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A cycloaliphatic tetracarboxylic dianhydride, octahydro-2,3,6,7-anthracenetetracarboxylic dianhydride (OHADA) was synthesized to obtain novel colorless polyimides (PIs). Herein, approaches for decolorizing an OHADA prototype and simplifying the entire process are described, and a plausible steric structure for OHADA is proposed. The polyaddition of OHADA and 2,2′-bis(trifluoromethyl)benzidine (TFMB) was unsuccessful; specifically, the reaction mixture remained inhomogeneous even after prolonged stirring. However, the modified one-pot process was applicable to the OHADA/TFMB system. The isolated PI powder form, as well as those for the other OHADA-based PIs, was highly soluble in numerous solvents and afforded a homogeneous and stable solution with a high solid content (20–30 wt%). Solution casting produced a colorless and ductile PI film with a very high glass transition temperature (Tg~300 °C). Furthermore, the OHADA/TFMB system exhibited remarkable thermal stability compared with those of the other related TFMB-derived semi-cycloaliphatic PIs. However, contrary to our expectations, this PI film did not exhibit a low linear coefficient of thermal expansion (CTE). This PI film also possessed excellent thermoplasticity, probably reflecting its peculiar steric structure. The use of an amide-containing diamine significantly enhanced the Tg (355 °C) and somewhat reduced the CTE (41.5 ppm K−1) while maintaining high optical transparency and excellent solubility.

An effective non‐linear optical limiting technology is proposed here based on backward stimulated Brillouin scattering in grade‐index optical fibres. The excellent non‐linear optical limiting performance is experimentally verified by using 0.5 and 1 m grade‐index quartz fibres at the wavelength of 1064 nm. The linear transmittance for 0.5 and 1 m fibres are both beyond 96% and the lowest non‐linear transmittance are 6.1% and 1.5%, respectively. This is the best non‐linear optical limiting performance that can be achieved at present.

The parametric catalogue of Italian earthquakes CPTI15 (Catalogo Parametrico dei Terremoti Italiani) represents the latest of a 45-years-long tradition of earthquake catalogues for Italy, and a significant innovation with respect to its predecessors. CPTI15 combines all known information on significant Italian earthquakes of the period 1000–2017, balancing instrumental and macroseismic data. Although the compilation criteria are the same as in the previous CPTI11 version, released in 2012, the catalogue has been revised as concerns: the time coverage, extended to 2017; the associated macroseismic data, improved in quantity and quality; the considered instrumental data, new and/or updated; the energy thresholds, lowered to maximum or epicentral intensity 5 or magnitude 4.0 (instead of 5–6 and 4.5, respectively); the determination of parameters from macroseismic data, based on a new calibration; the instrumental magnitudes, resulting from new sets of data and new conversion relationships to Mw. The catalogue considers and harmonizes data of different types and origins, both macroseismic and instrumental. For all earthquakes, the magnitude is given in terms of true or proxy moment magnitude (Mw), with the related uncertainty. The compilation procedure rigorously implements data and methods published in peer-reviewed journals. All data and methods are clearly indicated in the catalogue, in order to guarantee the maximum transparency of the compilation procedures. As compared to previous CPTI releases, the final CPTI15 catalogue shows a frequency–magnitude distribution coherent with current Italian instrumental catalogues, making it suitable for statistical analysis of the time-space property of the Italian seismicity.

Global climate change poses significant risks to coastal and riverine communities. Managed retreat, the purposeful movement of people and infrastructure out of vulnerable floodplains, is one possible adaptation strategy. The USA has already engaged in a limited amount of retreat by providing federal funds to purchase and demolish or relocate vulnerable properties. As retreat programs are expected to expand in size and frequency to address the increased risks posed by climate change, a review of how such property acquisition programs have been implemented is timely. Specifically, decisions made by government officials regarding where to acquire properties have significant potential social justice implications, as buyouts could promote or reduce existing social inequities, but it is unclear how such decisions are being made. A review of eight US buyout programs suggests that buyouts, as practiced, lack transparency, which may increase public distrust of the process and reduce participation. Moreover, decisions often involve political motivations and rely on cost-benefit logic that may promote disproportionate retreat in low-income or minority communities, continuing historic patterns of social inequity. However, as low-income communities in the USA also tend to be highly vulnerable to climate-exacerbated hazards, a decision not to relocate may also promote disproportionate harm. The buyout programs reviewed provide examples of how to mitigate these concerns through increased transparency, emphasis on relocation, explicit focus on social inequality, longer-term and larger-scale holistic approaches, and participatory pre-disaster planning. Further research on past programs is needed to evaluate outcomes and processes to improve future adaptation efforts.

Polyethylene terephthalate is a common plastic in many products such as viscose rayon for clothing, and packaging material in the food and beverage industries. Polyethylene terephthalate has beneficial properties such as light weight, high tensile strength, transparency and gas barrier. Nonetheless, there is actually increasing concern about plastic pollution and toxicity. Here we review the properties, occurrence, toxicity, remediation and analysis of polyethylene terephthalate as macroplastic, mesoplastic, microplastic and nanoplastic. Polyethylene terephthalate occurs in groundwater, drinking water, soils and sediments. Plastic uptake by humans induces diseases such as reducing migration and proliferation of human mesenchymal stem cells of bone marrow and endothelial progenitor cells. Polyethylene terephthalate can be degraded by physical, chemical and biological methods.

The exposure of sovereigns to climate risks is priced and can affect credit ratings and debt servicing costs. I argue that the climate risks to fiscal stability are not receiving adequate attention and discuss how to remedy the situation. After providing evidence of divergent climate risks to advanced economies, I describe the transmission channels from climate change to public finance. Then, I suggest how integrated assessment models (IAMs) can be linked with stochastic debt sustainability analysis (DSA) to inform our understanding of climate risks to sovereign debt dynamics and assess the available fiscal space to finance climate policies. I argue for adopting the narrative scenario architecture developed within the IPCC to bring structure and transparency to the analysis. The analysis is complicated by deep uncertainty —risks, ambiguity, and mis-specifications— of climate change. Using scenario trees, narrative scenarios, and ensembles of models, respectively, we can deal with these three challenges. I illustrate using two prominent IAMs to generate the debt dynamics of a high-debt country under climate risks to economic growth and find adverse effects from as early as 2030. I conclude with the policy implications for fiscal stability authorities.

PurposeIn the pile-soil interaction system, the disturbed soil directly affects the safety of the laterally loaded pile. The soil displacement field helps to evaluate the range and degree of soil disturbance. This study presents a method of visualiziing the displacement field of the soil around the laterally loaded pile by using transparent soil technology, which overcomes the measurement obstacles caused by the non-transparency of the real soil.MethodsGlass sand and transparent pore solution were mixed to make a saturated transparent soil with two particle sizes (0.1 ~ 0.5 mm and 0.5 ~ 1 mm). Instead of real soil, transparent soil was used to observe the degree of disturbance in the process of interaction with laterally loaded piles. In addition, particle image velocimetry (PIV) was used to capture the displacement of transparent soil particles. The displacement of each particle was integrated into the displacement field by a MATLAB program.ResultsWhen a horizontal force was applied on the top of the pile, the particles in front of the pile were compressed, producing observable movement within a certain area. From the displacement vector diagram, it could be seen that the displacement area of the soil surface in front of the pile increases as the layer thickness of large particle soil increases. The vertical displacement of soil in front of the pile was compacted to form a wedge-shaped area under the horizontal load. The angle between the direction of soil motion and the horizontal plane was positively correlated with the thickness of the soil layer.ConclusionTransparent soil and particle image velocimetry can help reveal the displacement trends of the soil around a laterally loaded pile. Based on this, an early warning can be provided when the displacement value and displacement angle of the soil around the laterally loaded pile exceeds the normal range.

The use of increasingly large and diverse datasets to guide urban climate action has implications for how, and by whom, local governments are held accountable. This Review focuses on emerging dynamics of accountability in data-driven urban climate change governance. Current understandings of the implications for accountability are examined based on three common rationales for prioritizing data-driven decision-making: standardization, transparency and capacity building. We conclude that the trend toward data-driven urban climate governance can incentivize city governments to prioritize narrowed metrics and external interests, inhibiting the broader transformations required to realize climate change goals. We offer priorities for research at the intersection of data-driven climate governance and the accountability of city governments.The shift to data-driven urban climate governance alters accountability. This Review examines critically the drivers of the shift—standardization, transparency and capacity building—and how best to achieve equitable climate mitigation outcomes within this context.