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1.
以壳聚糖/TiO2杂化材料为功能基体,采用分子印迹技术制备了Cu2 印迹杂化膜,并利用红外光谱分析对其进行了表征.吸附选择性研究结果表明:在含等浓度Cu2 、Zn2 和Pb2 的水溶液中,印迹杂化膜表现出对Cu2 具有良好的吸附选择性.通过SAS软件对印迹杂化膜吸附Cu2 的吸附条件进行优化,结果表明最佳吸附条件为:pH约3.6,铜离子浓度99 mg/L,温度60℃,理论吸附率最大响应值为88.97%.  相似文献   

2.
利用响应面法对溶胶-凝胶法制备的壳聚糖/TiO2杂化膜强度的反应参数进行优化,并利用FT-IR、XRD和SEM等方法对膜材料进行表征.在单因素实验的基础上,采用全因子试验法对壳聚糖的量、乙酸的量、钛酸四丁酯和正丁醇混合液的量三因素进行研究.通过对二次项回归方程求解得出三种因素的最佳配比分别是壳聚糖为0.27 g、冰乙酸为11.6 mL、混合液的量为0.54 mL,试验结果表明此条件下杂化膜的强度预测值为1 731 cN,与实验值接近.FT-IR图谱表明杂化膜有新键的产生,改变了原有的结构;XRD分析说明TiO2在杂化膜中为无定型态;SEM图表明杂化膜中有机相和无机相具有良好的相容性.  相似文献   

3.
以壳聚糖、钛酸正四丁酯等为主要原料。通过分子印迹技术制备了Pb^2+印迹杂化膜,并利用红外光谱、TGA对印迹杂化膜的结构进行了表征.研究了溶液中Pb^2+叶。质量浓度、pH、温度三个因素对印迹杂化膜吸附性能的影响,结果表明:Pb^2+质量浓度为100mg/L时,pH=3.5左右,温度60℃的条件下,该印迹杂化膜对Pb^2+有良好的吸附能力.  相似文献   

4.
选用微波场诱导改性磷石膏作为吸附剂,采用批式振荡吸附法研究改性磷石膏对重金属离子Cu2+,Zn2+,pb2+和Cd2+的吸附动力学及吸附热力学特性,提出吸附机理.研究结果表明:微波场改性磷石膏对Cu2+,Zn2+,pb2+和Cd2+的吸附平衡数据符合Langmuir和Freundlich吸附等温方程,但Freundlich方程能够更好地描述吸附等温线.在改性磷石膏对重金属离子吸附的初始阶段,Lagergren伪一级动力学方程、Lagergren伪二级动力学方程、Elovich方程、粒子内扩散模型均能很好地反映吸附模式,而整个吸附过程则遵循Lagergren伪二级动力学方程,其吸附过程是液膜扩散和粒子内扩散共同作用的结果;Cu2+,Zn2+,pb2+和Cd2+的平衡吸附量分别为3.937 0,3.993 6,2.627 4和3.319 0 mg/g;微波场改性后的磷石膏对Cu2+,Zn2-和Cd2+的吸附是吸热反应,对pb2+的吸附为放热反应.  相似文献   

5.
以膨润土为主要原料,碱熔制备A沸石,结合静态吸附实验,研究膨润土、A沸石对溶液中锶的吸附以及吸附过程中动力学和热力学. 结果表明,膨润土、沸石对Sr2+的吸附能力受初始浓度影响,膨润土、沸石在吸附过程中的规律趋势大致相同. 膨润土和沸石对Sr2+的等温吸附过程符合Langmuir等温吸附模型,吸附机制为单分子层的阳离子交换吸附.膨润土和沸石对Sr2+的吸附机制相似,其动力学吸附过程为化学反应控制的拟二级动力学吸附过程. 对吸附前后的膨润土、沸石进行XRD、SEM表征分析,膨润土、沸石在酸性溶液中进行吸附不会对自身骨架结构产生严重破坏或影响. A沸石对Sr2+的吸附量约为膨润土的3.9倍,表现出比膨润土更优秀的吸附能力.  相似文献   

6.
目的确定壳聚糖/沸石分子筛去除氨氮和硝酸盐氮的最佳投加量和最佳吸附时间,并建立吸附模型,同时验证模型的准确度.方法通过响应面(Response Surface M ethodology)试验设计方法,分析壳聚糖/沸石分子筛吸附颗粒对氨氮与硝酸盐氮去除的最佳投加量和最佳吸附时间.结果响应面法优化所得的最佳工艺条件为:壳聚糖/沸石分子筛投加量为6. 5~7. 0 g/L,吸附时间为6. 0~6. 5 h,在此条件下,原水中氨氮与硝酸盐氮的去除率达到最大,分别为80. 2%与40. 5%.试验结果与模型预测值相近,理论值与实测值相对误差均不超过2%.结论响应面法优化壳聚糖/沸石分子筛吸附氨氮和硝酸盐氮工艺参数合理.该新型吸附颗粒制备过程简单,操作方便,并能达到同步去除水中氨氮与硝酸盐氮的效果,可作为新型滤料用于北方地区水厂的提标改造.  相似文献   

7.
固载葡萄糖氧化酶的壳聚糖/二氧化硅杂化膜的制备及表征   总被引:10,自引:0,他引:10  
利用生物相容性良好的天然高分子聚合物壳聚糖(CS)与甲基三甲氧基硅烷(MTOS)通过原位溶胶-凝胶法制备壳聚糖/二氧化硅有机无机杂化复合膜,用此膜对葡萄糖氧化酶进行固定,用红外光谱法、扫描电镜法对膜进行了表征.以电沉积普鲁士蓝的玻碳电极和固定化酶膜构建葡萄糖生物传感器,用循环伏安法和记时电流法对固定化酶的效果进行了评价,结果表明,用于研制固定化酶生物传感器时,杂化膜比单纯的壳聚糖膜对底物的响应时间快并能很好地保持酶的活性.  相似文献   

8.
利用微波辅助Na OH对天然沸石进行改性,在单因素实验的基础上对改性条件进行了优化,得出沸石改性的最优实验条件为:Na OH改性液浓度为0.5 mol/L、微波功率480 W、微波辐射时间5 min.探讨改性沸石对Zn2+的吸附行为.结果表明:改性沸石对Zn2+的吸附能力明显增强.在优化实验条件下对质量浓度为50 mg/L的Zn2+的去除率达95.68%.Langmuir吸附模型比Freundlich吸附模型能更好地模拟改性沸石对Zn2+的吸附过程,吸附动力学方程以准二级动力学方程拟合的效果最优.  相似文献   

9.
制备了几种改性壳聚糖吸附剂,通过优化试验确定了制备改性壳聚糖吸附剂的乙酸/壳聚糖浓度配比及固化碱液条件,并比较了不同吸附剂对Hg2+的吸附性能.以分子印迹法结合交联胺化改性法制备的Hg2+分子印迹改性壳聚糖吸附剂小球(P-C-CTS-ex(Hg0.3))对Hg2+具有最高的吸附容量,在低浓度Hg2+(CHg2+<40mg/L)溶液中,此吸附剂对Hg2+的吸附容量可达9.017 mg/g,比未改性壳聚糖(CTS)的吸附量高出1倍以上.研究还揭示了交联前Hg2+对壳聚糖分子中的活性氨基的保护功能及除Hg2+后的分子印迹作用.循环再生实验表明,P-C-CTS-ex(Hg0.3)经过8个循环以后的吸附容量保持稳定,颜色与外观等基本不变,重复使用性能稳定;而未改性CTS吸附剂经过"吸附-脱附-再生"8个循环后,球体积明显变小,颜色逐渐变黄,吸附容量不稳定.这表明本研究制备的Hg2+分子印迹改性壳聚糖吸附剂的吸附容量和再生性能均明显优于普通壳聚糖吸附剂,具有应用于含Hg废水处理的潜力.  相似文献   

10.
根据人肝金属硫蛋白的基因序列,结合酿酒酵母菌密码子使用规律,改造并合成了可在酵母细胞内高效表达的金属硫蛋白基因,并将该基因转入酵母细胞内进行了表达.以野生型菌株为对照,初步测定了酿酒酵母INVSC1-mt菌株对pb2+的吸附作用.研究结果表明,金属硫蛋白基因的表达有助于提高酿酒酵母细胞对pb2的吸附作用,其最大吸附量比野生型菌株提高了11%.同时,酿酒酵母INVSC1-mt菌株吸附pb2+的速度较快,在30 min时,其吸附率就达到了96.03%,吸附量为5.76 mg/g湿重细胞.而野生型菌株至120 min时,其吸附率才达到90.44%.  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.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
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   

15.
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   

16.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

17.
以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.  相似文献   

18.
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   

19.
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   

20.
Quality traits in wheat (Triticum aestirum L.) were studied by quantitative trait locus (QTL) analysis in a recombinant inbred line (RIL) population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross (ChSh). Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.  相似文献   

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