Wyniki wyszukiwania - BazTech

1

Kinetic research of quinoline, pyridine and phenol adsorption on modified coking coal

Sun X., Xu H., Wang J., Ning K., Huang G., Yu Y., Ma L.

Physicochemical Problems of Mineral Processing

|

2018

|

Vol. 54, iss. 3

965--974

EN

Adsorption is widely used in wastewater treatment. In this work, the removal of quinoline, pyridine and phenol from coking wastewater by using modified coking coal, which was treated by four different modification methods i.e. acidification sodium hydroxide (5 mol/dm3), hydrochloric acid (5 mol/dm3) and acetic acid (5 mol/dm3) and low-temperature (105 oC) oxidation, was investigated. The modified coal was characterized by the surface area analysis, SEM, total acidity and basicity and FT-IR. The results showed that the surface area from high to low follows the order: modification with acetic acid, modification with hydrochloric acid, raw coal, modification with sodium hydroxide and modification with low-temperature. Experimental data were fitted to pseudo-first-order, pseudo-second-order and intra-particle diffusion. The adsorption of all followed pseudo-second-order kinetics. The result showed that the removal efficiency of coal modified by hydrochloric acid and acetic acid are higher than raw coal, while modified by sodium hydroxide and low-temperature are lower than raw coal., The coal modified by hydroxide acid had the best adsorption capacity.

2

Optimization of differentiation time of mesenchymal-stem-cell to tenocyte under a cyclic stretching with a microgrooved culture membrane and selected measurement cells

Morita Y., Yamashita T., Toku Y., Yu Y.

Acta of Bioengineering and Biomechanics

|

2018

|

Vol. 20, no. 1

3--10

EN

There is a need for efficient stem cell-to-tenocyte differentiation techniques for tendon tissue engineering. More than 1 week is required for tenogenic differentiation with chemical stimuli, including co-culturing. Research has begun to examine the utility of mechanical stimuli, which reduces the differentiation time to several days. However, the precise length of time required to differentiate human bone marrow-derived mesenchymal stem cells (hBMSCs) into tenocytes has not been clarified. Understanding the precise time required is important for future tissue engineering projects. Therefore, in this study, a method was developed to more precisely determine the length of time required to differentiate hBMSCs into tenocytes with cyclic stretching stimulus. Methods: First, it had to be determined how stretching stimulation affected the cells. Microgrooved culture membranes were used to suppress cell orientation behavior. Then, only cells oriented parallel to the microgrooves were selected and evaluated for protein synthesis levels for differentiation. Results: The results revealed that growing cells on the microgrooved membrane and selecting optimally-oriented cells for measurement improved the accuracy of the differentiation evaluation, and that hBMSCs differentiated into tenocytes in approximately 10 h. Conclusions: The differentiation time corresponded to the time required for cellular cytoskeleton reorganization and cellular morphology alterations. This suggests that cells, when subjected to mechanical stimulus, secrete mRNAs and proteins for both cytoskeleton reorganization and differentiation.

3

Energy feature of a multi-flow column flotation process

Cheng G., Yu Y., Ma L., Xia W., Xu H.

Physicochemical Problems of Mineral Processing

|

2017

|

Vol. 53, iss. 2

1266--1284

EN

A cyclonic-static micro-bubble flotation column (FCSMC) has been widely used in mineral separation. FCSMC includes countercurrent, cyclone and jet flow mineralization zones in a single column. In this study, the energy feature of the three different zones was compared. The turbulent flow was evaluated in terms of the turbulent kinetic energy (k) and the turbulent dissipation rate (ε). An appropriate computing model was determined by comparing the flow field value measured by PIV with the results of the Fluent numerical simulation. Jet flow separation exhibited the maximum k and ε values among the three columns, whereas counter-current separation displayed the minimum values. The high circulating volumetric flowrate means great energy input and turbulent intensity. The higher turbulent dissipation rate, the smaller the bubble is. The better performance of the FCSMC was mainly attributed to the multiple mineralization steps. The floatability of mineral particles gradually decreases with an increase in flotation time, the mineralization energy gradually increased to overcome the decrease in mineral floatability. By contrast, the countercurrent was beneficial for recovering the coarse particles, and the jet flow was beneficial for recovering the fine particles.

4

A Note on Spiking Neural P Systems with Homogenous Neurons and Synapses

Yu Y., Wu T., Xu J., Wang Y., He J.

Fundamenta Informaticae

|

2017

|

Vol. 150, nr 2

231--240

EN

Spiking neural (SN, for short) P systems are a class of computation models inspired from the way in which neurons communicate by exchanging spikes. SN P systems with homogenous neurons and synapses are a new variant of SN P systems, where the spiking and forgetting rules are placed on synapses instead of in neurons and each synapse has the same set of spiking and forgetting rules. Recent studies illustrated that this variant of SN P systems is Turing universal as both number generating and accepting devices. In this note, we prove that SN P systems with homogenous neurons and synapses without the feature of delay are also Turing universal. This result gives a positive answer to an open problem formulated in [K. Jiang, et al. Neurocomputing 171(2016) 1548-1555] “whether SN P systems with homogenous neurons and synapses are Turing universal when the feature of delay is not used”.

5

Synthesis and Theoretical Studies of a New Insensitive Explosive, 2’-Methyl-3-nitro-2’H-[1,3’-bi(1,2,4-triazole)]-5,5’-diamine

Luo J., Liu Y., Liu Y., Wang J., Chai T., Yuan J., Chang S., Yu Y., Jing S., Ma H.

Central European Journal of Energetic Materials

|

2017

|

Vol. 14, no. 2

269--280

EN

A new insensitive energetic material 2’-methyl-3-nitro-2’H-[1,3’-bi(1,2,4-triazole)]-5,5’-diamine (1) was prepared by a three-step synthesis from commercially available chemicals. The energetic title compound was comprehensively characterized by various means, including FT-IR, multinuclear (1H, 13C, 14N) NMR spectroscopy, elemental analysis, HPLC and thermal analysis. The sensitivities of the synthesized material towards various external stimuli (impact, friction) were determined according to the BAM method. The optimized structure and related thermodynamic parameters were obtained at the DFT-B3LYP/6-31+G** theoretical level. The detonation properties of the material were also predicted according to the Kamlet-Jacobs formulae and the Monte-Carlo method. The results show that the density, heat of formation, detonation velocity, detonation pressure, impact sensitivity and purity were 1.83 g/cm3, 369 kJ/mol, 7.52 km/s, 25.4 GPa, 82.3 J and 97.7%, respectively. In addition, the compound was an insensitive high explosive which could meet the requirements of high energetic materials.

6

Study on Underwater Explosive Welding of Al-Steel Coaxial Pipes

Yu Y., Ma H., Zhao K., Shen Z., Cheng Y.

Central European Journal of Energetic Materials

|

2017

|

Vol. 14, no. 1

251--265

EN

In order to solve the aluminum surface ablation issue of Al-Steel bimetallic pipes manufactured by the explosive welding technique, a novel explosive welding system has been designed to weld Al-Steel coaxial pipes. The stand-off distance was chosen according to an empirical formula. A special Explosive Cord with an aluminum coating was used as the explosive. Four experiments were performed using Explosive Cords 1, 2, 3 and 4, respectively. In each experiment, three reliable PVDF (Polyvinylidene Fluoride) piezoelectric film sensors were used to sample the impact pressure between the parent pipe and the flyer pipe along the detonation direction. p-t Curves were obtained at different points on the bimetallic pipe manufactured by Explosive Cord 1. In order to observe the inner surface and to judge the bonding interface, specimens were cut along the axial direction. BSE (Backscattering Electron) images of the interfaces were obtained. According to these pictures from all of the specimens cut along the axial direction, the surface ablation phenomenon has disappeared. The bimetallic pipe manufactured by the new welding system using Explosive Cord 3 has an irregular wavy interface, between micro and small wavy interface, which is one of the best bonding forms.

7

Study on transport packages used for food freshness preservation based on thermal analysis

Yu Y.

Archives of Thermodynamics

|

2016

|

Vol. 37, no. 4

121--135

EN

In recent time, as the Chinese consumption level increases, the consumption quantity of high-value fruits, vegetables and seafood products have been increasing year by year. As a consequence, the traffic volume of refrigerated products also increases yearly and the popularization degree of the cold-chain transportation enhances. A low-temperature environment should be guaranteed during transportation, thus there is about 40% of diesel oil should be consumed by the refrigerating system and the cold-chain transportation becomes very costly. This study aimed to explore methods that could reduce the cost of transport packages of refrigerated products. On the basis of the heat transfer theory and the fluid mechanics theory, the heat exchanging process of corrugated cases during the operation of refrigerating system was analyzed, the heat transfer process of corrugated cases and refrigerator van was theoretically analyzed and the heat balance equation of corrugated cases was constructed.

8

Distribution and sources of n-alkanes in surface sediments of Taihu Lake, China

Yu Y., Li Y., Guo Z., Zou H.

Archives of Environmental Protection

|

2016

|

Vol. 42, no. 1

49--55

EN

The last study on n-alkanes in surface sediments of Taihu Lake was in 2000, only 13 surface sediment samples were analysed, in order to have a comprehensive and up-to-date understanding of n-alkanes in the surface sediments of Taihu Lake, 41 surface sediment samples were analyzed by GC-MS. C10 to C37 were detected, the total concentrations of n-alkanes ranged from 2109 ng g−1 to 9096 ng gg−1 (dry weight). There was strong odd carbon predominance in long chain n-alkanes and even carbon predominance in short chain n-alkanes. When this finding was combined with the analysis results of wax n-alkanes (WaxCn), carbon preference index (CPI), unresolved complex mixture (UCM), hopanes and steranes, it was considered that the long chain n-alkanes were mainly from terrigenous higher plants, and that the short chain n-alkanes mainly originated from bacteria and algae in the lake, compared with previous studies, there were no obvious anthropogenic petrogenic inputs. Terrestrial and aquatic hydrocarbons ratio (TAR) and C21−/C25+ indicated that terrigenous input was higher than aquatic sources and the nearshore n-alkanes were mainly from land-derived sources. Moreover, the distribution of short chain n-alkanes presented a relatively uniform pattern, while the long chain n-alkanes presented a trend that concentrations dropped from nearshore places to the middle of lake.

9

Data sensitive recommendation based on community detection

Su Ch., Yu Y., Xie X., Wang Y.

Foundations of Computing and Decision Sciences

|

2015

|

Vol. 40, No. 2

143--159

EN

Collaborative filtering is one of the most successful and widely used recommendation systems. A hybrid collaborative filtering method called data sensitive recommendation based on community detection (DSRCD) is proposed as a solution to cold start and data sparsity problems in CF. Data sensitive similarity is combined with Pearson similarity to calculate the similarity between users. α is the control parameter. A predicted rating mechanism is used to solve data sparsity problem and to obtain more accurate recommendation. Both user-user similarity and item-item similarity are considered in predicted rating mechanism. β is the control parameter. Moreover, in the constructed K-nearest neighbour set, both user-community similarity and user-user similarity are considered. The target user is either in the community or has some correlation to the community. Calculating the user-community similarity can cope with cold start problem. To calculate the recommendation, movielens data sets are used in the experiments. First, parameters αandβare tested and DSRCD is compared with traditional collaborative filtering recommendation algorithm (TCF) and Zhao’s algorithm. DSRCD always has better results than TCF. When K = 30, we have better performance results than Zhao’s algorithm.

10

Phase change of chlorite in reducing atmosphere

Liu X., Yu Y., Chen W., Liu X.

Physicochemical Problems of Mineral Processing

|

2014

|

Vol. 50, iss. 2

607--614

EN

Magnetizing roasting is an important pre-treatment technique for beneficiation of hematite and limonite ores. Reduction mechanisms of these iron minerals have been fully studied while the mechanism of reduction of chlorite is not well understood. In this study, a reduction roasting study examining the phase change of chlorite with roasting temperature was undertaken. The major finding from this study was that chlorite partially was reduced to magnetite by carbon at 750 ⁰C, and the newly formed magnetite was finely disseminated within quartz and olivine. It was demonstrated that these locked magnetite particles would be reported to iron concentrate by low intensity magnetic separation resulting in high impurity content, especially SiO2 and Al2O3 contents in the concentrate.

11

Ultra-wide bandwidth wavelength selective couplers based on the all solid multi-core Ge-doped fibre

Li X., Sun B., Yu Y.

Opto-Electronics Review

|

2014

|

Vol. 22, No. 3

166-170

EN

A novel wavelength selective coupler based on the all solid nine-core Ge-doped fibre has been proposed. The wavelength selective coupler is based on the phenomenon of a multi-core coupling. All the cores are made of Ge-doped silica and the index of central core is larger than the outer core. At the fixed fibre length, the different wavelength can be selected. The performances of coupling and propagation characteristics have been numerically investigated by using a full beam propagation method (BPM). Simulation results show that the all solid nine-core Ge-doped fibre can achieve simultaneous shorter coupler length and wideband filtering characteristics. The 0.763 mm and 0.745 mm wavelength selective coupler are proposed to achieve different wavelength division and the bandwidth is up to the 400 nm, and 300 nm, respectively.

12

Batch extractive distillation of mixture methanol-acetonitrile using aniline as a asolvent

Li G., Yu Y., Bai P.

Polish Journal of Chemical Technology

|

2012

|

Vol. 14, nr 3

48-53

EN

Methanol and acetonitrile form a minimum azeotrope at 336.74 K, which contains methanol 76.89 mas%. The simulation and the experiment to separate the mixture by batch extractive distillation using aniline as entrainer is performed. Based on the experimental and simulative VLE data, aniline is chosen to be the suitable solvent. The sensitivity analysis about the number of stages, the refl ux ratio, the solvent feed stage and the solvent fl ow rate is conducted to obtain the optimal parameters and confi guration of the extractive distillation column with minimal energy requirements. The most appropriate confi guration is 30 theoretical stages. The optimal entrainer feeding stage is 8 with a solvent fl ow rate of 20kg/h and the refl ux ratio of 2.0, respectively. The simulation results show the effect of the main variables on the extractive distillation process. The experiment is carried out to corroborate the feasibility of the separation of methanol-acetonitrile by batch extractive distillation.

13

Optimization of hopper design by genetic algorithms

Yu Y., Pettersson F., Saxén H.

Computer Methods in Materials Science

|

2011

|

Vol. 11, No. 1

28-33

EN

In the handling of particulate matters, hoppers are frequently used as intermediate storages, but during their filling and emptying, particle size segregation may occur. The hopper geometry is known to affect the outflow pattern (mass flow or funnel flow), and possible inserts in the hopper can also affect the patterns and particle segregation. The present work studies the size segregation in hoppers by discrete element modeling. Due to the prohibitive computational effort required by the numerical technique, a factorial plan was applied to design a set of DEM experiments, where the geometry of the system was varied. The results of the DEM simulations form the basis for a black-box modeling, where the outflow patterns were described by a neural network. Using the arising neural model, the geometry was optimized by a genetic algorithm with respect to particle segregation of the outflow. The most promising solutions were finally verified by DEM simulations. Thus, the paper proposes a method by which complex software models can be used in challenging design problems avoiding excessive computational burden.

PL

Zbiorniki różnego typu są często używane jako pośrednie magazyny przy przechowywaniu i transporcie materiałów sypkich. Podczas napełniania i opróżniania zbiorników może wystąpić zjawisko segregacji cząstek. Kształt zsypu ma wpływ na schemat wypływu cząstek ze zbiornika (przepływ masowy lub lejkowaty), a poszczególne elementy zsypu mogą wpływać na sposób segregacji cząstek. W pracy przeprowadzono badania stopnia segregacji w zsypie wykorzystując metodę elementów dyskretnych (ang. discrete element modeling DEM). Ze względu na długie czasy obliczeń w tej metodzie, do prowadzenia obliczeń numerycznych zastosowano plan eksperymentu, w którym zmiennymi parametrami były kształt wstawki w zsypie oraz jej położenie. Uzyskane wyniki stanowią podstawę do opracowania modelu z wykorzystaniem sztucznej sieci neuronowej. Wykorzystując ten model przeprowadzono optymalizację kształtu wstawki metodą algorytmów genetycznych, przyjmując segregację jako funkcję celu. Najlepsze wyniki zostały następnie zweryfikowane metodą elementów dyskretnych. W konsekwencji zaproponowana metoda pozwala na rozwiązanie skomplikowanych problemów projektowania unikając znacznych nakładów obliczeniowych.

14

Ocena wzrostu niezawodności w bezzałogowym statku latającym podczas kolejnych faz badania w locie

Yu Y., Cui W., Song B., Wang S.

Eksploatacja i Niezawodność

|

2010

|

nr 2

43-47

PL

Samoloty muszą być testowane w locie podczas procesu ich opracowywania i dla zapewnienia niezawodności powinny przejść, podczas faz badania w locie, proces wzrostu niezawodności obejmujący kolejne etapy: testowania, poszukiwania ukrytego uszkodzenia, udoskonalania i ponownego testowania. Jednakże z powodu złożonej budowy samolotów i wysokich kosztów badań w locie, badania wzrostu niezawodności z reguły przeprowadza się na małych próbkach. Trudno jest zatem ocenić wzrost niezawodności w kolejnych fazach badań w locie. W niniejszej pracy do estymacji wzrostu niezawodności zastosowano metodę bayesowską dla dwumianowego wzrostu niezawodności opartą na rozkładzie a priori Dirichleta oraz obliczono parametry rozkładu a posteriori wykorzystując metodę symulacji Markov-Chain Monte Carlo. Metodę zastosowano w kolejnych fazach badań w locie bezzałogowego statku latającego (Unmanned Aerial Vehicle), a użyty przykład pokazuje, iż metoda oparta na rozkładzie a priori Dirichleta może skrócić czas badań w locie. Parametry rozkładu a priori łatwo jest potwierdzić na podstawie uprzednio znanych informacji. Proponowana metoda nadaje się do oceny badań wzrostu niezawodności podczas kolejnych etapów badań w locie.

EN

It is necessary for airplanes to be fl ight-tested during the development process, and they should pass the testing/failurefi nding/improvement/re-testing reliability growth process during the fl ight-testing phases to ensure its reliability. However, due to airplane complexity and the high costs of fl ight-testing, the reliability growth testing is usually done with small samples. It is thus diffi cult to estimate the reliability growth during the fl ight-testing phases. In this paper, Bayesian method for binomial reliability growth based on the Dirichlet prior distribution is applied to reliability growth estimation, and the parameters of the posterior distribution are calculated by using the simulation method of Markov-Chain Monte Carlo. The method is applied to the Unmanned Aerial Vehicle test fl ight phases, and the example shows that the method based on the Dirichlet prior distribution can save the fl ight-testing time. It is easy to confi rm the parameters of the prior distribution by using the prior information. The proposed method is suitable for reliability growth testing estimation during fl ight-testing stages.

15

Modelowanie i symulacja zabezpieczenia materiałowego jednostki bojowej ukierunkowanego na realizację misji

Li D., Yu Y., Zhang L., Zhang Y.

Eksploatacja i Niezawodność

|

2010

|

nr 2

51-54

PL

W artykule przedstawiamy ramy modelowania i symulacji ukierunkowanego na realizację misji Systemu Zabezpieczenia Materiałowego Jednostki Bojowej (Combat Unit Material Support System, CUMSS). Opisujemy proces zabezpieczania materiałowego, analizujemy jego charakterystyki i optymalizujemy zasoby. Prezentowany model opiera się na obszernej analizie procesu eksploatacji oraz procesu wykorzystania zasobów. Skonstruowano strukturę federacyjną i model obiektowy federacji dla zabezpieczenia materiałowego jednostki bojowej. Przedstawiono, na podstawie przykładowej misji, federacje dla zdarzeń dyskretnych, zdarzeń ciągłych i procesu podejmowania decyzji. Do analizy charakterystyk CUMSS w przedstawionym przykładzie misji użyto symulacji.

EN

In this paper, we present a framework for modeling and simulation of a mission-oriented Combat Unit Materiel Support System (CUMSS). We describe the process of materiel support, analyze its performance, and optimize the resources. This model is based on a comprehensive analysis of the maintenance process and the resource utilization process. A federation framework and a federation object model are constructed for combat unit materiel support. For an example, mission, we provide the federations for the discrete events, the continuous events, and the decision-making process. Simulation is used to analyze the performance of CUMSS for this example mission.

16

Science, technology and strategy for minimizing GHG emission in steel industry

Cang D., Xiong G., Zhang X., Yu Y., Cheng X., Fang C.

Zeszyty Naukowe. Inżynieria Środowiska / Politechnika Opolska

|

2003

|

Vol. 291, z. 4

557-562

EN

In order to minimize CO2 emission from iron and steel-making processes to abate greenhouse gas impact, the considerations and some practice of science and technology as well as its strategy completed and on going in Chinese steel industry are summarized. Two available ways for the minimizing in China so far: (1) Minimizing carbon-consumption (fossil energy-saving) in all the processes of steel industry which is the most realizable measure for reducing CO2 emission. (2) To look for new alternative reaction medium in the processes where producing more C02 like Ha in blast furnace etc and new processes for iron and steel making which discharge less CO2 . Some new ideas like macro-based measures are put forward for minimizing CO2 emission in steel industry.

17

Research, technology and current situation of iron resources diversity in Chinese steel industry

Cang D., Xiong G., Yu Y., Cheng X., Zong Y.

Zeszyty Naukowe. Inżynieria Środowiska / Politechnika Opolska

|

2003

|

Vol. 291, z. 4

549-555

EN

The current situation of Chinese steel industry, the multi-iron resources and its recovery as well as utilization were introduced in this paper. The main concerned research activities and technology in China were introduced as well. Some new considerations and suggestion were put forward to increase the use of various recycled iron resources and appropriate degradation of iron ore. A new suggestion was made to establish an international research center for the developing of ultra steel making process which uses more various iron resources and degradation iron ore.

18

Renewable energy and its application in China

Cang D., Zhang X., Xiong G., Cheng X., Yu Y., Zong Y.

Zeszyty Naukowe. Inżynieria Środowiska / Politechnika Opolska

|

2003

|

Vol. 291, z. 4

427-433

EN

The general situation of renewable energy and its application in China are introduced in this report based on the statistics data from the Chinese government which includes wind energy, hydraulic power energy, Ocean energy, geothermal energy, solar energy and the bio-mass energy (but not the utilization of tide energy, temperature difference energy in Ocean for power generation and salt concentration difference energy in Ocean for power generation). The future developing of some renewable energy in China is introduced in the report as well.

19

Asymptotic behavior of solutions of second order neutral difference equations with "maxima"

Luo J., Yu Y.

Demonstratio Mathematica

|

2001

|

Vol. 34, nr 1

83-89

EN

Second order neutral difference equations with "maxima" are considered and some asymptotic properties of nonoscillatory solutions are given.

20

On the distance between adjacent zerores of solutions of first order neutral differential equations

Zhou Y., Yu Y., Feng B.

Demonstratio Mathematica

|

1999

|

Vol. 32, nr 1

31-40