纳滤膜技术浓缩分离含镍离子溶液

采用纳滤膜法对较高浓度含Ni2+离子溶液进行了高倍数浓缩,考察了操作压力、进料液流量、原水Ni2+离子质量浓度和pH等因素对分离过程性能的影响.结果表明,纳滤膜对Ni2+的截留率随操作压力、进料液流量和原水Ni2+质量浓度的增加而增大,膜通量则随进水Ni2+的质量浓度增加而减小.对于Ni2+质量浓度为3900 mg·L-1,pH为3的NiSO4溶液原水,在操作压力1.4MPa条件下,经截留液全循环工艺运行,纳滤淡化出水Ni2+的截留率均保持在99.6%以上,浓缩液中Ni2+质量浓度最高可能达到23 510mg·L-1,浓缩倍数超过6.研究表明,选择适宜的纳滤膜用于重金属废水的高倍数浓缩,实现有价金属的资源化回收具有良好的技术可行性.     

改进型降流式BAF处理微污染河水

对降流式BAF进行优化设计,克服了普通降流式BAF曝气不均匀,水头损失大,反冲洗周期短的缺点.利用改进型降流式BAF对两种污染程度不同的河水进行处理,结果表明,对NH4+-N质量浓度均值分别为1.03mg·L-1和2.50mg·L-1的原水,BAF出水均值分别为0.17mg·L-1和0.60mg·L-1,去除率分别达到84.25%和75.87%,并且NO2--N没有出现累积现象;对CODMn均值分别为3.23 mg·L-1和5.33 mg·L-1的原水,BAF出水均值分别为2.41 mg·L-1和2.44mg·L-1,去除率分别达到24.05%和46.56%.     

当代建筑叙事学的本体建构——叙事视野下的空间特征、方法及其对创新教育的启示

通过案例分析、交叉学科研究等,解析了建筑叙事内在的要素属性、空间结构、建构策略和文化意义。认为空间叙事的双重特征逻辑性和文学性及其内外双层语义是当代建筑叙事的核心内容;因此在构筑理性的物质空间的同时,需要建构空间的深层语义;同时结合西方建筑教育实践,指出叙事教学对于培养建筑创新能力的积极作用。     

A water-soluble organic-inorganic hybrid material based on polyhedral oligomeric silsesquioxane and polyvinyl alcohol

A novel series of organic-inorganic hybrid materials involving cage-like octa(3-chloroammoniumpropyl)silsesquioxane and Polyvinyl alcohol (OCAPS/PVA) were prepared via solution blending method. The obtained hybrid films were optically transparent and soluble in water. OCAPS/PVA hybrids were characterized by FT-IR, wide-angle X-ray diffraction (WAXD) scanning electronic microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), differential scanning calorimetry (DSC), thermogravimetry analysis (TGA) and tensile test. The results showed that the hydrogen bond interactions were formed between OCAPS and PVA. OCAPS could be dispersed well in PVA matrix till its content was 10 wt%, while the aggregation and crystallization of OCAPS were observed when the content was up to 15 wt%. The glass transition temperature (T _g ) of OCAPS/PVA was found to increase from 53 °C to 60 °C, and the melting temperature (T _m ) decreased from 180 °C to 171 °C with increasing OCAPS content from 0 wt% to 15 wt%. The thermal stability of PVA main chain was improved by the addition of OCAPS and the thermal residue ratio also increased. The tensile strength of OCAPS/PVA decreased from 28 MPa to 19 MPa, while the elongation at break of hybrid films increased from 121% to 175%.     

Tensile and Fracture Properties of 15 vol% SiC_p/2009Al Composites Fabricated by Hot Isostatic Pressing and Hot Extrusion Processes

15 vol% silicon carbide particle （SiCp）-reinforced 2009A1 matrix （15 vol% SiCp/2009A1） composites were fabricated by hot isostatic pressing （HIP） and hot extrusion processes. The tensile and fracture properties of 15 vol% SiCp/ 2009Al were studied. The results showed that hot extrusion increased the ultimate tensile strength （UTS）, yield strength （YS）, elongation （EL）, reduction in area （RA）, and fracture toughness of the composites. The heat treatment resulted in the increase in UTS, YS, and fracture toughness, but a decrease in EL and RA. Both hot extrusion and heat treatment had negligible effects on elastic modulus （E）. With the increase of SiCp size, the UTS, YS, and E decreased, but the EL and RA increased. The fracture toughness increased first and then decreased with increasing SiCp size, and when the SiCp size was about 7 μm, the composites obtained the maximum fracture toughness value of 31.74 MPa m^1/2.     

The influence of oxygen and nitrogen contamination on the densification behavior of cryomilled copper powders during spark plasma sintering

It has been found difficult to fully densify some mechanically milled pure metal powders by spark plasma sintering (SPS). In this study, the densification behavior of cryomilled, nanostructured (NS) Cu powders during SPS was related to changes to the chemistry of the powders. The results showed that the presence of very small amounts of O and N in the powders, which were introduced during cryomilling and handling, significantly influenced the densification response. Moreover, reduction/removal of O/N via thermal annealing of the powders before SPS led to complete densification of the powders during subsequent SPS. The mechanisms responsible for this behavior were ascertained: O and N existed in the cryomilled powders in the form of thermally unstable compounds, and the subsequent thermal decomposition of these compounds during SPS generated the gaseous species, leading to porosity formation and incomplete densification; annealing of the powders before SPS removed the gases which resulted from thermal decomposition, thereby facilitating complete consolidation during subsequent SPS.     

一种新型膦酸防垢剂的合成及性能研究

通过正交实验确定了合成新型膦酸防垢剂 YJ 1的最佳条件 ,并主要研究了这种防垢剂对 Ca CO3、Ca SO4、Ba SO4和 Sr SO4的阻垢性能 ,同时与其它几种常用同类防垢剂进行了比较。     

一种新型的强流相对论等离子回旋管

本文介绍了一种新型的强流相对论器件——强流相对论等离子回旋管。叙述了在强流相对论性器件中填充等离子体实现空间电荷补偿的原理,及苏联科学院普通物理所在3cm波段获得的实验结果。     

多组份单分子系统反应途径的计算机模拟

对于n≥3的多元单分子系统的化学反应途径,按自由能最速下降原则,在计算机上成功地进行了模拟。该法对复杂系统的反应研究、催化剂开发、反应器设计等具有指导意义。     

国际化设计合作的有益尝试

本文以职业建筑师个人的视点客观地记述了广州国际会议展览中心的设计过程。通过不同文化背景下的中日建筑师辛勤的努力,为今后日益增多的国际化设计合作提供了可借鉴的成功经验。