Search

AbstractThe wet desulfurization yields slurry with a moderate temperature and stable supply and thus holds promise for waste heat utilization. However, the corrosive nature and solid particle content of desulfurization slurry from the wet desulfurization process pose potential erosion challenges in waste heat utilization heat exchangers, which is an aspect scarcely explored in the existing literature. The present study aimed to investigate the erosion characteristics in desulfurization slurry heat exchangers using numerical simulation approaches, which can offer crucial insights for practical application in low-grade energy recovery. The result identified slurry mass flow rate and composition as essential factors of erosion distribution. Higher mass flow rates enhance heat transfer efficiency. Still, paradoxically, lower flow rates lead to more pronounced erosion, with a slurry mass flow rate of 35 kg/s resulting in nearly double the erosion compared to the benchmark condition of 56 kg/s. This phenomenon is ascribed to lower fluid velocities in the heat tubes, where the influence of changed velocity diminishes, but slurry exhibits more stable flow at higher mass flow rates. Furthermore, it is also observed that both elevated solids content and particle size lead to an increase in erosion rates. The difference in erosion caused by solid particles with particle sizes in the range of 200–350 µm is marginal. The heat exchanger structure and arrangement also impact fluid flow and erosion. While the difference in fluid flow between vertically and horizontally arranged heat exchangers is negligible, the erosion was significantly reduced to 1/10 in the vertical arrangement. The no-tube-in-window heat exchangers, designed to minimize vibration, exhibit reduced heat transfer capacity alongside diminished and more uniform erosion. The augmentation of tube passes reduces overall erosion but focalizes severe erosion at the slurry inlet, which presents a potential design solution. [ABSTRACT FROM AUTHOR]

As global climate change continues, drought episodes have become increasingly frequent. Studying plant stress tolerance is urgently needed to ensure food security. The common ice plant is one of the model halophyte plants for plant stress biology research. This study aimed to investigate the functions of a newly discovered transcription factor, Homeobox 7 (HB7), from the ice plant in response to drought stress. An efficient Agrobacterium-mediated transformation method was established in the ice plant, where ectopic McHB7 expression may be sustained for four weeks. The McHB7 overexpression (OE) plants displayed drought tolerance, and the activities of redox enzymes and chlorophyll content in the OE plants were higher than the wild type. Quantitative proteomics revealed 1910 and 495 proteins significantly changed in the OE leaves compared to the wild type under the control and drought conditions, respectively. Most increased proteins were involved in the tricarboxylic acid cycle, photosynthesis, glycolysis, pyruvate metabolism, and oxidative phosphorylation pathways. Some were found to participate in abscisic acid signaling or response. Furthermore, the abscisic acid levels increased in the OE compared with the wild type. McHB7 was revealed to bind to the promoter motifs of Early Responsive to Dehydration genes and abscisic acid-responsive genes, and protein–protein interaction analysis revealed candidate proteins responsive to stresses and hormones (e.g., abscisic acid). To conclude, McHB7 may contribute to enhance plant drought tolerance through abscisic acid signaling. [ABSTRACT FROM AUTHOR]

Tar-rich coal holds the potential to substitute the supply of oil-gas resources. The in-situ pyrolysis contributes to efficient resource utilization and can potentially achieve net-zero CO2 emissions. However, it is challenging to efficiently separate oil-gas resources, which are predominated by tar, from multiphase products of in-situ pyrolysis of tar-rich coal. Additionally, the difference in fluid properties yields significant influences on separation performance, while the understanding of the separation characteristics of high-viscosity fluid remains insufficient. In this study, the separation process of pyrolysis products from tar-rich coal was investigated using the computational fluid dynamics simulation approach. The flow field, pressure drop, separation efficiency and distribution characteristics were analyzed. The simulation results indicate that the volute cyclone separator exhibits commendable separation efficiency, exceeding 98%. Meanwhile, in handling tars containing a high concentration of light oil, the separator demonstrates remarkable adaptability. The separation efficiency of solid particles decreases from 89% to 83% when the system contains a high content of pitch. The particle diameter exerts great influence on the flow field. The separation efficiencies are 99% and 0.37%, respectively, when the particle sizes are selected as 0.1 mm and 0.001 mm. In the scope of this study, the optimal working conditions of the cyclone separator were determined, which provides data support for improving the separation efficiency and recovery rate of the oil-gas resources. [ABSTRACT FROM AUTHOR]

Zhejiang Province is both the birthplace of the theory that both the mountain of gold and silver and the lushmountain with lucid waters are required (also known as the Two Mountains theory) and the first ecological province in China. The study on the vegetation ecological quality of Zhejiang can be used as an important reference for the construction of ecological civilization. Based on multi - source remote sensing data and meteorological observation data, this study investigated the spatio - temporal variations of vegetation ecological quality in Zhejiang during 2000-2020, as well as their response to climate factors and human activities. The results show that: (1) Both the fractional vegetation cover (FVC) and the net primary production (NPP) in Zhejiang showed an upward trend during 2000-2020, with significantly increased vegetation greenness; (2) The vegetation eco - environmental quality in Zhejiang showed a fluctuating upward trend during 2000-2020, with the vegetation ecological quality indices (VEQIs) of mountainous areas significantly higher than those of basin and plain areas; (3) The dominant factor driving the VEQI variations in Zhejiang during 2000-2020 is human activities, while climate factors occupied a dominant position only in some areas of southwestern Zhejiang. This study deepens the understanding of the spatio - temporal variations of vegetation ecological quality in Zhejiang and their driving factors and, thus, is of great significance for the construction of ecological civilization in Zhejiang and even other regions in China. [ABSTRACT FROM AUTHOR]

To study the transformation and release of fuel K, the combustion of corn stalk and wheat straw were performed in a reactor with a fixed bed between 400–1000°C. Measurements of weight and elemental composition, chemical fractionation analysis, and low‐temperature ashing coupled with X‐ray diffraction (XRD) analysis were conducted on biomass and residual samples. The effects of biomass species, temperature and duration time of combustion, oxygen concentration, and pretreatment of water washing were evaluated. The results show that compared with wheat straw, corn stalk has a lower K release, which is much more sensitive to the combustion temperature than to the oxygen concentration. The inorganic potassium occurs as KClO3 and KClO4 in wheat straw and KCl and KClO4 in corn stalk. K2SO4 appears through sulphation of KCl as combustion happens at 800°C or above. When the combustion temperature reached 900°C for corn stalk and 1000°C for wheat straw, some KCl changed into K2Si2O5, which contains insoluble K. K2Ca(SO4)2 appears as corn stalk and wheat straw are burnt at 1000 and 900°C, respectively. Along with the proceeding of wheat straw combustion, more ion‐exchangeable and water‐soluble K transform to the insoluble K with the increasing temperature. The pretreatment of water washing removes nearly all the water‐soluble K from the corn stalk and significantly decreases the K release from 3.26–0.27 mg g−1 in quantity and from 26.74%–14.84% in ratio at 1000°C, respectively. [ABSTRACT FROM AUTHOR]

The F-box family exists in a wide variety of plants and plays an extremely important role in plant growth, development and stress responses. However, systematic studies of F-box family have not been reported in populus trichocarpa. In the present study, 245 PtrFBX proteins in total were identified, and a phylogenetic tree was constructed on the basis of their C-terminal conserved domains, which was divided into 16 groups (A–P). F-box proteins were located in 19 chromosomes and six scaffolds, and segmental duplication was main force for the evolution of the F-box family in poplar. Collinearity analysis was conducted between poplar and other species including Arabidopsis thaliana, Glycine max, Anemone vitifolia Buch, Oryza sativa and Zea mays, which indicated that poplar has a relatively close relationship with G. max. The promoter regions of PtrFBX genes mainly contain two kinds of cis-elements, including hormone-responsive elements and stress-related elements. Transcriptome analysis indicated that there were 82 differentially expressed PtrFBX genes (DEGs), among which 64 DEGs were in the roots, 17 in the leaves and 26 in the stems. In addition, a co-expression network analysis of four representative PtrFBX genes indicated that their co-expression gene sets were mainly involved in abiotic stress responses and complex physiological processes. Using bioinformatic methods, we explored the structure, evolution and expression pattern of F-box genes in poplar, which provided clues to the molecular function of F-box family members and the screening of salt-tolerant PtrFBX genes. [ABSTRACT FROM AUTHOR]

Extreme environments, especially drought and high salt conditions, seriously affect plant growth and development. Ethylene-responsive factor (ERF) transcription factors play an important role in salt stress response. In this study, a significantly upregulated ERF gene was identified in 84K (Populus alba × P. glandulosa), which was named PagERF072. PagERF072 was confirmed to be a nuclear-localized protein. The results of yeast two-hybrid (Y2H) assay showed that PagERF072 protein exhibited no self-activating activity, and yeast one-hybrid (Y1H) demonstrated that PagERF072 could specifically bind to GCC-box element. Under salt stress, the transgenic poplar lines overexpressing PagERF072 showed improved salt tolerance. The activities of peroxidase (POD), superoxide dismutase (SOD) and catalase (CAT) in transgenic poplars were significantly increased relative to those of wild-type (WT) plants, whereas malondialdehyde (MDA) content showed an opposite trend. In addition, reactive oxygen species (ROS) was significantly reduced, and the expression levels of POD- and SOD-related genes were significantly increased in transgenic poplars under salt stress compared with WT. All results indicate that overexpression of the PagERF072 gene can improve the salt tolerance of transgenic poplars. [ABSTRACT FROM AUTHOR]

Understanding the response of tropospheric ozone (O3) to nitrogen dioxide (NO2) change is important for local O3 control. The relationship between O3 and NO2 at county scale in China has been extensively studied using models, but there is a lack of results from direct measurements. In this study, we used measurements of O3, NO2 and meteorological conditions from a dense network in the Yangtze River Delta (YRD), and satellite observed formaldehyde (HCHO) and NO2 column densities for the analysis of O3 variabilities and its relationship to NO2. As a result, severe O3 pollution occurred mainly in Shanghai city, southern Jiangsu and northern Zhejiang provinces in YRD during April–September. In addition, meteorological conditions could explain 54% the diurnal O3 variation over YRD. During April–September 2015–2021, O3 showed a significant positive relationship (r = 0.61 ± 0.10) with NO2 after removing the impact from meteorological conditions. However, the relationship could be reversed with NO2 concentration change. Our result suggested that the controllable O3 related to NO2 change is up to 100 μg·m−3 in megacities over Shanghai and northern Zhejiang province. The O3 is much more sensitive to the NO2 reduction in megacities than surrounding areas. Our results evaluate the different impacts of NO2 changes on O3 formation, which provides explanation for the simultaneously alleviated O3 pollution and reduced NO2 in 2020 in Shanghai and northern Zhejiang, as well as the increased O3 in most counties before 2019 with reduced NO2 during October–March. The driving mechanism as revealed from this study for O3 and NO2 will be valuable for the O3 abatement through NO2 reduction at sub-county scale over YRD in China. [ABSTRACT FROM AUTHOR]

In the context of global warming, how to measure summer climate suitability at a local scale is important for meteorological services. Considering meteorological and ecological conditions, body comfort, and the atmospheric environment, an assessment method for summer climate suitability for Zhejiang Province is proposed. In this paper, a summer suitable index (SSI) for Zhejiang is calculated, including four secondary indices: a summer cool index (SCI), a comfort days index (CDI), a good air days index (GADI) and a vegetation cover index (VCI). Using a local evaluation criterion, summer climate suitable areas are distinguished objectively according to the SSI. The results show that especially suitable regions account for 4.97% of Zhejiang Province, very suitable regions account for 22.2%, suitable regions account for 39.58%, and general regions account for 33.25%. The summer climate suitable areas are located mainly in high mountains and hills and coastal island areas while plain areas cannot be considered a suitable destination for summer tourism. By comparison and discussion, the SSI is demonstrated to capture summer climate suitability well. In contrast to a fixed evaluation index, benchmark values obtained for the SSI depend on the local climate and the index is straightforward to apply. [ABSTRACT FROM AUTHOR]

The low‐low temperature electrostatic precipitator (LLT‐ESP) has been applied in many power plants to improve the emission performance. In this study, a number of fix‐bed experiments were conducted, which simulated the operation condition of LLT‐ESP. The effect of chemical composition on the adsorption characteristics of ash samples and the agglomeration after adsorption were studied. The results show that the agglomeration of ash particles occurs in three forms, including agglomeration among small particles, adhesion of loose pellets to large particles, and agglomeration among large particles. The capacity of ash particles to adsorb sulphuric acid is less affected by the increase of added amounts of NaCl or KCl. At the same time, the added amount of NaCl or KCl also has little effect on the agglomeration degree of ash particles. The addition of MgO, CaO, Fe2O3, Na2CO3, or K2CO3 from 0% to 13.3%, 22.4%, 23.9%, 18.4%, or 14.2%, promotes the adsorption of sulphuric acid by ash particles from 1.95 mg g−1 to 7.33, 7.71, 6.72, 5.1, or 5.44 mg g−1 (based on sulphur content), respectively, thereby promoting the agglomeration between ash particles. As the addition amount increases, the agglomeration phenomenon among particles becomes more conspicuous. The form of agglomeration changes from agglomeration among small particles to agglomeration among large particles. In addition, the addition of MgO or CaO has great influence on the adsorption and agglomeration. [ABSTRACT FROM AUTHOR]

The ANSYS Fluent 2020 R2 software is used to study the flow and combustion characteristics of a new type biomass circulating fluidized bed boiler. The velocity distribution characteristics, particle separation efficiency and temperature field distribution in the built-in cyclone separator are studied. The results show that the velocity distribution of the flue gas in the cyclone separator decreases gradually from periphery to center, which can form the vortex area. When excess air coefficient is between 1.15-1.2, the separation effect of the separator is the best, which can reach more than 96.5%. The excess air coefficient obviously affects the combustion condition in the boiler, with the increase of excess air coefficient, the temperature increases first and then decreases, and the optimal excess air coefficient is 1.15. [ABSTRACT FROM AUTHOR]

This work investigates the effect of the resampling spatial resolution (RSR) on the retrieval of ocean surface wind speed from satellite-borne Synthetic Aperture Radar (SAR) images. For this purpose, 358 RADARSAT-2(RS-2) fine-beam quad-polarized SAR images and in-situ National Data Buoy Centre (NDBC) and China State Oceanic Administration (SOA) buoy measurements from selected geographic locations are used in this paper. In order to obtain better accuracy SAR-retrieved wind speeds, CMOD5.N function, Z2011 polarization ratio (PR) model and C2PO model constitute the best models for VV-, HH- and cross-polarized SAR images, respectively. The resulting statistical analysis suggests that better accuracy wind speeds can be retrieved at somewhat coarser resolutions. The optimal RSR for the VV-, HH-, VH- and HV-polarized channels are 850, 1050,1350 and 1450 m, respectively, with RMSEs of 1.74, 2.03, 1.61 and 1.83 m/s. [ABSTRACT FROM AUTHOR]

Optical connectivity, which has been widely deployed in today's datacenters and high-performance computing (HPC) systems, is a disruptive technological revolution to the IT industry in the new Millennium. In our journey to debut an Exascale supercomputer, a completely new computing concept, called memory-driven computing, was innovated recently. This new computing architecture brings challenges and opportunities for novel optical interconnect solutions. Here, we first discuss our strategy to develop appropriate optical link solutions for different data traffic scenarios in memory-driven HPCs. Then, we present detailed review on recent work to demonstrate fully photonics-electronics-integrated single- and multi-wavelength directly modulated laser (DML) transmitters on silicon for the first time. Compact heterogeneous microring lasers and laser arrays were fabricated as photonic engines to work with a customized complementary metal-oxide semiconductor (CMOS) driver circuit. Microring lasers based on conventional quantum well and new quantum dot lasing medium were compared in the experiment. Thermal shunt and MOS capacitor structures were integrated into the lasers for effective thermal management and ultra low-energy tuning. It enables a controllable dense wavelength division multiplexing (DWDM) link architecture in an HPC environment. An equivalent microring laser circuit model was constructed to allow photonics-electronics co-simulation. Equalization functionality in the CMOS driver circuit proved to be critical to achieve up to 14 Gb/s direct modulation with 6 dB extinction ratio. Finally, the on-going and future work is discussed towards more robust, higher speed, and more energy efficient DML transmitters. [ABSTRACT FROM AUTHOR]

Uncontrolled metastasis significantly contributes to high lethality of patients suffering from ovarian cancer. To date, the detailed molecular mechanisms which account for ovarian tumor cell spreading and metastasis remain largely unknown. In a recent study, we have demonstrated that aberrantly high expression of the non-receptor tyrosine kinase FER is responsible for ovarian tumor cell metastasis both in vitro and in vivo. Mechanistically, we indentified Hepatocyte Growth Factor Receptor HGFR/MET as a novel substrate of FER, and through which the kinase FER modulates ovarian cancer cell motility and invasiveness in a ligand-independent manner. We also observed aberrantly high expression of PAK1 kinase in cancer cells, and RNAi-mediated knockdown of FER kinase inactivated the RAC1-PAK1 signaling pathway and decreased metastatic potential of CAOV4 ovarian cancer cells. Overall, our study revealed a previously uncharacterized, pro-metastatic role of the kinase FER in ovarian cancer through the MET-RAC1-PAK1 pathway. Further efforts are essential to investigating beneficial outcomes towards targeting the RAC1-PAK1 signaling pathway in reducing metastatic burden of this deadly disease. [ABSTRACT FROM AUTHOR]

A typhoon is one of the most dangerous natural disasters in the Yangtze River Delta of China. Based on an integrated assessment of the disaster risk elements, including hazard factor, exposure, and vulnerability, the risk level of a typhoon disaster for the Yangtze River Delta as a county-level unit was ultimately determined. The result shows that the risk levels of typhoon hazard factor are gradually weakened from the southeastern coastal areas to the northwest, and the highest-risk areas are located in the southeastern coastal regions. Due to many towns, dense population, a developed economy, and a huge disaster-bearing body in the north of the Yangtze River Delta, which is also located on the plain for a high susceptibility to a disaster-breeding environment, the exposure risk level in the northern areas is higher than in the south. The most vulnerable counties are Chun'an, Xianju, Tiantai, and Sanmen in Zhejiang Province, and Baoying and Xinghua in Jiangsu Province. The highest-risk areas for a typhoon disaster are primarily located in the southeastern coastal areas of Zhejiang Province, Hangzhou Bay, and Shanghai near the Yangtze River Estuary, while the lowest-risk areas are distributed in the western portion of Hangzhou and the northern area of the Yangtze River Delta. [ABSTRACT FROM AUTHOR]