用大气压下空气辉光放电对聚四氟乙烯进行表面改性

通过放电的电气特性测量和发光特性观察,界定了空气中大气压下辉光放电(APGD)和介质阻挡放电(DBD)的不同放电特点.用扫描电子显微镜(SEM)观察、接触角测量和X射线光电子能谱分析(XPS)等手段,研究了空气中APGD和DBD对聚四氟乙烯(PTFE)表面进行改性的效果,并分析了APGD和DBD处理效果不同的原因.实验结果表明:PTFE表面经APGD和DBD处理后,其表面微观样貌和表面化学成分均发生变化,且APGD的处理效果优于DBD.APGD可以对PTFE表面进行更为均匀的处理,经APGD处理40s后,PTFE表面的w(O)从0增加到21%,表面的水接触角从118°下降到53°.     

常压等离子体对聚乳酸非织造材料的改性处理

采用常压氩气介质阻挡放电(DBD)等离子体对聚乳酸(PLA)纺黏非织造材料进行表面改性处理,以提高材料的亲水和染色性能.考察了等离子体处理电压对PLA非织造材料的表面形貌、接触角、芯吸高度、表面化学成分、染色性能以及拉伸断裂强力的影响规律.研究结果表明:经氩气DBD等离子体处理后,PLA非织造材料的表面粗糙度明显增加;随着等离子体处理电压的增加,PLA非织造材料的接触角先减小后增加,当处理电压为200 V时,接触角达到最小值,此时材料的芯吸和染色性能的提高最显著.     

介质阻挡放电及其在聚合物表面刻蚀中的应用

介质阻挡放电(DBD)是在大气压条件下产生非平衡等离子体的一种常规技术,在许多方面有着广泛的应用.介绍了笔者自行研制的DBD装置,讨论了使用该装置所产生的常压低温等离子体对聚合物材料表面刻蚀处理后,材料上染率、粗糙化、润湿性、生物相容性和表面形貌等方面的变化.探讨了DBD在这些方面的应用前景.     

DBD等离子体处理对芳纶织物结构性能的影响

为改善芳纶织物增强复合材料的界面黏结性能,采用常压氦-氧介质阻挡放电(DBD)等离子体处理对芳纶织物进行表面改性,研究氧气流量变化对织物等离子体处理效果的影响.通过测试处理前后芳纶织物的表面形貌、结构组成、润湿性能、粗糙度和拉伸性能来表征等离子体的改性效果.结果表明:DBD等离子体处理后,芳纶纤维的表面经过刻蚀,粗糙程度明显增加;纤维的化学组成没有显著变化,仅CO等极性基团有所增加;芳纶织物的润湿性显著改善;拉伸性能略有提高.综合考虑,氧气流量为10mL/min时处理效果较好.     

可伐合金在模拟现场N2/H2O二元气氛下的氧化行为

采用称重法、X射线衍射(XRD)和扫描电子显微镜(SEM)研究了可伐合金(Fe-29Ni-17Co)在模拟现场N2/H2O二元气氛下的氧化行为. 可伐合金在1000℃不同露点的N2中氧化的增重曲线表明其氧化动力学遵循抛物线规律. XRD和SEM分析显示了在上述条件下表面氧化物的组成和形貌. 通过热力学计算说明可伐合金在现场的N2/H2O二元气氛下氧化时,外界空气会渗入炉内增加氧分压,导致表面氧化物中不可避免存在α-Fe2O3. 在露点温度较高和氧化时间较长时,生成α-Fe2O3的数量会超过Fe3O4.     

316奥氏体不锈钢渗N/镀CrN复合改性层组织与性能

分别在400、440、480 ℃下对316奥氏体不锈钢进行12 h的渗氮处理,再对渗氮后的试样进行物理气相沉积(PVD)镀CrN薄膜.采用扫描电镜(SEM)、光学显微镜(OM)、X射线衍射仪(XRD)、维氏显微硬度计和材料表面综合测试仪(HSR-2M)、电化学工作站等对复合改性层的表面形貌、截面形貌、成分、显微硬度、耐磨性以及耐蚀性进行测试.结果表明:400 ℃离子渗N/镀CrN试样耐磨性最差,耐蚀性最好;而480 ℃离子渗N/镀CrN试样耐磨性最好,耐蚀性最差;但比相同温度下单独渗氮试样的综合性能好.     

掺氮可见光响应TiO2-xNx光催化薄膜的制备及性能初探

采用反应磁控溅射法在玻璃基片上制备N掺杂TiO2-xNx薄膜和纯TiO2薄膜,并且对两种薄膜样品分别进行了300、400和500℃的退火处理.采用X射线光电子能谱仪(XPS)、X射线衍射仪(XRD)、扫描电子显微镜(SEM)和紫外-可见光光度计(UV-Vis)对经过退火处理的样品进行了表征.结果表明:成功制备了N掺杂TiO2-xNx薄膜,部分N进入了TiO2薄膜晶格,并且以N-O键形式存在;N掺杂TiO2-xNx薄膜和纯TiO2薄膜相对比,晶型和表面形貌没有什么太大的区别,但通过紫外-可见光吸收谱图可以发现经过400℃退火处理的N掺杂TiO2-xNx薄膜吸收带边从纯TiO2薄膜的400 nm红移到455 nm.     

常压介质阻挡放电等离子体处理纤维的ESR研究

探讨常压介质阻挡放电(DBD)等离子体的反应机理,采用电子自旋共振技术研究经DBD处理的3种典型纺织纤维所产生的自由基.分析比较了不同处理时间,不同纤维含潮率下羊毛纤维中所产生的各种自由基的电子自旋共振谱,以及同一处理条件下不同种类纤维的ESR谱.结果表明,常压DBD等离子体反应能够有效地促成纺织纤维表面自由基的生成.纤维含潮率是平行于等离子体处理时间,纤维大分子结构等参数,是影响自由基产物的重要因素之一.当纤维中的水分含量达到一定程度时,纤维回潮会抑制等离子体处理过程中自由基的生成.     

不同气氛介质阻挡放电等离子体对芳纶表面的改性

为了改善芳纶的表面性能,利用介质阻挡放电,对其表面进行改性.在Ar,Ar/O2,Ar/N2不同气氛介质阻挡等离子体的处理后,探究芳纶表面所产生的不同作用效果机理,同时考察了O2和N2的流量对芳纶表面作用效果的影响.采用了微脱胶法、X射线光电子能谱(XPS)以及原子力显微镜(AFM)分别对处理后芳纶表面黏结性能、表面元素和官能团的变化以及表面粗糙程度的变化进行了比较.结果表明:对芳纶表面的改性是由刻蚀作用还是活性基团占主导与放电气体的种类密切相关,而通入气体的流量也会影响表面改性的处理效果.     

用低氧分压法在35Cr45Ni合金表面制备

在H2-H2O所形成的低氧分压气氛下氧化35Cr45Ni合金,在合金表面形成具有抑制催化结焦能力的氧化膜;用能谱仪(EDS)、X射线衍射(XRD)、划痕仪分析氧化膜的成分、物相组成以及氧化膜与基体的结合状况,用结焦试验评价氧化膜的抗结焦性能,并用扫描电镜(SEM)分析氧化处理和未经氧化处理试样结焦后的表面形貌.结果表明:经低氧分压处理的合金表面铁、镍含量降低,在金属表面形成了以Cr2O3、 MnCr2O4为主要成分的氧化膜,氧化温度为800,900,1000 ℃时氧化膜的临界载荷分别为9.75,15.55,11.6 N,结焦抑制率分别达到了81%,93%,56%;氧化膜可有效抑制丝状催化焦炭的产生.     

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.     

An Analysis of Catherine＇s Character——Wuthering Heights

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.     

Lower Paleozoic oil relationships within Williston Basin, Canada

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.     

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.     

Design and analysis of generic LBS application developing platform

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.     

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