Forward osmosis coupled with lime-soda ash softening for volume minimization of reverse osmosis concentrate and CaCO3 recovery: A case study on the coal chemical industry

• Forward osmosis (FO) coupled with chemical softening for CCI ROC minimization • Effective removal of scale precursor ions by lime-soda ash softening • Enhanced water recovery from 54% to 86% by mitigation of FO membrane scaling • High-purity CaCO₃ was recovered from the softening sludge • Membrane cleaning efficiency of 88.5% was obtained by EDTA for softened ROC Reverse osmosis (RO) is frequently used for water reclamation from treated wastewater or desalination plants. The RO concentrate (ROC) produced from the coal chemical industry (CCI) generally contains refractory organic pollutants and extremely high-concentration inorganic salts with a dissolved solids content of more than 20 g/L contributed by inorganic ions, such as Na⁺, Ca²⁺, Mg²⁺, Cl⁻, and SO₄²⁻. To address this issue, in this study, we focused on coupling forward osmosis (FO) with chemical softening (FO-CS) for the volume minimization of CCI ROC and the recovery of valuable resources in the form of CaCO₃. In the case of the real raw CCI ROC, softening treatment by lime-soda ash was shown to effectively remove Ca²⁺/Ba²⁺ (>98.5%) and Mg²⁺/Sr²⁺/Si (>80%), as well as significantly mitigate membrane scaling during FO. The softened ROC and raw ROC corresponded to a maximum water recovery of 86% and 54%, respectively. During cyclic FO tests (4 × 10 h), a 27% decline in the water flux was observed for raw ROC, whereas only 4% was observed for softened ROC. The cleaning efficiency using EDTA was also found to be considerably higher for softened ROC (88.5%) than that for raw ROC (49.0%). In addition, CaCO₃ (92.2% purity) was recovered from the softening sludge with an average yield of 5.6 kg/m³ treated ROC. This study provides a proof-of-concept demonstration of the FO-CS coupling process for ROC volume minimization and valuable resources recovery, which makes the treatment of CCI ROC more efficient and more economical.     

大倾角煤层开采覆岩破断机制研究

为了探究大倾角煤层开采覆岩变形、失稳、破断的演化特征,结合潘二矿1212(3)工作面地质与工程条件,采用数值模拟、物理模拟、理论分析相结合的方法,分析了大倾角煤层开采覆岩变形破坏规律,探讨了巨厚砂岩直覆和无坚硬岩层2种条件下大倾角煤层开采顶板破断失稳形式。研究结果表明:受倾角影响直接顶冒落、滑移,充填下部采空区,基本顶中上部挠度最大而发生断裂,破断裂纹逐渐向基本顶两侧及相邻岩层演化;大倾角煤层倾向岩层间的联动时序性破断是形成非对称拱形承载结构的主因;预裂爆破巨厚砂岩顶板、充填开采软弱岩层工作面可促使关键块体组成的拱形承载结构形成,保证大倾角工作面安全回采。     

Prenatal and presymptomatic diagnosis of the marfan syndrome using fluorescence pcr and an automated sequencer

The Marfan syndrome (MFS) is a heritable connective tissue disorder characterized by skeletal, ocular, and cardiovascular abnormalities. Defects in fibrillin, an elastin-associated microfibrillar protein, are now known to cause MFS. Since the discovery of fibrillin as the gene responsible for MFS, requests for prenatal and presymptomatic diagnosis have become common-place. Here we report the use of the polymerase chain reaction (PCR), using fluorescence labelled primers and an automated sequencer, to establish linkage data for “molecular diagnosis”. The mistaken clinical diagnosis of MFS based on the appearance of a common cardiovascular manifestation, mitral valve prolapse, and a positive family history is also discussed.     

长江三角洲空问运输联系与经济结构的时空演化特征分析

本文对长江三角洲1985-2000年各城市客、货运量进行了分析，总结出改革开放以来该区域空间运输联系的时空演化特征。长江三角洲客运量分布的廊道效应逐渐显著，货运量极化效应减弱。空间运输联系的时空演化反映了长江三角洲经济结构的推移特点。长江三角洲走廊经济突显，成为区域经济发展的有力带动轴；区域内浙东北经济崛起，成为与苏南地区相抗衡的经济板块；长江三角洲区域经济发展天平已出现向南倾斜的趋势。针对以上结论，本文认为长江三角洲地区应加快综台交通运输网络的建设，培育具有强大辐射效应的走廊经济，推动省、市之间协调合作与共同发展。     

北京市生产性土地的部门关联效应分析

本文基于生态足迹的投入产出模型,利用改进的HEM方法和北京市2007年投入产出表及相关数据,计算生产性土地的部门关联效应指标,对北京市9部门块土地资源关联效应进行了分析.研究结果表明:土地资源纵向总效应超过直接消耗的部门块主要由制造业、建筑业和服务业等部门构成;采选业部门块有更大的土地资源转让潜力;其他部门块都要从本部门块以外获取土地资源,导致各部门块的外部后向关联及外部前向关联都很大.本文认为:生产性土地的关联效应实际上是经济系统部门间土地资源需求的转移,最终需求总量不变,其结构调整就不会对土地资源总量产生影响;改进的HEM方法结合生态足迹最终需求,分析直接土地资源消耗数量,分解影响部门土地资源的组成因素,可以更直接、明确地量化部门间以及部门内部土地资源的关联关系;如果能够以实物型投入产出表代替货币型投入产出表,可以更加科学地反映经济系统中各产业部门土地资源的关联特性.     

上海与长江经济带经济联系研究

以上海为龙头的长江经济带,在国家“T”型开发战略中具有重要的地位和作用。基于中国城市统计年鉴2006年统计数据,从联系节点、联系通道和联系作用量3方面,定量分析上海与长江经济带的经济联系。结果表明：（1）长江经济带中心城市空间等级分布不均,呈现出“一极,多心组团”及沿铁路干线分布的空间格局;（2）上海与长江三角洲地区城市间的可达性明显优于中西部城市,而城市客货流则多集中在上海与重庆、成都、武汉、南京等二、三级中心城市之间;（3）经济联系随空间距离增加而衰减,与上海经济联系紧密的城市主要集中在沪宁-沪杭-杭甬铁路沿线,中西部地区城市与上海经济联系作用量很弱。有必要进一步加强上海与长江经济带经济联系,对此提出了几点优化策略。     

Towards an integrated approach of disaster and environment management: A case study of Thua Thien Hue province, central Viet Nam

Objetivo: El objetivo de este estudio era examinar los problemas emocionales y comportamentales de niños refugiados no acompañados que fueron repatriados a Vietnam de los centros de refugiados de Hong-Kong y del Sudeste asiático. Los niños fueron comparados con una muestra emparejada de niños que nunca dejaron Vietnam.Método: La muestra estaba compuesta por un total de 455 niños vietnamitas de edades comprendidas entre los 10 y los 22 años. Un total de 238 niños habían residido previamente sin sus padres en campos de refugiados. Se recogieron datos aplicando la versión de autoinforme para jóvenes del Achenbach (Youth Self-Report), la Escala de Autoeficacia Percibida de Cowen, una escala de Soporte Social y una escala de Exposición al Trauma.Resultados: No se observaron diferencias significativas entre los grupos de niños en la puntuación total del YSR. Los niños previamente refugiados tuvieron puntuaciones más bajas que los niños del grupo control en la escala de “problemas de conducta externalizados”. Se observó una tendencia en los niños refugiados a presentar puntuaciones más altas que los niños del grupo control en la escala de “problemas de conducta internalizados”. No se observaron diferencias entre los dos grupos en la eficacia autopercibida, el número de fuentes de apoyo social y las experiencias de apoyo social. Otros análisis mostraron que una interacción significativa entre la condición de inmigrantes de los niños y su percepción subjetiva del actual nivel de vida explicó las diferencias en las puntuaciones en el YSR.Conclusión: Los resultados sugieren que la experiencia de vivir sin sus padres en un campo de refugiados no conduce a presentar más problemas emocionales y de conducta en los años posteriores inmediatos a la repatriación.

浅谈如何做好建设项目环境影响评价与规划环境影响评价的联动

围绕建设项目环境影响评价和规划环境影响评价的特点,通过在评价思路、评价内容、评价方法等方面的比较,分析其差异,从而找到两者在评价时间、评价内容等方面的联动途径,以提高环境影响评价工作的效果和效率。