5 GHz Optical Front End in 0.35um CMOS

With the advantages of low cost, low power consumption, high reliability and potential for large scale integration, CMOS monolithically integrated active pixel chips have significant application in optical sensing systems. The optical front end presented in this thesis will have application in Optical Scanning Acoustic Microscope System (O-SAM), which involves a totally non-contact method of acquiring images of the interaction between surface acoustic waves (SAWs) and a solid material to be characterized. In this work, an ultra fast optical front-end using improved regulated cascade scheme is developed based on AMS 0.35mm CMOS technology. The receiver consists of an integrated photodiode, a transimpedance amplifier, a mixer, an IF amplifier and an output buffer. By treating the n-well in standard CMOS technology as a screening terminal to block the slow photo-generated bulk carriers and interdigitizing shallow p+ junctions as the active region, the integrated photodiode operates up to 4.9 GHz with no process modification. Its responsivity was measured to be 0.016 A/W. With multi-inductive-series peaking technique, the improved ReGulated-Cascade (RGC) transimpedance amplifier achieves an experimentally measured -3dB bandwidth of more than 6 GHz and a transimpedance gain of 51 dBW, which is the fastest reported TIA in CMOS 0.35mm technology. The 5 GHz Gilbert cell mixer produces a conversion gain of 11 dB, which greatly minimized the noise contribution from the IF stage. The noise figure and input IIP3 of the mixer were measured to be 15.7 dB and 1.5 dBm, respectively. The IF amplifier and output buffer pick up and further amplify the signal for post processing. The optical front end demonstrates a typical equivalent input noise current of 35 pA=pHz at 5 GHz, and a total transimpedance gain of 83 dB ohm whileconsuming a total current of 40 mA from 3.3 V power supply. The -3 dB bandwidth for the optical front end was measured to be 4.9 GHz. All the prototype chips, including the optical front end, and the individual circuits including the photodiode, TIA, mixer were probe-tested and all the measurements were taken with Anritsu VNA 37397D and Anritsu spectrum analyser MS2721A

5 GHz Optical Front End in 0.35um CMOS

With the advantages of low cost, low power consumption, high reliability and potential for large scale integration, CMOS monolithically integrated active pixel chips have significant application in optical sensing systems. The optical front end presented in this thesis will have application in Optical Scanning Acoustic Microscope System (O-SAM), which involves a totally non-contact method of acquiring images of the interaction between surface acoustic waves (SAWs) and a solid material to be characterized. In this work, an ultra fast optical front-end using improved regulated cascade scheme is developed based on AMS 0.35mm CMOS technology. The receiver consists of an integrated photodiode, a transimpedance amplifier, a mixer, an IF amplifier and an output buffer. By treating the n-well in standard CMOS technology as a screening terminal to block the slow photo-generated bulk carriers and interdigitizing shallow p+ junctions as the active region, the integrated photodiode operates up to 4.9 GHz with no process modification. Its responsivity was measured to be 0.016 A/W. With multi-inductive-series peaking technique, the improved ReGulated-Cascade (RGC) transimpedance amplifier achieves an experimentally measured -3dB bandwidth of more than 6 GHz and a transimpedance gain of 51 dBW, which is the fastest reported TIA in CMOS 0.35mm technology. The 5 GHz Gilbert cell mixer produces a conversion gain of 11 dB, which greatly minimized the noise contribution from the IF stage. The noise figure and input IIP3 of the mixer were measured to be 15.7 dB and 1.5 dBm, respectively. The IF amplifier and output buffer pick up and further amplify the signal for post processing. The optical front end demonstrates a typical equivalent input noise current of 35 pA=pHz at 5 GHz, and a total transimpedance gain of 83 dB ohm whileconsuming a total current of 40 mA from 3.3 V power supply. The -3 dB bandwidth for the optical front end was measured to be 4.9 GHz. All the prototype chips, including the optical front end, and the individual circuits including the photodiode, TIA, mixer were probe-tested and all the measurements were taken with Anritsu VNA 37397D and Anritsu spectrum analyser MS2721A

2D Materials Graphene related materials for thermal management Graphene related materials for thermal management

International audienceAlmost 15 years have gone ever since the discovery of graphene as a single atom layer. Numerous papers have been published to demonstrate its high electron mobility, excellent thermal and mechanical as well as optical properties. We have recently seen more and more applications towards using graphene in commercial products. This paper is an attempt to review and summarize the current status of the research of the thermal properties of graphene and other 2D based materials including the manufacturing and characterization techniques and their applications, especially in electronics and power modules. It is obvious from the review that graphene has penetrated the market and gets more and more applications in commercial electronics thermal management context. In the paper, we also made a critical analysis of how mature the manufacturing processes are; what are the accuracies and challenges with the various characterization techniques and what are the remaining questions and issues left before we see further more applications in this exciting and fascinating field. TOPICAL REVIE

Rigid–Flexible Contact Analysis of an Inflated Membrane Balloon with Various Contact Conditions

Considering the Mooney–Rivlin hyperelastic model, a semi-analytical approach is introduced to analyze the rigid–flexible contact behavior of an inflated membrane balloon between two plates with various interface conditions. This approach is based on differential formulation, and the coupling properties of equilibrium equations are well-solved. In order to verify the reliability of the proposed theoretical model, an experimental test was designed, by which some important contact characteristics and patterns (no-slip condition) were obtained. Two special phenomena were observed for the meridian stretch ratio with different friction coefficients. One is that the intersection points of all curves fall in a small interval, and the intersection of any two curves represents the same changing rate of the horizontal ordinate, resulting in the maximum difference. The other is the dividing point, where the stretch ratio decreases on the left and increases on the right due to the introduction of friction. These results provide solid guidance and support for our understanding of the rigid–flexible contact behavior of inflated membrane balloons

Study on Biological Characteristics and Mechanism of Paclitaxel Induced Drug Resistance in Endometrial Carcinoma Cells

Objective. To study the biological characteristics of paclitaxel resistant endometrial carcinoma cells and its mechanism of drug resistance. Method. The paclitaxel resistant cell lines were established by high-dose paclitaxel (TAX) injection. The IC50 of paclitaxel was determined by CCK-8 assay in Ishikawa and Ishikawa-TAX. The cell cycle and apoptosis rate were detected by flow cytometry. Western blot was used to detect the expression of p-AKT and p-p70S6K. The expression of drug resistance-related genes Pgp and MDR1 was determined by RT-PCR. Cell viability was determined by soft agarose assay and invasive ability in vitro by transwell assay. Results. Paclitaxel and NVP-BEZ235 cotreatment group can further inhibit the clonogenicity and invasion of Ishikawa and Ishikawa-TAX cells compared with paclitaxel alone and NVP-BEZ235 treatment group. Paclitaxel and NVP-BEZ235 cotreated groups increased the apoptosis rate of Ishikawa and increased G0/G1 phase arrest in both cells. Paclitaxel alone significantly inhibited p-AK and p-p70 S6K protein expression in Ishikawa and Ishikawa-TAX cells and the inhibition was enhanced by NVP-BEZ235 when cotreated with paclitaxel. Conclusion. Paclitaxel can inhibit Ishikawa and Ishikawa-TAX cell via PI3K/Akt/mTOR signaling pathway. Paclitaxel and NVP-BEZ235 cotreatment can enhance the inhibitory effect

Study of interwall interaction during the pull separation of ultra-long double-walled carbon nanotubes under lateral loading

The successful fabrication of ultra-long carbon nanotubes (CNTs) makes CNTs ideal candidates for bearing systems due to the long sliding distance with low interwall interaction. However, it is difficult to measure the pull-out forces of ultra-long CNTs along their axes in real-time because of the difficulty of performing long-distance pull-out experiments. In this study, we proposed a lateral loading method to measure the interwall interaction force of ultra-long CNTs. By using a theoretical model and multi-scale finite element simulations, we could predict the interwall interaction force from the pull-out force in lateral loading. This pull-out force depends on the length of CNTs, and a critical length divides the pull-out force into two categories: maximum pull-out force due to local buckling and steady pull-out force due to sliding. In order to correctly measure the interwall interaction force by lateral loading, for the DWCNTs with the outer tube diameter of 0.955 nm, we have to make sure the lengths are greater than this critical value (54.2 nm) as experimental subjects. (c) 2023 Elsevier Ltd. All rights reserved

Characterization of Initial Parameter Information for Lifetime Prediction of Electronic Devices.

Newly manufactured electronic devices are subject to different levels of potential defects existing among the initial parameter information of the devices. In this study, a characterization of electromagnetic relays that were operated at their optimal performance with appropriate and steady parameter values was performed to estimate the levels of their potential defects and to develop a lifetime prediction model. First, the initial parameter information value and stability were quantified to measure the performance of the electronics. In particular, the values of the initial parameter information were estimated using the probability-weighted average method, whereas the stability of the parameter information was determined by using the difference between the extrema and end points of the fitting curves for the initial parameter information. Second, a lifetime prediction model for small-sized samples was proposed on the basis of both measures. Finally, a model for the relationship of the initial contact resistance and stability over the lifetime of the sampled electromagnetic relays was proposed and verified. A comparison of the actual and predicted lifetimes of the relays revealed a 15.4% relative error, indicating that the lifetime of electronic devices can be predicted based on their initial parameter information

Study of interwall interaction during the pull separation of ultra-long double-walled carbon nanotubes under lateral loading

The successful fabrication of ultra-long carbon nanotubes (CNTs) makes CNTs ideal candidates for bearing systems due to the long sliding distance with low interwall interaction. However, it is difficult to measure the pull-out forces of ultra-long CNTs along their axes in real-time because of the difficulty of performing long-distance pull-out experiments. In this study, we proposed a lateral loading method to measure the interwall interaction force of ultra-long CNTs. By using a theoretical model and multi-scale finite element simulations, we could predict the interwall interaction force from the pull-out force in lateral loading. This pull-out force depends on the length of CNTs, and a critical length divides the pull-out force into two categories: maximum pull-out force due to local buckling and steady pull-out force due to sliding. In order to correctly measure the interwall interaction force by lateral loading, for the DWCNTs with the outer tube diameter of 0.955 nm, we have to make sure the lengths are greater than this critical value (54.2 nm) as experimental subjects. (c) 2023 Elsevier Ltd. All rights reserved

Mathematical derivation of simplified calculation of symmetrical Green function

[Objectives] This paper studies the way to reduce the elements used for calculating the hydrodynamic coefficient for movement of a large floating body with boundary element method and to quicken the calculation.[Methods] Based on the characteristic of the symmetrical floating body that the coefficient matrix can be considered as a circulant matrix during solvement of source intensity of singular point,a simplified calculation method of symmetrical Green function is proposed. Besides,detailed mathematical derivation is carried out and the physical meanings are explained.[Results] It is found that, through this method, the process of solving the hydrodynamic coefficient for wave movement of symmetrical floating body can be quickened significantly. For the floating body with one symmetrical plane,it only needs to solve half of the elements of the coefficient matrix of source intensity;meanwhile the time of solving linear equations is reduced by one quarter. And for the floating body with two symmetrical planes,it only needs to solve a quarter of elements of the coefficient matrix of source intensity;meanwhile the time of solving linear equations is reduced by one sixteenth.[Conclusions] The numerical results show that the proposed symmetrical simplification method is effective,and can greatly improve the calculation efficiency

Promoting Healthy Village Construction: Challenges and Countermeasures

Healthcare is an important component for poverty alleviation in China, and it requires constant efforts as this sector in the rural areas in China will remain underdeveloped and short of high-quality resources for a long time. Moreover, promoting healthy village construction is crucial for consolidating and expanding the key achievements obtained in poverty alleviation and for implementing the rural revitalization strategy in China. This study uses policy research, field research, data analysis, and expert discussion methods. We first summarize the practical needs for promoting healthy village construction and present the achievements and main problems regarding healthcare improvement for poverty alleviation. Subsequently, we explore the development objectives and key tasks for healthy village construction and propose several countermeasures prospectively. To prevent the population that have been lifted out of poverty from returning to it due to illness and better meet their diverse needs for health, we suggest that China should (1) increase government financial investment and scientifically optimize the layout of health resources and human resources; (2) provide health services based on the whole life cycle and the whole process of health; (3) maximize the unique advantages of traditional Chinese medicine to draw a bottom line for epidemic prevention and control in rural areas; (4) ensure drug security based on the healthcare service coordination mechanism within the country region; (5) establish a regional adjustment and balancing mechanism for medical insurance funds to ensure the accuracy and fairness of health policies; and (6) conduct rural doctors training programs