Chloromethylated poly（phthalazinone ether sulfone ketone） （CMPPESK） was prepared from poly（phthalazinone ether sulfone ketone） （PPESK） using chloromethyl octyl ethers （CMOE） with lower toxicity as chlorometh...Chloromethylated poly（phthalazinone ether sulfone ketone） （CMPPESK） was prepared from poly（phthalazinone ether sulfone ketone） （PPESK） using chloromethyl octyl ethers （CMOE） with lower toxicity as chloromethylated regent. CMPPESK was soluble in N-methyl-2-pyrrolidone （NMP）, N,N-dimethylacetamide （DMAc） and chloroform. Quaternized poly（phthalazinone ether sulfone ketone） （QAPPESK） was prepared from CMPPESK by quaternization. QAPPESK had excellent solvent resistance, which was only partly soluble in sulfuric acid （98%） and swollen in N,N-dimethylformamide （DMF）. The vanadium redox flow battery （V-RFB） using QAPPESK anion-exchange membrane had better performance with 88.3% of overall energy efficiency.展开更多
In 2004, Wang Chengyan, a 13-year-old Mongolian girl in the Tumote Left Banner of Inner Mongolia, took up her schoolbag again and marched into the classroom of six grade of a local primary school. With her face shinin...In 2004, Wang Chengyan, a 13-year-old Mongolian girl in the Tumote Left Banner of Inner Mongolia, took up her schoolbag again and marched into the classroom of six grade of a local primary school. With her face shining with brilliance, she told her friends： ＂It is brothers and sisters studying in Japan who have paid my way to school.＂展开更多
The novel thermal stable composite nanofiltra-tion membranes were prepared through the interfacial polymerization of piperazine and trimesoyl chloride on the poly(phthalazinone ether)ultrafiltration substrate.The effe...The novel thermal stable composite nanofiltra-tion membranes were prepared through the interfacial polymerization of piperazine and trimesoyl chloride on the poly(phthalazinone ether)ultrafiltration substrate.The effects of polymerization and testing conditions on membrane performance were studied.The surface morphologies of the substrate and the composite mem-branes were observed by means of scanning electron microscopy(SEM)and atomic force microscopy(AFM).The separation properties of membranes for dyes and salts were tested.The composite membranes show good ther-mal stability.The rejection for Na2SO_(4) was kept over 96%,1.0 MPa and 80℃.When tested at 1.0 MPa and 60℃,the rejection of the composite membrane for dyes was kept at the rejection for NaCl was lower than 20%.展开更多
Vibration energy harvesting can solve the energy supplying problem of systems like wireless sensors networks.The Galfenol cantilever beam energy harvester is suitable for this application.According to the electromecha...Vibration energy harvesting can solve the energy supplying problem of systems like wireless sensors networks.The Galfenol cantilever beam energy harvester is suitable for this application.According to the electromechanical conversion principle,the constitutive relation of Galfenol is built.A magnetization model is also established,based on the hysteresis model of Galfenol.Combining the magneto-mechanical coupling model,the constitutive relation of Galfenol and the electromagnetic induction law,the mathematical model of Galfenol vibration energy harvester is established.A hyperbolic curve-shaped cantilever beam is designed and its performance is compared to three types of cantilever beams:rectangle,trapezoidal,and triangle.The stress distribution,modal analysis and frequency response of these four shapes of beams are compared.The hyperbolic beam is more suitable for low frequency vibration harvesting.The strain on the beams,output voltage and power output response to these energy harvesters,under different natural vibration frequencies,are determined by simulation.Finally,the simulation results are compared to experimental electric outputs of all four types of prototype beams.The comparative study showed consistency between the experimental and the simulation results,and also that the peak-to-peak induction voltage value of the hyperbolic beam is larger than other shapes of energy harvesters,whose average value is at 269.8 mV.The maximum power output of the hyperbolic beam is 403.8μW when connected with a 50Ω resistance.展开更多
Embryogenesis is central to the life cycle of higher plants,which starts from division of the single-cell zygote and culminates in formation of the mature embryo with major cell precursors.Such a process generally inv...Embryogenesis is central to the life cycle of higher plants,which starts from division of the single-cell zygote and culminates in formation of the mature embryo with major cell precursors.Such a process generally involves tightly orchestrated cell division,differentiation,and pattern formation.展开更多
基金partly financed by the Major State Basic Research Development Program of China(No.2003 CB615700)the National Natural Science Foundation of China(No.20604005).
文摘Chloromethylated poly（phthalazinone ether sulfone ketone） （CMPPESK） was prepared from poly（phthalazinone ether sulfone ketone） （PPESK） using chloromethyl octyl ethers （CMOE） with lower toxicity as chloromethylated regent. CMPPESK was soluble in N-methyl-2-pyrrolidone （NMP）, N,N-dimethylacetamide （DMAc） and chloroform. Quaternized poly（phthalazinone ether sulfone ketone） （QAPPESK） was prepared from CMPPESK by quaternization. QAPPESK had excellent solvent resistance, which was only partly soluble in sulfuric acid （98%） and swollen in N,N-dimethylformamide （DMF）. The vanadium redox flow battery （V-RFB） using QAPPESK anion-exchange membrane had better performance with 88.3% of overall energy efficiency.
文摘In 2004, Wang Chengyan, a 13-year-old Mongolian girl in the Tumote Left Banner of Inner Mongolia, took up her schoolbag again and marched into the classroom of six grade of a local primary school. With her face shining with brilliance, she told her friends： ＂It is brothers and sisters studying in Japan who have paid my way to school.＂
基金supported by the National High Technology Research and Development Program of China(No.2003AA33G030)the National Basic Research Program of China(No.2003CB615700).
文摘The novel thermal stable composite nanofiltra-tion membranes were prepared through the interfacial polymerization of piperazine and trimesoyl chloride on the poly(phthalazinone ether)ultrafiltration substrate.The effects of polymerization and testing conditions on membrane performance were studied.The surface morphologies of the substrate and the composite mem-branes were observed by means of scanning electron microscopy(SEM)and atomic force microscopy(AFM).The separation properties of membranes for dyes and salts were tested.The composite membranes show good ther-mal stability.The rejection for Na2SO_(4) was kept over 96%,1.0 MPa and 80℃.When tested at 1.0 MPa and 60℃,the rejection of the composite membrane for dyes was kept at the rejection for NaCl was lower than 20%.
基金supported by the Natural Science Foundation of Zhejiang Province(Grant LY17E050026)the National Natural Science Foundation of China(Grant 51805126).
文摘Vibration energy harvesting can solve the energy supplying problem of systems like wireless sensors networks.The Galfenol cantilever beam energy harvester is suitable for this application.According to the electromechanical conversion principle,the constitutive relation of Galfenol is built.A magnetization model is also established,based on the hysteresis model of Galfenol.Combining the magneto-mechanical coupling model,the constitutive relation of Galfenol and the electromagnetic induction law,the mathematical model of Galfenol vibration energy harvester is established.A hyperbolic curve-shaped cantilever beam is designed and its performance is compared to three types of cantilever beams:rectangle,trapezoidal,and triangle.The stress distribution,modal analysis and frequency response of these four shapes of beams are compared.The hyperbolic beam is more suitable for low frequency vibration harvesting.The strain on the beams,output voltage and power output response to these energy harvesters,under different natural vibration frequencies,are determined by simulation.Finally,the simulation results are compared to experimental electric outputs of all four types of prototype beams.The comparative study showed consistency between the experimental and the simulation results,and also that the peak-to-peak induction voltage value of the hyperbolic beam is larger than other shapes of energy harvesters,whose average value is at 269.8 mV.The maximum power output of the hyperbolic beam is 403.8μW when connected with a 50Ω resistance.
基金grants from the National Key R&D Program of China(2018YFA0903202)the China Postdoctoral Science Foundation(230210538)。
文摘Embryogenesis is central to the life cycle of higher plants,which starts from division of the single-cell zygote and culminates in formation of the mature embryo with major cell precursors.Such a process generally involves tightly orchestrated cell division,differentiation,and pattern formation.
