The interval‐valued Pythagorean fuzzy sets can easily handle uncertain information more flexibly in the process of decision making. Considering the interrelationship among the input arguments, we extend the Bonferroni mean and the geometric Bonferroni mean to the interval‐valued Pythagorean fuzzy environment and solve its practical application problems. First, we develop the interval‐valued Pythagorean fuzzy Bonferroni mean and the weighted interval‐valued Pythagorean fuzzy Bonferroni mean (WIVPFBM) operators. The properties of these aggregation operators are investigated. Then, we also develop the interval‐valued Pythagorean fuzzy geometric Bonferroni mean and the weighted interval‐valued Pythagorean fuzzy geometric Bonferroni mean (WIVPFGBM) operators and analyze their properties. Third, we utilize the WIVPFBM and WIVPFGBM operators to fuse the information in the interval‐valued Pythagorean fuzzy multicriteria group decision making (IVPFMCGDM) problem, which can obtain much more information in the process of group decision making. With the aid of the linear assignment method, we present its extension and further design a new algorithm for the application of IVPFMCGDM. Finally, an example is given to elaborate our proposed algorithm and validate its excellent performance.

No abstract

No abstract

Conventional singlephoton emission computed tomography (SPECT) relies on mechanical collimation whose resolution and sensitivity are interdependent, the best performance a SPECT system can attain is only a compromise of these two equally desired properties. To simultaneously achieve high resolution and sensitivity, we propose to use sensitive detectors constructed in a multi-layer interspaced mosaic detectors (MATRICES) architecture to accomplish part of the collimation needed. We name this new approach selfcollimation.We evaluate three self-collimating SPECT systems and report their imaging performance: 1) A simulated human brain SPECT achieves 3.88% sensitivity, it clearly resolves 0.5-mm and 1.0-mm hot-rod patterns at noise-free and realistic count-levels, respectively; 2) a simulated mouse SPECT achieves 1.25% sensitivity, it clearly resolves 50-μm and 100-μm hot-rod patterns at noise-free and realistic count-levels, respectively; 3) a SPECT prototype achieves 0.14% sensitivity and clearly separates 0.3-mm-diameter point sources of which the center-to-center neighbor distance is also 0.3 mm. Simulated contrast phantom studies show excellent resolution and signal-to-noise performance.The unprecedented system performance demonstrated by these 3 SPECT scanners is a clear manifestation of the superiority of the self-collimating approach over conventional mechanical collimation. It represents a potential paradigm shift in SPECT technology development.

The development of highly efficient, green, and economical materials for radioactive iodine capture has great significance in the safe development of nuclear energy. Here, organosolv lignin (OL) extracted from poplar sawdust was first used to synthesize a series of microporous lignin-based hypercross-linked polymers (LHCPs). Specifically, lignin-based copolymers (LCPs) were synthesized by the grafted copolymerization of OL combined with 4-vinylbenzyl chloride and divinylbenzene, and then the in situ Friedel–Crafts reaction was performed with the structure of LCPs to obtain LHCPs with a high Brunauer–Emmett–Teller surface area (S BET: 1076.32–1449.56 m2/g), hierarchical pore structure, and good stability. Interestingly, the polarity of LCPs and porosity of LHCPs can be well-controlled by adjusting the feeding amount of lignin. Taking advantage of abundant O-containing groups of the lignin skeleton as well as the high BET surface area of LHCPs, these lignin-based polymers were first applied to iodine adsorption, and LHCP-3 displayed an enhanced iodine vapor adsorption capacity of up to 253 wt % at 348 K and 1 bar. In addition, these LHCPs were also used for the adsorption of an iodine solution, and they exhibited a fast adsorption rate and good reusability, and adsorption isotherms can be better matched with Freundlich models. This study offered a feasible way to develop the fascinating microporous lignin-based polymers, which can not only increase the added value of lignin from biorefineries but also provide promising adsorbents for environmental remediation.