H∞ Control for Externally Excited Building Structures with Active Mass Damper under Actuator Saturation

This paper investigates the application of active mass dampers to mitigate the vibrations of building structures subjected to unknown external excitations under controller saturation conditions. By utilizing an H∞ control strategy, the optimal state feedback controller is derived by solving the linear matrix inequality problem for controller saturation. Case studies show that the proposed controller is capable of stabilizing the closed-loop system with good control performance and effectively suppressing vibrations in building structures under unknown external excitation. When compared to controllers that do not consider saturation, the proposed controller requires lower gain and results in reduced energy consumption. The research findings provide valuable insights for addressing real-world building structure control problems, contributing to both theoretical significance and practical applications.

Self-triggered Consensus Control for Linear Multi-agent Systems With Input Saturation

In this paper, we study the consensus problem for a class of linear multi-agent systems(MASs) with consideration of input saturation under the self-triggered mechanism. In the context of discrete-time systems, a self-triggered strategy is developed to determine the time interval between the adjacent triggers. The triggering condition is designed by using the current sampled consensus error. Furthermore, the consensus control protocol is designed by means of a state feedback approach. It is shown that the considered multi-agent systems can reach consensus with the presented algorithm. Some sufficient conditions are proposed in the form of linear matrix inequalities(LMIs) to show the positively invariant property of the domain of attraction(DOA). Moreover, some sufficient conditions of controller synthesis are provided to enlarge the volume of the DOA and obtain the control gain matrix. A numerical example is simulated to demonstrate the effectiveness of the theoretical analysis results.

Adaptive Consensus of Non-Strict Feedback Switched Multi-Agent Systems With Input Saturations

This paper considers the leader-following consensus for a class of nonlinear switched multi-agent systems(MASs)with non-strict feedback forms and input saturations under unknown switching mechanisms.First,in virtue of Gaussian error functions,the saturation nonlinearities are represented by asymmetric saturation models.Second,neural networks are utilized to approximate some unknown packaged functions,and the structural property of Gaussian basis functions is introduced to handle the non-strict feedback terms.Third,by using the backstepping process,a common Lyapunov function is constructed for all the subsystems of the followers.At last,we propose an adaptive consensus protocol,under which the tracking error under arbitrary switching converges to a small neighborhood of the origin.The effectiveness of the proposed protocol is illustrated by a simulation example.

MATHEMATICAL AND PHYSICAL MODELS OF HEAT AND MASS TRANSFER PROCESS IN SATURATOR

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Pseudoscalar Top-Bottom Quark-Antiquark Composite as the Resonance with 28 GeV at the LHC: Hadron Masses and Higgs Boson Masses Based on the Periodic Table of Elementary Particles

This paper posits that the observed resonance with 28 GeV at the LHC is the pseudoscalar top-bottom quark-antiquark composite which has the calculated mass of 27.9 GeV derived from the periodic table of elementary particles. The calculated mass is for the mass of?. In the periodic table of elementary particles, t quark (13.2 GeV) in the pseudoscalar top-bottom quark-antiquark composite is only a part of full t quark (175.4 GeV), so pseudoscalar?(26.4 GeV) cannot exist independently, and can exist only in the top-bottom quark-antiquark composite. As shown in the observation at the LHC, the resonance with 28 GeV weakens significantly at the higher energy collision (13 TeV), because at the higher collision energy, low-mass pseudoscalar? in the composite likely becomes independent full high-mass vector? moving out of the composite. The periodic table of elementary particles is based on the seven mass dimensional orbitals derived from the seven extra dimensions of 11 spacetime dimensional membrane. The calculated masses of hadrons are in excellent agreement with the observed masses of hadrons by using only five known constants. For examples, the calculated masses of proton, neutron, pion (π±), and pion (±0) are 938.261, 939.425, 139.540, and 134.982 MeV in excellent agreement with the observed 938.272, 939.565, 139.570, and 134.977MeV, respectively with 0.0006%, 0.01%, 0.02%, and 0.004%, respectively for the difference between the calculated and observed mass. The calculated masses of the Higgs bosons as the intermediate vector boson composites are in excellent agreements with the observed masses. In conclusion, the calculated masses of the top-bottom quark-antiquark composite (27.9 GeV), hadrons, and the Higgs bosons by the periodic table of elementary particles are in excellent agreement with the observed masses of resonance with 28 GeV at the LHC, hadrons, and the Higgs bosons, respectively.

Mechanical Response of Saturated Geological Rock Mass under Tidal Force

In this paper,the mechanical response of saturated geological rock under tidal force is explored by poroelastic theory.First,we use the free energy formula of saturated rock under a tidal force to study the relationships of pore pressure with stress,and stress with strain.Then we analyze the relationship between rock strain and tidal potential by the equilibrium differential equations of saturated rock under tidal force.Finally,we derive the physical relationship between the two parameters (pore pressure and tidal mean stress) of saturated rock and tidal potential.The relationship shows that:pore pressure is directly proportional with tidal potential,but tidal mean stress of saturated rock is inversely proportional with tidal potential.The ratio coefficient is related not only to the Lame coefficients of rock skeletons,but also to the Biot modulus.By using this model to analyze observational well water level of C-18 well which locates in Huili,Sichuan Province,the well level response coefficient (D) was estimated.This way,we derive the Skempton coefficient (B),the coefficient A and C which refer to the response coefficients of pore pressure and tidal stress to tidal potential respectively.Then we compare the differences among each coefficient in coupling and uncoupling conditions.It shows that for saturated rocks,the response of stress and pore pressure to earth tides is a product of coupling,and it is necessary to take into account the coupling effect when we study the mechanical response.The model will provide the basis not only for the study of mechanics and hydrodynamics of well-confined aquifer systems,and the mechanics of faulting under tidal force,but also for quantitative research of the triggering mechanism of tidal forces.

常压密闭微波消解-电感耦合等离子体质谱法测定磷矿石中的稀土元素

磷矿石中的稀土元素测定方法主要使用电感耦合等离子体质谱法(ICP-MS),样品处理方式主要采用敞口混合酸溶和碱熔。传统的酸溶和碱熔处理矿石样品时间较长,试剂加入量大,操作过程较为繁琐,且易造成环境污染。微波消解直接向样品释放能量,工作效率高,且易挥发元素被保留在消化溶液中,防止挥发造成结果偏差及环境污染。本文采用微波消解对磷矿石进行处理,并在二次消解过程中加入饱和硼酸络合溶矿过程中产生的不溶物氟化钙,在线加入铑和铼双内标的方式,建立了ICP-MS测定磷矿石中15种稀土元素的方法。结果表明:二次消解过程中加入饱和硼酸能有效地络合沉淀,彻底溶解样品,经上机测定后15种稀土元素的相对标准偏差(RSD)在0.68%~4.52%之间,回收率在93.1%~106.6%之间,方法检出限为0.003~0.029μg/g。选取两个磷矿石样品,用本方法与混合酸(盐酸-硝酸-氢氟酸-硫酸)酸溶方法进行对比试验,相对标准偏差在-5.82%~5.99%之间,表明本方法测定稀土元素是有效可行的。对于样品的前处理方法,酸溶、碱熔和微波消解都有各自的特点,微波密封消解能避免一些能形成易挥发组分的损失并且外源性污染少。本方法拓展了测定磷矿石中稀土元素的样品前处理方法,操作性强,是对现行方法的有益补充。

生物结皮生长发育对黄绵土抗侵蚀性能的影响

[目的]黄土高原退耕还林(草)工程驱动的生物结皮发育可显著抑制土壤侵蚀,为探明土壤抗侵蚀性能随生物结皮生长发育的变化特征及其响应机制。[方法]设置藻结皮、藓结皮和自然演替结皮3个处理,培育176天,系统研究生物结皮不同发育阶段及其类型差异对黄绵土抗侵蚀性能的影响。[结果](1)生物结皮盖度、厚度、生物量、叶绿素和粗糙度随生长时间均显著增加,培育初期藓结皮较高,培育末期自然演替结皮反而最高。(2)随生物结皮发育,土壤黏结力呈幂函数增强,较初期增加39.8%~60.3%;质量损失率呈指数函数减小,较初期降低45.6%~57.3%;饱和导水率变化趋势较为复杂,但培育末期均最低(0.08~0.12 mm/min)。(3)土壤黏结力随生物结皮盖度、厚度、叶绿素、生物量和表面粗糙度的增加呈幂函数增长,质量损失率随生物结皮盖度、厚度、叶绿素、生物量和表面粗糙度的增加呈指数函数下降。(4)土壤抗侵蚀综合指数(C_(ser))可表示为盖度(Cov)、厚度(T)和生物量(B)的幂函数(Cser=0.279 Cov^(0.194)T^(0.188)B0.119,R^(2)=0.73,p<0.05)。[结论]黄土高原生物结皮发育可显著提高黄绵土抗侵蚀性能,藓结皮效果最强。

泰兴市非饱和带与饱和带间固液界面传质模型的推导

非饱和带与饱和带紧密相联,建立两者交界处的固液界面传质模型,可以为非饱和带耦合饱和带模型提供一定理论基础,对更好地预测地下水污染趋势也非常有意义。文章以江苏省泰兴市为研究对象,将吸附与解吸、颗粒薄膜扩散、分配作用、稀释作用4种固液界面反应和非饱和带、饱和带的特性结合,推导出将非饱和带与饱和带联系在一起的固液界面传质模型。使用Matlab模拟模型参数改变时,地下水中污染物浓度的变化。结果表明,该模型是可行的,但是污染场地、污染物种类可能会对模型模拟结果造成影响。

地下水位对核电结构地震反应的影响分析

核电结构大多沿海或沿江、河而建,在地下水位以下,土体孔隙中的流体对土层的地震响应有较大影响,进而影响核电结构的响应。本文采用饱和多孔介质模型,考虑土-结相互作用效应,分析地下水位对核电结构地震反应的影响。通过传递矩阵方法,得到干土-饱和土水平成层场地的自由场,并结合透射人工边界,实现土-结相互作用分析的波动输入;采用土-结相互作用的分区并行计算方法,实现饱和土和结构相互作用分析。其中,含地下水位的场地土体采用广义饱和多孔介质模型描述,通过自编FORTRAN程序用集中质量显式有限元结合透射人工边界进行模拟,结构通过ANSYS中的隐式有限元进行分析。以某一核电结构为例,分析了0,−10,−20,−30,−40 m不同地下水位的五种场地上,土-基础-核电结构体系的动力响应。结果表明,地下水位对基础和结构的位移影响不大,对加速度的影响较大。

基于特征模型的永磁同步直线电机自适应控制

为了解决永磁同步直线电机系统的参数不确定性、建模不确定性及饱和非线性等问题,提出一种基于特征模型的自适应控制器。依据特征模型理论描述永磁同步直线电机系统,采用自适应和鲁棒控制方法设计控制器。建立永磁同步直线电机的特征模型,并给出具体建立步骤,使得控制器设计变得简单,易于工程实现。通过设计参数自适应律对系统未知特征参数进行估计,可实现对系统模型的精确补偿,同时在控制器中添加带有误差积分的鲁棒控制项,提高系统对不确定参数及未知干扰的鲁棒性。此外,由于饱和特性的存在,导致控制器产生windup问题,给系统的控制性能和稳定性造成不利影响。因此,该控制器中还带有抗饱和控制项,能够提升系统的抗饱和能力。最后,通过对比实验验证了所提控制器的有效性。

Simulation of coupled flowing-reaction-deformation with mass transfer in heap leaching processes

Governing equations for a fully coupled flowing-reaction-deformation behavior with mass transfer in heap leaching are developed. The model equations are solved using an explicit finite difference method under the conditions of invariable application rate and constant hydraulic head. The distribution of the degree of the saturation, as well as the distributions of the concentration of the reagent and the solute is given. A cubic relationship between the mineral recovery and the leaching duration is obtained based on the numerical results. The relationship can be used to predict the recovery percentage of the valuable metal.

Hadron multiplicities in p+p and p+Pb collisions at the LHC

Experiments at the Large Hadron Collider(LHC)have measured multiplicity distributions in p+p and p+Pb collisions at a new domain of collision energy.Based on considering an energy-dependent broadening of the nucleon's density distribution,charged hadron multiplicities are studied with the phenomenological saturation model and the evolution equation dependent saturation model.By assuming the saturation scale has a small dependence on the 3-dimensional root mean square(rms)radius at different energy,the theoretical results are in good agreement with the experimental data from CMS and ALICE collaboration.The predictive results in p+p collisions at s^(1/2)=14 TeV of the LHC are also given.

The Elliptic Flow of Multi-Strange Hadrons in [S_(NN)]^(1/2)= 200 GeV Au + Au Collisions at STAR

Azimuthal anisotropy, especially for the multi-strange hadrons, is expected to be sensitive to the dynamical evolution in the early stage of high energy nuclear collisions. In this paper we present the latest results of multi-strange hadron elliptic flow in Au ＋ Au collisions at √SNN=200GeV from the STAR experiment at RHIC. The number-of-quark scaling is evidenced with φ（ss） and Ω（sss） with highly statistical data, which shows strange quark collectivity at RHIC. The u2 of φ meson is found to be consistent with that of proton within statistical error bars at pw 〈 1 GeV/c.

Carbon Solubility and Mass Action Concentrations of Fe-Cr-C Melts

An empirical equation of carbon solubility in Fe-Cr-C melts is regressed based on the experimental data from references. Acalculating model of mass action concentrations for these melts is formulated on the basis of the coexistence theory of metaIlic melts in-volving compound formation, the phase diagram of Cr-C system as well as thermodynamic data of Fe-Cr-C melts. According to the mod-el, the standard Gibbs free energies of formation of CrC and Cr3C2 are obtained. Satisfactory agreement between the calculated and me-asured values shows that the model can reflect the structural characteristics of Fe-Cr-C melts.

Electromagnetic Splitting of Meson Mass

The calculation of meson masses based on the 5D homogeneous space-time quantum projection was shown explicitly in a previous paper. There are no adjustable parameters, except the quark rest mass. In this article, we like to propose two 5 quarks baryons yet unreported;a bound state of the proton and π+, which should have a mass of roughly 33.8 GeV and that of the proton and J/Ψ, which has an approximate mass of 125 GeV close to the already found 6 quarks proton-proton- boson resonance.

砂型3D打印材料对类软岩力学特性影响规律及机理

煤矿巷道围岩普遍岩性软弱、节理裂隙发育,软岩力学是煤矿巷道围岩控制的基础。由于软岩在力学与结构等方面的特殊性,物理试验中存在试样难以符合现场裂隙特征、离散性强等问题,严重制约软岩力学或裂隙岩体力学试验研究。3D打印技术因其数字建模、精度高等技术优势,突破了浇筑法在制作复杂裂隙试样上的局限,被广泛应用于岩石力学试验研究,但采用该技术打印成型的试件受打印材料和参数的影响规律还需深入研究。基于砂型3D打印技术,通过力学试验、声发射监测、电镜扫描等手段,研究不同类型砂粉和不同黏结剂饱和度对类软岩试样的力学特性的影响规律及机理。结果表明:不同类型砂粉由于其颗粒形状、粒径、排列形态等因素,对成型试样的力学特性、破坏模式等影响显著;黏结剂饱和度与试样强度呈正相关关系,相同砂粉类型前提下,改变黏结剂饱和度能将试样强度提高5倍,同时声发射事件信号与能量也随黏结剂饱和度的增大而增大。研究结果揭示了砂型3D打印技术用于软岩物理模拟上的适用性,为精确、科学地还原具体工程条件的软弱煤岩力学特性提供重要依据。

水中总α放射性测量的超铀α核素探测效率研究

乏燃料处理厂运行、退役可能释放超铀核素到环境中,其环境水体和废水中总α放射性监测是环境监管重点工作。超铀α核素发出α射线能量和分支比不同,造成其探测效率有较大差异,准确分析其探测效率有利于提高测量准确性。通过蒙特卡洛模拟和实验装置模型,模拟20个不同质量厚度的13个超铀α核素的探测效率,并计算其计数率、探测效率等效因子、活度比计数率,进一步分析这些量与质量厚度的关系及对测量结果的影响。研究表明:当用^(241)Am作标准源,需要用探测效率等效因子、分支比、比例进行探测效率修正;当质量厚度小于2.548 mg/cm^(2)时,探测效率等效因子为0.72~1.00;当质量厚度大于饱和厚度时,探测效率的倒数与质量厚度呈线性关系,可以更优刻度探测效率;饱和厚度与α射线平均能量呈线性关系,可以最优进行质量厚度源制备。

水中总α放射性测量中样品质量厚度变化的影响及校正

通过试验和蒙特卡罗模拟了不同质量厚度的241 Am、天然α核素探测效率,分析探测效率、计数率、探测效率校正因子、探测效率倒数与质量厚度的关系以及探测效率、有效饱和厚度与能量的关系。研究表明:水中总α放射性测量,需要用探测效率校正因子、分支比和成分比例进行α核素探测效率修正;质量厚度7 mg/cm^(2),平衡铀探测效率校正因子为0.96;质量厚度2 mg/cm^(2),平衡钍探测效率校正因子为1.01、平衡226 Ra-222 Rn探测效率校正因子为1.05;质量厚度大于4 mg/cm^(2),天然铀、4%浓缩铀、97%浓缩铀探测效率校正因子基本恒定,分别为0.39、0.39、0.47;质量厚度小于0.510 mg/cm^(2),单个α核素辐射源的探测效率校正因子均大于0.70;质量厚度大于有效饱和厚度,探测效率的倒数与质量厚度成线性关系;有效饱和厚度与α射线能量成线性关系。

双遗忘因子最小二乘法车辆质量和时变坡度估计

针对双遗忘因子最小二乘法由于数据饱和导致车辆变质量估计失效,在坡道起步时导致坡度估计性能下降的问题,提出一种改进算法。建立了车辆行驶时的纵向动力学数学模型,并根据最小二乘递推估计理论得到双遗忘因子最小二乘递推估计模型;针对原始算法的变质量估计问题,通过引入车速作为车辆停车的判断参数,并在停车后重新初始化协方差矩阵来消除数据饱和的影响;采用AVL CRUISE与Matlab/Simulink联合仿真对识别算法进行了验证。仿真对比分析表明,有效地验证了改进算法的合理性和可靠性,提高了算法在车辆质量和坡度估计时的收敛速度和精度。