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The Near-infrared (NIR) nanothermometer has a novel application in medical treatment and biological sensing. Well dispersed β-NaYF4: Er3+ nanoparticles were synthesized and investigated for application of NIR optical temperature sensing. The fluorescence intensities of 837 nm and 980 nm with function of temperature were measured from 113 K to 443 K under 517 nm excitation. As the temperature rises, opposite changing trend of these two emissions was observed and confirmed theoretically. The fluorescence intensity ratios of 980 nm–837 nm in different temperatures were studied to investigate the NIR temperature sensing performance. High temperature sensitivity S (0.1914 K−1 at 443 K) and relative temperature sensitivity Sr (2.1% K−1 at 290 K) were obtained. Moreover, in the biological temperature sensing range from 270 K to 320 K, the value of Sr is greater than 2.0%. The result indicates that β-NaYF4: Er3+ NPs presents great NIR temperature sensing performance and has potential application in biological temperature sensing.

Weapon Target Assignment is a typical NP problem. In order to maximize the efficiency of air-defense missile cooperative operation in warship formation and improve the speed and precision of solving the problem, an online target assignment model of air-defense missile based on interception geometry is established. Adaptive large neighborhood search (ALNS) is applied to solve the model. According to the special requirements of model solving, two kinds of destroy operators and two kinds of repair operators are designed for ALNS algorithm, and the adaptive layer is designed to select operators with high search efficiency to improve the search efficiency. Through case analysis, it is proved that the proposed algorithm can solve the problem quickly and efficiently.

This paper develops a sliding mode control (SMC) approach for a class of uncertain nonlinear systems with unmatched uncertainties/disturbances. The newly proposed method is based on a novel fixed-time convergent sliding mode disturbance observer which can estimate the unmatched disturbance in a fixed time (time whose upper estimate is independent of the initial conditions). By designing a novel sliding surface based on the disturbance estimation, a disturbance-observer based SMC method can counteract the unmatched disturbance. Simulations verify the validity of the proposed approach.

A loss-of-thrust UAV (unmanned aerial vehicle) needs to land to a predetermined area, which not only requires a higher accuracy of landing area, but also needs to maintain a certain attitude angle. In this paper, the Schwartz inequality and state space form are used to derive the guidance law with angle constraint. The influence of heading error and angle constraint on aircraft landing area are analyzed quantitatively based on the adjoint method. The simulations show the range of the heading error and angle constraint on the condition of certain miss distance. Compared with traditional Monte-Carlo method, the method of adjoint in this paper has the advantages of small computation and simple data processing.

用共沉淀法制备了β-NaYF4：Er3+纳米颗粒.通过化学还原法、晶种生长法分别制备银纳米立方颗粒及金纳米棒，并将其掺杂到β-NaYF4：2% Er3+纳米颗粒中形成复合体系，利用表面等离子激元增强效应分别实现β-NaYF4：Er3+上转换发光的激发和发射增强.当银纳米立方颗粒掺杂量为60 μL时，上转换发光强度整体增强4.0倍；当金纳米棒掺杂量为60 μL时，上转换发光强度整体增强7.8倍.在此基础上，将两种贵金属纳米颗粒同时掺杂到β-NaYF4：Er3+纳米颗粒材料中，实现了该材料上转换发光激发和发射双增强，上转换发光强度增强了16.0倍.

An adaptive multivariable fast higher order sliding mode control (HOSMC) scheme for a class of uncertain MIMO nonlinear systems is proposed. Fast HOSMC is based on a switched finite-time control law for a chain of integrators, and fast convergence rate can be guaranteed even under large initial state errors condition. The additive uncertainty of the systems has a functional bound affine in the state norm. Based on integral sliding surfaces, an adaptive fast HOSMC strategy is proposed. Thus, the bounds of the uncertainties are not needed in the procedure of the controller design. The effectiveness of the proposed control scheme is illustrated through simulations.

In this paper, a robust adaptive higher order sliding mode attitude control scheme is proposed for near space hypersonic glide vehicles. This problem can be viewed as the finite time stabilization of a higher order input-output dynamic system with bounded uncertainties. The control scheme developed is based on geometric homogeneity and dual layer adaptive sliding mode control. Simulation results show the effectiveness of the proposed controller to track the guidance instruction for the 6-DOF model of hypersonic reentry vehicles.

In this paper, an alternative scheme to achieve output tracking for a class of uncertain systems which is designed using back-stepping control and sliding mode control (SMC) can provide exact tracking even in the presence of matched and unmatched disturbances. The newly proposed method is based on a nonlinear disturbance observer (NDOB) which can estimate the unmatched disturbance. Simulation verify the validity of the proposed approach.

This paper proposes a disturbance observer (DOB)-based adaptive non-homogeneous higher order sliding mode control (HOSMC) scheme. Given a large initial tracking error, the proposed HOSMC provides fast convergence rate by using non-homogeneous finite time stabilization. In addition, a disturbance observer based adaptive control method is employed to identify bounded uncertainties. To solve the overestimation problem, DOB is introduced to compensate for the low-passed uncertainties, and an adaptive first order sliding mode control term by using the equivalent control technique is employed to handle the fast-changing components of the uncertainties beyond the pass-band of DOB. Simulations show the effectiveness of the proposed algorithm.

The vertical tail of an aircraft produces a large radar signature and the requirement for stealth in new military aircraft necessitates the design of tailless aircraft. Without the vertical tail results in lateral-directional response characteristics which are a great deal different from those of conventional aircraft. In this paper, a robust controller designed for the tailless aircraft is presented. The controller's basic structure consists of an inner-loop DI controller wrapped around an outer-loop robust µ-synthesis controller. The inner-loop controller equalizes the tailless aircraft dynamics across the flight envelope, and the outer-loop controller addresses the issues of stability, performance, and robustness to tailless aircraft uncertainties.

Adaptive non-homogeneous higher order sliding mode control (HOSMC) scheme without switching gain over-estimation is proposed. Given a large initial tracking error, the proposed HOSMC algorithm provide fast convergence rate by using non-homogeneous finite time stabilization. In addition, the adaptive control method is employed to identify bounded uncertainties. To solve the overestimation problem, the equivalent control technique is used, and the switching gain can be designed as a small constant. Numerical simulation demonstrates the effectiveness of the proposed HOSMC algorithm.

A novel methodology for designing nonsingular terminal sliding mode controller (TSMC) for a class of uncertain nonlinear systems is introduced. The system states can be guaranteed to reach a integral terminal sliding surface in finite time and then converge to the origin in finite time, while the singularity problem is eliminated. Compared with many existing works on nonsingular TSMC, the proposed method exhibits three attractive features: (1) the switching gain is only required to be designed greater than the bound of the disturbances; (2)when using boundary layer to alleviate chattering, for constant or eventually constant disturbances, zero steady-state error can be achieved; and (3) can be applied to higher order systems directly. Simulation results are presented to illustrate the effectiveness of the proposed method.

Online identification and real-time aircraft model updating allows the adoption of more intelligent control methods. An identification algorithm called Fourier Transform Regression that uses the recursive Fourier transform and least-square methods is employed to identify the aerodynamic and control derivatives online. The main contribution of this paper is to adopt a vector of forgetting factors for tracking the time-varying parameters in system dynamics. Simulation results indicate that the proposed scheme works well.

An adaptive non-homogeneous higher order sliding mode control (HOSMC) method for a class of uncertain nonlinear systems is proposed in this paper. The HOSMC problem can be viewed as the finite time stabilization of a higher order input-output dynamic system with bounded uncertainties. Given a large initial tracking error, the proposed HOSMC algorithm provide fast convergence rate by using non-homogeneous finite time stabilization. In addition, the adaptive control method is employed to identify bounded uncertainties for eliminating the requirement of bounds needed in the conventional design. To solve the overestimation problem, equivalent control technique is used in this paper, and then the switching gain can be designed as a small constant. Numerical simulation on an omnidirectional mobile vehicle demonstrates the effectiveness of the proposed HOSMC algorithm.

We investigate optical absorption and emission spectra of Sm 3+ ions in Sm(DBM)3Phen-doped polymethyl methacrylate (PMMA). Based on the Judd–Ofelt theory, the optical intensity parameters are calculated to be Ω2 = 13.76×10−20 cm2, Ω4 = 3.41×10−20 cm2, Ω6 = 4.01×10−20 cm2 from the absorption spectrum of Sm(DBM)3Phen-doped polymethyl methacrylate. The optical intensity parameters have been used to calculate the total radiative transition rate (676.57 s −1 ) and radiative lifetime (1478 μs) of the 4 G 5/2 exciting state. The stimulated emission cross-sections σ ij and the fluorescence branch ratios for the 4 G 5/2→6 F J' and 4 G 5/2→6 H J' transitions are also evaluated. The analysis reveals that Sm(DBM)3Phen-doped PMMA is promising for applications in rare-earth-doped polymer devices.

A step-index polymer optical fibre (SI POF) containing rhodamine B in poly (methyl methacrylate) (PMMA) has been fabricated by a perform technique. The rhodamine B content of the doped SI POF is 5 ppm-wt. The spectra of the doped SI POF with different fibre lengths were measured. Amplified spontaneous emission (ASE) at 609 nm of an SI POF in length 40 cm has been observed at ambient temperature by end-pumping with a Nd:YAG laser operated at 532 nm. The threshold of absorbed pump power for the onset of ASE is about 0.003 mJ.

A guidance law derived by variable structure theory, to enable the imposition of a predetermined terminal engagement geometry to a maneuvering target, is presented in this paper. The interceptor assumed to have no knowledge about the maneuver type of the target is executing. The guidance law has the ability to simultaneously achieve design specifications on the miss distance and the final interceptor-target relative orientation. The latter specification may be used to enhance the performance of warhead, whose effectiveness is influenced by the terminal encounter geometry between interceptor and target. The guidance law is parameterized with the terminal conditions of miss distance and terminal encounter angle. The performance of the proposed guidance law is demonstrated by the simulation results.

The optical transition probability of Nd3+ (0.5 mol%) doped lanthanum-modified lead zirconate titanate (PLZT) is investigated. The absolute intensities of its forced electric dipole transitions between 400 nm and 1000 nm were measured, from which we obtain three phenomenological parameters, Ω2 = 0.787×10−20 cm2, Ω4 = 1.182×10−20 cm2, and Ω6 = 1.042×10−20 cm2, according to the Judd–Ofelt theory. The radiation lifetime (346.9 μs) of the 4F3/2 metastable state, the stimulated emission cross-section σij (2.49×10−21 cm2, 6.51×10−21 cm2, 2.17×10−21 cm2) and the fluorescence branch ratios are calculated. We also measured the fluorescence lifetime (155.84 μs) and calculated the quantum efficiency (46.1%). The analysis reveals that Nd3+-doped PLZT, based on its large electro-optical effect, has potential applications in active optical devices.

We investigate the polarized emission behaviour of an Eu3+ doped azo-polymer waveguide. Affected by the azobenzene groups in the photoinduced orientation process by the 532 nm linearly polarized laser, the ligands were realigned orderly perpendicular to the direction of the orientation direction. This leads to the polarized absorption and emission of the waveguide in the orientation direction. By an m-line apparatus based on the prism coupling technique, two guided propagation modes were observed in the waveguide, and the refractive index at 650 nm in TE polarizations is 1.7505.

An Eu-chelate-doped step-index polymer optical fibre (POF) is fabricated. Based on Judd-Ofelt (J-O) theory, the J-O parameters are calculated to be Ω2 = 16.93×10-20 cm2, Ω4 = 1.36×10-20 cm2, Ω6 = 6.75×10-20 cm2 from the emission spectrum of Eu(DBM)3Phen-doped polymethyl methacrylate (PMMA). The J-O parameters have been used to calculate the total radiative transition rate (555.78 s-1) and radiative lifetime (1799 µs) of the 5D0 exciting state. The stimulated emission cross-sections σij and the fluorescence branch ratios β for the 5D 0→7FJ' transitions are also evaluated. Analysis reveals that Eu(DBM)3Phen-doped PMMA is promising for use in rare-earth-doped polymer optical fibre devices.

We present the diffraction patterns observed in the gradient-index (GRIN) lens sensor experiment. Then the diffraction pattern of radial GRIN lens is explored by using matrix optics. The theoretical results agree with the experimental results of 27.9-mm-long GRIN lens with 2-mm diameter diffraction patterns.

Localization is an essential problem for application of Wireless Sensor Network (WSN). We introduce a mobile robot to localize the sensor nodes in cooperative way. Specifically, we consider sensors would provide range measurements between themselves. The localization strategy was set to be a mixed form of centralized and distributed manner considering the character of robot and WSN. The algorithm can efficiently fuse multiple measurements of the system to form conservative covariance estimates and avoid over-confident problem properly. The algorithm was described in a Bayes framework and proved to be efficient in simulation result.

Sporting goods industry is one of the most internationally competitive sports industries in China. More and more enterprises begin to make use of network marketing so as to tackle the competition and satisfy the demands of consumers. Pricing strategy has become the key to the success in network marketing. Sporting goods' consumers choose online shopping because of conveniently gaining a large number of product information. According to the characteristics of network marketing, this paper analyzes low-price, customization pricing, usage pricing, discount pricing, auction pricing and prestige pricing strategies. Sporting goods enterprises should choose the sound pricing strategies in accordance with the different characteristics of products and the status of the online market.

With the advances in the network technology and the development of the network market, more and more sports enterprises compete with each other through network advertising. In this paper, the basic forms of network advertising have been demonstrated. And its fundamental values include brand promotion, website promotion, sales promotion, online survey, customer relations and information issue. Based on the comparative analysis on network advertising of Li Ning, Nike, Adidas and other well-known sports enterprises, it is aimed to present the prospects of online advertising of China's sports enterprises.