MOEA/D with Adaptive Weight Adjustment

Recently, MOEA/D (multi-objective evolutionary algorithm based on decomposition) has achieved great success in the field of evolutionary multi-objective optimization and has attracted a lot of attention. It decomposes a multi-objective optimization problem (MOP) into a set of scalar subproblems using uniformly distributed aggregation weight vectors and provides an excellent general algorithmic framework of evolutionary multi-objective optimization. Generally, the uniformity of weight vectors in MOEA/D can ensure the diversity of the Pareto optimal solutions, however, it cannot work as well when the target MOP has a complex Pareto front (PF; i.e., discontinuous PF or PF with sharp peak or low tail). To remedy this, we propose an improved MOEA/D with adaptive weight vector adjustment (MOEA/D-AWA). According to the analysis of the geometric relationship between the weight vectors and the optimal solutions under the Chebyshev decomposition scheme, a new weight vector initialization method and an adaptive weight vector adjustment strategy are introduced in MOEA/D-AWA. The weights are adjusted periodically so that the weights of subproblems can be redistributed adaptively to obtain better uniformity of solutions. Meanwhile, computing efforts devoted to subproblems with duplicate optimal solution can be saved. Moreover, an external elite population is introduced to help adding new subproblems into real sparse regions rather than pseudo sparse regions of the complex PF, that is, discontinuous regions of the PF. MOEA/D-AWA has been compared with four state of the art MOEAs, namely the original MOEA/D, Adaptive-MOEA/D, [Formula: see text]-MOEA/D, and NSGA-II on 10 widely used test problems, two newly constructed complex problems, and two many-objective problems. Experimental results indicate that MOEA/D-AWA outperforms the benchmark algorithms in terms of the IGD metric, particularly when the PF of the MOP is complex.</jats:p

Metabolic interactions between dynamic bacterial subpopulations

Individual microbial species are known to occupy distinct metabolic niches within multi-species communities. However, it has remained largely unclear whether metabolic specialization can similarly occur within a clonal bacterial population. More specifically, it is not clear what functions such specialization could provide and how specialization could be coordinated dynamically. Here, we show that exponentially growing Bacillus subtilis cultures divide into distinct interacting metabolic subpopulations, including one population that produces acetate, and another population that differentially expresses metabolic genes for the production of acetoin, a pH-neutral storage molecule. These subpopulations exhibit distinct growth rates and dynamic interconversion between states. Furthermore, acetate concentration influences the relative sizes of the different subpopulations. These results show that clonal populations can use metabolic specialization to control the environment through a process of dynamic, environmentally-sensitive state-switching

Perovskite quantum dot topological laser

Various topological laser concepts have recently enabled the demonstration of robust light-emitting devices that are immune to structural deformations and tolerant to fabrication imperfections. Current realizations of photonic cavities with topological boundaries are often limited by outcoupling issues or poor directionality and require complex design and fabrication that hinder operation at small wavelengths. Here we propose a topological cavity design based on interface states between two one-dimensional photonic crystals with distinct Zak phases and demonstrate a lithography-free, single-mode perovskite laser emitting in the green. Few monolayers of solution processed all-inorganic cesium lead halide perovskite quantum dots are used as ultrathin gain medium. The topological laser has planar design with large output aperture, akin to vertical-cavity surface-emitting lasers (VCSELs) and is robust against variations of the thickness of the gain medium, from deeply subwavelength to thick quantum dot films. This experimental observation also unveils the topological nature of VCSELs, that is usually overlooked in the description of conventional Fabry-Perot cavity lasers. The design simplicity and topological characteristics make this perovskite quantum dot laser architecture suitable for low-cost and fabrication tolerant vertical emitting lasers operating across the visible spectral region

Cystatin C and risk of new-onset depressive symptoms among individuals with a normal creatinine-based estimated glomerular filtration rate: A prospective cohort study

The association between cystatin C and depressive symptoms in the general population has not been thoroughly elucidated to date. We investigated the association of cystatin C with new-onset depressive symptoms among individuals with normal creatinine-based estimated glomerular filtration rates (eGFR). In the China Health and Retirement Longitudinal Study, 5111 participants without depressive symptoms or renal dysfunction (eGFR \u3c 60 ml/min/1.73

Lightweight Triboelectric Nanogenerators Based on Hollow Stellate Cellulose Films Derived from Juncus effusus L. Aerenchyma

This study reports a facile delignification and natural drying process for synthesizing cellulose films using the unique surface roughness, porosity, and lightness of the hollow stellate cellulose (HSC) united aerenchyma of the wetland weed Juncus effusus L. By controlling the grafted amino/fluorine-bearing group content of various silane coupling agents, this work successfully manipulates the triboelectric polarities of HSC films after silanization. Subsequently, a layer of Ag nanowire electrodes is coated on one side of the silanized HSC friction layers, resulting in flexible, lightweight, semi-transparent HSC-based triboelectric nanogenerators (HSC-TENGs) featuring both macro-scale surface roughness and micro-nano inner pores. These all-in-one HSC-TENGs achieve the highest output voltage of 4.86 V, which is 28 times that of TENGs employing two pristine HSC films as triboelectric layers (PHSC-TENG). Finally, the HSC-TENG with the optimum output power is applied as a wearable self-powered sensor for gait analysis, demonstrating stable and sustainable performances in distinguishing different body motions such as walking, running, jumping, and calf raising. This study not only proposes a new cellulose-based TENG for future in-depth body locomotion analysis but also paves the way for converting differently structured aerenchyma from abundant problematic aquatic or wetland weeds into promising structural templates in multifunctional cellulose-based applications.</p

Lightweight Triboelectric Nanogenerators Based on Hollow Stellate Cellulose Films Derived from Juncus effusus L. Aerenchyma

This study reports a facile delignification and natural drying process for synthesizing cellulose films using the unique surface roughness, porosity, and lightness of the hollow stellate cellulose (HSC) united aerenchyma of the wetland weed Juncus effusus L. By controlling the grafted amino/fluorine-bearing group content of various silane coupling agents, this work successfully manipulates the triboelectric polarities of HSC films after silanization. Subsequently, a layer of Ag nanowire electrodes is coated on one side of the silanized HSC friction layers, resulting in flexible, lightweight, semi-transparent HSC-based triboelectric nanogenerators (HSC-TENGs) featuring both macro-scale surface roughness and micro-nano inner pores. These all-in-one HSC-TENGs achieve the highest output voltage of 4.86 V, which is 28 times that of TENGs employing two pristine HSC films as triboelectric layers (PHSC-TENG). Finally, the HSC-TENG with the optimum output power is applied as a wearable self-powered sensor for gait analysis, demonstrating stable and sustainable performances in distinguishing different body motions such as walking, running, jumping, and calf raising. This study not only proposes a new cellulose-based TENG for future in-depth body locomotion analysis but also paves the way for converting differently structured aerenchyma from abundant problematic aquatic or wetland weeds into promising structural templates in multifunctional cellulose-based applications.</p

Lightweight Triboelectric Nanogenerators Based on Hollow Stellate Cellulose Films Derived from Juncus effusus L. Aerenchyma

This study reports a facile delignification and natural drying process for synthesizing cellulose films using the unique surface roughness, porosity, and lightness of the hollow stellate cellulose (HSC) united aerenchyma of the wetland weed Juncus effusus L. By controlling the grafted amino/fluorine-bearing group content of various silane coupling agents, this work successfully manipulates the triboelectric polarities of HSC films after silanization. Subsequently, a layer of Ag nanowire electrodes is coated on one side of the silanized HSC friction layers, resulting in flexible, lightweight, semi-transparent HSC-based triboelectric nanogenerators (HSC-TENGs) featuring both macro-scale surface roughness and micro-nano inner pores. These all-in-one HSC-TENGs achieve the highest output voltage of 4.86 V, which is 28 times that of TENGs employing two pristine HSC films as triboelectric layers (PHSC-TENG). Finally, the HSC-TENG with the optimum output power is applied as a wearable self-powered sensor for gait analysis, demonstrating stable and sustainable performances in distinguishing different body motions such as walking, running, jumping, and calf raising. This study not only proposes a new cellulose-based TENG for future in-depth body locomotion analysis but also paves the way for converting differently structured aerenchyma from abundant problematic aquatic or wetland weeds into promising structural templates in multifunctional cellulose-based applications.</p

Lightweight Triboelectric Nanogenerators Based on Hollow Stellate Cellulose Films Derived from Juncus effusus L. Aerenchyma

This study reports a facile delignification and natural drying process for synthesizing cellulose films using the unique surface roughness, porosity, and lightness of the hollow stellate cellulose (HSC) united aerenchyma of the wetland weed Juncus effusus L. By controlling the grafted amino/fluorine-bearing group content of various silane coupling agents, this work successfully manipulates the triboelectric polarities of HSC films after silanization. Subsequently, a layer of Ag nanowire electrodes is coated on one side of the silanized HSC friction layers, resulting in flexible, lightweight, semi-transparent HSC-based triboelectric nanogenerators (HSC-TENGs) featuring both macro-scale surface roughness and micro-nano inner pores. These all-in-one HSC-TENGs achieve the highest output voltage of 4.86 V, which is 28 times that of TENGs employing two pristine HSC films as triboelectric layers (PHSC-TENG). Finally, the HSC-TENG with the optimum output power is applied as a wearable self-powered sensor for gait analysis, demonstrating stable and sustainable performances in distinguishing different body motions such as walking, running, jumping, and calf raising. This study not only proposes a new cellulose-based TENG for future in-depth body locomotion analysis but also paves the way for converting differently structured aerenchyma from abundant problematic aquatic or wetland weeds into promising structural templates in multifunctional cellulose-based applications.</p