Keggin anions behave differently from each other when they react with nucleic acids. The molybdenum series exhibits oxidative cleavage activity towards AMP and DNA. The mechanism of AMP damage and DNA cleavage caused ...Keggin anions behave differently from each other when they react with nucleic acids. The molybdenum series exhibits oxidative cleavage activity towards AMP and DNA. The mechanism of AMP damage and DNA cleavage caused by the molybdenum series is mainly oxidation and the oxidation sites are on the ribose parts other than on the adenine parts, while the hydrolysis probably makes significant contributions to the cleavage of DNA and to the damage of AMP caused by the tungsten series.展开更多
In 2020, all teachers have stepped on the forefront of "online teaching practice". This process has accelerated the connection between informatization and professional English teaching in secondary vocationa...In 2020, all teachers have stepped on the forefront of "online teaching practice". This process has accelerated the connection between informatization and professional English teaching in secondary vocational schools, brought challenges to online teaching and also triggered teachers thinking on the reform of professional English teaching. Taking UAV professional English in secondary vocational schools as an example, this paper analyzes the main problems existing in professional English teaching at this stage, compares the advantages and disadvantages of online and offline teaching, and points out that to create offline classroom in professional English teaching in secondary vocational schools, it is necessary to make effective use of information resources, cite teaching means and methods that can enhance students autonomy and participation and use all-round results evaluation, so as to improve the teaching effect.展开更多
文摘介绍了1.7 Mt/a渣油加氢装置的主要技术特点和催化剂装填情况,结合第一周期生产运行期间的主要操作参数、原料油及产品性质、物料平衡及装置能耗等情况,对装置运行情况进行了分析和总结。装填的第三代RHT渣油加氢催化剂级配及活性良好,能够满足生产需要,为催化裂化提供了优质原料,装置运行情况良好。通过优化换热系统和分馏操作,目前装置运行能耗为14.26 kg Eo/t,低于设计值,但还需进一步降低。同时对第一周期出现的高压换热器结垢和3.5 MPa蒸汽品质等问题进行了分析,为装置今后的运行提出了改进建议。
文摘Keggin anions behave differently from each other when they react with nucleic acids. The molybdenum series exhibits oxidative cleavage activity towards AMP and DNA. The mechanism of AMP damage and DNA cleavage caused by the molybdenum series is mainly oxidation and the oxidation sites are on the ribose parts other than on the adenine parts, while the hydrolysis probably makes significant contributions to the cleavage of DNA and to the damage of AMP caused by the tungsten series.
文摘In 2020, all teachers have stepped on the forefront of "online teaching practice". This process has accelerated the connection between informatization and professional English teaching in secondary vocational schools, brought challenges to online teaching and also triggered teachers thinking on the reform of professional English teaching. Taking UAV professional English in secondary vocational schools as an example, this paper analyzes the main problems existing in professional English teaching at this stage, compares the advantages and disadvantages of online and offline teaching, and points out that to create offline classroom in professional English teaching in secondary vocational schools, it is necessary to make effective use of information resources, cite teaching means and methods that can enhance students autonomy and participation and use all-round results evaluation, so as to improve the teaching effect.
