共查询到20条相似文献，搜索用时 93 毫秒
1.
系统总结了安捷伦7890毛细管色谱柱种类,分析了色谱柱的选择标准,介绍了安装、使用、老化等色谱柱注意事项,目的是提高色谱柱的使用效率,延长色谱柱的使用寿命。 相似文献
2.
3.
毛细管电色谱技术及应用的最新进展 总被引：1，自引：0，他引：1
沈淑君 《Journal of Zhangzhou Technical Institute》2008,10(1):17-20
介绍了毛细管电色谱技术的研究进展及其分类、特点及操作模式,着重介绍各类毛细管电色谱（填充柱-CEC、开管柱-CEC、整体柱-CEC）在手性药物分离及药物有效成分测定中的应用,并对毛细管电色谱技术的应用及发展做了展望。 相似文献
4.
研究了钨酸钠结晶水合物的低压色谱柱的色谱行为，并与常压色谱特征进行了比较。低压下该柱的柱效有较大的提高，且分析速度加快，检测灵敏度，分离度、拖尾因子等都得到了较好的改善，对极性较弱的有机化合物，特别是对于烷烃有良好的分离效果。 相似文献
5.
研究了钨酸钠结晶水合物的低压色谱柱的色谱行为 ,并与常压色谱特征进行了比较 .低压下该柱的柱效有较大的提高 ,且分析速度加快 ,检测灵敏度 ,分离度、拖尾因子等都得到了较好的改善 .对极性较弱的有机化合物 ,特别是对于烷烃有良好的分离效果 相似文献
6.
红曲米中红曲色素及Monaco link的提取与分离 总被引：2，自引：0，他引：2
本文主要研究了红曲米中红曲红、黄色素和Monaco link的分离方法。提出通过乙醇萃取、新的组合色谱柱(硅胶色谱柱和中性氧化铝色谱柱)分离程序分离上述三种物质的方法。红曲红色素、黄色素的色调分析显示分离效果良好。并用HPLC法测定了分离前后红曲样品中的Monaco link含量。 相似文献
7.
毛细管气相色谱法分离苯胺类化合物的研究 总被引：1，自引：0，他引：1
研究了邻甲苯胺，对氯苯胺，4，4’-二氨基二苯醚和联苯胺四种苯胺类化合物的气相色谱分离条件，从使用的分离柱，载气流速及柱温等色谱条件——做了研究，提出了色谱分离的最佳条件。 相似文献
8.
反冲色谱柱在分离渣油中胶质组分的应用 总被引：3，自引：0，他引：3
通过实验对比经典色谱柱与反冲色谱柱在分离渣油胶质组分中的效果，表明反冲谱柱可以提高色谱柱的柱收率，可以得到较为真实的胶质组分，有利于对胶质中的化学组成进行分析，对于研究胶质组分中的元素组成、结构特征、微量元素的含量、分布及存在形态具有一定的实用价值。 相似文献
9.
利用分子力学和量子化学方法计算出烷基硫醇类化合物的分子结构描述参数,用多元线性回归法建立化合物在不同极性色谱柱上的QSRR模型。烷基硫醇类化合物在不同极性色谱柱上的气相色谱保留指数与其拓扑指数之间具有较好的线性关系。建立的不同极性色谱柱上的烷基硫醇类化合物的色谱保留QSRR模型预测此类化合物的色谱保留值,具有较好的稳定性和准确性。 相似文献
10.
11.
罗艳萍 《读与写:教育教学刊》2008,5(6)
The communication of people partially is the communication of cultures. Culture has a direct effect on international commercial activities in all aspects. Different conceptions about time, space, equality, law and the like, lead people to deal with things in different ways. So to know cultures of the counterpart is to facil-itate our enterprises so as to have a smooth and successful communication in commercial activity. 相似文献
12.
邱崇丙 《唐山师范学院学报》2014,(1):21-23
汉字的六书,《说文》对“转注”一类,语焉不详。后世学者提及转注,也仅限于许慎所举出的例字。《汉字例说》一文,作者从转注的角度综合考虑,对部分现代常用字作了分析,跟传统的解释有所不同。希望能抛砖引玉,互相切磋,以推进学术研究。 相似文献
13.
Richard Denner 《海外英语》2007,(4):14-15
Rosco and I wait for the fishermen to return.I sit at a wooden bench near the store at Mt.Baker Resort and watch the clouds change shape. Rosco has my belt around his neck and an eight foot tow chain hooked to a tree. Dogs must be on a leash. Ducks and rabbits are loose. 相似文献
14.
Given a graph G,a subgraph C is called a clique of G if C is a complete subgraph of G maximal under inclusion and |C|≥2. A clique-transversal set S of G is a set of vertices of G such that S meets all cliques of G. The clique-transversal number, denoted as TC (G), is the minimum cardinality of a clique-transversal set in G. The clique-graph of G, denoted as K (G), is the graph obtained by taking the cliques of G as vertices, and two vertices are adjacent if and only if the corresponding cliques in G have nonempty intersection. Let F be a class of graphs G such that F={G|K(G) is a tree}. In this paper the graphs in F having independent clique-transversal sets are shown and thus TC (G)/|G|≤1/2 for all G ∈ F. 相似文献
15.
16.
17.
《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
18.
陈美曦 《山东教育学院学报》2008,23(2):103-107
Different nations have different social cultures, and the social culture of every nation is developing with the development of the nation, language is greatly influenced by social culture, which enables language to possess national and historical characteristics. Word is the smallest, independent, meaningful linguistic unit of language. It can well reflect the national and historical characteristics. From synchronic aspect, the social and cultural influence on word meaning is mainly embodied in conceptual and associative meanings of word. The incorrespondence of word meaning is a phenomenon that exists in both conceptual and associative meanings of word among different languages. From diachronic aspect, the development of social culture causes some changes of word meaning to some extent. Therefore, social culture plays a key role in vocabulary learning and mastery of a language. 相似文献
19.
Rachel Zupek 《海外英语》2007,(11):40-41
我们绝大部分人都同意一件事情——我们喜欢金钱。但是你对金钱的喜欢之情足够到让你创立一份事业么?.财富通常被人忽视,主要在于人们不能真正了 相似文献
20.
《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