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Fatigue Behavior and Mechanism of FV520B-I Owing to the Effect of Loading Frequency on the Fatigue Property in HCF and VHCF Regime

Wang J., Zhang Y., Shi B., Zhao Q., Sun Q., Zhang Z., Lu H.

Archives of Metallurgy and Materials

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2018

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Vol. 63, iss. 1

347--357

EN

Fatigue property of FV520B-I is affected by the ultrahigh loading frequency significantly, and the ultrasonic fatigue experimental data can’t be employed directly to analyze the fatigue failure in the actual remanufacturing engineering. However few theories about the effect of loading frequency on the fatigue property of FV520B-I has ever been proposed. In this paper, both ultrasonic experiment and conventional experiment are conducted out to obtain the fatigue data. The effect of loading frequency on the fatigue data distribution is discussed firstly, its fatigue limit declines with the increase of the loading frequency. Then the fracture surface observations are captured, the fatigue property and fatigue behavior mechanism of FV520B-I is examined by analyzing the fracture surface features, crack initiation and failure observations. A new material frequency correction factor is proposed and introduced to eliminate the influence of the loading frequency on the FV520B-I fatigue property. FV520B-I empirical fatigue life conversion model and fatigue strength conversion model are established with comprehensive use of a fitting algorithm based on the combination of experimental data and classic formula. A clear understand of the effect of loading frequency on the fatigue property of FV520B-I is novel and has an important significance in guaranteeing the accuracy of the actual fatigue analysis of FV520B-I in the remanufacturing engineering.

2

A Facile Synthesis of 3,3'-Dinitro-5,5'-diamino-bi-1,2,4-triazole and a Study of Its Thermal Decomposition

Ma Q., Lu H., Qu Y., Liao L., Li J., Fan G., Chen Y.

Central European Journal of Energetic Materials

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2017

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Vol. 14, no. 2

281--295

EN

3,3’-Dinitro-5,5’-diamino-bi-1,2,4-triazole (DABNT) was synthesized by a facile method and its crystalline density was determined as 1.839 g·cm−3 at 293(2) K by X-ray diffraction. Its thermal decomposition kinetics and mechanism were studied by means of differential scanning calorimetry-thermogravimetry (DCS-TG), in situ thermolysis by rapid-scan Fourier transform infrared spectroscopy (RSFTIR) and simultaneous TG-IR technology. The results showed that the apparent activation energies obtained by the Kissinger, Ozawa and Starink methods were 122.9 kJ·mol−1, 123.2 kJ·mol−1 and 123.5 kJ·mol−1, respectively. The thermodynamic parameters of ΔS≠, ΔH≠ and ΔG≠ were −37.5 J·K−1·mol−1, 118.4 kJ·mol−1 and 138.7 kJ·mol−1, respectively. The decomposition reaction process of DABNT starts with the transformation from a primary amine to a secondary amine and then the loss of one nitro-group from the DABNT structure. Gaseous products, such as N2O and H2O, were detected from decomposition in the range of 50-300 °C. Density functional theory (DFT) calculations were further employed to illustrate the decomposition mechanism. The above-mentioned information on the synthesis and thermal behaviour is quite useful for the scale-up and evaluation of the thermal safety of DABNT.

3

Numerical Study of the Effect of Furrows on Biosonar Beamforming in Aselliscus Stoliczkanus Bat

He W., Feng J., Gao L., Zhang Z., Lu H.

Archives of Acoustics

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2017

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Vol. 42, No. 3

395--399

EN

The Aselliscus Stoliczkanus bat, studied here, has intricately shaped structures surrounding the nostrils. These structures are hypothesised to have influence on animals’ acoustic radiation patterns. Using micro-tomography scanning technique, a 3D digital model of the noseleaf is reconstructed and biosonar beam pattern is analysed using a finite element method based on the 3D noseleaf model. The present research focuses on the conspicuous furrows in noseleaf, and our analysis allows to conclude the followings: a) structural details in noseleaf of Aselliscus Stoliczkanus bat can produce acoustic effects even if it is not adjacent to the nostrils, b) the furrows possess frequency-selective characteristics, c) the furrows have the function to manipulate the direction and width of the outgoing ultrasound wave.

4

Characterization of monochlorobenzene contamination in soils using geostatistical interpolation and 3D visualization for agrochemical industrial sites in southeast China

Ren L., Lu H., He L., Zhang Y.

Archives of Environmental Protection

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2016

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Vol. 42, no. 3

17--24

EN

Persistent organic pollutants (POPs) originating from agrochemical industries have become an urgent environmental problem worldwide. Ordinary kriging, as an optimal geostatistical interpolation technique, has been proved to be sufficiently robust for estimating values with finite sampled data in most of the cases. In this study, ordinary kriging interpolation integrate with 3D visualization methods is applied to characterize the monochlorobenzene contaminated soil for an agrochemical industrial site located in Jiangsu province. Based on 944 soil samples collected by Geoprobe 540MT and monitored by SGS environmental monitoring services, 3D visualization in terms of the spatial distribution of pollutants in potentially contaminated soil, the extent and severity of the pollution levels in different layers, high concentration levels and isolines of monochlorobenzene concentrations in this area are provided. From the obtained results, more information taking into account the spatial heterogeneity of soil area will be helpful for decision makers to develop and implement the soil remediation strategy in the future.

5

IRSL and post-IR IRSL residual doses recorded in modern dust samples from the Chinese loess plateau

Buylaert J.-P., Thiel Ch., Murray A. S., Vandenberghe D. A. G., Yi S., Lu H.

Geochronometria

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2011

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Vol. 38, no. 4

432-440

EN

Using a set of modern/young (0 to about 200 years old) dust samples collected from the Chinese Loess Plateau the bleachability of IRSL measured at 50°C (IR50) and post-IR50 elevated temperature IRSL (measured at 225°C and at 290°C) is investigated by measuring the apparent (residual) doses recorded by these signals. Doses recorded by quartz OSL are used as a reference. Allowing for differences in dose rates it seems that both IRSL and post-IR IRSL signals yield residual doses that are significantly larger than the doses measured in quartz. These residual doses can be largely explained by thermal transfer caused by preheating. Nevertheless, we advise against the use of a low temperature preheat (<200°C) with IR50 to date loess samples because, as has been reported before, the signal appears to be thermally unstable. In general, we conclude that it may not be advisable to apply post-IR IRSL dating to Chinese loess samples where residuals of up to ~20 Gy are a significant fraction of the total dose. However, these residuals quickly become unimportant when dating older samples, and this is the age range in which post-IR IRSL dating is likely to be most useful.

6

Nonlinearity-controllable all-optical logic gates based on broadband defect mode

Liu B., Tian H., Lu H., Ji Y.

Optica Applicata

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2010

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Vol. 40, nr 3

657--668

EN

To avoid the adverse effect of unstable nonlinear progress on the design of all-optical logic gates, the broadband defect mode of one-dimensional photonic crystal with dual-defects has been studied. By using transfer matrix method, influences of period number and refractive indices on crystal’s transmission spectrum are analyzed. It is pointed out that with proper parameters, broadband defect mode, which could be used to reduce the influence between the nonlinear refractive index and field distribution, can be gained. Due to this fact, the designed XOR, AND and NOT logic gates can be steadily controlled with low-threshold and high-contrast.

7

Hollow fiber-based liquid phase microextraction combined with high performance liquid chromatography for determination of flavonoids in Ginkgo biloba and urine

Lu H., Wang X., Liu X., Jiang S.

Chemia Analityczna

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2009

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Vol. 54, No. 3

309-319

EN

A hollow fibre membrane-based liquid phase microextraction (HF-LPME) method for determination of flavonoids in Ginkgo biloba leaves was developed. Three flavonoids: quercetin, kaempferol, and isorhamnetin were extracted and then analysed by high performance •-:; liquid chromatography. The factors affecting HF-LPME, including concentration of donor ,; and acceptor phases, concentration of NaCl, extraction time, and stirring speed were systematically investigated. Under the optimum conditions, calibration plots of reasonable linearity were constructed in the analyte's concentration range of 10-100 μg L-1. Up to 200-fold enrichment factor for quercetin and up to tens of folds for kaempferol and isorhamnetin ' were obtained. The method was applied to determine the concentrations of flavonoids in urine and was proven to be an convenient sample preparation technique.

PL

Opracowano metodę oznaczania flawonoidów w liściach Ginkgo biloba za pomocą ^ mikroekstrakcji z fazy ciekłej przy użyciu membranowego wydrążonego włókna. Ekstra-howano i analizowano trzy flawonoidy: kwercetynę, kempferol i izorhamnetynę stosując wysokosprawną chromatografię cieczową. Systematycznie zbadano następujące czynniki wpływające na mikroekstrakcję: stężenie donora i akceptora, stężenie NaCl, czas ekstrakcji oraz szybkość mieszania. W optymalnych warunkach uzyskano liniowy wykres krzywej kalibracji w zakresie stężenia analitu od l O do 100 μg L-1. Współczynnik zatężenia wynosił do 200 razy w przypadku kwercetyny i do dziesiątek razy w przypadku kempferolu oraz izorhamnetyny. Opracowaną metodę zastosowano do oznaczania zawartości flawonoidów w moczu. Stwierdzono, że metoda jest odpowiednia do przygotowywania próbek.