Isolation and characteristics of Arthrobacter sp. strain CW-1 for biodegradation of PAEs

Isolation of new bacterial strains and recognition of their metabolic activities are highly desirable for sustainability of natural ecosystems. Biodegradation of dimethyl phthalate (DMP) under anoxic conditions has been shown to occur as a series of sequential steps using strain CW-1 isolated from digested sludge of Sibao Wastewater Treatment Plant in Hangzhou,China. The microbial colony on LB medium was yellowish,3～5 mm in diameter,convex in the center,and embedded in mucous externally. The individual cells of strain CW-1 are irregular rods,measuring (0.6～0.7)×(0.9～1.0) μm,V-shaped,with clubbed ends,Gram positive and without any filaments. 16S rDNA (1438 bp) sequence analysis showed that the strain was related to Arthrobacter sp. CW-1 and can degrade PAEs utilizing nitrate as electron acceptor,but cannot mineralize DMP completely. The degradation pathway was recommended as: dimethyl phthalate (DMP)→monomethyl phthalate (MMP)→phthalic acid (PA). DMP biodeg-radation was a first order reaction with degradation rate constant of 0.3033 d-1 and half-life 2.25 d. The DMP conversion to PA by CW-1 could be described by using sequential kinetic model.     

Nitrogen transformations during co-composting of herbal residues, spent mushrooms, and sludge

Sewage sludge composting is an important environmental measure. The reduction of nitrogen loss is a critical aim of compost maturation, and the addition of spent mushrooms (SMs) and herbal residues (HRs) may be helpful. To evaluate the nitrogen transformations during co-composting of sewage sludge, SMs, and HRs, windrows were constructed in a residual processing plant. Dewatered sewage sludge and sawdust were mixed with SMs and HRs at two proportions on a fresh weight basis, 3:1:1 (sewage sludge:sawdust:SMs or HRs) and 3:1:2 (sewage sludge:sawdust:SMs or HRs). The mixture was then composted for 40 d. Changes in the physicochemical characteristic of sewage sludge during composting were recorded and analyzed. Addition of SMs and HRs accelerated the temperature rise, mediating a quicker composting maturation time compared to control. The addition also resulted in lower nitrogen losses and higher nitrate nitrogen levels in the compost products. Among the windrows, SM and HR addition improved the nitrogen status. The total nitrogen (TN) and nitrogen losses for SM and HR treatments ranged from 22.45 to 24.99 g/kg and from 10.2% to 22.4% over the control values (18.66–21.57 g/kg and 40.5%–64.2%, respectively). The pile with the highest proportion of SMs (3:1:2 (sewage sludge:sawdust:SMs)) had the highest TN level and the lowest nitrogen loss. The germination index (GI) values for all samples at maturity were above 80%, demonstrating optimal maturity. The addition of SMs and HRs augments sewage composting.     

在线写作自动评改系统在大学英语写作教学中的作用与影响

目前在我国的大学英语写作的教学方面,正在逐步推行把以句酷批改网为代表的在线写作自动评改系统引入教学中的改革措施。由于在线写作自动评改系统对软硬件和教师的使用技术要求较高,且还有一些非人为评改方面的缺陷,致使一些院校在实施改革时顾虑重重。本文着重阐明了在线写作自动评改系统对大学英语写作教学多方面的有力辅助作用,并就其更深远的教育和社会意义做出了分析。希望能使更多的教师投入到这一教学改革中来。     

浅析电力系统中性点接地方式

章通过分析电力系统中性点不同接地方式下的特点，解析我国电力系统从低压配电网到高压电网采用不同接地方式的主要原因。     

运动竞赛损伤心理因素分析

运动竞赛损伤是人们在运动竞技中无法回避的问题.通过文献法和访谈法,对运动竞赛损伤的危害及心理致因进行了分析探讨.研究认为:应激、动机、心理准备、唤醒水平和焦虑情绪等心理因素是引起运动竞赛损伤的重要原因.建议人们应更加重视竞赛损伤的心理学研究,从而最大限度地减少运动竞赛损伤的发生.     

“运动员第一，取胜第二”解析

教练工作需要正确、先进的教练哲学。文章对“运动员第一、取胜第二”这一教练哲学的实质、哲学涵义、如何建立形成进行了分析和探讨．旨在引起教练员对自身教学活动引起重视．并进行审视和思考。     

高职教育顶岗实习的系统设计与管理

顶岗实习作为关键的实践教学环节,是实施校企合作、工学结合人才培养模式改革的要点之一。为建立与学生素质培养、能力提高以及就业相结合的顶岗实习制度,高职院校应以企业、学生、学校多方共赢为基础,根据社会和企业对于毕业生的职业素质和专业能力要求,分析学生认知及职业素质养成规律,并充分考虑企业的利益,对顶岗实习进行系统设计。     

我国高水平大学拔尖创新人才培养的探索实践与启示

回顾了我国高水平大学拔尖创新人才培养的探索历程,总结了入选教育部＂基础学科拔尖学生培养试验计划＂的11所大学在拔尖创新人才培养方面的特色和措施,进而挖掘出些许启示。拔尖创新人才的培养应注重德育教育,科学制定人才培养目标,注重多元化培养,整合优势教育资源,完善教学奖励和考核制度。     

高职工科实训课教师教学效果评价的研究

在国、内外对教师教学效果评价研究成果的基础上,对高职工科实训课教学评价指标的重要性进行排序,根据研究结果编制"高职工科实训课教师教学效果评价问卷(学生用)",在广西四所高职院校共857名学生中进行的实证性研究证明该评价问卷具有很高的信度,客观反映了高职工科实训课教师教学效果,真实显示工科实训课教学各环节的工作状态或工作效果,为教学管理者和教师提供反馈信息,可有效调节和控制教学活动的实施.