地下水四氯化碳去除率的影响因素研究

通过实验室模拟淋溶试验,研究双金属介质对土壤地下水中四氯化碳的去除机理与效果。结果表明,从四氯化碳进入土壤200 h后,在淋溶柱底部取样口土壤样品中的浓度高于初始浓度,表现出土壤对四氯化碳的截留作用;50目的铁粉对于四氯化碳的去除效果较好;铁锌双金属组合对于四氯化碳的去除效果优于其他组合。采用响应曲面法对试验进行优化：在活性炭添加量25.8 g（对应四氯化碳40 mg的处理量）,环境p H值为6.2,Fe/Zn为0.853的条件下,四氯化碳去除率最高达到69.7%。实验结果验证了建立的二次多项式模型具有较高的可靠性。

多重制度逻辑下职业教育产教深度融合路径创新研究

当前,我国职业教育产教融合处于多元化的制度环境中,呈现出自发式、浅层次、松散式和低水平的状态。政府、学校、市场和文化等多重制度逻辑冲突造成职业教育产教融合深入推进的制度化困境。面对多重制度逻辑冲突的长期性和复杂性,职业教育产教融合需通过制度创新、主体行为创新、组织形式创新和协同创新等策略,有效整合和管理多重制度逻辑冲突,发挥职业教育对产业转型发展引领支撑作用,推动职业教育与经济社会协调发展。

Optimum conditions to treat high-concentration microparticle slime water with bioflocculants

We studied how bioflocculants,produced by white-rot fungi,affect flocculation in slime water.Based on a test in an orthogonal design,flocculation conditions were optimized.The results show that flocculation activity is at its highest when the following conditions are met:slime water concentration 27.42 g/L;coagulant aid(CaCl_2) mass concentration 5.0 g/L;two-segment stirrings:the first at a stirring speed of 60 r/min for 180 s and the second 180 r/min for 60 s;a pH of 11 and a flocculant concentration of 15 mL/L.The flocculation activity can be up to 98.71%of bioflocculants at the time.Further experiments indicate that most of the flocculation active material is found outside the mycelium cells.This is the extracellular secretion produced by mycelium cells during the fermentation process.This flocculant has strong thermal stability.Many kinds of cations have a flocculation function to assist bioflocculants.This aid-flocculation effect of the divalent cation Ca^(2+) is obvious in the bioflocculant produced by the white-rot fungus.Therefore,this is of great value when applied to control engineering in the battle against water pollution.

Physicochemical properties and heavy metals leachability of fly ash from coal-fired power plant

The physicochemical properties of fly ash from two kinds of coal-fired power plants were studied. Three aspects were examined: the micro-morphology, the mineral composition and the content of heavy metals. The results show that the fly ash from plants using a circulating fluidized bed are more irregular particles, while the particles from the plants using a pulverized coal-fired boiler are mainly spherical in shape. Quartz and mullite are the main crystalline phases in the ash. Clearly, both the technology and the coal used by a power plant can influence the mineral composition of the ash. The mineral composition of fly ash from a circulating fluidized bed is more complex than that from a pulverized coal-fired boiler. The quantity of elements found in the fly ash is greater than that found in the bottom ash for the same plant. Heavy metals are likely to be enriched in the fly ash. Heavy metal leachability was studied using two leaching methods. The results indicate that most of the heavy metals that leached during either batch leaching or column leaching experiments did not exceed the related maximum concentration standards. But Ni concentrations in the leachates from both batch and column tests exceed the standard. The highest excess rates in both tests were 572% and 497%, which levels might threaten the environment.

基于协同过滤算法与标签融合的农产品电商平台设计

用户在农产品电商平台购买时,经常出现信息量过载的问题,导致用户寻找心仪产品困难。同时,在新用户注册进入平台后,由于推荐初期冷启动问题,出现无法对新用户进行推荐的情况。基于用户寻找心仪产品困难和冷启动问题,提出利用协同过滤算法和标签融合,通过协同过滤算法为用户推荐喜爱的产品,并主动发现用户的潜在需求。在新用户登录时设置喜好标签,构造用户短期画像,在个性化的电商平台将用户可能需求的产品进行个性化推荐。