Regulatory potential of soil available carbon,nitrogen,and functional genes on N_(2)O emissions in two upland plantation systems

Dynamic nitrification and denitrification processes are affected by changes in soil redox conditions,and they play a vital role in regulating soil N_(2)O emissions in rice-based cultivation.It is imperative to understand the influences of different upland crop planting systems on soil N_(2)O emissions.In this study,we focused on two representative rotation systems in Central China:rapeseed–rice(RR)and wheat–rice(WR).We examined the biotic and abiotic processes underlying the impacts of these upland plantings on soil N_(2)O emissions.The results revealed that during the rapeseed-cultivated seasons in the RR rotation system,the average N_(2)O emissions were 1.24±0.20 and 0.81±0.11 kg N ha^(–1)for the first and second seasons,respectively.These values were comparable to the N_(2)O emissions observed during the first and second wheat-cultivated seasons in the WR rotation system(0.98±0.25 and 0.70±0.04 kg N ha^(–1),respectively).This suggests that upland cultivation has minimal impacts on soil N_(2)O emissions in the two rotation systems.Strong positive correlations were found between N_(2)O fluxes and soil ammonium(NH_(4)^(+)),nitrate(NO_(3)^(–)),microbial biomass nitrogen(MBN),and the ratio of soil dissolved organic carbon(DOC)to NO_(3)^(–)in both RR and WR rotation systems.Moreover,the presence of the AOA-amoA and nirK genes were positively associated with soil N_(2)O fluxes in the RR and WR systems,respectively.This implies that these genes may have different potential roles in facilitating microbial N_(2)O production in various upland plantation models.By using a structural equation model,we found that soil moisture,mineral N,MBN,and the AOA-amoA gene accounted for over 50%of the effects on N_(2)O emissions in the RR rotation system.In the WR rotation system,soil moisture,mineral N,MBN,and the AOA-amoA and nirK genes had a combined impact of over 70%on N_(2)O emissions.These findings demonstrate the interactive effects of functional genes and soil factors,including soil physical characteristics,available carbon and nitrogen,and their ratio,on soil N_(2)O emissions during upland cultivation seasons under rice-upland rotations.

Precise robust motion control of cell puncture mechanism driven by piezoelectric actuators with fractional-order nonsingular terminal slidingmode control

A novel robust controller is proposed in this study to realize the precise motion control of a cell puncture mechanism(CPM)driven by piezoelectric ceramics(PEAs).The entire dynamic model of CPM is constructed based on the Bouc–Wen model,and the nonlinear part of the dynamic model is optimized locally to facilitate the construction of a robust controller.A model-based,nonlinear robust controller is constructed using time-delay estimation(TDE)and fractional-order nonsingular terminal sliding mode(FONTSM).The proposed controller does not require prior knowledge of unknown disturbances due to its real-time online estimation and compensation of unknown terms by using the TDE technology.The controller also has finite-time convergence and high-precision trajectory tracking capabilities due to FONTSM manifold and fast terminal sliding mode-type reaching law.The stability of the closed-loop system is proved by Lyapunov stability theory.Computer simulation and hardware-in-loop simulation experiments of CPM verify that the proposed controller outperforms traditional terminal sliding mode controllers,such as the integer-order or model-free controller.The proposed controller can also continuously output without chattering and has high control accuracy.Zebrafish embryo is used as a verification target to complete the cell puncture experiment.From the engineering application perspective,the proposed control strategy can be effectively applied in a PEA-driven CPM.

A multiphysical-geochemical coupling model for caprock sealing efficiency in CO_(2) geosequestration

Precipitation or dissolution due to geochemical reactions has been observed in the caprocks for CO_(2) geosequestration.Geochemical reactions modify the caprock sealing efficiency with self-limiting or self-enhancement.However,the effect of this modification on the caprock sealing efficiency has not been fully investigated through multiphysical-geochemical coupling analysis.In this study,a multiphysical-geochemical coupling model was proposed to analyze caprock sealing efficiency.This coupling model considered the full couplings of caprock deformation,two-phase flow,CO_(2) concentration diffusion,geochemical reaction,and CO_(2) sorption.The two-phase flow only occurs in the fracture network and the CO_(2) may partially dissolve into water and diffuse through the concentration difference.The dissolved CO_(2) has geochemical reactions with some critical minerals,thus altering flow channels.The CO_(2) in the fracture network diffuses into matrix,causing the matrix swelling.This fully coupling model was validated with a penetration experiment on a cement cube and compared with two other models for CO_(2) storage plumes.Finally,the effects of geochemical reactions on penetration depth and pore pressure were studied through parametric study.The numerical simulations reveal that the coupling of geochemical reactions and matrix diffusion significantly affect the caprock sealing efficiency.Geochemical reactions occur at a short time after the arrival of CO_(2) concentration and modify the fracture porosity.The CO_(2) diffusion into the matrix requires a much longer time and mainly induces matrix swelling.These effects may produce selfenhancement or self-limiting depending on the flow rate in the fracture network,thus significantly modifying caprock sealing efficiency.

Analyzing the formation cause of Xidatan drinking mineral springs in island permafrost area on north slope of the Kunlun Mountains

The replenishment source of Xidatan drinking mineral springs in island permafrost area on north slope of the Kunlun Mountains are mainly the melting water from the modern glaciers bottom, snow and ice melting water, atmospheric precipitation, and surface water in Yuzhu Peak area on the Kunlun Mountains. This scenario is based on the survey of hydrogeology, water-conducting and water-controlling faults, and water chemistry, and on the EH-4 high-frequency electronic deep exploration. The original water recharges the deep groundwater at fracture zone of active normal faults F3 and F4 , then groundwater enriches at normal faults F2 and F2-1,2 , and then run northward. A water-rich triangle area is formed when groundwater reach the active reverse fault F1 . Groundwater then discharges through fracture zone of F1 , which is the major cause of the Xidatan mineral springs formation.

多国卫生应急管理体系框架现况与对比研究

目的比较多国卫生应急管理体系框架,分析不同国家卫生应急管理体系特征,为全球卫生应急管理体系的治理方向提供参考。方法聚焦多国卫生应急管理体系现状,旨在通过多国研究和对比,客观分析多国卫生应急管理体系中的短板与不足,提炼对于全球多国卫生应急管理体系治理方向的建议。结果多国在卫生主管部门及其职能、疾控机构及其职能、突发公共卫生事件参与机构及其职能方面大同小异,美国呈现出"垂直管理高度自治、横向管理职能高度分散"特征,英国采取的是"横向合作和纵向委托"的方式,德国强调属地化管理下的多样化协调。结论不同国家卫生应急管理体系具有不同特点,聚焦卫生应急管理体系的治理方向,多国在不同层次,如中央与地方的垂直管理、同级平行部门的横向管理间,应强化卫生应急管理的联动性、实效性和可操作性,强化法制支撑、健全管理体制、畅通运行机制。

The effect of dolomite amendment on soil organic carbon mineralization is determined by the dolomite size

Background:The size of lime material is vital for the efficiency of ameliorating soil acidity,thereby influencing soil biochemical processes.However,the effects of different sized lime material application on soil organic carbon(SOC)mineralization are yet to be elucidated.Therefore,a 35-day incubation experiment was conducted to determine the effects of three particle size fractions(0.5 to 0.25,0.25 to 0.15,and<0.15 mm)of dolomite on SOC mineralization of two acidic paddy soils.Results:CO_(2) emission was increased by 3–7%,11–21%,and 32–49%for coarse-,medium-,and fine-sized dolomite treatments,respectively,compared to the control in both soils.They also well conformed to a first-order model in all treatments,and the estimated decomposition rate constant was significantly higher in the fine-sized treatment than that of other treatments(P<0.05),indicating that SOC turnover rate was dependent on the dolomite size.The finer particle sizes were characterized with higher efficiencies of modifying soil pH,consequently resulting in higher dissolved organic carbon contents and microbial biomass carbon,eventually leading to higher CO_(2) emissions.Conclusions:The results demonstrate that the size of dolomite is a key factor in regulating SOC mineralization in acidic paddy soils when dolomite is applied to manipulate soil pH.

Human-robot interface based on sEMG envelope signal for the collaborative wearable robot

Surface electromyography(sEMG)control interface is a common method for human-centered robotics.Researchers have frequently improved the recognition accuracy of sEMG through multichannel or high-precision signal acquisition devices.However,this increases the cost and complexity of the control system.Therefore,this study developed a control interface based on the sEMG enveloped signal for a collaborative wearable robot to improve the accuracy of sEMG recognition based on the time-domain(TD)features.Specifically,an acquisition device is developed to obtain the sEMG envelope signal,and 11 types of TD features are extracted from the sEMG envelope signal acquired from the upper limb.Furthermore,a dimension reduction method based on the correlation coefficient is proposed,transforming the 11-dimensional feature into a five-dimensional envelope feature set without decreasing the accuracy.Moreover,a recognition algorithm based on a neural network has also been proposed for gesture classification.Finally,the recognition accuracy of the proposed method,principal component analysis(PCA)feature set,and Hudgins TD feature set is compared,with their accuracy at 84.39%,72.44%,and 70.89%,respectively.Therefore,the results indicate that the envelope feature set performs better than the common gesture recognition method based on signal channel sEMG envelope signal.

Construction of a Competency Evaluation Indicator System for Emergency Response Staff in Disease Control and Prevention Institutions ——China, 2023

What is already known about this topic?Currently,there is no established scientific standard to guide disease control and prevention organizations in the selection of emergency response personnel.Given the growing risk of significant infectious disease outbreaks,it is imperative to develop an evaluation system for assessing emergency response capabilities.