基于EMD-SA-SVR的超短期风电功率预测研究

针对风电功率的高随机和强波动性,提出一种基于EMD-SA-SVR的风电功率超短期预测方法。采用经验模态分解(Empirical Mode Decomposition, EMD)提取风电功率序列的不同特征。将原始序列分解为多个更具规律的模态,针对每个模态序列建立各自的预测模型,以消除不同特征之间的相互影响。鉴于支持向量回归(Support Vector Regression, SVR)好的泛化能力,研究建立基于SVR的各模态预测模型。进一步采用模拟退火(Simulated Annealing,SA)算法对SVR参数进行优化以解决模型选择的多极值复杂非线性问题,获得各模态分量的最优模型,进而汇总各模态分量的结果得到风电功率预测值。在某风电场历史数据上的对比分析表明,EMD-SA-SVR模型可以有效提高风电功率超短期预测精度。     

冲击能量对ESSO试验结果的影响

对90mm厚EH47船用钢板进行了不同冲击能量下的梯度温度型ESSO试验以分析冲击能量对试验结果的影响.结果表明,采用下限冲击能量测得的-10℃止裂韧性值与双重拉伸试验所测值基本一致,但根据WES:2815-2014规范确定的上限冲击能量测得的止裂韧性值明显低于前两者测得的结果,建议后续在ESSO试验中针对90mm厚钢板选用冲击能量下限值进行试验.     

时效温度对Mg-12Gd-3Y-1Sm-0.5Zr合金组织和力学性能的影响

采用X射线衍射、光学显微镜、透射电子显微镜、显微硬度和拉伸性能测试等手段,研究时效热处理温度对Mg-12Gd-3Y-1Sm-0.5Zr合金组织和性能的影响。结果表明,Mg-12Gd-3Y-1Sm-0.5Zr合金在200,250℃和300℃峰时效时,晶粒大小随时效温度的升高而逐渐增大,晶内颗粒状的第二相数量增多,硬度峰值出现的时间逐渐缩短。合金时效温度在200,250℃时,析出相为β′相,时效温度在300℃时,析出相为β相。合金在250℃峰时效时力学性能最优。在200,250℃峰时效热处理的合金在从室温到200,250℃和300℃拉伸过程中抗拉强度随拉伸温度的升高先升高后降低,出现了抗拉强度反常温度效应,而在300℃峰时效热处理后的合金未出现该反常现象。     

基于联合节点行为策略的WSN覆盖控制算法

针对无线传感器网络在对移动目标节点覆盖过程中出现网络能量快速消耗问题，提出了一种基于联合节点行为策略的覆盖算法。根据网络模型建立传感器节点与目标节点从属关系，确定覆盖关联模型；利用概率理论求解邻居节点冗余覆盖度，确定最少传感器节点数量；给出了邻居节点覆盖期望值的求解方法；仿真实验表明，该算法与其他算法在网络覆盖率和网络生存周期两个性能指标上均提升了12.39%和15.01%，从而验证了算法的有效性。     

Mechanical properties and compression sensibility of ironstone aggregate concrete

Radiation-shielding concrete was made with ironstone aggregate. The compressive strength is affected by multi factors. The electrical conductive properties and smart performance was discovered and investigated. Experimental results show that concrete conductivity rapidly declines with increasing loading, and the conductivity is much lower than the initial value of conductive aggregate of concrete, which may be related to special characters of ironstone. This kind of concrete has widely potential applications due to its special characters and low cost. Funded by the National Natural Science Foundation of China(No. 40674060)     

Fabricating a partial wetting structure for improving the toughness of intumescent flame-retardant HDPE

A multistep processing method was developed to fabricate a partial wetting morphology for improving toughness of flame retardant polymer. In the first step, high-density polyethylene (HDPE) and nylon 6 (PA6) were melt-extruded with intumescent flame retardant (IFR) for fabricating HDPE/PA6/IFR blends with a core–shell structure (core: IFR, shell: PA6). At the second step, maleic anhydride-grafted-linear low-density polyethylene (LLDPE-g-MAH) was melted with HDPE/PA6/IFR at processing temperatures slightly below the melting temperature of PA6 to produce a partial wetting morphology in which LLDPE-g-MAH phase with the sphere was dispersed at the HDPE/PA6 interface. The effect of the LLDPE-g-MAH content on the impact strength was investigated, and high toughness was exhibited in the blend with 2 wt % LLDPE-g-MAH. Its elongation at break and notched impact strength were 43 and 270% higher, respectively, than that of neat HDPE. The unique interface failure mode was responsible for the high impact strength. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48735.     

放射性气载流出物取样代表性分析

为获取核设施放射性气载流出物单点连续监测取样位置,提出基于随机轨道模型(DRW)的气-固多相湍流耦合方法求解代表性取样区域。借助k-epsilon湍流模型模拟连续相,并引入离散颗粒模型(DPM)模拟离散相,建立基于DRW模型的排风管道内流道气-固多相湍流耦合计算模型,计算了核设施气载流出物在管道内流道流场分布规律,分析了内流道流体气旋角、气流速度、示踪气体浓度、气溶胶粒子浓度与管道高度间的关联关系。分析结果表明,随着截面高度的增加,气旋角、气流速度变异系数(COV)、示踪气体浓度COV及示踪气体浓度最大值与平均值的偏差逐渐降低并趋于稳定,气溶胶粒子浓度COV在截面6与截面8满足取样代表性要求;基于计算流体动力学方法可快速地确定出代表性取样位置,为气载流出物单点取样现场试验提供了理论参考依据。     

Transdermal Delivery of Indirubin-Loaded Microemulsion Gel: Preparation,Characterization and Anti-Psoriatic Activity

Psoriasis is an immune disease caused by rapid and incomplete differentiation of skin basal cells. Natural products such as indirubin have historically served as excellent sources for the treatments of psoriasis. However, the poor solubility and bioavailability due to its plane and rigid crystal structure, which limits its efficacy. Herein, to improve the efficacy of indirubin, a hydrogel-based microemulsion drug delivery system was developed for transdermal delivery. The mean droplet size of the optimized microemulsion was 84.37 nm, with a polydispersity index (PDI) less than 0.2 and zeta potential value of 0~−20 mV. The transdermal flux and skin retention of indirubin at 24 h were 47.34 ± 3.59 μg/cm² and 8.77 ± 1.26 μg/cm², respectively. The optimized microemulsion was dispersed in carbomer 934 hydrogel to increase the consistency. The indirubin-loaded microemulsion gel was tested on an imiquimod-induced psoriasis mouse model. Results showed that this preparation can improve psoriasis symptoms by down-regulating the expression of IL-17A, Ki67, and CD4⁺T. This experiment provides great scalability for researchers to treat psoriasis, avoid first-pass effects, and increase the concentration of targeted drugs.     

酱鸡腿加工工艺参数优化

以鸡腿为材料,采用二次通用旋转组合试验设计优化酱鸡腿的加工工艺参数。结果表明：酱鸡腿最优加工工艺参数为油炸温度170 ℃、油炸时间70 s、煮制温度100 ℃、煮制时间2 h。在此条件下,加工酱鸡腿的综合评分预测值为0.47,验证实验综合评分值实测值为0.451,实验值和预测值吻合良好。该工艺得到的成品色泽金黄、肉丝粉白、可口,其中感官评分为78.678,嫩度为7.517 N,a*值为15.51。