The Experts below are selected from a list of 436029 Experts worldwide ranked by ideXlab platform
Hong Liu - One of the best experts on this subject based on the ideXlab platform.
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engineered microstructure derived hierarchical deformation of flexible Pressure sensor induces a supersensitive piezoresistive property in broad Pressure Range
Advanced Science, 2020Co-Authors: Duo Chen, Hong Liu, Wenxia LiuAbstract:Fabricating flexible Pressure sensors with high sensitivity in a broad Pressure Range is still a challenge. Herein, a flexible Pressure sensor with engineered microstructures on polydimethylsiloxane (PDMS) film is designed. The high performance of the sensor derives from its unique pyramid-wall-grid microstructure (PWGM). A square array of dome-topped pyramids and crossed strengthening walls on the film forms a multiheight hierarchical microstructure. Two pieces of PWGM flexible PDMS film, stacked face-to-face, form a piezoresistive sensor endowed with ultrahigh sensitivity across a very broad Pressure Range. The sensitivity of the device is as high as 383 665.9 and 269 662.9 kPa-1 in the Pressure Ranges 0-1.6 and 1.6-6 kPa, respectively. In the higher Pressure Range of 6.1-11 kPa, the sensitivity is 48 689.1 kPa-1, and even in the very high Pressure Range of 11-56 kPa, it stays at 1266.8 kPa-1. The Pressure sensor possesses excellent bending and torsional strain detection properties, is mechanically durable, and has potential applications in wearable biosensing for healthcare. In addition, 2 × 2 and 4 × 4 sensor arrays are prepared and characterized, suggesting the possibility of manufacturing a flexible tactile sensor.
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An investigation into the bust girth Range of Pressure comfort garment based on elastic sports vest
Journal of the Textile Institute, 2013Co-Authors: Hong Liu, Dongsheng Chen, Qufu Wei, Ruru PanAbstract:In an effort to convert the comfortable clothing Pressure Range on breast into the bust girth Range for Pressure comfort tight-fit garments, 25 healthy female students whose bodies are very close to 160/84 A served as subjects, the garments used were 20 elastic sports vests made of four types of extensibility fabrics with different bust girth and identical style. The objective clothing Pressure exerted on the subjects' breast was measured and subjective compressive feeling was evaluated as well. The comfortable Pressure Range on breast was found to be 0.96–1.355 kPa by studying the relationship between objective clothing Pressure and subjective compressive feeling. In conclusion, the comfortable Pressure Range on breast was converted into bust girth Range and shown in calculation equation, which could provide a novel calculation method for the bust girth design of Pressure comfort tight-fit garments.
Galen B. Fisher - One of the best experts on this subject based on the ideXlab platform.
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no co activity and selectivity over a pt10rh90 111 alloy catalyst in the 10 torr Pressure Range
Journal of Catalysis, 1994Co-Authors: K Y S Ng, David N Belton, Steven J Schmieg, Galen B. FisherAbstract:Abstract We have studied the effects of temperature, NO conversion, and NO-CO ratio on the activity and selectivity of the NO-CO reaction over a Pt 10 Rh 90 (111) surface. The NO-CO activity over the Pt 10 Rh 90 (111) is very similar to that over the Rh(111) surface from 573 to 648 K in that both surfaces have the same E a , reaction orders, products, and selectivities. The turnover numbers for the Pt 10 Rh 90 (111) alloy are slightly lower than those for Rh(111), when compared on a per surface atom basis; however, the rates per surface Rh atom are virtually unchanged. This behavior suggests that the primary effect of Pt is to dilute the Rh surface atom concentration; however, it is equally consistent with electronic modification of all surface atoms. The surface composition remains essentially unchanged over the Range of reaction conditions that we explored; however, we did not go extremely oxidizing, which is the condition known to have the largest effect on the surface composition. The Pt 10 Rh 90 (111) single crystal mimics the behavior of supported Pt-Rh catalysts in that both show high (∼ 75%) selectivity for N 2 O at low temperature, low conversion, or high NO-CO ratio and low or zero N 2 O production at high temperature and high NO conversion. Our conclusion is that the N 2 O selectivity and the overall reaction rate are controlled by the NO adsorption/desorption equilibrium. Adsorbed NO strongly inhibits the NO dissociation reaction, keeping surface N coverages low. However, once the temperature is raised or the NO Pressure lowered, surface NO coverages fall, accelerating the NO dissociation reaction and likewise increasing the N + N reaction. We conclude that these surface kinetics explain the curious N 2 O selectivities observed during light-off of supported catalysts.
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no co activity and selectivity over a pt10rh90 111 alloy catalyst in the 10 torr Pressure Range
Journal of Catalysis, 1994Co-Authors: K Y S Ng, David N Belton, Steven J Schmieg, Galen B. FisherAbstract:Abstract We have studied the effects of temperature, NO conversion, and NO-CO ratio on the activity and selectivity of the NO-CO reaction over a Pt 10 Rh 90 (111) surface. The NO-CO activity over the Pt 10 Rh 90 (111) is very similar to that over the Rh(111) surface from 573 to 648 K in that both surfaces have the same E a , reaction orders, products, and selectivities. The turnover numbers for the Pt 10 Rh 90 (111) alloy are slightly lower than those for Rh(111), when compared on a per surface atom basis; however, the rates per surface Rh atom are virtually unchanged. This behavior suggests that the primary effect of Pt is to dilute the Rh surface atom concentration; however, it is equally consistent with electronic modification of all surface atoms. The surface composition remains essentially unchanged over the Range of reaction conditions that we explored; however, we did not go extremely oxidizing, which is the condition known to have the largest effect on the surface composition. The Pt 10 Rh 90 (111) single crystal mimics the behavior of supported Pt-Rh catalysts in that both show high (∼ 75%) selectivity for N 2 O at low temperature, low conversion, or high NO-CO ratio and low or zero N 2 O production at high temperature and high NO conversion. Our conclusion is that the N 2 O selectivity and the overall reaction rate are controlled by the NO adsorption/desorption equilibrium. Adsorbed NO strongly inhibits the NO dissociation reaction, keeping surface N coverages low. However, once the temperature is raised or the NO Pressure lowered, surface NO coverages fall, accelerating the NO dissociation reaction and likewise increasing the N + N reaction. We conclude that these surface kinetics explain the curious N 2 O selectivities observed during light-off of supported catalysts.
Chris J Pickard - One of the best experts on this subject based on the ideXlab platform.
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high Pressure phases of group ii difluorides polymorphism and superionicity
Physical Review B, 2017Co-Authors: Joseph R Nelson, R J Needs, Chris J PickardAbstract:We investigate the high-Pressure behavior of beryllium, magnesium, and calcium difluorides using ab initio random structure searching and density functional theory (DFT) calculations, over the Pressure Range $0--70$ GPa. Beryllium fluoride exhibits extensive polymorphism at low Pressures, and we find two new phases for this compound---the silica moganite and ${\mathrm{CaCl}}_{2}$ structures---which are stable over the wide Pressure Range $12--57$ GPa. For magnesium fluoride, our searching results show that the orthorhombic ``O-I'' ${\mathrm{TiO}}_{2}$ structure $(Pbca,Z=8)$ is stable for this compound between 40 and 44 GPa. Our searches find no new phases at the static-lattice level for calcium difluoride between 0 and 70 GPa; however, a phase with $P\overline{6}2m$ symmetry is close to stability over this Pressure Range, and our calculations predict that this phase is stabilized at high temperature. The $P\overline{6}2m$ structure exhibits an unstable phonon mode at large volumes which may signal a transition to a superionic state at high temperatures. The group-II difluorides are isoelectronic to a number of other ${\mathrm{AB}}_{2}$-type compounds such as ${\mathrm{SiO}}_{2}$ and ${\mathrm{TiO}}_{2}$, and we discuss our results in light of these similarities.
K Y S Ng - One of the best experts on this subject based on the ideXlab platform.
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no co activity and selectivity over a pt10rh90 111 alloy catalyst in the 10 torr Pressure Range
Journal of Catalysis, 1994Co-Authors: K Y S Ng, David N Belton, Steven J Schmieg, Galen B. FisherAbstract:Abstract We have studied the effects of temperature, NO conversion, and NO-CO ratio on the activity and selectivity of the NO-CO reaction over a Pt 10 Rh 90 (111) surface. The NO-CO activity over the Pt 10 Rh 90 (111) is very similar to that over the Rh(111) surface from 573 to 648 K in that both surfaces have the same E a , reaction orders, products, and selectivities. The turnover numbers for the Pt 10 Rh 90 (111) alloy are slightly lower than those for Rh(111), when compared on a per surface atom basis; however, the rates per surface Rh atom are virtually unchanged. This behavior suggests that the primary effect of Pt is to dilute the Rh surface atom concentration; however, it is equally consistent with electronic modification of all surface atoms. The surface composition remains essentially unchanged over the Range of reaction conditions that we explored; however, we did not go extremely oxidizing, which is the condition known to have the largest effect on the surface composition. The Pt 10 Rh 90 (111) single crystal mimics the behavior of supported Pt-Rh catalysts in that both show high (∼ 75%) selectivity for N 2 O at low temperature, low conversion, or high NO-CO ratio and low or zero N 2 O production at high temperature and high NO conversion. Our conclusion is that the N 2 O selectivity and the overall reaction rate are controlled by the NO adsorption/desorption equilibrium. Adsorbed NO strongly inhibits the NO dissociation reaction, keeping surface N coverages low. However, once the temperature is raised or the NO Pressure lowered, surface NO coverages fall, accelerating the NO dissociation reaction and likewise increasing the N + N reaction. We conclude that these surface kinetics explain the curious N 2 O selectivities observed during light-off of supported catalysts.
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no co activity and selectivity over a pt10rh90 111 alloy catalyst in the 10 torr Pressure Range
Journal of Catalysis, 1994Co-Authors: K Y S Ng, David N Belton, Steven J Schmieg, Galen B. FisherAbstract:Abstract We have studied the effects of temperature, NO conversion, and NO-CO ratio on the activity and selectivity of the NO-CO reaction over a Pt 10 Rh 90 (111) surface. The NO-CO activity over the Pt 10 Rh 90 (111) is very similar to that over the Rh(111) surface from 573 to 648 K in that both surfaces have the same E a , reaction orders, products, and selectivities. The turnover numbers for the Pt 10 Rh 90 (111) alloy are slightly lower than those for Rh(111), when compared on a per surface atom basis; however, the rates per surface Rh atom are virtually unchanged. This behavior suggests that the primary effect of Pt is to dilute the Rh surface atom concentration; however, it is equally consistent with electronic modification of all surface atoms. The surface composition remains essentially unchanged over the Range of reaction conditions that we explored; however, we did not go extremely oxidizing, which is the condition known to have the largest effect on the surface composition. The Pt 10 Rh 90 (111) single crystal mimics the behavior of supported Pt-Rh catalysts in that both show high (∼ 75%) selectivity for N 2 O at low temperature, low conversion, or high NO-CO ratio and low or zero N 2 O production at high temperature and high NO conversion. Our conclusion is that the N 2 O selectivity and the overall reaction rate are controlled by the NO adsorption/desorption equilibrium. Adsorbed NO strongly inhibits the NO dissociation reaction, keeping surface N coverages low. However, once the temperature is raised or the NO Pressure lowered, surface NO coverages fall, accelerating the NO dissociation reaction and likewise increasing the N + N reaction. We conclude that these surface kinetics explain the curious N 2 O selectivities observed during light-off of supported catalysts.
Tian-ling Ren - One of the best experts on this subject based on the ideXlab platform.
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A graphene-based resistive Pressure sensor with record-high sensitivity in a wide Pressure Range
Scientific Reports, 2015Co-Authors: He Tian, Mohammad Ali Mohammad, Wentian Mi, Yi Shu, Qian-yi Xie, Xue-feng Wang, Cheng Li, Yi Yang, Tian-ling RenAbstract:Pressure sensors are a key component in electronic skin (e-skin) sensing systems. Most reported resistive Pressure sensors have a high sensitivity at low Pressures (5 kPa), which is inadequate for practical applications. For example, actions like a gentle touch and object manipulation have Pressures below 10 kPa, and 10-100 kPa, respectively. Maintaining a high sensitivity in a wide Pressure Range is in great demand. Here, a flexible, wide Range and ultra-sensitive resistive Pressure sensor with a foam-like structure based on laser-scribed graphene (LSG) is demonstrated. Benefitting from the large spacing between graphene layers and the unique v-shaped microstructure of the LSG, the sensitivity of the Pressure sensor is as high as 0.96 kPa(-1) in a wide Pressure Range (0 ~ 50 kPa). Considering both sensitivity and Pressure sensing Range, the Pressure sensor developed in this work is the best among all reported Pressure sensors to date. A model of the LSG Pressure sensor is also established, which agrees well with the experimental results. This work indicates that laser scribed flexible graphene Pressure sensors could be widely used for artificial e-skin, medical-sensing, bio-sensing and many other areas.
