高SiO2含量硅溶胶/聚丙烯酸酯复合乳液的制备

用硅溶胶、丙烯酸酯类单体，以过硫酸钾为引发剂，配以适当的乳化剂，采用乳液聚合法制成了高SiO₂含量硅溶胶-聚丙烯酸酯复合乳液。系统的研究了温度、乳化剂种类及用量、单体SiO₂质量比等因素对乳液稳定性的影响。结果表明：75℃为最佳反应温度；十二烷基硫酸钠(SDS)为最佳乳化剂；当SDS质量分数为0.45%～0.7%、单体SiO₂质量比为3时，可制得SiO₂质量分数为10%的复合乳液，且乳液的稳定性达到使用要求，此法制得的复合乳液的涂膜水白性较共混改性乳液（硅溶胶和纯丙乳液）和纯丙乳液的涂膜有显著的提高；TEM图片显示，复合乳液中，硅溶胶粒子是以纳米SiO₂粒子存在的，且在复合乳液中比在共混改性乳液（硅溶胶和纯丙乳液）中分散的更均匀。     

有机硅-丙烯酸酯共聚乳液的制备和性能研究

用γ-甲基丙烯酰氧丙基三甲氧基硅烷(MATS)与丙烯酸酯类单体进行乳液共聚，制备了有机硅丙烯酸酯共聚乳液．考察了聚合方法和有机硅单体含量对聚合过程稳定性的影响，详细讨论了有机硅单体用量对乳液粒径大小和粘度的影响，采用PCS跟踪了聚合过程的粒径大小，并对粒子形态采用TEM进行了表征．实验表明．采用种子乳液法时，乳液的聚合稳定性良好．聚合过程中乳胶粒径逐步增加．随MATS用量的增加．乳液的聚合稳定性变差，乳胶粒的平均粒径增加，乳液的粘度增大．乳胶粒子呈球形，粒径分布较窄。     

电极添加剂Nafion乳液对离子膜燃料电池放电性能的影响

离子交换膜燃料电池作为一种理想的氢能发电装置，是目前氢能研究开发的热点。用实验方法研究了电极添加剂Ｎａｆｉｏｎ乳液对离子交换膜燃料电池电化学性能的影响。实验结果表明，在电极中加入适量的Ｎａｆｉｏｎ乳液可以显著地提高电极的电催化反应活性。当电极中Ｎａｆｉｏｎ乳液的含量为３％￣５％时，燃料电池的放电电压和电流密度者处于高峰值状态。实验结果还发现，用不同方法配制的Ｎａｆｉｏｎ乳液对燃料电池放电性能的影响     

PSt／P（BA－BOA）复合乳液性能的研究

以丁氧基甲基丙烯酰胺（ＢＯＡ）为活性单体，采用种子乳液聚合方法制备了ＰＳｔ／Ｐ（ＢＡ－ＢＯＡ）〔聚苯乙烯／聚（丙烯酸丁酯－丁氧基甲基丙烯酰胺）〕核壳型复合乳液．用透射电子显微镜观察了乳液粒子的微观状态，采用粒度分析仪测定了乳液粒子的粒径及其分布，对乳液的流变性能进行了测试．考察了聚合方式、乳化剂用量对乳液性能的影响     

生物酶催化木素与酚共聚反应的研究

用过氧化物酶在微乳液中催化木质素与酚的聚合反应。结果表明，在微乳液系统中酶催化聚合反应速率很大。     

聚丙烯酸酯/TiO2纳米复合乳液的研究

以丙烯酸酯为原料、纳米TiO2粉体或浆料作为改性剂，采用不同改性工艺，制备丙烯酸酯／TiO2纳米复舍乳液，研究各种因素(反应温度、原料组成、配比和其它添加剂)对乳液性能的影响。结果表明：以油酸作为纳米粉体TiO2的表面改性剂，可明显改善复合乳液的各种性能；各种改性方法中，表面改性效果最佳；表面改性剂(油酸)的用量为(0．15—0．25)％时，复合乳液及其涂膜的性能最佳；表面改性的纳米粉体TiO2对复合乳液的改性效果优于直接用纳米浆料混合所得的纳米复合乳液。     

室温自交联含氟乳液的制备及涂膜性能

采用半连续乳液聚合方法制备了一种室温自交联合氟乳液，对影响含氟乳液涂膜性能的因素如N-MA含量(质量分数，下同)、成膜温度、含氟单体的用量及涂膜厚度等进行了分析．采用DSC法对乳液涂膜的玻璃化温度进行了测定，用Wilhelmy方法对膜的表面性能进行了表征，并通过人工加速老化实验来考察膜的耐老化性能．结果表明，所制得的乳液的性价比优于市场上的含氟乳液。     

PSt／P（BA—BOA）复合乳液性能的研究

以丁氧基甲基丙烯酰胺为活性单体，采用种子乳液聚合方向制备了ＰＳｔ／Ｐ（ＢＡ－ＢＯＡ）「聚苯乙烯／取（丙烯酸丁酯－丁氧基甲基丙烯酰胺）」核索型复合乳液。用透射电子显微镜观察了乳液粒子的微观状态，采用粒度分析仪测定了乳液粒子的粒径及其分布，对乳液的流变性能进行了测试。     

NP/DBS混合乳化剂对苯丙乳液性能的影响

分别采用丙烯酸丁酯和苯乙烯作为软硬单体，NP和DBS的混合乳化剂作为乳化体系，采用过硫酸钾作为引发剂，并引入功能性单体甲基丙烯酸，用半连续种子乳液聚合工艺来制备苯丙乳液．在聚合过程中改变加入的乳化剂量．研究了乳化剂对苯丙乳液的平均粒径、稳定性、吸水率、粘度和流变性等性质的影响．研究结果表明随着乳化剂用量的增大，乳液胶粒的平均粒径减小，而乳液的粘度和胶膜的吸水率却增大．乳液的稳定性受乳化剂中非离子乳化剂和阴离子乳化剂的质量配比影响较大，而乳液的流变性则与乳化剂的浓度无关．并对乳化剂对乳液性质的影响原因进行解释和分析．因此，在制备不同用途的苯丙乳液时，必须要严格控制乳化剂的浓度及配比．     

加料方法的不同对阴离子型聚氨酯乳液性能的影响

加料方法的不同直接影响到合成产物的结构，从而决定其产物具有不同的性质，用一步预聚体法和二步预聚体法合成了阴离子型聚氨酯乳液并研究其乳液粒径及乳胶膜的耐水性和力学性能方面的差异，研究结果表明二步预聚体法合成的乳液粒径较小，且其成膜物的耐水性及抗张强度，断裂伸长率者优于一步预聚体法合成的乳液。     

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.     

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.     

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.     

A computer generator for randomly layered structures

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

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

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