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To explore the influence factors of the red cell distribution width (RDW) level in knee osteoarthritis (KOA) patients, the difference in RDW before and after total knee arthroplasty (TKA), and further explain the clinical value of the RDW level in KOA patients. Information of 195 patients with KOA and 43 patients with meniscus injuries undergoing surgical treatment in the Surgery Department of Joint and Microsurgery Repair and the Surgery Department of Sports Trauma and Joint Arthroscopy of the First Affiliated Hospital of Anhui Medical University from June 1, 2020, to December 1, 2020, were collected. All included patients’ gender, age, height, medical history, blood lipid, erythrocyte sedimentation rate (ESR), CRP, RDW, anteroposterior and lateral X-ray images of the knee joint, and magnetic resonance imaging (MRI) of the knee joint were recorded. The difference in RDW of KOA patients with different severities before and after unilateral TKA surgery was compared, and the difference between KOA patients and patients with only meniscus injury was also compared for further analysis of the influence factors of the RDW level in moderate-severe KOA patients. Among moderate-severe KOA patients with different imaging severities, the RDW level was significantly different (P = 0.022). There was no statistical difference between the groups with and without the TKA history. The RDW level was higher in KOA patients than in patients with only meniscus injuries, and the difference was statistically significant P < 0.05 . To some extent, the RDW level could be taken as a predictor for the severity of moderate-severe KOA patients, and its elevation was primarily related to chondritis and synovitis caused by KOA, so it was suggested that the patients receive adjuvant anti-inflammation therapy after TKA surgery.

Aiming to deal with underwater localization for small-size robots in GPS-denied and structured environment, this paper proposed a novel multi-sensor fusion-based self-localization system using low-cost sensors. Based on multi-sensor information fusion, an Extended Kalman Filter (EKF) is utilized to synthesize the multi-source information from an Inertial Measurement Unit (IMU), optical flow, pressure sensor and ArUco markers, which enables the robot obtain a highly precise positioning. This method also can reduce the location drift over time owing to the loss of markers in pure markers-based localization. Specially, a velocity correction model is proposed using the angle information obtained by IMU, which can compensate optical flow-based velocity estimation errors caused by robot posture changes. Finally, to validate the performance of the proposed self-localization system, simulations are conducted using Gazebo simulator on the robot operating system (ROS). Moreover, a series of experiments in an indoor swimming pool are presented. Results of the proposed method and dead reckoning are compared in simulation and experiment to demonstrate the robustness and feasibility of the proposed localization system.

PurposeTo assess brain damage in a rat model of cerebral ischemia based on apparent diffusion coefficient (ADC) data obtained from multi-high b-values and evaluate the relationship between Aquaporin 4 (AQP4) expression and ADC.MethodsThirty eight male Sprague–Dawley rats were randomized into two groups: (1) sham controls (n = 6) and (2) cerebral ischemia (successful model, n = 19). All rats underwent diffusion-weighted imaging (DWI) with both standard b-values and multi-high b-values (2,500–4,500 s/mm2) using a 3.0-T device. Standard ADC (ADCst) maps and multi-high b-value ADCs (ADCmh) were calculated, respectively. Aquaporin 4 expression was quantified using Western blot. Relative values of ADCst and ADCmh, AQP4 expression were compared between the sham group and the ischemia group. Correlations between ADC values and AQP4 expression were evaluated.ResultsAt 0.5 h after suture insertion, the value of ADCmh on the lesion was obviously decreased, and there was no difference in lesion volume when compared with ADCst. After reperfusion, besides similar regions where ADCst values decreased, we also found additional large values on ADCmh within the cortex of the ipsilateral side or surrounding the lesion. The lesion evolution of the large value on ADCmh was quite different from other indicators. But the total ADCmh values were still significantly associated with ADCst. The AQP4 protein expression level was appreciably increased after middle cerebral artery occlusion (MCAO), but there was no correlation between AQP4 expression either with ADCmh or ADCst.ConclusionWe found the large values on ADCmh during the progression of cerebral infarction is varied, but there was no correlation between ADCmh values and AQP4 expression. ADCmh may indicate the heterogeneity of ischemia lesions, but the underlying pathological basis should be further explored.

A spin-related photocurrent excited by circularly polarized light is observed near the electrodes on a few-layer ReS

According to the relationship between the stator and rotor structure and magnetic flux density of the traditional flux switching motor with segmental rotor (SFSM), the mathematical model of the SFSM was established. It was found that the height of the stator pole shoe has a great influence on the no-load electromagnetic characteristics of the motor. After the flux barrier was added on the segmental rotor, it can effectively solve the problem that the positive and negative half period of the no-load electromotive force (EMF) waveform of the motor with low pole shoe height. Using the method of finite element (FEM) parametric simulation, the optimal size of the flux barrier was obtained. Compared with the traditional SFSM, the even harmonics in the phase winding EMF waveform were greatly reduced, and the inductance waveform tends to be sinusoidal. Finally, a prototype was made, and the correctness of the new segmental rotor structure was verified by experiments.

In this paper, the Petrov-Galerkin finite element interface method is modified to the vectorial form and applied to compute the band structure of phononic crystals with complicated scatterer geometry. Value-periodic subspace and projective grid are employed in this method. Complete mathematical model together with the continuity and equilibrium conditions on the scatterer interface as well as the Bloch-periodic boundary conditions on the unit cell are presented for these systems. We then apply this method to compute the band structure of three kinds of special phononic crystals: phononic crystal with anisotropic inclusions, phononic crystal containing piezoelectric materials and phononic crystal containing nano-piezoelectric materials. Taking advantage of asymmetric basis functions and non-body-fitted meshes, our method is suitable for the calculation and analysis of phononic crystals with complicated scatterer geometries. With plenty of numerical experiments, the accuracy and convergency of the proposed method is demonstrated. The influences of the rotation angle of anisotropic inclusion, complicated scatterer shape, filling fraction of the scatterers, and the rotation angle of the scatterers to the band structure of these three kinds of phononic crystals are investigated. This will provide a new perspective for the design and manufacture of phononic crystals with specific band structures.

The switched reluctance starter generator (SRSG) without field winding and the doubly salient electromagnetic starter generator (DSESG) with field winding are compared in this paper. The influences of two arrangements of each variable winding and spacing variable winding for the performance of the starter generator were studied. Mathematical models of start mode and power generation mode were established respectively, and the influencing factors of starting torque and power generation phase voltage were derived. Next, the finite element simulation software was used to simulate the electromagnetic characteristics of machine. Finally, prototype experiment was made. The finite element simulation and prototype experiment results proved that spacing excitation DSESG has a better prospect as automotive starter generator.

Background: Tyrosine kinase inhibitors (TKI) are recommended for pediatric Philadelphia-positive acute lymphoblastic leukemia (Ph+ ALL), and the one commonly used in China is imatinib. However, it's worth noting that clinical needs could not be met gradually with the increasing resistance of imatinib. Dasatinib, the second-generation TKI, has been proved by Food and Drug Administration because of the better efficacy and comparative safety. This study aims to supplement economic evidence for multi-dimensional value by comparing the cost-effectiveness between imatinib and dasatinib in treating pediatric patients with in China, and to help clinical rational drug use and drug policy adjustment. Methods: A decision tree model combined with a 10-year Markov model was established based on the published data and real-world cohort study. The main outcomes were incremental costs, which expressed in 2019 China yuan (CNY), and quality-adjusted life years (QALYs), both were discounted at 5%. Cost-effectiveness analysis was used to calculate the incremental cost-effectiveness ratio (ICER) between the two drugs in Chinese pediatric Ph+ ALL patients from the health system perspective. The Sensitivity analysis were conducted to assess the uncertainty and result robustness. The set willingness-to-pay (WTP) threshold was 1 times per capita GDP of China in 2019, recommended by the World Health Organization (WHO). Results: The total costs were CNY 1,020,995.35 and CNY 1,035,788.50 in imatinib group and dasatinib group over the simulative course of a decade, and the total QALYs were 2.59 and 4.84. Compared with the imatinib treatment group, the ICER of dasatinib treatment was around CNY 6,575.78/ QALY, which was less than the set threshold. The sensitive analysis indicated the robustness of the results. Conclusions: The cost-effectiveness analysis shows that dasatinib has potential cost-effective advantages compared with imatinib for pediatric Ph+ ALL patients under the set WTP threshold, which indicates that those patients could achieve more QALYs by paying acceptable fee.

Background Dasatinib and imatinib are the recommended tyrosine kinase inhibitors (TKIs) for treating pediatric Philadelphia-positive acute lymphoblastic leukemia (Ph + ALL), and the one which has been approved indication in China is imatinib. Recently, clinical demand for Ph + ALL treatment is becoming unmet gradually with the increasing resistance of imatinib. There are some studies reporting the better efficacy and comparative safety of dasatinib compared with imatinib, but no economic comparison has been published. This study aims to supplement economic evidence by comparing the cost-effectiveness between imatinib and dasatinib in treating pediatric patients with Ph+ ALL in China, and to help clinical rational drug use via multi-dimensional value assessment. Methods A decision tree model combined with a 10-year Markov model were established based on the disease progression. The parameters were collected from published literatures and our hospital’s electronic medical records. From the health system perspective, the incremental cost-effectiveness ratio (ICER) between the two treatment groups was calculated through cost-effectiveness analysis and then compared with the willingness-to-pay (WTP) threshold. The set WTP threshold in this study was 1 times per capita gross domestic product (GDP) of China, as recommended by the World Health Organization. Direct medical costs and quality-adjusted life years (QALYs) were calculated and discounted at 5%. The sensitivity analyses were conducted to assess the uncertainty and robustness of the results. Results The total costs were CNY 1,020,995.35 and CNY 1,035,788.50 in imatinib group and dasatinib group during the 10-year simulation, and the total QALYs were 2.59 and 4.84. Compared with the imatinib treatment group, the ICER was around CNY 6,575.78/ QALY, which was less than the set threshold CNY 70,892/ QALY. The sensitive analyses indicated the robustness of the results. Conclusions The cost-effectiveness analysis shows the potential cost-effective advantages of adding dasatinib comparing with adding imatinib for pediatric Ph + ALL patients in China under the set WTP threshold, which indicates that those patients could achieve more QALYs by paying acceptable fee.

The novel temperature-stable microwave dielectric ceramics of Ce0.5Sm0.5O1.75 were fabricated via the mixed oxide reaction method, with the detail information including crystal phase, microstructure, sintering behavior and microwave dielectric properties being systematically investigated. For crystal phase, all the diffraction patterns were indexed as cubic fluorite-type structure with Fm-3m (225) space group and exhibited a single phase with no obvious peak position shift. The grain growth was analyzed by density and average grain size. For microwave dielectric properties of Ce0.5Sm0.5O1.75 ceramics, the dielectric constant value (er) was dependent on density. The quality factors (Q × f values) were investigated considered with average grain size. And the temperature coefficient of resonant frequency (τf value) had no significant change during the sintering temperature range, which was found consistent with the trend of the dielectric constant value. The Ce0.5Sm0.5O1.75 ceramics sintered at 1475 °C for 4 h exhibited good microwave dielectric performances with er = 18.21, Q × f = 70,500 GHz, and τf = − 16.4 ppm/°C.

We proposed and developed a small bionic amphibious spherical robot system for tasks such as coastal environment monitoring and offshore autonomous search and rescue. Our third-generation bionic small amphibious spherical robots have many disadvantages, such as the lack of maneuverability and a small operating range. It is difficult to accomplish underwater autonomous motion control with these robots. Therefore, we proposed a fourth-generation amphibious spherical robot. However, the amphibious spherical robot developed in this project has a small and compact design, with limited sensors and external sensing options. This means that the robot has weak external information collection capabilities. We need to make the real time operation of the robot’s underwater motion control system more reliable. In this paper, we mainly used a fuzzy Proportional-Integral-Derivative (PID) control algorithm to design an underwater motion control system for a novel robot. Moreover, we compared PID with fuzzy PID control methods by carrying out experiments on heading and turning bow motions to verify that the fuzzy PID is more robust and exhibits good dynamic performance. We also carried out experiments on the three-dimensional (3D) motion control to validate the design of the underwater motion control system.

The purpose of this study was to explore the role and mechanism of the PI3K/AKT/mTOR signaling pathway in painful diabetic neuropathy (PDN). The diabetes mellitus (DM) model was established by intraperitoneal injection of streptozocin into SD rats. After 3 weeks of modeling, the DM + LY group was treated with PI3K inhibitor, the DM + vehicle group was treated with DMSO, and the DM group was untreated. The paw mechanical withdrawal thresholds (MWT) was measured by Von Frey filaments, and the expression of PI3K/AKT/mTOR pathway-related proteins and autophagy marker proteins were analyzed by Western blotting. We found that 3 weeks after modeling, the MWT values of diabetic rats were significantly reduced, p-PI3K, p-AKT and p-mTOR proteins expression in the spinal cord was increased, and Beclin1 and LC3-II expressions were reduced (P0.05). After administration of PI3K inhibitor, the MWT values in DM + LY group were improved, and the expressions of p-PI3K, p-AKT and p-mTOR proteins in the spinal cord were decreased significantly, and the expressions of Beclin1 and LC3-II were increased (P0.05). However, there were no significant changes in the DM + vehicle group compared with the DM group (P0.05). Therefore, we conclude that activation of the PI3K/AKT/mTOR pathway and impaired autophagy may be key factors that cause PDN. Inhibition of the PI3K/AKT/mTOR pathway could promote autophagy activity and alleviate PDN.

Finite-size effect plays a significant role in topology photonics not to mention in reality all experimental setups are in finite-size. A photonic bandgap is opened in the topological edge state dispersion if a topological photonic crystal with finite width is considered, and the bandgap size relies on the finite-size effect. Pseudospin-preserving and pseudospin-flipping processes can be realized when a selectively switch of the pseudospin of edge states are customized by our designs. Our microwave experiments also successfully demonstrate pseudospin switch-on and -off behaviors in a finite-width photonic crystal. By combining photonic crystals with finite widths, a multi-tunneling proposal of topological photonic crystals can also be achieved. Our study of the finite-size effect will provide new approaches and thoughts to improve the development of topological photonic devices in the future.

This paper presents a case example from China, where detailed deliberations were instrumental in bringing together national and subnational managers to tailor implementation protocols for neonatal care strategies at provincial and county levels. The China National Health Development Research Center (CNHDRC) organised deliberations to support the formulation of strategies for improving early essential neonatal care for rural areas. The aim was to help counties, the lowest level jurisdiction in China, learn what could work locally, and to help provinces and the national government learn what should inform national policy and be disseminated widely in China’s decentralised health system. It became clear that central-level stakeholders needed to learn how to help counties support the pilots. CNHDRC staff, national-level experts and academics visited pilot provinces and counties to discuss local policies, initiatives and challenges (including with patients), build a common understanding of the project and identify local support needs including by examining health records and observing health facilities. What followed were county-specific reports with priority interventions and implementation plans, which were further refined through county-level meetings. They helped central stakeholders better understand and address variations in county capacities and needs.

The ocean is a significant strategic resource, and the insufficient development and use of the ocean, as well as the increase in attention to the ocean, have led to the development of underwater robot technology. The need for in-depth marine exploration and the limitations of one underwater robot has sparked research on the underwater multi-robot system. In the underwater environment, weak communication is caused by the shielding effect of the seawater medium, which makes multi-robot systems difficult to form. Hence, we combine the robot’s vision system with the leader-follower structure to form a vision-based underwater formation method, in which the visual solution serves as the control system’s feedback. By using three small underwater robot platforms, the proposed method is proved to be effective and practicable through underwater formation experiments. Furthermore, the coordination period and error of the control system are analyzed.

To evaluate the diagnostic value of multi-ultra high b-value diffusion-weighted imaging (UHBV-DWI) in Alzheimer’s disease (AD), and to build a regression prediction modelfor AD.90 participants including 30 AD, 30 mild cognitive impairments (MCI) and 30 volunteers without neurological diseases were enrolled to perform with hippocampal volume, white matter hyperintensities volume (WMH volume), periventricular white matter hyperintensity (PVWMH) score, deep white matter hyperintensity (DWMH) score and UHBV-DWI.We found UHBV-DWI outperformed in the diagnosis of AD (AUC = 0.858), and multiple linear regression model: y = 0.515 + 0.018 *(WMH volume) + 0.221 *(ADCuh value)-0.359 *(left hippocampus volume) were established.So we came to a conclusion: UHBV-DWI is helpful for diagnosing AD, and the combination of WMH volume and left hippocampus volume has a better diagnostic performance.

In order to simplify parameter adjustment process of the AUV controller in the pool experiments, many researchers established the robot dynamics model and pre-adjusted the parameters in the simulation. This paper mainly studied the characteristics of underwater spherical robot hydrodynamic model and the verification of the model through experiments. First, we obtained the hydrodynamic force acting of the robot in different fluid environments through Computational Fluid Dynamic method. Then, the hydrodynamic coefficients of the dynamic model were calculated by the regression of the above force data. Finally, these hydrodynamic coefficients obtained from the above simulation were verified by pool experiments. The experimental results showed that these coefficients obtained by this method was well fitted with the experimental data and may be used as a reference for the hydrodynamic model. In addition, the nonlinear characteristics of hydrodynamic coefficients under different disturbances were also studied. This will provide further reference for model identification and control in complex underwater environment.

Amphibious robots has been a hot research direction. They can not only save cost, but also improve the efficiency of kinds of jobs and cope with various complex environments. Compared with the common multi-steering gear oscillating fins robot, this paper uses the 30 degrees of the opposite angle of the 12 groups, which can produce the fish fins of a similar function. The 12 drivers are connected to the 12 units of the lever, which can be driven by a single steering machine. The existing amphibious robots are mostly used by several steering gear to drive the fins, the structure redundancy and the control circuits are complex, and most of them are steering the direction of the rudder, which needs to be designed to turn to the body. Therefore, the fin components on both sides of this robot are driven by a corresponding steering machine, which is used to achieve acceleration and turn, and the adjustment mechanism of the fish fin is set up to realize the transformation of amphibians. Using Adams to simulate the motion of the rocker, the acceleration curve on the component is obtained. The corresponding speed and pressure curves were obtained by using fluent to simulate the fish fins of different phase angles. The research results are of great significance to the design and control of multi-modal motion in the next generation flexible underwater navigation and robot.

Trajectory tracking control is a basic problem in rescue, detection and obstacle avoidance tasks. The trajectory tracking process has its own constraints, and the core of model predictive control is to solve the quadratic programming problem with constraints, so MPC is used to solve the trajectory tracking problem of amphibious spherical robot in this paper. Firstly, based on the 3-DOF dynamic state space equation of the robot, the model is approximately linearized and discretized to facilitate the design of controller. To solve the difficulty of adjusting the weight matrix of MPC, an adaptive parameter adjustment method based on output error is designed in this paper. The linear trajectory and square trajectory are simulated on MATLAB and Gazebo simulation platform respectively. The simulation results verify the applicability and stability of the designed controller.

Binocular vision technology is an important branch of computer vision technology, which is widely used in robot motion, navigation, surgical treatment and many other fields. As is a crucial link, it is the basis of binocular vision technology to obtain the internal parameters of a digital camera. Traditional calibration methods, such as Zhengyou Zhang's method needs a calibration board, while the self-calibration method based on active vision needs to strictly control a camera to move in a designated way. Based on that, those methods can't be applied to simple and convenient occasions. In this paper, we aim to propose a new method of camera self-calibration by improving an existing QPSO algorithm with the EXIF information of digital camera photos. The method only needs to shot one object twice on different angles. We derive the conversion formula of equivalent focal length and pixel focal length and use it to initialize the algorithm. It is to find the optimal solution of the cost function transformed from the Kruppa equation by using the QPSO method. The experiment results proved that the improved method is better than the initial one and using the EXIF information to initialize the algorithm is feasible.

NdNbO4−x MgO (x = 0.5, 1.0, 2.0, 3.0, 4.0) ceramics with high Q × ƒ values were prepared via the conventional solid-state reaction. The effects of MgO additive on the microstructures and microwave dielectric properties of NdNbO4 ceramics were investigated through various approaches. Microscopic analysis showed that the NdNbO4 phase and MgO phase were coexisted, and the crystal structure of the two phases did not changed with the additional amount of MgO. The dielectric constant could be explained by bulk density as a function of sintering temperature and satisfied with the Lichtenecker logarithmic superposition rule. The Q × ƒ value increased quickly when the phase composition changed from single phase to multiphase and was afterwards linked to the grain growth. The change in the temperature coefficient of resonant frequency was not large and was consistent with that in the dielectric constant. When x = 3.0, MgO additive effectively stepped up the Q × ƒ value of NdNbO4 to 1,35,000 GHz, which was fourfold of pure phase.

The Q × ƒ values of SmNbO4 ceramics had been effectively optimized by MgO doping, and a series of high-Q SmNbO4-x MgO (0.5 ≤ x ≤ 4.0) ceramics had been successfully prepared with conventional solid reaction process. The phase composition, microstructure and microwave dielectric properties had been investigated with different content of MgO addition. Two phases, surrounded by each other which indexed as SmNbO4 and MgO, had been detected in SmNbO4-x MgO ceramics. It was found that the grain growth of SmNbO4-x MgO ceramics could be well promoted by MgO additive, owing to the similar c/a values between the two crystal structures. Based on the structural characteristic of SmNbO4-x MgO ceramics, the variation in dielectric constant of SmNbO4-x MgO ceramics was verified to satisfy with the Lichtenecker logarithmic mixing rule. Importantly, the Q × ƒ values of SmNbO4-x MgO ceramics increased as a function of MgO content, which was analyzed to result from the improved microstructure.

Lithium–sulfur (Li–S) batteries are considered as a next-generation energy storage solution thanks to the dramatic increase in their energy density and the accompanying low fabrication cost. Nonetheless, their practical applications have been hampered by critical challenges such as cycling instability, low sulfur utilisation and efficiency. Here, the interfacial growth of Ni(OH)2-encapsulated sulfur nanoparticles in a reduced graphene oxide free-standing matrix as Li–S cathodes has been highlighted, along with a detailed application investigation of the sandwich foam structure in Li–S batteries. Compared to sulfur composites based solely on a graphene host (S@rGO), this composite foam cathode could provide significant improvements in specific capacity and long-cycle stability with the effective confinement and promoted conversion of lithium polysulfides. Moreover, the sandwich foam composite cathode exhibits a high specific capacity of 1189 mA h g−1 (0.1 C), better rating performance (691 mA h g−1 at 2 C) and remarkable cycling stability, retaining 81% of the initial capacity after 200 cycles of charge–discharge at 0.2 C. Furthermore, Ni(OH)2 wrapping at the cathode–electrolyte interface offers vastly improved polysulfide shuttle suppression, which provides a new cathode encapsulation method for further developments of advanced Li–S cathodes.

In this paper, we propose a Petrov-Galerkin finite element interface method (PGFEIM) to solve the elliptic and elastic interface problems with Bloch-periodic boundary conditions. The main idea of this method is to choose the standard finite element basis independent of the interface to be the test function basis, and choose a piecewise linear function satisfying the jump conditions across the interface to be the solution basis. The grid we use is a non-body-fitted grid. The PGFEIM is capable of dealing with sharp-edged interface problems with matrix coefficients and nonhomogeneous jump conditions. Further, we extend this method to compute the band structure of anti-plane transverse waves and in-plane elastic waves in phononic crystals. Different acoustic impedance ratios, arbitrary complex scatterer geometries and various material properties are considered and discussed. Numerical experiments demonstrate that the PGFEIM is nearly second order accurate in the L ∞ norm for interface problems, and it is accurate and efficient for computing the band structure of phononic crystals.

Interventional surgery is widely used in the treatment of cardiovascular and cerebrovascular diseases, and the development of surgical robots can greatly reduce the fatigue and radiation risks brought to surgeons during surgery. In this paper, we present a novel interventional surgical robot which allows surgeons to fully use their operating skills during remote control. Fuzzy control theory is used to guarantee control precision during the master-slave operation. The safety force feedback control is designed based on the catheter and guidewire spring model, and the force-position control is designed to decrease the potential damage due to the control delay. This study first evaluates the force-position control strategy using a vascular model experiment, and then an in vivo experiment is used to evaluate the precision of the surgical robot controlling the catheter and guidewire to the designated position. The in vivo experiment results and surgeon's feedback demonstrate that the proposed surgical robot is able to perform complex remote surgery in clinical application. Graphical abstract Surgeons perform remote interventional animal surgery using interventional surgical robots.

This paper designs a novel legged, multi-vectored water-jet composite driving mechanism (LMWCDM) for the amphibious spherical robot (ASRobot) and presents modeling and experimental evaluation of this composite driving mechanism. In order to crawl on land flexibly, the robot was designed in SolidWorks and simulated in ADAMS environment with the sit to stand motion and a crawling gait. Then the simulation results, such as driving torques, guided the selection of servomotors in different joints. In aquatic environment, the dynamic modeling of ASRobot was analyzed by synthesizing the propulsive vectors of four propellers in each workspace of legs. Simplistically, multiple underwater locomotion, such as longitudinal and lateral motion, rotary motion, sinking and floating motion and cruising motion, were proposed. Thus, using a six-axis force/torque sensor at the equivalent mass center, a force and torque measuring mechanism was developed to obtain the direct propulsive effect and validate the modeling of the driving system. To evaluate the robot design and selection of servomotors, experiments of the sit to stand motion and crawling motion were conducted. Underwater testing experiments of LMWCDM were carried out to verify the modeling of rotary motion, sinking and floating motion. Besides, underwater test of the robot prototype also proved the highly flexible and swift motion.

MgO was designed as a new additive to optimize the microwave dielectric properties of LaNbO4 ceramics, and consequently the Q × ƒ values of LaNbO4 ceramics were effectively increased. The effects of MgO additive on phase composition, microstructure and microwave dielectric properties were discussed. LaNbO4, indexed as the main phase, had no obvious change, while the secondary phase related to MgO varied with different MgO content. The grain growth was evaluated by grain size and its distribution. The dielectric constant (er) was generally stable among the whole designed sintering temperature, but had some decrease with MgO (low permittivity) content increasing. The Q × ƒ values were not only affected by bulk densities during the sintering process, but also depended on the grain size and its distribution with different MgO contents. Sintered at 1425 °C for 4 h with x = 0.5, LaNbO4–xMgO ceramics possessed excellent performance: er = 19.8, Q × f = 94,440 GHz, τƒ = 6.1 ppm/°C.