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1

Influence of cutting angle on mechanical properties of rock cutting by conical pick based on finite element analysis

Qiao S., Zhang Z. Q., Zhu Z. M., Zhang K.

Mining Science

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2021

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Vol. 28

161--173

EN

In view of the current situation that it is difficult to obtain the actual cutting force received by the conical pick of Continuous-Miner and to deal with the characteristics of the cutting force. By using contact dynamics, rock mechanics, and finite element methods, based on the display dynamics analysis program ANSYS/LS-DYNA and the Holmquist–Johnson–Cook model, the contact mechanical characteristics between conical pick and rock are analyzed. The resultant force was obtained by obtaining the force curve of the conical pick under X, Y and Z directions, analysis of cutting gear cutting speed of 2.5 m/s, cutting depth of 5, 10, 15, 20 and 25 mm, cutting angle of 30°, 35°, 40°, 45°, 50° parameters of the size of cutting force and cutting ratio energy consumption, thus, the best cutting angle of the conical pick is obtained. The conclusions are as follows: when the cutting depth and cutting speed are constant, and the cutting angle is 45°, the mean cutting force received by the conical pick is the least, the specific energy consumption is the least, and the cutting efficiency is the highest. The best cutting angle of the conical pick should be 45°; When the cutting angle and cutting speed are constant, the energy needed by the cutter to cut the rock increases with the increase of cutting depth. The research results provide a theoretical basis for improving cutting efficiency and cutting life, and for choosing cutting angle and cutting thickness.

2

Research on a scheme of generating ultra-wideband doublet signal based on the cross-gain modulation in a semiconductor optical amplifier

Zhang K., Shao J.

Optica Applicata

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2018

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Vol. 48, nr 1

127--135

EN

We propose a novel scheme for generating ultra-wideband doublet signal based on the cross-gain modulation effect in a semiconductor optical amplifier. This scheme requires only a semiconductor optical amplifier and an optical source. By using OptiSystem software, we simulate and analyze the effect of the input signal light power and wavelength, the pulse width and injection current on the generated doublet pulse. In addition, the optimal range of parameters are also given in the simulation process.

3

Model construction and experimental verification of the equivalent elastic modulus of a double-helix wire rope

Chen H. Y., Zhang K., Bai Y. X., Ma Y., Deng H. Z.

Journal of Theoretical and Applied Mechanics

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2018

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Vol. 56 nr 4

951--960

EN

To accurately describe mechanical properties of a complex wire rope, a double-helix wire rope is used as an example in this study. According to the spatial structure characteristics of the central helical line of each wire rope, the spatial configuration curve for the double- -helix wire rope is obtained by using differential geometry theory. On the basis of this curve, the mathematical model of the equivalent elastic modulus of the wire rope is developed, and the elastic modulus of a 6×7+IWS wire rope is measured using a universal tensile testing machine. The experimental results are compared with the predicted results to verify correctness of the elastic modulus prediction of the double-helix wire rope.

4

A Secure Data Forwarding Protocol for Data Statistic Services in Multi-Hop Marine Sensor Networks

Wei L., Zhang K., Zhang L., Huang D.

Fundamenta Informaticae

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2018

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Vol. 157, nr 1/2

63--78

EN

Homomorphic encryption always allows the linear arithmetic operations performed over the ciphertext and then returns equaling results as if the operations are taken over the original plaintext, which is always used for data aggregation in wireless sensor networks to keep the confidentiality of the data and cut down the transmission overhead of the ciphertext. In the marine sensor networks, sensors collect the multiple data such as temperature, salinity, pressure, and chlorophyll concentration in the ocean using a single hardware unit for further statistical analysis such as computing the mean and the variance and making regression analysis. However, directly using the homomorphic encryption cannot perform well in marine sensor data forwarding since the data need to turn to satellites or vessels as relays and be forwarded in multi-hop way. The data are not expected to be decrypted until arriving the final destinations. To tackle these issues, we design a secure data forwarding protocol based on the Paillier homomorphic encryption and multi-use proxy re-encryption. We also evaluate the computational overhead in term of the delay in the transmission and operation in various test beds. The experiment results show that the additional computational overhead brought by cryptographic operations could be minor and it has the merit of providing fixed data size passing through the multi-hop transmission.

5

Three-dimensional distributed DC/IP method for altered tectonite-type gold ore deposits exploration: a case study of the Jiaojia gold metallogenic belt, Eastern China

Yan J., Zhang Y., Zhang K., Zhang Y., Hu H., Wang Z.

Acta Geophysica

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2018

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Vol. 66, no. 4

541--557

EN

To develop an effective method to identify ore-controlling faults, we studied the Jiaojia gold metallogenic belt, a most typical altered tectonite-type gold metallogenic belt in the Jiaodong Peninsula, China, and conducted experiments using the 3D distributed direct current-induced polarization (DC/IP) method. Firstly, we tested the ability of using 3D distributed DC/IP method to identify altered tectonite-type gold ore deposits by 3D synthetic modelling. We then collected real data of the Sizhuang gold deposit using the 3D distributed DC/IP method. The resistivity model obtained of this region is generally consistent with the known geological setting. Moreover, to obtain the information about the southern extension of the Jiaojia gold metallogenic belt, we conducted a 3D distributed DC/IP experiment in the Shijia area in the southern segment of the Jiaojia fault. The southern extension of the Jiaojia fault and tectonic evolution of shallow magma in this region were inferred from the 3D resistivity and chargeability models. Based on all the information above, we concluded that the 3D distributed DC/IP method has the advantages of 3D observations, high spatial resolution and great detection depth and will be one of the most effective methods for detecting altered tectonite-type gold ore deposits.

6

Characterization of Dinophysis acuminata from the Yellow Sea, China, and its response to different temperatures and Mesodinium prey

Gao H., An X., Liu L., Zhang K., Zheng D., Tong M.

Oceanological and Hydrobiological Studies

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2017

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Vol. 46, No. 4

439--450

EN

Dinophysis species are distributed worldwide and cause diarrheic shellfish poisoning (DSP). This paper documents the first successful culture of a Dinophysis (DAYS01) strain taken off Xiaoping Island, the Yellow Sea, China. The strain was identified as Dinophysis acuminata Claparède & Lachmann by morphological and phylogenetic analysis. The effects of temperature and different Mesodinium prey on the physiological and toxigenic characteristics of D. acuminata DAYS01 were also investigated. The results showed that the toxin concentration (toxin amount per ml of culture) increased with an increase in cell densities. Okadaic acid (OA), dinophysistoxin 1 (DTX1) and pectenotoxin 2 (PTX2) were the major toxin components of DAYS01, with the highest recorded toxin content of 5.66, 0.56 and 192.87 ng ml-1 culture medium, respectively. The prey type significantly influenced the growth yield in Dinophysis cultures. There was an effect of prey on the total toxin content, suggesting that the origin or strain of ciliate directly impacted the D. acuminata blooms and the overall toxin concentration in the system.

7

The electrical resistivity signature of a fault controlling gold mineralization and the implications for Mesozoic mineralization: a case study from the Jiaojia Fault, eastern China

Zhang K., Lü Q., Yan J., Hu H, Fu G.

Acta Geophysica

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2017

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Vol. 65, no. 4

727--741

EN

We use 3D audio magnetotelluric method to the south segment of Jiaojia fault belt, and obtain the 3D electrical model of this area. Regional geophysical data were combined in an analysis of strata and major structural distribution in the study area, and included the southern segment of the Jiaojia fault zone transformed into two fault assemblages. Together with the previous studies of the ore-controlling action of the Jiaojia fault belt and deposit characteristics, the two faults are considered to be favorable metallogenic provinces, because some important features coupled with them, such as the subordinate fault intersection zone and several fault assemblages in one fault zone. It was also suggested the control action of later fault with reversed downthrows to the ore distribution. These studies have enabled us to predict the presence of two likely target regions of mineralization, and are prospecting breakthrough in the southern section of Jiaojia in the Shandong Peninsula, China.

8

The effect of preparation method on the performance of PtSn/Al2O3 &enspcatalysts for acetic acid hydrogenation

Zhang K., Zhang H., Ma H., Ying W., Fang D.

Polish Journal of Chemical Technology

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2015

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Vol. 17, nr 1

11--17

EN

PtSn/Al2O3 &enspcatalysts with a given loading of 1 wt% Pt and 1 wt% Sn were prepared by co-impregnation or successive impregnation with aqueous solutions of Pt, Sn precursors and a commercial alumina. The catalysts were characterized by N2 &enspadsorption, H2-TPR (H2&ensp temperature-programmed reduction), H2-pulse chemisorption, XPS (X-ray photoelectron spectroscopy) and CO-FTIR (Fourier transform infrared spectroscopy), and tested in the hydrogenation of acetic acid. The results showed that the preparation method affected both the chemical properties and their performance in the hydrogenation of acetic acid. Sn enrichment on the catalysts surface was observed on the co-impregnated catalyst and catalyst in which the Pt precursor had been loaded first. It was found that the modification of Pt was a function of the sequence of Sn addition as revealed by CO-FTIR. Co-impregnated catalyst showed the highest activity and ethanol selectivity.

9

A Hybrid Distribution Algorithm Based on Membrane Computing for Solving the Multiobjective Multiple Traveling Salesman Problem

He J., Zhang K.

Fundamenta Informaticae

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2015

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Vol. 136, nr 3

199--208

EN

The multiobjective multiple traveling salesman problem (MmTSP), in which multiple salesmen and objectives are involved in a route, is known to be NP-hard. The MmTSP is more appropriate for real-life applications than the classical traveling salesman problem (TSP), however it has not received the same amount of attention. Due to the high complexity of the MmTSP, a promising algorithm for solving it must be based on a global search procedure. This paper proposes a hybrid global search algorithm, that belongs to the membrane computing framework. The search behavior of the algorithm is enhanced by a communication mechanism. The multichromosome representation is considered to reduce the excess runtime. The effectiveness of the proposed algorithm is tested on the MmTSP with disparately-scaled objective functions, salesmen and problem sizes. The experimental results are compared with the NSGA-II and several evolutionary strategies with decomposition, including simulated annealing algorithm, hill climbing method, pure evolutionary algorithm, and genetic algorithm.

10

Structure Design and Performance Analysis of Substation Area Backup Protection Communication Network in Smart Substation

Chen L., Zhang K., Xia Y., Hu G.

Przegląd Elektrotechniczny

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2013

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R. 89, nr 5

182-186

EN

In this paper, the general design of substation area backup protection (SABP) communication network in smart substation is proposed, and taking a practical 220kV smart substation for the application object, the communication network’s specific structure is constructed. Besides, the specific network’s real-time performance is studied based on theoretical analysis and OPNET simulation, and its reliability is calculated according to reliability block diagram and fault tree combining with Bayesian technology. The results show that the two performances can meet the requirements.

PL

W artykule przedstawiono projekt sieci komunikacyjnej na potrzeby rezerwowego systemu zabezpieczeń w obszarze inteligentnej podstacji elektroenergetycznej. Proponowaną strukturę sieci zaimplementowano dla inteligentnej podstacji 220kV. Przeprowadzono także symulacje (OPNET) i analizę teoretyczną wydajności sieci w czasie rzeczywistym oraz parametrycznie określono jej niezawodność.

11

Optimization model of the Joint operation of Pumped-Storage Hydro Plant and Wind Farm: Considering the Imbalances of Wind Power Output

Song W., Zhang K., Li L., Zeng M., Zhang G.

Przegląd Elektrotechniczny

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2013

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R. 89, nr 3b

207--211

EN

Since the future energy production of wind farm is uneasy to be precisely predicted, the integration of wind power into electric power system has been a difficult problem for many years. Recently, the widely emerged pumped-storage hydro plant can be used to balance the unstable output of wind farm, because the pumped-storage hydro plant can adjust its production to compensate wind power prediction errors. In this paper, a joint operation model between the wind farm and pumped-storage hydro plant is proposed. In this mode, there are two targets for the system: 1) maximizing the daily revenue of pumped-storage hydro plant; 2) partially compensating the deviations resulted from wind power output imbalances. Then we analyzed the economic benefits of pumped-storage hydro plant in the condition of both independent operation and joint operation. Finally, the model is applied in the actual operation of pumped-storage hydro plant. From the case study we can see that power incomes of pumped-storage hydro plant alone is reduced under joint operation model, while the comprehensive economic effect has actually increased in response to the stable output of wind power.

PL

W artykule przedstawiono model współpracy farmy wiatrowej z elektrownią szczytowo-pompową. Wspólna praca tych jednostek wynika z niestabilności energii wiatrowej i pozwala na jej redukcję. Zbudowany model umożliwia realizację dwóch celów: maksymalizacji dziennego zysku z magazynowania energii w elektrowni oraz częściowe ograniczenie wahań wytwarzanej energii, wynikające z niestabilności wiatru. Dokonano także analizy ekonomicznej zysków z pracy jednostek w trybach współpracy oraz pracy niezależnej. Przeprowadzono weryfikację opracowanego modelu na rzeczywistych danych.

12

Discussion on digitalization of Paper Fiber

Zhang K., Li Z., Xu Y., Wang S.

Przegląd Elektrotechniczny

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2012

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R. 88, nr 5b

113-115

EN

This paper introduced several testing methods of paper fiber parameters, such as projector method, microscopy method, polarized light method and grating method, and also compared the advantages and disadvantages of these methods. In order to express fiber distribution quantitatively, it put forward the idea of taking integrated multifunctional sensor of detection, judgment, self diagnosis, data processing and adaptive ability to test the distribution of paper fiber. It attempted to get the two-dimensional image of paper fiber distribution by this sensor, then used this image to analyze paper fiber parameters such as quantity, length, thickness, opacity, x-values distribution and y-values distribution, and discussed method of analyzing digitalization of paper fiber.

PL

W artykule opisano szereg metod analizy włókna papieru – głównie metody optyczne. Jak rezultat analizy proponuje się dwuwymiaropwy obraz struktury włókna.

13

Integrated algorithms for RFID-based multi-sensor indoor/outdoor positioning solutions

Zhu M., Retscher G., Zhang K.

Archiwum Fotogrametrii, Kartografii i Teledetekcji

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2011

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Vol. 22

451--465

EN

Position information is very important as people need it almost everywhere all the time. However, it is a challenging task to provide precise positions indoor/outdoor seamlessly. Outdoor positioning has been widely studied and accurate positions can usually be achieved by well developed GPS techniques but these techniques are difficult to be used indoors since GPS signal reception is limited. The alternative techniques that can be used for indoor positioning include, to name a few, Wireless Local Area Network (WLAN), bluetooth and Ultra Wideband (UWB) etc.. However, all of these have limitations. The main objectives of this paper are to investigate and develop algorithms for a low-cost and portable indoor personal positioning system using Radio Frequency Identification (RFID) and its integration with other positioning systems. An RFID system consists of three components, namely a control unit, an interrogator and a transponder that transmits data and communicates with the reader. An RFID tag can be incorporated into a product, animal or person for the purpose of identification and tracking using radio waves. In general, for RFID positioning in urban and indoor environments three different methods can be used, including cellular positioning, trilateration and location fingerprinting. In addition, the integration of RFID with other technologies is also discussed in this paper. A typical combination is to integrate RFID with relative positioning technologies such as MEMS INS to bridge the gaps between RFID tags for continuous positioning applications. Experiments are shown to demonstrate the improvements of integrating multiple sensors with RFID which can be employed successfully for personal positioning.

14

Syntheses and characterization of pH-sensitive hydrogel from poly(.gamma.-glutamic) acid

Yao B., Yang C., Zhang K., Ni C., Song H., Ni Z., Chen M.

Materials Science Poland

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2009

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Vol. 27, No. 1

319--327

EN

Novel pH-sensitive hydrogels were prepared through crosslinking of poly(.gamma.-glutamic) acid (.gamma.-PGA) by using 1,4-butanediol diglycidyl ether as a cross-linker, tetraethylammonium bromide as a catalyst, and reacting in DMSO. The dependence of the swelling ratio of the hydrogels on pH values, ionic strength and cross-linking degree was investigated. It was found that the pH-sensitive range was clearly extended through introducing multiple hydrogen bonds to the hydrogel network during the preparation. The swelling ratios of ?-PGA hydrogels increased with the increase in pH of the aqueous solution from 2 to 9. The swelling of the .gamma.-PGA hydrogels was firstly controlled by the ionization of carboxyl groups in the hydrogels within the pH range from 2 to 5, and then controlled by breaking of the multiple hydrogen bonds in the hydrogels within the pH range from 5 to 9. The swelling ratios of .gamma.-PGA hydrogels were also strongly dependent on the ionic strength of the medium and cross-linking degree of the hydrogels. Increasing the ionic strength and the crosslinking degree resulted in a decrease in the swelling ratio of the hydrogels.