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Search Results: 1 - 10 of 78253 matches for " Shihao Chen "
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A Cosmological Model without Singularity Based on RW Metric (1)  [PDF]
Shihao Chen
International Journal of Astronomy and Astrophysics (IJAA) , 2014, DOI: 10.4236/ijaa.2014.41023
Abstract: A new conjecture is proposed that there are two sorts of matter called s-matter and v-matter which are symmetric, whose masses are positive, but whose gravitational masses are opposite to each other. Based on the conjecture and the SUS(5) × SUV(5) gauge group, a cosmological model has been constructed and the following inferences have been derived. There are two sorts of symmetry breaking called V-breaking and S-breaking. In theV-breaking, SUV(5) breaks finally to SUV(3) × UV(1) so that
A Locally Conservative Energy-Momentum Tensor in the General Relativity Based on a Cosmological Model without Singularity  [PDF]
Shihao Chen
Journal of Modern Physics (JMP) , 2016, DOI: 10.4236/jmp.2016.73027
Abstract: According to the conventional theory it is difficult to define the energy-momentum tensor which is locally conservative. The energy-momentum tensor of the gravitational field is defined. Based on a cosmological model without singularity, the total energy-momentum tensor is defined which is locally conservative in the general relativity. The tensor of the gravitational mass is different from the energy-momentum tensor, and it satisfies the gravitational field equation and its covariant derivative is zero.
Structure of the Universe  [PDF]
Shihao Chen
International Journal of Astronomy and Astrophysics (IJAA) , 2018, DOI: 10.4236/ijaa.2018.84023
Abstract: Based on a cosmological model without singularity, a possible structure of the universe is presented. It is proved that there must simultaneously be two sorts of symmetry breaking in the universe. The universe is composed of infinite s-cosmic islands, infinite v-cosmic islands and infinite transition zone. The existing and changing forms of the cosmic islands must be diverse. The cosmological principle holds only approximately within a cosmic island. No information can be exchanged between an s-cosmic island and an adjacent v-cosmic island so that every observer thinks his cosmic island to be the whole universe. It is possible that some cosmic islands are contracting, some cosmic islands are expanding, and other cosmic islands are stable for a time. But the universe as a whole is always invariable and contains all possible existing forms of matter. To give a possible explanation for orphan quasars. To predict some characteristics of contracting large and huge black holes in a cosmic island. The characteristics of the light coming from the contracting huge black holes are that the intensity of the light is huge relatively to their distance, the red shifts are huge, the distribution of the huge red shifts and the orphan quasars are anisotropic, and luminescence spectrum is very wide.
Photoconductive Effect of Liquid and Utilization of Solar Energy  [PDF]
Ziwei Chen, Shihao Chen
Open Journal of Physical Chemistry (OJPC) , 2014, DOI: 10.4236/ojpc.2014.41003
Abstract:

Experiments described in this paper show that there is the photoconductive effect of liquid, i.e. when light shines into a sort of alkali, acid or salt solution, the conductivity of the solution will increase. The mechanism of the effect is explained as follows. When hydrated ions in the solution absorb photons with their high enough energies, they will decompose to naked ions and water-molecules. The naked ions can reach an anode or a cathode more easily and faster than the hydrated ions; It is possible that when a molecule in the solution absorbs a photon with its high enough energy, it will decompose to negative and positive ions. Based on the effect, a device producing hydrogen by the solar-energy had been devised.

A Way to Realize Controlled Nuclear Fusion by γ-Laser or γ-Ray  [PDF]
Shihao Chen, Ziwei Chen
World Journal of Nuclear Science and Technology (WJNST) , 2018, DOI: 10.4236/wjnst.2018.84016
Abstract: A way is proposed to realize controllable-nuclear fusion by γ-laser or γ-ray and ordinary laser with their certain frequencies and large enough intensities to irradiate a target ball. The function of ordinary laser is to heat the target nuclei and to realize the inertial confinement for the target nuclei. The target nuclei absorbing γ-photons will be in a certain excited state. The scattering cross-sections will be larger and the ignition temperature will be lower to realize fusion of the nuclei in their excited states than those of the nuclei in their ground states. In contrast with the nuclei applied in conventional fusion, e.g., deutons and tritons, according to the way, the nuclei applied to fusion should have the following characters: the nuclei have their excited states, one of the excited states has higher energy and longer lifetime, and the masses of the nuclei are lesser. Thus, the Lawson conditions can more easily be realized so that the controllable nuclear fusion is possibly realized by the way.
A Possible Candidate for Dark Matter
Shihao Chen
Physics , 2001,
Abstract: On the basis of a new quantum field theory without divergence presented by us we identify W-matter with dark matter and guess that the two new stars RXJ1865 and 3C58 and quasi-stellar objects are the compounds of a F-celestial body with a W-celestial body with massive enough mass, and some earthquakes, some tsunamis and some disasters in some areas like Bermuda are caused by W-objects. Keywords: Dark matter; W-matter; Quasi-stellar objects.
Study on the Impact of Local Public Expenditure on Housing Price—An Empirical Analysis Based on Provincial Panel Data  [PDF]
Shihao Li
Modern Economy (ME) , 2018, DOI: 10.4236/me.2018.92016
Abstract: Based on the discussion about transmission mechanism of local public expenditure on housing price under different housing market types, the paper performs an empirical study on the influence of various public expenditures on housing price by using Chinese panel data of provinces from 2007 to 2015. According to the result, public education expenditure and public transportation expenditure have prominent capitalization effect on housing price. Among the expansions of various local public expenditures, public education expenditure is the most effective type to promote the capitalization of commercial housing. In dynamic panel test, the capitalization effect of public expenditure maintains significant after the introduction of consumer expectation, which is consistent with the regression result of static panel. At last, the paper puts forward some relevant policy suggestions for the government to optimize the structure of public expenditure, guide consumer expectations reasonably and promote the sound development of real estate market.
Epitaxial Growth of Germanium on Silicon for Light Emitters
Chengzhao Chen,Cheng Li,Shihao Huang,Yuanyu Zheng,Hongkai Lai,Songyan Chen
International Journal of Photoenergy , 2012, DOI: 10.1155/2012/768605
Abstract: This paper describes the role of Ge as an enabler for light emitters on a Si platform. In spite of the large lattice mismatch of ~4.2% between Ge and Si, high-quality Ge layers can be epitaxially grown on Si by ultrahigh-vacuum chemical vapor deposition. Applications of the Ge layers to near-infrared light emitters with various structures are reviewed, including the tensile-strained Ge epilayer, the Ge epilayer with a delta-doping SiGe layer, and the Ge/SiGe multiple quantum wells on Si. The fundamentals of photoluminescence physics in the different Ge structures are discussed briefly.
One-Step Transepithelial Topography-Guided Ablation in the Treatment of Myopic Astigmatism
Aleksandar Stojanovic, Shihao Chen, Xiangjun Chen, Filip Stojanovic, Jia Zhang, Ting Zhang, Tor Paaske Utheim
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0066618
Abstract: Purpose To evaluate one-step topography-guided transepithelial ablation in the treatment of low to moderate myopic astigmatism using a 1KHz excimer laser. Methods Retrospective study of 117 consecutive eyes available for evaluation 12 months after surgery. Pre- and post-operative visual and refractive data as well as post-operative pain and haze were analyzed. A novel technique integrating custom refractive- and epithelial- ablation in a single uninterrupted procedure was used. Results The mean pre-operative spherical equivalent (SE) and the mean cylinder were: –3.22 diopters (D) ±1.54 (SD) (range –0.63 to –7.25 D) and –0.77 D ±0.65 (range 0 to –4.50 D), respectively. At 12 months after surgery: no eyes lost ≥2 lines of corrected distant visual acuity (CDVA). Safety and efficacy indexes were 1.27 and 1.09, respectively. Uncorrected distant visual acuity (UDVA) was ≥20/20 in 96.6% of the eyes. Manifest refraction spherical equivalent was within ±0.5 D of the desired refraction in 93.2% of the eyes. Average root mean square (RMS) wavefront error measured at central 6 mm, increased from 0.38 pre-operatively to 0.47 μm post-operatively. Refractive stability was achieved and sustained 1 month after surgery. No visually significant haze was registered during the observation period. Post-operative pain was reported in 4.5% of patients. Conclusions One-step transepithelial topography-guided treatment for low to moderate myopia and astigmatism performed with a 1 KHz laser, provided safe, effective, predictable and stable results with low pain and no visually significant haze.
Evaluation of the Efficacy of Excimer Laser Ablation of Cross-Linked Porcine Cornea
Shihao Chen, Yini Li, Aleksander Stojanovic, Jia Zhang, Yibo Wang, Qinmei Wang, Theo Seiler
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0046232
Abstract: Background Combination of riboflavin/UVA cross-linking (CXL) and excimer laser ablation is a promising therapy for treating corneal ectasia. The cornea is strengthened by cross-linking, while the irregular astigmatism is reduced by laser ablation. This study aims to compare the efficacy of excimer laser ablation on porcine corneas with and without cross-linking. Methods and Findings The porcine cornea was de-epithelialized and treated with 0.1% riboflavin solution for 30 minutes. A half of the cornea was exposed to UVA-radiation for another 30 minutes while the controlled half of the cornea was protected from the UVA using a metal shield. Photo therapeutic keratectomy (PTK) was then performed on the central cornea. Corneal thickness of 5 paired locations on the horizontal line, ±0.5, ±1.0, ±1.5, ±2.0, and ±2.5 mm from the central spot, were measured using optical coherence tomography prior to and after PTK. The ablation depth was then determined by the corneal thickness. There was a 9% difference (P<0.001) in the overall ablation depth between the CXL-half corneas (158±22 μm) and the control-half corneas (174±26 μm). The ablation depths of all 5 correspondent locations on the CXL-half were significantly smaller (P<0.001). Conclusion The efficacy of the laser ablation seems to be lower in cross-linked cornea. Current ablation algorithms may need to be modified for cross-linked corneas.
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