Solar-driven vapor generation offers an affordable and sustainable approach to solve global freshwater scarcity. Creating interfacial solar evaporators capable of increasing water production rates matching human water requirements is highly desirable but challenging due to the slow water transportation dynamics and unavoidable oil-fouling. Herein, a bio-inspired lotus-petiole-mimetic microstructured graphene/poly(N-acryloyl glycinamide) solar evaporator with integrated hydrophilic and hydrophobic microregions is developed. Through accurate control of the supramolecular interactions, the optimized solar evaporator incorporating unique structural features and wettability shows high light harvesting, enhanced water activation, and reduced energy demand for water vaporization, enabling a groundbreaking comprehensive performance along evaporation rate up to 3.4 kg m −2 h −1 and energy conversion efficiency of ≈93% under one sun irradiation (1 kW m −2 ). Molecular dynamics simulations reveal that the abundant hydrogen bonding sites of the polymeric networks can thermodynamically modulate the escape behavior of water molecules. Notably, neither decrease in evaporation rate nor fouling on solar evaporators is observed during the prolonged purification process toward nano/submicrometer emulsions, oily brines, actual seawater, and domestic wastewater. This study provides distinctive insights into water evaporation behaviors at a molecular level and pioneers a rational strategy to design high-yield freshwater-generation systems for wastewater containing complex contaminants.
Taxis are an important part of public transportation in nowadays. Taking a vacant taxi has become a difficult problem due to the imbalance between demand and supply of taxi service. People want to know where is better to wait for a vacant taxi in order to save their time in the fast-paced city life. Helpful information could be provided to the passengers by mining the historical GPS traces generated by taxis. In this paper, we propose a model based on taxi traffic flow (TTF) model to measure the difficulty of taking a vacant taxi on the road segments nearby. Furthermore, we calculate probability and expected waiting time of taking a vacant taxi based on TTF model. Afterwards, we detect the hotspots on the road segments expecting to offer more available information. Our research is based on the real historical taxi GPS data generated by 12000 taxis in Beijing. We conduct experiments to validate our model eventually and the experimental results are in line with the actual situation well relatively.
Histone deacetylases 1 (HDAC1), an enzyme that functions to remove acetyl molecules from ε-NH3 groups of lysine in histones, eliminates the histone acetylation at the promoter regions of tumor suppressor genes to block their expression during tumorigenesis. However, it remains unclear why HDAC1 fails to impair oncogene expression. Here we report that HDAC1 is unable to occupy at the promoters of oncogenes but maintains its occupancy with the tumor suppressors due to its interaction with CREPT (cell cycle-related and expression-elevated protein in tumor, also named RPRD1B), an oncoprotein highly expressed in tumors. We observed that CREPT competed with HDAC1 for binding to oncogene (such as CCND1, CLDN1, VEGFA, PPARD and BMP4) promoters but not the tumor suppressor gene (such as p21 and p27) promoters by a chromatin immunoprecipitation (ChIP) qPCR experiment. Using immunoprecipitation experiments, we deciphered that CREPT specifically occupied at the oncogene promoter via TCF4, a transcription factor activated by Wnt signaling. In addition, we performed a real-time quantitative PCR (qRT-PCR) analysis on cells that stably over-expressed CREPT and/or HDAC1, and we propose that HDAC1 inhibits CREPT to activate oncogene expression under Wnt signaling activation. Our findings revealed that HDAC1 functions differentially on tumor suppressors and oncogenes due to its interaction with the oncoprotein CREPT.
Abstract-This paper presents a 12bit 200Msps pipeline ADC fabricated in TSMC 0.18um CMOS technology. For high resolution pipeline ADC design, the operation speed is limited by sampling capacitance load of OTA inside the ADC. The proposed ADC is realized in split-based pipeline architecture, sampling capacitance of ADC is separated into two channels. Each channel only has half capacitance, which reduce capacitive loading of OTAs in each channel and realize high speed operation of the ADC. The ADC achieves an SNDR of 64.7dB, SFDR of 86.3dB with analog input frequency of 10MHz, sampling frequency of 100MHz and differential amplitude of 1.25Vpp without digital calibration. The power dissipation of ADC is 356mW at 1.8V supply.Index Terms-OTA, pipeline ADC, split-based.
I. INTRODUCTIONCMOS ADCs with sampling rate more than 100Msps and resolution more than 10bit are widely used in optical communication system, wireless and wired broadband communication systems [1]. Pipeline is the appropriate architecture widely used in this class of ADCs for its reasonable trade-offs among sampling rate, resolution and power. To realize the high sampling rate and high resolution pipeline ADC, the OTA to drive large sampling capacitance inside MDAC becomes the bottleneck which limits the sampling rate of ADC. Split ADC architecture is the useful method to reduce the capacitance need to be driven by OTA in pipeline ADC [2]. Split-based pipeline ADC consists of 2 independent ADCs with the same circuit structure which shares a same SHA [3]. The block diagram of traditional split ADC is shown in Fig. 1, The output code of ADC (A) and ADC(B) are X A and X B respectively. By average calculation, the final output code of the ADC can be written as Eq. 1, and difference between outputs of 2 ADCs can be written as Eq. 2.
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