组合钢管混凝土式防屈曲支撑

由于河北省图书馆加固改造工程的实际需要,开发出了一种新型组合钢管混凝土式防屈曲支撑。该新型支撑解决了全钢型防屈曲支撑在大长度时难以满足稳定性的问题,而且比起传统钢管混凝土约束的防屈曲支撑,无需考虑内芯与混凝土之间的粘结力问题,加工过程简便、施工速度快,且质量容易控制。现已对此类新型支撑完成了短试件和足尺试件的拟静力滞回性能试验,试验结果表明,新型支撑的滞回曲线饱满稳定,整体稳定性和局部稳定性较好,满足工程要求。     

核电安全

<正>2010年6月16日国家核安全局有关负责人向媒体通报,大亚湾核电站二号机组反应堆中的一根燃料棒包壳出现微小裂纹,其影响仅限于封闭的核反应堆一回路系统中,放射性物质未进入环境,未对环境造成影响和损害。该负责人指出,大亚湾核电站二号机组核反应堆一回路冷却     

微塑料对双齿围沙蚕生理代谢的影响研究

为探讨微塑料对双齿围沙蚕生理代谢的影响,本文研究了聚丙烯(PP)、聚酰胺(PA)和聚氯乙烯(PVC)3种微塑料在不同浓度(0.1％、1％和5％)和暴露时间下对双齿围沙蚕体内过氧化氢酶(CAT)、乙酰胆碱酯酶(AchE)活性以及代谢指标排氨率和呼吸速率的影响.结果表明,随微塑料浓度的升高,双齿围沙蚕体内CAT活性显著提升,5％浓度下双齿围沙蚕体内CAT活性最高;PVC对双齿围沙蚕体内AchE活性表现为低浓度(0.1％)抑制、高浓度(5％)促进的作用;PP和PA在不同浓度下对双齿围沙蚕体内AchE酶活性均表现为促进作用;随着微塑料浓度的升高,双齿围沙蚕的排氨率和呼吸速率显著升高(P<0.05).综上,微塑料在高浓度条件下,在一定时间内可以对双齿围沙蚕产生氧化胁迫作用,并一定程度上影响其排氨率和呼吸速率.     

Sewage sludge ditch for recovering heavy metals can improve crop yield and soil environmental quality

• Indirect use of sludge in ditches alongside plants was tested in field experiments. • The dried and stabilized sludge in ditches was recovered with heavy metals. • Cd, Pb, Cu and Zn in the planted soil were all in a safe range. • The indirect use of sludge increased plant yield, soil N content and C storage. The treatment and disposal of municipal sewage sludge (MSS) is an urgent problem to be resolved in many countries. Safely using the nutrients within MSS to increase crop yield and enhance the fertility of poor soil could contribute to achieving sustainable development. An indirect use of MSS in ditches alongside Pennisetum hybridum plants was studied in field plots for 30 months and the contents of heavy metals and macronutrients were monitored in soil, sludge and plant samples. We found that the yield of P. hybridum was significantly increased by 2.39 to 2.80 times and the treated plants had higher N content compared with no sludge. In addition, the organic matter (OM) and N contents in the planted soil increased significantly compared with the initial soil. The OM content in the planted soil of the MSS treatment was 2.9 to 5.2 times higher than that with no sludge, and N increased by 2.0 to 3.8 times. However, MSS had no significant effect on the N, P and K contents in the soil at the bottom of the MSS ditch, and the content of heavy metals (Cd, Pb, Cu and Zn) were also within the safe range. Moreover, the moisture content and phytotoxicity of MSS after this indirect use were reduced and the heavy metal contents changed little, which is favorable to the further disposal of recovered MSS. Therefore, this indirect use of MSS is beneficial to agricultural production, soil quality and environmental sustainability.     

Environmental effects and risk control of antibiotic resistance genes in the organic solid waste aerobic composting system: A review

• ARGs were detected in livestock manure, sludge, food waste and fermentation dregs. • The succession of microbial community is an important factor affecting ARGs. • Horizontal transfer mechanism of ARGs during composting should be further studied. Antibiotic resistance genes (ARGs) have been diffusely detected in several kinds of organic solid waste, such as livestock manure, sludge, antibiotic fermentation residues, and food waste, thus attracting great attention. Aerobic composting, which is an effective, harmless treatment method for organic solid waste to promote recycling, has been identified to also aid in ARG reduction. However, the effect of composting in removing ARGs from organic solid waste has recently become controversial. Thus, this article summarizes and reviews the research on ARGs in relation to composting in the past 5 years. ARGs in organic solid waste could spread in different environmental media, including soil and the atmosphere, which could widen environmental risks. However, the conventional composting technology had limited effect on ARGs removal from organic solid waste. Improved composting processes, such as hyperthermophilic temperature composting, could effectively remove ARGs, and the HGT of ARGs and the microbial communities are identified as vital influencing factors. Currently, during the composting process, ARGs were mainly affected by three response pathways, (I) “Microenvironment-ARGs”; (II) “Microenvironment-microorganisms-ARGs”; (III) “Microorganisms-horizontal gene transfer-ARGs”, respectively. Response pathway II had been studied the most which was believed that microbial community was an important factor affecting ARGs. In response pathway III, mainly believed that MGEs played an important role and paid less attention to eARGs. Further research on the role and impact of eARGs in ARGs may be considered in the future. It aims to provide support for further research on environmental risk control of ARGs in organic solid waste.     

2019年扬州市公共场所健康危害因素监测结果分析

为了提升扬州市公共场所卫生状况和传染病防控能力,按照国家标准于2019年对扬州市宾馆(酒店)类、沐浴类、理发店类、美容店类和候车室类5类公共场所的健康危害因素(空气质量和公共用品用具)进行监测,按照《公共场所卫生指标及限值要求》(GB 37488—2019)进行评价。结果表明,共监测空气质量样品216份,合格率为84.26%,共监测公共用品用具1 414份,合格率为96.46%,不同场所的空气质量合格率和公共用品用具微生物指标合格率差异均具有统计学意义(P 0.05)。不同类型公共用品用具监测项目中,金黄色葡萄球菌的合格率最高(100%),而真菌总数的合格率最低(93.75%)。各类公共用品用具中,拖鞋合格率最低(91.67%),床单相对较高(99.70%)。扬州市公共卫生状况总体良好,在空气质量监测中,物理项目和微生物项目合格率较低,在公共用品用具监测中,细菌总数和大肠菌群存在不合格现象。     

2006~2015年中国华北地区气溶胶的垂直分布特征

为研究高污染地区气溶胶形成机理提供理论依据,利用CALIPSO卫星提供的Level 2Profile和Level 2VFM产品,分析了华北地区2006～2015年532nm总后向散射系数,退偏振比,色比及不同类型气溶胶的时空变化特征,并结合地基观测资料,探讨了不同能见度下华北地区气溶胶垂直分布特征.结果表明：华北地区气溶胶粒子532nm总后向散射系数,退偏振比和色比范围依次为0.5×10^-3～8.0×10^-3km^-1sr^-1,0.14～0.3和0.6～2.0,且具有显著的季节和高度变化特征;能见度<5km时粒子散射能力最强,非球形最弱,粒径最小,对应的最大532nm总后向散射系数,最小退偏振比和最小色比依次为0.012km^-1sr^-1,0.092和0.856,能见度>10km时相反;污染沙尘,沙漠沙尘,污染大陆气溶胶和洁净海洋气溶胶集中在0～2km,出现的频率依次为13.81%,8.48%,5.45%和1.22%.     

Bibliometric analysis of ecosystem monitoring-related research in Africa: implications for ecological stewardship and scientific collaboration

Regional ecosystem monitoring is a central form of knowledge sharing and collaboration amongst scientists and decision makers on environmental health, land use change, and science-policy development. Despite the proliferation of such research networks on long-term monitoring on many continents, little has been achieved in Africa. This study aims to assess and examine the spatiotemporal trend and categorical patterns in ecosystem monitoring-related research in Africa for the benefits of conserving biodiversity and sustaining natural resource sectors for well-being and livelihood security, environmental planning, and ecological stewardship. A systematic review was conducted using bibliometric tools. Based on a set of search terms and peer-reviewed publications retrieved from various ecosystem monitoring networks and journal databases, further analysis was conducted using social network approaches, mapping tools, and content analysis. About 1442 scientific publications on ecosystem monitoring and related research were documented from 1987 to 2014 mostly published in English. The number of publication increased progressively since 1992 after the Convention on Biodiversity was signed and this trend peaked till 2008. South African Journal of Science was the most leading journal and Nature the most cited. Internationally coauthored and collaborative articles represented majority of the findings with the United Kingdom at the central position in the research network due to colonial relationships. Regional collaboration amongst countries is limited owing to language barriers and other institutional constraints such as funding and short-term projects. These findings have implication for prioritizing national and regional policies toward biodiversity science and its contribution to human well-being, food security, and global change responses.     

冶炼企业周边农田土壤的多环芳烃污染及其细菌群落效应

多环芳烃是一类持久性有机污染物,进入土壤后可能产生多方面生态效应。为研究多环芳烃对土壤微生物的影响,选取南京某冶炼企业周边农田样品,在分析污染物含量基础上,采用高通量测序、定量PCR等方法综合评价了土壤细菌多样性和组成以及多环芳烃降解细菌丰度等特征。17个土壤样品中,多环芳烃总量为0.25~31.08 mg·kg-1,并具有随污染源距离增加而降低的空间分布特征。与土壤理化性质如p H相比较,多环芳烃污染对土壤细菌的总体多样性和群落组成影响不显著。进一步分析发现多环芳烃与潜在降解微生物的相对丰度和降解功能基因(芳香环羟基化双加氧酶,PAH-RHDα)拷贝数显著正相关。污染较重样品的克隆、测序分析表明,土壤中PAH-RHDα基因主要属于革兰氏阳性细菌nid A3/fad A1类群,且与分支杆菌相关序列较为接近。这些结果综合评价了冶炼企业周边农田土壤多环芳烃污染对微生物群落的影响,提示土壤污染在多环芳烃潜在降解细菌中的富集作用,将为后续污染土壤生物修复提供重要科学依据。