曲轴止推轴承盖的锻造及锻模设计

此文以曲轴止推轴承盖锻件为例,较为详细地介绍了该锻件的锻造工艺过程及锻模设计要点。同时,说明了具有预锻和终锻工步的锻模设计成败的关键是预锻模膛的合理设计。     

探析环艺专业基础课程教学方式的革新

本文主要是围绕国内环艺专业的基础课程教学方式现状的不足以及分析基础课程所具有的特点,从而提出教学方式的革新,完善教学体系,培养社会专业人士,为各专业的学习与研究奠定基础。     

特大型铝合金锥环的冲压成形

在简要分析了某特大型铝合金锥环原有的铸造 车削制造工艺存在不足的基础上 ,指出对其采用板料冲压成形的必要性。应用冲压工艺理论 ,计算出了相应的冲压工艺参数。通过进一步分析确定出了两种合理的冲压成形方案 ,并巧妙地解决了该特大型铝合金锥环实际冲压时设备行程不足的问题     

电子式汽车转速表机芯零件——极环的成形工艺及经济性分析

分析了电子式汽车仪表转速表机芯关键零件之一极环的成形工艺及经济性,并把设计该零件模具的几种设想作对比,得到既经济,效率又高的零件成形工艺.     

转炉煤气净化回收“塔-环隙”技术在日钢的应用

日照钢铁公司第一炼钢厂的4座60 t转炉已扩容至最大铁水装入量73 t,吹炼周期进一步缩短。转炉的扩容和吹炼强度增加使得转炉一次烟气量大大增加,现有的煤气净化系统能力无法满足要求。通过将原有的"两文"煤气净化系统改造为新的"塔-环隙"系统,增加了炉口排烟能力,降低了烟气排放浓度,从根本上改善了车间内的工作环境。     

HRT对A2O工艺中典型多环麝香迁移转化的影响

研究了不同水力停留时间(hydraulic retention time,HRT)条件下佳乐麝香(galaxolide,HHCB)与吐纳麝香(tonalide,AHTN)在A2O工艺各池水相和泥相中的变化情况.采用固相萃取与气相质谱联用的方法对水相与泥相中目标物的质量浓度进行检测.结果表明,HRT主要影响HHCB在A2O工艺中的生物降解和随剩余污泥排放的比重,影响AHTN随剩余污泥排放的比重.随着HRT的增大,HHCB、AHTN在厌氧池中的去除率与去除贡献率逐渐减小,而缺氧池与好氧池的去除率与去除贡献率相对增大.2种目标物在4个HRT工况(6、8、10、12 h)下的总去除率分别为73.93%、73.05%、75.14%、76.00%和48.76%、44.27%、57.17%、62.9%.A2O工艺对HHCB的去除效果较好,而对AHTN的去除效果较差.HRT的增大对HHCB的去除影响不大,而对AHTN的去除有促进作用.     

焦化污染场地土壤多环芳烃的生物强化协同降解工艺研究

以某废弃焦化厂的多环芳烃（PAHs）污染土壤为研究对象,通过耦合表活淋洗、生物降解、化学氧化等技术设计了4种修复工艺,并进行了试验验证。结果表明：针对该实际焦化污染土壤,单一的生物泥浆降解工艺21 d后PAHs可实现58.64%的降解率;采用表活增溶＋化学氧化＋生物泥浆的降解工艺,26 d降解率可达到65.68%,但前置的化学氧化会抑制生物降解效果;采用干筛分+表活分批淋洗+化学氧化的降解工艺降解率可达到85.36%,有效缩短降解时间到13 d内,但土壤中残留的PAHs与土壤颗粒结合紧密,化学氧化降解率仍难以满足大于90%的要求;采用湿筛分+表活分批淋洗+生物泥浆+化学氧化的生物强化协同降解工艺,29 d降解率可达到95.32%,实现了土壤的修复目标。生物强化协同降解工艺路线,综合了多种修复技术的优点,实现了修复技术组合优化,为焦化污染土壤中多环芳烃降解修复提供了可行的工艺路径。

     

阻燃剂六溴环十二烷的逆流漂洗工艺改进

阻燃剂六溴环十二烷是一种重要的阻燃剂,原有生产工艺会产生大量的高难度处理废水,对周围环境产生极大的危害.本文根据清洁生产的原则,通过分析阻燃剂六溴环十二烷的生产工艺,决定对其漂洗工艺进行改进,即用酒精预洗涤初级物料,然后采取六级逆流漂洗工艺代替传统的连续洗涤方法,改进后的洗涤工艺可使原废水量的6 t/d减少到1 t/d,废水量减少了83.33%,浓缩后的废水可回收部分有用物质,同时使产品的质量得到进一步提高.     

燃煤电厂和垃圾焚烧电厂燃烧产物中卤代多环芳烃的赋存特征和毒性风险

研究了燃煤电厂和垃圾焚烧电厂燃烧产物中卤代多环芳烃(HPAHs)的赋存特征、生成机制和毒性效应.结果 表明,燃煤电厂和垃圾电厂飞灰中氯代PAHs(Cl-PAHs)的含量为1.06～ 1.67 ng·g-1和2.76 ng·g-1,溴代PAHs(Br-PAHs)的含量为26.4 ～ 44.2 ng·g-1和6.31 ng...     

转向螺母锻模块液态模锻工艺分析及模具设计

此文叙述了转向螺母锻模块液态模锻工艺及特点,对该工艺及模具设计作了较详细的分析研究。     

轿车车门内板冲压成形计算机仿真

介绍了采用基于动态显式算法的有限元分析软件包eta／DYNAFORM对典型的汽车覆盖件轿车车门内板冲压成形进行计算机仿真的全过程。论述了覆盖件冲压零件计算机仿真必须注意到的问题，并探讨了其中的关键技术。     

内循环厌氧反应器流动模型及反应过程模拟

为揭示内循环厌氧反应器放大过程中所出现的规律,本文对反应器中流动模型和反应过程进行了模拟研究,通过对主反应区的停留时间分布的实验研究,确定了主反应区流型可用一平推流与两个并联的全混流进行串联的三参数组合模型进行模拟.在实验范围内,平推流区所占的体积分数约为36%,两个全混流区所占的体积分数分别为53%和11%.结合厌氧反应动力学方程,应用组合模型模拟了实际反应器的状态,并和实验值进行了对比,发现反应器出口处CH_4体积流量最大误差为9.67%,在可允许的范围内.同时,模拟了基质初始COD和温度变化对反应器出口状态的影响.研究表明,与其它模型相比,组合模型计算简洁,同时又有较好的精度,能够满足反应器的设计需要.     

MBBR-MBR组合工艺处理生活污水试验中微生物种群结构的演变

采用移动床生物膜反应器(MBBR)-膜生物反应器(MBR)组合工艺进行生活污水处理试验,考察了组合工艺对污染物的去除效果,通过变性梯度凝胶电泳(DGGE)分析反应器内微生物种群组成及多样性变化,利用克隆文库分析微生物种群结构。结果表明:MBBR-MBR组合工艺稳定运行时对氨氮($NH_{4}^{+}$-N)和化学需氧量(COD_Cr)的平均去除率高达98%和97%;DGGE指纹图谱显示,反应器运行过程中微生物群落结构演变明显且与温度变化密切相关,逐渐形成适应污水处理的低温稳定种群,MBBR与MBR相比,其反应器内微生物种群更丰富,抗冲击负荷能力更强;克隆文库结果显示,MBBR与MBR内微生物优势种有较大差异,但同属变形菌门(Proteobacteria)。     

亚硝化/电化学生物反硝化全自养脱氮工艺研究

开发出了针对低C/N比高氨氮废水处理的亚硝化/电化学生物反硝化全自养脱氮新工艺,并对新工艺进行了系统的研究.试验结果表明,新工艺能取得较好的脱氮效果,在溶解氧为0.5～1.2mg·L-1,pH值为7.5～8.2,温度为17～30℃,进水氨氮浓度不高于1000 mg·L-1,C/N比不高于0.5,HRT不高于32h条件下,亚硝化/电化学反硝化工艺装置运行稳定,亚硝化段膜生物反应器(MBR)出水的氨氮去除率和亚硝氮生成率均能稳定在50%左右,MBR出水中的剩余氨氮和生成的亚硝氮经电化学生物反硝化段(硫碳混合反应器)处理后,最终出水总氮去除率超过95%;出水中的SO2-4浓度不高于1280 mg·L-1.新工艺最高氨氮负荷为1.11kg·m-3·d-1.     

MBBR-MBR组合工艺处理生活污水效能及膜污染研究

构建了移动床生物膜反应器(MBBR)-膜生物反应器(MBR)组合工艺处理生活污水,考察了其对污染物的去除效果和膜污染情况。结果表明,MBBR-MBR对$NH_{4}^{+}$-N和COD的去除率均能达到97%以上。MBR中跨膜压随运行时间延长呈先慢速增加后快速增加的特点,活性污泥微生物胞外聚合物(EPS)和微生物代谢产物(SMP)是膜污染的重要物质,普通的化学清洗并不能使MBR膜组件恢复到新膜的水平,膜污染呈不可逆性。EPS的表观分子量分布较广泛,而SMP的表观分子量呈单峰特征,主要以小分子量物质为主。     

A new process of combined pretreatment and dyeing: REST

Use of enzymes in textile processes has many advantages as far as the environmentally friendly processes are concerned. These advantages include water and energy savings, less chemical use, less fabric damage, mild and environmentally friendly process conditions. In this work, C.I. Reactive Yellow 15, C.I. Reactive Red 21 and C.I. Reactive Blue 19 were used to dye untreated woven cotton fabric in a laboratory scale dyeing machine, on a pilot scale jig and on a pilot scale winch by using a single bath combined process, in which various enzymes, namely, amylase, pectinase, and catalase were employed. This new process was named as the “Rapid Enzymatic Single-bath Treatment” (REST), since it was completed almost in half of the conventional dyeing time, and all of the stages, namely, desizing, scouring, bleaching and dyeing were carried out in a single bath without replacing the process water with fresh water until the end of the dyeing. In the REST process, the untreated, starch-sized fabric was first desized by amylase enzyme, and this was followed by a pectinase treatment in the same bath. The fabric was then bleached by H₂O₂ in the same bath, and after the hydrogen peroxide bleaching; the catalase enzyme was added to the bath to remove H₂O₂ residues before reactive dyeing. Without carrying out intermediate washings/rinsings between these processes, the reactive dyeing was carried out in a conventional way in the same bath, and finally, the fabric was taken from the bath and washed out. The colour yield was compared with the dyeings which were carried out conventionally in separate baths. Finally, the REST has many benefits in terms of water saving, reduced process time and energy consumptions compared to the conventional preparatory and dyeing process of cotton fabrics.     

A combined process coupling phytoremediation and in situ flushing for removal of arsenic in contaminated soil

Phytoremediation and soil washing are both potentially useful for remediating arsenic(As)-contaminated soils.We evaluated the effectiveness of a combined process coupling phytoremediation and in situ soil flushing for removal of As in contaminated soil through a pilot study.The results showed that growing Pteris vittata L.(P.v.) accompanied by soil flushing of phosphate(P.v./Flushing treatment) could significantly decrease the total As concentration of soil over a 37 day flushing period compared with the single flushing(Flushing treatment).The P.v./Flushing treatment removed 54.04% of soil As from contaminated soil compared to 47.16% in Flushing treatment,suggesting that the growth of P.vittata was beneficial for promoting the removal efficiency.We analyzed the As fractionation in soil and As concentration in soil solution to reveal the mechanism behind this combined process.Results showed that comparing with the control treatment,the percent of labile arsenate fraction significantly increased by 17% under P.v./Flushing treatment.As concentration in soil solution remained a high lever during the middle and later periods(51.26–56.22 mg/L),which was significantly higher than the Flushing treatment.Although soil flushing of phosphate for more than a month,P.vittata still had good accumulation and transfer capacity of As of the soil.The results of the research revealed that combination of phytoremediation and in situ soil flushing is available to remediate As-contaminated soils.     

生物塘-人工湿地工艺去除农田灌溉水中镉污染的效果

通过野外大田试验,探讨了生物塘-人工湿地工艺去除农田灌溉水中Cd污染的效果,并进一步分析了水力停留时间对Cd净化效果的影响及净化效果的日变化规律。结果表明:试验区灌溉水中全量Cd平均浓度为13.92 μg/L,是GB 5084—2005《农田灌溉水质标准》中Cd浓度限值的1.39倍,且以溶解态Cd为主,约占77.8%;经生物塘-人工湿地工艺处理后全量Cd平均去除率为42.0%,出水达标天数率为85.2%;组合工艺的Cd去除率随水力停留时间的延长呈先升高后降低趋势,最佳停留时间约为19 h;生物塘和人工湿地的Cd去除率日变化规律均呈早晚低、中午高的单峰曲线,Cd最大去除率出现在13:00左右。