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141.
利用油烟的特点,在水雾水膜式油烟净化基础上建立迷宫分离油烟装置.从降低能耗和提高油烟捕集效率的角度出发,利用统计学方法建立数学模型,按照正交设计布置试验,进行因素方差分析,应用SPSS、MATLAB软件进行正交设计数据处理,实现产品的结构优化.结果表明,湿式迷宫分离段的最优结构布置方式为:分离装置空腔直径为15 mm、宽度50 mm及表面波纹角度90°,并采用插板式滤油水箱治理含油废水,减少二次污染.本装置在传统油烟分离技术的基础上,结合离心分离、冷凝凝并、液体吸收净化、碱性除油等作用,提高了复合油烟净化设备的净化效率,减少油烟雾中的过水量,其最佳油烟气净化效率可达到96.91%.  相似文献   
142.
Concern over the possible relation between environmental aluminium exposure and Alzheimer's disease has prompted studies of all forms of human intake of this element including that from foods. Aluminium cookware, apart from other sources of dietary aluminium, is considered to be a potential source of this metal to human beings. Various research groups have carried out aluminium leaching experiments with food, beverages and water under different experimental conditions modified by varying the level of pH, chloride, fluoride, citrate, acetate etc. The results reported by different workers show marked discrepancies in levels of leached aluminum. The apparent reason for such discrepancy in levels of aluminum leached can be attributed to factors such as non-systematic and non-uniform experimental designs, non-standard conditions maintained during the experiments and choice of method for aluminium analysis. In order to assess accurately the contribution of aluminium ingestion by human beings through aluminium cookware, the present review emphasises the need of i) standard size aluminium plates obtained from the same lot for one set of experimentations; ii) real life cooking conditions to highlight the role of various complexing species present in food e.g. citrate, oxalate, acetate, tartrate etc.; iii) role of chemistry of aluminium in presence of acidic, basic and neutral cooking medium and iv) strict analytical control in the estimation of aluminium. Results of a systematic study by the authors conducted on the abovementioned lines are also described.  相似文献   
143.
Lactation imposes substantial physiological costs on mothers and should therefore not be directed towards foreign offspring. Such allonursing, however, is common in mammal species that share roosts. Hypotheses to explain allonursing among such plural breeders include misdirected parental care, milk evacuation, brood parasitism, reciprocity, and kin selection. The necessary behavioral data, in combination with data on kinship and kin recognition, have rarely been available to distinguish among these explanations, however. In this study, we provide evidence for cooperative nursing and adoption by plural-breeding females in a nocturnal primate, the gray mouse lemur (Microcebus murinus), in which females forage solitarily during the night, but form day-time sleeping groups with one to two other females. We observed 34 resident females in an 8 ha study area in Kirindy Forest, Madagascar, over three consecutive annual breeding seasons and determined genetic relationships among all members of this population. Five sleeping groups of adult females were filmed inside their roosts during one breeding season after females gave birth. The composition of groups changed substantially across years, but they always consisted of close maternal relatives. All females within a group gave birth to one to three infants. They regularly transferred only their own offspring among roosting sites, demonstrating an ability to discriminate between their own and other’s offspring, but they regularly groomed and nursed related offspring other than their own and adopted related dependent young after their mother’s death. Kin selection may therefore be the main selective force behind cooperative breeding among these closely related females with a high mortality risk, providing each of them with family insurance.  相似文献   
144.
北京市餐饮业大气污染物排放特征   总被引:1,自引:1,他引:0  
餐饮业是中国大型城市大气环境污染源之一.为了解餐饮业大气污染物的产生能力,本研究以北京为研究对象,选取41家不同菜系的餐饮企业,现场实地检测了净化设备前端的油烟、颗粒物和非甲烷总烃(NMHC)的产生浓度水平.结果表明,净化前油烟、颗粒物和NMHC的初始平均浓度约为1.93、 6.6和10.9 mg·m~(-3).提出了一种基于工作日与非工作日的估算污染物排放总量的计算方法.并基于北京市餐饮企业数量和本研究测得的排放因子,初步估算了2019年全市餐饮源主要污染物的初始产生总量,油烟、颗粒物和NMHC的年排放总量分别为5 512、 18 849和6 169 t.川湘菜、烧烤、烤鸭与家常菜产生的油烟与颗粒物浓度的Pearson系数均0.6,具有强相关性;其中川湘菜和烤鸭排放的Pearson系数均0.8,呈现极强相关性.  相似文献   
145.
Introduction. This study examined whether cognitive symptoms and health-related quality of life can be affected by welding fume exposure. Method. Participants consisted of welders (n?=?40) and welder assistants (n?=?25) from welding units as the exposed group, and office workers (n?=?44) as the non-exposed group. All participants were studied using ambient air monitoring and two types of questionnaires: the Cognitive Failures Questionnaire (CFQ) and the 36-item Short Form Health Survey (SF-36). Results. Welders and welder assistants were exposed to higher concentrations of all airborne metals than office employees, except for aluminum and chromium (p?p?M (SD)?=?54.84 (17.88)). The relationships between total CFQ score and the measured concentration of nickel at peak work rate was significant for welders. Conclusion. Cognitive symptoms and health-related quality of life were not related to the measures of welding fume exposure and further research should be performed to find other influencing factors.  相似文献   
146.
中式餐饮业油烟中非甲烷碳氢化合物排放特征研究   总被引:15,自引:4,他引:11  
使用挥发性有机物采样标准方法TO-14/15,选择了北京市5家不同菜系、不同营业规模的餐馆,在其营业时段,连续采集油烟中非甲烷碳氢(NMHCs)样品,使用气相色谱质谱联用仪(GC/MS)进行样品分析.研究了4大类72种NMHCs排放浓度和组分组成特点.不同采样餐馆的NMHCs排放浓度存在差异,与菜系类型、规模、上座率、...  相似文献   
147.
浅谈锅炉烟尘监测过程中的质量控制   总被引:1,自引:0,他引:1  
从采样前准备、现场检查、现场采样等方面出发,结合实际经验,对锅炉烟尘气监测工作谈一些自己的见解。  相似文献   
148.
以英国废弃烹调油的回收、处理和再生利用的产品为主线,结合与其相关的政策、法规及有效激励方法在废弃烹调油再生利用管理过程中的作用,详细介绍了英国废弃烹调油再生利用的管理现状,以期对我国废弃烹调油及其他废弃物的循环经济实践提供具体的参考案例。  相似文献   
149.
为改善焊接作业环境、保护职工健康,基于某铁路货车企业的生产工艺和焊接烟尘治理难点,从完善焊接烟尘治理技术方案、优化焊接方法和焊接结构、改造厂房加强换气通风等方面总结治理措施,提出了焊接烟尘综合治理的新方向,即融入绿色设计思维、提高工艺制造水平、结合智能制造和采取综合治理方案。  相似文献   
150.
餐饮油烟中挥发性有机物风险评估   总被引:15,自引:4,他引:11       下载免费PDF全文
餐饮油烟中的挥发性有机物(VOCs)通过参与大气化学反应、气味效应、毒性效应影响室内外环境及人体健康. 分别于冬夏两季(6月和12月)用餐高峰时段对天津某中型餐馆排放油烟中VOCs进行实地监测,通过气相色谱-质谱联用仪(GC-MS)分析得出厨房油烟VOCs中主要污染物为乙醇和丙烷;餐馆油烟去除效率不足30%,对环境影响显著;醛类是影响油烟排放源臭气指数的主要污染物,油烟平均嗅阈值与丁醛嗅阈值相当;厨房排放油烟中含氧有机物和烯烃是其光化学活性的主要贡献者,油烟单位数浓度活性为3.8×10-12,与正己烷相当;厨房油烟中1,3-丁二烯、苯的致癌风险分别为1.3×10-3和1.6×10-5,存在较大的人群潜在致癌风险.   相似文献   
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