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991.
992.
Nanoimprint lithography has two basic steps. The first is the imprint step in which a mold with nanostructures on its surface is pressed into a resin film on a substrate, followed by removal of the mold. The second step is the residual layer removal by a reactive ion etching (RIE). There is no report whether the properties of the imprinted structure after RIE change or not. In this work, the authors evaluated the Young’s modulus of the imprinted pillar after residual layer removal by RIE. In this experiment, hydrogen silsesquioxane (HSQ), a type of spin-on-glass, was used as an imprint material. The residual layer was etched by RIE using CHF3 gas. The Young’s modulus of imprinted pillar after RIE was measured via cantilever method. The Young’s modulus of HSQ pillar after RIE was twice as much as that of HSQ pillar before RIE. From the Fourier transform infrared measurement, it was founds the chemical structure of HSQ was changed by forming network structure due to heating by RIE plasma energy. These results indicate that the mechanical property of imprinted structure was changed in the residual layer removal step by using RIE. 相似文献
993.
LiVPO4F/C samples were synthesized by one-step solid-state reaction and two-step solid-state reaction methods, respectively. The X-ray diffraction (XRD), scanning electron microscopy (SEM) and electrochemical performance tests were adopted to characterize the properties of LiVPO4F/C. XRD results show that the LiVPO4F/C samples prepared by one-step solid-state reaction method have the same triclinic structure (space group as that synthesized by conventional two-step solid-state reaction. SEM image exhibits that the particle size of LiVPO4F/C prepared by one-step solid-state reaction method is smaller than that of the sample synthesized by two-step solid-state reaction. The improved electrochemical properties of the LiVPO4F/C are attributed to the depressed grain size and enhanced electrical conductivity produced via one-step solid-state reaction method using oxalic acid as both reduction agent and carbon sources. AC impedance measurements also show that the LiVPO4F/C synthesized by one-step solid-state reaction route significantly decreases the charge-transfer resistance. 相似文献
994.
When the number of users is finite, the performance improvement of the orthogonal random beamforming (ORBF) scheme is limited in high signal‐to‐noise ratio regions. In this paper, to improve the performance of the ORBF scheme, the user set and transmit power allocation are jointly determined to maximize sum rate under the total transmit power constraint. First, the transmit power allocation problem is expressed as a function of a given user set. Based on this expression, the optimal user set with the maximum sum rate is determined. The suboptimal procedure is also presented to reduce the computational complexity, which separates the user set selection procedure and transmit power allocation procedure. 相似文献
995.
The design and synthesis of an asymmetrical zinc phthalocyanine sensitizer modified with a catechol anchoring group is reported. The performance of this sensitizer was evaluated in a dye-sensitized solar cell. A strong interaction between the catechol dye and TiO2 (with the formation of a five-membered charge-transfer complex) was evidenced by a strong shift in the Q-band of the ZnPc-Cat from 680 nm in solution to 750 nm on TiO2, along with an appreciable absorption tail extending to ∼1000 nm. The fabricated solar cell containing the phthalocyanine sensitizer showed relatively high light-to-electron conversion efficiency (η = 0.92%), considering that few catechol dyes exceed η = 0.7% in dye-sensitized solar cells. Values of Isc = 2.53 mA cm−2 and Voc = 540 mV were obtained, referring to a standard N719 cell (η = 6.46%). A comparison of zinc phthalocyanine sensitizers bearing different anchoring groups affirmed the superiority of carboxylate groups relative to those bearing catechol groups in terms of cell performance. 相似文献
996.
Chul Kyu Jin Amir Bolouri Chung Gil Kang 《Metallurgical and Materials Transactions B》2014,45(3):1068-1080
We propose the possibility of fabricating A6061 thin plates using the rheology forging process. Electromagnetic stirring (EMS) is used to fabricate a semi-solid slurry. A thin plate is formed by injecting the slurry into the forging die. When the punch speed used to compress the slurry is low, turbulent flow occurs. When the punch speed is high, laminar flow occurs, and the solid and liquid phases move simultaneously. For a pressure of 150 MPa or below, incomplete filling behavior and cracks occur. For a pressure of 200 MPa or above, a durable formed product can be obtained. However, the differences between the mechanical properties according to the application of EMS and pressure are slight. The microstructure of the slurry without EMS has an unclear distinction between the liquid phase and solid phase. However, the microstructure of the thin plates formed by using this slurry has a clear distinction between the liquid and solid with respect to the spheroid shapes. The tensile strength and elongation for a thin plate formed with a punch speed of 300 mm/s and pressure of 250 MPa with EMS slurry are 169 MPa and 11.0 pct, respectively. After T6 heat treatment, the tensile strength improves to 305 MPa. 相似文献
997.
A broadband circularly polarized patch antenna with suspended structure is proposed. The suspended patch has a bow‐tie structure and a gap‐coupled feed. By connecting a resistor load to another gap‐coupled feed port at the opposite position, a wide impedance and axial ratio (AR) bandwidths are obtained. The proposed design has a very simple antenna structure with an impedance bandwidth of 44.5% and a 3‐dB AR bandwidth of 33.8%, respectively. The results show that the bandwidth of the patch antenna is successfully broadened using the suspended configuration, gap‐coupled feed, and resistor loading. © 2014 Wiley Periodicals, Inc. Int J RF and Microwave CAE 24:587–593, 2014. 相似文献
998.
Bae Jin Lee Chang Wook Kang Seong-Joon Kim Suk Joo Bae 《The International Journal of Advanced Manufacturing Technology》2014,71(1-4):219-231
In this paper, we examine the preventive maintenance policies for systems/items which are degraded continuously in time and the degree of deterioration that can be observed through periodic inspection. The items will be replaced preventively if the wear process exceeds a limit at periodic inspection or replaced immediately on failure. The limit is assumed to be random in taking individual variation to withstand damages or unmeasurable variables latent to failure into account. Continuous wear process is modeled via a gamma process. We derive an optimal wear limit for preventive replacement so that the long-run total expected cost per unit time is minimized. The proposed method is applied to a problem of block mat inspection for the barrier’s seabed protection. 相似文献
999.
Two different meat-cutting methods were used to prepare kung-wans in an attempt to produce low-salt products while retaining the same, or improved, textural and physicochemical properties of the standard high-salt formulation. The level of salt and the processing method significantly affected color, cooking yield, texture and changes in the secondary structures of proteins. Improved salt levels resulted in firmer texture. At the same salt levels, compared with chopping, the beating method resulted in higher L?-values, improved cooking yields and changes in the β-sheet content of the proteins, which resulted in an improved product with better texture. Using the beating process, the kung-wans prepared with 1% and 2% salt had similar L?-values, cooking yield and texture, and were better than those prepared by chopping with 2% salt. Overall, the beating process enabled lowering of the salt content, making the kung-wans more hard, brittle and elastic. 相似文献
1000.
Hao-Wu Lin Hao-Wei Kang Zheng-Yu Huang Chang-Wen Chen Yi-Hong Chen Li-Yen Lin Francis Lin Ken-Tsung Wong 《Organic Electronics》2012,13(10):1925-1929
Novel organic/ultrathin low work function metal bilayer cathode buffers for small molecule organic solar cells are proposed. Ultrathin low work function metal layers possess a high built-in electric field for effective carrier extraction and a high cathode reflectivity for maximum absorption in the photoactive layers. This leads to a significant increase of short circuit current density and fill factor of cells. By integrating this bilayer cathode buffer with DTDCTB:C60 small molecular heterojunction, the device exhibits a high power conversion efficiency of up to 5.28%, which is an improvement of 22% compared to a device with a traditional single organic layer buffer. 相似文献