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The polarization properties of grating-gate GaN-based high electron mobility transistors in the mid-infrared region have been investigated. However, due to the lack of research on the absorption characteristics of double-channel (DC) HEMTs in the mid-infrared band, the application potential of GaN-based HEMTs is limited. Therefore, this paper studied the absorption spectra of single-channel (SC) and double-channel grating-gate GaN-based HEMTs at different gate lengths in the mid-infrared region by using the Drude and Lorentz dispersion to model the conductive channel and GaN layer. Variation of different gate lengths changes the duty cycle, which affects the plasmon polarization and phonon polarization intensities. Using the finite-difference time-domain (FDTD) method, it was indicated that the symmetrical and asymmetrical plasmons are induced by the surface polarization field. By changing different gate lengths and sheet electron densities, significant plasmonic enhancement effects can be observed in DC-HEMTs. These promising findings suggest that the DC-HEMTs can be used to design multi-channel mid-infrared detectors, multi-channel mid-infrared modulators, and other multi-channel devices in the future. [ABSTRACT FROM AUTHOR]

Key message: ClLOX, is located on chromosome 2 and encodes a lipoxygenase gene, which induced watermelon powdery mildew resistance by inhibiting pathogen spread. Powdery mildew is one of the most severe fungal diseases reducing yield and quality of watermelon (Citrullus lanatus L.) and other cucurbit crops. Genes responsible for powdery mildew resistance in watermelon are highly valuable. In this study, we first identified the QTL pm-lox for powdery mildew resistance in watermelon, located within a 0.93 Mb interval of chromosome 2, via XP-GWAS method using two F2 populations. The F2:3 families from one of the F2 populations were then used for fine-mapping the pm-lox locus into a 9,883 bp physical region between 29,581,906 and 29,591,789, containing only two annotated genes. Of these, only ClG42_02g0161300 showed a significant differential expression between the resistant and susceptible lines after powdery mildew inoculation based on RNA sequencing (RNA-seq) and qRT-PCR analysis, and is designated ClLOX. Derived Cleaved Amplified Polymorphic Sequence (dCAPs) markers were developed and validated. In addition, our tests showed that the resistance was anti-spread rather than anti-infection of the pathogen. This study identified a new resistance gene (ClLOX), provided insights into the mechanism of powdery mildew resistance, and developed a molecular marker for watermelon breeding. [ABSTRACT FROM AUTHOR]

At present, the heat treatment process tends to focus on the strength and toughness of high strength steel, while ignoring the softening behavior of welding heat-affected zone (HAZ). The effect of austenitizing temperature and tempering temperature on mechanical properties and HAZ softening behavior of ultra-high strength steel (UHSS) are investigated. The results indicate that the optimum combination of strength, toughness and degree of HAZ softening can be achieved by quenching at 950 °C and tempering at 650 °C. With the increase of austenitizing temperature from 890 to 980 °C, more carbides dissolved in the matrix and the prior austenite grain size (PAGS) increased. Therefore, after tempering at 650 °C, the strength increases first and then decreases slightly under the combined effect of the enhancement of precipitation strengthening and the decline of grain boundary strengthening. When the tempering temperature increases from 350 to 650 °C, the toughness of the samples quenched at 950 °C increases from 27.3 to 73.1 J, attributed to the decrease of carbon content and dislocation density of the matrix, and the increase of high-angle grain boundary (HAGBs) density. The austenitizing temperature has a great influence on the degree of HAZ softening. With the austenitizing temperature increasing from 920 to 980 °C, the degree of HAZ softening becomes more serious due to the over-grown recrystallized grains and coarsened carbides. [ABSTRACT FROM AUTHOR]

Purpose: Lung cancer has significant genetic and phenotypic heterogeneity, leading to poor prognosis. Radiomic features have emerged as promising predictors of the tumor phenotype. However, the role of underlying information surrounding the cancer remains unclear. Materials and methods: We conducted a retrospective study of 508 patients with NSCLC from three institutions. Radiomics models were built using features from six tumor regions and seven classifiers to predict three prognostically significant tumor phenotypes. The models were evaluated and interpreted by the mean area under the receiver operating characteristic curve (AUC) under nested cross-validation and Shapley values. The best-performing predictive models corresponding to six tumor regions and three tumor phenotypes were identified for further comparative analysis. In addition, we designed five experiments with different voxel spacing to assess the sensitivity of the experimental results to the spatial resolution of the voxels. Results: Our results demonstrated that models based on 2D, 3D, and peritumoral region features yielded mean AUCs and 95% confidence intervals of 0.759 and [0.747–0.771] for lymphovascular invasion, 0.889 and [0.882–0.896] for pleural invasion, and 0.839 and [0.829–0.849] for T-staging in the testing cohort, which was significantly higher than all other models. Similar results were obtained for the model combining the three regional features at five voxel spacings. Conclusion: Our study revealed the predictive role of the developed methods with multi-regional features for the preoperative assessment of prognostic factors in NSCLC. The analysis of different voxel spacing and model interpretability strengthens the experimental findings and contributes to understanding the biological significance of the radiological phenotype. [ABSTRACT FROM AUTHOR]

Although crop domestication has greatly aided human civilization, the sequential domestication and regulation of most quality traits remain poorly understood. Here, we report the stepwise selection and regulation of major fruit quality traits that occurred during watermelon evolution. The levels of fruit cucurbitacins and flavonoids were negatively selected during speciation, whereas sugar and carotenoid contents were positively selected during domestication. Interestingly, fruit malic acid and citric acid showed the opposite selection trends during the improvement. We identified a novel gene cluster (CGC1, cucurbitacin gene cluster on chromosome 1) containing both regulatory and structural genes involved in cucurbitacin biosynthesis, which revealed a cascade of transcriptional regulation operating mechanisms. In the CGC1, an allele caused a single nucleotide change in ClERF1 binding sites (GCC-box) in the promoter of ClBh1, which resulted in reduced expression of ClBh1 and inhibition of cucurbitacin synthesis in cultivated watermelon. Functional analysis revealed that a rare insertion of 244 amino acids, which arose in C. amarus and became fixed in sweet watermelon, in ClOSC (oxidosqualene cyclase) was critical for the negative selection of cucurbitacins during watermelon evolution. This research provides an important resource for metabolomics-assisted breeding in watermelon and for exploring metabolic pathway regulation mechanisms. [ABSTRACT FROM AUTHOR]

China states to build new power system dominated by new energy power to promote the targets for peaking carbon emissions by 2030 and achieve carbon neutrality by 2060. Peaking regulation ancillary services provided by coal-fired power units is an essential solution to mitigate the volatility and instability of large-scale renewable energy for China's specific power mix. However, when the coal-fired power units operate at a low power output, the intensity of both coal consumption and carbon emissions gradually rises with the falling output rate. Moreover, cutting down the power output of coal-fired units frequently will damage the technical life. Given the impacts of power market reform and carbon mitigation targets, whether to participate in the energy market or the peaking regulation ancillary service market is an urgent issue for coal-fired power units. Considering the discrepancy in costs and benefits of various units at different output rate, this paper proposes a multi-objective optimization model to solve the issue from the perspective of the coal-fired power generators, in which both economic profit and carbon reduction goals are coordinated. Sequential quadratic programming is adopted to solve the nonlinear optimization problem. In order to study the difference in the decisions made by varied technical units, 7 different types of units are analyzed in the case study. The scenarios analysis indicates that large-capacity and new coal-fired power units are better to participate in energy market since it can give full play to the advantage of higher generation efficiency, while the small-capacity ones are suitable to provide flexible service in the peaking regulation ancillary service market. Besides, simple low-carbon objective will burden the cost of coal-fired power units and challenge the sustainable transition of power system. Hence, the power system should balance both economic profit of generators and national carbon mitigation targets during the low-carbon transition. [ABSTRACT FROM AUTHOR]

A rapid and convenient fluorescence glyphosate (GLYP) biosensor was developed based on DNA-templated copper nanoparticles (DNA-CuNPs). In the absence of GLYP, the DNA-CuNPs were formed through the reduction of Cu2+ by vitamin C (Vc). The DNA-CuNPs emitted intense fluorescence at 615 nm when being excited at 340 nm. In the presence of GLYP, GLYP can strongly chelate with Cu2+ by the phosphate and carboxyl groups to decrease the amount of free Cu2+. Due to the lack of free Cu2+, DNA-CuNPs cannot be formed, which caused the fluorescence to decrease. The whole detection process of this proposed GLYP biosensor can be completed within 14 min. Titration experiments showed that this biosensor had a linear relationship for GLYP in the range 1 to 18 µM with a limit of detection (LOD) of 0.47 µM. This biosensor showed obvious selectivity among other pesticides, even between GLYP and organophosphorus pesticides. This biosensor performed well for GLYP detection in real samples with recoveries of 88.0–104.0%. [ABSTRACT FROM AUTHOR]

Replacing conventional fossil fuel power plants with large-scale renewable energy sources (RES) is a crucial aspect of the decarbonization of the power sector and represents a key part of the carbon-neutral strategy of China. The high penetration rate of renewable energy in the electricity system, however, implies the challenges of dealing with the intermittency and fluctuation of RES. Power to gas (P2G), which can convert surplus renewable power into a chemical form of energy (i.e., synthetic gas), can help handle this challenge and supply new energy carriers for various energy sectors. By modeling three potential 2060 energy mix scenarios in China, this paper aims to describe the possible contribution of the high penetration rate of renewable energy combined with P2G in the future sustainable energy system. Different schemes are listed and compared, and the results are used in a basic economic evaluation of the synthetic gas production cost for the P2G plants. Ideally, nearly 18 million tons of carbon dioxide would be recycled and transformed into methane (around 9.37 km3) annually in China. Considering a zero price for the excess renewable power and future costs of the components, the levelized cost of energy (LCOE) of the final production of methane is estimated at 0.86 $/m3SNG. [ABSTRACT FROM AUTHOR]

The Western Pacific Subtropical High (WPSH) is a principal component of the East Asian summer monsoon system. This study was to compare the relationship between the WPSH and summer precipitation in Dongting Lake basin (24°35′-30°27′N, 107°13′-114°18′E) based on different datasets by employing the multivariate regression analysis. The observed precipitation data was from China Meteorological Data (CMD) sharing service system and the six gridded precipitation datasets were CFSR, ERA–Interim, CMAP, GPCP, CRU, and PREC/L, respectively. The WPSH exerted different influences on the precipitation of summer months. The indexes including westward extension ridge point index and northern boundary index in June, ridge line index and northern boundary index in July and August had important effect on the precipitation over Dongting Lake Basin. The gridded data could generally reproduce the relationship between the ridge line index and precipitation in July. The relationship between the northern boundary and the precipitation from gridded data was similar to that from observed data in June and July, while the relationship between the western extension ridge index and the precipitation in June could be reproduced by the gridded data except CFSR and ERA-Interim. Only in part area, the relationship between the intensity index and the CMD precipitation could be reproduced by gridded precipitation. The fitness of correlation in some area from the CMD could be reproduced by the gridded data. General speaking, GPCP precipitation data was more applicable to the Dongting Lake Basin in studying on the relationship between the precipitation and a single index of WPSH. [ABSTRACT FROM AUTHOR]

Due to the significant changes of economic growth rate, energy structure, and energy efficiency in China, whether energy policies should be adjusted is worthy of attention. This paper employs ARDL-ECM and Toda-Yamamoto causality to investigate the relationship between renewable energy, non-renewable energy, carbon emissions, economic growth, gross fixed capital formation, and urban population spanning the period 1960–2019 in China. The examined results of ARDL-ECM indicate that renewable energy both have positive impact on GDP in the short term and long term but non-renewable energy only have positive impact on GDP in the short term. Additionally, based on Toda-Yamamoto causality, this paper finds a unidirectional Granger causality running from economic growth to energy consumption and from energy consumption to carbon emissions. And there is a unidirectional Granger causality running from GDP to non-renewable energy consumption. It is worth noting that renewable energy consumption and economic growth have positive bidirectional influence on each other. The study findings suggest that stricter energy conservation and pollution emission reduction policy should be implemented and renewable energy should be applied on a larger scale in order to achieve the goal of sustainable economic development. [ABSTRACT FROM AUTHOR]

China is the largest carbon dioxide emitter in the world. Over the past decades, China has made great efforts to retard the carbon emission growth. This paper aims to quantify the driving forces of stagewise provincial carbon emission changes and expound the bottom-up provincial efforts aligned with China's carbon abatement targets. During 2007–2012, economic growth as the major contributing factor posed a great increase in provincial carbon emissions, especially in underdeveloped provinces such as Inner Mongolia, Anhui, Guangxi, Shaanxi, and Ningxia. During 2012–2017, the energy intensity effect replaced economic growth as the largest contributor to provincial carbon emission changes. In both two periods, industrial structure upgrading and renewable energy expansion are conducive to mitigate provincial carbon growth, and the power sector will continue to contribute to national decarbonization. Lastly, this paper provides insight into national and provincial carbon emission abatement. [ABSTRACT FROM AUTHOR]

New breeding technologies accelerate germplasm improvement and reduce the cost of goods in seed production1–3. Many such technologies could use in vivo paternal haploid induction (HI), which occurs when double fertilization precedes maternal (egg cell) genome loss. Engineering of the essential CENTROMERIC HISTONE (CENH3) gene induces paternal HI in Arabidopsis4–6. Despite conservation of CENH3 function across crops, CENH3-based HI has not been successful outside of the Arabidopsis model system7. Here we report a commercially operable paternal HI line in wheat with a ~7% HI rate, identified by screening genome-edited TaCENH3α-heteroallelic combinations. Unlike in Arabidopsis, edited alleles exhibited reduced transmission in female gametophytes, and heterozygous genotypes triggered higher HI rates than homozygous combinations. These developments might pave the way for the deployment of CENH3 HI technology in diverse crops. Gene editing induces paternal haploid plants in hexaploid wheat. [ABSTRACT FROM AUTHOR]

The developing countries and emerging economies are crucially contributing to global economic development, energy transition, and climate governance. This paper employs panel cointegration technique to investigate the long-run relationship between carbon emissions and five impacting factors (per capita GDP, primary energy consumption, international trade, fossil proportion, and quadratic per capita GDP) in 50 representative developing countries during 1995–2017. The empirical findings confirm the existence of long-run equilibrium, and the regressing coefficients of fully-modified OLS (FMOLS) indicate that (a) impacting features of the inverted U-shaped curve of Environmental Kuznets Curve (EKC) theory appear in a few countries, such as Mexico, Croatia, Kazakhstan, Iran, Algeria, Indonesia, and Thailand; (b) the energy consumption has statistically positive and significant impacts on boosting the carbon emissions; (c) the negative effect of international trade emerges in the developing nations enjoying trade surpluses; and (d) fossil energy share poses a mixed impact. This paper reveals that the vast and inspiring contribution of developing countries to global carbon emission reduction should attract more international attention and assistance. [ABSTRACT FROM AUTHOR]

The scope of this study is to analyze the carbon emissions intensity of electricity generation in "Belt and Road Initiative" (BRI) countries. The total CO2 emissions from electricity generation in BRI nations increases from 4232.34 Mt in 2013 to 4402.38 Mt in 2015, accounting for 34.45% of global CO2 emissions from electricity generation. Logarithmic mean Divisia index methodology is applied to analyze the drivers of carbon emissions intensity in BRI nations. The decomposition results revealed that the regional carbon emissions intensity in BRI nations increases during 2013–2015 and the power generation efficiency is the essential factor to improve carbon emissions performance in BRI developing countries. For BRI developing countries, promoting clean and efficient thermal power is a pragmatic priority for green power development. [ABSTRACT FROM AUTHOR]

The present study intends to explore the influence of intensity-modulated radiation therapy on the quality of life for patients with nasopharyngeal carcinoma, which provides a theoretical basis and practical foundation for clinical practice. The present study randomly enrolled 130 cases of patients with nasopharyngeal carcinoma (NPC) in different stages who were admitted in The Second Affiliated Hospital of Fujian Medical University and the First Affiliated Hospital of Chongqing Medical University from September 2007 to August 2012, including 65 cases in IMRT group who received intensity-modulated radiation therapy and 65 cases in CRT group who received conventional radiation therapy. The prescribed dose in the target region of radical radiation therapy was 72 Gy/36 f; the prescribed dose in the target region at high risk was 60-64 Gy/30-32 f; the prescribed dose in the target region at low risk was 50-54 Gy/25-27 f and 2 Gy/f, with conventional fractionated irradiation of 1 f/d and 5 f/w. The data of the quality of life for patients with NPC who received intensity-modulated radiation therapy and conventional radiation therapy were collected and analyzed by filling in the questionnaire survey, including the Quality of Life Questionnaire of Head and Neck 35 (QLQ-H&N35) and Shot Form 36 Health Survey Questionnaire (SF-36). RP, VT, BP, SF, and RE scores in eight fields in SF-36 Scale were declined during the radiation therapy and risen again after radiation therapy, and those measured at 6 months after radiation therapy were higher than those before radiation therapy (all P < 0.05). The scores in IMRT group measured at two and six months after radiation therapy were all higher than those in CRT group (all P < 0.05). The scores of head and neck pain, pararthria, dysphagia, social difficulty, sensory difficulty, difficulty in feeding, xerostomia, cough, sticky saliva, and sensory discomfort during the radiation therapy were lower than those before radiation therapy (all P < 0.05). Except for the scores of sticky saliva and xerostomia, the other scores measured at 6 months after radiation therapy were all lower than those before radiation therapy, and the scores of dysphagia, sticky saliva, and xerostomia in MRT group were lower than those in CRT group (all P < 0.05). Conventional radiation therapy and intensity-modulated radiation therapy can cause a decline the quality of life for the patient with head and neck cancer, but intensity-modulated radiation therapy can improve local tumor control rate and significantly reduce the incidence of adverse reactions. [ABSTRACT FROM AUTHOR]

We describe the plasmon resonances of AlGaN/GaN HEMT-array with a shifted gate at THz frequencies. By altering gate voltage and gate length, we obtained absorption spectra at different gate positions using the Drude dispersion to model the conductive channel layer. We observed that the asymmetry of the device’s gate position has no effect on the first-order mode of absorption but significantly impacts the second-order or higher-order modes. Through the electric field distribution, it can be found that in the first-order mode, different gate positions do not affect the electric field distribution. But in higher-order modes, when the gate is close to the source or drain, the 2D plasmons in the gated region will couple with the ungated 2D plasmons in the source and drain regions. In our simulation, the asymmetric gate position will have a higher absorption peak in the high-order mode. At the same time, the asymmetric gate structure under high-order mode can also reach higher modulation depth. The studies of these characteristics may have promising applications including high-responsivity quantum-dot THz detection, THz modulator, and other electrically tunable THz devices. [ABSTRACT FROM AUTHOR]