Ningbo UniversityZhejiang

Ningbo, China

Ningbo UniversityZhejiang

Ningbo, China

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Tong C.,Ningbo UniversityZhejiang | Lan T.,Ningbo UniversityZhejiang | Shi X.,Ningbo UniversityZhejiang
Control Engineering Practice | Year: 2017

As a multivariate statistical tool, the modified independent component analysis (MICA) has drawn considerable attention within the non-Gaussian process monitoring circle since it can solve two main problems in the original ICA method. Despite the diversity in applications, the determination logic for non-quadratic functions involved in the iterative procedures of MICA algorithm has always been empirical. Given that the MICA is an unsupervised modeling method, a direct rational study that can conclusively demonstrate which non-quadratic function is optimal for the general purpose of fault detection is inaccessible. The selection of non-quadratic functions is still a challenge that has rarely been attempted. Recognition of this issue and motivated by the superiority of ensemble learning strategy, a novel ensemble MICA (EMICA) modeling approach is presented for enhancing non-Gaussian process monitoring performance. Instead of focusing on a single non-quadratic function, the proposed method combines multiple base MICA models derived from different non-quadratic functions into an ensemble one, and the Bayesian inference is employed as a decision fusion method to form a unique monitoring index for fault detection. The enhanced fault detectability of the EMICA method is also illustrated on two industrial processes. © 2016 Elsevier Ltd


Tong C.,Ningbo UniversityZhejiang | Lan T.,Ningbo UniversityZhejiang | Shi X.,Ningbo UniversityZhejiang
Chemometrics and Intelligent Laboratory Systems | Year: 2016

The modified independent component analysis (MICA) has been proposed to tackle some shortcomings which existed in the original ICA iterative procedures and has found wide applications in non-Gaussian data modeling. Motivated by the success of MICA, the modified independent component regression (MICR) method for predicting quality properties of non-Gaussian processes keeps drawing attention within the soft sensing circle. However, the determination logic for non-quadratic functions involved in the iterative procedures of MICA algorithm has always been empirical. Without enough prior knowledge, no theoretical investigation can be carried out to conclusively prove which non-quadratic function is optimal for improving the precision of regression models. The selection of non-quadratic functions is still a challenge that has rarely been attempted. Recognition of this issue activates the current study, which proposes a novel soft sensing approach through taking advantage of ensemble learning strategy. Instead of focusing on a single non-quadratic function, the proposed ensemble MICR (EMICR) method takes all three non-quadratic functions into account and combines multiple base MICR models into an ensemble through assigning different weights. The enhanced soft sensing performance is validated through case studies on three non-Gaussian systems. © 2016 Elsevier B.V.


Tian S.-R.,Ningbo UniversityZhejiang | Yang G.-H.,Ningbo UniversityZhejiang | Li Z.,Ningbo UniversityZhejiang | Shi K.-Y.,Ningbo UniversityZhejiang | And 2 more authors.
Powder Technology | Year: 2016

Dual-layer granular beds consist of a lower layer of fine granules and an upper layer of coarse granules. In order to study the individual functions of the two granular layers with respect to filtration, a small granular bed filtering device (inner diameter of 100 mm) was employed. The two granular layers were separated using a wire mesh such that the upper layer was laid over the wire mesh. A welas® 3000 aerosol spectrometer was used to determine the dust concentrations and size distributions of the inlets and outlets of the upper and lower layers. According to the results, the upper layer was able to remove 96.08–98.78% of the dust. Moreover, owing to the features of the upper bed, including the coarse nature of its granules, its large voidage, and its deep-bed filtration ability, the pressure drop through the granular layer increased slowly with the amount of dust deposited. The lower layer, which had fine granules, was able to effectively remove the fine particulates that passed through the upper layer, reducing the dust concentration at the outlet to 3–7.5 mg/m3. The experimental results confirmed that the dual-layer granular bed filter exhibits unique synergistic properties, namely, a low pressure drop because of the upper layer and a high filtration efficiency because of the lower layer. © 2016 Elsevier B.V.


Zhang J.,Ningbo UniversityZhejiang | Wang P.,Ningbo UniversityZhejiang | Huang X.,Ningbo UniversityZhejiang | Xu J.,Ningbo UniversityZhejiang | And 7 more authors.
RSC Advances | Year: 2016

Thin film solar cells can work efficiently by successful interfacial charge separation/collection. The solution-processed perovskite (CH3NH3PbI3) film carries many trap states on the surface, which is detrimental to the high performance of solar cells. Therefore, it is of great urgency to control the interface in the device. In this study, polar silane molecules with amino end groups are self-assembled at the interface of the perovskite/hole transport materials, which works efficiently for the cells even without enough thermal annealing. It reforms the surface of the insufficiently annealed perovskite film, which leads to a normally performing solar cell without the S-shaped current density-voltage curve. For sufficiently annealed perovskite film, the small amount of PbI2 formed and a Si-O-Si network at the interface passivates the surface traps and acts as an energy barrier to reduce recombination in the perovskite solar cells. With the amino-ended silane modification, the optimized performance of the perovskite solar cell reaches 11.8%, which shows great advantages over the original device with a performance of 8.25% (0.92 Sun, AM1.5). © The Royal Society of Chemistry 2016.


Zhong J.Y.,Ningbo UniversityZhejiang | Zheng X.W.,Ningbo UniversityZhejiang | Ye H.D.,Zhejiang University | Cui H.B.,Ningbo UniversityZhejiang | And 8 more authors.
Genetics and Molecular Research | Year: 2015

APC is a tumor suppressor gene that is involved in the processes of cell migration and adhesion, transcriptional activation, and apoptosis. The goal of this study was to evaluate the contribution of the APC rs383830 polymorphism to coronary heart disease (CHD) in Han Chinese. A total of 783 patients with CHD and 737 controls were tested in the current association study. Although our study did not identify an association between the APC rs383830 polymorphism and CHD, a breakdown analysis by gender indicated there was a significant contribution of the rs383830 T allele to the risk of CHD in males (P = 0.046, odds ratio = 1.267, 95% confidence interval = 1.004-1.598). In conclusion, our study suggested a male-specific association of the APC rs383830 polymorphism with CHD. © FUNPEC-RP.


Yue G.,Ningbo UniversityZhejiang | Chen D.,Ningbo UniversityZhejiang | Wang P.,Ningbo UniversityZhejiang | Zhang J.,Ningbo UniversityZhejiang | And 2 more authors.
Electrochimica Acta | Year: 2016

The low cost graphite/carbon black counter electrodes were prepared under low-temperature for hole-conductor-free mesoscopic perovskite solar cells. Different mass fraction of carbon black particles in the interspace of graphite flakes not only modulates the connection of carbon black and graphite flakes, but also guarantees the good contact between the counter electrode and perovskite layer, which obviously improves the charge transport properties of the cells. The electrochemical impedance spectra and incident photon-to-current conversion efficiency study show evidences of it. Based on the optimized low-temperature carbon electrode (LTCE) with a thickness of 5 μm, power conversion efficiency about 7.29% and good stability are achieved for the hole-conductor-free mesoscopic perovskite solar cells. The abundant availability and excellent properties of such carbon materials based LTCEs offer a wide prospect for its further applications in perovskite solar cells. © 2016


Yan X.,Ningbo UniversityZhejiang
International Journal of Earth Sciences and Engineering | Year: 2015

Selected appropriate primary function and the Max. Spatial size based on fundamental principle of wavelet theory. Performed symmetric boundary continuation of lateral horizontal monitoring data. And then performed decomposition and re-construction of Mallat algorithm of the treated original data to obtain decomposed matrix equation to obtain decomposed low frequency coefficient Cj,k and high frequency coefficient dj,k. Adopted one-dimensional operation for wavelet reconstruction according to decomposed Cj,k and dj,k to remove high frequency partial interfered and eventually to obtain data after de-noise filtering that can be utilized and establish nonlinear method on stability of soft soil deep foundation pit based on Wavelet Transform-Mallat algorithm transform. Set soft soil deep foundation pit excavation in Dongguan as an example, and performed Wavelet Transform-Mallat algorithm transform based on the monitoring data obtained from construction phase. Eventually, obtained data with higher reliability which can be utilized for foundation pit stability analysis. Measurable indicators and numerical analysis contrast have been established to perform noise reduction and filtering effects quantitatively and qualitatively. Through the evaluation it can be seen that soft soil deep foundation pit stability nonlinearity method has high reliability through wavelet-Mallat algorithm and guiding function for engineering practice. © 2015 CAFET-INNOVA TECHNICAL SOCIETY. All rights reserved.


Han S.,Ningbo Institute of Materials Technology and Engineering | Han S.,Ningbo UniversityZhejiang | Xia Y.,Ningbo Institute of Materials Technology and Engineering | Wei Z.,Ningbo Institute of Materials Technology and Engineering | And 5 more authors.
Journal of Materials Chemistry A | Year: 2015

The Li-rich layered oxides are attractive electrode materials due to their high reversible specific capacity (>250 mA h g-1); however, the origin of their abnormal capacity is still ambiguous. In order to elucidate this curious anomaly, we compare the lattice oxygen oxidation states among the Li-rich layered oxide Li1.14Ni0.136Co0.136Mn0.544O2, Li2MnO3 and LiNi0.5Co0.2Mn0.3O2, the two components in Li-rich layered oxides, and the most common layered oxide LiCoO2 before and after initial charge-discharge. For simplicity, we employ chemical treatments of NO2BF4 and LiI acetonitrile solutions to simulate the electrochemical delithiation and lithiation processes. X-ray photoelectron spectroscopy (XPS) studies reveal that part of lattice oxygen in Li1.14Ni0.136Co0.136Mn0.544O2 and Li2MnO3 undergoes a reversible redox process (possibly O2- 虠 O22-), while this does not occur in LiNi0.5Co0.2Mn0.3O2 and LiCoO2. This indicates that the extra capacity of Li-rich layered oxides can be attributed to the reversible redox processes of oxygen in the Li2MnO3 component. Thermogravimetric analysis (TGA) further suggests that the formed O22- species in the delithiated Li1.14Ni0.136Co0.136Mn0.544O2 can decompose into O2 at about 210 °C. This phenomenon demonstrates a competitive relationship between extra capacity and thermal stability, which presents a big challenge for the practical applications of these materials. © The Royal Society of Chemistry 2015.


Huang L.,Nankai University | Sun X.,Nankai University | Li C.,Nankai University | Xu R.,Nankai University | And 8 more authors.
Solar Energy Materials and Solar Cells | Year: 2016

Device modeling of CH3NH3PbI3−xClx based electron transport layer-free planar perovskite solar cells was performed. The simulation was conducted by the program SCAPS (Solar Cell Capacitance Simulator). With appropriate physical parameters, a high open-circuit voltage of 1.04 V close to results reported experimentally was successfully reproduced in the simulation. Simulation results revealed a great dependence of PCE on the thickness and defect density of the perovskite layer. An optimum perovskite thickness of about 500 nm was confirmed and it well consistent with the thickness range of real devices was derived. Meanwhile, parameters including the FTO/perovskite interface defect density as well as the doping concentration of the front contact (FTO) were identified to significantly influence the performance of the device. In particular, the interface quality at the FTO/perovskite interface has greater impact on the device parameters than that at the perovskite/HTL interface, which suggests that more attention should be paid to the front FTO/perovskite interface to further enhance the performance of electron transport layer-free device. Appropriate interface defect passivation to reduce the interface defect density to the order of ~1015 cm−3 is necessary and urgently needed. Lastly, the effect of the electron and hole mobility and carrier diffusion length of CH3NH3PbI3−xClx were also analyzed and the results revealed that the mobility and diffusion length experimentally reported (~1.0 µm) are large and long enough for high efficiency. © 2016

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