膨胀阻燃聚丙烯燃烧残炭的结构分析

采用离子色谱法测定残炭提取液中离子及其含量,并用红外光谱仪和x-荧光光谱法（EDX）分析了残炭在浸泡前后的结构变化。结果表明,在超纯水中浸泡得到磷酸根离子;在80℃温度下,震荡提取72小时后,提取液中磷酸根离子浓度达到最大值;提取后残炭中磷含量显下降,P-O-P和P-O-C结构的吸收峰显著减小。说明,残炭中大部分的P-O-P和P-O-c键水解成磷酸根,残留的P可能进入残炭的环状结构或与环状结构直接相连。     

离子色谱法测定大气中的氮氧化物

为简便、快速地测定空气中氮氧化物的含量,建立以内含质量分数为0.9%过氧化氢的混合溶液(混合溶液由2.2 mmol/L的Na2CO3和2.7 mmol/L的NaHCO3组成),混合溶液为吸收液,吸收大气中的氮氧化物,使大气中的氮氧化物全部转变为硝酸根.用离子色谱法测定表明,吸收剂中硝酸根在0.1～60μg/mL的浓度范围,峰面积与浓度之间呈良好的线性关系,回归方程为Y=779563X 7021,相关系数为0.9996,检出限为0.002μ/g/mL.此方法简便、快速、准确、选择性好,对环境无二次污染,完全满足环境监测对大气中氮氧化物的测定.     

党参对鸡肝和胸肌中部分矿物元素含量的影响

目的:观察不同剂量党参对青脚麻鸡肝和胸肌中矿物元素含量的影响.方法:选取2周龄青脚麻鸡400只,随机均分4组,分别饮用党参提取物大(2 g/L)、中(1 g/L)、小(0.5g/L)剂量组和对照组(饮用自来水),连续饮用6周.第8周末各组随机抽样8只,雌雄各半,心脏采血处死,取肝脏和胸肌测定其部分矿物元素的含量.结果:与对照组比较,党参给药组能不同程度的降低肝脏中铁、镁、磷的含量,高剂量组能增加肝脏中锌、钙的含量(P＜0.01),增加胸肌中铁、锌、钙、镁的含量,降低磷的含量,高剂量作用明显(P＜0.01).结论:青脚麻鸡饮水中加入党参提取物,对肝脏和胸肌中矿物元素的沉积有一定影响.     

不同生境中的中华结缕草(Zoysia sinica Hance)和白茅(Imperata cylindrica(Linn.) Beauv.)在生长初期氮磷营养分配

对铜陵杨山冲铜尾矿废弃地和同区农田系统、安徽大学校园、合肥旱地四种生境中的中华结缕草和白茅的根、茎、叶器官中氮(N)、磷(P)浓度进行测定分析。结果表明:中华结缕草和白茅这两种植物的根、茎、叶中氮和磷的含量存在显著差异性(P<0.05),植物体内养分的浓度在物种之间有较大的差异。四种生境下两种植物体内氮和磷浓度均表现为叶>茎>根。两种植物各器官中磷的含量均低于氮的含量。铜尾矿中中华结缕草和白茅各器官内氮磷含量均低于其它三种生境,其中叶片的差异最少,表明它们已适应尾矿废弃地极端的营养贫瘠环境,以较小的养分要求完成了自身的生理生长过程。     

低磷水稻根表铁膜形成对养分吸收的影响

目的:分析水稻根表铁膜形成及其对水稻养分吸收的影响.为水稻施肥提供参考.方法:本试验以3种不同类型的水稻品种:磷敏感型水稻通粳981(TJ981)、耐低磷水稻郑旱6(ZH6)和根系扩展型水稻镇稻99(ZD99)为材料,采用营养液培养法,研究低磷(CK:LP=25:1)导致根表形成铁膜,营养元素(Fe、Cu、Mg、Ca、Zn、K等)在植株机体内的积累,以及根表铁膜对根系吸收营养元素的影响.结果:低磷处理水稻根系表面形成红棕色的铁膜,不同基因型水稻品种根表铁含量(以DCB-Fe含量计)存在差异,且铁膜的形成是不可逆的;水稻体内Fe含量显著增加;Cu在根部组织中含量显著增加,但地上部分变化不明显;其它元素(Mg、Ca、Zn、K)在不同水稻品种或同一品种的不同组织中的含量变化不一.结论:低磷导致根表铁膜的形成,且铁膜可促进水稻体内铁、铜含量的增加,但其对其它营养元素的吸收影响并未呈现一定的规律性.     

贵阳学院几种校园绿化植物根际土有效磷含量

以贵阳学院9种校园绿化植物为研究对象,采用0.5mol/L NaHCO3浸提—钼锑抗比色法,分别对其根际土壤有效磷含量进行测定.结果表明:校园内八角金盘(Fatsia japonica (Thunb.) Decne.et Planch.)等9种绿化植物根际土的有效磷含量处于中等水平.常绿灌木、落叶灌木和落叶乔木三种生态类型绿化植物的根际土有效磷含量和pH值具有相同的变化趋势,均表现为落叶灌木＜常绿灌木＜落叶乔木.绿化植物根际土有效磷含量在落叶乔木与常绿灌木和落叶灌木与落叶乔木间均存在显著差异(P＜0.05),而在常绿灌木和落叶灌木间无显著差异(P＞0.05).对生长发育期的校园绿化植物施用磷肥时,不同生态类型植物的施肥量应区别对待,建议灌木类植物较乔木类植物相对多施,而常绿类植物又较落叶类植物要相对少施.     

根的溢泌物与根际微生物关系的研究

从山西长治不同区域分布的松树、柏树、苹果树的根际及耕种 2 0年以上的耕地里 ,在不同的季节、不同深度采集土壤样品 .采用稀释混合平板法分离培养和活菌计数 ,研究了根际微生物种群与植物根溢泌活动之间的相互关系 .松树、柏树根际微生物种类和数量 ,在不同季节、不同土壤深度差别不显著 .苹果树根际、耕地土壤中微生物无论从种类和数量上 ,均与季节变化、土壤深度有相关性     

土壤中有效磷快速测定方法的研究

采用试纸法测定土壤中有效磷的含量,通过加入钼酸铵、酒石酸钠、抗坏血酸和硫酸的量对显色结果影响进行了研究,并利用组装的便携式磷酸根测定仪对土壤中有效磷测定方面的应用进行了探索。结果表明:试纸法检测范围为0.1~1.2μg/m L,基本能满足常规土壤中有效磷的快速测定;组装的便携式磷酸根测定仪测得的磷标准曲线线性关系较好,其相关性R2为0.9995,因此可准确的测定土壤中磷酸根浓度,进而快速求得土壤中有效磷含量。     

不同生境中的中华结缕草(Zoysia sinica Hance)和白茅(Imperata cylindrica(Linn.)Beauv.)在生长初期氮磷营养分配

对铜陵杨山冲铜尾矿废弃地和同区农田系统、安徽大学校园、合肥旱地四种生境中的中华结缕草和白茅的根、茎、叶器官中氮(N)、磷(P)浓度进行测定分析.结果表明:中华结缕草和白茅这两种植物的根、茎、叶中氮和磷的含量存在显著差异性(P＜0.05),植物体内养分的浓度在物种之间有较大的差异.四种生境下两种植物体内氮和磷浓度均表现为叶＞茎＞根.两种植物各器官中磷的含量均低于氮的含量.铜尾矿中中华结缕草和白茅各器官内氮磷含量均低于其它三种生境,其中叶片的差异最少,表明它们已适应尾矿废弃地极端的营养贫瘠环境,以较小的养分要求完成了自身的生理生长过程.     

硫氰酸亚铜产品纯度的测定

分别采用佛尔哈德返滴定法和间接碘量法测定了由废液制得硫氰酸亚铜产品中硫氰酸根和总铜的含量。硫氰酸根的待测试液由样品与NaOH溶液通过加热反应制备;测定总铜的试液分别采用硫酸—硝酸和过氧化氢—硝酸与样品反应制备,实验结果表明,用两种方法制备铜试液所测得的总铜含量无差异。所提出的用过氧化氢—硝酸制备总铜试液的方法较硫酸—硝酸制备方法具有方便、快捷的优点。     

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!     

胡主席在印度,我却在中国

Today, Sunday morning, I sit thinking and typing at my computer. My thoughts are in my homeland, India and my body is in China. The body is here and mind there for a good reason. Mr. Hu is president and I am resident and both are in each other's countries (what a difference the absence of one small letter makes!). Mr. Hu will return in a few days and I will stay on longer.