26,164 research outputs found
Comparative analysis of air-gap PD characteristics: vegetable oil/pressboard and mineral Oil/pressboard
No full textPartial Discharge (PD) is considered to be one of the main reasons for aging and degradation of the oil/pressboard insulation system in power transformers. Vegetable oils which own excellent dielectric performance are introduced as potential insulation liquids substituting traditional mineral oil. In this paper, an air-gap PD model was adopted to investigate the PD characteristics of refined rapeseed oil and Karamay 25# mineral oil that are both currently employed in liquid filled power transformers. The PD current pulse waveform analysis (PD-CPWA) method was used to investigate PD mechanisms of two different insulation systems: mineral oil/pressboard and vegetable oil/pressboard. For both insulation systems, phase resolved partial discharge (PRPD) patterns throughout the accelerated deterioration experiments were compared. The extracted ?-q-n plots with respect to various PD times were analyzed. It is found that, the air-gap PD stage characteristics of vegetable oil/pressboard are more notable. It has fewer double-peak pulses, smaller inception phase angle, lower charge amplitude, higher repetition rate, and more remarkable ‘rabbit-ear’ patterns than mineral oil/pressboard. The PD development process of both insulation systems can be characterized by four stages: initial discharge stage, weak developing stage, discharge burst stage and pre-breakdown stage
Tubifex conicus He, Wang & Cui 2012
No full textTubifex conicus He, Wang & Cui, 2012 (Figs 7–8) Tubifex conicus He, Wang & Cui, 2012: 160 –162, Fig. 1. New material. IHB XZ20150602 a–e, 5 mature specimens, whole-mounted in Canada balsam, from Gyaring Co, preserved in IHB, CAS. Gyaring Co (30°58' 43″N, 88°28′04″E), a lake located in northern Tibet of China, ca. 4,648–4,659 m asl. Water depth 11–37 m, water temperature 6.3–8.9°C, pH 6.3–8.9, dissolved oxygen 7.3–7.7 mg / L, conductivity 323–329 µs/cm. Collected by Yongde Cui and Baoqiang Wang on 2 June 2015. Description. Length 6.1–11.6 mm, width at genital segments X–XI 0.28–0.42 mm. Segments 38–65. Prostomium obtuse. Clitellum inconspicuous. No coelomocytes. Dorsal chaetae (0) 1 hair and 1–4 bifids per bundle. Hairs serrate, posteriorly generally absent (Fig. 7A, B). Dorsal bifids pectinate, upper and lower tooth subequal, with 2–3 fine intermediate teeth (Fig. 7A). Ventral chaetae bifid, 3–4 per bundle anteriorly, 2 per bundle posteriorly, upper tooth slightly longer than lower, with (0) 1–2 fine intermediate teeth (Fig. 7C, D). Ventral chaetae in X present, unmodified. Ventral chaetae in XI absent. Male pores paired in line with ventral chaetae, middle to posterior of XI. Chloragogen cells from VI onwards. Male genitalia paired in X–XI. Sperm funnel cup-shaped, 20 µm long, 40 µm wide (Fig. 8A,B: sf). Vas deferens 400–560 µm long, 12–15 µm wide, nearly 3–4 times as long as atrium, ciliated throughout and entering atrium apically (Fig. 8A, B: vd). Atrium spindle-shaped, 120–160 µm long, maximally 32–40 µm wide (Fig. 8A, B: at). Ejaculatory duct present. Prostate gland solid, 80–84 µm long, 60–64 µm wide, attached to ental portion of atrium (Fig. 8A, B: pr). Penis inconspicuous, surrounded by cuticular, symmetrical and funnel-shaped penial sheath. Penial sheath 36–40 µm long, 48–56 µm wide at ental end (Fig. 8A, B, C: ps). Testes paired in X, immediately behind septum 9/10. Ovaries paired in XI, immediately behind septum 10/11. Spermathecae absent. Remarks. The main difference of our redescription from T. conicus as originally described (He et al. 2012) is the absence of spermathecae. However, after our reinvestigation of the type series (holotype and paratypes), we are sure that the testes of T. conicus were mistaken for spermathecae in the original description. Further slight differences between the descriptions concern thickness of atrial epithelium (thicker in the redescription) and penial sheaths (thicker in the original description). They may relate to the stage of maturity or to different modes of interpretation of observations. The size and shape of atria in the original observation and this research are about the same. Penial sheaths appear to have a thick cuticle laterally in the holotype, but when comparing type series and our material, we found no significant differences in penial sheath thickness. Distribution and habitat. Known from Yamdrok Yumco (Lake Yamzho Yumco), Gyaring Co, Chargut Co, Uruni Co, Chikui Co, Amdo Tsonak Co, Tibet, China. All these lakes are located at above 4,000 m asl in Tibet. Gyaring Co, the locality of present redescribed materials, is about 300 km from the holotype locality of T. conicus, Yamdrok Yumco. Freshwater and brackish water.Published as part of Cui, Yongde, 2017, Four species of Tubifex Lamarck (Annelida: Oligochaeta: Naididae) from Tibet, China, pp. 366-378 in Zootaxa 4320 (2) on pages 371-372, DOI: 10.11646/zootaxa.4320.2.10, http://zenodo.org/record/89195
Robustagramma robustum Marshall & Cui 2005
No full textRobustagramma robustum group Diagnosis: Wing with second costal sector usually shorter than onehalf of third costal sector. Ejaculatory apodeme of male genitalia large, usually over 1/3 as long as aedeagal apodeme. Spermathecae peanutshaped; paired spermathecae different in shape and size from the single one.Published as part of Marshall, Stephen A. & Cui, Yongsheng, 2005, Systematics of Robustagramma, a new genus of New World Sphaeroceridae (Diptera), pp. 1-122 in Zootaxa 1026 (1) on pages 64-65, DOI: 10.11646/zootaxa.1026.1.1, http://zenodo.org/record/504981
Native p-type transparent conductive CuI via intrinsic defects
No full textThe ability of CuI to be doped p-type via the introduction of native defects has been investigated using first-principles pseudopotential calculations based on density functional theory. The Cu vacancy has a lower formation energy than any of the other native defects, which include I vacancy (V(I)), Cu interstitial (Cu(i)), I interstitial (I(i)), Cu antisite (Cu(I)), and I antisite (I(Cu)). Combined with its shallow acceptor level, it offers sufficient hole concentrations in CuI. The natural band alignments as compared to zinc-blende ZnS, ZnSe, and ZnTe have also been calculated in order to further identify the p-type dopability of CuI. It is found that CuI has a relatively high valence band maximum and conduction band minimum, which also makes it easy to dope CuI p-type in terms of the doping limit rule. In addition, the small effective mass of the light hole-about 0.303m(0)-can provide high mobility and p-type conductivity in CuI. All of these results make CuI an ideal candidate for native p-type materials (C) 2011 American Institute of Physics. [doi:10.1063/1.3633220
Beijing Olympic TV Transmission Tower
No full textTower summit, close view showing cross-bracing; The Ling Long Pagoda or Linglong Tower (Multifunctional Studio Tower) houses a part of the International Broadcast Center (IBC) [for the Olympic Games]. It is located near the Olympic Cauldron, on the northwest side of the Bird's Nest Stadium. "Ling Long" means delicate, and is referred to as the Delicate Tower in Chinese. The permanent structure is a three-sided tower. The tower contains 6 habitable pods with open space in between. One of the pods displays the Olympic rings. It is 128 m tall, with 7 habitable floors, each an equilateral triangle. The floors are subdivided into two levels. The glass-walled pods are held up by three supporting ribs at the three corners. After fierce competition for the project in 2007, the design work was won by Cui Kai, Fu Xiaoming, Kang Kai, Zhang Junying, architects of the Cui Kai Studio at the China Design Institute. Source: Wikipedia; http://en.wikipedia.org/wiki/Main_Page (accessed 7/16/2010
Optimal taxation in R&D driven endogenous growth models
No full textE' possibile incrementare il benessere e la crescita mediante imposte in somma fissa, il cui gettito non venga usato produttivamente? E' possibile incrementare il benessere e la crescita mediante imposte sul reddito da capitale i cui proventi vengano usati per sussidiare i salari? In questo lavoro dimostriamo come la risposta ad entrame le domande possa essere positiva in modelli di crescita endogena trainata da Ricerca e Sviluppo, sia del tipo con espansione della varietà dei beni sia del tipo con aumento della qualità dei beni. Il meccanismo chiave è l'aumento dell'offerta di lavoro che le politiche descritte possono indurre. Tali politiche agiranno sui due tipi di esternalità nel modello, la prima statica la seconda dinamica. Il peso relativo di queste esternalità determinerà il segno dell'effetto totale delle politiche sul benessere sociale. Mostriamo come, per valori dei parametri coerenti con le stime disponibili, crescita e benessere possano aumentare introducendo imposte in somma fissa, il cui gettito venga sprecato, mentre il programma di tassazione del capitale e sussidi ai salari possa aumentare il benessere, anche se la crescita può ridursi.Is it possible to increase growth and welfare by raising lump-sum taxes and disposing of the tax revenues? Is it possible to increase welfare by raising capital income taxes and redistributing the revenue as a subsidy to labor income? This thesis shows these may indeed be the case in
standard R&D models with technological change, represented either by an increase in the variety of intermediate goods or by creative destruction. The key mechanism is that with elastic labor supply the tax programs can
increase the employment rate in equilibrium. This creates two spillover effects on the R&D pace. In addition the tax programs themselves will have level effect on the instantaneous utility. The relative momentums of the spillovers and the level effect determine the sign of the welfare effect. It is shown that, for parameter values consistent with available estimates,
the growth and welfare can both be improved under the wasted lump-sum tax program, and that the welfare effect can be positive even if the long-run growth rate decreases after the increase in the capital income tax
rate
Robustagramma crassipalpus Cui and Marshall 2005
No full textRobustagramma crassipalpus group Diagnosis: Prosternum with 1–4 pairs of setulae. Palpus thickened, maximum palpal width one third of palpus length. Second costal sector over half as long as third costal sector; R 2+3 almost straight. Anterodorsal medial bristle of mid tibia relatively small, often not distinctly larger than surrounding setulae. Anterolateral margin of female sternite 8 articulating with tergite 8.Published as part of Marshall, Stephen A. & Cui, Yongsheng, 2005, Systematics of Robustagramma, a new genus of New World Sphaeroceridae (Diptera), pp. 1-122 in Zootaxa 1026 (1) on page 43, DOI: 10.11646/zootaxa.1026.1.1, http://zenodo.org/record/504981
Lithography assisted fiber-drawing nanomanufacturing
No full textWe present a high-throughput and scalable technique for the production of metal nanowires embedded in glass fibres by taking advantage of thin film properties and patterning techniques commonly used in planar microfabrication. This hybrid process enables the fabrication of single nanowires and nanowire arrays encased in a preform material within a single fibre draw, providing an alternative to costly and time-consuming iterative fibre drawing. This method allows the combination of materials with different thermal properties to create functional optoelectronic nanostructures. As a proof of principle of the potential of this technique, centimetre long gold nanowires (bulk Tm = 1064°C) embedded in silicate glass fibres (Tg = 567°C) were drawn in a single step with high aspect ratios (>104); such nanowires can be released from the glass matrix and show relatively high electrical conductivity. Overall, this fabrication method could enable mass manufacturing of metallic nanowires for plasmonics and nonlinear optics applications, as well as the integration of functional multimaterial structures for completely fiberised optoelectronic devices
Robustagramma robustinervus Cui and Marshall 2005
No full textRobustagramma robustinervus group Diagnosis: Two orbital bristles; postocellar bristles absent. Arista subequal to or longer than head height; aristal hairs over twice as long as basal width of arista.. Facial ridge between antennae distinctly broader than width of scape. Dorsocentral bristles in 2 postsutural pairs, anterior dorsocentral bristle slightly longer than middle prescutellar acrostichal bristles. Mid tibia with a single posterodorsal proximal bristle, an anterodorsal bristle near middle, and an anterodorsal, dorsal and posterodorsal distally; dorsal bristle very small. Wing of male with first costal sector thicker than second costal sector. Maximum width of palpus about 1/4 as long as palpus. Sternite 5 large but simple. Ducts of spermathecae about 1.5 times as long as spermatheca. Male with a pair of exceptionally large ventral sclerites, over 0.7X as long as distiphallus.Published as part of Marshall, Stephen A. & Cui, Yongsheng, 2005, Systematics of Robustagramma, a new genus of New World Sphaeroceridae (Diptera), pp. 1-122 in Zootaxa 1026 (1) on page 30, DOI: 10.11646/zootaxa.1026.1.1, http://zenodo.org/record/504981
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