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23 results on '"Cheng, He Ping"'

1. Formative Evaluation and World-Wide-Web Hypermedia.

Author

Gibbs, William J. and Cheng, He Ping

Abstract

This paper discusses a formative evaluation method by which to assess World-Wide-Web (WWW) documents. Also presented are the results from a pilot evaluation which examined users' interactions with Web documents and the effects of providing "document maps" to guide users to specific information. A video-split screen technique was used to record users interacting with the WWW and to assess the design of associated documents. Three female and two male subjects participated in the study; four were undergraduate students and one was a graduate student. Subjects were given two tasks: (1) to browse through the WWW and locate specific information/documents; and (2) to use and assess Eastern Illinois University's Department of Media Services Web site. At the completion of the session, subjects filled out a survey which collected information on their reactions toward the usefulness of the "document maps" and data related to their computer experience and knowledge of the WWW. Results indicated that the video-split screen method can be an effective means to assess WWW documents. Subjects need to be shown that a "document map" exists for their use and they must be explicitly informed as to its purpose and function. As WWW is used for the delivery of instruction, it is important to provide learners with a means of instructional support. Three figures present sample transcripts from the evaluation sessions and depict the time spent searching (by trials) and the number of times maps were used (by trial). (Contains 18 references.) (AEF)

Published
1995

2. Teaching English as a Foreign Language in China.

Author

Cheng, He-ping

Abstract

Reviews the political, economic, and educational situations in China to explain why the teaching of English as a foreign language (EFL) has revived and to forecast the development of EFL over the next two decades. Topics explored include language needs of students of science and technology, teaching methodologies, and teacher training. (CB)

Published
1988

8. Nitrogen dilution effect for small angle GDH experiment in JLab Hall-A

Author

Yan Xinhu, He Ju, Jiao Zheng, Liu Ren-Chen, Lue Hai-Jiang, Ye Yunxiu, and Cheng He-ping

Subjects
Physics, Nuclear and High Energy Physics, Scattering, Nuclear Theory, Astronomy and Astrophysics, Electron, Helicity, Dilution, Nuclear physics, Cross section (physics), Helium-3, Sum rule in quantum mechanics, Instrumentation, Electron scattering
Abstract

In the GDH sum rule measurement in JLab Hall-A, to obtain the cross section of electron scattering on polarized 3He and its asymmetry in different helicity states, the dilution effect from unpolarized nitrogen mixed in the polarized 3He target were calculated at different kinematic settings.

Published
2008

9. Rate-dependent characteristics of copper under plate impact

Author

Qi Mei-Lan, Cheng He-Ping, Li Ping, Pei Xiao-Yang, He Hong-Liang, and Peng Hui

Subjects
Shock wave, Materials science, Free surface velocity, Rate dependent, General Physics and Astronomy, chemistry.chemical_element, Strain rate, Spall, Copper, Maxima and minima, symbols.namesake, chemistry, symbols, Composite material, Doppler effect
Abstract

In this paper, the rate-dependent characteristics of oxygen-free high-purity copper (OFHC) under plate-impact loading is investigated experimentally. The velocity of flyers is measured by magnetic measurement system, and the free surface velocity of targets is measured by Doppler pins system (DPS). Characteristic parameters of free surface velocity are calculated using the measured data. Results show that the spall strength of OFHC is enhanced with the increase in strain rate. It is indicated that the rate from the minima to the spall peak grows slowly at low stain rate, but steeply at high strain rate. The slope as it appears, from the minima to the spall peak is very different as the strain rate increases, The interaction of shock waves in the copper samples is systematically analysed to access the slope characteristics.

Published
2014

12. First-principles study on the electronic structure and optical properties of RDX

Author

Dan Jiakun, Huang Zhi-Meng, Cheng He-Ping, Peng Hui, and Chen Guang-Hua

Subjects
Materials science, business.industry, General Physics and Astronomy, Optoelectronics, Electronic structure, business
Abstract

Electronic structure and optical properties of RDX are calculated by the first-principle density function theory pseudopotential method. The calculated results show that RDX is an insulator with a band gap of 3.43 eV, that the valence band of RDX is mainly composed of C-2s, C-2p, N-2s, N-2p and O-2s, O-2p, and that the conduction bands are mainly composed of N-2p and O-2p. The static dielectric function ε1(0) is 1.38, the imaginary part of dielectric function has five peaks and the largest peak is at the position corresponding to 4.6 eV of photon energy. The electronic direct transitions for these peaks are analyzed in detail. The absorption, reflectivity and loss function of RDX are analyzed in terms of calculated band structure and density of states. The results indicate that the RDX is not sensitive to the optical absorption nor to reflectivity nor to energy loss.

Published
2013

13. Experimental study of the spatial discontinuity of dynamic damage evolution

Author

LI Ping-SiChuan, Cheng He-Ping, Qi Mei-Lan, He Hong-Liang, Pei Xiao-Yang, and Peng Hui

Subjects
Shock wave, Coalescence (physics), Materials science, business.industry, Late stage, Nucleation, General Physics and Astronomy, Mechanics, Spatial distribution, Optics, Discontinuity (geotechnical engineering), Chromatic aberration, Stress relaxation, business
Abstract

In this paper, the damage evolution of high purity aluminum under shock loading is investigated experimentally. The surface profile measurement technique based on white light axial chromatic aberration is used to measure the cross-section of sample which is soft-recovered from dynamic impact experiments. Then, the cross-section image and 3-D surface topography are obtained by reconstruction of the data, the quantified damage is also calculated based on the data. The results show that in the early stage of damage evolution the spatial distribution of relative void volume is not continuous, which results from nucleation affect, size affect and stress relaxation. The damage curves show not only the maximum damage but also a second peak. In the late stage of damage evolution, the spatial distribution of damage increment is discontinuous, which results from the coalescence of voids. The damage of the coalescence region rapidly increases and the secondary peak of the damage curve disappears.

Published
2013

16. Contribution of spontaneous L-type Ca2+ channel activation to the genesis of Ca2+ sparks in resting cardiac myocytes

Author

Tang Yiqun, Cheng He-ping, Hao Xuemei, Edward G. Lakatta, Wu Caihong, Yang Dongmei, Zhang Guangqin, Bai Shuhua, and Fu Yu

Subjects
Calcium Channels, L-Type, In Vitro Techniques, General Biochemistry, Genetics and Molecular Biology, Membrane Potentials, law.invention, Rats, Sprague-Dawley, Cadmium Chloride, Confocal microscopy, law, Animals, Myocyte, Myocytes, Cardiac, Calcium Signaling, Ventricular myocytes, Interphase, Fluorescent Dyes, General Environmental Science, Membrane potential, Aniline Compounds, Microscopy, Confocal, Voltage-dependent calcium channel, Chemistry, Endoplasmic reticulum, Anatomy, musculoskeletal system, Rats, Xanthenes, cardiovascular system, Biophysics, Ca2 channels, General Agricultural and Biological Sciences, Intracellular
Abstract

Ca2+ sparks are the elementary events of intracellular Ca2+ release from the sarcoplasmic reticulum in cardiac myocytes. In order to investigate whether spontaneous L-type Ca2+ channel activation contributes to the genesis of spontaneous Ca2+ sparks, we used confocal laser scanning microscopy and fluo-4 to visualize local Ca2+ sparks in intact rat ventricular myocytes. In the presence of 0.2 mmol/L CdCl2 which inhibits spontaneous L-type Ca2+ channel activation, the rate of occurrence of spontaneous Ca2+ sparks was halved from 4.20 to 2.04 events/(100 microm x s), with temporal and spatial properties of individual Ca2+ sparks unchanged. Analysis of the Cd2+-sensitive spark production revealed an open probability of approximately 10(-5) for L-type channels at the rest membrane potentials (-80 mV). Thus, infrequent and stochastic openings of sarcolemmal L-type Ca2+ channels in resting heart cells contribute significantly to the production of spontaneous Ca2+ sparks.

Published
2004

17. Swim training sensitizes myocardial response to insulin: Role of Akt-dependent eNOS activation

Author

Zhang, Quan-Jiang, Li, Qiu-Xia, Zhang, Hai-Feng, Zhang, Kun-Ru, Guo, Wen-Yi, Wang, Hai-Chang, Zhou, Zhuan, Cheng, He-Ping, Ren, Jun, and Gao, Feng

Subjects
HYPOGLYCEMIC agents, PANCREATIC secretions, GLUCAGON, INSULIN
Abstract

Abstract: Objectives: Physical activity has been well known to benefit heart function. The improved autonomic nervous activity is considered to be mainly responsible for this beneficial effect. However, the precise mechanism behind the intrinsic myocardial responsiveness to exercise is still unclear. This study was designed to examine the effect of swim training on myocardial response to insulin with a special focus on the endogenous endothelial nitric oxide synthase (eNOS)–nitric oxide (NO) cascade. Methods: Adult male Sprague–Dawley (SD) rats were subjected to a 10-week free-loading swim training (3 h/day, 5 days/week). Contractile response to insulin at the levels of cardiomyocytes and isolated perfused heart, myocardial glucose uptake and post-insulin receptor signaling cascades were evaluated. Results: Swim training enhanced cardiac contractile response to insulin in cardiomyocytes and isolated perfused heart, respectively. The improved cardiac response was accompanied by facilitated insulin-stimulated glucose uptake, GLUT4 translocation and upregulation of Akt and eNOS expression (p <0.01). Treatment with insulin resulted in a 3.6- and 2.2-fold increase of eNOS phosphorylation (p <0.01), as well as a 3.0- and 1.9-fold increase of Akt phosphorylation in exercise and sedentary groups, respectively (p <0.01). In addition, exercise significantly facilitated insulin-induced myocardial NO production (p <0.01 vs. sedentary). Moreover, pretreatment with either LY294002, a phosphatidylinositol-3 kinase (PI-3K) inhibitor or l-NAME, a NOS inhibitor, abolished the exercise-induced sensitization of myocardial contractile response to insulin, insulin-induced NO production and phosphorylation of Akt and eNOS. Conclusion: These results demonstrate that swim training is capable of sensitizing myocardial contractile response to insulin via upregulation of Akt- and eNOS signaling cascades. [Copyright &y& Elsevier]

Published
2007
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19. The effect of the vasomotion on the mass transfer in microcirculation

Author

Wu Wang-yi and Cheng He-ping

Subjects
Physics, Mechanics of Materials, Applied Mathematics, Mechanical Engineering, Mass transfer, Vasomotion, Mechanics, Microcirculation
Abstract

This paper deals with the mass transfer in the microcirculation with vasomotion. The effect of the vasomotion on the mass transfer is analysed. It is shown that the vasomotion is of great importance to accelerate the mass transfer.

Published
1988

21. [Effects of 50 Hz sinusoidal magnetic field on Ca2+ release channel ryanodine receptor of sarcoplasmic reticulum vesicles].

Author

Liu RC, Xia RH, Cheng HP, and Zhou ZJ

Subjects
Animals, Rabbits, Sarcoplasmic Reticulum radiation effects, Calcium metabolism, Magnetic Fields adverse effects, Ryanodine Receptor Calcium Release Channel metabolism, Sarcoplasmic Reticulum metabolism
Abstract

Objective: To investigate the effects of sinusoidal magnetic field on isolated sarcoplasmic reticulum (SR) calcium release channel (RyR1) function., Methods: With the Ca2+ dynamic spectrum and isotope labeled methods, the Ca2+ release and [(3)H]-Ryanodine binding, the initial rates of NADH oxidation and the production of superoxide of SR exposed to 50 Hz sinusoidal magnetic field (MF) were investigated respectively., Results: 0.4 mT, 50 Hz sinusoidal MF exposure for 30 min increased SR Ca2+ release initial rate about 35% from (10.82 +/- 0.89) pmol.mg(-1) pro.s(-1) to (14.69 +/- 1.21) pmol.mg(-1) pro.s(-1); and the [(3)H]-Ryanodine binding by about 15% from (2.13 +/- 0.05) pmol/mg pro to (2.45 +/- 0.07) pmol/mg pro, which regulated by 1 mmol/L NADH with 1 mmol/L NAD+. Meanwhile MF upregulated the rate of NADH oxidation by about 22% from (0.88 +/- 0.11) x 10(-4) FI/s to (1.07 +/- 0.13) x 10(-4) FI/s and upregulated the production of superoxide by about 32% from (0.99 +/- 0.09) x 10(-5) FI/s to (1.31 +/- 0.06) x 10(-5) FI/s., Conclusion: 0.4 mT sinusoidal MF increases the activity of RyR1 within the low redox potential environment, and promotes NADH oxidase activity and superoxide production.

Published
2009

22. [Microscopic mechanism of excitation-contraction coupling in cardiac myocytes].

Author

Shen JX, Han TZ, and Cheng HP

Subjects
Animals, Heart physiology, Humans, Ion Channel Gating, Microscopy, Confocal, Sarcolemma physiology, Sarcoplasmic Reticulum drug effects, Sarcoplasmic Reticulum physiology, Sodium-Calcium Exchanger physiology, Calcium Channels, L-Type metabolism, Calcium Signaling, Myocardial Contraction, Myocytes, Cardiac physiology, Ryanodine Receptor Calcium Release Channel physiology
Abstract

Cardiac excitation-contraction coupling (ECC) is, in essence, a communication process between sarcolemmal voltage-dependent L-type calcium channels (LCCs) and ryanodine receptors (RyRs) of sarcoplasmic reticulum (SR) by the mechanism of calcium-induced calcium release (CICR). Recent advances displayed more information about the microscopic signaling between LCCs and RyRs. In calcium release couplons, the calcium influx through the opening of LCCs by membrane depolarization forms calcium sparklets locally which then act on the adjacent SR RyRs. Stochastic activation of RyRs discharges calcium sparks from different calcium couplons, which summate into global calcium transients. Therefore, ignition of calcium sparks by calcium sparklets constitutes the elementary events in ECC. This review focuses on the intermolecular signaling between LCCs and RyRs, to describe the microscopic view of CICR and ECC.

Published
2004

23. Blockade of paeoniflorin on sodium current in mouse hippocampal CA1 neurons.

Author

Zhang GQ, Hao XM, Chen SZ, Zhou PA, Cheng HP, and Wu CH

Subjects
Animals, Benzoates isolation & purification, Bridged-Ring Compounds isolation & purification, Glucosides isolation & purification, Membrane Potentials drug effects, Mice, Monoterpenes, Neurons physiology, Neuroprotective Agents pharmacology, Paeonia chemistry, Plants, Medicinal chemistry, Benzoates pharmacology, Bridged-Ring Compounds pharmacology, Glucosides pharmacology, Hippocampus cytology, Neurons drug effects, Sodium Channel Blockers pharmacology, Sodium Channels metabolism
Abstract

Aim: To study the blockade of paeoniflorin (Pae) on I(Na) in the acutely isolated hippocampus neurons of mice., Methods: The whole-cell patch clamp technique was used., Results: Pae inhibited I(Na) in frequency-dependent and concentration-dependent manners, with an IC50 of 271 micromol/L. Pae 0.3 mmol/L shifted the activation potential of the maximal I(Na) from -40 mV to -30 mV, shifted the steady-state activation and inactivation curves toward more positive and negative potentials by 10.8 mV, and 18.2 mV, respectively, and postponed the recovery of I(Na) inactivation state from (4.2+/-0.7) ms to (9.8+/-1.2) ms., Conclusion: Pae inhibited I(Na) in mouse hippocampus neurons.

Published
2003

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