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In this paper, a first-order system with hysteretic characteristics is used to describe the hysteresis caused by the inertia of the internal magnetic domain of magnetostrictive materials. A shape function is introduced to describe the interaction of different magnetic domains inside of magnetostrictive materials and the saturation properties of the hysteresis. Under a proposed frame of “first-order system (inertial system) + shape function” (ISSF-Duhem model), a new hysteresis model is proposed for magnetostrictive actuators. Specifically, the expression of the first-order system is constructed based on its general expression, and the Grompertz function is employed as the shape function. Feasibility and capability of the hysteresis model are verified and evaluated by describing and predicting the hysteresis of a commercial magnetostrictive actuator.

Based on the concept of “functional integration”, a novel integrated semi-active shock absorber with a magnetorheological (MR) inerter with tunable inertance, a MR damper with tunable damping and a coil spring, is proposed and investigated in this paper. The MR inerter mainly consists of a MR clutch, a ball-screw set, a flywheel, excitation coils and MR fluids. Inertance adjustment of the MR inerter can be realized through control of the duty cycle of the excitation current by pulse width modulation (PWM). The dynamic models of the semi-active shock absorber and the MR inerter are established based on MATLAB/SimMechanics, and the mechanical characteristics of the two are simulated. Moreover, the effectiveness of the PWM control for the inertance adjustment is verified. The mechanical behaviors of the semi-active shock absorber with different inertances and damping coefficients are obtained and analyzed.

A control algorithm for shock mitigation system based on magnetorheological energy absorber (MREA) under dropinduced excitation is experimentally investigated, with the objective of “soft landing” (i.e., the final velocity of the payload exactly reduces to zero when consuming the total piston stroke of the MREA). The dynamic model of the shock mitigation system is established. A feedforward damping force tracking approach based on a basic resistor-capacitor (RC) operatorbased hysteresis model is presented and is further employed to accurately describe and predict the hysteretic nonlinearity of the MREA. According to the real-time states of the dropped mass, including the displacement, velocity and acceleration, the system controller outputs the appropriate damping force command to the MREA to achieve the desired minimized deceleration of the payload. The feasibility and the capability of the designed control algorithm are validated via simulation analyses and experimental tests.

Inerters are a two-terminal mass element, and the forces applied at their two terminals are proportional to the relative acceleration between the two terminals. The volume and weight of inerters are much smaller than those of any conventional mass element providing a same generated force, which is beneficial to engineering applications. The inerter in mechanical system is completely corresponding to the capacitor in electrical system, which makes it more convenient to do related investigations based on mechanical-electrical analogies. A semi-active inerter (SAI) featuring magnetorheological (MR) effect with tunable inertance is proposed, designed and investigated to enhance the performance of the passive inerters. The proposed SAI consists of a flywheel, a flywheel housing, a ball screw, a connection sleeve, bearings, upper and lower covers, excitation coils and MR fluid. MR fluid fulfilled in the flywheel housing of the SAI is energized by the excitation coils with applied current, and correspondingly the mechanical characteristics of the SAI is tunable via the applied current. The mathematical model and the mechanical performance of the SAI is established and tested, respectively. The nonlinearity of the experimental results is analyzed and the nonlinear model of the SAI is further established. The preliminary principle verification of the continuous adjustment of the equivalent inertance of the SAI is conducted using the nonlinear model. Moreover, a compensator is proposed to address the problem of the phase difference between the controllable force and the real output force of the SAI, and continuous inertance adjustment of the SAI with a compensator is realized and analyzed.

Molecular imprinting has been considered as one of the most useful techniques for the preparation of specific receptors. In this study, a novel molecularly imprinted material (MIP) has been developed by combining PFOS as the template with soluble polybenzimidazole which wrapped over the surface of ferroferric oxide as the carrier. Kinetics experimental showed MIP had a sorption amount of 117.6mg/g for PFOS, high than 74.6mg/g of the none-imprinted polymer adsorbents（NIP）. Additionally, in the competitive environment with other pollutants, the sorption amount of PFOS for MIP is greater than NIP, due to the electrostatic interaction in recognizing the target compound.

To investigate the epidemiological characteristus of human caliciviruses (HuCVs) among children under 5 years of age with acute diarrhea and to estimate the disease burden in Lulong county.HuCVs were detected by enzyme linked immunosorbent assay (ELISA) and reverse transcription-polymerase chain reaction (RT-PCR). Some PCR amplicons were cloned and sequenced. Phylogenetic tree was constructed for strain characterization. The rate of HuCVs-attributed hospitalization was estimated according to the positive rate of HuCVs detection in fecal specimens collected from hospitalized diarrhea patients.Between July 1999 and June 2001, 708 fecal specimens were collected, of which 393 rotavirus-negative and 5 rotavirus-positive specimens were detected for HuCVs. Thirty-one point six percentage of fecal specimens from patients with diarrhea was HuCVs positive. Among inpatients, HuCVs positive rate was 17.5%. HuCVs detection was mainly distributed in 3 - 17 mouth-old children, in winter. All 11 strains belonged to NLV GII in which 6 strains GII-3, 2 strains GII-4 and 3 strains GII-7, and they shared 55.1% - 100% nucleotide identity. NLV GII-4 and GII-7 were identified in 2000, while NLV GII-3 and GII-7 in 2001. The preliminary estimate of HuCVs-attributed hospitalization rate was 3.6 per thousand.Human caliciviruses with different genotypes circulated among children in Lulong county with GII NLVs were the prevalent strains. The disease burden of HuCVs was second to rotavirus.