Dynamics and adaptive control of a dual-arm space robot with closed-loop constraints and uncertain inertial parameters

A dynamics-based adaptive control approach is proposed for a planar dual-arm space robot in the presence of closed-loop constraints and uncertain inertial parameters of the payload. The controller is capable of controlling the po- sition and attitude of both the satellite base and the payload grasped by the manipulator end effectors. The equations of motion in reduced-order form for the constrained system are derived by incorporating the constraint equations in terms of accelerations into Kane＇s equations of the unconstrained system. Model analysis shows that the resulting equations perfectly meet the requirement of adaptive controller design. Consequently, by using an indirect approach, an adaptive control scheme is proposed to accomplish position/attitude trajectory tracking control with the uncertain parameters be- ing estimated on-line. The actuator redundancy due to the closed-loop constraints is utilized to minimize a weighted norm of the joint torques. Global asymptotic stability is proven by using Lyapunov＇s method, and simulation results are also presented to demonstrate the effectiveness of the proposed approach.

Heinrich events recorded in a loess-paleosol sequence from Hexigten,Inner Mongolia

We describe the last glaciation climatic history Marine Isotope Stage(MIS, 2-4) from 66.7 ka to 14.5 ka in Hexigten, northeast Inner Mongolia, North China. The climate of the region experienced frequent and significant fluctuations between dry-cold and less dry-cold during the late MIS4. The climate was generally warm and humid during early MIS3(MIS3 c) and late MIS3(MIS3 a), whereas it was cold and dry in middle MIS3(MIS3 b) and during MIS2. In this study, the cold and dry conditions were correlated with a stronger East Asian winter monsoon and strong dune activity; whereas, warm and humid conditions were related to a stronger East Asian summer monsoon(EASM) and weak dune activity. This study establishes six distinct dry and cold intervals during the last glacial period(66.7-14.5 ka) based on optically stimulated luminescence data, multi-proxies record(magnetic susceptibility, grain size analysis, Rb/Sr, SiO2/TiO2) and chemical index of alteration(CIA). The last glacial period may be correlated with Heinrich events 1 to 6 which were further confirmed by comparison with the Hulu cave stalagmites and Greenland ice core records. It is concluded that the study area was substantially affected by the EASM, as compared with the loess-desert transition zone of the Chinese Loess Plateau, especially in MIS3 c and suggested that the East Asian monsoon played a pivotal role in the last glacial period climate and dune activity.

Constraints on Estimation of Radius of Double Pulsar PSR J0737-3039A and Its Neutron Star Nuclear Matter Composition

The aspect of formation and evolution of the recycled pulsar（PSR J0737-3039 A/B） is investigated, taking into account the contributions of accretion rate, radius and spin-evolution diagram（- diagram） in the double pulsar system. Accepting the spin-down age as a rough estimate（or often an upper limit） of the true age of the neutron star, we also impose the restrictions on the radius of this system. We calculate the radius of the recycled pulsar PSR J0737-3039 A ranges approximately from 8.14 to 25.74 km, and the composition of its neutron star nuclear matters is discussed in the mass-radius diagram.

A branch-and-bound algorithm for multi-dimensional quadratic 0-1 knapsack problems

In this paper, a branch-and-bound method for solving multi-dimensional quadratic 0-1 knapsack problems was studied. The method was based on the Lagrangian relaxation and the surrogate constraint technique for finding feasible solutions. The Lagrangian relaxations were solved with the maximum-flow algorithm and the Lagrangian bounds was determined with the outer approximation method. Computational results show the efficiency of the proposed method for multi-dimensional quadratic 0-1 knapsack problems.

Signaling pathway of insulin-like growth factor-Ⅱ as a target of molecular therapy for hepatoblastoma

AIM： To address the possibility that insulin-like growth factor （IGF）-Ⅱ is a growth factor and its signaling pathway so as to develop a molecular therapy for hepatoblastoma. METHODS： Huh-6 and HepG2, human hepatoblastoma cell lines, were used. IGF-Ⅱ was added to the medium deprived of serum. Western blot analysis was performed to clarify the expression of IGF-Ⅰ receptor （IGF-IR）. Inhibitors of IGF-IR （piclopodophyllin, PPP）, phosphatidyl-inositol （PI） 3-kinase （LY294002 and Wortmannin）, or mitogen-activated protein （MAP） kinase （PD98059） were added to unveil the signaling pathway of IGF-Ⅱ. Cells were analyzed morphologically with hematoxylin-eosin staining to reveal the mechanism of suppression of cell proliferation. RESULTS： IGF-Ⅱ stimulated cells proliferated to 2.7 （269% ± 76%） （mean ± SD） （Huh-6） and 2.1 （211% ± 85%） times （HepG2）. IGF-IR was expressed in Huh-6 and HepG2. PPP suppressed the cell number to 44% ± 11% （Huh-6） and 39% ± 5% （HepG2）. LY294002 and Wortmannin suppressed the cell number to 30% ± 5% （Huh-6）, 44% ± 0.4% （HepG2）, 49% ± 1.0% （Huh-6） and 46% ± 1.1% （HepG2）, respectively. PD98059 suppressed the cell number to 33% ± 11% for HepG2 but not for Huh-6. When cell proliferation was prohibited, many Huh-6 and HepG2 cells were dead with pyknotic or fragmented nuclei, suggesting apoptosis. CONCLUSION： IGF- Ⅱ was shown to be a growth factor of hepatoblastoma via IGF-Ⅰ receptor and PI3 kinase which were good candidates for target of molecular therapy.

A linear complementarity model for multibody systems with frictional unilateral and bilateral constraints

The Lagrange-I equations and measure differential equations for multibody systems with unilateral and bilateral constraints are constructed. For bilateral constraints, frictional forces and their impulses contain the products of the filled-in relay function induced by Coulomb friction and the absolute values of normal constraint reactions. With the time-stepping impulse-velocity scheme, the measure differential equations are discretized. The equations of horizontal linear complementarity problems （HLCPs）, which are used to compute the impulses, are constructed by decomposing the absolute function and the filled-in relay function. These HLCP equations degenerate into equations of LCPs for frictional unilateral constraints, or HLCPs for frictional bilateral constraints. Finally, a numerical simulation for multibody systems with both unilateral and bilateral constraints is presented.

内蒙古玉米产业高质量发展的思考

玉米是保障世界粮食安全的“压舱石”,是我国近年来粮食增产的主力军,也是内蒙古高质量发展的支柱产业,玉米产业的高质量发展对建设国家重要农畜产品生产基地具有重要意义。阐述内蒙古玉米产业的重要性和内蒙古玉米生产的制约因素,并从加强农田基本建设、夯实粮食丰产基础,强化农业科技支撑、提升玉米单产水平,强化农机配套研发、提升农业装备水平和培育新型经营主体、提升规模经营效益等方面提出内蒙古玉米产业发展的路径,以期推进内蒙古玉米产业高质量发展。

具有内点状态约束的机动再入弹道优化设计

高级机动弹头末制导装置开始工作时对弹头飞行速度和姿态有一定的要求。这就增加了内点约束,从而使机动再入弹道设计问题成为具有内点约束和终端约束更复杂的最优控制问题。利用遗传算法求解该问题,用多段插值方法进行染色体设计,设计了基于模拟退火思想的罚函数和适应度函数来处理各种约束。仿真结果表明,所设计的遗传算法效率高,对初值不敏感,能搜索到全局最优解。所设计的再入机动弹道能满足机动弹头对姿态、热流和速度的要求。

内蒙东部及邻区晚石炭世—二叠纪构造古地理环境及演变

建立构造地层等时格架和不同构造地理单元地层的沉积相变序列,研究化石群落古生态学、生物建造发育和大地构造对环境的制约,将内蒙东部及邻区晚石炭世-二叠纪构造古地理环境及演变分为三个阶段。古亚洲洋阶段(晚石炭世—早二叠世)、兴-蒙海槽阶段(中二叠世)和兴-蒙张裂海槽阶段(晚二叠世)。区内该时期构造古地理环境始终受两条构造线控制,从南到北呈现三分性。索伦山-西拉沐伦断裂以南属华北板块,查干敖包-阿荣旗断裂以北属西伯利亚板块,两大板块之间先期为宽阔海洋,后期变窄成海槽,并夹有多个中间地块,如贺根山地块、索伦山地块、黄岗梁地块和佳木斯地块等。各地块在不同时期相互愈合并增生到板块边缘。林西地区晚二叠世晚期生物礁和海相化石的发现,马达屯期大规模火山喷发,及暴露在内蒙巴林右旗与吉林九台县的P\T角度不整合,均证明兴-蒙海槽在晚二叠世末期最终闭合,并区域褶皱隆起。

内约束力的心理维度与培养途径

内约束力是个体受生物向群性和后天社会化的双重作用,发自内心的以善为取向对自我行为约束的一种内部力量。面对人们在处理自我与他人、自我与社会和自我与自然的关系时显现的非理性心态和非理性行为,强制手段包括法律、纪律等进行外约束效果有限,来自人内心的对自我欲望与行为理性约束的力量是强大的。内约束力包含群性认知、关怀社会、抵制诱惑、抑制冲动和友好交往五个心理维度,可以通过内化于心、外化于行和固化于身加以培养。

吸气式高超声速飞行器纵向机动飞行的鲁棒线性变参数控制

针对一个吸气式高超声速飞行器模型,研究了其鲁棒变增益控制问题。为处理对建模误差的鲁棒性问题,将标准的线性变参数(Linear Parameter-Varying)控制算法扩展到对参数和动态不确定性具有结构摄动的鲁棒性框架内。基于对建模不确定性的积分二次型约束(Integral Quadratic Constraint)刻画,以定标的线性矩阵不等式(Linear Matrix Inequality)形式给出了其鲁棒控制算法。考虑到描述飞行器动态数值非线性模型的复杂性,建立了其解析形式的曲线拟合模型。基于此解析模型,推导了LPV模型用于控制设计和开环分析。设计了以动压和马赫数为增益变量的飞行控制系统。控制器设计将LPV控制器和变增益比例积分补偿器组合成内外环结构,实现了姿态稳定性和精确的轨迹跟踪性能。非线性仿真结果证实了算法和应用的有效性。

基准与坐标系之间关系的探讨

由于自由网平差模型秩亏,法方程存在无穷多组解。从测量角度来看,就是网的绝对位置无法确定,网形浮动。为了解决这一问题,引入了基准(参考系)来固定测量网。也就是说,给定基准条件的同时也就给定了坐标系。那么基准条件中必然包含定义坐标系的信息。推导出一种法方程的通解,给出了由基准定义相应坐标系的相关公式,通过算例验证了基准和坐标系之间的关系。

强化监察机关内部监督的理论逻辑与制度建构

根据权力运行的普遍原理和自身权力的特性,监察机关的内部监督面临众多挑战。为了加强内部监督,有关方面已经建立了以分权制约权力、以民主制约权力、以程序制约权力、以督察制约权力的制度。但是,内部权力监督仍然发展不平衡。为此,必须加大巡视巡察力度、提升干部监督室的独立性、严格控制自由裁量权、实行请托事项报告制度等,激发监督活力,改善监督绩效。

大学生内约束力的调查与影响因素分析

面对市场经济条件下人们在处理自我与他人、自我与社会及自我与自然关系时出现的非理性心态与非理性行为,法律、纪律等外约束力效果有限,需要挖掘、培养人们的自我约束力量。实际调研数据表明,大学生内约束力水平总体呈正态分布;在群性认知、友好交往两个维度上相对较高,在关怀社会、抵制诱惑和抑制冲动三个维度上相对较低;不同性别、是否独生子女、是否党员及不同年级的大学生内约束力水平呈现显著差异;家庭教养方式、学校教育、社会文化因素是影响大学生内约束力的主要因素。

理想约束的基本类型

许多一般力学文献中 ,对理想约束基本类型的阐述不够完整 ,有的甚至不够准确。本文给出了粗糙接触面约束的概念 ,并将约束分为内约束和外约束 。

论区域共同富裕和“双碳”目标在碳资源富集区的实现——以内蒙古为例

“碳达峰”“碳中和”是国家行动,为此,国家制定了一系列实现“双碳”目标的政策,改变了碳资源富集区的产业发展环境。作为一项有时限的国家目标任务,以碳资源开发利用为主的资源型经济区需要培育发展非碳产业,推动碳产业优化升级,构建碳汇集体系。面对新发展阶段国际、国内产业发展的基本环境,内蒙古能源产业集聚区完成上述目标受发展基础方面的限制,实现“双碳”目标的减碳政策会对该类区域的产业发展产生新约束,对于实现全体人民共同富裕目标产生新阻碍。因此,对于内蒙古这样承担“减碳”主要任务的碳资源富集区来讲,完成“双碳”目标任务要与实现全体人民共同富裕相协调,需从精准支持各类行动主体出发,构建国家与省份之间的协同、支持机制,鼓励中央企业在内蒙古区域范围内向零碳、负碳产业转型,将内蒙古建设成为“绿色经济特区”。

驮背运输2车组系统内力复杂性及其处理技术对策

为了准确分析驮背运输2车组系统内力,提出并验证了复杂曲面接触摩擦简化处理技术对策。多体系统动态仿真分析表明:空载/重载单车可以实现车耳锁定、滚道支承以及地面支承3个平衡态及其传力路径转变,充分保障了货运汽车或集装箱半拖挂车公铁转运的100%滚装作业。利用复杂约束的拓扑关系图,提升了系统建模的模块化或模板建模程度。在全面考核仿真模型正确性的基础上,利用刚柔耦合仿真技术,深入研究了变形协调性和结构稳定性以及相关因素的影响规律,为轻量化车体优化设计提供了必要的技术支撑。局部高应力及其交替变化是判定结构损伤的主要依据之一,因而相关约束的内力性质需要通过刚柔耦合仿真加以具体分析,并非仅局限于几何空间研究域。

Java内部类的研究及应用

给出了Java内部类(Inner Class)的定义,在对其分类研究的基础上,分析了成员类、局部类和匿名类的基本特性、约束规则和引用方法,给出了各种内部类的使用方法、访问控制和应用实例。使用内部类简化了程序设计,符合信息隐藏原则,提高了程序的安全性、可理解性和运行效率。在Java面向对象技术(Object-Oriented Technique,OOT)教学与应用开发中收到了好的效果。

组合式选举:党内公推直选的模式选择与体制约束

公推直选是近年来党内民主发展的突出标志。作为基层党组织选举改革的主导方法,公推直选带有"组合式"选举的特征,它实现了竞争性选举与组织选拔制度的结合,组织选拔、群众参与和党员选举的组合,以及党内民主对人民民主的带动。然而,这一选举模式也潜在地隐含着竞争选举与组织选拔、党内民主与人民民主的内在张力。推动公推直选改革的深入,需要不断规范公推直选的操作机制,推进公推直选的制度化及配套制度建设,同时要适时地推进公推直选在地方党委的试点工作,不断拓展公推直选的适用范围。

对内蒙古西辽河流域“量水而行”工作的认识与思考

近年来,落实党中央国务院决策部署,围绕解决西辽河流域水资源问题,水利部在西辽河流域实施“量水而行”政策,取得初步成效。但是,受主观、客观等多种因素影响,该项工作目前仍存在一些难点。文章在分析水资源刚性约束条件下推进“量水而行”工作必要性和紧迫性的基础上,剖析推进“量水而行”工作面临的难点,研究提出相关政策建议,以期为扎实推动西辽河流域“量水而行”工作、落实水资源刚性约束有关要求提供参考。