The Effect of Procrastination on Physical Exercise among College Students—The Chain Effect of Exercise Commitment and Action Control

Background:Exercise procrastination is prevalent among college students,causing decline in physical fitness.It is imperative to investigate the mechanism affecting college students’physical activity behaviors.This study was aimed at investigating the effect of procrastination on college students’physical exercise behavior,and the chain mediation effects of exercise commitment and action control(AC),to provide a theoretical basis for interventions targeting physical exercise behavior among college students.Methods:A questionnaire survey was conducted using convenience sampling.The General Procrastination Scale,Exercise Commitment Scale,Action Control Scale,and Physical Activity Rating Scale-3 questionnaires were used.Participants were 581 college students(age 19.27±0.94 years;243 males and 338 females).Statistical methods of regression analysis and structural equation modeling(SEM)were applied.Results:Procrastination,exercise commitment,and action control were found to be significant predictors of physical exercise behavior.Among these predictors,exercise commitment and action control showed full mediation effects in the relationship between procrastination and physical exercise behavior,and explained 25.48%and 30.77%of the total variance,respectively.The chain mediation effect of exercise commitment-action control was significant,accounting for 22.60%of the total variance,and the total indirect effect was 79.33%.Conclusion:Therefore,higher procrastination was associated with less participation in physical exercise behavior among college students.Improvements in exercise commitment and volitional decision-making ability for physical exercise behavior promoted physical exercise behavior,and increased exercise commitment promoted volitional decision-making ability among the students.The chain reaction effect of exercise commitment and action control also buffered the negative effects of procrastination on physical exercise behavior,thereby increasing physical exercise behavior among college students.

Action Control of Soccer Robots Based on Simulated Human Intelligence

A multi-modal action control approach is proposed for an autonomous soccer robot when the bottom hardware is unchangeable. Different from existing methods, the proposed control approach defines actions with the principle of ＂perception-planning-action＂ inspired by human intelligence. Character extraction is used to divide the perception input into different modes. Different control modes are built by combining different control methods for the linear velocity and angular velocity. Based on production rules, the motion control is realized by connecting different perceptions to the corresponding control mode. Simulation and real experiments are conducted with the middle-sized robot Frontier-I, and the proposed method is compared with a proportional-integral-derivative （PID） control method to display its feasibility and performance. The results show that the multi-modal action control method can make robots react rapidly in a dynamic environment.

Application of Statistical Process Control for Setting Action Thresholds as Quality Assurance of Dose Verifications in External Beam Radiotherapy

Purpose: To test the concept of Statistical Process Control (SPC) as a Quality Assurance (QA) procedure for dose verifications in external beam radiation therapy in conventional and 3D Conformal Radiotherapy (3D-CRT) treatment of cervical cancer. Materials and Methods: A study of QA verification of target doses of 198 cervical cancer patients undergoing External Beam Radiotherapy (EBRT) treatments at two different cancer treatment centers in Kenya was conducted. The target doses were determined from measured entrance doses by the diode in vivo dosimetry. Process Behavior Charts (PBC) developed by SPC were applied for setting Action Thresholds (AT) on the target doses. The AT set was then proposed as QA limits for acceptance or rejection of verified target doses overtime of the EBRT process. Result and Discussion: Target doses for the 198 patients were calculated and SPC applied to test whether the action limits set by the Process Behavior Charts could be applied as QA for verified doses in EBRT. Results for the two sub-groups of n = 3 and n = 4 that were tested produced action thresholds which are within clinical dose specifications for both conventional AP/PA and 3D-CRT EBRT treatment techniques for cervical cancer. Conclusion: Action thresholds set by SPC were within the clinical dose specification of ±5% uncertainty for both conventional AP/PA and 3D-CRT EBRT treatment techniques for cervical cancer. So the concept of SPC could be applied in setting QA action limits for dose verifications in EBRT.

On the Generalization of Integrator and Integral Control Action

This paper provides a solution to generalize the integrator and the integral control action. It is achieved by defining two function sets to generalize the integrator and the integral control action, respectively, resorting to a stabilizing controller and adopting Lyapunov method to analyze the stability of the closed-loop system. By originating a powerful Lyapunov function, a universal theorem to ensure regionally as well as semi-globally asymptotic stability is established by some bounded information. Consequently, the justification of two propositions on the generalization of integrator and integral control action is verified. Moreover, the conditions used to define the function sets can be viewed as a class of sufficient conditions to design the integrator and the integral control action, respectively.

Characteristics of mining gas channel expansion in the remote overlying strata and its control of gas flow

The technology of pressure relief gas drainage is one of the most effective and economic for preventing gas emissions in underground mines.Based on current understanding of strata breakage and fracture development in overlying strata,the current study divides the overlying strata into the following three longitudinal zones in terms of the state of gas flow:a turbulent channel zone,a transitional circulation channel zone and a seepage channel zone.According to the key strata discrimination theory of controlling the overlying strata,the calculation method establishes that the step-type expansion of the mining gas channel corresponds to the advancing distance of working face,and this research also confrms the expanding rule that the mining gas channel in overlying strata follows the advancing distance of mining working face.Based on the geological conditions of Xinjing Coal Mine of Yangquan,this paper researches the expanding rule of mining gas channel as well as the control action of the channel acting on the pressure relief flow under the condition of the remote protective layer,and got the distance using inversion that the step-type expanding of mining gas channel is corresponding to the advancing distance of working face,which verifes the accuracy and feasibility of theoretical calculation method proposed in this study.The research provides the theoretical basis for choosing the technology of pressure relief gas drainage and designing the parameters of construction.

Modified Modeling of the Heart by Applying Nonlinear Oscillators and Designing Proper Control Signal

Rhythmic phenomena are one of the most striking manifestations of dynamic behavior in biological systems. Understanding the mechanisms of biological rhythms, is crucial for understanding the dynamic of life. Each type of dynamic behaviors may be related to the performance of both normal physiology and pathological. Conductive system of the heart can be stimulated to action as a network of elements and these elements show the oscillatory behavior then can be modeled as nonlinear oscillators. This paper provides the mathematical model of the heart rhythm by considering different states of Vanderpol nonlinear oscillators. Proposed oscillator model is designed in order to reproduce time series of action potential of natural pacemakers cardiac, such as SA or AV nodes. So model of heart is presented by a system of differential equations and to be considered chaotic or nonchaotic for different parameters of the model by using of the 0-1 test. Finally, the model is synchronized by applying an appropriate control signal, if it is needed.

中国大气污染防治政策与空气污染治理——基于城市级面板数据的实证研究

2013年颁布实施的《大气污染防治行动计划》是我国首个针对环境突出问题开展综合治理的行动计划;为巩固治理效果,应对动态变化的环境问题,2018年国务院进一步发布了《打赢蓝天保卫战三年行动计划》。研究利用中国258个城市2013年1月至2020年9月日度空气污染数据,实证检验了上述两阶段政策对空气质量的影响,并从不同污染物治理效果、时间和区域异质性等角度分析了政策效应的差异。结果指出:第一,“大气十条”和“蓝天保卫战”均显著降低了AQI、PM_(2.5)、PM_(10)、SO_(2)、NO_(2)、CO;第二,相比“大气十条”,“蓝天保卫战”对NO_(2)的减排效应更高,且实现对O_(3)的协同治理;第三,“大气十条”和“蓝天保卫战”对各污染物的减排效应因供暖时期、地区能源资源禀赋呈现出较强的异质性特征。

Optimal Control of Wind Turbines under Islanded Operation

In this paper, an optimal control scheme for wind turbine output torque and power regulation under the influence of wind disturbances is presented. The system considered is a dynamic mechanical-based model with pitch and generator torque actuators for controlling the pitch and generator torque. The performance of linear matrix inequality (LMI) formalism of linear quadratic regulator (LQR);linear quadratic regulator with integral action (LQRI) and model predictive control (MPC) were compared in response to a step change in wind disturbance. It is shown by Matlab simulation that the LQRI outperformed both LQR and MPC controllers.

General Concave Integral Control

In this paper, a class of fire-new general integral control, named general concave integral control, is proposed. It is derived by normalizing the bounded integral control action and concave function gain integrator, introducing the partial derivative of Lyapunov function into the integrator and originating a class of new strategy to transform ordinary control into general integral control. By using Lyapunov method along with LaSalle’s invariance principle, the theorem to ensure regionally as well as semi-globally asymptotic stability is established only by some bounded information. Moreover, the highlight point of this integral control strategy is that the integrator output could tend to infinity but the integral control action is finite. Therefore, a simple and ingenious method to design general integral control is founded. Simulation results showed that under the normal and perturbed cases, the optimum response in the whole domain of interest can all be achieved by a set of the same control gains, even under the case that the payload is changed abruptly.

基于措施优先级的失效模式和效应分析在结直肠术手术部位感染防控中的应用

目的评估结直肠手术后手术部位感染(SSI)防控措施执行的过程风险,探讨基于措施优先级的失效模式和效应分析(FMEA)的应用效果。方法应用基于措施优先级的FMEA评估结直肠手术后SSI防控措施执行的整个流程,对是否采取优化措施进行优先级排序,比较FMEA实施前后结直肠手术SSI防控措施依从项达标率、SSI发病率。结果评估后SSI高优先级防控措施7项,中优先级22项,对中优先级措施加强控制,重点对高优先级措施制定进一步的预防和可探测措施。改进后再评价结果显示,7项高优先级措施降至中优先级;16项中优先级措施降至低优先级。SSI防控措施执行达标率由77.15%(2566/3326)提高至92.47%(3096/3348),SSI发病率由6.04%(58/960)降至2.54%(60/2364)。结论运用基于措施优先级的FMEA可对结直肠手术SSI防控过程进行有效风险评估,并结合现状针对性采用预防性风险控制措施,可降低结直肠手术SSI发病率。

瑶药小钻的特征图谱及其安五脂素含量和抗炎活性研究

目的 建立瑶药小钻特征图谱及其主要成分安五脂素含量测定方法,并评价安五脂素抗炎活性。方法 采用高效液相色谱法,以乙腈-0.5%磷酸溶液为流动相进行梯度洗脱,采用《中药色谱指纹图谱相似度评价系统(2012版)》建立小钻药材的特征图谱和进行相似度评价,并测定小钻中安五脂素含量。以脂多糖诱导的RAW264.7巨噬细胞为炎症细胞模型,考察安五脂素对细胞上清液中肿瘤坏死因子α(TNF-α)、白细胞介素1β(IL-1β)、IL-6水平的影响。结果 10批小钻样品的特征图谱相似度为0.901~0.994;标定了9个共有峰,指认了3个成分,分别为长南五味子素E、南五味子内酯A、安五脂素;安五脂素的含量为(0.72±0.05)~(1.21±0.03)mg/g(n=3)。0.125~0.5μg/mL的安五脂素可显著降低炎症模型细胞上清液中TNF-α、IL-1β、IL-6水平(P<0.05或P<0.01)。结论 建立了小钻药材HPLC特征图谱及其安五脂素含量测定方法;安五脂素可能是小钻药材发挥抗炎作用的有效成分。

柔翼结构飞行器智能控制系统关键技术与途径

柔翼结构飞行器具有轻质、空间集成、重复使用、有较大的阻力面积和升力系数等优点,可实现巡航飞行、低速驻空、再入返回、气动减速、定点归航、着陆缓冲等功能,是当前的研究热点。智能控制系统是柔翼结构飞行器飞航与回收着陆系统的核心技术之一,结合智能技术在控制系统中的应用研究与工程实践,对柔翼结构飞行器智能控制系统及其技术特征进行了分析;介绍了刚-柔组合体一体化控制与仿真、环境感知与健康状态在线评估、航迹规划与跟踪飞行控制、集群飞行控制、着陆与缓冲智能控制、智能硬件容错与重构等关键技术。对柔翼结构飞行器智能控制系统的未来发展进行了思考,提出了飞行环境的智能及柔性感知、气动参数的在线识别、多任务模式自主执行及控制系统的演进学习等发展建议,通过对智能控制技术持续不断地研究与实践,为柔翼结构飞行器系统的研制提供强有力的支撑。

General Integral Control Design via Singular Perturbation Technique

This paper proposes a systematic method to design general integral control with the generic integrator and integral control action. No longer resorting to an ordinary control along with a known Lyapunov function, but synthesizing singular perturbation technique, mean value theorem, stability theorem of interval matrix and Lyapunov method, a universal theorem to ensure regionally as well as semi-globally asymptotic stability is established in terms of some bounded information. Its highlight point is that the error of integrator output can be used to stabilize the system, just like the system state, such that it does not need to take an extra and special effort to deal with the integral dynamic. Theoretical analysis and simulation results demonstrated that: general integral controller, which is tuned by this design method, has super strong robustness and can deal with nonlinearity and uncertainties of dynamics more forcefully.

蒲公英化学成分和药理作用研究进展及其质量标志物预测分析

蒲公英Taraxaci Herba是我国药食同源中药材之一。蒲公英化学成分类型丰富,药理作用应用广泛,现代研究表明,蒲公英中富含黄酮类、酚酸类、萜类、糖类、甾醇类、脂肪酸类、色素类等多种化学成分,具有抗肿瘤、抗炎、保肝利胆、抑菌、抗氧化、调节免疫等多重作用功效。通过文献汇总,对蒲公英化学成分和药理作用最新研究进展进行整理总结,并运用质量标志物(quality marker,Q-Marker)核心理念,围绕植物亲缘学及化学成分特有性,成分与药性和药效的关系以及化学成分可测性四个角度,并结合分子对接模拟分析方法,对蒲公英质量标志物预测分析。归纳出咖啡酸、绿原酸、芦丁、槲皮素、蒲公英甾醇、蒲公英多糖等成分可作为蒲公英主要的质量标志物的候选成分,为完善蒲公英质量标准提供依据,以期为蒲公英科学合理的质量控制以及后续的深入研究利用提供参考。

基于深度强化学习的机械臂多模混合控制

针对基于深度强化学习控制的机械臂动态避障能力不足,在作业过程中存在多任务冲突问题,提出一种基于双重角色和正则化批评者算法(DARC)的多模混合控制方法。将任务分解为多段避障模式,借助人工势场法的斥力引力思想设计奖励函数并分别进行训练;将经过初步训练的多个模式以距离阈值或奖励积累阈值进行切换控制,消除混合控制存在的冲突;结合机械臂单元运动学特点设计具有软体性质的多连杆机械臂平面仿真模型。实验验证所提方法能够有效提升机械臂动态避障能力,避免多任务间的冲突。

“大气污染物和温室气体协同控制”政策的实施效果研究

推动减污降碳协同增效是深入打好污染防治攻坚战,实现碳达峰的必然要求。将《大气污染防治行动计划》和《打赢蓝天保卫战三年行动计划》视为一个连贯政策,运用渐进双重差分法探究了于2015和2018年提出的“大气污染物和温室气体协同控制”政策实施效果。研究表明:“大气污染物和温室气体协同控制”政策显著提高了“SO_(2)-CO_(2)”排放强度协同度和“PM-CO_(2)”排放量(强度)协同度,但该政策对“SO_(2)-CO_(2)”排放量协同度无显著影响。机制分析表明,提升政府监管水平、弱化政企关系以及增强企业绿色创新是政策的主要传导机制。异质性分析表明,政策效果在不同能耗水平的城市中具有显著差异,比起高污染上市公司,高耗能中小企业在污染物和CO_(2)的协同减排措施上仍存在较大改善空间。研究结论对我国优化“持续深入打好蓝天保卫战”相关政策提供启示。

基于角色建模的运动员动作动画交互演示方法

为了更好地展示动画交互效果,提升用户的体验感,提出基于角色建模的运动员动作动画交互演示方法。基于人体骨骼模型和骨骼蒙皮实现角色建模,建立三维场景,为人物活动提供虚拟环境。通过PD控制器实现对角色模型的行为控制,虚拟交互技术则实现了动画制作交互式演示。实验结果表明:该研究方法能够较好地完成人体动作交互演示,并通过交互演示延迟时间验证,证明该方法应用下的交互演示灵敏度实现了研究的预期目标。

植物根际促生菌在烟草根茎类病害防治中的应用研究进展

烟草是重要的经济作物,经济价值高。烟草根茎类病害的发生导致一定的烟草损失。本文阐述了烟草根黑腐病、烟草黑胫病和烟草青枯病等烟草根茎类病害的发生和危害,分析了烟草根茎类病害的防治现状,包括农业防治、化学防治和生物防治等内容,提出了植物根际促生菌的研究进展,探讨了其作用机制及在防治烟草病害中的应用前景,总结了用于防治烟草病害的植物根际促生菌主要种类,提出了相关展望,以期为有效防治烟草根茎类病害和推广应用植物根际促生菌提供参考。

基于安全控制结构模型的高校实验室安全风险动态评估

为有效评估高校实验室安全风险状态和优化动态安全管理对策,提出一种基于多层安全控制结构模型的高校实验室安全动态评估方法。首先,建立一种多层安全控制结构模型,以确定高校实验室火灾爆炸事故的致因因素和控制缺陷;在此基础上,提出一种基于系统理论的事故模型和贝叶斯网络(BN)相结合的安全动态反馈评价方法,推断计算出高校实验室安全风险状态的概率、分析影响事故的风险因素,识别出高校实验室安全中的关键风险因素。研究表明:基于安全控制结构模型的风险动态评估方法涵盖了传统方法识别的所有风险,同时还能够发现潜在风险;对危险化学品的操作不正确,试验过程违反操作规程以及电气线路出现老化、短路或缺陷等因素是影响高校实验室安全风险的关键风险因素。

数字经济风险现象、形成机制研究综述

数字经济在经济结构中重要性的不断提升带动了相关理论研究的发展,但针对数字经济风险的研究较为滞后、零散,难以刻画其风险现象、形成与作用机制。本文通过对国内外相关文献的系统梳理,聚焦数字经济发展对经济风险基本理论发展的影响,基于“内涵界定—风险现象—形成机制”的逻辑链条,系统解析了数字经济风险的内涵与特征、风险现象,以及技术变革下的数字经济风险研究动态,初步构建了一个数字经济风险理论体系框架。