高温烟气除尘滤料过滤性能检测及对比分析

对3大类不同过滤方式的高温烟气除尘滤料的压力损失、过滤速度、分级效率等性能指标进行测试对比分析,得到滤料在清洁和集尘条件下压力损失随过滤时间、粉尘负荷的变化规律.从过滤机理综合分析,集尘滤料的过滤分级效率明显高于清洁滤料过滤效率,为滤料选用提供理论依据.     

Evaluation of a healthcare safety climate measurement tool

Problem

Psychometrically validated measurement tools are needed to evaluate an organization's safety climate. In 2000, Gershon and colleagues published a new healthcare safety climate measurement tool to determine its relationship to safe work behavior (Gershon, R., Karkashian, C., Grosch, J., Murphy, L., Escamilla-Cejudo, A., Flanagan, P., et al. (2000). Hospital safety climate and its relationship with safe work practices and workplace exposure incidents. American Journal of Infection Control, 28, 211-21). The present study evaluated the psychometric properties of the Gershon tool when modified to address respiratory rather than bloodborne pathogen exposures.

Method

Medical practitioners, nurses, and nurse aides (n = 460) were surveyed using the modified Gershon tool. Data were analyzed by factor analysis and psychometric properties of the tool evaluated.

Results

Eight safety climate dimensions were extracted from 25 items (Cronbach's alpha range: 0.62 - 0.88). Factor extractions and psychometric properties were reasonably consistent with those of the Gershon tool.

Impact on Industry

The Gershon safety climate tool appears to have sufficient reliability and validity for use by healthcare decision makers as an indicator of employee perceptions of safety in their institution.     

杨树刺槐混交林沙地土壤的水分—物理性质

研究了刺槐与杨树混交林后沙地土壤水分－物理性质变化的状况,结果表明,刺槐与杨树混交后,土壤水分－物理性质得到了改善,表现在土壤最大持水量增加,毛管持水量、田间持水量得以提高,土壤有效持水量也有了较大幅度的提高,刺槐与杨树混交后土壤总孔隙度、非毛管孔隙度、毛管孔隙度得到提高,并由此而改善了混交林土壤的渗透性能,表4参7     

干旱区土壤小麦根系界面Cd行为的环境影响研究——以甘肃省白银市区耕作灰钙土为例

通过大田环境-土壤-作物系统Cd行为的环境影响研究,初步发现,共存元素Cd、Cu、Ni、Pb、Zn对Cd元素在土壤-作物根系界面行为的影响表现为正效应,其影响顺序为Cd>Pb>Cu>Zn>Ni;pH值、粘粒、粗粉粒含量与根系Cd含量呈负相关;磷和砂粒含量与根系Cd含量呈正相关;细粉粒、粗粘粒、有机质和CEC     

生态修复工程实施后对土壤理化性质改善效益初探

通过监测和田地区生态修复项目实施后所取得生态效益的结果表明,生态修复项目实施后,由于项目区风速降低,温度和相对湿度的变化减少,提高了植被盖度,降低了风蚀量,促进了成土作用的进行,从而逐渐改善了土壤的理化性质。     

决策树模型在水环境监测网络中选取代表性样点的应用

地表水体中的硝酸盐污染已经成为全球关注的热点环境问题之一。现今,国内外均建立了相关的监测网络对地表水体的水质实施长期监测,但是却导致大量的监测数据累积,给后续的科学研究工作带来了不便,尤其是在庞大的监测网络中如何选取有代表性样点的研究点则成为急需解决的问题之一。以比利时弗拉芒地区地表水的长期监测物理化学指标为例,利用决策树模型评估地表水样点的硝酸盐污染来源专家分类的有效性,为点位优化提供理论依据。原有监测点位的污染源专家分类和模型输出的可匹配率为80%,优化后监测点位从原有47个点降低到30个点,提高了监测工作效率。     

北方泥炭地泥炭土矿化速率、温度敏感性及其影响因素研究

北方泥炭地是全球重要的碳汇,也是全球变暖最为敏感的区域之一.然而,由于泥炭地表层和亚表层泥炭土碳排放过程对全球变暖的响应过程及机制仍存在一定争议,目前对全球变暖背景下泥炭地碳排放的认识仍存在一定不足.本研究于2019年8月在大兴安岭满归泥炭地采集表层(0～10 cm)和亚表层(15～30 cm)泥炭土进行室内增温模拟有氧培养,测定其矿化速率、有机质性质和水解酶活性.结果表明,表层泥炭土矿化速率在5、15、25℃下培养时((142.8±66.9)～(545.3±30.6)、(575.0±62.1)～(1843.0±547.4)、(888.4±123.9)～(3646.7±167.9)μg·g^-1·d^-1)均高于亚表层((113.0±41.5)～(367.1±64.1)、(357.4±52.3)～(1122.1±218.8)、(697.1±38.1)～(2336.4±150.6)μg·g^-1·d^-1),但表层和亚表层矿化作用的温度敏感性不具有显著差异;培养过程中,表层与亚表层泥炭土β-1,4-N-乙酰葡...     

Biodegradation of chlorpyrifos by either single or combined cultures of some soilborne plant pathogenic fungi

Abstract

Biodegradation of chlorpyrifos was studied in liquid culture media amended with either single or combined eight different plant pathogenic fungi isolated from the continuous cropping wheat fields. The average recovery of chlorpyrifos from the liquid media was found to be 86.1%. The detection limit of chlorpyrifos by the analytical method used was 19 ppb. Data showed that the growth of mixed fungi at concentrations up to 200 ppm of chlorpyrifos was higher than in the control treatment. Chlorpyrifos concentrations declined in the medium of combined fungi more than it did in the medium of any single fungus with increase in the incubation period. The amount of chlorpyrifos recovered was 79.8 ppm (39.9%) in the combined fungal cultures after 21 days. However, those recovered from the media of Fusarium graminearum, F. oxysporum, Rhizoctonia solani, Cladosporhim cladosporiodes, Cephalosporium sp., Trichoderma viridi, Alternaria alternata, and Cladorrhinum brunnescens, ranged from 48.0 to 74.8%. The half‐life value (T_1/2) for chlorpynfos was 15.8 day in the medium amended with mixed fungi. However, for the single cultures it ranged from 19.3 to 33.0 day.     

Using Twitter to communicate conservation science from a professional conference

Scientists are increasingly using Twitter as a tool for communicating science. Twitter can promote scholarly discussion, disseminate research rapidly, and extend and diversify the scope of audiences reached. However, scientists also caution that if Twitter does not accurately convey science due to the inherent brevity of this media, misinformation could cascade quickly through social media. Data on whether Twitter effectively communicates conservation science and the types of user groups receiving these tweets are lacking. To address these knowledge gaps, we examined live tweeting as a means of communicating conservation science at the 2013 International Congress for Conservation Biology (ICCB). We quantified and compared the user groups sending and reading live tweets. We also surveyed presenters to determine their intended audiences, which we compared with the actual audiences reached through live tweeting. We also asked presenters how effectively tweets conveyed their research findings. Twitter reached 14 more professional audience categories relative to those attending and live tweeting at ICCB. However, the groups often reached through live tweeting were not the presenters’ intended audiences. Policy makers and government and non‐governmental organizations were rarely reached (0%, 4%, and 6% of audience, respectively), despite the intent of the presenters. Plenary talks were tweeted about 6.9 times more than all other oral or poster presentations combined. Over half the presenters believed the tweets about their talks were effective. Ineffective tweets were perceived as vague or missing the presenters’ main message. We recommend that presenters who want their science to be communicated accurately and broadly through Twitter should provide Twitter‐friendly summaries that incorporate relevant hashtags and usernames. Our results suggest that Twitter can be used to effectively communicate speakers’ findings to diverse audiences beyond conference walls.     

Utilization of cement kiln dust (CKD) in cement mortar and concrete—an overview

Solid waste management is one of the major environmental concerns around the world. Cement kiln dust (KKD), also known as by-pass dust, is a by-product of cement manufacturing. The environmental concerns related to Portland cement production, emission and disposal of CKD is becoming progressively significant. CKD is fine-grained, particulate material chiefly composed of oxidized, anhydrous, micron-sized particles collected from electrostatic precipitators during the high temperature production of clinker. Cement kiln dust so generated is partly reused in cement plant and landfilled. The beneficial uses of CKD are in highway uses, soil stabilization, use in cement mortar/concrete, CLSM, etc.Studies have shown that CKD could be used in making paste/mortar/concrete. This paper presents an overview of some of the research published on the use of CKD in cement paste/mortar/concrete. Effect of CKD on the cement paste/mortar/concrete properties like compressive strength, tensile strength properties (splitting tensile strength, flexural strength and toughness), durability (Freeze–thaw), hydration, setting time, sorptivity, electrical conductivity are presented. Use of CKD in making controlled low-strength materials (CLSM), asphalt concrete, as soil stabilizer, and leachate analysis are also discussed in this paper.