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Background A serious game–based cellphone augmented reality system (CARS) was developed for rehabilitation of stroke survivors, which is portable, convenient, and suitable for self-training. Objective This study aims to examine the effectiveness of CARS in improving upper limb motor function and cognitive function of stroke survivors via conducting a long-term randomized controlled trial and analyze the patient’s acceptance of the proposed system. Methods A double-blind randomized controlled trial was performed with 30 poststroke, subacute phase patients. All patients in both the experimental group (n=15) and the control group (n=15) performed a 1-hour session of therapy each day, 5 days per week for 2 weeks. Patients in the experimental group received 30 minutes of rehabilitation training with CARS and 30 minutes of conventional occupational therapy (OT) each session, while patients in the control group received conventional OT for the full 1 hour each session. The Fugl-Meyer Assessment of Upper Extremity (FMA-UE) subscale, Action Research Arm Test (ARAT), manual muscle test and Brunnstrom stage were used to assess motor function; the Mini-Mental State Examination, Add VS Sub, and Stroop Game were used to assess cognitive function; and the Barthel index was used to assess activities of daily living before and after the 2-week treatment period. In addition, the User Satisfaction Evaluation Questionnaire was used to reflect the patients’ adoption of the system in the experimental group after the final intervention. Results All the assessment scores of the experimental group and control group were significantly improved after intervention. After the intervention. The experimental group’s FMA-UE and ARAT scores increased by 11.47 and 5.86, respectively, and were both significantly higher than the increase of the control group. Similarly, the score of the Add VS Sub and Stroop Game in the experimental group increased by 7.53 and 6.83, respectively, after the intervention, which also represented a higher increase than that in the control group. The evaluation of the adoption of this system had 3 sub-dimensions. In terms of accessibility, the patients reported a mean score of 4.27 (SD 0.704) for the enjoyment of their experience with the system, a mean 4.33 (SD 0.816) for success in using the system, and a mean 4.67 (SD 0.617) for the ability to control the system. In terms of comfort, the patients reported a mean 4.40 (SD 0.737) for the clarity of information provided by the system and a mean 4.40 (SD 0.632) for comfort. In terms of acceptability, the patients reported a mean 4.27 (SD 0.884) for usefulness in their rehabilitation and a mean 4.67 (0.617) in agreeing that CARS is a suitable tool for home-based rehabilitation. Conclusions The rehabilitation based on combined CARS and conventional OT was more effective in improving both upper limb motor function and cognitive function than was conventional OT. Due to the low cost and ease of use, CARS is also potentially suitable for home-based rehabilitation. Trial Registration Chinese Clinical Trial Registry ChiCTR1800017568; https://tinyurl.com/xbkkyfyz

To diagnose the running state of bushing and avoid serious power grid accidents, online multi-parameter monitoring equipment for dissolved hydrogen, oil pressure and temperature in bushing oil was developed. The equipment includes three units: signal acquisition, control cabinet and data analysis. A new hydrogen sensor without oil–gas separation membrane and based on palladium alloy film technology was developed. A three-in-one sensor for hydrogen, oil temperature and pressure monitoring has been developed, which has the advantages of miniaturisation, lightweight and easy installation. Test results show the hydrogen measurement range of the sensor is 0–5000 ppm, and the accuracy can reach 10% or 15 ppm (with larger values). The pressure measurement range is 0–1.0 MPa, the resolution is 0.1 kPa, and the accuracy can reach 0.25 grade. The temperature measurement range is −40 to 105°C, and the accuracy is ±1°C. The measurement performance of the device fully meets the requirement of online monitoring of transformer bushing. The equipment has been put into operation in a 330 kV substation, which can monitor the bushing status online and help eliminate the early latent fault of bushing in the weak budding state.

To be able to set uniform inlet boundary conditions in simulation, there must be an inlet extension at the first guide vane. In the inlet extension, turbulence experiences strong numerical dissipation, which has not been paid attention to. In the current paper, the influence of the numerical dissipation of turbulence on accuracy in predicting heat transfer was discussed. Two cases, where the numerical dissipation of turbulence was neglected, were analysed. In the first case, wrong conclusion about effect of turbulence scale on heat transfer was drawn: blade heat transfer increases with inlet turbulence scale under the same inlet turbulence intensity. The mechanism for the wrong conclusion is that turbulence with larger scale numerically dissipates more slowly in the inlet extension so that turbulence intensity at blade leading edge is greater under turbulence with larger scale, it is the turbulence intensity not turbulence scale itself really affects heat transfer. In the second case, when the numerical dissipation of turbulence is neglected and turbulence parameters at measuring plane of inlet are directly as input for turbulence boundary condition, flow transition is postponed downstream and heat transfer error is greater, however, when the numerical dissipation of turbulence is considered and turbulence parameters at measuring plane are regard as benchmark and matched by adjusting parameters of inlet turbulence boundary condition, the result shows better agreement with experiment. Thus, the correct way to set turbulence boundary condition is to match turbulence parameters at measuring plane by adjusting parameters of inlet turbulence boundary.

Microwave power transmission has become a hot research topic in recent years. To overcome the constrain of traditional MPT techniques, a holographic metasurface antenna which can focus the radiation microwaves at 5.8GHz band is proposed in this paper. Simulation results show that the proposed antenna has a good impedance matching and excellent focusing ability as predicted. The proposed focusing method can pave the way to promising applications in MPT area, dramatical increasing the efficiencies.

The safe operation of maglev trains is inseparable from the health status of each component, and fault diagnosis of components is of great significance. In this paper, taking the bearing of a magnetic levitation motor as an example, a fault diagnosis method based on wavelet threshold denoising and correlation analysis combined with EMD(Empirical Mode Decomposition) decomposition and LSTM(Long Short-Term Memory) neural network is proposed. This article first compares the optimized EMD decomposition with traditional Time-frequency domain analysis to show the superiority of its performance. Then, Use the IMF component with the largest correlation coefficient obtained from the optimized EMD decomposition as the input of the LSTM neural network.Set network parameters and structure to complete the detection of bearing failure status. This paper uses a certain type of SKF bearing signal as an example to verify it. The results show that the method has a high accuracy in the diagnosis of normal status, gear fault, outer race fault, inner race fault and roller fault.

Potential prognostic biomarkers for patients with sepsis have yet to be identified. The present study evaluated the prognostic value of fibroblast growth factor 21 (FGF21) levels in patients with sepsis.A total of 120 consecutive Chinese patients with sepsis were prospectively included, and serum levels of FGF21 and biomarkers such as interleukin (IL)-6, tumor necrosis factor alpha (TNF-α), IL-10, procalcitonin (PCT), C-reactive protein (CRP), and lactate (LAC) were measured within 24 h after intensive care unit admission. The demographic and clinical characteristics including underlying diseases, Sequential Organ Failure Assessment (△SOFA), and acute physiology and chronic health evaluation II (APACHE II) scores were recorded. Patients were categorized into survival and non-survival groups according to the 28-day mortality. Correlations between FGF21, serum indicators, severity score and 28-day mortality were analyzed, and Cox regression analysis was performed to identify prognostic factors. Receiver operating characteristic (ROC) curve analysis was used to determine the optimal cut-off of FGF21 for survival prediction.Non-survivors had significantly higher levels of FGF21, IL-6, TNF-α, IL-10, PCT, CRP, and LAC as well as higher SOFA and APACHE II scores compared with the survivors. FGF21 levels were positively correlated with age, waist circumference, levels of IL-6, IL-10, TNF- α, PCT, CRP, and LAC, △SOFA and APACHE II scores. ROC curves showed that FGF21 had a high sensitivity of 81.3% and specificity of 89.8% for predicting 28-day mortality. Patients with a FGF21 levels3200 pg/ml had a significantly better survival rate than those with levels3200 pg/ml, and thus, FGF21 was an independent prognostic factor for survival.FGF21 could serve as a new prognostic biomarker for sepsis survival.

Satisfactory electrochemical stability of extrinsic-interfaces between electrodes and electrolyte is the prerequisite for the safe and durable applications of all-solid-state Lithium batteries (ALBs). Unfortunately, the oxidative decomposition of anions from Li-salt at the extrinsic-interfaces of cathode side leads to the electrochemical instability during charge process. Here, a novel composite polymer electrolyte (CPE) containing flyash-treated (FA) submicro/micron particles and poly(ethylene oxide) (PEO) matrix is reported. After the addition of FA filler, Li+ transference number increases from 0.21 to 0.37 and electrochemical stability window reaches 5.2 V. FA as filler can efficiently immobilize (trifluoromethanesulfonyl) imide (TFSI–) anions and mitigate their irreversible oxidative decomposition at the extrinsic-interface of cathode||CPE due to the internal binding interaction between TFSI– anions and FA particles. ALBs using CPE with FA can not only provide stable extrinsic-interfaces for uniform Li deposition, but also tolerate strong electrochemical polarization with excellent cycling performance.

In this paper, the imaging features of an incoherent holographic structure is analysed more thoroughly. The relation between the lateral resolution and frequency sampling step in an incoherent holographic system which is indeed a multi-view projection structure is formulated mathematically. Based on the presented mathematical relation the image resolution is improved through synthetically enlarging the lenses aperture. The non-uniform frequency sampling due to enlarging the lenses aperture is resolved through time-multiplexing. Through the proposed dual-mode, spatio-temporal, incoherent holographic structure, image quality and resolution is improved considerably. Experiments are performed to validate the claimed quality improvement.

Haptic feedback is one of the important ways to sense surrounding environment. In terms of grasping objects, the haptic feedback assists in improving accuracy and assists man to recognize the shape of object. Thus, restoring haptic feedback of amputee is very meaningful and challengeable. In this paper we present a self-developed transcutaneous electrical nerve stimulator which can stimulate neuromuscular by different waveform, frequency and voltage to generate haptic feedback for the amputee. The stimulator with multiple independent channels can generate up to 8 waveforms per electrode channel and can communicate any device by Bluetooth 4.0 using our custom communication protocol to improve the stimulator reliability. In order to choose the optimal stimulus waveform, frequency, current and location, the PC software have been designed to control the transcutaneous electrical nerve stimulator. We test the transcutaneous electrical nerve stimulator in human test. By questionnaire, pretest results showed that different stimulus location can evoke different figure movements, different stimulus waveforms can evoke different haptic sensation and the human have a same sense when stimulating in the same waveform.

In the teleoperation of lunar surface sampling, a four axis robotic arm is adopted to collect lunar soils and transfer them to the sealed pot. Due to the flexibility of slender sampling arm and interval error of the joint, it is difficult to control the end-effector aligned with the mouth of the sealed pot without any feedback. In order to handle this problem, this paper proposes a method to calculate the position and normal orientation of sealed pot with respect to end-effector by using the elliptic features obtained from the monocular vision camera, based on which the angle of each arm joint is to be solved. Due to the rotational symmetry of round sealed pot, it is difficult to determine the rotations of the normal of the sealed pot. Nevertheless, considering special configuration constraints of the robotic arm, we can ignore the influence of undetermined rotation and solve the four joint angles uniquely. Thus, error of joint angles could be corrected and an effective control is exerted to the arm to guide the end effector gradually approaching the sealed pot. Finally, the effectiveness of the method is verified by experiments.

Purpose – Picking up pistons in arbitrary poses is an important step on car engine assembly line. The authors usually use vision system to estimate the pose of the pistons and then guide a stable grasp. However, a piston in some poses, e.g. the mouth of the piston faces forward, is hardly to be directly grasped by the gripper. Thus, we need to reorient the piston to achieve a desired pose, i.e. let its mouth face upward, for grasping. Design/methodology/approach – This paper aims to present a vision-based picking system that can grasp pistons in arbitrary poses. The whole picking process is divided into two stages. At localization stage, a hierarchical approach is proposed to estimate the piston’s pose from image which usually involves both heavy noise and edge distortions. At grasping stage, multi-step robotic manipulations are designed to enable the piston to follow a nominal trajectory to reach to the minimum of the distance between the piston’s center and the support plane. That is, under the design input, the piston would be pushed to achieve a desired orientation. Findings – A target piston in arbitrary poses would be picked from the conveyor belt by the gripper with the proposed method. Practical implications – The designed robotic bin-picking system using vision is an advantage in terms of flexibility in automobile manufacturing industry. Originality/value – The authors develop a methodology that uses a pneumatic gripper and 2D vision information for picking up multiple pistons in arbitrary poses. The rough pose of the parts are detected based on a hierarchical approach for detection of multiple ellipses in the environment that usually involve edge distortions. The pose uncertainties of the piston are eliminated by multi-step robotic manipulations.

Dynamic performance is one of the most critical factors in many MEMS products, such as micro accelerometers, vibratory gyroscopes, micro deformable mirror, etc. Essentially, the dynamic behavior is totally determined by two factors: the internal factor, the stiffness of structure and the external factor, the damping of environment. In this paper both factors are analyzed accurately and a theoretical dynamic model of parallel-plate actuators is presented. The stiffness of the structure, i.e. the spring constant k of the suspension beam that supports the moving plate of the actuator, is achieved by many accurate experimental tests. The damping of environment, referring to the squeeze film damping coefficient c in parallel-plate actuators, is analyzed by calculation and FEA simulation. Further, we consider c a linear function of the actuator displacement, but not a constant value. This treatment greatly improves the accuracy of the dynamic model and could be applied in parallel-plate actuators with large displacement. Dynamic behaviors of the actuators under squeeze film damping, such as natural frequency, response time and bandwidth, are predicted based on the model. Three kinds of parallel-plate actuators are designed and fabricated using a surface micromachining process to verify the estimation of the presented theoretical model and experimental test results have showed good consistency with the theoretical analysis. The dynamic model proposed in this paper could be broadly applied in the MEMS/NEMS systems.

Deficiencies of current condition assessment method were described and next generation of Dynamic Condition Vector (DCV) assessment method was introduced at first. Typical structure and common operation of combination and expansion of DCV was illustrated by models and examples. Novel and necessary conception of dynamic element, dynamic operator and quasi-matrix operator was introduced with typical structural examples. Several prototypes of DCV for transformer, circuit-breaker, isolator, transmission line and cable were given. Finally, DCV assessment application in overall process was demonstrated. Overall process barrier was analyzed. Comparisons in assessment mathematical procedure and boundary condition limitation between current assessment method and DCV assessment method were made.

In order to improve the linkage of related auxiliary systems in intelligent substation and realize the complete monitoring and control functions of the equipment in the station, this paper integrates the technologies of Internet of Things, edge computing and big data to establish an auxiliary system of IoT intelligent substation. The overall structure of the system is introduced in detail. The effective calculation and reduction of the computing task of a single edge node is achieved by the application function and the edge calculation algorithm of task balancing allocation and scheduling, effectively improving the immediacy and security of the intelligent substation auxiliary system of the Internet of Things. The construction of transportation inspection has certain guiding significance.

China’s power grid is developing in the direction of informatization and increasingly large-scale at present. In view of the problems of optical cable interference and poor data security in the existing power grid detection system, a grid detection system based on wireless local area network (WLAN) and improved advanced encryption standard (AES) is proposed. Firstly, wireless local area network technology is introduced on the basis of the original power grid detection system to realize wireless transmission of power data. Then the newly-proposed system improves the S-BOX in the traditional AES encryption algorithm to improve the security of the algorithm. The improved AES encryption algorithm is applied to the grid detection system to realize the secure transmission of power data. Finally, the practical value of the grid detection system is verified by simulation.

Scientific investigation using the lunar rover is based on its position. Positioning the lunar rover is a key capability. This study presents a positioning method based on computer vision. The scale-invariant feature transform (SIFT) algorithm, correlation coefficient matching algorithm, least squares matching algorithm and bundle adjustment model are used together to navigate and position the rover between adjacent lunar stations. A stereoscopic navigation system was constructed in the laboratory, and used to test the feasibility and accuracy of the method. The results validated the relative accuracy of visual orientation to better than 4%. The algorithm was successfully applied to the positioning of the "Jade Rabbit" lunar rover.

Calcite with laminate structure was successfully prepared by culturing Synechocystis sp. PCC6803 with different concentrations of calcium chloride (CaCl₂) in BG11 media. S. PCC6803 was examined by scanning electron microscopy (SEM), transmission electron microscopy (TEM), laser confocal scanning microscope (LCSM) and energy dispersive spectroscopy (EDS). The effects of Ca²⁺ concentrations and pH values on calcification were investigated and the micro morphs of the CaCO₃ crystals were observed by means of SEM. These results showed that CaCO₃ crystals could be more easily formed with increasing the concentration of CaCl₂ in S. PCC6803 culture solution. S. PCC6803 could largely bind calcium ions, most of which were present in extracellular polymeric substances and on the cell wall. Inside the cells there were a lot of circular areas rich in calcium ions without the crystallization of calcium. Some cells produced a thicker gelatinous sheath outside of the translucent organic thin layer. And the cells inside also produced major changes that the original chloroplasts were almost transformed into starch grains whose sizes were from 0.5 to 1 μm with relatively uniform in sizes. At the same time the cell sizes significantly reduced to only about 8-9 μm almost changing to half of its original diameters. The calcite crystals with a highly preferred orientation induced by S. PCC6803 were observed with X-ray diffraction (XRD). A critical implication was that S. PCC6803 could induce bio-calcification and then mediate the further growth of CaCO₃ crystals in the biological system.

A microelectromechanical systems (MEMS) micromirror is demonstrated in this paper. The micromirror is actuated by an electrostatic force and can achieve a large out of plane stroke by eliminating the electrostatic pull-in effect. The micromirror consists of a mirror of 400 mu m by 400 mu m in the center, a spring and three fixed bottom electrodes each side. Design principles and the analytical model are both developed, and they are verified by finite element analysis (FEA). The resonant frequency for the piston movement of the designed micromirror is about 2.5 kHz by FEA simulation. The micromirror prototype has been fabricated by a surface micromachining process and it is successfully tested using a microsystem analyzer. An out of plane stroke of 1.65 mu m is observed at 100 V and it agrees well with the predicted result from analytical model. (c) 2010 Elsevier B.V. All rights reserved.

A structured lens with a large numerical aperture for high diffraction efficiency is proposed. This structured lens is formed by varying high-refractive-index-dielectric (HRID) square holes in a metallic film. Compared with previous structured lenses formed by varying air square holes, the modulated wavefront at the exit pupil of the structured lens is smoother and the diffraction efficiency is greatly improved. A dielectric film was introduced as a buffer layer to reduce the energy loss at the interface caused by the great impedance mismatching between air and the high refractive index dielectric. A lens with an aperture of 100 µm and a focal length of 50 µm was designed; its diffraction efficiency has been raised from 22.8% to 47.2% by the finite difference and time domain (FDTD) algorithm. This structured lens has the advantages of not only light weight and high compactness, but also large numerical aperture, high diffraction efficiency, and good imaging quality.

Under solid oxide fuel cells (SOFCs) operating atmosphere, volatile Cr species are generated over the chromia scale of chromia-forming alloy interconnects, poisoning the cathodes and causing the rapid degradation of the fuel cell performance. In this study, the influence of the cathode composition and A-site deficiency of Perovskite ABO3 cathodes on their tolerance to Cr poisoning was investigated in detail through the electrochemical polarization and electrochemical impedance spectroscopy (EIS) analysis. Results showed that 5 mol% La-site deficient cathodes, La0.75Sr0.2BO3−δ (B = Mn, Fe), presented a good performance in resistance to Cr poisoning and electrocatalytic activity to oxygen reduction reaction in the presence of alloy interconnects under a constant current density of 0.2 A cm−2 in oxygen at 1073 K. B-site atom of Perovskite ABO3 cathodes has a strong influence on the mechanism of Cr deposition and cathodes performance, while proper A-site deficiency can greatly improve the cathodes electrochemical performance and slow down Cr deposition.

Massive ferrous sulfate with excess sulfuric acid is produced in titanium dioxide industry each year, ending up stockpiled or in landfills as solid waste, which is hazardous to environment and in urgent demand to be recycled. In this study, waste ferrous sulfate was used as a second raw material to synthesize nano α-Fe2O3 red pigment powders with a bacteria-assisted oxidation process by Acidithiobacillus ferrooxidans. The synthesis route, mainly consisting of bio-oxidation, precipitation and calcination, was investigated by means of titration, thermogravimetric analysis (TGA), X-ray diffraction (XRD), scanning electron microscope (SEM) and X-ray fluorescence (XRF) to obtain optimum conditions. Under the optimum conditions, nano α-Fe2O3 red pigment powders contained 98.24wt.% of Fe2O3 were successfully prepared, with a morphology of spheroidal and particle size ranged from 22nm to 86nm and averaged at 45nm. Moreover, the resulting product fulfilled ISO 1248-2006, the standards of iron oxide pigments.

This paper shows a novel method to extract hand Representative Point (RP) based on 2-dimensional laser range scanner for hand motion estimation on projecting system. Image-projecting Desktop Arm Trainer (IDAT) is a projecting system for hand-eye coordination training, in which a projector displays an exercise screen on the desktop, and a laser range scanner detects trainee's hand motion. To realize multi-user HMI and expand more entertainment functions in IDAT system, an Air Hockey application was developed in which the hand RP requires a high precision. To generate hand RP precisely, we proposed our method in two parts to solve the data error problem and changeable hand contour problem. In part one, a data modifier is proposed and a sub-experiment is carried out to establish a modifying function for correcting sensor original data. In part two, we proposed three RP algorithms and carried out an evaluation experiment to estimate the reliability of three algorithms under different conditions. From the result, we get the most reliable algorithm corresponding to different situations in which the error of hand RP is less than 9.6 mm.

We examine the feasibility of human identification using purely the ubiquitous visible light. Empowered by the Visible Light Communication (VLC), the identification system consists of VLC-enabled LED lights on the ceiling emitting light beacons, and photodiodes on the floor capturing a continuous stream of shadow maps each corresponding to an LED light. We leverage these shadow maps to localize a user's key boy joints in the 3D space and recognize the user based on the estimated body parameters (e.g., shoulder width, arm length). Preliminary results with 10 participants show 80\% success rate, i.e., correctly identifying 8 participants out of 10. The mean error of the body parameter estimation is 0.03 m. To extend the system to diverse practical settings, we discuss the our plan of incorporating advanced behavioral features to enhance the identification accuracy and robustness.

We present LiSense, the first-of-its-kind system that enables both data communication and fine-grained, real-time human skeleton reconstruction using Visible Light Communication (VLC). LiSense uses shadows created by the human body from blocked light and reconstructs 3D human skeleton postures in real time. We overcome two key challenges to realize shadow-based human sensing. First, multiple lights on the ceiling lead to diminished and complex shadow patterns on the floor. We design light beacons enabled by VLC to separate light rays from different light sources and recover the shadow pattern cast by each individual light. Second, we design an efficient inference algorithm to reconstruct user postures using 2D shadow information with a limited resolution collected by photodiodes embedded in the floor. We build a 3 m x 3 m LiSense testbed using off-the-shelf LEDs and photodiodes. Experiments show that LiSense reconstructs the 3D user skeleton at 60 Hz in real time with 10 degrees mean angular error for five body joints.

The structure aberrations of color separating grating (CSG), which is caused by the fabrication process, generate great modulations to the laser beam when CSG is used in the final optical system of a high power laser system. The beam modulations may lead to severe optical damages to CSG itself and the system. In this paper, a comprehensive fabrication error model for CSG is developed to study the beam modulation characteristics in the near field. Through theoretical calculations and simulations, the near field diffraction pattern of CSG is obtained, and the relationship between beam modulations and CSG structural aberrations is presented. The results show that beam modulations are mainly caused by the stair depth error and the slope error. This study provides a convenient way to estimate the possibility of optical damages induced by CSG.

A novel method is proposed to fabricate refractive micro lens array using dichromate gelatin (DCG) and an enzyme. DCG has optical properties similar to glass but is sensitive to UV light. The enzyme solution is used to develop the optically exposed DCG instead of a conventional water-isopropanol developer, which greatly enhances the surface relief depth. The continuous surface relief structure is realized by a coded grey-tone mask. A computer program has been developed to code an arbitrary 3D surface relief shape into a grey-tone mask design. The DCG properties and the lithography process are described. The grey-tone coding principle is presented. Unlike the current processes where patterned photoresist relief structure has to be transferred to a substrate material, the fabricated DCG micro lens array can be directly used as an optical element. The new process opens a new route of micro lens fabrication, which is simple and low cost. (C) 2001 Elsevier Science BY All rights reserved.

The major safety problem of in-service welding municipal gas pipelines is burn-through and hydrogen induced cracking. In this paper, a numerical model to analyze the thermodynamic characteristics (temperature field and allowable stress)during the welding process at different working conditions is established.. This model is then applied to a testing case: the leakage section of the Harbin-Yilan long distance transmission pipelines. In this case, the impact of working parameters during the welding process (pipe-wall casing thickness, welding energy input and velocity of the flow medium) on the temperature field and allowable stress is analyzed. The optimal working parameters to avoid burn through and hydrogen induced cracking are also derived. The testing case shows that the model developed in this paper is useful in providing technical support for online welding process, and therefore can be applied widely in practice.

Background: Several clinical trials have reported inconsistent findings for the effects of rosuvastatin (RSV) and atorvastatin (ATV) on renal function. The aim of this meta-analysis was to investigate the effects of these 2 statins on glomerular filtration rate (GFR) and proteinuria respectively, and determine which is better. Methods and Results: PubMed, CENTRAL, Web of Knowledge, and ClinicalTrials.gov website were searched for randomized controlled trials. Eligible studies reported GFR and/or proteinuria during treatment with RSV or ATV compared with control (placebo, no statins, or usual care), or RSV compared with ATV head to head. Trials that enrolled dialysis participants and teenagers were excluded. Statistical heterogeneity was assessed using the I2 statistic, and pooled results using the random-effects model. The standardized mean differences (SMD) and ratio of means (ROM) were measured, respectively, to analyze GFR and proteinuria. Sixteen trials with a total number of 24,278 participants were identified. Compared with control, changes in the SMD of GFR were 0.04 (95% confidence interval [CI]: 0.01-0.07) and 0.59 (95%CI: 0.12-1.06) for RSV and ATV, respectively. The ROMs of proteinuria were 0.59 (95%CI: 0.46-0.74) for RSV vs. the control group, and 1.23 (95%CI: 1.05-1.43) in the head-to-head comparison. Conclusions: Both RSV and ATV improve GFR, and ATV seems to be more effective in reducing proteinuria. The validity and clinical significance require high-quality intensive studies with composite clinic endpoints of kidney and death. (Circ J 2012; 76: 1259-1266)

The structure combining the microlens and DOE is not sensitive to the incident beam and can control the overall shape profile flexibly. So that the structure called DOE array is designed in this paper in order to shape the unstable laser beam to the four polar uniformity distribution. The paper gives the principle of the DOE array and the design process. The array element determines the profile of the output beam. It is designed using the G-S algorithm and the Adaptive Addition algorithm (A-A). The number of the DOEs is optimized and analyzed. The simulative diffraction efficiencies are 89% and non-uniformities are less than 3% when the incident beams are Gaussian, supper-Gaussian, paraboloid and random distributions. In experiment, diffraction efficiency of 77% and maximum non-uniformity of 5.6% are got on the condition of the different input laser beam. So the effect on the instability of the incident beam could be decreased.

Micro lens array (MLA) is the critical element for Shack-Hartmann wave front sensor. But conventional MLA based on diffractive optics shows strong chromatic aberration, which cause the MLA only works for narrow band. The broad band MLA requires continuous profile, which can not be fabricated using binary optics fabrication technique. In this presentation, we present the fabrication for continuous aspheric MLA by employing gray scale mask with one-step moving photolithography and one-step etching process. The fabricated MLA exhibits small surface roughness (rms < 5 nm), high uniformity of focal length (< 0.6%), nearly 100% filling factor and good focal spots quality approaching diffraction limit. The working wavelength shows wide band (0.45 ~ 0.7 mum), promising the MLA can be successfully employed in Shack-Hartmann systems with white light or multiple laser wavelengths.

Brillouin distributed optical fiber sensing system based on spontaneous Brillouin scattering frequency shift measurement may measure temperature in the optical fiber, due to the dependence of spontaneous Brillouin scattering frequency shift on temperature. In this paper, nonlinear theoretical models of the Brillouin spectrum in the BOTDR temperature sensing system are analyzed. The model parameters are optimized with Levenberg-Marquardt algorithm. By numerical calculation, it is indicated that pseudo-Voigt function can approach approximated the Voigt profile well and quickly.

The recent development of radio frequency (RF) microelectromechanical system (MEMS) technology has demonstrated great potential at the communication applications. The capacitors with tunable characteristics are now greatly required. Various structure designs of tunable capacitors have been reported, such as two or three parallel plates with a vertical electrostatic actuator showing a restricted tuning range due to the pull-in effect [1], comb-driven variable capacitors which can achieve a large tuning ratio but are poor at high insertion loss and controlling voltages and low Q-factor [2], and thermal-driven capacitors [3] having a disadvantage that their response speed is generally slower than that of electrostatic actuators. In this paper, we present two designs of MEMS electrostatically tunable capacitor; only one structural layer and one sacrificial layer are required. In Fig. 1, seven cantilever beams with constant length of 240μm, width of 60μm, thickness of 2μm are constructed as top electrodes on a coplanar waveguide transmission line. The separation between adjacent cantilevers is 600μm. The separated bottom electrodes, which are insulated by Si3 N4 of 150nm, are 100μm length and 60μm width. The bottom electrodes and CPW transmission line are isolated by Si3 N4 of 50nm, and the air gap is 2μm. The top electrodes can be driven individually by the separated bottom electrodes. Fig. 2 illustrates the second design has the varied cantilever width that changes from 60μm to 120μm. The length of bottom electrode that is directly treated as CPW transmission line is 4230μm and the width is 100μm; other structural parameters are the same as those of the first design. When an electrical potential is applied between the top and bottom electrodes of both designs, an attractive force is generated to pull the top cantilevers down, thus a variable capacitor is formed. The capacitor C is related to the overlap area A, the spacing d0 -d between the top and bottom electrodes. d0 is the initial gap and d is the displacement of the top electrode. C = eAd0 − d (1) The mechanical and RF performances of these two designs have been analyzed by FEA method. For the first design, when all beams are applied equal controlling voltages, the relationship between the capacitance in total and voltages is shown in Fig. 3 (a). When the voltage is 48V, the capacitance is 239.2fF but the tuning ratio is just about 1.2. Fig. 3 (b) shows the RF characteristic obtained by using HFSS when one, two, four or none of top electrodes are applied controlling voltage for a displacement of 0.6μm. The S-parameters vs. Frequency curves demonstrate that such design has a wide tunable frequency range from 0.1GHz to 70GHz, and the return loss can reach as large as −35dB at the self-resonating frequency of 15GHz and more than −20dB under 40GHz. In practical, it can be used as a distributed phase shifter. For the second design, the capacitor vs. voltage curve is shown in Fig. 4 (a). When a voltage of 48V is applied, the tuning ratio is very close to that of the first design. The main reason is that, when applied the same voltage, the displacements of cantilever beams with varied width are independent of the width and approximately have the same magnitudes. In Fig. 4 (b), S-parameter analyses have shown a wide narrow frequency range and large return loss compared to the first design when no voltage is applied.Copyright © 2008 by ASME

We present the lithography scheme that use high-numerical-aperture photon sieves array as focusing elements in a scanning X-ray maskless nanolithography system. The system operating at wavelength of 0.5~2nm synchrotron light sources radiated, each of a large array of photon sieves focuses incident X-ray into a diffraction-limited on-axis nanoscale spot on the substrate coated photoresist. The X-ray intensity of each spot is modulated by means of a spatial light modulator. Patterns of arbitrary geometry are exposed and written in a dot matrix fashion while the substrate on a stepping stage is precisely driven in two dimensions according to the computer program. The characteristics of synchrotron radiation light, resolution limits and depth of focus of the lithographic system are discussed. The design and fabrication of photon sieve are illustrated with a low-numerical-aperture amplitude-photon sieve fabricated on a chrome-coated quarts plate by means of laser-beam lithographic process, which minimum size of pinhole was 5.6um. The focusing performance of the photon sieve operating at wavelength of 632.8nm was simulated and tested.

An axicon is an optical element with rotational symmetry and cone shape, which is nowadays widely used in many fields of engineering, like laser beam shaping, imaging systems, optical testing, laser machining, etc. In this paper, we propose a new method to measure the cone angle and the shape of the axicon simultaneously by using a computer-generated hologram. This test is performed in a null-test configuration.

A maskless lithography imaging simulation using digital micromirror device (DMD) was investigated. The DMD acts as a reflective spatial light modulator. The micro-mirrors on DMD can be instructed by the computer to tilt them ±12° off their normal position which produces a mask pattern, and then the mask pattern can be carried onto the surface of wafer by the imaging system. Because the imaging of the maskless lithography is a complex process, it is necessary to simulate and analyze its practical process. In this paper, we present a partial coherent imaging model of maskless lithography considering the practical projection characterization of DMD. With the model, it is convenient to simulate the lithography of arbitrarily shaped microstructure using DMD. Through calculation, the spatial image in maskless lithography process based on gray scale photolithography with DMD real-time masks was obtained.

In order to form the proper aspherical microlens array profile with larger NA on photosensitive materials, a method is developed based on the characteristics of resist and processing parameters during development, for designing the exposure distribution, an experience formula has been proposed in the paper. Using the moving mask method, the exposure energy distribution function related to the photolithographic mask function can be determined by the experience formula. The profile control procedure is formed especially for the deeper relief profiles, after the binary mask data are slightly modified, the micro-structure with aspherical lens profile can be fabricated on the selected thicker resist, the micro relief profile error can be controlled in a certain range. The micro-profile is farther transferred to fused silica by ICP etching system. By our method, the fast microlens array elements with good fidelity and reasonable roughness have been fabricated and applied to the laser diode collimating system.

A new method for microlens profile design was developed based on the analysis to the main parameters of microlens array, including micro profile formation, the numerical aperture ( NA ), the maximum sag depth for the refractive lens and the minimum zones width for the diffractive lens. With the relationships among the parameters, the microlens array in different profile can be determined effectively. The moving mask method[1] is used to realize the required profiles, an unique photolithography system have been built for implementing the mask moving exposure in both X and Y directions for the creation of microlens array. By modifying the binary moving mask, optimizing the photosensitive materials and the processing technique, the microlens profile error can be controlled in the range of 0.4µm~3µm depending on effective reliefdepth of the microlens. In our method, both diffractive and refractive microlens array with larger NA and higher fill factor can be fabricated for satisfying a plenty of purposes.

The mysteries of near-Earth asteroid 4179 Toutatis have been more comprehensively unveiled by analyzing the optical images taken during the Chang'e-2 flyby in 2012. Compared with previous works, this paper concentrates on the photogrammetric relation between the Chang'e-2 spacecraft and Toutatis and the imaging shadow effect during the flyby. Accurate models of imaging and optical measurements are developed to study Toutatis's dimensions and rotational state at the time of imaging. As the illumination study shows, the shadowed region perpendicular to the long axis accounts for 27.78% of the Toutatis images, while the long axis of the body is fully captured. With a compensation on the shadow effect, the optical measurements reveal that Toutatis's long axis is 4354 ± 56 m, the maximum length is 4391 ± 56 m, and the spatial orientation described with the angles of direction cosine during the flyby is (12613 ± 029, 12298 ± 021, 12663 ± 046). Furthermore, a new triaxial ellipsoid of 4354 × 1835 × 2216 m and a volume of 7.5158 km3 are proposed based on the previous Toutatis shape model. The effectiveness of the proposed method is validated, since typical features such as the neck and endpoints agree well with the results simultaneously observed by the ground radar. Moreover, it also potentially provides a feasible approach to precisely calculate the spin period of Toutatis.

Performances of diffractive and refractive microlens array have been studied and compared. Besides the diffractive microlens array which can be fabricated by means of the microfabrication technologies, method for manufacturing continuous profile refractive microlens array with larger sag depth has been developed for solving the unique problems like diode laser alignment. Both diffractive and refractive microlens array with different numerical aperture and other parameters are fabricated according to the application requirements, experimental results are given.

The dynamic characteristic of transient secondary air system has the significance to ensure the airworthiness safety. This paper provides the component method to solve the secondary air system through the analysis between the component method and network method. And we carries out calculations for both steady and transient state problems by using the component method and network method toward series and parallel networks. The results agree well. Then,we couple the secondary air system with the main-flow components by component method to simulate the whole basin of aircraft engine. Finally, we analyze the change of performance and safety among the performance model, the whole engine model and the whole engine model which consider the cavity effect. Through the analysis of the results, we can predict that the whole engine model will provide help for the dynamic analysis of the secondary air system when the method develops maturely.