Achieving efficient adsorption and separation of C_(2)H_(2)/CO_(2)mixtures is a goal that people have always pursued to improve the situation of high energy consumption brought by traditional separation technologies i...Achieving efficient adsorption and separation of C_(2)H_(2)/CO_(2)mixtures is a goal that people have always pursued to improve the situation of high energy consumption brought by traditional separation technologies in industry today.High-nuclearity metal cluster-based MOFs with different functionalities are promising for this separation,but it is a complicated and difficult task to precisely control their structures.The strategy of pore-space partition(PSP)is a powerful way to construct this type MOFs,which has the characteristic of isostructural relationship,and can be resulted in a similar performance for them.Therefore,it is an interesting work to explore the effect of MOFs property by adjusting the size of PSP dividers.Herein,three tetranuclear Cu(Ⅱ)cluster-based MOFs(FJU-112/113/114)with dual functionalities has been successfully obtained by PSP strategy with various lengths of divider units.With the highest microporosity and unique functional site,FJU-114 realized a good improvement in the adsorption and separation performance of C_(2)H_(2)/CO_(2).The gas adsorption and lab-scale C_(2)H_(2)/CO_(2)breakthrough experiments demonstrated that FJU-114 exhibits the highest adsorption uptake of 77 cm^(3)/g for C_(2)H_(2),and shows the best separation factor of 4.2 among three MOFs.The GCMC simulation reveals that a stronger adsorption binding site of C_(2)H_(2)in FJU-114a located in the cage II near the unchanged tetranuclear copper node,combined with its high microporosity to achieve the effect of dual functionalities for the improvement performance of C_(2)H_(2)adsorption and separation.展开更多
A programmable multi-modulus frequency divider is designed and implemented in a 0. 35μm CMOS process. The multi-modulus frequency divider is a single chip with two dividers in series,which are divided by 4 or 5 presc...A programmable multi-modulus frequency divider is designed and implemented in a 0. 35μm CMOS process. The multi-modulus frequency divider is a single chip with two dividers in series,which are divided by 4 or 5 prescaler and by 128-255 multi-modulus frequency divider. In the circuit design, power and speed trade-offs are analyzed for the prescaler, and power optimization techniques are used according to the input frequency of each divider cell for the 128-255 multimodulus frequency divider. The chip is designed with ESD protected I/O PAD. The dividers chain can work as high as 2.4GHz with a single ended input signal and beyond 2.6GHz with differential input signals. The dual-modulus prescaler consumes 11mA of current while the 128-255 multi-modulus frequency divider consumes 17mA of current with a 3.3V power supply. The core area of the die without PAD is 0.65mm × 0.3mm. This programmable multi-modulus frequency divider can be used for 2.4GHz ISM band PLL-based frequency synthesizers. To our knowledge, this is the first reported multi-modulus frequency divider with this structure in China.展开更多
An integrated low power CMOS VCO and its divide by 2 dividers for WLAN transceivers are presented.The VCO is based on on chip symmetrical spiral inductor and differential diode and the divide by 2 dividers are b...An integrated low power CMOS VCO and its divide by 2 dividers for WLAN transceivers are presented.The VCO is based on on chip symmetrical spiral inductor and differential diode and the divide by 2 dividers are based on the ILFD technique.Due to differential LC tanks and ILFD techniques,power consumption is low.The circuit is implemented in a 0 18μm CMOS process.Measurements show the proposed circuit could produce 3 6/1 8GHz dual band LO signals with a wide tuning range and low phase noise.1 8GHz LO signals are quadrature.It consumes 5mA at V DD =1 5V.The size of die area is only 1 0mm×1 0mm.展开更多
基金financially supported by the National Natural Science Foundation of China(Nos.21975044,21971038,21922810 and 22271046)the Fujian Provincial Department of Science and Technology(Nos.2023J01355,2023J011106 and 2022R1022001).
文摘Achieving efficient adsorption and separation of C_(2)H_(2)/CO_(2)mixtures is a goal that people have always pursued to improve the situation of high energy consumption brought by traditional separation technologies in industry today.High-nuclearity metal cluster-based MOFs with different functionalities are promising for this separation,but it is a complicated and difficult task to precisely control their structures.The strategy of pore-space partition(PSP)is a powerful way to construct this type MOFs,which has the characteristic of isostructural relationship,and can be resulted in a similar performance for them.Therefore,it is an interesting work to explore the effect of MOFs property by adjusting the size of PSP dividers.Herein,three tetranuclear Cu(Ⅱ)cluster-based MOFs(FJU-112/113/114)with dual functionalities has been successfully obtained by PSP strategy with various lengths of divider units.With the highest microporosity and unique functional site,FJU-114 realized a good improvement in the adsorption and separation performance of C_(2)H_(2)/CO_(2).The gas adsorption and lab-scale C_(2)H_(2)/CO_(2)breakthrough experiments demonstrated that FJU-114 exhibits the highest adsorption uptake of 77 cm^(3)/g for C_(2)H_(2),and shows the best separation factor of 4.2 among three MOFs.The GCMC simulation reveals that a stronger adsorption binding site of C_(2)H_(2)in FJU-114a located in the cage II near the unchanged tetranuclear copper node,combined with its high microporosity to achieve the effect of dual functionalities for the improvement performance of C_(2)H_(2)adsorption and separation.
文摘A programmable multi-modulus frequency divider is designed and implemented in a 0. 35μm CMOS process. The multi-modulus frequency divider is a single chip with two dividers in series,which are divided by 4 or 5 prescaler and by 128-255 multi-modulus frequency divider. In the circuit design, power and speed trade-offs are analyzed for the prescaler, and power optimization techniques are used according to the input frequency of each divider cell for the 128-255 multimodulus frequency divider. The chip is designed with ESD protected I/O PAD. The dividers chain can work as high as 2.4GHz with a single ended input signal and beyond 2.6GHz with differential input signals. The dual-modulus prescaler consumes 11mA of current while the 128-255 multi-modulus frequency divider consumes 17mA of current with a 3.3V power supply. The core area of the die without PAD is 0.65mm × 0.3mm. This programmable multi-modulus frequency divider can be used for 2.4GHz ISM band PLL-based frequency synthesizers. To our knowledge, this is the first reported multi-modulus frequency divider with this structure in China.
文摘An integrated low power CMOS VCO and its divide by 2 dividers for WLAN transceivers are presented.The VCO is based on on chip symmetrical spiral inductor and differential diode and the divide by 2 dividers are based on the ILFD technique.Due to differential LC tanks and ILFD techniques,power consumption is low.The circuit is implemented in a 0 18μm CMOS process.Measurements show the proposed circuit could produce 3 6/1 8GHz dual band LO signals with a wide tuning range and low phase noise.1 8GHz LO signals are quadrature.It consumes 5mA at V DD =1 5V.The size of die area is only 1 0mm×1 0mm.
