氮磷钾营养对白肋烟农艺性状及氮组分含量的影响

探讨了氮磷钾营养与白肋烟农艺性状及氮组分含量的关系，结果表明，农艺性状及氮组分含量与施N量、N：P2O5及N：K2O比例关系密切，单产、比叶重、烟碱与施N量呈极显著正相关，单株叶面积、田间叶面积系数、上中等烟比例、硝酸还原酶（NR）活性与施N量呈显著正相关．三要素对茎围、单株叶面积、田间叶面积系数、单产、上中等烟比例、总氮、烟碱、硝酸还原酶（NR）活性的影响N〉K〉P，比叶重、蛋白质、可溶性蛋白质、总游离氨基酸的影响则为N〉P〉K．农艺性状与氮组分含量的关系也较密切，总氮与单株叶面积、叶面积系数、顶叶面积，烟碱与株高极显著正相关，总氮、烟碱、硝酸还原酶（NR）活性与茎围，蛋白质与单株叶面积、叶面积系数显著正相关，而氮／碱与株高、茎围极显著负相关．综合试验结果，以施N270～300kg／hm^2，N：P2O5：K2O为1：0．5～1：2较适宜．     

不同氦、磷、钾营养条件下白肋烟生长发育过程中有关化学物质的变化动态

采用定期取样杀青烘干化验分析的方法，探索在不同N，P，K营养条件下白肋烟生长发育过程中的糖、氮、烟碱等化学物质变化规律，结果表明：总糖、还原糖随生长期推进呈增加趋势，而总氮、蛋白质呈下降趋势；随施N量增加各生长期的总氮、蛋白质、烟碱增加，而旺长、成熟期总糖和伸根、旺长前期、成熟期的还原糖下降；随施P量增加各生长期的总氮和伸根、旺长前期、成熟期的蛋白质、烟碱增加，而旺长期的总糖、旺长前期的还原糖和旺长后期的蛋白质、烟碱下降；随施K量增加各生长期的总氮、烟碱、蛋白质下降；N，K对总糖和还原糖，N，P对烟碱、总氛、蛋白质影响较大．     

β-环糊精在酸性染料染色上的应用初探

本文主要利用紫外-可见分光光度法分析β-环糊精与四种酸性染料之间的作用，并探讨了加入不同浓度的β-环糊精对酸性染料染色性能的影响。     

烟碱:并非仅是有害成分

新烟碱类杀虫剂是全球第四大重要的杀虫剂,重点作用在害虫的烟碱乙酰胆碱受体(n ACh Rs).此外烟碱在医用方面也有了新的研究与突破,比如治疗帕金森综合征与炎症、老年痴呆症等方面就有很好的功效.本文概括性阐述了新烟碱类杀虫剂的结构特点、作用机理,阶段性归纳了本人关于稠环稳固的顺式衍生物层面的分析思考.希望能给烟碱的有益层面与用途带来参考.     

降碱灵对白肋烟上部叶开片及主要化学成分的影响

利用降碱灵（签剂）进行田间比较试验,探索其对白肋烟上部叶开片及主要化学成分的影响,结果表明：上部叶平均叶长增大13．48％～13．83％,叶宽增宽20．89％～22．99％,叶片增宽率大于叶长增长率;产量、产值、均价等经济性状差异较小,而外观质量有明显改善;化学成分上部叶总氮量下降0．29％～0．30％,烟碱量下降0．60％～0．63％;中部叶总氮下降0．05％～0．09％,烟碱下降0．35％～0．37％;总氮、烟碱量上部叶降幅大于中部叶;烟叶钾含量增加,且上部叶增率大于中部叶．综合效果A处理优于B处理．     

云南高原引种津巴布韦烤烟资源的评价

采用严格的田间小区品比试验对5个津巴布韦引进烤烟品种（系）和2个对照取样,对其9项重要化学成分进行检测．通过对比分析表明：津引烤娴资源的化学成分与K326相比,呈现“两糖低、烟碱低、氧化钾高”的三大显著特征;与云烟87相比,呈现“两糖低、淀粉低、氧化钾高、石油醚提取物高”的四大显著特征;在云南高原种植条件下,津引良种的烟叶氧化钾含量（质量分数）超过2％,石油醚提取物含量超过5％,总糖、还原糖分别低于31％和26％,淀粉含量低于3％和上部叶的烟碱含量低于2．5％．这说明,云南现有种植品种与津引品种有差异明显,在云南种植津巴布韦品种可以生产出类似津巴布韦的优质烟叶．     

烟碱对小白鼠精细胞染色体的影响

香烟的主要成分是烟碱,针对烟碱对生殖细胞染色体的影响进行了讨论。试验用香烟烟雾溶于水按不同剂量给小白鼠皮下注射,每天一次,在第１０天、第２０天、第３０天取样观察精细胞染色体数目。在精细胞减数分裂中期发现了非整倍体,而且非整倍体率与时间和剂量有关。在注射剂量为０．５ｍｌ／２０ｇ体重、注射３０天烟雾溶液的小白鼠中非整倍体率较高。     

戒烟还你健康的心脏和大脑

戒烟还你健康的心脏和大脑吸烟，是目前公认的诱发心脑血管病的高危因素。有关专家研究发现：吸烟２０年以上，每天吸烟２０支以上的人，冠心病发生率是下吸烟者的４倍，中风为３倍，心肌梗塞为３．６倍。冠心病碎死者约有６２％与吸烟有关。香烟中的尼古丁、烟碱、一氧化...     

干柱层析分离法从废烟粉中提取纯烟碱

废烟粉有较好的再利用价值,笔者对此进行了一些试验性的探索,由废烟粉提取纯烟碱是其综合利用的一个方面。本文提出在碱性条件下通过水蒸汽蒸馏法提取总烟碱。以薄层层析法寻求总烟碱分离条件,以干柱层析法进行实际分离获得纯烟碱,方法简便,提取、分离效果好,可供实际应用时借鉴与参考。     

关于烟草中提取烟碱实验的几点思考

烟碱是烟草中对人体造成危害的主要成分,传统的烟碱提取实验只是注重对化学基本操作的学习与巩固以及对烟碱的化学性质的了解,而忽略了烟碱在日常生活中的影响。现在提倡素质教育,在进行化学实验教学教授学生实验技能的同时应该与实际相结合起来,要让学生们充分认识到烟草中烟碱的危害以及对环境所造成的污染,增强学生的科研意识,提高学生的动手能力与理论联系实际的实践能力,激发学生的创造性思维,提高学生的综合素质。     

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?     

Western and Eastern culture differences in commercial field

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.     

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…     

风的曲线

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.