Fe_2(SO_4)_3·xH_2O催化酯化反应及其在酯内残留的研究

本文对用Fe2（SO4）3·xH2O做催化剂催化酯化反应进行了研究,首次报道了Fe2（SO4）3·xH2O在酯内的残留问题,为使用及改进Fe2（SO4）3·xH2O做为实用催化剂提供帮助．     

几种改性活性氧化铝颗粒吸附剂除氟实验研究

采用几种铝盐与铁盐,对相同粒径的颗粒活性氧化铝进行了吸附剂改性,并以优选了的改性方案为基础,研究了不同吸附剂粒径对吸附效果的影响。结果表明,活性Al2O3经改性后的静态吸附量是未改性的1.5～2倍;动态试验中,改性活性Al2O3的穿透时间为1.5～3.3d。用Al2(SO4)3和Fe2(SO4)3改性活性Al2O3的除氟效果较好。Φ1～2mm改性活性Al2O3的除氟性能远比Φ2～3mm改性活性Al2O3的好,前者的静态吸附量是后者的1.5倍左右,动态试验中,前者的穿透时间为11d,远长于后者(3.3d)。     

高中实验化学中硫酸亚铁铵制备的最佳条件研究

探究了新课改高中实验化学中硫酸亚铁铵制备过程中的试剂用量（硫酸和硫酸铵）对产品产量和纯度的影响。实验结果表明：制备硫酸亚铁铵的原料Fe和H2SO4的物质的量比控制在0．6-0．8的范围内生成的产品的产率和纯度都较高;原料（NH4）2SO4与Fe的物质的量比控制在1．1-0．9之间其产品产量和纯度较高。综合考虑产量和纯度,其最佳试剂量为：n（Fe）／n（H2SO4）在0．7左右,n[（NH）4SO4]／n（Fe）在1.0左右,在此条件下,铁的转化率达到97．3％,产品中硫酸亚铁铵的纯度为98．3％。     

锆改性颗粒活性氧化铝饮用水除氟研究

对锆改性颗粒活性氧化铝(Zr-GAA)的改性条件进行了研究,并对Zr-GAA的除氟性能进行了评价。结果表明,制备Zr-GAA锆的最佳质量浓度为2.0 g/L,此时锆的负载量为32.58 mg/g;Zr-GAA的吸附平衡时间为180min,吸附速率比GAA提高25%以上;Zr-GAA在低浓度下对氟离子吸附量提高显著,在氟离子的平衡浓度为1.0mg/L时,其吸附量为GAA的5.25倍;Zr-GAA的适用p H范围为4.5~9.7,较GAA明显增大;SO2-4和HCO-3对ZrGAA吸附量的影响较大。     

含铁分子筛从含氟水中深度分离除氟研究

以5°A分子筛为载体在FeC l3溶液中吸附Fe3 ,可使分子筛得到改性及改性后分子筛在含氟水中的除氟性能,获得了一种新的配体交换固液分离深度除氟材料。实验研究了该种含铁改性分子筛除氟材料在高氟水中的除氟效率和条件。结果表明,分子筛对F-离子有良好的吸附性能,在含氟4~40mg/L左右的水中,除氟率可高达99.0%以上,可使水中氟含量降至0.01mg/L以下。经测定,改性分子筛对氟的静态饱和吸附容量可达21.4mg F-/g-分子筛;水中常见共存离子对氟的吸附率无影响,表现出该种材料对氟吸附的高度选择性。提出了一种对含氟地下水和工业氟污染水的效果显著的深度除氟方法。     

电絮凝-微滤去除饮用水中的氟

饮用水中的氟离子对人体具有重要意义。该文采用电絮凝-微滤组合工艺技术,去除饮用水中超量的氟离子,并探讨电流密度、极板间距、pH值对除氟效果的影响。实验表明:电絮凝-微滤组合技术除氟效果明显;水中氟离子浓度的对数值与反应时间呈线性关系。所研究的电絮凝反应器的最佳工作参数为:电流密度σ=15.8 A/m2,极板间距d=1.0 cm,pH值在5.7～7.0范围内。水中SO42-和PO43-离子的存在会影响除氟效率,而阳离子Fe3 、Mg2 、Ca2 在一定程度上促进除氟反应的进行。     

电絮凝-微滤去除饮用水中氟

饮用水中的氟离子对人体具有重要意义,该文采用电絮凝-微滤组合工艺技术,去除饮用水中超量的氟离子,并探讨了电流密度、极板间距、pH值对除氟效果的影响。实验表明,电絮凝-微滤组合技术除氟效果明显。水中氟离子浓度的对数值与反应时间呈线性关系。所研究的电絮凝反应器的最佳工作参数为:电流密度σ=15.8A/m2,极板间距d=1.0cm,pH值在5.7～7.0范围内。水中SO24-和PO43-离子的存在会影响除氟效率,而阳离子Fe3 、Mg2 、Ca2 在一定程度上促进除氟反应的进行。     

活性氧化铝处理含氟地下水

综合比较了不同活化剂对Al2O3除氟能力的影响，从而选定Al2（SO4）3为活化剂；并对活化和再生方法进行了研究，提出了最佳的活化和再生工艺参数：对于Al2O3使用前的活化，采用4％Al2（SO4）3以滤料／活化剂=1：1的体积比活化4h即可取得良好的效果；而Al2O3吸附饱和后，再次使用前要再生以恢复其除氟能力，对于本试验使用的Al2O3采用4％Al2（SO4）3再生2h即可取得良好的再生效果。     

硫酸铁改性活性氧化铝除氟性能及机理探究

采用浸渍法制备质量分数为1.0%、2.5%的硫酸铁溶液改性活性氧化铝（1.0% Fe₂（SO₄）₃-MGAA、2.5% Fe₂（SO₄）₃-MGAA）,根据吸附等温实验和吸附动力学实验研究其对氟的吸附性能,从BET表征、零质子电荷点（pH_zpc）和pH缓冲强度等角度探讨吸附剂除氟机理。实验结果表明：活性氧化铝GAA、1.0% Fe₂（SO₄）₃-MGAA、2.5% Fe₂（SO₄）₃-MGAA 3种吸附剂除氟的吸附等温线均更好地符合Langmuir吸附,最大吸附量分别为8.78、14.08、16.78 mg/g,对20 mg/L高氟水去除率分别为34.5%、54.5%、66.5%;3种吸附剂对水中氟的吸附动力学符合准二级吸附速率方程;改性活性氧化铝表面存在的SO₄^2-和OH^-与F^-发生离子交换作用,SOFe²⁺与F^-产生配位作用,并存在一定的静电作用。改性后活性氧化铝pH缓冲强度均显著增强,数据分析发现pH缓冲强度与吸附性能呈正相关,因此可以从pH缓冲强度的角度初步预测改性效果。     

Fe3O4复合粉体的制备及其对重金属离子的吸附性能

本文研究了Fe3O4复合粉体的制备及其对重金属离子的吸附性能。采用溶剂热法合成出磁性Fe3O4纳米粉体,通过改进的St?ber法和沉淀聚合法对Fe3O4颗粒进行包覆SiO2和PMMA修饰,在氨基改性后进行了重金属离子的吸附测试。采用扫描电子显微镜（SEM）、X-射线衍射仪（XRD)和傅里叶变换—红外光谱（FTIR）对所制备的颗粒进行了组成、结构和形貌表征;通过紫外-可见分光光度仪（UV-vis）测定离子浓度来评价复合颗粒对金属离子的吸附性能。结果表明,制备的黑色Fe3O4粉体为尖晶石结构,室温下具有超顺磁性,有很好的磁分离性能;包覆后,得到了均匀、完整的复合微球,粒径大约800 nm;室温下,当pH=6时,微球在2.5小时时对Cu2+的最大吸附容量约为170 mg/g;当pH=7时,微球在2.5小时时对Ni2 的最大吸附量达到72 mg/g。     

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.     

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