5,974 research outputs found
In-process monitoring and analysis of bearing outer race way grinding based on the power signal
In production engineering, monitoring of the grinding process is critical for acquiring information on material removal, wheel performance, and workpiece quality. Here, a general model of the power signal and material removal rate is proposed to monitor the internal plunge grinding of a bearing outer race way product. Three continuous grinding cycles after dressing were used to analyse the roughing, semi-finishing, finishing and spark-out process under the same parameters. Based on the actual grinding process, a practical analysis method is applied to improve the general model to predict more accurately the power curve. Finally, estimations of grinding wheel performance and grind quality using the grinding power signal model (GPSM) coefficients are also presented. The experimental results showed that the improved power signal model is capable of solving the industrial problem of multi-stage in-feed grinding cycles and improving grind quality
Dexmedetomidine Pretreatment Attenuates Kidney Injury and Oxidative Stress during Orthotopic Autologous Liver Transplantation in Rats
published_or_final_versio
Antiviral treatment alters the frequency of activating and inhibitory receptor-expressing natural killer cells in chronic Hepatitis B virus infected patients
Natural killer (NK) cells play a critical role in innate antiviral immunity, but little is known about the impact of antiviral therapy on the frequency of NK cell subsets. To this aim, we performed this longitudinal study to examine the dynamic changes of the frequency of different subsets of NK cells in CHB patients after initiation of tenofovir or adefovir therapy. We found that NK cell numbers and subset distribution differ between CHB patients and normal subjects; furthermore, the association was found between ALT level and CD158b+ NK cell in HBV patients. In tenofovir group, the frequency of NK cells increased during the treatment accompanied by downregulated expression of NKG2A and KIR2DL3. In adefovir group, NK cell numbers did not differ during the treatment, but also accompanied by downregulated expression of NKG2A and KIR2DL3. Our results demonstrate that treatment with tenofovir leads to viral load reduction, and correlated with NK cell frequencies in peripheral blood of chronic hepatitis B virus infection. In addition, treatments with both tenofovir and adefovir in chronic HBV infected patients induce a decrease of the frequency of inhibitory receptor+ NK cells, which may account for the partial restoration of the function of NK cells in peripheral blood following treatment
Robust pinning of magnetic moments in pyrochlore iridates
Pyrochlore iridates A2Ir2O7 (A = rare earth elements, Y or Bi) hold great
promise for realizing novel electronic and magnetic states owing to the
interplay of spin-orbit coupling, electron correlation and geometrical
frustration. A prominent example is the formation of all-in/all-out
(AIAO)antiferromagnetic order in the Ir4+ sublattice that comprises of
corner-sharing tetrahedra. Here we report on an unusual magnetic phenomenon,
namely a cooling-field induced shift of magnetic hysteresis loop along
magnetization axis, and its possible origin in pyrochlore iridates with
non-magnetic Ir defects (e.g. Ir3+). In a simple model, we attribute the
magnetic hysteresis loop to the formation of ferromagnetic droplets in the AIAO
antiferromagnetic background. The weak ferromagnetism originates from canted
antiferromagnetic order of the Ir4+ moments surrounding each non-magnetic Ir
defect. The shift of hysteresis loop can be understood quantitatively based on
an exchange-bias like effect in which the moments at the shell of the FM
droplets are pinned by the AIAO AFM background via mainly the Heisenberg (J)
and Dzyaloshinsky-Moriya (D) interactions. The magnetic pinning is stable and
robust against the sweeping cycle and sweeping field up to 35 T, which is
possibly related to the magnetic octupolar nature of the AIAO order.Comment: 16 pages, 4 figure
Dexmedetomidine Inhibits TLR4/NF-κB Activation and Reduces Acute Kidney Injury after Orthotopic Autologous Liver Transplantation in Rats
published_or_final_versio
Dynamic changes of soil organic carbon under different land use type in Sanjiang Plain
The Sanjiang Plain in the northeast part of Heilongjiang Province is one of the largest freshwater marshes in China, which has been experienced intensive cultivation over past 50years. To understand the dynamic changes of soil organic carbon (SOC) after different durations of cultivation, soil samples down to a depth of 120 cm were collected in layers from the lowland and upland fields having been reclaimed for 5-25 years, with adjacent undisturbed wetland and forestland as the control. The study of the vertical distribution of SOC and its relationship with soil pH showed that the SOC content in undisturbed wetland and cultivated lowland rice fields had a marked decrease企om0-10 cm to 40-60 cm and a less change downward, and a similar variation trend was observed in undisturbed forestland and cultivated soybean fields, only with the difference that the SOC content in 0-10cm layer was much higher in forestland than in wetland, and lower in soybean fields than in rice fields. For undisturbed wetland, its SOC content in surface layer was decreased by 49.3% and 14.3% after claimed for 10 and 25 years, and for undisturbed forestland, 81.9% and 68.3% of its SOC in surface layer were lost after reclaimed for 5 years and 18 years, respectively. The soil pH in surface layer was decreased in the sequences of undisturbed wetland > lowland rice field reclaimed for 25 years > lowland rice field reclaimed for 10 years, and soybean field reclaimed for 5 years > soybean field reclaimed for 18 years > undisturbed forestland. All of these suggested that reclamation made a great loss of SOC in surface layer both in wetland and forestland, and the SOC loss was much greater in forestland than in wetland. The variation of surface soil pH under reclamation could be one of the factors inducing the SOC loss, and a longer period of reclamation combining with rational management could be favorable to the stabilization of SOC
Search for D to phi l nu and measurement of the branching fraction for D to phi pi
Using a data sample of integrated luminosity of about 33 pb collected
around 3.773 GeV with the BESII detector at the BEPC collider, the semileptonic
decays , and the hadronic
decay are studied. The upper limits of the branching
fractions are set to be 2.01% and 2.04% at the 90% confidence level. The ratio of the
branching fractions for relative to is measured to be . In addition, the
branching fraction for is obtained to be .Comment: 6 pages, 5 figures, to be published in Eur.Phys.J.
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