共查询到20条相似文献，搜索用时 62 毫秒
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为了解决饮酒驾车问题，通过对所给参考数据的分析，利用最小二乘法等有关数学知识，建立了饮酒后酒精在血液中的含量与时间关系的数学模型，从而根据司机的饮酒量，以及国家质检局发布的新标准，对司机酒后何时开车为酒后驾车问题作出了合理的解释。 相似文献
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结合药理学[2]，讨论酒精在血液中的吸收及排除时浓度的变化过程．通过建立二室模型，分别针对在短时间及长时间内摄入酒精时，酒精在人体血液中的浓度变化情况作具体的分析；同时，利用数学软件对相关参数进行估计，得到结论为：长时间多次摄入同质量的酒精比短时间摄入其浓度消除速率要小．最后对所给的实际问题做出解释． 相似文献
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近期,全国各地加大了对司机酒后驾车、醉酒驾车的执法检查力度.交警在执法的过程中使用了一种仪器可以测出血液中酒精的含量.学生对此很感兴趣. 相似文献
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赤楠茎叶果总黄酮提取与含量测定 总被引：16，自引：2，他引：16
以不同浓度的酒精、料液比、提取温度及提取时间等条件对赤楠茎叶果等不同器官的总黄酮的提取进行正交设计实验，并用聚酰胺吸附--硝酸铝显色法测定的总黄酮含量．结果表明：茎的最佳提取条件为55％乙醇70--80℃提取2h，含量为1．50％；叶为70％乙醇90～100℃提取1h，含量为7．43％；青果皮为55％乙醇70--80℃提取2h，含量为1．28％． 相似文献
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杨超 《中学生数理化(高中版)》2006,(9)
氧化还原反应是一类重要的化学反应,它在工农业生产、科学技术以及日常生活等方面有着广泛的应用．1．判断司机是否酒后驾车K_2Cr_2O_7是一种橙红色具有强氧化性的化合物,当它在酸性条件下被还原成Cr~(3+)时,颜色变为绿色．据此,当交警发现汽车行驶不正常时,就可上前阻拦,并让司机进行酒精检测．司机向填充了吸附有K_2Cr_2O_7的硅胶颗粒的装置吹气,如发现硅胶变色达到一定程度,即可判断司机是酒后驾车．这里酒精(CH_3CH_2OH)被氧化为醋酸(CH_3COOH)．该反应的化学方程式为： 相似文献
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聚合硅酸氯化铝的制备、结构和性能研究 总被引：4，自引：0，他引：4
制备了聚合硅酸氯化铝絮凝剂(PASC)，其制备条件为常温，常压，反应时间3～4h。pH值3．0～3．5，产物Al2O3含量8．0％～10．0％，SiO2含量1．0％～2．0％。红外光谱证实聚铝离子与聚硅离子间存在着一种非离子性的键合作用，说明形成了聚合度更大的无机高分子聚合物。应用实验表明PASC较PAC的絮凝效果更好，稳定性更高。 相似文献
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1．（江西卷，理8）四位好朋友在一次聚会上，他们按照各自的爱好选择了形状不同、内空高度相等、杯口半径相等的圆口酒杯，如图1所示，盛满酒后他们约定：先各自饮杯中酒的一半．设剩余酒的高度从左到右依次为h1、h2、h3、h4，则它们的大小关系正确的是（ ）．[第一段] 相似文献
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《海外英语》2007,(5):10-11
Many college freshmen arrive woefully unprepared to do college work, and as disadvantaged populations continue to grow, the share of the American work force that has made it through college is expected to plummet. Many experts blame that educational failure not just on high schools but also on colleges. School & College, a special report by The Chronicle, looks at efforts to fix the system. What reforms would better prepare students for college? What should schools and colleges be doing differently? How should state and federal officials help? 相似文献
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《海外英语》2007,(4):36
There are numbers of crossroads on our long and unpredictable life journey where we totally have no idea about which direction to choose. No matter what our decision is, we should not turn back, but face the music and go ahead instead. I am this kind of girl who always does try without regretting, one example is how I dealt with my love. 相似文献
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Migration occurs behind a variety of reasons and has a great effect on the whole world. People may migrate in order to improve their economic situation, or in order to escape civil strife, persecution, and environmental disasters. The impact of migration is complex, bringing both benefits anddisadvantages. This paper briefly talks about the causes of migration, the allocation of benefits, and the ways in which individual countries and the international community deal with this important subject. 相似文献
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Sister Carrie is one of the most controversial characters in American literature.Thought as a "fallen woman" firstly,she was defined as a "new woman" by some critics later. However, by digging into the motivaton behind the whole process of Carrie's "success", the relationship between Carrie and her creator (the author), the social conditions of then American, it can be found that Carrie has never been free-standing on her thought and she has never found her real-sdf even after becoming a famous actress. In a society dominated by mass consumerism Carrie is only an adherent of her own desires. She also is a representative of all those country girls flooded into cities, a symbol and a sacrifice of the urbanization of America in a time countryside was overcome by cities. 相似文献
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RUZBEHANI Mohsen 《重庆大学学报(英文版)》2004,3(1):20-25
1.IntroductionOne-cyclecontrolmethod,whichwasproposedaboutonedecadeago[1],hasbecomeanattractivemethodinspecialfieldssuchaspowerfactorcorrection[2-6],switchingamplifiers[7,8],etc.Themainideaofthiscontrollerisbasedonintegrationofdiodevoltageinone-cycleandforcesittobeexactlyequaltothereferencevalue.Themainadvantageofthiscontrollerisitsrealtimeabilitytorejectthevariationofinputvoltage[1].Despitethisgreatability,ithasnogoodperformancesinrejectingofloaddisturbanceandfollowingreferencecommands.Espec… 相似文献
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唐芳 《读与写:教育教学刊》2008,5(6)
During interview with English majors, it was found that a majority of students expressed disappointment with their experience of English literature classes. Students' dislike of learning English literature appears to be the major problem of teaching English literature in China. Reader response approach is a good way to solve this problem. In this paper, I explain the rationale behind the reader response approach, such as its origin, definition, features, assumptions, and strategies. Then I illustrate how reader response approach works as a teaching strategy by presenting several teaching models. At last I evaluate its usefuiness for teachers and present the advantages of reader response approach in Chinese context. 相似文献