Polisacharydy zawarte w pyłku chryzantem ekstrahowano wodą i wytrącano przy użyciu alkoholu. Cukier o charakterze obojętnym i 2 cukry o charakterze kwasowym rozdzielono, stosując chromatografię jonowymienną. Skład monosacharydów oznaczono metodą wysokosprawnej chromatografii cieczowej. Działanie przeciwnowotworowe polisacharydów oceniano, badając ich wpływ na proliferację komórek nowotworowych. Hamowanie proliferacji HCT116 nie było znaczące, gdy stężenie wynosiło 5 mg/mL (p > 0,05), jednak działanie to w stosunku do komórek nowotworowych HCT116 i HT-29 było znaczące przy tym samym stężeniu (p < 0,05). Nieprzetworzone wyciągi polisacharydowe miały większy wpływ na proliferację komórek in vitro raka jelita grubego niż poszczególne polisacharydy.
EN
Polysaccharides were extd. from Dendranthema indicum var. Asteraceae bee pollens with H2O (yield 7.9%), pptd. with EtOH and sepd. by ion-exchange chromatog. into a neutral sugar and 2 acidic ones. The monosaccharide compn. was detd. by high performance liq. chromatog. They contained rhamnose, galacturonic acid, glucose, galactose and arabinose. The anticancer activity of the polysaccharides was evaluated by studying their effect on proliferation of HCT116 and HT-29 cancer cells. The inhibitory effect of individual sugars on the proliferation of HCT116 was not significant when their concns. were 5 mg/mL, but the total polysaccharides showed a significant effect on proliferation of HCT116 and HT-29 tumor cells at the same concn
In this study, high silica glass fiber fabric/liquid silicone rubber (HSGFF/LSR) composite sheet filled with hollow glass microspheres (HGM) was prepared. The effects of HGM content on the mechanical, thermal insulation and dynamic mechanical properties of the composite sheet were investigated. The results showed that the compatibility and interfacial properties between HGM and the matrix were improved after the HGM was treated with a silane coupling agent, KH550. Composite, in which the HGM content was 7 % by weight, shows the most advantageous mechanical, insulating and damping properties.
PL
Na bazie tkaniny z włókien kwarcowych (HSGFF) nasyconej ciekłym kauczukiem silikonowym (LSR) otrzymywano kompozyty napełniane mikrosferami szklanymi (HGM). Badano wpływ dodatku mikrosfer na właściwości mechaniczne, izolacyjność cieplną i właściwości dynamiczno-mechaniczne kompozytowych arkuszy. Stwierdzono, że modyfikacja mikrosfer szklanych za pomocą silanowego czynnika sprzęgającego KH550 poprawiła kompatybilność i oddziaływania międzyfazowe cząsteczek HGM i nasyconej ciekłym kauczukiem tkaniny z włókien szklanych. Najkorzystniejsze właściwości mechaniczne, izolacyjne i tłumiące wykazywał kompozyt, w którym zawartość HGM wynosiła 7 % mas.
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Fuzzy approaches play an important role in the modeling of genetic regulatory networks (GRNs) with incomplete quantitative data. However, current fuzzy approaches such as fuzzy logic and fuzzy Petri nets (FPNs) can neither clearly describe causal relationships between genes as each interaction between genes is represented by a couple of fuzzy rules, nor easily deal with large GRNs. To address these issues, this paper presents a new class of colored fuzzy Petri nets (CFPNs) by combining colored Petri nets with FPNs, which makes it possible to clearly represent interactions among genes or to construct a compact model for a large GRN requiring many fuzzy rules. We give the definition of CFPNs and a simulation approach which incorporates a reasoning algorithm, as well as a detailed procedure for modeling and analyzing GRNs with CFPNs. We illustrate our approach using a simple example comprising six genes.
An experimental study was carried out on the fatigue behaviour of multi-axial warp-knitted fabric composites. Composite samples reinforced with multi-axial warp-knitted fabric/matrix were manufactured by the vacuum-assisted resin transfer moulding method. Tensile-tensile fatigue cycling was carried out at different load levels, and S-N curves, tensile stress-strain curve and stiffness degradation of the multi-axial composite samples were obtained. Finally post-fatigue tensile tests were done at a stress level of 75%, at the stages of 1/3N and 2/3N, and the equivalent residual strength and stiffness degradation were obtained.
PL
Dokonano oceny właściwości mechanicznych i zmęczeniowych kompozytowych dzianin wieloosiowych. Kompozyty wzmocnione dzianiną wieloosiową wytworzono przy zastosowaniu próżniowej metody formowania. Dokonano oceny zmęczenia materiału i właściwości wytrzymałościowych przy różnych poziomach obciążenia. Przedstawiono krzywe S-N, krzywą naprężenie-odkształcenie i degradację sztywności wieloosiowych próbek kompozytowych. Wykonano również testy zmęczenia materiału przy poziomie naprężenia 75%, w etapach 1/3N i 2/3N. Omówiono równoważną wytrzymałość szczątkową i degradację sztywności kompozytowych dzianin wieloosiowych.
In order to optimize the stope structure parameters in broken rock conditions, a novel method for the optimization of stope structure parameters is described. The method is based on the field investigation, laboratory tests and numerical simulation. The grey relational analysis (GRA) is applied to the optimization of the stope structure parameters in broken rock conditions with multiple performance characteristics. The influencing factors include stope height, pillar diameter, pillar spacing and pillar array pitch, the performance characteristics include maximum tensile strength, maximum compressive strength and ore recovery rate. The setting of influencing factors is accomplished using the four factors four levels Taguchi experiment design method, and 16 experiments are done by numerical simulation. Analysis of the grey relational grade indicates the first effect value of 0.219 is the pillar array pitch. In addition, the optimal stope structure parameters are as follows: the height of the stope is 3.5 m, the pillar diameter is 3.5 m, the pillar spacing is 3 m and the pillar array pitch is 5 m. In-situ measurement shows that all of the pillars can basically remain stable, ore recovery rate can be ensured to be more than 82%. This study indicates that the GRA method can efficiently applied to the optimization of stope structure parameters.
PL
W pracy zaproponowano nową metodę optymalizacji parametrów struktury przodka wybierkowego prowadzonego w warunkach pękania skał. Metoda opiera się na badaniach terenowych, wykorzystuje także badania laboratoryjne oraz symulacje numeryczne. Do optymalizacji parametrów struktury przodka wybierkowego prowadzonego w warunkach pękania skał dla wielu wariantów charakterystyki górotworu wykorzystano ‘szarą’ analizę relacyjną (GRA – Grey Relational Analysis). Uwzględnione czynniki wpływu to wysokość przodka, średnica filarów, rozstaw filarów, rozmieszczenie filarów oraz charakterystyki górotworu: maksymalna wytrzymałość na rozciąganie oraz ściskanie oraz uzysk rudy. Ustawienia czynników wpływu dokonano z wykorzystaniem czterech czynników i dla czterech poziomów wg metody Taguchi planowania eksperymentów; ponadto 16 eksperymentów wykonano z wykorzystaniem symulacji numerycznych. Wyniki ‘szarej’ analiza relacyjnej wskazują, że wartość efektywna dla pierwszego z czynników, czyli rozmieszczenia filarów, wyniosła 0.219. Ponadto, otrzymano następujące optymalne parametry przodka: wysokość przodka 3.5 m; średnica filarów 3.5 m, rozstęp pomiędzy filarami 3 m, rozciągłość filarów 5 m. Pomiary przeprowadzone in situ wykazały, że wszystkie filary zasadniczo powinny zachować stabilność, a uzysk rudy przekroczyć może 82%. Wyniki wskazują, że ‘szara’ analiza relacyjna może być z powodzeniem wykorzystywana do optymalizacji parametrów struktury przodka wybierkowego.
To solve the problem of large deformation soft rock roadway with complicated stress condition in Baluba copper mine, the characteristics of roadway deformation and failure modes are analyzed deeply on the basis of geological survey. Combined with the theoretical analysis and numerical simulation, the new reinforcement technology with floor mudsill and grouting anchor cable is proposed. Moreover, the three dimension numerical simulation model is established by the software FLAC-3D, the support parameter is optimized by it. The results show that the optical array pitch of the U-steel shelf arch is 0.8 m, and the optical array pitch of the grouting anchor cable is 2.4 m. At last, the field experiments are done all over the soft rock roadway. Engineering practice shows that the deformation of soft rock roadway in Baluba copper mine is effectively controlled by adopting the new reinforcement technology, which can provide certain references for similar engineering.
PL
W celu rozwiązania problemu powstawania znacznych odkształceń chodnika biegnącego w skale miękkiej w skomplikowanym układzie naprężeń, przeprowadzono dogłębną analizę warunków odkształceń i pękania skał w oparciu o badania geologiczne. W oparciu o rozważania teoretyczne i symulacje numeryczne, zaproponowano nową technologię wzmocnienia progu spągowego z iłowców z linami kotwiącymi osadzonymi w zaprawie. Na podstawie trójwymiarowego modelu do symulacji numerycznych opracowanego z wykorzystaniem oprogramowania FLAC-3D dokonano optymalizacji parametrów podpór. Wyniki pokazują, że optymalne rozmieszczenie stalowych podpór wykonanych z profili w kształcie U wyniesie 0.8 m, zaś optymalny rozstaw mocowań lin wynosi 2.4 m. W końcowym etapie przeprowadzono eksperymenty terenowe na całej długości chodnika. Praktyka inżynierska wskazuje, że odkształcenia chodników prowadzonych w skałach miękkich w kopalni Baluba mogą być skutecznie kontrolowane poprzez zastosowanie nowej metody wzmocnienia, która stanowić może podstawę dla opracowywania skutecznych technik wzmacniania stropu w chodnikach prowadzonych w podobnych warunkach geologicznych.
Considering the environmental pollution caused by waste rubber, some measures should be taken to improve the utilization rate of waste rubber. In this study, the effect of Ethylene Propylene Diene Monomer (EPDM) particles in the polyurethane (PU) foams on sound absorption behavior is investigated for improving sound environment within vehicles and reducing the environment pollution. EPDM particles of different contents and hardness are used as fillers for producing foams with different pore morphologies and sound absorption properties. The results show that adding EPDM to foam would produce smaller pores, higher density and bigger air-flow resistivity. Simultaneously, there are better sound absorption properties of the PU foam composites in the medium frequency region, and the better value can be obtained at the lower frequency with the content of EPDM increasing. The hardness of EPDM also shows better influence on sound absorption properties, especially in the medium frequency region. It means the foam pore morphologies have influence on sound absorption properties.
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Polytetrafluoroethylene (PTFE)/Kevlar fabric or fabric composites with excellent tribological properties have been considered as important materials used in bearings and bushing, for years. The components’ (PTFE, Kevlar, and the gap between PTFE and Kevlar) distribution of the PTFE/Kevlar fabric is uneven due to the textile structure controlling the wear process and behavior. The components’ area ratio on the worn surface varying with the wear depth was analyzed not only by the wear experiment, but also by the theoretical calculations with our previous wear geometry model. The wear process and behavior of the PTFE/Kevlar twill fabric were investigated under dry sliding conditions against AISI 1045 steel by using a ring-on-plate tribometer. The morphologies of the worn surface were observed by the confocal laser scanning microscopy (CLSM). The wear process of the PTFE/Kevlar twill fabric was divided into five layers according to the distribution characteristics of Kevlar. It showed that the friction coefficients and wear rates changed with the wear depth, the order of the antiwear performance of the previous three layers was Layer III>Layer II>Layer I due to the area ratio variation of PTFE and Kevlar with the wear depth.
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The present work has reported the compression properties of polyurethane-based warp-knitted spacer fabric composites (PWSF). In order to investigate the effect of structural parameters of fabric on the compression performance of composites, a series of warp-knitted spacer fabrics (WSF) with different structural parameters including spacer yarn inclination angle, thickness, fineness of spacer yarns, and outer layer structure have been involved. The produced composites have been characterized for compression properties. The energy-absorption performance during the compression process has been determined as a function of the efficiency and the compression stress obtained from compression tests. The results show that the composites based on spacer fabrics having smaller spacer yarns inclination angle, higher fabric thickness, finer spacer yarn, and larger mesh in outer layers perform better with respect to energy-absorption properties at lower stress level, whereas at higher stress level, the best energy-absorption abilities are obtained in case of spacer fabrics constructed of larger spacer yarn inclination angle, lower fabric thickness, coarser spacer yarn, and smaller mesh in surface layers.
A carbide-free bainitic microstructure is suitable for achieving a combination of ultra high strength and high ductility. In this work, a steel containing nominally 0.34C-2Mn-1.5Si-1Cr (wt.%) was produced via industrial hot rolling and laboratory heat treatments. The austenitization (900°C, 30 min.) and austempering (300-400°C, 3 h) treatments were done in salt bath furnaces. The austempering treatments were designed to approximately simulate the coiling step, following hot rolling and run-out-table cooling, when the bainitic transformation would take place and certain amount of austenite would be stabilized due to suppression of carbide precipitation. The microstructures and various mechanical properties (tensile properties, bendability, flangeability, and room and subzero temperature impact toughness) relevant for applications were characterized. It was found that the mechanical properties were highly dependent on the stability of the retained austenite, presence of martensite in the microstructure and the size of the microstructural constituents. The highest amount of retained austenite (~ 27 wt.%) was obtained in the sample austempered at 375°C but due to lower austenite stability and coarser overall microstructure, the sample exhibited lower tensile ductility, bendability, flangeability and impact toughness. The sample austempered at 400°C also showed poor properties due to the presence of initial martensite and coarse microstructure. The best combination of mechanical properties was achieved for the samples austempered at 325-350°C with a lower amount of retained austenite but with the highest mechanical stability.
In this study, an effective optimization approach was proposed to improve acoustical behaviors of PU foams. The important parameters of PU foams: content of water, silicone oil and catalyst A1 were chosen and their effects on sound absorption coefficient and transmission loss of PU foams were studied by using Taguchi methods. In addition, bamboo chips were incorporated into PU foams as fillers to improve the acoustical properties of PU foams. Four controlled factors: the content of water, silicone oil, catalyst A1 and bamboo chips with three levels for each factor were chosen and Taguchi method based on orthogonal array L9 (34) was employed to conduct the experiments. Based on the results of Taguchi’s orthogonal array L9 (34), signal-to noise (S/N) analysis was used and developed to determine an optimal formulation of PU-bamboo-chips foam composites.
Assessing the risks of steering system faults in underwater vehicles is a human-machine-environment (HME) systematic safety field that studies faults in the steering system itself, the driver’s human reliability (HR) and various environmental conditions. This paper proposed a fault risk assessment method for an underwater vehicle steering system based on virtual prototyping and Monte Carlo simulation. A virtual steering system prototype was established and validated to rectify a lack of historic fault data. Fault injection and simulation were conducted to acquire fault simulation data. A Monte Carlo simulation was adopted that integrated randomness due to the human operator and environment. Randomness and uncertainty of the human, machine and environment were integrated in the method to obtain a probabilistic risk indicator. To verify the proposed method, a case of stuck rudder fault (SRF) risk assessment was studied. This method may provide a novel solution for fault risk assessment of a vehicle or other general HME system.
The dynamic strength and accumulated plastic strain are two important parameters for evaluating the dynamic response of soil. As a special clay, the remolded red clay is often used as the high speed railway subgrade filling, but studies on its dynamic characteristics are few. For a thorough analysis of the suitability of the remolded red clay as the subgrade filling, a series of long-term cyclic load triaxial test under different load histories are carried out. Considering the influence of compactness, confining pressure, consolidation ratio, vibration frequency and dynamic load to the remolded red clay dynamic property, the tests obtain the development curves of the dynamic strength and accumulated plastic strain under different test conditions. Then, through curve fitting method, two different hyperbolic models respectively for the dynamic strength and accumulated plastic strain are built, which can match the test datum well. By applying the dynamic strength model, the critical dynamic strength of the remolded red clay are gained. Meanwhile, for providing basic datum and reference for relevant projects, all key parameters for the dynamic strength and accumulated plastic strain of the remolded red clay are given in the paper.
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In this paper, the mechanical properties (compression and impact behaviours) of three-dimension structure (3D-structure) composites based on warp-knitted spacer fabrics have been thoroughly investigated. In order to discuss the effect of fabric structural parameters on the mechanical performance of composites, six different types of warp-knitted spacer fabrics having different structural parameters (such as outer layer structure, diameter of spacer yarn, spacer yarn inclination angle and thickness) were involved for comparison study. The 3D-structure composites were fabricated based on a flexible polyurethane foam. The produced composites were characterised for compression and impact properties. The findings obtained indicate that the fabric structural parameters have strong influence on the compression and impact responses of 3D-structure composites. Additionally, the impact test carried out on the 3D-structure composites shows that the impact loads do not affect the integrity of composite structure. All the results reveal that the product exhibits promising mechanical performance and its service life can be sustained.
In light of the issue of radiolysis of the solvent system in PUREX process, alpha and gamma radiation stability of tributyl phosphate (TBP)/kerosene (OK) have been studied in this paper, in which 238Pu dissolved in the organic phase and 60Co are selected as alpha and gamma irradiation sources, respectively. The amount of the degradation products not easily removed after the washing process has been measured by the plutonium retention. The effects of the absorbed dose, the TBP volume fraction, the cumulative absorbed dose and the presence of UO2 2+ and Zr4+ on the radiolysis of the solvents have been investigated. The results have indicated that the Pu retention increases with the increase of the absorbed dose after alpha or gamma irradiation, and is larger for the solvent containing less TBP. There is competition between UO2 2+ and Pu4+ to complex with the degradation products, and Zr4+ accelerates the radiolysis of the system.
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The paper g describes a model meant for analysis of the wear geometry of plain woven fabric composites. The referred model consists of a mathematical description of plain woven fabric based on Peirce’s model coupled with a stratified method for the solution of the wear geometry. The evolutions of the wear area ratio of weft yarn, warp yarn and matrix resin on the worn surface are simulated by MatLab software in combination of warp and weft yarn diameters, warp and weft yarn-to-yarn distances, fabric structure phases (SPs). By comparing theoretical and experimental results from the PTFE/Kevlar fabric wear experiment, it can be concluded that the model can present a trend of the component area ratio variations along with the thickness of fabric, but has a inherently large error in quantitative analysis as an idealized model.
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We consider the analogue of Lévy area, defined as an iterated stochastic integral, obtained by replacing two independent component onedimensional Brownian motions by the mutually non-commuting momentum and position Brownian motions P and Q of either Fock or non-Fock quantum stochastic calculus, which are also stochastically independent in a certain sense. We show that the resulting quantum Lévy area is trivially distributed in the Fock case, but has a non-trivial distribution in non-Fock quantum stochastic calculus which, after rescaling, interpolates between the trivial distribution and that of classical Lévy area in the “infinite temperature” limit. We also show that it behaves differently from the classical Lévy area under a kind of time reversal, in both the Fock and non-Fock cases.
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The stability of a general Linear Time-Invariant (LTI) Ultra-WideBand (UWB) Channel Impulse Response (CIR) model is investigated. Since the s-domain or z-domain function of the UWB CIR has an extremely high number of singularities, it cannot be automatically guaranteed that none of the poles falls on the right-half of the s-plane or outside the unit-circle of the z-plane. Hence the stability analysis necessitates the exhaustive testing of classical stability criterion for a potentially excessive number of poles. We circumvent this arduous task by developing the closed-form time-domain response of the so-called homogenous, non-homogenous and vectorial LTI causal UWB system. Furthermore, the normalized settling time of the step response is evaluated for diverse damping coefficients. Finally, a stability case-study is provided with the aid of Nichols chart.
PL
Zbadano stabilność ultra szerokopasmowego kanału LTI. Ponieważ na płaszczyźnie s i z odpowiedź impulsowa ma wiele osobliwości nie można automatycznie zagwarantować, że wszystkie są w prawe połówce płaszczyzny s lub wewnątrz koła jednostkowego z. W pracy zaproponowano metodę określania stabilności kanału.
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The one-dimensional Ag/SiO2 metallic-dielectric photonic crystals (PCs) have been prepared. The absorption enhancement effect over the corresponding metal of 1D Ag/SiO2 metallic-dielectric multi-layer structures has been measured. The enhancement effect increases with the number of layers increasing. The origin of this phenomenon and its effect on the transmittance and reflectance have been discussed.
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The master sintering curve (MSC) is quite useful for analyzing the shrinkage behaviour of ceramics. In this study, the shrinkage behaviour for ?-Al2O3 with a mean particle size of 350 nm during constantheating- rate sintering were evaluated based on the MSC theory. An MSC for the above powder has been constructed using dilatometry data containing heating rates lower than 5 °C/min only with the help of combined-stage sintering model. The validity of the MSC has been verified by a few experimental runs. A comparison between predicted and experimental shrinkage curves showed good consistency, thus confirming that it is possible to control shrinkage behaviour using the MSC. The concept of the MSC has been used to evaluate the apparent activation energy for the above powder, and a high value of 1035 kJ/mol was obtained.
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