A multimode interference(MMI)structure is designed to simplify the fabrication of quantum cascade laser(QCL)phase-locked arrays.The MMI geometry is optimized with a sufficient output channel distance to accommodate co...A multimode interference(MMI)structure is designed to simplify the fabrication of quantum cascade laser(QCL)phase-locked arrays.The MMI geometry is optimized with a sufficient output channel distance to accommodate conventional photolithography and wet etching process by which power amplifier array is fabricated without using the complicated two-step etching-regrowth or dry etching technique.The far-field pattern with periodically modulated peaks reveals that the beams from the arrays are phase-locked.Furthermore,the frequency tuning performance of the MMI-based phase-locked arrays is studied using the Littrow-configuration external cavity structure.A wavelength tuning range of more than 60 cm^(−1) is demonstrated,which will eventually realize the high power,frequency tunable,large-scale phase-locked arrays,and their application in spectroscopy.展开更多
To investigate the design strategy of highly loaded tandem cascades at both the midspan and endwall,the overall performance and flow mechanisms of four typical tandem cascades based on the optimization were analyzed f...To investigate the design strategy of highly loaded tandem cascades at both the midspan and endwall,the overall performance and flow mechanisms of four typical tandem cascades based on the optimization were analyzed from multiple perspectives numerically.The results show that the interference effects on the Front Blade(FB)and Rear Blade(RB)should not be overlooked during the design phase,and the design strategies at the midspan and endwall are completely different.At the midspan,the optimization aims to increase the interference effects and the strength of the gap jet while maintaining the same load on the FB and RB.However,the endwall optimal airfoil exhibits weakening interference effects,advancement of the gap jet location,and load transfer from the FB to RB.Through further analysis of flow characteristics,the midspan optimal airfoil is beneficial for inhibiting the low-energy fluid from interacting with the suction surface of RB under the design condition,but results in earlier occurrence of corner stall.The endwall optimal airfoil helps suppress the development of the secondary flow and delay the onset of corner stall.Furthermore,by combining the benefits of these two design approaches,additional forward sweep effects are achieved,further enhancing the performance of the tandem cascade.展开更多
In this paper, rejection of multiple narrowband interferers in a binary phase shift keying modulated orthogonal frequency division multiplexing (BPSK-OFDM) system is investigated. The BPSK-OFDM system in consideration...In this paper, rejection of multiple narrowband interferers in a binary phase shift keying modulated orthogonal frequency division multiplexing (BPSK-OFDM) system is investigated. The BPSK-OFDM system in consideration operates in an additive white Gaussian noise (AWGN) channel. A cascade complex coefficient adaptive infinite impulse response (IIR) notch filter with gradient-based algorithm is used to reject the interferers. Bit error ratio (BER) performance of the system is studied and a general closed-form expression is derived assuming negligible steady-state leakage NBI and by estimating the decision variable as Gaussian distributed based on Central Limit Theorem (CLT). Dependence of the BER performance on the notch bandwidth coefficient is demonstrated by the analysis. Extensive simulation results are included to substantiate accuracy of the analysis.展开更多
A new kind of tunable optical filter is proposed for DWDM optical communication application. It is based on cascaded polarization interference filter (PIF). The period and bandpass width of each PIF are decided by its...A new kind of tunable optical filter is proposed for DWDM optical communication application. It is based on cascaded polarization interference filter (PIF). The period and bandpass width of each PIF are decided by its optical path difference between o-ray and e-ray (OPDOE). When their OPDOEs are proportionately designed, the tuning range and bandpass width depend on OPDOE in the first and the last PIF, respectively. The tuning range, bandpass width and crosstalk are independent each other. The crosstalk is related to the OPDOE ratios among PIFs and can be suppressed by designing the PIF's OPDOE. A set of OPDOE is suggested that are l1, 2 × l1, 22 ×l1, 23 ×l1, 24 ×l1, ..., 2N-4 × l1, 15 × 2N-7 ×l1, 10 × 2N-6 × l1 and 2N-2 ×l1 from the first to the last. This suggested OPDOEs can yield -50-dB crosstalk for any tuning range and bandpass width. The insert loss is less than 1 dB. As its loose alignment requirement, there is no limitation on cascaded PIF number. When 11 PIFs are cascaded, it can achieve 170-nm tuning range, -50-dB crosstalk, bandpass width applicable to 25-GHz channel spacing and 1 dB insert loss.展开更多
Glucose oxidase(GOx)-based starvation therapy has emerged as a promising strategy in tumor therapy.However,the non-specific catalytic activity and premature degradation of GOx during systemic circulation have limited ...Glucose oxidase(GOx)-based starvation therapy has emerged as a promising strategy in tumor therapy.However,the non-specific catalytic activity and premature degradation of GOx during systemic circulation have limited its therapeutic efficacy in tumor regions.In this study,we present the synthesis of ultrasound/glutathione dual-responsive ZIF-8-GOx@copper-polydopamine@liposome-L-arginine(ZGCLL)nanoparticles,designed to concurrently achieve ion interference therapy,starvation therapy,and ultrasound-catalyzed gas therapy.The ZIF-8-GOx nanoparticles are prepared via a co-precipitation method,followed by the encapsulation of a copper-polydopamine(Cu-PDA)shell on the particle surface.Subsequently,liposomes and L-arginine are incorporated to form ZGCLL.The Cu-PDA shell exhibits responsiveness to the elevated level of glutathione in tumor microenvironment,leading to its degradation,mitigating the risk of unintended degradation and“off-target”effect of GOx in normal tissues.The exposure of ZIF-8 results in zinc overload and activates the catalytic reaction of GOx.The consequent depletion of glucose facilitates starvation therapy,while the generated H2O2,in synergy with zinc ions,intensifies oxidative stress.H_(2)O_(2)can produce more potent reactive oxygen species when exposed to ultrasound,which subsequently react with L-arginine to generate higher levels of nitric oxide for gas therapy.Both in vitro and in vivo studies demonstrate that this platform achieves precise and efficient antitumor effects.This research offers an innovative strategy for the development of cascade catalytic reaction systems and targeted therapeutic platforms.展开更多
基金supported by the National Basic Research Program of China(Grant Nos.2018YFA0209103 and 2018YFB2200504)the National Natural Science Foundation of China(Grant Nos.61991430,61774146,61790583,61674144,61774150,and 61805168)+1 种基金the Beijing Municipal Science&Technology Commission,China(Grant No.Z201100004020006)the Key Projects of the Chinese Academy of Sciences(Grant Nos.2018147,YJKYYQ20190002,QYZDJ-SSW-JSC027,and XDB43000000).
文摘A multimode interference(MMI)structure is designed to simplify the fabrication of quantum cascade laser(QCL)phase-locked arrays.The MMI geometry is optimized with a sufficient output channel distance to accommodate conventional photolithography and wet etching process by which power amplifier array is fabricated without using the complicated two-step etching-regrowth or dry etching technique.The far-field pattern with periodically modulated peaks reveals that the beams from the arrays are phase-locked.Furthermore,the frequency tuning performance of the MMI-based phase-locked arrays is studied using the Littrow-configuration external cavity structure.A wavelength tuning range of more than 60 cm^(−1) is demonstrated,which will eventually realize the high power,frequency tunable,large-scale phase-locked arrays,and their application in spectroscopy.
基金sponsored by the National Natural Science Foundation of China(Nos.52106057 and 92152301)the Fundamental Research Funds for the Central Universities,China(No.D5000210483)+2 种基金the Foundation of State Level Key Laboratory of Airfoil and Cascade Aerodynamics,China(Nos.D5150210006 and D5050220008)the 111 Project,China(No.B17037)the Key Laboratory of Flow Visualization and Measurement Techniques,AVIC Aerodynamics Research Institute,China(No.D5110220177).
文摘To investigate the design strategy of highly loaded tandem cascades at both the midspan and endwall,the overall performance and flow mechanisms of four typical tandem cascades based on the optimization were analyzed from multiple perspectives numerically.The results show that the interference effects on the Front Blade(FB)and Rear Blade(RB)should not be overlooked during the design phase,and the design strategies at the midspan and endwall are completely different.At the midspan,the optimization aims to increase the interference effects and the strength of the gap jet while maintaining the same load on the FB and RB.However,the endwall optimal airfoil exhibits weakening interference effects,advancement of the gap jet location,and load transfer from the FB to RB.Through further analysis of flow characteristics,the midspan optimal airfoil is beneficial for inhibiting the low-energy fluid from interacting with the suction surface of RB under the design condition,but results in earlier occurrence of corner stall.The endwall optimal airfoil helps suppress the development of the secondary flow and delay the onset of corner stall.Furthermore,by combining the benefits of these two design approaches,additional forward sweep effects are achieved,further enhancing the performance of the tandem cascade.
文摘In this paper, rejection of multiple narrowband interferers in a binary phase shift keying modulated orthogonal frequency division multiplexing (BPSK-OFDM) system is investigated. The BPSK-OFDM system in consideration operates in an additive white Gaussian noise (AWGN) channel. A cascade complex coefficient adaptive infinite impulse response (IIR) notch filter with gradient-based algorithm is used to reject the interferers. Bit error ratio (BER) performance of the system is studied and a general closed-form expression is derived assuming negligible steady-state leakage NBI and by estimating the decision variable as Gaussian distributed based on Central Limit Theorem (CLT). Dependence of the BER performance on the notch bandwidth coefficient is demonstrated by the analysis. Extensive simulation results are included to substantiate accuracy of the analysis.
文摘A new kind of tunable optical filter is proposed for DWDM optical communication application. It is based on cascaded polarization interference filter (PIF). The period and bandpass width of each PIF are decided by its optical path difference between o-ray and e-ray (OPDOE). When their OPDOEs are proportionately designed, the tuning range and bandpass width depend on OPDOE in the first and the last PIF, respectively. The tuning range, bandpass width and crosstalk are independent each other. The crosstalk is related to the OPDOE ratios among PIFs and can be suppressed by designing the PIF's OPDOE. A set of OPDOE is suggested that are l1, 2 × l1, 22 ×l1, 23 ×l1, 24 ×l1, ..., 2N-4 × l1, 15 × 2N-7 ×l1, 10 × 2N-6 × l1 and 2N-2 ×l1 from the first to the last. This suggested OPDOEs can yield -50-dB crosstalk for any tuning range and bandpass width. The insert loss is less than 1 dB. As its loose alignment requirement, there is no limitation on cascaded PIF number. When 11 PIFs are cascaded, it can achieve 170-nm tuning range, -50-dB crosstalk, bandpass width applicable to 25-GHz channel spacing and 1 dB insert loss.
基金supported by the National Natural Science Foundation of China(No.52172289)Fundamental Research Funds for the Central Universities,Beijing Life Science Academy(BLSA,No:2023400CA0100)the Funds of the Natural Science Foundation of Hangzhou under Grant No.2024SZRYBH180004.
文摘Glucose oxidase(GOx)-based starvation therapy has emerged as a promising strategy in tumor therapy.However,the non-specific catalytic activity and premature degradation of GOx during systemic circulation have limited its therapeutic efficacy in tumor regions.In this study,we present the synthesis of ultrasound/glutathione dual-responsive ZIF-8-GOx@copper-polydopamine@liposome-L-arginine(ZGCLL)nanoparticles,designed to concurrently achieve ion interference therapy,starvation therapy,and ultrasound-catalyzed gas therapy.The ZIF-8-GOx nanoparticles are prepared via a co-precipitation method,followed by the encapsulation of a copper-polydopamine(Cu-PDA)shell on the particle surface.Subsequently,liposomes and L-arginine are incorporated to form ZGCLL.The Cu-PDA shell exhibits responsiveness to the elevated level of glutathione in tumor microenvironment,leading to its degradation,mitigating the risk of unintended degradation and“off-target”effect of GOx in normal tissues.The exposure of ZIF-8 results in zinc overload and activates the catalytic reaction of GOx.The consequent depletion of glucose facilitates starvation therapy,while the generated H2O2,in synergy with zinc ions,intensifies oxidative stress.H_(2)O_(2)can produce more potent reactive oxygen species when exposed to ultrasound,which subsequently react with L-arginine to generate higher levels of nitric oxide for gas therapy.Both in vitro and in vivo studies demonstrate that this platform achieves precise and efficient antitumor effects.This research offers an innovative strategy for the development of cascade catalytic reaction systems and targeted therapeutic platforms.
