氧气和二氧化碳在血液中的运输方式

本文论述了氧气和二氧化碳在血液中的运输方式。     

工学结合实践课堂的设计与实施

工学结合人才培养模式是高等职业教育探索的方向,通过课堂学习和实际工作相结合,工学结合实践活动,使学生在实践中学习,在学习中实践,使学生既掌握了理论知识,又锻炼了实际操作能力,有利于学生职业能力的培养。     

实验教学体系的研究与实践——机械设计制造及其自动化专业实验教学改革

针对机械设计制造及其自动化专业实验教学现状,将部分实验进行综合、汇总并以＂独立课程＂的方式进行;同时鼓励学生进行课外作品的创作,建立了课内实验与课外相结合的实验教学新体系,保证了学生的基本实验技能,锻炼和提高了动手能力和工程意识。     

2020春季开学第一课语文教学案例

随着疫情形势的逐渐好转,各行各业相继复工复产,各中小学校也将陆续开学。为了抚慰疫情给孩子们的心灵带来的影响,时值春季,我们选择了毛泽东的《七绝·咏蛙》作为开学后语文教学的第一课。     

Anisotropic fluoride nanocrystals modulated by facet-specific passivation and their disordered surfaces

Rutile-type fluorides have been proven to be active components in the context of emerging antiferr-omagnetic devices. However, controlled synthesis of low-dimensional, in particular two-dimensional (2D), fluorides in a predictable and deterministic manner remains unrealized because of a lack of efficient anisotropic control, which impedes their further development in reduced dimensions. We report here that altered passivation of {110} growing facets can direct the synthesis of rutile-type fluoride nanocrystals into well-defined zero-dimensional (0D) particulates, one-dimensional (1D) rods and 2D sheets in a colloidal approach. The obtained nanocrystals show positive exchange bias and enhanced magnetic transition temperature from the coexistence of long-range antiferromagnetic order and disordered surface spins, making them strong alternatives for flexible magnetic devices and sensors.     

Molecular design revitalizes the low-cost PTV-polymer for highly efficient organic solar cells

Developing photovoltaic materials with simple chemical structures and easy synthesis still remains a major challenge in the industrialization process of organic solar cells (OSCs). Herein, an ester substituted poly(thiophene vinylene) derivative, PTVT-T, was designed and synthesized in very few steps by adopting commercially available raw materials. The ester groups on the thiophene units enable PTVT-T to have a planar and stable conformation. Moreover, PTVT-T presents a wide absorption band and strong aggregation effect in solution, which are the key characteristics needed to realize high performance in non-fullerene-acceptor (NFA)-based OSCs. We then prepared OSCs by blending PTVT-T with three representative fullerene- and NF-based acceptors, PC₇₁BM, IT-4F and BTP-eC9. It was found that PTVT-T can work well with all the acceptors, showing great potential to match new emerging NFAs. Particularly, a remarkable power conversion efficiency of 16.20% is achieved in a PTVT-T:BTP-eC9-based device, which is the highest value among the counterparts based on PTV derivatives. This work demonstrates that PTVT-T shows great potential for the future commercialization of OSCs.     

《历史与社会》教学实践中的问题和困惑

2002年秋,伴随着新一轮课程改革的全面推行,《历史与社会》新教材在匆忙中诞生,又在匆忙中走进课堂。面对着崭新的教材,既无可供借鉴的经验,也缺乏可以参考的书籍,“摸着石头过河”是初执教时的心态。如今,通过3年多的教学实践,我们欣喜地看到,在教师的教学理念和课堂教学实践、学生的学业评价和学习方式的改变等方面取得了显著的成效。尤其是以自主、合作、探究为主的学习方式,真正体现了“以学生发展为本”的新理念,更有利于学生的主动发展和综合素质的全面提高。但是在新课程教学实施过程中也碰到许多问题,有过许多困惑。在这里提出来与…     

Injectable hybrid inorganic nanoscaffold as rapid stem cell assembly template for cartilage repair

Cartilage injuries are often devastating and most cannot be cured because of the intrinsically low regenerative capacity of cartilage tissues. Although stem-cell therapy has shown enormous potential for cartilage repair, the therapeutic outcome has been restricted by low survival rates and poor chondrocyte differentiation in vivo. Here, we report an injectable hybrid inorganic (IHI) nanoscaffold that facilitates fast assembly, enhances survival and regulates chondrogenic differentiation of stem cells. IHI nanoscaffolds that strongly bind to extracellular matrix (ECM) proteins assemble stem cells through synergistic 3D cell–cell and cell–matrix interactions, creating a favorable physical microenvironment for stem-cell survival and differentiation in vitro and in vivo. Additionally, chondrogenic factors can be loaded into nanoscaffolds with a high capacity, which allows deep, homogenous drug delivery into assembled 3D stem-cell-derived tissues for effective control over the soluble microenvironment of stem cells. The developed IHI nanoscaffolds that assemble with stem cells are injectable. They also scavenge reactive oxygen species and timely biodegrade for proper integration into injured cartilage tissues. Implantation of stem-cell-assembled IHI nanoscaffolds into injured cartilage results in accelerated tissue regeneration and functional recovery. By establishing our IHI nanoscaffold-templated 3D stem-cell assembly method, we provide a promising approach to better overcoming the inhibitory microenvironment associated with cartilage injuries and to advance current stem-cell-based tissue engineering.     

教育与代际收入流动关系(下)——基于研究方法与经验发现的文献述评

中西方有关代际收入流动的研究成果十分丰富.就教育与代际收入关系的实证研究而言,现有研究在方法上大体可以分为三类:第一类研究使用断代分析法或倍差分析法对国家教育制度或政策效果进行评价;第二类研究使用中间变量法或代际系数分解法,探究不同的教育获得变量对代际收入流动性的影响;第三类研究基于经济学基本理论建立数据模型,并使用经验数据对模型拟合,对教育与代际收入关系进行了丰富且有趣的探讨.各国实证研究均显示教育确实对代际收入流动性具有一定的解释力度.西方国家研究显示:第一,教育对代际流动的净效应在30％-40％左右,而我国少数几项研究显示教育的解释力度在10％左右;第二,教育对收入流动性的解释力度存在时间、地区、性别、收入、职业等多方面的差异;第三,不同阶段的教育促进代际收入流动的作用不同,早期教育的作用大于高等教育;第四,延长教育年限和延迟分流对代际收入流动具有正向促进作用,而教育扩张和教育机会增加则不必然带来代际收入流动的提升.未来研究可将重点放在基于中国现实背景的研究以及国际比较研究,而计量模型的完善及对教育获得变量的详尽考察对于提高研究质量至关重要.