33 research outputs found
Synthesis and Properties of LaSrNiO and LaSrNiO
Superconductivity has been realized in films of LaSrNiO. Here
we report synthesis and characterization of polycrystalline samples of
LaSrNiO and LaSrNiO ().
Magnetization and resistivity measurements reveal that LaSrNiO
are paramagnetic metals and LaSrNiO exhibit insulating
behavior. Superconductivity is not detected in bulk samples of
LaSrNiO. The absence of superconductivity in bulk
LaSrNiO may be due to the generation of hydroxide during
reduction or a small amount of nickel impurities. The effect of interface in
films of LaSrNiO may also play a role for superconductivity.Comment: 9 pages, 4 figure
Coexistence of ferromagnetism, antiferromagnetism, and superconductivity in magnetically anisotropic (Eu,La)FeAs2
Materials with exceptional magnetism and superconductivity usually conceive
emergent physical phenomena. Here, we investigate the physical properties of
the (Eu,La)FeAs2 system with double magnetic sublattices. The parent EuFeAs2
shows anisotropy-associated magnetic behaviors, such as Eu-related moment
canting and exchange bias. Through La doping, the magnetic anisotropy is
enhanced with ferromagnetism of Eu2+ realized in the overdoped region, and a
special exchange bias of the superposed ferromagnetic/superconducting loop
revealed in Eu0.8La0.2FeAs2. Meanwhile, the Fe-related antiferromagnetism shows
unusual robustness against La doping. Theoretical calculation and 57Fe
M\"ossbauer spectroscopy investigation reveal a doping-tunable dual
itinerant/localized nature of the Fe-related antiferromagnetism. Coexistence of
the Eu-related ferromagnetism, Fe-related robust antiferromagnetism, and
superconductivity is further revealed in Eu0.8La0.2FeAs2, providing a platform
for further exploration of potential applications and emergent physics.
Finally, an electronic phase diagram is established for (Eu,La)FeAs2 with the
whole superconducting dome adjacent to the Fe-related antiferromagnetic phase,
which is of benefit for seeking underlying clues to high-temperature
superconductivity.Comment: 13 pages, 6 figures for the main tex
Single crystal growth and superconductivity in RbNiSe
We report the synthesis and characterization of RbNiSe, an analog of
the iron chalcogenide superconductor RbFeSe, via transport, angle
resolved photoemission spectroscopy, and density functional theory
calculations. A superconducting transition at = 1.20 K is identified.
In normal state, RbNiSe shows paramagnetic and Fermi liquid behaviors.
A large Sommerfeld coefficient yields a heavy effective electron mass of
. In the superconducting state, zero-field electronic
specific-heat data can be described by a two-gap BCS model, indicating
that RbNiSe is a multi-gap superconductor. Our density functional
theory calculations and angle resolved photoemission spectroscopy measurements
demonstrate that RbNiSe exhibits relatively weak correlations and
multi-band characteristics, consistent with the multi-gap superconductivity.Comment: 7 pages, 4 figure
Responses of photosynthesis, chlorophyll fluorescence, and grain yield of maize to controlled-release urea and irrigation after anthesis
Controlled-release urea (CRU) is a new type of urea, which may increase crop nitrogen (N)-use efficiency compared with conventional urea (CU), but the conditions where it outperforms urea are not well defined. A field experiment assessing responses of plant growth and grain yield of maize to CRU and irrigation was conducted on a typical agricultural farm in Shandong, China. Five treatments of the two types of urea (75, 150kg N ha(-1), 0kg N ha(-1)) were applied as basal fertilizer when sowing maize, and two water treatments (W-0 and W-1) were used 23 d after anthesis. Net photosynthetic rate (P-N) and chlorophyll concentration as well as leaf-area index (LAI) increased significantly by both CRU and CU application, with the increases being larger in CRU-treated plants than in CU-treated plants at grain filling and maturing stages. CRU significantly enhanced the maximum photochemical efficiency (F-v/F-m), PSII coefficient of photochemical fluorescence quenching (q(P)), and actual quantum yield of PSII electron transformation (phi(PSII)) but decreased the nonphotochemical quenching (NPQ). Cob-leaf N concentration of CRU-treated plants was significantly higher than that of CU-treated plants under no irrigation, but not in the irrigation treatment 30 d after anthesis. Significant positive correlations were found between cob-leaf N concentration and P-N both with and without irrigation. Grain yield of maize was significantly higher in the CRU treatment than in the CU treatment under both irrigation conditions. In conclusion, CRU as a basal application appeared to increase the N-use efficiency for maize relative to CU especially by maintaining N supply after anthesis
Lubricating Oil Pollution Detection Sensor Design
Metal abrasive particle content in lubricating oil is an important index to judge the degree of deterioration of lubricating oil. Established a spiral electrode capacitance sensor by the finite element software ANSYS, the simulation result shows that the sensor is sensitive to the content of metal abrasive particle in lubricating oil, not affect by the metal abrasive particle itself. According to the simulation optimization model to make the real sensor, and designed lubricating oil pollution degree measurement system with the MS3110 capacitance detection circuit and MCU. Experiments show that it can distinguish metal abrasive particle from the change of 0.1 %-0.5 % content, this change can determine the degree of pollution of metal abrasive particle in lubricating oil, provides a simple and feasible method for the oil pollution detection