宁淮高速公路膨胀土边坡生态土壤稳定剂土质改性试验研究

介绍了STW型生态土壤稳定剂对宁淮高速公路边坡膨胀土的胀缩性、水稳性、强度、抗冲刷性等的改性试验研究,并结合现场试验,分析了STW型生态土壤稳定剂用于膨胀土边坡坡面防护的效果。试验结果表明:STW型生态土壤稳定剂改性膨胀土的胀缩性,随着稳定剂掺量的增大而减小;改性土的水稳性,随着稳定剂稀释浓度的增大而增强;同时,改性土的强度得到显著提高,抗冲刷性能得到明显增强,具有显著的防治水土流失、促进表层固化、提高坡面稳定的效果。     

Effects of cadmium on forearm bone density after reduction of exposure for 10 years in a Chinese population

The main focus of this study was to evaluate long term effects of cadmium on forearm bone mineral density after stopping ingestion of cadmium-polluted rice for 10 years in a Chinese population. A total of 532 persons (338 women and 194 men), living in control, moderately and heavily polluted areas, were included in this study. The residents living in the polluted area ceased ingesting cadmium-polluted rice in 1996. All participants were require to answer a questionnaire and the bone mineral density (BMD) was measured by dual energy X-ray absorptiometry (DXA) at the proximal radius and ulna. Samples of urine and blood were collected for determination of cadmium in urine (UCd) and blood (BCd).The BMD of subjects living in the heavily polluted area was significantly lower than that of those living in control area in both men and women (p < 0.01). For the people living in the moderately polluted area, only the women's BMD was greatly lower compared to that in the control area (p < 0.05). The BMD declined with the increasing BCd and UCd in both sexes, especially in the highest level (BCd > 5 µg/L, UCd > 10 µg/g crea) groups (p < 0.01). It was found that there were significant differences in the prevalence of osteoporosis among the different areas (χ² = 13.046, p = 0.0003) and different UCd groups (χ² = 4.511, p = 0.0337) in women, but not in men (χ² = 0.962, p = 0.3268; χ² = 1.906, p = 0.1675). But a significant difference exists in the prevalence of osteoporosis among different BCd groups in both genders (χ² = 9.304, p = 0.00229, in women; χ² = 4603, p = 0.0319, in men). This study suggested that cadmium could play a long-term role on bone and more attention should be paid to cadmium effects on bone metabolism after reduction of exposure.     

Perfluorosulfonates and perfluorocarboxylates in snow and rain in Dalian,China

Samples of precipitation events (snow and rain) in Dalian, a typical coastal town in China, were analyzed for perfluorosulfonates (PFSAs) and perfluorocarboxylates (PFCAs) to investigate atmospheric contamination by these compounds. In the snow event on December 16, 2006, samples were collected from 21 different sites and in another 6 precipitation events, samples were collected from a single location. Four PFSAs (C4, C6, C8, C10) and seven PFCAs (C6–12) were analyzed. Among the homologues, perfluorooctane sulfonate (PFOS) concentrations were the highest with a geometric mean (GM) of 145 ng/L (n = 21) during the snow event on December 16, 2006, followed by perfluorooctanoate (PFOA) with a GM of 24.7 ng/L (n = 21). Concentrations of perfluorobutane sulfonate (PFBS), perfluorohexane sulfonate (PFHxS) and perfluoroheptanoate (PFHpA) were more than two orders of magnitude lower than that of PFOS. Other PFSAs and PFCAs were found to be below the limit of detection in all the samples. In other 6 precipitation events, PFSAs and PFCAs were detected approximately in the same order of magnitude in both snow and rain. The results indicate that wet deposition may be a potential transport mechanism of perfluorinated chemicals in the environment.     

大坝拦截对河流水溶解组分化学组成的影响分析——以夏季乌江渡水库为例

以乌江渡水库为主要研究对象,揭示了大坝拦截条件下的夏季水化学特征：阴离子以HCO-3,SO2-4为主,阳离子以Ca2+,Mg2+为主,其余离子含量低于10%,说明了碳酸盐岩的风化对水体化学组成起到了主要控制作用,蒸发盐岩石的风化对水体化学组成影响较小。水库水体存在温度分层现象,形成了不同层位的水体有着不同的水化学组成,即水化学分层。水化学的分层形成了溶解组分在水库垂直深度上的规律分布,比如受藻类的影响,Si和叶绿素随深度成相反的变化特征;HCO-3受光合作用和有机质降解的影响,30 m 以上随着水深的增加而递增,30 m 以下呈现相反趋势;水库泄水方式明显改变了水化学各种参数和离子在水体中的分配。乌江水库两主要支流（息烽河和偏岩河）分别对乌江渡坝前水体中的Ca2+,SO2-4,HCO-3,Mg2+和K+,Na+,Cl-有贡献。网箱养鱼、生活污水、农业施肥、酸性矿山废水以及酸雨沉降都会对水体造成不同程度的污染。     

稀土在废水处理中的应用进展

综述了国内稀土金属在废水处理中的最新应用进展,总结了稀土复合吸附剂的制备方法及其在含磷、氨氮、砷、氟、铬、镉等废水处理中的效果,讨论了稀土复合混凝剂和稀土催化剂在染料、助剂、化工等高浓度有机废水处理中的应用,为找到高效环保的处理工业废水的方法提供了依据.     

企业生产安全事故的“基因”分析

思索生产安全事故频发共性表象"违法、违章"背后的原因,提出"生产安全事故基因"概念。分析得出"去小概率性"、"社会责任缺失"和"非货币化产出分析能力短缺"3种生产安全事故基因,前两种基因是不可去基因,后一种是可去基因,三者会在不同的条件下以显性或隐性的形式呈现,并作用于生产过程;提出企业组织安全进化的常规对策——完善市场经济环境,创新对策——教育要为"安全"生产服务,强调学历教育系统在创新对策中的重要地位和作用。通过"基因"分析及其对策,为安全生产培养安全管理人员和相关人才,推动安全生产,实现经济与社会和谐发展。     

中国区域能源、经济与环境耦合的动态演化

文章全面解析了系统耦合机制,以此为基础构建了能源、经济与环境三系统耦合模型,测算了1995—2014年中国四大区域三大系统间的耦合协调水平,并从时空两个维度对区域三系统交互关系的变化特征以及差异做出了全面讨论。结果表明,1各省区经济和环境综合指数呈持续上升的良好态势,而能源综合指数在小幅波动中保持了较为稳定的发展状态,同时三者关系极为密切,具体表现为三类指数的变动具有显著的相关性。2三系统交互作用的耦合度均保持不断递增的演化趋势,但绝对水平较低,且区域间差异较为明显,整体上呈现由东到西递减态势。3三系统的耦合变化与能源-经济、能源-环境和经济-环境三类二元系统的协调发展具有密切的相关性。4在探索三系统耦合协调的持续发展路径时,需重点引导三系统打破固有束缚,通过有秩序的相互配合产生单个系统所不具备的发展能力。而从现实状态看,在当前面临经济下行、资源环境不可持续以及区域发展差异扩大等问题的严峻挑战,各省区需结合本区域实际发展状况和比较优势制定发展规划。东部需以雄厚的经济实力为基础强化技术创新,以带动能源高效利用和环境保护;中部和东北需调整能源消费结构并提高能源利用效率;西部则应将重点放在绿色发展和防范环境风险两方面。     

Factors influencing farmers’ decisions on nitrogen fertilizer application in the Liangzihu Lake basin,Central China

Overuse of nitrogen (N) fertilizers in agriculture activities has caused severe water pollution in China. The lack of data at producer level hampers decision makers in the development and implementation of efficient policies to curb excessive N-fertilizer use. In a survey of 300 farm households in the Liangzihu Lake basin, we identified factors associated with farmers’ decisions on N-fertilizer use and application rate. Household survey and multiple linear regression models indicate that the average application rate in the study region is 229 kg N ha^?1, which exceeds the recommended rate for maximum profit for cereal crops (maize, wheat, and rice) in China of 150–180 kg N ha^?1. High N-application rates are associated with low farmland productivity (coefficient = ?15.66, p = 0.02), a high share of off-farm income (coefficient = 27.14, p = 0.003), and a low education level of the household head (coefficient = ?10.83, p = 0.039). Neither physical infrastructure nor access to input markets appears to be related to N-application rates. It may be concluded that excessive use of N in agriculture of Central China is mainly a problem of insufficient awareness and high share of off-farm income.     

Measurement of public awareness of climate change in China: based on a national survey with 4,025 samples

Just before the new round of UN climate change conference in Bonn, a survey report, named as the Climate Change in the Chinese Mind 2017, was released in Beijing. The investigation was conducted in the form of a computer-assisted telephone survey with a sample size of 4,025 samples, covering 332 prefecture-level administrative units and four municipalities in China. Urban-rural proportion and sex proportion were specially taken into account, so as to demonstrate the Chinese public awareness objectively. The investigation measures the public awareness from six aspects, which includes climate change beliefs, impacts, response, policies, actions, and the assessment of the effectiveness of climate communication. This article presents the key findings of the survey and provides further insights behind the data.     

The fungicide difenoconazole alters mRNA expression levels of human CYP3A4 in HepG2 cells

The fungicide difenoconazole has been frequently detected in agricultural products, soils and surface waters, causing increasingly public concern due to toxicological properties. Although systemic triazole fungicides can inhibit the enzymatic activity of many CYP450 isozymes, how difenoconazole affects the human CYP3A4 still remains largely unknown. We thus investigated the effect of difenoconazole on normal mRNA expression and protein expression of human CYP3A4 by real-time quantitative PCR and western blot, respectively. Results show that the exposure to difenoconazole from 0.01 to 0.5 μM for 24 h down-regulates mRNA expression levels of human CYP3A4 in HepG2 cells. We also found that difenoconazole could inhibit the enzymatic activity of human CYP3A4 in a concentration-dependent mode. The IC₅₀ of difenoconazole for inhibition of CYP3A4 activity is 0.41 µM, showing a stronger inhibitor in comparison with ketoconazole. Overall, our findings indicate the potential risk of difenoconazole for the disruption of human CYP3A4.