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  • 1
    Language: English
    In: The journal of physical chemistry. A, 25 August 2011, Vol.115(33), pp.9259-64
    Description: The charge carrier transporting ability in the polymorphism of tris(8-hydroxyquinolinato)aluminum(III) (Alq(3)) has been studied using density functional theory (DFT) and Marcus charge transport theory. α- and β-Alq(3) composed of mer-Alq(3) molecules have stronger electron-transporting property (n-type materials) compared with their hole-transporting ability. In contrast, γ- and δ-Alq(3) formed by fac-Alq(3) molecules possess stronger hole-transporting character than their electron-transporting ability. The detailed theoretical calculations indicate the reason lies in the differences of HOMO and LUMO distribution states of the two kinds of isomers, and the different molecular packing modes of charge-transporting pathways for different phases.
    Keywords: Aluminum (Metal) -- Electric Properties ; Aluminum (Metal) -- Structure ; Density Functional Theory -- Usage ; Isomers (Chemistry) -- Research ; Charge Transfer -- Research;
    ISSN: 10895639
    E-ISSN: 1520-5215
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  • 2
    Language: English
    In: Thin Solid Films, 30 October 2015, Vol.593, pp.150-157
    Description: Potassium chloride films on a clean iron surface are used as a model system to explore the interfacial structure of the films and the dependence of that structure on film thickness and pressure. The interfacial structure of one-, two-, three- and four-layer films is measured experimentally using low-energy electron diffraction. Those findings are then complemented by molecular dynamics simulations in which the atomic interaction between the film and substrate is tuned to match film thickness-dependent sublimation activation energy obtained from temperature-programmed desorption measurements. The resultant simulation reliably predicts the structure of thicker films and is then used to study the effect of pressure on the distribution of the lattice constant within and between each layer of the potassium chloride films. Findings indicate that both film thickness and pressure affect the structure within the films as well as the degree of registry between the film and adjacent substrate.
    Keywords: Boundary Lubrication ; Potassium Chloride ; Molecular Dynamics Simulations ; Pressure Dependence ; Engineering ; Physics
    ISSN: 0040-6090
    E-ISSN: 1879-2731
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  • 3
    Language: English
    In: PLoS ONE, 01 January 2014, Vol.9(7), p.e100837
    Description: BACKGROUND:Accurate classification of non-small cell lung cancer (NSCLC) using morphological features has several limitations. However, the use of thyroid transcription factor 1 (TTF-1) and Napsin A as markers for the identification of various subtypes of NSCLC has shown promise. This meta-analysis was designed to evaluate the diagnostic value of combined TTF-1 and Napsin A test to distinguish lung adenocarcinoma from squamous cell carcinoma. METHODS:The Medline, EMBASE and Web of Science databases were searched, along with the reference lists of relevant articles (up to May 4, 2014). Ten studies containing 1,446 subjects were identified. The sensitivity, specificity, diagnostic odds ratio (DOR) and area under the summary receiver operating characteristics curve (AUC) were calculated to estimate the combined diagnostic value of TTF-1 and Napsin A. RESULTS:The pooled sensitivity and specificity were 0.76 (95% CI: 0.69-0.83) and 1.00 (95% CI: 0.92-1.00), respectively. The positive and negative likelihood ratios were 877.60 (95% CI: 8.40-91533.40) and 0.24 (95% CI: 0.18-0.32). The DOR was 3719 (95% CI: 33-414884). The AUC was 0.92 (95%CI: 0.89-0.94). The patient's location was a source of heterogeneity for sensitivity. The patient's location, the study's sample size and the threshold used to determine positive staining were consistently found to be sources of heterogeneity for specificity in subgroup analyses and meta-regression. CONCLUSIONS:The combined test of TTF-1 and Napsin A presents a promising alternative method, useful to distinguish between lung adenocarcinoma and squamous cell carcinoma.
    Keywords: Sciences (General)
    E-ISSN: 1932-6203
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  • 4
    Language: English
    In: PLoS ONE, 01 January 2014, Vol.9(8), p.e104936
    Description: BACKGROUND: The presence of antibodies against the M-type phospholipase A2 receptor (PLA2R-AB) is considered to be a promising serological diagnostic biomarker of idiopathic membranous nephropathy (iMN). However, controversy remains about the diagnostic accuracy of serum PLA2R-AB testing. Here, we performed a comprehensive meta-analysis to assess the overall diagnostic value of serum PLA2R-AB testing in iMN detection. METHODS: PubMed, Embase, and CNKI (Chinese National Knowledge Infrastructure) were searched for relevant original articles through January 31, 2014. The summary sensitivity, specificity, positive likelihood ratio, negative likelihood ratio and diagnostic odds ratio (DOR) were estimated using the bivariate model. The heterogeneity among studies was explored by subgroup and meta-regression analysis. RESULTS: 9 articles, including 15 studies, were eventually identified with a total of 2212 patients. The summary sensitivity of all studies is 78% (95% CI: 66% to 87%) and the specificity is 99% (95% CI: 96% to 100%). The summary positive and negative likelihood ratios are 96.1 (95% CI, 19.5 to 472.1) and 0.22 (95% CI: 0.14 to 0.35), respectively. The DOR is 437 (95%CI, 74 to 2592). The subgroup analysis and meta-regression suggest the test interval is the main source of heterogeneity. CONCLUSIONS: Serum PLA2R-AB testing is a useful tool to detect iMN. In addition, considering the high heterogeneity and potential publication bias, further high quality studies are needed in the future.
    Keywords: Sciences (General)
    E-ISSN: 1932-6203
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  • 5
    Language: English
    In: Journal of the American Chemical Society, 24 March 2010, Vol.132(11), pp.3697-9
    Description: A new class of n-type semiconductors for organic thin film transistors (OTFTs), based on core-expanded naphthalene diimides fused with 2-(1,3-dithiol-2-ylidene)malonitrile groups, is reported. The first two representatives of these species, derived from long branched N-alkyl chains, have been successfully used as active layers for high-performance, ambient-stable, solution-processed n-channel OTFTs. Their bottom-gate top-contact devices fabricated by spin-coating methods exhibit high electron mobilities of up to 0.51 cm(2) V(-1) s(-1) with current on/off ratios of 10(5)-10(7), and small threshold voltages below 10 V under ambient conditions. As this class of n-type organic semiconductors has relatively low-lying LUMO levels and good film-formation ability, they also displayed good environmental stability even with prolonged exposure to ambient air. Both the device performance and the ambient stability are among the best for n-channel OTFTs reported to date.
    Keywords: Chemistry;
    ISSN: 00027863
    E-ISSN: 1520-5126
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  • 6
    Language: English
    In: Sensors & Actuators: B. Chemical, February 2018, Vol.255, pp.3505-3515
    Description: In this work, an ultrasensitive and low detection limit of toluene gas sensor based on SnO -decorated NiO nanostructure synthesized via a simple hydrothermal route was described. The test results demonstrated that the sensor based on SnO -decorated NiO nanostructure showed excellent sensitivity and selectivity toward toluene, giving a high response of 66.2–100 ppm, which was 50 times higher than that of the pure NiO nanospheres (1.3–100 ppm). Additionally, the sensor had surpassingly low detection limit (ppb-level), showing a response of 1.2–10 ppb toluene. Besides, the sensor also exhibited anti-humidity properties in some way, giving an acceptable response (11.1–10 ppm) to toluene at 90% relative humidity. The ultrasensitive characteristics and low detection limit could be explained from the variation of the carrier concentration caused by the change of the thickness of near-surface hole accumulation layer between p-type NiO and n-type SnO . Furthermore, the increase of oxygen adsorption also improved the sensing performance.
    Keywords: Sno2-Decorated Nio ; Heterojunction ; Toluene ; Gas Sensor ; Engineering
    ISSN: 0925-4005
    E-ISSN: 1873-3077
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  • 7
    Language: English
    In: Sensors & Actuators: B. Chemical, December 2017, Vol.253, pp.1152-1162
    Description: A simple hydrothermal route to the synthesis of Sn-doped NiO hierarchical nanostructure is described in this paper. Gas sensors were fabricated from the as-prepared NiO nanostructures, and their gas sensing properties were investigated for response to various target gases. The results indicated that the sensor based on 3.0 at.% Sn-doped NiO nanospheres showed superior selectivity toward xylene, giving a response of 20.2–100 ppm, which was 12 times higher than that of the undoped NiO nanospheres. Moreover, this sensor based on the 3.0 at.% Sn-doped NiO hierarchical nanostructure had ppb-level detection limit that the response to 0.3 ppm xylene was 1.2. The likely reason for the improved sensing properties is the change of carrier concentration and chemisorbed oxygen amount caused by the implantation of Sn ions in NiO nanostructures.
    Keywords: Sn-Doped Nio ; Hierarchical Nanostructure ; Xylene ; Gas Sensor ; Engineering
    ISSN: 0925-4005
    E-ISSN: 1873-3077
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  • 8
    In: TELKOMNIKA Indonesian Journal of Electrical Engineering, 06/27/2014, Vol.12(9)
    Description: Integrity constraint is important to make data certain in relation database. Though there is plenty of uncertain information that is valuable and need to be searched and to be used. Combined with probabilistic database theory and on the basis of summarizing former results, this paper gives a new query plan aiming at inconsistent database. It uses the constraint methods including union, product, subtraction, selection, projection and link to repair inconsistent data effectively. Its probabilistic calculation with four elements and probabilistic query rewriting can overcome shortcomings of inconsistent databases. The experiments show these methods can decrease conflict of data.
    Keywords: Engineering;
    ISSN: 2302-4046
    E-ISSN: 2087-278X
    Source: CrossRef
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  • 9
    Language: English
    In: Physical review. E, Statistical, nonlinear, and soft matter physics, July 2014, Vol.90(1), pp.012125
    Description: We have applied both the master equation method and harmonic transition state theory to interpret the velocity-dependent friction behavior observed in atomic friction experiments. To understand the discrepancy between attempt frequencies measured in atomic force microscopy experiments and those estimated by theoretical models, both thermal noise and instrumental noise are introduced into the model. It is found that the experimentally observed low attempt frequency and the transition point at low velocity regimes can be interpreted in terms of the instrumental noise inherent in atomic force microscopy. In contrast to previous models, this model also predicts (1) the existence of a two-slope curve of velocity dependence and (2) the decrease of critical velocity with temperature, which provides clues for further experimental verification of the influence of instrumental noise in friction measurements.
    Keywords: Artifacts ; Friction ; Microscopy, Atomic Force -- Instrumentation
    E-ISSN: 1550-2376
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  • 10
    Language: English
    In: Energy & Fuels, 10/13/2016
    Description: Blast furnace slag (BFS), a waste product of the iron manufacture process, contains a mass of silica obtained from gangue of the iron ores and ash content in fuels and fluxes. In recent years, large amounts of BFS have not been fully utilized, leading to the surrounding environmental pollution and the additional administration costs for steel enterprises in China. A simple method based on acid precipitation heated to 90-100 °C for 2 h was developed to produce white carbon black (WCB) from BFS. BFS and WCB washed by different concentrations of hydrochloric acid were characterized by X-ray fluorescence, scanning electron microscopy, X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) surface area, Fourier transform infrared spectroscopy (FTIR), and thermogravimetry and differential scanning calorimetry. White carbon black prepared by 5 mol/L acid (WCB5) contained 91.32% silica and 8.15% moisture. The major impurities of WCB produced from BFS were Ca, Mg, Al, and Ti. Acid washing resulted in impurities with a lower concentration. XRD revealed that WCB belonged to the amorphous material. FTIR data indicated the presence of siloxane and silanol groups. The BET surface area was 245 cm2/g. Moreover, the dibutyl phthalate (DBP) absorption value was controlled between 2.0 and 3.5. It showed that physical and chemical characteristics of WCB were up to the China industry standard (HG/T3061-1999).
    Keywords: Ftir-Spektroskopie ; Siliciumdioxid ; Eisenerz ; Brennstoff ; Stahl ; Salzsäure ; Amorpher Werkstoff ; Siloxan ; Phthalat ; Eisen ; Rußschwarz ; Produktionsprozess ; Umweltverschmutzung ; X-Strahl ; Röntgendiffraktion ; Kalorimetrie ; Syntheseverfahren ; Engineering ; Chemistry;
    ISSN: 0887-0624
    E-ISSN: 1520-5029
    Source: American Chemical Society (via CrossRef)
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