667 research outputs found
Jie dian cai liao jie mian fu jin de ju yu chang fen bu
No full textCheung Wing Yi = 介電材料界面附近的局域場分佈 / 張詠怡.Thesis submitted in: October 2004.Thesis (M.Phil.)--Chinese University of Hong Kong, 2005.Includes bibliographical references (leaves 81-85).Text in English; abstracts in English and Chinese.Cheung Wing Yi = Jie dian cai liao jie mian fu jin de ju yu chang fen bu / Zhang Yongyi.Chapter 1 --- Introduction --- p.2Chapter 2 --- Fundamentals --- p.10Chapter 2.1 --- Local Field --- p.10Chapter 2.2 --- Clausius-Mossotti Equation --- p.12Chapter 3 --- Multi-layer Formulation --- p.14Chapter 3.1 --- Developed Lekner Summation Method --- p.15Chapter 3.2 --- Formulation --- p.16Chapter 3.2.1 --- Interlayers --- p.16Chapter 3.2.2 --- Multi-layers --- p.22Chapter 3.3 --- Comparision with Ewald-Kornfeld Formulation --- p.26Chapter 3.4 --- Contact with macroscopic concepts --- p.30Chapter 4 --- Local Field Distribution near Sharp Interfaces --- p.32Chapter 4.1 --- Body-centered Tetragonal Lattices --- p.33Chapter 4.2 --- Simple Tetragonal and Body-centered Tetragonal Lattices --- p.39Chapter 4.3 --- Effects of Geometric Anisotropy --- p.43Chapter 5 --- Local Field Distribution for Graded Materials --- p.52Chapter 5.1 --- Bare Polarizability Gradient --- p.53Chapter 5.2 --- Temperature Gradient --- p.58Chapter 6 --- Optical Response for Drude Dielectric Gradation Profile --- p.63Chapter 7 --- Summary --- p.72Chapter A --- Lekner summation method --- p.74Chapter B --- Ewald-Kornfeld Formulation --- p.78Chapter C --- Langevin-Debye Equation --- p.8
Analysis of composite wing structures with a morphing leading edge
No full textOne of the main challenges for the civil aviation industry is the reduction of its environmental impact. Over the past years, improvements in performance efficiency have been achieved by simplifying the design of the structural components and using composite materials to reduce the overall weight. These approaches however, are not sufficient to meet the current demanding requirements set for a „greener‟ aircraft.
Significant changes in drag reduction and fuel consumption can be obtained by using new technologies, such as smart morphing structures. These concepts will in fact help flow laminarisation, which will increase the lift to drag ratio. Furthermore, the capability to adapt the wing shape will enable to optimise the aerodynamic performance not only for a single flight condition but during the entire mission. This will significantly improve the aircraft efficiency.
The current research work has been carried out as part of the European Commission founded Seventh Framework Program called „Smart High Lift Device for the Next Generation Wing‟ (SADE), which main aim is to develop and study morphing high lift devices. The author‟s investigation focused on developing a design concept for the actuation mechanism of a morphing leading edge device. A detailed structural analysis has been carried out in order to demonstrate its feasibility.In the first phase of the research the attention was directed on the preliminary design and analysis of the composite wing box. The parameters of the key structural components, such as skin, spars, ribs and stringers were set to satisfy the static stress and buckling requirements. Moreover, numerical and experimental studies were conducted to analyse the static failure and buckling behaviour of two typical composite wing structural components: a spar section and a web and base joint assembly.
In the second stage of the research, a design for the morphing leading edge actuation mechanism was developed. The actuation system was designed in such a way that the target shape was reached with minimum actuation force demand. A geometrical nonlinear FE analysis was conducted to simulate the leading edge morphing deflection and ensure that structural strength requirements were satisfied. Furthermore, the behaviour of the skin integrated with the internal actuation mechanism was modelled under the aerodynamic pressure, at different flight conditions and gust loads, in order to prove that the proposed actuation system can compete with the conventional rigid rib.
This study demonstrated that a feasible morphing leading edge design for a next generation large aircraft wing can be achieved. Developing the readiness of this technology will have a significant impact on aircraft efficiency and considerable contribution towards a more environmental friendly aviation
Sinoscarterella Nel, Fu & Huang 2022, gen. nov.
No full textGenus Sinoscarterella Nel, Fu & Huang, gen. nov. urn:lsid:zoobank.org:act: C837B59B-B7BC-4FBD- A306-9D0A4CCF45DB Type species. Sinoscarterella incompleta Nel, Fu & Huang, sp. nov. Etymology. Named after the Latin name sina for China, and the suffix ‘ scarterella ’, frequently employed for the fossil eoscarterelline genera. Gender feminine. Diagnosis. Forewing characters only. Forewing rugose, punctate; posterior curvature of main stem of RA; branches of CuA elongate; MP with 11 branches reaching wing margin; no branch of R basad emergence of RP; 5–6 anterior branches of RA; first branch of RA not pectinate; postclaval portion of membrane curved; first anterior branch of MP forked distad crossvein rp-m; first posterior branch of MP forked basad crossvein m-cua; first posterior branch of MP with 11 terminal branches reaching posterior wing margin; first fork of MP distad that of CuA.Published as part of Wang, Ye-hao, Nel, André, Fu, Yan-zhe, Su, Yi-tong, Cai, Chen-yang, Liu, Yu-ming, Gao, Jian & Huang, Di-ying, 2022, New insect fossils discovered from the Lower Jurassic Sangonghe Formation at the Turpan Basin, Xinjiang, NW China, pp. 183-194 in Palaeoentomology 5 (2) on page 186, DOI: 10.11646/palaeoentomology.5.2.12, http://zenodo.org/record/653036
Cong liang zi xin xi xue de jiao du tan tao yi xie liang zi xiang bian zhong de ji ben wen ti
No full textYu, Wing Chi = 從量子信息學的角度探討一些量子相變中的基本問題 / 余詠芝.Thesis Ph.D. Chinese University of Hong Kong 2014.Includes bibliographical references (leaves 131-139).Abstracts also in Chinese.Title from PDF title page (viewed on 03, November, 2016).Yu, Wing Chi = Cong liang zi xin xi xue de jiao du tan tao yi xie liang zi xiang bian zhong de ji ben wen ti / Yu Yongzhi
Spininola yuqingensis Huang & Yu & Hu 2022, sp. n.
No full textSpininola yuqingensis sp. n. (Figs 1–3) Type material. Holotype. male, Yuqing county, 876 m, Zunyi, Guizhou Prov., 23–24.vii.2021, coll. Yan-Qing Hu & Yong Yu. Paratypes. 3 males, with the same data as the holotype; 2 males, Yuqing county, 777 m, Zunyi, Guizhou Prov., 31.vii.2021, coll. Yan-Qing Hu & Yong Yu; 4 males, Yuqing county, 876 m, Zunyi, Guizhou Prov., 29.vii.2021, coll. YanQing Hu & Yong Yu. Diagnosis. The new species resembles Spininola nepali László, Ronkay & Ronkay, 2014 by the forewing patterns, but the two species can be easily distinguished by the configurations of the male genitalia. Compared with S. nepali, the new species has a slender uncus, a wide distally and long dorsal lobe of valva and a slightly sclerotized ventral lobe of valva. Spininola nepali has a short and pointed uncus, a short dorsal lobe of valva with a parallel margin distally and a short ventral lobe of valva with a strongly sclerotized and curved margin. Description. Adult (Fig. 1). Wingspan 14–17 mm. Head grayish white; antenna brown, bipectinate in male; labial palpus short, stretched forward, mostly covered with grayish scales. Thorax brown, collar gray. Abdomen brown. Forewing ground color grayish brown, costal margin brown from medial line to wing base, vein Sc black from antemedial line to wing base, terminal area pale brown; basal line undistinguished; antemedial line blackish brown; medial line poorly visible; postmedial line wavy, formed with black dots; subterminal line wavy, formed with black and short lines; terminal line blackish brown; cilia reddish brown. Hindwing unicolorous, grayish brown; discal spot gray. Male genitalia (Figs 2 & 3). Uncus slender, pointed at apex, almost as long as the spines located at top of ventral lobe of valva; tegumen thin, about 3x as long as uncus; valva divided at base; dorsal lobe broad distally, slender at base, two thirds sclerotized at costal margin; ventral lobe slightly sclerotized with parallel margin, a spine located at apex; harpe slender, S-shaped, sclerotized; sacculus 1/3x as long as the ventral lobe of valva; saccus small and V-shaped. Aedeagus long, slightly twisted; vesica without cornuti; coecum almost 1/5 × as long as aedeagus. Female. Unknown. Distribution. China (Guizhou). Etymology. The species name is derived from the name of the type-locality.Published as part of Huang, Zhen-Fu, Yu, Yong & Hu, Yan-Qing, 2022, Description of a new species of Spininola László, Ronkay & Witt, 2010 (Lepidoptera, Nolidae, Nolinae), with new records of Spininola in China, pp. 598-600 in Zootaxa 5195 (6) on page 598, DOI: 10.11646/zootaxa.5195.6.8, http://zenodo.org/record/722399
Wing-external store aerodynamic interferences of a subsonic aircraft
No full textModem fighter aircraft are mostly designed to carry its store externally. Installing store to an aircraft wing externally would have much engineering implication especially through the change in the aerodynamic characteristic. This research was carried out to study the application of the Computational Fluid Dynamics (CFD) method along with experimental methods in predicting the aerodynamic interference caused by these installations. Commercial CFD code. Fluent 5.3 had been validated using experimental results reported in the literature lor two dimensional, subsonic and transonic flow over the NACA 0012 and the RAE 2822 airfoil. Subsequently, low speed wind tunnel experiments were carried out over a wing model installed with an external store. The wing model was fabricated based on a digitized BAe Hawk 208 fighter wing. For further CFD code validation, the wind tunnel configurations were again simulated using the CFD method and its results were validated with the experimental results. Finally, a simplified full scale Hawk 208 aircraft model carrying an external store was simulated at various attitudes and flow speeds. In the two-dimensional subsonic flow, pressure distribution predicted by CFD was in good agreement and comparable to the experimental results. For the transonic two-dimensional flow validation, pressure distribution predicted by various flow models were slightly different from the experimental results (9% to -22.2% in term of CL). For wind tunnel configuration, an average of about 12% deviation in pressure distribution between the results predicted by the CFD method and measured in the wind tunnel. The results of the fu!! scale Hawk 208 simulation show that the aerodynamic interference caused by the store installation were mostly evidence on the lower wing surface and negligible on the upper surface at low angle of attack. This trend was reversed as the angle of attack was increased. The area of influence on the wing surface by store interference increased in line with the increased in airspeed
Spininola qianfengensis Huang & Yu & Hu 2021, sp. n.
No full textSpininola qianfengensis sp. n. (Figs 7–9) Type material. Holotype. male, Qianfeng District, 445 m, Guang’an, Sichuan Prov., 7.viii.2020, coll. Yanqing Hu & Yong Yu. Diagnosis. Spininola qianfengensis is similar to S. trilinea (Marumo, 1923) (Figs 10–12) in the configuration of the male genitalia, but the two species can be easily distinguished by the forewing patterns: qianfengensis has a grayish forewing ground color, a grayish head, a grayish black collar and a pale grayish black stripe along costal margin, while trilinea has a grayish white forewing ground color, a white head and collar and a brown stripe along costal margin from the medial line to the wing base. In the male genitalia, qianfengensis has a shorter harpe, a parallel margin of ventral lobe of the valva, a thick part of sclerotized margin of the valva, a U-shaped saccus, and a straight aedeagus, while trilinea has a longer harpe, a tapered ventral lobe of the valva, a thin part of sclerotized margin of the valva, a V-shaped saccus, and a curved aedeagus. Description. Adult (Fig. 7). Wingspan 15 mm. Head grayish; antenna grayish brown, bipectinate in male; labial palpus short, stretched forward, mostly covered with grayish brown scales. Thorax brown, collar grayish black. Abdomen brown. Forewing ground color grayish, costal margin pale grayish black from the medial line to the wing base; basal line poorly visible; antemedial line blackish brown, arcuate; medial line poorly visible; postmedial line feeble, sinuous; subterminal line feeble; terminal line grayish brown; cilia blackish brown. Hindwing unicolorous, grayish brown; discal spot unconspicuous. Male genitalia (Figs 8 & 9). Uncus tapered, pointed at apex, sclerotized, longer than the spine bearing at top of ventral lobe of the valva; tegumen thin, about 3 times as long as uncus; valva divided at base; dorsal lobe broad distally, slender at base, sclerotized at costal margin; ventral lobe with parallel margin, a spine at apex, sclerotized at ventral margin; harpe smaller, S-shaped, sclerotized, sharp at apex; sacculus 2/3 as long as the ventral lobe of the valva; saccus small and U-shaped. Aedeagus straight; vesica without cornuti. Female. Unknown. Distribution. China (Sichuan). Etymology. The species name is derived from the name of type-locality of the new species.Published as part of Huang, Zhen-Fu, Yu, Yong & Hu, Yan-Qing, 2021, Two new species and a new record of the genus Spininola László, Ronkay & Witt 2010 from China (Lepidoptera, Nolidae, Nolinae), pp. 484-488 in Zootaxa 5047 (4) on pages 485-487, DOI: 10.11646/zootaxa.5047.4.8, http://zenodo.org/record/554314
Spininola yongdingensis Huang & Yu & Hu 2021, sp. nov.
No full textSpininola yongdingensis sp. nov. (Figs 1–3) Type material. Holotype. male, Yongding District, 339 m, Zhangjiajie, Hunan Prov., 14.viii.2020, coll. Yanqing Hu & Yong Yu. Paratype. 1 male, with the same data as the holotype. Diagnosis. Spininola yongdingensis is very similar to S. longshengensis Hu, Yu & Wang, 2019 (Figs 4–6) in its external features, but the two species can be distinguished by the following differences: The new species has a grayish forewing ground color, a grayish black stripe along costal margin from the medial line to the wing base, a distinct and black antemedial line and a feeble postmedial line. Spininola longshengensis has a grayish brown forewing ground color, a brown and black stripe along costal margin from the medial line to the wing base, a feeble antemedial line, and a distinct postmedial line. In the male genitalia, S. yongdingensis has a thin and basally wide uncus, a straight dorsal lobe of the valva, a bent at 90-degree and round apically harpe, and a straight aedeagus. Spininola longshengensis has a tapered uncus, a curved dorsal lobe of the valva, a V-shaped and pointed apically harpe, and a curved aedeagus. Description. Adult (Fig. 1). Wingspan 16 mm. Head grayish with black hairs; antenna grayish brown, bipectinate in male; labial palpus short, stretched forward, mostly covered with grayish scales. Thorax grayish brown, collar grayish. Abdomen blackish brown. Forewing ground color grayish, costal margin grayish black from the medial line to the wing base, terminal and subterminal areas mostly grayish brown; basal line poorly visible; antemedial line black, just present at cell area; medial line poorly visible; postmedial line black, sinuous; subterminal line blackish brown, undulate; terminal line grayish brown; cilia blackish brown. Hindwing unicolorous, grayish brown; discal spot pale black. Male genitalia (Figs 2 & 3). Uncus distally slender, pointed at apex, almost as long as the spine bearing at top of ventral lobe of the valva; tegumen thin, about 4 times as long as uncus; valva divided at base, dorsal lobe longer than ventral lobe; dorsal lobe broad distally, slender at base, sclerotized at costal margin; ventral lobe with parallel margin, two spines at apex, sclerotized at ventral margin; harpe robust, basally bent at 90-degree, round at apex; sacculus 2/3 as long as the ventral lobe of the valva; saccus wide and U-shaped. Aedeagus straight; vesica without cornuti. Female. Unknown. Distribution. China (Hunan). Etymology. The species name is derived from the name of the type-locality of the new species.Published as part of Huang, Zhen-Fu, Yu, Yong & Hu, Yan-Qing, 2021, Two new species and a new record of the genus Spininola László, Ronkay & Witt 2010 from China (Lepidoptera, Nolidae, Nolinae), pp. 484-488 in Zootaxa 5047 (4) on page 485, DOI: 10.11646/zootaxa.5047.4.8, http://zenodo.org/record/554314
China's economic growth engine: The likely types of hardware failure, software failure and power supply failure
No full textThe 6th Plenum of the 16th Central Committee of the Communist Party of China (CPC) concluded on October 11, 2006, with the commitment to establish a harmonious society by 2020. The obvious implication from this commitment is that the present major social, economic and political trends are not leading to a harmonious society or, at least, not leading to a harmonious society fast enough. Analytically, if the Chinese economy is depicted as a speeding car, there are three classes of failures (a) a hardware failure from the breakdown of an economic mechanism, a development that is analogous to the collapse of the chassis of the car; (b) a software failure from a flaw in governance that creates frequent widespread social disorders that disrupt production economy-wide and discourage private investment, a situation similar to a car crash that resulted from a fight among the people inside the speeding car; and (c) a power supply failure from hitting either a natural limit or an externally-imposed limit, a situation that is akin, respectively, to the car running out of gas or to the car smashing into a barrier erected by an outsider. For hardware failure we discuss the possible weakening of China's fiscal position generated by the repeated recapitalization of the state banks. For software failure, we discuss possible social disorder caused by outmoded governance. And for power supply failure, we discuss the possible trade disputes from China’s chronic trade imbalances and the physical constraints posed by China’s rapidly deteriorating natural environment.China; growth; banks; environment
FIGURE 3 in New insect fossils discovered from the Lower Jurassic Sangonghe Formation at the Turpan Basin, Xinjiang, NW China
No full textFIGURE 3. Insect wing fragments from the Sangonghe Formation at Daheyan locality. A, Wing fragment of Odonatoptera, possibly a Protozygoptera of Permagrionidae type, NIGP180148. B, Probably a fragment of auchenorrhynchan hind wing, NIGP180149. C and D, A cockroach forewing without claval part, NIGP180150a, b. Scale = 5 mm in A, 2 mm in B–D.Published as part of Wang, Ye-hao, Nel, André, Fu, Yan-zhe, Su, Yi-tong, Cai, Chen-yang, Liu, Yu-ming, Gao, Jian & Huang, Di-ying, 2022, New insect fossils discovered from the Lower Jurassic Sangonghe Formation at the Turpan Basin, Xinjiang, NW China, pp. 183-194 in Palaeoentomology 5 (2) on page 186, DOI: 10.11646/palaeoentomology.5.2.12, http://zenodo.org/record/653036
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