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991.
On the basis of some new Liouville theorems, under suitableconditions, a priori estimates are obtained of positive solutionsof the problem
where RN (N 2) is a bounded smooth domain, p>1 and isa parameter, , q are given constants such that p1<<p*1, <q, p*=Np/(Np) if N > p and p*= when N p, and a(x) is a continuous nonnegative function. Makinguse of the LeraySchauder degree of a compact mappingand a priori estimates, the paper finds that the problem abovepossesses at least one positive solution. It also discussesthe corresponding perturbed problem, where a(x) is replacedby a(x)+, >0. The results are strikingly different from thoseobtained for the case =p1. 相似文献
992.
Research on the boron contamination at the p/i interface of microcrystalline silicon solar cells deposited in a single PECVD chamber 下载免费PDF全文
This paper studies boron contamination at the interface between the
p and i layers of μ c-Si:H solar cells deposited in a
single-chamber PECVD system. The boron depth profile in the i layer
was measured by Secondary Ion Mass Spectroscopy. It is found that
the mixed-phase μ c-Si:H materials with 40% crystalline
volume fraction is easy to be affected by the residual boron in the
reactor. The experimental results showed that a 500-nm thick μ
c-Si:H covering layer or a 30-seconds of hydrogen plasma treatment
can effectively reduce the boron contamination at the p/i interface.
However, from viewpoint of cost reduction, the hydrogen plasma
treatment is desirable for solar cell manufacture because the
substrate is not moved during the hydrogen plasma treatment. 相似文献
993.
Tapered dielectric structure in metal as a wavelength-selective surface plasmon polariton focuser 下载免费PDF全文
Symmetric tapered dielectric structures in metal have
demonstrated applications such as the nanofocusing of surface
plasmon polaritons, as well as the waveguiding of V-channel
polaritons. Yet the fabrication of smooth-surfaced tapered structure
remains an obstacle to most researchers. We have successfully
developed a handy method to fabricate metal-sandwiched tapered
nanostructures simply with electron beam lithography. Though these
structures are slightly different from conventional symmetric
V-shaped structures, systematic simulations show that similar
functionality of surface plasmon polariton nanofocusing can still be
achieved. When parameters are properly selected,
wavelength-selective nanofocusing of surface plasmon polaritons can
be obtained. 相似文献
994.
Wei Wang Li-Ping Pang Zun-Quan Xia 《应用数学学报(英文版)》2007,23(1):29-38
In this paper,the UV-theory and P-differential calculus are employed to study second-order ex-pansion of a class of D.C.functions and minimization problems.Under certain conditions,some properties ofthe U-Lagrangian,the second-order expansion of this class of functions along some trajectories are formulated.Some first and second order optimality conditions for the class of D.C.optimization problems are given. 相似文献
995.
996.
In this paper, textural characterization of an activated carbon derived from carbonized coconut shell char obtained at carbonization temperature of 600 °C for 2 h by CO2 activation was investigated. The effects of activation temperature, activation time and flow rate of CO2 on the BET surface area, total volume, micropore volume and yield of activated carbons prepared were evaluated systematically. The results showed that: (i) enhancing activation temperature was favorable to the formation of pores, widening of pores and an increase in mesopores; (ii) increasing activation time was favorable to the formation of micropores and mesopores, and longer activation time would result in collapsing of pores; (iii) increasing flow rate of CO2 was favorable to the reactions of all active sites and formation of pores, further increasing flow rate of CO2 would lead carbon to burn out and was unfavorable to the formation of pores. The degree of surface roughness of activated carbon prepared was measured by the fractal dimension which was calculated by FHH (Frenkel-Halsey-Hill) theory. The fractal dimensions of activated carbons prepared were greater than 2.6, indicating the activated carbon samples prepared had very irregular structures, and agreed well with those of average micropore size. 相似文献
997.
Wei Lin 《Journal of Mathematical Analysis and Applications》2007,332(1):709-726
In this paper, the initial value problem for a class of fractional differential equations is discussed, which generalizes the existent result to a wide class of fractional differential equations. Also the theoretical result established in the paper ensures the validity of chaos control of fractional differential equations. In particular, feed-back control of chaotic fractional differential equation is theoretically investigated and the fractional Lorenz system as a numerical example is further provided to verify the analytical result. 相似文献
998.
Khizar-ul-Haq M.A. Khan Z.L. Zhang X.W. Zhang J.M. Wei Jun Li 《Journal of luminescence》2009,129(10):1158-1162
Blue organic light-emitting devices based on wide bandgap host material, 2-(t-butyl)-9, 10-di-(2-naphthyl) anthracene (TBADN), blue fluorescent styrylamine dopant, p-bis(p-N,N-diphenyl-amino-styryl)benzene (DSA-Ph) have been realized by using molybdenum oxide (MoO3) as a buffer layer and 4,7-diphenyl-1,10-phenanthroline (BPhen) as the ETL. The typical device structure used was glass substrate/ITO/MoO3 (5 nm)/NPB (30 nm)/[TBADN: DSA-Ph (3 wt%)](35 nm)/BPhen (12 nm)/LiF (0.8 nm)/Al (100 nm). It was found that the MoO3∥BPhen-based device shows the lowest driving voltage and highest power efficiency among the referenced devices. At the current density of 20 mA/cm2, its driving voltage and power efficiency are 5.4 V and 4.7 Lm/W, respectively, which is independently reduced 46%, and improved 74% compared with those the m-MTDATA∥Alq3 is based on, respectively. The J-V curves of ‘hole-only’ devices reveal that a small hole injection barrier between MoO3∥NPB leads to a strong hole injection, resulting low driving voltage and high power efficiency. The results strongly indicate that carrier injection ability and balance shows a key significance in OLED performance. 相似文献
999.
Hongjun Liu Hongying Wang Xiaoli Li Yishan Wang Wei Zhao Chi Ruan 《Optics Communications》2009,282(9):1858-1860
Stacking chirped pulse optical parametric amplification based on a home-built Yb3+-doped mode-locked fiber laser and an all-fiber pulse stacker has been demonstrated. Energic 11 mJ shaped pulses with pulse duration of 2.3 ns and a net total gain of higher than 1.1 × 107 at fluctuation less than 2% rms are achieved by optical parametric amplification pumped by a Q-switched Nd:YAG frequency-doubled laser, which provides a simple and efficient amplification scheme for temporally shaped pulses by stacking chirped pulse. 相似文献
1000.
We propose a low-loss metal/dielectric waveguide for compact planar lightwave circuit. The basic waveguide structure is a metal-defined high-index-contrast strip waveguide based on silicon/silica. As the guide is designed for TE single mode waveguiding, extremely low propagation loss (e.g. <0.04 dB/cm), very low bend loss (e.g. 0.0043 dB/90°-turn) and small waveguide pitch of zero-crosstalk are theoretically achievable, and can be further improved by compromising with component size and density. Examples of multi-bends and device integration are demonstrated with numerical simulations. The proposal is compatible with silicon technology and appealing for development of silicon-based planar lightwave circuit. 相似文献