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1
Content available Concepts of optical velocity sensors using spatial frequency
100%
Ricklefs U. , Luo H.
Pomiary Automatyka Kontrola
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2012
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tom R. 58, nr 2
163-167
EN
Non contact optical correlation / spatial frequency sensors are typically used for the measurement of velocity in relation to a surface. Most of these sensors tend to unacceptable inaccuracy at low as well as at very high velocities. Furthermore uncertainties less than 1% are difficult to achieve. To overcome this problem, new algorithms have been evolved by analyzing the reasons for the imprecision.
PL
Bezdotykowe czujniki optyczne do pomiaru prędkości i wielkości pochodnych znajdują wiele zastosowań (np. wszystkie rodzaje pojazdów, większość pomiarów związanych z ruchem taśmociągów). W przeszłości szczególnie skuteczne - zwłaszcza do pomiaru prędkości - okazały się czujniki wykorzystujące metodę korelacyjną. Zaletą tej metody pomiarowej jest to, że nie wymaga skomplikowanej obróbki sygnału i pozwala na pomiary w czasie rzeczywistym. Stosowane również w tym celu metody bazujące na przetwarzaniu obrazu z kamery są często zbyt wolne, aby być mogły być stosowane np. w systemach sterowania. Niepewność pomiarów prędkości jest najczęściej na poziomie 1% i nie jest łatwo stosunkowo prostymi środkami ją zmniejszyć. Dodatkowo uwzględnienie warunków brzegowych prowadzi do zwiększenia błędów pomiaru. Ponadto nie jest możliwe wykonywanie pomiarów prędkości obiektu w stanie spoczynku. W stosowanych dotychczas czujnikach, na podstawie prowadzonej przestrzennej analizy częstotliwościowej, starano się optymalizować ich budowę. Przeprowadzone badania pokazały, że sygnały wyjściowe czujników mają charakter pojedynczych zaburzeń i badanie ich z zastosowaniem analizy Fouriera nie jest właściwe. W przedstawionym w pracy podejściu zastosowano dwa różne algorytmy do wyznaczania położenia przemieszczającego się obiektu. Główna idea proponowanego podejścia polega na zastosowaniu nakładających się funkcji sinusoidalnych do opisu rozkładu jasności powierzchni odniesienia, w stosunku do której przemieszcza się czujnik. Amplitudy i fazy tych funkcji sinusoidalnych są interpretowane jako wzory powierzchni, które służą do kodowania pozycji czujnika w sposób losowy. Przeprowadzono badania symulacyjne zaproponowanych metod, a ich przydatność potwierdzono eksperymentalnie.
2
Content available remote Simulation and Measurement of Complex Network Growth: the Interplay of Uniform and Preferential Attachment
100%
Luo H. , Horadam K.
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2008
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tom Vol. 84, nr 1
61-79
EN
The main discovery of the paper is the introduction and study of a new U-P complex network model, which aims to describe and analyze many common-featured real-world complex networks. This model employs a new functional form of the network growth rule: a linear combination of preferential and uniform attachment. In particular, the degree distribution of the model is first studied by using the computer simulation method, while the exact solution is also obtained analytically.
3
Labeling and tracking human amniotic epithelial cells with green fluorescent protein in an adeno-associated virus vector
80%
Huang X. , Luo H. , Huang F. , Liu X.
Cellular and Molecular Biology Letters
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2011
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tom 16
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nr 2
EN
Human amniotic epithelial cells (hAECs) are a recently identified type of stem cell. Thanks to their ready availability and the lower risk of teratoma formation, hAECs have been studied and tested for a variety of human disease treatments and tissue reconstruction efforts. This aim of this study was to establish a stable tracking system to further monitor hAECs in vivo after transplantation. hAECs were isolated from the placentas of patients who visited the Hunan Province Maternity and Child Care Hospitals between Jan 2008 and Jan 2009. Using the classic transfection/infection technique, we successfully introduced green fluorescent protein (GFP) into cultured hAECs with an adeno-associated virus (AAV) vector. The initial preparation of the AAV-GFP virus stock was titrated using HT1081 cells, and further used for the infection of hAECs. GFP+ hAECs preserve the capacity of differentiation into hepatocytelike cells with the expression of cytokeratin-18 (CK18) and albumin (ALB). AAV-GFP virus-infected hAECs were transplanted through the spleen into severe combined immune deficiency (SCID) mice via hepatectomy. Four weeks later, the GFP and human albumin expressions were examined in multiple organs through immunoflourence staining. In culture, over 50% of the hAECs were GFP-positive 3 days after infection. Following transplantation, AAV-GFPinfected hAECs survived and continued to express GFP in the host for up to 4 weeks. These cells were primarily found in the spleen and liver, expressing human albumin. This study provides a feasible and stable system to track hAECs. It may prove useful to further identify their biological characteristics after transplantation and to elucidate their beneficial roles for therapeutic purposes.
4
Content available Experimental and simulative study on accumulator function in the process of wave energy conversion
71%
Zhang W. , Liu Y. , Luo H. , Xue G. , Zhang J.
Polish Maritime Research
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2016
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tom nr 3
79--85
EN
In this paper, a floating-buoy wave energy converter using hydrostatic transmission system is studied. The entire work progress of wave energy power generation device is introduced, and the hydraulic transmission principles are emphasized through the simulation to verify the feasibility of design principle of hydraulic transmission system. The mathematical model of the accumulator is established and applied in the AMEsim simulation. The simulation results show that the accumulator plays an important role in the wave power hydraulic transmission system and that the correct configuration of accumulator parameters can improve the rapidity and stability of the system work. Experimental results are compared with the simulation results to validate the correctness of the simulation results. This would provide a valuable reference to the optimal design of wave power generation.
5
Experimental and simulative study on accumulator function in the process of wave energy conversion
71%
Zhang W. , Liu Y. , Luo H. , Xue G. , Zhang J.
|
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tom 23
|
nr 3
EN
In this paper, a floating-buoy wave energy converter using hydrostatic transmission system is studied. The entire work progress of wave energy power generation device is introduced, and the hydraulic transmission principles are emphasized through the simulation to verify the feasibility of design principle of hydraulic transmission system. The mathematical model of the accumulator is established and applied in the AMEsim simulation. The simulation results show that the accumulator plays an important role in the wave power hydraulic transmission system and that the correct configuration of accumulator parameters can improve the rapidity and stability of the system work. Experimental results are compared with the simulation results to validate the correctness of the simulation results. This would provide a valuable reference to the optimal design of wave power generation
6
Content available remote Investigation of propagation characteristics of UHF electromagnetic wave due to PD in switchgear
61%
Luo H. , Cheng P. , Liu H. , Kang K. , Yang F. , Yang Q.
Przegląd Elektrotechniczny
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2016
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tom R. 92, nr 6
98--101
EN
In order to investigate the propagation characteristics of ultra-high-frequency (UHF) electromagnetic wave caused by partial discharge (PD) in high voltage switchgear, a simulation model was established by using the finite-difference-time-domain (FDTD) method. The simulation results have useful information for the installation of UHF sensor to detect PDs in switchgear.
PL
Opracowano model numeryczny i przeprowadzono symulacje metodą różnic skończonych w dziedzinie czasu (FDTD) w celu określenia charakterystyk propagacyjnych sygnałów w zakresie ultra wysokich częstotliwości (UHF) generowanych przez wyładowania niezupełne (PD) w rozdzielnicy wysokonapięciowej. Wyniki symulacji umożliwiają poprawną instalację czujników do wykrywania wyładowań niezupełnych w rozdzielnicy.
7
Optimal design and numerical simulation on fish-like flexible hydrofoil propeller
61%
Xue G. , Liu Y. , Zhang M. , Zhang W. , Zhang J. , Luo H. , Jia R.
|
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tom 23
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nr 4
EN
Hydrofoil is widely used in underwater vehicle for the excellent hydrodynamic characteristics. Currently, researches are mostly about the rigid hydrofoil while the flexible hydrofoil, like the caudal fin, has not been studied adequately. In this paper, the fish was regarded as the bionic object. Then the kinematics model to describe the fish swimming was put forward. A fin-peduncle propulsion mechanism was designed based on the kinematics model to achieve the similar sine curve swimming model. The propulsion mechanism was optimized by Matlab to reduc the deviation between the output curve of the fin-peduncle propulsion mechanism and the ideal motion trajectory. Moreover, the motion phase angles among flexible articulations are optimized to reduce fluid resistance and improve propulsive efficiency. Finally, the fish-like hydrofoil oscillation is simulated by fluid-solid coupling method based on the Fluent. It was shown that the optimized flexible fish-like oscillation could generate the motion that follows the similar law of sine. The propulsive efficiency of oscillating hydrofoil propeller is much higher than that of the screw propeller, and the flexible oscillation has higher propulsive efficiency than the rigid oscillation without obvious fluid resistance increase
8
Sarcosporidiosis: an emerging disease in yaks (Bos grunniens) on the Qinghai Tibetan Plateau (QTP), China
61%
Li K. , Luo H. , Mehmood K. , Zhang H. , Shahzad M. , Abbas R. Z.
Acta Parasitologica
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2019
|
tom 64
|
nr 2
9
Content available remote Investigation of contact resistance influence on power cable joint temperature based on 3-d coupling model
61%
Luo H. , Cheng P. , Liu H. , Kang K. , Yang F. , Yang Q.
Przegląd Elektrotechniczny
|
2016
|
tom R. 92, nr 5
9--12
EN
Aiming at the overheating problem of cable joint, a 3-D finite element model of a single-core cable joint considering the coupling of electromagnetic field and temperature field has been built. In order to consider the heat losses generated by contact resistance of cable joint, the equivalent conductivity is calculated. The validity of the model and calculation method is verified by the comparison with analytical values.
PL
Do analizy zagadnienia przegrzania połączenia kablowego zbudowano trójwymiarowy model MES przy uwzględnieniu sprzężenia pola elektromagnetycznego i temperaturowego. W celu określenia strat ciepła wytwarzanego w rezystancji styku połączenia kablowego obliczono konduktywność zastępczą.
10
Content available remote Research on the UHF microstrip antenna for partial discharge detection in high voltage switchgear
61%
Luo H. , Cheng P. , Liu H. , Kang K. , Yang F. , Yang Q.
Przegląd Elektrotechniczny
|
2016
|
tom R. 92, nr 6
90--93
EN
In order to detect the ultra-high-frequency (UHF) signals generated from partial discharges (PDs) in high voltage switchgear, a microstrip antenna sensor is designed. Influences of geometric parameters on the capability of the proposed antenna sensor are researched by numerical simulation. Measured characteristic results show that this antenna sensor is very suitable for partial discharge detection.
PL
W celu wykrycia sygnałów w zakresie ultra wysokich częstotliwości (UHF) generowanych przez wyładowania niezupełne (PD) w rozdzielnicy wysokonapięciowej zaprojektowano czujnik w postaci anteny. Wpływ parametrów geometrycznych przetwornika na jego własności został zbadany za pomocą symulacji numerycznych. Wyniki pomiarów pozwalają stwierdzić, że powyższy czujnik umożliwia skuteczne wykrycie wyładowań niezupełnych.
11
Comparative analysis on mRNA expression and DNA methylation status of SYCE1 gene in testes of yaks and cattleyaks
51%
Luo H. , Yi C. , Wu S. , Yuan M. , Li P. , Gou Q. , Zhao W. , Cai X.
|
2020
|
tom 38
|
nr 1
12
Characterization of the complete mitochondrial genome of Metastrongylus salmi (M. salmi) derived from Tibetan pigs in Tibet, China
51%
Li K. , Shahzad M. , Zhang H. , Mehmood K. , Jiang X. , Luo H. , Zhang L. , Dong X. , Li J.
Acta Parasitologica
|
2018
|
tom 63
|
nr 2
13
Epidemiology of Toxoplasma gondii infection in native Tibetans in Tibet, China
51%
Li K. , Wang M. , Zhang H. , Lei Z. , Zhang L. , Luo H. , Qiu G. , Mehmood K. , Shahzad M. , Li J.
Acta Parasitologica
|
2017
|
tom 62
|
nr 3
14
Immobilizing metal-resistant sulfate-reducing bacteria for cadmium removal from aqueous solutions
51%
Zhang H. , Li H. , Luo D. , Chen Y. , Chen D. , Chen D. , Luo H. , Chen Z. , Li K.
Polish Journal of Environmental Studies
|
2018
|
tom 27
|
nr 6
EN
Immobilized sulfate-reducing bacteria (SRB) in polyvinyl alcohol (PVA)-sodium alginate matrix were applied as biosorbents to remove cadmium (Cd) from aqueous solutions. Multiple characterization techniques including scanning electron microscope (SEM)-energy dispersive spectrometer (EDS), and Fourier transform infrared (FT-IR) spectra indicate that immobilized beads provided a suitable microenvironment for SRB. Performance tests show that Cd removal was highly affected by pH value and temperature, with optimum temperature at 35ºC and pH value of 8.0. A pseudo second-order model was applied to describe the adsorption kinetic. FT-IR and x-ray photoelectron spectroscopy (XPS) analyses imply that biosorption, sulfide, and hydroxide precipitation are the main mechanisms for removing Cd. The immobilized SRB beads have great potential for remediating Cd-containing wastewater.
15
Content available remote Irregular shaping of polystyrene nanosphere array by plasma etching
51%
Luo H. , Liu T. , Ma J. , Wang W. , Li H. , Wang P. , Bai J. , Jing G.
Materials Science Poland
|
2013
|
tom Vol. 31, No. 3
331--337
EN
The morphology of nanospheres is crucial for designing the nanofabrication in the nanosphere lithography. Here, by plasma etching, the controllable tailoring of the nanosphere is realized and its morphology dependence on the initial shape, microscopic roughness, and the etching conditions is investigated quantitatively. The results show that the shape evolution strongly depends on the etching gas, power, and process duration. Particularly, the aspect ratio (diameter/height) significantly increases with violent etching, turning the spherical shape into tiny ellipsoidal nanoparticles. The findings are practical to the protocol of non-uniform etching of nanoobjects and provide the useful design tool for the device fabrication at nanoscale.
16
Integrated miRNAome and mRNAome analysis identifies candidate genes that mediate testis development promoted by vitamin E in sheep
51%
Gao Y. , Lu W. , Qu Y. , Jian L. , Diao Z. , Xiu P. , Machaty Z. , Luo H.
|
2020
|
tom 38
|
nr 3
17
Prevalence of three Oesophagostomum spp. from Tibetan pigs analyzed by genetic markers of nad1, cox3 and ITS1
41%
Li K. , Lan Y. , Luo H. , Shahzad M. , Zhang H. , Wang L. , Zhang L. , Liu D. , Liu X. , Hao Y. , Sizhu S. , Li J.
Acta Parasitologica
|
2017
|
tom 62
|
nr 1
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