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1.
基于四种分子量壳聚糖(72.4,166,305和400kDa)制备了四种羧甲基壳聚糖银噻苯咪唑(Ag-CMCTS-TBZ)水基复合抗菌剂。用傅立叶红外光谱、动力光散射粒度检测和最小抑菌浓度测试对其理化生物性能进行了表征。结果表明,四种水基复合抗菌剂都具备良好的广谱抗菌性能,对大肠杆菌、金黄色葡萄球菌、白色念珠菌的最小抑菌浓度在30~125mg/L,对黑曲霉、毛霉的最小抑菌浓度在100~1800mg/L,但并非表观粒度越小抗菌性能越强。  相似文献   

2.
将锌离子和季铵阳离子依次与蒙脱土进行离子交换反应,制备了新型改性蒙脱土复合抗菌剂,并探讨了其最佳制备工艺条件.所制备的复合抗菌剂中锌离子和十四烷基二甲基苄基季铵阳离子的质量分数分别为2.95%和12.18%.XRD和TG分析结果表明,锌离子和季铵阳离子已交换到蒙脱土中,且复合抗菌剂中季铵阳离子的热分解起始温度约为210℃.文中还研究了复合抗菌剂的抗菌活性,发现其对大肠杆菌(E.coli)、金黄色葡萄球菌(S.aureus)和绿脓杆菌(P.cteyttginosct)等几种典型细菌的最小抑菌浓度(MIC)均小于或等于300mg/L,具有良好的抗菌性能和比较广的抗菌谱;复合抗菌剂在50℃的去离子水中浸泡30h后,仍然保持较好的抗菌活性,显示出优异的耐水性能.  相似文献   

3.
羧甲基壳聚糖银噻苯咪唑的制备及其抑菌性能   总被引:4,自引:3,他引:4  
研究了一种新型广谱复合抗菌剂羧甲基壳聚糖银噻苯咪唑的制备与性能.抗菌实验结果表明:该新型复合抗菌剂能综合其单一组分抗菌剂或二元组分(羧甲基壳聚糖银和羧甲基壳聚糖噻苯咪唑)复合抗菌剂的优点,对大肠杆菌、金黄色葡萄球菌、白色念珠菌、黑曲霉和毛霉等代表性微生物的最小抑菌浓度分别为20×10-6、25×10-6、20×10-6、40×10-6和450×10-6 g/mL,具有优良的广谱抗菌效果;同时,克服了银离子的变色缺陷;银和噻苯咪唑分别与高分子羧甲基壳聚糖中的胺基和羧基发生了键合作用.  相似文献   

4.
采用MTT法等方法研究壳聚糖碘液对白色念珠菌的抑制作用,结果得到壳聚糖碘液的50%抑菌浓度(MIC50)和最小菌浓度(MBC)分别为250 mg/L和600 mg/L。实验结果表明壳聚糖碘液具有良好的杀白色念珠菌效果。  相似文献   

5.
为制备抗菌性能良好的新型高分子抗菌剂,以丙烯酸丁酯(BA)、甲基丙烯酸正丁酯(BMA)与聚六亚甲基盐酸胍功能化单体(M-PHGH),通过乳液聚合反应得到键合型的聚丙烯酸酯高分子抗菌乳液。采用FT-IR、SEM、激光粒度分析仪和最小抑菌浓度等测定方法对乳胶粒子的组成、结构和抗菌性能进行了表征,分别考察不同单体配比、引发剂用量及反应温度对聚丙烯酸酯抗菌乳液聚合反应的影响,探索聚合反应的最佳条件。结果表明,在引发剂用量为0.8 wt%、单体摩尔比为n(BA)∶n(BMA)∶n(M-PHGH)=25∶20∶1、反应温度为70℃的聚合条件下,可得到抗菌性能良好的高分子乳液,乳液对大肠杆菌的最小抑菌浓度为16 mg/L。  相似文献   

6.
载银复合颗粒作为一种重要的功能材料具有广泛的应用前景。本文以二氧化硅颗粒为载体,利用超声波化学镀银方法,制备出银/二氧化硅复合颗粒,并对产品进行了银含量分析和XRD、SEM表征,重点研究了复合颗粒的抗菌性能。通过实验知道载银二氧化硅复合材料对大肠杆菌的最小抑菌浓度分别为0.2g/L-0.3g/L,从实验数据看出,银含量低的对抗菌性能有更好的效果。  相似文献   

7.
粘土-壳聚糖复合吸附剂吸附铬(Ⅵ)离子性能的研究   总被引:1,自引:0,他引:1  
通过壳聚糖与粘土的结合,制备出复合吸附剂,并研究其对Cr(Ⅵ)离子的吸附性能.研究结果表明,与单一的粘土或壳聚糖相比,该吸附剂对Cr(Ⅵ)离子吸附速度快、吸附能力强.吸附除去Cr(Ⅵ)的最佳工艺条件是:壳聚糖与粘土质量比为0.04,pH值4~6,Cr(Ⅵ)离子的质量浓度≤10mg/L,吸附平衡时间为40min,吸附荆用量为8.0g/L.  相似文献   

8.
采用最小抑菌浓度(MIC)和最小杀菌浓度(MBC)首次对纳米In2O3,的抗菌性能进行了研究.试验结果表明,纳米In2O3具有较好的抑菌和杀菌活性,对大肠杆菌的MIC为0.04ms/mL;对大肠杆菌的MBC为0.3mg/mL.时间动力学研究表明,纳米In2O3,与大肠杆菌作用30min后杀菌率达到99%以上.  相似文献   

9.
为避免鱿鱼腐败变质,延长其货架期,以鱿鱼腐败菌为指示菌,测定花椒、大料、胡椒、壳聚糖以及鱼精蛋白的抑菌性能,选取抑菌性较好的保鲜剂进行响应面优化,筛选鱿鱼复合生物保鲜剂最佳配方,并进行平板验证.结果表明大料、壳聚糖和鱼精蛋白对鱿鱼腐败菌具有较好的抑菌效果,花椒和胡椒对鱿鱼腐败菌基本无抑制作用.壳聚糖和鱼精蛋白对鱿鱼腐败菌的最小抑菌浓度(MIC)分别为4.8 mg/mL和2.4 mg/mL.3种抑菌性能较好的保鲜剂对鱿鱼腐败菌抑制效果影响的主次顺序为鱼精蛋白壳聚糖大料,鱼精蛋白和壳聚糖添加量对复合保鲜剂的抑菌性能有极显著影响(P0.01),大料添加量对复合保鲜剂的抑菌性能影响不显著(P0.05).复合保鲜剂最佳配方为:鱼精蛋白2.39 mg/mL,壳聚糖4.8 mg/mL,大料100 mg/mL.平板验证结果显示,等量复合保鲜剂抑菌圈直径达到模型预测值的96.75%,说明获得的模型能够很好的预测复合生物保鲜剂对鱿鱼腐败菌的抑制作用.  相似文献   

10.
银型沸石抗菌剂的制备与性能研究   总被引:4,自引:0,他引:4  
采用离子交换法以4A沸石为载体制备了银/沸石复合抗菌剂,通过XRD、SEM技术对其组织结构和形貌进行了表征,并测试其抗菌性能。考察研究了溶液的初始浓度、pH以及反应温度和时间对抗菌剂载银量的影响,探讨了载银沸石抗菌剂的缓释性能。结果表明:最佳的制备工艺条件为:AgN03溶液的浓度为0.1mol/L,pH值为6~8,反应温度为50℃,反应时间4h,该条件下制备载银沸石抗菌剂的载银质量分数为0.78%,制得的抗菌剂具有良好的抗菌性能和缓释性。  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.
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   

20.
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   

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