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1.
恶臭物质的嗅觉阈值与致臭机理研究概况与展望   总被引:2,自引:0,他引:2  
嗅阈值是表征气味物质特性的重要指标,对认识异味污染的形成机理、恶臭评估及污染控制有重要意义.围绕嗅阈值的测定方法、嗅阈值与分子结构的关系及复合臭气评估模型,论述国内外相关研究的概况,在指出现有研究不足的同时,提出有待解决的关键问题及重点研究内容.  相似文献   
2.
用丙酮和正己烷(体积比为1∶1)作溶剂,在100℃和1 500 psi的压力下,用快速溶剂萃取仪从土壤中萃取出有机氯农药,用分子筛进行脱水和净化,GC-MS进行分析,对土壤中有机氯农药进行测定。方法的检出限为0.000 4~0.000 7 mg/kg,曲线的相关系数在0.998以上。对进口标准土进行测定,回收率为77.1%~105.2%,相对误差为-22.9%~5.2%,测定结果在证书允许误差范围内。用硅藻土制成高、中、低3个浓度级别的加标回收和精密度实验,加标回收率为84.3%~101.5%,相对标准偏差为0.6%~11.4%,表明方法准确可靠,方法用于实际土壤测定时发现土壤有不同程度的有机氯农药污染。  相似文献   
3.
Effective management refers to the ability of a protected area or indigenous territory to meet its objectives, particularly as they relate to the protection of biodiversity and forest cover. Effective management is achieved through a process of consolidation, which among other things requires legally protecting sites, integrating sites into land‐use planning, developing and implementing management and resource‐use plans, and securing long‐term funding to pay for recurrent costs. Effectively managing all protected areas and indigenous territories in the Amazon may be needed to avoid a deforestation tipping point beyond which regional climatic feedbacks and global climate change interact to catalyze irreversible drying and savannization of large areas. At present, protected areas and indigenous territories cover 45.5% (3.55 million km2) of the Amazon, most of the 60–70% forest cover required to maintain hydrologic and climatic function. Three independent evaluations of a long‐term large‐scale philanthropic initiative in the Amazon yielded insights into the challenges and advances toward achieving effective management of protected areas and indigenous territories. Over the life of the initiative, management of sites has improved considerably, particularly with respect to management planning and capacity building, but few sites are effectively managed and many lack sufficient long‐term financing, adequate governance, support of nongovernmental organizations, and the means to withstand economic pressures. The time and money required to complete consolidation is still poorly understood, but it is clear that philanthropic funding is critical so long as essential funding needs are not met by governments and other sources, which could be on the order of decades. Despite challenges, it is encouraging that legal protection has expanded greatly and management of sites is improving steadily. Management of protected areas in other developing countries could be informed by improvements that have occurred in Amazonian countries.  相似文献   
4.
根际土壤微生物是植物修复及其强化修复技术的重要组成部分,了解根际土壤微生物生态效应有助于深入探索修复机制,从而进一步提高修复效率.微生物生态效应反映土壤生态变化,对于有效评估强化调控生态风险具有重要意义.在总结污染土壤植物修复根际微生物生态效应研究的基础上,综述强化调控措施与根际土壤微生物可能存在的相互影响,并分析利用微生物分子生态学技术评估强化调控措施施用风险的可行性.  相似文献   
5.
The rise in the number of fungi that resisted antifungal action is of serious concern nowadays. In this study, the potential of acid condensate (AC) produced from microwave-assisted pyrolysis of palm kernel shell (PKS) was investigated for its antifungal properties through molecular docking evaluation. The phenolic-rich AC was determined for its chemical compositions using the GC–MS analysis where compounds with the highest phenolics content were further evaluated (using the Autodock Tools 1.5.7) for its potential enzymes/protein binding properties. From the GC–MS analysis, catechol, guaiacol and syringol were present at highest percentages. This directly correlates with results obtained from the molecular docking works where all these ligands managed to bind (indicated by H-bond, π-stacking, hydrophobic interaction) with some of the amino acid at the active sites which indicate its potential to inhibit substrate binding of this enzyme. As a conclusion, this study demonstrated the potential use of AC from agricultural biomass such as PKS as a natural-based antifungal agent that can reduce environmental and health impacts.  相似文献   
6.
We analyze the effect of CEO education on environmental decision-making. Using a unique sample of Danish firms from 1996 to 2012, we find that CEO education significantly improves firms' energy efficiency. We seek to derive causality using health shocks: the hospitalization of highly educated CEOs induces a drop in energy efficiency, whereas the hospitalization of less educated CEOs does not have any significant effect. Exploring the mechanisms at play, we show that our results are largely driven by advanced education in business degrees. Moreover, we show that CEO education is associated with greater environmental awareness: highly educated CEOs exhibit greater concerns for climate change, as measured by a survey of social preferences, and drive more environmentally efficient cars. Taken together, our findings suggest that education shapes managerial styles giving rise to greater sustainability in corporate actions.  相似文献   
7.
水环境中天然有机质会与砷形成络合物,进而影响砷的迁移、转化和生物毒性。研究利用超滤方法将腐殖酸(humic acid, HA)分为5个不同分子量的组分,以大型溞为受试生物,探究了不同分子量HA存在下砷对大型溞的毒性效应。结果表明,不同分子量的HA均缓解了As(Ⅲ)和As(Ⅴ)对大型溞的氧化应激损伤和细胞膜损伤,并降低了砷对MT的诱导量。其中1~30 k Da的HA对砷的缓解效果最好,1 k Da的HA毒性缓解效果最差,可能的原因是HA与砷的络合增加溶液中络合态砷的含量,而络合态砷难以进入细胞并被生物利用。不同分子量的HA对砷毒性的缓解差异与其跟砷的络合比例不同有关。  相似文献   
8.
Abstract

Multi-spectroscopic and molecular docking methods were used to study the interaction between triclosan (TCS) and bovine serum albumin (BSA). The results indicated that the fluorescence quenching of BSA by TCS was due to the formation of TCS–BSA complex through static quenching. This result was also demonstrated by time-resolved fluorescence experiment. The binding constants and number of binding sites between TCS and BSA were 1.30?×?105 M?1 and 1.17 at 298?K, respectively. The thermodynamic parameters were studied in detail which suggested that hydrophobic forces and hydrogen bond played major roles in the TCS–BSA interaction. Moreover, the site marker competitive experiments and docking studies revealed that TCS could bind BSA into site I in subdomain IIA. All the results of UV–vis spectrophotometry, circular dichroism spectroscopy and synchronous fluorescence spectroscopy showed that interaction between TCS and BSA induced conformation changes of BSA.  相似文献   
9.
Genetic diversity is a key factor for population survival and evolution. However, anthropogenic habitat disturbance can erode it, making populations more prone to extinction. Aiming to assess the global effects of habitat disturbance on plant genetic variation, we conducted a meta-analysis based on 92 case studies obtained from published literature. We compared the effects of habitat fragmentation and degradation on plant allelic richness and gene diversity (equivalent to expected heterozygosity) and tested whether such changes are sensitive to different life-forms, life spans, mating systems, and commonness. Anthropogenic disturbance had a negative effect on allelic richness, but not on gene diversity. Habitat fragmentation had a negative effect on genetic variation, whereas habitat degradation had no effect. When we examined the individual effects in fragmented habitats, allelic richness and gene diversity decreased, but this decrease was strongly dependent on certain plant traits. Specifically, common long-lived trees and self-incompatible species were more susceptible to allelic richness loss. Conversely, gene diversity decreased in common short-lived species (herbs) with self-compatible reproduction. In a wider geographical context, tropical plant communities were more sensitive to allelic richness loss, whereas temperate plant communities were more sensitive to gene diversity loss. Our synthesis showed complex responses to habitat disturbance among plant species. In many cases, the absence of effects could be the result of the time elapsed since the disturbance event or reproductive systems favoring self-pollination, but attention must be paid to those plant species that are more susceptible to losing genetic diversity, and appropriate conservation should be actions taken.  相似文献   
10.
合成了β-环糊精(β-CD)与偶氮染料酸性红GR(ARGR)的包结物,并采用红外光谱仪对ARGR、β-CD及β-CD与ARGR的包结物进行了表征,表征结果显示,β-CD与ARGR的包结物的特征峰的峰形和强度与β-CD相似,但峰位有明显的偏移,说明ARGR进入了β-CD空腔与β-CD发生了分子识别作用。采用TiO2作为催化剂,研究了β-CD分子识别后ARGR的光催化降解行为,实验结果表明,在ARGR质量浓度为20.0 mg/L、β-CD浓度为1.8×10-5 mol/L、体系pH为4.0、TiO2加入量为1.0 g/L、光催化反应时间为60 min的条件下,经β-CD分子识别后ARGR的光催化降解率可达100%。  相似文献   
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