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排序方式: 共有1780条查询结果,搜索用时 15 毫秒
251.
Shailesh Mishra Sushrut Das Shyam S. Pattnaik Sachin Kumar Binod K. Kanaujia 《国际射频与微波计算机辅助工程杂志》2020,30(1)
In this article, a three‐port nonplanar multiple‐input‐multiple‐output/diversity antenna with very high isolation between the radiating elements is presented. To realize diversity from the proposed three‐dimensional (3‐D) antenna configuration, three monopole radiating elements are arranged at an angle of 120°. The isolation between the radiators is enhanced by using a multilayered cylindrical decoupling structure and defected ground structure (DGS). The DGS reduces the coupling due to surface waves while the cylindrical decoupling structure reduces the coupling due to space waves. The proposed antenna offers consistent pervasive connectivity in the wireless communication environment due to its 3‐D geometry with multiple radiating elements and good diversity performance. The prototype is fabricated and measured result shows that more than 42 dB isolation is obtained at the center frequency 1.45 GHz. An increment of 1.2 dBi in the antenna gain is also achieved by using DGS and decoupling structure arrangement. The proposed antenna can be easily placed inside the cylindrical housing or it can be integrated with the existing electronics chip, thus nullifying the requirement for dedicated location in the system. 相似文献
252.
Nilesh K. Tiwari Abhishek Sharma Surya P. Singh M. Jaleel Akhtar Animesh Biswas 《国际射频与微波计算机辅助工程杂志》2020,30(2)
The purpose of this article is to provide a comprehensive investigation on the resonance phenomenon of microstrip line coupled complementary split‐ring resonator (CSRR) with different orientation and relative size. It is shown that when the relative size of the CSRR is smaller than the host line, the CSRR with its slit oriented orthogonal to the line axis will not excite effectively and show weak resonance behavior. However, when the slit is positioned along the line axis, the cross‐polarization effect comes into play, which excites the CSRR through the mixed coupling. To ensure the correctness, several numerical simulations are carried out for different substrate height and relative permittivity. Finally, a prototype is fabricated and measured for the experimental validation. 相似文献
253.
Li Jianquan Hu Renfen Liu Xiaokang Tiwari Prayag Pandey Hari Mohan Chen Wei Wang Benyou Jin Yaohong Yang Kaicheng 《Neural computing & applications》2020,32(12):7759-7768
Neural Computing and Applications - Word embeddings learned on external resources have succeeded in improving many NLP tasks. However, existing embedding models still face challenges in situations... 相似文献
254.
Srivastava Harshit Singh Amandeep Rajeev Arathy Tiwari Usha 《Wireless Personal Communications》2020,114(1):699-709
Wireless Personal Communications - An inherent disadvantage of a Microstrip Patch Antenna (MPA) is its narrow bandwidth and low gain. There are various techniques in the market that either enhances... 相似文献
255.
Kumar Manish Tripathi Rajeev Tiwari Sudarshan 《Multimedia Tools and Applications》2018,77(4):4491-4508
Multimedia Tools and Applications - Wireless Sensor Networks is a promising technology for industrial monitoring and process control. In industry the sensory measures should be delivered to control... 相似文献
256.
Parallax scrolling is a popular web technique used widely in product presentation websites, but its effect on user experience is unknown. Parallax scrolling allows the object displayed in the foreground to move faster than the object displayed in the background, so as to create a 3D effect. Dimensionality and scrolling (modality interactivity) are two major characteristics of this technique. A 2 (dimension) × 2 (modality interactivity) between-subjects (N = 295) online experiment revealed that parallax scrolling influences user engagement through two routes: the cue route (perceived coolness, perceived vividness) and the action route (natural mapping, perceived ease of use). User engagement is in turn associated with positive attitudes and behavioral intentions toward the website and the product. The theoretical contribution of the study is it examined interface feature of parallax scrolling on both user perceptions and user actions using the theory of interactive media effects (TIME). The practical contribution of the study is it provides a roadmap to web developers to emphasize affective factors (i.e., vividness, coolness) rather than cognitive factors (i.e., natural mapping, perceived usefulness) when it comes to improving the user experience of the product presentation websites. 相似文献
257.
Singh Neelam Singh Devesh Pratap Pant Bhasker Tiwari Umesh Kumar 《Wireless Personal Communications》2021,116(4):2819-2833
Wireless Personal Communications - Enterprise thrives on software applications that are built to fulfil the core business requirements. A single business application can offer a cluster of... 相似文献
258.
Infrared Transparent Germanate Glass-Ceramics 总被引:1,自引:0,他引:1
Shyam S. Bayya Jasbinder S. Sanghera Ishwar D. Aggarwal Joshua A. Wojcik 《Journal of the American Ceramic Society》2002,85(12):3114-3116
A new germanate glass-ceramic material in the BaO-Ga2 O3 -GeO2 system is developed for infrared (IR) dome and window applications. This glass-ceramic material has a grain size of ∼0.2–0.5 μm and is transparent in the 3–5 μm IR region. Glass ceramization results in 40% improvement in hardness, 65% increase in elastic modulus, 116% increase in strength, and 134% increase in fracture toughness over the base glass. 相似文献
259.
A study on high performance poly(ether‐ether‐ketone) (PEEK) composites prepared by incorporating aluminum oxide (Al2O3), 0 to 50 wt % by hot compaction at 15 MPa and 350°C was described. Density, thermogravimetric analysis/differential scanning calorimetry, and scanning electron microscopy (SEM) were employed to evaluate their density, thermal stability, crystallinity, and morphology. Experimental density was found higher than theoretical density, which indicates that composite samples are sound. It was found that the addition of micron sized (< 15 μm) Al2O3 increased the peak crystallization temperature by 12°C when compared with neat PEEK with insignificant increase in melting temperature. Half‐time of crystallization is reduced from 2.05 min for the neat PEEK to 1.08 min for PEEK incorporated with 30 wt % Al2O3 because of the strong nucleation effect of Al2O3. The thermal stability of composites in air atmosphere was increased by 26°C. However, thermal stability in nitrogen atmosphere decreases at lower concentration of Al2O3 but increases above 20 wt % of Al2O3. Uniform dispersion of Al2O3 particles was observed in PEEK polymer matrix by SEM. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4623–4631, 2006 相似文献
260.
Shyam Ramkrishna Garud Belagola Shivakumar Priyanka Navin Kumar Rastogi Maya Prakash 《臭氧:科学与工程》2018,40(3):198-208
Thermal processing is the most widely adopted technology for preservation of juices; however, it is associated with significant changes in nutritional quality and flavor. Combination of nonthermal hurdles (ozone 1.2 g/h, 10 min, and lactic acid 0.5%) reduced total bacterial count of sugarcane juice by 4.3 log and controlled enzymatic activity to a moderate level (reduction of 60% and 72% activity of polyphenol oxidase and peroxidase, respectively). Combined treatment was comparable to thermal treatment in maintaining microbial and sensory quality of sugarcane juice during 1-month storage under refrigerated conditions; however, additional hurdles may be required for extended storage. 相似文献