Study on improving output capability of high-power lasers providing short pulses by using different laser glasses together in the amplifier chain

We have discussed the optical and laser properties of different laser glass types. According to the properties of the gain and the B integral in the high-power laser amplifier chain, an optimal configuration is pointed out to improve the output capability at short pulses based on reducing nonlinear refractive index n₂. In this way, high gain glasses and low n₂ glasses are used in different amplifier stages simultaneously. The simulated results show that on the condition that the maximal output energies of both the configurations are same at 3 and 5 ns, the maximal output capability growth ratio of 30.48% () and 42.24% () for the optimal configuration can be obtained at 1 ns, respectively.     

Mathematical Modeling and Parameter Identification of a Planar Servo-Pneumatic Test Facility. Part I: Mathematical Modeling and Computer Simulation

High quality multi-axis test facilities used for testing heavy loads and large structures of industrial equipment are usually simulated, designed and controlled based on reduced model equations neglecting the inertia properties of the actuators. The design and control of servo-pneumatic test facilities used for testing small and light structures must take into account extended test facility models including the various inertia properties of the actuators. In this paper (Part I) an extended test facility model is presented including the various inertia properties and joints of the actuators. These extended model equations are represented in a form well suited to be directly implemented in control algorithms based on exact linearization techniques for real time control. This is done by stepwise projecting the inertia properties of the various actuator housings and actuator pistons down to the common mass of the test table and payload. The resulting extended model equations have the same form as the reduced model equations. They only include more complex system matrices and vector functions. These compact model equations turn out to be suitable for an efficient nonlinear controller design of these test facilities. Computer simulations and associated laboratory experiments show the necessity to use extended model equations in case of testing small and light structures. In Part II of this paper [1] the inertia parameters of the planar test facility will be identified in laboratory experiments.     

硒蒸气浓度对制备CIGS薄膜的影响

采用“预制层硒化法”制备CuIn_1-xGa_xSe₂ (CIGS)薄膜. 基于自主设计的“双层管式硒化装置”, 通过控制硒蒸气浓度优化退火工艺, 研究硒蒸气浓度对薄膜光电性能的影响. 利用俄歇电子能谱(AES)和X射线衍射分析(XRD)等手段对不同硒浓度氛围下生成的CIGS薄膜的成分和物相进行表征, 并在AM1.5、1000 W·m^-2的标准光照条件下比较相应CIGS电池器件的输出性能. 实验结果表明: 饱和硒蒸气下退火得到的样品, 基底钼膜遭到严重腐蚀破坏, 失去背电极功能; 在低浓度硒气氛下退火不能有效消除CIGS薄膜的偏析和缺陷, 以致光电转换效率低; 而在无硒惰性氛围下退火的样品, 生成了物相均一化的CIGS薄膜, 由此制备的CIGS电池取得了8.5%的转换效率.     

Single row facility layout problem using a permutation-based genetic algorithm

In this paper, a permutation-based genetic algorithm (GA) is applied to the NP-hard problem of arranging a number of facilities on a line with minimum cost, known as the single row facility layout problem (SRFLP). The GA individuals are obtained by using some rule-based as well as random permutations of the facilities, which are then improved towards the optimum by means of specially designed crossover and mutation operators. Such schemes led the GA to handle the SRFLP as an unconstrained optimization problem. In the computational experiments carried out with large-size instances of sizes from 60 to 80, available in the literature, the proposed GA improved several previously known best solutions.     

An integrated fuzzy simulation-fuzzy data envelopment analysis algorithm for job-shop layout optimization: The case of injection process with ambiguous data

This paper puts forward an integrated fuzzy simulation-fuzzy data envelopment analysis (FSFDEA) algorithm to cope with a special case of single-row facility layout problem (SRFLP). Discrete-event-simulation, a powerful tool for analyzing complex and stochastic systems, is employed for modeling different layout formations. Afterwards, a range-adjusted measure (RAM) is used as a data envelopment analysis (DEA) model for ranking the simulation results and finding the optimal layout design. Due to ambiguousness associated with the processing times, fuzzy sets theory is incorporated into the simulation model. Since the results of simulation are in the form of possibility distributions, the DEA model is treated on a fuzzy basis; therefore, a recent possibilistic programming approach is used to convert the fuzzy DEA model to an equivalent crisp one. The proposed FSFDEA algorithm is capable of modeling and optimizing small-sized SRFLP’s in stochastic, uncertain, and non-linear environments. The solution quality is inspected through a real case study in a refrigerator manufacturing company.     

不确定条件下的乡村中小学布局优化

学校的合理规划布局是实现教育资源优化配置、提高办学效益和推动教育均衡发展的重要途径。已有许多学者研究了学校的布局问题,但基本上都忽略了交通网络条件以及不确定因素对学校布局的影响。本研究将在前人研究基础上,重点考虑交通网络对乡村中小学选址的影响,并假设旅行时间具有不确定性,从而以最小化学生旅行成本、学校建设、道路修建和道路升级成本为目标,构建不确定条件下的设施区位设计模型。在算法求解方面提出混合模拟退火算法,用于确定新建学校的最佳位置,以及新道路的修建和原有道路的升级情况。最后,将提出的模型和算法应用到实际案例中。     

An approximation algorithm for a facility location problem with stochastic demands and inventories

We propose a 2-approximation algorithm for a facility location problem with stochastic demands. At open facilities, inventory is kept such that arriving requests find a zero inventory with (at most) some pre-specified probability. Costs incurred are expected transportation costs, facility operating costs and inventory costs.     

一种水下运动目标被动报警的新算法

根据矢量水听器的测向原理和算法，提出了一种目标方位角的变化实现水下运动目标低频高精度的报警方法。该报警系统以水下设施为平台，对靠近设施的运动目标的方位进行跟踪测量，并在目标距离水下设施最近时给出报警信号，以达到有效地避免事故的目的。与传统的利用声级变化报警或主动回波测距报警方法相比，该方法具有低频、作用距离远和高精度的特点。     

质子治癌进展

一些国家利用质子治癌取得良好疗效，质子束的优良剂量分布特性使剂量集中于肝瘤，减少了对周围正常组织不必要的伤害。文章介绍了治疗装置，治疗过程及其最近的发展。     

Single facility location on a network under mill and delivered pricing

^** E-mail: pelegrin{at}um.es Firms normally use either a mill price or a delivered pricepolicy, depending on market conditions (type of good, transportationway, customers location, costs, etc). In this paper, the problemof selecting the best location for an entering firm in competitionwith some pre-existing firms, under each price policy, is studiedon a network for the first time. With mill pricing, an equilibriumin price rarely exists and it is assumed that all competingfirms set a common mill price for all customers. With deliveredpricing, there exists a Nash equilibrium in price and it isassumed that the equilibrium price in each area is offered tothe customers in that area. In both cases, we consider thatcustomers buy from the cheapest facility and the same rulesare used for tie breaking in the lowest cost. While the profitmaximization problem for the entering firm always has optimalsolutions under mill pricing, this problem might not have anoptimal solution under delivered pricing. We show some discretizationresults and give procedures to find the full set of optimal,or -optimal, solutions to the problem under the two price policies.A comparison of results with the two price policies is givenby using an illustrative example.