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Self-irradiation effect induced by Pu α decay is an important influencing factor for long-term storage of Pu-based materials. In order to reveal the collision displacement cascade for uranium recoil nucleus induced by alpha decay in delta-phase plutonium at atomic level, we review the recent progress in self-irradiation of metallic plutonium and its alloys. We perform a molecular dynamics (MD) calculation on basis of modified embedded atom (MEAM) interatomic potentials, and obtain the minimum of displacement threshold energy (MDTE) for {1 1 1} lattice direction and microscopic evolution of He self-interstitial cluster. These findings are in agreement with previous experimental and theoretical results, and can be viewed as an essential input parameter for mesoscopic simulation to obtain the evolution of microscopic configuration at longer time and space, and might be also helpful for understanding the nucleation and growth mechanisms for vacancy and/or self-interstitial and its clusters, He-vacancy cluster and He bubbles in delta-phase plutonium and its alloys.

Biofouling, as one of the membrane foulings, is the major obstacle limiting the application of polyamide (PA) thin-film composite (TFC) nanofiltration (NF) membranes in reclamation of wastewaters and treatment of industrial fluids. Herein, we introduced a facile and effective strategy for the modification of traditional PA-TFC NF membranes to improve water permeability and biofouling resistance. Specifically, three reactive guanidine molecules were successfully bonded onto the surface of PA-TFC membranes using chemical reactions between the amine groups of guanidine and the residual acyl chloride groups on the nascent PA-TFC membrane. The covalent attachment of guanidines can significantly enhance water permeability without compromising salt rejection. For instance, for 2 g L−1 Na2SO4 aqueous solution, the water flux of NFM2 increased from 25.2 L m−2 h−1 to 68.4 L m−2 h−1 at 25 °C and 0.6 MPa compared to the traditional piperazine (PIP)–trimesoyl chloride (TMC) membrane, while around 98.3%. Na2SO4 rejection was maintained. Moreover, the membranes were endowed with easy-cleaning properties, which can remarkably prevent foulant adhesion, with the water flux recovery ratio being as high as 98.9%. The developed TFC membranes also showed excellent anti-adhesive and antimicrobial activities against Gram-negative Escherichia coli K12 (E. coli), Gram-positive Bacillus pumilus LDS33 (B. pumilus) and Aspergillus parasiticus JFS (A. parasiticus). Therefore, the resultant guanidinium-functionalized NF membranes which have integrated high permselectivity and superior fouling resistance properties are promising materials for fabricating a new generation of anti-fouling/antimicrobial surfaces that are applicable to many applications such as water desalination and softening and wastewater treatment.

Improving air quality and at the same time mitigating climate change, has become a focal point around the world, especially for emerging countries like China. In the current government administration in China, the plans for local air pollutants and CO 2 reduction are made separately and rely heavily on end-of-pipe measures. This type of stopgap strategy falls short of cost-effectiveness and reduction potential. Alternatively, a co-control planning method involving multi-pollutant co-reduction measures and least-cost optimization is proposed as a substitute solution. With a case study in Urumqi in Northwestern China, it is demonstrated that current local air pollutants and CO 2 reduction plans are either too expensive due to overlapped finance budget and overuse of end-of-pipe measures or sometimes counter-affect each other. To use the proposed method to make an improvement, co-control measure options are subsequently reviewed and screened using a co-control effects coordinate system and an indicator of unit cost of pollutant reduction. The co-control plan can then be designed with a linear programing method. To evaluate the economic feasibility of the co-control plan, a cost-benefit analysis is conducted. The results indicate that the co-control plan has an obvious advantage over the current plan in terms of multi-pollutant co-reduction and cost effectiveness. A sensitivity analysis verifies the robustness of the co-control plan approach. This approach could serve as an effective way of simultaneous reduction of local air pollutants and CO 2 with least cost. It is particularly useful for rapidly growing countries like China where both local air pollutants and CO 2 emissions are very high. The co-control plan strategy can provide important environmental plan and decision making support.