A new air exchange rate （AER） monitoring method using continuous CO2 sensors was developed and validated through both laboratory experiments and field studies. Controlled laboratory simulation tests were conducted i...
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A new air exchange rate （AER） monitoring method using continuous CO2 sensors was developed and validated through both laboratory experiments and field studies. Controlled laboratory simulation tests were conducted in a 1-m3 environmental chamber at different AERs （0.1-10.0 hr-1）. AERs were determined using the decay method based on box model assumptions. Field tests were conducted in classrooms, dormitories, meeting rooms and apartments during 2-5 weekdays using CO2 sensors coupled with data loggers. Indoor temperature, relative humidity （RH）, and CO2 concentrations were continuously monitored while outdoor parameters combined with on-site climate conditions were recorded. Statistical results indicated that good laboratory performance was achieved： duplicate precision was within 10%, and the measured AERs were 90%-120% of the real AERs. Average AERs were 1.22, 1.37, 1.10, 1.91 and 0.73 hr-l in dormitories, air-conditioned classrooms, classrooms with an air circulation cooling system, reading rooms, and meeting rooms, respectively. In an elderly particulate matter exposure study, all the homes had AER values ranging from 0.29 to 3.46 hr-1 in fall, and 0.12 to 1.39 hr-1 in winter with a median AER of 1.15.
Plastics have become omnipresent in modern life due to their versatility and ***,this convenience comes at the cost of substantial waste *** inherent chemical stability of plastics complicates its recycling,leading to...
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Plastics have become omnipresent in modern life due to their versatility and ***,this convenience comes at the cost of substantial waste *** inherent chemical stability of plastics complicates its recycling,leading to environmental pollution and ecological *** mini-review highlights recent advancements in addressing this challenge by oxidative transformation of polyethylene(PE)into new functional polymers,value-added chemicals,and carbon-based *** first discuss the introduction of hydroxyl,carbonyl groups onto PE with a focus on the functionalization degree and ***,approaches for PE oxidation into dicarboxylic acids and short-chain oxidized PE are described and compared,with an emphasis on the tandem reactions for converting mixed dicarboxylic acids into other value-added *** also briefly discuss the oxidative transformation of PE into carbon-based materials and summarize the progress in qualitative and quantitative analysis of oxidation ***,we conclude this mini-review by highlighting the challenges and opportunities in the field.
The methanol-to-olefins(MTO)reaction offers an alternative pathway for the production of low-carbon olefins from non-oil *** research has been impeded by a lack of comprehensive understanding of its underlying mechani...
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The methanol-to-olefins(MTO)reaction offers an alternative pathway for the production of low-carbon olefins from non-oil *** research has been impeded by a lack of comprehensive understanding of its underlying mechanism,despite the significant progress made in ***-situ solid-state nuclear magnetic resonance(ss NMR)spectroscopy has emerged as a pivotal tool,offering crucial insights into key species under real-time operando ***,the host–guest interaction between zeolites or surface species residing on zeolites and the reactant/active intermediates is revealed by the combination of in-situ^(13)C MAS NMR and 2D correlation ***,recent technological advancements in hyperpolarization(HP)methods,including HP^(129)Xe NMR and dynamic nuclear polarization(DNP),have significantly improved the sensitivity of ssNMR,enabling detailed structural and kinetic analysis as well as the detection of trace *** this feature article,we summarized recent advancements in(in-situ)ssNMR spectroscopy applied to MTO reaction processes,encompassing mechanistic investigations at various stages and the intricate host–guest *** theoretical insights into the dynamic evolution of MTO reactions lay a solid foundation for the optimization of catalytic processes and the development of efficient catalysts,thereby advancing the techniques towards more sustainable and economical production route for olefins.
Abstract The distribution of Seidel eigenvalues of cographs is investigated in this *** prove that there is no Seidel eigenvalue of nontrivial cographs in the interval (-1,1).We also show the optimality of the interva...
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Abstract The distribution of Seidel eigenvalues of cographs is investigated in this *** prove that there is no Seidel eigenvalue of nontrivial cographs in the interval (-1,1).We also show the optimality of the interval (-1,1) in the sense that for any■>0 either of the intervals(1,1+■) and (-1-■,-1) contains a Seidel eigenvalue of some cograph of order n when n is sufficiently large.
Core-shell colloidal particles with a polymer layer have broad applications in different ***,we developed a two-step method combining aqueous surface-initiated photoinduced polymerization-induced self-assembly and pho...
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Core-shell colloidal particles with a polymer layer have broad applications in different ***,we developed a two-step method combining aqueous surface-initiated photoinduced polymerization-induced self-assembly and photoinduced seeded reversible addition-fragmentation chain transfer (RAFT) polymerization to prepare a diverse set of core-shell colloidal particles with a well-defined polymer *** compositions,structures,and thicknesses of polymer layers could be conveniently regulated by using different types of monomers and feed[monomer]/[chain transfer agent]ratios during seeded RAFT polymerization.
To obtain high-entropy carbide (HEC) joints with excellent high-temperature performance, a (HfZrTiTaNb)C HEC joint featuring a direct diffusion-bonded interface with a Nb-based interlayer was successfully fabricated a...
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To obtain high-entropy carbide (HEC) joints with excellent high-temperature performance, a (HfZrTiTaNb)C HEC joint featuring a direct diffusion-bonded interface with a Nb-based interlayer was successfully fabricated at relatively low temperatures of 1150-1250 degrees C for 60 min under 10 MPa. Starting from a modified Ni/Nb/Ni composite interlayer with a Nb content of > 64 at%, an alloyed Nb2Ni layer was constructed in situ by accelerating the directional diffusion of Ni atoms from the high-entropy interface into the remaining pure Nb through the Ni-Nb eutectic liquid. Moreover, the excess liquid phase was squeezed out of the bonding region, ensuring the absence of Ni-based compounds. Leveraging the intrinsic interfacial stability and sluggish diffusion effect, the HEC with its original lattice structure, was capable of developing diffusion bonding with the Nb2Ni layer instead of interacting with the liquid phase. The high reliability of the HEC/Nb2Ni bonded interface was confirmed by the coherence of (1 3) (HEC)// (141) (Nb2Ni) and a calculated lattice misfit of 0.044. The HEC joint had a high room-temperature strength of 174 MPa because of the homogenous Nb2Ni layer, which exhibited nanohardness (15.2 +/- 1.5 GPa) and an elastic modulus of 219.9 +/- 17.5 GPa. Furthermore, the strength of the HEC joint did not decrease at 1000 degrees C, increasing by similar to 49% over that of HEC/Ni/HEC diffusion-bonded joints, which have stringent surface flatness requirements. This suggested that the HEC/Nb2Ni interface had excellent resistance to high-temperature softening, even though it was invariably the initial failure location. This work is informative for designing bonding structures and preparing HEC components.
Given the escalating intricacy and multifaceted nature of contemporary social systems,manually generating solutions to address pertinent social issues has become a formidable *** response to this challenge,the rapid d...
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Given the escalating intricacy and multifaceted nature of contemporary social systems,manually generating solutions to address pertinent social issues has become a formidable *** response to this challenge,the rapid development of artificial intelligence has spurred the exploration of computational methodologies aimed at automatically generating ***,current methods for the auto-generation of solutions mainly concentrate on local social regulations that pertain to specific ***,we report an automatic social operating system(ASOS)designed for general social solution generation built upon agent-based models that enables both global and local analyses and regulations of social problems across spatial and temporal *** adopts a hypergraph with extensible social semantics for a comprehensive and structured representation of social *** also incorporates a generalized protocol for standardized hypergraph operations and a symbolic hybrid framework that delivers interpretable solutions,yielding a balance between regulatory efficacy and functional *** demonstrate the effectiveness of the ASOS,we apply it to the domain of averting extreme events within international oil futures *** generating a new trading role supplemented by new mechanisms,ASOS can adeptly discern precarious market conditions and make front-running interventions for nonprofit *** study demonstrated that ASOS provides an efficient and systematic approach for generating solutions for enhancing our society.
In this paper, two new efficient fully nonconforming polynomial finite element methods on arbitrary convex quadrilaterals are constructed to solve the Brinkman problem. Both elements have 12 local degrees of freedom a...
In this paper, two new efficient fully nonconforming polynomial finite element methods on arbitrary convex quadrilaterals are constructed to solve the Brinkman problem. Both elements have 12 local degrees of freedom and are uniformly first-order convergent. For the first element, we carefully design a shape function space of only degree four, which is convenient for practical computation. Meanwhile, the velocity solution obtained by our second element has O（h2） convergence order in the case of Darcy limit. These new elements can be regarded as modifications of a known element to effectively improve the computational efficiency, only the shape function space is properly changed. We verify our theoretical findings by numerical examples.
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