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Due to the pervasive generalization challenges in optimization technology, there is a noticeable trend toward planning and diversifying optimization techniques. This paper focuses on particle swarm optimization algorithms, particularly their application in multi-objective optimization scenarios. Initially, the study examines basic particle swarm, standard particle swarm, and particle swarm algorithms with a shrinkage factor. Subsequently, an enhanced particle swarm optimization algorithm is proposed, incorporating a hybridization model and a convergence factor model tailored to the specific characteristics of particle swarm algorithms. This improved algorithm is then applied to multi-objective optimization problems, establishing a novel algorithm based on the fusion of the enhanced particle swarm approach with constrained optimization. Simulation experiments conducted on this model reveal significant findings. In low-dimensional settings, the algorithm achieves a 100% optimization success rate, marking an average improvement of 53.80%, 40.78%, and 24.76% over competing algorithms. Moreover, in multi-objective optimization simulation experiments, this algorithm generates 142 and 135 optimal solutions, outperforming traditional algorithms by 112 and 107 solutions, respectively. These results validate the efficiency and enhanced performance of the improved particle swarm-based multi-objective optimization algorithm, demonstrating its potential as an effective tool for addressing real-world optimization challenges.

Abstract A chemical reduction method for preparing monodispersed pure-phase copper colloids in water and ethylene glycol has been reported. Owing to the reduction property of ethylene glycol, the reaction rate in ethylene glycol is higher than that in water. In addition, the amount of reducing agent can be reduced largely. Ascorbic acid plays roles as reducing agent and antioxidant of colloidal copper, due to its ability to scavenge free radicals and reactive oxygen molecules. Thermogravimetric results reveal that the as-prepared copper nanoparticles have good stability, and they begin to be oxidized at above 210 °C. Polyvinyl pyrrolidone works both as size controller and polymeric capping agents, because it hinders the nuclei from aggregation through the polar groups, which strongly absorb the copper particles on the surface with coordination bonds.

Abstract Increasing interests have been paid to nanofluids because of the intriguing heat transfer enhancement performances presented by this kind of promising heat transfer media. We produced a series of nanofluids and measured their thermal conductivities. In this article, we discussed the measurements and the enhancements of the thermal conductivity of a variety of nanofluids. The base fluids used included those that are most employed heat transfer fluids, such as deionized water (DW), ethylene glycol (EG), glycerol, silicone oil, and the binary mixture of DW and EG. Various nanoparticles (NPs) involving Al2O3 NPs with different sizes, SiC NPs with different shapes, MgO NPs, ZnO NPs, SiO2 NPs, Fe3O4 NPs, TiO2 NPs, diamond NPs, and carbon nanotubes with different pretreatments were used as additives. Our findings demonstrated that the thermal conductivity enhancements of nanofluids could be influenced by multi-faceted factors including the volume fraction of the dispersed NPs, the tested temperature, the thermal conductivity of the base fluid, the size of the dispersed NPs, the pretreatment process, and the additives of the fluids. The thermal transport mechanisms in nanofluids were further discussed, and the promising approaches for optimizing the thermal conductivity of nanofluids have been proposed.

Smart contract represents an essential application scenario of blockchain technology.Smart contract technology improves programmability and scalability of blockchain, and has broad development prospects.However, a series of security incidents caused a great number of economic losses and weakened users’ confidence in the Ethereum platform.The security of smart contract has become a critical problem that restricts the further development of smart contract.Defects in smart contract code may cause serious consequences and cannot be modified once deployed, it is especially important to verify the correctness of smart contract in advance.In recent years, researchers have obtained many achievements in verification of smart contract, but there is a lack of systematic summary of these research results.Therefore, some basic principles of Ethereum were introduced, including the transaction, gas mechanism, storage and programming language.Eight common types of vulnerabilities in smart contract were summarized and their causes were explained.Some real security events were reviewed and some examples of vulnerability codes were presented.Then, the research work on automatic verification of smart contract based on symbolic execution, model checking and theorem proving was classified and summarized.Three open-source automated tools were selected, including Mythril, Slither and Oyente.And experiments were implemented to evaluate and compare the three tools from the aspects of efficiency, accuracy and the types of vulnerability can be detected.Furthermore, related review articles were surveyed, and the advantages of this paper compared with these works were summarized.The critical problems in the vulnerability detection technology of smart contract were also summarized and the direction of future research was proposed at last.

Halide perovskite solar cells have shown superior power conversion efficiency (PCE); however, long-term stability remains a challenge for their commercialization. The electron transport layer (ETL) and its interface with high electron transport ability, less charge recombination, and defect passivation capability are crucial for enhancing device stability. Tin oxide (SnO2), a promising ETL used in optoelectronic devices, suffers from intrinsic defects such as surface hydroxyls and a non-uniform morphology, which can negatively affect the device performance and shorten the device lifetime. In this study, we report a simple and effective method that employs ammonium oxalate (AMO) as an additive to induce gelation of SnO2 colloid solution. We found that gelation of the SnO2-ETL provides an effectively uniform surface morphology and prevents moisture infiltration, even under high humidity conditions. Moreover, the gelation of the ETL passivates interfacial defects (such as surface hydroxyls and oxygen vacancies) and enhances charge extraction from the perovskite layer. Additionally, the ammonium group promotes higher film crystallization, and thereby reduces charge recombination. As a result, optimized PSCs based on the gelated ETL achieved an improved PCE of up to 21.40%. The resulting PSCs without encapsulation also exhibited excellent moisture and thermal stability. Accordingly, this work suggests that employing a gelated ETL is a promising strategy to address the thermal instability of planar-PSCs. [ABSTRACT FROM AUTHOR]

Simple Summary: Defatting can be performed mechanically by cutting the frozen insect larvae and then pressing them to enable the leakage of intracellular fat, or chemically using petroleum ether extraction of the insect meal. This study aimed to investigate the effects of different defatting methods of black soldier fly (Hermetia illucens) larvae meal (BSFM) on the metabolic energy and nutrient digestibility in laying hens. The results show that both defatting methods of BSFM had no adverse effects on the metabolic energy and nutrient digestibility in young laying hens, but pressed black soldier fly meal (BSFMp) demonstrated better effects on the digestibility of metabolic energy and nutrients in the feed for young laying hens. This study aimed to investigate the effects of different defatting methods of black soldier fly (Hermetia illucens) larvae meal (BSFM) on the metabolic energy and nutrient digestibility in laying hens. Sixty young laying hens (Hy-Line W-36) aged 63 days were randomly divided into two groups (G1 and G2), each with five replicates of six hens housed in individual cages. Group G1 was fed 25% pressed black soldier fly meal (BSFMp) and 75% basal diet, and Group G2 was fed 25% extracted black soldier fly meal (BSFMe) and a 75% basal diet. Both diets included 5 g/kg chromium oxide as an external marker. A 7-day preliminary trial was followed by a 4-day experimental period. The results indicate that pressing and extracting significantly affected the digestibility of crude fat and total energy in BSFM, with BSFMp showing significantly higher crude fat digestibility than BSFMe. Similarly, total energy digestibility was also significantly higher in BSFMp. However, there were no significant differences in dry matter, organic matter, and crude protein digestibility between the two processing methods. The apparent metabolic energy values of BSFMp and BSFMe were 16.34 and 12.41 MJ/kg, respectively, showing a significant difference. The nitrogen-corrected metabolic energy values were 15.89 MJ/kg in BSFMp and 11.93 MJ/kg in BSFMe, indicating a highly significant difference. The digestibility of arginine and leucine in BSFMp was significantly higher than in BSFMe, while differences in lysine, cystine, threonine, tryptophan, and isoleucine were not significant. In conclusion, both defatting methods of BSFM had no adverse effects on the metabolic energy and nutrient digestibility in young laying hens, but BSFMp demonstrated better effects on the digestibility of metabolic energy and nutrients in the feed for young laying hens. [ABSTRACT FROM AUTHOR]

The purpose of this study is to prepare monodisperse silica mesoporous microspheres with narrow pore size distribution to promote their application in the field of liquid chromatography. An improved emulsion method was used to prepare silica mesoporous microspheres, and the rotary evaporation temperature, emulsification speed, dosage of porogen DMF, and dosage of the catalyst NH3·H2O were optimized. Subsequently, these microspheres were respectively treated by alkali–heating, calcination, and sieving. The D50 (particle size at the cumulative particle size distribution percentage of 50%) of as–prepared silica mesoporous microspheres is 26.3 μm, and the D90/D10 (the ratio of particle size at a cumulative particle size distribution percentage of 90% to a cumulative particle size distribution percentage of 10%) is 1.94. The resultant silica mesoporous microspheres have distinctive pore structures, with a pore volume of more than 1.0 cm3/g, an average pore size of 11.35 nm, and a median pore size of 13.4 nm. The silica mesoporous microspheres with a large particle size, uniform particle size distribution, large average pore size and pore volume, and narrow mesopore size distribution can basically meet the requirements of preparative liquid chromatographic columns. [ABSTRACT FROM AUTHOR]

As a kind of low temperature bulk heat storage material, calcium chloride hexahydrate has a great application prospect in heat storage and energy saving. However, the single calcium chloride hexahydrate phase change heat storage material has the disadvantages of low thermal conductivity and easy leakage when melting. Mesoporous silicon dioxide with large inner core and interpenetrating mesoporous channel structure can solve the above problems. Mesoporous silicon dioxide has the advantages of low density, low thermal expansion coefficient, low refractive index and large specific surface area. However, it has low thermal conductivity and needs to be combined with other materials with good thermal properties to enhance its thermal conductivity. MXene was used as the thermal conductivity enhancement material, mesoporous silicon dioxide was grown on its surface, and then the phase change material calcium chloride hexahydrate was loaded into it. By means of synchronous thermal analyzer and infrared thermal imager, it is proved that the heat storage performance, thermal stability and heat transfer rate of the composite phase change materials are significantly improved. The leakage of calcium chloride hexahydrate in the oven was also obviously inhibited by the carrier material. A kind of composite phase change heat storage material with excellent thermal properties and stability was successfully prepared. [ABSTRACT FROM AUTHOR]

Iris typhifolia Kitag is a perennial herbaceous species with high ornamental and applied value. Elucidating the mechanism of saline–alkali tolerance in Iris is crucial for their promotion in saline–alkali areas. Saline–alkali stress is one of the factors that affects plant growth, which has become a significant global issue. In this study, we measured the physiological and biochemical indexes of I. typhifolia, through germination and potting trials, to evaluate the resistance of I. typhifolia to different levels of artificial saline–alkali stress (0, 50, 100, 150, and 200 mmol·L−1). The results showed that artificial saline–alkali stress negatively impacted germination parameters, cell membrane integrity, and photosynthetic parameters. Different trends in osmoregulatory substances and endogenous hormones were observed. It was shown that I. typhifolia had a potential adaptability to the saline–alkali environment by enhancing its internal defense mechanism. Based on regression analyses, the germination threshold of I. typhifolia was calculated to be 87.15 mmol·L−1, which provided a theoretical basis for the application in soil saline–alkalization areas. [ABSTRACT FROM AUTHOR]

Nitride thermal conductive composite fillers were prepared by the mix and heat method. It's an environmentally friendly preparation method that can be mass-produced and does not use solvents. The loading of different metal nanoparticles (nickel, cobalt and silver) onto nitrides (aluminum nitride, boron nitride) and the amount of loading were investigated by scanning electron microscopy, X-ray diffractometer and TCI thermal conductivity meter, and the effect of composite ceramic thermally conductive filler on the thermal conductivity of polyvinyl alcohol-based composite thermal conductive film was examined. The results show that the metal nanoparticles were successfully loaded onto the nitrides without changing the crystal structure of the nitrides. And the size of the loaded metal particles increase with the increase of acetate content. In addition, the ceramic thermally conductive filler loaded with metal particles can effectively improve the thermal conductivity of polyvinyl alcohol-based composite thermally conductive film, and the thermal conductivity of Ag/AlN-0.05 thermally conductive film can reach 0.752 W/(m⋅K). [ABSTRACT FROM AUTHOR]