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Cross-linked polypropylene (XPP) foams are modified by a hot-stretching process and charged to be piezoelectric. The results show that a piezoelectric d33 -coefficient of 308pC/N is obtained for sample with an elongation ratio of 200%. The dynamic d33 value is smaller than the quasi-static value, which is probably due to the rise of Young’s modulus with increasing frequency. All the samples show pressure-independent d33 in the range up to 30 kPa. Improved d33 was obtained in the sample rough surface exposed to the corona during charging. Compared to linear PP, the stretched XPP shows pressure independence of d33 in larger range. 相似文献
996.
Li-Wen Cheng Yang Sheng Chang-Sheng Xia Wei Lu Michel Lestrade Zhan-Ming Li 《Optical and Quantum Electronics》2011,42(11-13):739-745
In this paper, we introduce a full 3D simulation for light power distribution of an InGaN/GaN MQW LED with a textured surface. Device simulation was performed with the APSYS software to get power distribution of light sources inside the LED. Based on this, ray tracing simulation was carried out to get light power distribution outside the LED. During the process of ray tracing, the textured surface was treated as a special material interface whose reflectivity, transmittance and refraction angle are obtained with a Finite-Difference Time-Domain (FDTD) method instead of using the usual Fresnel formulas for normal material interfaces. By comparing the ray tracing results with and without the textured surface, we found that the textured surface yields a smoother transmitted power distribution and greatly improved power extraction efficiency, which are comparable to experiment. These effects may be further improved by optimizing the texture geometry. 相似文献
997.
We studied the specific heat of graphene nanoribbons (GNRs) using an extended force constant model. We found that at low temperature, the specific heat decreases, and its variation with temperature increases with increasing GNR width. However, the specific heat increases with increasing GNR width after crossing a chaotic region. Free boundary conditions, -CHOH-terminated and armchair-edge-induced phonon nondegeneracy, shift and distortion and localized vibrational modes significantly influence GNR specific heat compared with periodic boundary conditions and bare and zigzag edges in GNRs. Finally, we found a uniform expression for specific heat vs. width at every temperature except for the chaotic region. 相似文献
998.
999.
Jun Wu Jun Xia Chen Jing Wei Lei Bao-ping Wang 《Applied Physics A: Materials Science & Processing》2011,105(1):221-224
Hierarchical ZnO (zinc oxide) nanostructures composed with nano-sheet and micro-flower structures (made from the nano-sheet)
have been generated on tinfoil substrate via a chemical bath deposition process. Benefiting from an inherent distinct lattice
constant compared with commonly used glass or other kinds of substrate, the tinfoil substrate played an important role on
the formation of the hierarchical ZnO nanostructures. The resulting hierarchical ZnO surface shows excellent superhydrophobicity
and extremely low water rolling angle after being modified with spin coating Teflon. The flexible and superhydrophobic characteristics
of such fabricated substrate will be beneficial for applications requiring bendable and lightweight superhydrophobic substrates.
In addition, the multifunctional properties of ZnO nanostructures are expected to broaden the applications to electronic and
optical applications. 相似文献
1000.
With CMOS scaling approaching its limits, there is a great need for advancements in novel devices, disruptive fabrication
technologies, advanced materials and alternative computer architectures for future nanoelectronic systems. The emergence of
memristive devices is one of promising solutions for the post-CMOS era. In this paper, we first introduce the fabrication
of transition metal oxide based memristor cross-bars using nanoimprint lithography (NIL). The fabrication technique is further
improved by using only one NIL step, reducing the fabrication efforts and improving the device performance. With shadow evaporation,
a host of devices such as 2-terminal lateral memristors and 3-terminal memristive devices (memistors) are also demonstrated.
By building memristor cross-bar arrays on foundry-made CMOS substrates using NIL, we have implemented hybrid nano/CMOS architecture.
This hybrid chip provides an FPGA-like functionality with reconfigurable memristors defining data paths to wire logic gates
into digital circuits. Future trends and issues with fabrication of memristive devices are also briefly discussed. 相似文献