无机盐对酵母菌产麦角固醇的影响

研究了PO4^3-、Mg^2 和Fe^2 对酵母菌细胞生长及麦角固醇合成的影响。结果表明：3种无机盐在所测试的浓度范围内均能促进酵母菌细胞生长，提高生物量，对麦角固醇的合成也有显著的促进作用。当培养基中分别加入2.0g／L的K2HPO4、1．5g／L的MgSO4和0.05g／L的FeSO4时，刺激麦角固醇合成作用最强，麦角固醇含量分别增加了39．7％、9.5％和35．2％。     

高效液相色谱法测定血浆中的二甲胺四环素

研究了高效液相色谱法测定血浆中二甲胺四环素的各种条件。并对其体内代谢动力学进行了研究。采用C18反相色谱柱,流动相为：0．2mol／L草酸胺：二甲基四胺：1mol／LEDTA（550：250：200,V：V：V）,用0．1mol／L氢氧化四丁基胺调pH6．2,紫外检测,h=355nm,线性范围为1-8ug／mL,检出限为0．2ng,日间和日内变异系数小于4．096％;二甲胺四环素在健康人体内呈现一级吸收二室开放模型特点。     

紫外分光光度法测定诺氟沙星的含量

用紫外分光光度法测定诺氟沙星的含量，选用0．1mol／L氢氧化钠为溶剂，在272．5nm波长处测定吸光度，诺氟沙星的线性范围为0-10μg／ml，相关系数r=0．9998。相对标准偏差为0．65％(n=6)。应用拟定的方法测定药物制剂中诺氟沙星的含量与文献方法一致。     

Winslow型流体电粘性的测定

本实验设计平行板拉式电粘议，测定Winslow型流体在0-5000V／mm的交流电场作用下，零剪切连年时的电粘性。本法操作简便，测定流体电粘性的范围广工有利于比较各种电粘性流体的电粘性大小。     

天丝／木代尔混纺产品混纺比的分光光度法测定

用65％硫酸溶解天丝、木代尔及天丝／木代尔混纺产品,测定所得溶液的紫外一可见吸收光谱,建立了测定天丝／木代尔混纺产品混纺比的分光光度法．采用该方法对天丝／木代尔混纺产品的混纺比进行了测定,分析结果与实际配比的偏差范围为-1．60～1．88％,误差在标准FZ／T01053．2007的允差范围内,为天丝／木代尔混纺产品的定量分析提供了一条可行途径．     

新鲜蔬菜中β-胡萝卜素提取和测定的研究

用三种不同方法提取不同新鲜蔬菜中的β-胡萝卜素,并对β-胡萝卜素含量进行测定.结果表明,比较优先的β-胡萝卜素提取方法是:试样用4%Na0H甲醇溶液在60℃-70℃皂化1 h,用3:7(v/v)的丙酮-石油醚混合溶剂提取,以MgO为吸附剂,丙酮一石油醚为洗脱剂分离,提取液用紫外分光光度计在波长447 nm,1cm比色皿条件下测定,得出蔬菜中β-胡萝卜素含量:胡萝卜为0.134 mg·g-1,红椒为0.0863 mg·g-1,菠菜为0.0426 mg·g-1.该方法工艺简单,提取率较高.     

野葛花中葛花苷紫外分光光度法检测

采用紫外-分光光度法测定野葛花中异黄酮化合物葛花苷的含量,紫外检测波长为265mm。葛花苷在 0．010-0．040mg／mL范围内呈良好线性关系,平均加样回收率为101．1％(n=4),平均RSD为0．69％(n=4)。     

苦味酸锰、钴、镍、铜、锌、镉与4′─硝基苯并─15─冠─5配合物的合成与表征

在乙腈─乙醇─水（2：2：1，V／V／V）的混合溶剂中制备了六种金属（锰、钴、镍、铜、锌、镉）苦味酸盐与4′─硝基苯并─15─冠─5的固态配合物，其组成为M（pic）2·2L·XH2（M＝Mn、CU，x＝2；M＝Co，Ni，Zn，Cd，x＝4；pic＝苦味酸根；L＝4′─NO2B15CS），并通过元素分析、红外光谱、紫外光谱和摩尔电导对该系列配合物进行了表征。     

维生素B_6的伏安法测定

本文用伏安法对药物中的维生素B6（VB6）进书测定。在0．05mol／L（CH3）4NBr－（CH3）4NOH底液中（pH-6．0～11．0），VB6在-1．88V（VS，SCE）产生一灵敏还原峰，峰高与VB6浓度在8．0×10-7～2．2×10－5mol／L范围内成线性关系，检测下限为2．0×－7mol／L，用本法，可直接测定药物中VB6的含量。     

由废腈纶丝制备高吸水性树脂

以腈纶（ＰＡＮ）废丝为原料,经碱皂化水解,甲醛交联制备了高吸水性树指,考察了不同水解条件和甲醛用量对树脂性能的影响,测定了树脂的吸水率和热稳定性,其最高吸水率可达４６０ｇ／ｇ。     

卡思卡特城堡

It is worthy of noting that, whilst Crookston Castle witnessed the earlier and happier portion of Mary's variegated life,     

不同的吃喝玩乐

一、吃和喝吃苹果 eat an apple, 吃药 take medicine,吃糖 have some sweets,吃饭 have one's meals,吃馆子 dine out,吃惊 be surprised/     

漏洞百出的教育

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?     

只要努力,不要后悔

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.     

浅谈移民问题

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.     

Sister Carrie, an Adherent of Desires

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.     

Improvement of one-cycle controller by use of proportional integral differential controller

1.IntroductionOne-cyclecontrolmethod,whichwasproposedaboutonedecadeago[1],hasbecomeanattractivemethodinspecialfieldssuchaspowerfactorcorrection[2-6],switchingamplifiers[7,8],etc.Themainideaofthiscontrollerisbasedonintegrationofdiodevoltageinone-cycleandforcesittobeexactlyequaltothereferencevalue.Themainadvantageofthiscontrollerisitsrealtimeabilitytorejectthevariationofinputvoltage[1].Despitethisgreatability,ithasnogoodperformancesinrejectingofloaddisturbanceandfollowingreferencecommands.Espec…     

库克斯顿城堡

城堡, 是欧洲典型的建筑之一, 每个城堡都有一个美丽的传说或是一段历史。从本期开始, 我们将推出“城堡之旅”, 带各位读者去浏览、观赏欧洲各地的城堡, 开始一段文化与历史的旅途!     

The Reader Response Approach to Teaching of English Literature

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.