教学课程资源库 更多>>

关键词： 工程造价咨询企业   分类推进   住房和城乡建设   建筑业   审批服务   证照   资质审批   建设工程企业  

摘要： 河北省住房和城乡建设厅印发《关于进一步做好建筑业和工程造价咨询企业“证照分离”改革有关工作的通知》,对建筑业和工程造价咨询企业资质审批许可事项’按照直接取消审批、审批改为备案、实行告知承诺、优化审批服务4种方式分类推进改革。

关键词： cocatalysts   hole-scavengers   sonodynamic therapy   sonosensitizers   vanadium tetrasulfide  

摘要： The development and optimization of sonosensitizers for elevating intratumoral reactive oxygen species (ROS) are definitely appealing in current sonodynamic therapy (SDT). Given this, branched vanadium tetrasulfide (VS4) nanodendrites with a narrower bandgap (compared with the most extensively explored sonosensitizers) are presented as a new source of sonosensitizer, which allows a more effortless separation of sono-triggered electron-hole pairs for ROS generation. Specifically, platinum (Pt) nanoparticles and endogenous high levels of glutathione (GSH) are rationally engineered to further optimize its sono-sensitized performance. As cocatalyst, Pt is conducive to trapping electrons, whereas GSH, as a natural hole-scavenger, tends to capture holes. Compared with the pristine VS4 sonosensitizer, the GSH-Pt-VS4 nanocomposite can greatly prolong the lifetime of the charge and confer a highly efficacious ROS production activity. Furthermore, such nanoplatforms are capable of reshaping tumor microenvironments to realize ROS overproduction, contributed by overcoming tumor hypoxia to improve SDT-triggered singlet oxygen production, catalyzing endogenic hydrogen peroxide into destructive hydroxyl radicals for chemodynamic therapy, and depleting GSH to amplify intratumoral oxidative stress. All these combined effects result in a significantly efficient tumor suppression outcome. This study enriches sonosensitizer research and proves that sonosensitizers can be rationally optimized by charge separation engineering strategy.

关键词： Thermally induced phase separation (TIPS)   Poly (l-lactic acid)   Chitosan   Peripheral nerve regeneration   Nerve tissue engineering  

摘要： Fabrication method is one of the essential factors which directly affect on the properties of scaffold. Several techniques have been well established to fabricate nanofibrous scaffolds such as electrospinning. However, preparing a three-dimensional (3-D) interconnected macro-pore scaffold essential for transporting the cell metabolites and nutrients is difficult using the electrospinning method. The main aim of this study was developing a highly porous scaffold by poly (L-lactic acid) (PLLA)/chitosan blend using liquid-liquid phase separation (LLPS) technique, a fast and cost-benefit method, in order to use in nerve tissue engineering. In addition, the effect of different polymeric concentrations on morphology, mechanical properties, hydrophilicity, in vitro degradation rate and pH alteration of the scaffolds were evaluated. Moreover, cell attachment, cell viability and cell proliferation of scaffolds as candidates for nerve tissue engineering was investigated. PLLA/chitosan blend not only had desirable structural properties, porosity, hydrophilicity, mechanical properties, degradation rate and pH alteration but also provided a favorable environment for attachment, viability, and proliferation of human neuroblastoma cells, exhibiting significant potential for nerve tissue engineering applications. However, the polymeric concentration in blend fabrication had influence on both characteristics and cell responses. It concluded that PLLA/chitosan nanofibrous 3-D scaffold fabricated by LLPS method as a suitable candidate for nerve tissue engineering.

关键词： Polarization  

摘要： As a green, visible-light-driven metal-free semiconductor material, graphitic carbon nitride (g-C3N4) has generated tremendous significance in the fields of environmental purification and energy conversion. Inducing a polarization effect by creating defects in g-C3N4 is a promising strategy for improving photocatalytic properties. The polarization effect in photocatalysts could be created by manufacturing vacancies, doping impurity atoms, constructing heterostructure, etc. Recently, defective g-C3N4 has attracted wide attention due to its remarkable performance in the separation and migration of photogenerated charge carriers. However, the relationship between defects and the polarization effect remains to be clarified in terms of improving the photocatalytic performance. In this minireview, we summarize the recent advances on how the polarization effect and defect engineering expedite the photogenerated carrier migration and separation to improve the photocatalytic properties of g-C3N4. Is it pure synergy or is there some degree of antagonism? Ultimately, the major challenges for simply constructing the polarization effect and internal electric field in g-C3N4 and inspiring perspectives for future opportunities in polarization-defect type photocatalysis are discussed. It is believed that this work can provide a new idea for the design of novel and efficient photocatalysts in the future.

关键词： 制药工程   制药分离   操作流程   分子蒸馏   膜分离  

摘要： 药品的研制质量,直接影响人们的生命安全,近年来国家对医疗卫生领域的关注度明显提高,一定程度上推动了制药工程健康发展。文章从制药工程概述入手,阐述了制药分离操作流程和特点,分别介绍了分子蒸馏技术、膜分离技术在制药工程中的应用,以供同行参考。

关键词： Cellulose acetate   ZIF-62 glass   Mixed matrix membrane   CO2 separation   Plasticization resistance  

摘要： Composite membranes typically used for gas separation are susceptible to interfacial voids and CO2 plasticization which adversely affects the gas permeation performance. This paper evaluates routes towards the enhancement of CO2 permeation performance and CO2 plasticization resistance of composite membranes using non-stoichiometric ZIF-62 MOF glass and cellulose acetate (CA). Single and mixed gas permeation results, obtained with CO2 and CH4, demonstrate that the presence of ZIF-62 glass in CA polymer enhanced the CO2 permeability and CO2/CH4 ideal selectivity from 15.8 to 84.8 Barrer and 12.2-35.3, respectively. The composite membrane loaded with 8 wt% of ZIF-62 glass showed the highest CO2 permeability and CO2/CH4 ideal selectivity of 84.8 Barrer and 35.3, which were 436.7% and 189.3% higher compared to the pristine CA membrane, respectively. A CO2 plasticization pressure of 26 bar was achieved for the composite membranes, which is 160% higher compared to the pristine CA membranes, at about 10 bar. The mechanisms for the materials stabilization and greater separation performance were attributed to higher pore size (7.3 angstrom) and significant CO2 adsorption on the unsaturated metal nodes followed by metal cites electrostatic interaction with CO2. These findings confirm the potential of ZIF-62 glass materials as promising materials solutions towards the design of composite membranes for CO2 separation at industrial scale.

关键词： 房屋建筑   市政基础设施工程   施工招标   评标定标   总承包招标   招标项目   组建方式   监管方式  

摘要： 近日,安徽省住建厅发布《关于开展全省房屋建筑和市政基础设施工程招标“评定分离”试点工作的通知》。明确:政府投资的房屋建筑和市政基础设施工程总承包招标、施工招标全部实施“评定分离”。1.启动部署阶段(2021年8月-9月):制定方案;印发办法,明确定标委员会组建方式及职责、评标定标方法和程序,完善“评定分离”招标项目监管方式。

关键词： 化工分离过程   课程教学   学习热情   工程素养   工程思维  

摘要： 化工分离技术是直接应用于企业生产实践的技术。本文讨论了新时代工程教育专业认证背景下《化工分离过程》课程的教学内容和教学方法创新,以学科前沿和高新技术激发学生学习热情,在课堂教学中介绍化工分离技术创新、清洁生产工艺和计算机辅助解决实际工程问题,以强化高阶工程素养和工程思维,将学生的知识掌握、能力提升与素质培养更好地有机融合。

关键词： 膜分离技术   环境工程   应用研究  

摘要： 随着环境污染问题越来越被人们所重视,解决环境污染的创新性新技术就显得极为重要。利用膜分离技术去解决环境工程中的环境污染问题效果较为理想,是目前应用较为广泛的一种先进的技术。本文通过对膜分离技术及其原理和特点进行分析,简单介绍了几种常见的膜分离技术,为我国环境污染防治工作者进行研究提供一定的技术理论参考。