共查询到20条相似文献，搜索用时 62 毫秒
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EM和高分子絮凝剂对庆大霉素生产废水进行处理，结果显示单独使用EM时最佳的接种量是0．3％～0．4％，pH为8，处理时间为36小时，处理温度取自然温度(室温)，经正交实验最佳组合为B3A3C1，即最佳的温度为30℃，最佳接种量为0．5％，最佳pH为5。处理后COD从20000mg／L降至1000mg／L左右，经高分子絮凝剂处理最佳的pH为8.／10000的絮凝剂聚丙烯酸钠加量为0．75～1．0mL／250mL废液，沉降时间为1．5～2．0h，主要污染指标COD降低到了350mg／L，达到了国家排放标准(≤350mg／L)。 相似文献
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聚合硅酸氯化铝的制备、结构和性能研究 总被引：4，自引：0，他引：4
制备了聚合硅酸氯化铝絮凝剂(PASC)，其制备条件为常温，常压，反应时间3～4h。pH值3．0～3．5，产物Al2O3含量8．0％～10．0％，SiO2含量1．0％～2．0％。红外光谱证实聚铝离子与聚硅离子间存在着一种非离子性的键合作用，说明形成了聚合度更大的无机高分子聚合物。应用实验表明PASC较PAC的絮凝效果更好，稳定性更高。 相似文献
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维生素C对苹果多酚氧化酶活力的影响 总被引：4，自引：0，他引：4
本文探讨了抗坏血酸在不同温度、酸度和浓度条件下对苹果片中多酚氧化酶活力的抑制效果。结果表明，该酶活力在1．O％～1．5％的抗坏血酸溶液中显著降低，1．O％抗坏血酸在pH3或pH4的条件下，能显著降低酶的活力，在50～60℃范围内15min能显著降低酶褐变。 相似文献
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灿烂甲酚蓝标记分光光度法测定核酸 总被引：3，自引：0，他引：3
研究了灿烂甲酚蓝与小牛胸腺DNA相互作用，提出了测定ctDNA的新的光度分析法。室温、pH8．1tris-HCl的条件下，ctDNA的加入使灿烂甲酚蓝在其最大吸收波长636nm处的吸光度明显下降，下降的程度与ctDNA的含量呈线性关系，ctDNA质量浓度在0～3．0μg／ml范围内与△A呈线性关系，线性回归方程为△A=0．0032 0．0984C(μg/ml）(r=0．9987)，方法的检出限（3σ／k)为0．125μg/ml。该方法具有仪器简单，快速，选择性好等特点，对合成样品中ctDNA测定，RSD％=1．5～1．9，回收率在101％～104％，结果令人满意。 相似文献
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以乙腈-甲醇-0．05mol／L磷酸二氢钾溶液（10：20：70）（用磷酸调节pH值为4．0）为流动相．采用迪马钻石C18（250mm×4．6mm，5μm）色谱柱及紫外检测器，建立了甲钴胺注射液中甲钴胺含量的反相高效液相色谱检测方法．柱温：40℃：检测波长为264nm；流速：1．0mL／min．本方法测定的日内精密度为0．59％，日间精密度为0．67％，回收率为99．7％～100．5％，在160～240μg／mL范围内线性关系满足要求（r=-0．9999）；结果表明方法准确、操作简单、专属性强，可用于定量测定甲钴胺注射液含量． 相似文献
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高砷酸性废水除砷新工艺 总被引：3，自引：0，他引：3
刘琦 《洛阳工业高等专科学校学报》2005,15(1):10-11,27
对高含砷废水(砷含量为10000mg／L左右)采用分步、催化氧化后絮凝沉淀的处理方法。一步处理：采用石灰乳，调pH=3～4去除SO4^2-；二步处理：采用NaOH溶液使PH=9～10的范围，回收重金属；三步处理：加入催化剂-活性炭和Fe^2 通入空气氧化，使溶液中的As(Ⅲ)和Fe^2 氧化成As(V)和Fe^3 ，然后用石灰乳控制pH=6-9，使高价砷酸根与Fe^3 生成难溶的FeAsO4沉淀。经过上述处理后溶液中的砷小于0．5mg/L。 相似文献
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微波法从马铃薯渣中提取果胶工艺的研究 总被引：15，自引：0，他引：15
以马铃薯渣为原料，在微波条件下，用稀硫酸溶液萃取、硫酸铝沉淀提取果胶．探讨了液料比、微波功率、加热时间、提取液pH值、饱和硫酸铝用量、盐析pH值、脱盐液用量和脱盐时间对果胶产率的影响．通过单因素实验确定最佳工艺条件为：液料比15ml／g、微波功率595w、加热时间6min、提取液pH值2．0、饱和硫酸铝用量4．0ml、盐析pH值5．0、脱盐液用量200．0ml、脱盐时间40mim．在此条件下，果胶产率为25．0％． 相似文献
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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
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《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
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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. 相似文献
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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. 相似文献
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RUZBEHANI Mohsen 《重庆大学学报(英文版)》2004,3(1):20-25
1.IntroductionOne-cyclecontrolmethod,whichwasproposedaboutonedecadeago[1],hasbecomeanattractivemethodinspecialfieldssuchaspowerfactorcorrection[2-6],switchingamplifiers[7,8],etc.Themainideaofthiscontrollerisbasedonintegrationofdiodevoltageinone-cycleandforcesittobeexactlyequaltothereferencevalue.Themainadvantageofthiscontrollerisitsrealtimeabilitytorejectthevariationofinputvoltage[1].Despitethisgreatability,ithasnogoodperformancesinrejectingofloaddisturbanceandfollowingreferencecommands.Espec… 相似文献
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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
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YANGShiguo 《重庆大学学报(英文版)》2004,3(1):86-88
The problem on the geometrc inequalities involving an n-dimensional simplex and its inscribed simplex is studied. Aninequality is established, which reveals that the difference between the squared circumradius of the n-dimensional simplex andthe squared distance between its circumcenter and barycenter times the squared circumradius of its inscribed simplex is not lessthan the 2(n-1)th power of n times its squared inradius, and is equal to when the simplex is regular and its inscribed siplex is atangent point one. Deduction from this inequality reaches a generalization of n-dimensional Euler inequality indicating that thecircumradius of the simplex is not less than the n-fold inradius. Another inequality is derived to present the relationship betweenthe circumradius of the n-dimensional simplex and the circumradius and inradius of its pedal simplex. 相似文献
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Rajesh Kanoi 《海外英语》2007,(1):52
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. 相似文献