新型无机高分子絮凝剂的净水作用及性能比较

1引言水处理问题，目前越来越被受到重视。水的处理问题一般有两个方面，一是从天然水体中（河水、湖泊水、地下水等）获得生活用水、工业用水等而须进行的生活用水处理；二是为防止工业废水、生活污水等引起环境水体污染而须进行的废水处理。于1984年4月完成的全国首次工业污染水调查结果指出，由国内40多个工业行业中16．8万家工矿企业所产生的工业废水年排放总量为291．8亿吨，其中仅有28．8％是经过处理后排放的，工业废水中所合污染物的年排放量为2125．9万吨。这表明我国由工业废水造成的水体污染问题还是相当严重，城市污水的治理问…     

化学综合测试题(四)B卷

一、填空题（每空3分，共36分）1．含杂质5％（杂质不含硫）的二氧化硫样品中，硫元素的百分含量为。2．把浓度为60％和10％的两种硫酸溶液混和成20％的溶液，所用两种硫酸溶液的质量比为。3．将含有CO、CO2、H2、N2、HCl的混和气体通过足量的NaOH溶液，充分反应后剩下气体；再通过足量的灼热的Fe2O3，冷却到室温后，剩余气体。4．某元素R的氯化物分子量为m，R的硝酸盐的分子量为n，则R的化合价数值为5．某＋5价非金属氧化物中，非金属元素和氧元素的质量比为7：20，该非金属元素的原子量是。6．根据下图：写出A、B、C、D各物质的分…     

火焰原子吸收光谱法测定五味子、榛蘑、蕨菜中的铜和锌

利用火焰原子吸收光谱法测定了五味子、榛蘑、蕨菜中的铜和锌含量。RSD为0.46％～1．2％，回收率为96．0％～100．4％，该方法简便，灵敏度高，结果准确，可用于中草药中微量元素的测定。     

球衣细菌利用废水积累PHB的研究

研究了在未灭菌的模拟酒精工业废水中，开放式培养球衣细菌时，细菌细胞内积累聚β-羟基丁酸(PHB)的情况．实验结果表明：30℃，摇床培养48h，菌干重达3．08mg／mL，PHB达0．31mg/mL；30℃半连续培养(稀释度D-0．1 h^-1)3天，平均每mL废水获菌干重1．35mg，获PHB0．13mg,在两种培养方式下，废水中糖类物质均被降解50％以上、实验提取的PHB样品的红外光谱吸收峰与PHB标准品相同．     

春施苯磺隆、噻吩磺隆防除麦田大龄杂草试验

小麦返青期喷洒75％苯磺隆19．5g～22．5g／hm^2或15％噻吩磺隆195g～225g／hm^2，对麦田大龄阔叶杂草有较好的防除效果，药后30d株防效39．5％～45．7％，鲜重防效73．3％～77．6％，株高防效77．2％～80．5％，对小麦无不良影响。     

日粮赖氨酸水平对固始鸡生长性能及胴体品质的影响

选择1日龄固始鸡600只，随机分成5个处理组，分别在基础日粮中添加0．00％、0．08％、0．16％、0．24％和0．32％的赖氨酸，研究日粮赖氨酸水平对0～63日龄固始鸡生长性能及胴体品质的影响。结果表明适度提高日粮赖氨酸水平可以提高固始鸡的增重、饲料转化率、全净膛率、胸肌率和腿肌率，且在0～21日龄、22～42日龄和43～63日龄时，日粮中总赖氨酸含量分别为1．00％、0．92％和0．87％较为适宜。     

气相法乙烯－1－丁烯共聚产物结构性能的研究

研究了乙烯－丁烯气相共聚产物结构性质．ＤＳＣ，１３ＣＮＭＲ及密度测定结果表明，共聚物熔点，结晶度，密度随共聚单体１丁烯含量增加而降低，共聚物分子链中丁烯链节摩尔数则随共聚单体丁烯含量增加而增加．当共聚单体１丁烯体积含量为１７％～３８％时，共聚物熔点１２１８～１１７０℃，结晶度３４９％～２２９％，密度０９３８７～０９１３５，共聚物分子链中丁烯链节摩尔含量为１３％～６８％．乙－丁气相共聚物用沸己烷抽提后，其熔点和结晶度升高了，但分子链中丁烯链节减少了，乙烯链节增加了．共聚产物的沸己烷可溶物分子量小，结晶度低，分子链中丁烯链节数大，为无规共聚物     

果树塑料大棚主要生态因子变化规律研究

塑料大棚内光照度(I)与外界光照度的变化趋势基本相似，但棚内低于棚外，透光率晴天在36．5％～49．6％之间，阴天在61．1％～69．2％之间，阴天高于晴天。棚内气温(ta)旬变化范围13．5～26．6℃，0cm地温(ts0)12．5～23．3℃，20cm地温(ts20)9．8～20．2℃，空气相对湿度(RH)55．4％～80．3％。晴天和阴天，I、ta、ts0先升后降，而RH先降后升，峰值和谷值均出现在14时。在不同环境因子的变化中．I起着主导作用，ta、ts0与I呈正相关，RH则与I、ta、ts0呈负相关。ts20在一天内较为平稳少变，与ts0相比受ta影响较小，且随时间的变化也较ta和ts0缓慢。     

毛细管气相色谱法测定面粉中的过氧化苯甲酰

采用毛细管气相色谱法测定面粉中过氧化苯甲酰的含量．方法的线性范围为0．0-500．0Ug／mL，检出限为1．0ng，RSD为0．564％～0．906％，回收率为92．7％-101．3％．该法可用于面粉质量的监测．     

稀土氯化物生产条件的研究

通过对稀土分离的试验，提出了稀土氯化物的生产条件，对产品进行质量分析，结果满意．     

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,     

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.     

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.     

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.     

团图为数的图中的闭团贯数

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.     

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.