Dissolution behavior of various elements from steelmaking slag into seawater

The mixture of steelmaking slag,soil or sand is a candidate material for the landfill in sea shore to improve the marine environment,because the ferrous ion contained in the steelmaking slag plays an important role in promoting the growth of various seaweeds.However,the dissolution mechanism of various elements from steelmaking slag into seawater is not clarified.To reveal the dissolution behavior of various elements from steelmaking slag into seawater,the dissolution experiment of slag and seawater mixture was conducted at room temperature with changing the basicity of slag and the mass ratio of slag and seawater.It is shown that Mg ion contained in the seawater plays a buffering action obviously on pH increase which is provided by the dissolution of Ca.The dissolution behavior of Si strongly depends on the basicity of slag,at the same time the mass ratio has a conspicuous influence on it for the lower basicity of slag.The dissolution amount of Fe is little and it is discussed by using the solubility diagram.     

双氯芬酸钠缓释片的制备和体外释放度研究

以氢化蓖麻油为骨架材料,乳糖为致孔剂,湿法制粒制备双氯芬酸钠缓释片,并进行体外释放度和稳定性考察。结果表明:该缓释片符合缓释片现行质量标准要求且稳定性较好。     

溶气析出式浮选柱处理含油废水的试验研究

针对含油废水中难分离的细粒级油分，结合溶气气浮技术和柱浮选技术的优点，提出利用溶气析出式浮选柱处理含油废水，研制了溶气析出式浮选柱及液位调节装置，建立了一套试验研究系统，采用十二烷基硫酸钠(SDS)为表面活性剂，聚合铝(PAC)、聚丙烯酰胺(PAM)为絮凝剂，通过系统试验，考察了溶气压力、进水pH值、处理量、回流比、泡沫层厚度、表面活性剂以及絮凝剂投加浓度等因素对除油率的影响，试验结果表明，在优化操作参数条件下，除油率可达90％以上。     

碱处理棉纤维结构及其在LiCl/DMAc中的溶解特性

采用NaOH溶液对棉纤维进行处理。通过X射线衍射研究了不同碱处理条件下棉纤维的晶面结构变化,表征了棉纤维的结晶度和晶粒尺寸。考察了碱处理棉纤维在LiCl/DMAc中的溶解性和溶解稳定性。结果表明碱处理后,棉纤维的晶面结构明显变化,棉纤维衍射峰发生明显的变化,结晶度和晶粒尺寸也有变化,且随碱的质量分数的变化非常明显,而处理温度和时间对这些变化影响不大。经过碱处理的棉纤维可以溶解于LiCl/DMAc中,在LiCl质量分数为10%时,棉纤维可以完全溶解,棉纤维/LiCl/DMAc溶液从第48 h开始产生相分离,数天后溶液开始结冻,形成冻胶,并且析出溶剂。     

Dissolution of konjac glucomannan with room temperature ionic liquids

Two kinds of new room temperature ionic liquids (RTILs), 1-allyl-3-methylimidazolium chloride (AMIMCl) and 1-butyl-3-methylimidazolium chloride (BMIMCl), were synthesized and used for the dissolution of konjac glucomannan (KGM). The experimental results showed that the solubility of KGM in AMIMCl was better than that in BMIMCl. Regenerated KGM were obtained by adding anhydrous alcohol to the KGM / ionic liquids solutions. Solubility, molecular weight, structure, and thermal property of the regenerated KGM were investigated by polarized optical microscopy (POM), viscosimetry, infrared spectroscopy (IR), X-ray diffraction technique (XRD), thermogravimetry (TG) and differential scanning calorimetry (DSC). It was demonstrated that the viscosity-averaged molecular weight of the KGM samples decreased after regeneration because of the molecular degradation of KGM. Results from IR and XRD indicated that the chemical structure and the crystalline form of regenerated KGM were not changed. Results from TG and DSC showed that the thermal stability of the regenerated KGM samples only slightly decreased. These results suggest that AMIMCl and BMIMCl are direct and effective solvents for KGM.     

区域利益冲突的化解模式研究

区域经济发展的非均衡性普遍存在于当今世界各国的经济发展过程中,而区域利益冲突则是区域经济协调发展的最大障碍。在分析我国区域利益冲突产生的根本原因的前提下,提出了解决我国区域利益冲突,促进区域经济协调发展的新模式。     

Colloid-facilitated effects on migration of radionuclides in fractured rock with a kinetic solubility-limited dissolution model

<正>Nuclides can move with groundwater either as solutes or colloids,where the latter mechanism generally results in much shorter traveling time as the nuclides interact strongly with solid phases,such as actinides.In the performance assessment,it is therefore essential to assess the relative importance of these two transport mechanisms for different nuclides.The relative importance of colloids depends on the nature and concentration of the colloids in groundwater.Plutonium(Pu),neptunium(Np),uranium(U) and americium(Am) are four nuclides of concern for the long-term emplacement of nuclear wastes at potential repository sites.These four actinides have a high potential for migrating if attached to iron oxide,clay or silica colloids in the groundwater.Strong sorption of the actinides by colloids in the groundwater may facilitate the transport of these nuclides along potential flow paths.The solubility-limited dissolution model can be used to assess the safety of the release of nuclear waste in geological disposal sites.Usually,it has been assumed that the solubility of the waste form is constant.If a nuclide reaches its solubility limit at an inner location near the waste form,it is unlikely that the same nuclide will reach its solubility limit at an outer location unless this nuclide has a parent nuclide.It is unlikely that the daughter nuclides will exceed their solubility limit due to decay of their parent nuclide.The present study investigates the effect of colloids on the transport of solubility-limited nuclides under the kinetic solubility-limited dissolution(KSLD) boundary condition in fractured media.The release rate of the nuclides is proportional to the difference between the saturation concentration and the inlet aqueous concentration of the nuclides.The presence of colloids decreases the aqueous concentration of nuclides and,thus,increases the release flux of nuclides from the waste form.     

贵州普定灯盏河岩溶泉的硫同位素季节变化特征

通过对贵州普定后寨地下河补给区的灯盏河岩溶泉为期1年的泉水水文地球化学特征与水中SO24-的硫同位素组成及季节性变化规律的分析,揭示灯盏河岩溶泉泉水中硫酸盐的来源及形成机理。结果表明：灯盏河岩溶泉的水化学类型主要为HCO3-.SO24--Ca2＋型,具有很高的硫酸盐浓度,且变化幅度较大,SO24-浓度为0.35～8.76mmol·L-1;灯盏河泉水SO24-的硫同位素组成为（3.80～25.76）×10-3,反映泉水的硫同位素组成主要受土壤有机硫氧化和石膏岩层溶解的控制;泉水硫同位素组成季节性变化明显,表现为旱季大于雨季,且旱季变化平缓,主要受石膏溶解的控制,而雨季变化幅度较大,反映雨季地下水硫酸盐土壤有机硫源贡献的增加及其季节性差异。     

FEM analyses for influences of stress-chemical solution on THM coupling in dual-porosity rock mass

The models of stress corrosion, pressure solution and free-face dissolution/precipitation were introduced. Taking a hypothetical nuclear waste repository in an unsaturated dual-porosity rock mass as the calculation objective, four cases were designed: 1) the fracture aperture is a function of stress corrosion, pressure solution and free-face dissolution/precipitation; 2) the fracture aperture changes with stress corrosion and pressure solution; 3) the fracture aperture changes with pressure solution and free-face dissolution/precipitation; 4) the fracture aperture is only a function of pressure solution, and the matrix porosity is also a function of stress in these four cases. Then, the corresponding two-dimensional FEM analyses for the coupled thermo-hydro-mechanical processes were carried out. The results show that the effects of stress corrosion are more prominent than those of pressure solution and free-face dissolution/precipitation, and the fracture aperture and relevant permeability caused by the stress corrosion are only about 1/5 and 1/1000 of the corresponding values created by the pressure solution and free-face dissolution/precipitation, respectively. Under the action of temperature field from released heat, the negative pore and fracture pressures in the computation domain rise continuously, and are inversely proportional to the sealing of fracture aperture. The vector fields of flow velocity of fracture water in the cases with and without considering stress corrosion are obviously different. The differences between the magnitudes and distributions of stresses within the rock mass are very small in all cases.     

基于离子液体的聚丙烯腈/纤维素共混体系溶解与流变性能研究

采用旋转流变仪对以1-乙基-3-甲基咪唑醋酸盐（[EMIM]Ac）为溶剂的聚丙烯腈/纤维素溶液的流变性能进行了研究.结果表明,溶液表观黏度随浓度的升高而增大,但随剪切速率的增加而降低,为典型的切力变稀流体;单组分PAN溶液A黏度最低,单组分纤维素溶液F黏度最大,不同共混比溶液的黏度及对温度的依赖性均介于两纯组分PAN和纤维素Cell之间.