The CaO doped 10NiO-NiFe2O4 composite ceramics were prepared by the cold isostatic pressing-sintering process, and the effects of CaO content on the phase composition, mechanical property and thermal shock resistance ...The CaO doped 10NiO-NiFe2O4 composite ceramics were prepared by the cold isostatic pressing-sintering process, and the effects of CaO content on the phase composition, mechanical property and thermal shock resistance of 10NiO-NiFe2O4 composite ceramics were studied. The results show that the samples mainly consist of NiO and NiFe2O4 when content of CaO is less than 4%(mass fraction), bending strength increases obviously by CaO doping. Bending strength of the samples doped with 2% CaO is above 185 MPa, but that of the samples without CaO is only 60 MPa. Fracture toughness is improved obviously by CaO doping, the samples doped with 2% CaO have the maximum fracture toughness of 2.12 MPa ·m1/2 , which is about two times of that of the undoped ceramics. CaO doping is bad to thermal shock resistance of 10NiO-NiFe2O4 composite ceramics.展开更多
With a kernel apricot cultivar Youzhu 07-3 as the test material, the effects of exogenous calcium and calcium inhibitor on the cold resistance of pistils were investigated. In the bud germination and enlargement perio...With a kernel apricot cultivar Youzhu 07-3 as the test material, the effects of exogenous calcium and calcium inhibitor on the cold resistance of pistils were investigated. In the bud germination and enlargement period, exogenous calcium and calcium ion inhibitor were sprayed to the kernel apdcot trees, respectively. At the full-bloom stage, a certain number of flower branches of kernel apricot were sam- pied and subjected to low-temperature stress indoor, and the soluble sugar content, MDA content, SOD activity and POD activity in the pistils were determined. The results showed that exogenous calcium increased the soluble sugar content, reduced the MDA content and improved the SOD and POD activity in pistils, and it significantly relieved the cold damage to pistils and improved the cold resistance of pistils; while exogenous calcium ion inhibitor showed the opposite effects.展开更多
The hydration and mechanical properties of Portland cement blended with low-CaO steel slag were studied and reported. The steel slag was used to replace cement up to 30% and then blended cement powder, paste and morta...The hydration and mechanical properties of Portland cement blended with low-CaO steel slag were studied and reported. The steel slag was used to replace cement up to 30% and then blended cement powder, paste and mortar samples prepared for the experiment. The quantitative analysis of XRD shows that ettringite formation is greatly reduced by incorporation of steel slag but there was a relatively low reduction of portlandite. Thermal analysis by TG shows that slag injection reduced portlandite content in the cement by at least 50%. Generally, the slag cement pastes required less water to form a workable paste compared to the reference cement, reducing as the slag content was increased. However, the setting times were higher than the reference. The permeability of the blended cement samples were lower than the control. The incorporation of 5% slag could not have an effect on the compressive strength of the concrete. The results confirmed that whilst cements with up to 15% slag content satisfied the strength requirements of class 42.5 N and those containing 20%-30% produce Class 32.5R cement.展开更多
Arbuscular mycorrhizal fungi(AMF)enhance plant tolerance to abiotic stresses like salinity and improve crop yield.However,their effects are variable,and the underlying cause of such variation remains largely unknown.T...Arbuscular mycorrhizal fungi(AMF)enhance plant tolerance to abiotic stresses like salinity and improve crop yield.However,their effects are variable,and the underlying cause of such variation remains largely unknown.This study aimed to assess how drought modifed the effect of AMF on plant resistance to high calcium-saline stress.A pot experiment was performed to examine how AMF inoculation affects the growth,photosynthetic activity,nutrient uptake and carbon(C),nitrogen(N)and phosphorus(P)stoichiometric ratio(C:N:P)of maize under high calcium stress and contrasting water conditions.The results showed that high calcium stress signifcantly reduced mycorrhizal colonization,biomass accumulation,C assimilation rate and C:N stoichiometric ratio in plant tissues.Besides,the adverse effects of calcium stress on photosynthesis were exacerbated under drought.AMF inoculation profoundly alleviated such reductions under drought and saline stress.However,it barely affected maize performance when subjected to calcium stress under well-watered conditions.Moreover,watering changed AMF impact on nutrient allocation in plant tissues.Under well-watered conditions,AMF stimulated P accumulation in roots and plant growth,but did not induce leaf P accumulation proportional to C and N,resulting in increased leaf C:P and N:P ratios under high calcium stress.In contrast,AMF decreased N content and the N:P ratio in leaves under drought.Overall,AMF inoculation improved maize resistance to calcium-salt stress through enhanced photosynthesis and modulation of nutrient stoichiometry,particularly under water defcit conditions.These results highlighted the regulatory role of AMF in carbon assimilation and nutrient homeostasis under compound stresses,and provide signifcant guidance on the improvement of crop yield in saline and arid regions.展开更多
Background Recently, it has been proposed that the autoantibodies against various cardiovascular receptors play a role in the pathogenesis of primary hypertension. In this study, we aimed to identify whether or not th...Background Recently, it has been proposed that the autoantibodies against various cardiovascular receptors play a role in the pathogenesis of primary hypertension. In this study, we aimed to identify whether or not there are autoantibodies against cardiovascular L-type Ca^2＋ channels in patients with primary hypertension. Methods A peptide corresponding to the sequence 2-16 of the alc-subunit of L-type Ca^2＋ channel was used as an antigen to screen the autoantibodies from 90 patients with primary hypertension and 45 healthy controls by an enzyme-linked immunosorbent assay （ELISA）. The clinical data of 90 hypertensive patients were compared between patients with and without these autoantibodies. Results Serum from 3 （6.7%） of the 45 healthy controls, 33 （36.7%） of 90 hypertensives showed positive responses in ELISA （P 〈0.01）. The prevalence of such autoantibodies in two subgroups of hypertensives with coronary heart disease （9/21, 57.14%, P 〈0.05） and left ventricular diastolic dysfunction （28/63, 44.4%, P 〈0.05） was higher than in those without the corresponding complications. And the patients with such autoantibodies had lower E/A than patients without such autoantibodies （0.803±0.191 vs 1.004±0.322, P=0.002）. Conclusion There are autoantibodies against vascular L-tyPe Ca^2＋ channels in patients with primary hvnertension.展开更多
Two-dimensional(2D) lead halide perovskite materials are emerging as one of promising light-absorbing materials in perovskite solar cells(PSCs), which show outstanding stability and defect passivation. Unfortunately, ...Two-dimensional(2D) lead halide perovskite materials are emerging as one of promising light-absorbing materials in perovskite solar cells(PSCs), which show outstanding stability and defect passivation. Unfortunately, the power conversion efficiency(PCE) of those stable 2D PSCs is still far behind that of 3D PSCs. Herein, we reported a simple in-situ growth technique for the ethylenediamine lead iodide(EDAPbI4) layer on the top of formamidinium lead iodide(FAPbI3) layer. The rationally designed layered architecture of2D-3 D perovskite film could improve the PCE of the PSCs. In addition, benefiting from the high moisture resistance and inhibited ion migration of EDAPbI4 layer, the 2D-3D-based devices showed obviously enhanced long-term stability,keeping the initial PCE value for 200 h and 90% of its initial PCE even after 500 h.展开更多
基金Project(2005CB623703) supported by the National Basic Research Program of China
文摘The CaO doped 10NiO-NiFe2O4 composite ceramics were prepared by the cold isostatic pressing-sintering process, and the effects of CaO content on the phase composition, mechanical property and thermal shock resistance of 10NiO-NiFe2O4 composite ceramics were studied. The results show that the samples mainly consist of NiO and NiFe2O4 when content of CaO is less than 4%(mass fraction), bending strength increases obviously by CaO doping. Bending strength of the samples doped with 2% CaO is above 185 MPa, but that of the samples without CaO is only 60 MPa. Fracture toughness is improved obviously by CaO doping, the samples doped with 2% CaO have the maximum fracture toughness of 2.12 MPa ·m1/2 , which is about two times of that of the undoped ceramics. CaO doping is bad to thermal shock resistance of 10NiO-NiFe2O4 composite ceramics.
基金Supported by Youth Foundation of Hebei Academy of Agriculture and Forestry Sciences(A2012100107)~~
文摘With a kernel apricot cultivar Youzhu 07-3 as the test material, the effects of exogenous calcium and calcium inhibitor on the cold resistance of pistils were investigated. In the bud germination and enlargement period, exogenous calcium and calcium ion inhibitor were sprayed to the kernel apdcot trees, respectively. At the full-bloom stage, a certain number of flower branches of kernel apricot were sam- pied and subjected to low-temperature stress indoor, and the soluble sugar content, MDA content, SOD activity and POD activity in the pistils were determined. The results showed that exogenous calcium increased the soluble sugar content, reduced the MDA content and improved the SOD and POD activity in pistils, and it significantly relieved the cold damage to pistils and improved the cold resistance of pistils; while exogenous calcium ion inhibitor showed the opposite effects.
文摘The hydration and mechanical properties of Portland cement blended with low-CaO steel slag were studied and reported. The steel slag was used to replace cement up to 30% and then blended cement powder, paste and mortar samples prepared for the experiment. The quantitative analysis of XRD shows that ettringite formation is greatly reduced by incorporation of steel slag but there was a relatively low reduction of portlandite. Thermal analysis by TG shows that slag injection reduced portlandite content in the cement by at least 50%. Generally, the slag cement pastes required less water to form a workable paste compared to the reference cement, reducing as the slag content was increased. However, the setting times were higher than the reference. The permeability of the blended cement samples were lower than the control. The incorporation of 5% slag could not have an effect on the compressive strength of the concrete. The results confirmed that whilst cements with up to 15% slag content satisfied the strength requirements of class 42.5 N and those containing 20%-30% produce Class 32.5R cement.
基金supported by China Postdoctoral Science Foundation(2021M703137)Chongqing Postdoctoral Science Foundation(cstc2021jcyj-bshX0195)+2 种基金Postdoctoral Foundation of Jiangsu Province of China(1501014B)Education Department of Sichuan Province(17ZB0211),the Ecological Security and Protection Key Laboratory of Sichuan Province(07144812)the Scientifc Research Foundation of Chongqing University of Technology(2021ZDZ022).
文摘Arbuscular mycorrhizal fungi(AMF)enhance plant tolerance to abiotic stresses like salinity and improve crop yield.However,their effects are variable,and the underlying cause of such variation remains largely unknown.This study aimed to assess how drought modifed the effect of AMF on plant resistance to high calcium-saline stress.A pot experiment was performed to examine how AMF inoculation affects the growth,photosynthetic activity,nutrient uptake and carbon(C),nitrogen(N)and phosphorus(P)stoichiometric ratio(C:N:P)of maize under high calcium stress and contrasting water conditions.The results showed that high calcium stress signifcantly reduced mycorrhizal colonization,biomass accumulation,C assimilation rate and C:N stoichiometric ratio in plant tissues.Besides,the adverse effects of calcium stress on photosynthesis were exacerbated under drought.AMF inoculation profoundly alleviated such reductions under drought and saline stress.However,it barely affected maize performance when subjected to calcium stress under well-watered conditions.Moreover,watering changed AMF impact on nutrient allocation in plant tissues.Under well-watered conditions,AMF stimulated P accumulation in roots and plant growth,but did not induce leaf P accumulation proportional to C and N,resulting in increased leaf C:P and N:P ratios under high calcium stress.In contrast,AMF decreased N content and the N:P ratio in leaves under drought.Overall,AMF inoculation improved maize resistance to calcium-salt stress through enhanced photosynthesis and modulation of nutrient stoichiometry,particularly under water defcit conditions.These results highlighted the regulatory role of AMF in carbon assimilation and nutrient homeostasis under compound stresses,and provide signifcant guidance on the improvement of crop yield in saline and arid regions.
基金This study was supported by a grant from the National Natural Science Foundation of China （No. C03030201）.
文摘Background Recently, it has been proposed that the autoantibodies against various cardiovascular receptors play a role in the pathogenesis of primary hypertension. In this study, we aimed to identify whether or not there are autoantibodies against cardiovascular L-type Ca^2＋ channels in patients with primary hypertension. Methods A peptide corresponding to the sequence 2-16 of the alc-subunit of L-type Ca^2＋ channel was used as an antigen to screen the autoantibodies from 90 patients with primary hypertension and 45 healthy controls by an enzyme-linked immunosorbent assay （ELISA）. The clinical data of 90 hypertensive patients were compared between patients with and without these autoantibodies. Results Serum from 3 （6.7%） of the 45 healthy controls, 33 （36.7%） of 90 hypertensives showed positive responses in ELISA （P 〈0.01）. The prevalence of such autoantibodies in two subgroups of hypertensives with coronary heart disease （9/21, 57.14%, P 〈0.05） and left ventricular diastolic dysfunction （28/63, 44.4%, P 〈0.05） was higher than in those without the corresponding complications. And the patients with such autoantibodies had lower E/A than patients without such autoantibodies （0.803±0.191 vs 1.004±0.322, P=0.002）. Conclusion There are autoantibodies against vascular L-tyPe Ca^2＋ channels in patients with primary hvnertension.
基金supported by the National Key Research and Development Program of China (2016YFA0202400)the 111 Project (B16016)+2 种基金the National Natural Science Foundation of China (51572080, 51702096 and U1705256)the Fundamental Research Funds for the Central Universities (2018ZD07, 2017MS021 and 2019MS027)the Double Top Construction Program of North China Electric Power University (XM1805314)
文摘Two-dimensional(2D) lead halide perovskite materials are emerging as one of promising light-absorbing materials in perovskite solar cells(PSCs), which show outstanding stability and defect passivation. Unfortunately, the power conversion efficiency(PCE) of those stable 2D PSCs is still far behind that of 3D PSCs. Herein, we reported a simple in-situ growth technique for the ethylenediamine lead iodide(EDAPbI4) layer on the top of formamidinium lead iodide(FAPbI3) layer. The rationally designed layered architecture of2D-3 D perovskite film could improve the PCE of the PSCs. In addition, benefiting from the high moisture resistance and inhibited ion migration of EDAPbI4 layer, the 2D-3D-based devices showed obviously enhanced long-term stability,keeping the initial PCE value for 200 h and 90% of its initial PCE even after 500 h.
