草业科学专业"草原生态化学"课程的教学改革与实践

文章重点阐述了"草原生态化学"课程体系、教学内容、实验课内容和教学手段的改革,强调学生实践能力的培养。     

激光测距仪在MATLAB辅助下的危岩体调查应用

由于罗盘在对高陡边坡危岩体调查中的局限性,提出一种基于激光测距技术非接触性获取危岩体结构面产状的方法,完成了危岩体稳定性初步评价系统.通过登封三皇寨景区停车场的危岩体实例,阐述了该系统的工作方法,验证了系统的可行性并得到了如下成果:(1)使用激光测距仪,能在部分场景代替罗盘完成危岩体调查,得到包括危岩体尺寸,控制性结构...     

教学型本科院校创新人才培养的有效实践

本文从教学型本科院校的创新型人才培养目标入手,介绍了我校构建创新教育体系、创新基地建设及创新导师队伍建设的教育教学改革思路、实践过程、特色与效果,为普通高等院校实施创新人才培养提供有效借鉴.     

精品课程"环境化学"的建设措施研究

文章论述了笔者承担讲授的本科精品课程"环境化学"建设的措施,以教学改革实践为基础,从教材建设、教学内容、教学手段等几个方面探讨了精品课程建设的途径。     

我国小学“三点半难题”的现状、问题及治理

我国小学“三点半难题”是教育改革与经济发展不协调的产物,是在为中小学生减负、规范中小学管理过程中衍生出的教育性问题,也是随着社会经济的发展、家庭结构的变化而产生的社会性难题.为应对“三点半难题”,现阶段主要形成了无人看管、老人接送、课后托管和父母接管四种办法.但这些办法非但没有彻底解决学生“监管真空期”的难题,反而引发出交通安全、食品安全、教育负效果等新问题.综合治理“三点半难题”,必须在思想层面秉承教育公平的理念,明确其公共福利的性质定位;在制度层面形成以政府担当为主导,以公立学校为主体,支持校外机构发展,社会成员广泛参与的多元治理体系;在实践层面以学生发展为目标,合理确定课后服务内容形式,坚持动态监评;形成思想、制度、实践层层推进,学校、家长、政府、社会共同参与的治理模式.     

Precision measurement of the Newtonian gravitational constant

The Newtonian gravitational constant G, which is one of the most important fundamental physical constants in nature, plays a significant role in the fields of theoretical physics, geophysics, astrophysics and astronomy. Although G was the first physical constant to be introduced in the history of science, it is considered to be one of the most difficult to measure accurately so far. Over the past two decades, eleven precision measurements of the gravitational constant have been performed, and the latest recommended value for G published by the Committee on Data for Science and Technology (CODATA) is (6.674 08 ± 0.000 31) × 10⁻¹¹ m³ kg⁻¹ s⁻² with a relative uncertainty of 47 parts per million. This uncertainty is the smallest compared with previous CODATA recommended values of G; however, it remains a relatively large uncertainty among other fundamental physical constants. In this paper we briefly review the history of the G measurement, and introduce eleven values of G adopted in CODATA 2014 after 2000 and our latest two values published in 2018 using two independent methods.     

Wearable skin-like optoelectronic systems with suppression of motion artifacts for cuff-less continuous blood pressure monitor

According to the statistics of the World Health Organization, an estimated 17.9 million people die from cardiovascular diseases each year, representing 31% of all global deaths. Continuous non-invasive arterial pressure (CNAP) is essential for the management of cardiovascular diseases. However, it is difficult to achieve long-term CNAP monitoring with the daily use of current devices due to irritation of the skin as well as the lack of motion artifacts suppression. Here, we report a high-performance skin-like optoelectronic system integrated with ultra-thin flexible circuits to monitor CNAP. We introduce a theoretical model via the virtual work principle for predicting the precise blood pressure and suppressing motion artifacts, and propose optical difference in the frequency domain for stable optical measurements in terms of skin-like devices. We compare the results with the blood pressure acquired by invasive (intra-arterial) blood pressure monitoring for >1500 min in total on 44 subjects in an intensive care unit. The maximum absolute errors of diastolic and systolic blood pressure were ±7/±10 mm Hg, respectively, in immobilized, and ±10/±14 mm Hg, respectively, in walking scenarios. These strategies provide advanced blood pressure monitoring techniques, which would directly address an unmet clinical need or daily use for a highly vulnerable population.