Surface mediated ligands addressing bottleneck of room-temperature synthesized inorganic perovskite nanocrystals toward efficient light-emitting diodes

Cesium lead halide perovskites (CsPbX3) have become superior candidates for perspective optoelectronic applications. However, room temperature synthesized CsPbX3 nanocrystals (NCs) suffer from serious lattice/surface traps, mostly induced by nonequilibrium reactions and polar solvent systems. Thus, direct assembly of such poor crystals cannot be available toward high efficiency light emitting diodes (LEDs). To address this issue, differing from the general post-treatment works, here we propose a double-terminal diamine bromide salt to in situ passivate the surface traps of room temperature synthesized CsPbBr3 NCs. High-quality NC solutions with photoluminescence quantum yield (PLQY) beyond 90% are obtained owing to the renovated surface bromide vacancies. Meanwhile, instead of longer oleylamine (OLA) ligand, the abridged diamine bromine ligand could significantly enhance charge transport throughout the NC film. In addition, the NC based LED performance is found related to chain length of the ligand, where the optimal luminance of 14021 Cd m(-2) and current efficiency of 25.5 Cd A(-1) are achieved by 1, 4-butanediamine bromide passivated NC devices. This work provides a direct efficient approach to meet the device application of room temperature synthesized perovskite NCs, underlines the significance of selective ligands to address the challenges of NC emitters in future displays and solid-state lighting

Valuing the effects of hydropower development on watershed ecosystem services: Case studies in the Jiulong River Watershed, Fujian Province, China

Hydropower development brings many negative impacts on watershed ecosystems which are not fully integrated into current decision-making largely because in practice few accept the cost and benefit beyond market. In this paper, a framework was proposed to valuate the effects on watershed ecosystem services caused by hydropower development. Watershed ecosystem services were classified into four categories of provisioning, regulating, cultural and supporting services; then effects on watershed ecosystem services caused by hydropower development were identified to 21 indicators. Thereafter various evaluation techniques including the market value method, opportunity cost approach, project restoration method, travel cost method, and contingent valuation method were determined and the models were developed to valuate these indicators reflecting specific watershed ecosystem services. This approach was applied to three representative hydropower projects (Daguan, Xizaikou and Tiangong) of Jiulong River Watershed in southeast China. It was concluded that for hydropower development: (1) the value ratio of negative impacts to positive benefits ranges from 64.09% to 91.18%, indicating that the negative impacts of hydropower development should be critically Studied during its environmental administration process; (2) the biodiversity loss and water quality degradation (together accounting for 80-94%) are the major negative impacts on watershed ecosystem services: (3) the average environmental cost per unit of electricity is up to 0.206 Yuan/kW h, which is about three quarters of its on-grid power tariff; and (4) the current water resource fee accounts for only about 4% of its negative impacts value, therefore a new compensatory method by paying for ecosystem services is necessary for sustainable hydropower development. These findings provide a clear picture of both positive and negative effects of hydropower development for decision-makers in the monetary term, and also provide a basis for further design of environmental instrument such as payment for watershed ecosystem services. (C) 2009 Elsevier Ltd. All rights reserved

Activation of PI3-Kinase Is Required for AMPA Receptor Insertion during LTP of mEPSCs in Cultured Hippocampal Neurons

AbstractHippocampal CA1 homosynaptic long-term potentiation (LTP) is expressed specifically at activated synapses. Increased insertion of postsynaptic α-amino-3-hydroxy-5-methyl-isoxazole-4-propionic acid receptors (AMPARs) appears to be crucial for CA1 LTP. However, the mechanism underlying AMPAR insertion during LTP remains largely unknown. We now report that phosphatidylinositol 3-kinase (PI3K) is complexed with AMPARs at synapses and activated by selective stimulation of synaptic N-methyl-D-aspartate (NMDA) receptors. Activation of the AMPAR-associated PI3K is required for the increased cell surface expression of AMPARs and LTP. Thus, our results strongly suggest that the AMPAR-PI3K complex may constitute a critical molecular signal responsible for AMPAR insertion at activated CA1 synapses during LTP, and consequently, this lipid kinase may serve to determine the polarity of NMDA receptor-dependent synaptic plasticity

Adapting Chinese cities to climate change

在第三次联合国住房和城市可持续发展大会（United Nations Conference on Housing and Sustainable Urban Development）召开之际，我院方秦华副教授在Science杂志Letters栏目撰文，对我国沿海地区在城市化和气候变化双重背景下的自然灾害风险防范问题提出科学建议。这是继今年5月在Nature杂志发表评论之后，方秦华副教授第二次在国际顶级刊物上发表环境管理领域研究进展。The destruction and degradation of coastal ecosystems impair urban resilience to typhoon disasters, which will become more intense as the environment grows warmer .Urbanizing Chinese coastal cities should develop climate-smart marine and coastal spatial planning that is resilient to climate change and minimizes carbon emissions . In addition, China needs ecosystem-based marine functional zoning, which identifies the critical components and processes of the marine ecosystem, to address conflicts between sea use and environment protection

Applying the Ocean Health Index framework to the city level: A case study of Xiamen, China

The Ocean Health Index (OHI), which provides a new insight into the assessment of ocean ecosystems, has attracted wide attention recently since it was proposed in 2012. It has been applied to assess the oceans at the global, national and regional levels. However, the application of the OHI framework at the city level has not been reported yet. In this study, the feasibility of applying the OHI framework to assess the health status of the oceans at the city level was explored by a case study in Xiamen of China (Xiamen OHI). Xiamen OHI aims at assessing the current status of ocean health in the Xiamen City, but not comparing to other regional or international OHI cases. Large adjustments including setting goals, parameters and reference points were undertaken to customize the OHI framework to the city scale in Xiamen. The results showed the overall score for Xiamen OHI was 52 out of 100, ranging from 28 to 96 across different goals. Goals related to ecological factors including Clean Waters, Coastal Storage, Coastal Protection received very low scores; on the contrary, goals related to social and economic factors including Tourism and Recreation, Sense of Place and Coastal Livelihoods and Economies were scored high. The case study of Xiamen OHI indicates the feasibility of the application of the OHI framework at the city level after necessary adjustments, and the results can also direct to effective ocean health improvement in the future. This study thus contributes to promote the application of OHI framework at the local levels

The cumulative effects assessment of a coastal ecological restoration project in China: An integrated perspective

© 2017 Elsevier Ltd Large scale coastal land-claim and sea-enclosing (CLASE) activities have caused habitat destruction, biodiversity losses and water deterioration, thus the local governments in China have recently undertaken seabed dredging and dyke opening (SDADO) as typical ecological restoration projects. However, some projects focus on a single impact on hydrodynamic conditions, water quality or marine organisms. In a case study in Xiamen, China, an integrated effects assessment framework centres on ecohydrology, using modeling of hydrodynamic conditions and statistical analysis of water quality, was developed to assess the effects of ecological restoration projects. The benefits of SDADO projects include improving hydrodynamic conditions and water quality, as a precursor to further marine biological improvements. This study highlights the need to comprehensively consider ecological effects of SDADO projects in the planning stage, and an integrative assessment method combining cumulative effects of hydrodynamic conditions, water quality and biological factors

How effective is a marine spatial plan: an evaluation case study in China

Marine/maritime spatial planning (MSP) aims to address conflicts between different sea uses and conflicts between such uses and marine environments. However, how to evaluate, particularly quantitatively evaluate, an MSP scheme on its performance of achieving the above objectives is still an issue. In this paper, an MSP scheme evaluation framework focusing on sea use compatibility and the protection degree of key ecological areas is put forward. First, the intensity of every sea use is graded on a scale of 1–10 based on its demand on marine resources and impacts on marine environments, and key ecological areas are identified based on scientific criteria for ecologically or biologically significant marine areas of the Convention on Biological Diversity (CBD). Then, a set of formulas are designed to calculate the conflict value among sea uses. The protection degree in a sea area is calculated through buffer zone tools and overlap analysis in Geographic Information System (GIS). The proposed method is applied to a case study of Xiamen, China, by comparing its marine spatial plans of version 2007 and version 2013. The results show that the sea use intensity increases from 3.51 to 4.20 on average in the Western Sea of Xiamen. The key ecological area protection value decreases from 0.59 to 0.45, and the sea use conflicts value decreases from 0.28 to 0.20. The results demonstrate that MSP is successful in reducing sea use conflicts in version 2013 in the context of an increasing sea use intensity. However, the protection degree of key ecological areas needs to be strengthened. Further statistical analysis of the results provides more information for the cause analysis of the performance changes. This information would inform potential revisions of the current marine spatial plan and future sea use management. The proposed method provides a feasible approach to analyse the MSP scheme in a quantitative way

Marine Functional Zoning in China: Experience and Prospects

State Oceanic Administration of China [200905005-06]; Xiamen University [2011121008]With rapid socioeconomic development in coastal and marine areas, degradation of the marine environment and destruction of marine ecosystems have received widespread attention. Traditional sector-by-sector management cannot effectively solve the problems in the various uses of sea areas. Marine spatial planning (MSP) is increasingly considered an effective tool that can resolve conflicts among various human uses as well as the conflicts between human uses and the marine environment. Many countries such as Australia, United Kingdom, Germany, Belgium, and United States have already initiated or implemented MSP. In China, marine functional zoning (MFZ) has developed independently since it was first proposed by the Chinese government in 1988. In this article, the evolution of MFZ in China was briefly introduced. The process of MFZ was summarized as the following elements: preparatory work, collecting data, defining and analyzing present and future conditions, developing the zoning scheme, approving and revising the zoning scheme. Through exploring the problems and deficiencies of existing MFZ from both technical and administrative perspectives, the principles and ways to improve MFZ in China were proposed in the context of international MSP practice before a new cycle of revision