The reservoir-monolithic type of the controlled release systems is investigated currently,however,the existing kinetic model could not describe the release process well because the release kinetics is rather complicat...The reservoir-monolithic type of the controlled release systems is investigated currently,however,the existing kinetic model could not describe the release process well because the release kinetics is rather complicated.In this paper,a simplified release kinetic model for diffusion-controlled monolithic matrix coated with outer membrane systems is proposed and verified by the experimental data of mercaptopurinum release experiment.It shows that the model can well describe the release mechanism (the relative error is under 3%) when drug loading (C d) is above its solubility limit (C s).At the same time,the release characteristics of special cases (D mD f and D mD f) are discussed theoretically.When D mD f the release rate becomes constant,namely,zero order release,and the release rate is independent of the drug membrane.This result provides the theoretical basis for the system of zero order release as well as how to control the release rate and the amount of drug release.When D mD f,the release rate is dependent on the drug release coefficient in the monolithic matrix,solubility and drug loading but independent of the process in the outer membrane,and it is similar to monolithic matrix type.展开更多
A 2. 4GHz CMOS monolithic transceiver front-end for IEEE 802. llb wireless LAN applications is presented. The receiver and transmitter are both of superheterodyne structure for good system performance. The frontend co...A 2. 4GHz CMOS monolithic transceiver front-end for IEEE 802. llb wireless LAN applications is presented. The receiver and transmitter are both of superheterodyne structure for good system performance. The frontend consists of five blocks., low noise amplifier,down-converter, up-converter, pre-amplifier, and LO buffer. Their input/output impedance are all on-chip matched to 50 Ω except the down-converter which has open-drain outputs. The transceiver RF front-end has been implemented in a 0. 18μm CMOS process. When the LNA and the down-converter are directly connected, the measured noise figure is 5.2dB, the measured available power gain 12. 5dB, the input l dB compression point --18dBm,and the third-order input intercept point --7dBm. The receiver front-end draws 13.6mA currents from the 1.8V power supply. When the up-converter and pre-amplifier are directly connected, the measured noise figure is 12.4dB, the power gain is 23. 8dB, the output ldB compression point is 1.5dBm, and the third-order output intercept point is 16dBm. The transmitter consumes 27.6mA current from the 1.8V power supply.展开更多
A 4-12GHz wideband power amplifier,using a balanced configuration with a strip line Lange coupler, is designed and fabricated. This power amplifier shows a maximum continuous wave output power of 29.5dBm at 8GHz cente...A 4-12GHz wideband power amplifier,using a balanced configuration with a strip line Lange coupler, is designed and fabricated. This power amplifier shows a maximum continuous wave output power of 29.5dBm at 8GHz center frequency with an associated gain of 8.5dB and a gain flatness of ＋ /- 0.6dB in the 4-12GHz frequency range.展开更多
文摘The reservoir-monolithic type of the controlled release systems is investigated currently,however,the existing kinetic model could not describe the release process well because the release kinetics is rather complicated.In this paper,a simplified release kinetic model for diffusion-controlled monolithic matrix coated with outer membrane systems is proposed and verified by the experimental data of mercaptopurinum release experiment.It shows that the model can well describe the release mechanism (the relative error is under 3%) when drug loading (C d) is above its solubility limit (C s).At the same time,the release characteristics of special cases (D mD f and D mD f) are discussed theoretically.When D mD f the release rate becomes constant,namely,zero order release,and the release rate is independent of the drug membrane.This result provides the theoretical basis for the system of zero order release as well as how to control the release rate and the amount of drug release.When D mD f,the release rate is dependent on the drug release coefficient in the monolithic matrix,solubility and drug loading but independent of the process in the outer membrane,and it is similar to monolithic matrix type.
文摘A 2. 4GHz CMOS monolithic transceiver front-end for IEEE 802. llb wireless LAN applications is presented. The receiver and transmitter are both of superheterodyne structure for good system performance. The frontend consists of five blocks., low noise amplifier,down-converter, up-converter, pre-amplifier, and LO buffer. Their input/output impedance are all on-chip matched to 50 Ω except the down-converter which has open-drain outputs. The transceiver RF front-end has been implemented in a 0. 18μm CMOS process. When the LNA and the down-converter are directly connected, the measured noise figure is 5.2dB, the measured available power gain 12. 5dB, the input l dB compression point --18dBm,and the third-order input intercept point --7dBm. The receiver front-end draws 13.6mA currents from the 1.8V power supply. When the up-converter and pre-amplifier are directly connected, the measured noise figure is 12.4dB, the power gain is 23. 8dB, the output ldB compression point is 1.5dBm, and the third-order output intercept point is 16dBm. The transmitter consumes 27.6mA current from the 1.8V power supply.
文摘A 4-12GHz wideband power amplifier,using a balanced configuration with a strip line Lange coupler, is designed and fabricated. This power amplifier shows a maximum continuous wave output power of 29.5dBm at 8GHz center frequency with an associated gain of 8.5dB and a gain flatness of ＋ /- 0.6dB in the 4-12GHz frequency range.
