2014

摘要： 农业是促进我国经济发展的主要支柱,关系到国际民生与国家安全,在国民经济发展中占据重要地位。在2014年关于农村发展的中央会议上提出了关于农业可持续发展面临的问题,在2017年的一号文件中也指出,要想有效处理农业环境中存在的问题,必须将低碳农业贯穿整个工作过程,才能满足中国可持续发展道路需要,实现高效、节能和绿色发展。

摘要： The major awkwardness when joining AA2014 lies in the presence of creation of oxide films and brittle intermetallic in the bond region. However, diffusion bonding can be used to join these alloys without much difficulty. This paper reveals the characterization of diffusion connection of aluminum alloy AA 2014 with and without applying copper powder. Joining was achieved in vacuum up to (1 × 10-5 mbar) by means of vacuum system. Aluminum alloy AA2014 samples were done as cylinder form and interlayer thickness was equal 100 μm, under joining conditions of (325°C - 475°C) and 4 MPa and period of (1 hour). The ultimate strength was found equal to 188.36 MPa. Bonding joint was examined using light microscope, (SEM) with (EDS) for determining microstructure and depth of diffusion and microhardness was also used at connection zone. XRD outcomes display that the main intermetallic compound phase formula was Al2C. The maximum depth of diffusion obtained was 19.1 μm.

摘要： Microstructure evolution of 2014 aluminum alloy was studied by hot compression deformation at 410?C to 470?C and strain rates of 0.07 s?1 to 0.53 s?1, to provide manufacturing references for aluminum plate. The deformation temperature and especially strain rate ranges were chosen very close to the actual processing condition. The results show that the stress-strain curves display a stable flow at the given deformation conditions, corresponding a dominant microstructure evolution behavior of dynamic recovery (DRV) and few dynamic recrystallization (DRX). After solution treated at 502?C for 3 hours, quasi in-situ observation shows that static recrystallization (SRX) develop typical fine grains with several microns at grain boundaries, while static recovery (SRV) dominants the microstructure evolution during the soaking time, leading to a similar microstructure to that of the as-deformed. The average low angle grain boundaries (LAGBs) and high angle grain boundaries (HAGBs) display weak differences between as-deformed and solution treated specimens, which reveals a good thermal stability of microstructure for 2014 alloy. However, the deformation at the lower temperature has an obvious trend to induce SRX during solution soaking.

摘要： 为了解释教师的全方位表现,美国康涅狄格州制订了有效教学评价标准。该评价标准从"课内观察"与"非课堂观察或实践的回顾"两个方面对教师进行评价,具体体现在学生参与学习、积极学习的计划、积极学习的指导、职业责任和教师领导力四个重要领域。该标准具有学生与教师相结合的评价理念、过程与结果相结合的评价取向、结论与反馈相结合的评价结果和操作与引领相结合的评价思路。借鉴美国康涅狄格州的有益经验,我国的教师评价应树立发展性的评价理念、制定可操作的指标体系和运用多元性的评价策略。

摘要： 尽管2014年高考已经过去几年了,但是围绕"理综能力测试卷I中第40(3)题的答案"的讨论并没有消失,广大高中师生以及一些生物学家对此依然存有疑义.本文对争辩双方的观点及理论进行了总结与阐述,并在此基础上结合文献研究进行了讨论,提出了自己的观点:细胞中的染色体数目与有丝分裂过程中染色体的数量(变化)属于不同的范畴,不能简单地将二者之间划为等号;该小题忽视了有丝分裂的干扰,表述中缺乏必要的限定条件或提示,是不完美的、有瑕疵的.

摘要： 一道有多余条件的好题——2014 年江苏卷理科第 17 题

摘要： 《国家学生体质健康标准》自2002年试行方案的推广,到2007年《标准》的正式颁布,至2014年对《标准》内容的修订、实施到现在也走过14个春秋.研究结合自《标准》实施后的相关研究成果,通过文献资料、对比法、逻辑推理、实地走访等研究方法,对新、旧《标准》内容的调整与变化进行对比研究,为能更好地解读修订后的新《标准》,分析其在具体实施工作中的规侓,利于新《标准》在学校体育工作中的实践应用,为科学客观反映学生的体质健康水平,提供参考建议.