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排序方式: 共有405条查询结果,搜索用时 15 毫秒
1.
Anh Tuan Thanh Pham Oanh Kieu Truong Le Dung Van Hoang Truong Huu Nguyen Trang Huyen Cao Pham Phuong Thanh Ngoc Vo Thang Bach Phan Vinh Cao Tran 《Journal of the European Ceramic Society》2021,41(6):3493-3500
Structure modification has been found to tune significantly the transparent-conducting performance, especially mobility and conductivity of hydrogenated Ga-doped ZnO (HGZO) films. The strong correlation between film thickness and mobility of the films is revealed. The mobility increases quickly with increasing the thickness from 350 to 900 nm, and then tends to be saturated at further thicknesses. A higher mobility than 50 cm2/Vs can be achieved, which is an extra-high value for polycrystalline ZnO films deposited by using the sputtering technique. The thickness-dependent mobility originates from scatterings on grain boundaries and dislocation-induced defects controlled by thin-film growth. Based on the Volmer-Weber model, an expansion model is built up to describe the thickness-dependent crystal growth of the HGZO films, especially at the thick films. As a result, the 800 nm-thick HGZO film obtains the highest performance with high mobility of 51.5 cm2/Vs, low resistivity of 5.3 × 10?4 Ωcm, and good transmittance of 83.3 %. 相似文献
2.
Thi Minh-Thuyen Radwan Amr Huynh Thong Hwang Won-Joo 《Wireless Personal Communications》2019,109(4):2289-2303
Wireless Personal Communications - In the formulating of power control for wireless networks, the radio channel is commonly formulated using static models of optimization or game theory. In these... 相似文献
3.
Effect of Supports and Promoters on the Performance of Ni-Based Catalysts in Ethanol Steam Reforming
Thanh Khoa Phung Thong Le Minh Pham Anh-Nga T. Nguyen Khanh B. Vu Ha Ngoc Giang Tuan-Anh Nguyen Thanh Cong Huynh Hong Duc Pham 《化学工程与技术》2020,43(4):672-688
Ethanol steam reforming (ESR) is one of the potential processes to convert ethanol into valuable products. Hydrogen produced from ESR is considered as green energy for the future and can be an excellent alternative to fossil fuels with the aim of mitigating the greenhouse gas effect. The ESR process has been well studied, using transition metals as catalysts coupled with both acidic and basic oxides as supports. Among various reported transition metals, Ni is an inexpensive material with activity comparable to that of noble metals, showing promising ethanol conversion and hydrogen yields. Additionally, different promoters and supports were utilized to enhance the hydrogen yield and the catalyst stability. This review summarizes and discusses the influences of the supports and promoters of Ni-based catalysts on the ESR process. 相似文献
4.
5.
In this paper, we study the complexity of deciding readiness and failure equivalences for finite state processes and recursively defined processes specified by normed context-free grammars (CFGs) in Greibach normal form (GNF). The results are as follows: (1) Readiness and failure equivalences for processes specified by normed GNF CFGs are both undecidable. For this class of processes, the regularity problem with respect to failure or readiness equivalence is also undecidable. Moreover, all these undecidability results hold even for locally unary processes. In the unary case, these problems become decidable. In fact, they are Πp2-complete, We also show that with respect to bisimulation equivalence, the regularity for processes specified by normed GNF CFGs is NL-complete. (2) Readiness and failure equivalences for finite state processes are PSPACE-complete. This holds even for locally unary finite state processes. These two equivalences are co-NP-complete for unary finite state processes. Further, for acyclic finite state processes, readiness and failure equivalences are co-NP-complete and they are NL-complete in the unary case. (3) For finite tree processes, we show that finite trace, readiness, and failure equivalences are all L-complete. Further, the results remain true for the unary case. Our results provide a complete characterization of the computational complexity of deciding readiness and failure equivalences for several important classes of processes. 相似文献
6.
CM West T Scott-Ward P Teng-umnuay H van der Wel E Kozarov A Huynh 《Canadian Metallurgical Quarterly》1996,271(20):12024-12035
A novel fucosyltransferase (cFTase) activity has been enriched over 10(6)-fold from the cytosolic compartment of Dictyostelium based on transfer of [3H]fucose from GDP-[3H]fucose to Galbeta1,3 GlcNAc beta-paranitrophenyl (paranitrophenyl-lacto-N-bioside or pNP-LNB). The activity behaved as a single component during purification over DEAE-, phenyl-, Reactive Blue-4-, GDP-adipate-, GDP-hexanolamine-, and Superdex gel filtration resins. The purified activity possessed an apparent Mr of 95 X 10(3), was Mg2+-dependent with a neutral pH optimum, and exhibited a Km for GDP-fucose of 0.34 microM, a Km for pNP-LNB of 0.6 mM, and a Vmax for pN-P-LNB of 620 nmol/min/mg protein. SDS-polyacrylamide gel electrophoresis analysis of the Superdex elution profile identified a polypeptide with an apparent Mr of 85 X 10(3), which coeluted with the cFTase activity and could be specifically photolabeled with the donor substrate inhibitor GDP-hexanolaminyl-azido-125I-salicylate. Based on substrate analogue studies, exoglycosidase digestions, and co-chromatography with fucosylated standards, the product of the reaction with pNP-LNB was Fucalpha1, 2Galbeta1,3GIcNAcbeta-pNP. The cFTase preferred substrates with a Galbeta1,3linkage, and thus its acceptor substrate specificity resembles the human Secretor-type alpha1,2- FTase. Afucosyl isoforms of the FP21 glycoprotein, GP21-I and GP21-II, were purified from the cytosol of a Dictyostelium mutant and found to be substrates for the cFTase, which exhibited an apparent K(m) of 0.21 microM and an apparent V(max) of 460 nmol/min/mg protein toward GP21-II. The highly purified cFTase was inhibited by the reaction products Fucalpha1,2Galbeta1,3GlcNAcbeta-pNP and FP21-II. FP21-I and recombinant FP21 were not inhibitory, suggesting that acceptor substrate specificity is based primarily on carbohydrate recognition. A cytosolic location for this step of FP21 glycosylation is implied by the isolation of the cFTase from the cytosolic fraction, its high affinity for its substrates, and its failure to be detected in crude membrane preparations. 相似文献
7.
Scalart P. Leclerc M. Fortier P. Huu Tue Huynh 《Broadcasting, IEEE Transactions on》1997,43(2):191-198
In this paper, we present a performance analysis of a coded orthogonal frequency division multiplexing DAB system that is power multiplexed over a commercial FM station. We model the mobile channel with a time-frequency scattering function. Results show that the performance of the FM demodulator is crucial, since the level of the residual FM signal has a strong influence on the BER performance of the COFDM system. As with other mobile communication systems, the use of interleaving greatly enhances the performances 相似文献
8.
Thi Kieu Oanh Nguyen Thi Luong Vu Minh Quan Nguyen Huynh Kim Khanh Ta Kyoung Sun Park Soo Hyeon Kim Chong Jai Kim Yeon Jin Jang Han Choe 《International journal of molecular sciences》2021,22(10)
Granulocyte-macrophage colony-stimulating factor (GM-CSF) is a member of the colony-stimulating factor (CSF) family, which functions to enhance the proliferation and differentiation of hematopoietic stem cells and other hematopoietic lineages such as neutrophils, dendritic cells, or macrophages. These proteins have thus generated considerable interest in clinical therapy research. A current obstacle to the prokaryotic production of human GM-CSF (hGM-CSF) is its low solubility when overexpressed and subsequent complex refolding processes. In our present study, the solubility of hGM-CSF was examined when combined with three N-terminal fusion tags in five E. coli strains at three different expression temperatures. In the five E. coli strains BL21 (DE3), ClearColi BL21 (DE3), LOBSTR, SHuffle T7 and Origami2 (DE3), the hexahistidine-tagged hGM-CSF showed the best expression but was insoluble in all cases at each examined temperature. Tagging with the maltose-binding protein (MBP) and the b′a′ domain of protein disulfide isomerase (PDIb′a′) greatly improved the soluble overexpression of hGM-CSF at 30 °C and 18 °C. The solubility was not improved using the Origami2 (DE3) and SHuffle T7 strains that have been engineered for disulfide bond formation. Two conventional chromatographic steps were used to purify hGM-CSF from the overexpressed PDIb′a′-hGM-CSF produced in ClearColi BL21 (DE3). In the experiment, 0.65 mg of hGM-CSF was isolated from a 0.5 L flask culture of these E. coli and showed a 98% purity by SDS-PAGE analysis and silver staining. The bioactivity of this purified hGM-CSF was measured at an EC50 of 16.4 ± 2 pM by a CCK8 assay in TF-1 human erythroleukemia cells. 相似文献
9.
10.
Bill Moran Du Q. Huynh Xuezhi Wang Michael Edwards Andrew Harris Barbara F. La Scala 《Digital Signal Processing》2009,19(5):793-808
We describe here a method for the analysis of materials on a conveyor belt using the natural gamma spectra collected with a BGO (Bismuth Germanate) gamma ray detector. This detector collects gamma ray emissions from the Potassium (K), Uranium (U), and Thorium (Th) atoms in the materials. Based on these data, and using a Poisson model for the data generation, a statistical model is proposed and an approximate maximum likelihood (ML) technique based on the expectation-maximization (EM) algorithm is then used to estimate the amount of each of the three elements in the material. The statistical model is further refined to incorporate parameters of drift in the detector and an estimation technique for this is developed and tested against real data. The Cramér–Rao lower bounds for the estimators are calculated. 相似文献