不同湿热预处理条件对餐厨垃圾厌氧发酵产氢的影响

采用湿热水解技术处理餐厨垃圾,研究不同湿热预处理温度与时间下餐厨垃圾w(VS)(VS为挥发性固体)、ρ(CODs_Cr)(CODs为溶解性化学需氧量)、ρ(TOC)、ρ(TN)等指标的变化,以评价湿热预处理对餐厨垃圾厌氧产氢效能的影响. 在此基础上,结合厌氧产氢动力学分析,确定厌氧发酵产氢的最佳湿热预处理条件. 结果表明:湿热预处理温度、时间对餐厨垃圾可浮油脱出量、w(VS)具有显著影响. 餐厨垃圾湿热预处理后ρ(CODs_Cr)、ρ(TOC)、ρ(TN)变化情况与w(VS)呈负相关. 餐厨垃圾经90℃湿热预处理30min后,可浮油脱出量为37.5mL/kg,w(VS)/w(TS)为95.12%,最大比产氢量达242.1mL/g,最大产氢速率为12.46mL/h,累积产氢率达0.88mol/mol,厌氧产氢启动时间为12.85h. 说明对餐厨垃圾进行适度的湿热预处理可有效提高有机物溶解性与生物可利用效率,进而提高厌氧发酵累积产氢量与产氢速率. 综合能耗、产出等因素,湿热预处理温度90℃,处理时长30min,为餐厨垃圾厌氧发酵产氢的最佳湿热预处理条件.      

Industries and lung cancer: A population-based case-control study in British Columbia

An investigation was conducted to identify high-risk industries for histological subtypes of lung cancer based on a large population-based case-control study in British Columbia, Canada. Occupational histories and information on smoking and relevant covariates were collected from 14,755 male incident cancer cases. Industrial risk factors for 2998 lung cancer cases, including histological subtypes were assessed by logistic regression using other cancer cases, excluding smoking-related cancers, as controls. An excess risk of lung cancer was found among workers in mining, metal manufacturing, and electric power systems for all histological-subtypes, and construction, water transport, health services for specific histological subtypes. Industrial associations that are unique to histological subtypes of lung cancer were identified. Future research needs to focus on confirming these histological associations, and identifying the risk from key exposures found within these industries (e.g. medical radiation, electromagnetic fields, and cooking fumes).     

Preconcentration of tin in environmental and biological samples by ion exchange using modified Amberlite XAD-2

Utilization of Amberlite XAD-2 surface modified by covalent immobilization of brilliant green through an azo spacer for adsorptive enrichment of Sn(II) from environmental and biological samples was highlighted. The resulting resin was characterized by Fourier transform infrared spectroscopy, elemental analysis, thermogravimetric analysis, and scanning electron microscopy. The resin retained Sn(II) ions at an optimum pH of 9.5 with a sorption capacity of 40 mg g^?1. The modified sorbent could be reused for 10 cycles without significant changes in sorption capacity. The recovery of Sn(II) was 98% when eluted with 0.1 mol L^?1 ethylenediaminetetraacetic acid. Scatchard analysis revealed that binding sites in the modified resin were homogeneous. The equilibrium adsorption data were analyzed using the Langmuir, Freundlich, Temkin, and Redlich–Peterson isotherm models. The method was applied with satisfactory results for determination of Sn(II) ions in human plasma and sea water.     

Evolutionary governance choice for corporate social responsibility: a forestry campaign case in South Korea

Firms select different governance types (e.g. internalisation, outsourcing or collaboration) for corporate social responsibility (CSR) activities. This paper examined how the choice of CSR governance type is influenced by social factors and organisational experiences and how changes in these factors affect the governance choice. These questions are especially meaningful in the context of developing countries with weak institutional environments and recent social change. With the unique phenomenon that is not readily explainable in terms of the extant theoretical groundwork on CSR governance choice, a case study of a South Korean forestry campaign by Yuhan-Kimberly was analysed. It was found that social circumstances triggered Yuhan-Kimberly's initiation of forestry projects, but the absence of social infrastructure limited the choice of governance type early on. Lack of experience also constrained the governance choice. Over time, environmental change and the accumulation of organisational knowledge caused the choice of governance to evolve. This study contributes to the CSR governance choice literature by exploring social and organisational determinants other than economic efficiency and by applying a dynamic perspective.     

自然灾害对我国农业的影响研究

通过对2000-2008年自然灾害发生面积与我国农业发展过程中的各项指标进行了对比分析和回归分析,得出了自然灾害对我国农业发展影响较为显著,并具体指出了旱灾、水灾等自然灾害对我国农业发展的影响.自然灾害通过影响农业单产、农业有效利用面积及农业总产值来影响农业,不同种类自然灾害的发生面积都处于不断波动之中,并呈现逐步提升之势,具有一定的区域性.最后指出了通过增强农业本身抵御自然灾害的能力和更好的预测农业自然灾害等,为各级政府制定抗灾减灾对策提供依据.     

常温下过硫酸盐氧化降解水中对氯苯胺

研究了常温下初始pH值对过硫酸盐氧化降解水中对氯苯胺(PCA)动力学过程的影响,并探讨了PCA降解的机理.结果表明,室温下,PCA的降解符合准一级动力学方程;pH值为3、5、7、9和11时,其一级动力学常数k分别为0.03×10-4、0.12×10-4、0.28×10-4、0.26×10-4和0.27×10-4s-1;酸性体系不利于PCA的降解,pH 7时PCA的降解速率最大,半衰期为6.88 h.通过LC/MS和GC/MS鉴定得到PCA降解的4种主要中间产物,分别为对氯硝基苯、对苯醌、1-(4氯苯)-3苯基脲和5-氯-2-(4氯苯二氮烯)苯酚,并在此基础上探讨了过硫酸盐氧化降解PCA的可能途径.     

Occupational accident: An example of fatalistic beliefs among medical waste workers in Bangladesh

This study was conducted to see whether fatalism is an important factor in explaining occupational accidents among medical waste operatives in Dhaka, Bangladesh. Data were collected using a variety of qualitative techniques and included observation, formal and informal dialogue. Sampling strategies included formal representative sampling, purposive and authoritative sampling. Employers did not supply PPE or offer training to their staff. Most workers (73%) did not wear PPE regularly, and a further 18% wore only insufficient PPE. Consequently, most waste workers (95%) reported that they had experienced occupational accidents, mostly (75%) from used needles and other sharps. These observations were associated with fatalistic beliefs among the participants, both managers and employees, who attributed these events to “fate” reflecting their perceived lack of control over such accidents. This study reveals many examples of a lack of organisational awareness that can occur within a culture of fatalism.     

基于因果依赖图的HAZOP推理方法研究

HAZOP分析方法自提出至今在石油化工领域一直被广泛应用,为代替传统HAZOP人工头脑风暴分析的过程,提出基于因果依赖图(CDG)的HAZOP推理方法,即CDG-HAZOP。首先建立系统的多级流模型,将系统生产过程抽象为流过程,用简单的功能图形符号来表示复杂的装置,然后利用多级流模型中的告警分析算法代替人工头脑风暴分析,推理偏差的可能原因和结果。CDG-HAZOP推理机制将传统HAZOP分析的重点由人工分析大量资料转移到多级流模型(MFM)的建立和校验上,能节约人工成本。将CDG-HAZOP推理方法用于催化裂化装置的反应-再生系统,对该系统可能发生的偏差进行原因和后果推理。     

提高军官常服皮鞋穿着与视觉舒适性探讨

本文通过军人脚型测量分析、军鞋审美取向调查分析、军鞋重量与运动性能试验分析等探讨研究,获得了脚型、式样、重量等相关数据,对于新式军鞋研究、生产和使用具有一定的参考作用。     

挤塑型聚苯乙烯泡沫塑料着火温度实验研究

研究了挤塑型聚苯乙烯(XPS)保温材料两种不同着火方式下的着火温度。采用南京江宁仪器分析厂生产的DW-02型点着温度测定仪对XPS的着火温度进行了测定。利用辐射引燃仪得到了2.2 cm厚挤塑型保温板在不同加热功率下的着火温度。结果表明:DW-02型点着温度测定仪测得的挤塑型聚苯乙烯保温材料的点燃温度约为355℃;热辐射引燃仪测得的2.2 cm厚保温板在不同加热功率下的着火温度是365-370℃,且引燃时间随着辐射引燃仪加热功率的增大而逐渐缩短;明火火源比热流辐射容易引燃挤塑型聚苯乙烯保温板。研究结论对FDS模拟挤塑型聚苯乙烯燃烧特性时,材料热解参数的设定有指引作用,对实际工程中遴选合适的外墙保温材料具有重要的参考价值。