Diversity surveys of soil bacterial community by cultivation--based methods and molecular fingerprinting techniques

By combining the cultivation methods with molecular fingerprinting techniques, the diversity surveys of soil bacterial community in 13 areas of China were carded out. The cultivable heterotrophic diversity was investigated by colony morphology on solid LB medium. Genetic diversity was measured as bands on denaturing gradient gel electrophoresis(DGGE) by the extraction and purification of the total soil DNA, and amplification of bacterial 16S rDNA fragments by polymerase chain reaction(PCR). The Shannon-Wiener indices of diversity(H), richness(S) and evenness(EH) were employed to estimate the diversity of soil bacterial community. The results showed that there was an obvious diversification existed in soil from the different areas. However, the genetic diverslty estimated by PCR-DGGE can provide more comprehensive information on bacterial community than the cultivation-based methods. Therefore, it is suggested to combine the traditional methods with genetic fingerprinting techniques to survey and estimate soil bacterial diversity.     

Long-term exposure to air pollution and cerebrovascular disease: findings from Beijing Health Management Cohort study

● This study explored the long-term association by double robust additive models. ● Individual exposure concentrations were assessed by integrating GAM, LUR and BPNN. ● PM_2.5, SO₂ and NO₂ are positively associated with cerebrovascular disease. ● CO could reduce the risk of cerebrovascular disease with the highest robustness. ● The elderly, women and people with normal BMI are at higher risk for air pollution. The relationship between air pollution and cerebrovascular disease has become a popular topic, yet research findings are highly heterogeneous. This study aims to investigate this association based on detailed individual health data and a precise evaluation of their exposure levels. The integrated models of generalized additive model, land use regression model and back propagation neural network were used to evaluate the exposure concentrations. And doubly robust additive model was conducted to explore the association between cerebrovascular disease and air pollution after adjusted for demographic characteristics, physical examination, disease information, geographic and socioeconomic status. A total of 25097 subjects were included in the Beijing Health Management Cohort from 2013 to 2018. With a 1 μg/m³ increase in the concentrations of PM_2.5, SO₂ and NO₂, the incidence risk of cerebrovascular disease increased by 1.02 (95% CI: 1.008–1.034), 1.06 (95% CI: 1.034–1.095) and 1.02 (95% CI: 1.010–1.029) respectively. Whereas CO exposure could decrease the risk, with an odds ratio of 0.38 (95% CI: 0.212–0.626). In the subgroup analysis, individuals under the age of 50 with normal BMI were at higher risk caused by PM_2.5, and SO₂ was considered more hazardous to women. Meanwhile, the protective effect of CO on women and those with normal BMI was stronger. Successful reduction of long-term exposure to PM_2.5, SO₂ and NO₂ would lead to substantial benefits for decrease the risk of cerebrovascular disease especially for the health of the susceptible individuals.     

高炉煤气泄露危害后果定量评价

2008年12月24日9时许,唐山遵化市港陆钢铁有限公司2号高炉重力除尘器顶部泄爆板爆裂造成煤气泄漏,事故发生时当班工人共44人,共造成44人中毒,其中17人死亡,27人受伤的重大安全事故。因此高炉煤气泄漏造成中毒、爆炸等事故是高炉炼铁系统存在的主要危险有害因素之一。     

基于灰局势决策的安全投资状况评价

对企业现有安全投资状况进行评价是合理进行安全投资的前提和基础。为此,将灰局势决策方法应用于安全投资状况评价问题上,通过一系列灰处理过程,得到一个可以评价各参评年份安全投资状况的综合效果测度值,以此为标准对安全投资状况进行综合评价。通过实例评价及分析,清晰展现了企业以往安全投资状况,为今后科学合理地制定安全投资策略指明了方向。     

深核集团安全生产管理实践

深核集团是一家投资管理型公司,下属多家子公司,行业跨度较大;各企业内部管理较多依靠社会聘用人员,产线员工均以外来劳务工为主,人员流动性大;设备自动化程度不高,部分设施陈旧,以上种种因素都加大了安全生产管理的难度。     

金属氧化物催化剂上吡啶催化燃烧

为了研究催化燃烧法净化挥发性有污染物的可能性,考察了金属氧化物催化剂上吡啶的氧化活性及氧化过程ＮＯｘ控制能力,吡啶氧化产物ＮＯｘ随反应温度升高呈现极大值。催化剂的氧化活性ＮＯｘ控制能力呈正比关系。     

生物水解（酸化）法处理高浓度洁霉素废水的降解机理研究

在应用生物水解（酸化）法处理高浓度洁霉素生产废水中试试验中,着重研究水解（酸化）反应中起主要作用的微生物菌群及其降解效率。同时采用GPC（凝胶渗透色谱）、GC/MS（色谱一质谱）等分析手段对水解（酸化）反应过程中有机物形态变化进行研究。结果表明,在水解（酸化）反应中起主要作用的有埃希氏菌属、发酵单胞菌属、气单胞菌属、变形杆菌属、柠檬酸杆菌属等。同时,水解（酸化）反应具有将洁霉素废水中的大分子有机物降解为小分子有机物的作用,可提高废水的可生化性。     

三氧化二砷冶炼废渣的危害及处理

三氧化二砷冶炼过程中产生大量含砷废渣,此类废渣对环境的危害极大,目前国内外常规的稳定化技术、固化技术难以从根本上解决其对环境的危害,通过大量的试验和实践,证明此类废渣在水泥行业中能有效地被利用,可彻底地消除三氧化二砷冶炼过程中的废渣污染问题。     

Modeling patterns of nonlinearity in ecosystem responses to temperature, CO2, and precipitation changes.

It is commonly acknowledged that ecosystem responses to global climate change are nonlinear. However, patterns of the nonlinearity have not been well characterized on ecosystem carbon and water processes. We used a terrestrial ecosystem (TECO) model to examine nonlinear patterns of ecosystem responses to changes in temperature, CO2, and precipitation individually or in combination. The TECO model was calibrated against experimental data obtained from a grassland ecosystem in the central United States and ran for 100 years with gradual change at 252 different scenarios. We primarily used the 100th-year results to explore nonlinearity of ecosystem responses. Variables examined in this study are net primary production (NPP), heterotrophic respiration (R(h)), net ecosystem carbon exchange (NEE), runoff, and evapotranspiration (ET). Our modeling results show that nonlinear patterns were parabolic, asymptotic, and threshold-like in response to temperature, CO2, and precipitation anomalies, respectively, for NPP, NEE, and R(h). Runoff and ET exhibited threshold-like pattern in response to both temperature and precipitation anomalies but were less sensitive to CO2 changes. Ecosystem responses to combined temperature, CO2, and precipitation anomalies differed considerably from the responses to individual factors in terms of response patterns and/or critical points of nonlinearity. Our results suggest that nonlinear patterns in response to multiple global-change factors were diverse and were considerably affected by combined climate anomalies on ecosystem carbon and water processes. The diverse response patterns in nonlinearity have profound implications for both experimental design and theoretical development.     

深圳市滨海湿地两个观光农业系统的能值整合研究

应用能值研究方法对深圳市海上田园旅游区的芦花湖和农家小院两个观光农业系统进行了生态经济分析.从系统和子系统两个层面,进行了能值产出、环境负载、可持续发展能力的评价与比较;与珠三角另一个观光农业系统(百万葵园)、两个基塘农业系统(菜-鱼、菜-猪-鱼)和一个巴西基塘系统(谷-猪-鱼)进行了横向比较.从货币收益的角度看,农家小院系统的费用使用效率、商品生产获利能力要优于芦花湖系统.但能值整合分析却显示出不一样的结果:两系统内旅游业子系统的能值交换率较高,而二者的农牧业子系统及农家小院系统的水产业子系统的能值交换率均较低,其生产效率仍有待提高.芦花湖系统的环境负载率为7.31,能值可持续发展指标为0.255,分别是农家小院的0.25倍和2.26倍,因而更具长远发展优势.与传统农业相比,观光农业的能值交换率和环境负载率整体偏高,表明其在经济效益创造上优于传统农业,但在自然资源利用和环境压力,以及可持续发展能力等方面与传统农业尚存在差距,在今后的发展中需借鉴传统农业的经验并加以改善,防止观光农业发展中绿色产业褐色化现象的发生.