Electrospinning technology was generally used to synthesis nanofiber, here we use it to fabricate pure ZnO nanoparticles (ZnO NPs) and Ce-doped (0.1 wt%, 0.8 wt%, 1.5 wt%) ZnO nanoparticles (ZnO:Ce ...NPs) via decrease the molecular weight of PVP in precursor liquid. Their microstructures were characterized by X-ray diffraction, scanning electron microscopy, Brunauer-Emmet-Teller and photoluminescence spectra. The results clearly indicated that the 0.8 wt% ZnO:Ce NPs shows smaller average grain size (70 nm) and a higher specific surface area (21.5 m2/g). The testing on gas sensing performance revealed that the 0.8 wt% ZnO:Ce NPs based sensor shows the highest response values and a well selectivity to acetone. The response and recovery time of ZnO NPs based sensors to 100 ppm acetone was about 13 and 7 s while these are about 10 and 9 s in ZnO:Ce NPs based sensors, respectively. These results demonstrated that the 0.8 wt% ZnO:Ce NPs based sensor can rapidly be detect and distinguish accurately acetone in ambient air. Moreover, the sensor shows good long-term stability and reproducibility of response. The sensing mechanism was also discussed and the results indicated that the gas diffusing channels and the electron depleted layer of the ZnO NPs based sensor was increased markedly after Ce-doped, which results in the response of the ZnO:Ce NPs based sensor increased.
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•The loose mesostructured provide more channel for gas diffusion.•Smaller average grain size (70 nm) and higher specific surface area (21.5 m2/g).•The response and recovery time of ZnO:Ce NPs based sensor was about 10 and 9 s.•Suitable Ce-doped could improve the response of the ZnO NPs base sensors.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Rare earth doped 12CaO·7Al2O3 (C12A7:RE with RE=Gd3+, Er3+, Ce3+, Tb3+, Eu3+, Eu2+) phosphors have been prepared and treated under different conditions to trap different anions in the nanocages of ...C12A7. The effects of the encaged anions on the optical spectroscopies of the RE doped C12A7 phosphors, including photoluminescence and color tuning, upconverted emissions, and cathodoluminescence, have been investigated. Electron paramagnetic resonance spectra are also studied in combination with the optical spectra. Crystal field modification of RE emission centers by the encaged anions is observed by both photoluminescence and electron paramagnetic resonance. A relationship between the ratio of green to red upconverted emissions of Er3+ and the amount of encaged OH− anions is established and the concentration of the OH− determined. Emission enhancement in C12A7:Ce3+,Tb3+ conductive phosphors is realized by a multiphase strategy, which has a potential application in field emission devices. Color tuning of C12A7:Eu3+/Eu2+ phosphor is also performed in the range from red to blue by controlling the sort and amount of encaged anions.
•Crystal field modification of C12A7:RE emission centers by the encaged anions is observed using PL and EPR measurements.•Relationship between IG/IR of Er3+ and encaged OH− groups is established. Concentration of the OH− is determined using the ratio.•CL and PL enhancement in C12A7:Ce3+,Tb3+ conductive phosphors is realized by a multiphase strategy.•Color tuning of C12A7:Eu3+/Eu2+ phosphor is performed from red to blue by controlling the sort and amount of encaged anions.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Isochronous Mass Spectrometry (IMS) in heavy-ion storage rings is an excellent experimental method for precision mass measurements of exotic nuclei. In the IMS, the storage ring is tuned in a special ...isochronous ion-optical mode. Thus, the mass-over-charge ratios of the stored ions are directly reflected by their respective revolution times in first order. However, the inevitable momentum spread of secondary ions increases the peak widths in the measured spectra and consequently limits the achieved mass precision. In order to achieve a higher mass resolving power, the ring aperture was reduced to 60 mm by applying a mechanical slit system at the dispersive straight section. The momentum acceptance was reduced as well as better isochronous conditions were achieved. The results showed a significant improvement of the mass resolving power reaching 5.2×105, though at the cost of about 40% ion loss.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
To explore etiology, optimize the search direction of etiology, and short-term efficacy evaluation of acute liver failure in children.
Children with acute liver failure who were diagnosed in the ...First Affiliated Hospital of Zhengzhou University from November 2011 to November 2019 were collected. Gender difference, age, living environment, etiological factors on the seasonal onset and different etiological profile of short-term prognosis were statistically analyzed. Chi-square test or Fisher's exact probability method was used to compare the rate and the constituent ratio between groups.
Among the 236 cases, 114 (48.31%) had unknown etiology and 122 (51.69%) had definite etiology. In the definite etiology group, 38 (16.10%), 27 (11.44%), 22 (9.32%), 15 (6.36%), 17 (7.20%), and 3 (1.27%) cases were related to drugs/toxicants, infection, congenital/vascular/biliary diseases, genetic metabolic diseases, tumor-related, and autoimmune diseases. In addition, the overall etiological distribution did not change statis
Summary
To explain the effects of short‐term N addition on plant biomass allocation and on carbon (C) and nitrogen (N) pools in an alpine scrub ecosystem, we carried out a field experiment in ...Sibiraea angustata scrubland on the eastern margin of the Qinghai‐Tibetan Plateau of China. After one and a half years of N addition at four rates (N0, control; N20, 20; N50, 50; N100, 100 kg N ha−1 year−1), we investigated the amount and allocation of biomass and the C and N pools in several parts of the ecosystem, including shrubs (leaves, shoots and branches, coarse roots and fine roots), grass (above‐ and below‐ground) and litter (wood and leaf debris) components, and seven depth intervals within the soil (0–5, 5–10, 10–20, 20–30, 30–50, 50–70 and 70–100 cm). The results were as follows: (i) total vegetation biomass showed a linear increase with the increase in N (P < 0.05), mainly from the increased root biomass in both shrubs and grasses, (ii) the ecosystem C and N storage were 36 and 3.26 kg m−2, respectively, of which the shrub, grass, litter and soil components contributed 11.08, 0.47, 0.25 and 88%, respectively, to the C pool and 3.07, 0.16, 0.08 and 97%, respectively, to the N pool, (iii) the ecosystem N pool did not change in response to the addition of N, whereas the ecosystem C pool responded linearly to increasing N (P < 0.05). These results suggest that the alpine scrub ecosystem functions as a net C sink under increasing atmospheric N deposition, mainly by promoting belowground C sequestration.
Highlights
Effects of short‐term N addition on biomass allocation and C and N pools in alpine scrub.
Response to N addition in C pool of components of the ecosystem and soil at depth (0–100 cm).
Root:shoot ratio of vegetation and ecosystem C pool increased linearly with increasing N.
Alpine scrub ecosystem may function as a net C sink under increasing atmospheric N deposition.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
The effects of V content (0–7 wt.%) on the structure and mechanical properties of TiZrAlV alloys were investigated. The phase composition changes as α' → α' + (α″ + β) → α″ + β → β + (α″) → β with ...increased V content from 0 wt.% to 7 wt.%. Specifically, the single β phase that is impossible to achieve in Ti–V binary alloys was obtained in the TiZrAlV alloy with an increased V content of 7 wt.%. The microstructure of alloys with <1 wt.% V was characterized by martensite filling the original β grains. Dynamic recrystallization occurred in alloys with >3 wt.% V. With increased V content, the recrystallization volume fraction increased, and changes in the elastic modulus and yield strength exhibited an antiparabolic trend. The alloy with 3 wt.% V had the minimum average elastic modulus (68 GPa) and an average yield strength (690 MPa). With increased V content, the trend of elongation was the reverse of the yield strength. However, the trend of tensile strength remarkably differed from that of the yield strength. The alloy with 3 wt.% V had favorable comprehensive properties: a maximum average elongation (12.7%) and a high average tensile strength (1358 MPa). The strengthening and toughening mechanisms of TiZrAlV alloys were also discussed.
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•Phase structure is greatly dependent on the V content.•Full β phase was obtained while V content reaches up 7 wt.%.•Dynamic recrystallization occurs in hot-rolled alloys with 3–7 wt.% V.•Alloys with V content from 1 to 7 wt.% have good mechanical properties.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
► Non-polar growth. ► Large red shift of the optical band gap is related to the decreasing of carrier concentration and incorporation of charged defects. ► The three main emission peaks may ...constitute white light. ► Non-polar growth of ZnO has improved greatly the luminous efficiency.
Pure zinc oxide (ZnO) and lead (Pb) doped zinc oxide (ZnO:Pb) films with different Pb doping concentrations were deposited on glass substrate by using radio frequency reactive magnetron sputtering technique. X-ray diffraction spectroscopy measurements showed that all samples with the (100) preferential orientation were growth of the non-polar. The results of X-ray photoelectron spectroscopy analysis suggested that the Pb ions were successfully doped into lattice of ZnO and the valence of Pb in the ZnO films was a mixed state of +2 and +4. Optical band gaps of the ZnO:Pb were 3.24, 2.92, 2.86 and 2.74eV with the increase of Pb doping concentration, it could attribute this red shift phenomenon to the decrease of carrier concentration. Photoluminescence measurements showed that a broad emission band including the two blue emission peaks are about at 437nm and 470nm, one green and red emission peaks are about at 510nm and 710nm, which may compound white light. Moreover, growth of non-polar ZnO enhanced enormously the luminous efficiency of photoluminescence in our experiment. The current–voltage measurements between two surface electrodes showed the increase in resistance with increase of Pb doping concentration.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Twenty‐one microsatellite markers were studied in three meiogynogenetic families of Cynoglossus semilaevis gunther for centromere mapping using half‐tetrad analysis. Among the 13 mapped loci, 10 were ...estimated to be located in the telomeric region, one in the centromeric region, and two in the intermediate region of the chromosome. This study provides a basis for constructing a linkage map of C. semilaevis.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
We have recently shown that intrastriatal injection of recombinant human erythropoietin (EPO) protects dopaminergic (DA) neurons in the substantia nigra (SN) from 6-hydroxydopamine (6-OHDA) toxicity ...in a rat model of Parkinson's disease. However, systemic administration of EPO did not protect nigral DA neurons, suggesting that the blood-brain barrier limits the passage of EPO protein into the brain. In the present study, we used an adeno-associated viral (AAV) serotype 9 (AAV9) vector to deliver the human EPO gene into the brain of 6-OHDA-lesioned rats. We observed that expression of the human EPO gene was robust and stable in the striatum and the SN for up to 10 weeks. EPO-immunoreactive (IR) cells were widespread throughout the injected striatum, and EPO-IR neurons and fibers were also found in the ipsilateral SN. Enzyme-linked immunosorbent assay and western blot analyses exhibited dramatic levels of EPO protein in the injected striatum. As a result, nigral DA neurons were protected against 6-OHDA-induced toxicity. Amphetamine-induced rotational asymmetry and spontaneous forelimb use asymmetry were both attenuated. Interestingly, we also observed that intrastriatal injection of AAV9-EPO vectors led to increased numbers of red blood cells in peripheral blood. This highlights the importance of using an inducible gene delivery system for EPO gene delivery.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
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