Control Approaches to Soil Pollution from Heavy Metals

With the continuous development of human society and economy and the continuous progress of industrial technology,more and more pollutants are discharged into the natural environment,and soil environment is also affected at the same time. Among pollutants leading to soil pollution,heavy metals have resulted in most serious soil pollution. Here,many control and restoration approaches to soil pollution from heavy metals are proposed,and characteristics and applicable conditions of various methods are compared,so as to provide theoretical references for the control and restoration of soil pollution from heavy metals in future.

Sex determination mechanisms and sex control approaches in aquaculture animals

Aquaculture is one of the most efficient modes of animal protein production and plays an important role in global food security.Aquaculture animals exhibit extraordinarily diverse sexual phenotypes and underlying mechanisms,providing an ideal system to perform sex determination research,one of the important areas in life science.Moreover,sex is also one of the most valuable traits because sexual dimorphism in growth,size,and other economic characteristics commonly exist in aquaculture animals.Here,we synthesize current knowledge of sex determination mechanisms,sex chromosome evolution,reproduction strategies,and sexual dimorphism,and also review several approaches for sex control in aquaculture animals,including artificial gynogenesis,application of sex-specific or sex chromosome-linked markers,artificial sex reversal,as well as gene editing.We anticipate that better understanding of sex determination mechanisms and innovation of sex control approaches will facilitate sustainable development of aquaculture.

A Lyapunov-based three-axis attitude intelligent control approach for unmanned aerial vehicle

A novel Lyapunov-based three-axis attitude intelligent control approach via allocation scheme is considered in the proposed research to deal with kinematics and dynamics regarding the unmanned aerial vehicle systems.There is a consensus among experts of this field that the new outcomes in the present complicated systems modeling and control are highly appreciated with respect to state-of-the-art.The control scheme presented here is organized in line with a new integration of the linear-nonlinear control approaches,as long as the angular velocities in the three axes of the system are accurately dealt with in the inner closed loop control.And the corresponding rotation angles are dealt with in the outer closed loop control.It should be noted that the linear control in the present outer loop is first designed through proportional based linear quadratic regulator(PD based LQR) approach under optimum coefficients,while the nonlinear control in the corresponding inner loop is then realized through Lyapunov-based approach in the presence of uncertainties and disturbances.In order to complete the inner closed loop control,there is a pulse-width pulse-frequency(PWPF) modulator to be able to handle on-off thrusters.Furthermore,the number of these on-off thrusters may be increased with respect to the investigated control efforts to provide the overall accurate performance of the system,where the control allocation scheme is realized in the proposed strategy.It may be shown that the dynamics and kinematics of the unmanned aerial vehicle systems have to be investigated through the quaternion matrix and its corresponding vector to avoid presenting singularity of the results.At the end,the investigated outcomes are presented in comparison with a number of potential benchmarks to verify the approach performance.

Cascade adaptive control of uncertain unified chaotic systems

The chaos control of uncertain unified chaotic systems is considered. Cascade adaptive control approach with only one control input is presented to stabilize states of the uncertain unified chaotic system at the zero equilibrium point. Since an adaptive controller based on dynamic compensation mechanism is employed, the exact model of the unified chaotic system is not necessarily required. By choosing appropriate controller parameters, chaotic phenomenon can be suppressed and the response speed is tunable. Sufficient condition for the asymptotic stability of the approach is derived. Numerical simulation results confirm that the cascade adaptive control approach with only one control signal is valid in chaos control of uncertain unified chaotic systems.

Nonlinear autopilot design for interceptors with tail fins and pulse thrusters via θ–D approach

The missile autopilot for an interceptor with tail fins and pulse thrusters is designed via the θ-D approach. The nonlin- ear dynamic model of the pitch and yaw motion of the missile is transformed into a linear-like structure with state-dependent coef- ficient （SDC） matrices. Based on the linear-like structure, a θ-D feedback controller is designed to steer the missile to track refer- ence acceleration commands. A sufficient condition that ensures the asymptotic stability of the tracking system is given based on Lyapunov＇s theorem. Numerical results show that the proposed autopilot achieves good tracking performance and the closed-loop tracking system is asymptotically stable.

Systematic evaluation of the clinical nursing pathway with the GRADE approach applied to functional exercise in patients with hip replacements before and after surgery

Objective： To evaluate the effect of the clinical nursing pathway applied to functional exercise in patients with hip replacements before and after the operation. Methods： The China National Knowledge Infrastructure （CNKI）, WanFang Data, Chinese science and technology journal database （VIP）, PubMed, Web of Science, EMBASE, CBM and the Cochrane Library （2015-5） were searched for randomized controlled trials （RCTs） on clinical nursing pathways for func- tional exercise in patients with hip replacements before and after surgery from June 2015 to January 2010. The references included in the literature were also retrieved. To meet the literature standard, 2 reviewers independently selected and extracted data according to the inclusion criteria and assessed the risks of bias. RevMan 5.3 software was used in this meta-analysis. The quality of evidence was evaluated using grade profiler3.6 software, the level recommended for grading. Results： A total of 15 RCTs and 1248 patients were included. The meta-analysis showed that, in the clinical nursing path group, the Harris score of hip function [SMD = 3.35, 95%CI （2.53, 4.16）, P 〈 0.00001 ] and incidence of thrombosis embolism [RR - 0.28, 95%0 （0.15, 0.53）, P 〈 0.0001 ], pulmonary infection [RR = 0.33, 95%CI （0.14, 0.82）, P = 0.02], urinary retention [RR - 0.22, 95%CI （0.09, 0.52）, P = 0.0005], constipation [RR = 0.20, 95%0 （0.10, 0.40）, P 〈 0.00001 ], patients＇ satisfaction for nursing care [RR -- 1.26, 95%0 （1.17, 1.36）, P 〈 0.00001 ] and shortened hospitalization times [5MD = -1.91, 95%C! （ 2.39, -1.43）, P 〈 0.0001 ]were statistically significantly better than those in the control group. However, in reducing joint dislocations [Rig = 0.25, 95%C1 （0.05, 1.15）, P - 0.08], pressure ulcers [RR = 0.25, 95%0 （0.03, 2.19）, P = 0.21], and incidence of complications [RR = 0.42, 95%0 （0.15, 1.12）, P = 0.08], there was no statis- tically significant difference between the two groups. Funnel plot analysis of the average length of stay showed that there might be some publication bias in the literature. The GRADE evaluation results showed that the level of Harris scores for hip function was moderate and the incidence of thrombosis, urinary retention and satisfaction of patients regarding nursing were low, and the rest of the factors analyzed were very low. Conclusions： The effect of the clinical nursing pathway applied to functional exercises in patients with hip replacements before and after surgery was significantly better than that of routine nursing. However, it was restricted by the evaluation grade of the research results and the standardization and uniformity of the research. The results of the above study need to be verified by more high-quality RCTs.

STUDIES ON FOREST WATER CYCLING

Principal ideas, research approaches and installations in both Liangshui and Maoershan Ecological Stations were diseussed. Significance of comparability and synchronous detennination in research methods were stressed. Comparison analysis was done on the results gained from diferent methods. Adaptive mechanisms of Mongolian oak (Quercus mongolica) to drought and unproductive sites wer expounded through hydrological cycling studies. Surface runoff and flood peak were decreased and the developing processes of flood peak were postponed or delayed because of the presence of huge forest canopy and forest floor. However, the conclusions of forest influences on total runoff,especially in spring and in the dry season t are significant to agricultul practices in notheast China and turned out contrary for satershed sizes or different approaches, which should be studied further.

Coupled Conductive-Convective-Radiative Heat Transfer in Hollow Blocks with Two Air Cells in the Vertical Direction Subjected to an Incident Solar Flux

This work presents the results of a set of steady-state numerical simulations about heat transfer in hollow blocks in the presence of coupled natural convection,conduction and radiation.Blocks with two air cells deep in the vertical direction and three identical cavities in the horizontal direction are considered(typically used for building ceilings).Moreover,their outside horizontal surface is subjected to an incident solar flux and outdoor environment temperature while the inside surface is exposed to typical indoor environment conditions.The flows are considered laminar and two-dimensional over the whole range of parameters examined.The conservation equations are solved by means of a finite difference method based on the control volumes approach,relying on the SIMPLE algorithm for what concerns the coupling of pressure and velocity.The effects of the number of cells in the horizontal direction and the thermal conductivity on the heat transfer through the alveolar structure have been investigated.The results show that the number of holes has a significant impact on the value of the overall heat flux through the considered structure.

An Optimal FASA Approach for UAV Trajectory Tracking Control

In this paper,a fully actuated system approach(FASA)-based control scheme is proposed for the trajectory tracking of a quadrotor unmanned aerial vehicle(UAV).System uncertainty,external disturbance and actuator constraint are all considered,which make the problem challenging.Inspired by the active disturbance rejection control(ADRC),tracking di®erentiator(TD)and extended state observer(ESO)are introduced for handling the uncertainties and generating the feedback signals.With the proposed feedback control law,the performance of the resulted closed loop system is related to its eigenstructure-eigenvalue and eigenvectors.Based on a type of control parametrization method,the parametrized eigenstructure of the closed loop system are optimized.A better performance is observed by comparative numerical simulation.

Common Fixed Point Theorems and Q-property for Quasi-contractive Mappings under c-distance on TVS-valued Cone Metric Spaces without the Normality

In this paper, we derive the stochastic maximum principle for optimal control problems of the forward-backward Markovian regime-switching system. The control system is described by an anticipated forward-backward stochastic pantograph equation and modulated by a continuous-time finite-state Markov chain. By virtue of classical variational approach, duality method, and convex analysis, we obtain a stochastic maximum principle for the optimal control.

Lines cluster approaching mode control for air-breathing hypersonic vehicle under disturbances and uncertainties

This paper investigates the velocity and altitude tracking control problem for airbreathing hypersonic vehicle(AHV)in the presence of external disturbances and parameter uncertainties.A composite controller containing improved lines cluster approaching mode control(LCAMC)and nonlinear disturbance observer(NDO)is developed to guarantee the tracking errors converge to zero and enhance the robustness of control system.Meanwhile,considering the multiple uncertain parameters,a genetic algorithm(GA)based Pareto uncertainty estimation is employed to predict the parameter uncertainties of the AHV dynamics.Besides,the mathematical proofs of proposed method are analyzed by utilizing Lyapunov theory.Simulation results demonstrate the effective tracking performance,excellent disturbance estimation and uncertainty estimation ability of the composite method.

The Controlled Approach in City Planning:Technique and Practice---Take,as an example,the control type of planning for the developing area of Chigang in Guangzhou

On the basis of the practice in Guangzhou in recent years,this article proposes the tech-nique of the“control”approach in city planning,and presents its specific application and ex-plorations with the example of the planning for the developing area of Chigang inGuangzhou.With the reform of the urban economic-political system and the advancement of theopen-door policy,significant changes are evolving in the ideas and the ways of city planningand design.To meet the demand of these developments,the new“control”approach in cityplanning and design is thus adopted.

Optimal Choice of Weighting Factors in Adaptive Linear Quadratic Control

Most of the processes in the industry have nonlinear behavior. Control of such processes with conventional control methods could lead to unstable, suboptimal, etc., results. On the other hand, the adaptive control is a technique widely used for controlling of nonlinear systems. The approach here is based on the recursive identification of the external linear model as a linear representation of the originally nonlinear system. The controller then reacts to the change of the working point or disturbances which could occur by the change of the parameters, structure, etc. The polynomial synthesis together with the linear quadratic(LQ) approach is employed here for the controller synthesis. These techniques satisfy basic control requirements such as the stability, the reference signal tracking and the disturbance attenuation. Resulted controller could be tuned with the choice of weighting factors in LQ approach. This work investigates the effect of these factors on control results. Proposed methods are tested on the mathematical model of the isothermal continuous stirred-tank reactor and simulated results are also verified on the real model of the continuous stirred tank reactor.

PM_(2.5) in China:Measurements,sources,visibility and health effects,and mitigation

Concern over the health effects of fine particles in the ambient environment led the U.S. Environmental Protection Agency to develop the first standard for PM2.5 （particulate matter less than 2.5 μm） in 1997. The Particle Technology Laboratory at the University of Minnesota has helped to establish the PM2.5 standard by developing many instruments and samplers to perform atmospheric measurements. In this paper, we review various aspects of PM2.5, including its measurement, source apportionment, visibility and health effects, and mitigation. We focus on PM2.s studies in China and where appropriate, compare them with those obtained in the U.S. Based on accurate PM2.5 sampling, chemical analysis, and source apportionment models, the major PM2.5 sources in China have been identified to be coal combustion, motor vehicle emissions, and industrial sources. Atmospheric visibility has been found to correlate well with PM2.s concentration. Sulfate, ammonium, and nitrate carried by PM2.s, commonly found in coal burning and vehicle emissions, are the dominant contributors to regional haze in China. Short-term exposure to PM2.s is strongly associated with the increased risk of morbidity and mortality from cardiovascular and respiratory diseases in China. The strategy for PMzs mitigation must be based on reducing the pollutants from the two primary sources of coal-fired power plants and vehicle emissions. Although conventional Particulate Emission Control Devices （PECD） such as electrostatic precipitators in Chinese coal-fired power plants are generally effective for large particles, most of them may not have high collection efficiency of PM2.5. Baghouse filtration is gradually incorporated into the PECD to increase the PM2.5 collection efficiency. By adopting stringent vehicle emissions standard such as Euro 5 and 6, the emissions from vehicles can be gradually reduced over the years. An integrative approach, from collaboration among academia, government, and industries, can effectively manage and mitigate the PM2.s pollution in China.

SINGULARLY PERTURBED BOUNDARY VALUE PROBLEMS

A class of singularly perturbed nonlinear two-*point boundary value problems of ordinary differeotial equstions is studied. Under suitable monotonicity assumptions, we show the existence and uniqueness of solutions by means of the homotopy approach and give an application in singular perturbations for optimal control problems.