• Transactions on Electrical and Electronic Materials
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• 제11권1호
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• pp.24-28
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• 2010

A simulation study of a current-mode direct current (DC)-DC buck converter is presented in this paper. The converter, with a fully integrated power module, is implemented by using sense method metal-oxide-semiconductor field-effect transistor (MOSFET) and bipolar complementary metal-oxide-semiconductor (BiCMOS) technology. When the MOSFET is used in a current sensor, the sensed inductor current with an internal ramp signal can be used for feedback control. In addition, the BiCMOS technology is applied in the converter for an accurate current sensing and a low power consumption. The DC-DC converter is designed using the standard $0.35\;{\mu}m$ CMOS process. An off-chip LC filter is designed with an inductance of 1 mH and a capacitance of 12.5 nF. The simulation results show that the error between the sensing signal and the inductor current can be controlled to be within 3%. The characteristics of the error amplification and output ripple are much improved, as compared to converters using conventional CMOS circuits.

• Animal Bioscience
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• 제34권3_spc호
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• pp.457-462
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• 2021

Objective: The aim of this study was to investigate the effects of Enteromorpha powder supplementation on reproduction-related hormones and genes in the late laying period of Zi geese. Methods: A total of 312 (1-year-old) Zi geese with similar laying rate were randomly divided into 2 groups with 6 replicates each, each with 21 female geese and 5 male geese. The control group was fed with a basal diet and the test group was fed with a diet containing 3% Enteromorpha powder. The trial period lasted for 7 weeks. Results: Our results showed that the laying rate was improved in the test group at each week of trial (p<0.01), and the levels of estradiol in serum and prolactin in ovary were increased compared with the control group (p<0.05). Conclusion: Based on above results, Enteromorpha powder supplementation at 3% could promote reproductive performance during the late laying period of Zi geese.

• Journal of Semiconductor Engineering
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• 제3권2호
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• pp.161-167
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• 2022

Electrical characteristics of LDMOS power device with LDD(Lightly Doped Drain) structure is studied with variation of the region of channel and LDD. The channel in LDMOSFET encloses a junction-type source and is believed to be an important parameter for determining the circuit operation of CMOS inverter. Two-dimensional TCAD MEDICI simulation is used to study hot-carrier effect, on-resistance Ron, breakdown voltage, and transient switching characteristic. The voltage-transfer characteristics and on-off switching properties are studied as a function of the channel length and doping levels. The digital logic levels of the output and input voltages are analyzed from the transfer curves and circuit operation. Study indicates that drain current significantly depends on the channel length rather than the LDD region, while the switching transient time is almost independent of the channel length. The high and low logic levels of the input voltage showed a strong dependency on the channel length, while the lateral substrate resistance from a latch-up path in the CMOS inverter was comparable to that of a typical CMOS inverter with a guard ring.

• Nuclear Engineering and Technology
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• 제54권11호
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• pp.4134-4145
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• 2022

The collimator is one of the high-heat-flux components used to avoid a series of vacuum and thermal problems. In this paper, the heat load distribution throughout the collimator is first calculated through experimental data, and a transient thermodynamic simulation analysis of the original model is carried out. The error of the pipe outlet temperature between the simulated and experimental values is 1.632%, indicating that the simulation result is reliable. Second, the model is optimized to improve the heat transfer performance of the collimator, including the contact mode between the pipe and the flange, the pipe material and the addition of a twisted tape in the pipe. It is concluded that the convective heat transfer coefficient of the optimized model is increased by 15.381% and the maximum wall temperature is reduced by 16.415%; thus, the heat transfer capacity of the optimized model is effectively improved. Third, to adapt the long-pulse steady-state operation of the experimental advanced superconducting Tokamak (EAST) in the future, steady-state simulations of the original and optimized collimators are carried out. The results show that the maximum temperature of the optimized model is reduced by 37.864% compared with that of the original model. The optimized model was changed as little as possible to obtain a better heat exchange structure on the premise of ensuring the consumption of the same mass flow rate of water so that the collimator can adapt to operational environments with higher heat fluxes and long pulses in the future. These research methods also provide a reference for the future design of components under high-energy and long-pulse operational conditions.

• 한국철학논집
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• 제28호
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• pp.447-476
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• 2010

1990년대 중국의 지식인들은 세계화된 자본주의 체제에 편입되고 자본의 지배가 심화되는 중국 사회의 변화에 직면했고 이를 설명해야 했다. 신좌파는 중국에서 자본주의적 발전이 가속화되는 현실에 문제를 제기했고, 신자유주의와의 논쟁은 1990년대 사상계의 큰 쟁점이 되었다. 이들은 '개혁'은 자유방임적이며 부가 집중되는 자본주의가 아닌 정치와 경제의 민주의 확대를 통해 사회분배의 공정성을 보장하여 빈부의 격차가 확대되는 것을 피해야 하는 것이며, '개방'은 자본의 논리를 무조건 받아들여 세계화된 자본주의 체계로 편입되는 것이 아닌 차이와 다원성의 문제를 고민해야 하는 것임을 주장한다. 이를 위해 서구 중심의 '계몽'과 '현대성'을 재검토하고, 모택동 사회주의를 재평가하며, 이를 기반으로 개혁개방 이후의 사회주의를 비판한다. 신좌파는 특히 계몽과 현대성이 어떻게 인식되었고, 어떻게 이해되어야 하는지를 깊이 있게 논의한다. 지금까지 중국에서의 계몽이 서구화와 동일하게 생각되었음을 반성하고, 현대성에 내재한 모순을 극복하려는 노력이 중국의 역사 속에 존재함을 강조한다. 그리고 이로부터 자본주의와 사회주의, 서양과 중국, 전통과 현대의 낡은 이분법을 넘어서 새로운 전망과 대안을 모색한다.