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51.
Note on the connectivity of line graphs 总被引:1,自引:0,他引:1
Let G be a connected graph with vertex set V(G), edge set E(G), vertex-connectivity κ(G) and edge-connectivity λ(G).A subset S of E(G) is called a restricted edge-cut if G−S is disconnected and each component contains at least two vertices. The restricted edge-connectivity λ2(G) is the minimum cardinality over all restricted edge-cuts. Clearly λ2(G)?λ(G)?κ(G).In 1969, Chartrand and Stewart have shown that
52.
Martin?MarciniszynEmail author Angelika?Steger Andreas?Wei?l 《Informatik-Spektrum》2004,27(3):248-254
53.
A continuous culture system was used to investigate ruminal digestion in response to increased pasture intake and three different substitution rates (SR) in a 4 x 4 Latin square design. The treatments were 1) low pasture (55 g dry matter (DM)/d, 2) medium pasture (MP, 65 g DM/d), 3) high pasture (75 g DM/d), and 4) pasture (45 g DM/d) plus concentrate (PC, 30 g DM/d). Treatments were designed to produce a low (0.33), medium (0.67), and high (1.00) SR (g of pasture/g of concentrate) by contrasting the low, medium, and high pasture intake treatments with the pasture plus concentrate treatment, respectively. Pasture was fed at 0630, 1000, 1730, and 2100 h, and concentrate at 0600 and 1700 h. Digestibility of DM and neutral detergent fiber were not affected by the amount of pasture. As the amount of pasture increased, pH decreased linearly, and total volatile fatty acid and NH3-N concentrations, and nonammonia N and bacterial N flows increased linearly. Concentrate supplementation did not affect DM digestibility at high SR but increased DM digestibility at low SR. Concentrate supplementation reduced pH and NH3-N concentrations at the three SR. Concentrate supplementation reduced the ratio of rumen degradable N to rumen degradable organic matter; however, the mechanism depended on the SR. High SR, concentrate supplementation reduced rumen degradable N, which reduced NIH-N concentration without affecting bacterial N flow. At low SR, concentrate supplementation increased rumen degradable organic matter, which reduced NH3-N concentration and increased bacterial N flow. Based on these results, at low SR, concentrate supplementation may enhance animal performance because of higher total DM intake and synthesis of microbial protein. 相似文献
54.
The paper proposes a hierarchical control design of an electro-hydraulic actuator, which is used to improve the roll stability of vehicles. The purpose of the control system is to generate a reference torque, which is required by the vehicle dynamic control. The control-oriented model of the actuator is formulated in two subsystems. The high-level hydromotor is described in a linear form, while the low-level spool valve is a polynomial system. These subsystems require different control strategies. At the high level, a linear parameter-varying control is used to guarantee performance specifications. At the low level, a control Lyapunov-function-based algorithm, which creates discrete control input values of the valve, is proposed. The interaction between the two subsystems is guaranteed by the spool displacement, which is control input at the high level and must be tracked at the low-level control. The spool displacement has physical constraints, which must also be incorporated into the control design. The robust design of the high-level control incorporates the imprecision of the low-level control as an uncertainty of the system. 相似文献
55.
Emulsion templating is an effective route to prepare low-density, interconnected macroporous polymers known as poly(merised)High and Medium Internal Phase (Ratio) Emulsions. Here, we provide evidence that the interconnectivity of polyMIPEs is strongly dependent on the initiator used for the polymerisation of the continuous phase of the template. The characteristic interconnected pore structure can be observed if an oil soluble initiator, we used α,α′-azoisobutyronitrile, is used irrespectively of the surfactant employed to stabilise the emulsion templates. However, polymerisation of the continuous emulsion phase initiated by water-soluble initiators such as redox initiators or potassium peroxodisulfate results in low pore interconnectivity or even closed celled polyMIPEs. 相似文献
56.
Ursula Bentrup Jörg Radnik Udo Armbruster Andreas Martin Jork Leiterer Franziska Emmerling Angelika Brückner 《Topics in Catalysis》2009,52(10):1350-1359
A new setup is presented which enables simultaneous wide- and small-angle X-ray scattering (WAXS/SAXS) and Raman spectroscopic
experiments during the synthesis of Mo-based mixed oxide catalyst precursors at the μ-spot beamline at the Berliner Elektronenspeicherring-Gesellschaft
für Synchrotronstrahlung (BESSY). Furthermore, we report about the separate monitoring of the same reactions under comparable
conditions by simultaneous combined ATR/UV–vis/Raman spectroscopic measurements. For testing the performance of both experimental
setups two syntheses were described comprising the precipitation of metal molybdates by mixing solutions of metal nitrates
and ammonium heptamolybdate. Additionally, the effect of H3PO4 admixture on precipitation was investigated. The combined evaluation of spectroscopic and WAXS/SAXS data allows the discrimination
between different molybdate species appearing in solution and precipitate. Furthermore, these molybdate species could be assigned
to separate phases of different crystallinity. 相似文献
57.
58.
The methods are reviewed for obtaining monolayer epithelium cultures both in normal and hyperplastic or malignant prostate glands. Preparation of pure epithelial tissue cultures is dealt with in detail. The major prostate cell lines are described. Special attention is paid to the markers of differentiation and sensitivity to hormones in normal and tumour prostatic cells in vitro. Prospects for the use of prostatic cell cultures as models in oncology are outlined. 相似文献
59.
Horst Biermann Ulrich Martin Christos G. Aneziris Anja Kolbe Angelika Müller Wolfgang Schärfl Mathias Herrmann 《Advanced Engineering Materials》2009,11(12):1000-1006
Novel composites on basis of austenitic stainless TRIP‐steel as matrix with reinforcements of Mg‐PSZ are presented. Compact rods were produced by cold isostatic pressing and sintering, square honeycomb samples by the ceramic extrusion technique. The samples are characterized by optical and scanning electron microscopy before and after deformation, showing the microstructure and the deformation‐ induced martensite formation. The mechanical properties of samples with 5 vol% zirconia are superior compared to zirconia‐free samples and composites with higher zirconia contents in terms of bending and compression tests. The honeycomb samples exhibit extraordinary high specific energy absorption in compression. 相似文献
60.