g-C3N4制备及其协同PDS可见光催化降解布洛芬的研究

以尿素为主要原料,采用热聚合法在不同条件下制备了光催化剂g-C3N4(石墨相碳化氮),通过改变尿素在马弗炉中加热的温度(350℃、400℃、450℃、500℃)和时间(0.5 h、1 h、1.5 h),得到不同烧结温度和时间的光催化剂,并对其进行X射线衍射(XRD)、扫描电子显微镜(SEM)、傅立叶红外光谱分析仪(FT-IR)、紫外可见漫反射光(UV-Vis)表征,并通过可见光光催化降解布洛芬试验,探究了制备温度、时间对g-C3N4光催化性能的影响;并在溶液中加入PDS(过硫酸钾),联合g-C3N4在可见光下光催化降解布洛芬。结果表明,当烧结温度为500℃、烧结时间为1.5 h时,制备的g-C3N4在可见光区有较强吸收且具有较大的比表面积,以致其表现出最佳的光催化性能;PDS的存在对布洛芬的降解有促进作用,且加快了g-C3N4对布洛芬的光催化降解,相比于纯g-C3N4,4 h内布洛芬的降解率由63%提升为90.5%。以异丙醇、甲醇、对苯醌、草酸钠、重铬酸钾、甲醇分别为羟基自由基(·OH)、·OH和硫酸根自由基(SO4^-·)、超氧自由基(·O2-)、空穴(h+)、电子(e^-)的捕获剂。通过对反应过程的活性物种鉴定,·OH、SO4^-·、h+、e^-均参与了布洛芬的光催化降解,其中h+在反应中的贡献率达到了82.9%,在降解布洛芬过程中起主导作用;在反应体系中添加PDS后,催化剂g-C3N4的荧光强度变小,即加入PDS能够有效降低g-C3N4的光生空穴与电子的复合率,提高g-C3N4的光催化性能。     

外源褪黑素对As3+胁迫下水稻种子萌发的影响

研究添加外源褪黑素对As³⁺胁迫下水稻种子萌发及生理指标的影响。结果表明添加外源褪黑素能促进As³⁺下水稻种子的萌发，提高水稻的发芽势和发芽率，促进水稻幼苗的生长。当As³⁺浓度为100 μmol L^-1时，添加100 μmol L^-1褪黑素使水稻种子发芽率和总根长比对照分别提高57.1%和50.0%。添加褪黑素能显著提高As³⁺胁迫下水稻幼苗中抗氧化酶系统过氧化氢酶(CAT)、过氧化物酶(POD)活性和超氧化物歧化酶(SOD)的活性，并降低水稻幼芽中丙二醛(MDA)的含量。当As³⁺浓度为100 μmol L^-1时，添加50 μmol L^-1和100 μmol L^-1褪黑素导致水稻幼芽中POD活性比对照处理分别提高57.5%和114.8%，CAT活性提高29.4%和53.8%，SOD活性提高31.5%和56.0%，丙二醛含量比对照处理降低16.5%和31.9%。添加褪黑素也能显著提高As³⁺胁迫下水稻的根系活力，当As³⁺浓度为100 μmol L^-1时，50、100 μmol L^-1褪黑素处理后根系活力比对照分别提高42.4%和124.1%。说明添加外源褪黑素可缓解As³⁺胁迫对水稻的脂质过氧化损害，有效降低As对水稻内膜的破坏，显著缓解As污染对水稻的毒害作用。     

Hybridization,agency discretion,and implementation of the U.S. Endangered Species Act

The U.S. Endangered Species Act (ESA) requires that the “best available scientific and commercial data” be used to protect imperiled species from extinction and preserve biodiversity. However, it does not provide specific guidance on how to apply this mandate. Scientific data can be uncertain and controversial, particularly regarding species delineation and hybridization issues. The U.S. Fish and Wildlife Service (FWS) had an evolving hybrid policy to guide protection decisions for individuals of hybrid origin. Currently, this policy is in limbo because it resulted in several controversial conservation decisions in the past. Biologists from FWS must interpret and apply the best available science to their recommendations and likely use considerable discretion in making recommendations for what species to list, how to define those species, and how to recover them. We used semistructured interviews to collect data on FWS biologists’ use of discretion to make recommendations for listed species with hybridization issues. These biologists had a large amount of discretion to determine the best available science and how to interpret it but generally deferred to the scientific consensus on the taxonomic status of an organism. Respondents viewed hybridization primarily as a problem in the context of the ESA, although biologists who had experience with hybridization issues were more likely to describe it in more nuanced terms. Many interviewees expressed a desire to continue the current case‐by‐case approach for handling hybridization issues, but some wanted more guidance on procedures (i.e., a “flexible” hybrid policy). Field‐level information can provide critical insight into which policies are working (or not working) and why. The FWS biologists’ we interviewed had a high level of discretion, which greatly influenced ESA implementation, particularly in the context of hybridization.     

Rank aggregation of local expert knowledge for conservation planning of the critically endangered saola

There has been much recent interest in using local knowledge and expert opinion for conservation planning, particularly for hard‐to‐detect species. Although it is possible to ask for direct estimation of quantities such as population size, relative abundance is easier to estimate. However, an expert's knowledge is often geographically restricted relative to the area of interest. Combining (or aggregating) experts’ assessments of relative abundance is difficult when each expert only knows a part of the area of interest. We used Google's PageRank algorithm to aggregate ranked abundance scores elicited from local experts through a rapid rural‐appraisal method. We applied this technique to conservation planning for the saola (Pseudoryx nghetinhensis), a poorly known bovid. Near a priority landscape for the species, composed of 3 contiguous protected areas, we asked groups of local people to indicate relative abundances of saola and other species by placing beans on community maps. For each village, we used this information to rank areas within the knowledge area of that village for saola abundance. We used simulations to compare alternative methods to aggregate the rankings from the different villages. The best‐performing method was then used to produce a single map of relative abundance across the entire landscape, an area larger than that known to any one village. This map has informed prioritization of surveys and conservation action in the continued absence of direct information about the saola.     

臭氧二级传递标准量值传递技术

臭氧(O_3)二级传递标准对O_3三级传递标准进行量值传递,开展了对分析类型、发生类型等不同类型O_3三级传递标准的量值传递实验。分析类型O_3三级传递标准6组校准斜率的相对标准偏差Sm为0.19%、截距的标准偏差SI为0.25 nmol/mol;发生类型O_3三级传递标准6组校准的Sm为0.67%、SI为0.20 nmol/mol,均符合美国环保局O_3二级传递标准量值传递的评价指标:6组多点校准斜率的相对标准偏差Sm≤3.7%,截距的标准偏差SI≤1.5 nmol/mol。进一步对分析类型、发生类型O_3三级传递标准分别进行了6个月的量值传递时间稳定性考察,O_3三级传递标准新的斜率与最近6组斜率均值的比值为0.965~1.037,且新计算的斜率的相对标准偏差Sm为0.37%~1.87%,截距的标准偏差SI为0.20~0.52 nmol/mol,均符合美国环保局量值传递评价指标的要求,建议至少每6个月采用O_3二级传递标准开展一次量值传递。     

Judging adaptive management practices of U.S. agencies

All U.S. federal agencies administering environmental laws purport to practice adaptive management (AM), but little is known about how they actually implement this conservation tool. A gap between the theory and practice of AM is revealed in judicial decisions reviewing agency adaptive management plans. We analyzed all U.S. federal court opinions published through 1 January 2015 to identify the agency AM practices courts found most deficient. The shortcomings included lack of clear objectives and processes, monitoring thresholds, and defined actions triggered by thresholds. This trio of agency shortcuts around critical, iterative steps characterizes what we call AM‐lite. Passive AM differs from active AM in its relative lack of management interventions through experimental strategies. In contrast, AM‐lite is a distinctive form of passive AM that fails to provide for the iterative steps necessary to learn from management. Courts have developed a sophisticated understanding of AM and often offer instructive rather than merely critical opinions. The role of the judiciary is limited by agency discretion under U.S. administrative law. But courts have overturned some agency AM‐lite practices and insisted on more rigorous analyses to ensure that the promised benefits of structured learning and fine‐tuned management have a reasonable likelihood of occurring. Nonetheless, there remains a mismatch in U.S. administrative law between the flexibility demanded by adaptive management and the legal objectives of transparency, public participation, and finality.     

Using global sensitivity analysis of demographic models for ecological impact assessment

Population viability analysis (PVA) is widely used to assess population‐level impacts of environmental changes on species. When combined with sensitivity analysis, PVA yields insights into the effects of parameter and model structure uncertainty. This helps researchers prioritize efforts for further data collection so that model improvements are efficient and helps managers prioritize conservation and management actions. Usually, sensitivity is analyzed by varying one input parameter at a time and observing the influence that variation has over model outcomes. This approach does not account for interactions among parameters. Global sensitivity analysis (GSA) overcomes this limitation by varying several model inputs simultaneously. Then, regression techniques allow measuring the importance of input‐parameter uncertainties. In many conservation applications, the goal of demographic modeling is to assess how different scenarios of impact or management cause changes in a population. This is challenging because the uncertainty of input‐parameter values can be confounded with the effect of impacts and management actions. We developed a GSA method that separates model outcome uncertainty resulting from parameter uncertainty from that resulting from projected ecological impacts or simulated management actions, effectively separating the 2 main questions that sensitivity analysis asks. We applied this method to assess the effects of predicted sea‐level rise on Snowy Plover (Charadrius nivosus). A relatively small number of replicate models (approximately 100) resulted in consistent measures of variable importance when not trying to separate the effects of ecological impacts from parameter uncertainty. However, many more replicate models (approximately 500) were required to separate these effects. These differences are important to consider when using demographic models to estimate ecological impacts of management actions.     

Antipoaching standards in onshore hydrocarbon concessions drawn from a Central African case study

Unsustainable hunting outside protected areas is threatening tropical biodiversity worldwide and requires conservationists to engage increasingly in antipoaching activities. Following the example of ecocertified logging companies, we argue that other extractive industries managing large concessions should engage in antipoaching activities as part of their environmental management plans. Onshore hydrocarbon concessions should also adopt antipoaching protocols as a standard because they represent a biodiversity threat comparable to logging. We examined the spatiotemporal patterns of small‐ and large‐mammal poaching in an onshore oil concession in Gabon, Central Africa, with a Bayesian occupancy model based on signs of poaching collected from 2010 to 2015 on antipoaching patrols. Patrol locations were initially determined based on local intelligence and past patrol successes (adaptive management) and subsequently with a systematic sampling of the concession. We generated maps of poaching probability in the concession and determined the temporal trends of this threat over 5 years. The spatiotemporal patterns of large‐ and small‐mammal poaching differed throughout the concession, and likely these groups will need different management strategies. By elucidating the relationship between site‐specific sampling effort and detection probability, the Bayesian method allowed us to set goals for future antipoaching patrols. Our results indicate that a combination of systematic sampling and adaptive management data is necessary to infer spatiotemporal patterns with the statistical method we used. On the basis of our case study, we recommend hydrocarbon companies interested in implementing efficient antipoaching activities in their onshore concessions to lay the foundation of long‐needed industry standards by: adequately measuring antipoaching effort; mixing adaptive management and balanced sampling; setting goals for antipoaching effort; pairing patrols with large‐mammal monitoring; supporting antipoaching patrols across the landscape; restricting access to their concessions; performing random searches for bushmeat and mammal products at points of entry; controlling urban and agricultural expansion; supporting bushmeat alternatives; and supporting land‐use planning.     

Considering connections between Hollywood and biodiversity conservation

Cinema offers a substantial opportunity to share messages with a wide audience. However, there is little research or evidence about the potential benefits and risks of cinema for conservation. Given their global reach, cinematic representations could be important in raising awareness of conservation issues and species of concern, as well as encouraging greater audience engagement due to their heightened emotional impact on viewers. Yet there are also risks associated with increased exposure, including heightened visitor pressure to environmentally sensitive areas or changes to consumer demand for endangered species. Conservationists can better understand and engage with the film industry by studying the impact of movies on audience awareness and behavior, identifying measurable impacts on conservation outcomes, and engaging directly with the movie industry, for example, in an advisory capacity. This improved understanding and engagement can harness the industry's potential to enhance the positive impacts of movies featuring species, sites, and issues of conservation concern and to mitigate any negative effects. A robust evidence base for evaluating and planning these engagements, and for informing related policy and management decisions, needs to be built.