Customization of ZrO2 loose/tight bilayer ultrafiltration membranes by reverse micelles-mediated aqueous sol-gel process for wastewater treatment

Two types of spherical zirconyl oxalate aqueous sols were successfully customized by a reverse micelles-mediated aqueous sol-gel process, and the sols were sequentially spin-coated on porous supports to prepare ZrO₂ loose/tight bilayer ultrafiltration membranes. After three times of spin-coating process, a defect-free ZrO₂ loose ultrafiltration membrane with pure water permeability of 110.5 ± 2.25 L m^?2 h^-1 bar^-1, molecular weight cut-off (MWCO) of 16.5 kDa and excellent rejection of up to 97.5 % for bovine serum albumin was fabricated. Then, the loose ultrafiltration membrane was used as a substrate to prepare ZrO₂ tight ultrafiltration membrane. Performances of tight ultrafiltration membrane regarding to permeability, retention of polyethylene glycol and treatment of dyes wastewater were evaluated. The tight ultrafiltration membrane with a thickness of 200 nm exhibited a pure water permeability of 22.5 ± 0.3 L m^-2 h^-1 bar^-1 and MWCO of 1150 Da. Additionally, the rejections of methyl red and methyl orange by the tight ultrafiltration membrane were both <65 %, while of alizarin red, direct red, bromocresol green and methyl blue achieved maximum values of 98.5 %, 99.2 %, 99.5 % and 99.6 %, respectively. The fouled membranes could restore the virgin performance for reuse by cleaning and low-temperature calcination.     

In situ preparation of a SiC–TiB2 composite and its wear fracture mechanism at high temperatures

Journal of Materials Science - The unsatisfactory high-temperature performance of commonly used silicon carbide (SiC)-based ceramics calls for a novel approach for their reinforcement. We present...     

焦炉煤气正、负压HPF脱硫工艺比较

对正、负压HPF脱硫工艺进行工艺特点和经济比较,并对2种工艺的设备、产品、原材料及消耗指标进行了对比,分析可知,操作运行费用2种工艺相当,而建设费用HPF正压脱硫工艺具有优势,因此,正压脱硫在焦化行业中应用广泛。     

硫酸铝、草酸钾及其共混物对α-半水石膏制备及性能的影响

制备高强石膏是磷石膏资源化的重要途经。为实现磷石膏资源化,采用蒸压水溶液法,以硫酸铝、草酸钾及其共混物为转晶剂,在蒸压温度为130 ℃、保温时间为6 h、液固质量比为0.5条件下制备了α-半水石膏。讨论了不同转晶剂对α-半水石膏形貌和力学性能的影响。结果表明,以硫酸铝为转晶剂时,所制备试样的形貌随转晶剂掺量的增大呈现由针状向长柱状、小晶粒向大晶粒发展的趋势,而以草酸钾为转晶剂制备的试样形貌多为短柱状、晶粒大小不一。当转晶剂总量为石膏量的0.6%、硫酸铝与草酸钾掺量比为5∶1时所制备的石膏试样具有晶粒尺寸大、晶体形貌规整（六方状晶体）的特点,其2 h抗折强度和2 d绝干抗压强度分别可达5.88、36.90 MPa。     

A restructured artificial bee colony optimizer combining life-cycle,local search and crossover operations for droplet property prediction in printable electronics fabrication

For printable electronics fabrication, a major challenge is the print resolution and accuracy delivered by a drop-on-demand piezoelectric inkjet printhead. In order to meet the challenging requirements of printable electronics fabrication, this paper proposes a novel restructured artificial bee colony optimizer called HABC for optimal prediction of the droplet volume and velocity. The main idea of HABC is to develop an adaptive and cooperative scheme by combining life-cycle, Powell’s search and crossover-based social learning strategies for complex optimizations. HABC is a more biologically-realistic model that the reproduce and die dynamically throughout the foraging process and the population size varies as the algorithm runs. With the crossover operator, the information exchange ability of the bees can be enhanced in the early exploration phase while the Powell’s search enables the bees deeply exploit around the promising area, which provides an appropriate balance between exploration and exploitation. The proposed algorithm is benchmarked against other four state-of-the-art bio-inspired algorithms using both classical and CEC2005 test function suites. Then HABC is applied to predict the printing quality using nano-silver ink. Statistical analysis of all these tests highlights the significant performance improvement due to the beneficial combination and shows that the proposed HABC outperforms the reference algorithms.     

冷剪机增能技术改造分析

冷剪机作为钢铁厂轧钢车间的重要生产设备,承担着剪切定尺钢材的任务,是整个生产系统中极为重要的一环,结合实际,对冷剪机生产作业损坏的主要原因进行研究,进而做出针对性的技术改造,通过改善剪子的力学状况,大幅减少剪切阻力,不仅能够提高冷剪剪切能力,增加轧钢生产线产能,而且还能节约成本,对于实际生产具有重大意义。     

基于层次分析的露天矿用电动挖掘机故障因素研究

结合实际生产状况,采用系统分析方法,对电动挖掘机故障因素做出相关研究,总结致使电动挖掘机产生故障的各项原因,结合层次分析法(AHP)构建模型,对各项因素进行分析研究,得出总体优先级,然后依据研究结果,针对性的提出整改意见。     

圆弧滑动的稳定性分析及软件实现

圆弧滑动边坡的稳定性验算最大的困难是寻找最危险的滑动圆弧,也就是确定最危险滑动圆弧的圆心位置。基于圆弧滑动面的假定,提出了一种运用模式搜索法确定边坡最危险滑动面及其对应的最小安全系数的方法。以Felle—nius条分法和简化Bishop法为基础,运用VB结合CAD的二次开发功能,编制出程序来搜索圆弧滑动边坡最危险滑动圆...     

Liquefactions of peat in supercritical water with a novel iron catalyst

Raw iron ore has been investigated for use as a catalyst in direct liquefaction of peat into bio-crude by supercritical water treatment. The liquefaction treatments were conducted at temperatures from 350 °C to 500 °C for a residence time from 10 min to 4 h. The supercritical water treatment of peat with the iron ore generally resulted in 19-40 wt% yield of heavy oil (HO) that has a higher heating value (HHV) of 30-37 MJ/kg. An increase in the operating temperature generally increased gas yield and decreased oil and char yields, while a maximum HO formation was observed at around 400 °C. At 400 °C for a residence time of 2 h, the addition of the raw iron ore in the operation produced HO at a very high yield of about 40 wt%, nearly doubling that of the treatment without catalyst. An increase of water-to-peat ratio led to enhanced formation of HO products, accompanied by a decrease in gas or char yield. The optimal reaction time appeared to be 2 h for the maximum HO production, and a longer residence time than 2 h generally led to a decrease in HO yield but an increase in gas yield. Compared with the raw iron ore, its H₂-reduced form and two synthesized iron-based catalysts (FeOOH and Fe₂O₃) all showed a lower activity for HO production. Some conventional biomass liquefaction catalysts (i.e., KOH, FeCl₃ and FeSO₄) showed negligible or even negative effects on the HO yield, while these catalysts were found very active for promoting the gas yields and hydrogen formation.     

Feature Selection with Data Field

A new feature selection method is proposed for high-dimensional data clustering on the basis of data field. With the potential entropy to evaluate the importance of feature subsets, features are filtered by removing unimportant features or noises from the original datasets. Experiments show that the proposed method can sharply reduce the number of dimensions and effectively improve the clustering performance on WDBC dataset.