摘要：This paper investigates the use of the method of inequalities （MoI） to design output-feedback compensators for the problem of the control of instabilities in a laminar plane Poiseuille flow. In common with many flows, the dynamics of streamwise vortices in plane Poiseuille flow are very non-normal. Consequently, small perturbations grow rapidly with a large transient that may trigger nonlinearities and lead to turbulence even though such perturbations would, in a linear flow model, eventually decay. such a system can be described as a conditionally linear system. The sensitivity is measured using the maximum transient energy growth, which is widely used in the fluid dynamics community. The paper considers two approaches. In the first approach, the MoI is used to design low-order proportional and proportional-integral （PI） controllers. In the second one, the MoI is combined with McFarlane and Glover＇s H∞ loop-shaping design procedure in a mixed-optimization approach.

摘要：Piezoelectric actuators fundamentally possess hysteresis behavior. Estimation of the hysteresis is usually demanded for enhancing the performance of piezo-actuated systems. This paper presents an observer-based scheme to estimate the hysteresis in piezo—actuated flexible beams. The observer is based on a nonlinearity observer method. The discrete-time Kalman-filter algorithm is adopted for determination of the observer gains. The major advantages of the presented scheme include ease of implementation and robustness to uncertainty of hysteresis parameters. simulation results demonstrate that the observer is able to estimate the hysteresis efficiently and has better robustness compared to the previous scheme existing in the literature. The present scheme was also successfully applied to a real-life system. Moreover, a control application example is included to demonstrate the effectiveness of the scheme.

摘要：艺术作为一种精神产品,体现着人们的审美和情感价值,具有宝贵的价值。但即便如此,在现代文明的冲击下,一些传统艺术仍在衰落。因此,政府是否应该资助艺术已经成为当代文化政策中的一个重要议题。本文分析了中国传统杂技艺术的发展现状,探讨了政府资助艺术的原因:作为艺术经费保障者、公共领域引导者和社会情感捍卫者。由此得出结论,政府对艺术的资助将对艺术的正常发展、城市形象的建设以及国家软实力的增强起到积极作用。最后,本文探讨了资金不足可能带来的问题:限制艺术家创作、政府补贴不平衡、影响艺术发展动力等,并提出了相应的解决方案。

摘要：2016 was a bad year for globalization. No one can doubt that much now. The decision in the UK to exit the European Union-the outcome of a referendum vote on June 23-was the first major shock. The fact that former British Prime Minister David Cameron, the chief architect of the event, resigned immediately after the vote and ended his political career a few weeks later was a powerful sign of just how badly political elites misjudged and misunderstood public sentiment.

摘要：The cell performance and temperature gradient of a tubular solid oxide fuel cell with indirect internal reformer （IIR-sOFC） fuelled by natural gas, containing a typical catalytic packed-bed reformer, a catalytic coated wall reformer, a catalytic annular reformer, and a novel catalytic annular-coated wall reformer were investigated with an aim to determine the most efficient internal reformer system. Among the four reformer designs, IIR-sOFC containing an annular-coated wall reformer exhibited the highest performance in terms of cell power density （0.67 *** 2） and electrical efficiency （68%） with an acceptable temperature gradient and a moderate pressure drop across the reformer （3.53 × 10 5 kPa）. IIR-sOFC with an annular-coated wall reformer was then studied over a range of operating conditions： inlet fuel temperature, operating pressure, steam to carbon （s ： C） ratio, gas flow pattern （co-flow and counter-flow pattern）, and natural gas compositions. The simulation results showed that the temperature gradient across the reformer could not be decreased using a lower fuel inlet temperature （1223 K-1173 K） and both the power density and electrical efficiency of the cell also decreased by lowering fuel inlet temperature. Operating in higher pressure mode （1-10 bar） improved the temperature gradient and cell performance. Increasing the s ： C ratio from 2 ： 1 to 4：1 could decrease the temperature drop across the reformer but also decrease the cell performance. The average temperature gradient was higher and smoother in IIR-sOFC under a co-flow pattern than that under a counter-flow pattern, leading to lower overpotential and higher cell performance. Natural gas compositions significantly affected the cell performance and temperature gradient. Natural gas containing lower methane content provided smoother temperature gradient in the system but showed lower power density and electrical efficiency.

摘要：This paper presents the automatic drug administration for the regulation of bispectral (BIs) index in the anesthesia process during the clinical surgery by controlling the concentration target of two drugs, namely, propofol and remifentanil. To realize the automatic drug administration, real clinical data are collected for 42 patients for the construction of patients’ models consisting of pharmacokinetic and pharmacodynamic models describing the dynamics reacting to the input drugs. A nominal anesthesia model is obtained by taking the average of 42 patients’ models for the design of control scheme. Three PID controllers are employed, namely linear PID controller, type-1 (T1) fuzzy PID controller and interval type-2 (IT2) fuzzy PID controller, to regulate the BIs index using the nominal patient’s model. The PID gains and membership functions are obtained using genetic algorithm (GA) by minimizing a cost function measuring the control performance. The best trained PID controllers are tested under different scenarios and compared in terms of control performance. simulation results show that the IT2 fuzzy PID controller offers the best control strategy regulating the BIs index while the T1 fuzzy PID controller comes the second.

摘要：Objective: Zirconia is increasingly being used in restorative dentistry but its removal is often a difficult procedure due to its resistance to cutting with conventional diamond burs. Zirconia cutting burs have been developed and this study aims to compare 4 such burs. Methods: 35 experienced restorative dentists selected from our Practice Based Network (PBN) were asked to evaluate the cutting of a 1 mm groove into zirconia using 4 burs A (Meisinger), B (ZR2-1 experimental bur from DIATECH), C (Komet) & D (DIATECH Z-Rex, a bur designed with enhanced bonding of diamond grit to bur shank). Responses regarding cutting time, performance and wear were recorded. Results: For best cutting times and also overall performance D performed best and C the worst, with little difference between burs A and B. Bur C also performed least well for wear on the bur. Conclusion: The newly designed zirconia cutting bur DIATECH Z-Rex with enhanced bonding of diamond grit performed best in the analysis by the 35 dentists.

摘要：L-（＋）-lactic acid production was studied by immobilized Lactobacillus rhamnosus T1sTR108 on crude pectin from Krung Kha Mao Leaves. Central composite design was employed to determine the maximum lactic acid production of 42.88 g L-1 in predicted model with the factors at 4.11 g L1 of pectin, 6.05 mLLl inoculum and 1.09 mm of bead diameter. statistical analyses demonstrated very high significance for the regression model, since the F-value computed 116.09 was much higher than the tabulated F-value 2.08 for the lactic acid production at 5% level for linear and quadratic polynomial regression models. The highest experimental lactic acid production was 43.57 g L^-1 at 96 h of fermentation, 1.58% higher than the predicted value.

摘要：L-（＋）-lactic acid production was studied by immobilized Lactobacillus rhamnosus TIsTR108 on crude pectin from Krung Kha Mao （Cissampelospareira L.） leaves. Central composite design was employed to determine the maximum lactic acid production of 45.40 g/L in predicted model （Y = 43.98 - 2.43X1 ＋ 1.02X2 ＋ 2.96X3 - 8.72X1^2 - 3.99X2^2 - 1.74X3^2） with the factors at 5.9 of cultural medium pH, 37.6 ℃ of process temperature and 202 rpm of liquid agitation. statistical analyses demonstrated very high significance for the regression model fitted the data adequately and explained the lactic acid production, since the F-value computed 54.89 was much higher than the tabulated F-value 2.08 for the lactic acid production at 5% level for linear and quadratic polynomial regression models. The highest experimental lactic acid production was 46.91 g/L at 72 h of fermentation.

摘要：由于系统的巨大规模,操作系统设计和实现的正确性很难用传统的方法进行描述和验证.在汇编层形式化地对系统模块的功能语义进行建模,提出一种汇编级的系统状态模型,作为汇编语言层设计和验证的纽带.通过定义系统状态模型的合法状态和状态转换函数来建立系统状态模型的论域,并以此来描述汇编层的论域.通过验证汇编层的功能模块的正确性来保证汇编语言层设计的正确性,达到对系统功能实现的正确性验证.同时,使用定理证明工具Isabelle/HOL来形式化地描述这一系统状态模型,基于这一形式化模型,在Isabelle/HOL中验证系统模块的功能语义的正确性.以实现的安全可信Os(verified secure operating system,简称VsOs)为例,阐述了所提出的形式化设计和验证方法,说明了这一方法的可行性.