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145 results on '"Wang, Yuan Ming"'

112. SRAM single event upset calculation and test using protons in the secondary beam in the BEPC

Author

Luo Yin-Hong, Zhang Keying, Wang Yuan-Ming, Guo Xiaoqiang, Zhang Feng-Qi, Chen Wei, and Guo Hongxia

Subjects
Physics, Proton, Electron, Condensed Matter Physics, Electronic, Optical and Magnetic Materials, law.invention, Nuclear physics, Cross section (physics), Positron, law, Single event upset, Materials Chemistry, Physics::Accelerator Physics, Static random-access memory, Electrical and Electronic Engineering, Collider, Beam (structure)
Abstract

The protons in the secondary beam in the Beijing Electron Positron Collider (BEPC) are first analyzed and a large proportion at the energy of 50–100 MeV supply a source gap of high energy protons. In this study, the proton energy spectrum of the secondary beam was obtained and a model for calculating the proton single event upset (SEU) cross section of a static random access memory (SRAM) cell has been presented in the BEPC secondary beam proton radiation environment. The proton SEU cross section for different characteristic dimensions has been calculated. The test of SRAM SEU cross sections has been designed, and a good linear relation between SEUs in SRAM and the fluence was found, which is evidence that an SEU has taken place in the SRAM. The SEU cross sections were measured in SRAM with different dimensions. The test result shows that the SEU cross section per bit will decrease with the decrease of the characteristic dimensions of the device, while the total SEU cross section still increases upon the increase of device capacity. The test data accords with the calculation results, so the high-energy proton SEU test on the proton beam in the BEPC secondary beam could be conducted.

Published
2011

133. THE ACCURATE CALCULATION AND ANALYSIS OF THE PROPAGATOR IN REAL SPACE DYNAMICAL ELECTRON DIFFRACTION CALCULATIONS

Author

Zhu Shi-Xue, Du Kui, Wang Zhong-Ming, and Wang Yuan-Ming

Subjects
Physics, Electron diffraction, Computation, Quantum mechanics, General Physics and Astronomy, Propagator, Space (mathematics)
Abstract

This paper is a systematic study of the real space dynamical electron diffraction involved in propagation calculation and sets down guidelines based on theoretical analysis for consistent and accurate computation for real space dynamical electron diffraction.

Published
1997

135. The extrapolation of Numerov's scheme for nonlinear two-point boundary value problems

Author

Wang, Yuan-Ming

Subjects
*BOUNDARY value problems, *DIFFERENTIAL equations, *EXTRAPOLATION, *ALGORITHMS
Abstract

Abstract: This paper is concerned with the extrapolation algorithm of Numerov''s scheme for semilinear and strongly nonlinear two-point boundary value problems. The asymptotic error expansion of the solution of Numerov''s scheme is obtained. Based on the asymptotic error expansion, Richardson''s extrapolation is constructed, and so the accuracy of the numerical solution is greatly increased. Numerical results are presented to demonstrate the efficiency of the extrapolation algorithm. [Copyright &y& Elsevier]

Published
2007
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136. Determination of Alkaline Phosphatase in Activated Sludge

Author

Yin, Jun, Wang, Yuan Ming, and Wang, Jian Hui

Abstract

Experiment disodium phenyl phosphate as a reaction basic, stromal hydrolysis produce phenol, the amount of phenol indirectly indicates the activity of Alkaline Phosphatase.Experiment by absorption wavelength, activated sludge volume, disodium phenyl phosphate, aluminum sulfate, reagent, temperature and other factors affecting the determination of Alkaline Phosphatase were studied.The experiments optimal reaction conditions initially identified. At 37°C, when activated sludge volume of 5mL, 15mL disodium phenyl phosphate absorbance measured at the maximum value, highest levels of Alkaline Phosphatase. Results show that, 0.25mL reagent optimum dosage for the trial, the best absorption wavelength through fitting the peak-valley is 590nm.

Published
2014
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137. A NEW METHOD FOR SIMULATING HIGH RESOLUTION ELECTRON MICROSCOPE IMAGES FROM NON-PERIODIC OBJECTS

Author

Wang Yuan-Ming, Chen Jiang-Hua, Hu Tian-Bao, and Zeng Xiao-Biao

Subjects
Diffraction, Physics, Operator (computer programming), Optics, Sampling (signal processing), business.industry, Fast Fourier transform, General Physics and Astronomy, Boundary (topology), business, Space (mathematics), High resolution electron microscope, Image (mathematics)
Abstract

It is shown that the dynamical diffraction calculation using periodic extension of the sampling boundary points leads to serious and artificial errors in the High Resolution Electron Microscope (HREM) image simulation for a non-periodic object in FFT Multi-Slice (FFTMS) method which is now routinely used for the simulation of HREM images from periodic objects.In a systematic study of the problem of induced numerical artifacts, a new method has been proposed for the HREM image simulation of non-periodic objects. It is based on some improvements in the calculation of the phase grating and the propagation operator to the Real Space Multi-Slice (RSMS) method, which are compatible with a non-periodic object.It can be seen from the comparison with the experimental HREM images that much more better agreement can be obtained by using Real Space Multi-Slice method for Non-periodic objects (RSMSN).

Published
1990

138. Quasi-real-space image simulation in high-resolution electron microscopy

Author

Qu Hua and Wang Yuan-Ming

Subjects
Normalization (statistics), Chemistry, Truncation, business.industry, General Chemical Engineering, Operator (physics), Mathematical analysis, General Physics and Astronomy, Electron, Space (mathematics), Image (mathematics), QRS complex, Optics, Wave function, business
Abstract

This paper reports a study of the quasi-real-space (QRS) method. It is an intermediate procedure between the real-space (RS) and multi-slice (MS) methods. With this technique, most of the numerical calculations are done in RS except that normalization is imposed beyond some threshold value, e.g. σ|φ|2 > 1[sdot]01, where φ is the wavefunction of the electron. It is also numerically shown that truncation of the propagation operator exp (λeδ) to second order in the RS method can lead to computational divergences and how they can be avoided by using the QRS method. Finally, results calculated by the QRS method are compared with those obtained by other existing slice methods. The QRS method gives results similar to the conventional MS calculation with competitive computational speed.

Published
1987

139. A convergence criterion for the real-space image simulation method

Author

Wang Yuan-Ming and Chen Jiang-Hua

Subjects
Physics and Astronomy (miscellaneous), business.industry, Slice thickness, Metals and Alloys, Condensed Matter Physics, Space (mathematics), Electronic, Optical and Magnetic Materials, Image (mathematics), Optics, Convergence (routing), General Materials Science, Image theory, Multislice, business, Divergence (statistics), Algorithm, Sampling interval, Mathematics
Abstract

A δ-e criterion in the real-space (RS) method for simulating high-resolution electron microscope images has been derived. This condition imposes a practical limitation in choosing the sampling interval δ and the slice thickness e for the RS method. The validity of the new criterion for the RS image simulation in high-resolution electron microscopy has been rigorously examined. It has been found that when the δ-e condition is satisfied, the RS method gives results similar to the conventional multislice method with a saving in computational time but avoiding the computing divergence which can arise in the RS method.

Published
1988

140. A NEW DEVELOPMENT IN THE REAL SPACE HIGH RESOLU-TION ELECTRON MICROSCOPE SIMULATION METHOD

Author

Wang Yuan-Ming, Hu Tian-Bao, and Chen Jiang-Hua

Subjects
Physics, High resolution electron microscopy, law, Slice thickness, Fast Fourier transform, General Physics and Astronomy, Development (differential geometry), Electron microscope, Divergence (statistics), Space (mathematics), Algorithm, law.invention, Image (mathematics)
Abstract

In a detailed study of the problem of induced numerical artifacts in the Real Space (RS) High Resolution Electron Microscopy (HREM) image simulation, a δ-ε criterion in the RS method for simulating HREM images has been derived. This condition imposes a practical limitation in choosing the sampling interval δ and the slice thickness ε for the RS method. It has been found that when the δ-ε condition is satisfied and a much more accurate formula is used for calculating the propagating factor p(r), the RS method gives results in satisfactory agreement with the conventional FFT multi-slice (FFTMS) method, but saving coputational time and avoiding the computing divergence that may arise in the RS method.

Published
1989

141. QUASI REAL SPACE (QRS) IMAGE SIMULATION IN HIGH RESOLUTION ELECTRON MICROSCOPY

Author

Qu Hua and Wang Yuan-Ming

Subjects
Physics, QRS complex, Truncation, Operator (physics), Mathematical analysis, General Physics and Astronomy, Multislice, Function (mathematics), Electron, Space (mathematics), Image (mathematics)
Abstract

This paper reports a study of the quasi real space (QRS) method. It is an intermediate procedure between the real space (RS) and multislice (MS) methods. With this technique, most of the numerical calculations are done in real space except that the rormalization is imposed beyond some threshold value, for example ∑|Φ|2>1.01 where Φ is the wave function of the electron. It is also shown why truncation of the propagation operator eλε△ to second order in the RS method can lead to computational divergencies and how they can be avoided by using the QRS method. Finally, results calculated by the QRS method are compared with other existing slice methods. The QRS method gives results similar to the conventional MS calculation with competitive computational speed.

Published
1986

143. [MicroRNA-125b regulates osteogenic differentiation of human periodontal ligament stem cells].

Author

DU L, Cao WJ, Tian Y, and Wang YM

Subjects
Cells, Cultured, Humans, Stem Cells, Cell Differentiation, MicroRNAs physiology, Osteogenesis, Periodontal Ligament physiology
Abstract

Purpose: To investigate the effect of microRNA-125b (miR-125b) on osteogenic differentiation of periodontal ligament stem cell (PDLSCs)., Methods: The surface factor of isolated PDLSCs was detected by flow cytometry. After transfected with miR-125b or anti-miR125b in PDLSCs, MTT and LDH were used to detect cell viability and cytotoxicity; ALP activity and calcium level were detected by ALP assay kit and calcium colorimetric assay kit. Western blot and RT-qPCR were used to determine the expression of osteogenesis-related genes. The interaction between miR-125b and connexin 43 (Cx43) was detected by dual luciferase gene reporter assay. The data were analyzed with SPSS 17.0 software., Results: The cultured PDLSCs showed the characteristics of mesenchymal stem cells. After transfected with miR-125b in PDLSCs, the cell viability was decreased, cytotoxicity was increased; ALP activity, calcium level and the expression of osteogenesis-related genes were significantly decreased. On the contrary, cell viability, ALP activity, calcium level and the expression of osteogenesis-related genes in PDLSCs were increased after anti-miR-125b transfection. Dual luciferase gene reporter assay showed that miR-125b could target Cx43. In addition, the effect of miR-125b on osteogenic differentiation of PDLSCs was reversed after Cx43 overexpression., Conclusions: miR-125b may inhibit osteogenic differentiation of PDLSCs by targeting Cx43.

Published
2018

144. [SiRNA silencing Rsk2 gene expression inhibits proliferation and osteogenic differentiation of human periodontal ligament cells].

Author

DU L, Cao WJ, and Wang YM

Subjects
Cell Proliferation, Cells, Cultured, Humans, Ribosomal Protein S6 Kinases, Ribosomal Protein S6 Kinases, 90-kDa, p38 Mitogen-Activated Protein Kinases metabolism, Cell Differentiation, Osteogenesis, Periodontal Ligament metabolism, RNA, Small Interfering
Abstract

Purpose: To study the effect of ribosomal S6 kinase (Rsk2) gene on proliferation and osteogenic differentiation of human periodontal ligament cells (hPDLCs) and underlying mechanism., Methods: Premolar surgically extracted were collected, the periodontal ligament was separated and hPDLCs were primarily cultured. Cells of 4 to 6 passage were used in the experiment. The silencing efficiency of small interfering RNA (siRNA) on Rsk2 in hPDLCs was detected by RT-PCR and Western blot. MTT assay was used to detect the effect of Rsk2 siRNA on cell proliferation. Alkaline phosphatase (ALP) kit was used to detect ALP activity. P38MAPK signal pathway inhibitor SB203580 was used to detect hPDLCs after transfection. Western blot was used to detect the effect of Rsk2 siRNA on MAPK signaling pathway p38 protein phosphorylation. The expressions of Runt-related transcription factor-2 (Runx2), osteocalcin (OCN) and osteogenic protein BMP2 were detected by RT-PCR and Western blot. The data were analyzed using SPSS18.0 software package., Results: The expression of Rsk2 was down-regulated by hPDLCs transfected with Rsk2 siRNA, the difference was statistically significant (P<0.05). Rsk2 siRNA significantly reduced phosphorylation of p38 protein (P<0.05), inhibition of hPDLCs proliferation (P<0.05), decreased ALP activity (P<0.01); the expression of Runx2, OCN and BMP2 was different, and the difference was statistically significant (P<0.05). After SB203580 treatment, hPDLCs transfected with Rsk2 siRNA showed increased cell proliferation, ALP activity, Runx2, OCN and BMP2 expression; compared with Rsk2 siRNA transfected hPDLCs, the difference was statistically significant., Conclusions: Rsk2 siRNA inhibits hPDLCs proliferation and osteogenic differentiation through p38MAPK signaling pathway.

Published
2017

145. A clinical evaluation of serological diagnosis for pancreatic cancer.

Author

Zhao XY, Yu SY, Da SP, Bai L, Guo XZ, Dai XJ, and Wang YM

Abstract

AIM:To assess the diagnostic values of tumor markers for pancreatic cancer.METHODS:Pancreatic cancer-associated antigen from colonic mucosa (PCAAc), pancreas-specific antigen (PaA), pancreatic oncofetal antigen (POA) and minimolecular pancreatic antigen (mPOA) were detected by double antibodies Sandwich ELISA; CA19-9,elastase 1 (E1), human pancreatic elastase 1 (HPE1) and carcinoembryonic antigen (CEA) by radioimmunoassay (RIA); general activities of ribo-nuclease (RNase) and its isoenzymes (RNase I and RNase I) by biochemistry and PAEG;glycylproline dipeptidyl aminopeptidase (GPDA) by biochemistry andalpha 1-antitrypsin (alpha1AT) by rocket immunoelectrophoresis (rocket-IE).RESULTS:The detection of serum POA,mPOA,PaA,PCAAc,CA19-9,RNase and RNase I was able to differentiate pancreatic cancer from the benign disorders and non-pancreatic malignancies with a sensitivity from 66.75% to 80.0% and a specificity from 88.5% to 96.69%. POA, mPOA, PCAAc, HPE1, E1 and GPDA were related to the pancreatic cancer at the head which demonstrated higher sensitivity from 63.64% to 85.71%. The detection of serum HPE1 was especially helpful for the diagnosis of pancreatic cancer with smaller diameters. The determination of 3 or 4 kinds of tumor markers simultaneously would increase the detection rate of pancreatic cancer, which will be an important procedure for the diagnosis of this malignancy.CONCLUSION:A single test of tumor markers is helpful to detect pancreatic cancer clinically,but the determination of 3 or 4 kinds of tumor markers simultaneously would significantly increase the detection rate of pancreatic cancer, which will be an important procedure for the diagnosis of this malignancy.

Published
1998
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