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Objective: This research aimed to study the preparation of standardized and stable sourdough starter, to explore the effects of different drying processes and protective agents on the survival rate of sourdough, and examine its storage activity. Methods: A variety of fruits were selected to prepare sourdough, the fermentation process was studied, and the strains were isolated and identified by ITs and 16s gene sequencing in the database. The optimum scheme was obtained by selecting the drying process, sample state and protectant formulation with the activity after drying and storage activity as indexes. Results: It was found that the bread prepared with grape sourdough had the best specific volume, porosity and hardness. On this basis, the drying survival rate and storage activity were used as indexes to study the combination of drying protectants. Finally, two better protective agent formulations were obtained by orthogonal experiment: ① Freeze-dried the dominant pure bacterial solution, skim milk 35%, maltodextrin 7.5% and trehalose 25%, and the drying survival rate was about 93%. ② Spray dried sourdough germ whole, skim milk 35%, maltodextrin 10% and trehalose 15%, and the drying survival rate was about 90%. Conclusion: It was found that the storage activity of the spray-dried starter decreased rapidly, while that of the freeze-dried starter was slower.

Does gender affect the risk of child abuse and neglect (CAN) in rural China? This study aims to answer this question through a national gender-balanced survey. An empirical investigation of 4943 children (M.sub.age = 12.08, 48.7% male) in eight provinces was finished in December 2019. The descriptive statistics, a mean analysis, and a linear regression are used to discuss the data. Two important findings can be summarized as follows. First, the risk of CAN in rural China differs across genders. The prevalence and severity of the physical and emotional abuse are higher among boys than among girls, while girls are more likely to suffer emotional neglect. Second, the risk factors for CAN also differ across genders. Girls are more likely than boys to be affected deeply by factors such as the experience of maternal intimate partner violence (IPV), parental educational attainment, children's age and academic performance, while boys are more associated with parental alcohol dependence than girls. The findings indicate that the prevalence of, severity of and risk factors for CAN differ significantly across genders, primarily because of gender inequality and the residual child welfare system., Author(s): Guowei Wan [sup.1] , Lan Li [sup.2] , Yao Gu [sup.3] Author Affiliations: (1) grid.216938.7, 0000 0000 9878 7032, Zhou Enlai School of Government, Nankai University, , Tianjin, China [...]

To increase specific surface area and light utilization of photo‐catalysts, a series of Fe3O4/Ag/BiVO4/sepiolite composites with different Fe3O4 contents were synthesized via co‐precipitation. The structure, composition, and optical properties of these composites were characterized using X‐ray diffraction (XRD), nitrogen adsorption and desorption (BET), UV‐Vis diffuse reflectance spectroscopy (UV‐Vis DRS), and fluorescence spectroscopy (PL). The photo‐catalytic activity of the composites was further evaluated using rhodamine B as a model for photo‐catalytic degradation. The results revealed that the composites with optimal Fe3O4 loading exhibited the narrowest bandgap width, approximately 2.13 eV, and the highest electron‐hole pair separation efficiency. Rhodamine B could be almost completely degraded within a short illumination time in the presence of the Fe3O4/Ag/BiVO4/sepiolite composites. The degradation mechanism of rhodamine B was proposed to involve the improvement of the photo‐catalytic activity of the resulting composites by the Fe3O4 and the Z‐type heterojunction structure. Additionally, the composites could be recycled and reused multiple times, making them an environmentally friendly and sustainable option. [ABSTRACT FROM AUTHOR]

The Holocene is a critical period for understanding the East Asian monsoon system (EAM) over long timescales, but high-precision dating and high-resolution records from the Holocene epoch at monsoonal margins of East Asia are lacking. Here, on the basis of closely spaced radiocarbon and optically stimulated luminescence dating results obtained from a typical loess–paleosol sequence on the northern Chinese Loess Plateau (CLP), we provide an independent age-based, high-resolution depositional record of East Asian summer (EASM) and winter monsoons (EAWM) variations over the past ~14 ka. We find that both the EASM and EAWM simultaneously strengthened sometime during the Holocene optimum (~7–5 ka BP), with greater seasonality, and weakened during the Late Holocene. These findings are counterintuitive to our understanding of the EAM variations based on loess records at suborbital scales during interglacial periods, providing an alternative scenario of the monsoon system evolution. We postulate that high-latitude forcing and surface feedbacks, such as vegetation change, have modulated the EAM variations during the Holocene warmth. [ABSTRACT FROM AUTHOR]

This paper proposes a fixed-time estimator-based distributed formation controller for a system consisting of multiple nonholonomic mobile robots, taking into consideration the stability of individuals and the effectiveness of internal communication. The desired trajectory of the formation is given by the virtual leader whose state is available only to some followers, and the information interaction within the followers is localized. To begin with, a distributed fixed-time sliding mode estimator is designed for each follower to estimate the state information of the virtual leader within a fixed time. Subsequently, based on the estimator, a formation controller is designed according to the trajectory tracking error of each follower. In addition, the Lyapunov function is constructed for stability analysis. Finally, simulation experiments are conducted in MATLAB/Simulink to demonstrate the effectiveness of the proposed estimator and controller, and the robustness of the control system is further verified by combining the actual situation of communication interruption and external disturbance. [ABSTRACT FROM AUTHOR]

Chemical losses of ambient reactive volatile organic compounds (VOCs) is a long-term issue yet to be resolved in VOC source apportionments. These losses substantially reduce the concentrations of highly reactive species in the apportioned factor profiles and result in the underestimation of source contributions. This review assesses the common methods and existing issues in ways to reduce losses and loss impacts in source analyses and suggest research directions for improved VOC source apportionments. Positive Matrix Factorization (PMF) is now the main VOC source analysis method compared to other mathematical models. The issue in using any apportionment tool is the processing of the data to be analyzed to reduce the impacts of reactive losses. Estimating the initial concentrations of ambient VOCs based on photochemical age has become the primary approach to reduce reactive loss effects in PMF except for selecting low reactivity species or nighttime data into the analysis. Currently, the initial concentration method only considers daytime reactions with hydroxyl (•OH) radicals. However, the •OH rate constants vary with temperature and that has not been considered. Losses from reactions with O3 and NO3 radicals especially for alkene species remain to be included. Thus, the accuracy of the photochemical-age estimation is uncertain. Beyond developing accurate quantitative approaches for reactive losses, source analyses methods for the consumed VOCs and the accurate quantification of different source contributions to O3 and secondary organic aerosols are important additional directions for future research. [ABSTRACT FROM AUTHOR]

This article develops an effective adaptive obstacle avoidance control strategy containing formation decision mechanism and a model predictive control–based formation controller for a multi-robot system working in a narrow alleyway environment. First, a decision mechanism containing two obstacle avoidance methods, homogeneous deformation and heterogeneous deformation, is established to provide a flexible choice for the formation to pass through the obstacle area, taking into account the formation safety and environment constraint. Furthermore, a formation bank is preset, and a performance evaluation system containing structural deformation, convergence speed, and energy consumption is established to help determine the best obstacle avoidance configuration. Then, a model predictive control–based formation controller with the leader–follower approach is utilized to realize the configuration switching and keeping. In the end, the simulation results verify the effectiveness of the proposed control strategy. [ABSTRACT FROM AUTHOR]