Jiang X.,Central South University of forestry and Technology |
Sommer S.G.,University of Southern Denmark |
Christensen K.V.,University of Southern Denmark
Energy Policy | Year: 2011
This article presents an overview of the development and future perspectives of the Chinese biogas industry. The development of the industry has the potential to improve the rural environment and produce significant amounts of sustainable energy for China. Barriers to the development are the relatively weak environmental policies, imperfect financial policies and lack of long-term follow-up services. The rapid economic development of China has also seen a development in the scales of biogas plants constructed. Although the technology has been improved, this review has identified problems in the construction and operation of Chinese biogas plants, particularly in the efficiency of household systems. All levels of China's government acknowledge this and recent biogas projects have more focus on quality and less on the quantity. The intention is to gradually introduce stricter environmental policies, to provide better service systems, improve the financial policies that support the construction and follow-up service of biogas projects, promote the use of standardized engineering equipment and materials and standards for plant construction and production. This will promote the development of biogas projects at various scales further, and reduce the dependency on fossil fuels and emissions of greenhouse gases. © 2011 Elsevier Ltd.
Li J.-B.,Central South University of forestry and Technology |
He M.-D.,Central South University of forestry and Technology |
Chen L.-Q.,Central South University of forestry and Technology
Optics Express | Year: 2014
We study theoretically four-wave parametric amplification arising from the nonlinear optical response of hybrid molecules composed of semiconductor quantum dots and metallic nanoparticles. It is shown that highly efficient four-wave parametric amplification can be achieved by adjusting the frequency and intensity of the pump field and the distance between the quantum dot and the metallic nanoparticle. Specifically, the induced probe-wave gain is tunable in a large range from 1 to 1.43 × 105. This gain reaches its maximum at the position of three-photon resonance. Our findings hold great promise for developing four-wave parametric oscillators. ©2014 Optical Society of America.
Zhang X.,Central South University of forestry and Technology |
Seo H.J.,Pukyong National University
Journal of Alloys and Compounds | Year: 2010
Novel Eu3+-doped NaCa4(BO3)3 phosphors were synthesized by solid-state reactions. The emission spectra exhibit well-known transitions from the 5D0 level to the lower 7F manifold. The excitation spectrum monitored with 613 nm consists of broad excitation band peaking at 265 nm and some narrow lines originated from the typical Eu3+ intra-4f6 transitions. The optimum Eu3+ doped concentration, the critical distance of the concentration quenching, the fluorescence decay curves, and the mechanism of concentration quenching are investigated. © 2010 Elsevier B.V. All rights reserved.
Tan J.,Central South University of forestry and Technology
Applied Mechanics and Materials | Year: 2013
Aiming at the problem that most of weighted association rules mining algorithms have not the anti-monotonicity, this paper presents a weighted support-confidence framework which supports anti-monotonicity. On this basis, weighted boolean association rules mining algorithm and weighted fuzzy association rules mining algorithm are presented, which use pruning strategy of Apriori algorithm so that improve the efficiency of frequent itemsets generated. Experimental results show that both algorithms have good performance. © (2013) Trans Tech Publications, Switzerland.
Zhang X.,Central South University of forestry and Technology |
Seo H.J.,Pukyong National University
Journal of Alloys and Compounds | Year: 2011
Luminescence properties of the Sm3+, Dy3+ doped LaMoBO6 phosphors are reported. LaMoBO6:Sm3+ exhibits orange emission corresponding to the 4G5/2 → 6H7/2 transition. LaMoBO6:Dy3+ exhibits two emission bands. The yellow band (570 nm) corresponds to the 4F9/2 → 6H13/2 transition, and the blue one (482 nm) corresponds to the 4F9/2 → 6H15/2 transition. The optimum concentration of Sm 3+ and Dy3+, the critical distance of the concentration quenching, and the decay curves have also been investigated. The analysis of the decay curves indicates that cross-relaxation is primarily responsible for the concentration quenching. © 2010 Elsevier B.V. All rights reserved.
Wen C.-P.,Central South University of forestry and Technology
Meitan Xuebao/Journal of the China Coal Society | Year: 2011
In order to improve the present methods of quantitatively assessment of gas burst during tunnel construction, attribute recognition model based on attribute mathematical theory was developed for assessment of gas burst in tunnel at the prospecting stage. Firstly, based on the analysis of main causes of gas burst in tunnel, seven parameters were chosen as the criterion indices for identification and classification of fatalness assessment of gas burst in tunnel; secondly, attribute measurement functions were rigorously constructed to compute attribute measurement of single index and synthetic attribute measurement; lastly, the identification and classification of fatalness assessment of gas tunnel samples were recognized by the confidence criterion, then attribute recognition model was proposed for comprehensive assessment of gas burst fatalness assessment of gas tunnel. An exemplification study shows that the synthetic assessment results obtained through attribute measurement analysis agree well with the results obtained by the extension assessment method and D, K method. As attribute mathematical theory can successfully resolve certain issues with a number of fuzzy attributes in comprehensive evaluation, and its confidence criterion is established on the basis of the ordered evaluation sets, consequently, it will enable the evaluation results be more reliable.
Ling K.,Central South University of forestry and Technology
International Journal of Digital Content Technology and its Applications | Year: 2011
The forest fire precautionary warning system is composed of wired and wireless communications. Its hardware and software adopt modular structure, so as to compose the system flexibly and adapt to forest fire precautionary warning system of different sizes, different circumstances and different requirements. Any part extracted from the whole system can constitute a complete system. In short, users can select the most rational allocation of software and hardware resources according to the actual situation in order to achieve a higher performance price ratio, which is extremely important for industrialization.
Li X.-Q.,University of Chinese Academy of Sciences |
Chen G.-R.,Central South University of forestry and Technology
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2015
In this paper, we investigate the Hawking radiation of massive spin-1 particles from 4-dimensional Kerr and Kerr-Newman black holes. By applying the Hamilton-Jacobi ansatz and the WKB approximation to the field equations of the massive bosons in Kerr and Kerr-Newman space-time, the quantum tunneling method is successfully implemented. As a result, we obtain the tunneling rate of the emitted vector particles and recover the standard Hawking temperature of both the two black holes. © 2015 The Authors.
Li Y.H.,Central South University of forestry and Technology
Applied Mechanics and Materials | Year: 2014
Efficiency and accuracy of forward problem are important in structural analysis. A real-time algorithm, called coefficient reduced-basis method, is applied to analyze a static problem. A truck frame is taken as an example. Results computed from finite element method, reduced-basis method and coefficient reduced-basis method are obtained. Comparing results from the three methods, coefficient reduced-basis method can get high-precision results quickly, which not separate the design parameters from the linear elastic operators. © (2014) Trans Tech Publications, Switzerland.
Zhan P.,Central South University of forestry and Technology
Environmental science and pollution research international | Year: 2010
BACKGROUND, AIM, AND SCOPE: For many years, highly concentrated wastewater generated from the pulp and paper industry has become the focus of much concern worldwide. The objectives of this study were to determine the treatment efficiency of the alkaline peroxide mechanical pulp (APMP) process wastewater using a sequencing batch reactor (SBR) and analyze the microbial dynamics of the wastewater treatment system using the random amplified polymorphic DNA (RAPD) method. MATERIALS AND METHODS: An SBR was applied to the treatment of APMP pulp and paper process wastewater. The wastewater characteristics and many physicochemical operator indicators in the wastewater treatment process were analyzed and determined according to standard methods. Microbial 16 S rDNA in active sludge was extracted, amplified, and analyzed using the RAPD method for the microbial dynamics of the wastewater treatment system. RESULTS AND DISCUSSION: Ten kinds of natural organic compounds of plants such as monoterpene were detected in the APMP pulp and paper process wastewater. With an influent chemical oxygen demand (COD) that varied in the range of 685.7 to 907.5 mg/L, the corresponding effluent COD was 176.5 to 266.1 mg/L and the removal efficiency was 70.3% to 79.8%. An optimal strain (S308: CAGGGGTGGA) was selected to study the population dynamics and diversity of the bacterial community. The RAPD-polymerase chain reaction (PCR) fingerprints showed very high polymorphism of the genetic bands (78-100%). Four groups of species were clustered using the unweighted pair group method with arithmetic (UPGMA) analysis, and the genetic distance was close between the species within each group. The Shannon-Weaver index was high and varied over time with the COD removal. CONCLUSIONS: The RAPD-PCR technique can be used to study microbial dynamics, which was shown to vary over time with the removal efficiency of SBR treating APMP pulp and paper process wastewater.