Autor: Li, K. - Prolib Integro

Skocz do pozycji: 1.

Tytuł:: Dinosaur assemblages from the Middle Jurassic Shaximiao Formation and Chuanjie Formation in the Sichuan-Yunnan Basin, China
Autorzy:: Li, K.
Yang, Ch.
Hu, F.
Tematy:: dinosaurs
Shaximiao Formation
Chuanjie Formation
Sichuan Basin
Yunnan Basin
Middle Jurassic; Pokaż więcej
Wydawca:: Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Powiązania:: https://bibliotekanauki.pl/articles/2061002.pdf Link otwiera się w nowym oknie
Opis:: The Shaximiao Formation (Sichuan Basin, China), and the corresponding Chuanjie Formation of the neighboring Yunnan Basin (Sichuan-Yunnan Basin), representing continental Mesozoic strata, are distinguished from other Chinese Mesozoic units because of the large area over which they are distributed, their lithological characteristics and their abundant vertebrate fossils. This paper analyses and summarizes the dinosaur fossils from the Shaximiao Formation and compares them to other vertebrate groups of the same or similar ages, both in China and abroad. For the first time, this paper presents the viewpoint that the upper member of the Shaximiao Formation is of Middle Jurassic age (Bathonian–Callovian). Furthermore, we claim that the entire Shaximiao Formation is of Bajocian–Callovian age (middle-late part of Middle Jurassic). This conclusion is supported by the age inferred from invertebrate fossils and radiometric dating (165–178 Ma). The composition, evolution and geological age of the vertebrate fauna (particularly dinosaur fossils), as well as their comparison to the dinosaur fauna from the other parts of the Sichuan-Yunnan Basin (Chuanjie Fm.) is discussed. Middle Jurassic dinosaur assemblages from China show marked differences compared with other dinosaur assemblages in the world, and this is explained by geographical isolation.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: Friction Between Footwear and Floor Covered With Solid Particles Under Dry and Wet Conditions
Autorzy:: Li, K. W.
Meng, F.
Zhang, W.
Tematy:: slip & fall
friction measurement
solid contaminants
Brungraber Mark II
upadek
tarcie
podłoga
obuwie; Pokaż więcej
Wydawca:: Centralny Instytut Ochrony Pracy
Powiązania:: https://bibliotekanauki.pl/articles/90294.pdf Link otwiera się w nowym oknie
Opis:: Solid particles on the floor, both dry and wet, are common but their effects on the friction on the floor were seldom discussed in the literature. In this study, friction measurements were conducted to test the effects of particle size of solid contaminants on the friction coefficient on the floor under footwear, floor, and surface conditions. The results supported the hypothesis that particle size of solids affected the friction coefficient and the effects depended on footwear, floor, and surface conditions. On dry surfaces, solid particles resulted in friction loss when the Neolite footwear pad was used. On the other hand, solid particles provided additional friction when measured with the ethylene vinyl acetate (EVA) footwear pad. On wet surfaces, introducing solid particles made the floors more slip-resistant and such effects depended on particle size. This study provides information for better understanding of the mechanism of slipping when solid contaminants are present.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: Design and test of a new high-current electronic current transformer with a Rogowski coil
Autorzy:: Zhang, M.
Li, K.
He, S.
Wang, J.
Tematy:: Rogowski coil
high-current
electronic current transformers
electrical measurements; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/221051.pdf Link otwiera się w nowym oknie
Opis:: This paper describes the design and test of a new high-current electronic current transformer based on a Rogowski coil. For better performances, electronic current transformers are used to replace conventional electro-magnetic inductive current transformers based on ferromagnetic cores and windings to measure high-current on the high voltage distribution grids. The design of a new high-current electronic current transformer is described in this paper. The principal schemes of the prototype and partial evaluation results are presented. Through relative tests it is known that the prototype has a wide dynamic range and frequency band, and it can allow high accuracy measurements.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 4.

Tytuł:: Effect of minor Cu addition on the precipitation sequence of an as-cast Al-Mg-Si 6005 alloy
Wpływ niewielkiej zawartości miedzi na sekwencje wydzieleń w odlewanych stopach Al-Mg-Si 6005
Autorzy:: Li, K.
Song, M.
Du, Y.
Fang, X.
Tematy:: stopy aluminium
dyfrakcja rentgenowska
transmisyjna mikroskopia elektronowa
badania twardości
aluminum alloys
precipitation
ageing
phase transformation; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/355082.pdf Link otwiera się w nowym oknie
Opis:: The whole precipitation sequences of two as-cast Al-Mg-Si 6005 alloys (containing no Cu or 0.1 wt.% Cu) at 150 degree Celsjus were investigated using X-ray diffraction, transmission electron microscopy and hardness examinations. The precipitation sequence of the Cu-free alloy can be expressed as: super-saturated solid solution (SSSS) → spherical G.P. zones → pre - β'' → β'' → U2 +Si + β _x → Si + β β _xwhile that of the Cu-containing alloy can be expressed as: SSSS → spherical G.P. zones + platelet-like G.P. zones → pre - β → β'' → Q' + β + Si → Q + β + Si. A new type of βprecipitate, namely β _x here, has been discovered in the Cu-free alloy. The addition of minor Cu is found to accelerate the microstructural evolution by inducing the formation of a new type of platelet-like G.P. zone along {111} _Al planes, and improve the hardening response at the over-aged stage by forming Q' and Q precipitates.
Kompletna sekwencja wydzieleń dwóch odlanych stopów Al-Mg-Si 6005 (zawierąjacych 0 i 0.1%.wag Cu), w temperaturze 150 stopni Celsjusza, została zbadana przy użyciu dyfrakcji rentgenowskiej, transmisyjnej mikroskopii elektronowej i badań twardości. Sekwencja wydzieleń w stopie nie zawierającym Cu może być przedstawiona następująco: przesycony roztwór stały → sferyczne strefy Guiniera-Prestona → pre - β'' → β'' → U2 +Si + β _x → Si + β β _x natomiast dla stopu zawierającego Cu następująco: przesycony roztwór stały → sferyczne i płytkowe strefy Guiniera-Prestona → pre - β → β'' → Q' + β + Si → Q + β + Si. Nowy rodzaj wydzieleń β, tj. β x , został odkryty w stopie niezawierajacym Cu. Stwierdzono, że dodatek niewielkiej ilości Cu przyspiesza zmiany mikrostruktury poprzez indukowanie tworzenia nowego typu płytkowych stref Guiniera-Prestona wzdłuż płaszczyzny {111}_Al. i poprawia utwardzenie poprzez tworzenie wydzieleń Q' i Q.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 5.

Tytuł:: Improved Roberts focusing evaluation method for an autofocusing system
Autorzy:: Yin, A.
Dai, Z.
Chen, B.
Li, K.
Tematy:: focus evaluation function
evaluation window
autofocusing; Pokaż więcej
Wydawca:: Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Powiązania:: https://bibliotekanauki.pl/articles/173381.pdf Link otwiera się w nowym oknie
Opis:: In this paper, a new focusing evaluation method based on local 2/8 center windows is proposed for an autofocusing system. We have proposed an evaluation function which improved the Roberts function with eight-neighborhood or four-neighborhood. The approximate optimal criteria window is selected by a 2/8 rule. Comparative experiments implemented with other methods have shown that the 2/8 rule method not only can find the approximate optimal evaluation window quickly, but also has better generality. This evaluation function of improved Roberts’ function has higher sensitivity and better real-time performance.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 6.

Tytuł:: An on-site calibration system for electronic instrument transformers based on LabVIEW
Autorzy:: Zhang, M.
Li, K.
Wang, J.
He, S.
Tematy:: calibration system
electronic instrument transformers
data acquisition
data synchronization
LabVIEW; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/221656.pdf Link otwiera się w nowym oknie
Opis:: Electronic voltage transformers (EVT) and electronic current transformers (ECT) are important instruments in a digital substation. For simple, rapid and convenient development, the paper proposed an on-site calibration system for electronic instrument transformers based on LabVIEW. In the system, analog signal sampling precision and dynamic range are guaranteed by the Agilent 3458A digital multimeter, and data synchronization is also achieved based on a self-developed PCI synchronization card. To improve the measurement accuracy, an error correction algorithm based on the Hanning window interpolation FFT has good suppression of frequency fluctuation and inter-harmonics interference. The human-computer interface and analysis algorithm are designed based on LabVIEW, and the adaptive communication technology is designed based on IEC61850 9-1/2. The calibration system can take into account pairs of digital output and analog output of the electronic voltage/current transformer calibration. The results of system tests show that the calibration system can meet the requirements of 0.2 class calibration accuracy, and the actual type test and on-site calibration also show that the system is easy to operate with convenience and satisfactory stability.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 7.

Tytuł:: Health Risks From Exposure to Metal-Working Fluids in Machining and Grinding Operations
Autorzy:: Li, K.
Aghazadeh, F.
Hatipkarasulu, S.
Ray, T. G.
Tematy:: machining safety
cutting fluid hazards
occupational illnesses
occupational cancer
metal working
obróbka metali
obróbka skrawaniem
ocena ryzyka zawodowego
zagrożenia zdrowia
szkodliwe czynniki fizyczne
choroba zawodowa
nowotwory; Pokaż więcej
Wydawca:: Centralny Instytut Ochrony Pracy
Powiązania:: https://bibliotekanauki.pl/articles/90609.pdf Link otwiera się w nowym oknie
Opis:: Metal-working fluids (MWFs) are used in machining and grinding operations to cool the tool and work, reduce the friction between the tool and work, improve the surface integrity of the work piece, and increase tool life and productivity. Health problems have been reported among workers exposed to MWFs, including incidences of respiratory, digestive and skin cancers, and increased rates of cough and phlegm. This paper reviews and discusses issues concerning health risks from exposure to MWFs in machining and grinding operations, the various factors that influence the degree of exposure, and control methods to reduce exposure to metal-working fluids.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 8.

Tytuł:: Design and analysis of interior composite-rotor bearingless permanent magnet synchronous motors with two layer permanent magnets
Autorzy:: Sun, X.
Su, B.
Chen, L.
Yang, Z.
Li, K.
Tematy:: bearingless motor
permanent magnet motor
finite element analysis
cogging torque
static electromagnetic characteristics
silnik z magnesem trwałym
analiza elementów skończonych
moment skręcający
właściwości elektromagnetyczne
silnik bezłożyskowy; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/200490.pdf Link otwiera się w nowym oknie
Opis:: In this paper, a new type of interior composite-rotor bearingless permanent magnet synchronous motors (BPMSMs) with two layer permanent magnets (PMs) is proposed. In order to reduce the torque ripple of this kind of motors, the sizes of PMs are optimized. Moreover, the magnetic field analysis of the interior composite-rotor BPMSM with two layer PMs is carried out by the finite element method (FEM). The corresponding static electronic magnetic characteristics at no load, including magnetic field, PM flux linkage and inductance, are studied in detail. In addition, electromagnetic torque characteristics and suspension force characteristics are also investigated thoroughly. The results of the analysis and simulation lay a significant foundation for further research on the interior composite-rotor BPMSMs with two layer PMs.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 9.

Tytuł:: Short-term variation in zooplankton community from Daya Bay with outbreaks of Penilia avirostris
Autorzy:: Li, K.
Yin, J.
Tan, Y.
Huang, L.
Song, X.
Tematy:: zooplankton
Penilia avirostris
outbreak
short-term variability
nuclear power plant
temporal variation
water temperature
salinity
chlorophyll a
aquaculture area
Daya Bay; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Oceanologii PAN
Powiązania:: https://bibliotekanauki.pl/articles/47644.pdf Link otwiera się w nowym oknie
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 10.

Tytuł:: Response of energy-size reduction to the control of circulating load in vertical spindle pulverizer
Autorzy:: Li, H.
He, Y.
Zhang, Y.
Ge, Z.
Xie, W.
Wang, S.
Li, K.
Tematy:: circulating load control
response of energy-size reduction
mixture grinding
energy efficiency; Pokaż więcej
Wydawca:: Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Powiązania:: https://bibliotekanauki.pl/articles/110803.pdf Link otwiera się w nowym oknie
Opis:: In the vertical spindle pulverizer (VSP), the large circulation ratio and high ash and sulfur contents in circulating load would result in intensive energy consumption and low grinding efficiency. Although the control of circulating load would help increase the energy efficiency, no quantitative study has been conducted due to the high temperature and pressure in the closed VSP. In this study, response of energy-size reduction to the control of circulating load was studied by the experimental simulation method. Coal mixtures with fine/coarse ratio of 11:1, 8:1 and 6:1 were ground by a lab-scale roller mill. Energy-size reductions of the coarse coal were compared to evaluate the influence of circulating load control. Results showed that the product with the coarse coal increased by 30% when the specific breakage energy was 1.0 kWht–1 as the circulation ratio decreased from 11 to 6. Meanwhile, a breakage characteristic index of the coarse coal was two times higher due to the cushioning effect of fines. Besides, decrease of circulation ratio led to increase of the breakage rate of coarse coal, and the energy saving improved by 57%. With the same energy input of 2.0 kWht-1, the yield of –0.09 mm pulverized fuel (PF) increased from 22 to 43%. Therefore, controlling the circulating load is an effective method to improve the breakage rate of coarse coal and energy efficiency for PF generation.
Dostawca treści:: Biblioteka Nauki

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