18,588 research outputs found
Improved AC conductance and Gray-Brown methods to characterize fast and slow traps in Ge metal–oxide–semiconductor capacitors
No full textWe use an improved AC conductance method and a modified Gray-Brown method to study fast interface traps and slow border traps in Ge-based MOS capacitors. The combined methods provide the corrected Fermi energy level (E) versus gate voltage (V-g) relationship, even in samples with high densities of traps that cause significant C-V distortion, the energy distribution of interface traps, their capture cross sections (sigma), as well as slow border traps. A wide range of sigma's in p-type Ge is found, indicating that there is more than one type of interface trap near the Ge valence band edge. In contrast, a constant sigma near the Ge conduction band edge is observed in n-type Ge. XPS results indicate that Ge suboxides near the interface are accountable for the detected slow border traps. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.3691898]This work is partially supported by the National Science
Foundation through MRSEC DMR 1119826, DTRA through
HDTRA 1-10-1-0042, and K. U. Leuven scholarship for the
first author Xiao Sun. Xiao Sun would also like to thank
AMSIMEC and EPI group in IMEC, Belgium for their help and
Benjamin Leung for his help in the preparation of this pape
Ge composition saturation behavior during low-temperature Si1-xGex growth by disilane and solid Ge molecular beam epitaxy
No full textGe composition dependence on the Ge cell temperature has been studied during the growth of Si1-xGex by disilane and solid Ge molecular beam epitaxy at a substrate temperature of 500 degrees C. It is found that the composition x increases and then saturates when the Ge cell temperature increases, which is different from the composition-dependent behavior in growth at high temperature as well as in growth by molecular beam epitaxy using disilane and germane. The enhanced hydrogen desorption from a Ge site alone cannot account for this abnormal composition-variation behavior. We attribute this behavior to the increase of rate constant of H desorption on a Si site when the Ge cell temperature increases
Tinodes falcata Peng & Ge & Sun & Wang 2022, n. sp.
No full textTinodes falcata Peng & Sun, n. sp. (Figs 1a–1c) Description: Length of each forewing 3.4–3.5 mm (n = 1). Specimen in alcohol with compound eyes black, legs and thorax brown, abdomen dark brown dorsally, pale yellow ventrally, wings light brown. Male genitalia: In lateral view, sternum IX fan-shaped (Fig. 1c). Tergum IX covered with tiny villi; nearly triangular in dorsal view (Fig. 1b), boomerang-shaped in lateral view (Fig. 1c). Segment X originating from anterior one-third of dorsal edges of sternum IX; membranous, anterior margins straight, narrowly stalked in lateral view (Fig. 1c). Superior appendages originating from bases of segment X; clubbed, each with distal half setose in dorsal and lateral views (Figs 1b, 1c). Phallic sheath process originating from phallus, consisting of paired lateral branches (lat. pha. she. pro) and unpaired inner branch (inn. pha. she. pro.); paired lateral ones slightly sigmoid in lateral view (Fig. 1c), each with seven spurs scattered in middle and subterminally; unpaired inner one strongly sclerotized, slightly shorter than paired branches, distal third curved posterodorsad, with sharp tip having small fork in lateral and dorsal views (Figs 1b, 1c). Phallus slightly longer than phallic sheath process, with distal half inflated about twice width of lateral paired branches of phallic sheath process in lateral view (Fig. 1c). In lateral view, phallic guide (pha. gui.) with subapex widened and then divided into two branches, dorsal branch slender, curved downwards distally; ventral branch of phallic guide short, with one long bristle (Fig. 1c). Coxopodites (cox.) each broadly rounded dorsally in lateral view, divided apically into large glabrous dorsal branch and short ventral one (Figs. 1a, 1c); harpagones situated mesally between coxopodite branches, each nearly as long as dorsal branch, with numerous setae mostly mesal (Figs 1a, 1c). Diagnosis: The species is unique in the genus Tinodes by its unpaired inner branch of the phallic sheath process (inn. pha. she. pro.). Holotype: Male, P. R. China, Zhe-jiang Province: An-ji city, Tian-huang-ping town, Da-xi village, Hengkeng-wu, 30.4706°N, 119.6619°E, alt. 290 m, 24 May 2017, light trap, leg. C. Sun & Y. Hu (NJAU). Distribution: China (Zhe-jiang). Etymology: The Latin adjective falcatus, -a, -um means “falcate, referring to the shape of the unpaired branch of the phallic sheath process in left lateral view.Published as part of Peng, Lang, Ge, Xin-Yu, Sun, Chang-Hai & Wang, Bei-Xin, 2022, Five new species of Tinodes (Trichoptera: Psychomyiidae) from China, pp. 280-290 in Zootaxa 5196 (2) on pages 281-283, DOI: 10.11646/zootaxa.5196.2.8, http://zenodo.org/record/722458
Tinodes yangae Peng & Ge & Sun & Wang 2022, n. sp.
No full textTinodes yangae Peng & Sun, n. sp. (Figs 4a–4d) Description: Length of each forewing 3.5–3.6 mm (n = 1). Specimens in alcohol with compound eyes black, legs and thorax dark brown, abdomen brown dorsally, pale yellow ventrally, wings light brown. Male genitalia: In lateral view, sternum IX nearly oblong, with each anterodorsal angles produced into projections (Fig. 4c). Tergum IX, segment X and horizontal part of inner branch of phallic sheath process fused into a complex, originating about halfway along upper margin of sternum IX, (Fig. 4c), vertical part of inner branch of phallic sheath process paired, each with three spines apically (Figs 4b, 4c); lateral branch of phallic sheath process paired and sparsely setose, each arched in lateral view and elongate tongue-shaped in dorsal view (Figs 4b, 4c). Superior appendages slightly S-shaped, issuing from protrusion of sternum IX in lateral view (Fig. 4c), extending dorsocaudad beyond apex of phallus (Fig. 4b). Phallus tapering from base to apex, in lateral view its basal half forming angle at about 90° with distal half (Fig. 4c). In dorsal view, phallic guide with apex expanded into a disc (Fig. 4d), in lateral view with apex bifurcate, dorsal branch straight upwards and acute, ventral branch triangular (Fig. 4c). Coxopodites ventrally fused mesally with posterior margin somewhat W-shaped in ventral view (Fig. 4a); in lateral view subrectangular, each with dorsal process triangular, smooth and hairless, and ventral process rounded, setose, shorter than dorsal process (Fig. 4c). Harpagones inserted between dorsal and ventral processes of coxopodite, tongue-shaped, setose and longer than dorsal processes of coxopodites in lateral view (Fig. 4c). Diagnosis: This species is similar to Tinodes eris Malicky & Sangpradub 2001 (in Malicky et al. 2001) from Thailand. However, the new species can be easily distinguished from it by the inner phallic sheath process with its base fused with the complex of tergum IX and X and the other portion free from the complex, vertical, and bifurcate. Holotype: Male, P. R. China, Si-chuan Province: Ya-an city, Zhou-gong river, 29.5900°N, 102.5900°E, atl. 600–800 m, 8 June 1996, light trap, leg. L. Yang & X. Wang (NJAU). Distribution: China (Si-chuan). Etymology: The new species is named after Prof. Lianfang Yang in honor of her great contributions to the Trichoptera fauna of China.Published as part of Peng, Lang, Ge, Xin-Yu, Sun, Chang-Hai & Wang, Bei-Xin, 2022, Five new species of Tinodes (Trichoptera: Psychomyiidae) from China, pp. 280-290 in Zootaxa 5196 (2) on page 286, DOI: 10.11646/zootaxa.5196.2.8, http://zenodo.org/record/722458
Mengzi zhu shu jie: [14 juan]. v.142
No full text趙氏[岐]註 ; 孫奭疏.綫裝.框17.9 x 12.5 公分, 9行21字, 小字雙行同, 白口, 無魚尾, 左右雙邊, 版心下刻"汲古閣".附: 孟子註疏題辭解.Xian zhuang.Kuang 17.9 x 12.5 gong fen, 9 hang 21 zi, xiao zi shuang hang tong, bai kou, wu yu wei, zuo you shuang bian, ban xin xia ke "Ji gu ge".Fu: Mengzi zhu shu ti ci jie.Zhao shi [Qi] zhu ; Sun Shi shu
Tinodes lini Peng & Ge & Sun & Wang 2022, n. sp.
No full textTinodes lini Peng & Sun, n. sp. (Figs 5a–5d) Description: Length of each forewing 3.4–3.5 mm (n = 2). Specimens in alcohol with compound eyes black, other parts brown to light brown. Male genitalia: In lateral view, anterolateral and anteroventral margins of sternum IX produced anterolaterad into slender protrusions and anteroventrad as obtuse process, respectively (Fig. 5c). Tergum IX and segment X completely fused with inner branch of phallic sheath process, forming complex, originating from upper margins of sternum IX in lateral view (Fig. 5c); in dorsal view, complex with apex bifurcate and with 9 spurs along each side (Fig. 5b). Paired lateral branch of phallic sheath processes in lateral view elongate, tongue-shaped, setose apically (Fig. 5c), in dorsal view posterior margin having deep U-shaped incision (Fig. 5d). Superior appendages with bases fused with anterolateral protrusion of sternum IX (Fig. 5c), in lateral view extending dorsocaudad to level of distal end of phallus and inferior appendages, tapering slightly from basal 1/4 to apex; in dorsal view with narrow base and then slightly diverging, each densely setose (Fig. 5b). Phallus tubular, distal half slenderer than basal half in lateral view (Fig. 5c). Phallic guide pincer-like in lateral view (Fig. 5c), with a pair of dorsal branches closely parallel with each other, curved downwards, and ventral branch directed caudoventrad and bearing three long bristles. Coxopodites in lateral view each subrectangular with dorsal process less hairy, slender (Fig. 5c); in ventral view coxopodites subtriangular, their inner margins separated by sclerotized groove, originating halfway from base of tongue-shaped lobe connecting them (Fig. 5a). Harpago of each inferior appendage inserted underneath dorsal branch of coxopodite, setose; in lateral view with upper margin curved slightly upwards beyond basal convexity and lower margin straight (Fig. 5c); in ventral view triangular (Fig. 5a). Diagnosis: This species is similar to Tinodes dactringa Johanson & Oláh 2008, from Vietnam, in having a ventral lobe connecting the coxopodites basally. However, the new species can be easily distinguished from it in that: (1) the phallic guide has a pair of dorsal branches closely parallel with each other (forming a pincer in Tinodes dactringa); (2) the ventral lobe between the coxopodites is rectangular with rounded corners, in ventral view extending slightly beyond the ventromesal apices of the coxopodites (the ventral lobe with acute posterolateral angles slightly produced laterally and extending far beyond the ventromesal apices of the coxopodites in Tinodes dactringa). Holotype: Male, P. R. China, Gui-zhou Province: Zun-yi city, Mei-tan county, Hei-wu-tan, 27.5381°N, 107.4961°E,, alt. 793 m, from 16 Sept to 26 Sept 2020, Malaise trap, leg. X. Lin (NJAU). Paratypes: 1 male, P. R . China, Jiang-su Province: Ju-rong city, Bao-hua Mountain National Forest Park, creek beside the north gate uphill, 32.1342°N, 119.0858°E, alt. 150 m, 7 May 2019, light trap, leg. Z. Chen (NJAU). Distribution: China (Gui-zhou, Jiang-su). Etymology: This new species named after Dr. Xiaolong Lin from Nankai University, Tianjin, P. R. China, in gratitude for his donation of a great amount of caddis specimens selflessly, for his valuable advice on solving problems we encountered in the phylogenetic analysis of Trichoptera, and for all his strong support for Trichoptera research.Published as part of Peng, Lang, Ge, Xin-Yu, Sun, Chang-Hai & Wang, Bei-Xin, 2022, Five new species of Tinodes (Trichoptera: Psychomyiidae) from China, pp. 280-290 in Zootaxa 5196 (2) on page 287, DOI: 10.11646/zootaxa.5196.2.8, http://zenodo.org/record/722458
Low-temperature growth properties of Si1-xGex by disilane and solid-Ge molecular beam epitaxy
No full textLow temperature (similar to 500 degrees C) growth properties of Si1-xGex by disilane and solid-Ge molecular beam epitaxy have been studied with an emphasis on surface morphology and growth kinetics. It is found that low-temperature growth(0.5). Ge composition dependence on substrate temperature, Ge cell temperature and disilane flow rate have been investigated. It is found that in low-temperature growth (less than or equal to 500 degrees C) and under large disilane flux, Ge composition increases with the increase of Ge flux and further increase of Ge flux leads to the saturation of Ge composition. Similar compositional dependence has been found at different growth temperatures. The saturated composition increases with the decrease of substrate temperature. The results can be explained if H desorption is assumed to occur from both Si and Ge monohydrides without diffusional exchange and the presence of Ge enhances H desorption on a Si site. (C) 1998 Elsevier Science B.V. All rights reserved
Nutrient availability mediates organic carbon turnover in paddy soils through regulating microbial metabolism
Get PDFNutrient availability significantly influences soil microbial communities and the soil organic carbon (SOC) cycle. Yet, the precise response of microbial metabolism, particularly carbon use efficiency (CUE), to varying nutrient levels, and the subsequent impact on microbial respiration in paddy soils, remains a key area of investigation. In this study, we utilized six paddy soils collected across a latitudinal gradient from Northeast to Southeast China to examine the effects of nutrient availability on CUE, employing the 18O water labeling approach. We also assessed associated microbial metabolic parameters, including growth, biomass, turnover rate, and extracellular enzyme activity, under different nitrogen, phosphorus, and potassium (NPK) fertilization regimes. Our results revealed that the highest NPK amendment rate (NPKH) generally led to the greatest microbial growth and biomass, coupled with the slowest microbial biomass turnover rates, especially in the southeastern paddy soils. This enhanced growth and biomass accumulation likely resulted from increased CUE following the alleviation of C and nutrient limitations through fertilization. Furthermore, we observed that reducing these limitations led to decreased extracellular enzyme activity and a corresponding reduction in microbial respiration. This suggests a critical balance between microbial investment in anabolic processes (biomass production) and catabolic processes (decomposition of soil organic matter) in determining CO2 loss from paddy soils. Overall, our findings indicate that soil microorganisms exhibiting higher CUE, faster growth, larger biomass, but lower CO2, turnover and extracellular enzyme activity contribute to reduced SOC mineralization and, consequently, limited release. These results suggest that strategic nutrient management in paddy soils has the potential to mitigate C emissions by effectively regulating key aspects of microbial metabolism, specifically by promoting a shift towards biomass production over decomposition
Boron diffusion in Ge+ premorphized and BF2+ implanted Si(001)
No full textThe annealing behavior of Si implanted with Ge and then BF2 has been characterized by double crystal X-ray diffraction (DCXRD) and secondary ion mass spectroscopy (SIMS). The results show that annealing at 600 degrees C for 60 minutes can only remove a little damage induced by implantation and nearly no redistribution of Ge and B atoms has occurred during the annealing. The initial crystallinity of Si is fully recovered after annealing at 950 degrees C for 60 minutes and accompanied by Ge diffusion. Very shallow boron junction depth has been formed. When annealing temperature rises to 1050 degrees C, B diffusion enhances, which leads to a deep diffusion and good distribution of B atoms into the Si substrate. The X-ray diffraction (004) rocking curves from the samples annealed at 1050 degrees C for 60 minutes display two SiGe peaks, which may be related to the B concentration profiles
Performance Investigation on p-Type Si-, Ge-, and Ge-Si Core-Shell Nanowire Schottky Barrier Transistors
No full textIn this paper, we investigate the working mechanism of p-channel Schottky barrier Ge-Si core-shell nanowire transistors and then study the impact factors on the device performance of Schottky barrier transistors using Si-, Ge-, and Ge-Si core-shell nanowires as channels. For Ge-Si core-shell channel devices, most holes tunnel at the source near the heterojuction and transport in the Ge core region. Ge channel devices can provide the largest drive current and core-shell devices have the smallest sub-threshold slope among above three types of transistors. It is also found that core-shell device's conductive currents vary a little when fixing Ge core radius and changing Si shell thickness, and core-shell devices' normalized drain current can be greatly enhanced by reducing nanowires' radius or increasing core radius. Moreover, the drivability of core-shell devices is insensitive to both silicide/channel and germanide/channel barrier heights, which will further relax the requirement for contact materials. (C) 2011 The Japan Society of Applied PhysicsPhysics, AppliedSCI(E)EICPCI-S(ISTP)
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