排序方式: 共有142条查询结果,搜索用时 15 毫秒
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Yanbing Gong 《Fuzzy Optimization and Decision Making》2011,10(4):311-321
One of the key issues in the theory of ordered weighted averaging operator is the determination of OWA operator weights. In
this paper, a simple combination approach for obtaining minimal disparity OWA operator weights is proposed. The proposed approach
generates the OWA operator weights by minimizing the combination disparity between any two adjacent weights and its expectation.
This involves the formulation and solution of a linear programming model and a quadratic programming model for a given degree
of orness. A numerical example demonstrated simpleness and effectiveness of the methods proposed in this paper. 相似文献
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收益共享契约是实现供应链系统绩效改善或完美协调的一种机制.考虑了零售商与供应商分别具有风险厌恶决策偏好情况下,在随机市场需求下建立了由单供应商和单零售商组成的二级供应链的收益共享契约模型,并对模型进行了分析,揭示了供应商和零售商的风险厌恶决策偏好对收益共享契约参数的影响.研究结果表明:当销售商(供应商)的风险厌恶控制在... 相似文献
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尿样用1% HNO3稀释50倍,并以209Bi为内标元素校准基体效应及信号漂移,用电感耦合等离子体-质谱法直接测定,外标法绘制校准曲线进行定量.分别用ICP-MS和双硫腙分光光度法测定同一批尿样中铅的含量,统计并比较两种方法的测定结果,结果经t检验差异无统计学意义.该方法测定尿样中铅的检出限为0.010mg/L,线性良... 相似文献
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Amar Si-Ammour Said Djennoune Maamar Bettayeb 《Communications in Nonlinear Science & Numerical Simulation》2009,14(5):2310-2318
In this paper, a sliding mode control design for fractional order systems with input and state time-delay is proposed. First, we consider a fractional order system without delay for which a sliding surface is proposed based on fractional integration of the state. Then, a stabilizing switching controller is derived. Second, a fractional system with state delay is considered. Third, a strategy including a fractional state predictor input delay compensation is developed. The existence of the sliding mode and the stability of the proposed control design are discussed. Numerical examples are given to illustrate the theoretical developments. 相似文献
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药物与靶点间的作用关系直接影响到药理和药效。药物-靶点结合能力、结合计量关系等信息是药物研发过程中必需的表征数据。人类癌基因c-myb在结直肠癌等多种癌症组织中存在过度表达,目前已成为结直肠癌、白血病等癌症疾病潜在的治疗靶点。位于癌基因c-myb启动子区的一段富含鸟嘌呤(G)的DNA序列,通过阳离子的诱导可自发折叠形成分子内G-四链体,而小分子的特异性识别可以稳定该G-四链体,进而调节基因的转录和表达过程。该文采用压力辅助毛细管电泳前沿分析(PACE-FA)结合电喷雾质谱(ESI-MS)研究人类癌基因c-myb启动子G-四链体(G4)与天然产物分子间的相互作用。PACE-FA法在毛细管电泳前沿分析(CE-FA)过程中施加一个与分析物迁移同向的压力,在保证结果准确度的前提下,能够大大加快分析速度。同时结合ESI-MS,可快速解析结合分子与靶点的亲合力和化学计量关系。首先,利用ESI-MS快速筛选出3种有亲合力的天然产物,亲合力大小依次为:土荆皮乙酸>丁溴东莨菪碱>荷叶碱。考虑到溶液相中存在特异性与非特异性结合,接着用PACE-FA法准确分析溶液相中结合的特异性和结合常数。结果发现:丁溴东莨菪碱能够特异性结合靶点G4 DNA,结合比为1:1,结合常数为1.18×105 L/mol;荷叶碱属于非特异性结合,而土荆皮乙酸并未与靶点G4 DNA形成复合物。该组合方法不仅分析速度快,而且能够提高亲和分析的准确度和特异性,有望应用于靶向药物先导结构的发现和作用机制评价。 相似文献
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Radiation processing of wastewater evaluated by toxicity assays 总被引:3,自引:0,他引:3
S. I. Borrely M. H. O. Sampa C. B. Pedroso H. Oikawa C. G. Silveira E. H. Cherbakian M. C. F. Santos 《Radiation Physics and Chemistry》2000,57(3-6):507-511
Biological assays have been applied to industrial effluents and sewage influents, from distinct sites, before and after being submitted to ionizing radiation treatment. The objective of this study was to evaluate the efficiency of radiation, mainly electron beam accelerator, for the acute toxicity removal. The selected sampling presented a very toxic level and the radiation process was efficient for toxicity removal for 87.7% of irradiated samples. The sewage influents required lower radiation doses to reduce toxicity when compared to raw industrial effluents. 相似文献
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Electrocatalysis on the degradation of methyl orange is investigated using Sb2O3‐loaded activated carbon (Sb2O3/AC), a new particle electrode. The electrode was prepared by an impregnation method. An orthogonal array with four factors and three levels was selected to carry out the experiment. Electrocatalysis on the degradation of methyl orange through Sb2O3/AC was characterized by a series of parameters, including the amount of the particle electrode, the concentration of Na2SO4, the cell voltage, and the electrolysis time, and the results were compared with those of a conventional AC particle electrode. The results indicate that calcination temperature has the greatest impact on the catalytic activity of the particle electrode. The optimal conditions for preparing the Sb2O3/AC electrode include an 8 mL SbCl3 solution, 90 min hydrolysis time, 400 °C calcination temperature, and 180 min calcination time. As well, the degradation efficiency of the Sb2O3/AC electrode is consistently higher than that of the AC electrode under the same electrolysis conditions. The electrochemical oxidation of methyl orange of both electrodes conformed to pseudo first‐order kinetics, but the rate constant of the Sb2O3/AC electrode was 2.29 times that of the AC electrode; this is likely due to the high electrocatalytic activity of the experimental electrode. The electrocatalysis results exhibited the synergetic effects of AC and Sb2O3 in the new particle electrode. 相似文献
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Flow injection analysis of ketoprofen based on the order transform second chemiluminescence reaction
Zhuang Y Cao G Ge C 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2012,85(1):139-144
This paper explores an order-transform-second-chemiluminescence (OTSCL) method combining the flow injection technique for the determination of ketoprofen. When ketoprofen solution was injected into the mixture after the end of the reaction of alkaline luminol and sodium periodate or sodium periodate solution was injected into the reaction mixture of ketoprofen and alkaline luminol, a new chemiluminescence (CL) reaction was initiated and strong CL signal was detected. A mechanism for the OTSCL has been proposed on the basis of the chemiluminescence kinetic characteristic, UV-visible absorption and chemiluminescent spectra. Under optimal experimental conditions, the CL response is proportional to the concentration of ketoprofen over the range of 2.0×10(-7) to 1.0×10(-5)mol/L with a correlation coefficient of 0.9950 and a detection limit of 8.0×10(-9)mol/L (3σ). The relative standard deviation for 11 repetitive determinations of 1.0×10(-6)mol/L ketoprofen is 2.9%. The utility of this method was demonstrated by determining ketoprofen in pharmaceutical formulations without interference from its potential impurities. 相似文献