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Objective: Rapid determination of organochlorine and pyrethroid pesticide residues in tea beverages. Methods: Selecting the non-ionic surfactant PEG-4000 as cloud point extraction, pesticides were extracted with isooctane by ultrasonic back extraction. The upper layer of isoctane solution was analyzed by Gas Chromatography/Mass. The isooctane solution was separated by HP-5 ms UI capillary column and analyzed qualitatively and quantitatively by GC/MS. Results: The eight pesticides showed a good linear relationship between 0.01～2.0 and 0.02～4.0 mg/L, respectively, with the correlation coefficients (R) of over 0.995. The detection limit and quantification limit of this method were 0.003~0.008 mg/L and 0.01~0.02 mg/L, respectively. The average recovery was 78.3%~98.4%, RSD was 2.7%~8.5% (n=6). Conclusion: The method is simple in operation, high in enrichment rate, practical, safe and economical, which is suitable for rapid determination of pesticide residues in tea drinks.

Hydrocolloids have good functional properties,such as improving emulsification,gelation,solubility and texture of food.In bakery products,hydrocolloids are used to improve the properties of dough,bread and cake,increase sensory quality and extend shelf life.Studies have reported the potential use of hydrocolloids in breads,biscuits,cakes and pasta preparation.Effects of common hydrocolloid (xanthan,guar,Arabic,k-carrageenan,karaya,alginate,methylcellulose,carboxy methyl cellulose,hydroxyl propyl methyl cellulose) on the rheology,physicochemistry,texture and other quality characteristics of baked foods were summarized.The addition of hydrocolloid significantly improves the color,appearance,flavor and overall acceptability of the product.

Active-polymer attracted increasing interest as an enhancing oil recovery technology in oilfield development owing to the characteristics of polymer and surfactant. Different types of active functional groups, which grafted on the polymer branched chain, have different effects on the oil displacement performance of the active-polymers. In this article, the determination of molecular size and viscosity of active-polymers were characterized by Scatterer and Rheometer to detect the expanded swept volume ability. And the Leica microscope was used to evaluate the emulsifying property of the active-polymers, which confirmed the oil sweep efficiency. Results show that the Type I active-polymer have a greater molecular size and stronger viscosity, which is a profile control system for expanding the swept volume. The emulsification performance of Type III active-polymer is more stable, which is suitable for improving the oil cleaning efficiency. The results obtained in this paper reveal the application prospect of the active-polymer to enhance oil recovery in the development of oilfields.

With the widespread application of rare earth elements analysis, the development of rapid detection technology of rare earth elements has increasingly become a necessity within the industry. Microwave Plasma Torch (MPT) as the ion source and Quadrupole Mass Spectrometry (QMS) as the mass analyzer to develop a method for fast detection of rare earth elements (REEs) in water and ore samples has been developed and discussed in this paper. With the MPT-QMS method, for elements Y, La, Ce, Nd, Eu in water samples, the limits of detection (LODs) are 11.0-60.5 μg/L, and the linear ranges are 50-1000 μg/L. When analyzing ore samples, the samples were firstly digested by acid solution and the sample solution formed an aerosol, which was then cooled to keep it dry. The aerosol entered the plasma by the centre tube of the MPT and formed REE ions. These ions enter the QMS, and concentrations of REE elements can be quantitatively determined. Repeated analyses of the same sample by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) yield similar results, indicating that the semi-quantitative analyses of MPT-QMS are precise and reliable. Therefore, MPT coupled with QMS is suitable for portable, rapid analysis of metal elements in water and can be used in the field of in situ quality monitoring of environmental and drinking water.

The rapid growth of edge devices and mobile applications has driven the adoption of edge computing to handle computing tasks closer to end-users. However, the heterogeneity of edge devices and their limited computing resources raise challenges in the efficient allocation of computing resources to complete services with different characteristics and preferences. In this paper, we delve into an edge scenario comprising multiple Edge Computing Servers (ECSs), multiple Device-to-Device (D2D) Edge Nodes (ENs), and multiple edge devices. In order to address the resource allocation challenge among ECSs, ENs, and edge devices in high-workload environments, as well as the pricing of edge resources within the resource market framework, we propose a Risk Assessment Contract Algorithm (RACA) based on risk assessment theory. The RACA enables ECSs to assess risks associated with local users by estimating their future revenue potential and updating the contract autonomously at present and in the future. ENs acquire additional resources from ECSs to efficiently complete local users' tasks. Simultaneously, ENs can also negotiate reasonable resource requests and pricing with ECSs by a Stackelberg game algorithm. Furthermore, we prove the unique existence of Nash equilibrium in the established game, implying that equilibrium solutions can stably converge through computational methods in heterogeneous environments. Finally, through simulation experiments on the dataset, we demonstrate that risk assessment can better enhance the overall profit capability of the system. Moreover, through multiple experiments, we showcase the stability of the contract's autonomous update capability. The RACA exhibits better utility in terms of system profit capabilities, stability in high-workload environments, and energy consumption. This work provides a more dynamic and effective solution to the resource allocation problem in edge systems under high-workload environments. [ABSTRACT FROM AUTHOR]

Ni3Si2O5(OH)4 rods (NS) were synthesized via a hydrothermal method, employing natural wollastonite as a template. The hierarchical Ni3Si2O5(OH)4 rods exhibited vertically oriented nanosheets, resulting in a substantial increase in the specific surface area (from 2.24 m2/g to 178.4 m2/g). Subsequently, a CdS/Ni3Si2O5(OH)4 composite photocatalyst (CdS/NS) was prepared using a chemical deposition method. CdS was uniformly loaded onto the surface of the Ni3Si2O5(OH)4 nanosheets, successfully forming a heterojunction with Ni3Si2O5(OH)4. The CdS/NS photocatalyst in the presence of lactic acid as a sacrificial agent demonstrated an impressive H2 production rate of 4.05 mmol h−1 g−1, around 40 times higher than pure CdS. The photocorrosion of CdS was effectively solved after loading. After four cycles, the performance of CdS/NS remained stable, showing the potential for sustainable applications. After photoexcitation, electrons moved from Ni3Si2O5(OH)4 to the valence band of CdS, where they interacted with the holes via an enhanced interface contact. Simultaneously, electrons in CdS transitioned to its conduction band, facilitating hydrogenation. The enhanced performance was attributed to the improved CdS dispersion by Ni3Si2O5(OH)4 loading and efficient photogenerated carrier separation through the heterojunction formation. This work provides new perspectives for broadening the applications of mineral materials and developing heterojunction photocatalysts with good dispersibility and recyclability. [ABSTRACT FROM AUTHOR]

Abstract We study the holographic Schwinger effect with magnetic field at RHIC and LHC energies by using the AdS/CFT correspondence. We consider both weak and strong magnetic field cases with $$B\ll T^2$$ B≪T2 and $$B\gg T^2$$ B≫T2 solutions respectively. Firstly, we calculate separating length of the particle pairs at finite magnetic field. It is found that for both weak and strong magnetic field solutions the maximum value of separating length decreases with the increase of magnetic field , which can be inferred that the virtual electron-positron pairs become real particles more easily. We also find that the magnetic field reduces the potential barrier and the critical field for the weak magnetic field solution, thus favors the Schwinger effect. With strong magnetic field solution, the magnetic field enhances the Schwinger effect when the pairs are in perpendicular to the magnetic field although the magnetic field increases the critical electric field.