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Tan C.,Yibin University | Wang J.,Yibin University | Wu T.,Yibin University | Qin X.,China Tobacco Chuanyu Industrial Corporation | Li M.,University of Sichuan
Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy | Year: 2010

Based on the combination of uninformative variable elimination (UVE), bootstrap and mutual information (MI), a simple ensemble algorithm, named ESPLS, is proposed for spectral multivariate calibration (MVC). In ESPLS, those uninformative variables are first removed; and then a preparatory training set is produced by bootstrap, on which a MI spectrum of retained variables is calculated. The variables that exhibit higher MI than a defined threshold form a subspace on which a candidate partial least-squares (PLS) model is constructed. This process is repeated. After a number of candidate models are obtained, a small part of models is picked out to construct an ensemble model by simple/weighted average. Four near/mid-infrared (NIR/MIR) spectral datasets concerning the determination of six components are used to verify the proposed ESPLS. The results indicate that ESPLS is superior to UVEPLS and its combination with MI-based variable selection (SPLS) in terms of both the accuracy and robustness. Besides, from the perspective of end-users, ESPLS does not increase the complexity of a calibration when enhancing its performance. © 2010 Elsevier B.V. All rights reserved. Source

Li G.,Henan Agricultural University | Li D.,China Tobacco Chuanyu Industrial Corporation | Wang X.,Henan University of Urban Construction | Guo C.,Henan Agricultural University
Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering | Year: 2011

Steam explosion as an effective pretreatment can separate hemi-cellulose, cellulose and lignin from lignocelluloses such as stalk and wood, and enhance yield of production from lignocelluloses with chemical and biological methods. Energy balance of corn stalk steam explosion and anaerobic fermentation were analyzed based on the experiments in the paper. The energy conversion rate of anaerobic fermentation with steam exploded corn stalk increased with the increasing of steam pressure at the same pressure retention time, and the maximums in the same steam pressure were got at the 90 s pressure retention time in each group. The minimum and maximum energy conversion rates of anaerobic fermentation with steam exploded corn stalk were 8.39% and 11.68% at room temperature, which are 1.38 times and 1.92 times than that of the control. But the analysis of incremental benefit-cost ratio showed the expended energy for steam explosion is greater than the increased additional energy output in anaerobic fermentation with steam exploded corn stalk compared with the control. From this point of view, it is not an economic way for steam explosion method. Source

Yu C.,Liaoning University of Technology | Sun Y.,Liaoning University of Technology | Sun Y.,China Tobacco Chuanyu Industrial Corporation | Fan X.,Liaoning University of Technology | And 2 more authors.
Particle and Particle Systems Characterization | Year: 2013

Hierarchical carbon-encapsulated iron nanoparticles (Fe@Cs) with typical core/shell structure are successfully synthesized from starch and iron nitrate by an easy-to-handle process at different carbonization temperatures (600-1000 °C). The nanoparticles are characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), nitrogen adsorption, and Fourier transform infrared spectroscopy (FTIR). The results show that the carbonization temperature has an important effect on the morphology, the core shape, the diameters, and the porous structure as well as performance of Fe@Cs. Fe@C samples carbonized at 900°C (Fe@C-900) show the relatively perfect quasi-spherical bcc-Fe core/carbon shell porous structure and their diameters are in a narrow range of 20-50 nm. The adsorption capabilities of Fe@C samples obtained at different carbonization temperatures for removal of thiophene from model oils are evaluated and compared in a batch-type adsorption system. It has been found that among all of the samples measured, Fe@C-900 shows the highest adsorption capability with an increase of 54% for thiophene in comparison with that of the commercial activated carbon. The feasibility of the as-prepared Fe@C-900 as a magnetically separable adsorbent is also demonstrated. Self-assembled chains of magnetic nanoparticles embedded in a bulk polymer are prepared by thermally curing a dispersion of the nanoparticles in a liquid monomer under the application of a magnetic field. Repulsive forces between the chains cause them to assemble into an array with quasiperiodic, micrometer-scale spacing, and the chains exhibit enhanced magnetic anisotropy along the chain axis. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

Xiao H.,Shanghai JiaoTong University | Ding J.,Tianjin Medicine Union Center | Gao S.,Shanghai JiaoTong University | Yang S.,University of Sichuan | And 2 more authors.
Asian Pacific Journal of Cancer Prevention | Year: 2011

It is well-known that tobacco smoke is a definite causative agent important for human health. Epidemiological research has proven that smoking is a cause of various serious and fatal diseases. However, never-smokers comprise a high proportion of non-small-cell lung cancer (NSCLC) patients. To determine whether lung cancer patients in never smokers have different genetic mutations from their counterparts in smokers, we comprehensively searched the Cochrane Library, Medline and EMbase from 1966 to Jun 2010 for the following terms: ("non-smoker" or "never-smoker") and ("lung cancer") and ("gene") limited to English and clinical trials. Although a significant fraction of lung cancers in never smokers may also be attributable to tobacco, many such cancers arise in the absence of detectable tobacco exposure, and may follow a very different molecular pathway of malignant formation, including EGFR gene mutation, P53 mutation and metabolic gene CYP1AIIle462Val polymorphism. These genes will help doctors to separate never-smoker lung cancer from smokers, and may present promising targets for therapy of never-smoker lung cancers. Future efforts should focus on further delineation of underlying biologic differences, identifying potential non-tobacco-related risk factors, and refining treatment strategies for different groups of lung cancerpatients. Source

Tan C.,Yibin University | Chen H.,Yibin University | Wu T.,Yibin University | Xu Z.,Yibin University | And 2 more authors.
Analytical Letters | Year: 2012

Based on wavelet transformation (WT) and mutual information (MI), a simple and effective procedure is proposed for multivariate calibration of near-infrared spectroscopy. In such a procedure, the original spectra of the training set are first transformed into a set of wavelet representations by wavelet prism transform. Then, the MI value between each wavelet coefficient variable and the dependent variable is calculated, resulting in a MI spectrum; by retaining a subset set of coefficients with higher MI, an update training set consisting of wavelet coefficients is obtained and reconstructed/converted back to the original domain. Based on this, a partial least square (PLS) model can be constructed and optimized. The optimal wavelet and decomposition level are determined by experiment. A NIR quantitative problem involving the determination of total sugar in tobacco is used to demonstrate the overall performance of the proposed procedure, named RPLS, meaning PLS in reconstructed original domain coupled with MI-induced variable selection in wavelet domain (RPLS). Three kinds of procedures, that is, conventional full-spectrum PLS in original domain (FPLS), PLS in original domain coupled with MI-induced variable selection (OPLS), and direct PLS in MI-based wavelet coefficients (WPLS), are used as reference. The result confirms that it can build more accurate and robust calibration models without increasing the complexity. © 2013 Copyright Taylor and Francis Group, LLC. Source

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