^(14)C-菲在营养液-火山石-小麦有控系统中的迁移和转化

利用放射性同位素示踪技术研究了１４Ｃ标记菲在有控系统中的迁移转化．结果表明，１４Ｃ菲在有控系统中降解较快，施入药品２４ｄ后仅有０．３２％的１４Ｃ－菲存留在植物、营养液和火山石中．植物吸收的１４Ｃ放射性大部分被结合到植物组织中，其它１４Ｃ主要以菲的极性代谢物形态存在．

Ecological control of forest pest： a new strategy for forest pest control

In comparison with integrated pest management and chemical control, the authors put forward a new strategy of forest pest control, named ecological control of forest pest （ECFP）. This paper reviewed the development history, summarized the concept and principles of ECFP, discussed the technology and methods of ECFP, and evaluated the ECFP and its application conditions.

Finite-time Control of Fuzzy Discrete-time Nonlinear System with Exogenous Disturbance

This paper give criterions on finite-time control of fuzzy discrete-time nonlinear system subject to exogenous disturbance.Employing the Lyapunov function theory,several suffcient conditions including relaxed ones are presented for finite-time stability via fuzzy controller laws.An illustrative example is given to demonstrate the effectiveness of the proposed method.

Adaptive Neuro-fuzzy Controller Design for Non-affine Nonlinear Systems

An adaptive neuro-fuzzy control is investigated for a class of non-affine nonlinear systems.To do so,rigorous description and quantification of the approximation error of the neuro-fuzzy controller are firstly discussed.Applying this result and Lyapunov stability theory,a novel updating algorithm to adapt the weights,centers,and widths of the neuro-fuzzy controller is presented.Consequently,the proposed design method is able to guarantee the stability of the closed-loop system and the convergence of the tracking error.Simulation results illustrate the effectiveness of the proposed adaptive neuro-fuzzy control scheme.

Design and passive analysis of a novel softness display device

Simulating the softness property of object is quite a challenge in virtual reality system. A novel softness display system was developed based on the principle of deformable length of elastic element control （DLEEC）. In the system, the equivalent stiffness of the device is adjustable, and is inversely proportional to the third power of the deformable length of elastic beam. PD position control is employed to guarantee the accurate softness display. The softness of the virtual objects in large scale can be felt with the softness display device. Compared with other haptic devices, the device is passive and exert the react force only when the operator ＂actively touch＂ the virtual objects. The stability of the softness display system was analyzed. It was theoretical proved that the system satisfied the criteria of wide impedance range ＂Z-width＂, and the performance was superior to an active system. The experimental results were presented.

Novel Algorithm for Active Noise Control Systems Based on Frequency Selective Filters

A novel algorithm for active noise control systems based on frequency selective filters （FSFANC） is presented in the paper. The FSFANC aims at the multi-tonal noise attenuation problem. One FSFANC system copes with one of the tonal components, and several FSFANC systems can run independently in paralld to cancel the selected multiple tones. The proposed algorithm adopts a simple structure with only two coefficients that can be explained as the real and imaginary parts of the structure to model the secondary path, and estimates the secondary path by injecting sinusoidal identification signals. Theoretical analysis and laboratory experiments show that the proposed algorithm possesses stone advantages, such as simpler structure, less computational burden, greater stability, and fast converging speed.

Vehicle Tracking in the Process of Transport of Dangerous Goods GPS/GSM Technology

In the paper it has reviewed the monitoring of vehicles in the transport of hazardous substances based on the using of GPS/GSM technology. The basic principles of the GPS concept and hardware have been exhibited which are implemented in locating the vehicle. They have also identified the locating techniques underlying the monitoring process. It has presented an active system for monitoring parameters of the means of transport.

Automatic Stabilization of an Adaptive Feedback Control for Noise Cancelling In-ear Headphones

Headphones with an integrated active noise cancellation system have been increasingly introduced to the consumer market in recent years. When exposing the human ear to active noise sources in this striking distance, the ensuring of a safe sound pressure level is vital. In feedback systems, this is coupled with the stability of the closed control loop; stable controller design is thus essential. However, changes in the control path during run-time can cause the stable control system to become unstable, resulting in an overdrive of the speakers in the headphones. This paper proposes a method, which enables the real-time analysis of the current system state and if necessary stabilizes the closed loop while maintaining the active noise reduction. This is achieved by estimating and evaluating the open loop behavior with an adaptive filter and subsequently limiting the controller gain in respect to the stability margin.

Controllability analysis of second-order multi-agent systems with directed and weighted interconnection

This article investigates the controllability problem of multi-agent systems. Each agent is assumed to be governed by a second-order consensus control law corresponding to a directed and weighted graph. Two types of topology are considered. The first is concerned with directed trees, which represent the class of topology with minimum information exchange among all controllable topologies. A very simple necessary and sufficient condition regarding the weighting scheme is obtained for the controllability of double integrator multi-agent systems in this scenario. The second is concerned with a more general graph that can be reduced to a directed tree by contracting a cluster of nodes to a component. A similar necessary and sufficient condition is derived. Finally, several illustrative examples are provided to demonstrate the theoretical analysis results.

New Results on H_∞ Control of Linear Systems with Interval Time-Varying Delays

This paper is focused on the H_(∞) control problem for linear systems with interval timevarying delays.By employing a reciprocally convex combination approach and a delay decomposition approach,some new delay-dependent bounded real lemmas(BRLs) are derived such that the closedloop system is asymptotically stable with a prescribed H_(∞) level.The BRLs are then used to solve the H_(∞) controller design by incorporating with the cone complementary approach.Three numerical examples are finally given to show the validity of the proposed method.

Research on hovering control scheme to non-circular orbit

An open-loop control system for hovering at any selected position on spacecraft orbit is first presented given that the satellite＇s engine provides continuous finite thrust. Actually, the hovering states are unstable considering perturbations and thrust errors, so a feedback sliding mode variable structure control, which is adaptive and chattering-free, is designed. Under this feedback control scheme, the high-frequency chattering phenomenon is avoided, while the system stays highly robust at the same time. Simulation results show that the feedback control thrusts are continuous and the steady-states error can be confmed to 10-4 m at the presence of uncertain perturbations. Finally, the feasibility of realizing hovering orbits is analyzed taking the ＂Moliya＂ and geosynchronous Earth orbit （GEO） satellites as examples.

State and Output Feedback Finite-time Guaranteed Cost Control of Linear It Stochastic Systems

The problem of guaranteed cost control based on finite-time stability for stochastic system is first investigated in this paper.The motivation of solving this problem arises from an observation that finite/infinite-horizon guaranteed cost control does not consider the transient performance of the closed-loop system,but guaranteed cost control based on finite-time stability involves this practical requirement.In order to explain this problem explicitly,a concept of the stochastic finite-time guaranteed cost control is introduced,and then some new sufficient conditions for the existence of state and output feedback finite-time guaranteed cost controllers are derived,which guarantee finite-time stochastic stability of closed-loop systems and an upper bound of a quadratic cost function.Furthermore,this problem is reduced to a convex optimization problem with matrix inequality constraints and a new solving algorithm is given.Finally,an example is given to illustrate the effectiveness of the proposed method.

Finite-Time Quasi-Synchronization of Two Nonidentical Chaotic Systems via Intermittent Control

This paper investigates the finite-time quasi-synchronization of two nonidentical Lur'e systems with parameter mismatches by using intermittent control. Based on Lyapunov stability theory and some differential inequality techniques, sufficient conditions for finite-time quasi-synchronization are derived and the explicit expression of error level is obtained. Meanwhile, a numerical simulation is given to illustrate the effectiveness of the theoretical results.

Control Protocol of Finite Dimensional Quantum Systems

An analytic control protocol of two types of finite dimensional quantum systems is proposed. The system can be driven to an arbitrary target state using cosine classical fields in finite cycles. The control parameters which are time periods of interaction between systems and control fields in each cycle are connected with the probability amplitudes of target states via trigonometrical functions and can be determined analytically.

Tunable thin-film filter with low angle sensitivity

Conventional angle-tuned thin-film filters have serious angle sensitivity for their low spacer effective refractive index, and it is difficult to fabricate their angle control system. In this paper, we propose and fabricate a novel 100 GHz angletuned thin-film filter stack with low angle sensitivity, which uses the high refractive index material TiO2 as the spacer, and its incident angle can be expanded to 25°. Compared with the traditional Ta2O5-SiO2 thin-film filter stack, the novel stack has fewer layers. Using the polarization beam splitters and the half wave plates, the polarization sensitivity of the angle-tuned filter can also be suppressed. Simulation results and the experiments show that the thin-film filter with low angle sensitivity has an effective tuning range of 33 nm, which can cover the whole C-band, and its angle control system is easy to be fabricated.