STATE-FEEDBACK ADAPTIVE STABILIZING CONTROL DESIGN FOR A CLASS OF HIGH-ORDER NONLINEAR SYSTEMS WITH UNKNOWN CONTROL COEFFICIENTS

In this paper, a new approach is successfully addressed to design the state-feedback adaptive stabilizing control law for a class of high-order nonlinear systems in triangular form and with unknown and nonidentical control coefficients, whose stabilizing control has been investigated recently under the knowledge that the lower bounds of the control coefficients are exactly known. In the present paper, without any knowledge of the lower bounds of the control coefficients, based on the adaptive technique and appropriately choosing design parameters, we give the recursive design procedure of the stabilizing control law by utilizing the approach of adding a power integrator together with tuning functions. The state-feedback adaptive control law designed not only preserves the equilibrium at the origin, but also guarantees the global asymptotic stability of the closed-loop states and the uniform boundedness of all the other closed-loop signals.     

男女大学生运动知觉能力的测定研究

本文研究结果表明:体育系学生无论男女,运动知觉能力明显高于普系学生,而且差异非常显著;只有上肢定位一项测验中,体育系男生与普系男生相比无明显差异。     

塔里木河流域干旱风险评估与区划

选取不同尺度的标准化降水指数为危险度指标和9个干旱易损度指标建立塔河流域的干旱风险评估模型,并分析了塔河流域干旱危险度、干旱易损性及干旱风险度的空间变化特征,研究结果表明:1)塔河流域北部和西部地区的SPI3的干旱危险度高,南部和东部地区干旱危险度低;塔河流域中部和西北部地区SPI12的干旱危险度高。塔河流域西北部和西南部地区的干旱易损度高于其他地区,其中西南部地区的干旱易损度最高。农业人口比重、总抚养比和因旱农业经济损失占GDP比重与干旱易损度的相关性最高。2)塔河流域中部地区和西部地区的女性与男性比、人口密度、文盲率、抚养比、农业人口比重、灌溉面积比重大于其他地区;中部地区和西部地区的粮食产量低于塔河流域其他地区。3)塔河流域西部的干旱风险等级是最高的,其次塔河南部和西北部地区的干旱风险等级较高,东北地区和东南地区的县市的干旱风险度较低。     

Enhancement in wheat leaf photophosphorylation and photosynthesis by spraying low concentration of NaHSO3

Spraying 1—2 mmol/L NaHSO₃ on the leaf of wheat results in enhancement of photosynthesis in leaves for about 3 d. The amount of ATP has been increased and the millisecond delayed light emission of the leaves has been enhanced, showing that the transmembrane proton motive force related to photophosphorylation is increased. Spraying PMS (a cofactor catalyzing cycle photophosphorylation) and NaHSO₃ separately or together on the leaves, 20% increase in photosynthesis has been observed in all the treatments. There is no additive effect when a mixture is applied, suggesting that the mechanism for NaHSO₃ promotion of photosynthesis is similar to PMS, and both of them enhance the supply of ATP.     

金果榄中脂肪酸成分的GC-MS分析

采用气相色谱-质谱联用法（GC-MS）测定金果榄中脂肪酸的组成,共鉴定了15个化学成分,确定了金果榄所含有的5种主要脂肪酸,其中亚油酸质量分数为38.94%、顺式-13-十八酸甲酯质量分数为24.97%、棕榈酸质量分数为18.77%、硬脂酸质量分数为5.94%、十七烷酸质量分数为3.12%.     

农业产业化发展限制因子的分析及解决途径

论述了农业产业化的意义与作用,并对农业产业化发展限制因子进行了分析。据此,提出了７条具体解决途径。     

大跨径三塔缆索承重桥梁力学参数敏感度分析

建立了主跨为1 400m的三塔悬索桥、三塔斜拉桥和三塔斜拉-悬吊协作体系3种桥型的有限元分析模型.考虑几何非线性效应,利用ANSYS参数化设计语言(APDL)编制了计算程序,分析了主梁的最大挠度、索塔塔顶最大位移及主缆抗滑移系数对主梁刚度、索塔刚度、塔梁约束刚度、矢跨比、中央扣等参数的敏感程度,并进一步确定了主梁刚度和索塔刚度合理取值范围.结果表明:主梁刚度对悬索桥影响较小;主塔刚度是3种桥型的核心参数;塔梁约束可改善3种桥型的力学性能;减小矢跨比或设置中央扣可提高结构刚度,但会降低主缆抗滑性能.     

桑白皮药材的品质检测及质量标准

采用薄层色谱法（TLC）对桑白皮的桑皮苷A、桑辛素、桑酮G进行了定性鉴别,并根据2015年版中国药典方法测定了不同产地不同生源桑白皮中水分、总灰分、酸不溶性灰分和浸出物,同时采用高效液相法（HPLC）测定了桑白皮中的桑皮苷A.结果表明,桑白皮中桑皮苷A、桑辛素、桑酮G斑点清晰、特征明显.最终建议桑白皮药材质量标准（以质量分数计）为：水分不超过13%,总灰分不超过9%,酸不溶性灰分不超过2.5%,水溶性热浸浸出物不得低于25%,以干燥品计,桑皮苷A质量分数不低于0.91%.     

The further result on global practical tracking for high-order uncertain nonlinear systems

This paper extends the unknown control coefficients with lower and upper constant bounds to the ones which may take arbitrarily large and /or small values.Since the existing methods are no longer applicable and the technical obstacles caused by the extensions are essential,new control design scheme should be exploited to the global practical tracking.By the approaches of Nussbaum-gain and adding a power integrator,the authors successfully propose the design scheme of the adaptive practical tracking controller for the systems.It is shown that the designed controller guarantees that all the closed-loop system states are bounded and the tracking error becomes prescribed arbitrarily small after a finite time.     

High-quality reconstruction of China's natural streamflow

Reconstruction of natural stream flow is fundamental to the sustainable management of water resources.In China,previous reconstructions from sparse and poor-qua...