In order to characterize the mechanical behaviors of the Velcro~? and Dual-lock fasteners, a series of tests including the butt-joint(BJ) monotonic tensile and shear, mixed tensile-shear with various loading angles, t...In order to characterize the mechanical behaviors of the Velcro~? and Dual-lock fasteners, a series of tests including the butt-joint(BJ) monotonic tensile and shear, mixed tensile-shear with various loading angles, the loading rates effects, the double cantilever beam(DCB) fracture and 180° peel experiments were performed. The tensile and shear tests results showed that the mechanical behaviors of Velcro~? fastener separation are analogous to ductile materials, and those of Dual-lock fasteners are more like brittle ones. The mixed tensile-shear with various loading angles tests results demonstrated that magnitudes of the peak stresses in 30°, 45°, and 60° have no significant differences, which are lower than those in the monotonic tensile or shear tests for the two fasteners. The effects of the loading rate tests show that the peak stresses of the Velcro~? fastener manifested good performance at the loading rate of 10 to 20 mm/min in the tensile and shear conditions, and the Dual-lock did it well around the loading rates of 10 to 20 mm/min in the tensile condition. The cohesive zone model(CZM) is employed to numerical predict the DCB fracture and the 180° peel tests. The CZM predictions results are proven to commendably capture the two tests separation processes, of the tow fasteners, and the numerical results agreed well with the peeling tests data of the Dual lock fasteners. The results and discussions in this study are expected to bring more understanding to engineers and designers about the performance of Velcro~? and Dual lock fasteners.展开更多
Selective activation of Pt(Ⅳ)prodrugs within tumors has emerged as a promising strategy in tumor treatment.Although progress has been made with photo-and ultrasound-activated Pt(Ⅳ)prodrugs,concerns remain over the n...Selective activation of Pt(Ⅳ)prodrugs within tumors has emerged as a promising strategy in tumor treatment.Although progress has been made with photo-and ultrasound-activated Pt(Ⅳ)prodrugs,concerns remain over the non-specific activation of photosensitizers(PS)and the potential for phototoxicity and chemical toxicity.In this study,a sequential dual-locked Pt(Ⅳ)nano-prodrug that can be activated by both the acidic tumor microenvironment and light was developed.The Pt(Ⅳ)prodrug was prepared by conjugating PS-locked Pt(Ⅳ)to a polymeric core,which was then chelated with metallo iron to lock its photoactivity and form a metallo-nano prodrug.Under acidic tumor microenvironment conditions,the metallo-nano prodrug undergoes dissociation of iron,triggering a reduction process in oxaliplatin under light irradiation,resulting in the activation of both chemotherapy and photodynamic therapy(PDT).Additionally,the prodrug could induce metallo-triggered ferroptosis and polarization of tumorassociated macrophages(TAM),thereby enhancing tumor inhibition.The dual-lock strategy employed in a nanoparticle delivery system represents an expansion in the application of platinum-based anticancer drugs,making it a promising new direction in cancer treatment.展开更多
根据CO分子在中红外波段的吸收特性,利用红外热辐射光源(IR55)和双通道热释电探测器(LM244),研制了一种差分式CO检测仪。通过双通道锁相放大器对探测器输出的两路信号进行处理,有效地抑制了系统噪声,提高了仪器的检测精度。介绍了系统...根据CO分子在中红外波段的吸收特性,利用红外热辐射光源(IR55)和双通道热释电探测器(LM244),研制了一种差分式CO检测仪。通过双通道锁相放大器对探测器输出的两路信号进行处理,有效地抑制了系统噪声,提高了仪器的检测精度。介绍了系统的检测原理,给出了光学系统和双通道锁相放大器的实现方案,该锁相放大器能提取的最小标准信号幅度为1 m V,移相误差小于0.2%。利用配备的体积分数为0~1×10^(-3)的CO样品,开展了气体检测实验。实验结果表明:系统的检测下限为1×10^(-5),相对测量误差小于15%。当气体体积分数为0×10^(-6)时,测得浓度的波动范围为-5.2×10^(-6)~6.2×10^(-6)。考虑静态配气时气体在气室中扩散的时间,仪器的响应时间约为58~62 s。同基于量子级联激光器和分布反馈激光器的CO检测仪相比,所研制的仪器具有结构简单、性价比高等优势,在煤矿、环保等场合的CO检测方面具有较好的应用前景。展开更多
谐振式光纤陀螺(R-FOG)是利基于光学Sagnac效应实现高精度的转动检测惯性传感器件。在R-FOG系统中,陀螺信号的处理占有非常重要的地位。根据R-FOG系统中,光纤环形谐振腔的谱线宽度高达几十MHz以及RFOG输出信号具有弱信号、大噪声特点。...谐振式光纤陀螺(R-FOG)是利基于光学Sagnac效应实现高精度的转动检测惯性传感器件。在R-FOG系统中,陀螺信号的处理占有非常重要的地位。根据R-FOG系统中,光纤环形谐振腔的谱线宽度高达几十MHz以及RFOG输出信号具有弱信号、大噪声特点。设计了一种用于提取被噪声淹没的微弱信号的双相位锁相放大器,优点在于不需要进行相位调整。在对双相位锁相放大器各部分电路进行具体设计和分析的基础上,完成了对整体电路的性能测试。测试结果表明,研制的锁相放大器在载波频率为900 k Hz时,将整个电路应用于R-FOG系统中,解调出的信号效果良好,可以实现锁频要求。展开更多
基金Sponsored by the National Natural Science Foundation of China(Grant Nos.10972200 and 11172270)
文摘In order to characterize the mechanical behaviors of the Velcro~? and Dual-lock fasteners, a series of tests including the butt-joint(BJ) monotonic tensile and shear, mixed tensile-shear with various loading angles, the loading rates effects, the double cantilever beam(DCB) fracture and 180° peel experiments were performed. The tensile and shear tests results showed that the mechanical behaviors of Velcro~? fastener separation are analogous to ductile materials, and those of Dual-lock fasteners are more like brittle ones. The mixed tensile-shear with various loading angles tests results demonstrated that magnitudes of the peak stresses in 30°, 45°, and 60° have no significant differences, which are lower than those in the monotonic tensile or shear tests for the two fasteners. The effects of the loading rate tests show that the peak stresses of the Velcro~? fastener manifested good performance at the loading rate of 10 to 20 mm/min in the tensile and shear conditions, and the Dual-lock did it well around the loading rates of 10 to 20 mm/min in the tensile condition. The cohesive zone model(CZM) is employed to numerical predict the DCB fracture and the 180° peel tests. The CZM predictions results are proven to commendably capture the two tests separation processes, of the tow fasteners, and the numerical results agreed well with the peeling tests data of the Dual lock fasteners. The results and discussions in this study are expected to bring more understanding to engineers and designers about the performance of Velcro~? and Dual lock fasteners.
基金supported by the Jiangsu Province Postgraduate Research Innovation Program and Jiangsu Province Postgraduate Practice Innovation Program Fund(021093002589,China)National Key Research and Development Program of China(2023YFB3813001)National Natural Science Foundation of China(52073145).
文摘Selective activation of Pt(Ⅳ)prodrugs within tumors has emerged as a promising strategy in tumor treatment.Although progress has been made with photo-and ultrasound-activated Pt(Ⅳ)prodrugs,concerns remain over the non-specific activation of photosensitizers(PS)and the potential for phototoxicity and chemical toxicity.In this study,a sequential dual-locked Pt(Ⅳ)nano-prodrug that can be activated by both the acidic tumor microenvironment and light was developed.The Pt(Ⅳ)prodrug was prepared by conjugating PS-locked Pt(Ⅳ)to a polymeric core,which was then chelated with metallo iron to lock its photoactivity and form a metallo-nano prodrug.Under acidic tumor microenvironment conditions,the metallo-nano prodrug undergoes dissociation of iron,triggering a reduction process in oxaliplatin under light irradiation,resulting in the activation of both chemotherapy and photodynamic therapy(PDT).Additionally,the prodrug could induce metallo-triggered ferroptosis and polarization of tumorassociated macrophages(TAM),thereby enhancing tumor inhibition.The dual-lock strategy employed in a nanoparticle delivery system represents an expansion in the application of platinum-based anticancer drugs,making it a promising new direction in cancer treatment.
文摘根据CO分子在中红外波段的吸收特性,利用红外热辐射光源(IR55)和双通道热释电探测器(LM244),研制了一种差分式CO检测仪。通过双通道锁相放大器对探测器输出的两路信号进行处理,有效地抑制了系统噪声,提高了仪器的检测精度。介绍了系统的检测原理,给出了光学系统和双通道锁相放大器的实现方案,该锁相放大器能提取的最小标准信号幅度为1 m V,移相误差小于0.2%。利用配备的体积分数为0~1×10^(-3)的CO样品,开展了气体检测实验。实验结果表明:系统的检测下限为1×10^(-5),相对测量误差小于15%。当气体体积分数为0×10^(-6)时,测得浓度的波动范围为-5.2×10^(-6)~6.2×10^(-6)。考虑静态配气时气体在气室中扩散的时间,仪器的响应时间约为58~62 s。同基于量子级联激光器和分布反馈激光器的CO检测仪相比,所研制的仪器具有结构简单、性价比高等优势,在煤矿、环保等场合的CO检测方面具有较好的应用前景。
文摘谐振式光纤陀螺(R-FOG)是利基于光学Sagnac效应实现高精度的转动检测惯性传感器件。在R-FOG系统中,陀螺信号的处理占有非常重要的地位。根据R-FOG系统中,光纤环形谐振腔的谱线宽度高达几十MHz以及RFOG输出信号具有弱信号、大噪声特点。设计了一种用于提取被噪声淹没的微弱信号的双相位锁相放大器,优点在于不需要进行相位调整。在对双相位锁相放大器各部分电路进行具体设计和分析的基础上,完成了对整体电路的性能测试。测试结果表明,研制的锁相放大器在载波频率为900 k Hz时,将整个电路应用于R-FOG系统中,解调出的信号效果良好,可以实现锁频要求。
