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1
Content available Study on transport packages used for food freshness preservation based on thermal analysis
100%
Yu Y.
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tom 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.
2
Content available remote Asymptotic behavior of solutions of second order neutral difference equations with "maxima"
63%
Luo J. , Yu Y.
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2001
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tom 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.
3
Content available Mathematical modelling of the unstationary friction interaction of the working elements of the locomotive disk brake
63%
Yu Y. , Sosnov I. I.
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tom 11B
4
Ecological stoichiometric characteristics of soil at different depths in a karst plateau mountain area of China
63%
Yu Y. , Chi Y.
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nr 1
5
Content available Batch extractive distillation of mixture methanol-acetonitrile using aniline as a asolvent
51%
Li G. , Yu Y. , Bai P.
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tom 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.
6
Content available remote Ultra-wide bandwidth wavelength selective couplers based on the all solid multi-core Ge-doped fibre
51%
Li X. , Sun B. , Yu Y.
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2014
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tom 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.
7
The first fossil bark-gnawing beetle from the Middle Jurassic of Inner Mongolia, China (Coleoptera: Trogossitidae)
45%
Yu Y. , Leschen R. A. B. , Slipinski A. , Ren D. , Pang H.
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nr 2
EN
A new bark-gnawing beetle genus Sinopeltis gen. nov., with two species (S. jurrasica sp. nov. (type species) and Sinopeltis amoena sp. nov.), is described based on two well-preserved impression fossils. Specimens were collected from the Middle Jurassic Jiulongshan Formation in Daohugou Village, Shantou Township, Ningcheng County, Inner Mongolia, China from a lacustrine paleoenvironment, making it the oldest fossil of the family. Sinopeltis is placed into Peltinae incertae sedis.
8
Content available remote A Note on Spiking Neural P Systems with Homogenous Neurons and Synapses
45%
Yu Y. , Wu T. , Xu J. , Wang Y. , He J.
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tom 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”.
9
Content available Study on Underwater Explosive Welding of Al-Steel Coaxial Pipes
45%
Yu Y. , Ma H. , Zhao K. , Shen Z. , Cheng Y.
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tom 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.
10
Content available Energy feature of a multi-flow column flotation process
45%
Cheng G. , Yu Y. , Ma L. , Xia W. , Xu H.
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2017
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tom 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.
11
The first record of Cretaceous thaneroclerids (Insecta: Coleoptera) from the Burmese amber
38%
Yu Y. , Deng C. , Kolibac J. , Slipinski A. , Ren D. , Jin J. , Pang H.
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nr 3
EN
A new genus of Thanerocleridae, Archaeozenodosus bellus Yu and Kolibac gen. et sp. nov., is described and illustrated from the Upper Cretaceous (Cenomanian, ca. 99 Ma) amber near the Hukawng Valley of northern Myanmar, making it the first Mesozoic record of the family. Morphological characters preserved in the Burmese amber highlight the diversity of thaneroclerids during the Late Mesozoic and provide data for future phylogenetic studies of Thanerocleridae.
12
Content available Kinetic research of quinoline, pyridine and phenol adsorption on modified coking coal
38%
Sun X. , Xu H. , Wang J. , Ning K. , Huang G. , Yu Y. , Ma L.
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tom 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.
13
Optimization of culturing conditions for production of somatic embryos and lignins of Schisandra chinensis (Turcz.) Baill
26%
Sun D. , Wang Z. , Yu Y. , Li C. , Qin H. , Xu P. , Zhao Y. , Liu Y. , Yang Y. , Fan S. , Ai J.
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nr 09
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