Laterally Electrostatically Driven Poly 3C-SiC Folded-Beam Resonant Microstructures

Micromachined comb-drive electrostatic resonators with folded-cantilever beams were designed and fabricated. A combination of Rayleigh＇s method and finite-element analysis was used to calculate the resonant frequency drift as we adjusted the device geometry and material parameters. Three micromachined lateral resonant resonators with different beam widths were fabricated. Their resonant frequencies were experimentally measured to be 64.5,147.2, and 255.5kHz, respectively, which are in good agreement with the simulated resonant frequency. It is shown that an improved frequency performance could be obtained on the poly 3C-SiC based device structural material systems with high Young＇s modulus.

Pressure effect study on the Ⅰ-Ⅴ property of the GaAs-based resonant tunnelling structure by photoluminescence measurement

This paper discusses the I-V property of the GaAs-based resonant tunnelling structure （RTS） under external uniaxial pressure by photoluminescence studies. Compressive pressure parallel to the [110] direction, whose value is determined by Hooke＇s law, is imposed on the sample by a helix micrometer. With the increase of the applied external uniaxial compressive pressure, the blue shift and splitting of the luminescence peaks were observed, which have some influence on the I-V curve of RTS from the point of view of the energy gap, and the splitting became more apparent with applied pressure. Full width at half maximum broadening could also be observed.

Impact of resonant magnetic perturbation on blob motion and structure using a gas puff imaging diagnostic on the HL-2A tokamak

The impact of resonant magnetic perturbation(RMP)on blob motion and structure in the SOL of the HL-2A tokamak is studied using a gas puff imaging diagnostic.Ellipse fitting is applied to study the structure and motion of blobs quantitatively.The radial locations,amplitudes and scale sizes of blobs are obtained based on the fitted ellipse.Furthermore,based on the measurement of blob location,the radial and poloidal velocities of blobs are calculated.With the application of RMP,the edge poloidal shear flow is significantly weakened and the wave number spectrum changes from quasisymmetric to significantly up-down asymmetric.The application of RMP also causes the detected blob location to be much further into the far scrape-off layer(SOL)and increases the blob amplitude.Blob poloidal velocity in the SOL is slowed.Larger-size and longer-lifetime blobs are observed with RMP.With the application of RMP,stronger-amplitude and larger-size blobs are detected in the far SOL and they may cause a more serious erosion problem to the first wall.

The Semi-Microscopic Description of the Gross Resonant Structure of ^(16)O+^(16)O system

Within the framework of nuclear molecular orbital model,the semi-micro-scopic description of the gross resonant structure of 16O+16O system is given.The pre-sent result is comparable to other theoretical results which are in agreement with the ex-isting experimental data.

Structure and immunomodulatory activity of Lentinus edodes polysaccharides modified by probiotic fermentation

Plant-based fermentations provide an untapped source for novel biotechnological applications.In this study,a probiotic named Lactobacillus fermentum 21828 was introduced to ferment Lentinus edodes.Polysaccharides were extracted from fermented and non-fermented L.edodes and purified via DEAE-52 and Sephadex G-100.The components designated F-LEP-2a and NF-LEP-2a were analyzed by FT-IR,HPGPC,HPAEC,SEM,GC-MS and NMR.The results revealed that probiotic fermentation increased the molecular weight from 1.16×10^(4) Da to 1.87×10^(4) Da and altered the proportions of glucose,galactose and mannose,in which glucose increased from 45.94%to 48.16%.Methylation analysis and NMR spectra indicated that F-LEP-2a and NF-LEP-2a had similar linkage patterns.Furthermore,their immunomodulatory activities were evaluated with immunosuppressive mice.NF-LEP and F-LEP improved immune organ indices,immunoglobulin(Ig G and Ig M)and cytokines concentrations;restored the antioxidation capacity of liver;and maintained the balance of gut microbiota.F-LEP displayed better moderating effects on the spleen index,immunoglobulin,cytokines and the diversity of gut microbiota than NF-LEP(200,400 mg/kg).Our study provides an efficient and environment-friendly way for the structural modification of polysaccharides,which helps to enhance their biological activity and promote their wide application in food,medicine and other fields.

Comparison of endoscopic ultrasound, computed tomography and magnetic resonance imaging in assessment of detailed structures of pancreatic cystic neoplasms

AIM To evaluate the advantages of endoscopic ultrasound(EUS) in the assessment of detailed structures of pancreatic cystic neoplasms(PCNs) compared to computed tomography(CT) and magnetic resonance imaging(MRI).METHODS All patients with indeterminate PCNs underwent CT, MRI, and EUS. The detailed information, including size, number, the presence of a papilla/nodule, the presence of a septum, and the morphology of the pancreatic duct of PCNs were compared among the three imaging modalities. The size of each PCN was determined using the largest diameter measured. A cyst consisting of several small cysts was referred to as a motherdaughter cyst. Disagreement among the three imaging modalities regarding the total number of mother cysts resulted in the assumption that the correct number was the one in which the majority of imaging modalities indicated.RESULTS A total of 52 females and 16 males were evaluated. The median size of the cysts was 42.5 mm by EUS, 42.0 mm by CT and 38.0 mm by MRI; there was no significant difference in size as assessed among the three imaging techniques. The diagnostic sensitivity and ability of EUS to classify PCNs were 98.5%(67/68) and 92.6%(63/68), respectively. These percentages were higher than those of CT(73.1%, P < 0.001; 17.1%, P < 0.001) and MRI(81.3%, P = 0.001; 20.3%, P < 0.001). EUS was also able to better assess the number of daughter cysts in mother cysts than CT(P = 0.003); however, there was no significant difference between EUS and MRI in assessing mother-daughter cysts(P = 0.254). The papilla/nodule detection rate by EUS was 35.3%(24/68), much higher than those by CT(5.8%, 3/52) and MRI(6.3%, 4/64). The detection rate of the septum by EUS was 60.3%(41/68), which was higher than those by CT(34.6%, 18/52) and by MRI(46.9%, 30/64); the difference between EUS and CT was significant(P = 0.02). The rate of visualizing the pancreatic duct using EUS was 100%, whereas using CT and MRI it was less than 10%.CONCLUSION EUS helps visualize the detailed structures of PCNs and has many advantages over CT and MRI. EUS is valuable in the diagnosis and assessment of PCNs.

Multifractal characteristics of shale and tight sandstone pore structures with nitrogen adsorption and nuclear magnetic resonance

Based on the experiments of nitrogen gas adsorption(N_2 GA) and nuclear magnetic resonance(NMR),the multifractal characteristics of pore structures in shale and tight s andstone from the Chang 7 member of Trias sic Yanchang Formation in Ordos Basin,NW China,are investigated.The multifractal spectra obtained from N2 GA and NMR are analyzed with pore throat structure parameters.The results show that the pore size distributions obtained from N2 GA and NMR are different,and the obtained multifractal characteristics vary from each other.The specific surface and total pore volume obtained by N2 GA experiment have correlations with multifractal characteristics.For the core samples with the similar specific surface,the value of the deviation of multifractal spectra Rd increases with the increase in the proportion of large pores.When the proportion of macropores is small,the Rd value will increase with the increase in specific surface.The multifractal characteristics of pore structures are influenced by specific surface area,average pore size and adsorption volume measured from N2 GA experiment.The multifractal characteristic parameters of tight sandstone measured from NMR spectra are larger than those of shale,which may be caused by the differences in pore size distribution and porosity of shale and tight sandstone.

Wave propagation control in periodic track structure through local resonance mechanism

Excessive vibration and noise radiation of the track structure can be caused by the operation of high speed trains.Though the track structure is characterized by obvious periodic properties and band gaps,the bandwidth is narrow and the elastic wave attenuation capability within the band gap is weak.In order to effectively control the vibration and noise of track structure,the local resonance mechanism is introduced to broaden the band gap and realize wave propagation control.The locally resonant units are attached periodically on the rail,forming a new locally resonant phononic crystal structure.Then the tuning of the elastic wave band gaps of track structure is discussed,and the formation mechanism of the band gap is explicated.The research results show that a new wide and adjustable locally resonant band gap is formed after the resonant units are introduced.The phenomenon of coupling and transition can be observed between the new locally resonant band gap and the original band gap of the periodic track structure with the band gap width reaching the maximum at the coupling position.The broader band gap can be applied for vibration and noise reduction in high speed railway track structure.

Revealing structure correlation between ionic liquid and metal-organic framework matrix

Solid-state batteries are rising rapidly in response to the fast-increasing energy demand.Metal-organic framework(MOF) loaded with ionic liquids has brought new opportunities for solid-state batteries owing to its good interfacial compatibility and high ionic conductivity. MOF-808 is selected to be filled with Li-contained ionic liquid for structure and ion dynamics investigation using nuclear magnetic resonance(NMR) and X-ray diffraction.This study finds that the introduced ionic liquid would partially soften the matrix of MOF-808 and thus yield amorphous phase. By selective isotope replacement under cycling symmetric ^(6)Li metal cell, Li^(+)ion is observed to mainly go cross ionic liquid in the open channel of matrix under potential polarization.

Characterization of Average Molecular Structure of Heavy Oil Fractions by ~1H Nuclear Magnetic Resonance and X-ray Diffraction

The chemical structure of heavy oil fractions obtained by liquid-solid adsorption chromatography was character-ized by 1 H nuclear magnetic resonance and X-ray diffraction.The molecular weight and molecular formula of asphaltene molecules were estimated by combining 1 H nuclear magnetic resonance and X-ray diffraction analyses,and were also ob-tained from vapor pressure osmometry and elemental analysis.Heteroatoms,such as S,N,and O atoms,were considered in the construction of average molecular structure of heavy oils.Two important structural parameters were proposed,including the number of alkyl chain substituents to aromatic rings and the number of total rings with heteroatoms.Ultimately,the av-erage molecular structures of polycyclic aromatics,heavy resins and asphaltene molecules were constructed.The number of α-,β-,γ-,and aromatic hydrogen atoms of the constructed average molecular structures fits well with the number of hydro-gen atoms derived from the experimental spectral data.

Molecular structure characterization of middle-high rank coal via^(13)C NMR,XPS,and FTIR spectroscopy

Elemental analysis,nuclear magnetic resonance carbon spectroscopy(^(13)C-NMR),X-ray photoelectron spectroscopy(XPS)and Fourier transform infrared spectroscopy(FTIR)experiments were carried out to determine the existence of aromatic structure,heteroatom structure and fat structure in coal.MS(materials studio)software was used to optimize and construct a 3D molecular structure model of coal.A method for establishing a coal molecular structure model was formed,which was“determination of key structures in coal,construction of planar molecular structure model,and optimization of three-dimensional molecular structure model”.The structural differences were compared and analyzed.The results show that with the increase of coal rank,the dehydrogenation of cycloalkanes in coal is continuously enhanced,and the content of heteroatoms in the aromatic ring decreases.The heteroatoms and branch chains in the coal are reduced,and the structure is more orderly and tight.The stability of the structure is determined by theπ-πinteraction between the aromatic rings in the nonbonding energy EN.Key Stretching Energy The size of EB determines how tight the structure is.The research results provide a method and reference for the study of the molecular structure of medium and high coal ranks.

Polarization-Insensitive Magnetic Quadrupole-Shaped and Electric Quadrupole-Shaped Fano Resonances Based on a Plasmonic Composite Structure

A combined structure with the unit cell consisting of four sub-units with 90° rotation in turn is designed. Each of sub-units is composed of two gold rods in transverse arrangement and one gold rod in longitudinal arrangement. Simulating electromagnetic responses of the structure, we verify that the structure exhibits the double Fano resonances, which originate from the coupling between magnetic quadrupoles and electric dipoles and the coupling between electric quadrupoles and electric dipoles. Simulation results also demonstrate that the structure is polarization-insensitive and shows an analogue of electromagnetically induced transparency at the two Fano resonances. Such a plasmonic structure has potential applications in photoelectric elements.

Dual-channel fiber-optic surface plasmon resonance sensor with cascaded coaxial dual-waveguide D-type structure and microsphere structure

To address the restriction of fiber-optic surface plasmon resonance(SPR) sensors in the field of multi-sample detection, a novel dual-channel fiber-optic SPR sensor based on the cascade of coaxial dual-waveguide D-type structure and microsphere structure is proposed in this paper. The fiber sidepolishing technique converts the coaxial dual-waveguide fiber into a D-type one, and the evanescent wave in the ring core leaks, generating a D-type sensing region;the fiber optic fused ball push technology converts the coaxial dual waveguides into microspheres, and the stimulated cladding mode evanescent wave leaks, producing the microsphere sensing region. By injecting light into the coaxial dual-waveguide middle core alone, the sensor can realize single-stage sensing in the microsphere sensing area;it can also realize dual-channel sensing in the D-type sensing area and microsphere sensing area by injecting light into the ring core. The refractive index measurement ranges for the two channels are 1.333–1.365 and 1.375–1.405, respectively, with detection sensitivities of 981.56 nm/RIU and 4138 nm/RIU. The sensor combines wavelength division multiplexing and space division multiplexing technologies, presenting a novel research concept for multi-channel fiber SPR sensors.

Mechanical Analysis and Measurements of a Multicomponent NbTi/Cu Superconducting Magnets Structure for the Fully Superconducting Electron Cyclotron Resonance Ion Source

A fully superconducting electron cyclotron resonance （ECR） ion source （SECRAL ID is currently being built in the Institute of Modern Physics, Chinese Academy of Sciences. Its key components are three superconducting solenoids （Nb-Ti/Cu） and six superconducting sextupoles （Nb-Ti/Cu）. Different from the conventional supercon- ducting ECR magnetic structure, the SEC17AL Ⅱ includes three superconducting solenoid coils＇ that are located inside the superconducting sextupoles. The SECRAL Ⅱ can significantly reduce the interaction forces between the sextupole and the solenoids, and the magnets can also be more compact in size. For this multi-component SECRAL Ⅱ generating its self field of -8 T and being often exposed to the high self field, the mechanical analysis has become the main issue to keep their stress at 〈200 MPa on coils. The analytical and experimental results in mechanics are presented in the SECRAL Ⅱ structure. To improve the accuracy and efficiency of analysis, according to the composite rule of micromechanics, the equivalent uniform windings are used to simulate the epoxy-impregnated Nb-Ti/Cu coils. In addition, using low temperature strain gauges and a wireless fast strain acquisition system, a fundamental experiment on the based on our analysis, the stresses and deformations optimized. strains developments of a sextupole is reported. Finally, for its assembly of each SECRAL Ⅱ coil will be further

Acute pancreatitis:Structured report template of magnetic resonance imaging

Acute pancreatitis(AP)is a common acute abdomen disease of the digestive system.It has a potentially fatal risk because of its variable severity and various complications.With the widespread application of the Revised Atlanta Classification,new requirements for AP imaging reports are introduced.Experts in abdominal radiology and pancreatology in the United States published the first structured computed tomography reporting template for AP in 2020.However,there is no corresponding structured magnetic resonance imaging(MRI)reporting template globally.Therefore,this article focuses on the structured MRI report of AP images from our pancreatitis imaging center,which is intended to improve the systematic understanding of this disease and standardize the writing of MRI structured reports.In the meantime,we aim to promote the clinical diagnosis and assessment of MRI efficacy for AP and its multiple complications.It is further intended to facilitate academic exchanges and scientific research between different medical centers.

APPLICATION OF THE ^(16)O(α,α) ^(16)O RESONANCE ELASTIC SCATTERING IN OXYGEN DEPTH PROFILING OF SIMOX STRUCTURES

The resonance nuclear elastic scattering 16O(α,α) 16O at 3.045 MeV has been used to profile oxygen distributions in SOI material synthesised by SIMOX technique. The buried SiO2 layer is produced by 1.8×1018 at./cm2 oxygen implantation at 500℃ and high temperature annealing at 1405℃ for 30 min. The experimental results show that after annealing sharp SiO2/Si interfaces at both sides of buried layer and a very good quality of top Si single crystal layer are obtained. The formation mechanism of the buried layer, correlated with SiO2 precipitates and dissolution, radiation enhanced diffusion and epitaxial growth, is discussed.

Resonance structure for 4s subshell in photoionization of Mn

It is shown that the 3d5(4X) 4s(5X)of 4s satellites ,except to the coupling between 3d54s(7,5S) and 3p→ 3d transition ,plays a key role on the magnitude of photoionization of 4s cross section .The coupled equation methodis improvedto calculate this resonance by including these channels .The results of calculations are compared with the experimental data from 4 6eV to 5 6eV photon energies,which are in good agreement with the experiment.

Effect of local structure on electron paramagnetic resonance spectra for trigonal [Cr(H_2O)_6]^(3+) coordination complex in the sulfate alums series:a ligand field theory study

A simple theoretical method is introduced for studying the interrelation between electronic and molecular structures.By diagonalizing the 120 × 120 complete energy matrices,the relationships between zero-field splitting （ZFS） parameter D and local distortion parameter △θ for Cr^3＋ ions doped,separately,in α- and β- alums are investigated.Our results indicate that there exists an approximately linear relationship between D and △θ in a temperature range 4.2-297 K and the signs of D and △θ are opposite to each other.Moreover,in order to understand the contribution of spin-orbit coupling coefficient ζ to ZFS parameter D,the relation between D and ζ is also discussed.

High-sensitivity Bloch surface wave sensor with Fano resonance in grating-coupled multilayer structures

A new type of device consisting of a lithium niobate film coupled with a distributed Bragg reflector(DBR)was theoretically proposed to explore and release Bloch surface waves for applications in sensing and detection.The film and grating made of lithium niobate(LiNbO_(3))were placed on both sides of the DBR and a concentrated electromagnetic field was formed at the film layer.By adjusting the spatial incidence angle of the incident light,two detection and analysis modes were obtained,including surface diffraction detection and guided Bloch detection.Surface diffraction detection was used to detect the gas molecule concentrations,while guided Bloch detection was applied for the concentration detection of biomolecule-modulated biological solutions.According to the drift of the Fano curve,the average sensor sensitivities from the analysis of the two modes were 1560°/RIU and 1161°/RIU,and the maximum detection sensitivity reached2320/RIU and 2200°/RIU,respectively.This study revealed the potential application of LiNbO_(3)as a tunable material when combined with DBR to construct a new type of biosensor,which offered broad application prospects in Bloch surface wave biosensors.

Nucleon Spin Structure Functions in the Resonance Region and the Duality

We discuss the nucleon spin structure function g1 and the difference between the proton and neutron targets , based on quark model calculation. Quark-hadron duality for the nucleon spin structure function is also analyzed. Effects of the Δ(1232) and Roper P11(1440) resonances on the spin structure function and on the difference are mentioned. The results of different models for the Roper resonance are also addressed.