无机抗菌剂和抗菌功能材料的现状和发展

综述了无机抗菌剂的种类、原理和制备方法,介绍了国内外抗菌功能材料的研究现状和动态,对银系和光催化系抗菌功能材料的应用以及发展前景进行了综述.     

无机抗菌剂和抗菌功能材料的现状和发展

综述了无机抗菌剂的种类、原理和制备方法 ,介绍了国内外抗菌功能材料的研究现状和动态 ,对银系和光催化系抗菌功能材料的应用以及发展前景进行了综述。     

多步沉淀法制备纳米无机复合抗菌粉体

目的研究一种以银、钛和锡为组分的新型纳米无机复合抗菌粉体的制备工艺。方法采用多步沉淀法,并通过单因素实验和正交实验确定最优工艺条件。结果最终产品的基本化学组成式为Ag0.03Sn0.16Ti0.35P0.11O0.34;产率达95.5%;粉体平均粒径50 nm;无外加光照、粉体浓度80mg/L时,30 min内其对大肠杆菌、金黄色葡萄球菌和白色念珠菌的抗菌率均达100%;粉体颜色浅,耐候性好。结论该方法制备的粉体具有较强的广谱抗菌效果,解决了银系抗菌剂易变色、对真菌作用效果不佳及钛系抗菌剂必须有光照才能起作用等问题。     

载银无机抗菌剂及其应用

着重介绍了载银无机抗菌剂的抗菌机理、性能指标．目前关于其抗菌机理有两种观点：(1)通过缓释Ag^ 发挥持久的抗菌效果;(2)银作为催化活性中心,产生具有很强的氧化还原作用的羟基自由基及活性氧离子,从而抑制或杀灭细菌．抗菌剂的性能主要通过抗菌能力、安全性、细菌抗药性等指标来反映．本文还简要介绍了沸石抗菌剂、我银磷酸钙抗菌剂、抗菌性羟基磷灰石、磷酸复盐抗菌剂、可溶性玻璃抗菌剂等几种载银无机抗菌剂的生产工艺,并对载银无机抗菌剂在抗菌陶瓷制品、抗菌塑料制品、抗菌纤维制品中的应用进行了讨论．     

自制抗菌剂 GD-1在棉织物上的抗菌性能

用γ-氯丙基三甲氧基硅烷与二乙胺反应,经季铵化反应制得抗菌剂GD-1,并对纯棉织物进行抗菌整理,测试整理后织物的抑菌率、白度、断裂强力、折皱回复角等性能．整理后棉织物对大肠杆菌和金黄色葡萄球菌的抑菌率分别为99.74％和99.37％,自制抗菌剂GD-1的最佳应用工艺为：GD-1用量20g/L ,pH＝6,80℃预烘,120℃焙烘．整理后的棉织物洗涤50次后,抑菌率仍能保持在80.95％左右．     

聚4-乙烯吡啶季铵盐的合成及绿色棉织物的抗菌整理

为了研究聚4-乙烯吡啶季铵盐对棉织物的抗菌性.以4-乙烯吡啶为单体,以无水甲醇为溶剂,以偶氮二异丁腈(AIBN)为引发剂,用溶液聚合的方法合成聚4-乙烯吡啶,用溴代正丁烷将其季铵化,制成季铵盐型抗菌剂,与不同浓度的交联剂配制成季铵盐抗菌整理剂对棉织物进行抗菌整理,以大肠杆菌为致病菌体,采用抑菌圈法测试其抗菌性能.实验结果表明:添加了不同浓度交联剂的抗菌效果不同,当交联剂的浓度为1~2g/L时棉织物的抗菌性能最好.     

银基玻璃抗菌剂/硅胶复合材料的制备与性能研究

以硅胶和玻璃系纳米银离子抗菌剂为原料，采用共混法制备了一系列抗菌剂含量为0.2 wt%～1.0 wt%的银基玻璃抗菌剂/硅胶复合材料，并研究了其耐热性能、力学性能、透过率和抗菌性能.结果表明，添加抗菌剂1.0 wt%的硅胶复合材料，其5%热分解温度位于459℃,较未添加抗菌剂有所提高；拉伸强度和拉伸弹性模量随抗菌剂含量增加而出现略微下降，分别为4.42～3.35 MPa, 1.13～1.02 MPa;透光性测试显示，随着抗菌剂的增加，透光性逐渐下降，但整体保持半透明状态，其中抗菌剂添加量为0.2 wt%样品的透过率为58%;硅胶复合材料抗菌性能测试结果显示，抗菌剂低添加量就可对大肠杆菌起到良好的抑制作用，1.0 wt%抗菌剂添加的样品抗菌率达到了99.68%,且在80℃高温水浴1 h后，其抗菌性能无明显影响.     

沉淀二氧化硅载银抗菌剂的制备及其抗菌性能

以沉淀二氧化硅为载体，吸附硝酸银后，在500℃下灼烧，制备了具有抗菌功能的线银沉淀二氧化硅抗菌剂，并检验了其抗菌性能；还对抗菌剂的抗菌机理进行了初步探讨。测试结果表明，沉淀二氧化硅的载银量在7％以上时，所制备的抗菌剂对绿脓杆菌、大肠杆菌和枯草杆菌的杀菌率达到100％，具有优异的抗菌性能，可用于抗菌塑料、抗菌食品包装、抗菌卫生纸和抗菌纺织制品等领域。     

新型纳米无机抗菌剂TiO2和ZnO的广谱抗菌性研究

 选择了革兰氏阴性细菌、革兰氏阳性细菌、芽孢杆菌、酵母菌和霉菌的代表菌株,采用三角瓶振荡法及纸片扩散法,对2种新型纳米无机抗菌剂:纳米TiO₂和纳米ZnO进行了广谱抗菌性研究,并通过与日本的纳米无机抗菌剂及有机抗菌剂进行比较,结果表明2种新型纳米抗菌剂不仅对所有代表菌株表现出很好的广谱抗菌性能,而且其抑菌能力强于日本无机抗菌剂和有机抗菌剂;在此基础上对相关抗菌剂的抗菌机理进行了分析讨论.     

水性抗菌耐污氟碳涂料的研究

以水性氟碳涂料为基础涂料,添加nano-TiO2/Ag复合型抗菌剂,在金属表面获得了一种抗菌、耐污涂层。详细地研究了复合抗菌剂用量对涂层杀菌率、接触角、耐污性能的影响,确定抗菌剂的含量为3%时,涂层具有良好的耐污、抗菌综合性能。通过对涂层表面形貌的微观表征,证实添加抗菌剂后,涂层表面均匀分布了一层纳米颗粒,使得涂层具有良好的耐污、抗菌性能。通过性能检测,表明制备的水性抗菌、耐污氟碳涂料,具有良好的理化性能,可以用于金属表面的装饰和防护。     

Markedness and its Interpretation in Language Use

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.     

Features of Women's language

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.     

低渗透非均质砂岩油藏启动压力梯度研究

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。     

On Tragic Consciousness In The Works By Ernest Hemingway

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.     

Jane Eyre——A Feminist In The 19th Century

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.     

Achieving Unusual States of Matter Under High Pressure

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-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

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-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

An affordable accurate evaluation of the binding conformations predicted by molecular docking studies in bio-system

Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of