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1.
为获得可用于氨基糖苷类抗生素多残留检测样品净化和富集过程中的固相萃取特异选择性填料,对以阿米卡星为模板,采用沉淀聚合方式制备分子印迹微球的方法进行了研究,并对合成的聚合物微球进行了性能表征.在反应温度为60℃,反应时间为24 h的条件下,优化的合成参数是:模板阿米卡星(AMK)、功能单体甲基丙烯酸(MAA)、交联剂二甲基丙烯酸乙二醇酯(EDGMA)的用量分别为0.05,0.2,1 mmol(物质的量比1∶4∶20),引发剂偶氮二异丁腈10 mg,溶剂为7 mL四氢呋喃和1 mL水.在该条件下,合成的阿米卡星印迹微球中存在不同性质的2类结合位点,高亲和性吸附位点平衡常数为1.244 mmol/L,其最大表观吸附量为85.99 μmol/g;低亲和性吸附位点平衡常数为15.385 mmol/L,其最大表观吸附量为596.48 μmol/g.印迹微球对同为氨基糖苷类抗生素的卡那霉素和奈替米星的吸附量达模板吸附量的78.2%和71.9%,重复使用次数不少于10次,具有直接用作固相萃取柱填料的潜力.  相似文献   

2.
建立了微球形氯嘧磺隆分子印迹聚合物的合成方法.优化了影响聚合物吸附性能的参数,对聚合物微球进行了性能表征.在氯嘧磺隆印迹微球的合成方法中,功能单体为甲基丙烯酸,交联剂为乙二醇二甲基丙烯酸酯,溶剂为乙腈,引发剂为偶氮二异丁腈,当其用量分别为0.25,1.5,5 mmol(物质的量比1:6:20)、30 mL和0.30 mmol时合成的分子印迹聚合物对氯嘧磺隆有最好的特异性吸附能力.运用Scatchard 方程测定了该聚合物的结合能力.结果表明,聚合物中具有两类亲和性吸附位点,高亲和性吸附位点的最大表现吸附量Qmax1为63.46 μmol/g,平衡常数Kd1为0.655 7 mmol/L;低亲和力吸附位点的最大表观吸附量Qmax2为437.085 μmol/g,平衡常数Kd2为11.00 mmol/L.聚合物微球在重复使用9次后吸附性能基本无下降.本制备方法具有无需研磨筛分即可得到分子印迹微球的特点,便于作为固相萃取柱和色谱柱的填料使用.  相似文献   

3.
建立了以沉淀聚合方式制备磺胺脒分子印迹聚合物微球的方法,其中磺胺脒用作模板分子,甲基丙烯酸用作功能单体,二甲基丙烯酸乙二醇酯用作交联剂.对印迹微球的选择性和吸附性能进行了研究.优化的反应物用量是:磺胺脒0.05mmol,甲基丙烯酸0.2mmol,二甲基丙烯酸乙二醇酯1mmol(摩尔比1∶4∶20).在此条件下,溶剂乙腈用量是5mL,引发剂偶氮二异丁腈用量是10mg,在60℃下热引发聚合反应24h,等温静态平衡实验结果表明,该印迹聚合物与相应的空白聚合物相比具有高的选择性和亲和性.Scatchard模型分析结果表明,该印迹聚合物在印迹过程中形成了2类不同的结合位点,高亲和性位点离解常数和最大表观吸附量分别为1.932mmol/L和196.06μmol/g,低亲和性位点离解常数和最大表观吸附量分别为23.843mmol/L和1 449.04μmol/g.印迹聚合物微球重复使用10次吸附性能无显著下降,具有作为固相萃取柱填料使用的潜力.  相似文献   

4.
杨本晓  唐瑾  鲜啟鸣  于红霞 《河南科学》2007,25(6):1047-1051
采用分子印迹技术,以双酚A为模板分子、2-乙烯吡啶为功能单体,通过微球法合成了对双酚A具有高度选择性的分子印迹聚合物(MIPs),以此印迹聚合物为固相萃取填料,试验了聚合物在结构相似底物竞争环境下对双酚A的特异选择性能.通过Scatchard分析,该聚合物对双酚A存在两类不同的结合位点,其中特异性结合的平衡常数达1.78×105 L/mol,表观最大吸附量为7.23μmol/g.固相萃取结果表明:合成的MIPs对双酚A具有高度的特异选择性,为从复杂环境介质中分离富集双酚A提供了一种快速有效的方法.  相似文献   

5.
采用甲基丙烯酸为功能单体,乙二醇二甲基丙烯酸酯为交联剂,合成了具有高选择性的L-帕珠沙星分子印迹聚合物.印迹聚合物对模板分子的结合量明显高于空白聚合物.通过Scatchard分析研究了聚合物的选择结合性能,结果表明:分子印迹聚合物在识别帕珠沙星分子的过程中存在两类结合位点;用多点结合模型进行计算得到高亲和力的结合位点的离解常数Kd,1和最大表观结合常数Qmax,1分别为23.08 μmol/L和3.65 μmol/g,低亲和力的结合位点的离解常数Kd,2和最大表观结合常数Qmax,2分别为0.43 mmol/L和27.28 μmol/g.实验表明,分子印迹聚合物对模板分子的结合量高于其他类似物,呈现出空白聚合物没有的高选择性.  相似文献   

6.
以手性药物左旋萘普生(S-naproxen)为模板分子,四乙烯基吡啶(4-VPy)为功能单体,采用表面印迹法,以介孔材料SBA-15为载体合成了能选择性识别S-naproxen的分子印迹聚合物微球.扫描电镜及孔结构分析结果表明,所合成的分子印迹聚合物微球具有粒径均匀、孔径分布窄、比表面积大等特点;同时扫描电镜、X射线衍射和红外光谱分析结果表明载体表面形成了分子印迹聚合物层,Scatchard分析表明分子印迹聚合物在自组装过程中存在两类结合位点,聚合物高亲和力和低亲和力结合位点的最大表观结合容量分别为Qmax1=2.504μmol/g,Qmax2=16.680μtmol/g;分子印迹聚合物的热力学研究表明,吸附过程可以自发进行.  相似文献   

7.
以安石榴甙为模板分子,丙烯酰胺为功能单体,乙二醇二甲基丙烯酸酯为交联剂,偶氮二异丁腈(AIBN)为引发剂,乙腈为溶剂,使用沉淀聚合方法,制备分子印迹聚合物,得到纳米级微球。等温吸附实验研究表明,印迹聚合物与空白聚合物相比,对目标分子具有更好的吸附性能,在研究浓度范围内,印迹聚合物对目标分子的最大吸附量为32.6μmol/g;Scatchard分析表明,印迹聚合物具有两种不同性能的结合位点,空白聚合物有一种结合位点,印迹聚合物的最大表观结合量为243μmol/g,空白聚合物的最大表观结合量为25.3μmol/g;底物选择实验表明分子印迹聚合物对安石榴甙具有更高的选择性能。  相似文献   

8.
以聚乙烯醇1735为分散剂、利福平为模板分子、甲基丙烯酸为功能单体、乙二醇二甲基丙烯酸酯为交联剂,用水溶液微悬浮聚合法制备了利福平分子印迹聚合物微球;在水溶液中,利用静态平衡结合法和Scatchard分析法研究了印迹聚合物的结合能力和选择性.结果表明,利福平溶液的浓度范围在5×10-5~1×10-4mol/L内,所制得的印迹聚合物内存在两类不等价的结合位点,根据实验数据计算得到高亲和力结合位点的离解常数和最大表观结合量分别为Kd1=1.08×10-2mg/mL和Qmax1=14.40 mg/g;低亲和力结合位点的离解常数和最大表观结合量分别为Kd2=7.18×10-3mg/mL和Qmax2=12.51 mg/g.结合底物的实验结果表明,利福平分子印迹聚合物微球对利福平呈现出了较高的吸附性能和选择识别特性,能较简便地用于利福平的分离和富集.  相似文献   

9.
美托洛尔分子印迹聚合物识别性能的研究   总被引:1,自引:0,他引:1  
采用紫外光引发的分子印迹技术,以美托洛尔为模板,甲基丙烯酸为功能单体,乙二醇二甲基丙烯酸酯为交联剂,成功制备了以美托洛尔(Metoprolol)为模板的分子印迹聚合物.结合底物的实验表明,该聚合物对美托洛尔具有优良的吸附选择性.并通过Scatchard方程研究了印迹聚合物对模板分子的结合特性,结果表明,功能单体甲基丙烯酸与模板分子在自组装过程中通过氢键和离子键形成了2类非等价的结合位点,并计算出2类不同结合位点的离解常数分别为Kd1=2.398×10-4mol/L,Kd2=6.364×10-4mol/L;最大表观结合量Qmax1=58.57μmol/g;Qmax2=86.13 μmol/g;分别为理论吸附量的50.53%和74.31%.  相似文献   

10.
以磺胺嘧啶为模板分子,运用分子印迹技术制备微球形分子印迹聚合物,通过Scatchard模型.求得分子印迹聚合物结合位点的离解常数为8.6μmol/L,最大表观结合量为185.7,μmol/g.分子印迹聚合物的等温吸附线方程符合Longmuir方程.分子印迹聚合物的选择性吸附随着溶剂极性的增加而减小,表明非极性共价键在分子识别中起重要作用.  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

14.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

15.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

16.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

17.
There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.  相似文献   

18.
In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.  相似文献   

19.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

20.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

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