纳米氧化锌粉的表面改性研究

以Zn(NO3)2·6H2O和CO(NH2)2为原料,采用均相沉淀法制备纳米氧化锌粉.用扫描电镜对产物粒度大小、形貌进行观察,并对其影响因素进行了探讨.结果表明,在反应温度为120℃,反应时间为2.5h时,所制的纳米氧化锌的产率最大.用不同的表面改性剂对纳米ZnO进行表面改性,粉体不再发生团聚.图6,表7,参5.     

纳米氧化锌粉体的合成

以Zn(NO3)2.6H2O和NH3.H2O为原料 ,采用直接沉淀法合成纳米氧化锌粉体 ,考察了反应温度、反应物配比、pH值、表面活性剂等因素对产物质量的影响 ,获得最佳工艺参数。用XRD、TEM对产物进行表征 ,结果表明 :产物为六方晶系 ,呈不规则柱状结构 ,平均粒径在70纳米左右 ,分散性良好。     

正交法选择纳米氧化镁的最佳合成条件

通过正交实验法,研究了直接沉淀法合成纳米氧化镁的诸因素对粒径和收率的影响.结果表明,在有表面活性剂TX—10的条件下,最佳反应物浓度MgCl2为1.2mol/L、NH3·H2O为0.2mol/L,反应温度为45℃,反应配比MgCl2∶NH3·H2O为1∶10,表面活性剂量为1.5‰和反应时间为25min时,得到的纳米氧化镁分散性好、收率高、粒径小且均匀.     

化学沉淀法制备纳米钛酸钡粉体

以TiCl4、BaCl2和NaOH为原料,采用化学沉淀法,通过控制结晶过程条件,制备纳米钛酸钡粉体,并利用红外光谱、X射线衍射、表面物理吸附和透射电镜对样品进行分析.结果表明,温度是影响颗粒大小的主要因素,制备过程中加入表面活性剂可提高粉体的分散性;采用800℃的煅烧温度可提高粉体的结晶度.在反应温度为80℃、反应时间...     

水热法制备纳米Fe3O4的研究

本实验以尿素、铁盐、亚铁盐等为原料,采用水热法制备了纳米Fe3O4．通过一次回归正交设计研究和讨论了表面活性剂SDS用量、反应温度、反应时间、尿素用量对产物粒径的影响,并通过快速登高法寻优得到了最优工艺条件：表面活性剂SDS用量0．4g、反应温度118℃、反应时间2．1h,尿素用量10g．在最优条件下制备的产物经XRD、TEM和激光粒度分析仪检测得知,产物大部分为球形Fe3O4。平均粒径27nm．     

纳米金红石型二氧化钛粉末的研制

以硫酸法制备钛白粉工艺的中间产物--钛液为原料,采用均匀沉淀法,外加自制晶种为金红石化促进剂,以十二烷基磺酸钠为表面活性剂,尿素为沉淀剂,制备纳米金红石型二氧化钛粒子;研究了反应物浓度、反应物配比、反应温度、反应时间等对粒子粒径及产物收率的影响;利用TEM,XRD,BET,ICP-AES等分析测试技术,对粉体粒子的形貌、粒径、晶型、比表面积和纯度进行表征.研究结果表明所得二氧化钛粒子为金红石型,形貌呈球形,平均粒径达80 nm,产品纯度达99.95%;该制备技术工艺新,生产成本低,工艺操作简单,易于实现工业化,便于用硫酸法生产钛白的厂家在原有工艺基础上对中间产品进行深加工.     

工艺条件对纳米钴粒子的粒径及形貌的影响

以锌粉、氯化钴为原料,用化学沉淀法制备纳米Co粒子。通过正交实验考察了反应温度、搅拌转速、反应时间等工艺条件对Co粒子的粒径及形貌的影响。用透射电镜(TEM)对试样进行了分析。实验表明:在反应物料浓度一定的条件下,Co粒子的形貌主要由反应温度决定;影响粒径的因素主次排序依次为反应温度、搅拌转速、反应时间;为制备不同粒径及形貌的纳米Co粒子提供了依据。     

化学沉淀法制备纳米氧化锆的研究

以氧氯化锆 (Zr OCl2 · 8H2 O)和氨水 (NH3· H2 O)为原料 ,采用化学沉淀法制备了纳米级氧化锆微粉 ,考察了反应温度、反应物浓度、溶液 p H值、煅烧温度和时间对产物粒径的影响 ,获得了最佳工艺条件 .通过透射电镜、X射线衍射研究了产品的粒度、形貌和结构 ,所得纳米 Zr O2 分散性良好 ,粒度分布均匀 ,平均粒径约 2 0 nm,粒子形状为球形     

超细氧化镁的直接沉淀法制备及其表征

通过正交实验法,研究了直接沉淀法合成超细氧化镁的诸因素对粒径和收率的影响,得到了最佳的工艺条件：反应物MgCl2浓度为1.2 mol/L,NH3·H2O浓度为0.2 mol/L,反应温度为45 ℃,反应配比MgCl2∶NH3·H2O为1∶10,表面活性剂量1.5‰,反应时间为25 min.用X-射线衍射、红外光谱、扫描电镜和粒度分析等对最佳条件下制得的MgO进行了表征.结果表明：该法得到的氧化镁分散性好、收率较高（60%）、平均粒径小（330 nm左右）且粒度分布均匀.     

溶剂热合成纳米Fe_3O_4及其性能表征

采用溶剂热还原方法,以FeCl3.6H2O和乙二醇为原料,采用双表面活性剂,在180℃条件下合成了粒径从72 nm到447 nm的纳米Fe3O4粒子,研究了NaAc.3H2O在体系中的作用,探讨了反应时间,铁源浓度和表面活性剂等反应条件对产物的影响.利用X射线粉末衍射(XRD),傅里叶变换红外光谱仪(FT-IR)、透射电子显微镜(TEM)、扫描电子显微镜(SEM)和振动样品磁强计(VSM)对产物进行了分析和表征.结果表明NaAc.3H2O在反应中起着引导产物生成和分散剂的作用,Fe3O4粒径受反应时间,铁源浓度和表面活性剂的影响.合成的Fe3O4粒子显示出高的磁性能,在生物医药方面具有潜在的应用价值.     

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.     

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.     

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.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

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.     

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.     

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.     

橡胶颗粒沥青混合料低温抗裂性试验研究

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.     

A computer generator for randomly layered structures

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

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.