxygen index value of 34.8%, and the flexural strength of ceramic residues formed at 800°C was 9.7 MPa. The residue of composites was approximately 58.6% at 700°C, which is significantly higher than that of neat silicone rubber. The scanning electron microscopy analysis depicted that a dense structure was formed as formed.     

杜仲叶茯砖茶加工过程中活性成分及微生物多样性

为了解杜仲叶茯砖茶加工过程中活性成分及微生物多样性，对杜仲叶茯砖茶不同加工阶段样品活性成分质量分数进行测定，进一步运用高通量测序技术分析各样品微生物多样性，并与10 种活性成分质量分数进行相关性分析。结果表明，杜仲叶茯砖茶加工过程中主要活性成分含量整体上均呈下降趋势。曲霉属（Aspergillus）为加工过程中的优势真菌，在原料至气蒸与成型阶段，其相对丰度逐步下降，进入发花阶段后丰度迅速上升，发花4 d相对丰度达95.58%，发花8 d及之后所有阶段相对丰度均在99.99%以上，为绝对优势菌群。杜仲叶茯砖茶加工过程中细菌群落种类丰富，分为7 个门、47 个属，其中的优势细菌属为红球菌属（Rhodococcus）、雷尔氏菌属（Ralstonia）和Burkholderia-Caballeronia-Paraburkholderia。原料至发花8 d阶段，细菌群落多样性较高，雷尔氏菌属为此过程中的优势细菌属，从发花12 d起，细菌群落多样性下降，结构趋于稳定，红球菌属相对丰度大幅上升，为发花后期及陈化阶段的优势细菌属。属水平上主要菌群丰度与活性成分的相关性分析结果表明，多糖、游离氨基酸、多酚、绿原酸、京尼平苷和桃叶珊瑚苷质量分数均与曲霉属菌群丰度呈显著负相关（P＜0.05），而与Apiotrichum丰度呈显著正相关（P＜0.05），总黄酮质量分数与曲霉属、Apiotrichum丰度分别呈显著负相关（P＜0.05）和极显著正相关（P＜0.01）。红球菌属丰度与水浸出物、多糖、总黄酮、游离氨基酸、多酚、绿原酸、京尼平苷质量分数均呈极显著负相关（P＜0.01），与京尼平苷酸、桃叶珊瑚苷质量分数均呈显著负相关（P＜0.05）。本研究加深了对杜仲叶茯砖茶加工过程中活性成分含量变化和微生物多样性的认识，为杜仲叶茯砖茶品质形成和提升提供了依据。     

High-resolution 3D imaging of microvascular architecture in human glioma tissues using X-ray phase-contrast computed tomography as a potential adjunct to histopathology

Gliomas are rich in blood vessels, and the generation of tumor-associated vessels plays an important role in glioma growth and transfer. Histology can directly depict microvascular architecture in the tumor, but it just provides two-dimensional (2D) images obtained by destroying three-dimensional (3D) tissue specimens. There is a lack of high-resolution 3D imaging methods for observing the microvasculature throughout the entire specimens. X-ray phase-contrast computed tomography (PCCT) which is an emerging imaging method has demonstrated its outstanding potential in imaging soft tissues. Thus, this study aims to evaluate the potential of PCCT as an adjunct to histopathology in nondestructive and 3D visualization of the microvascular architecture in human glioma tissues. In this study, seven resected glioma tissues were scanned via PCCT and then processed histologically. The obtained PCCT data was analyzed and compared with corresponding histological results. Significant anatomical structures of the glioma such as microvessels, thrombi inside the microvessels, and areas of vascular proliferation could be clearly presented via PCCT, confirmed by the histological findings. Moreover, PCCT data also provided additional 3D information such as morphological alterations of the microvasculature, 3D distribution of the thrombi and stenosis severity of the vessels in glioma tissues, which cannot be fully analyzed in 2D histological slices. In conclusion, this study demonstrated that PCCT can offer excellent images at a near-histological level and additional valuable information in screening gliomas, without impeding further histological investigations. Thus, this technique could be potentially used as an adjunct to conventional histopathology in 3D nondestructive characterization of glioma vasculature.     

Path towards achieving of China's 2020 carbon emission reduction target—A discussion of low-carbon energy policies at province level

Following the announcement of the China's 2020 national target for the reduction of the intensity of carbon dioxide emissions per unit of GDP by 40–45% compared with 2005 levels, Chinese provincial governments prepared to restructure provincial energy policy and plan their contribution to realizing the State reduction target.     

Ga改性的HZSM-5分子筛甲醇芳构化催化反应性能

以浸渍法和水热合成法向ZSM-5分子筛中引入Ga助剂对其进行改性。采用XRD、XPS、NH₃-TPD和SEM等技术对改性前后的分子筛进行了表征。结果表明,采用两种不同引入方式引入Ga助剂对分子筛的晶体结构、孔径及形貌影响均很小,而对分子筛酸性的影响与Ga的引入方式有关。其中,浸渍法引入Ga对分子筛的酸性影响不明显,只是其中的强酸位略有减少。而水热合成法引入Ga会显著增加分子筛的弱酸及强酸的酸量。在固定床反应器上考察了Ga的引入对HZSM-5催化剂甲醇芳构化催化性能的影响。结果表明,水热合成法引入Ga较浸渍法引入Ga更能提高甲醇芳构化反应的活性和芳烃选择性。此外,Ga改性HZSM-5分子筛对其甲醇芳构化反应中积炭反应的抑制起到积极作用。     

冷作模具焊补修复再制造技术的研究

汽车制造企业常用的高合金冷作模具在大批次生产任务中其刀口和成形面易发生失效,为此需要简便有效的焊补修复技术,以降低模具维修费用并延长模具寿命。通过焊丝成分分析、膨胀系数测量、堆焊后冲击韧性比较、宏观微观断口分析、硬度梯度测试以及金相组织观察等一系列方法,深入研究了基体模具堆焊修补后的性能变化。并运用正交实验法找到了优化的常用高合金冷作模具焊补修复再制造技术,在实际生产中得到应用。     

热熔胶用马来酸酐接枝聚乙烯研究进展

通过双螺杆挤出机将马来酸酐熔融接枝聚乙烯,制备的聚乙烯热熔胶具有粘接性能强、价格低等优点,广泛地应用于钢塑复合管。本文根据近年来聚乙烯热熔胶的研究方向,综述了新型引发剂及引发方式对接枝反应的影响;比较了不同种类聚乙烯接枝效果的差异;总结了改性单体对热熔胶性能的改善以及温度、挤出机螺杆结构和转速等工艺条件对聚乙烯热熔胶的影响。分别总结了化学滴定法和红外光谱法对接枝率的表征;简述了材料表面处理和涂胶工艺对剥离强度的影响。分析了热熔胶剥离强度传统制样方法的不足,并总结了能得到稳定真实剥离强度的制样方案。展望了低马来酸酐含量、高粘接强度的绿色环保型聚乙烯热熔胶的研究前景。