排序方式: 共有9条查询结果,搜索用时 15 毫秒
1
1.
为了解大学生对网购食品安全的感知现状和影响其安全感知的因素,本文以问卷调查方式,对500名在校大学生(大一至大四)进行了网购食品安全感知调查,并提出相应的对策和建议。结果表明,13.5%学生对食品安全非常关注,年级越高关注度越大;85%学生食品安全知识获取渠道来源于手机、电脑等电子产品,其中50.7%学生获得渠道来源于手机短视频;89.7%学生表示网购食品与商家宣传味道、功效等方面存在较大差异。分析可知,在网购食品安全方面,大学生存在食品安全意识不足、缺乏深层次安全意识以及商家虚假宣传较多等问题。基于此,本文进一步提出了加强高校食品安全知识培养、拓展食品安全知识传播途径,加强深层次安全意识以及提高食品安全监管力度,完善相关法律体系等建议。 相似文献
2.
Effects of hypoxia on learning-memory function and swimming capability of rat were studied and the ergonomics under hypoxic condition was also evaluated from the biological point of view. Three modes of hypoxia were designed and plots of oxygen concentration versus time for each group in hypoxic environment were produced. Results showed that the effects of hypoxia on learning-memory function and swimming capability were related with the time and strength of hypoxia. It had nothing to do with the individual difference of rat models. 10% O2 long-term intermittent anamorphosis hypoxia could improve the swimming capability of rat model significantly. Stimulating with proper level of hypoxia, carbon dioxide could improve ergonomics in airtight hypoxia environment. Under hypoxia condition, from the ergonomic point of view, 6% O2 is the important threshold and might belong in critical region. 相似文献
3.
4.
原子光谱法测定金花葵花瓣及种子中微量元素 总被引:1,自引:0,他引:1
金花葵微量元素的测定多采用原子光谱法,但因实验条件、样本预处理方法不一致,各测定方法间的重现性和可比性较差。采用原子吸收分光光度计测定微量元素铜、镁、铁、锰、铅、锌,采用原子荧光分光光度计测定微量元素硒。实验详细研究了微波消解与电热板消解法两种消解方法对含量测定的影响,对金花葵花瓣和种子中的微量元素含量进行了比较。结果表明微波消解法更有利于微量元素含量的测定,精密度与重现性更高。金花葵种子与花瓣相比,种子中的微量元素锌、镁、锰等含量均比花瓣中高,金花葵花瓣及种子中都含有微量元素硒,种子中的微量元素含量达0.063 5 mg/kg,花瓣中的含量为0.027 2 mg/kg。微量元素铅含量没有超标,金葵花种子的药用价值更高。 相似文献
5.
6.
7.
This work presents an approach to build a high-performance, low-viscous and replaceable separation matrix, semi-crosslinked polyacrylamide (semi-CPA) capillary gel electrophoresis. Non- denatured basic proteins, such as lysozyme, cytochrome C, ribonuclease A and trypsin were separa- ted. The impacts of monomer and cross-linker concentrations on protein separation were studied, and the ability of dynamic capillary inner wall coating was demonstrated. The UV absorption interfer- ence by semi-CPA gel matrix was successfully overcome by a partial filling technique, which results in sensitivity 20 times higher than other protein separation method. The excellent separation ability, reproducibility and dynamic coating ability made semi-CPA an ideal separation media in both capillar- y electrophoresis and microfluidic chip separation scheme. 相似文献
8.
采用气相色谱仪对三种聚氯乙烯电缆在300、400、500、600、700、800、900℃下燃烧时产生的烟气中苯系物的毒性进行实验研究,测定苯系物含量,以公式法分析人在不同体力活动下的苯的致癌风险及苯系物的非致癌风险。研究结果表明,三种电缆燃烧烟气中苯系物排放总量ZR-RVVZR-YJVYJV;苯系物中只有苯在500℃以上时的排放浓度超过了国家标准,但400℃以上时苯的致癌风险超过可接受范围,同样400℃以上时(不包括400℃时的轻微体力活动)开始出现非致癌风险。 相似文献
9.
1