A5101939731- Advanced MRI Techniques and Applications
- Numerical methods in inverse problems
- Superconducting Materials and Applications
- Atomic and Subatomic Physics Research
- Remote Sensing and Land Use
- NMR spectroscopy and applications
- Synthesis and properties of polymers
- High-Velocity Impact and Material Behavior
- Supercapacitor Materials and Fabrication
- Advanced NMR Techniques and Applications
- Environmental Changes in China
- Aluminum Alloys Composites Properties
- Wireless Power Transfer Systems
- Non-Destructive Testing Techniques
- Numerical methods in engineering
- Photonic and Optical Devices
- Microstructure and mechanical properties
- Adaptive optics and wavefront sensing
- Electromagnetic Simulation and Numerical Methods
- Corrosion Behavior and Inhibition
- Optical Systems and Laser Technology
- Climate change and permafrost
- Electromagnetic Fields and Biological Effects
- Silicone and Siloxane Chemistry
- Remote-Sensing Image Classification
Chinese Academy of Sciences
1998-2023
Institute of Optics and Electronics, Chinese Academy of Sciences
2022-2023
Institute of Electrical Engineering
2015-2017
University of Chinese Academy of Sciences
2016-2017
State Key Laboratory of Remote Sensing Science
2002-2004
Polyimide membranes have excellent physiochemical properties which make them valuable materials for optical area. However, common aromatic polyimide membrane trend to show low transmittance in visible region because of the charge-transfer complex (CTC) molecular structures. Moreover, it's trending high moisture uptakes hydrophilic imide rings structure. In this work, a composite with SiO2 antireflective on both sides was prepared. High (93% within 500~800 nm) and surface hydrophobicity...
A traditional tip-tilt mirror control system with an image loop is used to effectively reject structural vibrations in optical telescopes. However, its bandwidth restricted by low sampling rate and large time delay of imaging sensors, which insufficient suppress disturbances outside the bandwidth, even large-amplitude within bandwidth. This paper proposed a disturbance feedforward method base on fusion inertial gyro sensor solve this problem. Accurate measurement premise feedforward. Thus we...
A novel active shimming method is proposed for the correction of magnetic field nonuniformity superconducting (SC) magnet resonance imaging. Active utilizes several coils to correct specific harmonic components appear in inhomogeneous field, and each coil usually designed independently others, also takes no account presence main blocks. However, coupling among these SC shim exists, interaction between those zonal even-order are particularly significant. This coupling/interaction can lead...
In this paper, a set of novel whole-body gradient coils is designed for cylindrical magnetic resonance imaging (MRI) systems. For the sake high coil efficiency, design scheme focuses on volume occupied by patient, discounting large space under patient bed that unused during imaging. To further improve performance, are an unconventional, hybrid cylindrical-planar structure, where primary arranged chord-truncated former while shielding remain assemblies. new configuration, layers make best...
Abstract In Magnetic Resonance Imaging ( MRI ) equipment, a set of shim coils are designed to generate specific magnetic fields, thus eliminating harmonic components field obtain high level homogeneous within the region interesting ROI ). electromagnetic design process, in order produce desired field, deviation between calculated coil and theoretical is treated as kind traditional objective functions optimize distribution current density on surface skeleton. However, such function ill‐posed...
A novel method is proposed for the simulation study design of gradient coils in a magnetic resonance imaging (MRI) system which generate linear field gradients only region above patient's bed. In MRI, are usually designed to create linear-varying fields that typically described as diameter spherical volume (DSV). practice, space under bed not used imaging, but still treated part target conventional approaches. This work proposes new scheme DSV considered. study, coil patterns have been...
This paper proposes a numerical method with an inverse boundary element (IBEM) to design set of shim coils for open bipanar superconducting magnetic resonance imaging (MRI) system. For the traditional cylindrical MRI system, claustrophobics will suffer palpitations and anxiety attacks when they are enclosed in small area during scanning process. However, such structure provides room temperature bore, thus improving patients’ comfort. Based on IBEM, coil skeleton needs be divided into some...
Magnetic resonance imaging (MRI) has become one of the most powerful tools in modern medical diagnosis and interventional therapy. It can achieve very fast scanning due to synchronization time space under high field with homogeneity. High stability improve ratio signal noise resolution. an important diagnostic tool early stages cancer, evaluation efficacy treatment high-risk surgery, neuroscience, molecular imaging. On other hand, recent years, development openness magnets combine MRI...
In this paper, we present a novel nonlinear optimization algorithm for designing shim coil system, especially high-order axial coil, magnetic resonance imaging（MRI) system. an MRI equipment, in order to eliminate higher-order harmonic components of the field within volume interest（VOI), passive shimming（PS) is adopted traditional methods. However, such method suitable global shimming with low accuracy and poor target. Active shimming（AS) makes up shortcomings from PS set coils which are...
Abstract SiO 2 film coatings were used to modify the surface of metal mesh for corrosion protection using liquid phase deposition and sol‐gel methods at low temperature. Different techniques applied characterized as‐prepared samples. The results show an enhanced deposited samples in comparison unmodified samples, as well sample prepared with sol gel method provides better when compared phased sample, which mainly contributes its compact morphology. hydrophobic also exhibit excellent...
Passive shimming optimizations usually contain constrain condition about the maximum number of shim-piece on position where shim-pieces may be placed at, but papers do not involve how to set shim-piece. In traditional optimization method, is into a same constant. But, in this paper, determined according its and requirement magnetic field uniformity. By comparison these two methods, method can obtain better result which has smaller error with accurate calculation The numerical simulation open...
The research has been done to derive the soil moisture information at local scale by using single polarization, frequency sensors such as ERS-1/2, Radarsat, and JERS-1. There is a need develop technique estimate from these currently available data sources both regional scales. In this study, change detection algorithm was developed for multi-temporal 50m resolution Radarsat SCANSAR image data. It based on theory model analysis results, with correction of vegetation incident angle effects....
The Yellow River delta of China is the youngest land in formed by deposition sands along River. expends 40,000 ha every year into sea. second largest oilfield "Shenli Oilfield" and national wetland natural conservancy are located area. And over 100 saline land, which hampers agricultural development, area needs treatment makes use it. Nowadays one rapidly changing places China. Chinese government has listed development as first priority project "China's 21/sup st/ Century Agenda". Thus, this...
This paper proposes an efficient design method for designing MRI gradient coils on a cylindrical surface geometry, using inverse boundary element (IBEM). Based the approximate current density over whole space, magnetic field distribution can be obtained in discrete form. An objective function is found to evaluate minimum error between actual that generate and desired field. Finally, transformed winding pattern of gradients via relationship stream function. used arbitrary shapes. The examples...
An efficient design method of shim coils for an open bipanar superconducting magnetic resonance imaging (MRI) system is proposed, using inverse boundary element (IBEM). This first discretizes the coil space into some small flat triangular elements. By formulating magnetization distribution by discrete current density, objective function constructed to evaluate minimum error between axial field and desired field. In particular, self-induction added which used adjust deviation from ideal...
In this study, a lightweight composite polyimide film optic with antireflective coating was prepared using an ion-beam-assisted reactive sputtering method. It exhibited high transmittance in visible (87%, 0.5~0.8 μm), short (86%, 1.8~2.7 μm) and middle (78%, 3.3~5.4 wavelength infrared regions. Additionally, it also showed great optical homogeneity (0.006 λ RMS 0.034 PV, = 632.8 nm) smooth surfaces (RMS 0.786 nm). The thermal stability of the effectively maintained after coating. At same...
This paper analyzes the long sequence time series NDVI datasets and yields statistic results respectively, using simple differencing, slope map of biomass, principle component analysis techniques. The correlation characteristics for images change acquired according to algorithms mentioned above, implies that majority pixels different land covers have experienced nearly same changes in direction magnitude. biomass land-cover classifications between 1980s present are detected from satellite...