In order to enhance electrochemical properties of LiFePO4 （LFP） cathode materials, spherical porous nano/micro structured LFP/C cathode materials were synthesized by spray drying, followed by calcination. The result...In order to enhance electrochemical properties of LiFePO4 （LFP） cathode materials, spherical porous nano/micro structured LFP/C cathode materials were synthesized by spray drying, followed by calcination. The results show that the spherical precursors with the sizes of 0.5-5 μm can be completely converted to LFP/C when the calcination temperature is higher than 500 ℃. The LFP/C microspheres obtained at calcination temperature of 700 ℃ are composed of numerous particles with sizes of -20 nm, and have well-developed interconnected pore structure and large specific surface area of 28.77 mE/g. The specific discharge capacities of the LFP/C obtained at 700 ℃ are 162.43, 154.35 and 144.03 mA.h/g at 0.5C, 1C and 2C, respectively. Meanwhile, the capacity retentions can reach up to 100% after 50 cycles. The improved electrochemical properties of the materials are ascribed to a small Li＋ diffusion resistance and special structure of LFP/C microspheres.展开更多
Tomato is an important field crop,and nutritional imbalances frequently reduce its yield.Diagnosis and Recommendation Integrated System(DRIS),uses ratios for nutrient deficiency diagnosis instead of absolute concentra...Tomato is an important field crop,and nutritional imbalances frequently reduce its yield.Diagnosis and Recommendation Integrated System(DRIS),uses ratios for nutrient deficiency diagnosis instead of absolute concentration in plant tests.In this study,local DRIS norms for the field tomatoes were established and the nutrient(s)limiting tomatoes yield were determined.Tomato leaves were analyzed for nutrients,to identify nutritional status using the DRIS approach.One hundred tomatoes fields were selected from Chatter Plain Khyber Pakhtunkhwa and the Sheikupura Punjab Pakistan.The first fully matured leaf was sampled,rinsed,dried and ground for analyzing P,K,Ca,Mg,Cu,Fe,Mn and Zn using an Inductively Coupled Plasma Atomic Emission Spectrophotometer(ICP AES).Plant tissue N and S were measured by the combustion method.The tomatoes yields were recorded at each location.The data were divided into high-yielding(≥3.79 kg/10 plant)and low-yielding(<3.79 kg/10 plant)populations and norms were computed using standard DRIS procedures.High-yielding plant population had a statistically greater mean S and Fe than the low-yielding population.The average balance index,the sum of functions,for S and Fe were−11.04 and−5.17 which reflected deficiency of S and Fe.Plant nutrients norms established may optimize plant nutrition in field tomatoes for high yield.展开更多
Bionic adhesives with tip-expanded microstructural arrays have attracted considerable interest owing to their high adhesive performance at low preloads.Their mainstream manufacturing method is molding.Due to most mold...Bionic adhesives with tip-expanded microstructural arrays have attracted considerable interest owing to their high adhesive performance at low preloads.Their mainstream manufacturing method is molding.Due to most molds are made of silicon or silicon-based soft templates,and have poor wear resistant or vulnerability to high temperature,limiting their use in large-scale manufacturing.Nickel is widely used as an embossing mold in the micro/nano-imprint industrial process owing to its good mechanical properties.However,the processing of metal molds for the fabrication of tip-expanded microstructural arrays is extremely challenging.In this study,using electrodeposition techniques,the shape of the micropores is modified to obtain end-controlled pores.The effect of the non-uniformity of the electric field on the microporous morphology in the electrodeposition process is systematically investigated.Furthermore,the mechanism of non-uniformity evolution of the microporous morphology is revealed.The optimized microporous metal array is used as a mold to investigate the cavity evolution laws of the elastic cushions under pre-load during the manufacturing process.As a result,typical bionic adhesives with tip-expansion are obtained.Moreover,corresponding adhesion mechanics are analyzed.The results show that electrochemical modifications have broad application prospects in the fabrication of tip-expanded microstructures,providing a new method for the large-scale fabrication of bionic adhesives based on metal molds.展开更多
基金Project(2013AA050901)supported by the National High-tech Research and Development Program of China
文摘In order to enhance electrochemical properties of LiFePO4 （LFP） cathode materials, spherical porous nano/micro structured LFP/C cathode materials were synthesized by spray drying, followed by calcination. The results show that the spherical precursors with the sizes of 0.5-5 μm can be completely converted to LFP/C when the calcination temperature is higher than 500 ℃. The LFP/C microspheres obtained at calcination temperature of 700 ℃ are composed of numerous particles with sizes of -20 nm, and have well-developed interconnected pore structure and large specific surface area of 28.77 mE/g. The specific discharge capacities of the LFP/C obtained at 700 ℃ are 162.43, 154.35 and 144.03 mA.h/g at 0.5C, 1C and 2C, respectively. Meanwhile, the capacity retentions can reach up to 100% after 50 cycles. The improved electrochemical properties of the materials are ascribed to a small Li＋ diffusion resistance and special structure of LFP/C microspheres.
基金supporting current work by Taif University Researchers Supporting Project No.(TURSP–2020/288),Taif University,Taif,Saudi Arabia.
文摘Tomato is an important field crop,and nutritional imbalances frequently reduce its yield.Diagnosis and Recommendation Integrated System(DRIS),uses ratios for nutrient deficiency diagnosis instead of absolute concentration in plant tests.In this study,local DRIS norms for the field tomatoes were established and the nutrient(s)limiting tomatoes yield were determined.Tomato leaves were analyzed for nutrients,to identify nutritional status using the DRIS approach.One hundred tomatoes fields were selected from Chatter Plain Khyber Pakhtunkhwa and the Sheikupura Punjab Pakistan.The first fully matured leaf was sampled,rinsed,dried and ground for analyzing P,K,Ca,Mg,Cu,Fe,Mn and Zn using an Inductively Coupled Plasma Atomic Emission Spectrophotometer(ICP AES).Plant tissue N and S were measured by the combustion method.The tomatoes yields were recorded at each location.The data were divided into high-yielding(≥3.79 kg/10 plant)and low-yielding(<3.79 kg/10 plant)populations and norms were computed using standard DRIS procedures.High-yielding plant population had a statistically greater mean S and Fe than the low-yielding population.The average balance index,the sum of functions,for S and Fe were−11.04 and−5.17 which reflected deficiency of S and Fe.Plant nutrients norms established may optimize plant nutrition in field tomatoes for high yield.
基金the Natural Science Foundation of Jiangsu Province of China(No.BK20170796)the foundation of‘‘Jiangsu Provincial Key Laboratory of Bionic Functional Materials”of China(No.NJ2020026)+1 种基金the foundation of National Defense Key Laboratory of China(No.6142004190204)the National Natural Science Foundation of China(No.52075249)。
文摘Bionic adhesives with tip-expanded microstructural arrays have attracted considerable interest owing to their high adhesive performance at low preloads.Their mainstream manufacturing method is molding.Due to most molds are made of silicon or silicon-based soft templates,and have poor wear resistant or vulnerability to high temperature,limiting their use in large-scale manufacturing.Nickel is widely used as an embossing mold in the micro/nano-imprint industrial process owing to its good mechanical properties.However,the processing of metal molds for the fabrication of tip-expanded microstructural arrays is extremely challenging.In this study,using electrodeposition techniques,the shape of the micropores is modified to obtain end-controlled pores.The effect of the non-uniformity of the electric field on the microporous morphology in the electrodeposition process is systematically investigated.Furthermore,the mechanism of non-uniformity evolution of the microporous morphology is revealed.The optimized microporous metal array is used as a mold to investigate the cavity evolution laws of the elastic cushions under pre-load during the manufacturing process.As a result,typical bionic adhesives with tip-expansion are obtained.Moreover,corresponding adhesion mechanics are analyzed.The results show that electrochemical modifications have broad application prospects in the fabrication of tip-expanded microstructures,providing a new method for the large-scale fabrication of bionic adhesives based on metal molds.
