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Tytuł:
The Influence of Different Resin Cements and Pretreatments on the Bond Strength between Zirconia and Cement
Autorzy:
Sun, T.
Hu, C.
Wang, L.
Shao, L.
Powiązania:
https://bibliotekanauki.pl/articles/1218424.pdf
Data publikacji:
2014-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
87.85.jc
Opis:
The aim of this study was to analyze the influence of various luting materials and surface treatments on adhesive strength for zirconia ceramics and luting cements. The zirconia framework specimens were made into cylinders. Prior to cement, zirconia framework specimens underwent various surface treatments (sandblasting with 110 μm $Al_2O_3$ particles, milling with 240-grift silicon sand paper and silanization). Resin luting cement and glass ionomer luting cement were then applied on the surface of zirconia specimens. The specimens were then subjected to a shear force. The fractured surfaces were visually analyzed by scanning electron microscopy. The shear bond strength values of resin luting cement bonded to zirconia specimens were significantly higher than glass ionomer luting cement bonded to zirconia specimens (P < 0.05). The shear bond strength values of zirconia specimens sandblasted with 110 μm $Al_2O_3$ particles were significantly higher than those milled with silicon carbide papers and underwent silanization (P < 0.05). The shear bond strength values of zirconia specimens milled with silicon carbide papers and underwent silanization were not significantly different (P < 0.05). The highest shear bond strength values were achieved when the zirconia specimens were sandblasted and bonded to resin luting cement. Airborne-particle abrasion was an effective method which could enhance the bond strength of zirconia ceramics and cements. The resin luting cement exhibited a higher bond to zirconia than glass ionomer luting cement.
Źródło:
Acta Physica Polonica A; 2014, 125, 2; 313-315
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A generalized varying-domain optimization method for fuzzy goal programming with priorities based on a genetic algorithm
Autorzy:
Li, S. Y.
Hu, C. F.
Teng, C. J.
Powiązania:
https://bibliotekanauki.pl/articles/970454.pdf
Data publikacji:
2004
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
rozmyte programowanie celowe
priorytet
algorytm genetyczny
fuzzy goal programming
priorities
SQP
genetic algorithm
GENOCOP III
Opis:
This paper proposes a generalized domain optimization method for fuzzy goal programming with different priorities. According to the three possible styles of the objective function, the domain optimization method and its generalization are correspondingly proposed. This method can generate the results consistent with the decision-maker's priority expectations, according to which the goal with higher priority may have higher level of satisfaction. However, the reformulated optimization problem may be nonconvex for the reason of the nature of the original problem and the introduction of the varying-domain optimization method. It is possible to obtain a local optimal solution for nonconvex programming by the SQP algorithm. In order to get the global solution of the new programming problem, the co-evolutionary genetic algorithm, called GENOCOP III, is used instead of the SQP method. In this way the decision-maker can get. the optimum of the optimization problem. We demonstrate the power of this proposed method based on genetic algorithm by illustrative examples.
Źródło:
Control and Cybernetics; 2004, 33, 4; 633-652
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A numerical approach to predict the rotating stall in the vaneless diffuser of a centrifugal compressor using the eigenvalue method
Autorzy:
Hu, C.
Liu, P.
Zhu, X.
Chen, H.
Du, Z.
Powiązania:
https://bibliotekanauki.pl/articles/281006.pdf
Data publikacji:
2017
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
instability
vaneless diffuser
eigenvalue problem
spectral method
Opis:
A two-dimensional incompressible flow model is presented to study the occurrence of rotating stall in vaneless diffusers of centrifugal compressors. The diffuser considered has two parallel walls, and the undisturbed flow is assumed to be circumferentially uniform, isentropic, and to have no axial velocity. The linearized 2D Euler equations for an incompressible flow in a fixed frame of the coordinate system are considered. After discretization by a spectral collocation method based on Chebyshev-Gauss-Lobatto points, the generalized eigenvalue problem is solved through the QZ algorithm. The compressor stability is judged by the imaginary part of the eigenvalue obtained. Based on the 2D stability analysis, the influence of inflow angle, radius ratio and wave number are studied. The results from the present stability analysis are compared with some experimental measurement and Shen’s model. It is showed that diffuser instability increases rapidly and the stall rotational speed decreases quickly with an increase in the diffuser radius ratio. The largest critical inflow angle can be obtained when the wave number is around 3 ∼ 5 for the radius ratio between 1.5 to 2.2. It is also verified that the stability model proposed in this paper agrees well with experimental data and has the capability to predict the onset of rotating stall, especially for wide diffusers.
Źródło:
Journal of Theoretical and Applied Mechanics; 2017, 55, 2; 635-647
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Theoretical Profile of Ring-Spun Slub Yarn and its Experimental Validation
Teoretyczne oznaczenie geometrii fantazyjnej przędzy obrączkowej typu slub i weryfikacja eksperymentalna
Autorzy:
Ma, C Q
Zhou, B M
Liu, Y
Hu, C S
Powiązania:
https://bibliotekanauki.pl/articles/232346.pdf
Data publikacji:
2013
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Tematy:
slub yarn
mathematical model
slub profile
slub length
basic yarn length
przędza obrączkowa typu slub
model matematyczny
profil slub
długość slub
podstawowa długość przędzy
Opis:
A mathematical model for the yarn count of ring-spun slub yarn was established to predict the yarn profile based on process parameters such as the fibre length, the velocities of rollers and the time of over-feeding. The theoretical study shows that the slub length depends mostly on the process parameters above. The actual slub length is a fibre length greater than the slub length designed, and the actual length of basic yarn is a fibre length less than the length of basic yarn designed. The validity of the model was then verified using four sets of experiments. The experimental results agreed well with the model predictions and showed that the present model had high prediction accuracy, which may aid in the design and production of a desired slub yarn with controlling spinning parameters.
Model matematyczny masy liniowej przędzy obrączkowej typu slub został wyznaczony w celu określenia geometrii przędzy na podstawie parametrów procesu, takich jak długość włókien, prędkości rolek i wielkości naddatku. Badania teoretyczne wskazują, że długość odcinków przędzy typu slub zależy głównie od powyżej wymienionych parametrów procesu. W artykule podano właściwości zależności teoretycznych i rzeczywistych dla przędzy fantazyjnej. Prawidłowość tego modelu została następnie poddana weryfikacji przy użyciu cztery zestawów eksperymentalnych o zróżnicowanych warunkach. Wyniki badań eksperymentalnych potwierdziły przewidywania modelu i pokazały, że obecny model zapewnia wysoką dokładność przewidywania i dzięki temu ułatwia projektowanie i produkcję określonych włókien fantazyjnych.
Źródło:
Fibres & Textiles in Eastern Europe; 2013, 1 (97); 29-34
1230-3666
2300-7354
Pojawia się w:
Fibres & Textiles in Eastern Europe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Abiotic mechanisms for biochar effects on soil N2O emission
Autorzy:
He, C.
Manevski, K.
Andersen, M.N.
Hu, C.
Dong, W.
Li, J.
Powiązania:
https://bibliotekanauki.pl/articles/2082642.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Instytut Agrofizyki PAN
Tematy:
gas diffusion
mitigation
nitrous oxide
water
filled pore space
Opis:
In this research, sterile soil columns with different contents of biochar made from apple-tree residues (0, 1 and 5% w/w) at three levels of water filled pore space (40, 60, and 80%) were set up in the laboratory to study nitrous oxide diffusion and binding processes. The results indicated that nitrous oxide emission can be effectively mitigated at 5% biochar regardless of soil water content. However, 1% biochar stimulated nitrous oxide diffusion compared to the other biochar treatments, which was opposite to expectations due to the stronger aeration than adsorption effect, while 0% had a suppression effect between 1 and 5%. Nitrous oxide emissions increased with increasing water filled pore space due to concomitantly decreasing biochar tortuousity at high water content. The increase of nitrogen from 1.11 to 1.50% on the biochar surface in the 5% treatment, and from 1.11 to 1.46% in the 100% biochar treatment, suggested that the main abiotic mechanisms for mitigation of nitrous oxide emission is adsorption and subsequent reactions with C = C bonds on appletree biochar surfaces since C = O and C-O bonds both increased and C=C/C-C/C-H declined.
Źródło:
International Agrophysics; 2019, 33, 4; 537-546
0236-8722
Pojawia się w:
International Agrophysics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Theoretical Predictions of Lattice Parameters and Mechanical Properties of Pentaerythritol Tetranitrate under the Temperature and Pressure by Molecular Dynamics Simulations
Autorzy:
Tan, J.J.
Hu, C.
Li, Y.
Ge, N.
Chen, T.
Ji, G.
Powiązania:
https://bibliotekanauki.pl/articles/1033453.pdf
Data publikacji:
2017-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
molecular dynamics
lattice parameter
equation of state
elasticity
mechanical properties
Opis:
Molecular dynamics simulations with condensed-phase optimized molecular potentials for atomistic simulation studies force field are performed to investigate the structure, equation of state, and mechanical properties of high energetic material pentaerythritol tetranitrate. The equilibrium structural parameters, pressure-volume relationship and elastic constants at ambient conditions agree excellently with experiments. In addition, fitting the pressure-volume data to the Birch-Murnaghan or Murnaghan equation of state, the bulk modulus B₀ and its first pressure derivative B'₀ are obtained. Moreover, the elastic constants are calculated in the pressure range of 0-10 GPa at room temperature and in the temperature range of 200-400 K at the standard pressure, respectively. By the Voigt-Reuss-Hill approximation, the mechanical properties such as bulk modulus B, shear modulus G, and the Young modulus E are also obtained successfully. The predicted physical properties under temperature and pressure can provide powerful guidelines for the engineering application and further experimental investigations.
Źródło:
Acta Physica Polonica A; 2017, 131, 2; 318-323
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optically Detected Magnetic Resonance of Excess Electrons in CdTe/(Cd,Mg)Te Quantum Wells
Autorzy:
Hu, C. Y.
Ossau, W.
Yakovlev, D. R.
König, B.
Wojtowicz, T.
Karczewski, G.
Kossut, J.
Powiązania:
https://bibliotekanauki.pl/articles/1969094.pdf
Data publikacji:
1998-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
76.70.Hb
71.35.-y
71.35.Ji
Opis:
The spin resonance of excess electrons is observed with the detection either on the neutral or the negatively charged exciton X$\text{}^{-}$ emission in type I CdTe/(Cd,Mg)Te quantum wells with excess electrons of low density. It is found that the electron spin-dependent and electron spin-conserving formation and recombination of X$\text{}^{-}$ make the optical detection of the spin resonance of excess electrons feasible. For the first time, optically detected magnetic resonance is used to study fast optical transition processes in the nanosecond timescale where the microwave-induced magnetic transition rate is much lower than the optical transition rate.
Źródło:
Acta Physica Polonica A; 1998, 94, 2; 351-354
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Chemical Reactions and Electronic Functions of Carbon Cluster Arrays Studied by Scanning Tunneling Spectroscopy and High-resolution Electron Energy Loss Spectroscopy
Autorzy:
Kasuya, A.
Hu, C.-W.
Suto, S.
Tohji, K.
Takahashi, H.
Czajka, R.
Wawro, A.
Nishina, Y.
Powiązania:
https://bibliotekanauki.pl/articles/1968721.pdf
Data publikacji:
1998-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.16.Ch
61.14.Rq
73.61.Wp
Opis:
Novel nanometer scale structures have been produced by thermal heating or laser irradiation on the surface of single- and multi-layers of C$\text{}_{60}$ and C$\text{}_{84}$ on Si. These structures were examined by combined measurements of scanning tunneling spectroscopy and high resolution electron energy loss spectroscopy. The results show specific chemical reactions of substrate with carbon clusters having single- and double-bonded network. Covalent bonds are formed in some of these chemical reactions.
Źródło:
Acta Physica Polonica A; 1998, 93, 2; 317-322
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Argon Plasma in a New Process for Improving the Physical and Anti-bacterial Properties of Crosslinked Cotton Cellulose with Dimethyloldihydroxyethyleneurea-Maleic Acid
Zastosowanie plazmy niskotemperaturowej w środowisku argonu w procesie obróbki tkanin bawełnianych sieciowanych za pomocą kwasu dimetylodihydroxyetylenourylomaleinowego dla polepszenia właściwosci fizycznych oraz antybakteryjnych
Autorzy:
Tsou, C H
Suen, M C
Tsou, C Y
Chen, J C
Yeh, J T
Lin, S M
Lai, Y C
Hwang, J Z
Huang, S H
Hung, W S
Hu, C C
Lee, K R
Lai, J Y
Powiązania:
https://bibliotekanauki.pl/articles/232331.pdf
Data publikacji:
2015
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Tematy:
cotton
plasma
antibacterial
crosslinking
crosslink length
crosslinks number per anhydroglucose
surface distribution
odour absorption
bawełna
plazma
właściwości antybakteryjne
sieciowanie tkanin bawełnianych
kwas dimetylodihydroxyetylenourylomaleinowy
odporności na zagniecenia
pochłanianie zapachów
żywica termoutwardzalna
Opis:
This study reports the findings of an argon (Ar) plasma treatment added to the traditional pad-dry-cure process between dry and cure treatments. This new process is called the "paddry-plasma-cure process". The crosslinking agent was a mixture of dimethyloldihydroxyethyleneurea (DMDHEU) and maleic acid (MA). Results show that Ar plasma treatment can increase the bonded crosslinking agent (i.e., the nitrogen content). The dry crease recovery angle (DCRA), wet crease recovery angle (WCRA), and tensile strength retention (TSR) of the pad-dry-plasma-cure finished fabrics were higher than those of traditional pad-dry-cure finished fabrics at a given nitrogen content. Additionally it was found that the number of crosslinks per anhydroglucose unit (CL/AGU) and the length of crosslinks of pad-dry-plasma-cure-finished fabrics were higher than that of traditional pad-dry-cure finished fabrics at the same resin concentration in the pad bath. DCRA, WCRA and TSR values of pad-dry-plasma-cure-finished fabrics were higher than those of pad-dry-curefinished fabrics at the same CL/AGU value. However, activation energies for the pad-dryplasma-cure process were higher than those for the pad-dry-cure process. The anti-bacterial ability and odour absorption of the pad-dry-plasma-cure and pad-dry-plasma-cure finished fabrics were higher than those for the pad-dry-cure finished fabrics. The surface distribution of crosslinking agents for the pad-dry-plasma-cure process was higher than that of the pad-dry-cure process. Thus the pad-dry-plasma-cure process is excellent for improving the physical properties, bacterial inhibition, and odour absorption of finished cotton fabrics and for decreasing their formaldehyde release.
Artykułu odnosi się do problematyki możliwości i celowości wprowadzenia modyfikacji plazmowej w warunkach niskociśnieniowych i w środowisku argonu do konwencjonalnego procesu wykończenia przeciw mnącego z zastosowaniem reaktywnych żywic termoutwardzalnych. Badano kąt odprężenia na sucho i na mokro, i stwierdzono polepszenie właściwości odporności na zagniecenia w wyniku dodatkowego zastosowania plazmy. Badano również właściwości antybakteryjne i pochłanianie zapachów, które okazały się korzystniejsze dla dodatkowej obróbki plazmowej. W wyniku zmodyfikowanej obróbki uzyskano mniejsze wydzielanie formaldehydu z gotowej tkaniny.
Źródło:
Fibres & Textiles in Eastern Europe; 2015, 1 (109); 49-56
1230-3666
2300-7354
Pojawia się w:
Fibres & Textiles in Eastern Europe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An Algorithm for Interpolating Ship Motion Vectors
Autorzy:
Hu, Q.
Cai, F.
Yang, C.
Shi, C.
Powiązania:
https://bibliotekanauki.pl/articles/116863.pdf
Data publikacji:
2014
Wydawca:
Uniwersytet Morski w Gdyni. Wydział Nawigacyjny
Tematy:
Ship Motion
Ship Motion Vector
Automatic Identification System (AIS)
AIS Dynamic Information
Algorithm, Ship's Acceleration
AIS Data
Vector Function
Opis:
Interpolation of ship motion vectors is able to be used for estimating the lost ship AIS dynamic information, which is important for replaying marine accidents and for analysing marine traffic data. The previous methods can only interpolate ship’s position, while not including ship's course and speed. In this paper, vector function is used to express the relationship between the ship’s time and space coordinates, and the tangent of the vector function and its change rate are able to express physical characteristics of ship’s course, speed and acceleration. The given AIS dynamic information can be applied to calculate the parameters of ship's vector function and then the interpolation model for ship motion vectors is developed to estimate the lost ship dynamic information at any given moment. Experiment results show that the ship motion vector function is able to depict the characteristics of ship motions accurately and the model can estimate not only the ship’s position but also ship’s course and speed at any given moment with limited differences.
Źródło:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation; 2014, 8, 1; 35-40
2083-6473
2083-6481
Pojawia się w:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Calcite cements and the stratigraphical significance of the marine [delta^13]C carbonate reference curve for the Upper Cretaceous Chalk of England
Autorzy:
Jeans, C.
Hu, X.
Mortimore, R.
Powiązania:
https://bibliotekanauki.pl/articles/139078.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
cement kalcytowy
chemostratygrafia
izotopy
korelacja
kreda
krzywa referencyjna
ograniczenia
calcite cement
chemostratigraphy
correlation
Cretaceous
[delta^13]C reference curve
isotope events
limitations
Opis:
The hypothesis of Jarvis et al. (2006) that a [delta^13]C (calcite) reference curve based upon bulk samples from the Upper Cretaceous Chalk of England can be used as a primary criterion for trans-continental correlation is reviewed in the light of new stable isotope data from the Upper Albian and Cenomanian chalks of eastern England and from the Cenomanian to Campanian chalks of southern England. Evidence demonstrates that in the coloured chalks of eastern England the cements invariably have positive [delta^13]C values (up to 3.5[per mil]) except where they have been affected by hardground development when the cements have negative [delta^13]C values down to -6.5[per mil]. in contrast, the White Chalk of southern England may have cements with [delta^13]C values as negative as -8[per mil]. Modelling indicates that the coloured chalks may preserve a truer record of the primary palaeo-oceanographic [delta^13]C signal than the white and grey chalks of southern England. it is suggested that (1) many of the 72 isotope events described from the [delta^13]C (calcite) reference curve and proposed for correlation may reflect the effects of variations in the type and extent of calcite cementation; and (2) until much more is known about the patterns of calcite cementation in the Upper Cretaceous Chalk the use of minor isotope events for trans-continental stratigraphic correlation can only be applied with the utmost caution.
Źródło:
Acta Geologica Polonica; 2012, 62, 2; 173-196
0001-5709
Pojawia się w:
Acta Geologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Clustering Analysis for Identifying Areas of Collision Risk in Restricted Waters
Autorzy:
Xiang, Z.
Hu, Q.
Shi, C.
Powiązania:
https://bibliotekanauki.pl/articles/116062.pdf
Data publikacji:
2013
Wydawca:
Uniwersytet Morski w Gdyni. Wydział Nawigacyjny
Tematy:
anticollision
restricted waters
ship domain
Opis:
The identification of areas of collision risk in restricted waters could play an important role in VTS services. Based on the concept of ship domain, this paper introduces a model for identifying collision risk between vessels in restricted waters, then puts forward an improved DBSCAN clustering algorithm for identifying areas of high collision risk, finally, the visualization algorithm is presented. The experimental results in this paper show the algorithm is capable of identifying and rendering areas of collision risk in restricted waters.
Źródło:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation; 2013, 7, 1; 101-105
2083-6473
2083-6481
Pojawia się w:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The synergistic effect of boric acid and ammonium polyphosphate on the thermal degradation and flammability of pine-needles
Autorzy:
Li, L.
Hu, H.
Guo, C.
Powiązania:
https://bibliotekanauki.pl/articles/52633.pdf
Data publikacji:
2014
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Technologii Drewna
Tematy:
synergistic effect
boric acid
ammonium polyphosphate
thermal degradation
flammability
pine needle
needle
pyrolysis
temperature
flame retardant
Opis:
The synergistic effect of ammonium polyphosphate (APP) and boric acid (BA) on the flame retardancy and thermal degradation of pine needles was investigated. Thermogravimetric analysis (TGA) showed that the presence of an ammoniumpolyphosphate and boric acid system increased the char residue and decreased the pyrolysis temperature of the pine needles. The derivative thermogravimetric analysis (DTG) showed that the ammonium polyphosphate and boric acid had shifted the degradation peaks of the pine needles to lower temperatures. The cone calorimetry test results showed that the values of HRR, THR, SPR, TSP and the mass loss (%) of the pine needles treated with ammonium polyphosphate and boric acid (APP/BA = 3/2)were significantly lower than the other samples. Therefore, the APP and BA system had a better effect on the pine needles overall than the APP alone.
Źródło:
Drewno. Prace Naukowe. Doniesienia. Komunikaty; 2014, 57, 193
1644-3985
Pojawia się w:
Drewno. Prace Naukowe. Doniesienia. Komunikaty
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Geochemical and stable isotope patterns of calcite cementation in the Upper Cretaceous Chalk, UK: Direct evidence from calcite-filled vugs in brachiopods
Autorzy:
Hu, X.
Jeans, C.
Dickson, T.
Powiązania:
https://bibliotekanauki.pl/articles/139259.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
cement kalcytowy
diageneza
historia
izotopy stabilne
kreda
pierwiastki śladowe
wpływ drobnoustrojów
anoxia
calcite cement
chalk
diagenesis
history
Microbial influence
oxia
stable isotopes
suboxia
trace elements
Opis:
The history of research into the cementation of the Upper Cretaceous Chalk of the UK is reviewed. Calcite-filled vugs within the shell cavities of terebratulid brachiopods from the Cenomanian Chalk of eastern england have been investigated by cathodoluminesence imaging, staining, electron microprobe and stable isotope analysis. This has provided the first detailed analysis of the geochemistry of the Chalk.s cement. two cement series, suboxic and anoxic, are recognized. Both start with a Mg-rich calcite with positive [delta^13]C values considered to have been precipitated under oxic conditions influenced by aerobic ammonification. The suboxic series is characterized by positive [delta^13]C values that became increasingly so as cementation progressed, reaching values of 3.5[per mil]. Manganese is the dominant trace element in the earlier cement, iron in the later cement. Mn-and Fe-reducing microbes influenced cement precipitation and the trace element and [delta^13]C patterns. The anoxic series is characterized by [delta^13]C values that became increasingly negative as cementation progressed, reaching values of .6.5[per mil]. Trace elements are dominated by iron and manganese. Sulphate-reducing microbes influenced cement precipitation and the trace element and [delta^13]C patterns. Both cement series are related closely to lithofacies and early lithification pre-dating the regional hardening of the Chalk. The suboxic series occurs in chalk which was continuously deposited and contained hematite pigment and limited organic matter. The anoxic series was associated with slow to nil deposition and hardground development inc halks that originally contained hematite pigment but no longer do so, and an enhanced supply of organic matter.
Źródło:
Acta Geologica Polonica; 2012, 62, 2; 143-172
0001-5709
Pojawia się w:
Acta Geologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Plasma metabolic differences in cows affected by inactive ovaries or normal ovarian function post partum
Autorzy:
Zhao, C.
Hu, P.
Bai, Y.L.
Xia, C.
Powiązania:
https://bibliotekanauki.pl/articles/2087365.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
dairy cows
inactive ovaries
gas chromatography/mass spectrometry
multivariate statistical analysis
differential metabolites
Źródło:
Polish Journal of Veterinary Sciences; 2020, 23, 1; 59-67
1505-1773
Pojawia się w:
Polish Journal of Veterinary Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 42

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