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1

Shear properties of a honeycomb structure with zero Poisson’s ratio

Song L., Sun Y., Han Z., Wang T., Wang H., Yin C., Shen X.

Archives of Mechanics

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2023

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Vol. 75, nr 5

521--541

EN

Honeycomb structures with zero Poisson’s ratio show promising potential for application in variable-sweep wing aircraft. The shear properties of these honeycomb structures serve as a crucial indicator of their morphing capacity. This paper derives the linear and non-linear shear properties of a honeycomb structure with zero Poisson’s ratio. A modified factor is introduced to establish a relationship between the linear and non-linear shear modulus of the honeycomb structure, simplifying the calculation method of the non-linear shear modulus. The validity of theoretical predictions is then confirmed using the finite element method Furthermore, the influences of the geometric parameters on the shear properties of the honeycomb structure with zero Poisson’s ratio are investigated, highlighting the varying contributions of these cell geometric parameters to the shear properties.

2

Pre-formulation Compatibility Studies of 5-Amino-1H-tetrazole Nitrate with Several Typical Materials by Thermal and Non-thermal Techniques

Guo W., Han Z., Lin Q., Wang B.

Central European Journal of Energetic Materials

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2018

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Vol. 15, no. 1

100--114

EN

The aim of the present study was to assess the physicochemical compatibility of a promising energetic salt, 5-amino-1H-tetrazole nitrate (5-ATN), with some typical materials. Thermal techniques (differential scanning calorimetry (DSC) and vacuum stability test (VST)) and non-thermal techniques (X-ray diffractometry (XRD) and Fourier Transform Infrared Spectroscopy (FTIR)) were applied. Five energetic materials (TNT, RDX, HMX, CL-20 and AP) and three common additives (Al, DOS and F2604-2) were tested to evaluate their compatibility with 5-ATN. Based on the DSC results, except for AP that was only partially compatible with 5-ATN, all of the selected materials exhibited good compatible with 5-ATN. The VST test further confirmed the compatibility of the 5-ATN/AP mixtures. Combined with the thermal methods, the FTIR results agreed with the DSC findings. The XRD results showed some differences.

3

Multiscale simulation of major crack/minor cracks interplay with the corrected XFEM

Liu G., Zhou D., Bao Y., Ma J., Han Z.

Archives of Civil and Mechanical Engineering

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2017

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Vol. 17, no. 2

410--418

EN

The present work aims at saving computational cost of multiscale simulation on major crack/minor crack interaction problems. The multiscale extended finite element method (MsXFEM) used for the numerical simulation is developed on multiscale projection technique which enables different scale decomposition, and transition of field variables between different scales. Both macroscale and microscale problems are solved independently and alternatively, in the framework of XFEM. The improvement made in this paper is to employ corrected XFEM on the macroscale level, so that a more accurate boundary condition can be obtained for the microscale problem. The modification leads to a reduced necessary microscale domain size, meanwhile a solution of higher accuracy and enhanced convergence rate can be achieved. The numerical examples of minor cracks near a major one are studied, which show that the effect of minor cracks on major crack can be efficiently captured.

4

Application of ionic liquid-based ultrasonic-assisted extraction followed by rapid resolution LC-ESI/MS to chromone analysis from radix saposhnikoviae

Han Z., Xu M., Wang Y., Yang L., Han M.

Acta Chromatographica

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2017

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Vol. 29, no. 3

359--374

EN

Ionic liquid-based ultrasonic-assisted extraction (ILUAE) was successfully applied to the extraction of the four chromones (prim-O-glucosylcimifugin, cimifugin, 5-O-methylvisammioside, and sec-O-glucosylhamaudol) from Saposhnikovia divaricata (Radix Saposhnikoviae) for the first time. A series of l-alkyl-3-methylimidazolium ILs differing in anion and cation compositions was evaluated for extraction efficiency, and [C3MIM]Br was selected as the optimal solvent. In addition, ultrasound extraction parameters were optimized, and the chromones were directly quantified and analyzed by rapid resolution liquid chromatography-electrospray ionization/mass spectrometry (RRLC-ESI/MS). The optimal conditions were as follows: 0.4 M concentration of [C3MIM]Br, 20:1 solvent to solid ratio, and ultrasonic time, temperature, and frequency of 5 min, 40 °C, and 50 kHz, respectively. This approach obtained the highest extraction yield of 10.188 ± 0.473 mg g−1 for total chromones. Compared with regular UAE, the proposed approach exhibited a higher efficiency (61.56% increase) and shorter extraction time (nine times shorter). Also, ILUAE was an efficient, rapid, and simple sample preparation technique for extraction of chromones, and the established RRLC-DAD method could serve as a rapid and effective technique for extracting chromones from Radix Saposhnikoviae.

5

Soft-sediment deformation structures in cores from lacustrine slurry deposits of the Late Triassic Yanchang Fm. (central China)

Yang R., van Loon A. J., Yin W., Fan A., Han Z.

Geologos

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2016

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Vol. 22, No. 3

201--211

EN

The fine-grained autochthonous sedimentation in the deep part of a Late Triassic lake was frequently interrupted by gravity-induced mass flows. Some of these mass flows were so rich in water that they must have represented slurries. This can be deduced from the soft-sediment deformation structures that abound in cores from these lacustrine deposits which constitute the Yanchang Fm., which is present in the Ordos Basin (central China). The flows and the resulting SSDS were probably triggered by earthquakes, volcanic eruptions, shear stress of gravity flows, and/or the sudden release of overburden-induced excess pore-fluid pressure. The tectonically active setting, the depositional slope and the high sedimentation rate facilitated the development of soft-sediment deformations, which consist mainly of load casts and associated structures such as pseudonodules and flame structures. Sediments with such deformations were occasionally eroded by slurries and became embedded in their deposits.

6

Anchoring principles of a new energy-absorbing expandable rock bolt

Wen Z., Jiang Y., Han Z., Yang S., Wang X.

Engineering Transactions

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2016

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Vol. 64, iss. 1

89--103

EN

The greater the mine, the harder stability control will be. And the conventional rock bolts do not adapt well to the severe rock stress conditions. An ideal bolt having a high resistance and large deformation should be developed. Based on the test results and theoretical study, this paper proposes an energy-absorbing expandable rock bolt, which consists of the bar, sleeve, bolt plate, nut, and bolt end. The anchoring mechanism and its efficiency were systematically analysed in the laboratory and in practice: the anchoring mechanism and supporting density, especially the quantitative relationship, were deduced under the Energy Balance Theory, that is, EB = 1 2 · n · F0 (u0 + 2∆u). As Compared with the conventional bolt and large deformation bolts, the new type of bolt could provide a larger constant resistance, even in the soft rock roadway with large squeezing deformation, the pulling force can be achieved by F = A · σ · f2, it mainly being generated by a normal stress acting on the pore surface. These characteristics are helpful in making the supported roadway safe. The amount of released energy during the large deforming process of the surrounding rock is expressed through conservation of energy, which can provide reference to the quantitative calculation of the bolt supporting system.

7

Development and Validation of an LC–MS/MS Method for Determination of Tigecycline and Its Epimer in Human Plasma and Its Application in a Pharmacokinetic Study

Wang L., Hu X., Zhu H., Zhang X., Wang C., Han Z.

Acta Chromatographica

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2016

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Vol. 28, no. 2

239--253

EN

A rapid, selective, sensitive, and simple method for simultaneous determination of tigecycline and its epimer in human plasma samples was developed and validated by liquid chromatography–tandem mass spectrometry (LC–MS/MS). Sample preparation involved one-step protein precipitation by adding 0.1% formic acid–methanol and phosphate buffer (PB) solution to the plasma. Chromatographic separation was obtained with XBridge BEH C18 column (3.5 μm, 50 × 4.6 mm) through a 9.5-min gradient mobile phase at the flow rate of 0.6 mL min−1 at 4 °C. The calibration curves were linear over concentration 5.00–2000 ng mL−1 with correlation coefficient greater than 0.998. Intra-batch and inter-batch accuracy of the assay were in the ranges of −2.90% to 3.00%, and the corresponding precision was less than 6.97%. The extraction recovery of tigecycline and its epimer with the current method were 87.2% and 76.9%, respectively. The applied LC–MS/MS method was shown to be sufficiently sensitive and will be suitable for pharmacokinetic studies.

8

Research on deep joints and lode extension based on digital borehole camera technology

Han Z., Wang C., Zhu H.

Polish Maritime Research

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2015

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S 1

10--14

EN

Structure characteristics of rock and orebody in deep borehole are obtained by borehole camera technology. By investigating on the joints and fissures in Shapinggou molybdenum mine, the dominant orientation of joint fissure in surrounding rock and orebody were statistically analyzed. Applying the theory of metallogeny and geostatistics, the relationship between joint fissure and lode’s extension direction is explored. The results indicate that joints in the orebody of ZK61borehole have only one dominant orientation SE126° 68°, however, the dominant orientations of joints in surrounding rock were SE118° 73°, SW225° 70° and SE122° 65°, NE79° 63°. Then a preliminary conclusion showed that the lode’s extension direction is specific and it is influenced by joints of surrounding rock. Results of other boreholes are generally agree well with the ZK61, suggesting the analysis reliably reflects the lode’s extension properties and the conclusion presents important references for deep ore prospecting.

9

A simulation model of seawater vertical temperature by using back-propagation neural network

Zhao N., Han Z.

Polish Maritime Research

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2015

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S 1

82--88

EN

This study proposed a neural-network-based model to estimate the ocean vertical water temperature from the surface temperature in the northwest Pacific Ocean. The performance of the model and the sources of errors were assessed using the Gridded Argo dataset including 576 stations with 26 vertical levels from surface (0 m)–2,000 m over the period of 2007–2009. The parameter selection, model building, stability of the neural network were also investigated. According to the results, the averaged root mean square error (RMSE) of estimated temperature was 0.7378 °C and the correlation coefficient R was 0.9967. More than 67% of the estimates from the four selected months (January, April, July and October) lay within ± 0.5 °C. When counting with errors lower than ± 1°C, the lowest percentage was 83%.

10

The dynamics modeling and simulation for coupled double-rotor spindle system of high speed grynder

Hou Y., Wang S., Han Z.

Przegląd Elektrotechniczny

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2013

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R. 89, nr 1b

25--28

EN

This study was focused on the theoretical modeling and numerical simulation about the dynamic characteristics of coupled double-rotor spindle system of high speed grinder. The critical speeds of first three orders, the modes of variation and other dynamic characteristic parameters of the spindle system were analyzed and calculated. The results showed that the critical speeds of coupled double-rotor system were arranged in a similar increasing order as to those of each single rotor. It was thus indicated that the critical speeds of each order for coupled double-rotor system corresponded to those of single rotor. Furthermore, the main vibration modes of double-rotor system at each order were analyzed. The results indicated that vibration mode of each order of double rotors was the superimposition of the vibration mode of each single rotor. At variable critical speeds, the vibration mode of each single rotor in the system varied in its extent. If the critical speed of double-rotor system was close to that of a single rotor, then the superimposition of vibration modes of single rotors would become more significant under coupling state.

PL

W pracy położono nacisk na modelowanie teoretyczne i symulację numeryczną charakterystyk dynamicznych systemu wrzeciona ze sprzężonym podwójnym rotorem w wiertarce dużej szybkości, Przeanalizowano i obliczono szybkości krytyczne trzech pierwszych rzędów, typy wibracji i inne parametry charakterystyk dynamicznych systemu wrzeciona. Wykazano, że szybkości krytyczne systemu z rotorem podwójnym odpowiadają szybkości krytycznej odpowiednika z rotorem pojedynczym. Natomiast typy wibracji każdego rzędu rotora podwójnego są superpozycją typów wibracji pojedynczych rotorów. Jeśli szybkość krytyczna systemu z podwójnym rotorem jest bliska tej, jaką ma pojedynczy rotor, typy wibracji pojedynczych rotorów stają się bardziej znaczące pod wpływem stanu sprzężenia.

11

Optymalna alokacja zapewniająca bezpieczeństwo w układach procesowych oparta na przepływach sieciowych

Han Z., Gao J.

Eksploatacja i Niezawodność

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2011

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nr 1

27-34

PL

Bezpieczeństwo stanowi w inżynierii procesowej czynnik krytyczny, o którym należy pamiętać podczas całego czasu eksploatacji układów procesowych. W niniejszym artykule przedstawiono nową metodę optymalnej alokacji zasobów, opartą na przepływach w sieci, mającą zapewnić bezpieczeństwo układów procesowych. Istniejące optymalne alokacje zasobów wspierające bezpieczeństwo opierają się na rozwiązaniach fizycznych (np. unowocześnianiu podstawowych elementów wyposażenia i wbudowywaniu nadmiarowości) nieodpowiednich dla układów procesowych, które ulegają częstym awariom. Takie rozwiązania pociągają za sobą konieczność częstych alokacji fizycznych, które poważnie zakłócają normalne działanie całego układu. Dodatkowo, metody fizyczne stosuje się tylko wtedy, kiedy uszkodzenia układu nawarstwią sie do pewnego stopnia. Stan układu procesowego w inżynierii chemicznej często ulega wahaniom z powodu wielu czynników, takich jak niekontrolowane uwolnienie energii czy użycie niejednolitych materiałów produkcyjnych. Częste wahania mogą prowadzić do awarii układu. Konieczna jest zatem umiejętność unikania akumulacji błędów poprzez kontrolę wahań i stabilizację stanu układu, co prowadzi do zapewnienia bezpieczeństwa układu procesowego. W niniejszej pracy przedstawiamy metodę optymalnej alokacji, opartą na przepływach w sieci, która umożliwia osiągnięcie powyższego celu. Wedle nowej metody, przepływy osiągalne konstruuje się na podstawie przepływów w sieci układu, stanu wyposażenia układu oraz wymagań procesu. Wzory rozwiązań dla zmiennych stanu konstruowanych przepływów osiągalnych dają wartości korygujące, które używane są do kontrolowania wahań systemu i stabilizacji jego stanu. Prezentowane studium przypadku demonstruje możliwe zastosowania i efektywność proponowanej metody.

EN

Safety is a critical factor to be considered throughout the entire lifetime of process systems in process engineering. This paper presents a novel optimal resource allocation method based on network flows for assuring the safety of process systems. Existing optimal resource allocations for safety mainly depend on physical ways (for example, updating core equipments, and incorporating redundancies), which are not suitable for process systems experiencing frequent malfunctions. As a result, frequent physical allocations are needed, which severely interrupt the normal operation of the entire system. In addition, the physical methods are applied only when system faults accumulate to some extent. The state of a process system in chemical engineering often dithers due to many factors such as uncontrollable energy release and inconsistent production of materials. The frequent dithering can lead to the system failure. It is necessary to be able to avoid the accumulation of errors by controlling the dithering and stabilizing the system state, thus assuring the safety of the process system. In this paper, we propose a network flow-based optimal allocation method to achieve the above goal. Feasible flows will be constructed based on the system’s network flow, system equipment status, and process requirements. The solution formulas to the state variables of the constructed feasible flows give the adjustment values, which are used to control the dithering of the system, thus stabilize the system state. A case study is given to show the application and effectiveness of the proposed method.

12

Optimal resource allocation for safety in distributed complex electromechanical systems

Han Z., Gao J., Xing L., Chen F.

Eksploatacja i Niezawodność

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2011

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nr 2

4-12

EN

Existing optimal resource allocation for system safety mainly concentrates on series/parallel systems or systems that can be converted into series/parallel models. However, for some distributed complex electromechanical systems, it is very difficult or even impossible to refine them into a series/parallel model; in addition, the safety of some system units is immeasurable because of the coupling relationship complexity in the system composition structure. In this paper, a novel method based on complex networks and path set-based dynamic programming is proposed for the optimal resource allocation for maximal safety of distributed complex electromechanical systems with non-series-parallel structures. As a measurement of the system safety, safety importance is defined, which is a function of two safety feature parameters - accident loss and accident probability. A practical system is taken as an example to illustrate and verify the feasibility and applicability of the proposed method.

PL

Istniejące strategie optymalnej alokacji zasobów służące zapewnieniu bezpieczeństwa systemów skupiają się głównie na systemach szeregowo-równoległych lub na systemach, które można przekształcić w modele szeregowo-równoległe. Jednakże, w przypadku niektórych złożonych rozproszonych systemów elektromechanicznych, przetworzenie na model szeregowo-równoległy może być bardzo trudne lub wręcz niemożliwe. Dodatkowo, z powodu złożoności relacji sprzężeń w fizycznej strukturze tego rodzaju systemów, bezpieczeństwo niektórych jednostek systemowych jest niemierzalne. W niniejszym artykule przedstawiono nową metodę optymalnej alokacji zasobów gwarantującą maksymalne bezpieczeństwo złożonych rozproszonych systemów elektromechanicznych o strukturze innej niż szeregowo-równoległa. Metoda ta oparta jest na sieciach złożonych i wykorzystuje dynamiczne programowanie bazujące na zbiorach ścieżek. Jako miarę bezpieczeństwa systemu zastosowano pojęcie hierarchii bezpieczeństwa, zdefiniowane jako funkcja dwóch parametrów bezpieczeństwa: strat z tytułu awarii oraz prawdopodobieństwa awarii. Dla zilustrowania proponowanej metody i weryfikacji jej przydatności i możliwości zastosowania, przedstawiono przykład rzeczywistego systemu.

13

An oscillation criteria for third order neutral delay differential equations

Han Z., Li T., Sun S., Zhang C.

Journal of Applied Analysis

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2010

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Vol. 16, nr 2

295-303

EN

In this paper, we will establish some oscillation criteria for the third-order neutral delay differential equations (x(t) - a(t)x(τ (t)))''' + p(t)x(δ (t)) = 0, t ≥ t 0. To the best of our knowledge nothing is known regarding the qualitative behavior of these equations. Our results in this paper extend the results given in [Hanan, Oscillation criteria for third order differential equations, Pacific J. Math. 11 (1961) 919-944]. Some examples are considered to illustrate the main results.

14

Practical stability in terms of two measures for hybrid dynamic systems

Sun S., Han Z., Akin-Bohner E., Zhao P.

Bulletin of the Polish Academy of Sciences. Mathematics

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2010

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Vol. 58, no 3

221-237

EN

We study hybrid dynamic systems on time scales. Using Lyapunov-like functions, we obtain sufficient conditions for practical stability and strict practical stability in terms of two measures for hybrid dynamic systems on time scales.

15

The research on the reaction process of the sediments in hydrotreated lube base oils under ultraviolet radiation conditions

Wang H., Han Z., Wang R., Zhang Y., Zhao S.

Tribologia

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2003

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nr 2

107--114

EN

Hydrotreated lube base oil is superior to solvent refining base oil due to the higher viscosity index and lower volatility loss, however it is sensitive to sunlight or ultraviolet irradiation. On exposure to light and oxygen, some hydrotreated lube base oils became dark, haze and formed heavy sediments. The changes of the composition and the physical properties of the hydrotreated lube base oils exposed to ultraviolet light at 50š1°C were studied. Hydrotreated neutral oils (125N and 200N) prepared from Xinjiang crude oil (one of the oil fields in China) were used in this study; the formed sediments were analyzed by and XPS. The results showed that the physical properties of the base oils, i.e. the aromatics content in base oils increased with the exposure time, and nitrogen and sulfur containing decreased. Elemental analyses of the deposit showed that it is higher in nitrogen and sulfur content than that of the bulk of the oil. The results also showed that the relative percentage contents of nitrogen and sulfur in sediments are higher at the initial ultraviolet radiation stage and then became lower after ultimate stages. The precursors of forming the deposits are partially both hydrogenated heterocyclic compounds and hydrogenated polycyclic aromatic compounds, the reaction process is deduced.

PL

Hydrorafinowane oleje bazowe mają przewagę nad olejami po rafinacji rozpuszczalnikowej, ponieważ posiadają wyższy wskaźnik lepkości i mniejszą lotność. Niestety, są one czule na światło słoneczne oraz promieniowanie w nadfiolecie. W wyniku wystawienia na promieniowanie świetlne i tlen niektóre oleje hydrorafinowane stają się ciemne, nieprzezroczyste i dodatkowo pojawia się w nich osad. Autorzy prześledzili zmiany składu chemicznego i fizycznych właściwości hydrorafinowanych olejów bazowych zachodzące w wyniku naświetlania promieniami nadfioletowymi w temperaturze 50š1°C. Do badań użyto hydrorafinowanych olejów bazowych (oznaczonych 125 N i 200N) pochodzących z chińskich złóż Xinjiang. Wytrącone osady zbadano za pomocą FTIR i XPS. W wyniku badań stwierdzono, że stężenie związków aromatycznych w olejach bazowych zwiększało się w miarę upływu czasu, zaś zawartość azotu i siarki spadała. Analizy osadu wykazały, że zawartość w nich azotu i siarki przewyższa zawartość tych pierwiastków w oleju bazowym, z tym że także ona maleje w miarę czasu naświetlania. Odpowiedzialnymi za wytrącanie osadów są m.in. związki heterocykliczne i uwodornione policykliczne aromaty.