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[Objective] This study was aimed to explore the impact of different land use patterns on regional ecosystem carbon storage. [Methods] In this paper, using the SD-PLUS coupled model and the coupled shared socio-economic path and representative concentration path (SSP-RCP) scenario proposed by the Coupled Model Intercomparison Project Phase 6 (CMIP6), the land use changes in Shaanxi province in 2030 were projected, and then the different future scenarios simulated by the InVEST model were used to predict the Shaanxi Province’s carbon storage and its spatial distribution under different future scenarios simulated by the InVEST model. [Results] (1) The SD model constructed was tested historically, and its error was less than 5%, and the Kappa index of land use in 2020 simulated by the PLUS model was 0.86, and the accuracy and reliability of the model generally met the requirements. (2) Under the three scenarios, the area of future construction land increased, and the scenarios with the lowest to highest growth rates were: SSP126, SSP245, SSP585. Under all scenarios, the area of forest land increased, and the area of watersheds remained stable; the area of grassland had a small increase under the SSP126 scenario, and decreased in other scenarios; and the area of arable land decreased in all three scenarios. (3) Carbon stock in Shaanxi Province decreased under all three scenarios, with the decrease in carbon stock in the Guanzhong plain being the main reason for the decrease in carbon stock in Shaanxi province. [Conclusion] The area of ecological land occupied by the expansion of construction land is the smallest under the SSP126 scenario, which takes into account both socio-economic development and the need for ecological protection, and can provide a reference model for the future protection of land resources and high-quality development in Shaanxi province.

Background: The purpose of this study is to investigate the genotype and allele distribution of MTHFR rs1801133 in the Chinese population, and to analyze the relationship between gene polymorphism of MTHFR rs1801133 and risk of childhood leukemia. Methods: Blood samples and clinical data of childhood leukemia cases (n=1132) and age-matched healthy controls (n=1053) were collected. Genotypes and allele distribution of MTHFR rs1801133 were detected by PCR-RFLP. Logistic regression model was generated to analyze the relation between MTHFR rs1801133 and susceptibility to childhood leukemia and the chemotherapy response. Results: Age, sex, BMI and family history of tumor were comparable between childhood leukemia cases and healthy controls. Genotypes and allele distribution of MTHFR rs1801133 were remarkably correlated to the risk of childhood leukemia. Genotype risk of MTHFR rs1801133 was parallel to the susceptibility to childhood leukemia. Specifically, compared with people carrying AA allele of MTHFR rs1801133, higher risk of childhood leukemia may occur in people carrying AG+GG allele of MTHFR rs1801133 with a younger age (

In order to further improve the stability and accuracy of the pouring trajectory of the heavy-duty casting robot during the pouring operation, a new hybrid four-degree-of-freedom heavy-duty casting robot is taken as the research object, and a trajectory planning method based on the synthesis of the fifth-order polynomial and the sinusoidal acceleration motion law is proposed. The degree-of-freedom of the actuator is calculated by the topological structure theory of the robot mechanism, and the position of the parallel mechanism is solved by the closed-loop vector method, the kinematic position equation of the hybrid mechanism is derived according to the equivalent method and the geometric method. The trajectory planning of the robot is carried out by combining the fifth-order polynomial and the sinusoidal acceleration motion law. The Adams software is used to simulate the trajectory motion of the robot end, and the parameters obtained by the theoretical solution are verified. The results show that the trajectory based on the combination of the fifth-order polynomial and the sine acceleration motion law is smoother and more natural than the fifth-order polynomial, and the maximum speed of the robot end is reduced by 14%, avoiding the vibration due to excessive speed fluctuations.

Abstract Before a wide range of enhanced oil recovery (EOR) techniques were implemented for an oilfield, the EOR potential and economic evaluation of the techniques should be evaluated in advance for each reservoir to determine which EOR technique was proper. In an oilfield developed with fluvial delta reservoirs, the complicated distribution of scattered small reservoirs in vertical and horizontal directions brought trouble for evaluation work. A rapid and reliable evaluation model for EOR techniques applicability was necessary to deal with the evaluation simulation for many small reservoirs of an oilfield. Combining fraction theory model with auxiliary equations, which describe the effect of formation heterogeneity and mechanism of different EOR technique on fractional flow rate, an evaluation analysis method for EOR techniques applicability of gas flooding, foam flooding and surfactant flooding was proposed. In the gas flooding model, the minimum miscible pressure of impure gas was introduced, and the relative permeability was modified by the minimum miscible factor. In the foam flooding model, changes in the mobility ratio and chemical adsorption were considered and a reduction factor of mobility ratio was introduced. In the surfactant flooding model, calculation formulas of viscosity and interfacial tension as well as the relative permeability were introduced. Finally, the model was simulated for a low permeability reservoir, and the simulation results were compared with that from Eclipse software. The similar results, little calculation time and feasibility of predicting optimal injection parameter had shown the reliability of the rapid evaluation model.