Evaluation of the CropSyst Model during Wheat-Maize Rotations on the North China Plain for Identifying Soil Evaporation Losses

The North China Plain (NCP) is a major grain production zone that plays a critical role in ensuring China's food supply. Irrigation is commonly used during grain production; however, the high annual water deficit [precipitation (P) minus evapotranspiration (ET)] in typical irrigated cropland does not support double cropping systems (such as maize and wheat) and this has resulted in the steep decline in the water table (~0.8 m year−1 at the Luancheng station) that has taken place since the 1970s. The current study aimed to adapt and check the ability of the CropSyst model (Suite-4) to simulate actual evapotranspiration (ETa), biomass, and grain yield, and to identify major evaporation (E) losses from winter wheat (WW) and summer maize (SM) rotations. Field experiments were conducted at the Luancheng Agro-ecosystem station, NCP, in 2010–2011 to 2012–2013. The CropSyst model was calibrated on wheat/maize (from weekly leaf area/biomass data available for 2012–2013) and validated onto measured ETa, biomass, and grain yield at the experimental station from 2010–2011 to 2011–2012, by using model calibration parameters. The revalidation was performed with the ETa, biomass, grain yield, and simulated ETa partition for 2008–2009 WW [ETa partition was measured by the Micro-lysimeter (MLM) and isotopes approach available for this year]. For the WW crop, E was 30% of total ETa; but from 2010–11 to 2013, the annual average E was ~40% of ETa for the WW and SM rotation. Furthermore, the WW and SM rotation from 2010–2011 to 2012–2013 was divided into three growth periods; (i) pre-sowing irrigation (PSI; sowing at field capacity) to emergence period (EP), (ii) EP to canopy cover period (CC) and (iii) CC to harvesting period (HP), and E from each growth period was ~10, 60, and 30%, respectively. In general, error statistics such as RMSE, Willmott's d, and NRMSE in the model evaluation for wheat ETa (maize ETa) were 38.3 mm, 0.81, and 9.24% (31.74 mm, 0.73, and 11.89%); for wheat biomass (maize biomass) they were 1.25 Mg ha−1, 0.83, and 9.64% (0.78 Mg ha−1, 0.96, and 7.96%); and for wheat grain yield (maize grain yield) they were 0.65 Mg ha−1, 0.82, and 9.87% (0.2 Mg ha−1, 0.99, and 3.79%). The results showed that CropSyst is a valid model that can be use with a reliable degree of accuracy for optimizing WW and SM grain yield production and water requirement on the NCP

Internal Model Control for Rank-Deficient System with Time Delays Based on Damped Pseudo-Inverse

It is a challenge to design a satisfactory controller for a complex multivariable industrial system with minimal offsetting and a slow response. An internal model control method is proposed for rank-deficient systems with a time delay based on a damped pseudo-inverse. An internal model control was designed to obtain the desired dynamic characteristics of the system by transforming the time-delay system into a system without a time delay, following the Pade approximation approach. By introducing a damping factor, the internal model controller was designed based on a damped pseudo-inverse, since the inverse matrix of the rank-deficient system does not exist. Furthermore, a singular value decomposition was used to analyze the steady-state performance of the system. The selection of the damping factor was also presented, and a μ analysis was made to evaluate the stability of the system. To demonstrate the effectiveness of the proposed method, a crude distillation process with five inputs and four outputs was considered as an example. The simulation results illustrate that not only can the proposed strategy guarantee the system’s stability, but it also has a relatively good dynamic performance

Simulation research of the buffering capacity of non-convex particle system under impact loading

The behavior of granular materials under the action of external force is a fundamental problem for the dynamics of granular media. This paper investigates the buffering capacity of three-dimensional non-convex granular beds subjected to vertical impact using the discrete element methods. The results display the particle shape significantly affects the buffering capacity of the equal mass granular bed. And the influence of aspect ratio of non-convex particles on buffering capacity exhibits an obvious non-monotonicity. The functional mechanism of inter-particle friction is discussed. It is showed that the shape of the non-convex particles has a great effect on the contact number of granular system and probability density functions of inter-particle forces

Simulation research of the buffering capacity of non-convex particle system under impact loading

The behavior of granular materials under the action of external force is a fundamental problem for the dynamics of granular media. This paper investigates the buffering capacity of three-dimensional non-convex granular beds subjected to vertical impact using the discrete element methods. The results display the particle shape significantly affects the buffering capacity of the equal mass granular bed. And the influence of aspect ratio of non-convex particles on buffering capacity exhibits an obvious non-monotonicity. The functional mechanism of inter-particle friction is discussed. It is showed that the shape of the non-convex particles has a great effect on the contact number of granular system and probability density functions of inter-particle forces

Characteristic investigation of an electrochemical-thermal coupled model for a LiFePO4/Graphene hybrid cathode lithium-ion battery

It is a promising development strategy to use LiFePO4/Graphene (LFP/G) hybrid cathode lithium-ion batteries for electric vehicles (EVs), which can simultaneously solve issues of the lengthy charging time and the battery pack heat. To capture the characteristic regulation of the temperature distribution, the working voltage, the current density, and the total heat generation of the LFP/G battery, an electrochemical-thermal coupled model for the LFP/G battery was developed through a new modeling method in ANSYS FLUENT. The experimental results showed that tendencies of the temperature distribution and the working voltage were not only agreed well with simulations, but also accurately verified the hottest area of the LFP/G battery. Further studies used the comparative analyses of the maximal temperature between the LFP/G battery and the conventional LFP battery at different discharged C-rates, the results indicated that the LFP/G battery could restrain the increase of temperature through reduced contact resistances. Our results suggested that the electrochemical-thermal coupled model could be used for electric vehicles battery management system applications. Keywords: LiFePO4/Graphene, Lithium-ion battery, FLUENT, Electrochemical-thermal coupled mode

Spatio-temporal Agglomeration and Coupling Effects of Inputs and Outputs in China’s Biomedical Industry

Biomedical industry is one of the major development industries in the world and academics are interested in the inputs and outputs of biomedical industry. We used the inputs and outputs data of biomedical industry of 31 provinces and municipalities in China from 2009 to 2020 (except 2017). Using the Theil index and Moran’s I, the spatial distribution and agglomeration of the inputs and outputs of the biomedical industry among 31 provinces and municipalities were analyzed. To examine the coupling effects and possible relevant factors for the inputs and outputs of the biomedical industry, the coupling coordination degree (CCD) and spatial lag model (SLR) were used. The overall development of the biomedical industry in China’s 31 provinces and municipalities was found to be relatively balanced, with a high concentration in Jiangsu, Shandong, Zhejiang, and other provinces. Moreover, there is a widening development disparity between provinces. Government investment and enterprise investment have a significant impact on the development of the biomedical industry, with enterprise R&D capital investment being the most influential factor. In the meantime, the development of the biomedical industry has a close relationship with the investment and development levels of neighboring provinces

Effects of Enterococcus faecium Extracellular Vesicles on Growth Performance, Intestinal Morphology and Fecal Microbiota in Mice

【Objective】The study aimed to explore the effects of Enterococcus faecium extracellular vesicles (Efm-EV) on growth performance, immunity, intestinal morphology and fecal microbiota in mice, providing theoretical basis for the application of E. faecium as a microbial feed additive in animal production.【Method】A total of 20 male C57BL/6 mice were randomly divided into control group and experimental group with 10 replicates per group and 1 mouse per replicate. The experiment lasted for 5 days. Mice in the experimental group were given 500 μg Efm-EV suspension every other day by intragastric administration, with 150 μL for each mouse, and mice in the control group were given the same volume of PBS. Daily feed intake, and body weight at the beginning and end of the experiment of each mouse were recorded, average daily gain (ADG), average daily feed intake (ADFI) and feed/gain (F/G) of mice were calculated accordingly.【Result】Compared with the PBS treatment group, no significant change was observed in the final body weight (FBW), ADG, ADFI and F/G of mice in the Efm-EV treatment group. The serum immunoglobulin A (IgA) and immunoglobulin G (IgG) levels in the Efm-EV group were significantly decreased compared with those in PBS treatment group (P < 0.05), while the serum interleukin-10 (IL-10) level was significantly increased (P < 0.05), and there was no significant difference in serum tumor necrosis factor-α (TNF-α) level. Compared with the PBS treatment, Efm-EV treatment significantly increased duodenal villus height/crypt depth ratio (VH/CD) (P < 0.05). There were no significant changes in villus height (VH), crypt depth (CD) of duodenum, and VH, CD and VH/CD of jejunum and ileum. Efm-EV intragastric administration increased the number of Firmicutes and decreased the number of Bacteroidetes at the phylum level, increased the abundance of Lachnospiraceae and decreased the abundance of Muribaculaceae at the family level, significantly increased the abundance of Ruminococcaceae UCG009 at the genus level (P < 0.05).【Conclusion】Intragastric administration of Efm-EV can improve the anti-inflammatory level, the duodenal morphology and the relative abundance of Ruminococcaceae UCG009 in mice