Formulation to obtain the most reliable aggregate mix with quantity and other constraints

The aggregate batch mixing problem determines the proportion (or relative masses) in which aggregate batches with different gradations are to be blended so as to achieve a target mix with a given gradation. As shown in previous studies, the gradation of a batch is not homogeneous and should be considered stochastic. Also, when batches are blended in the field there are random variations in the masses or proportions of individual batches in the mix. Assuming batch gradation and blend masses as stochastic implies that the notion of a mix (blend) satisfying the gradation of a target mix becomes stochastic. In such a framework, every mix has a reliability with which it satisfies the definition of the target mix. In addition, a mix is also required to satisfy various restrictions. This article presents an optimization formulation to determine the most reliable mix while satisfying restrictions on available quantity, budget, etc.     

EVA-g-GMA的制备及其对PLA/PHBV共混物性能的影响

通过熔融聚合法先制备了乙烯-醋酸乙烯酯接枝甲基丙烯酸缩水甘油酯(EVA-gGMA),采用红外光谱仪和核磁共振对EVA-g-GMA的结构进行了表征。然后将不同质量分数的EVA-g-GMA加入到聚乳酸/聚(3-羟基丁酸酯-co-3-羟基戊酸酯)(PLA/PHBV)共混物中,对共混物的性能进行研究。结果表明:GMA成功接枝到EVA上,随着EVA-g-GMA加入量的增加,PHBV与PLA的Tg升高,结晶度逐渐下降;分散相在PLA基体中的分散逐渐均匀,粒径减小,相界面渐渐模糊;在EVA-g-GMA加入后,共混物粘度升高,断裂伸长率和冲击强度分别可达290.9%和43.5KJ·m-2,三元共混物的水蒸气阻隔性相对于PLA/PHBV略有下降。综合考虑各种因素,EVA-g-GMA的加入使得PLA/PHBV的整体性能得到极大改善。     

ROS scavenging Manganese-loaded mesoporous silica nanozymes for catalytic anti-inflammatory therapy

Reactive oxygen species (ROS) are reactive substances closely related to the inflammatory response, and previous studies have shown that anti-inflammatory therapy can achieve significant effects by scavenging ROS. Nanozymes are synthetic mimics of natural enzymes that are more stable, customizable, inexpensive, and catalytic for ROS. Therefore, we prepared a novel manganese-loaded mesoporous silica nanozyme (MnMSN) by template method and KMnO₄ oxidation surfactant templates. The physicochemical properties of the nanomaterials were investigated by XRD, TEM, SEM, size, Zeta potential and BET, etc. The results showed that MnMSN contains MnO₂ (Mn⁴⁺) and MnSiO₃ (Mn²⁺), and the particle size of MnMSN is smaller with the increase of KMnO₄ oxidation surfactant templates time, and the in vitro scavenging of ROS (H₂O₂, ·OH and ·O₂^–) is more effective. MnMSN has good cytocompatibility, scavenging intracellular ROS and inducing a shift from M1 to anti-inflammatory M2 phenotype. Furthermore, the intrinsic mechanism of MnMSN regulation of macrophage polarization was investigated by ELISA and qPCR, and the results showed that MnMSN is through scavenging ROS, leading to the down-regulation of NF-κB, which further leads to the down-regulation of TNF-α and IL-Iβ. The results of this work highlight the potential of MnMSN in catalyzing anti-inflammatory therapy.     

αB-spline: a linear singular blending B-spline

A linear singular blending (LSB) technique can enhance the shape—control capability of the B-spline. This capability is derived from the blending parameters defined at the B-spline control vertices and blends LSB line segments or bilinear surface patches with the B-spline curve or surface. Varying the blending parameters between zero and unity applies tension for reshaping. The reshaped curve or surface retains the same smoothness properties as the original B-spline; it possesses the same strict parametric continuities. This is different from the -spline, which introduces additional control to the B-spline by imposing geometrical continuities to the joints of curve segments or surface patches. For applications in which strict parametric continuities cannot be compromised, LSB provides an intuitive way to introduce tension to the B-spline.     

从数据中提取生料浆配料过程运行控制的模糊规则

将减法聚类、神经网络、最相邻原则、对提取后的规则进行调整等方法相结合,从过程数据中自动提取出模糊规则,从而实现在氧化铝生料浆配料过程中将生料浆的各项质量指标控制在目标值范围内.某氧化铝厂的应用结果表明,所提取的模糊规则不仅具有良好的完备性和可解释性,同时可根据工况的变化自动调整各个控制回路的设定值,实现了该过程的优化运行.     

提高牵引供电电能质量技术的研究

在分析输电线路中TCSC与SVC的设计所存在的相互矛盾的基础上,针对牵引供电系统中动态并联补偿装置与串联补偿装置的协调控制问题进行研究.在节能的前提下,得出了各补偿装置补偿容量的优化控制策略,并提出了一种动态并联补偿装置的定性定量控制技术.该控制系统有效地提高了补偿的速度和精度,并具有良好的跟踪负载变化的性能,对我国电气化铁路的改造具有重要意义.     

基于PSO的矿山企业动态配矿优化研究

采用粒子群优化(PSO)算法求解矿山企业动态配矿问题。依据开采条件圈定出可开采的矿块,用粒子的一位代表矿块,并用0或者1代表选择该矿块来开采,重新定义在约束条件下PSO粒子的运算与“飞行”规则,实现动态配矿优化的粒子群算法。该PSO算法实施简单,优化效果明显,通过2009年实际生产情况与优化结果的对比表明,该算法在生产成本几乎不变的情况下,明显提高了企业效率。     

Reactive scheduling in the multi-mode RCPSP

The multi-mode resource-constrained project scheduling problem (MRCPSP) involves the determination of a baseline schedule of the project activities, which can be executed in multiple modes, satisfying the precedence relations and resource constraints while minimizing the project duration. During the execution of the project, the baseline schedule may become infeasible due to activity duration and resource disruptions. We propose and evaluate a number of dedicated exact reactive scheduling procedures as well as a tabu search heuristic for repairing a disrupted schedule, under the assumption that no activity can be started before its baseline starting time. We report on promising computational results obtained on a set of benchmark problems.     

三相并联有源电力滤波器控制策略分析和仿真

该文首先介绍了三相并联型有源电力滤波器的主电路和工作原理,然后分析了基于瞬时无功功率理论的ip—iq电流检测算法并对比研究了滞环比较和三角载波比较两种控制策略,据此建立了仿真模型并进行仿真研究。仿真结果和仿真试验波形验证了该方法的准确性和有效性。     

A new data fusion model for high spatial- and temporal-resolution mapping of forest disturbance based on Landsat and MODIS

Investigating the temporal and spatial pattern of landscape disturbances is an important requirement for modeling ecosystem characteristics, including understanding changes in the terrestrial carbon cycle or mapping the quality and abundance of wildlife habitats. Data from the Landsat series of satellites have been successfully applied to map a range of biophysical vegetation parameters at a 30 m spatial resolution; the Landsat 16 day revisit cycle, however, which is often extended due to cloud cover, can be a major obstacle for monitoring short term disturbances and changes in vegetation characteristics through time.The development of data fusion techniques has helped to improve the temporal resolution of fine spatial resolution data by blending observations from sensors with differing spatial and temporal characteristics. This study introduces a new data fusion model for producing synthetic imagery and the detection of changes termed Spatial Temporal Adaptive Algorithm for mapping Reflectance Change (STAARCH). The algorithm is designed to detect changes in reflectance, denoting disturbance, using Tasseled Cap transformations of both Landsat TM/ETM and MODIS reflectance data. The algorithm has been tested over a 185 × 185 km study area in west-central Alberta, Canada. Results show that STAARCH was able to identify spatial and temporal changes in the landscape with a high level of detail. The spatial accuracy of the disturbed area was 93% when compared to the validation data set, while temporal changes in the landscape were correctly estimated for 87% to 89% of instances for the total disturbed area. The change sequence derived from STAARCH was also used to produce synthetic Landsat images for the study period for each available date of MODIS imagery. Comparison to existing Landsat observations showed that the change sequence derived from STAARCH helped to improve the prediction results when compared to previously published data fusion techniques.