As the largest energy infrastructure in China, the power sector consumed approximately half of China's coal over the past decade and threatened air quality and greenhouse gas (GHG) abatement targets. In this work, we assessed the evolution of coal-fired power plants and associated emissions in China during 2010-2030 by using a unit-based emission projection model, which integrated the historical power plant information, turnover of the future power plant fleet, and evolution of end-of-pipe control technologies. We found that, driven by stringent environmental legislation, SO2, NOx, and PM2.5 (particulate matter less than 2.5 mu m in diameter) emissions from coal-fired power plants decreased by 49%, 45%, and 24%, respectively, during 2010-2015, compared to 15% increase in CO2 emissions. In contrast to ever-increasing CO2 emissions until 2030 under current energy development plan- ning, we found that aggressive energy development planning could curb CO2 emissions from the peak before 2030. Owing to the implementation of a "near zero" emission control policy, we projected emissions of air pollutants will significantly decrease during 2016-2030. Early retirement of small and low-efficiency power plants would further reduce air pollutants and CO2 emissions. Our study explored various mitigation pathways for China's coal-fired power plants, which could reduce coal consumption, air pollutants, and CO2 emissions and improve energy efficiency.
This paper presents two D-band frequency quadruplers (FQs) employing different circuit techniques. First FQ is a 129–171-GHz stacked Gilbert-cell multiplier using a bootstrapping technique, which improves the bandwidth and the conversion gain with respect to the conventional topology. Stacked architecture enables current reuse for the second frequency doubler resulting in a compact and energy-efficient design. The circuit reaches 3-dB bandwidth of 42 GHz, which is the highest among similar reported quadruplers. It achieves 2.2-dBm saturated output power, 5-dB peak conversion gain, and 1.7% peak DC-to-RF efficiency. The stacked FQ occupies 0.08 mm2 and consumes 22.7 mA from 4.4-V supply. Second presented circuit is a transformer-based injection-locked FQ (T-ILFQ) employing an E-band push–push voltage-controlled oscillator (PP-VCO). The VCO is a self-buffered common-collector Colpitts oscillator with a transformer formed on emitter inductors. Proposed configuration does not reduce the tuning range of the VCO, thus providing wide locking range and high sensitivity with respect to the injected signal. The T-ILFQ achieves 21.1% locking range, which is the highest among other reported injection-locked frequency multipliers. The peak output power is −4 dBm and the input sensitivity reaches −22 dBm. The circuit occupies 0.09 mm2 and consumes 14.8 mA from 3.3-V supply.
To investigate three-dimensional (3D) genome organization in prokaryotic and eukaryotic cells, three main strategies are employed, namely nuclear proximity ligation-based methods, imaging tools (such as fluorescence in situ hybridization (FISH) and its derivatives), and computational/visualization methods. Proximity ligation-based methods are based on digestion and re-ligation of physically proximal cross-linked chromatin fragments accompanied by massively parallel DNA sequencing to measure the relative spatial proximity between genomic loci. Imaging tools enable direct visualization and quantification of spatial distances between genomic loci, and advanced implementation of (super-resolution) microscopy helps to significantly improve the resolution of images. Computational methods are used to map global 3D genome structures at various scales driven by experimental data, and visualization methods are used to visualize genome 3D structures in virtual 3D space-based on algorithms. In this review, we focus on the introduction of novel imaging and visualization methods to study 3D genomes. First, we introduce the progress made recently in 3D genome imaging in both fixed cell and live cells based on long-probe labeling, short-probe labeling, RNA FISH, and the CRISPR system. As the fluorescence-capturing capability of a particular microscope is very important for the sensitivity of bioimaging experiments, we also introduce two novel super-resolution microscopy methods, SDOM and low-power super-resolution STED, which have potential for time-lapse super-resolution live-cell imaging of chromatin. Finally, we review some software tools developed recently to visualize proximity ligation-based data. The imaging and visualization methods are complementary to each other, and all three strategies are not mutually exclusive. These methods provide powerful tools to explore the mechanisms of gene regulation and transcription in cell nuclei.
A drop-freeze array (PeKing University Ice Nucleation Array, PKU-INA) was developed based on the cold-stage method to investigate heterogeneous ice nucleation properties of atmospheric particles in the immersion freezing mode from -30 to 0 degrees C. The instrumental details as well as characterization and performance evaluation are described in this paper. A careful temperature calibration protocol was developed in our work. The uncertainties in the reported temperatures were found to be less than 0.4 degrees C at various cooling rates after calibration. We also measured the ice nucleation activities of droplets containing different mass concentrations of illite NX, and the results obtained in our work show good agreement with those reported previously using other instruments with similar principles. Overall, we show that our newly developed PKU-INA is a robust and reliable instrument for investigation of heterogeneous ice nucleation in the immersion freezing mode.
