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Wyszukujesz frazę "Zhao, Xin" wg kryterium: Autor


Tytuł:
Improved Prediction of Polar Motions by Piecewise Parameterization
Autorzy:
Wu, Yuanwei
Zhao, Xin
Yang, Xinyu
Powiązania:
https://bibliotekanauki.pl/articles/2174948.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Centrum Badań Kosmicznych PAN
Tematy:
earth rotation prediction
effective angular momentum functions
AAM
OAM
Opis:
Natioinal Time Service Center of Chinese Academy of Sciences, Lintong, Shaanxi, China e-mail: yuanwei.wu@ntsc.ac.cn ABSTRACT. On seanonal timescale, the variation of Earth rotation is mainly regulated by angular momentum exchanges between the solid Earth and the fluidal atmosphere, ocean and hydrosphere. In the 2nd EOP PCC, we developed Dill2019’s method for polar motion prediction, using piecewise autoagressive parameters. The maximum prediction errors within 90 days are 36 and 16 mas for polar motion x and y components, respectively. Compared with Bulletin A, the mean absolute error of polar motion y prediction is improved by 20% in all timescale, and with a maximum improvement of 49% on the 5th day. Whereas, for polar motion x, the performance is slightly better (2% - 8%) within 30 days but worse (−7%∼ −19%) within 30∼90 days. We found that the prediction accuracy is very sensitive to the quality of the angular momentum data. For example, on average, the prediction of polar motion y is around 2 times better than polar motion x. In addition, we found the accuracy of 30-90 days prediction is dramatically decreased in the year 2020. We suspect that such deterioration might be due to the pandemic of coronavirus COVID-19, which suppressed global airline activities by more than 60%, then result in a lose of air-borne meteorological data, which are important for weather forecast.
Źródło:
Artificial Satellites. Journal of Planetary Geodesy; 2022, 57, Special Issue 1; 290--299
2083-6104
Pojawia się w:
Artificial Satellites. Journal of Planetary Geodesy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Flotation and molecular dynamics simulation of muscovite with mixed anionic/cationic collectors
Autorzy:
Bai, Yang
Li, Caixia
An, Hongyun
Wang, Guoliang
Zhao, Xin
Zhang, Jinqi
Powiązania:
https://bibliotekanauki.pl/articles/110125.pdf
Data publikacji:
2020
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
muscovite
mixed anionic/cationic collectors
flotation
molecular dynamics simulation
Opis:
In this study, three kinds of anionic collectors (sodium oleate (NaOl), sodium dodecyl sulfonate (SDS) and naphthenic acid (NA)) were used in combination with dodecylamine (DDA) to investigate the flotation behavior of muscovite under the action of different mixed anionic/cationic collectors, and their mechanisms for adsorption on the muscovite (001) Surface were clarified using molecular dynamics simulations. The flotation results indicated that different mixed anionic/cationic collectors could improve the recovery of muscovite to varying degrees, but the optimum molar ratio of anionic collectors to DDA and the optimum mixed collector dosage were different. Molecular dynamics simulations showed that the mixed anionic/cationic collectors could significantly increase the hydrophobicity of the muscovite, as evidenced by the decrease in the calculated water molecule density on the muscovite surface and the diffusion coefficient of water molecules at the solid/liquid interface. The interaction between the amino group and the polar group of anionic collectors reduced the electrostatic repulsion between DDA cations and theoretically increased the adsorption capacity of the mixed anionic/cationic collectors on the muscovite surface. Moreover, DDA/NA and DDA/NaOl could improve the calculated carbon atom density on the muscovite surface, which enhanced the hydrophobic association between nonpolar carbon chains, thus further achieving an enhanced flotation performance.
Źródło:
Physicochemical Problems of Mineral Processing; 2020, 56, 2; 313-324
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Looking at the Impacts of Income Inequality on Environmental Governance in China
Analiza wpływu nierówności dochodowych na zarządzanie środowiskiem w Chinach
Autorzy:
Shi, Yao Bo
Zhao, Xin Xin
Jang, Chyi-Lu
Fu, Qiang
Chang, Chun-Ping
Powiązania:
https://bibliotekanauki.pl/articles/371481.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Komitet Człowiek i Środowisko PAN
Tematy:
income inequality
environmental governance
SYS-GMM
LSDVC
JEL codes
Q56
Q58
O15
nierówność dochodowa
zarządzanie środowiskiem
SYS_GMM
Opis:
This research investigates the impacts of income inequality (proxied by the Gini index) on environmental governance (proxied by per capita government investments on industrial pollution prevention) by employing the panel fixed effect model, system generalized method of moments and bias-corrected least-squares dummy variables model for 23 provinces from 1995 to 2014. The results indicate that income inequality exhibits significantly positive impacts on government environmental governance investment in China, which reveals that an increase in income inequality may help to improve environmental governance in China; we thus offer several remittable implications for those policy makers in Chinese provinces as well as governments of emergent economies like China.
W niniejszym artykule zbadano wpływ nierówności dochodów (wykorzystując przez indeks Giniego) na zarządzanie środowiskiem (uwzględniając inwestycje rządu per capita na zapobieganie zanieczyszczeniom przemysłowym) poprzez zastosowanie modelu o stałych efektach panelowych, uogólnionej metody systemowej momentów i skorygowanego odchylenia modelu zmiennych pozornych najmniejszych kwadratów dla 23 chińskich prowincji w latach 1995-2014. Wyniki wskazują, że nierówność dochodów może wywierać znaczny pozytywny wpływ na rządowe inwestycje w zarządzanie środowiskiem w Chinach, co pokazuje, że wzrost nierówności w dochodach może przyczynić się do poprawy zarządzania środowiskiem w Chinach; oferujemy zatem kilka wymiernych rozwiązań dla decydentów w chińskich prowincjach, a także dla rządów wschodzących gospodarek, takich jak Chiny.
Źródło:
Problemy Ekorozwoju; 2019, 14, 2; 63-70
1895-6912
Pojawia się w:
Problemy Ekorozwoju
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Compound fault detection in gearbox based on time synchronous resample and adaptive variational mode decomposition
Wykrywanie złożonych błędów przekładni na podstawie synchronicznego próbkowania wtórnego oraz adaptacyjnej metody wariacyjnej dekompozycji modalnej
Autorzy:
Zhang, Xin
Zhao, Jianmin
Powiązania:
https://bibliotekanauki.pl/articles/301230.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
compound fault
gearbox
time synchronous resample
adaptive variational mode decomposition
błąd złożony
przekładnia
synchroniczne próbkowanie wtórne
adaptacyjna metoda wariacyjnej dekompozycji modalnej
Opis:
Compound fault detection of gearboxes is an ambitious matter considering its interconnection and complication. An innovative means for compound fault detection based on time synchronous resample (TSR) and adaptive variational mode decomposition (AVMD) is put forward in this work. TSR used in the method can enhance fault signals of synchronous shaft gears by eliminating signal components independent of synchronous shaft. Therefore, the TSR is used to separate the synchronous shaft signal corresponding to the gear fault from the raw compound fault signal. Then a series of mode components are obtained by decomposing the synchronous shaft signals of all faults by AVMD. The variational mode decomposition (VMD) can overcome the mode aliasing problem of empirical mode decomposition (EMD), but the decomposition effect of VMD is affected by its parameter setting. Thus, the paper proposes an AVMD algorithm based on whale optimization algorithm (WOA). In the AVMD, the WOA is used to optimizes the parameters of the VMD. After AVMD decomposition, the correlated kurtosis of the mode components obtained by AVMD decomposition is calculated. Then the mode components with the maximum correlated kurtosis are selected to carry out envelope analysis. Finally, the compound fault feature can be found from the envelope spectrum to get the diagnosis results. In order to test the validity of the proposed method, a compound fault experiment is implemented in a gearbox. Through the analysis of the experimental data, it is proved that the method shows a good performance in the compound fault detection of gearbox.
Wykrywanie złożonych błędów przekładni stanowi trudne zagadnienie ze względu na ich skomplikowany charakter i powiązania wewnętrzne. W pracy zaproponowano nowatorską metodę wykrywania błędów złożonych opartą na synchronicznym próbkowaniu wtórnym (TSR) oraz adaptacyjnej metodzie wariacyjnej dekompozycji modalnej (AVMD). TSR pozwala wzmacniać sygnały błędów występujących w synchronicznych przekładniach walcowych, dzięki eliminacji składowych sygnału niezwiązanych z działaniem wału synchronicznego. Dlatego też w przedstawionych badaniach, TSR wykorzystano do wyodrębnienia sygnału wału synchronicznego odpowiadającego błędowi przekładni, z surowego sygnału błędu złożonego. Następnie wszystkie sygnały błędu wału synchronicznego poddano dekompozycji za pomocą AVMD, dzięki czemu otrzymano szereg składowych modalnych. Wariacyjna dekompozycja modalna (VMD) pozwala uniknąć problemu aliasingu, który występuje w przypadku empirycznej dekompozycji modalnej (EMD), przy czym efekt dekompozycji zależy od ustawień parametrów. Dlatego w artykule zaproponowano adaptacyjny algorytm VMD oparty na algorytmie optymalizacji wielorybów (WOA), który optymalizuje parametry VMD. Następnym krokiem po dekompozycji AVMD, było obliczenie skorelowanej kurtozy składowych modalnych otrzymanych na drodze tej dekompozycji. Składniki modalne o najwyższych wartościach skorelowanej kurtozy wykorzystano do przeprowadzenia analizy obwiedni. Błąd złożony wykrywano na podstawie widma obwiedni. Skuteczność proponowanej metody sprawdzono przeprowadzając doświadczenie na przekładni, w której występował błąd złożony. Wyniki eksperymentu pokazują, że proponowane podejście stanowi skuteczną metodę wykrywania złożonych błędów.
Źródło:
Eksploatacja i Niezawodność; 2020, 22, 1; 161-169
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modelling and optimisation of vacuum collection system for cruise ship kitchen garbage
Autorzy:
Du, Jun
Li, Ruonan
Wu, Xin
Zhao, Hang
Powiązania:
https://bibliotekanauki.pl/articles/259756.pdf
Data publikacji:
2020
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
kitchen waste vacuum collection
System modeling
Sorting algorithm
Model experiment
Opis:
Pollution of the marine environment by ship garbage is an urgent problem to be solved at home and abroad. The ship kitchen garbage vacuum collection system is a new environmental protection scheme for garbage disposal. It has many advantages, such as using a pipeline instead of manual operation, creating high-level sanitary conditions, realising completely closed garbage collection and transportation, eliminating cross-pollution, saving space and so on. In this paper, the system is modelled, and the calculation of pipeline pressure loss, the vacuum degree of the vacuum tank and the energy consumption of the system are briefly introduced. In order to reduce the energy consumption, an algorithm for the emptying and discharging port is presented. In order to solve the problem of optimising relevant parameters, the vacuum transport mechanism of garbage is studied based on an optimisation model of the pipe network, and the experimental platform of a simulation device is set up. In engineering, this is of great significance to the design of cruise ship garbage collection and treatment systems and the development of supporting technology.
Źródło:
Polish Maritime Research; 2020, 1; 152-161
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Human neutrophil peptide 3 could be functionally expressed in Rhodobacter sphaeroides
Autorzy:
Nie, Xin
Zhang, Li
Hu, Zongli
Liu, Yi
Zhao, Zhiping
Powiązania:
https://bibliotekanauki.pl/articles/1039101.pdf
Data publikacji:
2015
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
Rb. sphaeroides
HNP3
expression system
antimicrobial activity
spectral absorption
Opis:
Human neutrophil peptides (HNPs) possess high antimicrobial activities against a broad spectrum of microorganisms. Rhodobacter sphaeroides is the best-characterized photosynthetic bacterium and exhibits potential as a novel expression system. Up to date, no literature has been reported regarding expression of HNP3 in Rb. sphaeroides. In the present study, the HNP3 gene fragment was amplified by SOE PCR and ligated into photosynthetic bacteria light-harvesting complex 2 (LH2) expression vector leading to HNP3 fusion protein expression vector. The HNP3 fusion protein was successfully expressed as rapidly evaluated by the LH2 characteristic peaks at ~800 nm and ~850 nm before purification and SDS/PAGE. Subsequently, the HNP3 fusion protein was purified by one-step affinity chromatography, and could be rapidly detected by the color and the spectral absorption at ~800 nm and ~850 nm before SDS/PAGE. Antimicrobial activity assay suggested that the HNP3 fusion protein exhibited high antimicrobial activity towards E. coli. The present study may supply an insight into employing the novel Rb. sphaeroides expression system, exhibiting dramatic advantages over currently used commercial expression system, to heterologously express human neutrophil peptides.
Źródło:
Acta Biochimica Polonica; 2015, 62, 2; 259-263
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Estimation of the upper flammability limits for alkanes in air at increased pressures
Autorzy:
Wan, Xin
Wang, Min
Cao, Chunyan
Zhao, Shuang
Song, Zhiguo
Powiązania:
https://bibliotekanauki.pl/articles/2106480.pdf
Data publikacji:
2022
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
Upper flammability limit
Adiabatic flame temperature
High pressure
Alkanes
Opis:
A method is proposed to predict the upper flammability limits for alkanes in air at increased pressures. The upper flammability limits for methane, ethane, propane and n-butane/air mixtures at ambient temperature and initial pressure of 0.3 MPa–2.0 MPa are identified through the adiabatic flame temperature calculation model. The association of calculated adiabatic flame temperature with pressure is presented to determine the upper flammability limit. Research shows the good agreement between the forecast upper flammability limits with pressure dependence and the experimental upper flammability limit values. The average relative error of the estimated upper flammability limits for alkanes in air at high pressures reaches 2.52%.
Źródło:
Polish Journal of Chemical Technology; 2022, 24, 2; 35--41
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Generalized Stokes parameters of random electromagnetic quasi-homogeneous beams on propagation
Autorzy:
Chen, J
Xin, Y
Chen, Y
Chen, F
Zhao, Q
Powiązania:
https://bibliotekanauki.pl/articles/174819.pdf
Data publikacji:
2013
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
electromagnetic
quasi-homogeneous
generalized Stokes parameters
polarization
Opis:
The expressions for the elements of the on-axis and transverse generalized Stokes parameters of random electromagnetic quasi-homogeneous beams on propagation are presented and are used to study the polarization properties of the beams. Some typical numerical calculations of the on-axis and transverse Stokes parameters, polarization properties of the beams on propagation are illustrated. The results show that for different sources all the on-axis parameters are identical in the near field and keep fixed values in the far field. But the transverse parameters are affected greatly by the properties of the source even in the near field. We have also found that the spatial profiles of the transverse parameters remain unchanged upon propagation.
Źródło:
Optica Applicata; 2013, 43, 2; s. 205-216
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
New approach to spindle thermal extension measuring based on machine vision for the vertical maching centre
Autorzy:
Su, Dongxu
Cai, Xin
Li, Yang
Zhao, Wanhuan
Zhang, Huijie
Powiązania:
https://bibliotekanauki.pl/articles/1849108.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Spindle thermal extension measuring
machine vision
Gaussian sub-pixel fitting
thermal error compensation
Opis:
When machine tool spindles are running at a high rotation speed, thermal deformation will be introduced due to the generation of large amounts of heat, and machining accuracy will be influenced as a result, which is a generalized issue in numerous industries. In this paper, a new approach based on machine vision is presented for measurements of spindle thermal error. The measuring system is composed of a Complementary Metal-Oxide-Semiconductor (CMOS) camera, a backlight source and a PC. Images are captured at different rotation angles during end milling process. Meanwhile, the Canny edge detection and Gaussian sub-pixel fitting methods are applied to obtain the bottom edge of the end mill which is then used to calculate the lowest point coordinate of the tool. Finally, thermal extension of the spindle is obtained according to the change of the lowest point at different time steps of the machining process. This method is validated through comparison with experimental results from capacitive displacement sensors. Moreover, spindle thermal extension during the processing can be precisely measured and used for compensation in order to improve machining accuracy through the proposed method.
Źródło:
Metrology and Measurement Systems; 2021, 28, 2; 357-370
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
High-grade mutant OmpF induces decreased bacterial survival rate
Autorzy:
Zhao, Zhi-ping
Liu, Ting-ting
Zhang, Li
Luo, Min
Nie, Xin
Li, Zai-xin
Pan, Yu
Powiązania:
https://bibliotekanauki.pl/articles/1039304.pdf
Data publikacji:
2014
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
antibiotic resistance
mOmpF
OmpF
outer membrane protein
bacterial survival rate
Opis:
OmpF plays very important roles in the influx of antibiotics and bacterial survival in the presence of antibiotics. However, high-grade mutant OmpF and its function in decreasing bacterial survival rate have not been reported to date. In the present study, we cloned a high-grade mutant OmpF (mOmpF) and sequence analysis suggested that over 45 percent of the DNA sequence was significantly mutated, leading to dramatic changes in over 55 percent of the amino acid sequence. mOmpF protein was successfully expressed. When grown in the presence of antibiotic, the bacterial survival rate decreased and the antibiotic inhibition zone became larger with the increase of the mOmpF. It was concluded that concentration of high-grade mutant mOmpF dramatically influenced the bacterial survival rate. The study presented here may provide insights into better understanding of the relationships between structure and function of OmpF.
Źródło:
Acta Biochimica Polonica; 2014, 61, 2; 369-373
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparative effectiveness of biochar derived from tropical feedstocks on the adsorption for ammonium, nitrate and phosphate
Autorzy:
Zou, Ganghua
Shan, Ying
Dai, Minjie
Xin, Xiaoping
Nawaz, Muhammad
Zhao, Fengljang
Powiązania:
https://bibliotekanauki.pl/articles/2203133.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
nutrients
soil amendment
adsorption model
biochars
tropical feedstock
składniki odżywcze
model adsorpcji
odżywianie gleby
biowęgle
surowce tropikalne
Opis:
Biochar has been extensively studied as a soil amendment to reduce nutrients losses. However, the comparative effectiveness of biochar adsorption capacity for ammonium (NH4 -N), nitrate (NO3 -N), and phosphate (PO4-P) remains unknown. In the present study, the effects of feedstock (banana stem and coconut shell) and temperature (300, 500, and 700°C) on biochar adsorption ability for NH4-N, NO3-N, and PO4-P were investigated and fitted by three adsorption models, viz Freundlich, Langmuir, and linear. Freundlich (R2 = 0.95–0.99) and Langmuir (R2 = 0.91–0.95) models were found suitable for adsorption of NH4 -N. The maximum adsorption capacity (Qm) for coconut shell biochar increased with pyrolysis temperature (Qm = 12.8–15.5 mg g-1) and decreased for banana stem biochar (Qm = 12.9–9.7 mg g-1). In the case of NO3 -N adsorption, Freundlich (R2 = 0.82–0.99) and linear model (R2 = 1.00) were found suitable while Langmuir model showed much less contribution, similarly adsorption of PO4-P, was not supported by these three models. The minimum concentrations required for adsorption of phosphate were recorded as 36, 8, and 3 mg L-1 using pyrolyzed biochar at the temperatures of 300, 500, and 700°C, respectively. These results indicate that the feedstock and pyrolysis temperature, as well as aquatic nutrient concentration, were important factors for the adsorption of inorganic nitrogen and phosphorus.
Źródło:
Archives of Environmental Protection; 2022, 48, 4; 25--34
2083-4772
2083-4810
Pojawia się w:
Archives of Environmental Protection
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Free chlorine loss during spraying of membraneless acidic electrolyzed water and its antimicrobial effect on airborne bacteria from poultry house
Autorzy:
Zhao, Y.
Xin, H.
Zhao, D.
Zheng, W.
Tian, W.
Ma, H.
Liu, K.
Hu, H.
Wang, T.
Soupir, M.
Powiązania:
https://bibliotekanauki.pl/articles/49243.pdf
Data publikacji:
2014
Wydawca:
Instytut Medycyny Wsi
Źródło:
Annals of Agricultural and Environmental Medicine; 2014, 21, 2
1232-1966
Pojawia się w:
Annals of Agricultural and Environmental Medicine
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Spectral degrees of cross-polarization of stochastic anisotropic electromagnetic beams in modified non-Kolmogorov atmospheric turbulence
Autorzy:
Chen, F.
Chen, J.
Zhao, Q.
Chen, Y
Xin, Y.
Li, J.
Pan, H.
Powiązania:
https://bibliotekanauki.pl/articles/174614.pdf
Data publikacji:
2013
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
quasi-homogenous source
modified non-Kolmogorov turbulence
generalized Stokes parameters
Opis:
Based on the extended Huygens–Fresnel principle, variations in generalized Stokes parameters of stochastic anisotropic electromagnetic beams propagating through modified non-Kolmogorov atmospheric turbulence have been analyzed. The changes in generalized Stokes parameters with different turbulence parameters and source parameters were analyzed first. After that, the distributions of the spectral degrees of cross-polarization (SDCP) of isotropic beams and anisotropic beams were simulated. The results show that the profiles of distribution of SDCP of these two kinds of beams are very different in the near field, and will fluctuate through the propagation in atmospheric turbulence, but at last, when the propagation distance is long enough, the difference in the source makes a slight difference in the final profiles of SDCP in the output plane. They mainly depended on the turbulence perturbation, and in the weak turbulence, the profiles of final distribution show more flatter features.
Źródło:
Optica Applicata; 2013, 43, 4; 773-783
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Research on the Critical Sizes for Detonation of Cube-shaped Transfer Charges
Autorzy:
Zhao, Xiang-run
Jin, Shi-xin
Huang, Jin-hong
Li, Chao-zhen
Yan, Li-wei
Powiązania:
https://bibliotekanauki.pl/articles/358353.pdf
Data publikacji:
2019
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
explosive train
transfer charge
shock wave sensitivity
minimum safe separation distance
Opis:
In order to obtain the minimum size, thickness and safe separation distance, for the cube-shaped transfer charges used in MEMS (micro-electromechanical system) explosive trains, an explosive train using a JO-9C(III) cube-shaped transfer charge was designed for experimental research. Detonation transfer experiments and detonation interruption experiments were conducted in turn. In initial experiments, the electric detonators were all in the armed position, but different thicknesses of the cube-shaped transfer charges were used. In the later experiments, the thickness of the transfer charges were unchanged, but the separation distances were different. The detonation path of the transfer charge under unsafe conditions was analyzed using the shock wave attenuation law. The results showed that the minimum thickness ranged from 0.2 mm to 0.4 mm, the minimum safe separation distance ranged from 0.4 mm to 0.6 mm; and the cube-shaped transfer charge is detonated by a shock wave from a steel gap rather than air clearance when the safe separation distance is less than the minimum threshold. The thickness design value of the cube-shaped transfer charge (JO-9C(III)) should not be less than 0.6 mm, and the safe separation distance design value of the MEMS explosive train should not be less than 1 mm.
Źródło:
Central European Journal of Energetic Materials; 2019, 16, 1; 91-104
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Development and verification of a high-precision laser measurement system for straightness and parallelism measurement
Autorzy:
Xu, Peng
Li, Rui Jun
Zhao, Wen Kai
Chang, Zhen Xin
Ma, Shao Hua
Fan, Kuang Chao
Powiązania:
https://bibliotekanauki.pl/articles/1849006.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
straightness
parallelism
laser measurement system
machine tool
Opis:
A laser measurement system for measuring straightness and parallelism error using a semiconductor laser was proposed. The designing principle of the developed system was analyzed. Addressing at the question of the divergence angle of the semiconductor laser being quite large and the reduction of measurement accuracy caused by the diffraction effect of the light spot at the long working distance, the optical structure of the system was optimized through a series of simulations and experiments. A plano-convex lens was used to collimate the laser beam and concentrate the energy distribution of the diffraction effect. The working distance of the system was increased from 2.6 m to 4.6 m after the optical optimization, and the repeatability of the displacement measurement is kept within 2.2 m in the total measurement range. The performance of the developed system was verified by measuring the straightness of a machine tool through the comparison tests with two commercial multi-degree-of-freedom measurement systems. Two different measurement methods were used to verify the measurement accuracy. The comparison results show that during the straightness measurement of the machine tool, the laser head should be fixed in front of the moving axis, and the sensing part should move with the moving table of the machine tool. Results also show that the measurement error of the straightness measurement is less than 3 m compared with the commercial systems. The developed laser measurement system has the advantages of high precision, long working distance, low cost, and suitability for straightness and parallelism error measurement.
Źródło:
Metrology and Measurement Systems; 2021, 28, 3; 479-495
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł

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