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排序方式: 共有828条查询结果,搜索用时 312 毫秒
151.
M. Spth P. M. Sommeling J. A. M. van Roosmalen H. J. P. Smit N. P. G. van der Burg D. R. Mahieu N. J. Bakker J. M. Kroon 《Progress in Photovoltaics: Research and Applications》2003,11(3):207-220
A fully operational baseline consisting of dedicated equipment to process nanocrystalline dye‐sensitized solar cell devices has been installed at ECN. This baseline focuses on the production of glass/glass devices with dimensions up to 10×10 cm2. Present power conversion efficiencies of 6% obtained for cell areas of 2ċ5 cm2 are successfully translated to 100 cm2 devices with an active area of 68 cm2 by application of identical cell components. The power conversion efficiency with respect to total area was 4%. Processing of a large number of devices in the baseline shows good results in terms of process reliability and yield. The overall yield for a series of 27 devices (10×10 cm2) was 96%, while 84% (22 of the remaining 26 devices) generated a cell efficiency within 7% deviation from the average value (4ċ3%). The reproducibility of the titanium dioxide (TiO2) colloid synthesis has been investigated. The deviation from the average efficiency (4ċ9%) of three batches of colloid was at most 3ċ2%. These results prove that complete device manufacturing of nc‐DSC by a baseline process, starting with colloid synthesis is reproducible for surfaces up to 10×10 cm2. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
152.
Application of Smith Predictor Based on Single Neural Network in Cold Rolling Shape Control 总被引:4,自引:0,他引:4
WANG Yiqun SUN FD LIU Jian SUN Menghui XIE Yihan 《机械工程学报(英文版)》2009,22(2):282-286
Flatness is one of the most important criterion factors to evaluate the quality of the steel strip. To improve the strip' s flatness quality, the most frequently used methodology is to employ the closed-loop automatic shape control system. However, in the shape control system, the shape-meter is always installed at the down way of the exit of the cold rolling mill and can not sense the changes of the strip flatness in the rolling gap directly. This kind of installation results in the delay of the feedback in the control system. Therefore, the stability and response performance of the system are strongly affected by the delay. At present, there is still no mature way to design controllers for systems with time delay. Although the conventional PID controller used in most practical applications has the capability to comte the delay, the effect of the compensation is limited, especially for the systems with long time delay. Smith predictor, as a compensator for solving this problem, is now widely used in industry systems. However, the request of highly precise model of the system and the poor adaptive performance to the changes of related parameters limit the application of the Smith predictor in practice. In order to overcome the drawbacks of the Smith predictor, a new Smith predictor based on single neural network PID (SNN-PID) is proposed. Because the single neural network is employed into the Smith predictor to improve the controller's self-adaptability, the adaptive capability to the varying parameters of the system is improved. Meanwhile, for the purpose of solving the problems such as time-consuming and complicated calculation of the neural networks in real time, the learning coefficient of neural network is divided into several stages as usually done in expert control system. Therefore, the control system can obtain fast response due to the improved calculation speed of the neural networks. In order to validate the performance of the proposed controller, the experiment is conducted on the shape control system in a 300 mm four-high reversing cold rolling mill. The experimental results show that the SNN-PID with Smith predictor controller can effectively compeusate the delay effects and achieve better control performance than the conventional PIO controller. 相似文献
153.
Urban Economics and Urban Policy: Challenging Conventional Policy Wisdom. Paul C. Cheshire,Max Nathan and Henry G. Overman. Cheltenham: Elgar, 2014. 256 pp. £67.50, hardback. ISBN 978‐1‐78195‐251‐1; and 2015. 256 pp. £20, paperback. ISBN 978‐1‐78347‐525‐4.
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Martijn J. Smit 《Papers in Regional Science》2017,96(1):221-222
154.
Sizing and control of trailing edge flaps on a smart rotor for maximum power generation in low fatigue wind regimes
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Jeroen Smit Lars O. Bernhammer Sachin T. Navalkar Leonardo Bergami Mac Gaunaa 《风能》2016,19(4):607-624
An extension of the spectrum of applicability of rotors with active aerodynamic devices is presented in this paper. Besides the classical purpose of load alleviation, a secondary objective is established: optimization of power capture. As a first step, wind speed regions that contribute little to fatigue damage have been identified. In these regions, the turbine energy output can be increased by deflecting the trailing edge (TE) flap in order to track the maximum power coefficient as a function of local, instantaneous speed ratios. For this purpose, the TE flap configuration for maximum power generation has been using blade element momentum theory. As a first step, the operation in non‐uniform wind field conditions was analysed. Firstly, the deterministic fluctuation in local tip speed ratio due to wind shear was evaluated. The second effect is associated with time delays in adapting the rotor speed to inflow fluctuations caused by atmospheric turbulence. The increase in power generation obtained by accounting for wind shear has been demonstrated with an increase in energy production of 1%. Finally, a control logic based on inflow wind speeds has been devised, and the potential of enhanced power generation has been shown by time‐domain simulations. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
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156.
Alicyclobacillus species are thermo-acidophilic, endospore-forming bacteria that are able to survive pasteurisation and have been implicated in a number of spoilage incidents involving acidic foods and beverages. The aim of this study was to compare three isolation methods used for the detection of Alicyclobacillus acidoterrestris and to investigate the influence of incubation temperature on the growth of A. acidoterrestris and A. acidocaldarius. Peach juice samples inoculated with A. acidoterrestris K47 were analysed using either the International Federation of Fruit Juice Producers (IFU) Method No. 12 (Method A), which involved spread plating onto Bacillus acidoterrestris (BAT) agar at pH 4.0; Method B, which involved pour plating using potato dextrose agar (PDA) at pH 3.7; or Method C, which made use of membrane filtration followed by incubation on K agar at pH 3.7. The performance of the three methods differed significantly, with the IFU Method No. 12 recovering the highest percentage of cells at 75.97%, followed by Method B at 66.79% and Method C at 3.43%. These findings strengthen the proposal of the IFU for the use of the IFU Method No. 12 as a standard international method for the detection of Alicyclobacillus. To investigate the effect on growth of different incubation temperatures A. acidoterrestris (three strains) and A. acidocaldarius (two strains) were incubated at either 45 °C or 25 °C. Growth at 25 °C was slower and maximum cell concentrations were lower (1 × 105-106 cfu/mL compared to 1 × 107-108 cfu/mL) than at 45 °C for A. acidoterrestris. A. acidocaldarius was unable to grow at 25 °C and cell concentrations decreased by 1-2 logs. Since a growth temperature of 25 °C could not inhibit growth of A. acidoterrestris, cooling to room temperature (20°-25 °C) is not an effective control measure for A. acidoterrestris inhibition. 相似文献
157.
Marie-Therese Haider Nicole Ridlmaier Daniel J. Smit Hanna Taipaleenmki 《International journal of molecular sciences》2021,22(6)
Patients with advanced breast cancer are at high risk of developing bone metastasis. Despite treatment advances for primary breast cancer, metastatic bone disease remains incurable with a low relative survival. Hence, new therapeutic approaches are required to improve survival and treatment outcome for these patients. Bone is among the most frequent sites of metastasis in breast cancer. Once in the bone, disseminated tumor cells can acquire a dormant state and remain quiescent until they resume growth, resulting in overt metastasis. At this stage the disease is characterized by excessive, osteoclast-mediated osteolysis. Cells of the bone microenvironment including osteoclasts, osteoblasts and endothelial cells contribute to the initiation and progression of breast cancer bone metastasis. Direct cell-to-cell contact as well as soluble factors regulate the crosstalk between disseminated breast cancer cells and bone cells. In this complex signaling network interleukins (ILs) have been identified as key regulators since both, cancer cells and bone cells secrete ILs and express corresponding receptors. ILs regulate differentiation and function of bone cells, with several ILs being reported to act pro-osteoclastogenic. Consistently, the expression level of ILs (e.g., in serum) has been associated with poor prognosis in breast cancer. In this review we discuss the role of the most extensively investigated ILs during the establishment of breast cancer bone metastasis and highlight their potential as therapeutic targets in preventing metastatic outgrowth in bone. 相似文献
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160.
P Lu JF Urban XD Zhou SJ Chen K Madden M Moorman H Nguyen SC Morris FD Finkelman WC Gause 《Canadian Metallurgical Quarterly》1996,156(9):3327-3333
CD40/CD40 ligand interactions are required for the development of T cell-dependent Ab responses in vivo. The role of these cell surface molecules in contributing to T cell cytokine production and the development of effector populations other than B cells and T cells is, however, less well defined. We have examined the in vivo effects of blocking CD40/CD40 ligand interactions on the type 2 mucosal immune response that follows oral inoculation of mice with the nematode parasite, Heligmosomoides polygyrus. Administration of anti-gp39 (CD40L) mAb (MR1) blocked H. polygyrus-induced elevations in serum IgG1 levels and inhibited elevations in blood eosinophils and mucosal mast cells at day 14 after inoculation. Anti-gp39 mAb markedly inhibited B cell blastogenesis 8 days after H. polygyrus inoculation but did not inhibit elevations in B cell class II MHC expression. Maximal elevations in B7-2 expression required signaling through both CD40 and the IL-4R. Elevations in T cell cytokine gene expression and elevations in the number of IL-4-secreting cells were unaffected by treatment with anti-gp39 mAb, although IL-4 production was inhibited by anti-IL-4R mAb. These results suggest that CD40/CD40L interactions are not required to activate T cells to produce cytokines but are required for the activation and proliferation of other effector cells associated with the type 2 response. 相似文献